+++ /dev/null
-From ab51127cad79fdc5ff972e04acb2287c0799efc4 Mon Sep 17 00:00:00 2001
-From: Jens Axboe <axboe@kernel.dk>
-Date: Thu, 22 Dec 2022 14:30:11 -0700
-Subject: io_uring: import 5.15-stable io_uring
-
-From: Jens Axboe <axboe@kernel.dk>
-
-No upstream commit exists.
-
-This imports the io_uring codebase from 5.15.85, wholesale. Changes
-from that code base:
-
-- Drop IOCB_ALLOC_CACHE, we don't have that in 5.10.
-- Drop MKDIRAT/SYMLINKAT/LINKAT. Would require further VFS backports,
- and we don't support these in 5.10 to begin with.
-- sock_from_file() old style calling convention.
-- Use compat_get_bitmap() only for CONFIG_COMPAT=y
-
-Signed-off-by: Jens Axboe <axboe@kernel.dk>
-Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
----
- Makefile | 2
- fs/Makefile | 2
- fs/io-wq.c | 1242 ----
- fs/io-wq.h | 157
- fs/io_uring.c | 9971 ------------------------------------
- include/linux/io_uring.h | 46
- include/linux/sched.h | 3
- include/linux/syscalls.h | 2
- include/trace/events/io_uring.h | 121
- include/uapi/linux/io_uring.h | 115
- io_uring/Makefile | 6
- io_uring/io-wq.c | 1398 +++++
- io_uring/io-wq.h | 160
- io_uring/io_uring.c |10945 ++++++++++++++++++++++++++++++++++++++++
- kernel/exit.c | 2
- kernel/fork.c | 1
- kernel/sched/core.c | 2
- 17 files changed, 12704 insertions(+), 11471 deletions(-)
- delete mode 100644 fs/io-wq.c
- create mode 100644 io_uring/Makefile
- create mode 100644 io_uring/io-wq.c
- rename {fs => io_uring}/io-wq.h (81%)
- rename {fs => io_uring}/io_uring.c (51%)
-
---- a/Makefile
-+++ b/Makefile
-@@ -1128,7 +1128,7 @@ export MODORDER := $(extmod-prefix)modul
- export MODULES_NSDEPS := $(extmod-prefix)modules.nsdeps
-
- ifeq ($(KBUILD_EXTMOD),)
--core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
-+core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/ io_uring/
-
- vmlinux-dirs := $(patsubst %/,%,$(filter %/, \
- $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
---- a/fs/Makefile
-+++ b/fs/Makefile
-@@ -32,8 +32,6 @@ obj-$(CONFIG_TIMERFD) += timerfd.o
- obj-$(CONFIG_EVENTFD) += eventfd.o
- obj-$(CONFIG_USERFAULTFD) += userfaultfd.o
- obj-$(CONFIG_AIO) += aio.o
--obj-$(CONFIG_IO_URING) += io_uring.o
--obj-$(CONFIG_IO_WQ) += io-wq.o
- obj-$(CONFIG_FS_DAX) += dax.o
- obj-$(CONFIG_FS_ENCRYPTION) += crypto/
- obj-$(CONFIG_FS_VERITY) += verity/
---- a/fs/io-wq.c
-+++ /dev/null
-@@ -1,1242 +0,0 @@
--// SPDX-License-Identifier: GPL-2.0
--/*
-- * Basic worker thread pool for io_uring
-- *
-- * Copyright (C) 2019 Jens Axboe
-- *
-- */
--#include <linux/kernel.h>
--#include <linux/init.h>
--#include <linux/errno.h>
--#include <linux/sched/signal.h>
--#include <linux/mm.h>
--#include <linux/sched/mm.h>
--#include <linux/percpu.h>
--#include <linux/slab.h>
--#include <linux/kthread.h>
--#include <linux/rculist_nulls.h>
--#include <linux/fs_struct.h>
--#include <linux/task_work.h>
--#include <linux/blk-cgroup.h>
--#include <linux/audit.h>
--#include <linux/cpu.h>
--
--#include "../kernel/sched/sched.h"
--#include "io-wq.h"
--
--#define WORKER_IDLE_TIMEOUT (5 * HZ)
--
--enum {
-- IO_WORKER_F_UP = 1, /* up and active */
-- IO_WORKER_F_RUNNING = 2, /* account as running */
-- IO_WORKER_F_FREE = 4, /* worker on free list */
-- IO_WORKER_F_FIXED = 8, /* static idle worker */
-- IO_WORKER_F_BOUND = 16, /* is doing bounded work */
--};
--
--enum {
-- IO_WQ_BIT_EXIT = 0, /* wq exiting */
-- IO_WQ_BIT_CANCEL = 1, /* cancel work on list */
-- IO_WQ_BIT_ERROR = 2, /* error on setup */
--};
--
--enum {
-- IO_WQE_FLAG_STALLED = 1, /* stalled on hash */
--};
--
--/*
-- * One for each thread in a wqe pool
-- */
--struct io_worker {
-- refcount_t ref;
-- unsigned flags;
-- struct hlist_nulls_node nulls_node;
-- struct list_head all_list;
-- struct task_struct *task;
-- struct io_wqe *wqe;
--
-- struct io_wq_work *cur_work;
-- spinlock_t lock;
--
-- struct rcu_head rcu;
-- struct mm_struct *mm;
--#ifdef CONFIG_BLK_CGROUP
-- struct cgroup_subsys_state *blkcg_css;
--#endif
-- const struct cred *cur_creds;
-- const struct cred *saved_creds;
-- struct files_struct *restore_files;
-- struct nsproxy *restore_nsproxy;
-- struct fs_struct *restore_fs;
--};
--
--#if BITS_PER_LONG == 64
--#define IO_WQ_HASH_ORDER 6
--#else
--#define IO_WQ_HASH_ORDER 5
--#endif
--
--#define IO_WQ_NR_HASH_BUCKETS (1u << IO_WQ_HASH_ORDER)
--
--struct io_wqe_acct {
-- unsigned nr_workers;
-- unsigned max_workers;
-- atomic_t nr_running;
--};
--
--enum {
-- IO_WQ_ACCT_BOUND,
-- IO_WQ_ACCT_UNBOUND,
--};
--
--/*
-- * Per-node worker thread pool
-- */
--struct io_wqe {
-- struct {
-- raw_spinlock_t lock;
-- struct io_wq_work_list work_list;
-- unsigned long hash_map;
-- unsigned flags;
-- } ____cacheline_aligned_in_smp;
--
-- int node;
-- struct io_wqe_acct acct[2];
--
-- struct hlist_nulls_head free_list;
-- struct list_head all_list;
--
-- struct io_wq *wq;
-- struct io_wq_work *hash_tail[IO_WQ_NR_HASH_BUCKETS];
--};
--
--/*
-- * Per io_wq state
-- */
--struct io_wq {
-- struct io_wqe **wqes;
-- unsigned long state;
--
-- free_work_fn *free_work;
-- io_wq_work_fn *do_work;
--
-- struct task_struct *manager;
-- struct user_struct *user;
-- refcount_t refs;
-- struct completion done;
--
-- struct hlist_node cpuhp_node;
--
-- refcount_t use_refs;
--};
--
--static enum cpuhp_state io_wq_online;
--
--static bool io_worker_get(struct io_worker *worker)
--{
-- return refcount_inc_not_zero(&worker->ref);
--}
--
--static void io_worker_release(struct io_worker *worker)
--{
-- if (refcount_dec_and_test(&worker->ref))
-- wake_up_process(worker->task);
--}
--
--/*
-- * Note: drops the wqe->lock if returning true! The caller must re-acquire
-- * the lock in that case. Some callers need to restart handling if this
-- * happens, so we can't just re-acquire the lock on behalf of the caller.
-- */
--static bool __io_worker_unuse(struct io_wqe *wqe, struct io_worker *worker)
--{
-- bool dropped_lock = false;
--
-- if (worker->saved_creds) {
-- revert_creds(worker->saved_creds);
-- worker->cur_creds = worker->saved_creds = NULL;
-- }
--
-- if (current->files != worker->restore_files) {
-- __acquire(&wqe->lock);
-- raw_spin_unlock_irq(&wqe->lock);
-- dropped_lock = true;
--
-- task_lock(current);
-- current->files = worker->restore_files;
-- current->nsproxy = worker->restore_nsproxy;
-- task_unlock(current);
-- }
--
-- if (current->fs != worker->restore_fs)
-- current->fs = worker->restore_fs;
--
-- /*
-- * If we have an active mm, we need to drop the wq lock before unusing
-- * it. If we do, return true and let the caller retry the idle loop.
-- */
-- if (worker->mm) {
-- if (!dropped_lock) {
-- __acquire(&wqe->lock);
-- raw_spin_unlock_irq(&wqe->lock);
-- dropped_lock = true;
-- }
-- __set_current_state(TASK_RUNNING);
-- kthread_unuse_mm(worker->mm);
-- mmput(worker->mm);
-- worker->mm = NULL;
-- }
--
--#ifdef CONFIG_BLK_CGROUP
-- if (worker->blkcg_css) {
-- kthread_associate_blkcg(NULL);
-- worker->blkcg_css = NULL;
-- }
--#endif
-- if (current->signal->rlim[RLIMIT_FSIZE].rlim_cur != RLIM_INFINITY)
-- current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
-- return dropped_lock;
--}
--
--static inline struct io_wqe_acct *io_work_get_acct(struct io_wqe *wqe,
-- struct io_wq_work *work)
--{
-- if (work->flags & IO_WQ_WORK_UNBOUND)
-- return &wqe->acct[IO_WQ_ACCT_UNBOUND];
--
-- return &wqe->acct[IO_WQ_ACCT_BOUND];
--}
--
--static inline struct io_wqe_acct *io_wqe_get_acct(struct io_wqe *wqe,
-- struct io_worker *worker)
--{
-- if (worker->flags & IO_WORKER_F_BOUND)
-- return &wqe->acct[IO_WQ_ACCT_BOUND];
--
-- return &wqe->acct[IO_WQ_ACCT_UNBOUND];
--}
--
--static void io_worker_exit(struct io_worker *worker)
--{
-- struct io_wqe *wqe = worker->wqe;
-- struct io_wqe_acct *acct = io_wqe_get_acct(wqe, worker);
--
-- /*
-- * If we're not at zero, someone else is holding a brief reference
-- * to the worker. Wait for that to go away.
-- */
-- set_current_state(TASK_INTERRUPTIBLE);
-- if (!refcount_dec_and_test(&worker->ref))
-- schedule();
-- __set_current_state(TASK_RUNNING);
--
-- preempt_disable();
-- current->flags &= ~PF_IO_WORKER;
-- if (worker->flags & IO_WORKER_F_RUNNING)
-- atomic_dec(&acct->nr_running);
-- if (!(worker->flags & IO_WORKER_F_BOUND))
-- atomic_dec(&wqe->wq->user->processes);
-- worker->flags = 0;
-- preempt_enable();
--
-- raw_spin_lock_irq(&wqe->lock);
-- hlist_nulls_del_rcu(&worker->nulls_node);
-- list_del_rcu(&worker->all_list);
-- if (__io_worker_unuse(wqe, worker)) {
-- __release(&wqe->lock);
-- raw_spin_lock_irq(&wqe->lock);
-- }
-- acct->nr_workers--;
-- raw_spin_unlock_irq(&wqe->lock);
--
-- kfree_rcu(worker, rcu);
-- if (refcount_dec_and_test(&wqe->wq->refs))
-- complete(&wqe->wq->done);
--}
--
--static inline bool io_wqe_run_queue(struct io_wqe *wqe)
-- __must_hold(wqe->lock)
--{
-- if (!wq_list_empty(&wqe->work_list) &&
-- !(wqe->flags & IO_WQE_FLAG_STALLED))
-- return true;
-- return false;
--}
--
--/*
-- * Check head of free list for an available worker. If one isn't available,
-- * caller must wake up the wq manager to create one.
-- */
--static bool io_wqe_activate_free_worker(struct io_wqe *wqe)
-- __must_hold(RCU)
--{
-- struct hlist_nulls_node *n;
-- struct io_worker *worker;
--
-- n = rcu_dereference(hlist_nulls_first_rcu(&wqe->free_list));
-- if (is_a_nulls(n))
-- return false;
--
-- worker = hlist_nulls_entry(n, struct io_worker, nulls_node);
-- if (io_worker_get(worker)) {
-- wake_up_process(worker->task);
-- io_worker_release(worker);
-- return true;
-- }
--
-- return false;
--}
--
--/*
-- * We need a worker. If we find a free one, we're good. If not, and we're
-- * below the max number of workers, wake up the manager to create one.
-- */
--static void io_wqe_wake_worker(struct io_wqe *wqe, struct io_wqe_acct *acct)
--{
-- bool ret;
--
-- /*
-- * Most likely an attempt to queue unbounded work on an io_wq that
-- * wasn't setup with any unbounded workers.
-- */
-- if (unlikely(!acct->max_workers))
-- pr_warn_once("io-wq is not configured for unbound workers");
--
-- rcu_read_lock();
-- ret = io_wqe_activate_free_worker(wqe);
-- rcu_read_unlock();
--
-- if (!ret && acct->nr_workers < acct->max_workers)
-- wake_up_process(wqe->wq->manager);
--}
--
--static void io_wqe_inc_running(struct io_wqe *wqe, struct io_worker *worker)
--{
-- struct io_wqe_acct *acct = io_wqe_get_acct(wqe, worker);
--
-- atomic_inc(&acct->nr_running);
--}
--
--static void io_wqe_dec_running(struct io_wqe *wqe, struct io_worker *worker)
-- __must_hold(wqe->lock)
--{
-- struct io_wqe_acct *acct = io_wqe_get_acct(wqe, worker);
--
-- if (atomic_dec_and_test(&acct->nr_running) && io_wqe_run_queue(wqe))
-- io_wqe_wake_worker(wqe, acct);
--}
--
--static void io_worker_start(struct io_wqe *wqe, struct io_worker *worker)
--{
-- allow_kernel_signal(SIGINT);
--
-- current->flags |= PF_IO_WORKER;
--
-- worker->flags |= (IO_WORKER_F_UP | IO_WORKER_F_RUNNING);
-- worker->restore_files = current->files;
-- worker->restore_nsproxy = current->nsproxy;
-- worker->restore_fs = current->fs;
-- io_wqe_inc_running(wqe, worker);
--}
--
--/*
-- * Worker will start processing some work. Move it to the busy list, if
-- * it's currently on the freelist
-- */
--static void __io_worker_busy(struct io_wqe *wqe, struct io_worker *worker,
-- struct io_wq_work *work)
-- __must_hold(wqe->lock)
--{
-- bool worker_bound, work_bound;
--
-- if (worker->flags & IO_WORKER_F_FREE) {
-- worker->flags &= ~IO_WORKER_F_FREE;
-- hlist_nulls_del_init_rcu(&worker->nulls_node);
-- }
--
-- /*
-- * If worker is moving from bound to unbound (or vice versa), then
-- * ensure we update the running accounting.
-- */
-- worker_bound = (worker->flags & IO_WORKER_F_BOUND) != 0;
-- work_bound = (work->flags & IO_WQ_WORK_UNBOUND) == 0;
-- if (worker_bound != work_bound) {
-- io_wqe_dec_running(wqe, worker);
-- if (work_bound) {
-- worker->flags |= IO_WORKER_F_BOUND;
-- wqe->acct[IO_WQ_ACCT_UNBOUND].nr_workers--;
-- wqe->acct[IO_WQ_ACCT_BOUND].nr_workers++;
-- atomic_dec(&wqe->wq->user->processes);
-- } else {
-- worker->flags &= ~IO_WORKER_F_BOUND;
-- wqe->acct[IO_WQ_ACCT_UNBOUND].nr_workers++;
-- wqe->acct[IO_WQ_ACCT_BOUND].nr_workers--;
-- atomic_inc(&wqe->wq->user->processes);
-- }
-- io_wqe_inc_running(wqe, worker);
-- }
--}
--
--/*
-- * No work, worker going to sleep. Move to freelist, and unuse mm if we
-- * have one attached. Dropping the mm may potentially sleep, so we drop
-- * the lock in that case and return success. Since the caller has to
-- * retry the loop in that case (we changed task state), we don't regrab
-- * the lock if we return success.
-- */
--static bool __io_worker_idle(struct io_wqe *wqe, struct io_worker *worker)
-- __must_hold(wqe->lock)
--{
-- if (!(worker->flags & IO_WORKER_F_FREE)) {
-- worker->flags |= IO_WORKER_F_FREE;
-- hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list);
-- }
--
-- return __io_worker_unuse(wqe, worker);
--}
--
--static inline unsigned int io_get_work_hash(struct io_wq_work *work)
--{
-- return work->flags >> IO_WQ_HASH_SHIFT;
--}
--
--static struct io_wq_work *io_get_next_work(struct io_wqe *wqe)
-- __must_hold(wqe->lock)
--{
-- struct io_wq_work_node *node, *prev;
-- struct io_wq_work *work, *tail;
-- unsigned int hash;
--
-- wq_list_for_each(node, prev, &wqe->work_list) {
-- work = container_of(node, struct io_wq_work, list);
--
-- /* not hashed, can run anytime */
-- if (!io_wq_is_hashed(work)) {
-- wq_list_del(&wqe->work_list, node, prev);
-- return work;
-- }
--
-- /* hashed, can run if not already running */
-- hash = io_get_work_hash(work);
-- if (!(wqe->hash_map & BIT(hash))) {
-- wqe->hash_map |= BIT(hash);
-- /* all items with this hash lie in [work, tail] */
-- tail = wqe->hash_tail[hash];
-- wqe->hash_tail[hash] = NULL;
-- wq_list_cut(&wqe->work_list, &tail->list, prev);
-- return work;
-- }
-- }
--
-- return NULL;
--}
--
--static void io_wq_switch_mm(struct io_worker *worker, struct io_wq_work *work)
--{
-- if (worker->mm) {
-- kthread_unuse_mm(worker->mm);
-- mmput(worker->mm);
-- worker->mm = NULL;
-- }
--
-- if (mmget_not_zero(work->identity->mm)) {
-- kthread_use_mm(work->identity->mm);
-- worker->mm = work->identity->mm;
-- return;
-- }
--
-- /* failed grabbing mm, ensure work gets cancelled */
-- work->flags |= IO_WQ_WORK_CANCEL;
--}
--
--static inline void io_wq_switch_blkcg(struct io_worker *worker,
-- struct io_wq_work *work)
--{
--#ifdef CONFIG_BLK_CGROUP
-- if (!(work->flags & IO_WQ_WORK_BLKCG))
-- return;
-- if (work->identity->blkcg_css != worker->blkcg_css) {
-- kthread_associate_blkcg(work->identity->blkcg_css);
-- worker->blkcg_css = work->identity->blkcg_css;
-- }
--#endif
--}
--
--static void io_wq_switch_creds(struct io_worker *worker,
-- struct io_wq_work *work)
--{
-- const struct cred *old_creds = override_creds(work->identity->creds);
--
-- worker->cur_creds = work->identity->creds;
-- if (worker->saved_creds)
-- put_cred(old_creds); /* creds set by previous switch */
-- else
-- worker->saved_creds = old_creds;
--}
--
--static void io_impersonate_work(struct io_worker *worker,
-- struct io_wq_work *work)
--{
-- if ((work->flags & IO_WQ_WORK_FILES) &&
-- current->files != work->identity->files) {
-- task_lock(current);
-- current->files = work->identity->files;
-- current->nsproxy = work->identity->nsproxy;
-- task_unlock(current);
-- if (!work->identity->files) {
-- /* failed grabbing files, ensure work gets cancelled */
-- work->flags |= IO_WQ_WORK_CANCEL;
-- }
-- }
-- if ((work->flags & IO_WQ_WORK_FS) && current->fs != work->identity->fs)
-- current->fs = work->identity->fs;
-- if ((work->flags & IO_WQ_WORK_MM) && work->identity->mm != worker->mm)
-- io_wq_switch_mm(worker, work);
-- if ((work->flags & IO_WQ_WORK_CREDS) &&
-- worker->cur_creds != work->identity->creds)
-- io_wq_switch_creds(worker, work);
-- if (work->flags & IO_WQ_WORK_FSIZE)
-- current->signal->rlim[RLIMIT_FSIZE].rlim_cur = work->identity->fsize;
-- else if (current->signal->rlim[RLIMIT_FSIZE].rlim_cur != RLIM_INFINITY)
-- current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY;
-- io_wq_switch_blkcg(worker, work);
--#ifdef CONFIG_AUDIT
-- current->loginuid = work->identity->loginuid;
-- current->sessionid = work->identity->sessionid;
--#endif
--}
--
--static void io_assign_current_work(struct io_worker *worker,
-- struct io_wq_work *work)
--{
-- if (work) {
-- /* flush pending signals before assigning new work */
-- if (signal_pending(current))
-- flush_signals(current);
-- cond_resched();
-- }
--
--#ifdef CONFIG_AUDIT
-- current->loginuid = KUIDT_INIT(AUDIT_UID_UNSET);
-- current->sessionid = AUDIT_SID_UNSET;
--#endif
--
-- spin_lock_irq(&worker->lock);
-- worker->cur_work = work;
-- spin_unlock_irq(&worker->lock);
--}
--
--static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work);
--
--static void io_worker_handle_work(struct io_worker *worker)
-- __releases(wqe->lock)
--{
-- struct io_wqe *wqe = worker->wqe;
-- struct io_wq *wq = wqe->wq;
--
-- do {
-- struct io_wq_work *work;
--get_next:
-- /*
-- * If we got some work, mark us as busy. If we didn't, but
-- * the list isn't empty, it means we stalled on hashed work.
-- * Mark us stalled so we don't keep looking for work when we
-- * can't make progress, any work completion or insertion will
-- * clear the stalled flag.
-- */
-- work = io_get_next_work(wqe);
-- if (work)
-- __io_worker_busy(wqe, worker, work);
-- else if (!wq_list_empty(&wqe->work_list))
-- wqe->flags |= IO_WQE_FLAG_STALLED;
--
-- raw_spin_unlock_irq(&wqe->lock);
-- if (!work)
-- break;
-- io_assign_current_work(worker, work);
--
-- /* handle a whole dependent link */
-- do {
-- struct io_wq_work *old_work, *next_hashed, *linked;
-- unsigned int hash = io_get_work_hash(work);
--
-- next_hashed = wq_next_work(work);
-- io_impersonate_work(worker, work);
-- /*
-- * OK to set IO_WQ_WORK_CANCEL even for uncancellable
-- * work, the worker function will do the right thing.
-- */
-- if (test_bit(IO_WQ_BIT_CANCEL, &wq->state))
-- work->flags |= IO_WQ_WORK_CANCEL;
--
-- old_work = work;
-- linked = wq->do_work(work);
--
-- work = next_hashed;
-- if (!work && linked && !io_wq_is_hashed(linked)) {
-- work = linked;
-- linked = NULL;
-- }
-- io_assign_current_work(worker, work);
-- wq->free_work(old_work);
--
-- if (linked)
-- io_wqe_enqueue(wqe, linked);
--
-- if (hash != -1U && !next_hashed) {
-- raw_spin_lock_irq(&wqe->lock);
-- wqe->hash_map &= ~BIT_ULL(hash);
-- wqe->flags &= ~IO_WQE_FLAG_STALLED;
-- /* skip unnecessary unlock-lock wqe->lock */
-- if (!work)
-- goto get_next;
-- raw_spin_unlock_irq(&wqe->lock);
-- }
-- } while (work);
--
-- raw_spin_lock_irq(&wqe->lock);
-- } while (1);
--}
--
--static int io_wqe_worker(void *data)
--{
-- struct io_worker *worker = data;
-- struct io_wqe *wqe = worker->wqe;
-- struct io_wq *wq = wqe->wq;
--
-- io_worker_start(wqe, worker);
--
-- while (!test_bit(IO_WQ_BIT_EXIT, &wq->state)) {
-- set_current_state(TASK_INTERRUPTIBLE);
--loop:
-- raw_spin_lock_irq(&wqe->lock);
-- if (io_wqe_run_queue(wqe)) {
-- __set_current_state(TASK_RUNNING);
-- io_worker_handle_work(worker);
-- goto loop;
-- }
-- /* drops the lock on success, retry */
-- if (__io_worker_idle(wqe, worker)) {
-- __release(&wqe->lock);
-- goto loop;
-- }
-- raw_spin_unlock_irq(&wqe->lock);
-- if (signal_pending(current))
-- flush_signals(current);
-- if (schedule_timeout(WORKER_IDLE_TIMEOUT))
-- continue;
-- /* timed out, exit unless we're the fixed worker */
-- if (test_bit(IO_WQ_BIT_EXIT, &wq->state) ||
-- !(worker->flags & IO_WORKER_F_FIXED))
-- break;
-- }
--
-- if (test_bit(IO_WQ_BIT_EXIT, &wq->state)) {
-- raw_spin_lock_irq(&wqe->lock);
-- if (!wq_list_empty(&wqe->work_list))
-- io_worker_handle_work(worker);
-- else
-- raw_spin_unlock_irq(&wqe->lock);
-- }
--
-- io_worker_exit(worker);
-- return 0;
--}
--
--/*
-- * Called when a worker is scheduled in. Mark us as currently running.
-- */
--void io_wq_worker_running(struct task_struct *tsk)
--{
-- struct io_worker *worker = kthread_data(tsk);
-- struct io_wqe *wqe = worker->wqe;
--
-- if (!(worker->flags & IO_WORKER_F_UP))
-- return;
-- if (worker->flags & IO_WORKER_F_RUNNING)
-- return;
-- worker->flags |= IO_WORKER_F_RUNNING;
-- io_wqe_inc_running(wqe, worker);
--}
--
--/*
-- * Called when worker is going to sleep. If there are no workers currently
-- * running and we have work pending, wake up a free one or have the manager
-- * set one up.
-- */
--void io_wq_worker_sleeping(struct task_struct *tsk)
--{
-- struct io_worker *worker = kthread_data(tsk);
-- struct io_wqe *wqe = worker->wqe;
--
-- if (!(worker->flags & IO_WORKER_F_UP))
-- return;
-- if (!(worker->flags & IO_WORKER_F_RUNNING))
-- return;
--
-- worker->flags &= ~IO_WORKER_F_RUNNING;
--
-- raw_spin_lock_irq(&wqe->lock);
-- io_wqe_dec_running(wqe, worker);
-- raw_spin_unlock_irq(&wqe->lock);
--}
--
--static bool create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index)
--{
-- struct io_wqe_acct *acct = &wqe->acct[index];
-- struct io_worker *worker;
--
-- worker = kzalloc_node(sizeof(*worker), GFP_KERNEL, wqe->node);
-- if (!worker)
-- return false;
--
-- refcount_set(&worker->ref, 1);
-- worker->nulls_node.pprev = NULL;
-- worker->wqe = wqe;
-- spin_lock_init(&worker->lock);
--
-- worker->task = kthread_create_on_node(io_wqe_worker, worker, wqe->node,
-- "io_wqe_worker-%d/%d", index, wqe->node);
-- if (IS_ERR(worker->task)) {
-- kfree(worker);
-- return false;
-- }
-- kthread_bind_mask(worker->task, cpumask_of_node(wqe->node));
--
-- raw_spin_lock_irq(&wqe->lock);
-- hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list);
-- list_add_tail_rcu(&worker->all_list, &wqe->all_list);
-- worker->flags |= IO_WORKER_F_FREE;
-- if (index == IO_WQ_ACCT_BOUND)
-- worker->flags |= IO_WORKER_F_BOUND;
-- if (!acct->nr_workers && (worker->flags & IO_WORKER_F_BOUND))
-- worker->flags |= IO_WORKER_F_FIXED;
-- acct->nr_workers++;
-- raw_spin_unlock_irq(&wqe->lock);
--
-- if (index == IO_WQ_ACCT_UNBOUND)
-- atomic_inc(&wq->user->processes);
--
-- refcount_inc(&wq->refs);
-- wake_up_process(worker->task);
-- return true;
--}
--
--static inline bool io_wqe_need_worker(struct io_wqe *wqe, int index)
-- __must_hold(wqe->lock)
--{
-- struct io_wqe_acct *acct = &wqe->acct[index];
--
-- /* if we have available workers or no work, no need */
-- if (!hlist_nulls_empty(&wqe->free_list) || !io_wqe_run_queue(wqe))
-- return false;
-- return acct->nr_workers < acct->max_workers;
--}
--
--static bool io_wqe_worker_send_sig(struct io_worker *worker, void *data)
--{
-- send_sig(SIGINT, worker->task, 1);
-- return false;
--}
--
--/*
-- * Iterate the passed in list and call the specific function for each
-- * worker that isn't exiting
-- */
--static bool io_wq_for_each_worker(struct io_wqe *wqe,
-- bool (*func)(struct io_worker *, void *),
-- void *data)
--{
-- struct io_worker *worker;
-- bool ret = false;
--
-- list_for_each_entry_rcu(worker, &wqe->all_list, all_list) {
-- if (io_worker_get(worker)) {
-- /* no task if node is/was offline */
-- if (worker->task)
-- ret = func(worker, data);
-- io_worker_release(worker);
-- if (ret)
-- break;
-- }
-- }
--
-- return ret;
--}
--
--static bool io_wq_worker_wake(struct io_worker *worker, void *data)
--{
-- wake_up_process(worker->task);
-- return false;
--}
--
--/*
-- * Manager thread. Tasked with creating new workers, if we need them.
-- */
--static int io_wq_manager(void *data)
--{
-- struct io_wq *wq = data;
-- int node;
--
-- /* create fixed workers */
-- refcount_set(&wq->refs, 1);
-- for_each_node(node) {
-- if (!node_online(node))
-- continue;
-- if (create_io_worker(wq, wq->wqes[node], IO_WQ_ACCT_BOUND))
-- continue;
-- set_bit(IO_WQ_BIT_ERROR, &wq->state);
-- set_bit(IO_WQ_BIT_EXIT, &wq->state);
-- goto out;
-- }
--
-- complete(&wq->done);
--
-- while (!kthread_should_stop()) {
-- if (current->task_works)
-- task_work_run();
--
-- for_each_node(node) {
-- struct io_wqe *wqe = wq->wqes[node];
-- bool fork_worker[2] = { false, false };
--
-- if (!node_online(node))
-- continue;
--
-- raw_spin_lock_irq(&wqe->lock);
-- if (io_wqe_need_worker(wqe, IO_WQ_ACCT_BOUND))
-- fork_worker[IO_WQ_ACCT_BOUND] = true;
-- if (io_wqe_need_worker(wqe, IO_WQ_ACCT_UNBOUND))
-- fork_worker[IO_WQ_ACCT_UNBOUND] = true;
-- raw_spin_unlock_irq(&wqe->lock);
-- if (fork_worker[IO_WQ_ACCT_BOUND])
-- create_io_worker(wq, wqe, IO_WQ_ACCT_BOUND);
-- if (fork_worker[IO_WQ_ACCT_UNBOUND])
-- create_io_worker(wq, wqe, IO_WQ_ACCT_UNBOUND);
-- }
-- set_current_state(TASK_INTERRUPTIBLE);
-- schedule_timeout(HZ);
-- }
--
-- if (current->task_works)
-- task_work_run();
--
--out:
-- if (refcount_dec_and_test(&wq->refs)) {
-- complete(&wq->done);
-- return 0;
-- }
-- /* if ERROR is set and we get here, we have workers to wake */
-- if (test_bit(IO_WQ_BIT_ERROR, &wq->state)) {
-- rcu_read_lock();
-- for_each_node(node)
-- io_wq_for_each_worker(wq->wqes[node], io_wq_worker_wake, NULL);
-- rcu_read_unlock();
-- }
-- return 0;
--}
--
--static bool io_wq_can_queue(struct io_wqe *wqe, struct io_wqe_acct *acct,
-- struct io_wq_work *work)
--{
-- bool free_worker;
--
-- if (!(work->flags & IO_WQ_WORK_UNBOUND))
-- return true;
-- if (atomic_read(&acct->nr_running))
-- return true;
--
-- rcu_read_lock();
-- free_worker = !hlist_nulls_empty(&wqe->free_list);
-- rcu_read_unlock();
-- if (free_worker)
-- return true;
--
-- if (atomic_read(&wqe->wq->user->processes) >= acct->max_workers &&
-- !(capable(CAP_SYS_RESOURCE) || capable(CAP_SYS_ADMIN)))
-- return false;
--
-- return true;
--}
--
--static void io_run_cancel(struct io_wq_work *work, struct io_wqe *wqe)
--{
-- struct io_wq *wq = wqe->wq;
--
-- do {
-- struct io_wq_work *old_work = work;
--
-- work->flags |= IO_WQ_WORK_CANCEL;
-- work = wq->do_work(work);
-- wq->free_work(old_work);
-- } while (work);
--}
--
--static void io_wqe_insert_work(struct io_wqe *wqe, struct io_wq_work *work)
--{
-- unsigned int hash;
-- struct io_wq_work *tail;
--
-- if (!io_wq_is_hashed(work)) {
--append:
-- wq_list_add_tail(&work->list, &wqe->work_list);
-- return;
-- }
--
-- hash = io_get_work_hash(work);
-- tail = wqe->hash_tail[hash];
-- wqe->hash_tail[hash] = work;
-- if (!tail)
-- goto append;
--
-- wq_list_add_after(&work->list, &tail->list, &wqe->work_list);
--}
--
--static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work)
--{
-- struct io_wqe_acct *acct = io_work_get_acct(wqe, work);
-- bool do_wake;
-- unsigned long flags;
--
-- /*
-- * Do early check to see if we need a new unbound worker, and if we do,
-- * if we're allowed to do so. This isn't 100% accurate as there's a
-- * gap between this check and incrementing the value, but that's OK.
-- * It's close enough to not be an issue, fork() has the same delay.
-- */
-- if (unlikely(!io_wq_can_queue(wqe, acct, work))) {
-- io_run_cancel(work, wqe);
-- return;
-- }
--
-- raw_spin_lock_irqsave(&wqe->lock, flags);
-- io_wqe_insert_work(wqe, work);
-- wqe->flags &= ~IO_WQE_FLAG_STALLED;
-- do_wake = (work->flags & IO_WQ_WORK_CONCURRENT) ||
-- !atomic_read(&acct->nr_running);
-- raw_spin_unlock_irqrestore(&wqe->lock, flags);
--
-- if (do_wake)
-- io_wqe_wake_worker(wqe, acct);
--}
--
--void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work)
--{
-- struct io_wqe *wqe = wq->wqes[numa_node_id()];
--
-- io_wqe_enqueue(wqe, work);
--}
--
--/*
-- * Work items that hash to the same value will not be done in parallel.
-- * Used to limit concurrent writes, generally hashed by inode.
-- */
--void io_wq_hash_work(struct io_wq_work *work, void *val)
--{
-- unsigned int bit;
--
-- bit = hash_ptr(val, IO_WQ_HASH_ORDER);
-- work->flags |= (IO_WQ_WORK_HASHED | (bit << IO_WQ_HASH_SHIFT));
--}
--
--void io_wq_cancel_all(struct io_wq *wq)
--{
-- int node;
--
-- set_bit(IO_WQ_BIT_CANCEL, &wq->state);
--
-- rcu_read_lock();
-- for_each_node(node) {
-- struct io_wqe *wqe = wq->wqes[node];
--
-- io_wq_for_each_worker(wqe, io_wqe_worker_send_sig, NULL);
-- }
-- rcu_read_unlock();
--}
--
--struct io_cb_cancel_data {
-- work_cancel_fn *fn;
-- void *data;
-- int nr_running;
-- int nr_pending;
-- bool cancel_all;
--};
--
--static bool io_wq_worker_cancel(struct io_worker *worker, void *data)
--{
-- struct io_cb_cancel_data *match = data;
-- unsigned long flags;
--
-- /*
-- * Hold the lock to avoid ->cur_work going out of scope, caller
-- * may dereference the passed in work.
-- */
-- spin_lock_irqsave(&worker->lock, flags);
-- if (worker->cur_work &&
-- !(worker->cur_work->flags & IO_WQ_WORK_NO_CANCEL) &&
-- match->fn(worker->cur_work, match->data)) {
-- send_sig(SIGINT, worker->task, 1);
-- match->nr_running++;
-- }
-- spin_unlock_irqrestore(&worker->lock, flags);
--
-- return match->nr_running && !match->cancel_all;
--}
--
--static inline void io_wqe_remove_pending(struct io_wqe *wqe,
-- struct io_wq_work *work,
-- struct io_wq_work_node *prev)
--{
-- unsigned int hash = io_get_work_hash(work);
-- struct io_wq_work *prev_work = NULL;
--
-- if (io_wq_is_hashed(work) && work == wqe->hash_tail[hash]) {
-- if (prev)
-- prev_work = container_of(prev, struct io_wq_work, list);
-- if (prev_work && io_get_work_hash(prev_work) == hash)
-- wqe->hash_tail[hash] = prev_work;
-- else
-- wqe->hash_tail[hash] = NULL;
-- }
-- wq_list_del(&wqe->work_list, &work->list, prev);
--}
--
--static void io_wqe_cancel_pending_work(struct io_wqe *wqe,
-- struct io_cb_cancel_data *match)
--{
-- struct io_wq_work_node *node, *prev;
-- struct io_wq_work *work;
-- unsigned long flags;
--
--retry:
-- raw_spin_lock_irqsave(&wqe->lock, flags);
-- wq_list_for_each(node, prev, &wqe->work_list) {
-- work = container_of(node, struct io_wq_work, list);
-- if (!match->fn(work, match->data))
-- continue;
-- io_wqe_remove_pending(wqe, work, prev);
-- raw_spin_unlock_irqrestore(&wqe->lock, flags);
-- io_run_cancel(work, wqe);
-- match->nr_pending++;
-- if (!match->cancel_all)
-- return;
--
-- /* not safe to continue after unlock */
-- goto retry;
-- }
-- raw_spin_unlock_irqrestore(&wqe->lock, flags);
--}
--
--static void io_wqe_cancel_running_work(struct io_wqe *wqe,
-- struct io_cb_cancel_data *match)
--{
-- rcu_read_lock();
-- io_wq_for_each_worker(wqe, io_wq_worker_cancel, match);
-- rcu_read_unlock();
--}
--
--enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel,
-- void *data, bool cancel_all)
--{
-- struct io_cb_cancel_data match = {
-- .fn = cancel,
-- .data = data,
-- .cancel_all = cancel_all,
-- };
-- int node;
--
-- /*
-- * First check pending list, if we're lucky we can just remove it
-- * from there. CANCEL_OK means that the work is returned as-new,
-- * no completion will be posted for it.
-- */
-- for_each_node(node) {
-- struct io_wqe *wqe = wq->wqes[node];
--
-- io_wqe_cancel_pending_work(wqe, &match);
-- if (match.nr_pending && !match.cancel_all)
-- return IO_WQ_CANCEL_OK;
-- }
--
-- /*
-- * Now check if a free (going busy) or busy worker has the work
-- * currently running. If we find it there, we'll return CANCEL_RUNNING
-- * as an indication that we attempt to signal cancellation. The
-- * completion will run normally in this case.
-- */
-- for_each_node(node) {
-- struct io_wqe *wqe = wq->wqes[node];
--
-- io_wqe_cancel_running_work(wqe, &match);
-- if (match.nr_running && !match.cancel_all)
-- return IO_WQ_CANCEL_RUNNING;
-- }
--
-- if (match.nr_running)
-- return IO_WQ_CANCEL_RUNNING;
-- if (match.nr_pending)
-- return IO_WQ_CANCEL_OK;
-- return IO_WQ_CANCEL_NOTFOUND;
--}
--
--struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)
--{
-- int ret = -ENOMEM, node;
-- struct io_wq *wq;
--
-- if (WARN_ON_ONCE(!data->free_work || !data->do_work))
-- return ERR_PTR(-EINVAL);
-- if (WARN_ON_ONCE(!bounded))
-- return ERR_PTR(-EINVAL);
--
-- wq = kzalloc(sizeof(*wq), GFP_KERNEL);
-- if (!wq)
-- return ERR_PTR(-ENOMEM);
--
-- wq->wqes = kcalloc(nr_node_ids, sizeof(struct io_wqe *), GFP_KERNEL);
-- if (!wq->wqes)
-- goto err_wq;
--
-- ret = cpuhp_state_add_instance_nocalls(io_wq_online, &wq->cpuhp_node);
-- if (ret)
-- goto err_wqes;
--
-- wq->free_work = data->free_work;
-- wq->do_work = data->do_work;
--
-- /* caller must already hold a reference to this */
-- wq->user = data->user;
--
-- ret = -ENOMEM;
-- for_each_node(node) {
-- struct io_wqe *wqe;
-- int alloc_node = node;
--
-- if (!node_online(alloc_node))
-- alloc_node = NUMA_NO_NODE;
-- wqe = kzalloc_node(sizeof(struct io_wqe), GFP_KERNEL, alloc_node);
-- if (!wqe)
-- goto err;
-- wq->wqes[node] = wqe;
-- wqe->node = alloc_node;
-- wqe->acct[IO_WQ_ACCT_BOUND].max_workers = bounded;
-- atomic_set(&wqe->acct[IO_WQ_ACCT_BOUND].nr_running, 0);
-- if (wq->user) {
-- wqe->acct[IO_WQ_ACCT_UNBOUND].max_workers =
-- task_rlimit(current, RLIMIT_NPROC);
-- }
-- atomic_set(&wqe->acct[IO_WQ_ACCT_UNBOUND].nr_running, 0);
-- wqe->wq = wq;
-- raw_spin_lock_init(&wqe->lock);
-- INIT_WQ_LIST(&wqe->work_list);
-- INIT_HLIST_NULLS_HEAD(&wqe->free_list, 0);
-- INIT_LIST_HEAD(&wqe->all_list);
-- }
--
-- init_completion(&wq->done);
--
-- wq->manager = kthread_create(io_wq_manager, wq, "io_wq_manager");
-- if (!IS_ERR(wq->manager)) {
-- wake_up_process(wq->manager);
-- wait_for_completion(&wq->done);
-- if (test_bit(IO_WQ_BIT_ERROR, &wq->state)) {
-- ret = -ENOMEM;
-- goto err;
-- }
-- refcount_set(&wq->use_refs, 1);
-- reinit_completion(&wq->done);
-- return wq;
-- }
--
-- ret = PTR_ERR(wq->manager);
-- complete(&wq->done);
--err:
-- cpuhp_state_remove_instance_nocalls(io_wq_online, &wq->cpuhp_node);
-- for_each_node(node)
-- kfree(wq->wqes[node]);
--err_wqes:
-- kfree(wq->wqes);
--err_wq:
-- kfree(wq);
-- return ERR_PTR(ret);
--}
--
--bool io_wq_get(struct io_wq *wq, struct io_wq_data *data)
--{
-- if (data->free_work != wq->free_work || data->do_work != wq->do_work)
-- return false;
--
-- return refcount_inc_not_zero(&wq->use_refs);
--}
--
--static void __io_wq_destroy(struct io_wq *wq)
--{
-- int node;
--
-- cpuhp_state_remove_instance_nocalls(io_wq_online, &wq->cpuhp_node);
--
-- set_bit(IO_WQ_BIT_EXIT, &wq->state);
-- if (wq->manager)
-- kthread_stop(wq->manager);
--
-- rcu_read_lock();
-- for_each_node(node)
-- io_wq_for_each_worker(wq->wqes[node], io_wq_worker_wake, NULL);
-- rcu_read_unlock();
--
-- wait_for_completion(&wq->done);
--
-- for_each_node(node)
-- kfree(wq->wqes[node]);
-- kfree(wq->wqes);
-- kfree(wq);
--}
--
--void io_wq_destroy(struct io_wq *wq)
--{
-- if (refcount_dec_and_test(&wq->use_refs))
-- __io_wq_destroy(wq);
--}
--
--struct task_struct *io_wq_get_task(struct io_wq *wq)
--{
-- return wq->manager;
--}
--
--static bool io_wq_worker_affinity(struct io_worker *worker, void *data)
--{
-- struct task_struct *task = worker->task;
-- struct rq_flags rf;
-- struct rq *rq;
--
-- rq = task_rq_lock(task, &rf);
-- do_set_cpus_allowed(task, cpumask_of_node(worker->wqe->node));
-- task->flags |= PF_NO_SETAFFINITY;
-- task_rq_unlock(rq, task, &rf);
-- return false;
--}
--
--static int io_wq_cpu_online(unsigned int cpu, struct hlist_node *node)
--{
-- struct io_wq *wq = hlist_entry_safe(node, struct io_wq, cpuhp_node);
-- int i;
--
-- rcu_read_lock();
-- for_each_node(i)
-- io_wq_for_each_worker(wq->wqes[i], io_wq_worker_affinity, NULL);
-- rcu_read_unlock();
-- return 0;
--}
--
--static __init int io_wq_init(void)
--{
-- int ret;
--
-- ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "io-wq/online",
-- io_wq_cpu_online, NULL);
-- if (ret < 0)
-- return ret;
-- io_wq_online = ret;
-- return 0;
--}
--subsys_initcall(io_wq_init);
---- a/fs/io-wq.h
-+++ /dev/null
-@@ -1,157 +0,0 @@
--#ifndef INTERNAL_IO_WQ_H
--#define INTERNAL_IO_WQ_H
--
--#include <linux/io_uring.h>
--
--struct io_wq;
--
--enum {
-- IO_WQ_WORK_CANCEL = 1,
-- IO_WQ_WORK_HASHED = 2,
-- IO_WQ_WORK_UNBOUND = 4,
-- IO_WQ_WORK_NO_CANCEL = 8,
-- IO_WQ_WORK_CONCURRENT = 16,
--
-- IO_WQ_WORK_FILES = 32,
-- IO_WQ_WORK_FS = 64,
-- IO_WQ_WORK_MM = 128,
-- IO_WQ_WORK_CREDS = 256,
-- IO_WQ_WORK_BLKCG = 512,
-- IO_WQ_WORK_FSIZE = 1024,
--
-- IO_WQ_HASH_SHIFT = 24, /* upper 8 bits are used for hash key */
--};
--
--enum io_wq_cancel {
-- IO_WQ_CANCEL_OK, /* cancelled before started */
-- IO_WQ_CANCEL_RUNNING, /* found, running, and attempted cancelled */
-- IO_WQ_CANCEL_NOTFOUND, /* work not found */
--};
--
--struct io_wq_work_node {
-- struct io_wq_work_node *next;
--};
--
--struct io_wq_work_list {
-- struct io_wq_work_node *first;
-- struct io_wq_work_node *last;
--};
--
--static inline void wq_list_add_after(struct io_wq_work_node *node,
-- struct io_wq_work_node *pos,
-- struct io_wq_work_list *list)
--{
-- struct io_wq_work_node *next = pos->next;
--
-- pos->next = node;
-- node->next = next;
-- if (!next)
-- list->last = node;
--}
--
--static inline void wq_list_add_tail(struct io_wq_work_node *node,
-- struct io_wq_work_list *list)
--{
-- if (!list->first) {
-- list->last = node;
-- WRITE_ONCE(list->first, node);
-- } else {
-- list->last->next = node;
-- list->last = node;
-- }
-- node->next = NULL;
--}
--
--static inline void wq_list_cut(struct io_wq_work_list *list,
-- struct io_wq_work_node *last,
-- struct io_wq_work_node *prev)
--{
-- /* first in the list, if prev==NULL */
-- if (!prev)
-- WRITE_ONCE(list->first, last->next);
-- else
-- prev->next = last->next;
--
-- if (last == list->last)
-- list->last = prev;
-- last->next = NULL;
--}
--
--static inline void wq_list_del(struct io_wq_work_list *list,
-- struct io_wq_work_node *node,
-- struct io_wq_work_node *prev)
--{
-- wq_list_cut(list, node, prev);
--}
--
--#define wq_list_for_each(pos, prv, head) \
-- for (pos = (head)->first, prv = NULL; pos; prv = pos, pos = (pos)->next)
--
--#define wq_list_empty(list) (READ_ONCE((list)->first) == NULL)
--#define INIT_WQ_LIST(list) do { \
-- (list)->first = NULL; \
-- (list)->last = NULL; \
--} while (0)
--
--struct io_wq_work {
-- struct io_wq_work_node list;
-- struct io_identity *identity;
-- unsigned flags;
--};
--
--static inline struct io_wq_work *wq_next_work(struct io_wq_work *work)
--{
-- if (!work->list.next)
-- return NULL;
--
-- return container_of(work->list.next, struct io_wq_work, list);
--}
--
--typedef void (free_work_fn)(struct io_wq_work *);
--typedef struct io_wq_work *(io_wq_work_fn)(struct io_wq_work *);
--
--struct io_wq_data {
-- struct user_struct *user;
--
-- io_wq_work_fn *do_work;
-- free_work_fn *free_work;
--};
--
--struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data);
--bool io_wq_get(struct io_wq *wq, struct io_wq_data *data);
--void io_wq_destroy(struct io_wq *wq);
--
--void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work);
--void io_wq_hash_work(struct io_wq_work *work, void *val);
--
--static inline bool io_wq_is_hashed(struct io_wq_work *work)
--{
-- return work->flags & IO_WQ_WORK_HASHED;
--}
--
--void io_wq_cancel_all(struct io_wq *wq);
--
--typedef bool (work_cancel_fn)(struct io_wq_work *, void *);
--
--enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel,
-- void *data, bool cancel_all);
--
--struct task_struct *io_wq_get_task(struct io_wq *wq);
--
--#if defined(CONFIG_IO_WQ)
--extern void io_wq_worker_sleeping(struct task_struct *);
--extern void io_wq_worker_running(struct task_struct *);
--#else
--static inline void io_wq_worker_sleeping(struct task_struct *tsk)
--{
--}
--static inline void io_wq_worker_running(struct task_struct *tsk)
--{
--}
--#endif
--
--static inline bool io_wq_current_is_worker(void)
--{
-- return in_task() && (current->flags & PF_IO_WORKER);
--}
--#endif
---- a/fs/io_uring.c
-+++ /dev/null
-@@ -1,9971 +0,0 @@
--// SPDX-License-Identifier: GPL-2.0
--/*
-- * Shared application/kernel submission and completion ring pairs, for
-- * supporting fast/efficient IO.
-- *
-- * A note on the read/write ordering memory barriers that are matched between
-- * the application and kernel side.
-- *
-- * After the application reads the CQ ring tail, it must use an
-- * appropriate smp_rmb() to pair with the smp_wmb() the kernel uses
-- * before writing the tail (using smp_load_acquire to read the tail will
-- * do). It also needs a smp_mb() before updating CQ head (ordering the
-- * entry load(s) with the head store), pairing with an implicit barrier
-- * through a control-dependency in io_get_cqring (smp_store_release to
-- * store head will do). Failure to do so could lead to reading invalid
-- * CQ entries.
-- *
-- * Likewise, the application must use an appropriate smp_wmb() before
-- * writing the SQ tail (ordering SQ entry stores with the tail store),
-- * which pairs with smp_load_acquire in io_get_sqring (smp_store_release
-- * to store the tail will do). And it needs a barrier ordering the SQ
-- * head load before writing new SQ entries (smp_load_acquire to read
-- * head will do).
-- *
-- * When using the SQ poll thread (IORING_SETUP_SQPOLL), the application
-- * needs to check the SQ flags for IORING_SQ_NEED_WAKEUP *after*
-- * updating the SQ tail; a full memory barrier smp_mb() is needed
-- * between.
-- *
-- * Also see the examples in the liburing library:
-- *
-- * git://git.kernel.dk/liburing
-- *
-- * io_uring also uses READ/WRITE_ONCE() for _any_ store or load that happens
-- * from data shared between the kernel and application. This is done both
-- * for ordering purposes, but also to ensure that once a value is loaded from
-- * data that the application could potentially modify, it remains stable.
-- *
-- * Copyright (C) 2018-2019 Jens Axboe
-- * Copyright (c) 2018-2019 Christoph Hellwig
-- */
--#include <linux/kernel.h>
--#include <linux/init.h>
--#include <linux/errno.h>
--#include <linux/syscalls.h>
--#include <linux/compat.h>
--#include <net/compat.h>
--#include <linux/refcount.h>
--#include <linux/uio.h>
--#include <linux/bits.h>
--
--#include <linux/sched/signal.h>
--#include <linux/fs.h>
--#include <linux/file.h>
--#include <linux/fdtable.h>
--#include <linux/mm.h>
--#include <linux/mman.h>
--#include <linux/percpu.h>
--#include <linux/slab.h>
--#include <linux/kthread.h>
--#include <linux/blkdev.h>
--#include <linux/bvec.h>
--#include <linux/net.h>
--#include <net/sock.h>
--#include <net/af_unix.h>
--#include <net/scm.h>
--#include <linux/anon_inodes.h>
--#include <linux/sched/mm.h>
--#include <linux/uaccess.h>
--#include <linux/nospec.h>
--#include <linux/sizes.h>
--#include <linux/hugetlb.h>
--#include <linux/highmem.h>
--#include <linux/namei.h>
--#include <linux/fsnotify.h>
--#include <linux/fadvise.h>
--#include <linux/eventpoll.h>
--#include <linux/fs_struct.h>
--#include <linux/splice.h>
--#include <linux/task_work.h>
--#include <linux/pagemap.h>
--#include <linux/io_uring.h>
--#include <linux/blk-cgroup.h>
--#include <linux/audit.h>
--
--#define CREATE_TRACE_POINTS
--#include <trace/events/io_uring.h>
--
--#include <uapi/linux/io_uring.h>
--
--#include "internal.h"
--#include "io-wq.h"
--
--#define IORING_MAX_ENTRIES 32768
--#define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES)
--
--/*
-- * Shift of 9 is 512 entries, or exactly one page on 64-bit archs
-- */
--#define IORING_FILE_TABLE_SHIFT 9
--#define IORING_MAX_FILES_TABLE (1U << IORING_FILE_TABLE_SHIFT)
--#define IORING_FILE_TABLE_MASK (IORING_MAX_FILES_TABLE - 1)
--#define IORING_MAX_FIXED_FILES (64 * IORING_MAX_FILES_TABLE)
--#define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \
-- IORING_REGISTER_LAST + IORING_OP_LAST)
--
--struct io_uring {
-- u32 head ____cacheline_aligned_in_smp;
-- u32 tail ____cacheline_aligned_in_smp;
--};
--
--/*
-- * This data is shared with the application through the mmap at offsets
-- * IORING_OFF_SQ_RING and IORING_OFF_CQ_RING.
-- *
-- * The offsets to the member fields are published through struct
-- * io_sqring_offsets when calling io_uring_setup.
-- */
--struct io_rings {
-- /*
-- * Head and tail offsets into the ring; the offsets need to be
-- * masked to get valid indices.
-- *
-- * The kernel controls head of the sq ring and the tail of the cq ring,
-- * and the application controls tail of the sq ring and the head of the
-- * cq ring.
-- */
-- struct io_uring sq, cq;
-- /*
-- * Bitmasks to apply to head and tail offsets (constant, equals
-- * ring_entries - 1)
-- */
-- u32 sq_ring_mask, cq_ring_mask;
-- /* Ring sizes (constant, power of 2) */
-- u32 sq_ring_entries, cq_ring_entries;
-- /*
-- * Number of invalid entries dropped by the kernel due to
-- * invalid index stored in array
-- *
-- * Written by the kernel, shouldn't be modified by the
-- * application (i.e. get number of "new events" by comparing to
-- * cached value).
-- *
-- * After a new SQ head value was read by the application this
-- * counter includes all submissions that were dropped reaching
-- * the new SQ head (and possibly more).
-- */
-- u32 sq_dropped;
-- /*
-- * Runtime SQ flags
-- *
-- * Written by the kernel, shouldn't be modified by the
-- * application.
-- *
-- * The application needs a full memory barrier before checking
-- * for IORING_SQ_NEED_WAKEUP after updating the sq tail.
-- */
-- u32 sq_flags;
-- /*
-- * Runtime CQ flags
-- *
-- * Written by the application, shouldn't be modified by the
-- * kernel.
-- */
-- u32 cq_flags;
-- /*
-- * Number of completion events lost because the queue was full;
-- * this should be avoided by the application by making sure
-- * there are not more requests pending than there is space in
-- * the completion queue.
-- *
-- * Written by the kernel, shouldn't be modified by the
-- * application (i.e. get number of "new events" by comparing to
-- * cached value).
-- *
-- * As completion events come in out of order this counter is not
-- * ordered with any other data.
-- */
-- u32 cq_overflow;
-- /*
-- * Ring buffer of completion events.
-- *
-- * The kernel writes completion events fresh every time they are
-- * produced, so the application is allowed to modify pending
-- * entries.
-- */
-- struct io_uring_cqe cqes[] ____cacheline_aligned_in_smp;
--};
--
--struct io_mapped_ubuf {
-- u64 ubuf;
-- size_t len;
-- struct bio_vec *bvec;
-- unsigned int nr_bvecs;
-- unsigned long acct_pages;
--};
--
--struct fixed_file_table {
-- struct file **files;
--};
--
--struct fixed_file_ref_node {
-- struct percpu_ref refs;
-- struct list_head node;
-- struct list_head file_list;
-- struct fixed_file_data *file_data;
-- struct llist_node llist;
-- bool done;
--};
--
--struct fixed_file_data {
-- struct fixed_file_table *table;
-- struct io_ring_ctx *ctx;
--
-- struct fixed_file_ref_node *node;
-- struct percpu_ref refs;
-- struct completion done;
-- struct list_head ref_list;
-- spinlock_t lock;
-- bool quiesce;
--};
--
--struct io_buffer {
-- struct list_head list;
-- __u64 addr;
-- __u32 len;
-- __u16 bid;
--};
--
--struct io_restriction {
-- DECLARE_BITMAP(register_op, IORING_REGISTER_LAST);
-- DECLARE_BITMAP(sqe_op, IORING_OP_LAST);
-- u8 sqe_flags_allowed;
-- u8 sqe_flags_required;
-- bool registered;
--};
--
--struct io_sq_data {
-- refcount_t refs;
-- struct mutex lock;
--
-- /* ctx's that are using this sqd */
-- struct list_head ctx_list;
-- struct list_head ctx_new_list;
-- struct mutex ctx_lock;
--
-- struct task_struct *thread;
-- struct wait_queue_head wait;
--};
--
--struct io_ring_ctx {
-- struct {
-- struct percpu_ref refs;
-- } ____cacheline_aligned_in_smp;
--
-- struct {
-- unsigned int flags;
-- unsigned int compat: 1;
-- unsigned int limit_mem: 1;
-- unsigned int cq_overflow_flushed: 1;
-- unsigned int drain_next: 1;
-- unsigned int eventfd_async: 1;
-- unsigned int restricted: 1;
-- unsigned int sqo_dead: 1;
--
-- /*
-- * Ring buffer of indices into array of io_uring_sqe, which is
-- * mmapped by the application using the IORING_OFF_SQES offset.
-- *
-- * This indirection could e.g. be used to assign fixed
-- * io_uring_sqe entries to operations and only submit them to
-- * the queue when needed.
-- *
-- * The kernel modifies neither the indices array nor the entries
-- * array.
-- */
-- u32 *sq_array;
-- unsigned cached_sq_head;
-- unsigned sq_entries;
-- unsigned sq_mask;
-- unsigned sq_thread_idle;
-- unsigned cached_sq_dropped;
-- unsigned cached_cq_overflow;
-- unsigned long sq_check_overflow;
--
-- struct list_head defer_list;
-- struct list_head timeout_list;
-- struct list_head cq_overflow_list;
--
-- struct io_uring_sqe *sq_sqes;
-- } ____cacheline_aligned_in_smp;
--
-- struct io_rings *rings;
--
-- /* IO offload */
-- struct io_wq *io_wq;
--
-- /*
-- * For SQPOLL usage - we hold a reference to the parent task, so we
-- * have access to the ->files
-- */
-- struct task_struct *sqo_task;
--
-- /* Only used for accounting purposes */
-- struct mm_struct *mm_account;
--
--#ifdef CONFIG_BLK_CGROUP
-- struct cgroup_subsys_state *sqo_blkcg_css;
--#endif
--
-- struct io_sq_data *sq_data; /* if using sq thread polling */
--
-- struct wait_queue_head sqo_sq_wait;
-- struct wait_queue_entry sqo_wait_entry;
-- struct list_head sqd_list;
--
-- /*
-- * If used, fixed file set. Writers must ensure that ->refs is dead,
-- * readers must ensure that ->refs is alive as long as the file* is
-- * used. Only updated through io_uring_register(2).
-- */
-- struct fixed_file_data *file_data;
-- unsigned nr_user_files;
--
-- /* if used, fixed mapped user buffers */
-- unsigned nr_user_bufs;
-- struct io_mapped_ubuf *user_bufs;
--
-- struct user_struct *user;
--
-- const struct cred *creds;
--
--#ifdef CONFIG_AUDIT
-- kuid_t loginuid;
-- unsigned int sessionid;
--#endif
--
-- struct completion ref_comp;
-- struct completion sq_thread_comp;
--
-- /* if all else fails... */
-- struct io_kiocb *fallback_req;
--
--#if defined(CONFIG_UNIX)
-- struct socket *ring_sock;
--#endif
--
-- struct xarray io_buffers;
--
-- struct xarray personalities;
-- u32 pers_next;
--
-- struct {
-- unsigned cached_cq_tail;
-- unsigned cq_entries;
-- unsigned cq_mask;
-- atomic_t cq_timeouts;
-- unsigned cq_last_tm_flush;
-- unsigned long cq_check_overflow;
-- struct wait_queue_head cq_wait;
-- struct fasync_struct *cq_fasync;
-- struct eventfd_ctx *cq_ev_fd;
-- } ____cacheline_aligned_in_smp;
--
-- struct {
-- struct mutex uring_lock;
-- wait_queue_head_t wait;
-- } ____cacheline_aligned_in_smp;
--
-- struct {
-- spinlock_t completion_lock;
--
-- /*
-- * ->iopoll_list is protected by the ctx->uring_lock for
-- * io_uring instances that don't use IORING_SETUP_SQPOLL.
-- * For SQPOLL, only the single threaded io_sq_thread() will
-- * manipulate the list, hence no extra locking is needed there.
-- */
-- struct list_head iopoll_list;
-- struct hlist_head *cancel_hash;
-- unsigned cancel_hash_bits;
-- bool poll_multi_file;
--
-- spinlock_t inflight_lock;
-- struct list_head inflight_list;
-- } ____cacheline_aligned_in_smp;
--
-- struct delayed_work file_put_work;
-- struct llist_head file_put_llist;
--
-- struct work_struct exit_work;
-- struct io_restriction restrictions;
--};
--
--/*
-- * First field must be the file pointer in all the
-- * iocb unions! See also 'struct kiocb' in <linux/fs.h>
-- */
--struct io_poll_iocb {
-- struct file *file;
-- union {
-- struct wait_queue_head *head;
-- u64 addr;
-- };
-- __poll_t events;
-- bool done;
-- bool canceled;
-- struct wait_queue_entry wait;
--};
--
--struct io_close {
-- struct file *file;
-- struct file *put_file;
-- int fd;
--};
--
--struct io_timeout_data {
-- struct io_kiocb *req;
-- struct hrtimer timer;
-- struct timespec64 ts;
-- enum hrtimer_mode mode;
--};
--
--struct io_accept {
-- struct file *file;
-- struct sockaddr __user *addr;
-- int __user *addr_len;
-- int flags;
-- unsigned long nofile;
--};
--
--struct io_sync {
-- struct file *file;
-- loff_t len;
-- loff_t off;
-- int flags;
-- int mode;
--};
--
--struct io_cancel {
-- struct file *file;
-- u64 addr;
--};
--
--struct io_timeout {
-- struct file *file;
-- u32 off;
-- u32 target_seq;
-- struct list_head list;
--};
--
--struct io_timeout_rem {
-- struct file *file;
-- u64 addr;
--};
--
--struct io_rw {
-- /* NOTE: kiocb has the file as the first member, so don't do it here */
-- struct kiocb kiocb;
-- u64 addr;
-- u64 len;
--};
--
--struct io_connect {
-- struct file *file;
-- struct sockaddr __user *addr;
-- int addr_len;
--};
--
--struct io_sr_msg {
-- struct file *file;
-- union {
-- struct user_msghdr __user *umsg;
-- void __user *buf;
-- };
-- int msg_flags;
-- int bgid;
-- size_t len;
-- struct io_buffer *kbuf;
--};
--
--struct io_open {
-- struct file *file;
-- int dfd;
-- bool ignore_nonblock;
-- struct filename *filename;
-- struct open_how how;
-- unsigned long nofile;
--};
--
--struct io_files_update {
-- struct file *file;
-- u64 arg;
-- u32 nr_args;
-- u32 offset;
--};
--
--struct io_fadvise {
-- struct file *file;
-- u64 offset;
-- u32 len;
-- u32 advice;
--};
--
--struct io_madvise {
-- struct file *file;
-- u64 addr;
-- u32 len;
-- u32 advice;
--};
--
--struct io_epoll {
-- struct file *file;
-- int epfd;
-- int op;
-- int fd;
-- struct epoll_event event;
--};
--
--struct io_splice {
-- struct file *file_out;
-- struct file *file_in;
-- loff_t off_out;
-- loff_t off_in;
-- u64 len;
-- unsigned int flags;
--};
--
--struct io_provide_buf {
-- struct file *file;
-- __u64 addr;
-- __u32 len;
-- __u32 bgid;
-- __u16 nbufs;
-- __u16 bid;
--};
--
--struct io_statx {
-- struct file *file;
-- int dfd;
-- unsigned int mask;
-- unsigned int flags;
-- const char __user *filename;
-- struct statx __user *buffer;
--};
--
--struct io_completion {
-- struct file *file;
-- struct list_head list;
-- u32 cflags;
--};
--
--struct io_async_connect {
-- struct sockaddr_storage address;
--};
--
--struct io_async_msghdr {
-- struct iovec fast_iov[UIO_FASTIOV];
-- struct iovec *iov;
-- struct sockaddr __user *uaddr;
-- struct msghdr msg;
-- struct sockaddr_storage addr;
--};
--
--struct io_async_rw {
-- struct iovec fast_iov[UIO_FASTIOV];
-- const struct iovec *free_iovec;
-- struct iov_iter iter;
-- size_t bytes_done;
-- struct wait_page_queue wpq;
--};
--
--enum {
-- REQ_F_FIXED_FILE_BIT = IOSQE_FIXED_FILE_BIT,
-- REQ_F_IO_DRAIN_BIT = IOSQE_IO_DRAIN_BIT,
-- REQ_F_LINK_BIT = IOSQE_IO_LINK_BIT,
-- REQ_F_HARDLINK_BIT = IOSQE_IO_HARDLINK_BIT,
-- REQ_F_FORCE_ASYNC_BIT = IOSQE_ASYNC_BIT,
-- REQ_F_BUFFER_SELECT_BIT = IOSQE_BUFFER_SELECT_BIT,
--
-- REQ_F_LINK_HEAD_BIT,
-- REQ_F_FAIL_LINK_BIT,
-- REQ_F_INFLIGHT_BIT,
-- REQ_F_CUR_POS_BIT,
-- REQ_F_NOWAIT_BIT,
-- REQ_F_LINK_TIMEOUT_BIT,
-- REQ_F_ISREG_BIT,
-- REQ_F_NEED_CLEANUP_BIT,
-- REQ_F_POLLED_BIT,
-- REQ_F_BUFFER_SELECTED_BIT,
-- REQ_F_NO_FILE_TABLE_BIT,
-- REQ_F_WORK_INITIALIZED_BIT,
-- REQ_F_LTIMEOUT_ACTIVE_BIT,
--
-- /* not a real bit, just to check we're not overflowing the space */
-- __REQ_F_LAST_BIT,
--};
--
--enum {
-- /* ctx owns file */
-- REQ_F_FIXED_FILE = BIT(REQ_F_FIXED_FILE_BIT),
-- /* drain existing IO first */
-- REQ_F_IO_DRAIN = BIT(REQ_F_IO_DRAIN_BIT),
-- /* linked sqes */
-- REQ_F_LINK = BIT(REQ_F_LINK_BIT),
-- /* doesn't sever on completion < 0 */
-- REQ_F_HARDLINK = BIT(REQ_F_HARDLINK_BIT),
-- /* IOSQE_ASYNC */
-- REQ_F_FORCE_ASYNC = BIT(REQ_F_FORCE_ASYNC_BIT),
-- /* IOSQE_BUFFER_SELECT */
-- REQ_F_BUFFER_SELECT = BIT(REQ_F_BUFFER_SELECT_BIT),
--
-- /* head of a link */
-- REQ_F_LINK_HEAD = BIT(REQ_F_LINK_HEAD_BIT),
-- /* fail rest of links */
-- REQ_F_FAIL_LINK = BIT(REQ_F_FAIL_LINK_BIT),
-- /* on inflight list */
-- REQ_F_INFLIGHT = BIT(REQ_F_INFLIGHT_BIT),
-- /* read/write uses file position */
-- REQ_F_CUR_POS = BIT(REQ_F_CUR_POS_BIT),
-- /* must not punt to workers */
-- REQ_F_NOWAIT = BIT(REQ_F_NOWAIT_BIT),
-- /* has or had linked timeout */
-- REQ_F_LINK_TIMEOUT = BIT(REQ_F_LINK_TIMEOUT_BIT),
-- /* regular file */
-- REQ_F_ISREG = BIT(REQ_F_ISREG_BIT),
-- /* needs cleanup */
-- REQ_F_NEED_CLEANUP = BIT(REQ_F_NEED_CLEANUP_BIT),
-- /* already went through poll handler */
-- REQ_F_POLLED = BIT(REQ_F_POLLED_BIT),
-- /* buffer already selected */
-- REQ_F_BUFFER_SELECTED = BIT(REQ_F_BUFFER_SELECTED_BIT),
-- /* doesn't need file table for this request */
-- REQ_F_NO_FILE_TABLE = BIT(REQ_F_NO_FILE_TABLE_BIT),
-- /* io_wq_work is initialized */
-- REQ_F_WORK_INITIALIZED = BIT(REQ_F_WORK_INITIALIZED_BIT),
-- /* linked timeout is active, i.e. prepared by link's head */
-- REQ_F_LTIMEOUT_ACTIVE = BIT(REQ_F_LTIMEOUT_ACTIVE_BIT),
--};
--
--struct async_poll {
-- struct io_poll_iocb poll;
-- struct io_poll_iocb *double_poll;
--};
--
--/*
-- * NOTE! Each of the iocb union members has the file pointer
-- * as the first entry in their struct definition. So you can
-- * access the file pointer through any of the sub-structs,
-- * or directly as just 'ki_filp' in this struct.
-- */
--struct io_kiocb {
-- union {
-- struct file *file;
-- struct io_rw rw;
-- struct io_poll_iocb poll;
-- struct io_accept accept;
-- struct io_sync sync;
-- struct io_cancel cancel;
-- struct io_timeout timeout;
-- struct io_timeout_rem timeout_rem;
-- struct io_connect connect;
-- struct io_sr_msg sr_msg;
-- struct io_open open;
-- struct io_close close;
-- struct io_files_update files_update;
-- struct io_fadvise fadvise;
-- struct io_madvise madvise;
-- struct io_epoll epoll;
-- struct io_splice splice;
-- struct io_provide_buf pbuf;
-- struct io_statx statx;
-- /* use only after cleaning per-op data, see io_clean_op() */
-- struct io_completion compl;
-- };
--
-- /* opcode allocated if it needs to store data for async defer */
-- void *async_data;
-- u8 opcode;
-- /* polled IO has completed */
-- u8 iopoll_completed;
--
-- u16 buf_index;
-- u32 result;
--
-- struct io_ring_ctx *ctx;
-- unsigned int flags;
-- refcount_t refs;
-- struct task_struct *task;
-- u64 user_data;
--
-- struct list_head link_list;
--
-- /*
-- * 1. used with ctx->iopoll_list with reads/writes
-- * 2. to track reqs with ->files (see io_op_def::file_table)
-- */
-- struct list_head inflight_entry;
--
-- struct list_head iopoll_entry;
--
-- struct percpu_ref *fixed_file_refs;
-- struct callback_head task_work;
-- /* for polled requests, i.e. IORING_OP_POLL_ADD and async armed poll */
-- struct hlist_node hash_node;
-- struct async_poll *apoll;
-- struct io_wq_work work;
--};
--
--struct io_defer_entry {
-- struct list_head list;
-- struct io_kiocb *req;
-- u32 seq;
--};
--
--#define IO_IOPOLL_BATCH 8
--
--struct io_comp_state {
-- unsigned int nr;
-- struct list_head list;
-- struct io_ring_ctx *ctx;
--};
--
--struct io_submit_state {
-- struct blk_plug plug;
--
-- /*
-- * io_kiocb alloc cache
-- */
-- void *reqs[IO_IOPOLL_BATCH];
-- unsigned int free_reqs;
--
-- /*
-- * Batch completion logic
-- */
-- struct io_comp_state comp;
--
-- /*
-- * File reference cache
-- */
-- struct file *file;
-- unsigned int fd;
-- unsigned int has_refs;
-- unsigned int ios_left;
--};
--
--struct io_op_def {
-- /* needs req->file assigned */
-- unsigned needs_file : 1;
-- /* don't fail if file grab fails */
-- unsigned needs_file_no_error : 1;
-- /* hash wq insertion if file is a regular file */
-- unsigned hash_reg_file : 1;
-- /* unbound wq insertion if file is a non-regular file */
-- unsigned unbound_nonreg_file : 1;
-- /* opcode is not supported by this kernel */
-- unsigned not_supported : 1;
-- /* set if opcode supports polled "wait" */
-- unsigned pollin : 1;
-- unsigned pollout : 1;
-- /* op supports buffer selection */
-- unsigned buffer_select : 1;
-- /* must always have async data allocated */
-- unsigned needs_async_data : 1;
-- /* size of async data needed, if any */
-- unsigned short async_size;
-- unsigned work_flags;
--};
--
--static const struct io_op_def io_op_defs[] = {
-- [IORING_OP_NOP] = {},
-- [IORING_OP_READV] = {
-- .needs_file = 1,
-- .unbound_nonreg_file = 1,
-- .pollin = 1,
-- .buffer_select = 1,
-- .needs_async_data = 1,
-- .async_size = sizeof(struct io_async_rw),
-- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
-- IO_WQ_WORK_FILES,
-- },
-- [IORING_OP_WRITEV] = {
-- .needs_file = 1,
-- .hash_reg_file = 1,
-- .unbound_nonreg_file = 1,
-- .pollout = 1,
-- .needs_async_data = 1,
-- .async_size = sizeof(struct io_async_rw),
-- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
-- IO_WQ_WORK_FSIZE | IO_WQ_WORK_FILES,
-- },
-- [IORING_OP_FSYNC] = {
-- .needs_file = 1,
-- .work_flags = IO_WQ_WORK_BLKCG,
-- },
-- [IORING_OP_READ_FIXED] = {
-- .needs_file = 1,
-- .unbound_nonreg_file = 1,
-- .pollin = 1,
-- .async_size = sizeof(struct io_async_rw),
-- .work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_MM |
-- IO_WQ_WORK_FILES,
-- },
-- [IORING_OP_WRITE_FIXED] = {
-- .needs_file = 1,
-- .hash_reg_file = 1,
-- .unbound_nonreg_file = 1,
-- .pollout = 1,
-- .async_size = sizeof(struct io_async_rw),
-- .work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_FSIZE |
-- IO_WQ_WORK_MM | IO_WQ_WORK_FILES,
-- },
-- [IORING_OP_POLL_ADD] = {
-- .needs_file = 1,
-- .unbound_nonreg_file = 1,
-- },
-- [IORING_OP_POLL_REMOVE] = {},
-- [IORING_OP_SYNC_FILE_RANGE] = {
-- .needs_file = 1,
-- .work_flags = IO_WQ_WORK_BLKCG,
-- },
-- [IORING_OP_SENDMSG] = {
-- .needs_file = 1,
-- .unbound_nonreg_file = 1,
-- .pollout = 1,
-- .needs_async_data = 1,
-- .async_size = sizeof(struct io_async_msghdr),
-- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
-- IO_WQ_WORK_FS,
-- },
-- [IORING_OP_RECVMSG] = {
-- .needs_file = 1,
-- .unbound_nonreg_file = 1,
-- .pollin = 1,
-- .buffer_select = 1,
-- .needs_async_data = 1,
-- .async_size = sizeof(struct io_async_msghdr),
-- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
-- IO_WQ_WORK_FS,
-- },
-- [IORING_OP_TIMEOUT] = {
-- .needs_async_data = 1,
-- .async_size = sizeof(struct io_timeout_data),
-- .work_flags = IO_WQ_WORK_MM,
-- },
-- [IORING_OP_TIMEOUT_REMOVE] = {},
-- [IORING_OP_ACCEPT] = {
-- .needs_file = 1,
-- .unbound_nonreg_file = 1,
-- .pollin = 1,
-- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_FILES,
-- },
-- [IORING_OP_ASYNC_CANCEL] = {},
-- [IORING_OP_LINK_TIMEOUT] = {
-- .needs_async_data = 1,
-- .async_size = sizeof(struct io_timeout_data),
-- .work_flags = IO_WQ_WORK_MM,
-- },
-- [IORING_OP_CONNECT] = {
-- .needs_file = 1,
-- .unbound_nonreg_file = 1,
-- .pollout = 1,
-- .needs_async_data = 1,
-- .async_size = sizeof(struct io_async_connect),
-- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_FS,
-- },
-- [IORING_OP_FALLOCATE] = {
-- .needs_file = 1,
-- .work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_FSIZE,
-- },
-- [IORING_OP_OPENAT] = {
-- .work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_BLKCG |
-- IO_WQ_WORK_FS,
-- },
-- [IORING_OP_CLOSE] = {
-- .needs_file = 1,
-- .needs_file_no_error = 1,
-- .work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_BLKCG,
-- },
-- [IORING_OP_FILES_UPDATE] = {
-- .work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_MM,
-- },
-- [IORING_OP_STATX] = {
-- .work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_MM |
-- IO_WQ_WORK_FS | IO_WQ_WORK_BLKCG,
-- },
-- [IORING_OP_READ] = {
-- .needs_file = 1,
-- .unbound_nonreg_file = 1,
-- .pollin = 1,
-- .buffer_select = 1,
-- .async_size = sizeof(struct io_async_rw),
-- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
-- IO_WQ_WORK_FILES,
-- },
-- [IORING_OP_WRITE] = {
-- .needs_file = 1,
-- .hash_reg_file = 1,
-- .unbound_nonreg_file = 1,
-- .pollout = 1,
-- .async_size = sizeof(struct io_async_rw),
-- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
-- IO_WQ_WORK_FSIZE | IO_WQ_WORK_FILES,
-- },
-- [IORING_OP_FADVISE] = {
-- .needs_file = 1,
-- .work_flags = IO_WQ_WORK_BLKCG,
-- },
-- [IORING_OP_MADVISE] = {
-- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG,
-- },
-- [IORING_OP_SEND] = {
-- .needs_file = 1,
-- .unbound_nonreg_file = 1,
-- .pollout = 1,
-- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
-- IO_WQ_WORK_FS,
-- },
-- [IORING_OP_RECV] = {
-- .needs_file = 1,
-- .unbound_nonreg_file = 1,
-- .pollin = 1,
-- .buffer_select = 1,
-- .work_flags = IO_WQ_WORK_MM | IO_WQ_WORK_BLKCG |
-- IO_WQ_WORK_FS,
-- },
-- [IORING_OP_OPENAT2] = {
-- .work_flags = IO_WQ_WORK_FILES | IO_WQ_WORK_FS |
-- IO_WQ_WORK_BLKCG,
-- },
-- [IORING_OP_EPOLL_CTL] = {
-- .unbound_nonreg_file = 1,
-- .work_flags = IO_WQ_WORK_FILES,
-- },
-- [IORING_OP_SPLICE] = {
-- .needs_file = 1,
-- .hash_reg_file = 1,
-- .unbound_nonreg_file = 1,
-- .work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_FILES,
-- },
-- [IORING_OP_PROVIDE_BUFFERS] = {},
-- [IORING_OP_REMOVE_BUFFERS] = {},
-- [IORING_OP_TEE] = {
-- .needs_file = 1,
-- .hash_reg_file = 1,
-- .unbound_nonreg_file = 1,
-- },
--};
--
--enum io_mem_account {
-- ACCT_LOCKED,
-- ACCT_PINNED,
--};
--
--static void destroy_fixed_file_ref_node(struct fixed_file_ref_node *ref_node);
--static struct fixed_file_ref_node *alloc_fixed_file_ref_node(
-- struct io_ring_ctx *ctx);
--
--static void __io_complete_rw(struct io_kiocb *req, long res, long res2,
-- struct io_comp_state *cs);
--static void io_cqring_fill_event(struct io_kiocb *req, long res);
--static void io_put_req(struct io_kiocb *req);
--static void io_put_req_deferred(struct io_kiocb *req, int nr);
--static void io_double_put_req(struct io_kiocb *req);
--static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req);
--static void __io_queue_linked_timeout(struct io_kiocb *req);
--static void io_queue_linked_timeout(struct io_kiocb *req);
--static int __io_sqe_files_update(struct io_ring_ctx *ctx,
-- struct io_uring_files_update *ip,
-- unsigned nr_args);
--static void __io_clean_op(struct io_kiocb *req);
--static struct file *io_file_get(struct io_submit_state *state,
-- struct io_kiocb *req, int fd, bool fixed);
--static void __io_queue_sqe(struct io_kiocb *req, struct io_comp_state *cs);
--static void io_file_put_work(struct work_struct *work);
--
--static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
-- struct iovec **iovec, struct iov_iter *iter,
-- bool needs_lock);
--static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec,
-- const struct iovec *fast_iov,
-- struct iov_iter *iter, bool force);
--static void io_req_drop_files(struct io_kiocb *req);
--static void io_req_task_queue(struct io_kiocb *req);
--
--static struct kmem_cache *req_cachep;
--
--static const struct file_operations io_uring_fops;
--
--struct sock *io_uring_get_socket(struct file *file)
--{
--#if defined(CONFIG_UNIX)
-- if (file->f_op == &io_uring_fops) {
-- struct io_ring_ctx *ctx = file->private_data;
--
-- return ctx->ring_sock->sk;
-- }
--#endif
-- return NULL;
--}
--EXPORT_SYMBOL(io_uring_get_socket);
--
--static inline void io_clean_op(struct io_kiocb *req)
--{
-- if (req->flags & (REQ_F_NEED_CLEANUP | REQ_F_BUFFER_SELECTED))
-- __io_clean_op(req);
--}
--
--static inline bool __io_match_files(struct io_kiocb *req,
-- struct files_struct *files)
--{
-- if (req->file && req->file->f_op == &io_uring_fops)
-- return true;
--
-- return ((req->flags & REQ_F_WORK_INITIALIZED) &&
-- (req->work.flags & IO_WQ_WORK_FILES)) &&
-- req->work.identity->files == files;
--}
--
--static void io_refs_resurrect(struct percpu_ref *ref, struct completion *compl)
--{
-- bool got = percpu_ref_tryget(ref);
--
-- /* already at zero, wait for ->release() */
-- if (!got)
-- wait_for_completion(compl);
-- percpu_ref_resurrect(ref);
-- if (got)
-- percpu_ref_put(ref);
--}
--
--static bool io_match_task(struct io_kiocb *head,
-- struct task_struct *task,
-- struct files_struct *files)
--{
-- struct io_kiocb *link;
--
-- if (task && head->task != task) {
-- /* in terms of cancelation, always match if req task is dead */
-- if (head->task->flags & PF_EXITING)
-- return true;
-- return false;
-- }
-- if (!files)
-- return true;
-- if (__io_match_files(head, files))
-- return true;
-- if (head->flags & REQ_F_LINK_HEAD) {
-- list_for_each_entry(link, &head->link_list, link_list) {
-- if (__io_match_files(link, files))
-- return true;
-- }
-- }
-- return false;
--}
--
--
--static void io_sq_thread_drop_mm(void)
--{
-- struct mm_struct *mm = current->mm;
--
-- if (mm) {
-- kthread_unuse_mm(mm);
-- mmput(mm);
-- current->mm = NULL;
-- }
--}
--
--static int __io_sq_thread_acquire_mm(struct io_ring_ctx *ctx)
--{
-- struct mm_struct *mm;
--
-- if (current->flags & PF_EXITING)
-- return -EFAULT;
-- if (current->mm)
-- return 0;
--
-- /* Should never happen */
-- if (unlikely(!(ctx->flags & IORING_SETUP_SQPOLL)))
-- return -EFAULT;
--
-- task_lock(ctx->sqo_task);
-- mm = ctx->sqo_task->mm;
-- if (unlikely(!mm || !mmget_not_zero(mm)))
-- mm = NULL;
-- task_unlock(ctx->sqo_task);
--
-- if (mm) {
-- kthread_use_mm(mm);
-- return 0;
-- }
--
-- return -EFAULT;
--}
--
--static int io_sq_thread_acquire_mm(struct io_ring_ctx *ctx,
-- struct io_kiocb *req)
--{
-- if (!(io_op_defs[req->opcode].work_flags & IO_WQ_WORK_MM))
-- return 0;
-- return __io_sq_thread_acquire_mm(ctx);
--}
--
--static void io_sq_thread_associate_blkcg(struct io_ring_ctx *ctx,
-- struct cgroup_subsys_state **cur_css)
--
--{
--#ifdef CONFIG_BLK_CGROUP
-- /* puts the old one when swapping */
-- if (*cur_css != ctx->sqo_blkcg_css) {
-- kthread_associate_blkcg(ctx->sqo_blkcg_css);
-- *cur_css = ctx->sqo_blkcg_css;
-- }
--#endif
--}
--
--static void io_sq_thread_unassociate_blkcg(void)
--{
--#ifdef CONFIG_BLK_CGROUP
-- kthread_associate_blkcg(NULL);
--#endif
--}
--
--static inline void req_set_fail_links(struct io_kiocb *req)
--{
-- if ((req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) == REQ_F_LINK)
-- req->flags |= REQ_F_FAIL_LINK;
--}
--
--/*
-- * None of these are dereferenced, they are simply used to check if any of
-- * them have changed. If we're under current and check they are still the
-- * same, we're fine to grab references to them for actual out-of-line use.
-- */
--static void io_init_identity(struct io_identity *id)
--{
-- id->files = current->files;
-- id->mm = current->mm;
--#ifdef CONFIG_BLK_CGROUP
-- rcu_read_lock();
-- id->blkcg_css = blkcg_css();
-- rcu_read_unlock();
--#endif
-- id->creds = current_cred();
-- id->nsproxy = current->nsproxy;
-- id->fs = current->fs;
-- id->fsize = rlimit(RLIMIT_FSIZE);
--#ifdef CONFIG_AUDIT
-- id->loginuid = current->loginuid;
-- id->sessionid = current->sessionid;
--#endif
-- refcount_set(&id->count, 1);
--}
--
--static inline void __io_req_init_async(struct io_kiocb *req)
--{
-- memset(&req->work, 0, sizeof(req->work));
-- req->flags |= REQ_F_WORK_INITIALIZED;
--}
--
--/*
-- * Note: must call io_req_init_async() for the first time you
-- * touch any members of io_wq_work.
-- */
--static inline void io_req_init_async(struct io_kiocb *req)
--{
-- struct io_uring_task *tctx = req->task->io_uring;
--
-- if (req->flags & REQ_F_WORK_INITIALIZED)
-- return;
--
-- __io_req_init_async(req);
--
-- /* Grab a ref if this isn't our static identity */
-- req->work.identity = tctx->identity;
-- if (tctx->identity != &tctx->__identity)
-- refcount_inc(&req->work.identity->count);
--}
--
--static inline bool io_async_submit(struct io_ring_ctx *ctx)
--{
-- return ctx->flags & IORING_SETUP_SQPOLL;
--}
--
--static void io_ring_ctx_ref_free(struct percpu_ref *ref)
--{
-- struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs);
--
-- complete(&ctx->ref_comp);
--}
--
--static inline bool io_is_timeout_noseq(struct io_kiocb *req)
--{
-- return !req->timeout.off;
--}
--
--static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
--{
-- struct io_ring_ctx *ctx;
-- int hash_bits;
--
-- ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
-- if (!ctx)
-- return NULL;
--
-- ctx->fallback_req = kmem_cache_alloc(req_cachep, GFP_KERNEL);
-- if (!ctx->fallback_req)
-- goto err;
--
-- /*
-- * Use 5 bits less than the max cq entries, that should give us around
-- * 32 entries per hash list if totally full and uniformly spread.
-- */
-- hash_bits = ilog2(p->cq_entries);
-- hash_bits -= 5;
-- if (hash_bits <= 0)
-- hash_bits = 1;
-- ctx->cancel_hash_bits = hash_bits;
-- ctx->cancel_hash = kmalloc((1U << hash_bits) * sizeof(struct hlist_head),
-- GFP_KERNEL);
-- if (!ctx->cancel_hash)
-- goto err;
-- __hash_init(ctx->cancel_hash, 1U << hash_bits);
--
-- if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free,
-- PERCPU_REF_ALLOW_REINIT, GFP_KERNEL))
-- goto err;
--
-- ctx->flags = p->flags;
-- init_waitqueue_head(&ctx->sqo_sq_wait);
-- INIT_LIST_HEAD(&ctx->sqd_list);
-- init_waitqueue_head(&ctx->cq_wait);
-- INIT_LIST_HEAD(&ctx->cq_overflow_list);
-- init_completion(&ctx->ref_comp);
-- init_completion(&ctx->sq_thread_comp);
-- xa_init_flags(&ctx->io_buffers, XA_FLAGS_ALLOC1);
-- xa_init_flags(&ctx->personalities, XA_FLAGS_ALLOC1);
-- mutex_init(&ctx->uring_lock);
-- init_waitqueue_head(&ctx->wait);
-- spin_lock_init(&ctx->completion_lock);
-- INIT_LIST_HEAD(&ctx->iopoll_list);
-- INIT_LIST_HEAD(&ctx->defer_list);
-- INIT_LIST_HEAD(&ctx->timeout_list);
-- spin_lock_init(&ctx->inflight_lock);
-- INIT_LIST_HEAD(&ctx->inflight_list);
-- INIT_DELAYED_WORK(&ctx->file_put_work, io_file_put_work);
-- init_llist_head(&ctx->file_put_llist);
-- return ctx;
--err:
-- if (ctx->fallback_req)
-- kmem_cache_free(req_cachep, ctx->fallback_req);
-- kfree(ctx->cancel_hash);
-- kfree(ctx);
-- return NULL;
--}
--
--static bool req_need_defer(struct io_kiocb *req, u32 seq)
--{
-- if (unlikely(req->flags & REQ_F_IO_DRAIN)) {
-- struct io_ring_ctx *ctx = req->ctx;
--
-- return seq != ctx->cached_cq_tail
-- + READ_ONCE(ctx->cached_cq_overflow);
-- }
--
-- return false;
--}
--
--static void __io_commit_cqring(struct io_ring_ctx *ctx)
--{
-- struct io_rings *rings = ctx->rings;
--
-- /* order cqe stores with ring update */
-- smp_store_release(&rings->cq.tail, ctx->cached_cq_tail);
--}
--
--static void io_put_identity(struct io_uring_task *tctx, struct io_kiocb *req)
--{
-- if (req->work.identity == &tctx->__identity)
-- return;
-- if (refcount_dec_and_test(&req->work.identity->count))
-- kfree(req->work.identity);
--}
--
--static void io_req_clean_work(struct io_kiocb *req)
--{
-- if (!(req->flags & REQ_F_WORK_INITIALIZED))
-- return;
--
-- req->flags &= ~REQ_F_WORK_INITIALIZED;
--
-- if (req->work.flags & IO_WQ_WORK_MM) {
-- mmdrop(req->work.identity->mm);
-- req->work.flags &= ~IO_WQ_WORK_MM;
-- }
--#ifdef CONFIG_BLK_CGROUP
-- if (req->work.flags & IO_WQ_WORK_BLKCG) {
-- css_put(req->work.identity->blkcg_css);
-- req->work.flags &= ~IO_WQ_WORK_BLKCG;
-- }
--#endif
-- if (req->work.flags & IO_WQ_WORK_CREDS) {
-- put_cred(req->work.identity->creds);
-- req->work.flags &= ~IO_WQ_WORK_CREDS;
-- }
-- if (req->work.flags & IO_WQ_WORK_FS) {
-- struct fs_struct *fs = req->work.identity->fs;
--
-- spin_lock(&req->work.identity->fs->lock);
-- if (--fs->users)
-- fs = NULL;
-- spin_unlock(&req->work.identity->fs->lock);
-- if (fs)
-- free_fs_struct(fs);
-- req->work.flags &= ~IO_WQ_WORK_FS;
-- }
-- if (req->flags & REQ_F_INFLIGHT)
-- io_req_drop_files(req);
--
-- io_put_identity(req->task->io_uring, req);
--}
--
--/*
-- * Create a private copy of io_identity, since some fields don't match
-- * the current context.
-- */
--static bool io_identity_cow(struct io_kiocb *req)
--{
-- struct io_uring_task *tctx = req->task->io_uring;
-- const struct cred *creds = NULL;
-- struct io_identity *id;
--
-- if (req->work.flags & IO_WQ_WORK_CREDS)
-- creds = req->work.identity->creds;
--
-- id = kmemdup(req->work.identity, sizeof(*id), GFP_KERNEL);
-- if (unlikely(!id)) {
-- req->work.flags |= IO_WQ_WORK_CANCEL;
-- return false;
-- }
--
-- /*
-- * We can safely just re-init the creds we copied Either the field
-- * matches the current one, or we haven't grabbed it yet. The only
-- * exception is ->creds, through registered personalities, so handle
-- * that one separately.
-- */
-- io_init_identity(id);
-- if (creds)
-- id->creds = creds;
--
-- /* add one for this request */
-- refcount_inc(&id->count);
--
-- /* drop tctx and req identity references, if needed */
-- if (tctx->identity != &tctx->__identity &&
-- refcount_dec_and_test(&tctx->identity->count))
-- kfree(tctx->identity);
-- if (req->work.identity != &tctx->__identity &&
-- refcount_dec_and_test(&req->work.identity->count))
-- kfree(req->work.identity);
--
-- req->work.identity = id;
-- tctx->identity = id;
-- return true;
--}
--
--static bool io_grab_identity(struct io_kiocb *req)
--{
-- const struct io_op_def *def = &io_op_defs[req->opcode];
-- struct io_identity *id = req->work.identity;
-- struct io_ring_ctx *ctx = req->ctx;
--
-- if (def->work_flags & IO_WQ_WORK_FSIZE) {
-- if (id->fsize != rlimit(RLIMIT_FSIZE))
-- return false;
-- req->work.flags |= IO_WQ_WORK_FSIZE;
-- }
--#ifdef CONFIG_BLK_CGROUP
-- if (!(req->work.flags & IO_WQ_WORK_BLKCG) &&
-- (def->work_flags & IO_WQ_WORK_BLKCG)) {
-- rcu_read_lock();
-- if (id->blkcg_css != blkcg_css()) {
-- rcu_read_unlock();
-- return false;
-- }
-- /*
-- * This should be rare, either the cgroup is dying or the task
-- * is moving cgroups. Just punt to root for the handful of ios.
-- */
-- if (css_tryget_online(id->blkcg_css))
-- req->work.flags |= IO_WQ_WORK_BLKCG;
-- rcu_read_unlock();
-- }
--#endif
-- if (!(req->work.flags & IO_WQ_WORK_CREDS)) {
-- if (id->creds != current_cred())
-- return false;
-- get_cred(id->creds);
-- req->work.flags |= IO_WQ_WORK_CREDS;
-- }
--#ifdef CONFIG_AUDIT
-- if (!uid_eq(current->loginuid, id->loginuid) ||
-- current->sessionid != id->sessionid)
-- return false;
--#endif
-- if (!(req->work.flags & IO_WQ_WORK_FS) &&
-- (def->work_flags & IO_WQ_WORK_FS)) {
-- if (current->fs != id->fs)
-- return false;
-- spin_lock(&id->fs->lock);
-- if (!id->fs->in_exec) {
-- id->fs->users++;
-- req->work.flags |= IO_WQ_WORK_FS;
-- } else {
-- req->work.flags |= IO_WQ_WORK_CANCEL;
-- }
-- spin_unlock(¤t->fs->lock);
-- }
-- if (!(req->work.flags & IO_WQ_WORK_FILES) &&
-- (def->work_flags & IO_WQ_WORK_FILES) &&
-- !(req->flags & REQ_F_NO_FILE_TABLE)) {
-- if (id->files != current->files ||
-- id->nsproxy != current->nsproxy)
-- return false;
-- atomic_inc(&id->files->count);
-- get_nsproxy(id->nsproxy);
--
-- if (!(req->flags & REQ_F_INFLIGHT)) {
-- req->flags |= REQ_F_INFLIGHT;
--
-- spin_lock_irq(&ctx->inflight_lock);
-- list_add(&req->inflight_entry, &ctx->inflight_list);
-- spin_unlock_irq(&ctx->inflight_lock);
-- }
-- req->work.flags |= IO_WQ_WORK_FILES;
-- }
-- if (!(req->work.flags & IO_WQ_WORK_MM) &&
-- (def->work_flags & IO_WQ_WORK_MM)) {
-- if (id->mm != current->mm)
-- return false;
-- mmgrab(id->mm);
-- req->work.flags |= IO_WQ_WORK_MM;
-- }
--
-- return true;
--}
--
--static void io_prep_async_work(struct io_kiocb *req)
--{
-- const struct io_op_def *def = &io_op_defs[req->opcode];
-- struct io_ring_ctx *ctx = req->ctx;
-- struct io_identity *id;
--
-- io_req_init_async(req);
-- id = req->work.identity;
--
-- if (req->flags & REQ_F_FORCE_ASYNC)
-- req->work.flags |= IO_WQ_WORK_CONCURRENT;
--
-- if (req->flags & REQ_F_ISREG) {
-- if (def->hash_reg_file || (ctx->flags & IORING_SETUP_IOPOLL))
-- io_wq_hash_work(&req->work, file_inode(req->file));
-- } else if (!req->file || !S_ISBLK(file_inode(req->file)->i_mode)) {
-- if (def->unbound_nonreg_file)
-- req->work.flags |= IO_WQ_WORK_UNBOUND;
-- }
--
-- /* if we fail grabbing identity, we must COW, regrab, and retry */
-- if (io_grab_identity(req))
-- return;
--
-- if (!io_identity_cow(req))
-- return;
--
-- /* can't fail at this point */
-- if (!io_grab_identity(req))
-- WARN_ON(1);
--}
--
--static void io_prep_async_link(struct io_kiocb *req)
--{
-- struct io_kiocb *cur;
--
-- io_prep_async_work(req);
-- if (req->flags & REQ_F_LINK_HEAD)
-- list_for_each_entry(cur, &req->link_list, link_list)
-- io_prep_async_work(cur);
--}
--
--static struct io_kiocb *__io_queue_async_work(struct io_kiocb *req)
--{
-- struct io_ring_ctx *ctx = req->ctx;
-- struct io_kiocb *link = io_prep_linked_timeout(req);
--
-- trace_io_uring_queue_async_work(ctx, io_wq_is_hashed(&req->work), req,
-- &req->work, req->flags);
-- io_wq_enqueue(ctx->io_wq, &req->work);
-- return link;
--}
--
--static void io_queue_async_work(struct io_kiocb *req)
--{
-- struct io_kiocb *link;
--
-- /* init ->work of the whole link before punting */
-- io_prep_async_link(req);
-- link = __io_queue_async_work(req);
--
-- if (link)
-- io_queue_linked_timeout(link);
--}
--
--static void io_kill_timeout(struct io_kiocb *req, int status)
--{
-- struct io_timeout_data *io = req->async_data;
-- int ret;
--
-- ret = hrtimer_try_to_cancel(&io->timer);
-- if (ret != -1) {
-- if (status)
-- req_set_fail_links(req);
-- atomic_set(&req->ctx->cq_timeouts,
-- atomic_read(&req->ctx->cq_timeouts) + 1);
-- list_del_init(&req->timeout.list);
-- io_cqring_fill_event(req, status);
-- io_put_req_deferred(req, 1);
-- }
--}
--
--/*
-- * Returns true if we found and killed one or more timeouts
-- */
--static bool io_kill_timeouts(struct io_ring_ctx *ctx, struct task_struct *tsk,
-- struct files_struct *files)
--{
-- struct io_kiocb *req, *tmp;
-- int canceled = 0;
--
-- spin_lock_irq(&ctx->completion_lock);
-- list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list) {
-- if (io_match_task(req, tsk, files)) {
-- io_kill_timeout(req, -ECANCELED);
-- canceled++;
-- }
-- }
-- spin_unlock_irq(&ctx->completion_lock);
-- return canceled != 0;
--}
--
--static void __io_queue_deferred(struct io_ring_ctx *ctx)
--{
-- do {
-- struct io_defer_entry *de = list_first_entry(&ctx->defer_list,
-- struct io_defer_entry, list);
--
-- if (req_need_defer(de->req, de->seq))
-- break;
-- list_del_init(&de->list);
-- io_req_task_queue(de->req);
-- kfree(de);
-- } while (!list_empty(&ctx->defer_list));
--}
--
--static void io_flush_timeouts(struct io_ring_ctx *ctx)
--{
-- struct io_kiocb *req, *tmp;
-- u32 seq;
--
-- if (list_empty(&ctx->timeout_list))
-- return;
--
-- seq = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);
--
-- list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list) {
-- u32 events_needed, events_got;
--
-- if (io_is_timeout_noseq(req))
-- break;
--
-- /*
-- * Since seq can easily wrap around over time, subtract
-- * the last seq at which timeouts were flushed before comparing.
-- * Assuming not more than 2^31-1 events have happened since,
-- * these subtractions won't have wrapped, so we can check if
-- * target is in [last_seq, current_seq] by comparing the two.
-- */
-- events_needed = req->timeout.target_seq - ctx->cq_last_tm_flush;
-- events_got = seq - ctx->cq_last_tm_flush;
-- if (events_got < events_needed)
-- break;
--
-- io_kill_timeout(req, 0);
-- }
--
-- ctx->cq_last_tm_flush = seq;
--}
--
--static void io_commit_cqring(struct io_ring_ctx *ctx)
--{
-- io_flush_timeouts(ctx);
-- __io_commit_cqring(ctx);
--
-- if (unlikely(!list_empty(&ctx->defer_list)))
-- __io_queue_deferred(ctx);
--}
--
--static inline bool io_sqring_full(struct io_ring_ctx *ctx)
--{
-- struct io_rings *r = ctx->rings;
--
-- return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == r->sq_ring_entries;
--}
--
--static struct io_uring_cqe *io_get_cqring(struct io_ring_ctx *ctx)
--{
-- struct io_rings *rings = ctx->rings;
-- unsigned tail;
--
-- tail = ctx->cached_cq_tail;
-- /*
-- * writes to the cq entry need to come after reading head; the
-- * control dependency is enough as we're using WRITE_ONCE to
-- * fill the cq entry
-- */
-- if (tail - READ_ONCE(rings->cq.head) == rings->cq_ring_entries)
-- return NULL;
--
-- ctx->cached_cq_tail++;
-- return &rings->cqes[tail & ctx->cq_mask];
--}
--
--static inline bool io_should_trigger_evfd(struct io_ring_ctx *ctx)
--{
-- if (!ctx->cq_ev_fd)
-- return false;
-- if (READ_ONCE(ctx->rings->cq_flags) & IORING_CQ_EVENTFD_DISABLED)
-- return false;
-- if (!ctx->eventfd_async)
-- return true;
-- return io_wq_current_is_worker();
--}
--
--static void io_cqring_ev_posted(struct io_ring_ctx *ctx)
--{
-- if (wq_has_sleeper(&ctx->cq_wait)) {
-- wake_up_interruptible(&ctx->cq_wait);
-- kill_fasync(&ctx->cq_fasync, SIGIO, POLL_IN);
-- }
-- if (waitqueue_active(&ctx->wait))
-- wake_up(&ctx->wait);
-- if (ctx->sq_data && waitqueue_active(&ctx->sq_data->wait))
-- wake_up(&ctx->sq_data->wait);
-- if (io_should_trigger_evfd(ctx))
-- eventfd_signal(ctx->cq_ev_fd, 1);
--}
--
--static void io_cqring_mark_overflow(struct io_ring_ctx *ctx)
--{
-- if (list_empty(&ctx->cq_overflow_list)) {
-- clear_bit(0, &ctx->sq_check_overflow);
-- clear_bit(0, &ctx->cq_check_overflow);
-- ctx->rings->sq_flags &= ~IORING_SQ_CQ_OVERFLOW;
-- }
--}
--
--/* Returns true if there are no backlogged entries after the flush */
--static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force,
-- struct task_struct *tsk,
-- struct files_struct *files)
--{
-- struct io_rings *rings = ctx->rings;
-- struct io_kiocb *req, *tmp;
-- struct io_uring_cqe *cqe;
-- unsigned long flags;
-- LIST_HEAD(list);
--
-- if (!force) {
-- if ((ctx->cached_cq_tail - READ_ONCE(rings->cq.head) ==
-- rings->cq_ring_entries))
-- return false;
-- }
--
-- spin_lock_irqsave(&ctx->completion_lock, flags);
--
-- cqe = NULL;
-- list_for_each_entry_safe(req, tmp, &ctx->cq_overflow_list, compl.list) {
-- if (!io_match_task(req, tsk, files))
-- continue;
--
-- cqe = io_get_cqring(ctx);
-- if (!cqe && !force)
-- break;
--
-- list_move(&req->compl.list, &list);
-- if (cqe) {
-- WRITE_ONCE(cqe->user_data, req->user_data);
-- WRITE_ONCE(cqe->res, req->result);
-- WRITE_ONCE(cqe->flags, req->compl.cflags);
-- } else {
-- ctx->cached_cq_overflow++;
-- WRITE_ONCE(ctx->rings->cq_overflow,
-- ctx->cached_cq_overflow);
-- }
-- }
--
-- io_commit_cqring(ctx);
-- io_cqring_mark_overflow(ctx);
--
-- spin_unlock_irqrestore(&ctx->completion_lock, flags);
-- io_cqring_ev_posted(ctx);
--
-- while (!list_empty(&list)) {
-- req = list_first_entry(&list, struct io_kiocb, compl.list);
-- list_del(&req->compl.list);
-- io_put_req(req);
-- }
--
-- return cqe != NULL;
--}
--
--static void io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force,
-- struct task_struct *tsk,
-- struct files_struct *files)
--{
-- if (test_bit(0, &ctx->cq_check_overflow)) {
-- /* iopoll syncs against uring_lock, not completion_lock */
-- if (ctx->flags & IORING_SETUP_IOPOLL)
-- mutex_lock(&ctx->uring_lock);
-- __io_cqring_overflow_flush(ctx, force, tsk, files);
-- if (ctx->flags & IORING_SETUP_IOPOLL)
-- mutex_unlock(&ctx->uring_lock);
-- }
--}
--
--static void __io_cqring_fill_event(struct io_kiocb *req, long res,
-- unsigned int cflags)
--{
-- struct io_ring_ctx *ctx = req->ctx;
-- struct io_uring_cqe *cqe;
--
-- trace_io_uring_complete(ctx, req->user_data, res);
--
-- /*
-- * If we can't get a cq entry, userspace overflowed the
-- * submission (by quite a lot). Increment the overflow count in
-- * the ring.
-- */
-- cqe = io_get_cqring(ctx);
-- if (likely(cqe)) {
-- WRITE_ONCE(cqe->user_data, req->user_data);
-- WRITE_ONCE(cqe->res, res);
-- WRITE_ONCE(cqe->flags, cflags);
-- } else if (ctx->cq_overflow_flushed ||
-- atomic_read(&req->task->io_uring->in_idle)) {
-- /*
-- * If we're in ring overflow flush mode, or in task cancel mode,
-- * then we cannot store the request for later flushing, we need
-- * to drop it on the floor.
-- */
-- ctx->cached_cq_overflow++;
-- WRITE_ONCE(ctx->rings->cq_overflow, ctx->cached_cq_overflow);
-- } else {
-- if (list_empty(&ctx->cq_overflow_list)) {
-- set_bit(0, &ctx->sq_check_overflow);
-- set_bit(0, &ctx->cq_check_overflow);
-- ctx->rings->sq_flags |= IORING_SQ_CQ_OVERFLOW;
-- }
-- io_clean_op(req);
-- req->result = res;
-- req->compl.cflags = cflags;
-- refcount_inc(&req->refs);
-- list_add_tail(&req->compl.list, &ctx->cq_overflow_list);
-- }
--}
--
--static void io_cqring_fill_event(struct io_kiocb *req, long res)
--{
-- __io_cqring_fill_event(req, res, 0);
--}
--
--static void io_cqring_add_event(struct io_kiocb *req, long res, long cflags)
--{
-- struct io_ring_ctx *ctx = req->ctx;
-- unsigned long flags;
--
-- spin_lock_irqsave(&ctx->completion_lock, flags);
-- __io_cqring_fill_event(req, res, cflags);
-- io_commit_cqring(ctx);
-- spin_unlock_irqrestore(&ctx->completion_lock, flags);
--
-- io_cqring_ev_posted(ctx);
--}
--
--static void io_submit_flush_completions(struct io_comp_state *cs)
--{
-- struct io_ring_ctx *ctx = cs->ctx;
--
-- spin_lock_irq(&ctx->completion_lock);
-- while (!list_empty(&cs->list)) {
-- struct io_kiocb *req;
--
-- req = list_first_entry(&cs->list, struct io_kiocb, compl.list);
-- list_del(&req->compl.list);
-- __io_cqring_fill_event(req, req->result, req->compl.cflags);
--
-- /*
-- * io_free_req() doesn't care about completion_lock unless one
-- * of these flags is set. REQ_F_WORK_INITIALIZED is in the list
-- * because of a potential deadlock with req->work.fs->lock
-- */
-- if (req->flags & (REQ_F_FAIL_LINK|REQ_F_LINK_TIMEOUT
-- |REQ_F_WORK_INITIALIZED)) {
-- spin_unlock_irq(&ctx->completion_lock);
-- io_put_req(req);
-- spin_lock_irq(&ctx->completion_lock);
-- } else {
-- io_put_req(req);
-- }
-- }
-- io_commit_cqring(ctx);
-- spin_unlock_irq(&ctx->completion_lock);
--
-- io_cqring_ev_posted(ctx);
-- cs->nr = 0;
--}
--
--static void __io_req_complete(struct io_kiocb *req, long res, unsigned cflags,
-- struct io_comp_state *cs)
--{
-- if (!cs) {
-- io_cqring_add_event(req, res, cflags);
-- io_put_req(req);
-- } else {
-- io_clean_op(req);
-- req->result = res;
-- req->compl.cflags = cflags;
-- list_add_tail(&req->compl.list, &cs->list);
-- if (++cs->nr >= 32)
-- io_submit_flush_completions(cs);
-- }
--}
--
--static void io_req_complete(struct io_kiocb *req, long res)
--{
-- __io_req_complete(req, res, 0, NULL);
--}
--
--static inline bool io_is_fallback_req(struct io_kiocb *req)
--{
-- return req == (struct io_kiocb *)
-- ((unsigned long) req->ctx->fallback_req & ~1UL);
--}
--
--static struct io_kiocb *io_get_fallback_req(struct io_ring_ctx *ctx)
--{
-- struct io_kiocb *req;
--
-- req = ctx->fallback_req;
-- if (!test_and_set_bit_lock(0, (unsigned long *) &ctx->fallback_req))
-- return req;
--
-- return NULL;
--}
--
--static struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx,
-- struct io_submit_state *state)
--{
-- if (!state->free_reqs) {
-- gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;
-- size_t sz;
-- int ret;
--
-- sz = min_t(size_t, state->ios_left, ARRAY_SIZE(state->reqs));
-- ret = kmem_cache_alloc_bulk(req_cachep, gfp, sz, state->reqs);
--
-- /*
-- * Bulk alloc is all-or-nothing. If we fail to get a batch,
-- * retry single alloc to be on the safe side.
-- */
-- if (unlikely(ret <= 0)) {
-- state->reqs[0] = kmem_cache_alloc(req_cachep, gfp);
-- if (!state->reqs[0])
-- goto fallback;
-- ret = 1;
-- }
-- state->free_reqs = ret;
-- }
--
-- state->free_reqs--;
-- return state->reqs[state->free_reqs];
--fallback:
-- return io_get_fallback_req(ctx);
--}
--
--static inline void io_put_file(struct io_kiocb *req, struct file *file,
-- bool fixed)
--{
-- if (fixed)
-- percpu_ref_put(req->fixed_file_refs);
-- else
-- fput(file);
--}
--
--static void io_dismantle_req(struct io_kiocb *req)
--{
-- io_clean_op(req);
--
-- if (req->async_data)
-- kfree(req->async_data);
-- if (req->file)
-- io_put_file(req, req->file, (req->flags & REQ_F_FIXED_FILE));
--
-- io_req_clean_work(req);
--}
--
--static void __io_free_req(struct io_kiocb *req)
--{
-- struct io_uring_task *tctx = req->task->io_uring;
-- struct io_ring_ctx *ctx = req->ctx;
--
-- io_dismantle_req(req);
--
-- percpu_counter_dec(&tctx->inflight);
-- if (atomic_read(&tctx->in_idle))
-- wake_up(&tctx->wait);
-- put_task_struct(req->task);
--
-- if (likely(!io_is_fallback_req(req)))
-- kmem_cache_free(req_cachep, req);
-- else
-- clear_bit_unlock(0, (unsigned long *) &ctx->fallback_req);
-- percpu_ref_put(&ctx->refs);
--}
--
--static void io_kill_linked_timeout(struct io_kiocb *req)
--{
-- struct io_ring_ctx *ctx = req->ctx;
-- struct io_kiocb *link;
-- bool cancelled = false;
-- unsigned long flags;
--
-- spin_lock_irqsave(&ctx->completion_lock, flags);
-- link = list_first_entry_or_null(&req->link_list, struct io_kiocb,
-- link_list);
-- /*
-- * Can happen if a linked timeout fired and link had been like
-- * req -> link t-out -> link t-out [-> ...]
-- */
-- if (link && (link->flags & REQ_F_LTIMEOUT_ACTIVE)) {
-- struct io_timeout_data *io = link->async_data;
-- int ret;
--
-- list_del_init(&link->link_list);
-- ret = hrtimer_try_to_cancel(&io->timer);
-- if (ret != -1) {
-- io_cqring_fill_event(link, -ECANCELED);
-- io_commit_cqring(ctx);
-- cancelled = true;
-- }
-- }
-- req->flags &= ~REQ_F_LINK_TIMEOUT;
-- spin_unlock_irqrestore(&ctx->completion_lock, flags);
--
-- if (cancelled) {
-- io_cqring_ev_posted(ctx);
-- io_put_req(link);
-- }
--}
--
--static struct io_kiocb *io_req_link_next(struct io_kiocb *req)
--{
-- struct io_kiocb *nxt;
--
-- /*
-- * The list should never be empty when we are called here. But could
-- * potentially happen if the chain is messed up, check to be on the
-- * safe side.
-- */
-- if (unlikely(list_empty(&req->link_list)))
-- return NULL;
--
-- nxt = list_first_entry(&req->link_list, struct io_kiocb, link_list);
-- list_del_init(&req->link_list);
-- if (!list_empty(&nxt->link_list))
-- nxt->flags |= REQ_F_LINK_HEAD;
-- return nxt;
--}
--
--/*
-- * Called if REQ_F_LINK_HEAD is set, and we fail the head request
-- */
--static void io_fail_links(struct io_kiocb *req)
--{
-- struct io_ring_ctx *ctx = req->ctx;
-- unsigned long flags;
--
-- spin_lock_irqsave(&ctx->completion_lock, flags);
-- while (!list_empty(&req->link_list)) {
-- struct io_kiocb *link = list_first_entry(&req->link_list,
-- struct io_kiocb, link_list);
--
-- list_del_init(&link->link_list);
-- trace_io_uring_fail_link(req, link);
--
-- io_cqring_fill_event(link, -ECANCELED);
--
-- /*
-- * It's ok to free under spinlock as they're not linked anymore,
-- * but avoid REQ_F_WORK_INITIALIZED because it may deadlock on
-- * work.fs->lock.
-- */
-- if (link->flags & REQ_F_WORK_INITIALIZED)
-- io_put_req_deferred(link, 2);
-- else
-- io_double_put_req(link);
-- }
--
-- io_commit_cqring(ctx);
-- spin_unlock_irqrestore(&ctx->completion_lock, flags);
--
-- io_cqring_ev_posted(ctx);
--}
--
--static struct io_kiocb *__io_req_find_next(struct io_kiocb *req)
--{
-- req->flags &= ~REQ_F_LINK_HEAD;
-- if (req->flags & REQ_F_LINK_TIMEOUT)
-- io_kill_linked_timeout(req);
--
-- /*
-- * If LINK is set, we have dependent requests in this chain. If we
-- * didn't fail this request, queue the first one up, moving any other
-- * dependencies to the next request. In case of failure, fail the rest
-- * of the chain.
-- */
-- if (likely(!(req->flags & REQ_F_FAIL_LINK)))
-- return io_req_link_next(req);
-- io_fail_links(req);
-- return NULL;
--}
--
--static struct io_kiocb *io_req_find_next(struct io_kiocb *req)
--{
-- if (likely(!(req->flags & REQ_F_LINK_HEAD)))
-- return NULL;
-- return __io_req_find_next(req);
--}
--
--static int io_req_task_work_add(struct io_kiocb *req, bool twa_signal_ok)
--{
-- struct task_struct *tsk = req->task;
-- struct io_ring_ctx *ctx = req->ctx;
-- enum task_work_notify_mode notify;
-- int ret;
--
-- if (tsk->flags & PF_EXITING)
-- return -ESRCH;
--
-- /*
-- * SQPOLL kernel thread doesn't need notification, just a wakeup. For
-- * all other cases, use TWA_SIGNAL unconditionally to ensure we're
-- * processing task_work. There's no reliable way to tell if TWA_RESUME
-- * will do the job.
-- */
-- notify = TWA_NONE;
-- if (!(ctx->flags & IORING_SETUP_SQPOLL) && twa_signal_ok)
-- notify = TWA_SIGNAL;
--
-- ret = task_work_add(tsk, &req->task_work, notify);
-- if (!ret)
-- wake_up_process(tsk);
--
-- return ret;
--}
--
--static void __io_req_task_cancel(struct io_kiocb *req, int error)
--{
-- struct io_ring_ctx *ctx = req->ctx;
--
-- spin_lock_irq(&ctx->completion_lock);
-- io_cqring_fill_event(req, error);
-- io_commit_cqring(ctx);
-- spin_unlock_irq(&ctx->completion_lock);
--
-- io_cqring_ev_posted(ctx);
-- req_set_fail_links(req);
-- io_double_put_req(req);
--}
--
--static void io_req_task_cancel(struct callback_head *cb)
--{
-- struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
-- struct io_ring_ctx *ctx = req->ctx;
--
-- mutex_lock(&ctx->uring_lock);
-- __io_req_task_cancel(req, -ECANCELED);
-- mutex_unlock(&ctx->uring_lock);
-- percpu_ref_put(&ctx->refs);
--}
--
--static void __io_req_task_submit(struct io_kiocb *req)
--{
-- struct io_ring_ctx *ctx = req->ctx;
--
-- mutex_lock(&ctx->uring_lock);
-- if (!ctx->sqo_dead && !__io_sq_thread_acquire_mm(ctx))
-- __io_queue_sqe(req, NULL);
-- else
-- __io_req_task_cancel(req, -EFAULT);
-- mutex_unlock(&ctx->uring_lock);
--
-- if (ctx->flags & IORING_SETUP_SQPOLL)
-- io_sq_thread_drop_mm();
--}
--
--static void io_req_task_submit(struct callback_head *cb)
--{
-- struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
-- struct io_ring_ctx *ctx = req->ctx;
--
-- __io_req_task_submit(req);
-- percpu_ref_put(&ctx->refs);
--}
--
--static void io_req_task_queue(struct io_kiocb *req)
--{
-- int ret;
--
-- init_task_work(&req->task_work, io_req_task_submit);
-- percpu_ref_get(&req->ctx->refs);
--
-- ret = io_req_task_work_add(req, true);
-- if (unlikely(ret)) {
-- struct task_struct *tsk;
--
-- init_task_work(&req->task_work, io_req_task_cancel);
-- tsk = io_wq_get_task(req->ctx->io_wq);
-- task_work_add(tsk, &req->task_work, TWA_NONE);
-- wake_up_process(tsk);
-- }
--}
--
--static void io_queue_next(struct io_kiocb *req)
--{
-- struct io_kiocb *nxt = io_req_find_next(req);
--
-- if (nxt)
-- io_req_task_queue(nxt);
--}
--
--static void io_free_req(struct io_kiocb *req)
--{
-- io_queue_next(req);
-- __io_free_req(req);
--}
--
--struct req_batch {
-- void *reqs[IO_IOPOLL_BATCH];
-- int to_free;
--
-- struct task_struct *task;
-- int task_refs;
--};
--
--static inline void io_init_req_batch(struct req_batch *rb)
--{
-- rb->to_free = 0;
-- rb->task_refs = 0;
-- rb->task = NULL;
--}
--
--static void __io_req_free_batch_flush(struct io_ring_ctx *ctx,
-- struct req_batch *rb)
--{
-- kmem_cache_free_bulk(req_cachep, rb->to_free, rb->reqs);
-- percpu_ref_put_many(&ctx->refs, rb->to_free);
-- rb->to_free = 0;
--}
--
--static void io_req_free_batch_finish(struct io_ring_ctx *ctx,
-- struct req_batch *rb)
--{
-- if (rb->to_free)
-- __io_req_free_batch_flush(ctx, rb);
-- if (rb->task) {
-- struct io_uring_task *tctx = rb->task->io_uring;
--
-- percpu_counter_sub(&tctx->inflight, rb->task_refs);
-- if (atomic_read(&tctx->in_idle))
-- wake_up(&tctx->wait);
-- put_task_struct_many(rb->task, rb->task_refs);
-- rb->task = NULL;
-- }
--}
--
--static void io_req_free_batch(struct req_batch *rb, struct io_kiocb *req)
--{
-- if (unlikely(io_is_fallback_req(req))) {
-- io_free_req(req);
-- return;
-- }
-- if (req->flags & REQ_F_LINK_HEAD)
-- io_queue_next(req);
--
-- if (req->task != rb->task) {
-- if (rb->task) {
-- struct io_uring_task *tctx = rb->task->io_uring;
--
-- percpu_counter_sub(&tctx->inflight, rb->task_refs);
-- if (atomic_read(&tctx->in_idle))
-- wake_up(&tctx->wait);
-- put_task_struct_many(rb->task, rb->task_refs);
-- }
-- rb->task = req->task;
-- rb->task_refs = 0;
-- }
-- rb->task_refs++;
--
-- io_dismantle_req(req);
-- rb->reqs[rb->to_free++] = req;
-- if (unlikely(rb->to_free == ARRAY_SIZE(rb->reqs)))
-- __io_req_free_batch_flush(req->ctx, rb);
--}
--
--/*
-- * Drop reference to request, return next in chain (if there is one) if this
-- * was the last reference to this request.
-- */
--static struct io_kiocb *io_put_req_find_next(struct io_kiocb *req)
--{
-- struct io_kiocb *nxt = NULL;
--
-- if (refcount_dec_and_test(&req->refs)) {
-- nxt = io_req_find_next(req);
-- __io_free_req(req);
-- }
-- return nxt;
--}
--
--static void io_put_req(struct io_kiocb *req)
--{
-- if (refcount_dec_and_test(&req->refs))
-- io_free_req(req);
--}
--
--static void io_put_req_deferred_cb(struct callback_head *cb)
--{
-- struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
--
-- io_free_req(req);
--}
--
--static void io_free_req_deferred(struct io_kiocb *req)
--{
-- int ret;
--
-- init_task_work(&req->task_work, io_put_req_deferred_cb);
-- ret = io_req_task_work_add(req, true);
-- if (unlikely(ret)) {
-- struct task_struct *tsk;
--
-- tsk = io_wq_get_task(req->ctx->io_wq);
-- task_work_add(tsk, &req->task_work, TWA_NONE);
-- wake_up_process(tsk);
-- }
--}
--
--static inline void io_put_req_deferred(struct io_kiocb *req, int refs)
--{
-- if (refcount_sub_and_test(refs, &req->refs))
-- io_free_req_deferred(req);
--}
--
--static struct io_wq_work *io_steal_work(struct io_kiocb *req)
--{
-- struct io_kiocb *nxt;
--
-- /*
-- * A ref is owned by io-wq in which context we're. So, if that's the
-- * last one, it's safe to steal next work. False negatives are Ok,
-- * it just will be re-punted async in io_put_work()
-- */
-- if (refcount_read(&req->refs) != 1)
-- return NULL;
--
-- nxt = io_req_find_next(req);
-- return nxt ? &nxt->work : NULL;
--}
--
--static void io_double_put_req(struct io_kiocb *req)
--{
-- /* drop both submit and complete references */
-- if (refcount_sub_and_test(2, &req->refs))
-- io_free_req(req);
--}
--
--static unsigned io_cqring_events(struct io_ring_ctx *ctx)
--{
-- struct io_rings *rings = ctx->rings;
--
-- /* See comment at the top of this file */
-- smp_rmb();
-- return ctx->cached_cq_tail - READ_ONCE(rings->cq.head);
--}
--
--static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx)
--{
-- struct io_rings *rings = ctx->rings;
--
-- /* make sure SQ entry isn't read before tail */
-- return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head;
--}
--
--static unsigned int io_put_kbuf(struct io_kiocb *req, struct io_buffer *kbuf)
--{
-- unsigned int cflags;
--
-- cflags = kbuf->bid << IORING_CQE_BUFFER_SHIFT;
-- cflags |= IORING_CQE_F_BUFFER;
-- req->flags &= ~REQ_F_BUFFER_SELECTED;
-- kfree(kbuf);
-- return cflags;
--}
--
--static inline unsigned int io_put_rw_kbuf(struct io_kiocb *req)
--{
-- struct io_buffer *kbuf;
--
-- kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
-- return io_put_kbuf(req, kbuf);
--}
--
--static inline bool io_run_task_work(void)
--{
-- /*
-- * Not safe to run on exiting task, and the task_work handling will
-- * not add work to such a task.
-- */
-- if (unlikely(current->flags & PF_EXITING))
-- return false;
-- if (current->task_works) {
-- __set_current_state(TASK_RUNNING);
-- task_work_run();
-- return true;
-- }
--
-- return false;
--}
--
--static void io_iopoll_queue(struct list_head *again)
--{
-- struct io_kiocb *req;
--
-- do {
-- req = list_first_entry(again, struct io_kiocb, iopoll_entry);
-- list_del(&req->iopoll_entry);
-- __io_complete_rw(req, -EAGAIN, 0, NULL);
-- } while (!list_empty(again));
--}
--
--/*
-- * Find and free completed poll iocbs
-- */
--static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
-- struct list_head *done)
--{
-- struct req_batch rb;
-- struct io_kiocb *req;
-- LIST_HEAD(again);
--
-- /* order with ->result store in io_complete_rw_iopoll() */
-- smp_rmb();
--
-- io_init_req_batch(&rb);
-- while (!list_empty(done)) {
-- int cflags = 0;
--
-- req = list_first_entry(done, struct io_kiocb, iopoll_entry);
-- if (READ_ONCE(req->result) == -EAGAIN) {
-- req->result = 0;
-- req->iopoll_completed = 0;
-- list_move_tail(&req->iopoll_entry, &again);
-- continue;
-- }
-- list_del(&req->iopoll_entry);
--
-- if (req->flags & REQ_F_BUFFER_SELECTED)
-- cflags = io_put_rw_kbuf(req);
--
-- __io_cqring_fill_event(req, req->result, cflags);
-- (*nr_events)++;
--
-- if (refcount_dec_and_test(&req->refs))
-- io_req_free_batch(&rb, req);
-- }
--
-- io_commit_cqring(ctx);
-- if (ctx->flags & IORING_SETUP_SQPOLL)
-- io_cqring_ev_posted(ctx);
-- io_req_free_batch_finish(ctx, &rb);
--
-- if (!list_empty(&again))
-- io_iopoll_queue(&again);
--}
--
--static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events,
-- long min)
--{
-- struct io_kiocb *req, *tmp;
-- LIST_HEAD(done);
-- bool spin;
-- int ret;
--
-- /*
-- * Only spin for completions if we don't have multiple devices hanging
-- * off our complete list, and we're under the requested amount.
-- */
-- spin = !ctx->poll_multi_file && *nr_events < min;
--
-- ret = 0;
-- list_for_each_entry_safe(req, tmp, &ctx->iopoll_list, iopoll_entry) {
-- struct kiocb *kiocb = &req->rw.kiocb;
--
-- /*
-- * Move completed and retryable entries to our local lists.
-- * If we find a request that requires polling, break out
-- * and complete those lists first, if we have entries there.
-- */
-- if (READ_ONCE(req->iopoll_completed)) {
-- list_move_tail(&req->iopoll_entry, &done);
-- continue;
-- }
-- if (!list_empty(&done))
-- break;
--
-- ret = kiocb->ki_filp->f_op->iopoll(kiocb, spin);
-- if (ret < 0)
-- break;
--
-- /* iopoll may have completed current req */
-- if (READ_ONCE(req->iopoll_completed))
-- list_move_tail(&req->iopoll_entry, &done);
--
-- if (ret && spin)
-- spin = false;
-- ret = 0;
-- }
--
-- if (!list_empty(&done))
-- io_iopoll_complete(ctx, nr_events, &done);
--
-- return ret;
--}
--
--/*
-- * Poll for a minimum of 'min' events. Note that if min == 0 we consider that a
-- * non-spinning poll check - we'll still enter the driver poll loop, but only
-- * as a non-spinning completion check.
-- */
--static int io_iopoll_getevents(struct io_ring_ctx *ctx, unsigned int *nr_events,
-- long min)
--{
-- while (!list_empty(&ctx->iopoll_list) && !need_resched()) {
-- int ret;
--
-- ret = io_do_iopoll(ctx, nr_events, min);
-- if (ret < 0)
-- return ret;
-- if (*nr_events >= min)
-- return 0;
-- }
--
-- return 1;
--}
--
--/*
-- * We can't just wait for polled events to come to us, we have to actively
-- * find and complete them.
-- */
--static void io_iopoll_try_reap_events(struct io_ring_ctx *ctx)
--{
-- if (!(ctx->flags & IORING_SETUP_IOPOLL))
-- return;
--
-- mutex_lock(&ctx->uring_lock);
-- while (!list_empty(&ctx->iopoll_list)) {
-- unsigned int nr_events = 0;
--
-- io_do_iopoll(ctx, &nr_events, 0);
--
-- /* let it sleep and repeat later if can't complete a request */
-- if (nr_events == 0)
-- break;
-- /*
-- * Ensure we allow local-to-the-cpu processing to take place,
-- * in this case we need to ensure that we reap all events.
-- * Also let task_work, etc. to progress by releasing the mutex
-- */
-- if (need_resched()) {
-- mutex_unlock(&ctx->uring_lock);
-- cond_resched();
-- mutex_lock(&ctx->uring_lock);
-- }
-- }
-- mutex_unlock(&ctx->uring_lock);
--}
--
--static int io_iopoll_check(struct io_ring_ctx *ctx, long min)
--{
-- unsigned int nr_events = 0;
-- int iters = 0, ret = 0;
--
-- /*
-- * We disallow the app entering submit/complete with polling, but we
-- * still need to lock the ring to prevent racing with polled issue
-- * that got punted to a workqueue.
-- */
-- mutex_lock(&ctx->uring_lock);
-- do {
-- /*
-- * Don't enter poll loop if we already have events pending.
-- * If we do, we can potentially be spinning for commands that
-- * already triggered a CQE (eg in error).
-- */
-- if (test_bit(0, &ctx->cq_check_overflow))
-- __io_cqring_overflow_flush(ctx, false, NULL, NULL);
-- if (io_cqring_events(ctx))
-- break;
--
-- /*
-- * If a submit got punted to a workqueue, we can have the
-- * application entering polling for a command before it gets
-- * issued. That app will hold the uring_lock for the duration
-- * of the poll right here, so we need to take a breather every
-- * now and then to ensure that the issue has a chance to add
-- * the poll to the issued list. Otherwise we can spin here
-- * forever, while the workqueue is stuck trying to acquire the
-- * very same mutex.
-- */
-- if (!(++iters & 7)) {
-- mutex_unlock(&ctx->uring_lock);
-- io_run_task_work();
-- mutex_lock(&ctx->uring_lock);
-- }
--
-- ret = io_iopoll_getevents(ctx, &nr_events, min);
-- if (ret <= 0)
-- break;
-- ret = 0;
-- } while (min && !nr_events && !need_resched());
--
-- mutex_unlock(&ctx->uring_lock);
-- return ret;
--}
--
--static void kiocb_end_write(struct io_kiocb *req)
--{
-- /*
-- * Tell lockdep we inherited freeze protection from submission
-- * thread.
-- */
-- if (req->flags & REQ_F_ISREG) {
-- struct inode *inode = file_inode(req->file);
--
-- __sb_writers_acquired(inode->i_sb, SB_FREEZE_WRITE);
-- }
-- file_end_write(req->file);
--}
--
--static void io_complete_rw_common(struct kiocb *kiocb, long res,
-- struct io_comp_state *cs)
--{
-- struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
-- int cflags = 0;
--
-- if (kiocb->ki_flags & IOCB_WRITE)
-- kiocb_end_write(req);
--
-- if (res != req->result)
-- req_set_fail_links(req);
-- if (req->flags & REQ_F_BUFFER_SELECTED)
-- cflags = io_put_rw_kbuf(req);
-- __io_req_complete(req, res, cflags, cs);
--}
--
--#ifdef CONFIG_BLOCK
--static bool io_resubmit_prep(struct io_kiocb *req, int error)
--{
-- req_set_fail_links(req);
-- return false;
--}
--#endif
--
--static bool io_rw_reissue(struct io_kiocb *req, long res)
--{
--#ifdef CONFIG_BLOCK
-- umode_t mode = file_inode(req->file)->i_mode;
-- int ret;
--
-- if (!S_ISBLK(mode) && !S_ISREG(mode))
-- return false;
-- if ((res != -EAGAIN && res != -EOPNOTSUPP) || io_wq_current_is_worker())
-- return false;
-- /*
-- * If ref is dying, we might be running poll reap from the exit work.
-- * Don't attempt to reissue from that path, just let it fail with
-- * -EAGAIN.
-- */
-- if (percpu_ref_is_dying(&req->ctx->refs))
-- return false;
--
-- ret = io_sq_thread_acquire_mm(req->ctx, req);
--
-- if (io_resubmit_prep(req, ret)) {
-- refcount_inc(&req->refs);
-- io_queue_async_work(req);
-- return true;
-- }
--
--#endif
-- return false;
--}
--
--static void __io_complete_rw(struct io_kiocb *req, long res, long res2,
-- struct io_comp_state *cs)
--{
-- if (!io_rw_reissue(req, res))
-- io_complete_rw_common(&req->rw.kiocb, res, cs);
--}
--
--static void io_complete_rw(struct kiocb *kiocb, long res, long res2)
--{
-- struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
--
-- __io_complete_rw(req, res, res2, NULL);
--}
--
--static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2)
--{
-- struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
--
-- if (kiocb->ki_flags & IOCB_WRITE)
-- kiocb_end_write(req);
--
-- if (res != -EAGAIN && res != req->result)
-- req_set_fail_links(req);
--
-- WRITE_ONCE(req->result, res);
-- /* order with io_poll_complete() checking ->result */
-- smp_wmb();
-- WRITE_ONCE(req->iopoll_completed, 1);
--}
--
--/*
-- * After the iocb has been issued, it's safe to be found on the poll list.
-- * Adding the kiocb to the list AFTER submission ensures that we don't
-- * find it from a io_iopoll_getevents() thread before the issuer is done
-- * accessing the kiocb cookie.
-- */
--static void io_iopoll_req_issued(struct io_kiocb *req)
--{
-- struct io_ring_ctx *ctx = req->ctx;
--
-- /*
-- * Track whether we have multiple files in our lists. This will impact
-- * how we do polling eventually, not spinning if we're on potentially
-- * different devices.
-- */
-- if (list_empty(&ctx->iopoll_list)) {
-- ctx->poll_multi_file = false;
-- } else if (!ctx->poll_multi_file) {
-- struct io_kiocb *list_req;
--
-- list_req = list_first_entry(&ctx->iopoll_list, struct io_kiocb,
-- iopoll_entry);
-- if (list_req->file != req->file)
-- ctx->poll_multi_file = true;
-- }
--
-- /*
-- * For fast devices, IO may have already completed. If it has, add
-- * it to the front so we find it first.
-- */
-- if (READ_ONCE(req->iopoll_completed))
-- list_add(&req->iopoll_entry, &ctx->iopoll_list);
-- else
-- list_add_tail(&req->iopoll_entry, &ctx->iopoll_list);
--
-- if ((ctx->flags & IORING_SETUP_SQPOLL) &&
-- wq_has_sleeper(&ctx->sq_data->wait))
-- wake_up(&ctx->sq_data->wait);
--}
--
--static void __io_state_file_put(struct io_submit_state *state)
--{
-- if (state->has_refs)
-- fput_many(state->file, state->has_refs);
-- state->file = NULL;
--}
--
--static inline void io_state_file_put(struct io_submit_state *state)
--{
-- if (state->file)
-- __io_state_file_put(state);
--}
--
--/*
-- * Get as many references to a file as we have IOs left in this submission,
-- * assuming most submissions are for one file, or at least that each file
-- * has more than one submission.
-- */
--static struct file *__io_file_get(struct io_submit_state *state, int fd)
--{
-- if (!state)
-- return fget(fd);
--
-- if (state->file) {
-- if (state->fd == fd) {
-- state->has_refs--;
-- return state->file;
-- }
-- __io_state_file_put(state);
-- }
-- state->file = fget_many(fd, state->ios_left);
-- if (!state->file)
-- return NULL;
--
-- state->fd = fd;
-- state->has_refs = state->ios_left - 1;
-- return state->file;
--}
--
--static bool io_bdev_nowait(struct block_device *bdev)
--{
--#ifdef CONFIG_BLOCK
-- return !bdev || blk_queue_nowait(bdev_get_queue(bdev));
--#else
-- return true;
--#endif
--}
--
--/*
-- * If we tracked the file through the SCM inflight mechanism, we could support
-- * any file. For now, just ensure that anything potentially problematic is done
-- * inline.
-- */
--static bool io_file_supports_async(struct file *file, int rw)
--{
-- umode_t mode = file_inode(file)->i_mode;
--
-- if (S_ISBLK(mode)) {
-- if (io_bdev_nowait(file->f_inode->i_bdev))
-- return true;
-- return false;
-- }
-- if (S_ISSOCK(mode))
-- return true;
-- if (S_ISREG(mode)) {
-- if (io_bdev_nowait(file->f_inode->i_sb->s_bdev) &&
-- file->f_op != &io_uring_fops)
-- return true;
-- return false;
-- }
--
-- /* any ->read/write should understand O_NONBLOCK */
-- if (file->f_flags & O_NONBLOCK)
-- return true;
--
-- if (!(file->f_mode & FMODE_NOWAIT))
-- return false;
--
-- if (rw == READ)
-- return file->f_op->read_iter != NULL;
--
-- return file->f_op->write_iter != NULL;
--}
--
--static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
-- struct io_ring_ctx *ctx = req->ctx;
-- struct kiocb *kiocb = &req->rw.kiocb;
-- unsigned ioprio;
-- int ret;
--
-- if (S_ISREG(file_inode(req->file)->i_mode))
-- req->flags |= REQ_F_ISREG;
--
-- kiocb->ki_pos = READ_ONCE(sqe->off);
-- if (kiocb->ki_pos == -1 && !(req->file->f_mode & FMODE_STREAM)) {
-- req->flags |= REQ_F_CUR_POS;
-- kiocb->ki_pos = req->file->f_pos;
-- }
-- kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp));
-- kiocb->ki_flags = iocb_flags(kiocb->ki_filp);
-- ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags));
-- if (unlikely(ret))
-- return ret;
--
-- ioprio = READ_ONCE(sqe->ioprio);
-- if (ioprio) {
-- ret = ioprio_check_cap(ioprio);
-- if (ret)
-- return ret;
--
-- kiocb->ki_ioprio = ioprio;
-- } else
-- kiocb->ki_ioprio = get_current_ioprio();
--
-- /* don't allow async punt if RWF_NOWAIT was requested */
-- if (kiocb->ki_flags & IOCB_NOWAIT)
-- req->flags |= REQ_F_NOWAIT;
--
-- if (ctx->flags & IORING_SETUP_IOPOLL) {
-- if (!(kiocb->ki_flags & IOCB_DIRECT) ||
-- !kiocb->ki_filp->f_op->iopoll)
-- return -EOPNOTSUPP;
--
-- kiocb->ki_flags |= IOCB_HIPRI;
-- kiocb->ki_complete = io_complete_rw_iopoll;
-- req->iopoll_completed = 0;
-- } else {
-- if (kiocb->ki_flags & IOCB_HIPRI)
-- return -EINVAL;
-- kiocb->ki_complete = io_complete_rw;
-- }
--
-- req->rw.addr = READ_ONCE(sqe->addr);
-- req->rw.len = READ_ONCE(sqe->len);
-- req->buf_index = READ_ONCE(sqe->buf_index);
-- return 0;
--}
--
--static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret)
--{
-- switch (ret) {
-- case -EIOCBQUEUED:
-- break;
-- case -ERESTARTSYS:
-- case -ERESTARTNOINTR:
-- case -ERESTARTNOHAND:
-- case -ERESTART_RESTARTBLOCK:
-- /*
-- * We can't just restart the syscall, since previously
-- * submitted sqes may already be in progress. Just fail this
-- * IO with EINTR.
-- */
-- ret = -EINTR;
-- fallthrough;
-- default:
-- kiocb->ki_complete(kiocb, ret, 0);
-- }
--}
--
--static void kiocb_done(struct kiocb *kiocb, ssize_t ret,
-- struct io_comp_state *cs)
--{
-- struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
-- struct io_async_rw *io = req->async_data;
--
-- /* add previously done IO, if any */
-- if (io && io->bytes_done > 0) {
-- if (ret < 0)
-- ret = io->bytes_done;
-- else
-- ret += io->bytes_done;
-- }
--
-- if (req->flags & REQ_F_CUR_POS)
-- req->file->f_pos = kiocb->ki_pos;
-- if (ret >= 0 && kiocb->ki_complete == io_complete_rw)
-- __io_complete_rw(req, ret, 0, cs);
-- else
-- io_rw_done(kiocb, ret);
--}
--
--static ssize_t io_import_fixed(struct io_kiocb *req, int rw,
-- struct iov_iter *iter)
--{
-- struct io_ring_ctx *ctx = req->ctx;
-- size_t len = req->rw.len;
-- struct io_mapped_ubuf *imu;
-- u16 index, buf_index = req->buf_index;
-- size_t offset;
-- u64 buf_addr;
--
-- if (unlikely(buf_index >= ctx->nr_user_bufs))
-- return -EFAULT;
-- index = array_index_nospec(buf_index, ctx->nr_user_bufs);
-- imu = &ctx->user_bufs[index];
-- buf_addr = req->rw.addr;
--
-- /* overflow */
-- if (buf_addr + len < buf_addr)
-- return -EFAULT;
-- /* not inside the mapped region */
-- if (buf_addr < imu->ubuf || buf_addr + len > imu->ubuf + imu->len)
-- return -EFAULT;
--
-- /*
-- * May not be a start of buffer, set size appropriately
-- * and advance us to the beginning.
-- */
-- offset = buf_addr - imu->ubuf;
-- iov_iter_bvec(iter, rw, imu->bvec, imu->nr_bvecs, offset + len);
--
-- if (offset) {
-- /*
-- * Don't use iov_iter_advance() here, as it's really slow for
-- * using the latter parts of a big fixed buffer - it iterates
-- * over each segment manually. We can cheat a bit here, because
-- * we know that:
-- *
-- * 1) it's a BVEC iter, we set it up
-- * 2) all bvecs are PAGE_SIZE in size, except potentially the
-- * first and last bvec
-- *
-- * So just find our index, and adjust the iterator afterwards.
-- * If the offset is within the first bvec (or the whole first
-- * bvec, just use iov_iter_advance(). This makes it easier
-- * since we can just skip the first segment, which may not
-- * be PAGE_SIZE aligned.
-- */
-- const struct bio_vec *bvec = imu->bvec;
--
-- if (offset <= bvec->bv_len) {
-- iov_iter_advance(iter, offset);
-- } else {
-- unsigned long seg_skip;
--
-- /* skip first vec */
-- offset -= bvec->bv_len;
-- seg_skip = 1 + (offset >> PAGE_SHIFT);
--
-- iter->bvec = bvec + seg_skip;
-- iter->nr_segs -= seg_skip;
-- iter->count -= bvec->bv_len + offset;
-- iter->iov_offset = offset & ~PAGE_MASK;
-- }
-- }
--
-- return len;
--}
--
--static void io_ring_submit_unlock(struct io_ring_ctx *ctx, bool needs_lock)
--{
-- if (needs_lock)
-- mutex_unlock(&ctx->uring_lock);
--}
--
--static void io_ring_submit_lock(struct io_ring_ctx *ctx, bool needs_lock)
--{
-- /*
-- * "Normal" inline submissions always hold the uring_lock, since we
-- * grab it from the system call. Same is true for the SQPOLL offload.
-- * The only exception is when we've detached the request and issue it
-- * from an async worker thread, grab the lock for that case.
-- */
-- if (needs_lock)
-- mutex_lock(&ctx->uring_lock);
--}
--
--static struct io_buffer *io_buffer_select(struct io_kiocb *req, size_t *len,
-- int bgid, struct io_buffer *kbuf,
-- bool needs_lock)
--{
-- struct io_buffer *head;
--
-- if (req->flags & REQ_F_BUFFER_SELECTED)
-- return kbuf;
--
-- io_ring_submit_lock(req->ctx, needs_lock);
--
-- lockdep_assert_held(&req->ctx->uring_lock);
--
-- head = xa_load(&req->ctx->io_buffers, bgid);
-- if (head) {
-- if (!list_empty(&head->list)) {
-- kbuf = list_last_entry(&head->list, struct io_buffer,
-- list);
-- list_del(&kbuf->list);
-- } else {
-- kbuf = head;
-- xa_erase(&req->ctx->io_buffers, bgid);
-- }
-- if (*len > kbuf->len)
-- *len = kbuf->len;
-- } else {
-- kbuf = ERR_PTR(-ENOBUFS);
-- }
--
-- io_ring_submit_unlock(req->ctx, needs_lock);
--
-- return kbuf;
--}
--
--static void __user *io_rw_buffer_select(struct io_kiocb *req, size_t *len,
-- bool needs_lock)
--{
-- struct io_buffer *kbuf;
-- u16 bgid;
--
-- kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
-- bgid = req->buf_index;
-- kbuf = io_buffer_select(req, len, bgid, kbuf, needs_lock);
-- if (IS_ERR(kbuf))
-- return kbuf;
-- req->rw.addr = (u64) (unsigned long) kbuf;
-- req->flags |= REQ_F_BUFFER_SELECTED;
-- return u64_to_user_ptr(kbuf->addr);
--}
--
--#ifdef CONFIG_COMPAT
--static ssize_t io_compat_import(struct io_kiocb *req, struct iovec *iov,
-- bool needs_lock)
--{
-- struct compat_iovec __user *uiov;
-- compat_ssize_t clen;
-- void __user *buf;
-- ssize_t len;
--
-- uiov = u64_to_user_ptr(req->rw.addr);
-- if (!access_ok(uiov, sizeof(*uiov)))
-- return -EFAULT;
-- if (__get_user(clen, &uiov->iov_len))
-- return -EFAULT;
-- if (clen < 0)
-- return -EINVAL;
--
-- len = clen;
-- buf = io_rw_buffer_select(req, &len, needs_lock);
-- if (IS_ERR(buf))
-- return PTR_ERR(buf);
-- iov[0].iov_base = buf;
-- iov[0].iov_len = (compat_size_t) len;
-- return 0;
--}
--#endif
--
--static ssize_t __io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
-- bool needs_lock)
--{
-- struct iovec __user *uiov = u64_to_user_ptr(req->rw.addr);
-- void __user *buf;
-- ssize_t len;
--
-- if (copy_from_user(iov, uiov, sizeof(*uiov)))
-- return -EFAULT;
--
-- len = iov[0].iov_len;
-- if (len < 0)
-- return -EINVAL;
-- buf = io_rw_buffer_select(req, &len, needs_lock);
-- if (IS_ERR(buf))
-- return PTR_ERR(buf);
-- iov[0].iov_base = buf;
-- iov[0].iov_len = len;
-- return 0;
--}
--
--static ssize_t io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
-- bool needs_lock)
--{
-- if (req->flags & REQ_F_BUFFER_SELECTED) {
-- struct io_buffer *kbuf;
--
-- kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
-- iov[0].iov_base = u64_to_user_ptr(kbuf->addr);
-- iov[0].iov_len = kbuf->len;
-- return 0;
-- }
-- if (req->rw.len != 1)
-- return -EINVAL;
--
--#ifdef CONFIG_COMPAT
-- if (req->ctx->compat)
-- return io_compat_import(req, iov, needs_lock);
--#endif
--
-- return __io_iov_buffer_select(req, iov, needs_lock);
--}
--
--static ssize_t __io_import_iovec(int rw, struct io_kiocb *req,
-- struct iovec **iovec, struct iov_iter *iter,
-- bool needs_lock)
--{
-- void __user *buf = u64_to_user_ptr(req->rw.addr);
-- size_t sqe_len = req->rw.len;
-- ssize_t ret;
-- u8 opcode;
--
-- opcode = req->opcode;
-- if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) {
-- *iovec = NULL;
-- return io_import_fixed(req, rw, iter);
-- }
--
-- /* buffer index only valid with fixed read/write, or buffer select */
-- if (req->buf_index && !(req->flags & REQ_F_BUFFER_SELECT))
-- return -EINVAL;
--
-- if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) {
-- if (req->flags & REQ_F_BUFFER_SELECT) {
-- buf = io_rw_buffer_select(req, &sqe_len, needs_lock);
-- if (IS_ERR(buf))
-- return PTR_ERR(buf);
-- req->rw.len = sqe_len;
-- }
--
-- ret = import_single_range(rw, buf, sqe_len, *iovec, iter);
-- *iovec = NULL;
-- return ret;
-- }
--
-- if (req->flags & REQ_F_BUFFER_SELECT) {
-- ret = io_iov_buffer_select(req, *iovec, needs_lock);
-- if (!ret) {
-- ret = (*iovec)->iov_len;
-- iov_iter_init(iter, rw, *iovec, 1, ret);
-- }
-- *iovec = NULL;
-- return ret;
-- }
--
-- return __import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter,
-- req->ctx->compat);
--}
--
--static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
-- struct iovec **iovec, struct iov_iter *iter,
-- bool needs_lock)
--{
-- struct io_async_rw *iorw = req->async_data;
--
-- if (!iorw)
-- return __io_import_iovec(rw, req, iovec, iter, needs_lock);
-- *iovec = NULL;
-- return 0;
--}
--
--static inline loff_t *io_kiocb_ppos(struct kiocb *kiocb)
--{
-- return (kiocb->ki_filp->f_mode & FMODE_STREAM) ? NULL : &kiocb->ki_pos;
--}
--
--/*
-- * For files that don't have ->read_iter() and ->write_iter(), handle them
-- * by looping over ->read() or ->write() manually.
-- */
--static ssize_t loop_rw_iter(int rw, struct io_kiocb *req, struct iov_iter *iter)
--{
-- struct kiocb *kiocb = &req->rw.kiocb;
-- struct file *file = req->file;
-- ssize_t ret = 0;
--
-- /*
-- * Don't support polled IO through this interface, and we can't
-- * support non-blocking either. For the latter, this just causes
-- * the kiocb to be handled from an async context.
-- */
-- if (kiocb->ki_flags & IOCB_HIPRI)
-- return -EOPNOTSUPP;
-- if (kiocb->ki_flags & IOCB_NOWAIT)
-- return -EAGAIN;
--
-- while (iov_iter_count(iter)) {
-- struct iovec iovec;
-- ssize_t nr;
--
-- if (!iov_iter_is_bvec(iter)) {
-- iovec = iov_iter_iovec(iter);
-- } else {
-- iovec.iov_base = u64_to_user_ptr(req->rw.addr);
-- iovec.iov_len = req->rw.len;
-- }
--
-- if (rw == READ) {
-- nr = file->f_op->read(file, iovec.iov_base,
-- iovec.iov_len, io_kiocb_ppos(kiocb));
-- } else {
-- nr = file->f_op->write(file, iovec.iov_base,
-- iovec.iov_len, io_kiocb_ppos(kiocb));
-- }
--
-- if (nr < 0) {
-- if (!ret)
-- ret = nr;
-- break;
-- }
-- ret += nr;
-- if (!iov_iter_is_bvec(iter)) {
-- iov_iter_advance(iter, nr);
-- } else {
-- req->rw.addr += nr;
-- req->rw.len -= nr;
-- if (!req->rw.len)
-- break;
-- }
-- if (nr != iovec.iov_len)
-- break;
-- }
--
-- return ret;
--}
--
--static void io_req_map_rw(struct io_kiocb *req, const struct iovec *iovec,
-- const struct iovec *fast_iov, struct iov_iter *iter)
--{
-- struct io_async_rw *rw = req->async_data;
--
-- memcpy(&rw->iter, iter, sizeof(*iter));
-- rw->free_iovec = iovec;
-- rw->bytes_done = 0;
-- /* can only be fixed buffers, no need to do anything */
-- if (iov_iter_is_bvec(iter))
-- return;
-- if (!iovec) {
-- unsigned iov_off = 0;
--
-- rw->iter.iov = rw->fast_iov;
-- if (iter->iov != fast_iov) {
-- iov_off = iter->iov - fast_iov;
-- rw->iter.iov += iov_off;
-- }
-- if (rw->fast_iov != fast_iov)
-- memcpy(rw->fast_iov + iov_off, fast_iov + iov_off,
-- sizeof(struct iovec) * iter->nr_segs);
-- } else {
-- req->flags |= REQ_F_NEED_CLEANUP;
-- }
--}
--
--static inline int __io_alloc_async_data(struct io_kiocb *req)
--{
-- WARN_ON_ONCE(!io_op_defs[req->opcode].async_size);
-- req->async_data = kmalloc(io_op_defs[req->opcode].async_size, GFP_KERNEL);
-- return req->async_data == NULL;
--}
--
--static int io_alloc_async_data(struct io_kiocb *req)
--{
-- if (!io_op_defs[req->opcode].needs_async_data)
-- return 0;
--
-- return __io_alloc_async_data(req);
--}
--
--static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec,
-- const struct iovec *fast_iov,
-- struct iov_iter *iter, bool force)
--{
-- if (!force && !io_op_defs[req->opcode].needs_async_data)
-- return 0;
-- if (!req->async_data) {
-- if (__io_alloc_async_data(req))
-- return -ENOMEM;
--
-- io_req_map_rw(req, iovec, fast_iov, iter);
-- }
-- return 0;
--}
--
--static inline int io_rw_prep_async(struct io_kiocb *req, int rw)
--{
-- struct io_async_rw *iorw = req->async_data;
-- struct iovec *iov = iorw->fast_iov;
-- ssize_t ret;
--
-- ret = __io_import_iovec(rw, req, &iov, &iorw->iter, false);
-- if (unlikely(ret < 0))
-- return ret;
--
-- iorw->bytes_done = 0;
-- iorw->free_iovec = iov;
-- if (iov)
-- req->flags |= REQ_F_NEED_CLEANUP;
-- return 0;
--}
--
--static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
-- ssize_t ret;
--
-- ret = io_prep_rw(req, sqe);
-- if (ret)
-- return ret;
--
-- if (unlikely(!(req->file->f_mode & FMODE_READ)))
-- return -EBADF;
--
-- /* either don't need iovec imported or already have it */
-- if (!req->async_data)
-- return 0;
-- return io_rw_prep_async(req, READ);
--}
--
--/*
-- * This is our waitqueue callback handler, registered through lock_page_async()
-- * when we initially tried to do the IO with the iocb armed our waitqueue.
-- * This gets called when the page is unlocked, and we generally expect that to
-- * happen when the page IO is completed and the page is now uptodate. This will
-- * queue a task_work based retry of the operation, attempting to copy the data
-- * again. If the latter fails because the page was NOT uptodate, then we will
-- * do a thread based blocking retry of the operation. That's the unexpected
-- * slow path.
-- */
--static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode,
-- int sync, void *arg)
--{
-- struct wait_page_queue *wpq;
-- struct io_kiocb *req = wait->private;
-- struct wait_page_key *key = arg;
-- int ret;
--
-- wpq = container_of(wait, struct wait_page_queue, wait);
--
-- if (!wake_page_match(wpq, key))
-- return 0;
--
-- req->rw.kiocb.ki_flags &= ~IOCB_WAITQ;
-- list_del_init(&wait->entry);
--
-- init_task_work(&req->task_work, io_req_task_submit);
-- percpu_ref_get(&req->ctx->refs);
--
-- /* submit ref gets dropped, acquire a new one */
-- refcount_inc(&req->refs);
-- ret = io_req_task_work_add(req, true);
-- if (unlikely(ret)) {
-- struct task_struct *tsk;
--
-- /* queue just for cancelation */
-- init_task_work(&req->task_work, io_req_task_cancel);
-- tsk = io_wq_get_task(req->ctx->io_wq);
-- task_work_add(tsk, &req->task_work, TWA_NONE);
-- wake_up_process(tsk);
-- }
-- return 1;
--}
--
--/*
-- * This controls whether a given IO request should be armed for async page
-- * based retry. If we return false here, the request is handed to the async
-- * worker threads for retry. If we're doing buffered reads on a regular file,
-- * we prepare a private wait_page_queue entry and retry the operation. This
-- * will either succeed because the page is now uptodate and unlocked, or it
-- * will register a callback when the page is unlocked at IO completion. Through
-- * that callback, io_uring uses task_work to setup a retry of the operation.
-- * That retry will attempt the buffered read again. The retry will generally
-- * succeed, or in rare cases where it fails, we then fall back to using the
-- * async worker threads for a blocking retry.
-- */
--static bool io_rw_should_retry(struct io_kiocb *req)
--{
-- struct io_async_rw *rw = req->async_data;
-- struct wait_page_queue *wait = &rw->wpq;
-- struct kiocb *kiocb = &req->rw.kiocb;
--
-- /* never retry for NOWAIT, we just complete with -EAGAIN */
-- if (req->flags & REQ_F_NOWAIT)
-- return false;
--
-- /* Only for buffered IO */
-- if (kiocb->ki_flags & (IOCB_DIRECT | IOCB_HIPRI))
-- return false;
--
-- /*
-- * just use poll if we can, and don't attempt if the fs doesn't
-- * support callback based unlocks
-- */
-- if (file_can_poll(req->file) || !(req->file->f_mode & FMODE_BUF_RASYNC))
-- return false;
--
-- wait->wait.func = io_async_buf_func;
-- wait->wait.private = req;
-- wait->wait.flags = 0;
-- INIT_LIST_HEAD(&wait->wait.entry);
-- kiocb->ki_flags |= IOCB_WAITQ;
-- kiocb->ki_flags &= ~IOCB_NOWAIT;
-- kiocb->ki_waitq = wait;
-- return true;
--}
--
--static int io_iter_do_read(struct io_kiocb *req, struct iov_iter *iter)
--{
-- if (req->file->f_op->read_iter)
-- return call_read_iter(req->file, &req->rw.kiocb, iter);
-- else if (req->file->f_op->read)
-- return loop_rw_iter(READ, req, iter);
-- else
-- return -EINVAL;
--}
--
--static int io_read(struct io_kiocb *req, bool force_nonblock,
-- struct io_comp_state *cs)
--{
-- struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
-- struct kiocb *kiocb = &req->rw.kiocb;
-- struct iov_iter __iter, *iter = &__iter;
-- struct iov_iter iter_cp;
-- struct io_async_rw *rw = req->async_data;
-- ssize_t io_size, ret, ret2;
-- bool no_async;
--
-- if (rw)
-- iter = &rw->iter;
--
-- ret = io_import_iovec(READ, req, &iovec, iter, !force_nonblock);
-- if (ret < 0)
-- return ret;
-- iter_cp = *iter;
-- io_size = iov_iter_count(iter);
-- req->result = io_size;
-- ret = 0;
--
-- /* Ensure we clear previously set non-block flag */
-- if (!force_nonblock)
-- kiocb->ki_flags &= ~IOCB_NOWAIT;
-- else
-- kiocb->ki_flags |= IOCB_NOWAIT;
--
--
-- /* If the file doesn't support async, just async punt */
-- no_async = force_nonblock && !io_file_supports_async(req->file, READ);
-- if (no_async)
-- goto copy_iov;
--
-- ret = rw_verify_area(READ, req->file, io_kiocb_ppos(kiocb), io_size);
-- if (unlikely(ret))
-- goto out_free;
--
-- ret = io_iter_do_read(req, iter);
--
-- if (!ret) {
-- goto done;
-- } else if (ret == -EIOCBQUEUED) {
-- ret = 0;
-- goto out_free;
-- } else if (ret == -EAGAIN) {
-- /* IOPOLL retry should happen for io-wq threads */
-- if (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL))
-- goto done;
-- /* no retry on NONBLOCK marked file */
-- if (req->file->f_flags & O_NONBLOCK)
-- goto done;
-- /* some cases will consume bytes even on error returns */
-- *iter = iter_cp;
-- ret = 0;
-- goto copy_iov;
-- } else if (ret < 0) {
-- /* make sure -ERESTARTSYS -> -EINTR is done */
-- goto done;
-- }
--
-- /* read it all, or we did blocking attempt. no retry. */
-- if (!iov_iter_count(iter) || !force_nonblock ||
-- (req->file->f_flags & O_NONBLOCK) || !(req->flags & REQ_F_ISREG))
-- goto done;
--
-- io_size -= ret;
--copy_iov:
-- ret2 = io_setup_async_rw(req, iovec, inline_vecs, iter, true);
-- if (ret2) {
-- ret = ret2;
-- goto out_free;
-- }
-- if (no_async)
-- return -EAGAIN;
-- rw = req->async_data;
-- /* it's copied and will be cleaned with ->io */
-- iovec = NULL;
-- /* now use our persistent iterator, if we aren't already */
-- iter = &rw->iter;
--retry:
-- rw->bytes_done += ret;
-- /* if we can retry, do so with the callbacks armed */
-- if (!io_rw_should_retry(req)) {
-- kiocb->ki_flags &= ~IOCB_WAITQ;
-- return -EAGAIN;
-- }
--
-- /*
-- * Now retry read with the IOCB_WAITQ parts set in the iocb. If we
-- * get -EIOCBQUEUED, then we'll get a notification when the desired
-- * page gets unlocked. We can also get a partial read here, and if we
-- * do, then just retry at the new offset.
-- */
-- ret = io_iter_do_read(req, iter);
-- if (ret == -EIOCBQUEUED) {
-- ret = 0;
-- goto out_free;
-- } else if (ret > 0 && ret < io_size) {
-- /* we got some bytes, but not all. retry. */
-- kiocb->ki_flags &= ~IOCB_WAITQ;
-- goto retry;
-- }
--done:
-- kiocb_done(kiocb, ret, cs);
-- ret = 0;
--out_free:
-- /* it's reportedly faster than delegating the null check to kfree() */
-- if (iovec)
-- kfree(iovec);
-- return ret;
--}
--
--static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
-- ssize_t ret;
--
-- ret = io_prep_rw(req, sqe);
-- if (ret)
-- return ret;
--
-- if (unlikely(!(req->file->f_mode & FMODE_WRITE)))
-- return -EBADF;
--
-- /* either don't need iovec imported or already have it */
-- if (!req->async_data)
-- return 0;
-- return io_rw_prep_async(req, WRITE);
--}
--
--static int io_write(struct io_kiocb *req, bool force_nonblock,
-- struct io_comp_state *cs)
--{
-- struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
-- struct kiocb *kiocb = &req->rw.kiocb;
-- struct iov_iter __iter, *iter = &__iter;
-- struct iov_iter iter_cp;
-- struct io_async_rw *rw = req->async_data;
-- ssize_t ret, ret2, io_size;
--
-- if (rw)
-- iter = &rw->iter;
--
-- ret = io_import_iovec(WRITE, req, &iovec, iter, !force_nonblock);
-- if (ret < 0)
-- return ret;
-- iter_cp = *iter;
-- io_size = iov_iter_count(iter);
-- req->result = io_size;
--
-- /* Ensure we clear previously set non-block flag */
-- if (!force_nonblock)
-- kiocb->ki_flags &= ~IOCB_NOWAIT;
-- else
-- kiocb->ki_flags |= IOCB_NOWAIT;
--
-- /* If the file doesn't support async, just async punt */
-- if (force_nonblock && !io_file_supports_async(req->file, WRITE))
-- goto copy_iov;
--
-- /* file path doesn't support NOWAIT for non-direct_IO */
-- if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT) &&
-- (req->flags & REQ_F_ISREG))
-- goto copy_iov;
--
-- ret = rw_verify_area(WRITE, req->file, io_kiocb_ppos(kiocb), io_size);
-- if (unlikely(ret))
-- goto out_free;
--
-- /*
-- * Open-code file_start_write here to grab freeze protection,
-- * which will be released by another thread in
-- * io_complete_rw(). Fool lockdep by telling it the lock got
-- * released so that it doesn't complain about the held lock when
-- * we return to userspace.
-- */
-- if (req->flags & REQ_F_ISREG) {
-- sb_start_write(file_inode(req->file)->i_sb);
-- __sb_writers_release(file_inode(req->file)->i_sb,
-- SB_FREEZE_WRITE);
-- }
-- kiocb->ki_flags |= IOCB_WRITE;
--
-- if (req->file->f_op->write_iter)
-- ret2 = call_write_iter(req->file, kiocb, iter);
-- else if (req->file->f_op->write)
-- ret2 = loop_rw_iter(WRITE, req, iter);
-- else
-- ret2 = -EINVAL;
--
-- /*
-- * Raw bdev writes will return -EOPNOTSUPP for IOCB_NOWAIT. Just
-- * retry them without IOCB_NOWAIT.
-- */
-- if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT))
-- ret2 = -EAGAIN;
-- /* no retry on NONBLOCK marked file */
-- if (ret2 == -EAGAIN && (req->file->f_flags & O_NONBLOCK))
-- goto done;
-- if (!force_nonblock || ret2 != -EAGAIN) {
-- /* IOPOLL retry should happen for io-wq threads */
-- if ((req->ctx->flags & IORING_SETUP_IOPOLL) && ret2 == -EAGAIN)
-- goto copy_iov;
--done:
-- kiocb_done(kiocb, ret2, cs);
-- } else {
--copy_iov:
-- /* some cases will consume bytes even on error returns */
-- *iter = iter_cp;
-- ret = io_setup_async_rw(req, iovec, inline_vecs, iter, false);
-- if (!ret)
-- return -EAGAIN;
-- }
--out_free:
-- /* it's reportedly faster than delegating the null check to kfree() */
-- if (iovec)
-- kfree(iovec);
-- return ret;
--}
--
--static int __io_splice_prep(struct io_kiocb *req,
-- const struct io_uring_sqe *sqe)
--{
-- struct io_splice* sp = &req->splice;
-- unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL;
--
-- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-- return -EINVAL;
--
-- sp->file_in = NULL;
-- sp->len = READ_ONCE(sqe->len);
-- sp->flags = READ_ONCE(sqe->splice_flags);
--
-- if (unlikely(sp->flags & ~valid_flags))
-- return -EINVAL;
--
-- sp->file_in = io_file_get(NULL, req, READ_ONCE(sqe->splice_fd_in),
-- (sp->flags & SPLICE_F_FD_IN_FIXED));
-- if (!sp->file_in)
-- return -EBADF;
-- req->flags |= REQ_F_NEED_CLEANUP;
--
-- if (!S_ISREG(file_inode(sp->file_in)->i_mode)) {
-- /*
-- * Splice operation will be punted aync, and here need to
-- * modify io_wq_work.flags, so initialize io_wq_work firstly.
-- */
-- io_req_init_async(req);
-- req->work.flags |= IO_WQ_WORK_UNBOUND;
-- }
--
-- return 0;
--}
--
--static int io_tee_prep(struct io_kiocb *req,
-- const struct io_uring_sqe *sqe)
--{
-- if (READ_ONCE(sqe->splice_off_in) || READ_ONCE(sqe->off))
-- return -EINVAL;
-- return __io_splice_prep(req, sqe);
--}
--
--static int io_tee(struct io_kiocb *req, bool force_nonblock)
--{
-- struct io_splice *sp = &req->splice;
-- struct file *in = sp->file_in;
-- struct file *out = sp->file_out;
-- unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
-- long ret = 0;
--
-- if (force_nonblock)
-- return -EAGAIN;
-- if (sp->len)
-- ret = do_tee(in, out, sp->len, flags);
--
-- io_put_file(req, in, (sp->flags & SPLICE_F_FD_IN_FIXED));
-- req->flags &= ~REQ_F_NEED_CLEANUP;
--
-- if (ret != sp->len)
-- req_set_fail_links(req);
-- io_req_complete(req, ret);
-- return 0;
--}
--
--static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
-- struct io_splice* sp = &req->splice;
--
-- sp->off_in = READ_ONCE(sqe->splice_off_in);
-- sp->off_out = READ_ONCE(sqe->off);
-- return __io_splice_prep(req, sqe);
--}
--
--static int io_splice(struct io_kiocb *req, bool force_nonblock)
--{
-- struct io_splice *sp = &req->splice;
-- struct file *in = sp->file_in;
-- struct file *out = sp->file_out;
-- unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
-- loff_t *poff_in, *poff_out;
-- long ret = 0;
--
-- if (force_nonblock)
-- return -EAGAIN;
--
-- poff_in = (sp->off_in == -1) ? NULL : &sp->off_in;
-- poff_out = (sp->off_out == -1) ? NULL : &sp->off_out;
--
-- if (sp->len)
-- ret = do_splice(in, poff_in, out, poff_out, sp->len, flags);
--
-- io_put_file(req, in, (sp->flags & SPLICE_F_FD_IN_FIXED));
-- req->flags &= ~REQ_F_NEED_CLEANUP;
--
-- if (ret != sp->len)
-- req_set_fail_links(req);
-- io_req_complete(req, ret);
-- return 0;
--}
--
--/*
-- * IORING_OP_NOP just posts a completion event, nothing else.
-- */
--static int io_nop(struct io_kiocb *req, struct io_comp_state *cs)
--{
-- struct io_ring_ctx *ctx = req->ctx;
--
-- if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
-- return -EINVAL;
--
-- __io_req_complete(req, 0, 0, cs);
-- return 0;
--}
--
--static int io_prep_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
-- struct io_ring_ctx *ctx = req->ctx;
--
-- if (!req->file)
-- return -EBADF;
--
-- if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
-- return -EINVAL;
-- if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index ||
-- sqe->splice_fd_in))
-- return -EINVAL;
--
-- req->sync.flags = READ_ONCE(sqe->fsync_flags);
-- if (unlikely(req->sync.flags & ~IORING_FSYNC_DATASYNC))
-- return -EINVAL;
--
-- req->sync.off = READ_ONCE(sqe->off);
-- req->sync.len = READ_ONCE(sqe->len);
-- return 0;
--}
--
--static int io_fsync(struct io_kiocb *req, bool force_nonblock)
--{
-- loff_t end = req->sync.off + req->sync.len;
-- int ret;
--
-- /* fsync always requires a blocking context */
-- if (force_nonblock)
-- return -EAGAIN;
--
-- ret = vfs_fsync_range(req->file, req->sync.off,
-- end > 0 ? end : LLONG_MAX,
-- req->sync.flags & IORING_FSYNC_DATASYNC);
-- if (ret < 0)
-- req_set_fail_links(req);
-- io_req_complete(req, ret);
-- return 0;
--}
--
--static int io_fallocate_prep(struct io_kiocb *req,
-- const struct io_uring_sqe *sqe)
--{
-- if (sqe->ioprio || sqe->buf_index || sqe->rw_flags ||
-- sqe->splice_fd_in)
-- return -EINVAL;
-- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-- return -EINVAL;
--
-- req->sync.off = READ_ONCE(sqe->off);
-- req->sync.len = READ_ONCE(sqe->addr);
-- req->sync.mode = READ_ONCE(sqe->len);
-- return 0;
--}
--
--static int io_fallocate(struct io_kiocb *req, bool force_nonblock)
--{
-- int ret;
--
-- /* fallocate always requiring blocking context */
-- if (force_nonblock)
-- return -EAGAIN;
-- ret = vfs_fallocate(req->file, req->sync.mode, req->sync.off,
-- req->sync.len);
-- if (ret < 0)
-- req_set_fail_links(req);
-- io_req_complete(req, ret);
-- return 0;
--}
--
--static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
-- const char __user *fname;
-- int ret;
--
-- if (unlikely(sqe->ioprio || sqe->buf_index || sqe->splice_fd_in))
-- return -EINVAL;
-- if (unlikely(req->flags & REQ_F_FIXED_FILE))
-- return -EBADF;
--
-- /* open.how should be already initialised */
-- if (!(req->open.how.flags & O_PATH) && force_o_largefile())
-- req->open.how.flags |= O_LARGEFILE;
--
-- req->open.dfd = READ_ONCE(sqe->fd);
-- fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
-- req->open.filename = getname(fname);
-- if (IS_ERR(req->open.filename)) {
-- ret = PTR_ERR(req->open.filename);
-- req->open.filename = NULL;
-- return ret;
-- }
-- req->open.nofile = rlimit(RLIMIT_NOFILE);
-- req->open.ignore_nonblock = false;
-- req->flags |= REQ_F_NEED_CLEANUP;
-- return 0;
--}
--
--static int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
-- u64 flags, mode;
--
-- if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
-- return -EINVAL;
-- mode = READ_ONCE(sqe->len);
-- flags = READ_ONCE(sqe->open_flags);
-- req->open.how = build_open_how(flags, mode);
-- return __io_openat_prep(req, sqe);
--}
--
--static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
-- struct open_how __user *how;
-- size_t len;
-- int ret;
--
-- if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
-- return -EINVAL;
-- how = u64_to_user_ptr(READ_ONCE(sqe->addr2));
-- len = READ_ONCE(sqe->len);
-- if (len < OPEN_HOW_SIZE_VER0)
-- return -EINVAL;
--
-- ret = copy_struct_from_user(&req->open.how, sizeof(req->open.how), how,
-- len);
-- if (ret)
-- return ret;
--
-- return __io_openat_prep(req, sqe);
--}
--
--static int io_openat2(struct io_kiocb *req, bool force_nonblock)
--{
-- struct open_flags op;
-- struct file *file;
-- int ret;
--
-- if (force_nonblock && !req->open.ignore_nonblock)
-- return -EAGAIN;
--
-- ret = build_open_flags(&req->open.how, &op);
-- if (ret)
-- goto err;
--
-- ret = __get_unused_fd_flags(req->open.how.flags, req->open.nofile);
-- if (ret < 0)
-- goto err;
--
-- file = do_filp_open(req->open.dfd, req->open.filename, &op);
-- if (IS_ERR(file)) {
-- put_unused_fd(ret);
-- ret = PTR_ERR(file);
-- /*
-- * A work-around to ensure that /proc/self works that way
-- * that it should - if we get -EOPNOTSUPP back, then assume
-- * that proc_self_get_link() failed us because we're in async
-- * context. We should be safe to retry this from the task
-- * itself with force_nonblock == false set, as it should not
-- * block on lookup. Would be nice to know this upfront and
-- * avoid the async dance, but doesn't seem feasible.
-- */
-- if (ret == -EOPNOTSUPP && io_wq_current_is_worker()) {
-- req->open.ignore_nonblock = true;
-- refcount_inc(&req->refs);
-- io_req_task_queue(req);
-- return 0;
-- }
-- } else {
-- fsnotify_open(file);
-- fd_install(ret, file);
-- }
--err:
-- putname(req->open.filename);
-- req->flags &= ~REQ_F_NEED_CLEANUP;
-- if (ret < 0)
-- req_set_fail_links(req);
-- io_req_complete(req, ret);
-- return 0;
--}
--
--static int io_openat(struct io_kiocb *req, bool force_nonblock)
--{
-- return io_openat2(req, force_nonblock);
--}
--
--static int io_remove_buffers_prep(struct io_kiocb *req,
-- const struct io_uring_sqe *sqe)
--{
-- struct io_provide_buf *p = &req->pbuf;
-- u64 tmp;
--
-- if (sqe->ioprio || sqe->rw_flags || sqe->addr || sqe->len || sqe->off ||
-- sqe->splice_fd_in)
-- return -EINVAL;
--
-- tmp = READ_ONCE(sqe->fd);
-- if (!tmp || tmp > USHRT_MAX)
-- return -EINVAL;
--
-- memset(p, 0, sizeof(*p));
-- p->nbufs = tmp;
-- p->bgid = READ_ONCE(sqe->buf_group);
-- return 0;
--}
--
--static int __io_remove_buffers(struct io_ring_ctx *ctx, struct io_buffer *buf,
-- int bgid, unsigned nbufs)
--{
-- unsigned i = 0;
--
-- /* shouldn't happen */
-- if (!nbufs)
-- return 0;
--
-- /* the head kbuf is the list itself */
-- while (!list_empty(&buf->list)) {
-- struct io_buffer *nxt;
--
-- nxt = list_first_entry(&buf->list, struct io_buffer, list);
-- list_del(&nxt->list);
-- kfree(nxt);
-- if (++i == nbufs)
-- return i;
-- }
-- i++;
-- kfree(buf);
-- xa_erase(&ctx->io_buffers, bgid);
--
-- return i;
--}
--
--static int io_remove_buffers(struct io_kiocb *req, bool force_nonblock,
-- struct io_comp_state *cs)
--{
-- struct io_provide_buf *p = &req->pbuf;
-- struct io_ring_ctx *ctx = req->ctx;
-- struct io_buffer *head;
-- int ret = 0;
--
-- io_ring_submit_lock(ctx, !force_nonblock);
--
-- lockdep_assert_held(&ctx->uring_lock);
--
-- ret = -ENOENT;
-- head = xa_load(&ctx->io_buffers, p->bgid);
-- if (head)
-- ret = __io_remove_buffers(ctx, head, p->bgid, p->nbufs);
-- if (ret < 0)
-- req_set_fail_links(req);
--
-- /* need to hold the lock to complete IOPOLL requests */
-- if (ctx->flags & IORING_SETUP_IOPOLL) {
-- __io_req_complete(req, ret, 0, cs);
-- io_ring_submit_unlock(ctx, !force_nonblock);
-- } else {
-- io_ring_submit_unlock(ctx, !force_nonblock);
-- __io_req_complete(req, ret, 0, cs);
-- }
-- return 0;
--}
--
--static int io_provide_buffers_prep(struct io_kiocb *req,
-- const struct io_uring_sqe *sqe)
--{
-- unsigned long size, tmp_check;
-- struct io_provide_buf *p = &req->pbuf;
-- u64 tmp;
--
-- if (sqe->ioprio || sqe->rw_flags || sqe->splice_fd_in)
-- return -EINVAL;
--
-- tmp = READ_ONCE(sqe->fd);
-- if (!tmp || tmp > USHRT_MAX)
-- return -E2BIG;
-- p->nbufs = tmp;
-- p->addr = READ_ONCE(sqe->addr);
-- p->len = READ_ONCE(sqe->len);
--
-- if (check_mul_overflow((unsigned long)p->len, (unsigned long)p->nbufs,
-- &size))
-- return -EOVERFLOW;
-- if (check_add_overflow((unsigned long)p->addr, size, &tmp_check))
-- return -EOVERFLOW;
--
-- size = (unsigned long)p->len * p->nbufs;
-- if (!access_ok(u64_to_user_ptr(p->addr), size))
-- return -EFAULT;
--
-- p->bgid = READ_ONCE(sqe->buf_group);
-- tmp = READ_ONCE(sqe->off);
-- if (tmp > USHRT_MAX)
-- return -E2BIG;
-- p->bid = tmp;
-- return 0;
--}
--
--static int io_add_buffers(struct io_provide_buf *pbuf, struct io_buffer **head)
--{
-- struct io_buffer *buf;
-- u64 addr = pbuf->addr;
-- int i, bid = pbuf->bid;
--
-- for (i = 0; i < pbuf->nbufs; i++) {
-- buf = kmalloc(sizeof(*buf), GFP_KERNEL_ACCOUNT);
-- if (!buf)
-- break;
--
-- buf->addr = addr;
-- buf->len = min_t(__u32, pbuf->len, MAX_RW_COUNT);
-- buf->bid = bid;
-- addr += pbuf->len;
-- bid++;
-- if (!*head) {
-- INIT_LIST_HEAD(&buf->list);
-- *head = buf;
-- } else {
-- list_add_tail(&buf->list, &(*head)->list);
-- }
-- cond_resched();
-- }
--
-- return i ? i : -ENOMEM;
--}
--
--static int io_provide_buffers(struct io_kiocb *req, bool force_nonblock,
-- struct io_comp_state *cs)
--{
-- struct io_provide_buf *p = &req->pbuf;
-- struct io_ring_ctx *ctx = req->ctx;
-- struct io_buffer *head, *list;
-- int ret = 0;
--
-- io_ring_submit_lock(ctx, !force_nonblock);
--
-- lockdep_assert_held(&ctx->uring_lock);
--
-- list = head = xa_load(&ctx->io_buffers, p->bgid);
--
-- ret = io_add_buffers(p, &head);
-- if (ret >= 0 && !list) {
-- ret = xa_insert(&ctx->io_buffers, p->bgid, head, GFP_KERNEL);
-- if (ret < 0)
-- __io_remove_buffers(ctx, head, p->bgid, -1U);
-- }
-- if (ret < 0)
-- req_set_fail_links(req);
--
-- /* need to hold the lock to complete IOPOLL requests */
-- if (ctx->flags & IORING_SETUP_IOPOLL) {
-- __io_req_complete(req, ret, 0, cs);
-- io_ring_submit_unlock(ctx, !force_nonblock);
-- } else {
-- io_ring_submit_unlock(ctx, !force_nonblock);
-- __io_req_complete(req, ret, 0, cs);
-- }
-- return 0;
--}
--
--static int io_epoll_ctl_prep(struct io_kiocb *req,
-- const struct io_uring_sqe *sqe)
--{
--#if defined(CONFIG_EPOLL)
-- if (sqe->ioprio || sqe->buf_index || sqe->splice_fd_in)
-- return -EINVAL;
-- if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL)))
-- return -EINVAL;
--
-- req->epoll.epfd = READ_ONCE(sqe->fd);
-- req->epoll.op = READ_ONCE(sqe->len);
-- req->epoll.fd = READ_ONCE(sqe->off);
--
-- if (ep_op_has_event(req->epoll.op)) {
-- struct epoll_event __user *ev;
--
-- ev = u64_to_user_ptr(READ_ONCE(sqe->addr));
-- if (copy_from_user(&req->epoll.event, ev, sizeof(*ev)))
-- return -EFAULT;
-- }
--
-- return 0;
--#else
-- return -EOPNOTSUPP;
--#endif
--}
--
--static int io_epoll_ctl(struct io_kiocb *req, bool force_nonblock,
-- struct io_comp_state *cs)
--{
--#if defined(CONFIG_EPOLL)
-- struct io_epoll *ie = &req->epoll;
-- int ret;
--
-- ret = do_epoll_ctl(ie->epfd, ie->op, ie->fd, &ie->event, force_nonblock);
-- if (force_nonblock && ret == -EAGAIN)
-- return -EAGAIN;
--
-- if (ret < 0)
-- req_set_fail_links(req);
-- __io_req_complete(req, ret, 0, cs);
-- return 0;
--#else
-- return -EOPNOTSUPP;
--#endif
--}
--
--static int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
--#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
-- if (sqe->ioprio || sqe->buf_index || sqe->off || sqe->splice_fd_in)
-- return -EINVAL;
-- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-- return -EINVAL;
--
-- req->madvise.addr = READ_ONCE(sqe->addr);
-- req->madvise.len = READ_ONCE(sqe->len);
-- req->madvise.advice = READ_ONCE(sqe->fadvise_advice);
-- return 0;
--#else
-- return -EOPNOTSUPP;
--#endif
--}
--
--static int io_madvise(struct io_kiocb *req, bool force_nonblock)
--{
--#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
-- struct io_madvise *ma = &req->madvise;
-- int ret;
--
-- if (force_nonblock)
-- return -EAGAIN;
--
-- ret = do_madvise(current->mm, ma->addr, ma->len, ma->advice);
-- if (ret < 0)
-- req_set_fail_links(req);
-- io_req_complete(req, ret);
-- return 0;
--#else
-- return -EOPNOTSUPP;
--#endif
--}
--
--static int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
-- if (sqe->ioprio || sqe->buf_index || sqe->addr || sqe->splice_fd_in)
-- return -EINVAL;
-- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-- return -EINVAL;
--
-- req->fadvise.offset = READ_ONCE(sqe->off);
-- req->fadvise.len = READ_ONCE(sqe->len);
-- req->fadvise.advice = READ_ONCE(sqe->fadvise_advice);
-- return 0;
--}
--
--static int io_fadvise(struct io_kiocb *req, bool force_nonblock)
--{
-- struct io_fadvise *fa = &req->fadvise;
-- int ret;
--
-- if (force_nonblock) {
-- switch (fa->advice) {
-- case POSIX_FADV_NORMAL:
-- case POSIX_FADV_RANDOM:
-- case POSIX_FADV_SEQUENTIAL:
-- break;
-- default:
-- return -EAGAIN;
-- }
-- }
--
-- ret = vfs_fadvise(req->file, fa->offset, fa->len, fa->advice);
-- if (ret < 0)
-- req_set_fail_links(req);
-- io_req_complete(req, ret);
-- return 0;
--}
--
--static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
-- if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL)))
-- return -EINVAL;
-- if (sqe->ioprio || sqe->buf_index || sqe->splice_fd_in)
-- return -EINVAL;
-- if (req->flags & REQ_F_FIXED_FILE)
-- return -EBADF;
--
-- req->statx.dfd = READ_ONCE(sqe->fd);
-- req->statx.mask = READ_ONCE(sqe->len);
-- req->statx.filename = u64_to_user_ptr(READ_ONCE(sqe->addr));
-- req->statx.buffer = u64_to_user_ptr(READ_ONCE(sqe->addr2));
-- req->statx.flags = READ_ONCE(sqe->statx_flags);
--
-- return 0;
--}
--
--static int io_statx(struct io_kiocb *req, bool force_nonblock)
--{
-- struct io_statx *ctx = &req->statx;
-- int ret;
--
-- if (force_nonblock)
-- return -EAGAIN;
--
-- ret = do_statx(ctx->dfd, ctx->filename, ctx->flags, ctx->mask,
-- ctx->buffer);
--
-- if (ret < 0)
-- req_set_fail_links(req);
-- io_req_complete(req, ret);
-- return 0;
--}
--
--static int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
-- /*
-- * If we queue this for async, it must not be cancellable. That would
-- * leave the 'file' in an undeterminate state, and here need to modify
-- * io_wq_work.flags, so initialize io_wq_work firstly.
-- */
-- io_req_init_async(req);
--
-- if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
-- return -EINVAL;
-- if (sqe->ioprio || sqe->off || sqe->addr || sqe->len ||
-- sqe->rw_flags || sqe->buf_index || sqe->splice_fd_in)
-- return -EINVAL;
-- if (req->flags & REQ_F_FIXED_FILE)
-- return -EBADF;
--
-- req->close.fd = READ_ONCE(sqe->fd);
-- if ((req->file && req->file->f_op == &io_uring_fops))
-- return -EBADF;
--
-- req->close.put_file = NULL;
-- return 0;
--}
--
--static int io_close(struct io_kiocb *req, bool force_nonblock,
-- struct io_comp_state *cs)
--{
-- struct io_close *close = &req->close;
-- int ret;
--
-- /* might be already done during nonblock submission */
-- if (!close->put_file) {
-- ret = close_fd_get_file(close->fd, &close->put_file);
-- if (ret < 0)
-- return (ret == -ENOENT) ? -EBADF : ret;
-- }
--
-- /* if the file has a flush method, be safe and punt to async */
-- if (close->put_file->f_op->flush && force_nonblock) {
-- /* not safe to cancel at this point */
-- req->work.flags |= IO_WQ_WORK_NO_CANCEL;
-- /* was never set, but play safe */
-- req->flags &= ~REQ_F_NOWAIT;
-- /* avoid grabbing files - we don't need the files */
-- req->flags |= REQ_F_NO_FILE_TABLE;
-- return -EAGAIN;
-- }
--
-- /* No ->flush() or already async, safely close from here */
-- ret = filp_close(close->put_file, req->work.identity->files);
-- if (ret < 0)
-- req_set_fail_links(req);
-- fput(close->put_file);
-- close->put_file = NULL;
-- __io_req_complete(req, ret, 0, cs);
-- return 0;
--}
--
--static int io_prep_sfr(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
-- struct io_ring_ctx *ctx = req->ctx;
--
-- if (!req->file)
-- return -EBADF;
--
-- if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
-- return -EINVAL;
-- if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index ||
-- sqe->splice_fd_in))
-- return -EINVAL;
--
-- req->sync.off = READ_ONCE(sqe->off);
-- req->sync.len = READ_ONCE(sqe->len);
-- req->sync.flags = READ_ONCE(sqe->sync_range_flags);
-- return 0;
--}
--
--static int io_sync_file_range(struct io_kiocb *req, bool force_nonblock)
--{
-- int ret;
--
-- /* sync_file_range always requires a blocking context */
-- if (force_nonblock)
-- return -EAGAIN;
--
-- ret = sync_file_range(req->file, req->sync.off, req->sync.len,
-- req->sync.flags);
-- if (ret < 0)
-- req_set_fail_links(req);
-- io_req_complete(req, ret);
-- return 0;
--}
--
--#if defined(CONFIG_NET)
--static int io_setup_async_msg(struct io_kiocb *req,
-- struct io_async_msghdr *kmsg)
--{
-- struct io_async_msghdr *async_msg = req->async_data;
--
-- if (async_msg)
-- return -EAGAIN;
-- if (io_alloc_async_data(req)) {
-- if (kmsg->iov != kmsg->fast_iov)
-- kfree(kmsg->iov);
-- return -ENOMEM;
-- }
-- async_msg = req->async_data;
-- req->flags |= REQ_F_NEED_CLEANUP;
-- memcpy(async_msg, kmsg, sizeof(*kmsg));
-- return -EAGAIN;
--}
--
--static int io_sendmsg_copy_hdr(struct io_kiocb *req,
-- struct io_async_msghdr *iomsg)
--{
-- iomsg->iov = iomsg->fast_iov;
-- iomsg->msg.msg_name = &iomsg->addr;
-- return sendmsg_copy_msghdr(&iomsg->msg, req->sr_msg.umsg,
-- req->sr_msg.msg_flags, &iomsg->iov);
--}
--
--static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
-- struct io_async_msghdr *async_msg = req->async_data;
-- struct io_sr_msg *sr = &req->sr_msg;
-- int ret;
--
-- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-- return -EINVAL;
-- if (unlikely(sqe->addr2 || sqe->splice_fd_in || sqe->ioprio))
-- return -EINVAL;
--
-- sr->msg_flags = READ_ONCE(sqe->msg_flags);
-- sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
-- sr->len = READ_ONCE(sqe->len);
--
--#ifdef CONFIG_COMPAT
-- if (req->ctx->compat)
-- sr->msg_flags |= MSG_CMSG_COMPAT;
--#endif
--
-- if (!async_msg || !io_op_defs[req->opcode].needs_async_data)
-- return 0;
-- ret = io_sendmsg_copy_hdr(req, async_msg);
-- if (!ret)
-- req->flags |= REQ_F_NEED_CLEANUP;
-- return ret;
--}
--
--static int io_sendmsg(struct io_kiocb *req, bool force_nonblock,
-- struct io_comp_state *cs)
--{
-- struct io_async_msghdr iomsg, *kmsg;
-- struct socket *sock;
-- unsigned flags;
-- int min_ret = 0;
-- int ret;
--
-- sock = sock_from_file(req->file, &ret);
-- if (unlikely(!sock))
-- return ret;
--
-- if (req->async_data) {
-- kmsg = req->async_data;
-- kmsg->msg.msg_name = &kmsg->addr;
-- /* if iov is set, it's allocated already */
-- if (!kmsg->iov)
-- kmsg->iov = kmsg->fast_iov;
-- kmsg->msg.msg_iter.iov = kmsg->iov;
-- } else {
-- ret = io_sendmsg_copy_hdr(req, &iomsg);
-- if (ret)
-- return ret;
-- kmsg = &iomsg;
-- }
--
-- flags = req->sr_msg.msg_flags | MSG_NOSIGNAL;
-- if (flags & MSG_DONTWAIT)
-- req->flags |= REQ_F_NOWAIT;
-- else if (force_nonblock)
-- flags |= MSG_DONTWAIT;
--
-- if (flags & MSG_WAITALL)
-- min_ret = iov_iter_count(&kmsg->msg.msg_iter);
--
-- ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
-- if (force_nonblock && ret == -EAGAIN)
-- return io_setup_async_msg(req, kmsg);
-- if (ret == -ERESTARTSYS)
-- ret = -EINTR;
--
-- if (kmsg->iov != kmsg->fast_iov)
-- kfree(kmsg->iov);
-- req->flags &= ~REQ_F_NEED_CLEANUP;
-- if (ret < min_ret)
-- req_set_fail_links(req);
-- __io_req_complete(req, ret, 0, cs);
-- return 0;
--}
--
--static int io_send(struct io_kiocb *req, bool force_nonblock,
-- struct io_comp_state *cs)
--{
-- struct io_sr_msg *sr = &req->sr_msg;
-- struct msghdr msg;
-- struct iovec iov;
-- struct socket *sock;
-- unsigned flags;
-- int min_ret = 0;
-- int ret;
--
-- sock = sock_from_file(req->file, &ret);
-- if (unlikely(!sock))
-- return ret;
--
-- ret = import_single_range(WRITE, sr->buf, sr->len, &iov, &msg.msg_iter);
-- if (unlikely(ret))
-- return ret;
--
-- msg.msg_name = NULL;
-- msg.msg_control = NULL;
-- msg.msg_controllen = 0;
-- msg.msg_namelen = 0;
--
-- flags = req->sr_msg.msg_flags | MSG_NOSIGNAL;
-- if (flags & MSG_DONTWAIT)
-- req->flags |= REQ_F_NOWAIT;
-- else if (force_nonblock)
-- flags |= MSG_DONTWAIT;
--
-- if (flags & MSG_WAITALL)
-- min_ret = iov_iter_count(&msg.msg_iter);
--
-- msg.msg_flags = flags;
-- ret = sock_sendmsg(sock, &msg);
-- if (force_nonblock && ret == -EAGAIN)
-- return -EAGAIN;
-- if (ret == -ERESTARTSYS)
-- ret = -EINTR;
--
-- if (ret < min_ret)
-- req_set_fail_links(req);
-- __io_req_complete(req, ret, 0, cs);
-- return 0;
--}
--
--static int __io_recvmsg_copy_hdr(struct io_kiocb *req,
-- struct io_async_msghdr *iomsg)
--{
-- struct io_sr_msg *sr = &req->sr_msg;
-- struct iovec __user *uiov;
-- size_t iov_len;
-- int ret;
--
-- ret = __copy_msghdr_from_user(&iomsg->msg, sr->umsg,
-- &iomsg->uaddr, &uiov, &iov_len);
-- if (ret)
-- return ret;
--
-- if (req->flags & REQ_F_BUFFER_SELECT) {
-- if (iov_len > 1)
-- return -EINVAL;
-- if (copy_from_user(iomsg->iov, uiov, sizeof(*uiov)))
-- return -EFAULT;
-- sr->len = iomsg->iov[0].iov_len;
-- iov_iter_init(&iomsg->msg.msg_iter, READ, iomsg->iov, 1,
-- sr->len);
-- iomsg->iov = NULL;
-- } else {
-- ret = __import_iovec(READ, uiov, iov_len, UIO_FASTIOV,
-- &iomsg->iov, &iomsg->msg.msg_iter,
-- false);
-- if (ret > 0)
-- ret = 0;
-- }
--
-- return ret;
--}
--
--#ifdef CONFIG_COMPAT
--static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req,
-- struct io_async_msghdr *iomsg)
--{
-- struct compat_msghdr __user *msg_compat;
-- struct io_sr_msg *sr = &req->sr_msg;
-- struct compat_iovec __user *uiov;
-- compat_uptr_t ptr;
-- compat_size_t len;
-- int ret;
--
-- msg_compat = (struct compat_msghdr __user *) sr->umsg;
-- ret = __get_compat_msghdr(&iomsg->msg, msg_compat, &iomsg->uaddr,
-- &ptr, &len);
-- if (ret)
-- return ret;
--
-- uiov = compat_ptr(ptr);
-- if (req->flags & REQ_F_BUFFER_SELECT) {
-- compat_ssize_t clen;
--
-- if (len > 1)
-- return -EINVAL;
-- if (!access_ok(uiov, sizeof(*uiov)))
-- return -EFAULT;
-- if (__get_user(clen, &uiov->iov_len))
-- return -EFAULT;
-- if (clen < 0)
-- return -EINVAL;
-- sr->len = clen;
-- iomsg->iov[0].iov_len = clen;
-- iomsg->iov = NULL;
-- } else {
-- ret = __import_iovec(READ, (struct iovec __user *)uiov, len,
-- UIO_FASTIOV, &iomsg->iov,
-- &iomsg->msg.msg_iter, true);
-- if (ret < 0)
-- return ret;
-- }
--
-- return 0;
--}
--#endif
--
--static int io_recvmsg_copy_hdr(struct io_kiocb *req,
-- struct io_async_msghdr *iomsg)
--{
-- iomsg->msg.msg_name = &iomsg->addr;
-- iomsg->iov = iomsg->fast_iov;
--
--#ifdef CONFIG_COMPAT
-- if (req->ctx->compat)
-- return __io_compat_recvmsg_copy_hdr(req, iomsg);
--#endif
--
-- return __io_recvmsg_copy_hdr(req, iomsg);
--}
--
--static struct io_buffer *io_recv_buffer_select(struct io_kiocb *req,
-- bool needs_lock)
--{
-- struct io_sr_msg *sr = &req->sr_msg;
-- struct io_buffer *kbuf;
--
-- kbuf = io_buffer_select(req, &sr->len, sr->bgid, sr->kbuf, needs_lock);
-- if (IS_ERR(kbuf))
-- return kbuf;
--
-- sr->kbuf = kbuf;
-- req->flags |= REQ_F_BUFFER_SELECTED;
-- return kbuf;
--}
--
--static inline unsigned int io_put_recv_kbuf(struct io_kiocb *req)
--{
-- return io_put_kbuf(req, req->sr_msg.kbuf);
--}
--
--static int io_recvmsg_prep(struct io_kiocb *req,
-- const struct io_uring_sqe *sqe)
--{
-- struct io_async_msghdr *async_msg = req->async_data;
-- struct io_sr_msg *sr = &req->sr_msg;
-- int ret;
--
-- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-- return -EINVAL;
-- if (unlikely(sqe->addr2 || sqe->splice_fd_in || sqe->ioprio))
-- return -EINVAL;
--
-- sr->msg_flags = READ_ONCE(sqe->msg_flags);
-- sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
-- sr->len = READ_ONCE(sqe->len);
-- sr->bgid = READ_ONCE(sqe->buf_group);
--
--#ifdef CONFIG_COMPAT
-- if (req->ctx->compat)
-- sr->msg_flags |= MSG_CMSG_COMPAT;
--#endif
--
-- if (!async_msg || !io_op_defs[req->opcode].needs_async_data)
-- return 0;
-- ret = io_recvmsg_copy_hdr(req, async_msg);
-- if (!ret)
-- req->flags |= REQ_F_NEED_CLEANUP;
-- return ret;
--}
--
--static int io_recvmsg(struct io_kiocb *req, bool force_nonblock,
-- struct io_comp_state *cs)
--{
-- struct io_async_msghdr iomsg, *kmsg;
-- struct socket *sock;
-- struct io_buffer *kbuf;
-- unsigned flags;
-- int min_ret = 0;
-- int ret, cflags = 0;
--
-- sock = sock_from_file(req->file, &ret);
-- if (unlikely(!sock))
-- return ret;
--
-- if (req->async_data) {
-- kmsg = req->async_data;
-- kmsg->msg.msg_name = &kmsg->addr;
-- /* if iov is set, it's allocated already */
-- if (!kmsg->iov)
-- kmsg->iov = kmsg->fast_iov;
-- kmsg->msg.msg_iter.iov = kmsg->iov;
-- } else {
-- ret = io_recvmsg_copy_hdr(req, &iomsg);
-- if (ret)
-- return ret;
-- kmsg = &iomsg;
-- }
--
-- if (req->flags & REQ_F_BUFFER_SELECT) {
-- kbuf = io_recv_buffer_select(req, !force_nonblock);
-- if (IS_ERR(kbuf))
-- return PTR_ERR(kbuf);
-- kmsg->fast_iov[0].iov_base = u64_to_user_ptr(kbuf->addr);
-- iov_iter_init(&kmsg->msg.msg_iter, READ, kmsg->iov,
-- 1, req->sr_msg.len);
-- }
--
-- flags = req->sr_msg.msg_flags | MSG_NOSIGNAL;
-- if (flags & MSG_DONTWAIT)
-- req->flags |= REQ_F_NOWAIT;
-- else if (force_nonblock)
-- flags |= MSG_DONTWAIT;
--
-- if (flags & MSG_WAITALL)
-- min_ret = iov_iter_count(&kmsg->msg.msg_iter);
--
-- ret = __sys_recvmsg_sock(sock, &kmsg->msg, req->sr_msg.umsg,
-- kmsg->uaddr, flags);
-- if (force_nonblock && ret == -EAGAIN)
-- return io_setup_async_msg(req, kmsg);
-- if (ret == -ERESTARTSYS)
-- ret = -EINTR;
--
-- if (req->flags & REQ_F_BUFFER_SELECTED)
-- cflags = io_put_recv_kbuf(req);
-- if (kmsg->iov != kmsg->fast_iov)
-- kfree(kmsg->iov);
-- req->flags &= ~REQ_F_NEED_CLEANUP;
-- if (ret < min_ret || ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))))
-- req_set_fail_links(req);
-- __io_req_complete(req, ret, cflags, cs);
-- return 0;
--}
--
--static int io_recv(struct io_kiocb *req, bool force_nonblock,
-- struct io_comp_state *cs)
--{
-- struct io_buffer *kbuf;
-- struct io_sr_msg *sr = &req->sr_msg;
-- struct msghdr msg;
-- void __user *buf = sr->buf;
-- struct socket *sock;
-- struct iovec iov;
-- unsigned flags;
-- int min_ret = 0;
-- int ret, cflags = 0;
--
-- sock = sock_from_file(req->file, &ret);
-- if (unlikely(!sock))
-- return ret;
--
-- if (req->flags & REQ_F_BUFFER_SELECT) {
-- kbuf = io_recv_buffer_select(req, !force_nonblock);
-- if (IS_ERR(kbuf))
-- return PTR_ERR(kbuf);
-- buf = u64_to_user_ptr(kbuf->addr);
-- }
--
-- ret = import_single_range(READ, buf, sr->len, &iov, &msg.msg_iter);
-- if (unlikely(ret))
-- goto out_free;
--
-- msg.msg_name = NULL;
-- msg.msg_control = NULL;
-- msg.msg_controllen = 0;
-- msg.msg_namelen = 0;
-- msg.msg_iocb = NULL;
-- msg.msg_flags = 0;
--
-- flags = req->sr_msg.msg_flags | MSG_NOSIGNAL;
-- if (flags & MSG_DONTWAIT)
-- req->flags |= REQ_F_NOWAIT;
-- else if (force_nonblock)
-- flags |= MSG_DONTWAIT;
--
-- if (flags & MSG_WAITALL)
-- min_ret = iov_iter_count(&msg.msg_iter);
--
-- ret = sock_recvmsg(sock, &msg, flags);
-- if (force_nonblock && ret == -EAGAIN)
-- return -EAGAIN;
-- if (ret == -ERESTARTSYS)
-- ret = -EINTR;
--out_free:
-- if (req->flags & REQ_F_BUFFER_SELECTED)
-- cflags = io_put_recv_kbuf(req);
-- if (ret < min_ret || ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))))
-- req_set_fail_links(req);
-- __io_req_complete(req, ret, cflags, cs);
-- return 0;
--}
--
--static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
-- struct io_accept *accept = &req->accept;
--
-- if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
-- return -EINVAL;
-- if (sqe->ioprio || sqe->len || sqe->buf_index || sqe->splice_fd_in)
-- return -EINVAL;
--
-- accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
-- accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2));
-- accept->flags = READ_ONCE(sqe->accept_flags);
-- accept->nofile = rlimit(RLIMIT_NOFILE);
-- return 0;
--}
--
--static int io_accept(struct io_kiocb *req, bool force_nonblock,
-- struct io_comp_state *cs)
--{
-- struct io_accept *accept = &req->accept;
-- unsigned int file_flags = force_nonblock ? O_NONBLOCK : 0;
-- int ret;
--
-- if (req->file->f_flags & O_NONBLOCK)
-- req->flags |= REQ_F_NOWAIT;
--
-- ret = __sys_accept4_file(req->file, file_flags, accept->addr,
-- accept->addr_len, accept->flags,
-- accept->nofile);
-- if (ret == -EAGAIN && force_nonblock)
-- return -EAGAIN;
-- if (ret < 0) {
-- if (ret == -ERESTARTSYS)
-- ret = -EINTR;
-- req_set_fail_links(req);
-- }
-- __io_req_complete(req, ret, 0, cs);
-- return 0;
--}
--
--static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
-- struct io_connect *conn = &req->connect;
-- struct io_async_connect *io = req->async_data;
--
-- if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
-- return -EINVAL;
-- if (sqe->ioprio || sqe->len || sqe->buf_index || sqe->rw_flags ||
-- sqe->splice_fd_in)
-- return -EINVAL;
--
-- conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
-- conn->addr_len = READ_ONCE(sqe->addr2);
--
-- if (!io)
-- return 0;
--
-- return move_addr_to_kernel(conn->addr, conn->addr_len,
-- &io->address);
--}
--
--static int io_connect(struct io_kiocb *req, bool force_nonblock,
-- struct io_comp_state *cs)
--{
-- struct io_async_connect __io, *io;
-- unsigned file_flags;
-- int ret;
--
-- if (req->async_data) {
-- io = req->async_data;
-- } else {
-- ret = move_addr_to_kernel(req->connect.addr,
-- req->connect.addr_len,
-- &__io.address);
-- if (ret)
-- goto out;
-- io = &__io;
-- }
--
-- file_flags = force_nonblock ? O_NONBLOCK : 0;
--
-- ret = __sys_connect_file(req->file, &io->address,
-- req->connect.addr_len, file_flags);
-- if ((ret == -EAGAIN || ret == -EINPROGRESS) && force_nonblock) {
-- if (req->async_data)
-- return -EAGAIN;
-- if (io_alloc_async_data(req)) {
-- ret = -ENOMEM;
-- goto out;
-- }
-- io = req->async_data;
-- memcpy(req->async_data, &__io, sizeof(__io));
-- return -EAGAIN;
-- }
-- if (ret == -ERESTARTSYS)
-- ret = -EINTR;
--out:
-- if (ret < 0)
-- req_set_fail_links(req);
-- __io_req_complete(req, ret, 0, cs);
-- return 0;
--}
--#else /* !CONFIG_NET */
--static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
-- return -EOPNOTSUPP;
--}
--
--static int io_sendmsg(struct io_kiocb *req, bool force_nonblock,
-- struct io_comp_state *cs)
--{
-- return -EOPNOTSUPP;
--}
--
--static int io_send(struct io_kiocb *req, bool force_nonblock,
-- struct io_comp_state *cs)
--{
-- return -EOPNOTSUPP;
--}
--
--static int io_recvmsg_prep(struct io_kiocb *req,
-- const struct io_uring_sqe *sqe)
--{
-- return -EOPNOTSUPP;
--}
--
--static int io_recvmsg(struct io_kiocb *req, bool force_nonblock,
-- struct io_comp_state *cs)
--{
-- return -EOPNOTSUPP;
--}
--
--static int io_recv(struct io_kiocb *req, bool force_nonblock,
-- struct io_comp_state *cs)
--{
-- return -EOPNOTSUPP;
--}
--
--static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
-- return -EOPNOTSUPP;
--}
--
--static int io_accept(struct io_kiocb *req, bool force_nonblock,
-- struct io_comp_state *cs)
--{
-- return -EOPNOTSUPP;
--}
--
--static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
-- return -EOPNOTSUPP;
--}
--
--static int io_connect(struct io_kiocb *req, bool force_nonblock,
-- struct io_comp_state *cs)
--{
-- return -EOPNOTSUPP;
--}
--#endif /* CONFIG_NET */
--
--struct io_poll_table {
-- struct poll_table_struct pt;
-- struct io_kiocb *req;
-- int nr_entries;
-- int error;
--};
--
--static int __io_async_wake(struct io_kiocb *req, struct io_poll_iocb *poll,
-- __poll_t mask, task_work_func_t func)
--{
-- bool twa_signal_ok;
-- int ret;
--
-- /* for instances that support it check for an event match first: */
-- if (mask && !(mask & poll->events))
-- return 0;
--
-- trace_io_uring_task_add(req->ctx, req->opcode, req->user_data, mask);
--
-- list_del_init(&poll->wait.entry);
--
-- req->result = mask;
-- init_task_work(&req->task_work, func);
-- percpu_ref_get(&req->ctx->refs);
--
-- /*
-- * If we using the signalfd wait_queue_head for this wakeup, then
-- * it's not safe to use TWA_SIGNAL as we could be recursing on the
-- * tsk->sighand->siglock on doing the wakeup. Should not be needed
-- * either, as the normal wakeup will suffice.
-- */
-- twa_signal_ok = (poll->head != &req->task->sighand->signalfd_wqh);
--
-- /*
-- * If this fails, then the task is exiting. When a task exits, the
-- * work gets canceled, so just cancel this request as well instead
-- * of executing it. We can't safely execute it anyway, as we may not
-- * have the needed state needed for it anyway.
-- */
-- ret = io_req_task_work_add(req, twa_signal_ok);
-- if (unlikely(ret)) {
-- struct task_struct *tsk;
--
-- WRITE_ONCE(poll->canceled, true);
-- tsk = io_wq_get_task(req->ctx->io_wq);
-- task_work_add(tsk, &req->task_work, TWA_NONE);
-- wake_up_process(tsk);
-- }
-- return 1;
--}
--
--static bool io_poll_rewait(struct io_kiocb *req, struct io_poll_iocb *poll)
-- __acquires(&req->ctx->completion_lock)
--{
-- struct io_ring_ctx *ctx = req->ctx;
--
-- if (!req->result && !READ_ONCE(poll->canceled)) {
-- struct poll_table_struct pt = { ._key = poll->events };
--
-- req->result = vfs_poll(req->file, &pt) & poll->events;
-- }
--
-- spin_lock_irq(&ctx->completion_lock);
-- if (!req->result && !READ_ONCE(poll->canceled)) {
-- add_wait_queue(poll->head, &poll->wait);
-- return true;
-- }
--
-- return false;
--}
--
--static struct io_poll_iocb *io_poll_get_double(struct io_kiocb *req)
--{
-- /* pure poll stashes this in ->async_data, poll driven retry elsewhere */
-- if (req->opcode == IORING_OP_POLL_ADD)
-- return req->async_data;
-- return req->apoll->double_poll;
--}
--
--static struct io_poll_iocb *io_poll_get_single(struct io_kiocb *req)
--{
-- if (req->opcode == IORING_OP_POLL_ADD)
-- return &req->poll;
-- return &req->apoll->poll;
--}
--
--static void io_poll_remove_double(struct io_kiocb *req)
--{
-- struct io_poll_iocb *poll = io_poll_get_double(req);
--
-- lockdep_assert_held(&req->ctx->completion_lock);
--
-- if (poll && poll->head) {
-- struct wait_queue_head *head = poll->head;
--
-- spin_lock(&head->lock);
-- list_del_init(&poll->wait.entry);
-- if (poll->wait.private)
-- refcount_dec(&req->refs);
-- poll->head = NULL;
-- spin_unlock(&head->lock);
-- }
--}
--
--static void io_poll_complete(struct io_kiocb *req, __poll_t mask, int error)
--{
-- struct io_ring_ctx *ctx = req->ctx;
--
-- io_poll_remove_double(req);
-- req->poll.done = true;
-- io_cqring_fill_event(req, error ? error : mangle_poll(mask));
-- io_commit_cqring(ctx);
--}
--
--static void io_poll_task_func(struct callback_head *cb)
--{
-- struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
-- struct io_ring_ctx *ctx = req->ctx;
-- struct io_kiocb *nxt;
--
-- if (io_poll_rewait(req, &req->poll)) {
-- spin_unlock_irq(&ctx->completion_lock);
-- } else {
-- hash_del(&req->hash_node);
-- io_poll_complete(req, req->result, 0);
-- spin_unlock_irq(&ctx->completion_lock);
--
-- nxt = io_put_req_find_next(req);
-- io_cqring_ev_posted(ctx);
-- if (nxt)
-- __io_req_task_submit(nxt);
-- }
--
-- percpu_ref_put(&ctx->refs);
--}
--
--static int io_poll_double_wake(struct wait_queue_entry *wait, unsigned mode,
-- int sync, void *key)
--{
-- struct io_kiocb *req = wait->private;
-- struct io_poll_iocb *poll = io_poll_get_single(req);
-- __poll_t mask = key_to_poll(key);
--
-- /* for instances that support it check for an event match first: */
-- if (mask && !(mask & poll->events))
-- return 0;
--
-- list_del_init(&wait->entry);
--
-- if (poll && poll->head) {
-- bool done;
--
-- spin_lock(&poll->head->lock);
-- done = list_empty(&poll->wait.entry);
-- if (!done)
-- list_del_init(&poll->wait.entry);
-- /* make sure double remove sees this as being gone */
-- wait->private = NULL;
-- spin_unlock(&poll->head->lock);
-- if (!done) {
-- /* use wait func handler, so it matches the rq type */
-- poll->wait.func(&poll->wait, mode, sync, key);
-- }
-- }
-- refcount_dec(&req->refs);
-- return 1;
--}
--
--static void io_init_poll_iocb(struct io_poll_iocb *poll, __poll_t events,
-- wait_queue_func_t wake_func)
--{
-- poll->head = NULL;
-- poll->done = false;
-- poll->canceled = false;
-- poll->events = events;
-- INIT_LIST_HEAD(&poll->wait.entry);
-- init_waitqueue_func_entry(&poll->wait, wake_func);
--}
--
--static void __io_queue_proc(struct io_poll_iocb *poll, struct io_poll_table *pt,
-- struct wait_queue_head *head,
-- struct io_poll_iocb **poll_ptr)
--{
-- struct io_kiocb *req = pt->req;
--
-- /*
-- * The file being polled uses multiple waitqueues for poll handling
-- * (e.g. one for read, one for write). Setup a separate io_poll_iocb
-- * if this happens.
-- */
-- if (unlikely(pt->nr_entries)) {
-- struct io_poll_iocb *poll_one = poll;
--
-- /* already have a 2nd entry, fail a third attempt */
-- if (*poll_ptr) {
-- pt->error = -EINVAL;
-- return;
-- }
-- /* double add on the same waitqueue head, ignore */
-- if (poll->head == head)
-- return;
-- poll = kmalloc(sizeof(*poll), GFP_ATOMIC);
-- if (!poll) {
-- pt->error = -ENOMEM;
-- return;
-- }
-- io_init_poll_iocb(poll, poll_one->events, io_poll_double_wake);
-- refcount_inc(&req->refs);
-- poll->wait.private = req;
-- *poll_ptr = poll;
-- }
--
-- pt->nr_entries++;
-- poll->head = head;
--
-- if (poll->events & EPOLLEXCLUSIVE)
-- add_wait_queue_exclusive(head, &poll->wait);
-- else
-- add_wait_queue(head, &poll->wait);
--}
--
--static void io_async_queue_proc(struct file *file, struct wait_queue_head *head,
-- struct poll_table_struct *p)
--{
-- struct io_poll_table *pt = container_of(p, struct io_poll_table, pt);
-- struct async_poll *apoll = pt->req->apoll;
--
-- __io_queue_proc(&apoll->poll, pt, head, &apoll->double_poll);
--}
--
--static void io_async_task_func(struct callback_head *cb)
--{
-- struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
-- struct async_poll *apoll = req->apoll;
-- struct io_ring_ctx *ctx = req->ctx;
--
-- trace_io_uring_task_run(req->ctx, req->opcode, req->user_data);
--
-- if (io_poll_rewait(req, &apoll->poll)) {
-- spin_unlock_irq(&ctx->completion_lock);
-- percpu_ref_put(&ctx->refs);
-- return;
-- }
--
-- /* If req is still hashed, it cannot have been canceled. Don't check. */
-- if (hash_hashed(&req->hash_node))
-- hash_del(&req->hash_node);
--
-- io_poll_remove_double(req);
-- spin_unlock_irq(&ctx->completion_lock);
--
-- if (!READ_ONCE(apoll->poll.canceled))
-- __io_req_task_submit(req);
-- else
-- __io_req_task_cancel(req, -ECANCELED);
--
-- percpu_ref_put(&ctx->refs);
-- kfree(apoll->double_poll);
-- kfree(apoll);
--}
--
--static int io_async_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
-- void *key)
--{
-- struct io_kiocb *req = wait->private;
-- struct io_poll_iocb *poll = &req->apoll->poll;
--
-- trace_io_uring_poll_wake(req->ctx, req->opcode, req->user_data,
-- key_to_poll(key));
--
-- return __io_async_wake(req, poll, key_to_poll(key), io_async_task_func);
--}
--
--static void io_poll_req_insert(struct io_kiocb *req)
--{
-- struct io_ring_ctx *ctx = req->ctx;
-- struct hlist_head *list;
--
-- list = &ctx->cancel_hash[hash_long(req->user_data, ctx->cancel_hash_bits)];
-- hlist_add_head(&req->hash_node, list);
--}
--
--static __poll_t __io_arm_poll_handler(struct io_kiocb *req,
-- struct io_poll_iocb *poll,
-- struct io_poll_table *ipt, __poll_t mask,
-- wait_queue_func_t wake_func)
-- __acquires(&ctx->completion_lock)
--{
-- struct io_ring_ctx *ctx = req->ctx;
-- bool cancel = false;
--
-- if (req->file->f_op->may_pollfree) {
-- spin_lock_irq(&ctx->completion_lock);
-- return -EOPNOTSUPP;
-- }
--
-- INIT_HLIST_NODE(&req->hash_node);
-- io_init_poll_iocb(poll, mask, wake_func);
-- poll->file = req->file;
-- poll->wait.private = req;
--
-- ipt->pt._key = mask;
-- ipt->req = req;
-- ipt->error = 0;
-- ipt->nr_entries = 0;
--
-- mask = vfs_poll(req->file, &ipt->pt) & poll->events;
-- if (unlikely(!ipt->nr_entries) && !ipt->error)
-- ipt->error = -EINVAL;
--
-- spin_lock_irq(&ctx->completion_lock);
-- if (ipt->error)
-- io_poll_remove_double(req);
-- if (likely(poll->head)) {
-- spin_lock(&poll->head->lock);
-- if (unlikely(list_empty(&poll->wait.entry))) {
-- if (ipt->error)
-- cancel = true;
-- ipt->error = 0;
-- mask = 0;
-- }
-- if (mask || ipt->error)
-- list_del_init(&poll->wait.entry);
-- else if (cancel)
-- WRITE_ONCE(poll->canceled, true);
-- else if (!poll->done) /* actually waiting for an event */
-- io_poll_req_insert(req);
-- spin_unlock(&poll->head->lock);
-- }
--
-- return mask;
--}
--
--static bool io_arm_poll_handler(struct io_kiocb *req)
--{
-- const struct io_op_def *def = &io_op_defs[req->opcode];
-- struct io_ring_ctx *ctx = req->ctx;
-- struct async_poll *apoll;
-- struct io_poll_table ipt;
-- __poll_t mask, ret;
-- int rw;
--
-- if (!req->file || !file_can_poll(req->file))
-- return false;
-- if (req->flags & REQ_F_POLLED)
-- return false;
-- if (def->pollin)
-- rw = READ;
-- else if (def->pollout)
-- rw = WRITE;
-- else
-- return false;
-- /* if we can't nonblock try, then no point in arming a poll handler */
-- if (!io_file_supports_async(req->file, rw))
-- return false;
--
-- apoll = kmalloc(sizeof(*apoll), GFP_ATOMIC);
-- if (unlikely(!apoll))
-- return false;
-- apoll->double_poll = NULL;
--
-- req->flags |= REQ_F_POLLED;
-- req->apoll = apoll;
--
-- mask = 0;
-- if (def->pollin)
-- mask |= POLLIN | POLLRDNORM;
-- if (def->pollout)
-- mask |= POLLOUT | POLLWRNORM;
--
-- /* If reading from MSG_ERRQUEUE using recvmsg, ignore POLLIN */
-- if ((req->opcode == IORING_OP_RECVMSG) &&
-- (req->sr_msg.msg_flags & MSG_ERRQUEUE))
-- mask &= ~POLLIN;
--
-- mask |= POLLERR | POLLPRI;
--
-- ipt.pt._qproc = io_async_queue_proc;
--
-- ret = __io_arm_poll_handler(req, &apoll->poll, &ipt, mask,
-- io_async_wake);
-- if (ret || ipt.error) {
-- io_poll_remove_double(req);
-- spin_unlock_irq(&ctx->completion_lock);
-- kfree(apoll->double_poll);
-- kfree(apoll);
-- return false;
-- }
-- spin_unlock_irq(&ctx->completion_lock);
-- trace_io_uring_poll_arm(ctx, req->opcode, req->user_data, mask,
-- apoll->poll.events);
-- return true;
--}
--
--static bool __io_poll_remove_one(struct io_kiocb *req,
-- struct io_poll_iocb *poll)
--{
-- bool do_complete = false;
--
-- spin_lock(&poll->head->lock);
-- WRITE_ONCE(poll->canceled, true);
-- if (!list_empty(&poll->wait.entry)) {
-- list_del_init(&poll->wait.entry);
-- do_complete = true;
-- }
-- spin_unlock(&poll->head->lock);
-- hash_del(&req->hash_node);
-- return do_complete;
--}
--
--static bool io_poll_remove_one(struct io_kiocb *req)
--{
-- bool do_complete;
--
-- io_poll_remove_double(req);
--
-- if (req->opcode == IORING_OP_POLL_ADD) {
-- do_complete = __io_poll_remove_one(req, &req->poll);
-- } else {
-- struct async_poll *apoll = req->apoll;
--
-- /* non-poll requests have submit ref still */
-- do_complete = __io_poll_remove_one(req, &apoll->poll);
-- if (do_complete) {
-- io_put_req(req);
-- kfree(apoll->double_poll);
-- kfree(apoll);
-- }
-- }
--
-- if (do_complete) {
-- io_cqring_fill_event(req, -ECANCELED);
-- io_commit_cqring(req->ctx);
-- req_set_fail_links(req);
-- io_put_req_deferred(req, 1);
-- }
--
-- return do_complete;
--}
--
--/*
-- * Returns true if we found and killed one or more poll requests
-- */
--static bool io_poll_remove_all(struct io_ring_ctx *ctx, struct task_struct *tsk,
-- struct files_struct *files)
--{
-- struct hlist_node *tmp;
-- struct io_kiocb *req;
-- int posted = 0, i;
--
-- spin_lock_irq(&ctx->completion_lock);
-- for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
-- struct hlist_head *list;
--
-- list = &ctx->cancel_hash[i];
-- hlist_for_each_entry_safe(req, tmp, list, hash_node) {
-- if (io_match_task(req, tsk, files))
-- posted += io_poll_remove_one(req);
-- }
-- }
-- spin_unlock_irq(&ctx->completion_lock);
--
-- if (posted)
-- io_cqring_ev_posted(ctx);
--
-- return posted != 0;
--}
--
--static int io_poll_cancel(struct io_ring_ctx *ctx, __u64 sqe_addr)
--{
-- struct hlist_head *list;
-- struct io_kiocb *req;
--
-- list = &ctx->cancel_hash[hash_long(sqe_addr, ctx->cancel_hash_bits)];
-- hlist_for_each_entry(req, list, hash_node) {
-- if (sqe_addr != req->user_data)
-- continue;
-- if (io_poll_remove_one(req))
-- return 0;
-- return -EALREADY;
-- }
--
-- return -ENOENT;
--}
--
--static int io_poll_remove_prep(struct io_kiocb *req,
-- const struct io_uring_sqe *sqe)
--{
-- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-- return -EINVAL;
-- if (sqe->ioprio || sqe->off || sqe->len || sqe->buf_index ||
-- sqe->poll_events)
-- return -EINVAL;
--
-- req->poll.addr = READ_ONCE(sqe->addr);
-- return 0;
--}
--
--/*
-- * Find a running poll command that matches one specified in sqe->addr,
-- * and remove it if found.
-- */
--static int io_poll_remove(struct io_kiocb *req)
--{
-- struct io_ring_ctx *ctx = req->ctx;
-- u64 addr;
-- int ret;
--
-- addr = req->poll.addr;
-- spin_lock_irq(&ctx->completion_lock);
-- ret = io_poll_cancel(ctx, addr);
-- spin_unlock_irq(&ctx->completion_lock);
--
-- if (ret < 0)
-- req_set_fail_links(req);
-- io_req_complete(req, ret);
-- return 0;
--}
--
--static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
-- void *key)
--{
-- struct io_kiocb *req = wait->private;
-- struct io_poll_iocb *poll = &req->poll;
--
-- return __io_async_wake(req, poll, key_to_poll(key), io_poll_task_func);
--}
--
--static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head,
-- struct poll_table_struct *p)
--{
-- struct io_poll_table *pt = container_of(p, struct io_poll_table, pt);
--
-- __io_queue_proc(&pt->req->poll, pt, head, (struct io_poll_iocb **) &pt->req->async_data);
--}
--
--static int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
-- struct io_poll_iocb *poll = &req->poll;
-- u32 events;
--
-- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-- return -EINVAL;
-- if (sqe->addr || sqe->ioprio || sqe->off || sqe->len || sqe->buf_index)
-- return -EINVAL;
--
-- events = READ_ONCE(sqe->poll32_events);
--#ifdef __BIG_ENDIAN
-- events = swahw32(events);
--#endif
-- poll->events = demangle_poll(events) | EPOLLERR | EPOLLHUP |
-- (events & EPOLLEXCLUSIVE);
-- return 0;
--}
--
--static int io_poll_add(struct io_kiocb *req)
--{
-- struct io_poll_iocb *poll = &req->poll;
-- struct io_ring_ctx *ctx = req->ctx;
-- struct io_poll_table ipt;
-- __poll_t mask;
--
-- ipt.pt._qproc = io_poll_queue_proc;
--
-- mask = __io_arm_poll_handler(req, &req->poll, &ipt, poll->events,
-- io_poll_wake);
--
-- if (mask) { /* no async, we'd stolen it */
-- ipt.error = 0;
-- io_poll_complete(req, mask, 0);
-- }
-- spin_unlock_irq(&ctx->completion_lock);
--
-- if (mask) {
-- io_cqring_ev_posted(ctx);
-- io_put_req(req);
-- }
-- return ipt.error;
--}
--
--static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer)
--{
-- struct io_timeout_data *data = container_of(timer,
-- struct io_timeout_data, timer);
-- struct io_kiocb *req = data->req;
-- struct io_ring_ctx *ctx = req->ctx;
-- unsigned long flags;
--
-- spin_lock_irqsave(&ctx->completion_lock, flags);
-- list_del_init(&req->timeout.list);
-- atomic_set(&req->ctx->cq_timeouts,
-- atomic_read(&req->ctx->cq_timeouts) + 1);
--
-- io_cqring_fill_event(req, -ETIME);
-- io_commit_cqring(ctx);
-- spin_unlock_irqrestore(&ctx->completion_lock, flags);
--
-- io_cqring_ev_posted(ctx);
-- req_set_fail_links(req);
-- io_put_req(req);
-- return HRTIMER_NORESTART;
--}
--
--static int __io_timeout_cancel(struct io_kiocb *req)
--{
-- struct io_timeout_data *io = req->async_data;
-- int ret;
--
-- ret = hrtimer_try_to_cancel(&io->timer);
-- if (ret == -1)
-- return -EALREADY;
-- list_del_init(&req->timeout.list);
--
-- req_set_fail_links(req);
-- io_cqring_fill_event(req, -ECANCELED);
-- io_put_req_deferred(req, 1);
-- return 0;
--}
--
--static int io_timeout_cancel(struct io_ring_ctx *ctx, __u64 user_data)
--{
-- struct io_kiocb *req;
-- int ret = -ENOENT;
--
-- list_for_each_entry(req, &ctx->timeout_list, timeout.list) {
-- if (user_data == req->user_data) {
-- ret = 0;
-- break;
-- }
-- }
--
-- if (ret == -ENOENT)
-- return ret;
--
-- return __io_timeout_cancel(req);
--}
--
--static int io_timeout_remove_prep(struct io_kiocb *req,
-- const struct io_uring_sqe *sqe)
--{
-- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-- return -EINVAL;
-- if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
-- return -EINVAL;
-- if (sqe->ioprio || sqe->buf_index || sqe->len || sqe->timeout_flags ||
-- sqe->splice_fd_in)
-- return -EINVAL;
--
-- req->timeout_rem.addr = READ_ONCE(sqe->addr);
-- return 0;
--}
--
--/*
-- * Remove or update an existing timeout command
-- */
--static int io_timeout_remove(struct io_kiocb *req)
--{
-- struct io_ring_ctx *ctx = req->ctx;
-- int ret;
--
-- spin_lock_irq(&ctx->completion_lock);
-- ret = io_timeout_cancel(ctx, req->timeout_rem.addr);
--
-- io_cqring_fill_event(req, ret);
-- io_commit_cqring(ctx);
-- spin_unlock_irq(&ctx->completion_lock);
-- io_cqring_ev_posted(ctx);
-- if (ret < 0)
-- req_set_fail_links(req);
-- io_put_req(req);
-- return 0;
--}
--
--static int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
-- bool is_timeout_link)
--{
-- struct io_timeout_data *data;
-- unsigned flags;
-- u32 off = READ_ONCE(sqe->off);
--
-- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-- return -EINVAL;
-- if (sqe->ioprio || sqe->buf_index || sqe->len != 1 ||
-- sqe->splice_fd_in)
-- return -EINVAL;
-- if (off && is_timeout_link)
-- return -EINVAL;
-- flags = READ_ONCE(sqe->timeout_flags);
-- if (flags & ~IORING_TIMEOUT_ABS)
-- return -EINVAL;
--
-- req->timeout.off = off;
--
-- if (!req->async_data && io_alloc_async_data(req))
-- return -ENOMEM;
--
-- data = req->async_data;
-- data->req = req;
--
-- if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr)))
-- return -EFAULT;
--
-- if (flags & IORING_TIMEOUT_ABS)
-- data->mode = HRTIMER_MODE_ABS;
-- else
-- data->mode = HRTIMER_MODE_REL;
--
-- INIT_LIST_HEAD(&req->timeout.list);
-- hrtimer_init(&data->timer, CLOCK_MONOTONIC, data->mode);
-- return 0;
--}
--
--static int io_timeout(struct io_kiocb *req)
--{
-- struct io_ring_ctx *ctx = req->ctx;
-- struct io_timeout_data *data = req->async_data;
-- struct list_head *entry;
-- u32 tail, off = req->timeout.off;
--
-- spin_lock_irq(&ctx->completion_lock);
--
-- /*
-- * sqe->off holds how many events that need to occur for this
-- * timeout event to be satisfied. If it isn't set, then this is
-- * a pure timeout request, sequence isn't used.
-- */
-- if (io_is_timeout_noseq(req)) {
-- entry = ctx->timeout_list.prev;
-- goto add;
-- }
--
-- tail = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);
-- req->timeout.target_seq = tail + off;
--
-- /* Update the last seq here in case io_flush_timeouts() hasn't.
-- * This is safe because ->completion_lock is held, and submissions
-- * and completions are never mixed in the same ->completion_lock section.
-- */
-- ctx->cq_last_tm_flush = tail;
--
-- /*
-- * Insertion sort, ensuring the first entry in the list is always
-- * the one we need first.
-- */
-- list_for_each_prev(entry, &ctx->timeout_list) {
-- struct io_kiocb *nxt = list_entry(entry, struct io_kiocb,
-- timeout.list);
--
-- if (io_is_timeout_noseq(nxt))
-- continue;
-- /* nxt.seq is behind @tail, otherwise would've been completed */
-- if (off >= nxt->timeout.target_seq - tail)
-- break;
-- }
--add:
-- list_add(&req->timeout.list, entry);
-- data->timer.function = io_timeout_fn;
-- hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode);
-- spin_unlock_irq(&ctx->completion_lock);
-- return 0;
--}
--
--static bool io_cancel_cb(struct io_wq_work *work, void *data)
--{
-- struct io_kiocb *req = container_of(work, struct io_kiocb, work);
--
-- return req->user_data == (unsigned long) data;
--}
--
--static int io_async_cancel_one(struct io_ring_ctx *ctx, void *sqe_addr)
--{
-- enum io_wq_cancel cancel_ret;
-- int ret = 0;
--
-- cancel_ret = io_wq_cancel_cb(ctx->io_wq, io_cancel_cb, sqe_addr, false);
-- switch (cancel_ret) {
-- case IO_WQ_CANCEL_OK:
-- ret = 0;
-- break;
-- case IO_WQ_CANCEL_RUNNING:
-- ret = -EALREADY;
-- break;
-- case IO_WQ_CANCEL_NOTFOUND:
-- ret = -ENOENT;
-- break;
-- }
--
-- return ret;
--}
--
--static void io_async_find_and_cancel(struct io_ring_ctx *ctx,
-- struct io_kiocb *req, __u64 sqe_addr,
-- int success_ret)
--{
-- unsigned long flags;
-- int ret;
--
-- ret = io_async_cancel_one(ctx, (void *) (unsigned long) sqe_addr);
-- if (ret != -ENOENT) {
-- spin_lock_irqsave(&ctx->completion_lock, flags);
-- goto done;
-- }
--
-- spin_lock_irqsave(&ctx->completion_lock, flags);
-- ret = io_timeout_cancel(ctx, sqe_addr);
-- if (ret != -ENOENT)
-- goto done;
-- ret = io_poll_cancel(ctx, sqe_addr);
--done:
-- if (!ret)
-- ret = success_ret;
-- io_cqring_fill_event(req, ret);
-- io_commit_cqring(ctx);
-- spin_unlock_irqrestore(&ctx->completion_lock, flags);
-- io_cqring_ev_posted(ctx);
--
-- if (ret < 0)
-- req_set_fail_links(req);
-- io_put_req(req);
--}
--
--static int io_async_cancel_prep(struct io_kiocb *req,
-- const struct io_uring_sqe *sqe)
--{
-- if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-- return -EINVAL;
-- if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
-- return -EINVAL;
-- if (sqe->ioprio || sqe->off || sqe->len || sqe->cancel_flags ||
-- sqe->splice_fd_in)
-- return -EINVAL;
--
-- req->cancel.addr = READ_ONCE(sqe->addr);
-- return 0;
--}
--
--static int io_async_cancel(struct io_kiocb *req)
--{
-- struct io_ring_ctx *ctx = req->ctx;
--
-- io_async_find_and_cancel(ctx, req, req->cancel.addr, 0);
-- return 0;
--}
--
--static int io_files_update_prep(struct io_kiocb *req,
-- const struct io_uring_sqe *sqe)
--{
-- if (unlikely(req->ctx->flags & IORING_SETUP_SQPOLL))
-- return -EINVAL;
-- if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
-- return -EINVAL;
-- if (sqe->ioprio || sqe->rw_flags)
-- return -EINVAL;
--
-- req->files_update.offset = READ_ONCE(sqe->off);
-- req->files_update.nr_args = READ_ONCE(sqe->len);
-- if (!req->files_update.nr_args)
-- return -EINVAL;
-- req->files_update.arg = READ_ONCE(sqe->addr);
-- return 0;
--}
--
--static int io_files_update(struct io_kiocb *req, bool force_nonblock,
-- struct io_comp_state *cs)
--{
-- struct io_ring_ctx *ctx = req->ctx;
-- struct io_uring_files_update up;
-- int ret;
--
-- if (force_nonblock)
-- return -EAGAIN;
--
-- up.offset = req->files_update.offset;
-- up.fds = req->files_update.arg;
--
-- mutex_lock(&ctx->uring_lock);
-- ret = __io_sqe_files_update(ctx, &up, req->files_update.nr_args);
-- mutex_unlock(&ctx->uring_lock);
--
-- if (ret < 0)
-- req_set_fail_links(req);
-- __io_req_complete(req, ret, 0, cs);
-- return 0;
--}
--
--static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
-- switch (req->opcode) {
-- case IORING_OP_NOP:
-- return 0;
-- case IORING_OP_READV:
-- case IORING_OP_READ_FIXED:
-- case IORING_OP_READ:
-- return io_read_prep(req, sqe);
-- case IORING_OP_WRITEV:
-- case IORING_OP_WRITE_FIXED:
-- case IORING_OP_WRITE:
-- return io_write_prep(req, sqe);
-- case IORING_OP_POLL_ADD:
-- return io_poll_add_prep(req, sqe);
-- case IORING_OP_POLL_REMOVE:
-- return io_poll_remove_prep(req, sqe);
-- case IORING_OP_FSYNC:
-- return io_prep_fsync(req, sqe);
-- case IORING_OP_SYNC_FILE_RANGE:
-- return io_prep_sfr(req, sqe);
-- case IORING_OP_SENDMSG:
-- case IORING_OP_SEND:
-- return io_sendmsg_prep(req, sqe);
-- case IORING_OP_RECVMSG:
-- case IORING_OP_RECV:
-- return io_recvmsg_prep(req, sqe);
-- case IORING_OP_CONNECT:
-- return io_connect_prep(req, sqe);
-- case IORING_OP_TIMEOUT:
-- return io_timeout_prep(req, sqe, false);
-- case IORING_OP_TIMEOUT_REMOVE:
-- return io_timeout_remove_prep(req, sqe);
-- case IORING_OP_ASYNC_CANCEL:
-- return io_async_cancel_prep(req, sqe);
-- case IORING_OP_LINK_TIMEOUT:
-- return io_timeout_prep(req, sqe, true);
-- case IORING_OP_ACCEPT:
-- return io_accept_prep(req, sqe);
-- case IORING_OP_FALLOCATE:
-- return io_fallocate_prep(req, sqe);
-- case IORING_OP_OPENAT:
-- return io_openat_prep(req, sqe);
-- case IORING_OP_CLOSE:
-- return io_close_prep(req, sqe);
-- case IORING_OP_FILES_UPDATE:
-- return io_files_update_prep(req, sqe);
-- case IORING_OP_STATX:
-- return io_statx_prep(req, sqe);
-- case IORING_OP_FADVISE:
-- return io_fadvise_prep(req, sqe);
-- case IORING_OP_MADVISE:
-- return io_madvise_prep(req, sqe);
-- case IORING_OP_OPENAT2:
-- return io_openat2_prep(req, sqe);
-- case IORING_OP_EPOLL_CTL:
-- return io_epoll_ctl_prep(req, sqe);
-- case IORING_OP_SPLICE:
-- return io_splice_prep(req, sqe);
-- case IORING_OP_PROVIDE_BUFFERS:
-- return io_provide_buffers_prep(req, sqe);
-- case IORING_OP_REMOVE_BUFFERS:
-- return io_remove_buffers_prep(req, sqe);
-- case IORING_OP_TEE:
-- return io_tee_prep(req, sqe);
-- }
--
-- printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
-- req->opcode);
-- return-EINVAL;
--}
--
--static int io_req_defer_prep(struct io_kiocb *req,
-- const struct io_uring_sqe *sqe)
--{
-- if (!sqe)
-- return 0;
-- if (io_alloc_async_data(req))
-- return -EAGAIN;
-- return io_req_prep(req, sqe);
--}
--
--static u32 io_get_sequence(struct io_kiocb *req)
--{
-- struct io_kiocb *pos;
-- struct io_ring_ctx *ctx = req->ctx;
-- u32 total_submitted, nr_reqs = 1;
--
-- if (req->flags & REQ_F_LINK_HEAD)
-- list_for_each_entry(pos, &req->link_list, link_list)
-- nr_reqs++;
--
-- total_submitted = ctx->cached_sq_head - ctx->cached_sq_dropped;
-- return total_submitted - nr_reqs;
--}
--
--static int io_req_defer(struct io_kiocb *req, const struct io_uring_sqe *sqe)
--{
-- struct io_ring_ctx *ctx = req->ctx;
-- struct io_defer_entry *de;
-- int ret;
-- u32 seq;
--
-- /* Still need defer if there is pending req in defer list. */
-- if (likely(list_empty_careful(&ctx->defer_list) &&
-- !(req->flags & REQ_F_IO_DRAIN)))
-- return 0;
--
-- seq = io_get_sequence(req);
-- /* Still a chance to pass the sequence check */
-- if (!req_need_defer(req, seq) && list_empty_careful(&ctx->defer_list))
-- return 0;
--
-- if (!req->async_data) {
-- ret = io_req_defer_prep(req, sqe);
-- if (ret)
-- return ret;
-- }
-- io_prep_async_link(req);
-- de = kmalloc(sizeof(*de), GFP_KERNEL);
-- if (!de)
-- return -ENOMEM;
--
-- spin_lock_irq(&ctx->completion_lock);
-- if (!req_need_defer(req, seq) && list_empty(&ctx->defer_list)) {
-- spin_unlock_irq(&ctx->completion_lock);
-- kfree(de);
-- io_queue_async_work(req);
-- return -EIOCBQUEUED;
-- }
--
-- trace_io_uring_defer(ctx, req, req->user_data);
-- de->req = req;
-- de->seq = seq;
-- list_add_tail(&de->list, &ctx->defer_list);
-- spin_unlock_irq(&ctx->completion_lock);
-- return -EIOCBQUEUED;
--}
--
--static void io_req_drop_files(struct io_kiocb *req)
--{
-- struct io_ring_ctx *ctx = req->ctx;
-- struct io_uring_task *tctx = req->task->io_uring;
-- unsigned long flags;
--
-- if (req->work.flags & IO_WQ_WORK_FILES) {
-- put_files_struct(req->work.identity->files);
-- put_nsproxy(req->work.identity->nsproxy);
-- }
-- spin_lock_irqsave(&ctx->inflight_lock, flags);
-- list_del(&req->inflight_entry);
-- spin_unlock_irqrestore(&ctx->inflight_lock, flags);
-- req->flags &= ~REQ_F_INFLIGHT;
-- req->work.flags &= ~IO_WQ_WORK_FILES;
-- if (atomic_read(&tctx->in_idle))
-- wake_up(&tctx->wait);
--}
--
--static void __io_clean_op(struct io_kiocb *req)
--{
-- if (req->flags & REQ_F_BUFFER_SELECTED) {
-- switch (req->opcode) {
-- case IORING_OP_READV:
-- case IORING_OP_READ_FIXED:
-- case IORING_OP_READ:
-- kfree((void *)(unsigned long)req->rw.addr);
-- break;
-- case IORING_OP_RECVMSG:
-- case IORING_OP_RECV:
-- kfree(req->sr_msg.kbuf);
-- break;
-- }
-- req->flags &= ~REQ_F_BUFFER_SELECTED;
-- }
--
-- if (req->flags & REQ_F_NEED_CLEANUP) {
-- switch (req->opcode) {
-- case IORING_OP_READV:
-- case IORING_OP_READ_FIXED:
-- case IORING_OP_READ:
-- case IORING_OP_WRITEV:
-- case IORING_OP_WRITE_FIXED:
-- case IORING_OP_WRITE: {
-- struct io_async_rw *io = req->async_data;
-- if (io->free_iovec)
-- kfree(io->free_iovec);
-- break;
-- }
-- case IORING_OP_RECVMSG:
-- case IORING_OP_SENDMSG: {
-- struct io_async_msghdr *io = req->async_data;
-- if (io->iov != io->fast_iov)
-- kfree(io->iov);
-- break;
-- }
-- case IORING_OP_SPLICE:
-- case IORING_OP_TEE:
-- io_put_file(req, req->splice.file_in,
-- (req->splice.flags & SPLICE_F_FD_IN_FIXED));
-- break;
-- case IORING_OP_OPENAT:
-- case IORING_OP_OPENAT2:
-- if (req->open.filename)
-- putname(req->open.filename);
-- break;
-- }
-- req->flags &= ~REQ_F_NEED_CLEANUP;
-- }
--}
--
--static int io_issue_sqe(struct io_kiocb *req, bool force_nonblock,
-- struct io_comp_state *cs)
--{
-- struct io_ring_ctx *ctx = req->ctx;
-- int ret;
--
-- switch (req->opcode) {
-- case IORING_OP_NOP:
-- ret = io_nop(req, cs);
-- break;
-- case IORING_OP_READV:
-- case IORING_OP_READ_FIXED:
-- case IORING_OP_READ:
-- ret = io_read(req, force_nonblock, cs);
-- break;
-- case IORING_OP_WRITEV:
-- case IORING_OP_WRITE_FIXED:
-- case IORING_OP_WRITE:
-- ret = io_write(req, force_nonblock, cs);
-- break;
-- case IORING_OP_FSYNC:
-- ret = io_fsync(req, force_nonblock);
-- break;
-- case IORING_OP_POLL_ADD:
-- ret = io_poll_add(req);
-- break;
-- case IORING_OP_POLL_REMOVE:
-- ret = io_poll_remove(req);
-- break;
-- case IORING_OP_SYNC_FILE_RANGE:
-- ret = io_sync_file_range(req, force_nonblock);
-- break;
-- case IORING_OP_SENDMSG:
-- ret = io_sendmsg(req, force_nonblock, cs);
-- break;
-- case IORING_OP_SEND:
-- ret = io_send(req, force_nonblock, cs);
-- break;
-- case IORING_OP_RECVMSG:
-- ret = io_recvmsg(req, force_nonblock, cs);
-- break;
-- case IORING_OP_RECV:
-- ret = io_recv(req, force_nonblock, cs);
-- break;
-- case IORING_OP_TIMEOUT:
-- ret = io_timeout(req);
-- break;
-- case IORING_OP_TIMEOUT_REMOVE:
-- ret = io_timeout_remove(req);
-- break;
-- case IORING_OP_ACCEPT:
-- ret = io_accept(req, force_nonblock, cs);
-- break;
-- case IORING_OP_CONNECT:
-- ret = io_connect(req, force_nonblock, cs);
-- break;
-- case IORING_OP_ASYNC_CANCEL:
-- ret = io_async_cancel(req);
-- break;
-- case IORING_OP_FALLOCATE:
-- ret = io_fallocate(req, force_nonblock);
-- break;
-- case IORING_OP_OPENAT:
-- ret = io_openat(req, force_nonblock);
-- break;
-- case IORING_OP_CLOSE:
-- ret = io_close(req, force_nonblock, cs);
-- break;
-- case IORING_OP_FILES_UPDATE:
-- ret = io_files_update(req, force_nonblock, cs);
-- break;
-- case IORING_OP_STATX:
-- ret = io_statx(req, force_nonblock);
-- break;
-- case IORING_OP_FADVISE:
-- ret = io_fadvise(req, force_nonblock);
-- break;
-- case IORING_OP_MADVISE:
-- ret = io_madvise(req, force_nonblock);
-- break;
-- case IORING_OP_OPENAT2:
-- ret = io_openat2(req, force_nonblock);
-- break;
-- case IORING_OP_EPOLL_CTL:
-- ret = io_epoll_ctl(req, force_nonblock, cs);
-- break;
-- case IORING_OP_SPLICE:
-- ret = io_splice(req, force_nonblock);
-- break;
-- case IORING_OP_PROVIDE_BUFFERS:
-- ret = io_provide_buffers(req, force_nonblock, cs);
-- break;
-- case IORING_OP_REMOVE_BUFFERS:
-- ret = io_remove_buffers(req, force_nonblock, cs);
-- break;
-- case IORING_OP_TEE:
-- ret = io_tee(req, force_nonblock);
-- break;
-- default:
-- ret = -EINVAL;
-- break;
-- }
--
-- if (ret)
-- return ret;
--
-- /* If the op doesn't have a file, we're not polling for it */
-- if ((ctx->flags & IORING_SETUP_IOPOLL) && req->file) {
-- const bool in_async = io_wq_current_is_worker();
--
-- /* workqueue context doesn't hold uring_lock, grab it now */
-- if (in_async)
-- mutex_lock(&ctx->uring_lock);
--
-- io_iopoll_req_issued(req);
--
-- if (in_async)
-- mutex_unlock(&ctx->uring_lock);
-- }
--
-- return 0;
--}
--
--static struct io_wq_work *io_wq_submit_work(struct io_wq_work *work)
--{
-- struct io_kiocb *req = container_of(work, struct io_kiocb, work);
-- struct io_kiocb *timeout;
-- int ret = 0;
--
-- timeout = io_prep_linked_timeout(req);
-- if (timeout)
-- io_queue_linked_timeout(timeout);
--
-- /* if NO_CANCEL is set, we must still run the work */
-- if ((work->flags & (IO_WQ_WORK_CANCEL|IO_WQ_WORK_NO_CANCEL)) ==
-- IO_WQ_WORK_CANCEL) {
-- ret = -ECANCELED;
-- }
--
-- if (!ret) {
-- do {
-- ret = io_issue_sqe(req, false, NULL);
-- /*
-- * We can get EAGAIN for polled IO even though we're
-- * forcing a sync submission from here, since we can't
-- * wait for request slots on the block side.
-- */
-- if (ret != -EAGAIN)
-- break;
-- cond_resched();
-- } while (1);
-- }
--
-- if (ret) {
-- struct io_ring_ctx *lock_ctx = NULL;
--
-- if (req->ctx->flags & IORING_SETUP_IOPOLL)
-- lock_ctx = req->ctx;
--
-- /*
-- * io_iopoll_complete() does not hold completion_lock to
-- * complete polled io, so here for polled io, we can not call
-- * io_req_complete() directly, otherwise there maybe concurrent
-- * access to cqring, defer_list, etc, which is not safe. Given
-- * that io_iopoll_complete() is always called under uring_lock,
-- * so here for polled io, we also get uring_lock to complete
-- * it.
-- */
-- if (lock_ctx)
-- mutex_lock(&lock_ctx->uring_lock);
--
-- req_set_fail_links(req);
-- io_req_complete(req, ret);
--
-- if (lock_ctx)
-- mutex_unlock(&lock_ctx->uring_lock);
-- }
--
-- return io_steal_work(req);
--}
--
--static inline struct file *io_file_from_index(struct io_ring_ctx *ctx,
-- int index)
--{
-- struct fixed_file_table *table;
--
-- table = &ctx->file_data->table[index >> IORING_FILE_TABLE_SHIFT];
-- return table->files[index & IORING_FILE_TABLE_MASK];
--}
--
--static struct file *io_file_get(struct io_submit_state *state,
-- struct io_kiocb *req, int fd, bool fixed)
--{
-- struct io_ring_ctx *ctx = req->ctx;
-- struct file *file;
--
-- if (fixed) {
-- if (unlikely((unsigned int)fd >= ctx->nr_user_files))
-- return NULL;
-- fd = array_index_nospec(fd, ctx->nr_user_files);
-- file = io_file_from_index(ctx, fd);
-- if (file) {
-- req->fixed_file_refs = &ctx->file_data->node->refs;
-- percpu_ref_get(req->fixed_file_refs);
-- }
-- } else {
-- trace_io_uring_file_get(ctx, fd);
-- file = __io_file_get(state, fd);
-- }
--
-- if (file && file->f_op == &io_uring_fops &&
-- !(req->flags & REQ_F_INFLIGHT)) {
-- io_req_init_async(req);
-- req->flags |= REQ_F_INFLIGHT;
--
-- spin_lock_irq(&ctx->inflight_lock);
-- list_add(&req->inflight_entry, &ctx->inflight_list);
-- spin_unlock_irq(&ctx->inflight_lock);
-- }
--
-- return file;
--}
--
--static int io_req_set_file(struct io_submit_state *state, struct io_kiocb *req,
-- int fd)
--{
-- bool fixed;
--
-- fixed = (req->flags & REQ_F_FIXED_FILE) != 0;
-- if (unlikely(!fixed && io_async_submit(req->ctx)))
-- return -EBADF;
--
-- req->file = io_file_get(state, req, fd, fixed);
-- if (req->file || io_op_defs[req->opcode].needs_file_no_error)
-- return 0;
-- return -EBADF;
--}
--
--static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer)
--{
-- struct io_timeout_data *data = container_of(timer,
-- struct io_timeout_data, timer);
-- struct io_kiocb *req = data->req;
-- struct io_ring_ctx *ctx = req->ctx;
-- struct io_kiocb *prev = NULL;
-- unsigned long flags;
--
-- spin_lock_irqsave(&ctx->completion_lock, flags);
--
-- /*
-- * We don't expect the list to be empty, that will only happen if we
-- * race with the completion of the linked work.
-- */
-- if (!list_empty(&req->link_list)) {
-- prev = list_entry(req->link_list.prev, struct io_kiocb,
-- link_list);
-- list_del_init(&req->link_list);
-- if (!refcount_inc_not_zero(&prev->refs))
-- prev = NULL;
-- }
--
-- list_del(&req->timeout.list);
-- spin_unlock_irqrestore(&ctx->completion_lock, flags);
--
-- if (prev) {
-- io_async_find_and_cancel(ctx, req, prev->user_data, -ETIME);
-- io_put_req_deferred(prev, 1);
-- } else {
-- io_cqring_add_event(req, -ETIME, 0);
-- io_put_req_deferred(req, 1);
-- }
-- return HRTIMER_NORESTART;
--}
--
--static void __io_queue_linked_timeout(struct io_kiocb *req)
--{
-- /*
-- * If the list is now empty, then our linked request finished before
-- * we got a chance to setup the timer
-- */
-- if (!list_empty(&req->link_list)) {
-- struct io_timeout_data *data = req->async_data;
--
-- data->timer.function = io_link_timeout_fn;
-- hrtimer_start(&data->timer, timespec64_to_ktime(data->ts),
-- data->mode);
-- }
--}
--
--static void io_queue_linked_timeout(struct io_kiocb *req)
--{
-- struct io_ring_ctx *ctx = req->ctx;
--
-- spin_lock_irq(&ctx->completion_lock);
-- __io_queue_linked_timeout(req);
-- spin_unlock_irq(&ctx->completion_lock);
--
-- /* drop submission reference */
-- io_put_req(req);
--}
--
--static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req)
--{
-- struct io_kiocb *nxt;
--
-- if (!(req->flags & REQ_F_LINK_HEAD))
-- return NULL;
-- if (req->flags & REQ_F_LINK_TIMEOUT)
-- return NULL;
--
-- nxt = list_first_entry_or_null(&req->link_list, struct io_kiocb,
-- link_list);
-- if (!nxt || nxt->opcode != IORING_OP_LINK_TIMEOUT)
-- return NULL;
--
-- nxt->flags |= REQ_F_LTIMEOUT_ACTIVE;
-- req->flags |= REQ_F_LINK_TIMEOUT;
-- return nxt;
--}
--
--static void __io_queue_sqe(struct io_kiocb *req, struct io_comp_state *cs)
--{
-- struct io_kiocb *linked_timeout;
-- const struct cred *old_creds = NULL;
-- int ret;
--
--again:
-- linked_timeout = io_prep_linked_timeout(req);
--
-- if ((req->flags & REQ_F_WORK_INITIALIZED) &&
-- (req->work.flags & IO_WQ_WORK_CREDS) &&
-- req->work.identity->creds != current_cred()) {
-- if (old_creds)
-- revert_creds(old_creds);
-- if (old_creds == req->work.identity->creds)
-- old_creds = NULL; /* restored original creds */
-- else
-- old_creds = override_creds(req->work.identity->creds);
-- }
--
-- ret = io_issue_sqe(req, true, cs);
--
-- /*
-- * We async punt it if the file wasn't marked NOWAIT, or if the file
-- * doesn't support non-blocking read/write attempts
-- */
-- if (ret == -EAGAIN && !(req->flags & REQ_F_NOWAIT)) {
-- if (!io_arm_poll_handler(req)) {
-- /*
-- * Queued up for async execution, worker will release
-- * submit reference when the iocb is actually submitted.
-- */
-- io_queue_async_work(req);
-- }
--
-- if (linked_timeout)
-- io_queue_linked_timeout(linked_timeout);
-- } else if (likely(!ret)) {
-- /* drop submission reference */
-- req = io_put_req_find_next(req);
-- if (linked_timeout)
-- io_queue_linked_timeout(linked_timeout);
--
-- if (req) {
-- if (!(req->flags & REQ_F_FORCE_ASYNC))
-- goto again;
-- io_queue_async_work(req);
-- }
-- } else {
-- /* un-prep timeout, so it'll be killed as any other linked */
-- req->flags &= ~REQ_F_LINK_TIMEOUT;
-- req_set_fail_links(req);
-- io_put_req(req);
-- io_req_complete(req, ret);
-- }
--
-- if (old_creds)
-- revert_creds(old_creds);
--}
--
--static void io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
-- struct io_comp_state *cs)
--{
-- int ret;
--
-- ret = io_req_defer(req, sqe);
-- if (ret) {
-- if (ret != -EIOCBQUEUED) {
--fail_req:
-- req_set_fail_links(req);
-- io_put_req(req);
-- io_req_complete(req, ret);
-- }
-- } else if (req->flags & REQ_F_FORCE_ASYNC) {
-- if (!req->async_data) {
-- ret = io_req_defer_prep(req, sqe);
-- if (unlikely(ret))
-- goto fail_req;
-- }
-- io_queue_async_work(req);
-- } else {
-- if (sqe) {
-- ret = io_req_prep(req, sqe);
-- if (unlikely(ret))
-- goto fail_req;
-- }
-- __io_queue_sqe(req, cs);
-- }
--}
--
--static inline void io_queue_link_head(struct io_kiocb *req,
-- struct io_comp_state *cs)
--{
-- if (unlikely(req->flags & REQ_F_FAIL_LINK)) {
-- io_put_req(req);
-- io_req_complete(req, -ECANCELED);
-- } else
-- io_queue_sqe(req, NULL, cs);
--}
--
--static int io_submit_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
-- struct io_kiocb **link, struct io_comp_state *cs)
--{
-- struct io_ring_ctx *ctx = req->ctx;
-- int ret;
--
-- /*
-- * If we already have a head request, queue this one for async
-- * submittal once the head completes. If we don't have a head but
-- * IOSQE_IO_LINK is set in the sqe, start a new head. This one will be
-- * submitted sync once the chain is complete. If none of those
-- * conditions are true (normal request), then just queue it.
-- */
-- if (*link) {
-- struct io_kiocb *head = *link;
--
-- /*
-- * Taking sequential execution of a link, draining both sides
-- * of the link also fullfils IOSQE_IO_DRAIN semantics for all
-- * requests in the link. So, it drains the head and the
-- * next after the link request. The last one is done via
-- * drain_next flag to persist the effect across calls.
-- */
-- if (req->flags & REQ_F_IO_DRAIN) {
-- head->flags |= REQ_F_IO_DRAIN;
-- ctx->drain_next = 1;
-- }
-- ret = io_req_defer_prep(req, sqe);
-- if (unlikely(ret)) {
-- /* fail even hard links since we don't submit */
-- head->flags |= REQ_F_FAIL_LINK;
-- return ret;
-- }
-- trace_io_uring_link(ctx, req, head);
-- list_add_tail(&req->link_list, &head->link_list);
--
-- /* last request of a link, enqueue the link */
-- if (!(req->flags & (REQ_F_LINK | REQ_F_HARDLINK))) {
-- io_queue_link_head(head, cs);
-- *link = NULL;
-- }
-- } else {
-- if (unlikely(ctx->drain_next)) {
-- req->flags |= REQ_F_IO_DRAIN;
-- ctx->drain_next = 0;
-- }
-- if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) {
-- req->flags |= REQ_F_LINK_HEAD;
-- INIT_LIST_HEAD(&req->link_list);
--
-- ret = io_req_defer_prep(req, sqe);
-- if (unlikely(ret))
-- req->flags |= REQ_F_FAIL_LINK;
-- *link = req;
-- } else {
-- io_queue_sqe(req, sqe, cs);
-- }
-- }
--
-- return 0;
--}
--
--/*
-- * Batched submission is done, ensure local IO is flushed out.
-- */
--static void io_submit_state_end(struct io_submit_state *state)
--{
-- if (!list_empty(&state->comp.list))
-- io_submit_flush_completions(&state->comp);
-- blk_finish_plug(&state->plug);
-- io_state_file_put(state);
-- if (state->free_reqs)
-- kmem_cache_free_bulk(req_cachep, state->free_reqs, state->reqs);
--}
--
--/*
-- * Start submission side cache.
-- */
--static void io_submit_state_start(struct io_submit_state *state,
-- struct io_ring_ctx *ctx, unsigned int max_ios)
--{
-- blk_start_plug(&state->plug);
-- state->comp.nr = 0;
-- INIT_LIST_HEAD(&state->comp.list);
-- state->comp.ctx = ctx;
-- state->free_reqs = 0;
-- state->file = NULL;
-- state->ios_left = max_ios;
--}
--
--static void io_commit_sqring(struct io_ring_ctx *ctx)
--{
-- struct io_rings *rings = ctx->rings;
--
-- /*
-- * Ensure any loads from the SQEs are done at this point,
-- * since once we write the new head, the application could
-- * write new data to them.
-- */
-- smp_store_release(&rings->sq.head, ctx->cached_sq_head);
--}
--
--/*
-- * Fetch an sqe, if one is available. Note that sqe_ptr will point to memory
-- * that is mapped by userspace. This means that care needs to be taken to
-- * ensure that reads are stable, as we cannot rely on userspace always
-- * being a good citizen. If members of the sqe are validated and then later
-- * used, it's important that those reads are done through READ_ONCE() to
-- * prevent a re-load down the line.
-- */
--static const struct io_uring_sqe *io_get_sqe(struct io_ring_ctx *ctx)
--{
-- u32 *sq_array = ctx->sq_array;
-- unsigned head;
--
-- /*
-- * The cached sq head (or cq tail) serves two purposes:
-- *
-- * 1) allows us to batch the cost of updating the user visible
-- * head updates.
-- * 2) allows the kernel side to track the head on its own, even
-- * though the application is the one updating it.
-- */
-- head = READ_ONCE(sq_array[ctx->cached_sq_head & ctx->sq_mask]);
-- if (likely(head < ctx->sq_entries))
-- return &ctx->sq_sqes[head];
--
-- /* drop invalid entries */
-- ctx->cached_sq_dropped++;
-- WRITE_ONCE(ctx->rings->sq_dropped, ctx->cached_sq_dropped);
-- return NULL;
--}
--
--static inline void io_consume_sqe(struct io_ring_ctx *ctx)
--{
-- ctx->cached_sq_head++;
--}
--
--/*
-- * Check SQE restrictions (opcode and flags).
-- *
-- * Returns 'true' if SQE is allowed, 'false' otherwise.
-- */
--static inline bool io_check_restriction(struct io_ring_ctx *ctx,
-- struct io_kiocb *req,
-- unsigned int sqe_flags)
--{
-- if (!ctx->restricted)
-- return true;
--
-- if (!test_bit(req->opcode, ctx->restrictions.sqe_op))
-- return false;
--
-- if ((sqe_flags & ctx->restrictions.sqe_flags_required) !=
-- ctx->restrictions.sqe_flags_required)
-- return false;
--
-- if (sqe_flags & ~(ctx->restrictions.sqe_flags_allowed |
-- ctx->restrictions.sqe_flags_required))
-- return false;
--
-- return true;
--}
--
--#define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK| \
-- IOSQE_IO_HARDLINK | IOSQE_ASYNC | \
-- IOSQE_BUFFER_SELECT)
--
--static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
-- const struct io_uring_sqe *sqe,
-- struct io_submit_state *state)
--{
-- unsigned int sqe_flags;
-- int id, ret;
--
-- req->opcode = READ_ONCE(sqe->opcode);
-- req->user_data = READ_ONCE(sqe->user_data);
-- req->async_data = NULL;
-- req->file = NULL;
-- req->ctx = ctx;
-- req->flags = 0;
-- /* one is dropped after submission, the other at completion */
-- refcount_set(&req->refs, 2);
-- req->task = current;
-- req->result = 0;
--
-- if (unlikely(req->opcode >= IORING_OP_LAST))
-- return -EINVAL;
--
-- if (unlikely(io_sq_thread_acquire_mm(ctx, req)))
-- return -EFAULT;
--
-- sqe_flags = READ_ONCE(sqe->flags);
-- /* enforce forwards compatibility on users */
-- if (unlikely(sqe_flags & ~SQE_VALID_FLAGS))
-- return -EINVAL;
--
-- if (unlikely(!io_check_restriction(ctx, req, sqe_flags)))
-- return -EACCES;
--
-- if ((sqe_flags & IOSQE_BUFFER_SELECT) &&
-- !io_op_defs[req->opcode].buffer_select)
-- return -EOPNOTSUPP;
--
-- id = READ_ONCE(sqe->personality);
-- if (id) {
-- struct io_identity *iod;
--
-- iod = xa_load(&ctx->personalities, id);
-- if (unlikely(!iod))
-- return -EINVAL;
-- refcount_inc(&iod->count);
--
-- __io_req_init_async(req);
-- get_cred(iod->creds);
-- req->work.identity = iod;
-- req->work.flags |= IO_WQ_WORK_CREDS;
-- }
--
-- /* same numerical values with corresponding REQ_F_*, safe to copy */
-- req->flags |= sqe_flags;
--
-- if (!io_op_defs[req->opcode].needs_file)
-- return 0;
--
-- ret = io_req_set_file(state, req, READ_ONCE(sqe->fd));
-- state->ios_left--;
-- return ret;
--}
--
--static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr)
--{
-- struct io_submit_state state;
-- struct io_kiocb *link = NULL;
-- int i, submitted = 0;
--
-- /* if we have a backlog and couldn't flush it all, return BUSY */
-- if (test_bit(0, &ctx->sq_check_overflow)) {
-- if (!__io_cqring_overflow_flush(ctx, false, NULL, NULL))
-- return -EBUSY;
-- }
--
-- /* make sure SQ entry isn't read before tail */
-- nr = min3(nr, ctx->sq_entries, io_sqring_entries(ctx));
--
-- if (!percpu_ref_tryget_many(&ctx->refs, nr))
-- return -EAGAIN;
--
-- percpu_counter_add(¤t->io_uring->inflight, nr);
-- refcount_add(nr, ¤t->usage);
--
-- io_submit_state_start(&state, ctx, nr);
--
-- for (i = 0; i < nr; i++) {
-- const struct io_uring_sqe *sqe;
-- struct io_kiocb *req;
-- int err;
--
-- sqe = io_get_sqe(ctx);
-- if (unlikely(!sqe)) {
-- io_consume_sqe(ctx);
-- break;
-- }
-- req = io_alloc_req(ctx, &state);
-- if (unlikely(!req)) {
-- if (!submitted)
-- submitted = -EAGAIN;
-- break;
-- }
-- io_consume_sqe(ctx);
-- /* will complete beyond this point, count as submitted */
-- submitted++;
--
-- err = io_init_req(ctx, req, sqe, &state);
-- if (unlikely(err)) {
--fail_req:
-- io_put_req(req);
-- io_req_complete(req, err);
-- break;
-- }
--
-- trace_io_uring_submit_sqe(ctx, req->opcode, req->user_data,
-- true, io_async_submit(ctx));
-- err = io_submit_sqe(req, sqe, &link, &state.comp);
-- if (err)
-- goto fail_req;
-- }
--
-- if (unlikely(submitted != nr)) {
-- int ref_used = (submitted == -EAGAIN) ? 0 : submitted;
-- struct io_uring_task *tctx = current->io_uring;
-- int unused = nr - ref_used;
--
-- percpu_ref_put_many(&ctx->refs, unused);
-- percpu_counter_sub(&tctx->inflight, unused);
-- put_task_struct_many(current, unused);
-- }
-- if (link)
-- io_queue_link_head(link, &state.comp);
-- io_submit_state_end(&state);
--
-- /* Commit SQ ring head once we've consumed and submitted all SQEs */
-- io_commit_sqring(ctx);
--
-- return submitted;
--}
--
--static inline void io_ring_set_wakeup_flag(struct io_ring_ctx *ctx)
--{
-- /* Tell userspace we may need a wakeup call */
-- spin_lock_irq(&ctx->completion_lock);
-- ctx->rings->sq_flags |= IORING_SQ_NEED_WAKEUP;
-- spin_unlock_irq(&ctx->completion_lock);
--}
--
--static inline void io_ring_clear_wakeup_flag(struct io_ring_ctx *ctx)
--{
-- spin_lock_irq(&ctx->completion_lock);
-- ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP;
-- spin_unlock_irq(&ctx->completion_lock);
--}
--
--static int io_sq_wake_function(struct wait_queue_entry *wqe, unsigned mode,
-- int sync, void *key)
--{
-- struct io_ring_ctx *ctx = container_of(wqe, struct io_ring_ctx, sqo_wait_entry);
-- int ret;
--
-- ret = autoremove_wake_function(wqe, mode, sync, key);
-- if (ret) {
-- unsigned long flags;
--
-- spin_lock_irqsave(&ctx->completion_lock, flags);
-- ctx->rings->sq_flags &= ~IORING_SQ_NEED_WAKEUP;
-- spin_unlock_irqrestore(&ctx->completion_lock, flags);
-- }
-- return ret;
--}
--
--enum sq_ret {
-- SQT_IDLE = 1,
-- SQT_SPIN = 2,
-- SQT_DID_WORK = 4,
--};
--
--static enum sq_ret __io_sq_thread(struct io_ring_ctx *ctx,
-- unsigned long start_jiffies, bool cap_entries)
--{
-- unsigned long timeout = start_jiffies + ctx->sq_thread_idle;
-- struct io_sq_data *sqd = ctx->sq_data;
-- unsigned int to_submit;
-- int ret = 0;
--
--again:
-- if (!list_empty(&ctx->iopoll_list)) {
-- unsigned nr_events = 0;
--
-- mutex_lock(&ctx->uring_lock);
-- if (!list_empty(&ctx->iopoll_list) && !need_resched())
-- io_do_iopoll(ctx, &nr_events, 0);
-- mutex_unlock(&ctx->uring_lock);
-- }
--
-- to_submit = io_sqring_entries(ctx);
--
-- /*
-- * If submit got -EBUSY, flag us as needing the application
-- * to enter the kernel to reap and flush events.
-- */
-- if (!to_submit || ret == -EBUSY || need_resched()) {
-- /*
-- * Drop cur_mm before scheduling, we can't hold it for
-- * long periods (or over schedule()). Do this before
-- * adding ourselves to the waitqueue, as the unuse/drop
-- * may sleep.
-- */
-- io_sq_thread_drop_mm();
--
-- /*
-- * We're polling. If we're within the defined idle
-- * period, then let us spin without work before going
-- * to sleep. The exception is if we got EBUSY doing
-- * more IO, we should wait for the application to
-- * reap events and wake us up.
-- */
-- if (!list_empty(&ctx->iopoll_list) || need_resched() ||
-- (!time_after(jiffies, timeout) && ret != -EBUSY &&
-- !percpu_ref_is_dying(&ctx->refs)))
-- return SQT_SPIN;
--
-- prepare_to_wait(&sqd->wait, &ctx->sqo_wait_entry,
-- TASK_INTERRUPTIBLE);
--
-- /*
-- * While doing polled IO, before going to sleep, we need
-- * to check if there are new reqs added to iopoll_list,
-- * it is because reqs may have been punted to io worker
-- * and will be added to iopoll_list later, hence check
-- * the iopoll_list again.
-- */
-- if ((ctx->flags & IORING_SETUP_IOPOLL) &&
-- !list_empty_careful(&ctx->iopoll_list)) {
-- finish_wait(&sqd->wait, &ctx->sqo_wait_entry);
-- goto again;
-- }
--
-- to_submit = io_sqring_entries(ctx);
-- if (!to_submit || ret == -EBUSY)
-- return SQT_IDLE;
-- }
--
-- finish_wait(&sqd->wait, &ctx->sqo_wait_entry);
-- io_ring_clear_wakeup_flag(ctx);
--
-- /* if we're handling multiple rings, cap submit size for fairness */
-- if (cap_entries && to_submit > 8)
-- to_submit = 8;
--
-- mutex_lock(&ctx->uring_lock);
-- if (likely(!percpu_ref_is_dying(&ctx->refs) && !ctx->sqo_dead))
-- ret = io_submit_sqes(ctx, to_submit);
-- mutex_unlock(&ctx->uring_lock);
--
-- if (!io_sqring_full(ctx) && wq_has_sleeper(&ctx->sqo_sq_wait))
-- wake_up(&ctx->sqo_sq_wait);
--
-- return SQT_DID_WORK;
--}
--
--static void io_sqd_init_new(struct io_sq_data *sqd)
--{
-- struct io_ring_ctx *ctx;
--
-- while (!list_empty(&sqd->ctx_new_list)) {
-- ctx = list_first_entry(&sqd->ctx_new_list, struct io_ring_ctx, sqd_list);
-- init_wait(&ctx->sqo_wait_entry);
-- ctx->sqo_wait_entry.func = io_sq_wake_function;
-- list_move_tail(&ctx->sqd_list, &sqd->ctx_list);
-- complete(&ctx->sq_thread_comp);
-- }
--}
--
--static int io_sq_thread(void *data)
--{
-- struct cgroup_subsys_state *cur_css = NULL;
-- const struct cred *old_cred = NULL;
-- struct io_sq_data *sqd = data;
-- struct io_ring_ctx *ctx;
-- unsigned long start_jiffies;
--
-- start_jiffies = jiffies;
-- while (!kthread_should_stop()) {
-- enum sq_ret ret = 0;
-- bool cap_entries;
--
-- /*
-- * Any changes to the sqd lists are synchronized through the
-- * kthread parking. This synchronizes the thread vs users,
-- * the users are synchronized on the sqd->ctx_lock.
-- */
-- if (kthread_should_park()) {
-- kthread_parkme();
-- /*
-- * When sq thread is unparked, in case the previous park operation
-- * comes from io_put_sq_data(), which means that sq thread is going
-- * to be stopped, so here needs to have a check.
-- */
-- if (kthread_should_stop())
-- break;
-- }
--
-- if (unlikely(!list_empty(&sqd->ctx_new_list)))
-- io_sqd_init_new(sqd);
--
-- cap_entries = !list_is_singular(&sqd->ctx_list);
--
-- list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) {
-- if (current->cred != ctx->creds) {
-- if (old_cred)
-- revert_creds(old_cred);
-- old_cred = override_creds(ctx->creds);
-- }
-- io_sq_thread_associate_blkcg(ctx, &cur_css);
--#ifdef CONFIG_AUDIT
-- current->loginuid = ctx->loginuid;
-- current->sessionid = ctx->sessionid;
--#endif
--
-- ret |= __io_sq_thread(ctx, start_jiffies, cap_entries);
--
-- io_sq_thread_drop_mm();
-- }
--
-- if (ret & SQT_SPIN) {
-- io_run_task_work();
-- io_sq_thread_drop_mm();
-- cond_resched();
-- } else if (ret == SQT_IDLE) {
-- if (kthread_should_park())
-- continue;
-- list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
-- io_ring_set_wakeup_flag(ctx);
-- schedule();
-- start_jiffies = jiffies;
-- list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
-- io_ring_clear_wakeup_flag(ctx);
-- }
-- }
--
-- io_run_task_work();
-- io_sq_thread_drop_mm();
--
-- if (cur_css)
-- io_sq_thread_unassociate_blkcg();
-- if (old_cred)
-- revert_creds(old_cred);
--
-- kthread_parkme();
--
-- return 0;
--}
--
--struct io_wait_queue {
-- struct wait_queue_entry wq;
-- struct io_ring_ctx *ctx;
-- unsigned to_wait;
-- unsigned nr_timeouts;
--};
--
--static inline bool io_should_wake(struct io_wait_queue *iowq)
--{
-- struct io_ring_ctx *ctx = iowq->ctx;
--
-- /*
-- * Wake up if we have enough events, or if a timeout occurred since we
-- * started waiting. For timeouts, we always want to return to userspace,
-- * regardless of event count.
-- */
-- return io_cqring_events(ctx) >= iowq->to_wait ||
-- atomic_read(&ctx->cq_timeouts) != iowq->nr_timeouts;
--}
--
--static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode,
-- int wake_flags, void *key)
--{
-- struct io_wait_queue *iowq = container_of(curr, struct io_wait_queue,
-- wq);
--
-- /*
-- * Cannot safely flush overflowed CQEs from here, ensure we wake up
-- * the task, and the next invocation will do it.
-- */
-- if (io_should_wake(iowq) || test_bit(0, &iowq->ctx->cq_check_overflow))
-- return autoremove_wake_function(curr, mode, wake_flags, key);
-- return -1;
--}
--
--static int io_run_task_work_sig(void)
--{
-- if (io_run_task_work())
-- return 1;
-- if (!signal_pending(current))
-- return 0;
-- if (current->jobctl & JOBCTL_TASK_WORK) {
-- spin_lock_irq(¤t->sighand->siglock);
-- current->jobctl &= ~JOBCTL_TASK_WORK;
-- recalc_sigpending();
-- spin_unlock_irq(¤t->sighand->siglock);
-- return 1;
-- }
-- return -EINTR;
--}
--
--/*
-- * Wait until events become available, if we don't already have some. The
-- * application must reap them itself, as they reside on the shared cq ring.
-- */
--static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
-- const sigset_t __user *sig, size_t sigsz)
--{
-- struct io_wait_queue iowq = {
-- .wq = {
-- .private = current,
-- .func = io_wake_function,
-- .entry = LIST_HEAD_INIT(iowq.wq.entry),
-- },
-- .ctx = ctx,
-- .to_wait = min_events,
-- };
-- struct io_rings *rings = ctx->rings;
-- int ret = 0;
--
-- do {
-- io_cqring_overflow_flush(ctx, false, NULL, NULL);
-- if (io_cqring_events(ctx) >= min_events)
-- return 0;
-- if (!io_run_task_work())
-- break;
-- } while (1);
--
-- if (sig) {
--#ifdef CONFIG_COMPAT
-- if (in_compat_syscall())
-- ret = set_compat_user_sigmask((const compat_sigset_t __user *)sig,
-- sigsz);
-- else
--#endif
-- ret = set_user_sigmask(sig, sigsz);
--
-- if (ret)
-- return ret;
-- }
--
-- iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts);
-- trace_io_uring_cqring_wait(ctx, min_events);
-- do {
-- io_cqring_overflow_flush(ctx, false, NULL, NULL);
-- prepare_to_wait_exclusive(&ctx->wait, &iowq.wq,
-- TASK_INTERRUPTIBLE);
-- /* make sure we run task_work before checking for signals */
-- ret = io_run_task_work_sig();
-- if (ret > 0) {
-- finish_wait(&ctx->wait, &iowq.wq);
-- continue;
-- }
-- else if (ret < 0)
-- break;
-- if (io_should_wake(&iowq))
-- break;
-- if (test_bit(0, &ctx->cq_check_overflow)) {
-- finish_wait(&ctx->wait, &iowq.wq);
-- continue;
-- }
-- schedule();
-- } while (1);
-- finish_wait(&ctx->wait, &iowq.wq);
--
-- restore_saved_sigmask_unless(ret == -EINTR);
--
-- return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0;
--}
--
--static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
--{
--#if defined(CONFIG_UNIX)
-- if (ctx->ring_sock) {
-- struct sock *sock = ctx->ring_sock->sk;
-- struct sk_buff *skb;
--
-- while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
-- kfree_skb(skb);
-- }
--#else
-- int i;
--
-- for (i = 0; i < ctx->nr_user_files; i++) {
-- struct file *file;
--
-- file = io_file_from_index(ctx, i);
-- if (file)
-- fput(file);
-- }
--#endif
--}
--
--static void io_file_ref_kill(struct percpu_ref *ref)
--{
-- struct fixed_file_data *data;
--
-- data = container_of(ref, struct fixed_file_data, refs);
-- complete(&data->done);
--}
--
--static void io_sqe_files_set_node(struct fixed_file_data *file_data,
-- struct fixed_file_ref_node *ref_node)
--{
-- spin_lock_bh(&file_data->lock);
-- file_data->node = ref_node;
-- list_add_tail(&ref_node->node, &file_data->ref_list);
-- spin_unlock_bh(&file_data->lock);
-- percpu_ref_get(&file_data->refs);
--}
--
--
--static void io_sqe_files_kill_node(struct fixed_file_data *data)
--{
-- struct fixed_file_ref_node *ref_node = NULL;
--
-- spin_lock_bh(&data->lock);
-- ref_node = data->node;
-- spin_unlock_bh(&data->lock);
-- if (ref_node)
-- percpu_ref_kill(&ref_node->refs);
--}
--
--static int io_file_ref_quiesce(struct fixed_file_data *data,
-- struct io_ring_ctx *ctx)
--{
-- int ret;
-- struct fixed_file_ref_node *backup_node;
--
-- if (data->quiesce)
-- return -ENXIO;
--
-- data->quiesce = true;
-- do {
-- backup_node = alloc_fixed_file_ref_node(ctx);
-- if (!backup_node)
-- break;
--
-- io_sqe_files_kill_node(data);
-- percpu_ref_kill(&data->refs);
-- flush_delayed_work(&ctx->file_put_work);
--
-- ret = wait_for_completion_interruptible(&data->done);
-- if (!ret)
-- break;
--
-- percpu_ref_resurrect(&data->refs);
-- io_sqe_files_set_node(data, backup_node);
-- backup_node = NULL;
-- reinit_completion(&data->done);
-- mutex_unlock(&ctx->uring_lock);
-- ret = io_run_task_work_sig();
-- mutex_lock(&ctx->uring_lock);
--
-- if (ret < 0)
-- break;
-- backup_node = alloc_fixed_file_ref_node(ctx);
-- ret = -ENOMEM;
-- if (!backup_node)
-- break;
-- } while (1);
-- data->quiesce = false;
--
-- if (backup_node)
-- destroy_fixed_file_ref_node(backup_node);
-- return ret;
--}
--
--static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
--{
-- struct fixed_file_data *data = ctx->file_data;
-- unsigned nr_tables, i;
-- int ret;
--
-- /*
-- * percpu_ref_is_dying() is to stop parallel files unregister
-- * Since we possibly drop uring lock later in this function to
-- * run task work.
-- */
-- if (!data || percpu_ref_is_dying(&data->refs))
-- return -ENXIO;
-- ret = io_file_ref_quiesce(data, ctx);
-- if (ret)
-- return ret;
--
-- __io_sqe_files_unregister(ctx);
-- nr_tables = DIV_ROUND_UP(ctx->nr_user_files, IORING_MAX_FILES_TABLE);
-- for (i = 0; i < nr_tables; i++)
-- kfree(data->table[i].files);
-- kfree(data->table);
-- percpu_ref_exit(&data->refs);
-- kfree(data);
-- ctx->file_data = NULL;
-- ctx->nr_user_files = 0;
-- return 0;
--}
--
--static void io_put_sq_data(struct io_sq_data *sqd)
--{
-- if (refcount_dec_and_test(&sqd->refs)) {
-- /*
-- * The park is a bit of a work-around, without it we get
-- * warning spews on shutdown with SQPOLL set and affinity
-- * set to a single CPU.
-- */
-- if (sqd->thread) {
-- kthread_park(sqd->thread);
-- kthread_stop(sqd->thread);
-- }
--
-- kfree(sqd);
-- }
--}
--
--static struct io_sq_data *io_attach_sq_data(struct io_uring_params *p)
--{
-- struct io_ring_ctx *ctx_attach;
-- struct io_sq_data *sqd;
-- struct fd f;
--
-- f = fdget(p->wq_fd);
-- if (!f.file)
-- return ERR_PTR(-ENXIO);
-- if (f.file->f_op != &io_uring_fops) {
-- fdput(f);
-- return ERR_PTR(-EINVAL);
-- }
--
-- ctx_attach = f.file->private_data;
-- sqd = ctx_attach->sq_data;
-- if (!sqd) {
-- fdput(f);
-- return ERR_PTR(-EINVAL);
-- }
--
-- refcount_inc(&sqd->refs);
-- fdput(f);
-- return sqd;
--}
--
--static struct io_sq_data *io_get_sq_data(struct io_uring_params *p)
--{
-- struct io_sq_data *sqd;
--
-- if (p->flags & IORING_SETUP_ATTACH_WQ)
-- return io_attach_sq_data(p);
--
-- sqd = kzalloc(sizeof(*sqd), GFP_KERNEL);
-- if (!sqd)
-- return ERR_PTR(-ENOMEM);
--
-- refcount_set(&sqd->refs, 1);
-- INIT_LIST_HEAD(&sqd->ctx_list);
-- INIT_LIST_HEAD(&sqd->ctx_new_list);
-- mutex_init(&sqd->ctx_lock);
-- mutex_init(&sqd->lock);
-- init_waitqueue_head(&sqd->wait);
-- return sqd;
--}
--
--static void io_sq_thread_unpark(struct io_sq_data *sqd)
-- __releases(&sqd->lock)
--{
-- if (!sqd->thread)
-- return;
-- kthread_unpark(sqd->thread);
-- mutex_unlock(&sqd->lock);
--}
--
--static void io_sq_thread_park(struct io_sq_data *sqd)
-- __acquires(&sqd->lock)
--{
-- if (!sqd->thread)
-- return;
-- mutex_lock(&sqd->lock);
-- kthread_park(sqd->thread);
--}
--
--static void io_sq_thread_stop(struct io_ring_ctx *ctx)
--{
-- struct io_sq_data *sqd = ctx->sq_data;
--
-- if (sqd) {
-- if (sqd->thread) {
-- /*
-- * We may arrive here from the error branch in
-- * io_sq_offload_create() where the kthread is created
-- * without being waked up, thus wake it up now to make
-- * sure the wait will complete.
-- */
-- wake_up_process(sqd->thread);
-- wait_for_completion(&ctx->sq_thread_comp);
--
-- io_sq_thread_park(sqd);
-- }
--
-- mutex_lock(&sqd->ctx_lock);
-- list_del(&ctx->sqd_list);
-- mutex_unlock(&sqd->ctx_lock);
--
-- if (sqd->thread) {
-- finish_wait(&sqd->wait, &ctx->sqo_wait_entry);
-- io_sq_thread_unpark(sqd);
-- }
--
-- io_put_sq_data(sqd);
-- ctx->sq_data = NULL;
-- }
--}
--
--static void io_finish_async(struct io_ring_ctx *ctx)
--{
-- io_sq_thread_stop(ctx);
--
-- if (ctx->io_wq) {
-- io_wq_destroy(ctx->io_wq);
-- ctx->io_wq = NULL;
-- }
--}
--
--#if defined(CONFIG_UNIX)
--/*
-- * Ensure the UNIX gc is aware of our file set, so we are certain that
-- * the io_uring can be safely unregistered on process exit, even if we have
-- * loops in the file referencing.
-- */
--static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset)
--{
-- struct sock *sk = ctx->ring_sock->sk;
-- struct scm_fp_list *fpl;
-- struct sk_buff *skb;
-- int i, nr_files;
--
-- fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
-- if (!fpl)
-- return -ENOMEM;
--
-- skb = alloc_skb(0, GFP_KERNEL);
-- if (!skb) {
-- kfree(fpl);
-- return -ENOMEM;
-- }
--
-- skb->sk = sk;
-- skb->scm_io_uring = 1;
--
-- nr_files = 0;
-- fpl->user = get_uid(ctx->user);
-- for (i = 0; i < nr; i++) {
-- struct file *file = io_file_from_index(ctx, i + offset);
--
-- if (!file)
-- continue;
-- fpl->fp[nr_files] = get_file(file);
-- unix_inflight(fpl->user, fpl->fp[nr_files]);
-- nr_files++;
-- }
--
-- if (nr_files) {
-- fpl->max = SCM_MAX_FD;
-- fpl->count = nr_files;
-- UNIXCB(skb).fp = fpl;
-- skb->destructor = unix_destruct_scm;
-- refcount_add(skb->truesize, &sk->sk_wmem_alloc);
-- skb_queue_head(&sk->sk_receive_queue, skb);
--
-- for (i = 0; i < nr; i++) {
-- struct file *file = io_file_from_index(ctx, i + offset);
--
-- if (file)
-- fput(file);
-- }
-- } else {
-- kfree_skb(skb);
-- free_uid(fpl->user);
-- kfree(fpl);
-- }
--
-- return 0;
--}
--
--/*
-- * If UNIX sockets are enabled, fd passing can cause a reference cycle which
-- * causes regular reference counting to break down. We rely on the UNIX
-- * garbage collection to take care of this problem for us.
-- */
--static int io_sqe_files_scm(struct io_ring_ctx *ctx)
--{
-- unsigned left, total;
-- int ret = 0;
--
-- total = 0;
-- left = ctx->nr_user_files;
-- while (left) {
-- unsigned this_files = min_t(unsigned, left, SCM_MAX_FD);
--
-- ret = __io_sqe_files_scm(ctx, this_files, total);
-- if (ret)
-- break;
-- left -= this_files;
-- total += this_files;
-- }
--
-- if (!ret)
-- return 0;
--
-- while (total < ctx->nr_user_files) {
-- struct file *file = io_file_from_index(ctx, total);
--
-- if (file)
-- fput(file);
-- total++;
-- }
--
-- return ret;
--}
--#else
--static int io_sqe_files_scm(struct io_ring_ctx *ctx)
--{
-- return 0;
--}
--#endif
--
--static int io_sqe_alloc_file_tables(struct fixed_file_data *file_data,
-- unsigned nr_tables, unsigned nr_files)
--{
-- int i;
--
-- for (i = 0; i < nr_tables; i++) {
-- struct fixed_file_table *table = &file_data->table[i];
-- unsigned this_files;
--
-- this_files = min(nr_files, IORING_MAX_FILES_TABLE);
-- table->files = kcalloc(this_files, sizeof(struct file *),
-- GFP_KERNEL_ACCOUNT);
-- if (!table->files)
-- break;
-- nr_files -= this_files;
-- }
--
-- if (i == nr_tables)
-- return 0;
--
-- for (i = 0; i < nr_tables; i++) {
-- struct fixed_file_table *table = &file_data->table[i];
-- kfree(table->files);
-- }
-- return 1;
--}
--
--static void io_ring_file_put(struct io_ring_ctx *ctx, struct file *file)
--{
--#if defined(CONFIG_UNIX)
-- struct sock *sock = ctx->ring_sock->sk;
-- struct sk_buff_head list, *head = &sock->sk_receive_queue;
-- struct sk_buff *skb;
-- int i;
--
-- __skb_queue_head_init(&list);
--
-- /*
-- * Find the skb that holds this file in its SCM_RIGHTS. When found,
-- * remove this entry and rearrange the file array.
-- */
-- skb = skb_dequeue(head);
-- while (skb) {
-- struct scm_fp_list *fp;
--
-- fp = UNIXCB(skb).fp;
-- for (i = 0; i < fp->count; i++) {
-- int left;
--
-- if (fp->fp[i] != file)
-- continue;
--
-- unix_notinflight(fp->user, fp->fp[i]);
-- left = fp->count - 1 - i;
-- if (left) {
-- memmove(&fp->fp[i], &fp->fp[i + 1],
-- left * sizeof(struct file *));
-- }
-- fp->count--;
-- if (!fp->count) {
-- kfree_skb(skb);
-- skb = NULL;
-- } else {
-- __skb_queue_tail(&list, skb);
-- }
-- fput(file);
-- file = NULL;
-- break;
-- }
--
-- if (!file)
-- break;
--
-- __skb_queue_tail(&list, skb);
--
-- skb = skb_dequeue(head);
-- }
--
-- if (skb_peek(&list)) {
-- spin_lock_irq(&head->lock);
-- while ((skb = __skb_dequeue(&list)) != NULL)
-- __skb_queue_tail(head, skb);
-- spin_unlock_irq(&head->lock);
-- }
--#else
-- fput(file);
--#endif
--}
--
--struct io_file_put {
-- struct list_head list;
-- struct file *file;
--};
--
--static void __io_file_put_work(struct fixed_file_ref_node *ref_node)
--{
-- struct fixed_file_data *file_data = ref_node->file_data;
-- struct io_ring_ctx *ctx = file_data->ctx;
-- struct io_file_put *pfile, *tmp;
--
-- list_for_each_entry_safe(pfile, tmp, &ref_node->file_list, list) {
-- list_del(&pfile->list);
-- io_ring_file_put(ctx, pfile->file);
-- kfree(pfile);
-- }
--
-- percpu_ref_exit(&ref_node->refs);
-- kfree(ref_node);
-- percpu_ref_put(&file_data->refs);
--}
--
--static void io_file_put_work(struct work_struct *work)
--{
-- struct io_ring_ctx *ctx;
-- struct llist_node *node;
--
-- ctx = container_of(work, struct io_ring_ctx, file_put_work.work);
-- node = llist_del_all(&ctx->file_put_llist);
--
-- while (node) {
-- struct fixed_file_ref_node *ref_node;
-- struct llist_node *next = node->next;
--
-- ref_node = llist_entry(node, struct fixed_file_ref_node, llist);
-- __io_file_put_work(ref_node);
-- node = next;
-- }
--}
--
--static void io_file_data_ref_zero(struct percpu_ref *ref)
--{
-- struct fixed_file_ref_node *ref_node;
-- struct fixed_file_data *data;
-- struct io_ring_ctx *ctx;
-- bool first_add = false;
-- int delay = HZ;
--
-- ref_node = container_of(ref, struct fixed_file_ref_node, refs);
-- data = ref_node->file_data;
-- ctx = data->ctx;
--
-- spin_lock_bh(&data->lock);
-- ref_node->done = true;
--
-- while (!list_empty(&data->ref_list)) {
-- ref_node = list_first_entry(&data->ref_list,
-- struct fixed_file_ref_node, node);
-- /* recycle ref nodes in order */
-- if (!ref_node->done)
-- break;
-- list_del(&ref_node->node);
-- first_add |= llist_add(&ref_node->llist, &ctx->file_put_llist);
-- }
-- spin_unlock_bh(&data->lock);
--
-- if (percpu_ref_is_dying(&data->refs))
-- delay = 0;
--
-- if (!delay)
-- mod_delayed_work(system_wq, &ctx->file_put_work, 0);
-- else if (first_add)
-- queue_delayed_work(system_wq, &ctx->file_put_work, delay);
--}
--
--static struct fixed_file_ref_node *alloc_fixed_file_ref_node(
-- struct io_ring_ctx *ctx)
--{
-- struct fixed_file_ref_node *ref_node;
--
-- ref_node = kzalloc(sizeof(*ref_node), GFP_KERNEL);
-- if (!ref_node)
-- return NULL;
--
-- if (percpu_ref_init(&ref_node->refs, io_file_data_ref_zero,
-- 0, GFP_KERNEL)) {
-- kfree(ref_node);
-- return NULL;
-- }
-- INIT_LIST_HEAD(&ref_node->node);
-- INIT_LIST_HEAD(&ref_node->file_list);
-- ref_node->file_data = ctx->file_data;
-- ref_node->done = false;
-- return ref_node;
--}
--
--static void destroy_fixed_file_ref_node(struct fixed_file_ref_node *ref_node)
--{
-- percpu_ref_exit(&ref_node->refs);
-- kfree(ref_node);
--}
--
--static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
-- unsigned nr_args)
--{
-- __s32 __user *fds = (__s32 __user *) arg;
-- unsigned nr_tables, i;
-- struct file *file;
-- int fd, ret = -ENOMEM;
-- struct fixed_file_ref_node *ref_node;
-- struct fixed_file_data *file_data;
--
-- if (ctx->file_data)
-- return -EBUSY;
-- if (!nr_args)
-- return -EINVAL;
-- if (nr_args > IORING_MAX_FIXED_FILES)
-- return -EMFILE;
-- if (nr_args > rlimit(RLIMIT_NOFILE))
-- return -EMFILE;
--
-- file_data = kzalloc(sizeof(*ctx->file_data), GFP_KERNEL_ACCOUNT);
-- if (!file_data)
-- return -ENOMEM;
-- file_data->ctx = ctx;
-- init_completion(&file_data->done);
-- INIT_LIST_HEAD(&file_data->ref_list);
-- spin_lock_init(&file_data->lock);
--
-- nr_tables = DIV_ROUND_UP(nr_args, IORING_MAX_FILES_TABLE);
-- file_data->table = kcalloc(nr_tables, sizeof(*file_data->table),
-- GFP_KERNEL_ACCOUNT);
-- if (!file_data->table)
-- goto out_free;
--
-- if (percpu_ref_init(&file_data->refs, io_file_ref_kill,
-- PERCPU_REF_ALLOW_REINIT, GFP_KERNEL))
-- goto out_free;
--
-- if (io_sqe_alloc_file_tables(file_data, nr_tables, nr_args))
-- goto out_ref;
-- ctx->file_data = file_data;
--
-- for (i = 0; i < nr_args; i++, ctx->nr_user_files++) {
-- struct fixed_file_table *table;
-- unsigned index;
--
-- if (copy_from_user(&fd, &fds[i], sizeof(fd))) {
-- ret = -EFAULT;
-- goto out_fput;
-- }
-- /* allow sparse sets */
-- if (fd == -1)
-- continue;
--
-- file = fget(fd);
-- ret = -EBADF;
-- if (!file)
-- goto out_fput;
--
-- /*
-- * Don't allow io_uring instances to be registered. If UNIX
-- * isn't enabled, then this causes a reference cycle and this
-- * instance can never get freed. If UNIX is enabled we'll
-- * handle it just fine, but there's still no point in allowing
-- * a ring fd as it doesn't support regular read/write anyway.
-- */
-- if (file->f_op == &io_uring_fops) {
-- fput(file);
-- goto out_fput;
-- }
-- table = &file_data->table[i >> IORING_FILE_TABLE_SHIFT];
-- index = i & IORING_FILE_TABLE_MASK;
-- table->files[index] = file;
-- }
--
-- ret = io_sqe_files_scm(ctx);
-- if (ret) {
-- io_sqe_files_unregister(ctx);
-- return ret;
-- }
--
-- ref_node = alloc_fixed_file_ref_node(ctx);
-- if (!ref_node) {
-- io_sqe_files_unregister(ctx);
-- return -ENOMEM;
-- }
--
-- io_sqe_files_set_node(file_data, ref_node);
-- return ret;
--out_fput:
-- for (i = 0; i < ctx->nr_user_files; i++) {
-- file = io_file_from_index(ctx, i);
-- if (file)
-- fput(file);
-- }
-- for (i = 0; i < nr_tables; i++)
-- kfree(file_data->table[i].files);
-- ctx->nr_user_files = 0;
--out_ref:
-- percpu_ref_exit(&file_data->refs);
--out_free:
-- kfree(file_data->table);
-- kfree(file_data);
-- ctx->file_data = NULL;
-- return ret;
--}
--
--static int io_sqe_file_register(struct io_ring_ctx *ctx, struct file *file,
-- int index)
--{
--#if defined(CONFIG_UNIX)
-- struct sock *sock = ctx->ring_sock->sk;
-- struct sk_buff_head *head = &sock->sk_receive_queue;
-- struct sk_buff *skb;
--
-- /*
-- * See if we can merge this file into an existing skb SCM_RIGHTS
-- * file set. If there's no room, fall back to allocating a new skb
-- * and filling it in.
-- */
-- spin_lock_irq(&head->lock);
-- skb = skb_peek(head);
-- if (skb) {
-- struct scm_fp_list *fpl = UNIXCB(skb).fp;
--
-- if (fpl->count < SCM_MAX_FD) {
-- __skb_unlink(skb, head);
-- spin_unlock_irq(&head->lock);
-- fpl->fp[fpl->count] = get_file(file);
-- unix_inflight(fpl->user, fpl->fp[fpl->count]);
-- fpl->count++;
-- spin_lock_irq(&head->lock);
-- __skb_queue_head(head, skb);
-- } else {
-- skb = NULL;
-- }
-- }
-- spin_unlock_irq(&head->lock);
--
-- if (skb) {
-- fput(file);
-- return 0;
-- }
--
-- return __io_sqe_files_scm(ctx, 1, index);
--#else
-- return 0;
--#endif
--}
--
--static int io_queue_file_removal(struct fixed_file_data *data,
-- struct file *file)
--{
-- struct io_file_put *pfile;
-- struct fixed_file_ref_node *ref_node = data->node;
--
-- pfile = kzalloc(sizeof(*pfile), GFP_KERNEL);
-- if (!pfile)
-- return -ENOMEM;
--
-- pfile->file = file;
-- list_add(&pfile->list, &ref_node->file_list);
--
-- return 0;
--}
--
--static int __io_sqe_files_update(struct io_ring_ctx *ctx,
-- struct io_uring_files_update *up,
-- unsigned nr_args)
--{
-- struct fixed_file_data *data = ctx->file_data;
-- struct fixed_file_ref_node *ref_node;
-- struct file *file;
-- __s32 __user *fds;
-- int fd, i, err;
-- __u32 done;
-- bool needs_switch = false;
--
-- if (check_add_overflow(up->offset, nr_args, &done))
-- return -EOVERFLOW;
-- if (done > ctx->nr_user_files)
-- return -EINVAL;
--
-- ref_node = alloc_fixed_file_ref_node(ctx);
-- if (!ref_node)
-- return -ENOMEM;
--
-- done = 0;
-- fds = u64_to_user_ptr(up->fds);
-- while (nr_args) {
-- struct fixed_file_table *table;
-- unsigned index;
--
-- err = 0;
-- if (copy_from_user(&fd, &fds[done], sizeof(fd))) {
-- err = -EFAULT;
-- break;
-- }
-- i = array_index_nospec(up->offset, ctx->nr_user_files);
-- table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
-- index = i & IORING_FILE_TABLE_MASK;
-- if (table->files[index]) {
-- file = table->files[index];
-- err = io_queue_file_removal(data, file);
-- if (err)
-- break;
-- table->files[index] = NULL;
-- needs_switch = true;
-- }
-- if (fd != -1) {
-- file = fget(fd);
-- if (!file) {
-- err = -EBADF;
-- break;
-- }
-- /*
-- * Don't allow io_uring instances to be registered. If
-- * UNIX isn't enabled, then this causes a reference
-- * cycle and this instance can never get freed. If UNIX
-- * is enabled we'll handle it just fine, but there's
-- * still no point in allowing a ring fd as it doesn't
-- * support regular read/write anyway.
-- */
-- if (file->f_op == &io_uring_fops) {
-- fput(file);
-- err = -EBADF;
-- break;
-- }
-- table->files[index] = file;
-- err = io_sqe_file_register(ctx, file, i);
-- if (err) {
-- table->files[index] = NULL;
-- fput(file);
-- break;
-- }
-- }
-- nr_args--;
-- done++;
-- up->offset++;
-- }
--
-- if (needs_switch) {
-- percpu_ref_kill(&data->node->refs);
-- io_sqe_files_set_node(data, ref_node);
-- } else
-- destroy_fixed_file_ref_node(ref_node);
--
-- return done ? done : err;
--}
--
--static int io_sqe_files_update(struct io_ring_ctx *ctx, void __user *arg,
-- unsigned nr_args)
--{
-- struct io_uring_files_update up;
--
-- if (!ctx->file_data)
-- return -ENXIO;
-- if (!nr_args)
-- return -EINVAL;
-- if (copy_from_user(&up, arg, sizeof(up)))
-- return -EFAULT;
-- if (up.resv)
-- return -EINVAL;
--
-- return __io_sqe_files_update(ctx, &up, nr_args);
--}
--
--static void io_free_work(struct io_wq_work *work)
--{
-- struct io_kiocb *req = container_of(work, struct io_kiocb, work);
--
-- /* Consider that io_steal_work() relies on this ref */
-- io_put_req(req);
--}
--
--static int io_init_wq_offload(struct io_ring_ctx *ctx,
-- struct io_uring_params *p)
--{
-- struct io_wq_data data;
-- struct fd f;
-- struct io_ring_ctx *ctx_attach;
-- unsigned int concurrency;
-- int ret = 0;
--
-- data.user = ctx->user;
-- data.free_work = io_free_work;
-- data.do_work = io_wq_submit_work;
--
-- if (!(p->flags & IORING_SETUP_ATTACH_WQ)) {
-- /* Do QD, or 4 * CPUS, whatever is smallest */
-- concurrency = min(ctx->sq_entries, 4 * num_online_cpus());
--
-- ctx->io_wq = io_wq_create(concurrency, &data);
-- if (IS_ERR(ctx->io_wq)) {
-- ret = PTR_ERR(ctx->io_wq);
-- ctx->io_wq = NULL;
-- }
-- return ret;
-- }
--
-- f = fdget(p->wq_fd);
-- if (!f.file)
-- return -EBADF;
--
-- if (f.file->f_op != &io_uring_fops) {
-- ret = -EINVAL;
-- goto out_fput;
-- }
--
-- ctx_attach = f.file->private_data;
-- /* @io_wq is protected by holding the fd */
-- if (!io_wq_get(ctx_attach->io_wq, &data)) {
-- ret = -EINVAL;
-- goto out_fput;
-- }
--
-- ctx->io_wq = ctx_attach->io_wq;
--out_fput:
-- fdput(f);
-- return ret;
--}
--
--static int io_uring_alloc_task_context(struct task_struct *task)
--{
-- struct io_uring_task *tctx;
-- int ret;
--
-- tctx = kmalloc(sizeof(*tctx), GFP_KERNEL);
-- if (unlikely(!tctx))
-- return -ENOMEM;
--
-- ret = percpu_counter_init(&tctx->inflight, 0, GFP_KERNEL);
-- if (unlikely(ret)) {
-- kfree(tctx);
-- return ret;
-- }
--
-- xa_init(&tctx->xa);
-- init_waitqueue_head(&tctx->wait);
-- tctx->last = NULL;
-- atomic_set(&tctx->in_idle, 0);
-- tctx->sqpoll = false;
-- io_init_identity(&tctx->__identity);
-- tctx->identity = &tctx->__identity;
-- task->io_uring = tctx;
-- return 0;
--}
--
--void __io_uring_free(struct task_struct *tsk)
--{
-- struct io_uring_task *tctx = tsk->io_uring;
--
-- WARN_ON_ONCE(!xa_empty(&tctx->xa));
-- WARN_ON_ONCE(refcount_read(&tctx->identity->count) != 1);
-- if (tctx->identity != &tctx->__identity)
-- kfree(tctx->identity);
-- percpu_counter_destroy(&tctx->inflight);
-- kfree(tctx);
-- tsk->io_uring = NULL;
--}
--
--static int io_sq_offload_create(struct io_ring_ctx *ctx,
-- struct io_uring_params *p)
--{
-- int ret;
--
-- if (ctx->flags & IORING_SETUP_SQPOLL) {
-- struct io_sq_data *sqd;
--
-- ret = -EPERM;
-- if (!capable(CAP_SYS_ADMIN))
-- goto err;
--
-- sqd = io_get_sq_data(p);
-- if (IS_ERR(sqd)) {
-- ret = PTR_ERR(sqd);
-- goto err;
-- }
--
-- ctx->sq_data = sqd;
-- io_sq_thread_park(sqd);
-- mutex_lock(&sqd->ctx_lock);
-- list_add(&ctx->sqd_list, &sqd->ctx_new_list);
-- mutex_unlock(&sqd->ctx_lock);
-- io_sq_thread_unpark(sqd);
--
-- ctx->sq_thread_idle = msecs_to_jiffies(p->sq_thread_idle);
-- if (!ctx->sq_thread_idle)
-- ctx->sq_thread_idle = HZ;
--
-- if (sqd->thread)
-- goto done;
--
-- if (p->flags & IORING_SETUP_SQ_AFF) {
-- int cpu = p->sq_thread_cpu;
--
-- ret = -EINVAL;
-- if (cpu >= nr_cpu_ids)
-- goto err;
-- if (!cpu_online(cpu))
-- goto err;
--
-- sqd->thread = kthread_create_on_cpu(io_sq_thread, sqd,
-- cpu, "io_uring-sq");
-- } else {
-- sqd->thread = kthread_create(io_sq_thread, sqd,
-- "io_uring-sq");
-- }
-- if (IS_ERR(sqd->thread)) {
-- ret = PTR_ERR(sqd->thread);
-- sqd->thread = NULL;
-- goto err;
-- }
-- ret = io_uring_alloc_task_context(sqd->thread);
-- if (ret)
-- goto err;
-- } else if (p->flags & IORING_SETUP_SQ_AFF) {
-- /* Can't have SQ_AFF without SQPOLL */
-- ret = -EINVAL;
-- goto err;
-- }
--
--done:
-- ret = io_init_wq_offload(ctx, p);
-- if (ret)
-- goto err;
--
-- return 0;
--err:
-- io_finish_async(ctx);
-- return ret;
--}
--
--static void io_sq_offload_start(struct io_ring_ctx *ctx)
--{
-- struct io_sq_data *sqd = ctx->sq_data;
--
-- ctx->flags &= ~IORING_SETUP_R_DISABLED;
-- if ((ctx->flags & IORING_SETUP_SQPOLL) && sqd && sqd->thread)
-- wake_up_process(sqd->thread);
--}
--
--static inline void __io_unaccount_mem(struct user_struct *user,
-- unsigned long nr_pages)
--{
-- atomic_long_sub(nr_pages, &user->locked_vm);
--}
--
--static inline int __io_account_mem(struct user_struct *user,
-- unsigned long nr_pages)
--{
-- unsigned long page_limit, cur_pages, new_pages;
--
-- /* Don't allow more pages than we can safely lock */
-- page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
--
-- do {
-- cur_pages = atomic_long_read(&user->locked_vm);
-- new_pages = cur_pages + nr_pages;
-- if (new_pages > page_limit)
-- return -ENOMEM;
-- } while (atomic_long_cmpxchg(&user->locked_vm, cur_pages,
-- new_pages) != cur_pages);
--
-- return 0;
--}
--
--static void io_unaccount_mem(struct io_ring_ctx *ctx, unsigned long nr_pages,
-- enum io_mem_account acct)
--{
-- if (ctx->limit_mem)
-- __io_unaccount_mem(ctx->user, nr_pages);
--
-- if (ctx->mm_account) {
-- if (acct == ACCT_LOCKED)
-- ctx->mm_account->locked_vm -= nr_pages;
-- else if (acct == ACCT_PINNED)
-- atomic64_sub(nr_pages, &ctx->mm_account->pinned_vm);
-- }
--}
--
--static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages,
-- enum io_mem_account acct)
--{
-- int ret;
--
-- if (ctx->limit_mem) {
-- ret = __io_account_mem(ctx->user, nr_pages);
-- if (ret)
-- return ret;
-- }
--
-- if (ctx->mm_account) {
-- if (acct == ACCT_LOCKED)
-- ctx->mm_account->locked_vm += nr_pages;
-- else if (acct == ACCT_PINNED)
-- atomic64_add(nr_pages, &ctx->mm_account->pinned_vm);
-- }
--
-- return 0;
--}
--
--static void io_mem_free(void *ptr)
--{
-- struct page *page;
--
-- if (!ptr)
-- return;
--
-- page = virt_to_head_page(ptr);
-- if (put_page_testzero(page))
-- free_compound_page(page);
--}
--
--static void *io_mem_alloc(size_t size)
--{
-- gfp_t gfp_flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP |
-- __GFP_NORETRY;
--
-- return (void *) __get_free_pages(gfp_flags, get_order(size));
--}
--
--static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries,
-- size_t *sq_offset)
--{
-- struct io_rings *rings;
-- size_t off, sq_array_size;
--
-- off = struct_size(rings, cqes, cq_entries);
-- if (off == SIZE_MAX)
-- return SIZE_MAX;
--
--#ifdef CONFIG_SMP
-- off = ALIGN(off, SMP_CACHE_BYTES);
-- if (off == 0)
-- return SIZE_MAX;
--#endif
--
-- if (sq_offset)
-- *sq_offset = off;
--
-- sq_array_size = array_size(sizeof(u32), sq_entries);
-- if (sq_array_size == SIZE_MAX)
-- return SIZE_MAX;
--
-- if (check_add_overflow(off, sq_array_size, &off))
-- return SIZE_MAX;
--
-- return off;
--}
--
--static unsigned long ring_pages(unsigned sq_entries, unsigned cq_entries)
--{
-- size_t pages;
--
-- pages = (size_t)1 << get_order(
-- rings_size(sq_entries, cq_entries, NULL));
-- pages += (size_t)1 << get_order(
-- array_size(sizeof(struct io_uring_sqe), sq_entries));
--
-- return pages;
--}
--
--static int io_sqe_buffer_unregister(struct io_ring_ctx *ctx)
--{
-- int i, j;
--
-- if (!ctx->user_bufs)
-- return -ENXIO;
--
-- for (i = 0; i < ctx->nr_user_bufs; i++) {
-- struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
--
-- for (j = 0; j < imu->nr_bvecs; j++)
-- unpin_user_page(imu->bvec[j].bv_page);
--
-- if (imu->acct_pages)
-- io_unaccount_mem(ctx, imu->acct_pages, ACCT_PINNED);
-- kvfree(imu->bvec);
-- imu->nr_bvecs = 0;
-- }
--
-- kfree(ctx->user_bufs);
-- ctx->user_bufs = NULL;
-- ctx->nr_user_bufs = 0;
-- return 0;
--}
--
--static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst,
-- void __user *arg, unsigned index)
--{
-- struct iovec __user *src;
--
--#ifdef CONFIG_COMPAT
-- if (ctx->compat) {
-- struct compat_iovec __user *ciovs;
-- struct compat_iovec ciov;
--
-- ciovs = (struct compat_iovec __user *) arg;
-- if (copy_from_user(&ciov, &ciovs[index], sizeof(ciov)))
-- return -EFAULT;
--
-- dst->iov_base = u64_to_user_ptr((u64)ciov.iov_base);
-- dst->iov_len = ciov.iov_len;
-- return 0;
-- }
--#endif
-- src = (struct iovec __user *) arg;
-- if (copy_from_user(dst, &src[index], sizeof(*dst)))
-- return -EFAULT;
-- return 0;
--}
--
--/*
-- * Not super efficient, but this is just a registration time. And we do cache
-- * the last compound head, so generally we'll only do a full search if we don't
-- * match that one.
-- *
-- * We check if the given compound head page has already been accounted, to
-- * avoid double accounting it. This allows us to account the full size of the
-- * page, not just the constituent pages of a huge page.
-- */
--static bool headpage_already_acct(struct io_ring_ctx *ctx, struct page **pages,
-- int nr_pages, struct page *hpage)
--{
-- int i, j;
--
-- /* check current page array */
-- for (i = 0; i < nr_pages; i++) {
-- if (!PageCompound(pages[i]))
-- continue;
-- if (compound_head(pages[i]) == hpage)
-- return true;
-- }
--
-- /* check previously registered pages */
-- for (i = 0; i < ctx->nr_user_bufs; i++) {
-- struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
--
-- for (j = 0; j < imu->nr_bvecs; j++) {
-- if (!PageCompound(imu->bvec[j].bv_page))
-- continue;
-- if (compound_head(imu->bvec[j].bv_page) == hpage)
-- return true;
-- }
-- }
--
-- return false;
--}
--
--static int io_buffer_account_pin(struct io_ring_ctx *ctx, struct page **pages,
-- int nr_pages, struct io_mapped_ubuf *imu,
-- struct page **last_hpage)
--{
-- int i, ret;
--
-- for (i = 0; i < nr_pages; i++) {
-- if (!PageCompound(pages[i])) {
-- imu->acct_pages++;
-- } else {
-- struct page *hpage;
--
-- hpage = compound_head(pages[i]);
-- if (hpage == *last_hpage)
-- continue;
-- *last_hpage = hpage;
-- if (headpage_already_acct(ctx, pages, i, hpage))
-- continue;
-- imu->acct_pages += page_size(hpage) >> PAGE_SHIFT;
-- }
-- }
--
-- if (!imu->acct_pages)
-- return 0;
--
-- ret = io_account_mem(ctx, imu->acct_pages, ACCT_PINNED);
-- if (ret)
-- imu->acct_pages = 0;
-- return ret;
--}
--
--static int io_sqe_buffer_register(struct io_ring_ctx *ctx, void __user *arg,
-- unsigned nr_args)
--{
-- struct vm_area_struct **vmas = NULL;
-- struct page **pages = NULL;
-- struct page *last_hpage = NULL;
-- int i, j, got_pages = 0;
-- int ret = -EINVAL;
--
-- if (ctx->user_bufs)
-- return -EBUSY;
-- if (!nr_args || nr_args > UIO_MAXIOV)
-- return -EINVAL;
--
-- ctx->user_bufs = kcalloc(nr_args, sizeof(struct io_mapped_ubuf),
-- GFP_KERNEL);
-- if (!ctx->user_bufs)
-- return -ENOMEM;
--
-- for (i = 0; i < nr_args; i++) {
-- struct io_mapped_ubuf *imu = &ctx->user_bufs[i];
-- unsigned long off, start, end, ubuf;
-- int pret, nr_pages;
-- struct iovec iov;
-- size_t size;
--
-- ret = io_copy_iov(ctx, &iov, arg, i);
-- if (ret)
-- goto err;
--
-- /*
-- * Don't impose further limits on the size and buffer
-- * constraints here, we'll -EINVAL later when IO is
-- * submitted if they are wrong.
-- */
-- ret = -EFAULT;
-- if (!iov.iov_base || !iov.iov_len)
-- goto err;
--
-- /* arbitrary limit, but we need something */
-- if (iov.iov_len > SZ_1G)
-- goto err;
--
-- ubuf = (unsigned long) iov.iov_base;
-- end = (ubuf + iov.iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
-- start = ubuf >> PAGE_SHIFT;
-- nr_pages = end - start;
--
-- ret = 0;
-- if (!pages || nr_pages > got_pages) {
-- kvfree(vmas);
-- kvfree(pages);
-- pages = kvmalloc_array(nr_pages, sizeof(struct page *),
-- GFP_KERNEL);
-- vmas = kvmalloc_array(nr_pages,
-- sizeof(struct vm_area_struct *),
-- GFP_KERNEL);
-- if (!pages || !vmas) {
-- ret = -ENOMEM;
-- goto err;
-- }
-- got_pages = nr_pages;
-- }
--
-- imu->bvec = kvmalloc_array(nr_pages, sizeof(struct bio_vec),
-- GFP_KERNEL);
-- ret = -ENOMEM;
-- if (!imu->bvec)
-- goto err;
--
-- ret = 0;
-- mmap_read_lock(current->mm);
-- pret = pin_user_pages(ubuf, nr_pages,
-- FOLL_WRITE | FOLL_LONGTERM,
-- pages, vmas);
-- if (pret == nr_pages) {
-- /* don't support file backed memory */
-- for (j = 0; j < nr_pages; j++) {
-- struct vm_area_struct *vma = vmas[j];
--
-- if (vma->vm_file &&
-- !is_file_hugepages(vma->vm_file)) {
-- ret = -EOPNOTSUPP;
-- break;
-- }
-- }
-- } else {
-- ret = pret < 0 ? pret : -EFAULT;
-- }
-- mmap_read_unlock(current->mm);
-- if (ret) {
-- /*
-- * if we did partial map, or found file backed vmas,
-- * release any pages we did get
-- */
-- if (pret > 0)
-- unpin_user_pages(pages, pret);
-- kvfree(imu->bvec);
-- goto err;
-- }
--
-- ret = io_buffer_account_pin(ctx, pages, pret, imu, &last_hpage);
-- if (ret) {
-- unpin_user_pages(pages, pret);
-- kvfree(imu->bvec);
-- goto err;
-- }
--
-- off = ubuf & ~PAGE_MASK;
-- size = iov.iov_len;
-- for (j = 0; j < nr_pages; j++) {
-- size_t vec_len;
--
-- vec_len = min_t(size_t, size, PAGE_SIZE - off);
-- imu->bvec[j].bv_page = pages[j];
-- imu->bvec[j].bv_len = vec_len;
-- imu->bvec[j].bv_offset = off;
-- off = 0;
-- size -= vec_len;
-- }
-- /* store original address for later verification */
-- imu->ubuf = ubuf;
-- imu->len = iov.iov_len;
-- imu->nr_bvecs = nr_pages;
--
-- ctx->nr_user_bufs++;
-- }
-- kvfree(pages);
-- kvfree(vmas);
-- return 0;
--err:
-- kvfree(pages);
-- kvfree(vmas);
-- io_sqe_buffer_unregister(ctx);
-- return ret;
--}
--
--static int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg)
--{
-- __s32 __user *fds = arg;
-- int fd;
--
-- if (ctx->cq_ev_fd)
-- return -EBUSY;
--
-- if (copy_from_user(&fd, fds, sizeof(*fds)))
-- return -EFAULT;
--
-- ctx->cq_ev_fd = eventfd_ctx_fdget(fd);
-- if (IS_ERR(ctx->cq_ev_fd)) {
-- int ret = PTR_ERR(ctx->cq_ev_fd);
-- ctx->cq_ev_fd = NULL;
-- return ret;
-- }
--
-- return 0;
--}
--
--static int io_eventfd_unregister(struct io_ring_ctx *ctx)
--{
-- if (ctx->cq_ev_fd) {
-- eventfd_ctx_put(ctx->cq_ev_fd);
-- ctx->cq_ev_fd = NULL;
-- return 0;
-- }
--
-- return -ENXIO;
--}
--
--static void io_destroy_buffers(struct io_ring_ctx *ctx)
--{
-- struct io_buffer *buf;
-- unsigned long index;
--
-- xa_for_each(&ctx->io_buffers, index, buf)
-- __io_remove_buffers(ctx, buf, index, -1U);
--}
--
--static void io_ring_ctx_free(struct io_ring_ctx *ctx)
--{
-- io_finish_async(ctx);
-- io_sqe_buffer_unregister(ctx);
--
-- if (ctx->sqo_task) {
-- put_task_struct(ctx->sqo_task);
-- ctx->sqo_task = NULL;
-- }
--
--#ifdef CONFIG_BLK_CGROUP
-- if (ctx->sqo_blkcg_css)
-- css_put(ctx->sqo_blkcg_css);
--#endif
--
-- mutex_lock(&ctx->uring_lock);
-- io_sqe_files_unregister(ctx);
-- mutex_unlock(&ctx->uring_lock);
-- io_eventfd_unregister(ctx);
-- io_destroy_buffers(ctx);
--
--#if defined(CONFIG_UNIX)
-- if (ctx->ring_sock) {
-- ctx->ring_sock->file = NULL; /* so that iput() is called */
-- sock_release(ctx->ring_sock);
-- }
--#endif
--
-- if (ctx->mm_account) {
-- mmdrop(ctx->mm_account);
-- ctx->mm_account = NULL;
-- }
--
-- io_mem_free(ctx->rings);
-- io_mem_free(ctx->sq_sqes);
--
-- percpu_ref_exit(&ctx->refs);
-- free_uid(ctx->user);
-- put_cred(ctx->creds);
-- kfree(ctx->cancel_hash);
-- kmem_cache_free(req_cachep, ctx->fallback_req);
-- kfree(ctx);
--}
--
--static __poll_t io_uring_poll(struct file *file, poll_table *wait)
--{
-- struct io_ring_ctx *ctx = file->private_data;
-- __poll_t mask = 0;
--
-- poll_wait(file, &ctx->cq_wait, wait);
-- /*
-- * synchronizes with barrier from wq_has_sleeper call in
-- * io_commit_cqring
-- */
-- smp_rmb();
-- if (!io_sqring_full(ctx))
-- mask |= EPOLLOUT | EPOLLWRNORM;
--
-- /*
-- * Don't flush cqring overflow list here, just do a simple check.
-- * Otherwise there could possible be ABBA deadlock:
-- * CPU0 CPU1
-- * ---- ----
-- * lock(&ctx->uring_lock);
-- * lock(&ep->mtx);
-- * lock(&ctx->uring_lock);
-- * lock(&ep->mtx);
-- *
-- * Users may get EPOLLIN meanwhile seeing nothing in cqring, this
-- * pushs them to do the flush.
-- */
-- if (io_cqring_events(ctx) || test_bit(0, &ctx->cq_check_overflow))
-- mask |= EPOLLIN | EPOLLRDNORM;
--
-- return mask;
--}
--
--static int io_uring_fasync(int fd, struct file *file, int on)
--{
-- struct io_ring_ctx *ctx = file->private_data;
--
-- return fasync_helper(fd, file, on, &ctx->cq_fasync);
--}
--
--static int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id)
--{
-- struct io_identity *iod;
--
-- iod = xa_erase(&ctx->personalities, id);
-- if (iod) {
-- put_cred(iod->creds);
-- if (refcount_dec_and_test(&iod->count))
-- kfree(iod);
-- return 0;
-- }
--
-- return -EINVAL;
--}
--
--static void io_ring_exit_work(struct work_struct *work)
--{
-- struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx,
-- exit_work);
--
-- /*
-- * If we're doing polled IO and end up having requests being
-- * submitted async (out-of-line), then completions can come in while
-- * we're waiting for refs to drop. We need to reap these manually,
-- * as nobody else will be looking for them.
-- */
-- do {
-- io_iopoll_try_reap_events(ctx);
-- } while (!wait_for_completion_timeout(&ctx->ref_comp, HZ/20));
-- io_ring_ctx_free(ctx);
--}
--
--static bool io_cancel_ctx_cb(struct io_wq_work *work, void *data)
--{
-- struct io_kiocb *req = container_of(work, struct io_kiocb, work);
--
-- return req->ctx == data;
--}
--
--static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
--{
-- unsigned long index;
-- struct io_identify *iod;
--
-- mutex_lock(&ctx->uring_lock);
-- percpu_ref_kill(&ctx->refs);
-- /* if force is set, the ring is going away. always drop after that */
--
-- if (WARN_ON_ONCE((ctx->flags & IORING_SETUP_SQPOLL) && !ctx->sqo_dead))
-- ctx->sqo_dead = 1;
--
-- ctx->cq_overflow_flushed = 1;
-- if (ctx->rings)
-- __io_cqring_overflow_flush(ctx, true, NULL, NULL);
-- mutex_unlock(&ctx->uring_lock);
--
-- io_kill_timeouts(ctx, NULL, NULL);
-- io_poll_remove_all(ctx, NULL, NULL);
--
-- if (ctx->io_wq)
-- io_wq_cancel_cb(ctx->io_wq, io_cancel_ctx_cb, ctx, true);
--
-- /* if we failed setting up the ctx, we might not have any rings */
-- io_iopoll_try_reap_events(ctx);
-- xa_for_each(&ctx->personalities, index, iod)
-- io_unregister_personality(ctx, index);
--
-- /*
-- * Do this upfront, so we won't have a grace period where the ring
-- * is closed but resources aren't reaped yet. This can cause
-- * spurious failure in setting up a new ring.
-- */
-- io_unaccount_mem(ctx, ring_pages(ctx->sq_entries, ctx->cq_entries),
-- ACCT_LOCKED);
--
-- INIT_WORK(&ctx->exit_work, io_ring_exit_work);
-- /*
-- * Use system_unbound_wq to avoid spawning tons of event kworkers
-- * if we're exiting a ton of rings at the same time. It just adds
-- * noise and overhead, there's no discernable change in runtime
-- * over using system_wq.
-- */
-- queue_work(system_unbound_wq, &ctx->exit_work);
--}
--
--static int io_uring_release(struct inode *inode, struct file *file)
--{
-- struct io_ring_ctx *ctx = file->private_data;
--
-- file->private_data = NULL;
-- io_ring_ctx_wait_and_kill(ctx);
-- return 0;
--}
--
--struct io_task_cancel {
-- struct task_struct *task;
-- struct files_struct *files;
--};
--
--static bool io_cancel_task_cb(struct io_wq_work *work, void *data)
--{
-- struct io_kiocb *req = container_of(work, struct io_kiocb, work);
-- struct io_task_cancel *cancel = data;
-- bool ret;
--
-- if (cancel->files && (req->flags & REQ_F_LINK_TIMEOUT)) {
-- unsigned long flags;
-- struct io_ring_ctx *ctx = req->ctx;
--
-- /* protect against races with linked timeouts */
-- spin_lock_irqsave(&ctx->completion_lock, flags);
-- ret = io_match_task(req, cancel->task, cancel->files);
-- spin_unlock_irqrestore(&ctx->completion_lock, flags);
-- } else {
-- ret = io_match_task(req, cancel->task, cancel->files);
-- }
-- return ret;
--}
--
--static void io_cancel_defer_files(struct io_ring_ctx *ctx,
-- struct task_struct *task,
-- struct files_struct *files)
--{
-- struct io_defer_entry *de = NULL;
-- LIST_HEAD(list);
--
-- spin_lock_irq(&ctx->completion_lock);
-- list_for_each_entry_reverse(de, &ctx->defer_list, list) {
-- if (io_match_task(de->req, task, files)) {
-- list_cut_position(&list, &ctx->defer_list, &de->list);
-- break;
-- }
-- }
-- spin_unlock_irq(&ctx->completion_lock);
--
-- while (!list_empty(&list)) {
-- de = list_first_entry(&list, struct io_defer_entry, list);
-- list_del_init(&de->list);
-- req_set_fail_links(de->req);
-- io_put_req(de->req);
-- io_req_complete(de->req, -ECANCELED);
-- kfree(de);
-- }
--}
--
--static int io_uring_count_inflight(struct io_ring_ctx *ctx,
-- struct task_struct *task,
-- struct files_struct *files)
--{
-- struct io_kiocb *req;
-- int cnt = 0;
--
-- spin_lock_irq(&ctx->inflight_lock);
-- list_for_each_entry(req, &ctx->inflight_list, inflight_entry)
-- cnt += io_match_task(req, task, files);
-- spin_unlock_irq(&ctx->inflight_lock);
-- return cnt;
--}
--
--static void io_uring_cancel_files(struct io_ring_ctx *ctx,
-- struct task_struct *task,
-- struct files_struct *files)
--{
-- while (!list_empty_careful(&ctx->inflight_list)) {
-- struct io_task_cancel cancel = { .task = task, .files = files };
-- DEFINE_WAIT(wait);
-- int inflight;
--
-- inflight = io_uring_count_inflight(ctx, task, files);
-- if (!inflight)
-- break;
--
-- io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb, &cancel, true);
-- io_poll_remove_all(ctx, task, files);
-- io_kill_timeouts(ctx, task, files);
-- /* cancellations _may_ trigger task work */
-- io_run_task_work();
--
-- prepare_to_wait(&task->io_uring->wait, &wait,
-- TASK_UNINTERRUPTIBLE);
-- if (inflight == io_uring_count_inflight(ctx, task, files))
-- schedule();
-- finish_wait(&task->io_uring->wait, &wait);
-- }
--}
--
--static void __io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
-- struct task_struct *task)
--{
-- while (1) {
-- struct io_task_cancel cancel = { .task = task, .files = NULL, };
-- enum io_wq_cancel cret;
-- bool ret = false;
--
-- cret = io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb, &cancel, true);
-- if (cret != IO_WQ_CANCEL_NOTFOUND)
-- ret = true;
--
-- /* SQPOLL thread does its own polling */
-- if (!(ctx->flags & IORING_SETUP_SQPOLL)) {
-- while (!list_empty_careful(&ctx->iopoll_list)) {
-- io_iopoll_try_reap_events(ctx);
-- ret = true;
-- }
-- }
--
-- ret |= io_poll_remove_all(ctx, task, NULL);
-- ret |= io_kill_timeouts(ctx, task, NULL);
-- if (!ret)
-- break;
-- io_run_task_work();
-- cond_resched();
-- }
--}
--
--static void io_disable_sqo_submit(struct io_ring_ctx *ctx)
--{
-- mutex_lock(&ctx->uring_lock);
-- ctx->sqo_dead = 1;
-- if (ctx->flags & IORING_SETUP_R_DISABLED)
-- io_sq_offload_start(ctx);
-- mutex_unlock(&ctx->uring_lock);
--
-- /* make sure callers enter the ring to get error */
-- if (ctx->rings)
-- io_ring_set_wakeup_flag(ctx);
--}
--
--/*
-- * We need to iteratively cancel requests, in case a request has dependent
-- * hard links. These persist even for failure of cancelations, hence keep
-- * looping until none are found.
-- */
--static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
-- struct files_struct *files)
--{
-- struct task_struct *task = current;
--
-- if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) {
-- io_disable_sqo_submit(ctx);
-- task = ctx->sq_data->thread;
-- atomic_inc(&task->io_uring->in_idle);
-- io_sq_thread_park(ctx->sq_data);
-- }
--
-- io_cancel_defer_files(ctx, task, files);
-- io_cqring_overflow_flush(ctx, true, task, files);
--
-- if (!files)
-- __io_uring_cancel_task_requests(ctx, task);
-- else
-- io_uring_cancel_files(ctx, task, files);
--
-- if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) {
-- atomic_dec(&task->io_uring->in_idle);
-- io_sq_thread_unpark(ctx->sq_data);
-- }
--}
--
--/*
-- * Note that this task has used io_uring. We use it for cancelation purposes.
-- */
--static int io_uring_add_task_file(struct io_ring_ctx *ctx, struct file *file)
--{
-- struct io_uring_task *tctx = current->io_uring;
-- int ret;
--
-- if (unlikely(!tctx)) {
-- ret = io_uring_alloc_task_context(current);
-- if (unlikely(ret))
-- return ret;
-- tctx = current->io_uring;
-- }
-- if (tctx->last != file) {
-- void *old = xa_load(&tctx->xa, (unsigned long)file);
--
-- if (!old) {
-- get_file(file);
-- ret = xa_err(xa_store(&tctx->xa, (unsigned long)file,
-- file, GFP_KERNEL));
-- if (ret) {
-- fput(file);
-- return ret;
-- }
-- }
-- tctx->last = file;
-- }
--
-- /*
-- * This is race safe in that the task itself is doing this, hence it
-- * cannot be going through the exit/cancel paths at the same time.
-- * This cannot be modified while exit/cancel is running.
-- */
-- if (!tctx->sqpoll && (ctx->flags & IORING_SETUP_SQPOLL))
-- tctx->sqpoll = true;
--
-- return 0;
--}
--
--/*
-- * Remove this io_uring_file -> task mapping.
-- */
--static void io_uring_del_task_file(struct file *file)
--{
-- struct io_uring_task *tctx = current->io_uring;
--
-- if (tctx->last == file)
-- tctx->last = NULL;
-- file = xa_erase(&tctx->xa, (unsigned long)file);
-- if (file)
-- fput(file);
--}
--
--static void io_uring_remove_task_files(struct io_uring_task *tctx)
--{
-- struct file *file;
-- unsigned long index;
--
-- xa_for_each(&tctx->xa, index, file)
-- io_uring_del_task_file(file);
--}
--
--void __io_uring_files_cancel(struct files_struct *files)
--{
-- struct io_uring_task *tctx = current->io_uring;
-- struct file *file;
-- unsigned long index;
--
-- /* make sure overflow events are dropped */
-- atomic_inc(&tctx->in_idle);
-- xa_for_each(&tctx->xa, index, file)
-- io_uring_cancel_task_requests(file->private_data, files);
-- atomic_dec(&tctx->in_idle);
--
-- if (files)
-- io_uring_remove_task_files(tctx);
--}
--
--static s64 tctx_inflight(struct io_uring_task *tctx)
--{
-- unsigned long index;
-- struct file *file;
-- s64 inflight;
--
-- inflight = percpu_counter_sum(&tctx->inflight);
-- if (!tctx->sqpoll)
-- return inflight;
--
-- /*
-- * If we have SQPOLL rings, then we need to iterate and find them, and
-- * add the pending count for those.
-- */
-- xa_for_each(&tctx->xa, index, file) {
-- struct io_ring_ctx *ctx = file->private_data;
--
-- if (ctx->flags & IORING_SETUP_SQPOLL) {
-- struct io_uring_task *__tctx = ctx->sqo_task->io_uring;
--
-- inflight += percpu_counter_sum(&__tctx->inflight);
-- }
-- }
--
-- return inflight;
--}
--
--/*
-- * Find any io_uring fd that this task has registered or done IO on, and cancel
-- * requests.
-- */
--void __io_uring_task_cancel(void)
--{
-- struct io_uring_task *tctx = current->io_uring;
-- DEFINE_WAIT(wait);
-- s64 inflight;
--
-- /* make sure overflow events are dropped */
-- atomic_inc(&tctx->in_idle);
--
-- /* trigger io_disable_sqo_submit() */
-- if (tctx->sqpoll)
-- __io_uring_files_cancel(NULL);
--
-- do {
-- /* read completions before cancelations */
-- inflight = tctx_inflight(tctx);
-- if (!inflight)
-- break;
-- __io_uring_files_cancel(NULL);
--
-- prepare_to_wait(&tctx->wait, &wait, TASK_UNINTERRUPTIBLE);
--
-- /*
-- * If we've seen completions, retry without waiting. This
-- * avoids a race where a completion comes in before we did
-- * prepare_to_wait().
-- */
-- if (inflight == tctx_inflight(tctx))
-- schedule();
-- finish_wait(&tctx->wait, &wait);
-- } while (1);
--
-- atomic_dec(&tctx->in_idle);
--
-- io_uring_remove_task_files(tctx);
--}
--
--static int io_uring_flush(struct file *file, void *data)
--{
-- struct io_uring_task *tctx = current->io_uring;
-- struct io_ring_ctx *ctx = file->private_data;
--
-- if (fatal_signal_pending(current) || (current->flags & PF_EXITING))
-- io_uring_cancel_task_requests(ctx, NULL);
--
-- if (!tctx)
-- return 0;
--
-- /* we should have cancelled and erased it before PF_EXITING */
-- WARN_ON_ONCE((current->flags & PF_EXITING) &&
-- xa_load(&tctx->xa, (unsigned long)file));
--
-- /*
-- * fput() is pending, will be 2 if the only other ref is our potential
-- * task file note. If the task is exiting, drop regardless of count.
-- */
-- if (atomic_long_read(&file->f_count) != 2)
-- return 0;
--
-- if (ctx->flags & IORING_SETUP_SQPOLL) {
-- /* there is only one file note, which is owned by sqo_task */
-- WARN_ON_ONCE(ctx->sqo_task != current &&
-- xa_load(&tctx->xa, (unsigned long)file));
-- /* sqo_dead check is for when this happens after cancellation */
-- WARN_ON_ONCE(ctx->sqo_task == current && !ctx->sqo_dead &&
-- !xa_load(&tctx->xa, (unsigned long)file));
--
-- io_disable_sqo_submit(ctx);
-- }
--
-- if (!(ctx->flags & IORING_SETUP_SQPOLL) || ctx->sqo_task == current)
-- io_uring_del_task_file(file);
-- return 0;
--}
--
--static void *io_uring_validate_mmap_request(struct file *file,
-- loff_t pgoff, size_t sz)
--{
-- struct io_ring_ctx *ctx = file->private_data;
-- loff_t offset = pgoff << PAGE_SHIFT;
-- struct page *page;
-- void *ptr;
--
-- switch (offset) {
-- case IORING_OFF_SQ_RING:
-- case IORING_OFF_CQ_RING:
-- ptr = ctx->rings;
-- break;
-- case IORING_OFF_SQES:
-- ptr = ctx->sq_sqes;
-- break;
-- default:
-- return ERR_PTR(-EINVAL);
-- }
--
-- page = virt_to_head_page(ptr);
-- if (sz > page_size(page))
-- return ERR_PTR(-EINVAL);
--
-- return ptr;
--}
--
--#ifdef CONFIG_MMU
--
--static int io_uring_mmap(struct file *file, struct vm_area_struct *vma)
--{
-- size_t sz = vma->vm_end - vma->vm_start;
-- unsigned long pfn;
-- void *ptr;
--
-- ptr = io_uring_validate_mmap_request(file, vma->vm_pgoff, sz);
-- if (IS_ERR(ptr))
-- return PTR_ERR(ptr);
--
-- pfn = virt_to_phys(ptr) >> PAGE_SHIFT;
-- return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot);
--}
--
--#else /* !CONFIG_MMU */
--
--static int io_uring_mmap(struct file *file, struct vm_area_struct *vma)
--{
-- return vma->vm_flags & (VM_SHARED | VM_MAYSHARE) ? 0 : -EINVAL;
--}
--
--static unsigned int io_uring_nommu_mmap_capabilities(struct file *file)
--{
-- return NOMMU_MAP_DIRECT | NOMMU_MAP_READ | NOMMU_MAP_WRITE;
--}
--
--static unsigned long io_uring_nommu_get_unmapped_area(struct file *file,
-- unsigned long addr, unsigned long len,
-- unsigned long pgoff, unsigned long flags)
--{
-- void *ptr;
--
-- ptr = io_uring_validate_mmap_request(file, pgoff, len);
-- if (IS_ERR(ptr))
-- return PTR_ERR(ptr);
--
-- return (unsigned long) ptr;
--}
--
--#endif /* !CONFIG_MMU */
--
--static int io_sqpoll_wait_sq(struct io_ring_ctx *ctx)
--{
-- int ret = 0;
-- DEFINE_WAIT(wait);
--
-- do {
-- if (!io_sqring_full(ctx))
-- break;
--
-- prepare_to_wait(&ctx->sqo_sq_wait, &wait, TASK_INTERRUPTIBLE);
--
-- if (unlikely(ctx->sqo_dead)) {
-- ret = -EOWNERDEAD;
-- break;
-- }
--
-- if (!io_sqring_full(ctx))
-- break;
--
-- schedule();
-- } while (!signal_pending(current));
--
-- finish_wait(&ctx->sqo_sq_wait, &wait);
-- return ret;
--}
--
--SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit,
-- u32, min_complete, u32, flags, const sigset_t __user *, sig,
-- size_t, sigsz)
--{
-- struct io_ring_ctx *ctx;
-- long ret = -EBADF;
-- int submitted = 0;
-- struct fd f;
--
-- io_run_task_work();
--
-- if (flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP |
-- IORING_ENTER_SQ_WAIT))
-- return -EINVAL;
--
-- f = fdget(fd);
-- if (!f.file)
-- return -EBADF;
--
-- ret = -EOPNOTSUPP;
-- if (f.file->f_op != &io_uring_fops)
-- goto out_fput;
--
-- ret = -ENXIO;
-- ctx = f.file->private_data;
-- if (!percpu_ref_tryget(&ctx->refs))
-- goto out_fput;
--
-- ret = -EBADFD;
-- if (ctx->flags & IORING_SETUP_R_DISABLED)
-- goto out;
--
-- /*
-- * For SQ polling, the thread will do all submissions and completions.
-- * Just return the requested submit count, and wake the thread if
-- * we were asked to.
-- */
-- ret = 0;
-- if (ctx->flags & IORING_SETUP_SQPOLL) {
-- io_cqring_overflow_flush(ctx, false, NULL, NULL);
--
-- if (unlikely(ctx->sqo_dead)) {
-- ret = -EOWNERDEAD;
-- goto out;
-- }
-- if (flags & IORING_ENTER_SQ_WAKEUP)
-- wake_up(&ctx->sq_data->wait);
-- if (flags & IORING_ENTER_SQ_WAIT) {
-- ret = io_sqpoll_wait_sq(ctx);
-- if (ret)
-- goto out;
-- }
-- submitted = to_submit;
-- } else if (to_submit) {
-- ret = io_uring_add_task_file(ctx, f.file);
-- if (unlikely(ret))
-- goto out;
-- mutex_lock(&ctx->uring_lock);
-- submitted = io_submit_sqes(ctx, to_submit);
-- mutex_unlock(&ctx->uring_lock);
--
-- if (submitted != to_submit)
-- goto out;
-- }
-- if (flags & IORING_ENTER_GETEVENTS) {
-- min_complete = min(min_complete, ctx->cq_entries);
--
-- /*
-- * When SETUP_IOPOLL and SETUP_SQPOLL are both enabled, user
-- * space applications don't need to do io completion events
-- * polling again, they can rely on io_sq_thread to do polling
-- * work, which can reduce cpu usage and uring_lock contention.
-- */
-- if (ctx->flags & IORING_SETUP_IOPOLL &&
-- !(ctx->flags & IORING_SETUP_SQPOLL)) {
-- ret = io_iopoll_check(ctx, min_complete);
-- } else {
-- ret = io_cqring_wait(ctx, min_complete, sig, sigsz);
-- }
-- }
--
--out:
-- percpu_ref_put(&ctx->refs);
--out_fput:
-- fdput(f);
-- return submitted ? submitted : ret;
--}
--
--#ifdef CONFIG_PROC_FS
--static int io_uring_show_cred(struct seq_file *m, unsigned int id,
-- const struct io_identity *iod)
--{
-- const struct cred *cred = iod->creds;
-- struct user_namespace *uns = seq_user_ns(m);
-- struct group_info *gi;
-- kernel_cap_t cap;
-- unsigned __capi;
-- int g;
--
-- seq_printf(m, "%5d\n", id);
-- seq_put_decimal_ull(m, "\tUid:\t", from_kuid_munged(uns, cred->uid));
-- seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->euid));
-- seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->suid));
-- seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->fsuid));
-- seq_put_decimal_ull(m, "\n\tGid:\t", from_kgid_munged(uns, cred->gid));
-- seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->egid));
-- seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->sgid));
-- seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->fsgid));
-- seq_puts(m, "\n\tGroups:\t");
-- gi = cred->group_info;
-- for (g = 0; g < gi->ngroups; g++) {
-- seq_put_decimal_ull(m, g ? " " : "",
-- from_kgid_munged(uns, gi->gid[g]));
-- }
-- seq_puts(m, "\n\tCapEff:\t");
-- cap = cred->cap_effective;
-- CAP_FOR_EACH_U32(__capi)
-- seq_put_hex_ll(m, NULL, cap.cap[CAP_LAST_U32 - __capi], 8);
-- seq_putc(m, '\n');
-- return 0;
--}
--
--static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m)
--{
-- struct io_sq_data *sq = NULL;
-- bool has_lock;
-- int i;
--
-- /*
-- * Avoid ABBA deadlock between the seq lock and the io_uring mutex,
-- * since fdinfo case grabs it in the opposite direction of normal use
-- * cases. If we fail to get the lock, we just don't iterate any
-- * structures that could be going away outside the io_uring mutex.
-- */
-- has_lock = mutex_trylock(&ctx->uring_lock);
--
-- if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL))
-- sq = ctx->sq_data;
--
-- seq_printf(m, "SqThread:\t%d\n", sq ? task_pid_nr(sq->thread) : -1);
-- seq_printf(m, "SqThreadCpu:\t%d\n", sq ? task_cpu(sq->thread) : -1);
-- seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
-- for (i = 0; has_lock && i < ctx->nr_user_files; i++) {
-- struct fixed_file_table *table;
-- struct file *f;
--
-- table = &ctx->file_data->table[i >> IORING_FILE_TABLE_SHIFT];
-- f = table->files[i & IORING_FILE_TABLE_MASK];
-- if (f)
-- seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname);
-- else
-- seq_printf(m, "%5u: <none>\n", i);
-- }
-- seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs);
-- for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) {
-- struct io_mapped_ubuf *buf = &ctx->user_bufs[i];
--
-- seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf,
-- (unsigned int) buf->len);
-- }
-- if (has_lock && !xa_empty(&ctx->personalities)) {
-- unsigned long index;
-- const struct io_identity *iod;
--
-- seq_printf(m, "Personalities:\n");
-- xa_for_each(&ctx->personalities, index, iod)
-- io_uring_show_cred(m, index, iod);
-- }
-- seq_printf(m, "PollList:\n");
-- spin_lock_irq(&ctx->completion_lock);
-- for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
-- struct hlist_head *list = &ctx->cancel_hash[i];
-- struct io_kiocb *req;
--
-- hlist_for_each_entry(req, list, hash_node)
-- seq_printf(m, " op=%d, task_works=%d\n", req->opcode,
-- req->task->task_works != NULL);
-- }
-- spin_unlock_irq(&ctx->completion_lock);
-- if (has_lock)
-- mutex_unlock(&ctx->uring_lock);
--}
--
--static void io_uring_show_fdinfo(struct seq_file *m, struct file *f)
--{
-- struct io_ring_ctx *ctx = f->private_data;
--
-- if (percpu_ref_tryget(&ctx->refs)) {
-- __io_uring_show_fdinfo(ctx, m);
-- percpu_ref_put(&ctx->refs);
-- }
--}
--#endif
--
--static const struct file_operations io_uring_fops = {
-- .release = io_uring_release,
-- .flush = io_uring_flush,
-- .mmap = io_uring_mmap,
--#ifndef CONFIG_MMU
-- .get_unmapped_area = io_uring_nommu_get_unmapped_area,
-- .mmap_capabilities = io_uring_nommu_mmap_capabilities,
--#endif
-- .poll = io_uring_poll,
-- .fasync = io_uring_fasync,
--#ifdef CONFIG_PROC_FS
-- .show_fdinfo = io_uring_show_fdinfo,
--#endif
--};
--
--static int io_allocate_scq_urings(struct io_ring_ctx *ctx,
-- struct io_uring_params *p)
--{
-- struct io_rings *rings;
-- size_t size, sq_array_offset;
--
-- /* make sure these are sane, as we already accounted them */
-- ctx->sq_entries = p->sq_entries;
-- ctx->cq_entries = p->cq_entries;
--
-- size = rings_size(p->sq_entries, p->cq_entries, &sq_array_offset);
-- if (size == SIZE_MAX)
-- return -EOVERFLOW;
--
-- rings = io_mem_alloc(size);
-- if (!rings)
-- return -ENOMEM;
--
-- ctx->rings = rings;
-- ctx->sq_array = (u32 *)((char *)rings + sq_array_offset);
-- rings->sq_ring_mask = p->sq_entries - 1;
-- rings->cq_ring_mask = p->cq_entries - 1;
-- rings->sq_ring_entries = p->sq_entries;
-- rings->cq_ring_entries = p->cq_entries;
-- ctx->sq_mask = rings->sq_ring_mask;
-- ctx->cq_mask = rings->cq_ring_mask;
--
-- size = array_size(sizeof(struct io_uring_sqe), p->sq_entries);
-- if (size == SIZE_MAX) {
-- io_mem_free(ctx->rings);
-- ctx->rings = NULL;
-- return -EOVERFLOW;
-- }
--
-- ctx->sq_sqes = io_mem_alloc(size);
-- if (!ctx->sq_sqes) {
-- io_mem_free(ctx->rings);
-- ctx->rings = NULL;
-- return -ENOMEM;
-- }
--
-- return 0;
--}
--
--static int io_uring_install_fd(struct io_ring_ctx *ctx, struct file *file)
--{
-- int ret, fd;
--
-- fd = get_unused_fd_flags(O_RDWR | O_CLOEXEC);
-- if (fd < 0)
-- return fd;
--
-- ret = io_uring_add_task_file(ctx, file);
-- if (ret) {
-- put_unused_fd(fd);
-- return ret;
-- }
-- fd_install(fd, file);
-- return fd;
--}
--
--/*
-- * Allocate an anonymous fd, this is what constitutes the application
-- * visible backing of an io_uring instance. The application mmaps this
-- * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
-- * we have to tie this fd to a socket for file garbage collection purposes.
-- */
--static struct file *io_uring_get_file(struct io_ring_ctx *ctx)
--{
-- struct file *file;
--#if defined(CONFIG_UNIX)
-- int ret;
--
-- ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
-- &ctx->ring_sock);
-- if (ret)
-- return ERR_PTR(ret);
--#endif
--
-- file = anon_inode_getfile("[io_uring]", &io_uring_fops, ctx,
-- O_RDWR | O_CLOEXEC);
--#if defined(CONFIG_UNIX)
-- if (IS_ERR(file)) {
-- sock_release(ctx->ring_sock);
-- ctx->ring_sock = NULL;
-- } else {
-- ctx->ring_sock->file = file;
-- }
--#endif
-- return file;
--}
--
--static int io_uring_create(unsigned entries, struct io_uring_params *p,
-- struct io_uring_params __user *params)
--{
-- struct user_struct *user = NULL;
-- struct io_ring_ctx *ctx;
-- struct file *file;
-- bool limit_mem;
-- int ret;
--
-- if (!entries)
-- return -EINVAL;
-- if (entries > IORING_MAX_ENTRIES) {
-- if (!(p->flags & IORING_SETUP_CLAMP))
-- return -EINVAL;
-- entries = IORING_MAX_ENTRIES;
-- }
--
-- /*
-- * Use twice as many entries for the CQ ring. It's possible for the
-- * application to drive a higher depth than the size of the SQ ring,
-- * since the sqes are only used at submission time. This allows for
-- * some flexibility in overcommitting a bit. If the application has
-- * set IORING_SETUP_CQSIZE, it will have passed in the desired number
-- * of CQ ring entries manually.
-- */
-- p->sq_entries = roundup_pow_of_two(entries);
-- if (p->flags & IORING_SETUP_CQSIZE) {
-- /*
-- * If IORING_SETUP_CQSIZE is set, we do the same roundup
-- * to a power-of-two, if it isn't already. We do NOT impose
-- * any cq vs sq ring sizing.
-- */
-- if (!p->cq_entries)
-- return -EINVAL;
-- if (p->cq_entries > IORING_MAX_CQ_ENTRIES) {
-- if (!(p->flags & IORING_SETUP_CLAMP))
-- return -EINVAL;
-- p->cq_entries = IORING_MAX_CQ_ENTRIES;
-- }
-- p->cq_entries = roundup_pow_of_two(p->cq_entries);
-- if (p->cq_entries < p->sq_entries)
-- return -EINVAL;
-- } else {
-- p->cq_entries = 2 * p->sq_entries;
-- }
--
-- user = get_uid(current_user());
-- limit_mem = !capable(CAP_IPC_LOCK);
--
-- if (limit_mem) {
-- ret = __io_account_mem(user,
-- ring_pages(p->sq_entries, p->cq_entries));
-- if (ret) {
-- free_uid(user);
-- return ret;
-- }
-- }
--
-- ctx = io_ring_ctx_alloc(p);
-- if (!ctx) {
-- if (limit_mem)
-- __io_unaccount_mem(user, ring_pages(p->sq_entries,
-- p->cq_entries));
-- free_uid(user);
-- return -ENOMEM;
-- }
-- ctx->compat = in_compat_syscall();
-- ctx->user = user;
-- ctx->creds = get_current_cred();
--#ifdef CONFIG_AUDIT
-- ctx->loginuid = current->loginuid;
-- ctx->sessionid = current->sessionid;
--#endif
-- ctx->sqo_task = get_task_struct(current);
--
-- /*
-- * This is just grabbed for accounting purposes. When a process exits,
-- * the mm is exited and dropped before the files, hence we need to hang
-- * on to this mm purely for the purposes of being able to unaccount
-- * memory (locked/pinned vm). It's not used for anything else.
-- */
-- mmgrab(current->mm);
-- ctx->mm_account = current->mm;
--
--#ifdef CONFIG_BLK_CGROUP
-- /*
-- * The sq thread will belong to the original cgroup it was inited in.
-- * If the cgroup goes offline (e.g. disabling the io controller), then
-- * issued bios will be associated with the closest cgroup later in the
-- * block layer.
-- */
-- rcu_read_lock();
-- ctx->sqo_blkcg_css = blkcg_css();
-- ret = css_tryget_online(ctx->sqo_blkcg_css);
-- rcu_read_unlock();
-- if (!ret) {
-- /* don't init against a dying cgroup, have the user try again */
-- ctx->sqo_blkcg_css = NULL;
-- ret = -ENODEV;
-- goto err;
-- }
--#endif
--
-- /*
-- * Account memory _before_ installing the file descriptor. Once
-- * the descriptor is installed, it can get closed at any time. Also
-- * do this before hitting the general error path, as ring freeing
-- * will un-account as well.
-- */
-- io_account_mem(ctx, ring_pages(p->sq_entries, p->cq_entries),
-- ACCT_LOCKED);
-- ctx->limit_mem = limit_mem;
--
-- ret = io_allocate_scq_urings(ctx, p);
-- if (ret)
-- goto err;
--
-- ret = io_sq_offload_create(ctx, p);
-- if (ret)
-- goto err;
--
-- if (!(p->flags & IORING_SETUP_R_DISABLED))
-- io_sq_offload_start(ctx);
--
-- memset(&p->sq_off, 0, sizeof(p->sq_off));
-- p->sq_off.head = offsetof(struct io_rings, sq.head);
-- p->sq_off.tail = offsetof(struct io_rings, sq.tail);
-- p->sq_off.ring_mask = offsetof(struct io_rings, sq_ring_mask);
-- p->sq_off.ring_entries = offsetof(struct io_rings, sq_ring_entries);
-- p->sq_off.flags = offsetof(struct io_rings, sq_flags);
-- p->sq_off.dropped = offsetof(struct io_rings, sq_dropped);
-- p->sq_off.array = (char *)ctx->sq_array - (char *)ctx->rings;
--
-- memset(&p->cq_off, 0, sizeof(p->cq_off));
-- p->cq_off.head = offsetof(struct io_rings, cq.head);
-- p->cq_off.tail = offsetof(struct io_rings, cq.tail);
-- p->cq_off.ring_mask = offsetof(struct io_rings, cq_ring_mask);
-- p->cq_off.ring_entries = offsetof(struct io_rings, cq_ring_entries);
-- p->cq_off.overflow = offsetof(struct io_rings, cq_overflow);
-- p->cq_off.cqes = offsetof(struct io_rings, cqes);
-- p->cq_off.flags = offsetof(struct io_rings, cq_flags);
--
-- p->features = IORING_FEAT_SINGLE_MMAP | IORING_FEAT_NODROP |
-- IORING_FEAT_SUBMIT_STABLE | IORING_FEAT_RW_CUR_POS |
-- IORING_FEAT_CUR_PERSONALITY | IORING_FEAT_FAST_POLL |
-- IORING_FEAT_POLL_32BITS;
--
-- if (copy_to_user(params, p, sizeof(*p))) {
-- ret = -EFAULT;
-- goto err;
-- }
--
-- file = io_uring_get_file(ctx);
-- if (IS_ERR(file)) {
-- ret = PTR_ERR(file);
-- goto err;
-- }
--
-- /*
-- * Install ring fd as the very last thing, so we don't risk someone
-- * having closed it before we finish setup
-- */
-- ret = io_uring_install_fd(ctx, file);
-- if (ret < 0) {
-- io_disable_sqo_submit(ctx);
-- /* fput will clean it up */
-- fput(file);
-- return ret;
-- }
--
-- trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags);
-- return ret;
--err:
-- io_disable_sqo_submit(ctx);
-- io_ring_ctx_wait_and_kill(ctx);
-- return ret;
--}
--
--/*
-- * Sets up an aio uring context, and returns the fd. Applications asks for a
-- * ring size, we return the actual sq/cq ring sizes (among other things) in the
-- * params structure passed in.
-- */
--static long io_uring_setup(u32 entries, struct io_uring_params __user *params)
--{
-- struct io_uring_params p;
-- int i;
--
-- if (copy_from_user(&p, params, sizeof(p)))
-- return -EFAULT;
-- for (i = 0; i < ARRAY_SIZE(p.resv); i++) {
-- if (p.resv[i])
-- return -EINVAL;
-- }
--
-- if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL |
-- IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE |
-- IORING_SETUP_CLAMP | IORING_SETUP_ATTACH_WQ |
-- IORING_SETUP_R_DISABLED))
-- return -EINVAL;
--
-- return io_uring_create(entries, &p, params);
--}
--
--SYSCALL_DEFINE2(io_uring_setup, u32, entries,
-- struct io_uring_params __user *, params)
--{
-- return io_uring_setup(entries, params);
--}
--
--static int io_probe(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args)
--{
-- struct io_uring_probe *p;
-- size_t size;
-- int i, ret;
--
-- size = struct_size(p, ops, nr_args);
-- if (size == SIZE_MAX)
-- return -EOVERFLOW;
-- p = kzalloc(size, GFP_KERNEL);
-- if (!p)
-- return -ENOMEM;
--
-- ret = -EFAULT;
-- if (copy_from_user(p, arg, size))
-- goto out;
-- ret = -EINVAL;
-- if (memchr_inv(p, 0, size))
-- goto out;
--
-- p->last_op = IORING_OP_LAST - 1;
-- if (nr_args > IORING_OP_LAST)
-- nr_args = IORING_OP_LAST;
--
-- for (i = 0; i < nr_args; i++) {
-- p->ops[i].op = i;
-- if (!io_op_defs[i].not_supported)
-- p->ops[i].flags = IO_URING_OP_SUPPORTED;
-- }
-- p->ops_len = i;
--
-- ret = 0;
-- if (copy_to_user(arg, p, size))
-- ret = -EFAULT;
--out:
-- kfree(p);
-- return ret;
--}
--
--static int io_register_personality(struct io_ring_ctx *ctx)
--{
-- struct io_identity *iod;
-- u32 id;
-- int ret;
--
-- iod = kmalloc(sizeof(*iod), GFP_KERNEL);
-- if (unlikely(!iod))
-- return -ENOMEM;
--
-- io_init_identity(iod);
-- iod->creds = get_current_cred();
--
-- ret = xa_alloc_cyclic(&ctx->personalities, &id, (void *)iod,
-- XA_LIMIT(0, USHRT_MAX), &ctx->pers_next, GFP_KERNEL);
-- if (ret < 0) {
-- put_cred(iod->creds);
-- kfree(iod);
-- return ret;
-- }
-- return id;
--}
--
--static int io_register_restrictions(struct io_ring_ctx *ctx, void __user *arg,
-- unsigned int nr_args)
--{
-- struct io_uring_restriction *res;
-- size_t size;
-- int i, ret;
--
-- /* Restrictions allowed only if rings started disabled */
-- if (!(ctx->flags & IORING_SETUP_R_DISABLED))
-- return -EBADFD;
--
-- /* We allow only a single restrictions registration */
-- if (ctx->restrictions.registered)
-- return -EBUSY;
--
-- if (!arg || nr_args > IORING_MAX_RESTRICTIONS)
-- return -EINVAL;
--
-- size = array_size(nr_args, sizeof(*res));
-- if (size == SIZE_MAX)
-- return -EOVERFLOW;
--
-- res = memdup_user(arg, size);
-- if (IS_ERR(res))
-- return PTR_ERR(res);
--
-- ret = 0;
--
-- for (i = 0; i < nr_args; i++) {
-- switch (res[i].opcode) {
-- case IORING_RESTRICTION_REGISTER_OP:
-- if (res[i].register_op >= IORING_REGISTER_LAST) {
-- ret = -EINVAL;
-- goto out;
-- }
--
-- __set_bit(res[i].register_op,
-- ctx->restrictions.register_op);
-- break;
-- case IORING_RESTRICTION_SQE_OP:
-- if (res[i].sqe_op >= IORING_OP_LAST) {
-- ret = -EINVAL;
-- goto out;
-- }
--
-- __set_bit(res[i].sqe_op, ctx->restrictions.sqe_op);
-- break;
-- case IORING_RESTRICTION_SQE_FLAGS_ALLOWED:
-- ctx->restrictions.sqe_flags_allowed = res[i].sqe_flags;
-- break;
-- case IORING_RESTRICTION_SQE_FLAGS_REQUIRED:
-- ctx->restrictions.sqe_flags_required = res[i].sqe_flags;
-- break;
-- default:
-- ret = -EINVAL;
-- goto out;
-- }
-- }
--
--out:
-- /* Reset all restrictions if an error happened */
-- if (ret != 0)
-- memset(&ctx->restrictions, 0, sizeof(ctx->restrictions));
-- else
-- ctx->restrictions.registered = true;
--
-- kfree(res);
-- return ret;
--}
--
--static int io_register_enable_rings(struct io_ring_ctx *ctx)
--{
-- if (!(ctx->flags & IORING_SETUP_R_DISABLED))
-- return -EBADFD;
--
-- if (ctx->restrictions.registered)
-- ctx->restricted = 1;
--
-- io_sq_offload_start(ctx);
-- return 0;
--}
--
--static bool io_register_op_must_quiesce(int op)
--{
-- switch (op) {
-- case IORING_UNREGISTER_FILES:
-- case IORING_REGISTER_FILES_UPDATE:
-- case IORING_REGISTER_PROBE:
-- case IORING_REGISTER_PERSONALITY:
-- case IORING_UNREGISTER_PERSONALITY:
-- return false;
-- default:
-- return true;
-- }
--}
--
--static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
-- void __user *arg, unsigned nr_args)
-- __releases(ctx->uring_lock)
-- __acquires(ctx->uring_lock)
--{
-- int ret;
--
-- /*
-- * We're inside the ring mutex, if the ref is already dying, then
-- * someone else killed the ctx or is already going through
-- * io_uring_register().
-- */
-- if (percpu_ref_is_dying(&ctx->refs))
-- return -ENXIO;
--
-- if (io_register_op_must_quiesce(opcode)) {
-- percpu_ref_kill(&ctx->refs);
--
-- /*
-- * Drop uring mutex before waiting for references to exit. If
-- * another thread is currently inside io_uring_enter() it might
-- * need to grab the uring_lock to make progress. If we hold it
-- * here across the drain wait, then we can deadlock. It's safe
-- * to drop the mutex here, since no new references will come in
-- * after we've killed the percpu ref.
-- */
-- mutex_unlock(&ctx->uring_lock);
-- do {
-- ret = wait_for_completion_interruptible(&ctx->ref_comp);
-- if (!ret)
-- break;
-- ret = io_run_task_work_sig();
-- if (ret < 0)
-- break;
-- } while (1);
-- mutex_lock(&ctx->uring_lock);
--
-- if (ret) {
-- io_refs_resurrect(&ctx->refs, &ctx->ref_comp);
-- return ret;
-- }
-- }
--
-- if (ctx->restricted) {
-- if (opcode >= IORING_REGISTER_LAST) {
-- ret = -EINVAL;
-- goto out;
-- }
--
-- if (!test_bit(opcode, ctx->restrictions.register_op)) {
-- ret = -EACCES;
-- goto out;
-- }
-- }
--
-- switch (opcode) {
-- case IORING_REGISTER_BUFFERS:
-- ret = io_sqe_buffer_register(ctx, arg, nr_args);
-- break;
-- case IORING_UNREGISTER_BUFFERS:
-- ret = -EINVAL;
-- if (arg || nr_args)
-- break;
-- ret = io_sqe_buffer_unregister(ctx);
-- break;
-- case IORING_REGISTER_FILES:
-- ret = io_sqe_files_register(ctx, arg, nr_args);
-- break;
-- case IORING_UNREGISTER_FILES:
-- ret = -EINVAL;
-- if (arg || nr_args)
-- break;
-- ret = io_sqe_files_unregister(ctx);
-- break;
-- case IORING_REGISTER_FILES_UPDATE:
-- ret = io_sqe_files_update(ctx, arg, nr_args);
-- break;
-- case IORING_REGISTER_EVENTFD:
-- case IORING_REGISTER_EVENTFD_ASYNC:
-- ret = -EINVAL;
-- if (nr_args != 1)
-- break;
-- ret = io_eventfd_register(ctx, arg);
-- if (ret)
-- break;
-- if (opcode == IORING_REGISTER_EVENTFD_ASYNC)
-- ctx->eventfd_async = 1;
-- else
-- ctx->eventfd_async = 0;
-- break;
-- case IORING_UNREGISTER_EVENTFD:
-- ret = -EINVAL;
-- if (arg || nr_args)
-- break;
-- ret = io_eventfd_unregister(ctx);
-- break;
-- case IORING_REGISTER_PROBE:
-- ret = -EINVAL;
-- if (!arg || nr_args > 256)
-- break;
-- ret = io_probe(ctx, arg, nr_args);
-- break;
-- case IORING_REGISTER_PERSONALITY:
-- ret = -EINVAL;
-- if (arg || nr_args)
-- break;
-- ret = io_register_personality(ctx);
-- break;
-- case IORING_UNREGISTER_PERSONALITY:
-- ret = -EINVAL;
-- if (arg)
-- break;
-- ret = io_unregister_personality(ctx, nr_args);
-- break;
-- case IORING_REGISTER_ENABLE_RINGS:
-- ret = -EINVAL;
-- if (arg || nr_args)
-- break;
-- ret = io_register_enable_rings(ctx);
-- break;
-- case IORING_REGISTER_RESTRICTIONS:
-- ret = io_register_restrictions(ctx, arg, nr_args);
-- break;
-- default:
-- ret = -EINVAL;
-- break;
-- }
--
--out:
-- if (io_register_op_must_quiesce(opcode)) {
-- /* bring the ctx back to life */
-- percpu_ref_reinit(&ctx->refs);
-- reinit_completion(&ctx->ref_comp);
-- }
-- return ret;
--}
--
--SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode,
-- void __user *, arg, unsigned int, nr_args)
--{
-- struct io_ring_ctx *ctx;
-- long ret = -EBADF;
-- struct fd f;
--
-- f = fdget(fd);
-- if (!f.file)
-- return -EBADF;
--
-- ret = -EOPNOTSUPP;
-- if (f.file->f_op != &io_uring_fops)
-- goto out_fput;
--
-- ctx = f.file->private_data;
--
-- mutex_lock(&ctx->uring_lock);
-- ret = __io_uring_register(ctx, opcode, arg, nr_args);
-- mutex_unlock(&ctx->uring_lock);
-- trace_io_uring_register(ctx, opcode, ctx->nr_user_files, ctx->nr_user_bufs,
-- ctx->cq_ev_fd != NULL, ret);
--out_fput:
-- fdput(f);
-- return ret;
--}
--
--static int __init io_uring_init(void)
--{
--#define __BUILD_BUG_VERIFY_ELEMENT(stype, eoffset, etype, ename) do { \
-- BUILD_BUG_ON(offsetof(stype, ename) != eoffset); \
-- BUILD_BUG_ON(sizeof(etype) != sizeof_field(stype, ename)); \
--} while (0)
--
--#define BUILD_BUG_SQE_ELEM(eoffset, etype, ename) \
-- __BUILD_BUG_VERIFY_ELEMENT(struct io_uring_sqe, eoffset, etype, ename)
-- BUILD_BUG_ON(sizeof(struct io_uring_sqe) != 64);
-- BUILD_BUG_SQE_ELEM(0, __u8, opcode);
-- BUILD_BUG_SQE_ELEM(1, __u8, flags);
-- BUILD_BUG_SQE_ELEM(2, __u16, ioprio);
-- BUILD_BUG_SQE_ELEM(4, __s32, fd);
-- BUILD_BUG_SQE_ELEM(8, __u64, off);
-- BUILD_BUG_SQE_ELEM(8, __u64, addr2);
-- BUILD_BUG_SQE_ELEM(16, __u64, addr);
-- BUILD_BUG_SQE_ELEM(16, __u64, splice_off_in);
-- BUILD_BUG_SQE_ELEM(24, __u32, len);
-- BUILD_BUG_SQE_ELEM(28, __kernel_rwf_t, rw_flags);
-- BUILD_BUG_SQE_ELEM(28, /* compat */ int, rw_flags);
-- BUILD_BUG_SQE_ELEM(28, /* compat */ __u32, rw_flags);
-- BUILD_BUG_SQE_ELEM(28, __u32, fsync_flags);
-- BUILD_BUG_SQE_ELEM(28, /* compat */ __u16, poll_events);
-- BUILD_BUG_SQE_ELEM(28, __u32, poll32_events);
-- BUILD_BUG_SQE_ELEM(28, __u32, sync_range_flags);
-- BUILD_BUG_SQE_ELEM(28, __u32, msg_flags);
-- BUILD_BUG_SQE_ELEM(28, __u32, timeout_flags);
-- BUILD_BUG_SQE_ELEM(28, __u32, accept_flags);
-- BUILD_BUG_SQE_ELEM(28, __u32, cancel_flags);
-- BUILD_BUG_SQE_ELEM(28, __u32, open_flags);
-- BUILD_BUG_SQE_ELEM(28, __u32, statx_flags);
-- BUILD_BUG_SQE_ELEM(28, __u32, fadvise_advice);
-- BUILD_BUG_SQE_ELEM(28, __u32, splice_flags);
-- BUILD_BUG_SQE_ELEM(32, __u64, user_data);
-- BUILD_BUG_SQE_ELEM(40, __u16, buf_index);
-- BUILD_BUG_SQE_ELEM(42, __u16, personality);
-- BUILD_BUG_SQE_ELEM(44, __s32, splice_fd_in);
--
-- BUILD_BUG_ON(ARRAY_SIZE(io_op_defs) != IORING_OP_LAST);
-- BUILD_BUG_ON(__REQ_F_LAST_BIT >= 8 * sizeof(int));
-- req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC);
-- return 0;
--};
--__initcall(io_uring_init);
---- a/include/linux/io_uring.h
-+++ b/include/linux/io_uring.h
-@@ -5,50 +5,20 @@
- #include <linux/sched.h>
- #include <linux/xarray.h>
-
--struct io_identity {
-- struct files_struct *files;
-- struct mm_struct *mm;
--#ifdef CONFIG_BLK_CGROUP
-- struct cgroup_subsys_state *blkcg_css;
--#endif
-- const struct cred *creds;
-- struct nsproxy *nsproxy;
-- struct fs_struct *fs;
-- unsigned long fsize;
--#ifdef CONFIG_AUDIT
-- kuid_t loginuid;
-- unsigned int sessionid;
--#endif
-- refcount_t count;
--};
--
--struct io_uring_task {
-- /* submission side */
-- struct xarray xa;
-- struct wait_queue_head wait;
-- struct file *last;
-- struct percpu_counter inflight;
-- struct io_identity __identity;
-- struct io_identity *identity;
-- atomic_t in_idle;
-- bool sqpoll;
--};
--
- #if defined(CONFIG_IO_URING)
- struct sock *io_uring_get_socket(struct file *file);
--void __io_uring_task_cancel(void);
--void __io_uring_files_cancel(struct files_struct *files);
-+void __io_uring_cancel(bool cancel_all);
- void __io_uring_free(struct task_struct *tsk);
-
--static inline void io_uring_task_cancel(void)
-+static inline void io_uring_files_cancel(void)
- {
-- if (current->io_uring && !xa_empty(¤t->io_uring->xa))
-- __io_uring_task_cancel();
-+ if (current->io_uring)
-+ __io_uring_cancel(false);
- }
--static inline void io_uring_files_cancel(struct files_struct *files)
-+static inline void io_uring_task_cancel(void)
- {
-- if (current->io_uring && !xa_empty(¤t->io_uring->xa))
-- __io_uring_files_cancel(files);
-+ if (current->io_uring)
-+ __io_uring_cancel(true);
- }
- static inline void io_uring_free(struct task_struct *tsk)
- {
-@@ -63,7 +33,7 @@ static inline struct sock *io_uring_get_
- static inline void io_uring_task_cancel(void)
- {
- }
--static inline void io_uring_files_cancel(struct files_struct *files)
-+static inline void io_uring_files_cancel(void)
- {
- }
- static inline void io_uring_free(struct task_struct *tsk)
---- a/include/linux/sched.h
-+++ b/include/linux/sched.h
-@@ -885,6 +885,9 @@ struct task_struct {
- /* CLONE_CHILD_CLEARTID: */
- int __user *clear_child_tid;
-
-+ /* PF_IO_WORKER */
-+ void *pf_io_worker;
-+
- u64 utime;
- u64 stime;
- #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
---- a/include/linux/syscalls.h
-+++ b/include/linux/syscalls.h
-@@ -341,7 +341,7 @@ asmlinkage long sys_io_uring_setup(u32 e
- struct io_uring_params __user *p);
- asmlinkage long sys_io_uring_enter(unsigned int fd, u32 to_submit,
- u32 min_complete, u32 flags,
-- const sigset_t __user *sig, size_t sigsz);
-+ const void __user *argp, size_t argsz);
- asmlinkage long sys_io_uring_register(unsigned int fd, unsigned int op,
- void __user *arg, unsigned int nr_args);
-
---- a/include/trace/events/io_uring.h
-+++ b/include/trace/events/io_uring.h
-@@ -12,11 +12,11 @@ struct io_wq_work;
- /**
- * io_uring_create - called after a new io_uring context was prepared
- *
-- * @fd: corresponding file descriptor
-- * @ctx: pointer to a ring context structure
-+ * @fd: corresponding file descriptor
-+ * @ctx: pointer to a ring context structure
- * @sq_entries: actual SQ size
- * @cq_entries: actual CQ size
-- * @flags: SQ ring flags, provided to io_uring_setup(2)
-+ * @flags: SQ ring flags, provided to io_uring_setup(2)
- *
- * Allows to trace io_uring creation and provide pointer to a context, that can
- * be used later to find correlated events.
-@@ -49,15 +49,15 @@ TRACE_EVENT(io_uring_create,
- );
-
- /**
-- * io_uring_register - called after a buffer/file/eventfd was succesfully
-+ * io_uring_register - called after a buffer/file/eventfd was successfully
- * registered for a ring
- *
-- * @ctx: pointer to a ring context structure
-- * @opcode: describes which operation to perform
-+ * @ctx: pointer to a ring context structure
-+ * @opcode: describes which operation to perform
- * @nr_user_files: number of registered files
- * @nr_user_bufs: number of registered buffers
- * @cq_ev_fd: whether eventfs registered or not
-- * @ret: return code
-+ * @ret: return code
- *
- * Allows to trace fixed files/buffers/eventfds, that could be registered to
- * avoid an overhead of getting references to them for every operation. This
-@@ -142,16 +142,16 @@ TRACE_EVENT(io_uring_queue_async_work,
- TP_ARGS(ctx, rw, req, work, flags),
-
- TP_STRUCT__entry (
-- __field( void *, ctx )
-- __field( int, rw )
-- __field( void *, req )
-+ __field( void *, ctx )
-+ __field( int, rw )
-+ __field( void *, req )
- __field( struct io_wq_work *, work )
- __field( unsigned int, flags )
- ),
-
- TP_fast_assign(
- __entry->ctx = ctx;
-- __entry->rw = rw;
-+ __entry->rw = rw;
- __entry->req = req;
- __entry->work = work;
- __entry->flags = flags;
-@@ -196,10 +196,10 @@ TRACE_EVENT(io_uring_defer,
-
- /**
- * io_uring_link - called before the io_uring request added into link_list of
-- * another request
-+ * another request
- *
-- * @ctx: pointer to a ring context structure
-- * @req: pointer to a linked request
-+ * @ctx: pointer to a ring context structure
-+ * @req: pointer to a linked request
- * @target_req: pointer to a previous request, that would contain @req
- *
- * Allows to track linked requests, to understand dependencies between requests
-@@ -212,8 +212,8 @@ TRACE_EVENT(io_uring_link,
- TP_ARGS(ctx, req, target_req),
-
- TP_STRUCT__entry (
-- __field( void *, ctx )
-- __field( void *, req )
-+ __field( void *, ctx )
-+ __field( void *, req )
- __field( void *, target_req )
- ),
-
-@@ -244,7 +244,7 @@ TRACE_EVENT(io_uring_cqring_wait,
- TP_ARGS(ctx, min_events),
-
- TP_STRUCT__entry (
-- __field( void *, ctx )
-+ __field( void *, ctx )
- __field( int, min_events )
- ),
-
-@@ -272,7 +272,7 @@ TRACE_EVENT(io_uring_fail_link,
- TP_ARGS(req, link),
-
- TP_STRUCT__entry (
-- __field( void *, req )
-+ __field( void *, req )
- __field( void *, link )
- ),
-
-@@ -290,38 +290,42 @@ TRACE_EVENT(io_uring_fail_link,
- * @ctx: pointer to a ring context structure
- * @user_data: user data associated with the request
- * @res: result of the request
-+ * @cflags: completion flags
- *
- */
- TRACE_EVENT(io_uring_complete,
-
-- TP_PROTO(void *ctx, u64 user_data, long res),
-+ TP_PROTO(void *ctx, u64 user_data, int res, unsigned cflags),
-
-- TP_ARGS(ctx, user_data, res),
-+ TP_ARGS(ctx, user_data, res, cflags),
-
- TP_STRUCT__entry (
- __field( void *, ctx )
- __field( u64, user_data )
-- __field( long, res )
-+ __field( int, res )
-+ __field( unsigned, cflags )
- ),
-
- TP_fast_assign(
- __entry->ctx = ctx;
- __entry->user_data = user_data;
- __entry->res = res;
-+ __entry->cflags = cflags;
- ),
-
-- TP_printk("ring %p, user_data 0x%llx, result %ld",
-+ TP_printk("ring %p, user_data 0x%llx, result %d, cflags %x",
- __entry->ctx, (unsigned long long)__entry->user_data,
-- __entry->res)
-+ __entry->res, __entry->cflags)
- );
-
--
- /**
- * io_uring_submit_sqe - called before submitting one SQE
- *
- * @ctx: pointer to a ring context structure
-+ * @req: pointer to a submitted request
- * @opcode: opcode of request
- * @user_data: user data associated with the request
-+ * @flags request flags
- * @force_nonblock: whether a context blocking or not
- * @sq_thread: true if sq_thread has submitted this SQE
- *
-@@ -330,41 +334,60 @@ TRACE_EVENT(io_uring_complete,
- */
- TRACE_EVENT(io_uring_submit_sqe,
-
-- TP_PROTO(void *ctx, u8 opcode, u64 user_data, bool force_nonblock,
-- bool sq_thread),
-+ TP_PROTO(void *ctx, void *req, u8 opcode, u64 user_data, u32 flags,
-+ bool force_nonblock, bool sq_thread),
-
-- TP_ARGS(ctx, opcode, user_data, force_nonblock, sq_thread),
-+ TP_ARGS(ctx, req, opcode, user_data, flags, force_nonblock, sq_thread),
-
- TP_STRUCT__entry (
- __field( void *, ctx )
-+ __field( void *, req )
- __field( u8, opcode )
- __field( u64, user_data )
-+ __field( u32, flags )
- __field( bool, force_nonblock )
- __field( bool, sq_thread )
- ),
-
- TP_fast_assign(
- __entry->ctx = ctx;
-+ __entry->req = req;
- __entry->opcode = opcode;
- __entry->user_data = user_data;
-+ __entry->flags = flags;
- __entry->force_nonblock = force_nonblock;
- __entry->sq_thread = sq_thread;
- ),
-
-- TP_printk("ring %p, op %d, data 0x%llx, non block %d, sq_thread %d",
-- __entry->ctx, __entry->opcode,
-- (unsigned long long) __entry->user_data,
-- __entry->force_nonblock, __entry->sq_thread)
-+ TP_printk("ring %p, req %p, op %d, data 0x%llx, flags %u, "
-+ "non block %d, sq_thread %d", __entry->ctx, __entry->req,
-+ __entry->opcode, (unsigned long long)__entry->user_data,
-+ __entry->flags, __entry->force_nonblock, __entry->sq_thread)
- );
-
-+/*
-+ * io_uring_poll_arm - called after arming a poll wait if successful
-+ *
-+ * @ctx: pointer to a ring context structure
-+ * @req: pointer to the armed request
-+ * @opcode: opcode of request
-+ * @user_data: user data associated with the request
-+ * @mask: request poll events mask
-+ * @events: registered events of interest
-+ *
-+ * Allows to track which fds are waiting for and what are the events of
-+ * interest.
-+ */
- TRACE_EVENT(io_uring_poll_arm,
-
-- TP_PROTO(void *ctx, u8 opcode, u64 user_data, int mask, int events),
-+ TP_PROTO(void *ctx, void *req, u8 opcode, u64 user_data,
-+ int mask, int events),
-
-- TP_ARGS(ctx, opcode, user_data, mask, events),
-+ TP_ARGS(ctx, req, opcode, user_data, mask, events),
-
- TP_STRUCT__entry (
- __field( void *, ctx )
-+ __field( void *, req )
- __field( u8, opcode )
- __field( u64, user_data )
- __field( int, mask )
-@@ -373,16 +396,17 @@ TRACE_EVENT(io_uring_poll_arm,
-
- TP_fast_assign(
- __entry->ctx = ctx;
-+ __entry->req = req;
- __entry->opcode = opcode;
- __entry->user_data = user_data;
- __entry->mask = mask;
- __entry->events = events;
- ),
-
-- TP_printk("ring %p, op %d, data 0x%llx, mask 0x%x, events 0x%x",
-- __entry->ctx, __entry->opcode,
-- (unsigned long long) __entry->user_data,
-- __entry->mask, __entry->events)
-+ TP_printk("ring %p, req %p, op %d, data 0x%llx, mask 0x%x, events 0x%x",
-+ __entry->ctx, __entry->req, __entry->opcode,
-+ (unsigned long long) __entry->user_data,
-+ __entry->mask, __entry->events)
- );
-
- TRACE_EVENT(io_uring_poll_wake,
-@@ -437,27 +461,40 @@ TRACE_EVENT(io_uring_task_add,
- __entry->mask)
- );
-
-+/*
-+ * io_uring_task_run - called when task_work_run() executes the poll events
-+ * notification callbacks
-+ *
-+ * @ctx: pointer to a ring context structure
-+ * @req: pointer to the armed request
-+ * @opcode: opcode of request
-+ * @user_data: user data associated with the request
-+ *
-+ * Allows to track when notified poll events are processed
-+ */
- TRACE_EVENT(io_uring_task_run,
-
-- TP_PROTO(void *ctx, u8 opcode, u64 user_data),
-+ TP_PROTO(void *ctx, void *req, u8 opcode, u64 user_data),
-
-- TP_ARGS(ctx, opcode, user_data),
-+ TP_ARGS(ctx, req, opcode, user_data),
-
- TP_STRUCT__entry (
- __field( void *, ctx )
-+ __field( void *, req )
- __field( u8, opcode )
- __field( u64, user_data )
- ),
-
- TP_fast_assign(
- __entry->ctx = ctx;
-+ __entry->req = req;
- __entry->opcode = opcode;
- __entry->user_data = user_data;
- ),
-
-- TP_printk("ring %p, op %d, data 0x%llx",
-- __entry->ctx, __entry->opcode,
-- (unsigned long long) __entry->user_data)
-+ TP_printk("ring %p, req %p, op %d, data 0x%llx",
-+ __entry->ctx, __entry->req, __entry->opcode,
-+ (unsigned long long) __entry->user_data)
- );
-
- #endif /* _TRACE_IO_URING_H */
---- a/include/uapi/linux/io_uring.h
-+++ b/include/uapi/linux/io_uring.h
-@@ -42,23 +42,25 @@ struct io_uring_sqe {
- __u32 statx_flags;
- __u32 fadvise_advice;
- __u32 splice_flags;
-+ __u32 rename_flags;
-+ __u32 unlink_flags;
-+ __u32 hardlink_flags;
- };
- __u64 user_data; /* data to be passed back at completion time */
-+ /* pack this to avoid bogus arm OABI complaints */
- union {
-- struct {
-- /* pack this to avoid bogus arm OABI complaints */
-- union {
-- /* index into fixed buffers, if used */
-- __u16 buf_index;
-- /* for grouped buffer selection */
-- __u16 buf_group;
-- } __attribute__((packed));
-- /* personality to use, if used */
-- __u16 personality;
-- __s32 splice_fd_in;
-- };
-- __u64 __pad2[3];
-+ /* index into fixed buffers, if used */
-+ __u16 buf_index;
-+ /* for grouped buffer selection */
-+ __u16 buf_group;
-+ } __attribute__((packed));
-+ /* personality to use, if used */
-+ __u16 personality;
-+ union {
-+ __s32 splice_fd_in;
-+ __u32 file_index;
- };
-+ __u64 __pad2[2];
- };
-
- enum {
-@@ -132,6 +134,9 @@ enum {
- IORING_OP_PROVIDE_BUFFERS,
- IORING_OP_REMOVE_BUFFERS,
- IORING_OP_TEE,
-+ IORING_OP_SHUTDOWN,
-+ IORING_OP_RENAMEAT,
-+ IORING_OP_UNLINKAT,
-
- /* this goes last, obviously */
- IORING_OP_LAST,
-@@ -145,8 +150,13 @@ enum {
- /*
- * sqe->timeout_flags
- */
--#define IORING_TIMEOUT_ABS (1U << 0)
--
-+#define IORING_TIMEOUT_ABS (1U << 0)
-+#define IORING_TIMEOUT_UPDATE (1U << 1)
-+#define IORING_TIMEOUT_BOOTTIME (1U << 2)
-+#define IORING_TIMEOUT_REALTIME (1U << 3)
-+#define IORING_LINK_TIMEOUT_UPDATE (1U << 4)
-+#define IORING_TIMEOUT_CLOCK_MASK (IORING_TIMEOUT_BOOTTIME | IORING_TIMEOUT_REALTIME)
-+#define IORING_TIMEOUT_UPDATE_MASK (IORING_TIMEOUT_UPDATE | IORING_LINK_TIMEOUT_UPDATE)
- /*
- * sqe->splice_flags
- * extends splice(2) flags
-@@ -154,6 +164,21 @@ enum {
- #define SPLICE_F_FD_IN_FIXED (1U << 31) /* the last bit of __u32 */
-
- /*
-+ * POLL_ADD flags. Note that since sqe->poll_events is the flag space, the
-+ * command flags for POLL_ADD are stored in sqe->len.
-+ *
-+ * IORING_POLL_ADD_MULTI Multishot poll. Sets IORING_CQE_F_MORE if
-+ * the poll handler will continue to report
-+ * CQEs on behalf of the same SQE.
-+ *
-+ * IORING_POLL_UPDATE Update existing poll request, matching
-+ * sqe->addr as the old user_data field.
-+ */
-+#define IORING_POLL_ADD_MULTI (1U << 0)
-+#define IORING_POLL_UPDATE_EVENTS (1U << 1)
-+#define IORING_POLL_UPDATE_USER_DATA (1U << 2)
-+
-+/*
- * IO completion data structure (Completion Queue Entry)
- */
- struct io_uring_cqe {
-@@ -166,8 +191,10 @@ struct io_uring_cqe {
- * cqe->flags
- *
- * IORING_CQE_F_BUFFER If set, the upper 16 bits are the buffer ID
-+ * IORING_CQE_F_MORE If set, parent SQE will generate more CQE entries
- */
- #define IORING_CQE_F_BUFFER (1U << 0)
-+#define IORING_CQE_F_MORE (1U << 1)
-
- enum {
- IORING_CQE_BUFFER_SHIFT = 16,
-@@ -226,6 +253,7 @@ struct io_cqring_offsets {
- #define IORING_ENTER_GETEVENTS (1U << 0)
- #define IORING_ENTER_SQ_WAKEUP (1U << 1)
- #define IORING_ENTER_SQ_WAIT (1U << 2)
-+#define IORING_ENTER_EXT_ARG (1U << 3)
-
- /*
- * Passed in for io_uring_setup(2). Copied back with updated info on success
-@@ -253,6 +281,10 @@ struct io_uring_params {
- #define IORING_FEAT_CUR_PERSONALITY (1U << 4)
- #define IORING_FEAT_FAST_POLL (1U << 5)
- #define IORING_FEAT_POLL_32BITS (1U << 6)
-+#define IORING_FEAT_SQPOLL_NONFIXED (1U << 7)
-+#define IORING_FEAT_EXT_ARG (1U << 8)
-+#define IORING_FEAT_NATIVE_WORKERS (1U << 9)
-+#define IORING_FEAT_RSRC_TAGS (1U << 10)
-
- /*
- * io_uring_register(2) opcodes and arguments
-@@ -272,16 +304,62 @@ enum {
- IORING_REGISTER_RESTRICTIONS = 11,
- IORING_REGISTER_ENABLE_RINGS = 12,
-
-+ /* extended with tagging */
-+ IORING_REGISTER_FILES2 = 13,
-+ IORING_REGISTER_FILES_UPDATE2 = 14,
-+ IORING_REGISTER_BUFFERS2 = 15,
-+ IORING_REGISTER_BUFFERS_UPDATE = 16,
-+
-+ /* set/clear io-wq thread affinities */
-+ IORING_REGISTER_IOWQ_AFF = 17,
-+ IORING_UNREGISTER_IOWQ_AFF = 18,
-+
-+ /* set/get max number of io-wq workers */
-+ IORING_REGISTER_IOWQ_MAX_WORKERS = 19,
-+
- /* this goes last */
- IORING_REGISTER_LAST
- };
-
-+/* io-wq worker categories */
-+enum {
-+ IO_WQ_BOUND,
-+ IO_WQ_UNBOUND,
-+};
-+
-+/* deprecated, see struct io_uring_rsrc_update */
- struct io_uring_files_update {
- __u32 offset;
- __u32 resv;
- __aligned_u64 /* __s32 * */ fds;
- };
-
-+struct io_uring_rsrc_register {
-+ __u32 nr;
-+ __u32 resv;
-+ __u64 resv2;
-+ __aligned_u64 data;
-+ __aligned_u64 tags;
-+};
-+
-+struct io_uring_rsrc_update {
-+ __u32 offset;
-+ __u32 resv;
-+ __aligned_u64 data;
-+};
-+
-+struct io_uring_rsrc_update2 {
-+ __u32 offset;
-+ __u32 resv;
-+ __aligned_u64 data;
-+ __aligned_u64 tags;
-+ __u32 nr;
-+ __u32 resv2;
-+};
-+
-+/* Skip updating fd indexes set to this value in the fd table */
-+#define IORING_REGISTER_FILES_SKIP (-2)
-+
- #define IO_URING_OP_SUPPORTED (1U << 0)
-
- struct io_uring_probe_op {
-@@ -329,4 +407,11 @@ enum {
- IORING_RESTRICTION_LAST
- };
-
-+struct io_uring_getevents_arg {
-+ __u64 sigmask;
-+ __u32 sigmask_sz;
-+ __u32 pad;
-+ __u64 ts;
-+};
-+
- #endif
---- /dev/null
-+++ b/io_uring/Makefile
-@@ -0,0 +1,6 @@
-+# SPDX-License-Identifier: GPL-2.0
-+#
-+# Makefile for io_uring
-+
-+obj-$(CONFIG_IO_URING) += io_uring.o
-+obj-$(CONFIG_IO_WQ) += io-wq.o
---- /dev/null
-+++ b/io_uring/io-wq.c
-@@ -0,0 +1,1398 @@
-+// SPDX-License-Identifier: GPL-2.0
-+/*
-+ * Basic worker thread pool for io_uring
-+ *
-+ * Copyright (C) 2019 Jens Axboe
-+ *
-+ */
-+#include <linux/kernel.h>
-+#include <linux/init.h>
-+#include <linux/errno.h>
-+#include <linux/sched/signal.h>
-+#include <linux/percpu.h>
-+#include <linux/slab.h>
-+#include <linux/rculist_nulls.h>
-+#include <linux/cpu.h>
-+#include <linux/tracehook.h>
-+#include <uapi/linux/io_uring.h>
-+
-+#include "io-wq.h"
-+
-+#define WORKER_IDLE_TIMEOUT (5 * HZ)
-+
-+enum {
-+ IO_WORKER_F_UP = 1, /* up and active */
-+ IO_WORKER_F_RUNNING = 2, /* account as running */
-+ IO_WORKER_F_FREE = 4, /* worker on free list */
-+ IO_WORKER_F_BOUND = 8, /* is doing bounded work */
-+};
-+
-+enum {
-+ IO_WQ_BIT_EXIT = 0, /* wq exiting */
-+};
-+
-+enum {
-+ IO_ACCT_STALLED_BIT = 0, /* stalled on hash */
-+};
-+
-+/*
-+ * One for each thread in a wqe pool
-+ */
-+struct io_worker {
-+ refcount_t ref;
-+ unsigned flags;
-+ struct hlist_nulls_node nulls_node;
-+ struct list_head all_list;
-+ struct task_struct *task;
-+ struct io_wqe *wqe;
-+
-+ struct io_wq_work *cur_work;
-+ spinlock_t lock;
-+
-+ struct completion ref_done;
-+
-+ unsigned long create_state;
-+ struct callback_head create_work;
-+ int create_index;
-+
-+ union {
-+ struct rcu_head rcu;
-+ struct work_struct work;
-+ };
-+};
-+
-+#if BITS_PER_LONG == 64
-+#define IO_WQ_HASH_ORDER 6
-+#else
-+#define IO_WQ_HASH_ORDER 5
-+#endif
-+
-+#define IO_WQ_NR_HASH_BUCKETS (1u << IO_WQ_HASH_ORDER)
-+
-+struct io_wqe_acct {
-+ unsigned nr_workers;
-+ unsigned max_workers;
-+ int index;
-+ atomic_t nr_running;
-+ struct io_wq_work_list work_list;
-+ unsigned long flags;
-+};
-+
-+enum {
-+ IO_WQ_ACCT_BOUND,
-+ IO_WQ_ACCT_UNBOUND,
-+ IO_WQ_ACCT_NR,
-+};
-+
-+/*
-+ * Per-node worker thread pool
-+ */
-+struct io_wqe {
-+ raw_spinlock_t lock;
-+ struct io_wqe_acct acct[2];
-+
-+ int node;
-+
-+ struct hlist_nulls_head free_list;
-+ struct list_head all_list;
-+
-+ struct wait_queue_entry wait;
-+
-+ struct io_wq *wq;
-+ struct io_wq_work *hash_tail[IO_WQ_NR_HASH_BUCKETS];
-+
-+ cpumask_var_t cpu_mask;
-+};
-+
-+/*
-+ * Per io_wq state
-+ */
-+struct io_wq {
-+ unsigned long state;
-+
-+ free_work_fn *free_work;
-+ io_wq_work_fn *do_work;
-+
-+ struct io_wq_hash *hash;
-+
-+ atomic_t worker_refs;
-+ struct completion worker_done;
-+
-+ struct hlist_node cpuhp_node;
-+
-+ struct task_struct *task;
-+
-+ struct io_wqe *wqes[];
-+};
-+
-+static enum cpuhp_state io_wq_online;
-+
-+struct io_cb_cancel_data {
-+ work_cancel_fn *fn;
-+ void *data;
-+ int nr_running;
-+ int nr_pending;
-+ bool cancel_all;
-+};
-+
-+static bool create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index);
-+static void io_wqe_dec_running(struct io_worker *worker);
-+static bool io_acct_cancel_pending_work(struct io_wqe *wqe,
-+ struct io_wqe_acct *acct,
-+ struct io_cb_cancel_data *match);
-+static void create_worker_cb(struct callback_head *cb);
-+static void io_wq_cancel_tw_create(struct io_wq *wq);
-+
-+static bool io_worker_get(struct io_worker *worker)
-+{
-+ return refcount_inc_not_zero(&worker->ref);
-+}
-+
-+static void io_worker_release(struct io_worker *worker)
-+{
-+ if (refcount_dec_and_test(&worker->ref))
-+ complete(&worker->ref_done);
-+}
-+
-+static inline struct io_wqe_acct *io_get_acct(struct io_wqe *wqe, bool bound)
-+{
-+ return &wqe->acct[bound ? IO_WQ_ACCT_BOUND : IO_WQ_ACCT_UNBOUND];
-+}
-+
-+static inline struct io_wqe_acct *io_work_get_acct(struct io_wqe *wqe,
-+ struct io_wq_work *work)
-+{
-+ return io_get_acct(wqe, !(work->flags & IO_WQ_WORK_UNBOUND));
-+}
-+
-+static inline struct io_wqe_acct *io_wqe_get_acct(struct io_worker *worker)
-+{
-+ return io_get_acct(worker->wqe, worker->flags & IO_WORKER_F_BOUND);
-+}
-+
-+static void io_worker_ref_put(struct io_wq *wq)
-+{
-+ if (atomic_dec_and_test(&wq->worker_refs))
-+ complete(&wq->worker_done);
-+}
-+
-+static void io_worker_cancel_cb(struct io_worker *worker)
-+{
-+ struct io_wqe_acct *acct = io_wqe_get_acct(worker);
-+ struct io_wqe *wqe = worker->wqe;
-+ struct io_wq *wq = wqe->wq;
-+
-+ atomic_dec(&acct->nr_running);
-+ raw_spin_lock(&worker->wqe->lock);
-+ acct->nr_workers--;
-+ raw_spin_unlock(&worker->wqe->lock);
-+ io_worker_ref_put(wq);
-+ clear_bit_unlock(0, &worker->create_state);
-+ io_worker_release(worker);
-+}
-+
-+static bool io_task_worker_match(struct callback_head *cb, void *data)
-+{
-+ struct io_worker *worker;
-+
-+ if (cb->func != create_worker_cb)
-+ return false;
-+ worker = container_of(cb, struct io_worker, create_work);
-+ return worker == data;
-+}
-+
-+static void io_worker_exit(struct io_worker *worker)
-+{
-+ struct io_wqe *wqe = worker->wqe;
-+ struct io_wq *wq = wqe->wq;
-+
-+ while (1) {
-+ struct callback_head *cb = task_work_cancel_match(wq->task,
-+ io_task_worker_match, worker);
-+
-+ if (!cb)
-+ break;
-+ io_worker_cancel_cb(worker);
-+ }
-+
-+ if (refcount_dec_and_test(&worker->ref))
-+ complete(&worker->ref_done);
-+ wait_for_completion(&worker->ref_done);
-+
-+ raw_spin_lock(&wqe->lock);
-+ if (worker->flags & IO_WORKER_F_FREE)
-+ hlist_nulls_del_rcu(&worker->nulls_node);
-+ list_del_rcu(&worker->all_list);
-+ preempt_disable();
-+ io_wqe_dec_running(worker);
-+ worker->flags = 0;
-+ current->flags &= ~PF_IO_WORKER;
-+ preempt_enable();
-+ raw_spin_unlock(&wqe->lock);
-+
-+ kfree_rcu(worker, rcu);
-+ io_worker_ref_put(wqe->wq);
-+ do_exit(0);
-+}
-+
-+static inline bool io_acct_run_queue(struct io_wqe_acct *acct)
-+{
-+ if (!wq_list_empty(&acct->work_list) &&
-+ !test_bit(IO_ACCT_STALLED_BIT, &acct->flags))
-+ return true;
-+ return false;
-+}
-+
-+/*
-+ * Check head of free list for an available worker. If one isn't available,
-+ * caller must create one.
-+ */
-+static bool io_wqe_activate_free_worker(struct io_wqe *wqe,
-+ struct io_wqe_acct *acct)
-+ __must_hold(RCU)
-+{
-+ struct hlist_nulls_node *n;
-+ struct io_worker *worker;
-+
-+ /*
-+ * Iterate free_list and see if we can find an idle worker to
-+ * activate. If a given worker is on the free_list but in the process
-+ * of exiting, keep trying.
-+ */
-+ hlist_nulls_for_each_entry_rcu(worker, n, &wqe->free_list, nulls_node) {
-+ if (!io_worker_get(worker))
-+ continue;
-+ if (io_wqe_get_acct(worker) != acct) {
-+ io_worker_release(worker);
-+ continue;
-+ }
-+ if (wake_up_process(worker->task)) {
-+ io_worker_release(worker);
-+ return true;
-+ }
-+ io_worker_release(worker);
-+ }
-+
-+ return false;
-+}
-+
-+/*
-+ * We need a worker. If we find a free one, we're good. If not, and we're
-+ * below the max number of workers, create one.
-+ */
-+static bool io_wqe_create_worker(struct io_wqe *wqe, struct io_wqe_acct *acct)
-+{
-+ /*
-+ * Most likely an attempt to queue unbounded work on an io_wq that
-+ * wasn't setup with any unbounded workers.
-+ */
-+ if (unlikely(!acct->max_workers))
-+ pr_warn_once("io-wq is not configured for unbound workers");
-+
-+ raw_spin_lock(&wqe->lock);
-+ if (acct->nr_workers >= acct->max_workers) {
-+ raw_spin_unlock(&wqe->lock);
-+ return true;
-+ }
-+ acct->nr_workers++;
-+ raw_spin_unlock(&wqe->lock);
-+ atomic_inc(&acct->nr_running);
-+ atomic_inc(&wqe->wq->worker_refs);
-+ return create_io_worker(wqe->wq, wqe, acct->index);
-+}
-+
-+static void io_wqe_inc_running(struct io_worker *worker)
-+{
-+ struct io_wqe_acct *acct = io_wqe_get_acct(worker);
-+
-+ atomic_inc(&acct->nr_running);
-+}
-+
-+static void create_worker_cb(struct callback_head *cb)
-+{
-+ struct io_worker *worker;
-+ struct io_wq *wq;
-+ struct io_wqe *wqe;
-+ struct io_wqe_acct *acct;
-+ bool do_create = false;
-+
-+ worker = container_of(cb, struct io_worker, create_work);
-+ wqe = worker->wqe;
-+ wq = wqe->wq;
-+ acct = &wqe->acct[worker->create_index];
-+ raw_spin_lock(&wqe->lock);
-+ if (acct->nr_workers < acct->max_workers) {
-+ acct->nr_workers++;
-+ do_create = true;
-+ }
-+ raw_spin_unlock(&wqe->lock);
-+ if (do_create) {
-+ create_io_worker(wq, wqe, worker->create_index);
-+ } else {
-+ atomic_dec(&acct->nr_running);
-+ io_worker_ref_put(wq);
-+ }
-+ clear_bit_unlock(0, &worker->create_state);
-+ io_worker_release(worker);
-+}
-+
-+static bool io_queue_worker_create(struct io_worker *worker,
-+ struct io_wqe_acct *acct,
-+ task_work_func_t func)
-+{
-+ struct io_wqe *wqe = worker->wqe;
-+ struct io_wq *wq = wqe->wq;
-+
-+ /* raced with exit, just ignore create call */
-+ if (test_bit(IO_WQ_BIT_EXIT, &wq->state))
-+ goto fail;
-+ if (!io_worker_get(worker))
-+ goto fail;
-+ /*
-+ * create_state manages ownership of create_work/index. We should
-+ * only need one entry per worker, as the worker going to sleep
-+ * will trigger the condition, and waking will clear it once it
-+ * runs the task_work.
-+ */
-+ if (test_bit(0, &worker->create_state) ||
-+ test_and_set_bit_lock(0, &worker->create_state))
-+ goto fail_release;
-+
-+ atomic_inc(&wq->worker_refs);
-+ init_task_work(&worker->create_work, func);
-+ worker->create_index = acct->index;
-+ if (!task_work_add(wq->task, &worker->create_work, TWA_SIGNAL)) {
-+ /*
-+ * EXIT may have been set after checking it above, check after
-+ * adding the task_work and remove any creation item if it is
-+ * now set. wq exit does that too, but we can have added this
-+ * work item after we canceled in io_wq_exit_workers().
-+ */
-+ if (test_bit(IO_WQ_BIT_EXIT, &wq->state))
-+ io_wq_cancel_tw_create(wq);
-+ io_worker_ref_put(wq);
-+ return true;
-+ }
-+ io_worker_ref_put(wq);
-+ clear_bit_unlock(0, &worker->create_state);
-+fail_release:
-+ io_worker_release(worker);
-+fail:
-+ atomic_dec(&acct->nr_running);
-+ io_worker_ref_put(wq);
-+ return false;
-+}
-+
-+static void io_wqe_dec_running(struct io_worker *worker)
-+ __must_hold(wqe->lock)
-+{
-+ struct io_wqe_acct *acct = io_wqe_get_acct(worker);
-+ struct io_wqe *wqe = worker->wqe;
-+
-+ if (!(worker->flags & IO_WORKER_F_UP))
-+ return;
-+
-+ if (atomic_dec_and_test(&acct->nr_running) && io_acct_run_queue(acct)) {
-+ atomic_inc(&acct->nr_running);
-+ atomic_inc(&wqe->wq->worker_refs);
-+ raw_spin_unlock(&wqe->lock);
-+ io_queue_worker_create(worker, acct, create_worker_cb);
-+ raw_spin_lock(&wqe->lock);
-+ }
-+}
-+
-+/*
-+ * Worker will start processing some work. Move it to the busy list, if
-+ * it's currently on the freelist
-+ */
-+static void __io_worker_busy(struct io_wqe *wqe, struct io_worker *worker,
-+ struct io_wq_work *work)
-+ __must_hold(wqe->lock)
-+{
-+ if (worker->flags & IO_WORKER_F_FREE) {
-+ worker->flags &= ~IO_WORKER_F_FREE;
-+ hlist_nulls_del_init_rcu(&worker->nulls_node);
-+ }
-+}
-+
-+/*
-+ * No work, worker going to sleep. Move to freelist, and unuse mm if we
-+ * have one attached. Dropping the mm may potentially sleep, so we drop
-+ * the lock in that case and return success. Since the caller has to
-+ * retry the loop in that case (we changed task state), we don't regrab
-+ * the lock if we return success.
-+ */
-+static void __io_worker_idle(struct io_wqe *wqe, struct io_worker *worker)
-+ __must_hold(wqe->lock)
-+{
-+ if (!(worker->flags & IO_WORKER_F_FREE)) {
-+ worker->flags |= IO_WORKER_F_FREE;
-+ hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list);
-+ }
-+}
-+
-+static inline unsigned int io_get_work_hash(struct io_wq_work *work)
-+{
-+ return work->flags >> IO_WQ_HASH_SHIFT;
-+}
-+
-+static bool io_wait_on_hash(struct io_wqe *wqe, unsigned int hash)
-+{
-+ struct io_wq *wq = wqe->wq;
-+ bool ret = false;
-+
-+ spin_lock_irq(&wq->hash->wait.lock);
-+ if (list_empty(&wqe->wait.entry)) {
-+ __add_wait_queue(&wq->hash->wait, &wqe->wait);
-+ if (!test_bit(hash, &wq->hash->map)) {
-+ __set_current_state(TASK_RUNNING);
-+ list_del_init(&wqe->wait.entry);
-+ ret = true;
-+ }
-+ }
-+ spin_unlock_irq(&wq->hash->wait.lock);
-+ return ret;
-+}
-+
-+static struct io_wq_work *io_get_next_work(struct io_wqe_acct *acct,
-+ struct io_worker *worker)
-+ __must_hold(wqe->lock)
-+{
-+ struct io_wq_work_node *node, *prev;
-+ struct io_wq_work *work, *tail;
-+ unsigned int stall_hash = -1U;
-+ struct io_wqe *wqe = worker->wqe;
-+
-+ wq_list_for_each(node, prev, &acct->work_list) {
-+ unsigned int hash;
-+
-+ work = container_of(node, struct io_wq_work, list);
-+
-+ /* not hashed, can run anytime */
-+ if (!io_wq_is_hashed(work)) {
-+ wq_list_del(&acct->work_list, node, prev);
-+ return work;
-+ }
-+
-+ hash = io_get_work_hash(work);
-+ /* all items with this hash lie in [work, tail] */
-+ tail = wqe->hash_tail[hash];
-+
-+ /* hashed, can run if not already running */
-+ if (!test_and_set_bit(hash, &wqe->wq->hash->map)) {
-+ wqe->hash_tail[hash] = NULL;
-+ wq_list_cut(&acct->work_list, &tail->list, prev);
-+ return work;
-+ }
-+ if (stall_hash == -1U)
-+ stall_hash = hash;
-+ /* fast forward to a next hash, for-each will fix up @prev */
-+ node = &tail->list;
-+ }
-+
-+ if (stall_hash != -1U) {
-+ bool unstalled;
-+
-+ /*
-+ * Set this before dropping the lock to avoid racing with new
-+ * work being added and clearing the stalled bit.
-+ */
-+ set_bit(IO_ACCT_STALLED_BIT, &acct->flags);
-+ raw_spin_unlock(&wqe->lock);
-+ unstalled = io_wait_on_hash(wqe, stall_hash);
-+ raw_spin_lock(&wqe->lock);
-+ if (unstalled) {
-+ clear_bit(IO_ACCT_STALLED_BIT, &acct->flags);
-+ if (wq_has_sleeper(&wqe->wq->hash->wait))
-+ wake_up(&wqe->wq->hash->wait);
-+ }
-+ }
-+
-+ return NULL;
-+}
-+
-+static bool io_flush_signals(void)
-+{
-+ if (unlikely(test_thread_flag(TIF_NOTIFY_SIGNAL))) {
-+ __set_current_state(TASK_RUNNING);
-+ tracehook_notify_signal();
-+ return true;
-+ }
-+ return false;
-+}
-+
-+static void io_assign_current_work(struct io_worker *worker,
-+ struct io_wq_work *work)
-+{
-+ if (work) {
-+ io_flush_signals();
-+ cond_resched();
-+ }
-+
-+ spin_lock(&worker->lock);
-+ worker->cur_work = work;
-+ spin_unlock(&worker->lock);
-+}
-+
-+static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work);
-+
-+static void io_worker_handle_work(struct io_worker *worker)
-+ __releases(wqe->lock)
-+{
-+ struct io_wqe_acct *acct = io_wqe_get_acct(worker);
-+ struct io_wqe *wqe = worker->wqe;
-+ struct io_wq *wq = wqe->wq;
-+ bool do_kill = test_bit(IO_WQ_BIT_EXIT, &wq->state);
-+
-+ do {
-+ struct io_wq_work *work;
-+get_next:
-+ /*
-+ * If we got some work, mark us as busy. If we didn't, but
-+ * the list isn't empty, it means we stalled on hashed work.
-+ * Mark us stalled so we don't keep looking for work when we
-+ * can't make progress, any work completion or insertion will
-+ * clear the stalled flag.
-+ */
-+ work = io_get_next_work(acct, worker);
-+ if (work)
-+ __io_worker_busy(wqe, worker, work);
-+
-+ raw_spin_unlock(&wqe->lock);
-+ if (!work)
-+ break;
-+ io_assign_current_work(worker, work);
-+ __set_current_state(TASK_RUNNING);
-+
-+ /* handle a whole dependent link */
-+ do {
-+ struct io_wq_work *next_hashed, *linked;
-+ unsigned int hash = io_get_work_hash(work);
-+
-+ next_hashed = wq_next_work(work);
-+
-+ if (unlikely(do_kill) && (work->flags & IO_WQ_WORK_UNBOUND))
-+ work->flags |= IO_WQ_WORK_CANCEL;
-+ wq->do_work(work);
-+ io_assign_current_work(worker, NULL);
-+
-+ linked = wq->free_work(work);
-+ work = next_hashed;
-+ if (!work && linked && !io_wq_is_hashed(linked)) {
-+ work = linked;
-+ linked = NULL;
-+ }
-+ io_assign_current_work(worker, work);
-+ if (linked)
-+ io_wqe_enqueue(wqe, linked);
-+
-+ if (hash != -1U && !next_hashed) {
-+ /* serialize hash clear with wake_up() */
-+ spin_lock_irq(&wq->hash->wait.lock);
-+ clear_bit(hash, &wq->hash->map);
-+ clear_bit(IO_ACCT_STALLED_BIT, &acct->flags);
-+ spin_unlock_irq(&wq->hash->wait.lock);
-+ if (wq_has_sleeper(&wq->hash->wait))
-+ wake_up(&wq->hash->wait);
-+ raw_spin_lock(&wqe->lock);
-+ /* skip unnecessary unlock-lock wqe->lock */
-+ if (!work)
-+ goto get_next;
-+ raw_spin_unlock(&wqe->lock);
-+ }
-+ } while (work);
-+
-+ raw_spin_lock(&wqe->lock);
-+ } while (1);
-+}
-+
-+static int io_wqe_worker(void *data)
-+{
-+ struct io_worker *worker = data;
-+ struct io_wqe_acct *acct = io_wqe_get_acct(worker);
-+ struct io_wqe *wqe = worker->wqe;
-+ struct io_wq *wq = wqe->wq;
-+ bool last_timeout = false;
-+ char buf[TASK_COMM_LEN];
-+
-+ worker->flags |= (IO_WORKER_F_UP | IO_WORKER_F_RUNNING);
-+
-+ snprintf(buf, sizeof(buf), "iou-wrk-%d", wq->task->pid);
-+ set_task_comm(current, buf);
-+
-+ while (!test_bit(IO_WQ_BIT_EXIT, &wq->state)) {
-+ long ret;
-+
-+ set_current_state(TASK_INTERRUPTIBLE);
-+loop:
-+ raw_spin_lock(&wqe->lock);
-+ if (io_acct_run_queue(acct)) {
-+ io_worker_handle_work(worker);
-+ goto loop;
-+ }
-+ /* timed out, exit unless we're the last worker */
-+ if (last_timeout && acct->nr_workers > 1) {
-+ acct->nr_workers--;
-+ raw_spin_unlock(&wqe->lock);
-+ __set_current_state(TASK_RUNNING);
-+ break;
-+ }
-+ last_timeout = false;
-+ __io_worker_idle(wqe, worker);
-+ raw_spin_unlock(&wqe->lock);
-+ if (io_flush_signals())
-+ continue;
-+ ret = schedule_timeout(WORKER_IDLE_TIMEOUT);
-+ if (signal_pending(current)) {
-+ struct ksignal ksig;
-+
-+ if (!get_signal(&ksig))
-+ continue;
-+ break;
-+ }
-+ last_timeout = !ret;
-+ }
-+
-+ if (test_bit(IO_WQ_BIT_EXIT, &wq->state)) {
-+ raw_spin_lock(&wqe->lock);
-+ io_worker_handle_work(worker);
-+ }
-+
-+ io_worker_exit(worker);
-+ return 0;
-+}
-+
-+/*
-+ * Called when a worker is scheduled in. Mark us as currently running.
-+ */
-+void io_wq_worker_running(struct task_struct *tsk)
-+{
-+ struct io_worker *worker = tsk->pf_io_worker;
-+
-+ if (!worker)
-+ return;
-+ if (!(worker->flags & IO_WORKER_F_UP))
-+ return;
-+ if (worker->flags & IO_WORKER_F_RUNNING)
-+ return;
-+ worker->flags |= IO_WORKER_F_RUNNING;
-+ io_wqe_inc_running(worker);
-+}
-+
-+/*
-+ * Called when worker is going to sleep. If there are no workers currently
-+ * running and we have work pending, wake up a free one or create a new one.
-+ */
-+void io_wq_worker_sleeping(struct task_struct *tsk)
-+{
-+ struct io_worker *worker = tsk->pf_io_worker;
-+
-+ if (!worker)
-+ return;
-+ if (!(worker->flags & IO_WORKER_F_UP))
-+ return;
-+ if (!(worker->flags & IO_WORKER_F_RUNNING))
-+ return;
-+
-+ worker->flags &= ~IO_WORKER_F_RUNNING;
-+
-+ raw_spin_lock(&worker->wqe->lock);
-+ io_wqe_dec_running(worker);
-+ raw_spin_unlock(&worker->wqe->lock);
-+}
-+
-+static void io_init_new_worker(struct io_wqe *wqe, struct io_worker *worker,
-+ struct task_struct *tsk)
-+{
-+ tsk->pf_io_worker = worker;
-+ worker->task = tsk;
-+ set_cpus_allowed_ptr(tsk, wqe->cpu_mask);
-+ tsk->flags |= PF_NO_SETAFFINITY;
-+
-+ raw_spin_lock(&wqe->lock);
-+ hlist_nulls_add_head_rcu(&worker->nulls_node, &wqe->free_list);
-+ list_add_tail_rcu(&worker->all_list, &wqe->all_list);
-+ worker->flags |= IO_WORKER_F_FREE;
-+ raw_spin_unlock(&wqe->lock);
-+ wake_up_new_task(tsk);
-+}
-+
-+static bool io_wq_work_match_all(struct io_wq_work *work, void *data)
-+{
-+ return true;
-+}
-+
-+static inline bool io_should_retry_thread(long err)
-+{
-+ /*
-+ * Prevent perpetual task_work retry, if the task (or its group) is
-+ * exiting.
-+ */
-+ if (fatal_signal_pending(current))
-+ return false;
-+
-+ switch (err) {
-+ case -EAGAIN:
-+ case -ERESTARTSYS:
-+ case -ERESTARTNOINTR:
-+ case -ERESTARTNOHAND:
-+ return true;
-+ default:
-+ return false;
-+ }
-+}
-+
-+static void create_worker_cont(struct callback_head *cb)
-+{
-+ struct io_worker *worker;
-+ struct task_struct *tsk;
-+ struct io_wqe *wqe;
-+
-+ worker = container_of(cb, struct io_worker, create_work);
-+ clear_bit_unlock(0, &worker->create_state);
-+ wqe = worker->wqe;
-+ tsk = create_io_thread(io_wqe_worker, worker, wqe->node);
-+ if (!IS_ERR(tsk)) {
-+ io_init_new_worker(wqe, worker, tsk);
-+ io_worker_release(worker);
-+ return;
-+ } else if (!io_should_retry_thread(PTR_ERR(tsk))) {
-+ struct io_wqe_acct *acct = io_wqe_get_acct(worker);
-+
-+ atomic_dec(&acct->nr_running);
-+ raw_spin_lock(&wqe->lock);
-+ acct->nr_workers--;
-+ if (!acct->nr_workers) {
-+ struct io_cb_cancel_data match = {
-+ .fn = io_wq_work_match_all,
-+ .cancel_all = true,
-+ };
-+
-+ while (io_acct_cancel_pending_work(wqe, acct, &match))
-+ raw_spin_lock(&wqe->lock);
-+ }
-+ raw_spin_unlock(&wqe->lock);
-+ io_worker_ref_put(wqe->wq);
-+ kfree(worker);
-+ return;
-+ }
-+
-+ /* re-create attempts grab a new worker ref, drop the existing one */
-+ io_worker_release(worker);
-+ schedule_work(&worker->work);
-+}
-+
-+static void io_workqueue_create(struct work_struct *work)
-+{
-+ struct io_worker *worker = container_of(work, struct io_worker, work);
-+ struct io_wqe_acct *acct = io_wqe_get_acct(worker);
-+
-+ if (!io_queue_worker_create(worker, acct, create_worker_cont))
-+ kfree(worker);
-+}
-+
-+static bool create_io_worker(struct io_wq *wq, struct io_wqe *wqe, int index)
-+{
-+ struct io_wqe_acct *acct = &wqe->acct[index];
-+ struct io_worker *worker;
-+ struct task_struct *tsk;
-+
-+ __set_current_state(TASK_RUNNING);
-+
-+ worker = kzalloc_node(sizeof(*worker), GFP_KERNEL, wqe->node);
-+ if (!worker) {
-+fail:
-+ atomic_dec(&acct->nr_running);
-+ raw_spin_lock(&wqe->lock);
-+ acct->nr_workers--;
-+ raw_spin_unlock(&wqe->lock);
-+ io_worker_ref_put(wq);
-+ return false;
-+ }
-+
-+ refcount_set(&worker->ref, 1);
-+ worker->wqe = wqe;
-+ spin_lock_init(&worker->lock);
-+ init_completion(&worker->ref_done);
-+
-+ if (index == IO_WQ_ACCT_BOUND)
-+ worker->flags |= IO_WORKER_F_BOUND;
-+
-+ tsk = create_io_thread(io_wqe_worker, worker, wqe->node);
-+ if (!IS_ERR(tsk)) {
-+ io_init_new_worker(wqe, worker, tsk);
-+ } else if (!io_should_retry_thread(PTR_ERR(tsk))) {
-+ kfree(worker);
-+ goto fail;
-+ } else {
-+ INIT_WORK(&worker->work, io_workqueue_create);
-+ schedule_work(&worker->work);
-+ }
-+
-+ return true;
-+}
-+
-+/*
-+ * Iterate the passed in list and call the specific function for each
-+ * worker that isn't exiting
-+ */
-+static bool io_wq_for_each_worker(struct io_wqe *wqe,
-+ bool (*func)(struct io_worker *, void *),
-+ void *data)
-+{
-+ struct io_worker *worker;
-+ bool ret = false;
-+
-+ list_for_each_entry_rcu(worker, &wqe->all_list, all_list) {
-+ if (io_worker_get(worker)) {
-+ /* no task if node is/was offline */
-+ if (worker->task)
-+ ret = func(worker, data);
-+ io_worker_release(worker);
-+ if (ret)
-+ break;
-+ }
-+ }
-+
-+ return ret;
-+}
-+
-+static bool io_wq_worker_wake(struct io_worker *worker, void *data)
-+{
-+ set_notify_signal(worker->task);
-+ wake_up_process(worker->task);
-+ return false;
-+}
-+
-+static void io_run_cancel(struct io_wq_work *work, struct io_wqe *wqe)
-+{
-+ struct io_wq *wq = wqe->wq;
-+
-+ do {
-+ work->flags |= IO_WQ_WORK_CANCEL;
-+ wq->do_work(work);
-+ work = wq->free_work(work);
-+ } while (work);
-+}
-+
-+static void io_wqe_insert_work(struct io_wqe *wqe, struct io_wq_work *work)
-+{
-+ struct io_wqe_acct *acct = io_work_get_acct(wqe, work);
-+ unsigned int hash;
-+ struct io_wq_work *tail;
-+
-+ if (!io_wq_is_hashed(work)) {
-+append:
-+ wq_list_add_tail(&work->list, &acct->work_list);
-+ return;
-+ }
-+
-+ hash = io_get_work_hash(work);
-+ tail = wqe->hash_tail[hash];
-+ wqe->hash_tail[hash] = work;
-+ if (!tail)
-+ goto append;
-+
-+ wq_list_add_after(&work->list, &tail->list, &acct->work_list);
-+}
-+
-+static bool io_wq_work_match_item(struct io_wq_work *work, void *data)
-+{
-+ return work == data;
-+}
-+
-+static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work)
-+{
-+ struct io_wqe_acct *acct = io_work_get_acct(wqe, work);
-+ unsigned work_flags = work->flags;
-+ bool do_create;
-+
-+ /*
-+ * If io-wq is exiting for this task, or if the request has explicitly
-+ * been marked as one that should not get executed, cancel it here.
-+ */
-+ if (test_bit(IO_WQ_BIT_EXIT, &wqe->wq->state) ||
-+ (work->flags & IO_WQ_WORK_CANCEL)) {
-+ io_run_cancel(work, wqe);
-+ return;
-+ }
-+
-+ raw_spin_lock(&wqe->lock);
-+ io_wqe_insert_work(wqe, work);
-+ clear_bit(IO_ACCT_STALLED_BIT, &acct->flags);
-+
-+ rcu_read_lock();
-+ do_create = !io_wqe_activate_free_worker(wqe, acct);
-+ rcu_read_unlock();
-+
-+ raw_spin_unlock(&wqe->lock);
-+
-+ if (do_create && ((work_flags & IO_WQ_WORK_CONCURRENT) ||
-+ !atomic_read(&acct->nr_running))) {
-+ bool did_create;
-+
-+ did_create = io_wqe_create_worker(wqe, acct);
-+ if (likely(did_create))
-+ return;
-+
-+ raw_spin_lock(&wqe->lock);
-+ /* fatal condition, failed to create the first worker */
-+ if (!acct->nr_workers) {
-+ struct io_cb_cancel_data match = {
-+ .fn = io_wq_work_match_item,
-+ .data = work,
-+ .cancel_all = false,
-+ };
-+
-+ if (io_acct_cancel_pending_work(wqe, acct, &match))
-+ raw_spin_lock(&wqe->lock);
-+ }
-+ raw_spin_unlock(&wqe->lock);
-+ }
-+}
-+
-+void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work)
-+{
-+ struct io_wqe *wqe = wq->wqes[numa_node_id()];
-+
-+ io_wqe_enqueue(wqe, work);
-+}
-+
-+/*
-+ * Work items that hash to the same value will not be done in parallel.
-+ * Used to limit concurrent writes, generally hashed by inode.
-+ */
-+void io_wq_hash_work(struct io_wq_work *work, void *val)
-+{
-+ unsigned int bit;
-+
-+ bit = hash_ptr(val, IO_WQ_HASH_ORDER);
-+ work->flags |= (IO_WQ_WORK_HASHED | (bit << IO_WQ_HASH_SHIFT));
-+}
-+
-+static bool io_wq_worker_cancel(struct io_worker *worker, void *data)
-+{
-+ struct io_cb_cancel_data *match = data;
-+
-+ /*
-+ * Hold the lock to avoid ->cur_work going out of scope, caller
-+ * may dereference the passed in work.
-+ */
-+ spin_lock(&worker->lock);
-+ if (worker->cur_work &&
-+ match->fn(worker->cur_work, match->data)) {
-+ set_notify_signal(worker->task);
-+ match->nr_running++;
-+ }
-+ spin_unlock(&worker->lock);
-+
-+ return match->nr_running && !match->cancel_all;
-+}
-+
-+static inline void io_wqe_remove_pending(struct io_wqe *wqe,
-+ struct io_wq_work *work,
-+ struct io_wq_work_node *prev)
-+{
-+ struct io_wqe_acct *acct = io_work_get_acct(wqe, work);
-+ unsigned int hash = io_get_work_hash(work);
-+ struct io_wq_work *prev_work = NULL;
-+
-+ if (io_wq_is_hashed(work) && work == wqe->hash_tail[hash]) {
-+ if (prev)
-+ prev_work = container_of(prev, struct io_wq_work, list);
-+ if (prev_work && io_get_work_hash(prev_work) == hash)
-+ wqe->hash_tail[hash] = prev_work;
-+ else
-+ wqe->hash_tail[hash] = NULL;
-+ }
-+ wq_list_del(&acct->work_list, &work->list, prev);
-+}
-+
-+static bool io_acct_cancel_pending_work(struct io_wqe *wqe,
-+ struct io_wqe_acct *acct,
-+ struct io_cb_cancel_data *match)
-+ __releases(wqe->lock)
-+{
-+ struct io_wq_work_node *node, *prev;
-+ struct io_wq_work *work;
-+
-+ wq_list_for_each(node, prev, &acct->work_list) {
-+ work = container_of(node, struct io_wq_work, list);
-+ if (!match->fn(work, match->data))
-+ continue;
-+ io_wqe_remove_pending(wqe, work, prev);
-+ raw_spin_unlock(&wqe->lock);
-+ io_run_cancel(work, wqe);
-+ match->nr_pending++;
-+ /* not safe to continue after unlock */
-+ return true;
-+ }
-+
-+ return false;
-+}
-+
-+static void io_wqe_cancel_pending_work(struct io_wqe *wqe,
-+ struct io_cb_cancel_data *match)
-+{
-+ int i;
-+retry:
-+ raw_spin_lock(&wqe->lock);
-+ for (i = 0; i < IO_WQ_ACCT_NR; i++) {
-+ struct io_wqe_acct *acct = io_get_acct(wqe, i == 0);
-+
-+ if (io_acct_cancel_pending_work(wqe, acct, match)) {
-+ if (match->cancel_all)
-+ goto retry;
-+ return;
-+ }
-+ }
-+ raw_spin_unlock(&wqe->lock);
-+}
-+
-+static void io_wqe_cancel_running_work(struct io_wqe *wqe,
-+ struct io_cb_cancel_data *match)
-+{
-+ rcu_read_lock();
-+ io_wq_for_each_worker(wqe, io_wq_worker_cancel, match);
-+ rcu_read_unlock();
-+}
-+
-+enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel,
-+ void *data, bool cancel_all)
-+{
-+ struct io_cb_cancel_data match = {
-+ .fn = cancel,
-+ .data = data,
-+ .cancel_all = cancel_all,
-+ };
-+ int node;
-+
-+ /*
-+ * First check pending list, if we're lucky we can just remove it
-+ * from there. CANCEL_OK means that the work is returned as-new,
-+ * no completion will be posted for it.
-+ */
-+ for_each_node(node) {
-+ struct io_wqe *wqe = wq->wqes[node];
-+
-+ io_wqe_cancel_pending_work(wqe, &match);
-+ if (match.nr_pending && !match.cancel_all)
-+ return IO_WQ_CANCEL_OK;
-+ }
-+
-+ /*
-+ * Now check if a free (going busy) or busy worker has the work
-+ * currently running. If we find it there, we'll return CANCEL_RUNNING
-+ * as an indication that we attempt to signal cancellation. The
-+ * completion will run normally in this case.
-+ */
-+ for_each_node(node) {
-+ struct io_wqe *wqe = wq->wqes[node];
-+
-+ io_wqe_cancel_running_work(wqe, &match);
-+ if (match.nr_running && !match.cancel_all)
-+ return IO_WQ_CANCEL_RUNNING;
-+ }
-+
-+ if (match.nr_running)
-+ return IO_WQ_CANCEL_RUNNING;
-+ if (match.nr_pending)
-+ return IO_WQ_CANCEL_OK;
-+ return IO_WQ_CANCEL_NOTFOUND;
-+}
-+
-+static int io_wqe_hash_wake(struct wait_queue_entry *wait, unsigned mode,
-+ int sync, void *key)
-+{
-+ struct io_wqe *wqe = container_of(wait, struct io_wqe, wait);
-+ int i;
-+
-+ list_del_init(&wait->entry);
-+
-+ rcu_read_lock();
-+ for (i = 0; i < IO_WQ_ACCT_NR; i++) {
-+ struct io_wqe_acct *acct = &wqe->acct[i];
-+
-+ if (test_and_clear_bit(IO_ACCT_STALLED_BIT, &acct->flags))
-+ io_wqe_activate_free_worker(wqe, acct);
-+ }
-+ rcu_read_unlock();
-+ return 1;
-+}
-+
-+struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)
-+{
-+ int ret, node, i;
-+ struct io_wq *wq;
-+
-+ if (WARN_ON_ONCE(!data->free_work || !data->do_work))
-+ return ERR_PTR(-EINVAL);
-+ if (WARN_ON_ONCE(!bounded))
-+ return ERR_PTR(-EINVAL);
-+
-+ wq = kzalloc(struct_size(wq, wqes, nr_node_ids), GFP_KERNEL);
-+ if (!wq)
-+ return ERR_PTR(-ENOMEM);
-+ ret = cpuhp_state_add_instance_nocalls(io_wq_online, &wq->cpuhp_node);
-+ if (ret)
-+ goto err_wq;
-+
-+ refcount_inc(&data->hash->refs);
-+ wq->hash = data->hash;
-+ wq->free_work = data->free_work;
-+ wq->do_work = data->do_work;
-+
-+ ret = -ENOMEM;
-+ for_each_node(node) {
-+ struct io_wqe *wqe;
-+ int alloc_node = node;
-+
-+ if (!node_online(alloc_node))
-+ alloc_node = NUMA_NO_NODE;
-+ wqe = kzalloc_node(sizeof(struct io_wqe), GFP_KERNEL, alloc_node);
-+ if (!wqe)
-+ goto err;
-+ wq->wqes[node] = wqe;
-+ if (!alloc_cpumask_var(&wqe->cpu_mask, GFP_KERNEL))
-+ goto err;
-+ cpumask_copy(wqe->cpu_mask, cpumask_of_node(node));
-+ wqe->node = alloc_node;
-+ wqe->acct[IO_WQ_ACCT_BOUND].max_workers = bounded;
-+ wqe->acct[IO_WQ_ACCT_UNBOUND].max_workers =
-+ task_rlimit(current, RLIMIT_NPROC);
-+ INIT_LIST_HEAD(&wqe->wait.entry);
-+ wqe->wait.func = io_wqe_hash_wake;
-+ for (i = 0; i < IO_WQ_ACCT_NR; i++) {
-+ struct io_wqe_acct *acct = &wqe->acct[i];
-+
-+ acct->index = i;
-+ atomic_set(&acct->nr_running, 0);
-+ INIT_WQ_LIST(&acct->work_list);
-+ }
-+ wqe->wq = wq;
-+ raw_spin_lock_init(&wqe->lock);
-+ INIT_HLIST_NULLS_HEAD(&wqe->free_list, 0);
-+ INIT_LIST_HEAD(&wqe->all_list);
-+ }
-+
-+ wq->task = get_task_struct(data->task);
-+ atomic_set(&wq->worker_refs, 1);
-+ init_completion(&wq->worker_done);
-+ return wq;
-+err:
-+ io_wq_put_hash(data->hash);
-+ cpuhp_state_remove_instance_nocalls(io_wq_online, &wq->cpuhp_node);
-+ for_each_node(node) {
-+ if (!wq->wqes[node])
-+ continue;
-+ free_cpumask_var(wq->wqes[node]->cpu_mask);
-+ kfree(wq->wqes[node]);
-+ }
-+err_wq:
-+ kfree(wq);
-+ return ERR_PTR(ret);
-+}
-+
-+static bool io_task_work_match(struct callback_head *cb, void *data)
-+{
-+ struct io_worker *worker;
-+
-+ if (cb->func != create_worker_cb && cb->func != create_worker_cont)
-+ return false;
-+ worker = container_of(cb, struct io_worker, create_work);
-+ return worker->wqe->wq == data;
-+}
-+
-+void io_wq_exit_start(struct io_wq *wq)
-+{
-+ set_bit(IO_WQ_BIT_EXIT, &wq->state);
-+}
-+
-+static void io_wq_cancel_tw_create(struct io_wq *wq)
-+{
-+ struct callback_head *cb;
-+
-+ while ((cb = task_work_cancel_match(wq->task, io_task_work_match, wq)) != NULL) {
-+ struct io_worker *worker;
-+
-+ worker = container_of(cb, struct io_worker, create_work);
-+ io_worker_cancel_cb(worker);
-+ }
-+}
-+
-+static void io_wq_exit_workers(struct io_wq *wq)
-+{
-+ int node;
-+
-+ if (!wq->task)
-+ return;
-+
-+ io_wq_cancel_tw_create(wq);
-+
-+ rcu_read_lock();
-+ for_each_node(node) {
-+ struct io_wqe *wqe = wq->wqes[node];
-+
-+ io_wq_for_each_worker(wqe, io_wq_worker_wake, NULL);
-+ }
-+ rcu_read_unlock();
-+ io_worker_ref_put(wq);
-+ wait_for_completion(&wq->worker_done);
-+
-+ for_each_node(node) {
-+ spin_lock_irq(&wq->hash->wait.lock);
-+ list_del_init(&wq->wqes[node]->wait.entry);
-+ spin_unlock_irq(&wq->hash->wait.lock);
-+ }
-+ put_task_struct(wq->task);
-+ wq->task = NULL;
-+}
-+
-+static void io_wq_destroy(struct io_wq *wq)
-+{
-+ int node;
-+
-+ cpuhp_state_remove_instance_nocalls(io_wq_online, &wq->cpuhp_node);
-+
-+ for_each_node(node) {
-+ struct io_wqe *wqe = wq->wqes[node];
-+ struct io_cb_cancel_data match = {
-+ .fn = io_wq_work_match_all,
-+ .cancel_all = true,
-+ };
-+ io_wqe_cancel_pending_work(wqe, &match);
-+ free_cpumask_var(wqe->cpu_mask);
-+ kfree(wqe);
-+ }
-+ io_wq_put_hash(wq->hash);
-+ kfree(wq);
-+}
-+
-+void io_wq_put_and_exit(struct io_wq *wq)
-+{
-+ WARN_ON_ONCE(!test_bit(IO_WQ_BIT_EXIT, &wq->state));
-+
-+ io_wq_exit_workers(wq);
-+ io_wq_destroy(wq);
-+}
-+
-+struct online_data {
-+ unsigned int cpu;
-+ bool online;
-+};
-+
-+static bool io_wq_worker_affinity(struct io_worker *worker, void *data)
-+{
-+ struct online_data *od = data;
-+
-+ if (od->online)
-+ cpumask_set_cpu(od->cpu, worker->wqe->cpu_mask);
-+ else
-+ cpumask_clear_cpu(od->cpu, worker->wqe->cpu_mask);
-+ return false;
-+}
-+
-+static int __io_wq_cpu_online(struct io_wq *wq, unsigned int cpu, bool online)
-+{
-+ struct online_data od = {
-+ .cpu = cpu,
-+ .online = online
-+ };
-+ int i;
-+
-+ rcu_read_lock();
-+ for_each_node(i)
-+ io_wq_for_each_worker(wq->wqes[i], io_wq_worker_affinity, &od);
-+ rcu_read_unlock();
-+ return 0;
-+}
-+
-+static int io_wq_cpu_online(unsigned int cpu, struct hlist_node *node)
-+{
-+ struct io_wq *wq = hlist_entry_safe(node, struct io_wq, cpuhp_node);
-+
-+ return __io_wq_cpu_online(wq, cpu, true);
-+}
-+
-+static int io_wq_cpu_offline(unsigned int cpu, struct hlist_node *node)
-+{
-+ struct io_wq *wq = hlist_entry_safe(node, struct io_wq, cpuhp_node);
-+
-+ return __io_wq_cpu_online(wq, cpu, false);
-+}
-+
-+int io_wq_cpu_affinity(struct io_wq *wq, cpumask_var_t mask)
-+{
-+ int i;
-+
-+ rcu_read_lock();
-+ for_each_node(i) {
-+ struct io_wqe *wqe = wq->wqes[i];
-+
-+ if (mask)
-+ cpumask_copy(wqe->cpu_mask, mask);
-+ else
-+ cpumask_copy(wqe->cpu_mask, cpumask_of_node(i));
-+ }
-+ rcu_read_unlock();
-+ return 0;
-+}
-+
-+/*
-+ * Set max number of unbounded workers, returns old value. If new_count is 0,
-+ * then just return the old value.
-+ */
-+int io_wq_max_workers(struct io_wq *wq, int *new_count)
-+{
-+ int prev[IO_WQ_ACCT_NR];
-+ bool first_node = true;
-+ int i, node;
-+
-+ BUILD_BUG_ON((int) IO_WQ_ACCT_BOUND != (int) IO_WQ_BOUND);
-+ BUILD_BUG_ON((int) IO_WQ_ACCT_UNBOUND != (int) IO_WQ_UNBOUND);
-+ BUILD_BUG_ON((int) IO_WQ_ACCT_NR != 2);
-+
-+ for (i = 0; i < 2; i++) {
-+ if (new_count[i] > task_rlimit(current, RLIMIT_NPROC))
-+ new_count[i] = task_rlimit(current, RLIMIT_NPROC);
-+ }
-+
-+ for (i = 0; i < IO_WQ_ACCT_NR; i++)
-+ prev[i] = 0;
-+
-+ rcu_read_lock();
-+ for_each_node(node) {
-+ struct io_wqe *wqe = wq->wqes[node];
-+ struct io_wqe_acct *acct;
-+
-+ raw_spin_lock(&wqe->lock);
-+ for (i = 0; i < IO_WQ_ACCT_NR; i++) {
-+ acct = &wqe->acct[i];
-+ if (first_node)
-+ prev[i] = max_t(int, acct->max_workers, prev[i]);
-+ if (new_count[i])
-+ acct->max_workers = new_count[i];
-+ }
-+ raw_spin_unlock(&wqe->lock);
-+ first_node = false;
-+ }
-+ rcu_read_unlock();
-+
-+ for (i = 0; i < IO_WQ_ACCT_NR; i++)
-+ new_count[i] = prev[i];
-+
-+ return 0;
-+}
-+
-+static __init int io_wq_init(void)
-+{
-+ int ret;
-+
-+ ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN, "io-wq/online",
-+ io_wq_cpu_online, io_wq_cpu_offline);
-+ if (ret < 0)
-+ return ret;
-+ io_wq_online = ret;
-+ return 0;
-+}
-+subsys_initcall(io_wq_init);
---- /dev/null
-+++ b/io_uring/io-wq.h
-@@ -0,0 +1,160 @@
-+#ifndef INTERNAL_IO_WQ_H
-+#define INTERNAL_IO_WQ_H
-+
-+#include <linux/refcount.h>
-+
-+struct io_wq;
-+
-+enum {
-+ IO_WQ_WORK_CANCEL = 1,
-+ IO_WQ_WORK_HASHED = 2,
-+ IO_WQ_WORK_UNBOUND = 4,
-+ IO_WQ_WORK_CONCURRENT = 16,
-+
-+ IO_WQ_HASH_SHIFT = 24, /* upper 8 bits are used for hash key */
-+};
-+
-+enum io_wq_cancel {
-+ IO_WQ_CANCEL_OK, /* cancelled before started */
-+ IO_WQ_CANCEL_RUNNING, /* found, running, and attempted cancelled */
-+ IO_WQ_CANCEL_NOTFOUND, /* work not found */
-+};
-+
-+struct io_wq_work_node {
-+ struct io_wq_work_node *next;
-+};
-+
-+struct io_wq_work_list {
-+ struct io_wq_work_node *first;
-+ struct io_wq_work_node *last;
-+};
-+
-+static inline void wq_list_add_after(struct io_wq_work_node *node,
-+ struct io_wq_work_node *pos,
-+ struct io_wq_work_list *list)
-+{
-+ struct io_wq_work_node *next = pos->next;
-+
-+ pos->next = node;
-+ node->next = next;
-+ if (!next)
-+ list->last = node;
-+}
-+
-+static inline void wq_list_add_tail(struct io_wq_work_node *node,
-+ struct io_wq_work_list *list)
-+{
-+ node->next = NULL;
-+ if (!list->first) {
-+ list->last = node;
-+ WRITE_ONCE(list->first, node);
-+ } else {
-+ list->last->next = node;
-+ list->last = node;
-+ }
-+}
-+
-+static inline void wq_list_cut(struct io_wq_work_list *list,
-+ struct io_wq_work_node *last,
-+ struct io_wq_work_node *prev)
-+{
-+ /* first in the list, if prev==NULL */
-+ if (!prev)
-+ WRITE_ONCE(list->first, last->next);
-+ else
-+ prev->next = last->next;
-+
-+ if (last == list->last)
-+ list->last = prev;
-+ last->next = NULL;
-+}
-+
-+static inline void wq_list_del(struct io_wq_work_list *list,
-+ struct io_wq_work_node *node,
-+ struct io_wq_work_node *prev)
-+{
-+ wq_list_cut(list, node, prev);
-+}
-+
-+#define wq_list_for_each(pos, prv, head) \
-+ for (pos = (head)->first, prv = NULL; pos; prv = pos, pos = (pos)->next)
-+
-+#define wq_list_empty(list) (READ_ONCE((list)->first) == NULL)
-+#define INIT_WQ_LIST(list) do { \
-+ (list)->first = NULL; \
-+ (list)->last = NULL; \
-+} while (0)
-+
-+struct io_wq_work {
-+ struct io_wq_work_node list;
-+ unsigned flags;
-+};
-+
-+static inline struct io_wq_work *wq_next_work(struct io_wq_work *work)
-+{
-+ if (!work->list.next)
-+ return NULL;
-+
-+ return container_of(work->list.next, struct io_wq_work, list);
-+}
-+
-+typedef struct io_wq_work *(free_work_fn)(struct io_wq_work *);
-+typedef void (io_wq_work_fn)(struct io_wq_work *);
-+
-+struct io_wq_hash {
-+ refcount_t refs;
-+ unsigned long map;
-+ struct wait_queue_head wait;
-+};
-+
-+static inline void io_wq_put_hash(struct io_wq_hash *hash)
-+{
-+ if (refcount_dec_and_test(&hash->refs))
-+ kfree(hash);
-+}
-+
-+struct io_wq_data {
-+ struct io_wq_hash *hash;
-+ struct task_struct *task;
-+ io_wq_work_fn *do_work;
-+ free_work_fn *free_work;
-+};
-+
-+struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data);
-+void io_wq_exit_start(struct io_wq *wq);
-+void io_wq_put_and_exit(struct io_wq *wq);
-+
-+void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work);
-+void io_wq_hash_work(struct io_wq_work *work, void *val);
-+
-+int io_wq_cpu_affinity(struct io_wq *wq, cpumask_var_t mask);
-+int io_wq_max_workers(struct io_wq *wq, int *new_count);
-+
-+static inline bool io_wq_is_hashed(struct io_wq_work *work)
-+{
-+ return work->flags & IO_WQ_WORK_HASHED;
-+}
-+
-+typedef bool (work_cancel_fn)(struct io_wq_work *, void *);
-+
-+enum io_wq_cancel io_wq_cancel_cb(struct io_wq *wq, work_cancel_fn *cancel,
-+ void *data, bool cancel_all);
-+
-+#if defined(CONFIG_IO_WQ)
-+extern void io_wq_worker_sleeping(struct task_struct *);
-+extern void io_wq_worker_running(struct task_struct *);
-+#else
-+static inline void io_wq_worker_sleeping(struct task_struct *tsk)
-+{
-+}
-+static inline void io_wq_worker_running(struct task_struct *tsk)
-+{
-+}
-+#endif
-+
-+static inline bool io_wq_current_is_worker(void)
-+{
-+ return in_task() && (current->flags & PF_IO_WORKER) &&
-+ current->pf_io_worker;
-+}
-+#endif
---- /dev/null
-+++ b/io_uring/io_uring.c
-@@ -0,0 +1,10945 @@
-+// SPDX-License-Identifier: GPL-2.0
-+/*
-+ * Shared application/kernel submission and completion ring pairs, for
-+ * supporting fast/efficient IO.
-+ *
-+ * A note on the read/write ordering memory barriers that are matched between
-+ * the application and kernel side.
-+ *
-+ * After the application reads the CQ ring tail, it must use an
-+ * appropriate smp_rmb() to pair with the smp_wmb() the kernel uses
-+ * before writing the tail (using smp_load_acquire to read the tail will
-+ * do). It also needs a smp_mb() before updating CQ head (ordering the
-+ * entry load(s) with the head store), pairing with an implicit barrier
-+ * through a control-dependency in io_get_cqe (smp_store_release to
-+ * store head will do). Failure to do so could lead to reading invalid
-+ * CQ entries.
-+ *
-+ * Likewise, the application must use an appropriate smp_wmb() before
-+ * writing the SQ tail (ordering SQ entry stores with the tail store),
-+ * which pairs with smp_load_acquire in io_get_sqring (smp_store_release
-+ * to store the tail will do). And it needs a barrier ordering the SQ
-+ * head load before writing new SQ entries (smp_load_acquire to read
-+ * head will do).
-+ *
-+ * When using the SQ poll thread (IORING_SETUP_SQPOLL), the application
-+ * needs to check the SQ flags for IORING_SQ_NEED_WAKEUP *after*
-+ * updating the SQ tail; a full memory barrier smp_mb() is needed
-+ * between.
-+ *
-+ * Also see the examples in the liburing library:
-+ *
-+ * git://git.kernel.dk/liburing
-+ *
-+ * io_uring also uses READ/WRITE_ONCE() for _any_ store or load that happens
-+ * from data shared between the kernel and application. This is done both
-+ * for ordering purposes, but also to ensure that once a value is loaded from
-+ * data that the application could potentially modify, it remains stable.
-+ *
-+ * Copyright (C) 2018-2019 Jens Axboe
-+ * Copyright (c) 2018-2019 Christoph Hellwig
-+ */
-+#include <linux/kernel.h>
-+#include <linux/init.h>
-+#include <linux/errno.h>
-+#include <linux/syscalls.h>
-+#include <linux/compat.h>
-+#include <net/compat.h>
-+#include <linux/refcount.h>
-+#include <linux/uio.h>
-+#include <linux/bits.h>
-+
-+#include <linux/sched/signal.h>
-+#include <linux/fs.h>
-+#include <linux/file.h>
-+#include <linux/fdtable.h>
-+#include <linux/mm.h>
-+#include <linux/mman.h>
-+#include <linux/percpu.h>
-+#include <linux/slab.h>
-+#include <linux/blkdev.h>
-+#include <linux/bvec.h>
-+#include <linux/net.h>
-+#include <net/sock.h>
-+#include <net/af_unix.h>
-+#include <net/scm.h>
-+#include <linux/anon_inodes.h>
-+#include <linux/sched/mm.h>
-+#include <linux/uaccess.h>
-+#include <linux/nospec.h>
-+#include <linux/sizes.h>
-+#include <linux/hugetlb.h>
-+#include <linux/highmem.h>
-+#include <linux/namei.h>
-+#include <linux/fsnotify.h>
-+#include <linux/fadvise.h>
-+#include <linux/eventpoll.h>
-+#include <linux/splice.h>
-+#include <linux/task_work.h>
-+#include <linux/pagemap.h>
-+#include <linux/io_uring.h>
-+#include <linux/tracehook.h>
-+
-+#define CREATE_TRACE_POINTS
-+#include <trace/events/io_uring.h>
-+
-+#include <uapi/linux/io_uring.h>
-+
-+#include "../fs/internal.h"
-+#include "io-wq.h"
-+
-+#define IORING_MAX_ENTRIES 32768
-+#define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES)
-+#define IORING_SQPOLL_CAP_ENTRIES_VALUE 8
-+
-+/* only define max */
-+#define IORING_MAX_FIXED_FILES (1U << 15)
-+#define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \
-+ IORING_REGISTER_LAST + IORING_OP_LAST)
-+
-+#define IO_RSRC_TAG_TABLE_SHIFT (PAGE_SHIFT - 3)
-+#define IO_RSRC_TAG_TABLE_MAX (1U << IO_RSRC_TAG_TABLE_SHIFT)
-+#define IO_RSRC_TAG_TABLE_MASK (IO_RSRC_TAG_TABLE_MAX - 1)
-+
-+#define IORING_MAX_REG_BUFFERS (1U << 14)
-+
-+#define SQE_VALID_FLAGS (IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK| \
-+ IOSQE_IO_HARDLINK | IOSQE_ASYNC | \
-+ IOSQE_BUFFER_SELECT)
-+#define IO_REQ_CLEAN_FLAGS (REQ_F_BUFFER_SELECTED | REQ_F_NEED_CLEANUP | \
-+ REQ_F_POLLED | REQ_F_INFLIGHT | REQ_F_CREDS)
-+
-+#define IO_TCTX_REFS_CACHE_NR (1U << 10)
-+
-+struct io_uring {
-+ u32 head ____cacheline_aligned_in_smp;
-+ u32 tail ____cacheline_aligned_in_smp;
-+};
-+
-+/*
-+ * This data is shared with the application through the mmap at offsets
-+ * IORING_OFF_SQ_RING and IORING_OFF_CQ_RING.
-+ *
-+ * The offsets to the member fields are published through struct
-+ * io_sqring_offsets when calling io_uring_setup.
-+ */
-+struct io_rings {
-+ /*
-+ * Head and tail offsets into the ring; the offsets need to be
-+ * masked to get valid indices.
-+ *
-+ * The kernel controls head of the sq ring and the tail of the cq ring,
-+ * and the application controls tail of the sq ring and the head of the
-+ * cq ring.
-+ */
-+ struct io_uring sq, cq;
-+ /*
-+ * Bitmasks to apply to head and tail offsets (constant, equals
-+ * ring_entries - 1)
-+ */
-+ u32 sq_ring_mask, cq_ring_mask;
-+ /* Ring sizes (constant, power of 2) */
-+ u32 sq_ring_entries, cq_ring_entries;
-+ /*
-+ * Number of invalid entries dropped by the kernel due to
-+ * invalid index stored in array
-+ *
-+ * Written by the kernel, shouldn't be modified by the
-+ * application (i.e. get number of "new events" by comparing to
-+ * cached value).
-+ *
-+ * After a new SQ head value was read by the application this
-+ * counter includes all submissions that were dropped reaching
-+ * the new SQ head (and possibly more).
-+ */
-+ u32 sq_dropped;
-+ /*
-+ * Runtime SQ flags
-+ *
-+ * Written by the kernel, shouldn't be modified by the
-+ * application.
-+ *
-+ * The application needs a full memory barrier before checking
-+ * for IORING_SQ_NEED_WAKEUP after updating the sq tail.
-+ */
-+ u32 sq_flags;
-+ /*
-+ * Runtime CQ flags
-+ *
-+ * Written by the application, shouldn't be modified by the
-+ * kernel.
-+ */
-+ u32 cq_flags;
-+ /*
-+ * Number of completion events lost because the queue was full;
-+ * this should be avoided by the application by making sure
-+ * there are not more requests pending than there is space in
-+ * the completion queue.
-+ *
-+ * Written by the kernel, shouldn't be modified by the
-+ * application (i.e. get number of "new events" by comparing to
-+ * cached value).
-+ *
-+ * As completion events come in out of order this counter is not
-+ * ordered with any other data.
-+ */
-+ u32 cq_overflow;
-+ /*
-+ * Ring buffer of completion events.
-+ *
-+ * The kernel writes completion events fresh every time they are
-+ * produced, so the application is allowed to modify pending
-+ * entries.
-+ */
-+ struct io_uring_cqe cqes[] ____cacheline_aligned_in_smp;
-+};
-+
-+enum io_uring_cmd_flags {
-+ IO_URING_F_NONBLOCK = 1,
-+ IO_URING_F_COMPLETE_DEFER = 2,
-+};
-+
-+struct io_mapped_ubuf {
-+ u64 ubuf;
-+ u64 ubuf_end;
-+ unsigned int nr_bvecs;
-+ unsigned long acct_pages;
-+ struct bio_vec bvec[];
-+};
-+
-+struct io_ring_ctx;
-+
-+struct io_overflow_cqe {
-+ struct io_uring_cqe cqe;
-+ struct list_head list;
-+};
-+
-+struct io_fixed_file {
-+ /* file * with additional FFS_* flags */
-+ unsigned long file_ptr;
-+};
-+
-+struct io_rsrc_put {
-+ struct list_head list;
-+ u64 tag;
-+ union {
-+ void *rsrc;
-+ struct file *file;
-+ struct io_mapped_ubuf *buf;
-+ };
-+};
-+
-+struct io_file_table {
-+ struct io_fixed_file *files;
-+};
-+
-+struct io_rsrc_node {
-+ struct percpu_ref refs;
-+ struct list_head node;
-+ struct list_head rsrc_list;
-+ struct io_rsrc_data *rsrc_data;
-+ struct llist_node llist;
-+ bool done;
-+};
-+
-+typedef void (rsrc_put_fn)(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc);
-+
-+struct io_rsrc_data {
-+ struct io_ring_ctx *ctx;
-+
-+ u64 **tags;
-+ unsigned int nr;
-+ rsrc_put_fn *do_put;
-+ atomic_t refs;
-+ struct completion done;
-+ bool quiesce;
-+};
-+
-+struct io_buffer {
-+ struct list_head list;
-+ __u64 addr;
-+ __u32 len;
-+ __u16 bid;
-+};
-+
-+struct io_restriction {
-+ DECLARE_BITMAP(register_op, IORING_REGISTER_LAST);
-+ DECLARE_BITMAP(sqe_op, IORING_OP_LAST);
-+ u8 sqe_flags_allowed;
-+ u8 sqe_flags_required;
-+ bool registered;
-+};
-+
-+enum {
-+ IO_SQ_THREAD_SHOULD_STOP = 0,
-+ IO_SQ_THREAD_SHOULD_PARK,
-+};
-+
-+struct io_sq_data {
-+ refcount_t refs;
-+ atomic_t park_pending;
-+ struct mutex lock;
-+
-+ /* ctx's that are using this sqd */
-+ struct list_head ctx_list;
-+
-+ struct task_struct *thread;
-+ struct wait_queue_head wait;
-+
-+ unsigned sq_thread_idle;
-+ int sq_cpu;
-+ pid_t task_pid;
-+ pid_t task_tgid;
-+
-+ unsigned long state;
-+ struct completion exited;
-+};
-+
-+#define IO_COMPL_BATCH 32
-+#define IO_REQ_CACHE_SIZE 32
-+#define IO_REQ_ALLOC_BATCH 8
-+
-+struct io_submit_link {
-+ struct io_kiocb *head;
-+ struct io_kiocb *last;
-+};
-+
-+struct io_submit_state {
-+ struct blk_plug plug;
-+ struct io_submit_link link;
-+
-+ /*
-+ * io_kiocb alloc cache
-+ */
-+ void *reqs[IO_REQ_CACHE_SIZE];
-+ unsigned int free_reqs;
-+
-+ bool plug_started;
-+
-+ /*
-+ * Batch completion logic
-+ */
-+ struct io_kiocb *compl_reqs[IO_COMPL_BATCH];
-+ unsigned int compl_nr;
-+ /* inline/task_work completion list, under ->uring_lock */
-+ struct list_head free_list;
-+
-+ unsigned int ios_left;
-+};
-+
-+struct io_ring_ctx {
-+ /* const or read-mostly hot data */
-+ struct {
-+ struct percpu_ref refs;
-+
-+ struct io_rings *rings;
-+ unsigned int flags;
-+ unsigned int compat: 1;
-+ unsigned int drain_next: 1;
-+ unsigned int eventfd_async: 1;
-+ unsigned int restricted: 1;
-+ unsigned int off_timeout_used: 1;
-+ unsigned int drain_active: 1;
-+ } ____cacheline_aligned_in_smp;
-+
-+ /* submission data */
-+ struct {
-+ struct mutex uring_lock;
-+
-+ /*
-+ * Ring buffer of indices into array of io_uring_sqe, which is
-+ * mmapped by the application using the IORING_OFF_SQES offset.
-+ *
-+ * This indirection could e.g. be used to assign fixed
-+ * io_uring_sqe entries to operations and only submit them to
-+ * the queue when needed.
-+ *
-+ * The kernel modifies neither the indices array nor the entries
-+ * array.
-+ */
-+ u32 *sq_array;
-+ struct io_uring_sqe *sq_sqes;
-+ unsigned cached_sq_head;
-+ unsigned sq_entries;
-+ struct list_head defer_list;
-+
-+ /*
-+ * Fixed resources fast path, should be accessed only under
-+ * uring_lock, and updated through io_uring_register(2)
-+ */
-+ struct io_rsrc_node *rsrc_node;
-+ struct io_file_table file_table;
-+ unsigned nr_user_files;
-+ unsigned nr_user_bufs;
-+ struct io_mapped_ubuf **user_bufs;
-+
-+ struct io_submit_state submit_state;
-+ struct list_head timeout_list;
-+ struct list_head ltimeout_list;
-+ struct list_head cq_overflow_list;
-+ struct xarray io_buffers;
-+ struct xarray personalities;
-+ u32 pers_next;
-+ unsigned sq_thread_idle;
-+ } ____cacheline_aligned_in_smp;
-+
-+ /* IRQ completion list, under ->completion_lock */
-+ struct list_head locked_free_list;
-+ unsigned int locked_free_nr;
-+
-+ const struct cred *sq_creds; /* cred used for __io_sq_thread() */
-+ struct io_sq_data *sq_data; /* if using sq thread polling */
-+
-+ struct wait_queue_head sqo_sq_wait;
-+ struct list_head sqd_list;
-+
-+ unsigned long check_cq_overflow;
-+
-+ struct {
-+ unsigned cached_cq_tail;
-+ unsigned cq_entries;
-+ struct eventfd_ctx *cq_ev_fd;
-+ struct wait_queue_head poll_wait;
-+ struct wait_queue_head cq_wait;
-+ unsigned cq_extra;
-+ atomic_t cq_timeouts;
-+ unsigned cq_last_tm_flush;
-+ } ____cacheline_aligned_in_smp;
-+
-+ struct {
-+ spinlock_t completion_lock;
-+
-+ spinlock_t timeout_lock;
-+
-+ /*
-+ * ->iopoll_list is protected by the ctx->uring_lock for
-+ * io_uring instances that don't use IORING_SETUP_SQPOLL.
-+ * For SQPOLL, only the single threaded io_sq_thread() will
-+ * manipulate the list, hence no extra locking is needed there.
-+ */
-+ struct list_head iopoll_list;
-+ struct hlist_head *cancel_hash;
-+ unsigned cancel_hash_bits;
-+ bool poll_multi_queue;
-+ } ____cacheline_aligned_in_smp;
-+
-+ struct io_restriction restrictions;
-+
-+ /* slow path rsrc auxilary data, used by update/register */
-+ struct {
-+ struct io_rsrc_node *rsrc_backup_node;
-+ struct io_mapped_ubuf *dummy_ubuf;
-+ struct io_rsrc_data *file_data;
-+ struct io_rsrc_data *buf_data;
-+
-+ struct delayed_work rsrc_put_work;
-+ struct llist_head rsrc_put_llist;
-+ struct list_head rsrc_ref_list;
-+ spinlock_t rsrc_ref_lock;
-+ };
-+
-+ /* Keep this last, we don't need it for the fast path */
-+ struct {
-+ #if defined(CONFIG_UNIX)
-+ struct socket *ring_sock;
-+ #endif
-+ /* hashed buffered write serialization */
-+ struct io_wq_hash *hash_map;
-+
-+ /* Only used for accounting purposes */
-+ struct user_struct *user;
-+ struct mm_struct *mm_account;
-+
-+ /* ctx exit and cancelation */
-+ struct llist_head fallback_llist;
-+ struct delayed_work fallback_work;
-+ struct work_struct exit_work;
-+ struct list_head tctx_list;
-+ struct completion ref_comp;
-+ u32 iowq_limits[2];
-+ bool iowq_limits_set;
-+ };
-+};
-+
-+struct io_uring_task {
-+ /* submission side */
-+ int cached_refs;
-+ struct xarray xa;
-+ struct wait_queue_head wait;
-+ const struct io_ring_ctx *last;
-+ struct io_wq *io_wq;
-+ struct percpu_counter inflight;
-+ atomic_t inflight_tracked;
-+ atomic_t in_idle;
-+
-+ spinlock_t task_lock;
-+ struct io_wq_work_list task_list;
-+ struct callback_head task_work;
-+ bool task_running;
-+};
-+
-+/*
-+ * First field must be the file pointer in all the
-+ * iocb unions! See also 'struct kiocb' in <linux/fs.h>
-+ */
-+struct io_poll_iocb {
-+ struct file *file;
-+ struct wait_queue_head *head;
-+ __poll_t events;
-+ struct wait_queue_entry wait;
-+};
-+
-+struct io_poll_update {
-+ struct file *file;
-+ u64 old_user_data;
-+ u64 new_user_data;
-+ __poll_t events;
-+ bool update_events;
-+ bool update_user_data;
-+};
-+
-+struct io_close {
-+ struct file *file;
-+ int fd;
-+ u32 file_slot;
-+};
-+
-+struct io_timeout_data {
-+ struct io_kiocb *req;
-+ struct hrtimer timer;
-+ struct timespec64 ts;
-+ enum hrtimer_mode mode;
-+ u32 flags;
-+};
-+
-+struct io_accept {
-+ struct file *file;
-+ struct sockaddr __user *addr;
-+ int __user *addr_len;
-+ int flags;
-+ u32 file_slot;
-+ unsigned long nofile;
-+};
-+
-+struct io_sync {
-+ struct file *file;
-+ loff_t len;
-+ loff_t off;
-+ int flags;
-+ int mode;
-+};
-+
-+struct io_cancel {
-+ struct file *file;
-+ u64 addr;
-+};
-+
-+struct io_timeout {
-+ struct file *file;
-+ u32 off;
-+ u32 target_seq;
-+ struct list_head list;
-+ /* head of the link, used by linked timeouts only */
-+ struct io_kiocb *head;
-+ /* for linked completions */
-+ struct io_kiocb *prev;
-+};
-+
-+struct io_timeout_rem {
-+ struct file *file;
-+ u64 addr;
-+
-+ /* timeout update */
-+ struct timespec64 ts;
-+ u32 flags;
-+ bool ltimeout;
-+};
-+
-+struct io_rw {
-+ /* NOTE: kiocb has the file as the first member, so don't do it here */
-+ struct kiocb kiocb;
-+ u64 addr;
-+ u64 len;
-+};
-+
-+struct io_connect {
-+ struct file *file;
-+ struct sockaddr __user *addr;
-+ int addr_len;
-+};
-+
-+struct io_sr_msg {
-+ struct file *file;
-+ union {
-+ struct compat_msghdr __user *umsg_compat;
-+ struct user_msghdr __user *umsg;
-+ void __user *buf;
-+ };
-+ int msg_flags;
-+ int bgid;
-+ size_t len;
-+ struct io_buffer *kbuf;
-+};
-+
-+struct io_open {
-+ struct file *file;
-+ int dfd;
-+ u32 file_slot;
-+ struct filename *filename;
-+ struct open_how how;
-+ unsigned long nofile;
-+};
-+
-+struct io_rsrc_update {
-+ struct file *file;
-+ u64 arg;
-+ u32 nr_args;
-+ u32 offset;
-+};
-+
-+struct io_fadvise {
-+ struct file *file;
-+ u64 offset;
-+ u32 len;
-+ u32 advice;
-+};
-+
-+struct io_madvise {
-+ struct file *file;
-+ u64 addr;
-+ u32 len;
-+ u32 advice;
-+};
-+
-+struct io_epoll {
-+ struct file *file;
-+ int epfd;
-+ int op;
-+ int fd;
-+ struct epoll_event event;
-+};
-+
-+struct io_splice {
-+ struct file *file_out;
-+ loff_t off_out;
-+ loff_t off_in;
-+ u64 len;
-+ int splice_fd_in;
-+ unsigned int flags;
-+};
-+
-+struct io_provide_buf {
-+ struct file *file;
-+ __u64 addr;
-+ __u32 len;
-+ __u32 bgid;
-+ __u16 nbufs;
-+ __u16 bid;
-+};
-+
-+struct io_statx {
-+ struct file *file;
-+ int dfd;
-+ unsigned int mask;
-+ unsigned int flags;
-+ const char __user *filename;
-+ struct statx __user *buffer;
-+};
-+
-+struct io_shutdown {
-+ struct file *file;
-+ int how;
-+};
-+
-+struct io_rename {
-+ struct file *file;
-+ int old_dfd;
-+ int new_dfd;
-+ struct filename *oldpath;
-+ struct filename *newpath;
-+ int flags;
-+};
-+
-+struct io_unlink {
-+ struct file *file;
-+ int dfd;
-+ int flags;
-+ struct filename *filename;
-+};
-+
-+struct io_mkdir {
-+ struct file *file;
-+ int dfd;
-+ umode_t mode;
-+ struct filename *filename;
-+};
-+
-+struct io_symlink {
-+ struct file *file;
-+ int new_dfd;
-+ struct filename *oldpath;
-+ struct filename *newpath;
-+};
-+
-+struct io_hardlink {
-+ struct file *file;
-+ int old_dfd;
-+ int new_dfd;
-+ struct filename *oldpath;
-+ struct filename *newpath;
-+ int flags;
-+};
-+
-+struct io_completion {
-+ struct file *file;
-+ u32 cflags;
-+};
-+
-+struct io_async_connect {
-+ struct sockaddr_storage address;
-+};
-+
-+struct io_async_msghdr {
-+ struct iovec fast_iov[UIO_FASTIOV];
-+ /* points to an allocated iov, if NULL we use fast_iov instead */
-+ struct iovec *free_iov;
-+ struct sockaddr __user *uaddr;
-+ struct msghdr msg;
-+ struct sockaddr_storage addr;
-+};
-+
-+struct io_async_rw {
-+ struct iovec fast_iov[UIO_FASTIOV];
-+ const struct iovec *free_iovec;
-+ struct iov_iter iter;
-+ struct iov_iter_state iter_state;
-+ size_t bytes_done;
-+ struct wait_page_queue wpq;
-+};
-+
-+enum {
-+ REQ_F_FIXED_FILE_BIT = IOSQE_FIXED_FILE_BIT,
-+ REQ_F_IO_DRAIN_BIT = IOSQE_IO_DRAIN_BIT,
-+ REQ_F_LINK_BIT = IOSQE_IO_LINK_BIT,
-+ REQ_F_HARDLINK_BIT = IOSQE_IO_HARDLINK_BIT,
-+ REQ_F_FORCE_ASYNC_BIT = IOSQE_ASYNC_BIT,
-+ REQ_F_BUFFER_SELECT_BIT = IOSQE_BUFFER_SELECT_BIT,
-+
-+ /* first byte is taken by user flags, shift it to not overlap */
-+ REQ_F_FAIL_BIT = 8,
-+ REQ_F_INFLIGHT_BIT,
-+ REQ_F_CUR_POS_BIT,
-+ REQ_F_NOWAIT_BIT,
-+ REQ_F_LINK_TIMEOUT_BIT,
-+ REQ_F_NEED_CLEANUP_BIT,
-+ REQ_F_POLLED_BIT,
-+ REQ_F_BUFFER_SELECTED_BIT,
-+ REQ_F_COMPLETE_INLINE_BIT,
-+ REQ_F_REISSUE_BIT,
-+ REQ_F_CREDS_BIT,
-+ REQ_F_REFCOUNT_BIT,
-+ REQ_F_ARM_LTIMEOUT_BIT,
-+ /* keep async read/write and isreg together and in order */
-+ REQ_F_NOWAIT_READ_BIT,
-+ REQ_F_NOWAIT_WRITE_BIT,
-+ REQ_F_ISREG_BIT,
-+
-+ /* not a real bit, just to check we're not overflowing the space */
-+ __REQ_F_LAST_BIT,
-+};
-+
-+enum {
-+ /* ctx owns file */
-+ REQ_F_FIXED_FILE = BIT(REQ_F_FIXED_FILE_BIT),
-+ /* drain existing IO first */
-+ REQ_F_IO_DRAIN = BIT(REQ_F_IO_DRAIN_BIT),
-+ /* linked sqes */
-+ REQ_F_LINK = BIT(REQ_F_LINK_BIT),
-+ /* doesn't sever on completion < 0 */
-+ REQ_F_HARDLINK = BIT(REQ_F_HARDLINK_BIT),
-+ /* IOSQE_ASYNC */
-+ REQ_F_FORCE_ASYNC = BIT(REQ_F_FORCE_ASYNC_BIT),
-+ /* IOSQE_BUFFER_SELECT */
-+ REQ_F_BUFFER_SELECT = BIT(REQ_F_BUFFER_SELECT_BIT),
-+
-+ /* fail rest of links */
-+ REQ_F_FAIL = BIT(REQ_F_FAIL_BIT),
-+ /* on inflight list, should be cancelled and waited on exit reliably */
-+ REQ_F_INFLIGHT = BIT(REQ_F_INFLIGHT_BIT),
-+ /* read/write uses file position */
-+ REQ_F_CUR_POS = BIT(REQ_F_CUR_POS_BIT),
-+ /* must not punt to workers */
-+ REQ_F_NOWAIT = BIT(REQ_F_NOWAIT_BIT),
-+ /* has or had linked timeout */
-+ REQ_F_LINK_TIMEOUT = BIT(REQ_F_LINK_TIMEOUT_BIT),
-+ /* needs cleanup */
-+ REQ_F_NEED_CLEANUP = BIT(REQ_F_NEED_CLEANUP_BIT),
-+ /* already went through poll handler */
-+ REQ_F_POLLED = BIT(REQ_F_POLLED_BIT),
-+ /* buffer already selected */
-+ REQ_F_BUFFER_SELECTED = BIT(REQ_F_BUFFER_SELECTED_BIT),
-+ /* completion is deferred through io_comp_state */
-+ REQ_F_COMPLETE_INLINE = BIT(REQ_F_COMPLETE_INLINE_BIT),
-+ /* caller should reissue async */
-+ REQ_F_REISSUE = BIT(REQ_F_REISSUE_BIT),
-+ /* supports async reads */
-+ REQ_F_NOWAIT_READ = BIT(REQ_F_NOWAIT_READ_BIT),
-+ /* supports async writes */
-+ REQ_F_NOWAIT_WRITE = BIT(REQ_F_NOWAIT_WRITE_BIT),
-+ /* regular file */
-+ REQ_F_ISREG = BIT(REQ_F_ISREG_BIT),
-+ /* has creds assigned */
-+ REQ_F_CREDS = BIT(REQ_F_CREDS_BIT),
-+ /* skip refcounting if not set */
-+ REQ_F_REFCOUNT = BIT(REQ_F_REFCOUNT_BIT),
-+ /* there is a linked timeout that has to be armed */
-+ REQ_F_ARM_LTIMEOUT = BIT(REQ_F_ARM_LTIMEOUT_BIT),
-+};
-+
-+struct async_poll {
-+ struct io_poll_iocb poll;
-+ struct io_poll_iocb *double_poll;
-+};
-+
-+typedef void (*io_req_tw_func_t)(struct io_kiocb *req, bool *locked);
-+
-+struct io_task_work {
-+ union {
-+ struct io_wq_work_node node;
-+ struct llist_node fallback_node;
-+ };
-+ io_req_tw_func_t func;
-+};
-+
-+enum {
-+ IORING_RSRC_FILE = 0,
-+ IORING_RSRC_BUFFER = 1,
-+};
-+
-+/*
-+ * NOTE! Each of the iocb union members has the file pointer
-+ * as the first entry in their struct definition. So you can
-+ * access the file pointer through any of the sub-structs,
-+ * or directly as just 'ki_filp' in this struct.
-+ */
-+struct io_kiocb {
-+ union {
-+ struct file *file;
-+ struct io_rw rw;
-+ struct io_poll_iocb poll;
-+ struct io_poll_update poll_update;
-+ struct io_accept accept;
-+ struct io_sync sync;
-+ struct io_cancel cancel;
-+ struct io_timeout timeout;
-+ struct io_timeout_rem timeout_rem;
-+ struct io_connect connect;
-+ struct io_sr_msg sr_msg;
-+ struct io_open open;
-+ struct io_close close;
-+ struct io_rsrc_update rsrc_update;
-+ struct io_fadvise fadvise;
-+ struct io_madvise madvise;
-+ struct io_epoll epoll;
-+ struct io_splice splice;
-+ struct io_provide_buf pbuf;
-+ struct io_statx statx;
-+ struct io_shutdown shutdown;
-+ struct io_rename rename;
-+ struct io_unlink unlink;
-+ struct io_mkdir mkdir;
-+ struct io_symlink symlink;
-+ struct io_hardlink hardlink;
-+ /* use only after cleaning per-op data, see io_clean_op() */
-+ struct io_completion compl;
-+ };
-+
-+ /* opcode allocated if it needs to store data for async defer */
-+ void *async_data;
-+ u8 opcode;
-+ /* polled IO has completed */
-+ u8 iopoll_completed;
-+
-+ u16 buf_index;
-+ u32 result;
-+
-+ struct io_ring_ctx *ctx;
-+ unsigned int flags;
-+ atomic_t refs;
-+ struct task_struct *task;
-+ u64 user_data;
-+
-+ struct io_kiocb *link;
-+ struct percpu_ref *fixed_rsrc_refs;
-+
-+ /* used with ctx->iopoll_list with reads/writes */
-+ struct list_head inflight_entry;
-+ struct io_task_work io_task_work;
-+ /* for polled requests, i.e. IORING_OP_POLL_ADD and async armed poll */
-+ struct hlist_node hash_node;
-+ struct async_poll *apoll;
-+ struct io_wq_work work;
-+ const struct cred *creds;
-+
-+ /* store used ubuf, so we can prevent reloading */
-+ struct io_mapped_ubuf *imu;
-+ /* stores selected buf, valid IFF REQ_F_BUFFER_SELECTED is set */
-+ struct io_buffer *kbuf;
-+ atomic_t poll_refs;
-+};
-+
-+struct io_tctx_node {
-+ struct list_head ctx_node;
-+ struct task_struct *task;
-+ struct io_ring_ctx *ctx;
-+};
-+
-+struct io_defer_entry {
-+ struct list_head list;
-+ struct io_kiocb *req;
-+ u32 seq;
-+};
-+
-+struct io_op_def {
-+ /* needs req->file assigned */
-+ unsigned needs_file : 1;
-+ /* hash wq insertion if file is a regular file */
-+ unsigned hash_reg_file : 1;
-+ /* unbound wq insertion if file is a non-regular file */
-+ unsigned unbound_nonreg_file : 1;
-+ /* opcode is not supported by this kernel */
-+ unsigned not_supported : 1;
-+ /* set if opcode supports polled "wait" */
-+ unsigned pollin : 1;
-+ unsigned pollout : 1;
-+ /* op supports buffer selection */
-+ unsigned buffer_select : 1;
-+ /* do prep async if is going to be punted */
-+ unsigned needs_async_setup : 1;
-+ /* should block plug */
-+ unsigned plug : 1;
-+ /* size of async data needed, if any */
-+ unsigned short async_size;
-+};
-+
-+static const struct io_op_def io_op_defs[] = {
-+ [IORING_OP_NOP] = {},
-+ [IORING_OP_READV] = {
-+ .needs_file = 1,
-+ .unbound_nonreg_file = 1,
-+ .pollin = 1,
-+ .buffer_select = 1,
-+ .needs_async_setup = 1,
-+ .plug = 1,
-+ .async_size = sizeof(struct io_async_rw),
-+ },
-+ [IORING_OP_WRITEV] = {
-+ .needs_file = 1,
-+ .hash_reg_file = 1,
-+ .unbound_nonreg_file = 1,
-+ .pollout = 1,
-+ .needs_async_setup = 1,
-+ .plug = 1,
-+ .async_size = sizeof(struct io_async_rw),
-+ },
-+ [IORING_OP_FSYNC] = {
-+ .needs_file = 1,
-+ },
-+ [IORING_OP_READ_FIXED] = {
-+ .needs_file = 1,
-+ .unbound_nonreg_file = 1,
-+ .pollin = 1,
-+ .plug = 1,
-+ .async_size = sizeof(struct io_async_rw),
-+ },
-+ [IORING_OP_WRITE_FIXED] = {
-+ .needs_file = 1,
-+ .hash_reg_file = 1,
-+ .unbound_nonreg_file = 1,
-+ .pollout = 1,
-+ .plug = 1,
-+ .async_size = sizeof(struct io_async_rw),
-+ },
-+ [IORING_OP_POLL_ADD] = {
-+ .needs_file = 1,
-+ .unbound_nonreg_file = 1,
-+ },
-+ [IORING_OP_POLL_REMOVE] = {},
-+ [IORING_OP_SYNC_FILE_RANGE] = {
-+ .needs_file = 1,
-+ },
-+ [IORING_OP_SENDMSG] = {
-+ .needs_file = 1,
-+ .unbound_nonreg_file = 1,
-+ .pollout = 1,
-+ .needs_async_setup = 1,
-+ .async_size = sizeof(struct io_async_msghdr),
-+ },
-+ [IORING_OP_RECVMSG] = {
-+ .needs_file = 1,
-+ .unbound_nonreg_file = 1,
-+ .pollin = 1,
-+ .buffer_select = 1,
-+ .needs_async_setup = 1,
-+ .async_size = sizeof(struct io_async_msghdr),
-+ },
-+ [IORING_OP_TIMEOUT] = {
-+ .async_size = sizeof(struct io_timeout_data),
-+ },
-+ [IORING_OP_TIMEOUT_REMOVE] = {
-+ /* used by timeout updates' prep() */
-+ },
-+ [IORING_OP_ACCEPT] = {
-+ .needs_file = 1,
-+ .unbound_nonreg_file = 1,
-+ .pollin = 1,
-+ },
-+ [IORING_OP_ASYNC_CANCEL] = {},
-+ [IORING_OP_LINK_TIMEOUT] = {
-+ .async_size = sizeof(struct io_timeout_data),
-+ },
-+ [IORING_OP_CONNECT] = {
-+ .needs_file = 1,
-+ .unbound_nonreg_file = 1,
-+ .pollout = 1,
-+ .needs_async_setup = 1,
-+ .async_size = sizeof(struct io_async_connect),
-+ },
-+ [IORING_OP_FALLOCATE] = {
-+ .needs_file = 1,
-+ },
-+ [IORING_OP_OPENAT] = {},
-+ [IORING_OP_CLOSE] = {},
-+ [IORING_OP_FILES_UPDATE] = {},
-+ [IORING_OP_STATX] = {},
-+ [IORING_OP_READ] = {
-+ .needs_file = 1,
-+ .unbound_nonreg_file = 1,
-+ .pollin = 1,
-+ .buffer_select = 1,
-+ .plug = 1,
-+ .async_size = sizeof(struct io_async_rw),
-+ },
-+ [IORING_OP_WRITE] = {
-+ .needs_file = 1,
-+ .hash_reg_file = 1,
-+ .unbound_nonreg_file = 1,
-+ .pollout = 1,
-+ .plug = 1,
-+ .async_size = sizeof(struct io_async_rw),
-+ },
-+ [IORING_OP_FADVISE] = {
-+ .needs_file = 1,
-+ },
-+ [IORING_OP_MADVISE] = {},
-+ [IORING_OP_SEND] = {
-+ .needs_file = 1,
-+ .unbound_nonreg_file = 1,
-+ .pollout = 1,
-+ },
-+ [IORING_OP_RECV] = {
-+ .needs_file = 1,
-+ .unbound_nonreg_file = 1,
-+ .pollin = 1,
-+ .buffer_select = 1,
-+ },
-+ [IORING_OP_OPENAT2] = {
-+ },
-+ [IORING_OP_EPOLL_CTL] = {
-+ .unbound_nonreg_file = 1,
-+ },
-+ [IORING_OP_SPLICE] = {
-+ .needs_file = 1,
-+ .hash_reg_file = 1,
-+ .unbound_nonreg_file = 1,
-+ },
-+ [IORING_OP_PROVIDE_BUFFERS] = {},
-+ [IORING_OP_REMOVE_BUFFERS] = {},
-+ [IORING_OP_TEE] = {
-+ .needs_file = 1,
-+ .hash_reg_file = 1,
-+ .unbound_nonreg_file = 1,
-+ },
-+ [IORING_OP_SHUTDOWN] = {
-+ .needs_file = 1,
-+ },
-+ [IORING_OP_RENAMEAT] = {},
-+ [IORING_OP_UNLINKAT] = {},
-+};
-+
-+/* requests with any of those set should undergo io_disarm_next() */
-+#define IO_DISARM_MASK (REQ_F_ARM_LTIMEOUT | REQ_F_LINK_TIMEOUT | REQ_F_FAIL)
-+
-+static bool io_disarm_next(struct io_kiocb *req);
-+static void io_uring_del_tctx_node(unsigned long index);
-+static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
-+ struct task_struct *task,
-+ bool cancel_all);
-+static void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd);
-+
-+static void io_fill_cqe_req(struct io_kiocb *req, s32 res, u32 cflags);
-+
-+static void io_put_req(struct io_kiocb *req);
-+static void io_put_req_deferred(struct io_kiocb *req);
-+static void io_dismantle_req(struct io_kiocb *req);
-+static void io_queue_linked_timeout(struct io_kiocb *req);
-+static int __io_register_rsrc_update(struct io_ring_ctx *ctx, unsigned type,
-+ struct io_uring_rsrc_update2 *up,
-+ unsigned nr_args);
-+static void io_clean_op(struct io_kiocb *req);
-+static struct file *io_file_get(struct io_ring_ctx *ctx,
-+ struct io_kiocb *req, int fd, bool fixed);
-+static void __io_queue_sqe(struct io_kiocb *req);
-+static void io_rsrc_put_work(struct work_struct *work);
-+
-+static void io_req_task_queue(struct io_kiocb *req);
-+static void io_submit_flush_completions(struct io_ring_ctx *ctx);
-+static int io_req_prep_async(struct io_kiocb *req);
-+
-+static int io_install_fixed_file(struct io_kiocb *req, struct file *file,
-+ unsigned int issue_flags, u32 slot_index);
-+static int io_close_fixed(struct io_kiocb *req, unsigned int issue_flags);
-+
-+static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer);
-+
-+static struct kmem_cache *req_cachep;
-+
-+static const struct file_operations io_uring_fops;
-+
-+struct sock *io_uring_get_socket(struct file *file)
-+{
-+#if defined(CONFIG_UNIX)
-+ if (file->f_op == &io_uring_fops) {
-+ struct io_ring_ctx *ctx = file->private_data;
-+
-+ return ctx->ring_sock->sk;
-+ }
-+#endif
-+ return NULL;
-+}
-+EXPORT_SYMBOL(io_uring_get_socket);
-+
-+static inline void io_tw_lock(struct io_ring_ctx *ctx, bool *locked)
-+{
-+ if (!*locked) {
-+ mutex_lock(&ctx->uring_lock);
-+ *locked = true;
-+ }
-+}
-+
-+#define io_for_each_link(pos, head) \
-+ for (pos = (head); pos; pos = pos->link)
-+
-+/*
-+ * Shamelessly stolen from the mm implementation of page reference checking,
-+ * see commit f958d7b528b1 for details.
-+ */
-+#define req_ref_zero_or_close_to_overflow(req) \
-+ ((unsigned int) atomic_read(&(req->refs)) + 127u <= 127u)
-+
-+static inline bool req_ref_inc_not_zero(struct io_kiocb *req)
-+{
-+ WARN_ON_ONCE(!(req->flags & REQ_F_REFCOUNT));
-+ return atomic_inc_not_zero(&req->refs);
-+}
-+
-+static inline bool req_ref_put_and_test(struct io_kiocb *req)
-+{
-+ if (likely(!(req->flags & REQ_F_REFCOUNT)))
-+ return true;
-+
-+ WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req));
-+ return atomic_dec_and_test(&req->refs);
-+}
-+
-+static inline void req_ref_get(struct io_kiocb *req)
-+{
-+ WARN_ON_ONCE(!(req->flags & REQ_F_REFCOUNT));
-+ WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req));
-+ atomic_inc(&req->refs);
-+}
-+
-+static inline void __io_req_set_refcount(struct io_kiocb *req, int nr)
-+{
-+ if (!(req->flags & REQ_F_REFCOUNT)) {
-+ req->flags |= REQ_F_REFCOUNT;
-+ atomic_set(&req->refs, nr);
-+ }
-+}
-+
-+static inline void io_req_set_refcount(struct io_kiocb *req)
-+{
-+ __io_req_set_refcount(req, 1);
-+}
-+
-+static inline void io_req_set_rsrc_node(struct io_kiocb *req)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+
-+ if (!req->fixed_rsrc_refs) {
-+ req->fixed_rsrc_refs = &ctx->rsrc_node->refs;
-+ percpu_ref_get(req->fixed_rsrc_refs);
-+ }
-+}
-+
-+static void io_refs_resurrect(struct percpu_ref *ref, struct completion *compl)
-+{
-+ bool got = percpu_ref_tryget(ref);
-+
-+ /* already at zero, wait for ->release() */
-+ if (!got)
-+ wait_for_completion(compl);
-+ percpu_ref_resurrect(ref);
-+ if (got)
-+ percpu_ref_put(ref);
-+}
-+
-+static bool io_match_task(struct io_kiocb *head, struct task_struct *task,
-+ bool cancel_all)
-+ __must_hold(&req->ctx->timeout_lock)
-+{
-+ struct io_kiocb *req;
-+
-+ if (task && head->task != task)
-+ return false;
-+ if (cancel_all)
-+ return true;
-+
-+ io_for_each_link(req, head) {
-+ if (req->flags & REQ_F_INFLIGHT)
-+ return true;
-+ }
-+ return false;
-+}
-+
-+static bool io_match_linked(struct io_kiocb *head)
-+{
-+ struct io_kiocb *req;
-+
-+ io_for_each_link(req, head) {
-+ if (req->flags & REQ_F_INFLIGHT)
-+ return true;
-+ }
-+ return false;
-+}
-+
-+/*
-+ * As io_match_task() but protected against racing with linked timeouts.
-+ * User must not hold timeout_lock.
-+ */
-+static bool io_match_task_safe(struct io_kiocb *head, struct task_struct *task,
-+ bool cancel_all)
-+{
-+ bool matched;
-+
-+ if (task && head->task != task)
-+ return false;
-+ if (cancel_all)
-+ return true;
-+
-+ if (head->flags & REQ_F_LINK_TIMEOUT) {
-+ struct io_ring_ctx *ctx = head->ctx;
-+
-+ /* protect against races with linked timeouts */
-+ spin_lock_irq(&ctx->timeout_lock);
-+ matched = io_match_linked(head);
-+ spin_unlock_irq(&ctx->timeout_lock);
-+ } else {
-+ matched = io_match_linked(head);
-+ }
-+ return matched;
-+}
-+
-+static inline void req_set_fail(struct io_kiocb *req)
-+{
-+ req->flags |= REQ_F_FAIL;
-+}
-+
-+static inline void req_fail_link_node(struct io_kiocb *req, int res)
-+{
-+ req_set_fail(req);
-+ req->result = res;
-+}
-+
-+static void io_ring_ctx_ref_free(struct percpu_ref *ref)
-+{
-+ struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs);
-+
-+ complete(&ctx->ref_comp);
-+}
-+
-+static inline bool io_is_timeout_noseq(struct io_kiocb *req)
-+{
-+ return !req->timeout.off;
-+}
-+
-+static void io_fallback_req_func(struct work_struct *work)
-+{
-+ struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx,
-+ fallback_work.work);
-+ struct llist_node *node = llist_del_all(&ctx->fallback_llist);
-+ struct io_kiocb *req, *tmp;
-+ bool locked = false;
-+
-+ percpu_ref_get(&ctx->refs);
-+ llist_for_each_entry_safe(req, tmp, node, io_task_work.fallback_node)
-+ req->io_task_work.func(req, &locked);
-+
-+ if (locked) {
-+ if (ctx->submit_state.compl_nr)
-+ io_submit_flush_completions(ctx);
-+ mutex_unlock(&ctx->uring_lock);
-+ }
-+ percpu_ref_put(&ctx->refs);
-+
-+}
-+
-+static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
-+{
-+ struct io_ring_ctx *ctx;
-+ int hash_bits;
-+
-+ ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
-+ if (!ctx)
-+ return NULL;
-+
-+ /*
-+ * Use 5 bits less than the max cq entries, that should give us around
-+ * 32 entries per hash list if totally full and uniformly spread.
-+ */
-+ hash_bits = ilog2(p->cq_entries);
-+ hash_bits -= 5;
-+ if (hash_bits <= 0)
-+ hash_bits = 1;
-+ ctx->cancel_hash_bits = hash_bits;
-+ ctx->cancel_hash = kmalloc((1U << hash_bits) * sizeof(struct hlist_head),
-+ GFP_KERNEL);
-+ if (!ctx->cancel_hash)
-+ goto err;
-+ __hash_init(ctx->cancel_hash, 1U << hash_bits);
-+
-+ ctx->dummy_ubuf = kzalloc(sizeof(*ctx->dummy_ubuf), GFP_KERNEL);
-+ if (!ctx->dummy_ubuf)
-+ goto err;
-+ /* set invalid range, so io_import_fixed() fails meeting it */
-+ ctx->dummy_ubuf->ubuf = -1UL;
-+
-+ if (percpu_ref_init(&ctx->refs, io_ring_ctx_ref_free,
-+ PERCPU_REF_ALLOW_REINIT, GFP_KERNEL))
-+ goto err;
-+
-+ ctx->flags = p->flags;
-+ init_waitqueue_head(&ctx->sqo_sq_wait);
-+ INIT_LIST_HEAD(&ctx->sqd_list);
-+ init_waitqueue_head(&ctx->poll_wait);
-+ INIT_LIST_HEAD(&ctx->cq_overflow_list);
-+ init_completion(&ctx->ref_comp);
-+ xa_init_flags(&ctx->io_buffers, XA_FLAGS_ALLOC1);
-+ xa_init_flags(&ctx->personalities, XA_FLAGS_ALLOC1);
-+ mutex_init(&ctx->uring_lock);
-+ init_waitqueue_head(&ctx->cq_wait);
-+ spin_lock_init(&ctx->completion_lock);
-+ spin_lock_init(&ctx->timeout_lock);
-+ INIT_LIST_HEAD(&ctx->iopoll_list);
-+ INIT_LIST_HEAD(&ctx->defer_list);
-+ INIT_LIST_HEAD(&ctx->timeout_list);
-+ INIT_LIST_HEAD(&ctx->ltimeout_list);
-+ spin_lock_init(&ctx->rsrc_ref_lock);
-+ INIT_LIST_HEAD(&ctx->rsrc_ref_list);
-+ INIT_DELAYED_WORK(&ctx->rsrc_put_work, io_rsrc_put_work);
-+ init_llist_head(&ctx->rsrc_put_llist);
-+ INIT_LIST_HEAD(&ctx->tctx_list);
-+ INIT_LIST_HEAD(&ctx->submit_state.free_list);
-+ INIT_LIST_HEAD(&ctx->locked_free_list);
-+ INIT_DELAYED_WORK(&ctx->fallback_work, io_fallback_req_func);
-+ return ctx;
-+err:
-+ kfree(ctx->dummy_ubuf);
-+ kfree(ctx->cancel_hash);
-+ kfree(ctx);
-+ return NULL;
-+}
-+
-+static void io_account_cq_overflow(struct io_ring_ctx *ctx)
-+{
-+ struct io_rings *r = ctx->rings;
-+
-+ WRITE_ONCE(r->cq_overflow, READ_ONCE(r->cq_overflow) + 1);
-+ ctx->cq_extra--;
-+}
-+
-+static bool req_need_defer(struct io_kiocb *req, u32 seq)
-+{
-+ if (unlikely(req->flags & REQ_F_IO_DRAIN)) {
-+ struct io_ring_ctx *ctx = req->ctx;
-+
-+ return seq + READ_ONCE(ctx->cq_extra) != ctx->cached_cq_tail;
-+ }
-+
-+ return false;
-+}
-+
-+#define FFS_ASYNC_READ 0x1UL
-+#define FFS_ASYNC_WRITE 0x2UL
-+#ifdef CONFIG_64BIT
-+#define FFS_ISREG 0x4UL
-+#else
-+#define FFS_ISREG 0x0UL
-+#endif
-+#define FFS_MASK ~(FFS_ASYNC_READ|FFS_ASYNC_WRITE|FFS_ISREG)
-+
-+static inline bool io_req_ffs_set(struct io_kiocb *req)
-+{
-+ return IS_ENABLED(CONFIG_64BIT) && (req->flags & REQ_F_FIXED_FILE);
-+}
-+
-+static void io_req_track_inflight(struct io_kiocb *req)
-+{
-+ if (!(req->flags & REQ_F_INFLIGHT)) {
-+ req->flags |= REQ_F_INFLIGHT;
-+ atomic_inc(&req->task->io_uring->inflight_tracked);
-+ }
-+}
-+
-+static struct io_kiocb *__io_prep_linked_timeout(struct io_kiocb *req)
-+{
-+ if (WARN_ON_ONCE(!req->link))
-+ return NULL;
-+
-+ req->flags &= ~REQ_F_ARM_LTIMEOUT;
-+ req->flags |= REQ_F_LINK_TIMEOUT;
-+
-+ /* linked timeouts should have two refs once prep'ed */
-+ io_req_set_refcount(req);
-+ __io_req_set_refcount(req->link, 2);
-+ return req->link;
-+}
-+
-+static inline struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req)
-+{
-+ if (likely(!(req->flags & REQ_F_ARM_LTIMEOUT)))
-+ return NULL;
-+ return __io_prep_linked_timeout(req);
-+}
-+
-+static void io_prep_async_work(struct io_kiocb *req)
-+{
-+ const struct io_op_def *def = &io_op_defs[req->opcode];
-+ struct io_ring_ctx *ctx = req->ctx;
-+
-+ if (!(req->flags & REQ_F_CREDS)) {
-+ req->flags |= REQ_F_CREDS;
-+ req->creds = get_current_cred();
-+ }
-+
-+ req->work.list.next = NULL;
-+ req->work.flags = 0;
-+ if (req->flags & REQ_F_FORCE_ASYNC)
-+ req->work.flags |= IO_WQ_WORK_CONCURRENT;
-+
-+ if (req->flags & REQ_F_ISREG) {
-+ if (def->hash_reg_file || (ctx->flags & IORING_SETUP_IOPOLL))
-+ io_wq_hash_work(&req->work, file_inode(req->file));
-+ } else if (!req->file || !S_ISBLK(file_inode(req->file)->i_mode)) {
-+ if (def->unbound_nonreg_file)
-+ req->work.flags |= IO_WQ_WORK_UNBOUND;
-+ }
-+}
-+
-+static void io_prep_async_link(struct io_kiocb *req)
-+{
-+ struct io_kiocb *cur;
-+
-+ if (req->flags & REQ_F_LINK_TIMEOUT) {
-+ struct io_ring_ctx *ctx = req->ctx;
-+
-+ spin_lock_irq(&ctx->timeout_lock);
-+ io_for_each_link(cur, req)
-+ io_prep_async_work(cur);
-+ spin_unlock_irq(&ctx->timeout_lock);
-+ } else {
-+ io_for_each_link(cur, req)
-+ io_prep_async_work(cur);
-+ }
-+}
-+
-+static void io_queue_async_work(struct io_kiocb *req, bool *locked)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+ struct io_kiocb *link = io_prep_linked_timeout(req);
-+ struct io_uring_task *tctx = req->task->io_uring;
-+
-+ /* must not take the lock, NULL it as a precaution */
-+ locked = NULL;
-+
-+ BUG_ON(!tctx);
-+ BUG_ON(!tctx->io_wq);
-+
-+ /* init ->work of the whole link before punting */
-+ io_prep_async_link(req);
-+
-+ /*
-+ * Not expected to happen, but if we do have a bug where this _can_
-+ * happen, catch it here and ensure the request is marked as
-+ * canceled. That will make io-wq go through the usual work cancel
-+ * procedure rather than attempt to run this request (or create a new
-+ * worker for it).
-+ */
-+ if (WARN_ON_ONCE(!same_thread_group(req->task, current)))
-+ req->work.flags |= IO_WQ_WORK_CANCEL;
-+
-+ trace_io_uring_queue_async_work(ctx, io_wq_is_hashed(&req->work), req,
-+ &req->work, req->flags);
-+ io_wq_enqueue(tctx->io_wq, &req->work);
-+ if (link)
-+ io_queue_linked_timeout(link);
-+}
-+
-+static void io_kill_timeout(struct io_kiocb *req, int status)
-+ __must_hold(&req->ctx->completion_lock)
-+ __must_hold(&req->ctx->timeout_lock)
-+{
-+ struct io_timeout_data *io = req->async_data;
-+
-+ if (hrtimer_try_to_cancel(&io->timer) != -1) {
-+ if (status)
-+ req_set_fail(req);
-+ atomic_set(&req->ctx->cq_timeouts,
-+ atomic_read(&req->ctx->cq_timeouts) + 1);
-+ list_del_init(&req->timeout.list);
-+ io_fill_cqe_req(req, status, 0);
-+ io_put_req_deferred(req);
-+ }
-+}
-+
-+static void io_queue_deferred(struct io_ring_ctx *ctx)
-+{
-+ while (!list_empty(&ctx->defer_list)) {
-+ struct io_defer_entry *de = list_first_entry(&ctx->defer_list,
-+ struct io_defer_entry, list);
-+
-+ if (req_need_defer(de->req, de->seq))
-+ break;
-+ list_del_init(&de->list);
-+ io_req_task_queue(de->req);
-+ kfree(de);
-+ }
-+}
-+
-+static void io_flush_timeouts(struct io_ring_ctx *ctx)
-+ __must_hold(&ctx->completion_lock)
-+{
-+ u32 seq = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);
-+ struct io_kiocb *req, *tmp;
-+
-+ spin_lock_irq(&ctx->timeout_lock);
-+ list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list) {
-+ u32 events_needed, events_got;
-+
-+ if (io_is_timeout_noseq(req))
-+ break;
-+
-+ /*
-+ * Since seq can easily wrap around over time, subtract
-+ * the last seq at which timeouts were flushed before comparing.
-+ * Assuming not more than 2^31-1 events have happened since,
-+ * these subtractions won't have wrapped, so we can check if
-+ * target is in [last_seq, current_seq] by comparing the two.
-+ */
-+ events_needed = req->timeout.target_seq - ctx->cq_last_tm_flush;
-+ events_got = seq - ctx->cq_last_tm_flush;
-+ if (events_got < events_needed)
-+ break;
-+
-+ io_kill_timeout(req, 0);
-+ }
-+ ctx->cq_last_tm_flush = seq;
-+ spin_unlock_irq(&ctx->timeout_lock);
-+}
-+
-+static void __io_commit_cqring_flush(struct io_ring_ctx *ctx)
-+{
-+ if (ctx->off_timeout_used)
-+ io_flush_timeouts(ctx);
-+ if (ctx->drain_active)
-+ io_queue_deferred(ctx);
-+}
-+
-+static inline void io_commit_cqring(struct io_ring_ctx *ctx)
-+{
-+ if (unlikely(ctx->off_timeout_used || ctx->drain_active))
-+ __io_commit_cqring_flush(ctx);
-+ /* order cqe stores with ring update */
-+ smp_store_release(&ctx->rings->cq.tail, ctx->cached_cq_tail);
-+}
-+
-+static inline bool io_sqring_full(struct io_ring_ctx *ctx)
-+{
-+ struct io_rings *r = ctx->rings;
-+
-+ return READ_ONCE(r->sq.tail) - ctx->cached_sq_head == ctx->sq_entries;
-+}
-+
-+static inline unsigned int __io_cqring_events(struct io_ring_ctx *ctx)
-+{
-+ return ctx->cached_cq_tail - READ_ONCE(ctx->rings->cq.head);
-+}
-+
-+static inline struct io_uring_cqe *io_get_cqe(struct io_ring_ctx *ctx)
-+{
-+ struct io_rings *rings = ctx->rings;
-+ unsigned tail, mask = ctx->cq_entries - 1;
-+
-+ /*
-+ * writes to the cq entry need to come after reading head; the
-+ * control dependency is enough as we're using WRITE_ONCE to
-+ * fill the cq entry
-+ */
-+ if (__io_cqring_events(ctx) == ctx->cq_entries)
-+ return NULL;
-+
-+ tail = ctx->cached_cq_tail++;
-+ return &rings->cqes[tail & mask];
-+}
-+
-+static inline bool io_should_trigger_evfd(struct io_ring_ctx *ctx)
-+{
-+ if (likely(!ctx->cq_ev_fd))
-+ return false;
-+ if (READ_ONCE(ctx->rings->cq_flags) & IORING_CQ_EVENTFD_DISABLED)
-+ return false;
-+ return !ctx->eventfd_async || io_wq_current_is_worker();
-+}
-+
-+/*
-+ * This should only get called when at least one event has been posted.
-+ * Some applications rely on the eventfd notification count only changing
-+ * IFF a new CQE has been added to the CQ ring. There's no depedency on
-+ * 1:1 relationship between how many times this function is called (and
-+ * hence the eventfd count) and number of CQEs posted to the CQ ring.
-+ */
-+static void io_cqring_ev_posted(struct io_ring_ctx *ctx)
-+{
-+ /*
-+ * wake_up_all() may seem excessive, but io_wake_function() and
-+ * io_should_wake() handle the termination of the loop and only
-+ * wake as many waiters as we need to.
-+ */
-+ if (wq_has_sleeper(&ctx->cq_wait))
-+ wake_up_all(&ctx->cq_wait);
-+ if (ctx->sq_data && waitqueue_active(&ctx->sq_data->wait))
-+ wake_up(&ctx->sq_data->wait);
-+ if (io_should_trigger_evfd(ctx))
-+ eventfd_signal(ctx->cq_ev_fd, 1);
-+ if (waitqueue_active(&ctx->poll_wait))
-+ wake_up_interruptible(&ctx->poll_wait);
-+}
-+
-+static void io_cqring_ev_posted_iopoll(struct io_ring_ctx *ctx)
-+{
-+ /* see waitqueue_active() comment */
-+ smp_mb();
-+
-+ if (ctx->flags & IORING_SETUP_SQPOLL) {
-+ if (waitqueue_active(&ctx->cq_wait))
-+ wake_up_all(&ctx->cq_wait);
-+ }
-+ if (io_should_trigger_evfd(ctx))
-+ eventfd_signal(ctx->cq_ev_fd, 1);
-+ if (waitqueue_active(&ctx->poll_wait))
-+ wake_up_interruptible(&ctx->poll_wait);
-+}
-+
-+/* Returns true if there are no backlogged entries after the flush */
-+static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force)
-+{
-+ bool all_flushed, posted;
-+
-+ if (!force && __io_cqring_events(ctx) == ctx->cq_entries)
-+ return false;
-+
-+ posted = false;
-+ spin_lock(&ctx->completion_lock);
-+ while (!list_empty(&ctx->cq_overflow_list)) {
-+ struct io_uring_cqe *cqe = io_get_cqe(ctx);
-+ struct io_overflow_cqe *ocqe;
-+
-+ if (!cqe && !force)
-+ break;
-+ ocqe = list_first_entry(&ctx->cq_overflow_list,
-+ struct io_overflow_cqe, list);
-+ if (cqe)
-+ memcpy(cqe, &ocqe->cqe, sizeof(*cqe));
-+ else
-+ io_account_cq_overflow(ctx);
-+
-+ posted = true;
-+ list_del(&ocqe->list);
-+ kfree(ocqe);
-+ }
-+
-+ all_flushed = list_empty(&ctx->cq_overflow_list);
-+ if (all_flushed) {
-+ clear_bit(0, &ctx->check_cq_overflow);
-+ WRITE_ONCE(ctx->rings->sq_flags,
-+ ctx->rings->sq_flags & ~IORING_SQ_CQ_OVERFLOW);
-+ }
-+
-+ if (posted)
-+ io_commit_cqring(ctx);
-+ spin_unlock(&ctx->completion_lock);
-+ if (posted)
-+ io_cqring_ev_posted(ctx);
-+ return all_flushed;
-+}
-+
-+static bool io_cqring_overflow_flush(struct io_ring_ctx *ctx)
-+{
-+ bool ret = true;
-+
-+ if (test_bit(0, &ctx->check_cq_overflow)) {
-+ /* iopoll syncs against uring_lock, not completion_lock */
-+ if (ctx->flags & IORING_SETUP_IOPOLL)
-+ mutex_lock(&ctx->uring_lock);
-+ ret = __io_cqring_overflow_flush(ctx, false);
-+ if (ctx->flags & IORING_SETUP_IOPOLL)
-+ mutex_unlock(&ctx->uring_lock);
-+ }
-+
-+ return ret;
-+}
-+
-+/* must to be called somewhat shortly after putting a request */
-+static inline void io_put_task(struct task_struct *task, int nr)
-+{
-+ struct io_uring_task *tctx = task->io_uring;
-+
-+ if (likely(task == current)) {
-+ tctx->cached_refs += nr;
-+ } else {
-+ percpu_counter_sub(&tctx->inflight, nr);
-+ if (unlikely(atomic_read(&tctx->in_idle)))
-+ wake_up(&tctx->wait);
-+ put_task_struct_many(task, nr);
-+ }
-+}
-+
-+static void io_task_refs_refill(struct io_uring_task *tctx)
-+{
-+ unsigned int refill = -tctx->cached_refs + IO_TCTX_REFS_CACHE_NR;
-+
-+ percpu_counter_add(&tctx->inflight, refill);
-+ refcount_add(refill, ¤t->usage);
-+ tctx->cached_refs += refill;
-+}
-+
-+static inline void io_get_task_refs(int nr)
-+{
-+ struct io_uring_task *tctx = current->io_uring;
-+
-+ tctx->cached_refs -= nr;
-+ if (unlikely(tctx->cached_refs < 0))
-+ io_task_refs_refill(tctx);
-+}
-+
-+static __cold void io_uring_drop_tctx_refs(struct task_struct *task)
-+{
-+ struct io_uring_task *tctx = task->io_uring;
-+ unsigned int refs = tctx->cached_refs;
-+
-+ if (refs) {
-+ tctx->cached_refs = 0;
-+ percpu_counter_sub(&tctx->inflight, refs);
-+ put_task_struct_many(task, refs);
-+ }
-+}
-+
-+static bool io_cqring_event_overflow(struct io_ring_ctx *ctx, u64 user_data,
-+ s32 res, u32 cflags)
-+{
-+ struct io_overflow_cqe *ocqe;
-+
-+ ocqe = kmalloc(sizeof(*ocqe), GFP_ATOMIC | __GFP_ACCOUNT);
-+ if (!ocqe) {
-+ /*
-+ * If we're in ring overflow flush mode, or in task cancel mode,
-+ * or cannot allocate an overflow entry, then we need to drop it
-+ * on the floor.
-+ */
-+ io_account_cq_overflow(ctx);
-+ return false;
-+ }
-+ if (list_empty(&ctx->cq_overflow_list)) {
-+ set_bit(0, &ctx->check_cq_overflow);
-+ WRITE_ONCE(ctx->rings->sq_flags,
-+ ctx->rings->sq_flags | IORING_SQ_CQ_OVERFLOW);
-+
-+ }
-+ ocqe->cqe.user_data = user_data;
-+ ocqe->cqe.res = res;
-+ ocqe->cqe.flags = cflags;
-+ list_add_tail(&ocqe->list, &ctx->cq_overflow_list);
-+ return true;
-+}
-+
-+static inline bool __io_fill_cqe(struct io_ring_ctx *ctx, u64 user_data,
-+ s32 res, u32 cflags)
-+{
-+ struct io_uring_cqe *cqe;
-+
-+ trace_io_uring_complete(ctx, user_data, res, cflags);
-+
-+ /*
-+ * If we can't get a cq entry, userspace overflowed the
-+ * submission (by quite a lot). Increment the overflow count in
-+ * the ring.
-+ */
-+ cqe = io_get_cqe(ctx);
-+ if (likely(cqe)) {
-+ WRITE_ONCE(cqe->user_data, user_data);
-+ WRITE_ONCE(cqe->res, res);
-+ WRITE_ONCE(cqe->flags, cflags);
-+ return true;
-+ }
-+ return io_cqring_event_overflow(ctx, user_data, res, cflags);
-+}
-+
-+static noinline void io_fill_cqe_req(struct io_kiocb *req, s32 res, u32 cflags)
-+{
-+ __io_fill_cqe(req->ctx, req->user_data, res, cflags);
-+}
-+
-+static noinline bool io_fill_cqe_aux(struct io_ring_ctx *ctx, u64 user_data,
-+ s32 res, u32 cflags)
-+{
-+ ctx->cq_extra++;
-+ return __io_fill_cqe(ctx, user_data, res, cflags);
-+}
-+
-+static void io_req_complete_post(struct io_kiocb *req, s32 res,
-+ u32 cflags)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+
-+ spin_lock(&ctx->completion_lock);
-+ __io_fill_cqe(ctx, req->user_data, res, cflags);
-+ /*
-+ * If we're the last reference to this request, add to our locked
-+ * free_list cache.
-+ */
-+ if (req_ref_put_and_test(req)) {
-+ if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) {
-+ if (req->flags & IO_DISARM_MASK)
-+ io_disarm_next(req);
-+ if (req->link) {
-+ io_req_task_queue(req->link);
-+ req->link = NULL;
-+ }
-+ }
-+ io_dismantle_req(req);
-+ io_put_task(req->task, 1);
-+ list_add(&req->inflight_entry, &ctx->locked_free_list);
-+ ctx->locked_free_nr++;
-+ } else {
-+ if (!percpu_ref_tryget(&ctx->refs))
-+ req = NULL;
-+ }
-+ io_commit_cqring(ctx);
-+ spin_unlock(&ctx->completion_lock);
-+
-+ if (req) {
-+ io_cqring_ev_posted(ctx);
-+ percpu_ref_put(&ctx->refs);
-+ }
-+}
-+
-+static inline bool io_req_needs_clean(struct io_kiocb *req)
-+{
-+ return req->flags & IO_REQ_CLEAN_FLAGS;
-+}
-+
-+static inline void io_req_complete_state(struct io_kiocb *req, s32 res,
-+ u32 cflags)
-+{
-+ if (io_req_needs_clean(req))
-+ io_clean_op(req);
-+ req->result = res;
-+ req->compl.cflags = cflags;
-+ req->flags |= REQ_F_COMPLETE_INLINE;
-+}
-+
-+static inline void __io_req_complete(struct io_kiocb *req, unsigned issue_flags,
-+ s32 res, u32 cflags)
-+{
-+ if (issue_flags & IO_URING_F_COMPLETE_DEFER)
-+ io_req_complete_state(req, res, cflags);
-+ else
-+ io_req_complete_post(req, res, cflags);
-+}
-+
-+static inline void io_req_complete(struct io_kiocb *req, s32 res)
-+{
-+ __io_req_complete(req, 0, res, 0);
-+}
-+
-+static void io_req_complete_failed(struct io_kiocb *req, s32 res)
-+{
-+ req_set_fail(req);
-+ io_req_complete_post(req, res, 0);
-+}
-+
-+static void io_req_complete_fail_submit(struct io_kiocb *req)
-+{
-+ /*
-+ * We don't submit, fail them all, for that replace hardlinks with
-+ * normal links. Extra REQ_F_LINK is tolerated.
-+ */
-+ req->flags &= ~REQ_F_HARDLINK;
-+ req->flags |= REQ_F_LINK;
-+ io_req_complete_failed(req, req->result);
-+}
-+
-+/*
-+ * Don't initialise the fields below on every allocation, but do that in
-+ * advance and keep them valid across allocations.
-+ */
-+static void io_preinit_req(struct io_kiocb *req, struct io_ring_ctx *ctx)
-+{
-+ req->ctx = ctx;
-+ req->link = NULL;
-+ req->async_data = NULL;
-+ /* not necessary, but safer to zero */
-+ req->result = 0;
-+}
-+
-+static void io_flush_cached_locked_reqs(struct io_ring_ctx *ctx,
-+ struct io_submit_state *state)
-+{
-+ spin_lock(&ctx->completion_lock);
-+ list_splice_init(&ctx->locked_free_list, &state->free_list);
-+ ctx->locked_free_nr = 0;
-+ spin_unlock(&ctx->completion_lock);
-+}
-+
-+/* Returns true IFF there are requests in the cache */
-+static bool io_flush_cached_reqs(struct io_ring_ctx *ctx)
-+{
-+ struct io_submit_state *state = &ctx->submit_state;
-+ int nr;
-+
-+ /*
-+ * If we have more than a batch's worth of requests in our IRQ side
-+ * locked cache, grab the lock and move them over to our submission
-+ * side cache.
-+ */
-+ if (READ_ONCE(ctx->locked_free_nr) > IO_COMPL_BATCH)
-+ io_flush_cached_locked_reqs(ctx, state);
-+
-+ nr = state->free_reqs;
-+ while (!list_empty(&state->free_list)) {
-+ struct io_kiocb *req = list_first_entry(&state->free_list,
-+ struct io_kiocb, inflight_entry);
-+
-+ list_del(&req->inflight_entry);
-+ state->reqs[nr++] = req;
-+ if (nr == ARRAY_SIZE(state->reqs))
-+ break;
-+ }
-+
-+ state->free_reqs = nr;
-+ return nr != 0;
-+}
-+
-+/*
-+ * A request might get retired back into the request caches even before opcode
-+ * handlers and io_issue_sqe() are done with it, e.g. inline completion path.
-+ * Because of that, io_alloc_req() should be called only under ->uring_lock
-+ * and with extra caution to not get a request that is still worked on.
-+ */
-+static struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx)
-+ __must_hold(&ctx->uring_lock)
-+{
-+ struct io_submit_state *state = &ctx->submit_state;
-+ gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;
-+ int ret, i;
-+
-+ BUILD_BUG_ON(ARRAY_SIZE(state->reqs) < IO_REQ_ALLOC_BATCH);
-+
-+ if (likely(state->free_reqs || io_flush_cached_reqs(ctx)))
-+ goto got_req;
-+
-+ ret = kmem_cache_alloc_bulk(req_cachep, gfp, IO_REQ_ALLOC_BATCH,
-+ state->reqs);
-+
-+ /*
-+ * Bulk alloc is all-or-nothing. If we fail to get a batch,
-+ * retry single alloc to be on the safe side.
-+ */
-+ if (unlikely(ret <= 0)) {
-+ state->reqs[0] = kmem_cache_alloc(req_cachep, gfp);
-+ if (!state->reqs[0])
-+ return NULL;
-+ ret = 1;
-+ }
-+
-+ for (i = 0; i < ret; i++)
-+ io_preinit_req(state->reqs[i], ctx);
-+ state->free_reqs = ret;
-+got_req:
-+ state->free_reqs--;
-+ return state->reqs[state->free_reqs];
-+}
-+
-+static inline void io_put_file(struct file *file)
-+{
-+ if (file)
-+ fput(file);
-+}
-+
-+static void io_dismantle_req(struct io_kiocb *req)
-+{
-+ unsigned int flags = req->flags;
-+
-+ if (io_req_needs_clean(req))
-+ io_clean_op(req);
-+ if (!(flags & REQ_F_FIXED_FILE))
-+ io_put_file(req->file);
-+ if (req->fixed_rsrc_refs)
-+ percpu_ref_put(req->fixed_rsrc_refs);
-+ if (req->async_data) {
-+ kfree(req->async_data);
-+ req->async_data = NULL;
-+ }
-+}
-+
-+static void __io_free_req(struct io_kiocb *req)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+
-+ io_dismantle_req(req);
-+ io_put_task(req->task, 1);
-+
-+ spin_lock(&ctx->completion_lock);
-+ list_add(&req->inflight_entry, &ctx->locked_free_list);
-+ ctx->locked_free_nr++;
-+ spin_unlock(&ctx->completion_lock);
-+
-+ percpu_ref_put(&ctx->refs);
-+}
-+
-+static inline void io_remove_next_linked(struct io_kiocb *req)
-+{
-+ struct io_kiocb *nxt = req->link;
-+
-+ req->link = nxt->link;
-+ nxt->link = NULL;
-+}
-+
-+static bool io_kill_linked_timeout(struct io_kiocb *req)
-+ __must_hold(&req->ctx->completion_lock)
-+ __must_hold(&req->ctx->timeout_lock)
-+{
-+ struct io_kiocb *link = req->link;
-+
-+ if (link && link->opcode == IORING_OP_LINK_TIMEOUT) {
-+ struct io_timeout_data *io = link->async_data;
-+
-+ io_remove_next_linked(req);
-+ link->timeout.head = NULL;
-+ if (hrtimer_try_to_cancel(&io->timer) != -1) {
-+ list_del(&link->timeout.list);
-+ io_fill_cqe_req(link, -ECANCELED, 0);
-+ io_put_req_deferred(link);
-+ return true;
-+ }
-+ }
-+ return false;
-+}
-+
-+static void io_fail_links(struct io_kiocb *req)
-+ __must_hold(&req->ctx->completion_lock)
-+{
-+ struct io_kiocb *nxt, *link = req->link;
-+
-+ req->link = NULL;
-+ while (link) {
-+ long res = -ECANCELED;
-+
-+ if (link->flags & REQ_F_FAIL)
-+ res = link->result;
-+
-+ nxt = link->link;
-+ link->link = NULL;
-+
-+ trace_io_uring_fail_link(req, link);
-+ io_fill_cqe_req(link, res, 0);
-+ io_put_req_deferred(link);
-+ link = nxt;
-+ }
-+}
-+
-+static bool io_disarm_next(struct io_kiocb *req)
-+ __must_hold(&req->ctx->completion_lock)
-+{
-+ bool posted = false;
-+
-+ if (req->flags & REQ_F_ARM_LTIMEOUT) {
-+ struct io_kiocb *link = req->link;
-+
-+ req->flags &= ~REQ_F_ARM_LTIMEOUT;
-+ if (link && link->opcode == IORING_OP_LINK_TIMEOUT) {
-+ io_remove_next_linked(req);
-+ io_fill_cqe_req(link, -ECANCELED, 0);
-+ io_put_req_deferred(link);
-+ posted = true;
-+ }
-+ } else if (req->flags & REQ_F_LINK_TIMEOUT) {
-+ struct io_ring_ctx *ctx = req->ctx;
-+
-+ spin_lock_irq(&ctx->timeout_lock);
-+ posted = io_kill_linked_timeout(req);
-+ spin_unlock_irq(&ctx->timeout_lock);
-+ }
-+ if (unlikely((req->flags & REQ_F_FAIL) &&
-+ !(req->flags & REQ_F_HARDLINK))) {
-+ posted |= (req->link != NULL);
-+ io_fail_links(req);
-+ }
-+ return posted;
-+}
-+
-+static struct io_kiocb *__io_req_find_next(struct io_kiocb *req)
-+{
-+ struct io_kiocb *nxt;
-+
-+ /*
-+ * If LINK is set, we have dependent requests in this chain. If we
-+ * didn't fail this request, queue the first one up, moving any other
-+ * dependencies to the next request. In case of failure, fail the rest
-+ * of the chain.
-+ */
-+ if (req->flags & IO_DISARM_MASK) {
-+ struct io_ring_ctx *ctx = req->ctx;
-+ bool posted;
-+
-+ spin_lock(&ctx->completion_lock);
-+ posted = io_disarm_next(req);
-+ if (posted)
-+ io_commit_cqring(req->ctx);
-+ spin_unlock(&ctx->completion_lock);
-+ if (posted)
-+ io_cqring_ev_posted(ctx);
-+ }
-+ nxt = req->link;
-+ req->link = NULL;
-+ return nxt;
-+}
-+
-+static inline struct io_kiocb *io_req_find_next(struct io_kiocb *req)
-+{
-+ if (likely(!(req->flags & (REQ_F_LINK|REQ_F_HARDLINK))))
-+ return NULL;
-+ return __io_req_find_next(req);
-+}
-+
-+static void ctx_flush_and_put(struct io_ring_ctx *ctx, bool *locked)
-+{
-+ if (!ctx)
-+ return;
-+ if (*locked) {
-+ if (ctx->submit_state.compl_nr)
-+ io_submit_flush_completions(ctx);
-+ mutex_unlock(&ctx->uring_lock);
-+ *locked = false;
-+ }
-+ percpu_ref_put(&ctx->refs);
-+}
-+
-+static void tctx_task_work(struct callback_head *cb)
-+{
-+ bool locked = false;
-+ struct io_ring_ctx *ctx = NULL;
-+ struct io_uring_task *tctx = container_of(cb, struct io_uring_task,
-+ task_work);
-+
-+ while (1) {
-+ struct io_wq_work_node *node;
-+
-+ if (!tctx->task_list.first && locked && ctx->submit_state.compl_nr)
-+ io_submit_flush_completions(ctx);
-+
-+ spin_lock_irq(&tctx->task_lock);
-+ node = tctx->task_list.first;
-+ INIT_WQ_LIST(&tctx->task_list);
-+ if (!node)
-+ tctx->task_running = false;
-+ spin_unlock_irq(&tctx->task_lock);
-+ if (!node)
-+ break;
-+
-+ do {
-+ struct io_wq_work_node *next = node->next;
-+ struct io_kiocb *req = container_of(node, struct io_kiocb,
-+ io_task_work.node);
-+
-+ if (req->ctx != ctx) {
-+ ctx_flush_and_put(ctx, &locked);
-+ ctx = req->ctx;
-+ /* if not contended, grab and improve batching */
-+ locked = mutex_trylock(&ctx->uring_lock);
-+ percpu_ref_get(&ctx->refs);
-+ }
-+ req->io_task_work.func(req, &locked);
-+ node = next;
-+ } while (node);
-+
-+ cond_resched();
-+ }
-+
-+ ctx_flush_and_put(ctx, &locked);
-+
-+ /* relaxed read is enough as only the task itself sets ->in_idle */
-+ if (unlikely(atomic_read(&tctx->in_idle)))
-+ io_uring_drop_tctx_refs(current);
-+}
-+
-+static void io_req_task_work_add(struct io_kiocb *req)
-+{
-+ struct task_struct *tsk = req->task;
-+ struct io_uring_task *tctx = tsk->io_uring;
-+ enum task_work_notify_mode notify;
-+ struct io_wq_work_node *node;
-+ unsigned long flags;
-+ bool running;
-+
-+ WARN_ON_ONCE(!tctx);
-+
-+ spin_lock_irqsave(&tctx->task_lock, flags);
-+ wq_list_add_tail(&req->io_task_work.node, &tctx->task_list);
-+ running = tctx->task_running;
-+ if (!running)
-+ tctx->task_running = true;
-+ spin_unlock_irqrestore(&tctx->task_lock, flags);
-+
-+ /* task_work already pending, we're done */
-+ if (running)
-+ return;
-+
-+ /*
-+ * SQPOLL kernel thread doesn't need notification, just a wakeup. For
-+ * all other cases, use TWA_SIGNAL unconditionally to ensure we're
-+ * processing task_work. There's no reliable way to tell if TWA_RESUME
-+ * will do the job.
-+ */
-+ notify = (req->ctx->flags & IORING_SETUP_SQPOLL) ? TWA_NONE : TWA_SIGNAL;
-+ if (!task_work_add(tsk, &tctx->task_work, notify)) {
-+ wake_up_process(tsk);
-+ return;
-+ }
-+
-+ spin_lock_irqsave(&tctx->task_lock, flags);
-+ tctx->task_running = false;
-+ node = tctx->task_list.first;
-+ INIT_WQ_LIST(&tctx->task_list);
-+ spin_unlock_irqrestore(&tctx->task_lock, flags);
-+
-+ while (node) {
-+ req = container_of(node, struct io_kiocb, io_task_work.node);
-+ node = node->next;
-+ if (llist_add(&req->io_task_work.fallback_node,
-+ &req->ctx->fallback_llist))
-+ schedule_delayed_work(&req->ctx->fallback_work, 1);
-+ }
-+}
-+
-+static void io_req_task_cancel(struct io_kiocb *req, bool *locked)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+
-+ /* not needed for normal modes, but SQPOLL depends on it */
-+ io_tw_lock(ctx, locked);
-+ io_req_complete_failed(req, req->result);
-+}
-+
-+static void io_req_task_submit(struct io_kiocb *req, bool *locked)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+
-+ io_tw_lock(ctx, locked);
-+ /* req->task == current here, checking PF_EXITING is safe */
-+ if (likely(!(req->task->flags & PF_EXITING)))
-+ __io_queue_sqe(req);
-+ else
-+ io_req_complete_failed(req, -EFAULT);
-+}
-+
-+static void io_req_task_queue_fail(struct io_kiocb *req, int ret)
-+{
-+ req->result = ret;
-+ req->io_task_work.func = io_req_task_cancel;
-+ io_req_task_work_add(req);
-+}
-+
-+static void io_req_task_queue(struct io_kiocb *req)
-+{
-+ req->io_task_work.func = io_req_task_submit;
-+ io_req_task_work_add(req);
-+}
-+
-+static void io_req_task_queue_reissue(struct io_kiocb *req)
-+{
-+ req->io_task_work.func = io_queue_async_work;
-+ io_req_task_work_add(req);
-+}
-+
-+static inline void io_queue_next(struct io_kiocb *req)
-+{
-+ struct io_kiocb *nxt = io_req_find_next(req);
-+
-+ if (nxt)
-+ io_req_task_queue(nxt);
-+}
-+
-+static void io_free_req(struct io_kiocb *req)
-+{
-+ io_queue_next(req);
-+ __io_free_req(req);
-+}
-+
-+static void io_free_req_work(struct io_kiocb *req, bool *locked)
-+{
-+ io_free_req(req);
-+}
-+
-+struct req_batch {
-+ struct task_struct *task;
-+ int task_refs;
-+ int ctx_refs;
-+};
-+
-+static inline void io_init_req_batch(struct req_batch *rb)
-+{
-+ rb->task_refs = 0;
-+ rb->ctx_refs = 0;
-+ rb->task = NULL;
-+}
-+
-+static void io_req_free_batch_finish(struct io_ring_ctx *ctx,
-+ struct req_batch *rb)
-+{
-+ if (rb->ctx_refs)
-+ percpu_ref_put_many(&ctx->refs, rb->ctx_refs);
-+ if (rb->task)
-+ io_put_task(rb->task, rb->task_refs);
-+}
-+
-+static void io_req_free_batch(struct req_batch *rb, struct io_kiocb *req,
-+ struct io_submit_state *state)
-+{
-+ io_queue_next(req);
-+ io_dismantle_req(req);
-+
-+ if (req->task != rb->task) {
-+ if (rb->task)
-+ io_put_task(rb->task, rb->task_refs);
-+ rb->task = req->task;
-+ rb->task_refs = 0;
-+ }
-+ rb->task_refs++;
-+ rb->ctx_refs++;
-+
-+ if (state->free_reqs != ARRAY_SIZE(state->reqs))
-+ state->reqs[state->free_reqs++] = req;
-+ else
-+ list_add(&req->inflight_entry, &state->free_list);
-+}
-+
-+static void io_submit_flush_completions(struct io_ring_ctx *ctx)
-+ __must_hold(&ctx->uring_lock)
-+{
-+ struct io_submit_state *state = &ctx->submit_state;
-+ int i, nr = state->compl_nr;
-+ struct req_batch rb;
-+
-+ spin_lock(&ctx->completion_lock);
-+ for (i = 0; i < nr; i++) {
-+ struct io_kiocb *req = state->compl_reqs[i];
-+
-+ __io_fill_cqe(ctx, req->user_data, req->result,
-+ req->compl.cflags);
-+ }
-+ io_commit_cqring(ctx);
-+ spin_unlock(&ctx->completion_lock);
-+ io_cqring_ev_posted(ctx);
-+
-+ io_init_req_batch(&rb);
-+ for (i = 0; i < nr; i++) {
-+ struct io_kiocb *req = state->compl_reqs[i];
-+
-+ if (req_ref_put_and_test(req))
-+ io_req_free_batch(&rb, req, &ctx->submit_state);
-+ }
-+
-+ io_req_free_batch_finish(ctx, &rb);
-+ state->compl_nr = 0;
-+}
-+
-+/*
-+ * Drop reference to request, return next in chain (if there is one) if this
-+ * was the last reference to this request.
-+ */
-+static inline struct io_kiocb *io_put_req_find_next(struct io_kiocb *req)
-+{
-+ struct io_kiocb *nxt = NULL;
-+
-+ if (req_ref_put_and_test(req)) {
-+ nxt = io_req_find_next(req);
-+ __io_free_req(req);
-+ }
-+ return nxt;
-+}
-+
-+static inline void io_put_req(struct io_kiocb *req)
-+{
-+ if (req_ref_put_and_test(req))
-+ io_free_req(req);
-+}
-+
-+static inline void io_put_req_deferred(struct io_kiocb *req)
-+{
-+ if (req_ref_put_and_test(req)) {
-+ req->io_task_work.func = io_free_req_work;
-+ io_req_task_work_add(req);
-+ }
-+}
-+
-+static unsigned io_cqring_events(struct io_ring_ctx *ctx)
-+{
-+ /* See comment at the top of this file */
-+ smp_rmb();
-+ return __io_cqring_events(ctx);
-+}
-+
-+static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx)
-+{
-+ struct io_rings *rings = ctx->rings;
-+
-+ /* make sure SQ entry isn't read before tail */
-+ return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head;
-+}
-+
-+static unsigned int io_put_kbuf(struct io_kiocb *req, struct io_buffer *kbuf)
-+{
-+ unsigned int cflags;
-+
-+ cflags = kbuf->bid << IORING_CQE_BUFFER_SHIFT;
-+ cflags |= IORING_CQE_F_BUFFER;
-+ req->flags &= ~REQ_F_BUFFER_SELECTED;
-+ kfree(kbuf);
-+ return cflags;
-+}
-+
-+static inline unsigned int io_put_rw_kbuf(struct io_kiocb *req)
-+{
-+ struct io_buffer *kbuf;
-+
-+ if (likely(!(req->flags & REQ_F_BUFFER_SELECTED)))
-+ return 0;
-+ kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
-+ return io_put_kbuf(req, kbuf);
-+}
-+
-+static inline bool io_run_task_work(void)
-+{
-+ if (test_thread_flag(TIF_NOTIFY_SIGNAL) || current->task_works) {
-+ __set_current_state(TASK_RUNNING);
-+ tracehook_notify_signal();
-+ return true;
-+ }
-+
-+ return false;
-+}
-+
-+/*
-+ * Find and free completed poll iocbs
-+ */
-+static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
-+ struct list_head *done)
-+{
-+ struct req_batch rb;
-+ struct io_kiocb *req;
-+
-+ /* order with ->result store in io_complete_rw_iopoll() */
-+ smp_rmb();
-+
-+ io_init_req_batch(&rb);
-+ while (!list_empty(done)) {
-+ req = list_first_entry(done, struct io_kiocb, inflight_entry);
-+ list_del(&req->inflight_entry);
-+
-+ io_fill_cqe_req(req, req->result, io_put_rw_kbuf(req));
-+ (*nr_events)++;
-+
-+ if (req_ref_put_and_test(req))
-+ io_req_free_batch(&rb, req, &ctx->submit_state);
-+ }
-+
-+ io_commit_cqring(ctx);
-+ io_cqring_ev_posted_iopoll(ctx);
-+ io_req_free_batch_finish(ctx, &rb);
-+}
-+
-+static int io_do_iopoll(struct io_ring_ctx *ctx, unsigned int *nr_events,
-+ long min)
-+{
-+ struct io_kiocb *req, *tmp;
-+ LIST_HEAD(done);
-+ bool spin;
-+
-+ /*
-+ * Only spin for completions if we don't have multiple devices hanging
-+ * off our complete list, and we're under the requested amount.
-+ */
-+ spin = !ctx->poll_multi_queue && *nr_events < min;
-+
-+ list_for_each_entry_safe(req, tmp, &ctx->iopoll_list, inflight_entry) {
-+ struct kiocb *kiocb = &req->rw.kiocb;
-+ int ret;
-+
-+ /*
-+ * Move completed and retryable entries to our local lists.
-+ * If we find a request that requires polling, break out
-+ * and complete those lists first, if we have entries there.
-+ */
-+ if (READ_ONCE(req->iopoll_completed)) {
-+ list_move_tail(&req->inflight_entry, &done);
-+ continue;
-+ }
-+ if (!list_empty(&done))
-+ break;
-+
-+ ret = kiocb->ki_filp->f_op->iopoll(kiocb, spin);
-+ if (unlikely(ret < 0))
-+ return ret;
-+ else if (ret)
-+ spin = false;
-+
-+ /* iopoll may have completed current req */
-+ if (READ_ONCE(req->iopoll_completed))
-+ list_move_tail(&req->inflight_entry, &done);
-+ }
-+
-+ if (!list_empty(&done))
-+ io_iopoll_complete(ctx, nr_events, &done);
-+
-+ return 0;
-+}
-+
-+/*
-+ * We can't just wait for polled events to come to us, we have to actively
-+ * find and complete them.
-+ */
-+static void io_iopoll_try_reap_events(struct io_ring_ctx *ctx)
-+{
-+ if (!(ctx->flags & IORING_SETUP_IOPOLL))
-+ return;
-+
-+ mutex_lock(&ctx->uring_lock);
-+ while (!list_empty(&ctx->iopoll_list)) {
-+ unsigned int nr_events = 0;
-+
-+ io_do_iopoll(ctx, &nr_events, 0);
-+
-+ /* let it sleep and repeat later if can't complete a request */
-+ if (nr_events == 0)
-+ break;
-+ /*
-+ * Ensure we allow local-to-the-cpu processing to take place,
-+ * in this case we need to ensure that we reap all events.
-+ * Also let task_work, etc. to progress by releasing the mutex
-+ */
-+ if (need_resched()) {
-+ mutex_unlock(&ctx->uring_lock);
-+ cond_resched();
-+ mutex_lock(&ctx->uring_lock);
-+ }
-+ }
-+ mutex_unlock(&ctx->uring_lock);
-+}
-+
-+static int io_iopoll_check(struct io_ring_ctx *ctx, long min)
-+{
-+ unsigned int nr_events = 0;
-+ int ret = 0;
-+
-+ /*
-+ * We disallow the app entering submit/complete with polling, but we
-+ * still need to lock the ring to prevent racing with polled issue
-+ * that got punted to a workqueue.
-+ */
-+ mutex_lock(&ctx->uring_lock);
-+ /*
-+ * Don't enter poll loop if we already have events pending.
-+ * If we do, we can potentially be spinning for commands that
-+ * already triggered a CQE (eg in error).
-+ */
-+ if (test_bit(0, &ctx->check_cq_overflow))
-+ __io_cqring_overflow_flush(ctx, false);
-+ if (io_cqring_events(ctx))
-+ goto out;
-+ do {
-+ /*
-+ * If a submit got punted to a workqueue, we can have the
-+ * application entering polling for a command before it gets
-+ * issued. That app will hold the uring_lock for the duration
-+ * of the poll right here, so we need to take a breather every
-+ * now and then to ensure that the issue has a chance to add
-+ * the poll to the issued list. Otherwise we can spin here
-+ * forever, while the workqueue is stuck trying to acquire the
-+ * very same mutex.
-+ */
-+ if (list_empty(&ctx->iopoll_list)) {
-+ u32 tail = ctx->cached_cq_tail;
-+
-+ mutex_unlock(&ctx->uring_lock);
-+ io_run_task_work();
-+ mutex_lock(&ctx->uring_lock);
-+
-+ /* some requests don't go through iopoll_list */
-+ if (tail != ctx->cached_cq_tail ||
-+ list_empty(&ctx->iopoll_list))
-+ break;
-+ }
-+ ret = io_do_iopoll(ctx, &nr_events, min);
-+ } while (!ret && nr_events < min && !need_resched());
-+out:
-+ mutex_unlock(&ctx->uring_lock);
-+ return ret;
-+}
-+
-+static void kiocb_end_write(struct io_kiocb *req)
-+{
-+ /*
-+ * Tell lockdep we inherited freeze protection from submission
-+ * thread.
-+ */
-+ if (req->flags & REQ_F_ISREG) {
-+ struct super_block *sb = file_inode(req->file)->i_sb;
-+
-+ __sb_writers_acquired(sb, SB_FREEZE_WRITE);
-+ sb_end_write(sb);
-+ }
-+}
-+
-+#ifdef CONFIG_BLOCK
-+static bool io_resubmit_prep(struct io_kiocb *req)
-+{
-+ struct io_async_rw *rw = req->async_data;
-+
-+ if (!rw)
-+ return !io_req_prep_async(req);
-+ iov_iter_restore(&rw->iter, &rw->iter_state);
-+ return true;
-+}
-+
-+static bool io_rw_should_reissue(struct io_kiocb *req)
-+{
-+ umode_t mode = file_inode(req->file)->i_mode;
-+ struct io_ring_ctx *ctx = req->ctx;
-+
-+ if (!S_ISBLK(mode) && !S_ISREG(mode))
-+ return false;
-+ if ((req->flags & REQ_F_NOWAIT) || (io_wq_current_is_worker() &&
-+ !(ctx->flags & IORING_SETUP_IOPOLL)))
-+ return false;
-+ /*
-+ * If ref is dying, we might be running poll reap from the exit work.
-+ * Don't attempt to reissue from that path, just let it fail with
-+ * -EAGAIN.
-+ */
-+ if (percpu_ref_is_dying(&ctx->refs))
-+ return false;
-+ /*
-+ * Play it safe and assume not safe to re-import and reissue if we're
-+ * not in the original thread group (or in task context).
-+ */
-+ if (!same_thread_group(req->task, current) || !in_task())
-+ return false;
-+ return true;
-+}
-+#else
-+static bool io_resubmit_prep(struct io_kiocb *req)
-+{
-+ return false;
-+}
-+static bool io_rw_should_reissue(struct io_kiocb *req)
-+{
-+ return false;
-+}
-+#endif
-+
-+static bool __io_complete_rw_common(struct io_kiocb *req, long res)
-+{
-+ if (req->rw.kiocb.ki_flags & IOCB_WRITE) {
-+ kiocb_end_write(req);
-+ fsnotify_modify(req->file);
-+ } else {
-+ fsnotify_access(req->file);
-+ }
-+ if (res != req->result) {
-+ if ((res == -EAGAIN || res == -EOPNOTSUPP) &&
-+ io_rw_should_reissue(req)) {
-+ req->flags |= REQ_F_REISSUE;
-+ return true;
-+ }
-+ req_set_fail(req);
-+ req->result = res;
-+ }
-+ return false;
-+}
-+
-+static inline int io_fixup_rw_res(struct io_kiocb *req, unsigned res)
-+{
-+ struct io_async_rw *io = req->async_data;
-+
-+ /* add previously done IO, if any */
-+ if (io && io->bytes_done > 0) {
-+ if (res < 0)
-+ res = io->bytes_done;
-+ else
-+ res += io->bytes_done;
-+ }
-+ return res;
-+}
-+
-+static void io_req_task_complete(struct io_kiocb *req, bool *locked)
-+{
-+ unsigned int cflags = io_put_rw_kbuf(req);
-+ int res = req->result;
-+
-+ if (*locked) {
-+ struct io_ring_ctx *ctx = req->ctx;
-+ struct io_submit_state *state = &ctx->submit_state;
-+
-+ io_req_complete_state(req, res, cflags);
-+ state->compl_reqs[state->compl_nr++] = req;
-+ if (state->compl_nr == ARRAY_SIZE(state->compl_reqs))
-+ io_submit_flush_completions(ctx);
-+ } else {
-+ io_req_complete_post(req, res, cflags);
-+ }
-+}
-+
-+static void __io_complete_rw(struct io_kiocb *req, long res, long res2,
-+ unsigned int issue_flags)
-+{
-+ if (__io_complete_rw_common(req, res))
-+ return;
-+ __io_req_complete(req, issue_flags, io_fixup_rw_res(req, res), io_put_rw_kbuf(req));
-+}
-+
-+static void io_complete_rw(struct kiocb *kiocb, long res, long res2)
-+{
-+ struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
-+
-+ if (__io_complete_rw_common(req, res))
-+ return;
-+ req->result = io_fixup_rw_res(req, res);
-+ req->io_task_work.func = io_req_task_complete;
-+ io_req_task_work_add(req);
-+}
-+
-+static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2)
-+{
-+ struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
-+
-+ if (kiocb->ki_flags & IOCB_WRITE)
-+ kiocb_end_write(req);
-+ if (unlikely(res != req->result)) {
-+ if (res == -EAGAIN && io_rw_should_reissue(req)) {
-+ req->flags |= REQ_F_REISSUE;
-+ return;
-+ }
-+ }
-+
-+ WRITE_ONCE(req->result, res);
-+ /* order with io_iopoll_complete() checking ->result */
-+ smp_wmb();
-+ WRITE_ONCE(req->iopoll_completed, 1);
-+}
-+
-+/*
-+ * After the iocb has been issued, it's safe to be found on the poll list.
-+ * Adding the kiocb to the list AFTER submission ensures that we don't
-+ * find it from a io_do_iopoll() thread before the issuer is done
-+ * accessing the kiocb cookie.
-+ */
-+static void io_iopoll_req_issued(struct io_kiocb *req)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+ const bool in_async = io_wq_current_is_worker();
-+
-+ /* workqueue context doesn't hold uring_lock, grab it now */
-+ if (unlikely(in_async))
-+ mutex_lock(&ctx->uring_lock);
-+
-+ /*
-+ * Track whether we have multiple files in our lists. This will impact
-+ * how we do polling eventually, not spinning if we're on potentially
-+ * different devices.
-+ */
-+ if (list_empty(&ctx->iopoll_list)) {
-+ ctx->poll_multi_queue = false;
-+ } else if (!ctx->poll_multi_queue) {
-+ struct io_kiocb *list_req;
-+ unsigned int queue_num0, queue_num1;
-+
-+ list_req = list_first_entry(&ctx->iopoll_list, struct io_kiocb,
-+ inflight_entry);
-+
-+ if (list_req->file != req->file) {
-+ ctx->poll_multi_queue = true;
-+ } else {
-+ queue_num0 = blk_qc_t_to_queue_num(list_req->rw.kiocb.ki_cookie);
-+ queue_num1 = blk_qc_t_to_queue_num(req->rw.kiocb.ki_cookie);
-+ if (queue_num0 != queue_num1)
-+ ctx->poll_multi_queue = true;
-+ }
-+ }
-+
-+ /*
-+ * For fast devices, IO may have already completed. If it has, add
-+ * it to the front so we find it first.
-+ */
-+ if (READ_ONCE(req->iopoll_completed))
-+ list_add(&req->inflight_entry, &ctx->iopoll_list);
-+ else
-+ list_add_tail(&req->inflight_entry, &ctx->iopoll_list);
-+
-+ if (unlikely(in_async)) {
-+ /*
-+ * If IORING_SETUP_SQPOLL is enabled, sqes are either handle
-+ * in sq thread task context or in io worker task context. If
-+ * current task context is sq thread, we don't need to check
-+ * whether should wake up sq thread.
-+ */
-+ if ((ctx->flags & IORING_SETUP_SQPOLL) &&
-+ wq_has_sleeper(&ctx->sq_data->wait))
-+ wake_up(&ctx->sq_data->wait);
-+
-+ mutex_unlock(&ctx->uring_lock);
-+ }
-+}
-+
-+static bool io_bdev_nowait(struct block_device *bdev)
-+{
-+ return !bdev || blk_queue_nowait(bdev_get_queue(bdev));
-+}
-+
-+/*
-+ * If we tracked the file through the SCM inflight mechanism, we could support
-+ * any file. For now, just ensure that anything potentially problematic is done
-+ * inline.
-+ */
-+static bool __io_file_supports_nowait(struct file *file, int rw)
-+{
-+ umode_t mode = file_inode(file)->i_mode;
-+
-+ if (S_ISBLK(mode)) {
-+ if (IS_ENABLED(CONFIG_BLOCK) &&
-+ io_bdev_nowait(I_BDEV(file->f_mapping->host)))
-+ return true;
-+ return false;
-+ }
-+ if (S_ISSOCK(mode))
-+ return true;
-+ if (S_ISREG(mode)) {
-+ if (IS_ENABLED(CONFIG_BLOCK) &&
-+ io_bdev_nowait(file->f_inode->i_sb->s_bdev) &&
-+ file->f_op != &io_uring_fops)
-+ return true;
-+ return false;
-+ }
-+
-+ /* any ->read/write should understand O_NONBLOCK */
-+ if (file->f_flags & O_NONBLOCK)
-+ return true;
-+
-+ if (!(file->f_mode & FMODE_NOWAIT))
-+ return false;
-+
-+ if (rw == READ)
-+ return file->f_op->read_iter != NULL;
-+
-+ return file->f_op->write_iter != NULL;
-+}
-+
-+static bool io_file_supports_nowait(struct io_kiocb *req, int rw)
-+{
-+ if (rw == READ && (req->flags & REQ_F_NOWAIT_READ))
-+ return true;
-+ else if (rw == WRITE && (req->flags & REQ_F_NOWAIT_WRITE))
-+ return true;
-+
-+ return __io_file_supports_nowait(req->file, rw);
-+}
-+
-+static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
-+ int rw)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+ struct kiocb *kiocb = &req->rw.kiocb;
-+ struct file *file = req->file;
-+ unsigned ioprio;
-+ int ret;
-+
-+ if (!io_req_ffs_set(req) && S_ISREG(file_inode(file)->i_mode))
-+ req->flags |= REQ_F_ISREG;
-+
-+ kiocb->ki_pos = READ_ONCE(sqe->off);
-+ if (kiocb->ki_pos == -1) {
-+ if (!(file->f_mode & FMODE_STREAM)) {
-+ req->flags |= REQ_F_CUR_POS;
-+ kiocb->ki_pos = file->f_pos;
-+ } else {
-+ kiocb->ki_pos = 0;
-+ }
-+ }
-+ kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp));
-+ kiocb->ki_flags = iocb_flags(kiocb->ki_filp);
-+ ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags));
-+ if (unlikely(ret))
-+ return ret;
-+
-+ /*
-+ * If the file is marked O_NONBLOCK, still allow retry for it if it
-+ * supports async. Otherwise it's impossible to use O_NONBLOCK files
-+ * reliably. If not, or it IOCB_NOWAIT is set, don't retry.
-+ */
-+ if ((kiocb->ki_flags & IOCB_NOWAIT) ||
-+ ((file->f_flags & O_NONBLOCK) && !io_file_supports_nowait(req, rw)))
-+ req->flags |= REQ_F_NOWAIT;
-+
-+ ioprio = READ_ONCE(sqe->ioprio);
-+ if (ioprio) {
-+ ret = ioprio_check_cap(ioprio);
-+ if (ret)
-+ return ret;
-+
-+ kiocb->ki_ioprio = ioprio;
-+ } else
-+ kiocb->ki_ioprio = get_current_ioprio();
-+
-+ if (ctx->flags & IORING_SETUP_IOPOLL) {
-+ if (!(kiocb->ki_flags & IOCB_DIRECT) ||
-+ !kiocb->ki_filp->f_op->iopoll)
-+ return -EOPNOTSUPP;
-+
-+ kiocb->ki_flags |= IOCB_HIPRI;
-+ kiocb->ki_complete = io_complete_rw_iopoll;
-+ req->iopoll_completed = 0;
-+ } else {
-+ if (kiocb->ki_flags & IOCB_HIPRI)
-+ return -EINVAL;
-+ kiocb->ki_complete = io_complete_rw;
-+ }
-+
-+ /* used for fixed read/write too - just read unconditionally */
-+ req->buf_index = READ_ONCE(sqe->buf_index);
-+ req->imu = NULL;
-+
-+ if (req->opcode == IORING_OP_READ_FIXED ||
-+ req->opcode == IORING_OP_WRITE_FIXED) {
-+ struct io_ring_ctx *ctx = req->ctx;
-+ u16 index;
-+
-+ if (unlikely(req->buf_index >= ctx->nr_user_bufs))
-+ return -EFAULT;
-+ index = array_index_nospec(req->buf_index, ctx->nr_user_bufs);
-+ req->imu = ctx->user_bufs[index];
-+ io_req_set_rsrc_node(req);
-+ }
-+
-+ req->rw.addr = READ_ONCE(sqe->addr);
-+ req->rw.len = READ_ONCE(sqe->len);
-+ return 0;
-+}
-+
-+static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret)
-+{
-+ switch (ret) {
-+ case -EIOCBQUEUED:
-+ break;
-+ case -ERESTARTSYS:
-+ case -ERESTARTNOINTR:
-+ case -ERESTARTNOHAND:
-+ case -ERESTART_RESTARTBLOCK:
-+ /*
-+ * We can't just restart the syscall, since previously
-+ * submitted sqes may already be in progress. Just fail this
-+ * IO with EINTR.
-+ */
-+ ret = -EINTR;
-+ fallthrough;
-+ default:
-+ kiocb->ki_complete(kiocb, ret, 0);
-+ }
-+}
-+
-+static void kiocb_done(struct kiocb *kiocb, ssize_t ret,
-+ unsigned int issue_flags)
-+{
-+ struct io_kiocb *req = container_of(kiocb, struct io_kiocb, rw.kiocb);
-+
-+ if (req->flags & REQ_F_CUR_POS)
-+ req->file->f_pos = kiocb->ki_pos;
-+ if (ret >= 0 && (kiocb->ki_complete == io_complete_rw))
-+ __io_complete_rw(req, ret, 0, issue_flags);
-+ else
-+ io_rw_done(kiocb, ret);
-+
-+ if (req->flags & REQ_F_REISSUE) {
-+ req->flags &= ~REQ_F_REISSUE;
-+ if (io_resubmit_prep(req)) {
-+ io_req_task_queue_reissue(req);
-+ } else {
-+ unsigned int cflags = io_put_rw_kbuf(req);
-+ struct io_ring_ctx *ctx = req->ctx;
-+
-+ ret = io_fixup_rw_res(req, ret);
-+ req_set_fail(req);
-+ if (!(issue_flags & IO_URING_F_NONBLOCK)) {
-+ mutex_lock(&ctx->uring_lock);
-+ __io_req_complete(req, issue_flags, ret, cflags);
-+ mutex_unlock(&ctx->uring_lock);
-+ } else {
-+ __io_req_complete(req, issue_flags, ret, cflags);
-+ }
-+ }
-+ }
-+}
-+
-+static int __io_import_fixed(struct io_kiocb *req, int rw, struct iov_iter *iter,
-+ struct io_mapped_ubuf *imu)
-+{
-+ size_t len = req->rw.len;
-+ u64 buf_end, buf_addr = req->rw.addr;
-+ size_t offset;
-+
-+ if (unlikely(check_add_overflow(buf_addr, (u64)len, &buf_end)))
-+ return -EFAULT;
-+ /* not inside the mapped region */
-+ if (unlikely(buf_addr < imu->ubuf || buf_end > imu->ubuf_end))
-+ return -EFAULT;
-+
-+ /*
-+ * May not be a start of buffer, set size appropriately
-+ * and advance us to the beginning.
-+ */
-+ offset = buf_addr - imu->ubuf;
-+ iov_iter_bvec(iter, rw, imu->bvec, imu->nr_bvecs, offset + len);
-+
-+ if (offset) {
-+ /*
-+ * Don't use iov_iter_advance() here, as it's really slow for
-+ * using the latter parts of a big fixed buffer - it iterates
-+ * over each segment manually. We can cheat a bit here, because
-+ * we know that:
-+ *
-+ * 1) it's a BVEC iter, we set it up
-+ * 2) all bvecs are PAGE_SIZE in size, except potentially the
-+ * first and last bvec
-+ *
-+ * So just find our index, and adjust the iterator afterwards.
-+ * If the offset is within the first bvec (or the whole first
-+ * bvec, just use iov_iter_advance(). This makes it easier
-+ * since we can just skip the first segment, which may not
-+ * be PAGE_SIZE aligned.
-+ */
-+ const struct bio_vec *bvec = imu->bvec;
-+
-+ if (offset <= bvec->bv_len) {
-+ iov_iter_advance(iter, offset);
-+ } else {
-+ unsigned long seg_skip;
-+
-+ /* skip first vec */
-+ offset -= bvec->bv_len;
-+ seg_skip = 1 + (offset >> PAGE_SHIFT);
-+
-+ iter->bvec = bvec + seg_skip;
-+ iter->nr_segs -= seg_skip;
-+ iter->count -= bvec->bv_len + offset;
-+ iter->iov_offset = offset & ~PAGE_MASK;
-+ }
-+ }
-+
-+ return 0;
-+}
-+
-+static int io_import_fixed(struct io_kiocb *req, int rw, struct iov_iter *iter)
-+{
-+ if (WARN_ON_ONCE(!req->imu))
-+ return -EFAULT;
-+ return __io_import_fixed(req, rw, iter, req->imu);
-+}
-+
-+static void io_ring_submit_unlock(struct io_ring_ctx *ctx, bool needs_lock)
-+{
-+ if (needs_lock)
-+ mutex_unlock(&ctx->uring_lock);
-+}
-+
-+static void io_ring_submit_lock(struct io_ring_ctx *ctx, bool needs_lock)
-+{
-+ /*
-+ * "Normal" inline submissions always hold the uring_lock, since we
-+ * grab it from the system call. Same is true for the SQPOLL offload.
-+ * The only exception is when we've detached the request and issue it
-+ * from an async worker thread, grab the lock for that case.
-+ */
-+ if (needs_lock)
-+ mutex_lock(&ctx->uring_lock);
-+}
-+
-+static struct io_buffer *io_buffer_select(struct io_kiocb *req, size_t *len,
-+ int bgid, struct io_buffer *kbuf,
-+ bool needs_lock)
-+{
-+ struct io_buffer *head;
-+
-+ if (req->flags & REQ_F_BUFFER_SELECTED)
-+ return kbuf;
-+
-+ io_ring_submit_lock(req->ctx, needs_lock);
-+
-+ lockdep_assert_held(&req->ctx->uring_lock);
-+
-+ head = xa_load(&req->ctx->io_buffers, bgid);
-+ if (head) {
-+ if (!list_empty(&head->list)) {
-+ kbuf = list_last_entry(&head->list, struct io_buffer,
-+ list);
-+ list_del(&kbuf->list);
-+ } else {
-+ kbuf = head;
-+ xa_erase(&req->ctx->io_buffers, bgid);
-+ }
-+ if (*len > kbuf->len)
-+ *len = kbuf->len;
-+ } else {
-+ kbuf = ERR_PTR(-ENOBUFS);
-+ }
-+
-+ io_ring_submit_unlock(req->ctx, needs_lock);
-+
-+ return kbuf;
-+}
-+
-+static void __user *io_rw_buffer_select(struct io_kiocb *req, size_t *len,
-+ bool needs_lock)
-+{
-+ struct io_buffer *kbuf;
-+ u16 bgid;
-+
-+ kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
-+ bgid = req->buf_index;
-+ kbuf = io_buffer_select(req, len, bgid, kbuf, needs_lock);
-+ if (IS_ERR(kbuf))
-+ return kbuf;
-+ req->rw.addr = (u64) (unsigned long) kbuf;
-+ req->flags |= REQ_F_BUFFER_SELECTED;
-+ return u64_to_user_ptr(kbuf->addr);
-+}
-+
-+#ifdef CONFIG_COMPAT
-+static ssize_t io_compat_import(struct io_kiocb *req, struct iovec *iov,
-+ bool needs_lock)
-+{
-+ struct compat_iovec __user *uiov;
-+ compat_ssize_t clen;
-+ void __user *buf;
-+ ssize_t len;
-+
-+ uiov = u64_to_user_ptr(req->rw.addr);
-+ if (!access_ok(uiov, sizeof(*uiov)))
-+ return -EFAULT;
-+ if (__get_user(clen, &uiov->iov_len))
-+ return -EFAULT;
-+ if (clen < 0)
-+ return -EINVAL;
-+
-+ len = clen;
-+ buf = io_rw_buffer_select(req, &len, needs_lock);
-+ if (IS_ERR(buf))
-+ return PTR_ERR(buf);
-+ iov[0].iov_base = buf;
-+ iov[0].iov_len = (compat_size_t) len;
-+ return 0;
-+}
-+#endif
-+
-+static ssize_t __io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
-+ bool needs_lock)
-+{
-+ struct iovec __user *uiov = u64_to_user_ptr(req->rw.addr);
-+ void __user *buf;
-+ ssize_t len;
-+
-+ if (copy_from_user(iov, uiov, sizeof(*uiov)))
-+ return -EFAULT;
-+
-+ len = iov[0].iov_len;
-+ if (len < 0)
-+ return -EINVAL;
-+ buf = io_rw_buffer_select(req, &len, needs_lock);
-+ if (IS_ERR(buf))
-+ return PTR_ERR(buf);
-+ iov[0].iov_base = buf;
-+ iov[0].iov_len = len;
-+ return 0;
-+}
-+
-+static ssize_t io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
-+ bool needs_lock)
-+{
-+ if (req->flags & REQ_F_BUFFER_SELECTED) {
-+ struct io_buffer *kbuf;
-+
-+ kbuf = (struct io_buffer *) (unsigned long) req->rw.addr;
-+ iov[0].iov_base = u64_to_user_ptr(kbuf->addr);
-+ iov[0].iov_len = kbuf->len;
-+ return 0;
-+ }
-+ if (req->rw.len != 1)
-+ return -EINVAL;
-+
-+#ifdef CONFIG_COMPAT
-+ if (req->ctx->compat)
-+ return io_compat_import(req, iov, needs_lock);
-+#endif
-+
-+ return __io_iov_buffer_select(req, iov, needs_lock);
-+}
-+
-+static int io_import_iovec(int rw, struct io_kiocb *req, struct iovec **iovec,
-+ struct iov_iter *iter, bool needs_lock)
-+{
-+ void __user *buf = u64_to_user_ptr(req->rw.addr);
-+ size_t sqe_len = req->rw.len;
-+ u8 opcode = req->opcode;
-+ ssize_t ret;
-+
-+ if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) {
-+ *iovec = NULL;
-+ return io_import_fixed(req, rw, iter);
-+ }
-+
-+ /* buffer index only valid with fixed read/write, or buffer select */
-+ if (req->buf_index && !(req->flags & REQ_F_BUFFER_SELECT))
-+ return -EINVAL;
-+
-+ if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) {
-+ if (req->flags & REQ_F_BUFFER_SELECT) {
-+ buf = io_rw_buffer_select(req, &sqe_len, needs_lock);
-+ if (IS_ERR(buf))
-+ return PTR_ERR(buf);
-+ req->rw.len = sqe_len;
-+ }
-+
-+ ret = import_single_range(rw, buf, sqe_len, *iovec, iter);
-+ *iovec = NULL;
-+ return ret;
-+ }
-+
-+ if (req->flags & REQ_F_BUFFER_SELECT) {
-+ ret = io_iov_buffer_select(req, *iovec, needs_lock);
-+ if (!ret)
-+ iov_iter_init(iter, rw, *iovec, 1, (*iovec)->iov_len);
-+ *iovec = NULL;
-+ return ret;
-+ }
-+
-+ return __import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter,
-+ req->ctx->compat);
-+}
-+
-+static inline loff_t *io_kiocb_ppos(struct kiocb *kiocb)
-+{
-+ return (kiocb->ki_filp->f_mode & FMODE_STREAM) ? NULL : &kiocb->ki_pos;
-+}
-+
-+/*
-+ * For files that don't have ->read_iter() and ->write_iter(), handle them
-+ * by looping over ->read() or ->write() manually.
-+ */
-+static ssize_t loop_rw_iter(int rw, struct io_kiocb *req, struct iov_iter *iter)
-+{
-+ struct kiocb *kiocb = &req->rw.kiocb;
-+ struct file *file = req->file;
-+ ssize_t ret = 0;
-+
-+ /*
-+ * Don't support polled IO through this interface, and we can't
-+ * support non-blocking either. For the latter, this just causes
-+ * the kiocb to be handled from an async context.
-+ */
-+ if (kiocb->ki_flags & IOCB_HIPRI)
-+ return -EOPNOTSUPP;
-+ if (kiocb->ki_flags & IOCB_NOWAIT)
-+ return -EAGAIN;
-+
-+ while (iov_iter_count(iter)) {
-+ struct iovec iovec;
-+ ssize_t nr;
-+
-+ if (!iov_iter_is_bvec(iter)) {
-+ iovec = iov_iter_iovec(iter);
-+ } else {
-+ iovec.iov_base = u64_to_user_ptr(req->rw.addr);
-+ iovec.iov_len = req->rw.len;
-+ }
-+
-+ if (rw == READ) {
-+ nr = file->f_op->read(file, iovec.iov_base,
-+ iovec.iov_len, io_kiocb_ppos(kiocb));
-+ } else {
-+ nr = file->f_op->write(file, iovec.iov_base,
-+ iovec.iov_len, io_kiocb_ppos(kiocb));
-+ }
-+
-+ if (nr < 0) {
-+ if (!ret)
-+ ret = nr;
-+ break;
-+ }
-+ ret += nr;
-+ if (!iov_iter_is_bvec(iter)) {
-+ iov_iter_advance(iter, nr);
-+ } else {
-+ req->rw.addr += nr;
-+ req->rw.len -= nr;
-+ if (!req->rw.len)
-+ break;
-+ }
-+ if (nr != iovec.iov_len)
-+ break;
-+ }
-+
-+ return ret;
-+}
-+
-+static void io_req_map_rw(struct io_kiocb *req, const struct iovec *iovec,
-+ const struct iovec *fast_iov, struct iov_iter *iter)
-+{
-+ struct io_async_rw *rw = req->async_data;
-+
-+ memcpy(&rw->iter, iter, sizeof(*iter));
-+ rw->free_iovec = iovec;
-+ rw->bytes_done = 0;
-+ /* can only be fixed buffers, no need to do anything */
-+ if (iov_iter_is_bvec(iter))
-+ return;
-+ if (!iovec) {
-+ unsigned iov_off = 0;
-+
-+ rw->iter.iov = rw->fast_iov;
-+ if (iter->iov != fast_iov) {
-+ iov_off = iter->iov - fast_iov;
-+ rw->iter.iov += iov_off;
-+ }
-+ if (rw->fast_iov != fast_iov)
-+ memcpy(rw->fast_iov + iov_off, fast_iov + iov_off,
-+ sizeof(struct iovec) * iter->nr_segs);
-+ } else {
-+ req->flags |= REQ_F_NEED_CLEANUP;
-+ }
-+}
-+
-+static inline int io_alloc_async_data(struct io_kiocb *req)
-+{
-+ WARN_ON_ONCE(!io_op_defs[req->opcode].async_size);
-+ req->async_data = kmalloc(io_op_defs[req->opcode].async_size, GFP_KERNEL);
-+ return req->async_data == NULL;
-+}
-+
-+static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec,
-+ const struct iovec *fast_iov,
-+ struct iov_iter *iter, bool force)
-+{
-+ if (!force && !io_op_defs[req->opcode].needs_async_setup)
-+ return 0;
-+ if (!req->async_data) {
-+ struct io_async_rw *iorw;
-+
-+ if (io_alloc_async_data(req)) {
-+ kfree(iovec);
-+ return -ENOMEM;
-+ }
-+
-+ io_req_map_rw(req, iovec, fast_iov, iter);
-+ iorw = req->async_data;
-+ /* we've copied and mapped the iter, ensure state is saved */
-+ iov_iter_save_state(&iorw->iter, &iorw->iter_state);
-+ }
-+ return 0;
-+}
-+
-+static inline int io_rw_prep_async(struct io_kiocb *req, int rw)
-+{
-+ struct io_async_rw *iorw = req->async_data;
-+ struct iovec *iov = iorw->fast_iov;
-+ int ret;
-+
-+ ret = io_import_iovec(rw, req, &iov, &iorw->iter, false);
-+ if (unlikely(ret < 0))
-+ return ret;
-+
-+ iorw->bytes_done = 0;
-+ iorw->free_iovec = iov;
-+ if (iov)
-+ req->flags |= REQ_F_NEED_CLEANUP;
-+ iov_iter_save_state(&iorw->iter, &iorw->iter_state);
-+ return 0;
-+}
-+
-+static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-+{
-+ if (unlikely(!(req->file->f_mode & FMODE_READ)))
-+ return -EBADF;
-+ return io_prep_rw(req, sqe, READ);
-+}
-+
-+/*
-+ * This is our waitqueue callback handler, registered through lock_page_async()
-+ * when we initially tried to do the IO with the iocb armed our waitqueue.
-+ * This gets called when the page is unlocked, and we generally expect that to
-+ * happen when the page IO is completed and the page is now uptodate. This will
-+ * queue a task_work based retry of the operation, attempting to copy the data
-+ * again. If the latter fails because the page was NOT uptodate, then we will
-+ * do a thread based blocking retry of the operation. That's the unexpected
-+ * slow path.
-+ */
-+static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode,
-+ int sync, void *arg)
-+{
-+ struct wait_page_queue *wpq;
-+ struct io_kiocb *req = wait->private;
-+ struct wait_page_key *key = arg;
-+
-+ wpq = container_of(wait, struct wait_page_queue, wait);
-+
-+ if (!wake_page_match(wpq, key))
-+ return 0;
-+
-+ req->rw.kiocb.ki_flags &= ~IOCB_WAITQ;
-+ list_del_init(&wait->entry);
-+ io_req_task_queue(req);
-+ return 1;
-+}
-+
-+/*
-+ * This controls whether a given IO request should be armed for async page
-+ * based retry. If we return false here, the request is handed to the async
-+ * worker threads for retry. If we're doing buffered reads on a regular file,
-+ * we prepare a private wait_page_queue entry and retry the operation. This
-+ * will either succeed because the page is now uptodate and unlocked, or it
-+ * will register a callback when the page is unlocked at IO completion. Through
-+ * that callback, io_uring uses task_work to setup a retry of the operation.
-+ * That retry will attempt the buffered read again. The retry will generally
-+ * succeed, or in rare cases where it fails, we then fall back to using the
-+ * async worker threads for a blocking retry.
-+ */
-+static bool io_rw_should_retry(struct io_kiocb *req)
-+{
-+ struct io_async_rw *rw = req->async_data;
-+ struct wait_page_queue *wait = &rw->wpq;
-+ struct kiocb *kiocb = &req->rw.kiocb;
-+
-+ /* never retry for NOWAIT, we just complete with -EAGAIN */
-+ if (req->flags & REQ_F_NOWAIT)
-+ return false;
-+
-+ /* Only for buffered IO */
-+ if (kiocb->ki_flags & (IOCB_DIRECT | IOCB_HIPRI))
-+ return false;
-+
-+ /*
-+ * just use poll if we can, and don't attempt if the fs doesn't
-+ * support callback based unlocks
-+ */
-+ if (file_can_poll(req->file) || !(req->file->f_mode & FMODE_BUF_RASYNC))
-+ return false;
-+
-+ wait->wait.func = io_async_buf_func;
-+ wait->wait.private = req;
-+ wait->wait.flags = 0;
-+ INIT_LIST_HEAD(&wait->wait.entry);
-+ kiocb->ki_flags |= IOCB_WAITQ;
-+ kiocb->ki_flags &= ~IOCB_NOWAIT;
-+ kiocb->ki_waitq = wait;
-+ return true;
-+}
-+
-+static inline int io_iter_do_read(struct io_kiocb *req, struct iov_iter *iter)
-+{
-+ if (req->file->f_op->read_iter)
-+ return call_read_iter(req->file, &req->rw.kiocb, iter);
-+ else if (req->file->f_op->read)
-+ return loop_rw_iter(READ, req, iter);
-+ else
-+ return -EINVAL;
-+}
-+
-+static bool need_read_all(struct io_kiocb *req)
-+{
-+ return req->flags & REQ_F_ISREG ||
-+ S_ISBLK(file_inode(req->file)->i_mode);
-+}
-+
-+static int io_read(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
-+ struct kiocb *kiocb = &req->rw.kiocb;
-+ struct iov_iter __iter, *iter = &__iter;
-+ struct io_async_rw *rw = req->async_data;
-+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
-+ struct iov_iter_state __state, *state;
-+ ssize_t ret, ret2;
-+
-+ if (rw) {
-+ iter = &rw->iter;
-+ state = &rw->iter_state;
-+ /*
-+ * We come here from an earlier attempt, restore our state to
-+ * match in case it doesn't. It's cheap enough that we don't
-+ * need to make this conditional.
-+ */
-+ iov_iter_restore(iter, state);
-+ iovec = NULL;
-+ } else {
-+ ret = io_import_iovec(READ, req, &iovec, iter, !force_nonblock);
-+ if (ret < 0)
-+ return ret;
-+ state = &__state;
-+ iov_iter_save_state(iter, state);
-+ }
-+ req->result = iov_iter_count(iter);
-+
-+ /* Ensure we clear previously set non-block flag */
-+ if (!force_nonblock)
-+ kiocb->ki_flags &= ~IOCB_NOWAIT;
-+ else
-+ kiocb->ki_flags |= IOCB_NOWAIT;
-+
-+ /* If the file doesn't support async, just async punt */
-+ if (force_nonblock && !io_file_supports_nowait(req, READ)) {
-+ ret = io_setup_async_rw(req, iovec, inline_vecs, iter, true);
-+ return ret ?: -EAGAIN;
-+ }
-+
-+ ret = rw_verify_area(READ, req->file, io_kiocb_ppos(kiocb), req->result);
-+ if (unlikely(ret)) {
-+ kfree(iovec);
-+ return ret;
-+ }
-+
-+ ret = io_iter_do_read(req, iter);
-+
-+ if (ret == -EAGAIN || (req->flags & REQ_F_REISSUE)) {
-+ req->flags &= ~REQ_F_REISSUE;
-+ /* IOPOLL retry should happen for io-wq threads */
-+ if (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ goto done;
-+ /* no retry on NONBLOCK nor RWF_NOWAIT */
-+ if (req->flags & REQ_F_NOWAIT)
-+ goto done;
-+ ret = 0;
-+ } else if (ret == -EIOCBQUEUED) {
-+ goto out_free;
-+ } else if (ret <= 0 || ret == req->result || !force_nonblock ||
-+ (req->flags & REQ_F_NOWAIT) || !need_read_all(req)) {
-+ /* read all, failed, already did sync or don't want to retry */
-+ goto done;
-+ }
-+
-+ /*
-+ * Don't depend on the iter state matching what was consumed, or being
-+ * untouched in case of error. Restore it and we'll advance it
-+ * manually if we need to.
-+ */
-+ iov_iter_restore(iter, state);
-+
-+ ret2 = io_setup_async_rw(req, iovec, inline_vecs, iter, true);
-+ if (ret2)
-+ return ret2;
-+
-+ iovec = NULL;
-+ rw = req->async_data;
-+ /*
-+ * Now use our persistent iterator and state, if we aren't already.
-+ * We've restored and mapped the iter to match.
-+ */
-+ if (iter != &rw->iter) {
-+ iter = &rw->iter;
-+ state = &rw->iter_state;
-+ }
-+
-+ do {
-+ /*
-+ * We end up here because of a partial read, either from
-+ * above or inside this loop. Advance the iter by the bytes
-+ * that were consumed.
-+ */
-+ iov_iter_advance(iter, ret);
-+ if (!iov_iter_count(iter))
-+ break;
-+ rw->bytes_done += ret;
-+ iov_iter_save_state(iter, state);
-+
-+ /* if we can retry, do so with the callbacks armed */
-+ if (!io_rw_should_retry(req)) {
-+ kiocb->ki_flags &= ~IOCB_WAITQ;
-+ return -EAGAIN;
-+ }
-+
-+ req->result = iov_iter_count(iter);
-+ /*
-+ * Now retry read with the IOCB_WAITQ parts set in the iocb. If
-+ * we get -EIOCBQUEUED, then we'll get a notification when the
-+ * desired page gets unlocked. We can also get a partial read
-+ * here, and if we do, then just retry at the new offset.
-+ */
-+ ret = io_iter_do_read(req, iter);
-+ if (ret == -EIOCBQUEUED)
-+ return 0;
-+ /* we got some bytes, but not all. retry. */
-+ kiocb->ki_flags &= ~IOCB_WAITQ;
-+ iov_iter_restore(iter, state);
-+ } while (ret > 0);
-+done:
-+ kiocb_done(kiocb, ret, issue_flags);
-+out_free:
-+ /* it's faster to check here then delegate to kfree */
-+ if (iovec)
-+ kfree(iovec);
-+ return 0;
-+}
-+
-+static int io_write_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-+{
-+ if (unlikely(!(req->file->f_mode & FMODE_WRITE)))
-+ return -EBADF;
-+ return io_prep_rw(req, sqe, WRITE);
-+}
-+
-+static int io_write(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
-+ struct kiocb *kiocb = &req->rw.kiocb;
-+ struct iov_iter __iter, *iter = &__iter;
-+ struct io_async_rw *rw = req->async_data;
-+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
-+ struct iov_iter_state __state, *state;
-+ ssize_t ret, ret2;
-+
-+ if (rw) {
-+ iter = &rw->iter;
-+ state = &rw->iter_state;
-+ iov_iter_restore(iter, state);
-+ iovec = NULL;
-+ } else {
-+ ret = io_import_iovec(WRITE, req, &iovec, iter, !force_nonblock);
-+ if (ret < 0)
-+ return ret;
-+ state = &__state;
-+ iov_iter_save_state(iter, state);
-+ }
-+ req->result = iov_iter_count(iter);
-+
-+ /* Ensure we clear previously set non-block flag */
-+ if (!force_nonblock)
-+ kiocb->ki_flags &= ~IOCB_NOWAIT;
-+ else
-+ kiocb->ki_flags |= IOCB_NOWAIT;
-+
-+ /* If the file doesn't support async, just async punt */
-+ if (force_nonblock && !io_file_supports_nowait(req, WRITE))
-+ goto copy_iov;
-+
-+ /* file path doesn't support NOWAIT for non-direct_IO */
-+ if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT) &&
-+ (req->flags & REQ_F_ISREG))
-+ goto copy_iov;
-+
-+ ret = rw_verify_area(WRITE, req->file, io_kiocb_ppos(kiocb), req->result);
-+ if (unlikely(ret))
-+ goto out_free;
-+
-+ /*
-+ * Open-code file_start_write here to grab freeze protection,
-+ * which will be released by another thread in
-+ * io_complete_rw(). Fool lockdep by telling it the lock got
-+ * released so that it doesn't complain about the held lock when
-+ * we return to userspace.
-+ */
-+ if (req->flags & REQ_F_ISREG) {
-+ sb_start_write(file_inode(req->file)->i_sb);
-+ __sb_writers_release(file_inode(req->file)->i_sb,
-+ SB_FREEZE_WRITE);
-+ }
-+ kiocb->ki_flags |= IOCB_WRITE;
-+
-+ if (req->file->f_op->write_iter)
-+ ret2 = call_write_iter(req->file, kiocb, iter);
-+ else if (req->file->f_op->write)
-+ ret2 = loop_rw_iter(WRITE, req, iter);
-+ else
-+ ret2 = -EINVAL;
-+
-+ if (req->flags & REQ_F_REISSUE) {
-+ req->flags &= ~REQ_F_REISSUE;
-+ ret2 = -EAGAIN;
-+ }
-+
-+ /*
-+ * Raw bdev writes will return -EOPNOTSUPP for IOCB_NOWAIT. Just
-+ * retry them without IOCB_NOWAIT.
-+ */
-+ if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT))
-+ ret2 = -EAGAIN;
-+ /* no retry on NONBLOCK nor RWF_NOWAIT */
-+ if (ret2 == -EAGAIN && (req->flags & REQ_F_NOWAIT))
-+ goto done;
-+ if (!force_nonblock || ret2 != -EAGAIN) {
-+ /* IOPOLL retry should happen for io-wq threads */
-+ if ((req->ctx->flags & IORING_SETUP_IOPOLL) && ret2 == -EAGAIN)
-+ goto copy_iov;
-+done:
-+ kiocb_done(kiocb, ret2, issue_flags);
-+ } else {
-+copy_iov:
-+ iov_iter_restore(iter, state);
-+ ret = io_setup_async_rw(req, iovec, inline_vecs, iter, false);
-+ if (!ret) {
-+ if (kiocb->ki_flags & IOCB_WRITE)
-+ kiocb_end_write(req);
-+ return -EAGAIN;
-+ }
-+ return ret;
-+ }
-+out_free:
-+ /* it's reportedly faster than delegating the null check to kfree() */
-+ if (iovec)
-+ kfree(iovec);
-+ return ret;
-+}
-+
-+static int io_renameat_prep(struct io_kiocb *req,
-+ const struct io_uring_sqe *sqe)
-+{
-+ struct io_rename *ren = &req->rename;
-+ const char __user *oldf, *newf;
-+
-+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+ if (sqe->ioprio || sqe->buf_index || sqe->splice_fd_in)
-+ return -EINVAL;
-+ if (unlikely(req->flags & REQ_F_FIXED_FILE))
-+ return -EBADF;
-+
-+ ren->old_dfd = READ_ONCE(sqe->fd);
-+ oldf = u64_to_user_ptr(READ_ONCE(sqe->addr));
-+ newf = u64_to_user_ptr(READ_ONCE(sqe->addr2));
-+ ren->new_dfd = READ_ONCE(sqe->len);
-+ ren->flags = READ_ONCE(sqe->rename_flags);
-+
-+ ren->oldpath = getname(oldf);
-+ if (IS_ERR(ren->oldpath))
-+ return PTR_ERR(ren->oldpath);
-+
-+ ren->newpath = getname(newf);
-+ if (IS_ERR(ren->newpath)) {
-+ putname(ren->oldpath);
-+ return PTR_ERR(ren->newpath);
-+ }
-+
-+ req->flags |= REQ_F_NEED_CLEANUP;
-+ return 0;
-+}
-+
-+static int io_renameat(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_rename *ren = &req->rename;
-+ int ret;
-+
-+ if (issue_flags & IO_URING_F_NONBLOCK)
-+ return -EAGAIN;
-+
-+ ret = do_renameat2(ren->old_dfd, ren->oldpath, ren->new_dfd,
-+ ren->newpath, ren->flags);
-+
-+ req->flags &= ~REQ_F_NEED_CLEANUP;
-+ if (ret < 0)
-+ req_set_fail(req);
-+ io_req_complete(req, ret);
-+ return 0;
-+}
-+
-+static int io_unlinkat_prep(struct io_kiocb *req,
-+ const struct io_uring_sqe *sqe)
-+{
-+ struct io_unlink *un = &req->unlink;
-+ const char __user *fname;
-+
-+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+ if (sqe->ioprio || sqe->off || sqe->len || sqe->buf_index ||
-+ sqe->splice_fd_in)
-+ return -EINVAL;
-+ if (unlikely(req->flags & REQ_F_FIXED_FILE))
-+ return -EBADF;
-+
-+ un->dfd = READ_ONCE(sqe->fd);
-+
-+ un->flags = READ_ONCE(sqe->unlink_flags);
-+ if (un->flags & ~AT_REMOVEDIR)
-+ return -EINVAL;
-+
-+ fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
-+ un->filename = getname(fname);
-+ if (IS_ERR(un->filename))
-+ return PTR_ERR(un->filename);
-+
-+ req->flags |= REQ_F_NEED_CLEANUP;
-+ return 0;
-+}
-+
-+static int io_unlinkat(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_unlink *un = &req->unlink;
-+ int ret;
-+
-+ if (issue_flags & IO_URING_F_NONBLOCK)
-+ return -EAGAIN;
-+
-+ if (un->flags & AT_REMOVEDIR)
-+ ret = do_rmdir(un->dfd, un->filename);
-+ else
-+ ret = do_unlinkat(un->dfd, un->filename);
-+
-+ req->flags &= ~REQ_F_NEED_CLEANUP;
-+ if (ret < 0)
-+ req_set_fail(req);
-+ io_req_complete(req, ret);
-+ return 0;
-+}
-+
-+static int io_shutdown_prep(struct io_kiocb *req,
-+ const struct io_uring_sqe *sqe)
-+{
-+#if defined(CONFIG_NET)
-+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+ if (unlikely(sqe->ioprio || sqe->off || sqe->addr || sqe->rw_flags ||
-+ sqe->buf_index || sqe->splice_fd_in))
-+ return -EINVAL;
-+
-+ req->shutdown.how = READ_ONCE(sqe->len);
-+ return 0;
-+#else
-+ return -EOPNOTSUPP;
-+#endif
-+}
-+
-+static int io_shutdown(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+#if defined(CONFIG_NET)
-+ struct socket *sock;
-+ int ret;
-+
-+ if (issue_flags & IO_URING_F_NONBLOCK)
-+ return -EAGAIN;
-+
-+ sock = sock_from_file(req->file, &ret);
-+ if (unlikely(!sock))
-+ return ret;
-+
-+ ret = __sys_shutdown_sock(sock, req->shutdown.how);
-+ if (ret < 0)
-+ req_set_fail(req);
-+ io_req_complete(req, ret);
-+ return 0;
-+#else
-+ return -EOPNOTSUPP;
-+#endif
-+}
-+
-+static int __io_splice_prep(struct io_kiocb *req,
-+ const struct io_uring_sqe *sqe)
-+{
-+ struct io_splice *sp = &req->splice;
-+ unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL;
-+
-+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+
-+ sp->len = READ_ONCE(sqe->len);
-+ sp->flags = READ_ONCE(sqe->splice_flags);
-+ if (unlikely(sp->flags & ~valid_flags))
-+ return -EINVAL;
-+ sp->splice_fd_in = READ_ONCE(sqe->splice_fd_in);
-+ return 0;
-+}
-+
-+static int io_tee_prep(struct io_kiocb *req,
-+ const struct io_uring_sqe *sqe)
-+{
-+ if (READ_ONCE(sqe->splice_off_in) || READ_ONCE(sqe->off))
-+ return -EINVAL;
-+ return __io_splice_prep(req, sqe);
-+}
-+
-+static int io_tee(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_splice *sp = &req->splice;
-+ struct file *out = sp->file_out;
-+ unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
-+ struct file *in;
-+ long ret = 0;
-+
-+ if (issue_flags & IO_URING_F_NONBLOCK)
-+ return -EAGAIN;
-+
-+ in = io_file_get(req->ctx, req, sp->splice_fd_in,
-+ (sp->flags & SPLICE_F_FD_IN_FIXED));
-+ if (!in) {
-+ ret = -EBADF;
-+ goto done;
-+ }
-+
-+ if (sp->len)
-+ ret = do_tee(in, out, sp->len, flags);
-+
-+ if (!(sp->flags & SPLICE_F_FD_IN_FIXED))
-+ io_put_file(in);
-+done:
-+ if (ret != sp->len)
-+ req_set_fail(req);
-+ io_req_complete(req, ret);
-+ return 0;
-+}
-+
-+static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-+{
-+ struct io_splice *sp = &req->splice;
-+
-+ sp->off_in = READ_ONCE(sqe->splice_off_in);
-+ sp->off_out = READ_ONCE(sqe->off);
-+ return __io_splice_prep(req, sqe);
-+}
-+
-+static int io_splice(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_splice *sp = &req->splice;
-+ struct file *out = sp->file_out;
-+ unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
-+ loff_t *poff_in, *poff_out;
-+ struct file *in;
-+ long ret = 0;
-+
-+ if (issue_flags & IO_URING_F_NONBLOCK)
-+ return -EAGAIN;
-+
-+ in = io_file_get(req->ctx, req, sp->splice_fd_in,
-+ (sp->flags & SPLICE_F_FD_IN_FIXED));
-+ if (!in) {
-+ ret = -EBADF;
-+ goto done;
-+ }
-+
-+ poff_in = (sp->off_in == -1) ? NULL : &sp->off_in;
-+ poff_out = (sp->off_out == -1) ? NULL : &sp->off_out;
-+
-+ if (sp->len)
-+ ret = do_splice(in, poff_in, out, poff_out, sp->len, flags);
-+
-+ if (!(sp->flags & SPLICE_F_FD_IN_FIXED))
-+ io_put_file(in);
-+done:
-+ if (ret != sp->len)
-+ req_set_fail(req);
-+ io_req_complete(req, ret);
-+ return 0;
-+}
-+
-+/*
-+ * IORING_OP_NOP just posts a completion event, nothing else.
-+ */
-+static int io_nop(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+
-+ if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+
-+ __io_req_complete(req, issue_flags, 0, 0);
-+ return 0;
-+}
-+
-+static int io_fsync_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+
-+ if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+ if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index ||
-+ sqe->splice_fd_in))
-+ return -EINVAL;
-+
-+ req->sync.flags = READ_ONCE(sqe->fsync_flags);
-+ if (unlikely(req->sync.flags & ~IORING_FSYNC_DATASYNC))
-+ return -EINVAL;
-+
-+ req->sync.off = READ_ONCE(sqe->off);
-+ req->sync.len = READ_ONCE(sqe->len);
-+ return 0;
-+}
-+
-+static int io_fsync(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ loff_t end = req->sync.off + req->sync.len;
-+ int ret;
-+
-+ /* fsync always requires a blocking context */
-+ if (issue_flags & IO_URING_F_NONBLOCK)
-+ return -EAGAIN;
-+
-+ ret = vfs_fsync_range(req->file, req->sync.off,
-+ end > 0 ? end : LLONG_MAX,
-+ req->sync.flags & IORING_FSYNC_DATASYNC);
-+ if (ret < 0)
-+ req_set_fail(req);
-+ io_req_complete(req, ret);
-+ return 0;
-+}
-+
-+static int io_fallocate_prep(struct io_kiocb *req,
-+ const struct io_uring_sqe *sqe)
-+{
-+ if (sqe->ioprio || sqe->buf_index || sqe->rw_flags ||
-+ sqe->splice_fd_in)
-+ return -EINVAL;
-+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+
-+ req->sync.off = READ_ONCE(sqe->off);
-+ req->sync.len = READ_ONCE(sqe->addr);
-+ req->sync.mode = READ_ONCE(sqe->len);
-+ return 0;
-+}
-+
-+static int io_fallocate(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ int ret;
-+
-+ /* fallocate always requiring blocking context */
-+ if (issue_flags & IO_URING_F_NONBLOCK)
-+ return -EAGAIN;
-+ ret = vfs_fallocate(req->file, req->sync.mode, req->sync.off,
-+ req->sync.len);
-+ if (ret < 0)
-+ req_set_fail(req);
-+ else
-+ fsnotify_modify(req->file);
-+ io_req_complete(req, ret);
-+ return 0;
-+}
-+
-+static int __io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-+{
-+ const char __user *fname;
-+ int ret;
-+
-+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+ if (unlikely(sqe->ioprio || sqe->buf_index))
-+ return -EINVAL;
-+ if (unlikely(req->flags & REQ_F_FIXED_FILE))
-+ return -EBADF;
-+
-+ /* open.how should be already initialised */
-+ if (!(req->open.how.flags & O_PATH) && force_o_largefile())
-+ req->open.how.flags |= O_LARGEFILE;
-+
-+ req->open.dfd = READ_ONCE(sqe->fd);
-+ fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
-+ req->open.filename = getname(fname);
-+ if (IS_ERR(req->open.filename)) {
-+ ret = PTR_ERR(req->open.filename);
-+ req->open.filename = NULL;
-+ return ret;
-+ }
-+
-+ req->open.file_slot = READ_ONCE(sqe->file_index);
-+ if (req->open.file_slot && (req->open.how.flags & O_CLOEXEC))
-+ return -EINVAL;
-+
-+ req->open.nofile = rlimit(RLIMIT_NOFILE);
-+ req->flags |= REQ_F_NEED_CLEANUP;
-+ return 0;
-+}
-+
-+static int io_openat_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-+{
-+ u64 mode = READ_ONCE(sqe->len);
-+ u64 flags = READ_ONCE(sqe->open_flags);
-+
-+ req->open.how = build_open_how(flags, mode);
-+ return __io_openat_prep(req, sqe);
-+}
-+
-+static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-+{
-+ struct open_how __user *how;
-+ size_t len;
-+ int ret;
-+
-+ how = u64_to_user_ptr(READ_ONCE(sqe->addr2));
-+ len = READ_ONCE(sqe->len);
-+ if (len < OPEN_HOW_SIZE_VER0)
-+ return -EINVAL;
-+
-+ ret = copy_struct_from_user(&req->open.how, sizeof(req->open.how), how,
-+ len);
-+ if (ret)
-+ return ret;
-+
-+ return __io_openat_prep(req, sqe);
-+}
-+
-+static int io_openat2(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct open_flags op;
-+ struct file *file;
-+ bool resolve_nonblock, nonblock_set;
-+ bool fixed = !!req->open.file_slot;
-+ int ret;
-+
-+ ret = build_open_flags(&req->open.how, &op);
-+ if (ret)
-+ goto err;
-+ nonblock_set = op.open_flag & O_NONBLOCK;
-+ resolve_nonblock = req->open.how.resolve & RESOLVE_CACHED;
-+ if (issue_flags & IO_URING_F_NONBLOCK) {
-+ /*
-+ * Don't bother trying for O_TRUNC, O_CREAT, or O_TMPFILE open,
-+ * it'll always -EAGAIN
-+ */
-+ if (req->open.how.flags & (O_TRUNC | O_CREAT | O_TMPFILE))
-+ return -EAGAIN;
-+ op.lookup_flags |= LOOKUP_CACHED;
-+ op.open_flag |= O_NONBLOCK;
-+ }
-+
-+ if (!fixed) {
-+ ret = __get_unused_fd_flags(req->open.how.flags, req->open.nofile);
-+ if (ret < 0)
-+ goto err;
-+ }
-+
-+ file = do_filp_open(req->open.dfd, req->open.filename, &op);
-+ if (IS_ERR(file)) {
-+ /*
-+ * We could hang on to this 'fd' on retrying, but seems like
-+ * marginal gain for something that is now known to be a slower
-+ * path. So just put it, and we'll get a new one when we retry.
-+ */
-+ if (!fixed)
-+ put_unused_fd(ret);
-+
-+ ret = PTR_ERR(file);
-+ /* only retry if RESOLVE_CACHED wasn't already set by application */
-+ if (ret == -EAGAIN &&
-+ (!resolve_nonblock && (issue_flags & IO_URING_F_NONBLOCK)))
-+ return -EAGAIN;
-+ goto err;
-+ }
-+
-+ if ((issue_flags & IO_URING_F_NONBLOCK) && !nonblock_set)
-+ file->f_flags &= ~O_NONBLOCK;
-+ fsnotify_open(file);
-+
-+ if (!fixed)
-+ fd_install(ret, file);
-+ else
-+ ret = io_install_fixed_file(req, file, issue_flags,
-+ req->open.file_slot - 1);
-+err:
-+ putname(req->open.filename);
-+ req->flags &= ~REQ_F_NEED_CLEANUP;
-+ if (ret < 0)
-+ req_set_fail(req);
-+ __io_req_complete(req, issue_flags, ret, 0);
-+ return 0;
-+}
-+
-+static int io_openat(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ return io_openat2(req, issue_flags);
-+}
-+
-+static int io_remove_buffers_prep(struct io_kiocb *req,
-+ const struct io_uring_sqe *sqe)
-+{
-+ struct io_provide_buf *p = &req->pbuf;
-+ u64 tmp;
-+
-+ if (sqe->ioprio || sqe->rw_flags || sqe->addr || sqe->len || sqe->off ||
-+ sqe->splice_fd_in)
-+ return -EINVAL;
-+
-+ tmp = READ_ONCE(sqe->fd);
-+ if (!tmp || tmp > USHRT_MAX)
-+ return -EINVAL;
-+
-+ memset(p, 0, sizeof(*p));
-+ p->nbufs = tmp;
-+ p->bgid = READ_ONCE(sqe->buf_group);
-+ return 0;
-+}
-+
-+static int __io_remove_buffers(struct io_ring_ctx *ctx, struct io_buffer *buf,
-+ int bgid, unsigned nbufs)
-+{
-+ unsigned i = 0;
-+
-+ /* shouldn't happen */
-+ if (!nbufs)
-+ return 0;
-+
-+ /* the head kbuf is the list itself */
-+ while (!list_empty(&buf->list)) {
-+ struct io_buffer *nxt;
-+
-+ nxt = list_first_entry(&buf->list, struct io_buffer, list);
-+ list_del(&nxt->list);
-+ kfree(nxt);
-+ if (++i == nbufs)
-+ return i;
-+ cond_resched();
-+ }
-+ i++;
-+ kfree(buf);
-+ xa_erase(&ctx->io_buffers, bgid);
-+
-+ return i;
-+}
-+
-+static int io_remove_buffers(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_provide_buf *p = &req->pbuf;
-+ struct io_ring_ctx *ctx = req->ctx;
-+ struct io_buffer *head;
-+ int ret = 0;
-+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
-+
-+ io_ring_submit_lock(ctx, !force_nonblock);
-+
-+ lockdep_assert_held(&ctx->uring_lock);
-+
-+ ret = -ENOENT;
-+ head = xa_load(&ctx->io_buffers, p->bgid);
-+ if (head)
-+ ret = __io_remove_buffers(ctx, head, p->bgid, p->nbufs);
-+ if (ret < 0)
-+ req_set_fail(req);
-+
-+ /* complete before unlock, IOPOLL may need the lock */
-+ __io_req_complete(req, issue_flags, ret, 0);
-+ io_ring_submit_unlock(ctx, !force_nonblock);
-+ return 0;
-+}
-+
-+static int io_provide_buffers_prep(struct io_kiocb *req,
-+ const struct io_uring_sqe *sqe)
-+{
-+ unsigned long size, tmp_check;
-+ struct io_provide_buf *p = &req->pbuf;
-+ u64 tmp;
-+
-+ if (sqe->ioprio || sqe->rw_flags || sqe->splice_fd_in)
-+ return -EINVAL;
-+
-+ tmp = READ_ONCE(sqe->fd);
-+ if (!tmp || tmp > USHRT_MAX)
-+ return -E2BIG;
-+ p->nbufs = tmp;
-+ p->addr = READ_ONCE(sqe->addr);
-+ p->len = READ_ONCE(sqe->len);
-+
-+ if (check_mul_overflow((unsigned long)p->len, (unsigned long)p->nbufs,
-+ &size))
-+ return -EOVERFLOW;
-+ if (check_add_overflow((unsigned long)p->addr, size, &tmp_check))
-+ return -EOVERFLOW;
-+
-+ size = (unsigned long)p->len * p->nbufs;
-+ if (!access_ok(u64_to_user_ptr(p->addr), size))
-+ return -EFAULT;
-+
-+ p->bgid = READ_ONCE(sqe->buf_group);
-+ tmp = READ_ONCE(sqe->off);
-+ if (tmp > USHRT_MAX)
-+ return -E2BIG;
-+ p->bid = tmp;
-+ return 0;
-+}
-+
-+static int io_add_buffers(struct io_provide_buf *pbuf, struct io_buffer **head)
-+{
-+ struct io_buffer *buf;
-+ u64 addr = pbuf->addr;
-+ int i, bid = pbuf->bid;
-+
-+ for (i = 0; i < pbuf->nbufs; i++) {
-+ buf = kmalloc(sizeof(*buf), GFP_KERNEL_ACCOUNT);
-+ if (!buf)
-+ break;
-+
-+ buf->addr = addr;
-+ buf->len = min_t(__u32, pbuf->len, MAX_RW_COUNT);
-+ buf->bid = bid;
-+ addr += pbuf->len;
-+ bid++;
-+ if (!*head) {
-+ INIT_LIST_HEAD(&buf->list);
-+ *head = buf;
-+ } else {
-+ list_add_tail(&buf->list, &(*head)->list);
-+ }
-+ cond_resched();
-+ }
-+
-+ return i ? i : -ENOMEM;
-+}
-+
-+static int io_provide_buffers(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_provide_buf *p = &req->pbuf;
-+ struct io_ring_ctx *ctx = req->ctx;
-+ struct io_buffer *head, *list;
-+ int ret = 0;
-+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
-+
-+ io_ring_submit_lock(ctx, !force_nonblock);
-+
-+ lockdep_assert_held(&ctx->uring_lock);
-+
-+ list = head = xa_load(&ctx->io_buffers, p->bgid);
-+
-+ ret = io_add_buffers(p, &head);
-+ if (ret >= 0 && !list) {
-+ ret = xa_insert(&ctx->io_buffers, p->bgid, head,
-+ GFP_KERNEL_ACCOUNT);
-+ if (ret < 0)
-+ __io_remove_buffers(ctx, head, p->bgid, -1U);
-+ }
-+ if (ret < 0)
-+ req_set_fail(req);
-+ /* complete before unlock, IOPOLL may need the lock */
-+ __io_req_complete(req, issue_flags, ret, 0);
-+ io_ring_submit_unlock(ctx, !force_nonblock);
-+ return 0;
-+}
-+
-+static int io_epoll_ctl_prep(struct io_kiocb *req,
-+ const struct io_uring_sqe *sqe)
-+{
-+#if defined(CONFIG_EPOLL)
-+ if (sqe->ioprio || sqe->buf_index || sqe->splice_fd_in)
-+ return -EINVAL;
-+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+
-+ req->epoll.epfd = READ_ONCE(sqe->fd);
-+ req->epoll.op = READ_ONCE(sqe->len);
-+ req->epoll.fd = READ_ONCE(sqe->off);
-+
-+ if (ep_op_has_event(req->epoll.op)) {
-+ struct epoll_event __user *ev;
-+
-+ ev = u64_to_user_ptr(READ_ONCE(sqe->addr));
-+ if (copy_from_user(&req->epoll.event, ev, sizeof(*ev)))
-+ return -EFAULT;
-+ }
-+
-+ return 0;
-+#else
-+ return -EOPNOTSUPP;
-+#endif
-+}
-+
-+static int io_epoll_ctl(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+#if defined(CONFIG_EPOLL)
-+ struct io_epoll *ie = &req->epoll;
-+ int ret;
-+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
-+
-+ ret = do_epoll_ctl(ie->epfd, ie->op, ie->fd, &ie->event, force_nonblock);
-+ if (force_nonblock && ret == -EAGAIN)
-+ return -EAGAIN;
-+
-+ if (ret < 0)
-+ req_set_fail(req);
-+ __io_req_complete(req, issue_flags, ret, 0);
-+ return 0;
-+#else
-+ return -EOPNOTSUPP;
-+#endif
-+}
-+
-+static int io_madvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-+{
-+#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
-+ if (sqe->ioprio || sqe->buf_index || sqe->off || sqe->splice_fd_in)
-+ return -EINVAL;
-+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+
-+ req->madvise.addr = READ_ONCE(sqe->addr);
-+ req->madvise.len = READ_ONCE(sqe->len);
-+ req->madvise.advice = READ_ONCE(sqe->fadvise_advice);
-+ return 0;
-+#else
-+ return -EOPNOTSUPP;
-+#endif
-+}
-+
-+static int io_madvise(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+#if defined(CONFIG_ADVISE_SYSCALLS) && defined(CONFIG_MMU)
-+ struct io_madvise *ma = &req->madvise;
-+ int ret;
-+
-+ if (issue_flags & IO_URING_F_NONBLOCK)
-+ return -EAGAIN;
-+
-+ ret = do_madvise(current->mm, ma->addr, ma->len, ma->advice);
-+ if (ret < 0)
-+ req_set_fail(req);
-+ io_req_complete(req, ret);
-+ return 0;
-+#else
-+ return -EOPNOTSUPP;
-+#endif
-+}
-+
-+static int io_fadvise_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-+{
-+ if (sqe->ioprio || sqe->buf_index || sqe->addr || sqe->splice_fd_in)
-+ return -EINVAL;
-+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+
-+ req->fadvise.offset = READ_ONCE(sqe->off);
-+ req->fadvise.len = READ_ONCE(sqe->len);
-+ req->fadvise.advice = READ_ONCE(sqe->fadvise_advice);
-+ return 0;
-+}
-+
-+static int io_fadvise(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_fadvise *fa = &req->fadvise;
-+ int ret;
-+
-+ if (issue_flags & IO_URING_F_NONBLOCK) {
-+ switch (fa->advice) {
-+ case POSIX_FADV_NORMAL:
-+ case POSIX_FADV_RANDOM:
-+ case POSIX_FADV_SEQUENTIAL:
-+ break;
-+ default:
-+ return -EAGAIN;
-+ }
-+ }
-+
-+ ret = vfs_fadvise(req->file, fa->offset, fa->len, fa->advice);
-+ if (ret < 0)
-+ req_set_fail(req);
-+ __io_req_complete(req, issue_flags, ret, 0);
-+ return 0;
-+}
-+
-+static int io_statx_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-+{
-+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+ if (sqe->ioprio || sqe->buf_index || sqe->splice_fd_in)
-+ return -EINVAL;
-+ if (req->flags & REQ_F_FIXED_FILE)
-+ return -EBADF;
-+
-+ req->statx.dfd = READ_ONCE(sqe->fd);
-+ req->statx.mask = READ_ONCE(sqe->len);
-+ req->statx.filename = u64_to_user_ptr(READ_ONCE(sqe->addr));
-+ req->statx.buffer = u64_to_user_ptr(READ_ONCE(sqe->addr2));
-+ req->statx.flags = READ_ONCE(sqe->statx_flags);
-+
-+ return 0;
-+}
-+
-+static int io_statx(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_statx *ctx = &req->statx;
-+ int ret;
-+
-+ if (issue_flags & IO_URING_F_NONBLOCK)
-+ return -EAGAIN;
-+
-+ ret = do_statx(ctx->dfd, ctx->filename, ctx->flags, ctx->mask,
-+ ctx->buffer);
-+
-+ if (ret < 0)
-+ req_set_fail(req);
-+ io_req_complete(req, ret);
-+ return 0;
-+}
-+
-+static int io_close_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-+{
-+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+ if (sqe->ioprio || sqe->off || sqe->addr || sqe->len ||
-+ sqe->rw_flags || sqe->buf_index)
-+ return -EINVAL;
-+ if (req->flags & REQ_F_FIXED_FILE)
-+ return -EBADF;
-+
-+ req->close.fd = READ_ONCE(sqe->fd);
-+ req->close.file_slot = READ_ONCE(sqe->file_index);
-+ if (req->close.file_slot && req->close.fd)
-+ return -EINVAL;
-+
-+ return 0;
-+}
-+
-+static int io_close(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct files_struct *files = current->files;
-+ struct io_close *close = &req->close;
-+ struct fdtable *fdt;
-+ struct file *file = NULL;
-+ int ret = -EBADF;
-+
-+ if (req->close.file_slot) {
-+ ret = io_close_fixed(req, issue_flags);
-+ goto err;
-+ }
-+
-+ spin_lock(&files->file_lock);
-+ fdt = files_fdtable(files);
-+ if (close->fd >= fdt->max_fds) {
-+ spin_unlock(&files->file_lock);
-+ goto err;
-+ }
-+ file = fdt->fd[close->fd];
-+ if (!file || file->f_op == &io_uring_fops) {
-+ spin_unlock(&files->file_lock);
-+ file = NULL;
-+ goto err;
-+ }
-+
-+ /* if the file has a flush method, be safe and punt to async */
-+ if (file->f_op->flush && (issue_flags & IO_URING_F_NONBLOCK)) {
-+ spin_unlock(&files->file_lock);
-+ return -EAGAIN;
-+ }
-+
-+ ret = __close_fd_get_file(close->fd, &file);
-+ spin_unlock(&files->file_lock);
-+ if (ret < 0) {
-+ if (ret == -ENOENT)
-+ ret = -EBADF;
-+ goto err;
-+ }
-+
-+ /* No ->flush() or already async, safely close from here */
-+ ret = filp_close(file, current->files);
-+err:
-+ if (ret < 0)
-+ req_set_fail(req);
-+ if (file)
-+ fput(file);
-+ __io_req_complete(req, issue_flags, ret, 0);
-+ return 0;
-+}
-+
-+static int io_sfr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+
-+ if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+ if (unlikely(sqe->addr || sqe->ioprio || sqe->buf_index ||
-+ sqe->splice_fd_in))
-+ return -EINVAL;
-+
-+ req->sync.off = READ_ONCE(sqe->off);
-+ req->sync.len = READ_ONCE(sqe->len);
-+ req->sync.flags = READ_ONCE(sqe->sync_range_flags);
-+ return 0;
-+}
-+
-+static int io_sync_file_range(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ int ret;
-+
-+ /* sync_file_range always requires a blocking context */
-+ if (issue_flags & IO_URING_F_NONBLOCK)
-+ return -EAGAIN;
-+
-+ ret = sync_file_range(req->file, req->sync.off, req->sync.len,
-+ req->sync.flags);
-+ if (ret < 0)
-+ req_set_fail(req);
-+ io_req_complete(req, ret);
-+ return 0;
-+}
-+
-+#if defined(CONFIG_NET)
-+static int io_setup_async_msg(struct io_kiocb *req,
-+ struct io_async_msghdr *kmsg)
-+{
-+ struct io_async_msghdr *async_msg = req->async_data;
-+
-+ if (async_msg)
-+ return -EAGAIN;
-+ if (io_alloc_async_data(req)) {
-+ kfree(kmsg->free_iov);
-+ return -ENOMEM;
-+ }
-+ async_msg = req->async_data;
-+ req->flags |= REQ_F_NEED_CLEANUP;
-+ memcpy(async_msg, kmsg, sizeof(*kmsg));
-+ if (async_msg->msg.msg_name)
-+ async_msg->msg.msg_name = &async_msg->addr;
-+ /* if were using fast_iov, set it to the new one */
-+ if (!async_msg->free_iov)
-+ async_msg->msg.msg_iter.iov = async_msg->fast_iov;
-+
-+ return -EAGAIN;
-+}
-+
-+static int io_sendmsg_copy_hdr(struct io_kiocb *req,
-+ struct io_async_msghdr *iomsg)
-+{
-+ iomsg->msg.msg_name = &iomsg->addr;
-+ iomsg->free_iov = iomsg->fast_iov;
-+ return sendmsg_copy_msghdr(&iomsg->msg, req->sr_msg.umsg,
-+ req->sr_msg.msg_flags, &iomsg->free_iov);
-+}
-+
-+static int io_sendmsg_prep_async(struct io_kiocb *req)
-+{
-+ int ret;
-+
-+ ret = io_sendmsg_copy_hdr(req, req->async_data);
-+ if (!ret)
-+ req->flags |= REQ_F_NEED_CLEANUP;
-+ return ret;
-+}
-+
-+static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-+{
-+ struct io_sr_msg *sr = &req->sr_msg;
-+
-+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+ if (unlikely(sqe->addr2 || sqe->file_index))
-+ return -EINVAL;
-+ if (unlikely(sqe->addr2 || sqe->file_index || sqe->ioprio))
-+ return -EINVAL;
-+
-+ sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
-+ sr->len = READ_ONCE(sqe->len);
-+ sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
-+ if (sr->msg_flags & MSG_DONTWAIT)
-+ req->flags |= REQ_F_NOWAIT;
-+
-+#ifdef CONFIG_COMPAT
-+ if (req->ctx->compat)
-+ sr->msg_flags |= MSG_CMSG_COMPAT;
-+#endif
-+ return 0;
-+}
-+
-+static int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_async_msghdr iomsg, *kmsg;
-+ struct socket *sock;
-+ unsigned flags;
-+ int min_ret = 0;
-+ int ret;
-+
-+ sock = sock_from_file(req->file, &ret);
-+ if (unlikely(!sock))
-+ return ret;
-+
-+ kmsg = req->async_data;
-+ if (!kmsg) {
-+ ret = io_sendmsg_copy_hdr(req, &iomsg);
-+ if (ret)
-+ return ret;
-+ kmsg = &iomsg;
-+ }
-+
-+ flags = req->sr_msg.msg_flags;
-+ if (issue_flags & IO_URING_F_NONBLOCK)
-+ flags |= MSG_DONTWAIT;
-+ if (flags & MSG_WAITALL)
-+ min_ret = iov_iter_count(&kmsg->msg.msg_iter);
-+
-+ ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
-+ if ((issue_flags & IO_URING_F_NONBLOCK) && ret == -EAGAIN)
-+ return io_setup_async_msg(req, kmsg);
-+ if (ret == -ERESTARTSYS)
-+ ret = -EINTR;
-+
-+ /* fast path, check for non-NULL to avoid function call */
-+ if (kmsg->free_iov)
-+ kfree(kmsg->free_iov);
-+ req->flags &= ~REQ_F_NEED_CLEANUP;
-+ if (ret < min_ret)
-+ req_set_fail(req);
-+ __io_req_complete(req, issue_flags, ret, 0);
-+ return 0;
-+}
-+
-+static int io_send(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_sr_msg *sr = &req->sr_msg;
-+ struct msghdr msg;
-+ struct iovec iov;
-+ struct socket *sock;
-+ unsigned flags;
-+ int min_ret = 0;
-+ int ret;
-+
-+ sock = sock_from_file(req->file, &ret);
-+ if (unlikely(!sock))
-+ return ret;
-+
-+ ret = import_single_range(WRITE, sr->buf, sr->len, &iov, &msg.msg_iter);
-+ if (unlikely(ret))
-+ return ret;
-+
-+ msg.msg_name = NULL;
-+ msg.msg_control = NULL;
-+ msg.msg_controllen = 0;
-+ msg.msg_namelen = 0;
-+
-+ flags = req->sr_msg.msg_flags;
-+ if (issue_flags & IO_URING_F_NONBLOCK)
-+ flags |= MSG_DONTWAIT;
-+ if (flags & MSG_WAITALL)
-+ min_ret = iov_iter_count(&msg.msg_iter);
-+
-+ msg.msg_flags = flags;
-+ ret = sock_sendmsg(sock, &msg);
-+ if ((issue_flags & IO_URING_F_NONBLOCK) && ret == -EAGAIN)
-+ return -EAGAIN;
-+ if (ret == -ERESTARTSYS)
-+ ret = -EINTR;
-+
-+ if (ret < min_ret)
-+ req_set_fail(req);
-+ __io_req_complete(req, issue_flags, ret, 0);
-+ return 0;
-+}
-+
-+static int __io_recvmsg_copy_hdr(struct io_kiocb *req,
-+ struct io_async_msghdr *iomsg)
-+{
-+ struct io_sr_msg *sr = &req->sr_msg;
-+ struct iovec __user *uiov;
-+ size_t iov_len;
-+ int ret;
-+
-+ ret = __copy_msghdr_from_user(&iomsg->msg, sr->umsg,
-+ &iomsg->uaddr, &uiov, &iov_len);
-+ if (ret)
-+ return ret;
-+
-+ if (req->flags & REQ_F_BUFFER_SELECT) {
-+ if (iov_len > 1)
-+ return -EINVAL;
-+ if (copy_from_user(iomsg->fast_iov, uiov, sizeof(*uiov)))
-+ return -EFAULT;
-+ sr->len = iomsg->fast_iov[0].iov_len;
-+ iomsg->free_iov = NULL;
-+ } else {
-+ iomsg->free_iov = iomsg->fast_iov;
-+ ret = __import_iovec(READ, uiov, iov_len, UIO_FASTIOV,
-+ &iomsg->free_iov, &iomsg->msg.msg_iter,
-+ false);
-+ if (ret > 0)
-+ ret = 0;
-+ }
-+
-+ return ret;
-+}
-+
-+#ifdef CONFIG_COMPAT
-+static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req,
-+ struct io_async_msghdr *iomsg)
-+{
-+ struct io_sr_msg *sr = &req->sr_msg;
-+ struct compat_iovec __user *uiov;
-+ compat_uptr_t ptr;
-+ compat_size_t len;
-+ int ret;
-+
-+ ret = __get_compat_msghdr(&iomsg->msg, sr->umsg_compat, &iomsg->uaddr,
-+ &ptr, &len);
-+ if (ret)
-+ return ret;
-+
-+ uiov = compat_ptr(ptr);
-+ if (req->flags & REQ_F_BUFFER_SELECT) {
-+ compat_ssize_t clen;
-+
-+ if (len > 1)
-+ return -EINVAL;
-+ if (!access_ok(uiov, sizeof(*uiov)))
-+ return -EFAULT;
-+ if (__get_user(clen, &uiov->iov_len))
-+ return -EFAULT;
-+ if (clen < 0)
-+ return -EINVAL;
-+ sr->len = clen;
-+ iomsg->free_iov = NULL;
-+ } else {
-+ iomsg->free_iov = iomsg->fast_iov;
-+ ret = __import_iovec(READ, (struct iovec __user *)uiov, len,
-+ UIO_FASTIOV, &iomsg->free_iov,
-+ &iomsg->msg.msg_iter, true);
-+ if (ret < 0)
-+ return ret;
-+ }
-+
-+ return 0;
-+}
-+#endif
-+
-+static int io_recvmsg_copy_hdr(struct io_kiocb *req,
-+ struct io_async_msghdr *iomsg)
-+{
-+ iomsg->msg.msg_name = &iomsg->addr;
-+
-+#ifdef CONFIG_COMPAT
-+ if (req->ctx->compat)
-+ return __io_compat_recvmsg_copy_hdr(req, iomsg);
-+#endif
-+
-+ return __io_recvmsg_copy_hdr(req, iomsg);
-+}
-+
-+static struct io_buffer *io_recv_buffer_select(struct io_kiocb *req,
-+ bool needs_lock)
-+{
-+ struct io_sr_msg *sr = &req->sr_msg;
-+ struct io_buffer *kbuf;
-+
-+ kbuf = io_buffer_select(req, &sr->len, sr->bgid, sr->kbuf, needs_lock);
-+ if (IS_ERR(kbuf))
-+ return kbuf;
-+
-+ sr->kbuf = kbuf;
-+ req->flags |= REQ_F_BUFFER_SELECTED;
-+ return kbuf;
-+}
-+
-+static inline unsigned int io_put_recv_kbuf(struct io_kiocb *req)
-+{
-+ return io_put_kbuf(req, req->sr_msg.kbuf);
-+}
-+
-+static int io_recvmsg_prep_async(struct io_kiocb *req)
-+{
-+ int ret;
-+
-+ ret = io_recvmsg_copy_hdr(req, req->async_data);
-+ if (!ret)
-+ req->flags |= REQ_F_NEED_CLEANUP;
-+ return ret;
-+}
-+
-+static int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-+{
-+ struct io_sr_msg *sr = &req->sr_msg;
-+
-+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+ if (unlikely(sqe->addr2 || sqe->file_index))
-+ return -EINVAL;
-+ if (unlikely(sqe->addr2 || sqe->file_index || sqe->ioprio))
-+ return -EINVAL;
-+
-+ sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
-+ sr->len = READ_ONCE(sqe->len);
-+ sr->bgid = READ_ONCE(sqe->buf_group);
-+ sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
-+ if (sr->msg_flags & MSG_DONTWAIT)
-+ req->flags |= REQ_F_NOWAIT;
-+
-+#ifdef CONFIG_COMPAT
-+ if (req->ctx->compat)
-+ sr->msg_flags |= MSG_CMSG_COMPAT;
-+#endif
-+ return 0;
-+}
-+
-+static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_async_msghdr iomsg, *kmsg;
-+ struct socket *sock;
-+ struct io_buffer *kbuf;
-+ unsigned flags;
-+ int min_ret = 0;
-+ int ret, cflags = 0;
-+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
-+
-+ sock = sock_from_file(req->file, &ret);
-+ if (unlikely(!sock))
-+ return ret;
-+
-+ kmsg = req->async_data;
-+ if (!kmsg) {
-+ ret = io_recvmsg_copy_hdr(req, &iomsg);
-+ if (ret)
-+ return ret;
-+ kmsg = &iomsg;
-+ }
-+
-+ if (req->flags & REQ_F_BUFFER_SELECT) {
-+ kbuf = io_recv_buffer_select(req, !force_nonblock);
-+ if (IS_ERR(kbuf))
-+ return PTR_ERR(kbuf);
-+ kmsg->fast_iov[0].iov_base = u64_to_user_ptr(kbuf->addr);
-+ kmsg->fast_iov[0].iov_len = req->sr_msg.len;
-+ iov_iter_init(&kmsg->msg.msg_iter, READ, kmsg->fast_iov,
-+ 1, req->sr_msg.len);
-+ }
-+
-+ flags = req->sr_msg.msg_flags;
-+ if (force_nonblock)
-+ flags |= MSG_DONTWAIT;
-+ if (flags & MSG_WAITALL)
-+ min_ret = iov_iter_count(&kmsg->msg.msg_iter);
-+
-+ ret = __sys_recvmsg_sock(sock, &kmsg->msg, req->sr_msg.umsg,
-+ kmsg->uaddr, flags);
-+ if (force_nonblock && ret == -EAGAIN)
-+ return io_setup_async_msg(req, kmsg);
-+ if (ret == -ERESTARTSYS)
-+ ret = -EINTR;
-+
-+ if (req->flags & REQ_F_BUFFER_SELECTED)
-+ cflags = io_put_recv_kbuf(req);
-+ /* fast path, check for non-NULL to avoid function call */
-+ if (kmsg->free_iov)
-+ kfree(kmsg->free_iov);
-+ req->flags &= ~REQ_F_NEED_CLEANUP;
-+ if (ret < min_ret || ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))))
-+ req_set_fail(req);
-+ __io_req_complete(req, issue_flags, ret, cflags);
-+ return 0;
-+}
-+
-+static int io_recv(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_buffer *kbuf;
-+ struct io_sr_msg *sr = &req->sr_msg;
-+ struct msghdr msg;
-+ void __user *buf = sr->buf;
-+ struct socket *sock;
-+ struct iovec iov;
-+ unsigned flags;
-+ int min_ret = 0;
-+ int ret, cflags = 0;
-+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
-+
-+ sock = sock_from_file(req->file, &ret);
-+ if (unlikely(!sock))
-+ return ret;
-+
-+ if (req->flags & REQ_F_BUFFER_SELECT) {
-+ kbuf = io_recv_buffer_select(req, !force_nonblock);
-+ if (IS_ERR(kbuf))
-+ return PTR_ERR(kbuf);
-+ buf = u64_to_user_ptr(kbuf->addr);
-+ }
-+
-+ ret = import_single_range(READ, buf, sr->len, &iov, &msg.msg_iter);
-+ if (unlikely(ret))
-+ goto out_free;
-+
-+ msg.msg_name = NULL;
-+ msg.msg_control = NULL;
-+ msg.msg_controllen = 0;
-+ msg.msg_namelen = 0;
-+ msg.msg_iocb = NULL;
-+ msg.msg_flags = 0;
-+
-+ flags = req->sr_msg.msg_flags;
-+ if (force_nonblock)
-+ flags |= MSG_DONTWAIT;
-+ if (flags & MSG_WAITALL)
-+ min_ret = iov_iter_count(&msg.msg_iter);
-+
-+ ret = sock_recvmsg(sock, &msg, flags);
-+ if (force_nonblock && ret == -EAGAIN)
-+ return -EAGAIN;
-+ if (ret == -ERESTARTSYS)
-+ ret = -EINTR;
-+out_free:
-+ if (req->flags & REQ_F_BUFFER_SELECTED)
-+ cflags = io_put_recv_kbuf(req);
-+ if (ret < min_ret || ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))))
-+ req_set_fail(req);
-+ __io_req_complete(req, issue_flags, ret, cflags);
-+ return 0;
-+}
-+
-+static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-+{
-+ struct io_accept *accept = &req->accept;
-+
-+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+ if (sqe->ioprio || sqe->len || sqe->buf_index)
-+ return -EINVAL;
-+
-+ accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
-+ accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2));
-+ accept->flags = READ_ONCE(sqe->accept_flags);
-+ accept->nofile = rlimit(RLIMIT_NOFILE);
-+
-+ accept->file_slot = READ_ONCE(sqe->file_index);
-+ if (accept->file_slot && (accept->flags & SOCK_CLOEXEC))
-+ return -EINVAL;
-+ if (accept->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
-+ return -EINVAL;
-+ if (SOCK_NONBLOCK != O_NONBLOCK && (accept->flags & SOCK_NONBLOCK))
-+ accept->flags = (accept->flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
-+ return 0;
-+}
-+
-+static int io_accept(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_accept *accept = &req->accept;
-+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
-+ unsigned int file_flags = force_nonblock ? O_NONBLOCK : 0;
-+ bool fixed = !!accept->file_slot;
-+ struct file *file;
-+ int ret, fd;
-+
-+ if (req->file->f_flags & O_NONBLOCK)
-+ req->flags |= REQ_F_NOWAIT;
-+
-+ if (!fixed) {
-+ fd = __get_unused_fd_flags(accept->flags, accept->nofile);
-+ if (unlikely(fd < 0))
-+ return fd;
-+ }
-+ file = do_accept(req->file, file_flags, accept->addr, accept->addr_len,
-+ accept->flags);
-+
-+ if (IS_ERR(file)) {
-+ if (!fixed)
-+ put_unused_fd(fd);
-+ ret = PTR_ERR(file);
-+ if (ret == -EAGAIN && force_nonblock)
-+ return -EAGAIN;
-+ if (ret == -ERESTARTSYS)
-+ ret = -EINTR;
-+ req_set_fail(req);
-+ } else if (!fixed) {
-+ fd_install(fd, file);
-+ ret = fd;
-+ } else {
-+ ret = io_install_fixed_file(req, file, issue_flags,
-+ accept->file_slot - 1);
-+ }
-+ __io_req_complete(req, issue_flags, ret, 0);
-+ return 0;
-+}
-+
-+static int io_connect_prep_async(struct io_kiocb *req)
-+{
-+ struct io_async_connect *io = req->async_data;
-+ struct io_connect *conn = &req->connect;
-+
-+ return move_addr_to_kernel(conn->addr, conn->addr_len, &io->address);
-+}
-+
-+static int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-+{
-+ struct io_connect *conn = &req->connect;
-+
-+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+ if (sqe->ioprio || sqe->len || sqe->buf_index || sqe->rw_flags ||
-+ sqe->splice_fd_in)
-+ return -EINVAL;
-+
-+ conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
-+ conn->addr_len = READ_ONCE(sqe->addr2);
-+ return 0;
-+}
-+
-+static int io_connect(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_async_connect __io, *io;
-+ unsigned file_flags;
-+ int ret;
-+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
-+
-+ if (req->async_data) {
-+ io = req->async_data;
-+ } else {
-+ ret = move_addr_to_kernel(req->connect.addr,
-+ req->connect.addr_len,
-+ &__io.address);
-+ if (ret)
-+ goto out;
-+ io = &__io;
-+ }
-+
-+ file_flags = force_nonblock ? O_NONBLOCK : 0;
-+
-+ ret = __sys_connect_file(req->file, &io->address,
-+ req->connect.addr_len, file_flags);
-+ if ((ret == -EAGAIN || ret == -EINPROGRESS) && force_nonblock) {
-+ if (req->async_data)
-+ return -EAGAIN;
-+ if (io_alloc_async_data(req)) {
-+ ret = -ENOMEM;
-+ goto out;
-+ }
-+ memcpy(req->async_data, &__io, sizeof(__io));
-+ return -EAGAIN;
-+ }
-+ if (ret == -ERESTARTSYS)
-+ ret = -EINTR;
-+out:
-+ if (ret < 0)
-+ req_set_fail(req);
-+ __io_req_complete(req, issue_flags, ret, 0);
-+ return 0;
-+}
-+#else /* !CONFIG_NET */
-+#define IO_NETOP_FN(op) \
-+static int io_##op(struct io_kiocb *req, unsigned int issue_flags) \
-+{ \
-+ return -EOPNOTSUPP; \
-+}
-+
-+#define IO_NETOP_PREP(op) \
-+IO_NETOP_FN(op) \
-+static int io_##op##_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) \
-+{ \
-+ return -EOPNOTSUPP; \
-+} \
-+
-+#define IO_NETOP_PREP_ASYNC(op) \
-+IO_NETOP_PREP(op) \
-+static int io_##op##_prep_async(struct io_kiocb *req) \
-+{ \
-+ return -EOPNOTSUPP; \
-+}
-+
-+IO_NETOP_PREP_ASYNC(sendmsg);
-+IO_NETOP_PREP_ASYNC(recvmsg);
-+IO_NETOP_PREP_ASYNC(connect);
-+IO_NETOP_PREP(accept);
-+IO_NETOP_FN(send);
-+IO_NETOP_FN(recv);
-+#endif /* CONFIG_NET */
-+
-+struct io_poll_table {
-+ struct poll_table_struct pt;
-+ struct io_kiocb *req;
-+ int nr_entries;
-+ int error;
-+};
-+
-+#define IO_POLL_CANCEL_FLAG BIT(31)
-+#define IO_POLL_RETRY_FLAG BIT(30)
-+#define IO_POLL_REF_MASK GENMASK(29, 0)
-+
-+/*
-+ * We usually have 1-2 refs taken, 128 is more than enough and we want to
-+ * maximise the margin between this amount and the moment when it overflows.
-+ */
-+#define IO_POLL_REF_BIAS 128
-+
-+static bool io_poll_get_ownership_slowpath(struct io_kiocb *req)
-+{
-+ int v;
-+
-+ /*
-+ * poll_refs are already elevated and we don't have much hope for
-+ * grabbing the ownership. Instead of incrementing set a retry flag
-+ * to notify the loop that there might have been some change.
-+ */
-+ v = atomic_fetch_or(IO_POLL_RETRY_FLAG, &req->poll_refs);
-+ if (v & IO_POLL_REF_MASK)
-+ return false;
-+ return !(atomic_fetch_inc(&req->poll_refs) & IO_POLL_REF_MASK);
-+}
-+
-+/*
-+ * If refs part of ->poll_refs (see IO_POLL_REF_MASK) is 0, it's free. We can
-+ * bump it and acquire ownership. It's disallowed to modify requests while not
-+ * owning it, that prevents from races for enqueueing task_work's and b/w
-+ * arming poll and wakeups.
-+ */
-+static inline bool io_poll_get_ownership(struct io_kiocb *req)
-+{
-+ if (unlikely(atomic_read(&req->poll_refs) >= IO_POLL_REF_BIAS))
-+ return io_poll_get_ownership_slowpath(req);
-+ return !(atomic_fetch_inc(&req->poll_refs) & IO_POLL_REF_MASK);
-+}
-+
-+static void io_poll_mark_cancelled(struct io_kiocb *req)
-+{
-+ atomic_or(IO_POLL_CANCEL_FLAG, &req->poll_refs);
-+}
-+
-+static struct io_poll_iocb *io_poll_get_double(struct io_kiocb *req)
-+{
-+ /* pure poll stashes this in ->async_data, poll driven retry elsewhere */
-+ if (req->opcode == IORING_OP_POLL_ADD)
-+ return req->async_data;
-+ return req->apoll->double_poll;
-+}
-+
-+static struct io_poll_iocb *io_poll_get_single(struct io_kiocb *req)
-+{
-+ if (req->opcode == IORING_OP_POLL_ADD)
-+ return &req->poll;
-+ return &req->apoll->poll;
-+}
-+
-+static void io_poll_req_insert(struct io_kiocb *req)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+ struct hlist_head *list;
-+
-+ list = &ctx->cancel_hash[hash_long(req->user_data, ctx->cancel_hash_bits)];
-+ hlist_add_head(&req->hash_node, list);
-+}
-+
-+static void io_init_poll_iocb(struct io_poll_iocb *poll, __poll_t events,
-+ wait_queue_func_t wake_func)
-+{
-+ poll->head = NULL;
-+#define IO_POLL_UNMASK (EPOLLERR|EPOLLHUP|EPOLLNVAL|EPOLLRDHUP)
-+ /* mask in events that we always want/need */
-+ poll->events = events | IO_POLL_UNMASK;
-+ INIT_LIST_HEAD(&poll->wait.entry);
-+ init_waitqueue_func_entry(&poll->wait, wake_func);
-+}
-+
-+static inline void io_poll_remove_entry(struct io_poll_iocb *poll)
-+{
-+ struct wait_queue_head *head = smp_load_acquire(&poll->head);
-+
-+ if (head) {
-+ spin_lock_irq(&head->lock);
-+ list_del_init(&poll->wait.entry);
-+ poll->head = NULL;
-+ spin_unlock_irq(&head->lock);
-+ }
-+}
-+
-+static void io_poll_remove_entries(struct io_kiocb *req)
-+{
-+ struct io_poll_iocb *poll = io_poll_get_single(req);
-+ struct io_poll_iocb *poll_double = io_poll_get_double(req);
-+
-+ /*
-+ * While we hold the waitqueue lock and the waitqueue is nonempty,
-+ * wake_up_pollfree() will wait for us. However, taking the waitqueue
-+ * lock in the first place can race with the waitqueue being freed.
-+ *
-+ * We solve this as eventpoll does: by taking advantage of the fact that
-+ * all users of wake_up_pollfree() will RCU-delay the actual free. If
-+ * we enter rcu_read_lock() and see that the pointer to the queue is
-+ * non-NULL, we can then lock it without the memory being freed out from
-+ * under us.
-+ *
-+ * Keep holding rcu_read_lock() as long as we hold the queue lock, in
-+ * case the caller deletes the entry from the queue, leaving it empty.
-+ * In that case, only RCU prevents the queue memory from being freed.
-+ */
-+ rcu_read_lock();
-+ io_poll_remove_entry(poll);
-+ if (poll_double)
-+ io_poll_remove_entry(poll_double);
-+ rcu_read_unlock();
-+}
-+
-+/*
-+ * All poll tw should go through this. Checks for poll events, manages
-+ * references, does rewait, etc.
-+ *
-+ * Returns a negative error on failure. >0 when no action require, which is
-+ * either spurious wakeup or multishot CQE is served. 0 when it's done with
-+ * the request, then the mask is stored in req->result.
-+ */
-+static int io_poll_check_events(struct io_kiocb *req)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+ struct io_poll_iocb *poll = io_poll_get_single(req);
-+ int v;
-+
-+ /* req->task == current here, checking PF_EXITING is safe */
-+ if (unlikely(req->task->flags & PF_EXITING))
-+ io_poll_mark_cancelled(req);
-+
-+ do {
-+ v = atomic_read(&req->poll_refs);
-+
-+ /* tw handler should be the owner, and so have some references */
-+ if (WARN_ON_ONCE(!(v & IO_POLL_REF_MASK)))
-+ return 0;
-+ if (v & IO_POLL_CANCEL_FLAG)
-+ return -ECANCELED;
-+ /*
-+ * cqe.res contains only events of the first wake up
-+ * and all others are be lost. Redo vfs_poll() to get
-+ * up to date state.
-+ */
-+ if ((v & IO_POLL_REF_MASK) != 1)
-+ req->result = 0;
-+ if (v & IO_POLL_RETRY_FLAG) {
-+ req->result = 0;
-+ /*
-+ * We won't find new events that came in between
-+ * vfs_poll and the ref put unless we clear the
-+ * flag in advance.
-+ */
-+ atomic_andnot(IO_POLL_RETRY_FLAG, &req->poll_refs);
-+ v &= ~IO_POLL_RETRY_FLAG;
-+ }
-+
-+ if (!req->result) {
-+ struct poll_table_struct pt = { ._key = poll->events };
-+
-+ req->result = vfs_poll(req->file, &pt) & poll->events;
-+ }
-+
-+ /* multishot, just fill an CQE and proceed */
-+ if (req->result && !(poll->events & EPOLLONESHOT)) {
-+ __poll_t mask = mangle_poll(req->result & poll->events);
-+ bool filled;
-+
-+ spin_lock(&ctx->completion_lock);
-+ filled = io_fill_cqe_aux(ctx, req->user_data, mask,
-+ IORING_CQE_F_MORE);
-+ io_commit_cqring(ctx);
-+ spin_unlock(&ctx->completion_lock);
-+ if (unlikely(!filled))
-+ return -ECANCELED;
-+ io_cqring_ev_posted(ctx);
-+ } else if (req->result) {
-+ return 0;
-+ }
-+
-+ /* force the next iteration to vfs_poll() */
-+ req->result = 0;
-+
-+ /*
-+ * Release all references, retry if someone tried to restart
-+ * task_work while we were executing it.
-+ */
-+ } while (atomic_sub_return(v & IO_POLL_REF_MASK, &req->poll_refs) &
-+ IO_POLL_REF_MASK);
-+
-+ return 1;
-+}
-+
-+static void io_poll_task_func(struct io_kiocb *req, bool *locked)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+ int ret;
-+
-+ ret = io_poll_check_events(req);
-+ if (ret > 0)
-+ return;
-+
-+ if (!ret) {
-+ req->result = mangle_poll(req->result & req->poll.events);
-+ } else {
-+ req->result = ret;
-+ req_set_fail(req);
-+ }
-+
-+ io_poll_remove_entries(req);
-+ spin_lock(&ctx->completion_lock);
-+ hash_del(&req->hash_node);
-+ spin_unlock(&ctx->completion_lock);
-+ io_req_complete_post(req, req->result, 0);
-+}
-+
-+static void io_apoll_task_func(struct io_kiocb *req, bool *locked)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+ int ret;
-+
-+ ret = io_poll_check_events(req);
-+ if (ret > 0)
-+ return;
-+
-+ io_poll_remove_entries(req);
-+ spin_lock(&ctx->completion_lock);
-+ hash_del(&req->hash_node);
-+ spin_unlock(&ctx->completion_lock);
-+
-+ if (!ret)
-+ io_req_task_submit(req, locked);
-+ else
-+ io_req_complete_failed(req, ret);
-+}
-+
-+static void __io_poll_execute(struct io_kiocb *req, int mask)
-+{
-+ req->result = mask;
-+ if (req->opcode == IORING_OP_POLL_ADD)
-+ req->io_task_work.func = io_poll_task_func;
-+ else
-+ req->io_task_work.func = io_apoll_task_func;
-+
-+ trace_io_uring_task_add(req->ctx, req->opcode, req->user_data, mask);
-+ io_req_task_work_add(req);
-+}
-+
-+static inline void io_poll_execute(struct io_kiocb *req, int res)
-+{
-+ if (io_poll_get_ownership(req))
-+ __io_poll_execute(req, res);
-+}
-+
-+static void io_poll_cancel_req(struct io_kiocb *req)
-+{
-+ io_poll_mark_cancelled(req);
-+ /* kick tw, which should complete the request */
-+ io_poll_execute(req, 0);
-+}
-+
-+static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
-+ void *key)
-+{
-+ struct io_kiocb *req = wait->private;
-+ struct io_poll_iocb *poll = container_of(wait, struct io_poll_iocb,
-+ wait);
-+ __poll_t mask = key_to_poll(key);
-+
-+ if (unlikely(mask & POLLFREE)) {
-+ io_poll_mark_cancelled(req);
-+ /* we have to kick tw in case it's not already */
-+ io_poll_execute(req, 0);
-+
-+ /*
-+ * If the waitqueue is being freed early but someone is already
-+ * holds ownership over it, we have to tear down the request as
-+ * best we can. That means immediately removing the request from
-+ * its waitqueue and preventing all further accesses to the
-+ * waitqueue via the request.
-+ */
-+ list_del_init(&poll->wait.entry);
-+
-+ /*
-+ * Careful: this *must* be the last step, since as soon
-+ * as req->head is NULL'ed out, the request can be
-+ * completed and freed, since aio_poll_complete_work()
-+ * will no longer need to take the waitqueue lock.
-+ */
-+ smp_store_release(&poll->head, NULL);
-+ return 1;
-+ }
-+
-+ /* for instances that support it check for an event match first */
-+ if (mask && !(mask & poll->events))
-+ return 0;
-+
-+ if (io_poll_get_ownership(req))
-+ __io_poll_execute(req, mask);
-+ return 1;
-+}
-+
-+static void __io_queue_proc(struct io_poll_iocb *poll, struct io_poll_table *pt,
-+ struct wait_queue_head *head,
-+ struct io_poll_iocb **poll_ptr)
-+{
-+ struct io_kiocb *req = pt->req;
-+
-+ /*
-+ * The file being polled uses multiple waitqueues for poll handling
-+ * (e.g. one for read, one for write). Setup a separate io_poll_iocb
-+ * if this happens.
-+ */
-+ if (unlikely(pt->nr_entries)) {
-+ struct io_poll_iocb *first = poll;
-+
-+ /* double add on the same waitqueue head, ignore */
-+ if (first->head == head)
-+ return;
-+ /* already have a 2nd entry, fail a third attempt */
-+ if (*poll_ptr) {
-+ if ((*poll_ptr)->head == head)
-+ return;
-+ pt->error = -EINVAL;
-+ return;
-+ }
-+
-+ poll = kmalloc(sizeof(*poll), GFP_ATOMIC);
-+ if (!poll) {
-+ pt->error = -ENOMEM;
-+ return;
-+ }
-+ io_init_poll_iocb(poll, first->events, first->wait.func);
-+ *poll_ptr = poll;
-+ }
-+
-+ pt->nr_entries++;
-+ poll->head = head;
-+ poll->wait.private = req;
-+
-+ if (poll->events & EPOLLEXCLUSIVE)
-+ add_wait_queue_exclusive(head, &poll->wait);
-+ else
-+ add_wait_queue(head, &poll->wait);
-+}
-+
-+static void io_poll_queue_proc(struct file *file, struct wait_queue_head *head,
-+ struct poll_table_struct *p)
-+{
-+ struct io_poll_table *pt = container_of(p, struct io_poll_table, pt);
-+
-+ __io_queue_proc(&pt->req->poll, pt, head,
-+ (struct io_poll_iocb **) &pt->req->async_data);
-+}
-+
-+static int __io_arm_poll_handler(struct io_kiocb *req,
-+ struct io_poll_iocb *poll,
-+ struct io_poll_table *ipt, __poll_t mask)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+
-+ INIT_HLIST_NODE(&req->hash_node);
-+ io_init_poll_iocb(poll, mask, io_poll_wake);
-+ poll->file = req->file;
-+ poll->wait.private = req;
-+
-+ ipt->pt._key = mask;
-+ ipt->req = req;
-+ ipt->error = 0;
-+ ipt->nr_entries = 0;
-+
-+ /*
-+ * Take the ownership to delay any tw execution up until we're done
-+ * with poll arming. see io_poll_get_ownership().
-+ */
-+ atomic_set(&req->poll_refs, 1);
-+ mask = vfs_poll(req->file, &ipt->pt) & poll->events;
-+
-+ if (mask && (poll->events & EPOLLONESHOT)) {
-+ io_poll_remove_entries(req);
-+ /* no one else has access to the req, forget about the ref */
-+ return mask;
-+ }
-+ if (!mask && unlikely(ipt->error || !ipt->nr_entries)) {
-+ io_poll_remove_entries(req);
-+ if (!ipt->error)
-+ ipt->error = -EINVAL;
-+ return 0;
-+ }
-+
-+ spin_lock(&ctx->completion_lock);
-+ io_poll_req_insert(req);
-+ spin_unlock(&ctx->completion_lock);
-+
-+ if (mask) {
-+ /* can't multishot if failed, just queue the event we've got */
-+ if (unlikely(ipt->error || !ipt->nr_entries)) {
-+ poll->events |= EPOLLONESHOT;
-+ ipt->error = 0;
-+ }
-+ __io_poll_execute(req, mask);
-+ return 0;
-+ }
-+
-+ /*
-+ * Try to release ownership. If we see a change of state, e.g.
-+ * poll was waken up, queue up a tw, it'll deal with it.
-+ */
-+ if (atomic_cmpxchg(&req->poll_refs, 1, 0) != 1)
-+ __io_poll_execute(req, 0);
-+ return 0;
-+}
-+
-+static void io_async_queue_proc(struct file *file, struct wait_queue_head *head,
-+ struct poll_table_struct *p)
-+{
-+ struct io_poll_table *pt = container_of(p, struct io_poll_table, pt);
-+ struct async_poll *apoll = pt->req->apoll;
-+
-+ __io_queue_proc(&apoll->poll, pt, head, &apoll->double_poll);
-+}
-+
-+enum {
-+ IO_APOLL_OK,
-+ IO_APOLL_ABORTED,
-+ IO_APOLL_READY
-+};
-+
-+static int io_arm_poll_handler(struct io_kiocb *req)
-+{
-+ const struct io_op_def *def = &io_op_defs[req->opcode];
-+ struct io_ring_ctx *ctx = req->ctx;
-+ struct async_poll *apoll;
-+ struct io_poll_table ipt;
-+ __poll_t mask = EPOLLONESHOT | POLLERR | POLLPRI;
-+ int ret;
-+
-+ if (!req->file || !file_can_poll(req->file))
-+ return IO_APOLL_ABORTED;
-+ if (req->flags & REQ_F_POLLED)
-+ return IO_APOLL_ABORTED;
-+ if (!def->pollin && !def->pollout)
-+ return IO_APOLL_ABORTED;
-+
-+ if (def->pollin) {
-+ mask |= POLLIN | POLLRDNORM;
-+
-+ /* If reading from MSG_ERRQUEUE using recvmsg, ignore POLLIN */
-+ if ((req->opcode == IORING_OP_RECVMSG) &&
-+ (req->sr_msg.msg_flags & MSG_ERRQUEUE))
-+ mask &= ~POLLIN;
-+ } else {
-+ mask |= POLLOUT | POLLWRNORM;
-+ }
-+
-+ apoll = kmalloc(sizeof(*apoll), GFP_ATOMIC);
-+ if (unlikely(!apoll))
-+ return IO_APOLL_ABORTED;
-+ apoll->double_poll = NULL;
-+ req->apoll = apoll;
-+ req->flags |= REQ_F_POLLED;
-+ ipt.pt._qproc = io_async_queue_proc;
-+
-+ ret = __io_arm_poll_handler(req, &apoll->poll, &ipt, mask);
-+ if (ret || ipt.error)
-+ return ret ? IO_APOLL_READY : IO_APOLL_ABORTED;
-+
-+ trace_io_uring_poll_arm(ctx, req, req->opcode, req->user_data,
-+ mask, apoll->poll.events);
-+ return IO_APOLL_OK;
-+}
-+
-+/*
-+ * Returns true if we found and killed one or more poll requests
-+ */
-+static bool io_poll_remove_all(struct io_ring_ctx *ctx, struct task_struct *tsk,
-+ bool cancel_all)
-+{
-+ struct hlist_node *tmp;
-+ struct io_kiocb *req;
-+ bool found = false;
-+ int i;
-+
-+ spin_lock(&ctx->completion_lock);
-+ for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
-+ struct hlist_head *list;
-+
-+ list = &ctx->cancel_hash[i];
-+ hlist_for_each_entry_safe(req, tmp, list, hash_node) {
-+ if (io_match_task_safe(req, tsk, cancel_all)) {
-+ hlist_del_init(&req->hash_node);
-+ io_poll_cancel_req(req);
-+ found = true;
-+ }
-+ }
-+ }
-+ spin_unlock(&ctx->completion_lock);
-+ return found;
-+}
-+
-+static struct io_kiocb *io_poll_find(struct io_ring_ctx *ctx, __u64 sqe_addr,
-+ bool poll_only)
-+ __must_hold(&ctx->completion_lock)
-+{
-+ struct hlist_head *list;
-+ struct io_kiocb *req;
-+
-+ list = &ctx->cancel_hash[hash_long(sqe_addr, ctx->cancel_hash_bits)];
-+ hlist_for_each_entry(req, list, hash_node) {
-+ if (sqe_addr != req->user_data)
-+ continue;
-+ if (poll_only && req->opcode != IORING_OP_POLL_ADD)
-+ continue;
-+ return req;
-+ }
-+ return NULL;
-+}
-+
-+static bool io_poll_disarm(struct io_kiocb *req)
-+ __must_hold(&ctx->completion_lock)
-+{
-+ if (!io_poll_get_ownership(req))
-+ return false;
-+ io_poll_remove_entries(req);
-+ hash_del(&req->hash_node);
-+ return true;
-+}
-+
-+static int io_poll_cancel(struct io_ring_ctx *ctx, __u64 sqe_addr,
-+ bool poll_only)
-+ __must_hold(&ctx->completion_lock)
-+{
-+ struct io_kiocb *req = io_poll_find(ctx, sqe_addr, poll_only);
-+
-+ if (!req)
-+ return -ENOENT;
-+ io_poll_cancel_req(req);
-+ return 0;
-+}
-+
-+static __poll_t io_poll_parse_events(const struct io_uring_sqe *sqe,
-+ unsigned int flags)
-+{
-+ u32 events;
-+
-+ events = READ_ONCE(sqe->poll32_events);
-+#ifdef __BIG_ENDIAN
-+ events = swahw32(events);
-+#endif
-+ if (!(flags & IORING_POLL_ADD_MULTI))
-+ events |= EPOLLONESHOT;
-+ return demangle_poll(events) | (events & (EPOLLEXCLUSIVE|EPOLLONESHOT));
-+}
-+
-+static int io_poll_update_prep(struct io_kiocb *req,
-+ const struct io_uring_sqe *sqe)
-+{
-+ struct io_poll_update *upd = &req->poll_update;
-+ u32 flags;
-+
-+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+ if (sqe->ioprio || sqe->buf_index || sqe->splice_fd_in)
-+ return -EINVAL;
-+ flags = READ_ONCE(sqe->len);
-+ if (flags & ~(IORING_POLL_UPDATE_EVENTS | IORING_POLL_UPDATE_USER_DATA |
-+ IORING_POLL_ADD_MULTI))
-+ return -EINVAL;
-+ /* meaningless without update */
-+ if (flags == IORING_POLL_ADD_MULTI)
-+ return -EINVAL;
-+
-+ upd->old_user_data = READ_ONCE(sqe->addr);
-+ upd->update_events = flags & IORING_POLL_UPDATE_EVENTS;
-+ upd->update_user_data = flags & IORING_POLL_UPDATE_USER_DATA;
-+
-+ upd->new_user_data = READ_ONCE(sqe->off);
-+ if (!upd->update_user_data && upd->new_user_data)
-+ return -EINVAL;
-+ if (upd->update_events)
-+ upd->events = io_poll_parse_events(sqe, flags);
-+ else if (sqe->poll32_events)
-+ return -EINVAL;
-+
-+ return 0;
-+}
-+
-+static int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-+{
-+ struct io_poll_iocb *poll = &req->poll;
-+ u32 flags;
-+
-+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+ if (sqe->ioprio || sqe->buf_index || sqe->off || sqe->addr)
-+ return -EINVAL;
-+ flags = READ_ONCE(sqe->len);
-+ if (flags & ~IORING_POLL_ADD_MULTI)
-+ return -EINVAL;
-+
-+ io_req_set_refcount(req);
-+ poll->events = io_poll_parse_events(sqe, flags);
-+ return 0;
-+}
-+
-+static int io_poll_add(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_poll_iocb *poll = &req->poll;
-+ struct io_poll_table ipt;
-+ int ret;
-+
-+ ipt.pt._qproc = io_poll_queue_proc;
-+
-+ ret = __io_arm_poll_handler(req, &req->poll, &ipt, poll->events);
-+ if (!ret && ipt.error)
-+ req_set_fail(req);
-+ ret = ret ?: ipt.error;
-+ if (ret)
-+ __io_req_complete(req, issue_flags, ret, 0);
-+ return 0;
-+}
-+
-+static int io_poll_update(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+ struct io_kiocb *preq;
-+ int ret2, ret = 0;
-+
-+ spin_lock(&ctx->completion_lock);
-+ preq = io_poll_find(ctx, req->poll_update.old_user_data, true);
-+ if (!preq || !io_poll_disarm(preq)) {
-+ spin_unlock(&ctx->completion_lock);
-+ ret = preq ? -EALREADY : -ENOENT;
-+ goto out;
-+ }
-+ spin_unlock(&ctx->completion_lock);
-+
-+ if (req->poll_update.update_events || req->poll_update.update_user_data) {
-+ /* only mask one event flags, keep behavior flags */
-+ if (req->poll_update.update_events) {
-+ preq->poll.events &= ~0xffff;
-+ preq->poll.events |= req->poll_update.events & 0xffff;
-+ preq->poll.events |= IO_POLL_UNMASK;
-+ }
-+ if (req->poll_update.update_user_data)
-+ preq->user_data = req->poll_update.new_user_data;
-+
-+ ret2 = io_poll_add(preq, issue_flags);
-+ /* successfully updated, don't complete poll request */
-+ if (!ret2)
-+ goto out;
-+ }
-+ req_set_fail(preq);
-+ io_req_complete(preq, -ECANCELED);
-+out:
-+ if (ret < 0)
-+ req_set_fail(req);
-+ /* complete update request, we're done with it */
-+ io_req_complete(req, ret);
-+ return 0;
-+}
-+
-+static void io_req_task_timeout(struct io_kiocb *req, bool *locked)
-+{
-+ req_set_fail(req);
-+ io_req_complete_post(req, -ETIME, 0);
-+}
-+
-+static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer)
-+{
-+ struct io_timeout_data *data = container_of(timer,
-+ struct io_timeout_data, timer);
-+ struct io_kiocb *req = data->req;
-+ struct io_ring_ctx *ctx = req->ctx;
-+ unsigned long flags;
-+
-+ spin_lock_irqsave(&ctx->timeout_lock, flags);
-+ list_del_init(&req->timeout.list);
-+ atomic_set(&req->ctx->cq_timeouts,
-+ atomic_read(&req->ctx->cq_timeouts) + 1);
-+ spin_unlock_irqrestore(&ctx->timeout_lock, flags);
-+
-+ req->io_task_work.func = io_req_task_timeout;
-+ io_req_task_work_add(req);
-+ return HRTIMER_NORESTART;
-+}
-+
-+static struct io_kiocb *io_timeout_extract(struct io_ring_ctx *ctx,
-+ __u64 user_data)
-+ __must_hold(&ctx->timeout_lock)
-+{
-+ struct io_timeout_data *io;
-+ struct io_kiocb *req;
-+ bool found = false;
-+
-+ list_for_each_entry(req, &ctx->timeout_list, timeout.list) {
-+ found = user_data == req->user_data;
-+ if (found)
-+ break;
-+ }
-+ if (!found)
-+ return ERR_PTR(-ENOENT);
-+
-+ io = req->async_data;
-+ if (hrtimer_try_to_cancel(&io->timer) == -1)
-+ return ERR_PTR(-EALREADY);
-+ list_del_init(&req->timeout.list);
-+ return req;
-+}
-+
-+static int io_timeout_cancel(struct io_ring_ctx *ctx, __u64 user_data)
-+ __must_hold(&ctx->completion_lock)
-+ __must_hold(&ctx->timeout_lock)
-+{
-+ struct io_kiocb *req = io_timeout_extract(ctx, user_data);
-+
-+ if (IS_ERR(req))
-+ return PTR_ERR(req);
-+
-+ req_set_fail(req);
-+ io_fill_cqe_req(req, -ECANCELED, 0);
-+ io_put_req_deferred(req);
-+ return 0;
-+}
-+
-+static clockid_t io_timeout_get_clock(struct io_timeout_data *data)
-+{
-+ switch (data->flags & IORING_TIMEOUT_CLOCK_MASK) {
-+ case IORING_TIMEOUT_BOOTTIME:
-+ return CLOCK_BOOTTIME;
-+ case IORING_TIMEOUT_REALTIME:
-+ return CLOCK_REALTIME;
-+ default:
-+ /* can't happen, vetted at prep time */
-+ WARN_ON_ONCE(1);
-+ fallthrough;
-+ case 0:
-+ return CLOCK_MONOTONIC;
-+ }
-+}
-+
-+static int io_linked_timeout_update(struct io_ring_ctx *ctx, __u64 user_data,
-+ struct timespec64 *ts, enum hrtimer_mode mode)
-+ __must_hold(&ctx->timeout_lock)
-+{
-+ struct io_timeout_data *io;
-+ struct io_kiocb *req;
-+ bool found = false;
-+
-+ list_for_each_entry(req, &ctx->ltimeout_list, timeout.list) {
-+ found = user_data == req->user_data;
-+ if (found)
-+ break;
-+ }
-+ if (!found)
-+ return -ENOENT;
-+
-+ io = req->async_data;
-+ if (hrtimer_try_to_cancel(&io->timer) == -1)
-+ return -EALREADY;
-+ hrtimer_init(&io->timer, io_timeout_get_clock(io), mode);
-+ io->timer.function = io_link_timeout_fn;
-+ hrtimer_start(&io->timer, timespec64_to_ktime(*ts), mode);
-+ return 0;
-+}
-+
-+static int io_timeout_update(struct io_ring_ctx *ctx, __u64 user_data,
-+ struct timespec64 *ts, enum hrtimer_mode mode)
-+ __must_hold(&ctx->timeout_lock)
-+{
-+ struct io_kiocb *req = io_timeout_extract(ctx, user_data);
-+ struct io_timeout_data *data;
-+
-+ if (IS_ERR(req))
-+ return PTR_ERR(req);
-+
-+ req->timeout.off = 0; /* noseq */
-+ data = req->async_data;
-+ list_add_tail(&req->timeout.list, &ctx->timeout_list);
-+ hrtimer_init(&data->timer, io_timeout_get_clock(data), mode);
-+ data->timer.function = io_timeout_fn;
-+ hrtimer_start(&data->timer, timespec64_to_ktime(*ts), mode);
-+ return 0;
-+}
-+
-+static int io_timeout_remove_prep(struct io_kiocb *req,
-+ const struct io_uring_sqe *sqe)
-+{
-+ struct io_timeout_rem *tr = &req->timeout_rem;
-+
-+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+ if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
-+ return -EINVAL;
-+ if (sqe->ioprio || sqe->buf_index || sqe->len || sqe->splice_fd_in)
-+ return -EINVAL;
-+
-+ tr->ltimeout = false;
-+ tr->addr = READ_ONCE(sqe->addr);
-+ tr->flags = READ_ONCE(sqe->timeout_flags);
-+ if (tr->flags & IORING_TIMEOUT_UPDATE_MASK) {
-+ if (hweight32(tr->flags & IORING_TIMEOUT_CLOCK_MASK) > 1)
-+ return -EINVAL;
-+ if (tr->flags & IORING_LINK_TIMEOUT_UPDATE)
-+ tr->ltimeout = true;
-+ if (tr->flags & ~(IORING_TIMEOUT_UPDATE_MASK|IORING_TIMEOUT_ABS))
-+ return -EINVAL;
-+ if (get_timespec64(&tr->ts, u64_to_user_ptr(sqe->addr2)))
-+ return -EFAULT;
-+ } else if (tr->flags) {
-+ /* timeout removal doesn't support flags */
-+ return -EINVAL;
-+ }
-+
-+ return 0;
-+}
-+
-+static inline enum hrtimer_mode io_translate_timeout_mode(unsigned int flags)
-+{
-+ return (flags & IORING_TIMEOUT_ABS) ? HRTIMER_MODE_ABS
-+ : HRTIMER_MODE_REL;
-+}
-+
-+/*
-+ * Remove or update an existing timeout command
-+ */
-+static int io_timeout_remove(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_timeout_rem *tr = &req->timeout_rem;
-+ struct io_ring_ctx *ctx = req->ctx;
-+ int ret;
-+
-+ if (!(req->timeout_rem.flags & IORING_TIMEOUT_UPDATE)) {
-+ spin_lock(&ctx->completion_lock);
-+ spin_lock_irq(&ctx->timeout_lock);
-+ ret = io_timeout_cancel(ctx, tr->addr);
-+ spin_unlock_irq(&ctx->timeout_lock);
-+ spin_unlock(&ctx->completion_lock);
-+ } else {
-+ enum hrtimer_mode mode = io_translate_timeout_mode(tr->flags);
-+
-+ spin_lock_irq(&ctx->timeout_lock);
-+ if (tr->ltimeout)
-+ ret = io_linked_timeout_update(ctx, tr->addr, &tr->ts, mode);
-+ else
-+ ret = io_timeout_update(ctx, tr->addr, &tr->ts, mode);
-+ spin_unlock_irq(&ctx->timeout_lock);
-+ }
-+
-+ if (ret < 0)
-+ req_set_fail(req);
-+ io_req_complete_post(req, ret, 0);
-+ return 0;
-+}
-+
-+static int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
-+ bool is_timeout_link)
-+{
-+ struct io_timeout_data *data;
-+ unsigned flags;
-+ u32 off = READ_ONCE(sqe->off);
-+
-+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+ if (sqe->ioprio || sqe->buf_index || sqe->len != 1 ||
-+ sqe->splice_fd_in)
-+ return -EINVAL;
-+ if (off && is_timeout_link)
-+ return -EINVAL;
-+ flags = READ_ONCE(sqe->timeout_flags);
-+ if (flags & ~(IORING_TIMEOUT_ABS | IORING_TIMEOUT_CLOCK_MASK))
-+ return -EINVAL;
-+ /* more than one clock specified is invalid, obviously */
-+ if (hweight32(flags & IORING_TIMEOUT_CLOCK_MASK) > 1)
-+ return -EINVAL;
-+
-+ INIT_LIST_HEAD(&req->timeout.list);
-+ req->timeout.off = off;
-+ if (unlikely(off && !req->ctx->off_timeout_used))
-+ req->ctx->off_timeout_used = true;
-+
-+ if (!req->async_data && io_alloc_async_data(req))
-+ return -ENOMEM;
-+
-+ data = req->async_data;
-+ data->req = req;
-+ data->flags = flags;
-+
-+ if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr)))
-+ return -EFAULT;
-+
-+ INIT_LIST_HEAD(&req->timeout.list);
-+ data->mode = io_translate_timeout_mode(flags);
-+ hrtimer_init(&data->timer, io_timeout_get_clock(data), data->mode);
-+
-+ if (is_timeout_link) {
-+ struct io_submit_link *link = &req->ctx->submit_state.link;
-+
-+ if (!link->head)
-+ return -EINVAL;
-+ if (link->last->opcode == IORING_OP_LINK_TIMEOUT)
-+ return -EINVAL;
-+ req->timeout.head = link->last;
-+ link->last->flags |= REQ_F_ARM_LTIMEOUT;
-+ }
-+ return 0;
-+}
-+
-+static int io_timeout(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+ struct io_timeout_data *data = req->async_data;
-+ struct list_head *entry;
-+ u32 tail, off = req->timeout.off;
-+
-+ spin_lock_irq(&ctx->timeout_lock);
-+
-+ /*
-+ * sqe->off holds how many events that need to occur for this
-+ * timeout event to be satisfied. If it isn't set, then this is
-+ * a pure timeout request, sequence isn't used.
-+ */
-+ if (io_is_timeout_noseq(req)) {
-+ entry = ctx->timeout_list.prev;
-+ goto add;
-+ }
-+
-+ tail = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);
-+ req->timeout.target_seq = tail + off;
-+
-+ /* Update the last seq here in case io_flush_timeouts() hasn't.
-+ * This is safe because ->completion_lock is held, and submissions
-+ * and completions are never mixed in the same ->completion_lock section.
-+ */
-+ ctx->cq_last_tm_flush = tail;
-+
-+ /*
-+ * Insertion sort, ensuring the first entry in the list is always
-+ * the one we need first.
-+ */
-+ list_for_each_prev(entry, &ctx->timeout_list) {
-+ struct io_kiocb *nxt = list_entry(entry, struct io_kiocb,
-+ timeout.list);
-+
-+ if (io_is_timeout_noseq(nxt))
-+ continue;
-+ /* nxt.seq is behind @tail, otherwise would've been completed */
-+ if (off >= nxt->timeout.target_seq - tail)
-+ break;
-+ }
-+add:
-+ list_add(&req->timeout.list, entry);
-+ data->timer.function = io_timeout_fn;
-+ hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode);
-+ spin_unlock_irq(&ctx->timeout_lock);
-+ return 0;
-+}
-+
-+struct io_cancel_data {
-+ struct io_ring_ctx *ctx;
-+ u64 user_data;
-+};
-+
-+static bool io_cancel_cb(struct io_wq_work *work, void *data)
-+{
-+ struct io_kiocb *req = container_of(work, struct io_kiocb, work);
-+ struct io_cancel_data *cd = data;
-+
-+ return req->ctx == cd->ctx && req->user_data == cd->user_data;
-+}
-+
-+static int io_async_cancel_one(struct io_uring_task *tctx, u64 user_data,
-+ struct io_ring_ctx *ctx)
-+{
-+ struct io_cancel_data data = { .ctx = ctx, .user_data = user_data, };
-+ enum io_wq_cancel cancel_ret;
-+ int ret = 0;
-+
-+ if (!tctx || !tctx->io_wq)
-+ return -ENOENT;
-+
-+ cancel_ret = io_wq_cancel_cb(tctx->io_wq, io_cancel_cb, &data, false);
-+ switch (cancel_ret) {
-+ case IO_WQ_CANCEL_OK:
-+ ret = 0;
-+ break;
-+ case IO_WQ_CANCEL_RUNNING:
-+ ret = -EALREADY;
-+ break;
-+ case IO_WQ_CANCEL_NOTFOUND:
-+ ret = -ENOENT;
-+ break;
-+ }
-+
-+ return ret;
-+}
-+
-+static int io_try_cancel_userdata(struct io_kiocb *req, u64 sqe_addr)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+ int ret;
-+
-+ WARN_ON_ONCE(!io_wq_current_is_worker() && req->task != current);
-+
-+ ret = io_async_cancel_one(req->task->io_uring, sqe_addr, ctx);
-+ if (ret != -ENOENT)
-+ return ret;
-+
-+ spin_lock(&ctx->completion_lock);
-+ spin_lock_irq(&ctx->timeout_lock);
-+ ret = io_timeout_cancel(ctx, sqe_addr);
-+ spin_unlock_irq(&ctx->timeout_lock);
-+ if (ret != -ENOENT)
-+ goto out;
-+ ret = io_poll_cancel(ctx, sqe_addr, false);
-+out:
-+ spin_unlock(&ctx->completion_lock);
-+ return ret;
-+}
-+
-+static int io_async_cancel_prep(struct io_kiocb *req,
-+ const struct io_uring_sqe *sqe)
-+{
-+ if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ return -EINVAL;
-+ if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
-+ return -EINVAL;
-+ if (sqe->ioprio || sqe->off || sqe->len || sqe->cancel_flags ||
-+ sqe->splice_fd_in)
-+ return -EINVAL;
-+
-+ req->cancel.addr = READ_ONCE(sqe->addr);
-+ return 0;
-+}
-+
-+static int io_async_cancel(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+ u64 sqe_addr = req->cancel.addr;
-+ struct io_tctx_node *node;
-+ int ret;
-+
-+ ret = io_try_cancel_userdata(req, sqe_addr);
-+ if (ret != -ENOENT)
-+ goto done;
-+
-+ /* slow path, try all io-wq's */
-+ io_ring_submit_lock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
-+ ret = -ENOENT;
-+ list_for_each_entry(node, &ctx->tctx_list, ctx_node) {
-+ struct io_uring_task *tctx = node->task->io_uring;
-+
-+ ret = io_async_cancel_one(tctx, req->cancel.addr, ctx);
-+ if (ret != -ENOENT)
-+ break;
-+ }
-+ io_ring_submit_unlock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
-+done:
-+ if (ret < 0)
-+ req_set_fail(req);
-+ io_req_complete_post(req, ret, 0);
-+ return 0;
-+}
-+
-+static int io_rsrc_update_prep(struct io_kiocb *req,
-+ const struct io_uring_sqe *sqe)
-+{
-+ if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
-+ return -EINVAL;
-+ if (sqe->ioprio || sqe->rw_flags || sqe->splice_fd_in)
-+ return -EINVAL;
-+
-+ req->rsrc_update.offset = READ_ONCE(sqe->off);
-+ req->rsrc_update.nr_args = READ_ONCE(sqe->len);
-+ if (!req->rsrc_update.nr_args)
-+ return -EINVAL;
-+ req->rsrc_update.arg = READ_ONCE(sqe->addr);
-+ return 0;
-+}
-+
-+static int io_files_update(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+ struct io_uring_rsrc_update2 up;
-+ int ret;
-+
-+ up.offset = req->rsrc_update.offset;
-+ up.data = req->rsrc_update.arg;
-+ up.nr = 0;
-+ up.tags = 0;
-+ up.resv = 0;
-+ up.resv2 = 0;
-+
-+ io_ring_submit_lock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
-+ ret = __io_register_rsrc_update(ctx, IORING_RSRC_FILE,
-+ &up, req->rsrc_update.nr_args);
-+ io_ring_submit_unlock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
-+
-+ if (ret < 0)
-+ req_set_fail(req);
-+ __io_req_complete(req, issue_flags, ret, 0);
-+ return 0;
-+}
-+
-+static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-+{
-+ switch (req->opcode) {
-+ case IORING_OP_NOP:
-+ return 0;
-+ case IORING_OP_READV:
-+ case IORING_OP_READ_FIXED:
-+ case IORING_OP_READ:
-+ return io_read_prep(req, sqe);
-+ case IORING_OP_WRITEV:
-+ case IORING_OP_WRITE_FIXED:
-+ case IORING_OP_WRITE:
-+ return io_write_prep(req, sqe);
-+ case IORING_OP_POLL_ADD:
-+ return io_poll_add_prep(req, sqe);
-+ case IORING_OP_POLL_REMOVE:
-+ return io_poll_update_prep(req, sqe);
-+ case IORING_OP_FSYNC:
-+ return io_fsync_prep(req, sqe);
-+ case IORING_OP_SYNC_FILE_RANGE:
-+ return io_sfr_prep(req, sqe);
-+ case IORING_OP_SENDMSG:
-+ case IORING_OP_SEND:
-+ return io_sendmsg_prep(req, sqe);
-+ case IORING_OP_RECVMSG:
-+ case IORING_OP_RECV:
-+ return io_recvmsg_prep(req, sqe);
-+ case IORING_OP_CONNECT:
-+ return io_connect_prep(req, sqe);
-+ case IORING_OP_TIMEOUT:
-+ return io_timeout_prep(req, sqe, false);
-+ case IORING_OP_TIMEOUT_REMOVE:
-+ return io_timeout_remove_prep(req, sqe);
-+ case IORING_OP_ASYNC_CANCEL:
-+ return io_async_cancel_prep(req, sqe);
-+ case IORING_OP_LINK_TIMEOUT:
-+ return io_timeout_prep(req, sqe, true);
-+ case IORING_OP_ACCEPT:
-+ return io_accept_prep(req, sqe);
-+ case IORING_OP_FALLOCATE:
-+ return io_fallocate_prep(req, sqe);
-+ case IORING_OP_OPENAT:
-+ return io_openat_prep(req, sqe);
-+ case IORING_OP_CLOSE:
-+ return io_close_prep(req, sqe);
-+ case IORING_OP_FILES_UPDATE:
-+ return io_rsrc_update_prep(req, sqe);
-+ case IORING_OP_STATX:
-+ return io_statx_prep(req, sqe);
-+ case IORING_OP_FADVISE:
-+ return io_fadvise_prep(req, sqe);
-+ case IORING_OP_MADVISE:
-+ return io_madvise_prep(req, sqe);
-+ case IORING_OP_OPENAT2:
-+ return io_openat2_prep(req, sqe);
-+ case IORING_OP_EPOLL_CTL:
-+ return io_epoll_ctl_prep(req, sqe);
-+ case IORING_OP_SPLICE:
-+ return io_splice_prep(req, sqe);
-+ case IORING_OP_PROVIDE_BUFFERS:
-+ return io_provide_buffers_prep(req, sqe);
-+ case IORING_OP_REMOVE_BUFFERS:
-+ return io_remove_buffers_prep(req, sqe);
-+ case IORING_OP_TEE:
-+ return io_tee_prep(req, sqe);
-+ case IORING_OP_SHUTDOWN:
-+ return io_shutdown_prep(req, sqe);
-+ case IORING_OP_RENAMEAT:
-+ return io_renameat_prep(req, sqe);
-+ case IORING_OP_UNLINKAT:
-+ return io_unlinkat_prep(req, sqe);
-+ }
-+
-+ printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
-+ req->opcode);
-+ return -EINVAL;
-+}
-+
-+static int io_req_prep_async(struct io_kiocb *req)
-+{
-+ if (!io_op_defs[req->opcode].needs_async_setup)
-+ return 0;
-+ if (WARN_ON_ONCE(req->async_data))
-+ return -EFAULT;
-+ if (io_alloc_async_data(req))
-+ return -EAGAIN;
-+
-+ switch (req->opcode) {
-+ case IORING_OP_READV:
-+ return io_rw_prep_async(req, READ);
-+ case IORING_OP_WRITEV:
-+ return io_rw_prep_async(req, WRITE);
-+ case IORING_OP_SENDMSG:
-+ return io_sendmsg_prep_async(req);
-+ case IORING_OP_RECVMSG:
-+ return io_recvmsg_prep_async(req);
-+ case IORING_OP_CONNECT:
-+ return io_connect_prep_async(req);
-+ }
-+ printk_once(KERN_WARNING "io_uring: prep_async() bad opcode %d\n",
-+ req->opcode);
-+ return -EFAULT;
-+}
-+
-+static u32 io_get_sequence(struct io_kiocb *req)
-+{
-+ u32 seq = req->ctx->cached_sq_head;
-+
-+ /* need original cached_sq_head, but it was increased for each req */
-+ io_for_each_link(req, req)
-+ seq--;
-+ return seq;
-+}
-+
-+static bool io_drain_req(struct io_kiocb *req)
-+{
-+ struct io_kiocb *pos;
-+ struct io_ring_ctx *ctx = req->ctx;
-+ struct io_defer_entry *de;
-+ int ret;
-+ u32 seq;
-+
-+ if (req->flags & REQ_F_FAIL) {
-+ io_req_complete_fail_submit(req);
-+ return true;
-+ }
-+
-+ /*
-+ * If we need to drain a request in the middle of a link, drain the
-+ * head request and the next request/link after the current link.
-+ * Considering sequential execution of links, IOSQE_IO_DRAIN will be
-+ * maintained for every request of our link.
-+ */
-+ if (ctx->drain_next) {
-+ req->flags |= REQ_F_IO_DRAIN;
-+ ctx->drain_next = false;
-+ }
-+ /* not interested in head, start from the first linked */
-+ io_for_each_link(pos, req->link) {
-+ if (pos->flags & REQ_F_IO_DRAIN) {
-+ ctx->drain_next = true;
-+ req->flags |= REQ_F_IO_DRAIN;
-+ break;
-+ }
-+ }
-+
-+ /* Still need defer if there is pending req in defer list. */
-+ spin_lock(&ctx->completion_lock);
-+ if (likely(list_empty_careful(&ctx->defer_list) &&
-+ !(req->flags & REQ_F_IO_DRAIN))) {
-+ spin_unlock(&ctx->completion_lock);
-+ ctx->drain_active = false;
-+ return false;
-+ }
-+ spin_unlock(&ctx->completion_lock);
-+
-+ seq = io_get_sequence(req);
-+ /* Still a chance to pass the sequence check */
-+ if (!req_need_defer(req, seq) && list_empty_careful(&ctx->defer_list))
-+ return false;
-+
-+ ret = io_req_prep_async(req);
-+ if (ret)
-+ goto fail;
-+ io_prep_async_link(req);
-+ de = kmalloc(sizeof(*de), GFP_KERNEL);
-+ if (!de) {
-+ ret = -ENOMEM;
-+fail:
-+ io_req_complete_failed(req, ret);
-+ return true;
-+ }
-+
-+ spin_lock(&ctx->completion_lock);
-+ if (!req_need_defer(req, seq) && list_empty(&ctx->defer_list)) {
-+ spin_unlock(&ctx->completion_lock);
-+ kfree(de);
-+ io_queue_async_work(req, NULL);
-+ return true;
-+ }
-+
-+ trace_io_uring_defer(ctx, req, req->user_data);
-+ de->req = req;
-+ de->seq = seq;
-+ list_add_tail(&de->list, &ctx->defer_list);
-+ spin_unlock(&ctx->completion_lock);
-+ return true;
-+}
-+
-+static void io_clean_op(struct io_kiocb *req)
-+{
-+ if (req->flags & REQ_F_BUFFER_SELECTED) {
-+ switch (req->opcode) {
-+ case IORING_OP_READV:
-+ case IORING_OP_READ_FIXED:
-+ case IORING_OP_READ:
-+ kfree((void *)(unsigned long)req->rw.addr);
-+ break;
-+ case IORING_OP_RECVMSG:
-+ case IORING_OP_RECV:
-+ kfree(req->sr_msg.kbuf);
-+ break;
-+ }
-+ }
-+
-+ if (req->flags & REQ_F_NEED_CLEANUP) {
-+ switch (req->opcode) {
-+ case IORING_OP_READV:
-+ case IORING_OP_READ_FIXED:
-+ case IORING_OP_READ:
-+ case IORING_OP_WRITEV:
-+ case IORING_OP_WRITE_FIXED:
-+ case IORING_OP_WRITE: {
-+ struct io_async_rw *io = req->async_data;
-+
-+ kfree(io->free_iovec);
-+ break;
-+ }
-+ case IORING_OP_RECVMSG:
-+ case IORING_OP_SENDMSG: {
-+ struct io_async_msghdr *io = req->async_data;
-+
-+ kfree(io->free_iov);
-+ break;
-+ }
-+ case IORING_OP_OPENAT:
-+ case IORING_OP_OPENAT2:
-+ if (req->open.filename)
-+ putname(req->open.filename);
-+ break;
-+ case IORING_OP_RENAMEAT:
-+ putname(req->rename.oldpath);
-+ putname(req->rename.newpath);
-+ break;
-+ case IORING_OP_UNLINKAT:
-+ putname(req->unlink.filename);
-+ break;
-+ }
-+ }
-+ if ((req->flags & REQ_F_POLLED) && req->apoll) {
-+ kfree(req->apoll->double_poll);
-+ kfree(req->apoll);
-+ req->apoll = NULL;
-+ }
-+ if (req->flags & REQ_F_INFLIGHT) {
-+ struct io_uring_task *tctx = req->task->io_uring;
-+
-+ atomic_dec(&tctx->inflight_tracked);
-+ }
-+ if (req->flags & REQ_F_CREDS)
-+ put_cred(req->creds);
-+
-+ req->flags &= ~IO_REQ_CLEAN_FLAGS;
-+}
-+
-+static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+ const struct cred *creds = NULL;
-+ int ret;
-+
-+ if ((req->flags & REQ_F_CREDS) && req->creds != current_cred())
-+ creds = override_creds(req->creds);
-+
-+ switch (req->opcode) {
-+ case IORING_OP_NOP:
-+ ret = io_nop(req, issue_flags);
-+ break;
-+ case IORING_OP_READV:
-+ case IORING_OP_READ_FIXED:
-+ case IORING_OP_READ:
-+ ret = io_read(req, issue_flags);
-+ break;
-+ case IORING_OP_WRITEV:
-+ case IORING_OP_WRITE_FIXED:
-+ case IORING_OP_WRITE:
-+ ret = io_write(req, issue_flags);
-+ break;
-+ case IORING_OP_FSYNC:
-+ ret = io_fsync(req, issue_flags);
-+ break;
-+ case IORING_OP_POLL_ADD:
-+ ret = io_poll_add(req, issue_flags);
-+ break;
-+ case IORING_OP_POLL_REMOVE:
-+ ret = io_poll_update(req, issue_flags);
-+ break;
-+ case IORING_OP_SYNC_FILE_RANGE:
-+ ret = io_sync_file_range(req, issue_flags);
-+ break;
-+ case IORING_OP_SENDMSG:
-+ ret = io_sendmsg(req, issue_flags);
-+ break;
-+ case IORING_OP_SEND:
-+ ret = io_send(req, issue_flags);
-+ break;
-+ case IORING_OP_RECVMSG:
-+ ret = io_recvmsg(req, issue_flags);
-+ break;
-+ case IORING_OP_RECV:
-+ ret = io_recv(req, issue_flags);
-+ break;
-+ case IORING_OP_TIMEOUT:
-+ ret = io_timeout(req, issue_flags);
-+ break;
-+ case IORING_OP_TIMEOUT_REMOVE:
-+ ret = io_timeout_remove(req, issue_flags);
-+ break;
-+ case IORING_OP_ACCEPT:
-+ ret = io_accept(req, issue_flags);
-+ break;
-+ case IORING_OP_CONNECT:
-+ ret = io_connect(req, issue_flags);
-+ break;
-+ case IORING_OP_ASYNC_CANCEL:
-+ ret = io_async_cancel(req, issue_flags);
-+ break;
-+ case IORING_OP_FALLOCATE:
-+ ret = io_fallocate(req, issue_flags);
-+ break;
-+ case IORING_OP_OPENAT:
-+ ret = io_openat(req, issue_flags);
-+ break;
-+ case IORING_OP_CLOSE:
-+ ret = io_close(req, issue_flags);
-+ break;
-+ case IORING_OP_FILES_UPDATE:
-+ ret = io_files_update(req, issue_flags);
-+ break;
-+ case IORING_OP_STATX:
-+ ret = io_statx(req, issue_flags);
-+ break;
-+ case IORING_OP_FADVISE:
-+ ret = io_fadvise(req, issue_flags);
-+ break;
-+ case IORING_OP_MADVISE:
-+ ret = io_madvise(req, issue_flags);
-+ break;
-+ case IORING_OP_OPENAT2:
-+ ret = io_openat2(req, issue_flags);
-+ break;
-+ case IORING_OP_EPOLL_CTL:
-+ ret = io_epoll_ctl(req, issue_flags);
-+ break;
-+ case IORING_OP_SPLICE:
-+ ret = io_splice(req, issue_flags);
-+ break;
-+ case IORING_OP_PROVIDE_BUFFERS:
-+ ret = io_provide_buffers(req, issue_flags);
-+ break;
-+ case IORING_OP_REMOVE_BUFFERS:
-+ ret = io_remove_buffers(req, issue_flags);
-+ break;
-+ case IORING_OP_TEE:
-+ ret = io_tee(req, issue_flags);
-+ break;
-+ case IORING_OP_SHUTDOWN:
-+ ret = io_shutdown(req, issue_flags);
-+ break;
-+ case IORING_OP_RENAMEAT:
-+ ret = io_renameat(req, issue_flags);
-+ break;
-+ case IORING_OP_UNLINKAT:
-+ ret = io_unlinkat(req, issue_flags);
-+ break;
-+ default:
-+ ret = -EINVAL;
-+ break;
-+ }
-+
-+ if (creds)
-+ revert_creds(creds);
-+ if (ret)
-+ return ret;
-+ /* If the op doesn't have a file, we're not polling for it */
-+ if ((ctx->flags & IORING_SETUP_IOPOLL) && req->file)
-+ io_iopoll_req_issued(req);
-+
-+ return 0;
-+}
-+
-+static struct io_wq_work *io_wq_free_work(struct io_wq_work *work)
-+{
-+ struct io_kiocb *req = container_of(work, struct io_kiocb, work);
-+
-+ req = io_put_req_find_next(req);
-+ return req ? &req->work : NULL;
-+}
-+
-+static void io_wq_submit_work(struct io_wq_work *work)
-+{
-+ struct io_kiocb *req = container_of(work, struct io_kiocb, work);
-+ struct io_kiocb *timeout;
-+ int ret = 0;
-+
-+ /* one will be dropped by ->io_free_work() after returning to io-wq */
-+ if (!(req->flags & REQ_F_REFCOUNT))
-+ __io_req_set_refcount(req, 2);
-+ else
-+ req_ref_get(req);
-+
-+ timeout = io_prep_linked_timeout(req);
-+ if (timeout)
-+ io_queue_linked_timeout(timeout);
-+
-+ /* either cancelled or io-wq is dying, so don't touch tctx->iowq */
-+ if (work->flags & IO_WQ_WORK_CANCEL)
-+ ret = -ECANCELED;
-+
-+ if (!ret) {
-+ do {
-+ ret = io_issue_sqe(req, 0);
-+ /*
-+ * We can get EAGAIN for polled IO even though we're
-+ * forcing a sync submission from here, since we can't
-+ * wait for request slots on the block side.
-+ */
-+ if (ret != -EAGAIN || !(req->ctx->flags & IORING_SETUP_IOPOLL))
-+ break;
-+ cond_resched();
-+ } while (1);
-+ }
-+
-+ /* avoid locking problems by failing it from a clean context */
-+ if (ret)
-+ io_req_task_queue_fail(req, ret);
-+}
-+
-+static inline struct io_fixed_file *io_fixed_file_slot(struct io_file_table *table,
-+ unsigned i)
-+{
-+ return &table->files[i];
-+}
-+
-+static inline struct file *io_file_from_index(struct io_ring_ctx *ctx,
-+ int index)
-+{
-+ struct io_fixed_file *slot = io_fixed_file_slot(&ctx->file_table, index);
-+
-+ return (struct file *) (slot->file_ptr & FFS_MASK);
-+}
-+
-+static void io_fixed_file_set(struct io_fixed_file *file_slot, struct file *file)
-+{
-+ unsigned long file_ptr = (unsigned long) file;
-+
-+ if (__io_file_supports_nowait(file, READ))
-+ file_ptr |= FFS_ASYNC_READ;
-+ if (__io_file_supports_nowait(file, WRITE))
-+ file_ptr |= FFS_ASYNC_WRITE;
-+ if (S_ISREG(file_inode(file)->i_mode))
-+ file_ptr |= FFS_ISREG;
-+ file_slot->file_ptr = file_ptr;
-+}
-+
-+static inline struct file *io_file_get_fixed(struct io_ring_ctx *ctx,
-+ struct io_kiocb *req, int fd)
-+{
-+ struct file *file;
-+ unsigned long file_ptr;
-+
-+ if (unlikely((unsigned int)fd >= ctx->nr_user_files))
-+ return NULL;
-+ fd = array_index_nospec(fd, ctx->nr_user_files);
-+ file_ptr = io_fixed_file_slot(&ctx->file_table, fd)->file_ptr;
-+ file = (struct file *) (file_ptr & FFS_MASK);
-+ file_ptr &= ~FFS_MASK;
-+ /* mask in overlapping REQ_F and FFS bits */
-+ req->flags |= (file_ptr << REQ_F_NOWAIT_READ_BIT);
-+ io_req_set_rsrc_node(req);
-+ return file;
-+}
-+
-+static struct file *io_file_get_normal(struct io_ring_ctx *ctx,
-+ struct io_kiocb *req, int fd)
-+{
-+ struct file *file = fget(fd);
-+
-+ trace_io_uring_file_get(ctx, fd);
-+
-+ /* we don't allow fixed io_uring files */
-+ if (file && unlikely(file->f_op == &io_uring_fops))
-+ io_req_track_inflight(req);
-+ return file;
-+}
-+
-+static inline struct file *io_file_get(struct io_ring_ctx *ctx,
-+ struct io_kiocb *req, int fd, bool fixed)
-+{
-+ if (fixed)
-+ return io_file_get_fixed(ctx, req, fd);
-+ else
-+ return io_file_get_normal(ctx, req, fd);
-+}
-+
-+static void io_req_task_link_timeout(struct io_kiocb *req, bool *locked)
-+{
-+ struct io_kiocb *prev = req->timeout.prev;
-+ int ret = -ENOENT;
-+
-+ if (prev) {
-+ if (!(req->task->flags & PF_EXITING))
-+ ret = io_try_cancel_userdata(req, prev->user_data);
-+ io_req_complete_post(req, ret ?: -ETIME, 0);
-+ io_put_req(prev);
-+ } else {
-+ io_req_complete_post(req, -ETIME, 0);
-+ }
-+}
-+
-+static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer)
-+{
-+ struct io_timeout_data *data = container_of(timer,
-+ struct io_timeout_data, timer);
-+ struct io_kiocb *prev, *req = data->req;
-+ struct io_ring_ctx *ctx = req->ctx;
-+ unsigned long flags;
-+
-+ spin_lock_irqsave(&ctx->timeout_lock, flags);
-+ prev = req->timeout.head;
-+ req->timeout.head = NULL;
-+
-+ /*
-+ * We don't expect the list to be empty, that will only happen if we
-+ * race with the completion of the linked work.
-+ */
-+ if (prev) {
-+ io_remove_next_linked(prev);
-+ if (!req_ref_inc_not_zero(prev))
-+ prev = NULL;
-+ }
-+ list_del(&req->timeout.list);
-+ req->timeout.prev = prev;
-+ spin_unlock_irqrestore(&ctx->timeout_lock, flags);
-+
-+ req->io_task_work.func = io_req_task_link_timeout;
-+ io_req_task_work_add(req);
-+ return HRTIMER_NORESTART;
-+}
-+
-+static void io_queue_linked_timeout(struct io_kiocb *req)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+
-+ spin_lock_irq(&ctx->timeout_lock);
-+ /*
-+ * If the back reference is NULL, then our linked request finished
-+ * before we got a chance to setup the timer
-+ */
-+ if (req->timeout.head) {
-+ struct io_timeout_data *data = req->async_data;
-+
-+ data->timer.function = io_link_timeout_fn;
-+ hrtimer_start(&data->timer, timespec64_to_ktime(data->ts),
-+ data->mode);
-+ list_add_tail(&req->timeout.list, &ctx->ltimeout_list);
-+ }
-+ spin_unlock_irq(&ctx->timeout_lock);
-+ /* drop submission reference */
-+ io_put_req(req);
-+}
-+
-+static void __io_queue_sqe(struct io_kiocb *req)
-+ __must_hold(&req->ctx->uring_lock)
-+{
-+ struct io_kiocb *linked_timeout;
-+ int ret;
-+
-+issue_sqe:
-+ ret = io_issue_sqe(req, IO_URING_F_NONBLOCK|IO_URING_F_COMPLETE_DEFER);
-+
-+ /*
-+ * We async punt it if the file wasn't marked NOWAIT, or if the file
-+ * doesn't support non-blocking read/write attempts
-+ */
-+ if (likely(!ret)) {
-+ if (req->flags & REQ_F_COMPLETE_INLINE) {
-+ struct io_ring_ctx *ctx = req->ctx;
-+ struct io_submit_state *state = &ctx->submit_state;
-+
-+ state->compl_reqs[state->compl_nr++] = req;
-+ if (state->compl_nr == ARRAY_SIZE(state->compl_reqs))
-+ io_submit_flush_completions(ctx);
-+ return;
-+ }
-+
-+ linked_timeout = io_prep_linked_timeout(req);
-+ if (linked_timeout)
-+ io_queue_linked_timeout(linked_timeout);
-+ } else if (ret == -EAGAIN && !(req->flags & REQ_F_NOWAIT)) {
-+ linked_timeout = io_prep_linked_timeout(req);
-+
-+ switch (io_arm_poll_handler(req)) {
-+ case IO_APOLL_READY:
-+ if (linked_timeout)
-+ io_queue_linked_timeout(linked_timeout);
-+ goto issue_sqe;
-+ case IO_APOLL_ABORTED:
-+ /*
-+ * Queued up for async execution, worker will release
-+ * submit reference when the iocb is actually submitted.
-+ */
-+ io_queue_async_work(req, NULL);
-+ break;
-+ }
-+
-+ if (linked_timeout)
-+ io_queue_linked_timeout(linked_timeout);
-+ } else {
-+ io_req_complete_failed(req, ret);
-+ }
-+}
-+
-+static inline void io_queue_sqe(struct io_kiocb *req)
-+ __must_hold(&req->ctx->uring_lock)
-+{
-+ if (unlikely(req->ctx->drain_active) && io_drain_req(req))
-+ return;
-+
-+ if (likely(!(req->flags & (REQ_F_FORCE_ASYNC | REQ_F_FAIL)))) {
-+ __io_queue_sqe(req);
-+ } else if (req->flags & REQ_F_FAIL) {
-+ io_req_complete_fail_submit(req);
-+ } else {
-+ int ret = io_req_prep_async(req);
-+
-+ if (unlikely(ret))
-+ io_req_complete_failed(req, ret);
-+ else
-+ io_queue_async_work(req, NULL);
-+ }
-+}
-+
-+/*
-+ * Check SQE restrictions (opcode and flags).
-+ *
-+ * Returns 'true' if SQE is allowed, 'false' otherwise.
-+ */
-+static inline bool io_check_restriction(struct io_ring_ctx *ctx,
-+ struct io_kiocb *req,
-+ unsigned int sqe_flags)
-+{
-+ if (likely(!ctx->restricted))
-+ return true;
-+
-+ if (!test_bit(req->opcode, ctx->restrictions.sqe_op))
-+ return false;
-+
-+ if ((sqe_flags & ctx->restrictions.sqe_flags_required) !=
-+ ctx->restrictions.sqe_flags_required)
-+ return false;
-+
-+ if (sqe_flags & ~(ctx->restrictions.sqe_flags_allowed |
-+ ctx->restrictions.sqe_flags_required))
-+ return false;
-+
-+ return true;
-+}
-+
-+static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
-+ const struct io_uring_sqe *sqe)
-+ __must_hold(&ctx->uring_lock)
-+{
-+ struct io_submit_state *state;
-+ unsigned int sqe_flags;
-+ int personality, ret = 0;
-+
-+ /* req is partially pre-initialised, see io_preinit_req() */
-+ req->opcode = READ_ONCE(sqe->opcode);
-+ /* same numerical values with corresponding REQ_F_*, safe to copy */
-+ req->flags = sqe_flags = READ_ONCE(sqe->flags);
-+ req->user_data = READ_ONCE(sqe->user_data);
-+ req->file = NULL;
-+ req->fixed_rsrc_refs = NULL;
-+ req->task = current;
-+
-+ /* enforce forwards compatibility on users */
-+ if (unlikely(sqe_flags & ~SQE_VALID_FLAGS))
-+ return -EINVAL;
-+ if (unlikely(req->opcode >= IORING_OP_LAST))
-+ return -EINVAL;
-+ if (!io_check_restriction(ctx, req, sqe_flags))
-+ return -EACCES;
-+
-+ if ((sqe_flags & IOSQE_BUFFER_SELECT) &&
-+ !io_op_defs[req->opcode].buffer_select)
-+ return -EOPNOTSUPP;
-+ if (unlikely(sqe_flags & IOSQE_IO_DRAIN))
-+ ctx->drain_active = true;
-+
-+ personality = READ_ONCE(sqe->personality);
-+ if (personality) {
-+ req->creds = xa_load(&ctx->personalities, personality);
-+ if (!req->creds)
-+ return -EINVAL;
-+ get_cred(req->creds);
-+ req->flags |= REQ_F_CREDS;
-+ }
-+ state = &ctx->submit_state;
-+
-+ /*
-+ * Plug now if we have more than 1 IO left after this, and the target
-+ * is potentially a read/write to block based storage.
-+ */
-+ if (!state->plug_started && state->ios_left > 1 &&
-+ io_op_defs[req->opcode].plug) {
-+ blk_start_plug(&state->plug);
-+ state->plug_started = true;
-+ }
-+
-+ if (io_op_defs[req->opcode].needs_file) {
-+ req->file = io_file_get(ctx, req, READ_ONCE(sqe->fd),
-+ (sqe_flags & IOSQE_FIXED_FILE));
-+ if (unlikely(!req->file))
-+ ret = -EBADF;
-+ }
-+
-+ state->ios_left--;
-+ return ret;
-+}
-+
-+static int io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req,
-+ const struct io_uring_sqe *sqe)
-+ __must_hold(&ctx->uring_lock)
-+{
-+ struct io_submit_link *link = &ctx->submit_state.link;
-+ int ret;
-+
-+ ret = io_init_req(ctx, req, sqe);
-+ if (unlikely(ret)) {
-+fail_req:
-+ /* fail even hard links since we don't submit */
-+ if (link->head) {
-+ /*
-+ * we can judge a link req is failed or cancelled by if
-+ * REQ_F_FAIL is set, but the head is an exception since
-+ * it may be set REQ_F_FAIL because of other req's failure
-+ * so let's leverage req->result to distinguish if a head
-+ * is set REQ_F_FAIL because of its failure or other req's
-+ * failure so that we can set the correct ret code for it.
-+ * init result here to avoid affecting the normal path.
-+ */
-+ if (!(link->head->flags & REQ_F_FAIL))
-+ req_fail_link_node(link->head, -ECANCELED);
-+ } else if (!(req->flags & (REQ_F_LINK | REQ_F_HARDLINK))) {
-+ /*
-+ * the current req is a normal req, we should return
-+ * error and thus break the submittion loop.
-+ */
-+ io_req_complete_failed(req, ret);
-+ return ret;
-+ }
-+ req_fail_link_node(req, ret);
-+ } else {
-+ ret = io_req_prep(req, sqe);
-+ if (unlikely(ret))
-+ goto fail_req;
-+ }
-+
-+ /* don't need @sqe from now on */
-+ trace_io_uring_submit_sqe(ctx, req, req->opcode, req->user_data,
-+ req->flags, true,
-+ ctx->flags & IORING_SETUP_SQPOLL);
-+
-+ /*
-+ * If we already have a head request, queue this one for async
-+ * submittal once the head completes. If we don't have a head but
-+ * IOSQE_IO_LINK is set in the sqe, start a new head. This one will be
-+ * submitted sync once the chain is complete. If none of those
-+ * conditions are true (normal request), then just queue it.
-+ */
-+ if (link->head) {
-+ struct io_kiocb *head = link->head;
-+
-+ if (!(req->flags & REQ_F_FAIL)) {
-+ ret = io_req_prep_async(req);
-+ if (unlikely(ret)) {
-+ req_fail_link_node(req, ret);
-+ if (!(head->flags & REQ_F_FAIL))
-+ req_fail_link_node(head, -ECANCELED);
-+ }
-+ }
-+ trace_io_uring_link(ctx, req, head);
-+ link->last->link = req;
-+ link->last = req;
-+
-+ /* last request of a link, enqueue the link */
-+ if (!(req->flags & (REQ_F_LINK | REQ_F_HARDLINK))) {
-+ link->head = NULL;
-+ io_queue_sqe(head);
-+ }
-+ } else {
-+ if (req->flags & (REQ_F_LINK | REQ_F_HARDLINK)) {
-+ link->head = req;
-+ link->last = req;
-+ } else {
-+ io_queue_sqe(req);
-+ }
-+ }
-+
-+ return 0;
-+}
-+
-+/*
-+ * Batched submission is done, ensure local IO is flushed out.
-+ */
-+static void io_submit_state_end(struct io_submit_state *state,
-+ struct io_ring_ctx *ctx)
-+{
-+ if (state->link.head)
-+ io_queue_sqe(state->link.head);
-+ if (state->compl_nr)
-+ io_submit_flush_completions(ctx);
-+ if (state->plug_started)
-+ blk_finish_plug(&state->plug);
-+}
-+
-+/*
-+ * Start submission side cache.
-+ */
-+static void io_submit_state_start(struct io_submit_state *state,
-+ unsigned int max_ios)
-+{
-+ state->plug_started = false;
-+ state->ios_left = max_ios;
-+ /* set only head, no need to init link_last in advance */
-+ state->link.head = NULL;
-+}
-+
-+static void io_commit_sqring(struct io_ring_ctx *ctx)
-+{
-+ struct io_rings *rings = ctx->rings;
-+
-+ /*
-+ * Ensure any loads from the SQEs are done at this point,
-+ * since once we write the new head, the application could
-+ * write new data to them.
-+ */
-+ smp_store_release(&rings->sq.head, ctx->cached_sq_head);
-+}
-+
-+/*
-+ * Fetch an sqe, if one is available. Note this returns a pointer to memory
-+ * that is mapped by userspace. This means that care needs to be taken to
-+ * ensure that reads are stable, as we cannot rely on userspace always
-+ * being a good citizen. If members of the sqe are validated and then later
-+ * used, it's important that those reads are done through READ_ONCE() to
-+ * prevent a re-load down the line.
-+ */
-+static const struct io_uring_sqe *io_get_sqe(struct io_ring_ctx *ctx)
-+{
-+ unsigned head, mask = ctx->sq_entries - 1;
-+ unsigned sq_idx = ctx->cached_sq_head++ & mask;
-+
-+ /*
-+ * The cached sq head (or cq tail) serves two purposes:
-+ *
-+ * 1) allows us to batch the cost of updating the user visible
-+ * head updates.
-+ * 2) allows the kernel side to track the head on its own, even
-+ * though the application is the one updating it.
-+ */
-+ head = READ_ONCE(ctx->sq_array[sq_idx]);
-+ if (likely(head < ctx->sq_entries))
-+ return &ctx->sq_sqes[head];
-+
-+ /* drop invalid entries */
-+ ctx->cq_extra--;
-+ WRITE_ONCE(ctx->rings->sq_dropped,
-+ READ_ONCE(ctx->rings->sq_dropped) + 1);
-+ return NULL;
-+}
-+
-+static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr)
-+ __must_hold(&ctx->uring_lock)
-+{
-+ int submitted = 0;
-+
-+ /* make sure SQ entry isn't read before tail */
-+ nr = min3(nr, ctx->sq_entries, io_sqring_entries(ctx));
-+ if (!percpu_ref_tryget_many(&ctx->refs, nr))
-+ return -EAGAIN;
-+ io_get_task_refs(nr);
-+
-+ io_submit_state_start(&ctx->submit_state, nr);
-+ while (submitted < nr) {
-+ const struct io_uring_sqe *sqe;
-+ struct io_kiocb *req;
-+
-+ req = io_alloc_req(ctx);
-+ if (unlikely(!req)) {
-+ if (!submitted)
-+ submitted = -EAGAIN;
-+ break;
-+ }
-+ sqe = io_get_sqe(ctx);
-+ if (unlikely(!sqe)) {
-+ list_add(&req->inflight_entry, &ctx->submit_state.free_list);
-+ break;
-+ }
-+ /* will complete beyond this point, count as submitted */
-+ submitted++;
-+ if (io_submit_sqe(ctx, req, sqe))
-+ break;
-+ }
-+
-+ if (unlikely(submitted != nr)) {
-+ int ref_used = (submitted == -EAGAIN) ? 0 : submitted;
-+ int unused = nr - ref_used;
-+
-+ current->io_uring->cached_refs += unused;
-+ percpu_ref_put_many(&ctx->refs, unused);
-+ }
-+
-+ io_submit_state_end(&ctx->submit_state, ctx);
-+ /* Commit SQ ring head once we've consumed and submitted all SQEs */
-+ io_commit_sqring(ctx);
-+
-+ return submitted;
-+}
-+
-+static inline bool io_sqd_events_pending(struct io_sq_data *sqd)
-+{
-+ return READ_ONCE(sqd->state);
-+}
-+
-+static inline void io_ring_set_wakeup_flag(struct io_ring_ctx *ctx)
-+{
-+ /* Tell userspace we may need a wakeup call */
-+ spin_lock(&ctx->completion_lock);
-+ WRITE_ONCE(ctx->rings->sq_flags,
-+ ctx->rings->sq_flags | IORING_SQ_NEED_WAKEUP);
-+ spin_unlock(&ctx->completion_lock);
-+}
-+
-+static inline void io_ring_clear_wakeup_flag(struct io_ring_ctx *ctx)
-+{
-+ spin_lock(&ctx->completion_lock);
-+ WRITE_ONCE(ctx->rings->sq_flags,
-+ ctx->rings->sq_flags & ~IORING_SQ_NEED_WAKEUP);
-+ spin_unlock(&ctx->completion_lock);
-+}
-+
-+static int __io_sq_thread(struct io_ring_ctx *ctx, bool cap_entries)
-+{
-+ unsigned int to_submit;
-+ int ret = 0;
-+
-+ to_submit = io_sqring_entries(ctx);
-+ /* if we're handling multiple rings, cap submit size for fairness */
-+ if (cap_entries && to_submit > IORING_SQPOLL_CAP_ENTRIES_VALUE)
-+ to_submit = IORING_SQPOLL_CAP_ENTRIES_VALUE;
-+
-+ if (!list_empty(&ctx->iopoll_list) || to_submit) {
-+ unsigned nr_events = 0;
-+ const struct cred *creds = NULL;
-+
-+ if (ctx->sq_creds != current_cred())
-+ creds = override_creds(ctx->sq_creds);
-+
-+ mutex_lock(&ctx->uring_lock);
-+ if (!list_empty(&ctx->iopoll_list))
-+ io_do_iopoll(ctx, &nr_events, 0);
-+
-+ /*
-+ * Don't submit if refs are dying, good for io_uring_register(),
-+ * but also it is relied upon by io_ring_exit_work()
-+ */
-+ if (to_submit && likely(!percpu_ref_is_dying(&ctx->refs)) &&
-+ !(ctx->flags & IORING_SETUP_R_DISABLED))
-+ ret = io_submit_sqes(ctx, to_submit);
-+ mutex_unlock(&ctx->uring_lock);
-+
-+ if (to_submit && wq_has_sleeper(&ctx->sqo_sq_wait))
-+ wake_up(&ctx->sqo_sq_wait);
-+ if (creds)
-+ revert_creds(creds);
-+ }
-+
-+ return ret;
-+}
-+
-+static void io_sqd_update_thread_idle(struct io_sq_data *sqd)
-+{
-+ struct io_ring_ctx *ctx;
-+ unsigned sq_thread_idle = 0;
-+
-+ list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
-+ sq_thread_idle = max(sq_thread_idle, ctx->sq_thread_idle);
-+ sqd->sq_thread_idle = sq_thread_idle;
-+}
-+
-+static bool io_sqd_handle_event(struct io_sq_data *sqd)
-+{
-+ bool did_sig = false;
-+ struct ksignal ksig;
-+
-+ if (test_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state) ||
-+ signal_pending(current)) {
-+ mutex_unlock(&sqd->lock);
-+ if (signal_pending(current))
-+ did_sig = get_signal(&ksig);
-+ cond_resched();
-+ mutex_lock(&sqd->lock);
-+ }
-+ return did_sig || test_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state);
-+}
-+
-+static int io_sq_thread(void *data)
-+{
-+ struct io_sq_data *sqd = data;
-+ struct io_ring_ctx *ctx;
-+ unsigned long timeout = 0;
-+ char buf[TASK_COMM_LEN];
-+ DEFINE_WAIT(wait);
-+
-+ snprintf(buf, sizeof(buf), "iou-sqp-%d", sqd->task_pid);
-+ set_task_comm(current, buf);
-+
-+ if (sqd->sq_cpu != -1)
-+ set_cpus_allowed_ptr(current, cpumask_of(sqd->sq_cpu));
-+ else
-+ set_cpus_allowed_ptr(current, cpu_online_mask);
-+ current->flags |= PF_NO_SETAFFINITY;
-+
-+ mutex_lock(&sqd->lock);
-+ while (1) {
-+ bool cap_entries, sqt_spin = false;
-+
-+ if (io_sqd_events_pending(sqd) || signal_pending(current)) {
-+ if (io_sqd_handle_event(sqd))
-+ break;
-+ timeout = jiffies + sqd->sq_thread_idle;
-+ }
-+
-+ cap_entries = !list_is_singular(&sqd->ctx_list);
-+ list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) {
-+ int ret = __io_sq_thread(ctx, cap_entries);
-+
-+ if (!sqt_spin && (ret > 0 || !list_empty(&ctx->iopoll_list)))
-+ sqt_spin = true;
-+ }
-+ if (io_run_task_work())
-+ sqt_spin = true;
-+
-+ if (sqt_spin || !time_after(jiffies, timeout)) {
-+ cond_resched();
-+ if (sqt_spin)
-+ timeout = jiffies + sqd->sq_thread_idle;
-+ continue;
-+ }
-+
-+ prepare_to_wait(&sqd->wait, &wait, TASK_INTERRUPTIBLE);
-+ if (!io_sqd_events_pending(sqd) && !current->task_works) {
-+ bool needs_sched = true;
-+
-+ list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) {
-+ io_ring_set_wakeup_flag(ctx);
-+
-+ if ((ctx->flags & IORING_SETUP_IOPOLL) &&
-+ !list_empty_careful(&ctx->iopoll_list)) {
-+ needs_sched = false;
-+ break;
-+ }
-+ if (io_sqring_entries(ctx)) {
-+ needs_sched = false;
-+ break;
-+ }
-+ }
-+
-+ if (needs_sched) {
-+ mutex_unlock(&sqd->lock);
-+ schedule();
-+ mutex_lock(&sqd->lock);
-+ }
-+ list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
-+ io_ring_clear_wakeup_flag(ctx);
-+ }
-+
-+ finish_wait(&sqd->wait, &wait);
-+ timeout = jiffies + sqd->sq_thread_idle;
-+ }
-+
-+ io_uring_cancel_generic(true, sqd);
-+ sqd->thread = NULL;
-+ list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
-+ io_ring_set_wakeup_flag(ctx);
-+ io_run_task_work();
-+ mutex_unlock(&sqd->lock);
-+
-+ complete(&sqd->exited);
-+ do_exit(0);
-+}
-+
-+struct io_wait_queue {
-+ struct wait_queue_entry wq;
-+ struct io_ring_ctx *ctx;
-+ unsigned cq_tail;
-+ unsigned nr_timeouts;
-+};
-+
-+static inline bool io_should_wake(struct io_wait_queue *iowq)
-+{
-+ struct io_ring_ctx *ctx = iowq->ctx;
-+ int dist = ctx->cached_cq_tail - (int) iowq->cq_tail;
-+
-+ /*
-+ * Wake up if we have enough events, or if a timeout occurred since we
-+ * started waiting. For timeouts, we always want to return to userspace,
-+ * regardless of event count.
-+ */
-+ return dist >= 0 || atomic_read(&ctx->cq_timeouts) != iowq->nr_timeouts;
-+}
-+
-+static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode,
-+ int wake_flags, void *key)
-+{
-+ struct io_wait_queue *iowq = container_of(curr, struct io_wait_queue,
-+ wq);
-+
-+ /*
-+ * Cannot safely flush overflowed CQEs from here, ensure we wake up
-+ * the task, and the next invocation will do it.
-+ */
-+ if (io_should_wake(iowq) || test_bit(0, &iowq->ctx->check_cq_overflow))
-+ return autoremove_wake_function(curr, mode, wake_flags, key);
-+ return -1;
-+}
-+
-+static int io_run_task_work_sig(void)
-+{
-+ if (io_run_task_work())
-+ return 1;
-+ if (!signal_pending(current))
-+ return 0;
-+ if (test_thread_flag(TIF_NOTIFY_SIGNAL))
-+ return -ERESTARTSYS;
-+ return -EINTR;
-+}
-+
-+/* when returns >0, the caller should retry */
-+static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx,
-+ struct io_wait_queue *iowq,
-+ ktime_t timeout)
-+{
-+ int ret;
-+
-+ /* make sure we run task_work before checking for signals */
-+ ret = io_run_task_work_sig();
-+ if (ret || io_should_wake(iowq))
-+ return ret;
-+ /* let the caller flush overflows, retry */
-+ if (test_bit(0, &ctx->check_cq_overflow))
-+ return 1;
-+
-+ if (!schedule_hrtimeout(&timeout, HRTIMER_MODE_ABS))
-+ return -ETIME;
-+ return 1;
-+}
-+
-+/*
-+ * Wait until events become available, if we don't already have some. The
-+ * application must reap them itself, as they reside on the shared cq ring.
-+ */
-+static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
-+ const sigset_t __user *sig, size_t sigsz,
-+ struct __kernel_timespec __user *uts)
-+{
-+ struct io_wait_queue iowq;
-+ struct io_rings *rings = ctx->rings;
-+ ktime_t timeout = KTIME_MAX;
-+ int ret;
-+
-+ do {
-+ io_cqring_overflow_flush(ctx);
-+ if (io_cqring_events(ctx) >= min_events)
-+ return 0;
-+ if (!io_run_task_work())
-+ break;
-+ } while (1);
-+
-+ if (uts) {
-+ struct timespec64 ts;
-+
-+ if (get_timespec64(&ts, uts))
-+ return -EFAULT;
-+ timeout = ktime_add_ns(timespec64_to_ktime(ts), ktime_get_ns());
-+ }
-+
-+ if (sig) {
-+#ifdef CONFIG_COMPAT
-+ if (in_compat_syscall())
-+ ret = set_compat_user_sigmask((const compat_sigset_t __user *)sig,
-+ sigsz);
-+ else
-+#endif
-+ ret = set_user_sigmask(sig, sigsz);
-+
-+ if (ret)
-+ return ret;
-+ }
-+
-+ init_waitqueue_func_entry(&iowq.wq, io_wake_function);
-+ iowq.wq.private = current;
-+ INIT_LIST_HEAD(&iowq.wq.entry);
-+ iowq.ctx = ctx;
-+ iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts);
-+ iowq.cq_tail = READ_ONCE(ctx->rings->cq.head) + min_events;
-+
-+ trace_io_uring_cqring_wait(ctx, min_events);
-+ do {
-+ /* if we can't even flush overflow, don't wait for more */
-+ if (!io_cqring_overflow_flush(ctx)) {
-+ ret = -EBUSY;
-+ break;
-+ }
-+ prepare_to_wait_exclusive(&ctx->cq_wait, &iowq.wq,
-+ TASK_INTERRUPTIBLE);
-+ ret = io_cqring_wait_schedule(ctx, &iowq, timeout);
-+ finish_wait(&ctx->cq_wait, &iowq.wq);
-+ cond_resched();
-+ } while (ret > 0);
-+
-+ restore_saved_sigmask_unless(ret == -EINTR);
-+
-+ return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0;
-+}
-+
-+static void io_free_page_table(void **table, size_t size)
-+{
-+ unsigned i, nr_tables = DIV_ROUND_UP(size, PAGE_SIZE);
-+
-+ for (i = 0; i < nr_tables; i++)
-+ kfree(table[i]);
-+ kfree(table);
-+}
-+
-+static void **io_alloc_page_table(size_t size)
-+{
-+ unsigned i, nr_tables = DIV_ROUND_UP(size, PAGE_SIZE);
-+ size_t init_size = size;
-+ void **table;
-+
-+ table = kcalloc(nr_tables, sizeof(*table), GFP_KERNEL_ACCOUNT);
-+ if (!table)
-+ return NULL;
-+
-+ for (i = 0; i < nr_tables; i++) {
-+ unsigned int this_size = min_t(size_t, size, PAGE_SIZE);
-+
-+ table[i] = kzalloc(this_size, GFP_KERNEL_ACCOUNT);
-+ if (!table[i]) {
-+ io_free_page_table(table, init_size);
-+ return NULL;
-+ }
-+ size -= this_size;
-+ }
-+ return table;
-+}
-+
-+static void io_rsrc_node_destroy(struct io_rsrc_node *ref_node)
-+{
-+ percpu_ref_exit(&ref_node->refs);
-+ kfree(ref_node);
-+}
-+
-+static void io_rsrc_node_ref_zero(struct percpu_ref *ref)
-+{
-+ struct io_rsrc_node *node = container_of(ref, struct io_rsrc_node, refs);
-+ struct io_ring_ctx *ctx = node->rsrc_data->ctx;
-+ unsigned long flags;
-+ bool first_add = false;
-+ unsigned long delay = HZ;
-+
-+ spin_lock_irqsave(&ctx->rsrc_ref_lock, flags);
-+ node->done = true;
-+
-+ /* if we are mid-quiesce then do not delay */
-+ if (node->rsrc_data->quiesce)
-+ delay = 0;
-+
-+ while (!list_empty(&ctx->rsrc_ref_list)) {
-+ node = list_first_entry(&ctx->rsrc_ref_list,
-+ struct io_rsrc_node, node);
-+ /* recycle ref nodes in order */
-+ if (!node->done)
-+ break;
-+ list_del(&node->node);
-+ first_add |= llist_add(&node->llist, &ctx->rsrc_put_llist);
-+ }
-+ spin_unlock_irqrestore(&ctx->rsrc_ref_lock, flags);
-+
-+ if (first_add)
-+ mod_delayed_work(system_wq, &ctx->rsrc_put_work, delay);
-+}
-+
-+static struct io_rsrc_node *io_rsrc_node_alloc(struct io_ring_ctx *ctx)
-+{
-+ struct io_rsrc_node *ref_node;
-+
-+ ref_node = kzalloc(sizeof(*ref_node), GFP_KERNEL);
-+ if (!ref_node)
-+ return NULL;
-+
-+ if (percpu_ref_init(&ref_node->refs, io_rsrc_node_ref_zero,
-+ 0, GFP_KERNEL)) {
-+ kfree(ref_node);
-+ return NULL;
-+ }
-+ INIT_LIST_HEAD(&ref_node->node);
-+ INIT_LIST_HEAD(&ref_node->rsrc_list);
-+ ref_node->done = false;
-+ return ref_node;
-+}
-+
-+static void io_rsrc_node_switch(struct io_ring_ctx *ctx,
-+ struct io_rsrc_data *data_to_kill)
-+{
-+ WARN_ON_ONCE(!ctx->rsrc_backup_node);
-+ WARN_ON_ONCE(data_to_kill && !ctx->rsrc_node);
-+
-+ if (data_to_kill) {
-+ struct io_rsrc_node *rsrc_node = ctx->rsrc_node;
-+
-+ rsrc_node->rsrc_data = data_to_kill;
-+ spin_lock_irq(&ctx->rsrc_ref_lock);
-+ list_add_tail(&rsrc_node->node, &ctx->rsrc_ref_list);
-+ spin_unlock_irq(&ctx->rsrc_ref_lock);
-+
-+ atomic_inc(&data_to_kill->refs);
-+ percpu_ref_kill(&rsrc_node->refs);
-+ ctx->rsrc_node = NULL;
-+ }
-+
-+ if (!ctx->rsrc_node) {
-+ ctx->rsrc_node = ctx->rsrc_backup_node;
-+ ctx->rsrc_backup_node = NULL;
-+ }
-+}
-+
-+static int io_rsrc_node_switch_start(struct io_ring_ctx *ctx)
-+{
-+ if (ctx->rsrc_backup_node)
-+ return 0;
-+ ctx->rsrc_backup_node = io_rsrc_node_alloc(ctx);
-+ return ctx->rsrc_backup_node ? 0 : -ENOMEM;
-+}
-+
-+static int io_rsrc_ref_quiesce(struct io_rsrc_data *data, struct io_ring_ctx *ctx)
-+{
-+ int ret;
-+
-+ /* As we may drop ->uring_lock, other task may have started quiesce */
-+ if (data->quiesce)
-+ return -ENXIO;
-+
-+ data->quiesce = true;
-+ do {
-+ ret = io_rsrc_node_switch_start(ctx);
-+ if (ret)
-+ break;
-+ io_rsrc_node_switch(ctx, data);
-+
-+ /* kill initial ref, already quiesced if zero */
-+ if (atomic_dec_and_test(&data->refs))
-+ break;
-+ mutex_unlock(&ctx->uring_lock);
-+ flush_delayed_work(&ctx->rsrc_put_work);
-+ ret = wait_for_completion_interruptible(&data->done);
-+ if (!ret) {
-+ mutex_lock(&ctx->uring_lock);
-+ if (atomic_read(&data->refs) > 0) {
-+ /*
-+ * it has been revived by another thread while
-+ * we were unlocked
-+ */
-+ mutex_unlock(&ctx->uring_lock);
-+ } else {
-+ break;
-+ }
-+ }
-+
-+ atomic_inc(&data->refs);
-+ /* wait for all works potentially completing data->done */
-+ flush_delayed_work(&ctx->rsrc_put_work);
-+ reinit_completion(&data->done);
-+
-+ ret = io_run_task_work_sig();
-+ mutex_lock(&ctx->uring_lock);
-+ } while (ret >= 0);
-+ data->quiesce = false;
-+
-+ return ret;
-+}
-+
-+static u64 *io_get_tag_slot(struct io_rsrc_data *data, unsigned int idx)
-+{
-+ unsigned int off = idx & IO_RSRC_TAG_TABLE_MASK;
-+ unsigned int table_idx = idx >> IO_RSRC_TAG_TABLE_SHIFT;
-+
-+ return &data->tags[table_idx][off];
-+}
-+
-+static void io_rsrc_data_free(struct io_rsrc_data *data)
-+{
-+ size_t size = data->nr * sizeof(data->tags[0][0]);
-+
-+ if (data->tags)
-+ io_free_page_table((void **)data->tags, size);
-+ kfree(data);
-+}
-+
-+static int io_rsrc_data_alloc(struct io_ring_ctx *ctx, rsrc_put_fn *do_put,
-+ u64 __user *utags, unsigned nr,
-+ struct io_rsrc_data **pdata)
-+{
-+ struct io_rsrc_data *data;
-+ int ret = -ENOMEM;
-+ unsigned i;
-+
-+ data = kzalloc(sizeof(*data), GFP_KERNEL);
-+ if (!data)
-+ return -ENOMEM;
-+ data->tags = (u64 **)io_alloc_page_table(nr * sizeof(data->tags[0][0]));
-+ if (!data->tags) {
-+ kfree(data);
-+ return -ENOMEM;
-+ }
-+
-+ data->nr = nr;
-+ data->ctx = ctx;
-+ data->do_put = do_put;
-+ if (utags) {
-+ ret = -EFAULT;
-+ for (i = 0; i < nr; i++) {
-+ u64 *tag_slot = io_get_tag_slot(data, i);
-+
-+ if (copy_from_user(tag_slot, &utags[i],
-+ sizeof(*tag_slot)))
-+ goto fail;
-+ }
-+ }
-+
-+ atomic_set(&data->refs, 1);
-+ init_completion(&data->done);
-+ *pdata = data;
-+ return 0;
-+fail:
-+ io_rsrc_data_free(data);
-+ return ret;
-+}
-+
-+static bool io_alloc_file_tables(struct io_file_table *table, unsigned nr_files)
-+{
-+ table->files = kvcalloc(nr_files, sizeof(table->files[0]),
-+ GFP_KERNEL_ACCOUNT);
-+ return !!table->files;
-+}
-+
-+static void io_free_file_tables(struct io_file_table *table)
-+{
-+ kvfree(table->files);
-+ table->files = NULL;
-+}
-+
-+static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
-+{
-+#if defined(CONFIG_UNIX)
-+ if (ctx->ring_sock) {
-+ struct sock *sock = ctx->ring_sock->sk;
-+ struct sk_buff *skb;
-+
-+ while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
-+ kfree_skb(skb);
-+ }
-+#else
-+ int i;
-+
-+ for (i = 0; i < ctx->nr_user_files; i++) {
-+ struct file *file;
-+
-+ file = io_file_from_index(ctx, i);
-+ if (file)
-+ fput(file);
-+ }
-+#endif
-+ io_free_file_tables(&ctx->file_table);
-+ io_rsrc_data_free(ctx->file_data);
-+ ctx->file_data = NULL;
-+ ctx->nr_user_files = 0;
-+}
-+
-+static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
-+{
-+ unsigned nr = ctx->nr_user_files;
-+ int ret;
-+
-+ if (!ctx->file_data)
-+ return -ENXIO;
-+
-+ /*
-+ * Quiesce may unlock ->uring_lock, and while it's not held
-+ * prevent new requests using the table.
-+ */
-+ ctx->nr_user_files = 0;
-+ ret = io_rsrc_ref_quiesce(ctx->file_data, ctx);
-+ ctx->nr_user_files = nr;
-+ if (!ret)
-+ __io_sqe_files_unregister(ctx);
-+ return ret;
-+}
-+
-+static void io_sq_thread_unpark(struct io_sq_data *sqd)
-+ __releases(&sqd->lock)
-+{
-+ WARN_ON_ONCE(sqd->thread == current);
-+
-+ /*
-+ * Do the dance but not conditional clear_bit() because it'd race with
-+ * other threads incrementing park_pending and setting the bit.
-+ */
-+ clear_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state);
-+ if (atomic_dec_return(&sqd->park_pending))
-+ set_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state);
-+ mutex_unlock(&sqd->lock);
-+}
-+
-+static void io_sq_thread_park(struct io_sq_data *sqd)
-+ __acquires(&sqd->lock)
-+{
-+ WARN_ON_ONCE(sqd->thread == current);
-+
-+ atomic_inc(&sqd->park_pending);
-+ set_bit(IO_SQ_THREAD_SHOULD_PARK, &sqd->state);
-+ mutex_lock(&sqd->lock);
-+ if (sqd->thread)
-+ wake_up_process(sqd->thread);
-+}
-+
-+static void io_sq_thread_stop(struct io_sq_data *sqd)
-+{
-+ WARN_ON_ONCE(sqd->thread == current);
-+ WARN_ON_ONCE(test_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state));
-+
-+ set_bit(IO_SQ_THREAD_SHOULD_STOP, &sqd->state);
-+ mutex_lock(&sqd->lock);
-+ if (sqd->thread)
-+ wake_up_process(sqd->thread);
-+ mutex_unlock(&sqd->lock);
-+ wait_for_completion(&sqd->exited);
-+}
-+
-+static void io_put_sq_data(struct io_sq_data *sqd)
-+{
-+ if (refcount_dec_and_test(&sqd->refs)) {
-+ WARN_ON_ONCE(atomic_read(&sqd->park_pending));
-+
-+ io_sq_thread_stop(sqd);
-+ kfree(sqd);
-+ }
-+}
-+
-+static void io_sq_thread_finish(struct io_ring_ctx *ctx)
-+{
-+ struct io_sq_data *sqd = ctx->sq_data;
-+
-+ if (sqd) {
-+ io_sq_thread_park(sqd);
-+ list_del_init(&ctx->sqd_list);
-+ io_sqd_update_thread_idle(sqd);
-+ io_sq_thread_unpark(sqd);
-+
-+ io_put_sq_data(sqd);
-+ ctx->sq_data = NULL;
-+ }
-+}
-+
-+static struct io_sq_data *io_attach_sq_data(struct io_uring_params *p)
-+{
-+ struct io_ring_ctx *ctx_attach;
-+ struct io_sq_data *sqd;
-+ struct fd f;
-+
-+ f = fdget(p->wq_fd);
-+ if (!f.file)
-+ return ERR_PTR(-ENXIO);
-+ if (f.file->f_op != &io_uring_fops) {
-+ fdput(f);
-+ return ERR_PTR(-EINVAL);
-+ }
-+
-+ ctx_attach = f.file->private_data;
-+ sqd = ctx_attach->sq_data;
-+ if (!sqd) {
-+ fdput(f);
-+ return ERR_PTR(-EINVAL);
-+ }
-+ if (sqd->task_tgid != current->tgid) {
-+ fdput(f);
-+ return ERR_PTR(-EPERM);
-+ }
-+
-+ refcount_inc(&sqd->refs);
-+ fdput(f);
-+ return sqd;
-+}
-+
-+static struct io_sq_data *io_get_sq_data(struct io_uring_params *p,
-+ bool *attached)
-+{
-+ struct io_sq_data *sqd;
-+
-+ *attached = false;
-+ if (p->flags & IORING_SETUP_ATTACH_WQ) {
-+ sqd = io_attach_sq_data(p);
-+ if (!IS_ERR(sqd)) {
-+ *attached = true;
-+ return sqd;
-+ }
-+ /* fall through for EPERM case, setup new sqd/task */
-+ if (PTR_ERR(sqd) != -EPERM)
-+ return sqd;
-+ }
-+
-+ sqd = kzalloc(sizeof(*sqd), GFP_KERNEL);
-+ if (!sqd)
-+ return ERR_PTR(-ENOMEM);
-+
-+ atomic_set(&sqd->park_pending, 0);
-+ refcount_set(&sqd->refs, 1);
-+ INIT_LIST_HEAD(&sqd->ctx_list);
-+ mutex_init(&sqd->lock);
-+ init_waitqueue_head(&sqd->wait);
-+ init_completion(&sqd->exited);
-+ return sqd;
-+}
-+
-+#if defined(CONFIG_UNIX)
-+/*
-+ * Ensure the UNIX gc is aware of our file set, so we are certain that
-+ * the io_uring can be safely unregistered on process exit, even if we have
-+ * loops in the file referencing.
-+ */
-+static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset)
-+{
-+ struct sock *sk = ctx->ring_sock->sk;
-+ struct scm_fp_list *fpl;
-+ struct sk_buff *skb;
-+ int i, nr_files;
-+
-+ fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
-+ if (!fpl)
-+ return -ENOMEM;
-+
-+ skb = alloc_skb(0, GFP_KERNEL);
-+ if (!skb) {
-+ kfree(fpl);
-+ return -ENOMEM;
-+ }
-+
-+ skb->sk = sk;
-+ skb->scm_io_uring = 1;
-+
-+ nr_files = 0;
-+ fpl->user = get_uid(current_user());
-+ for (i = 0; i < nr; i++) {
-+ struct file *file = io_file_from_index(ctx, i + offset);
-+
-+ if (!file)
-+ continue;
-+ fpl->fp[nr_files] = get_file(file);
-+ unix_inflight(fpl->user, fpl->fp[nr_files]);
-+ nr_files++;
-+ }
-+
-+ if (nr_files) {
-+ fpl->max = SCM_MAX_FD;
-+ fpl->count = nr_files;
-+ UNIXCB(skb).fp = fpl;
-+ skb->destructor = unix_destruct_scm;
-+ refcount_add(skb->truesize, &sk->sk_wmem_alloc);
-+ skb_queue_head(&sk->sk_receive_queue, skb);
-+
-+ for (i = 0; i < nr; i++) {
-+ struct file *file = io_file_from_index(ctx, i + offset);
-+
-+ if (file)
-+ fput(file);
-+ }
-+ } else {
-+ kfree_skb(skb);
-+ free_uid(fpl->user);
-+ kfree(fpl);
-+ }
-+
-+ return 0;
-+}
-+
-+/*
-+ * If UNIX sockets are enabled, fd passing can cause a reference cycle which
-+ * causes regular reference counting to break down. We rely on the UNIX
-+ * garbage collection to take care of this problem for us.
-+ */
-+static int io_sqe_files_scm(struct io_ring_ctx *ctx)
-+{
-+ unsigned left, total;
-+ int ret = 0;
-+
-+ total = 0;
-+ left = ctx->nr_user_files;
-+ while (left) {
-+ unsigned this_files = min_t(unsigned, left, SCM_MAX_FD);
-+
-+ ret = __io_sqe_files_scm(ctx, this_files, total);
-+ if (ret)
-+ break;
-+ left -= this_files;
-+ total += this_files;
-+ }
-+
-+ if (!ret)
-+ return 0;
-+
-+ while (total < ctx->nr_user_files) {
-+ struct file *file = io_file_from_index(ctx, total);
-+
-+ if (file)
-+ fput(file);
-+ total++;
-+ }
-+
-+ return ret;
-+}
-+#else
-+static int io_sqe_files_scm(struct io_ring_ctx *ctx)
-+{
-+ return 0;
-+}
-+#endif
-+
-+static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
-+{
-+ struct file *file = prsrc->file;
-+#if defined(CONFIG_UNIX)
-+ struct sock *sock = ctx->ring_sock->sk;
-+ struct sk_buff_head list, *head = &sock->sk_receive_queue;
-+ struct sk_buff *skb;
-+ int i;
-+
-+ __skb_queue_head_init(&list);
-+
-+ /*
-+ * Find the skb that holds this file in its SCM_RIGHTS. When found,
-+ * remove this entry and rearrange the file array.
-+ */
-+ skb = skb_dequeue(head);
-+ while (skb) {
-+ struct scm_fp_list *fp;
-+
-+ fp = UNIXCB(skb).fp;
-+ for (i = 0; i < fp->count; i++) {
-+ int left;
-+
-+ if (fp->fp[i] != file)
-+ continue;
-+
-+ unix_notinflight(fp->user, fp->fp[i]);
-+ left = fp->count - 1 - i;
-+ if (left) {
-+ memmove(&fp->fp[i], &fp->fp[i + 1],
-+ left * sizeof(struct file *));
-+ }
-+ fp->count--;
-+ if (!fp->count) {
-+ kfree_skb(skb);
-+ skb = NULL;
-+ } else {
-+ __skb_queue_tail(&list, skb);
-+ }
-+ fput(file);
-+ file = NULL;
-+ break;
-+ }
-+
-+ if (!file)
-+ break;
-+
-+ __skb_queue_tail(&list, skb);
-+
-+ skb = skb_dequeue(head);
-+ }
-+
-+ if (skb_peek(&list)) {
-+ spin_lock_irq(&head->lock);
-+ while ((skb = __skb_dequeue(&list)) != NULL)
-+ __skb_queue_tail(head, skb);
-+ spin_unlock_irq(&head->lock);
-+ }
-+#else
-+ fput(file);
-+#endif
-+}
-+
-+static void __io_rsrc_put_work(struct io_rsrc_node *ref_node)
-+{
-+ struct io_rsrc_data *rsrc_data = ref_node->rsrc_data;
-+ struct io_ring_ctx *ctx = rsrc_data->ctx;
-+ struct io_rsrc_put *prsrc, *tmp;
-+
-+ list_for_each_entry_safe(prsrc, tmp, &ref_node->rsrc_list, list) {
-+ list_del(&prsrc->list);
-+
-+ if (prsrc->tag) {
-+ bool lock_ring = ctx->flags & IORING_SETUP_IOPOLL;
-+
-+ io_ring_submit_lock(ctx, lock_ring);
-+ spin_lock(&ctx->completion_lock);
-+ io_fill_cqe_aux(ctx, prsrc->tag, 0, 0);
-+ io_commit_cqring(ctx);
-+ spin_unlock(&ctx->completion_lock);
-+ io_cqring_ev_posted(ctx);
-+ io_ring_submit_unlock(ctx, lock_ring);
-+ }
-+
-+ rsrc_data->do_put(ctx, prsrc);
-+ kfree(prsrc);
-+ }
-+
-+ io_rsrc_node_destroy(ref_node);
-+ if (atomic_dec_and_test(&rsrc_data->refs))
-+ complete(&rsrc_data->done);
-+}
-+
-+static void io_rsrc_put_work(struct work_struct *work)
-+{
-+ struct io_ring_ctx *ctx;
-+ struct llist_node *node;
-+
-+ ctx = container_of(work, struct io_ring_ctx, rsrc_put_work.work);
-+ node = llist_del_all(&ctx->rsrc_put_llist);
-+
-+ while (node) {
-+ struct io_rsrc_node *ref_node;
-+ struct llist_node *next = node->next;
-+
-+ ref_node = llist_entry(node, struct io_rsrc_node, llist);
-+ __io_rsrc_put_work(ref_node);
-+ node = next;
-+ }
-+}
-+
-+static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
-+ unsigned nr_args, u64 __user *tags)
-+{
-+ __s32 __user *fds = (__s32 __user *) arg;
-+ struct file *file;
-+ int fd, ret;
-+ unsigned i;
-+
-+ if (ctx->file_data)
-+ return -EBUSY;
-+ if (!nr_args)
-+ return -EINVAL;
-+ if (nr_args > IORING_MAX_FIXED_FILES)
-+ return -EMFILE;
-+ if (nr_args > rlimit(RLIMIT_NOFILE))
-+ return -EMFILE;
-+ ret = io_rsrc_node_switch_start(ctx);
-+ if (ret)
-+ return ret;
-+ ret = io_rsrc_data_alloc(ctx, io_rsrc_file_put, tags, nr_args,
-+ &ctx->file_data);
-+ if (ret)
-+ return ret;
-+
-+ ret = -ENOMEM;
-+ if (!io_alloc_file_tables(&ctx->file_table, nr_args))
-+ goto out_free;
-+
-+ for (i = 0; i < nr_args; i++, ctx->nr_user_files++) {
-+ if (copy_from_user(&fd, &fds[i], sizeof(fd))) {
-+ ret = -EFAULT;
-+ goto out_fput;
-+ }
-+ /* allow sparse sets */
-+ if (fd == -1) {
-+ ret = -EINVAL;
-+ if (unlikely(*io_get_tag_slot(ctx->file_data, i)))
-+ goto out_fput;
-+ continue;
-+ }
-+
-+ file = fget(fd);
-+ ret = -EBADF;
-+ if (unlikely(!file))
-+ goto out_fput;
-+
-+ /*
-+ * Don't allow io_uring instances to be registered. If UNIX
-+ * isn't enabled, then this causes a reference cycle and this
-+ * instance can never get freed. If UNIX is enabled we'll
-+ * handle it just fine, but there's still no point in allowing
-+ * a ring fd as it doesn't support regular read/write anyway.
-+ */
-+ if (file->f_op == &io_uring_fops) {
-+ fput(file);
-+ goto out_fput;
-+ }
-+ io_fixed_file_set(io_fixed_file_slot(&ctx->file_table, i), file);
-+ }
-+
-+ ret = io_sqe_files_scm(ctx);
-+ if (ret) {
-+ __io_sqe_files_unregister(ctx);
-+ return ret;
-+ }
-+
-+ io_rsrc_node_switch(ctx, NULL);
-+ return ret;
-+out_fput:
-+ for (i = 0; i < ctx->nr_user_files; i++) {
-+ file = io_file_from_index(ctx, i);
-+ if (file)
-+ fput(file);
-+ }
-+ io_free_file_tables(&ctx->file_table);
-+ ctx->nr_user_files = 0;
-+out_free:
-+ io_rsrc_data_free(ctx->file_data);
-+ ctx->file_data = NULL;
-+ return ret;
-+}
-+
-+static int io_sqe_file_register(struct io_ring_ctx *ctx, struct file *file,
-+ int index)
-+{
-+#if defined(CONFIG_UNIX)
-+ struct sock *sock = ctx->ring_sock->sk;
-+ struct sk_buff_head *head = &sock->sk_receive_queue;
-+ struct sk_buff *skb;
-+
-+ /*
-+ * See if we can merge this file into an existing skb SCM_RIGHTS
-+ * file set. If there's no room, fall back to allocating a new skb
-+ * and filling it in.
-+ */
-+ spin_lock_irq(&head->lock);
-+ skb = skb_peek(head);
-+ if (skb) {
-+ struct scm_fp_list *fpl = UNIXCB(skb).fp;
-+
-+ if (fpl->count < SCM_MAX_FD) {
-+ __skb_unlink(skb, head);
-+ spin_unlock_irq(&head->lock);
-+ fpl->fp[fpl->count] = get_file(file);
-+ unix_inflight(fpl->user, fpl->fp[fpl->count]);
-+ fpl->count++;
-+ spin_lock_irq(&head->lock);
-+ __skb_queue_head(head, skb);
-+ } else {
-+ skb = NULL;
-+ }
-+ }
-+ spin_unlock_irq(&head->lock);
-+
-+ if (skb) {
-+ fput(file);
-+ return 0;
-+ }
-+
-+ return __io_sqe_files_scm(ctx, 1, index);
-+#else
-+ return 0;
-+#endif
-+}
-+
-+static int io_queue_rsrc_removal(struct io_rsrc_data *data, unsigned idx,
-+ struct io_rsrc_node *node, void *rsrc)
-+{
-+ u64 *tag_slot = io_get_tag_slot(data, idx);
-+ struct io_rsrc_put *prsrc;
-+
-+ prsrc = kzalloc(sizeof(*prsrc), GFP_KERNEL);
-+ if (!prsrc)
-+ return -ENOMEM;
-+
-+ prsrc->tag = *tag_slot;
-+ *tag_slot = 0;
-+ prsrc->rsrc = rsrc;
-+ list_add(&prsrc->list, &node->rsrc_list);
-+ return 0;
-+}
-+
-+static int io_install_fixed_file(struct io_kiocb *req, struct file *file,
-+ unsigned int issue_flags, u32 slot_index)
-+{
-+ struct io_ring_ctx *ctx = req->ctx;
-+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
-+ bool needs_switch = false;
-+ struct io_fixed_file *file_slot;
-+ int ret = -EBADF;
-+
-+ io_ring_submit_lock(ctx, !force_nonblock);
-+ if (file->f_op == &io_uring_fops)
-+ goto err;
-+ ret = -ENXIO;
-+ if (!ctx->file_data)
-+ goto err;
-+ ret = -EINVAL;
-+ if (slot_index >= ctx->nr_user_files)
-+ goto err;
-+
-+ slot_index = array_index_nospec(slot_index, ctx->nr_user_files);
-+ file_slot = io_fixed_file_slot(&ctx->file_table, slot_index);
-+
-+ if (file_slot->file_ptr) {
-+ struct file *old_file;
-+
-+ ret = io_rsrc_node_switch_start(ctx);
-+ if (ret)
-+ goto err;
-+
-+ old_file = (struct file *)(file_slot->file_ptr & FFS_MASK);
-+ ret = io_queue_rsrc_removal(ctx->file_data, slot_index,
-+ ctx->rsrc_node, old_file);
-+ if (ret)
-+ goto err;
-+ file_slot->file_ptr = 0;
-+ needs_switch = true;
-+ }
-+
-+ *io_get_tag_slot(ctx->file_data, slot_index) = 0;
-+ io_fixed_file_set(file_slot, file);
-+ ret = io_sqe_file_register(ctx, file, slot_index);
-+ if (ret) {
-+ file_slot->file_ptr = 0;
-+ goto err;
-+ }
-+
-+ ret = 0;
-+err:
-+ if (needs_switch)
-+ io_rsrc_node_switch(ctx, ctx->file_data);
-+ io_ring_submit_unlock(ctx, !force_nonblock);
-+ if (ret)
-+ fput(file);
-+ return ret;
-+}
-+
-+static int io_close_fixed(struct io_kiocb *req, unsigned int issue_flags)
-+{
-+ unsigned int offset = req->close.file_slot - 1;
-+ struct io_ring_ctx *ctx = req->ctx;
-+ struct io_fixed_file *file_slot;
-+ struct file *file;
-+ int ret;
-+
-+ io_ring_submit_lock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
-+ ret = -ENXIO;
-+ if (unlikely(!ctx->file_data))
-+ goto out;
-+ ret = -EINVAL;
-+ if (offset >= ctx->nr_user_files)
-+ goto out;
-+ ret = io_rsrc_node_switch_start(ctx);
-+ if (ret)
-+ goto out;
-+
-+ offset = array_index_nospec(offset, ctx->nr_user_files);
-+ file_slot = io_fixed_file_slot(&ctx->file_table, offset);
-+ ret = -EBADF;
-+ if (!file_slot->file_ptr)
-+ goto out;
-+
-+ file = (struct file *)(file_slot->file_ptr & FFS_MASK);
-+ ret = io_queue_rsrc_removal(ctx->file_data, offset, ctx->rsrc_node, file);
-+ if (ret)
-+ goto out;
-+
-+ file_slot->file_ptr = 0;
-+ io_rsrc_node_switch(ctx, ctx->file_data);
-+ ret = 0;
-+out:
-+ io_ring_submit_unlock(ctx, !(issue_flags & IO_URING_F_NONBLOCK));
-+ return ret;
-+}
-+
-+static int __io_sqe_files_update(struct io_ring_ctx *ctx,
-+ struct io_uring_rsrc_update2 *up,
-+ unsigned nr_args)
-+{
-+ u64 __user *tags = u64_to_user_ptr(up->tags);
-+ __s32 __user *fds = u64_to_user_ptr(up->data);
-+ struct io_rsrc_data *data = ctx->file_data;
-+ struct io_fixed_file *file_slot;
-+ struct file *file;
-+ int fd, i, err = 0;
-+ unsigned int done;
-+ bool needs_switch = false;
-+
-+ if (!ctx->file_data)
-+ return -ENXIO;
-+ if (up->offset + nr_args > ctx->nr_user_files)
-+ return -EINVAL;
-+
-+ for (done = 0; done < nr_args; done++) {
-+ u64 tag = 0;
-+
-+ if ((tags && copy_from_user(&tag, &tags[done], sizeof(tag))) ||
-+ copy_from_user(&fd, &fds[done], sizeof(fd))) {
-+ err = -EFAULT;
-+ break;
-+ }
-+ if ((fd == IORING_REGISTER_FILES_SKIP || fd == -1) && tag) {
-+ err = -EINVAL;
-+ break;
-+ }
-+ if (fd == IORING_REGISTER_FILES_SKIP)
-+ continue;
-+
-+ i = array_index_nospec(up->offset + done, ctx->nr_user_files);
-+ file_slot = io_fixed_file_slot(&ctx->file_table, i);
-+
-+ if (file_slot->file_ptr) {
-+ file = (struct file *)(file_slot->file_ptr & FFS_MASK);
-+ err = io_queue_rsrc_removal(data, i, ctx->rsrc_node, file);
-+ if (err)
-+ break;
-+ file_slot->file_ptr = 0;
-+ needs_switch = true;
-+ }
-+ if (fd != -1) {
-+ file = fget(fd);
-+ if (!file) {
-+ err = -EBADF;
-+ break;
-+ }
-+ /*
-+ * Don't allow io_uring instances to be registered. If
-+ * UNIX isn't enabled, then this causes a reference
-+ * cycle and this instance can never get freed. If UNIX
-+ * is enabled we'll handle it just fine, but there's
-+ * still no point in allowing a ring fd as it doesn't
-+ * support regular read/write anyway.
-+ */
-+ if (file->f_op == &io_uring_fops) {
-+ fput(file);
-+ err = -EBADF;
-+ break;
-+ }
-+ *io_get_tag_slot(data, i) = tag;
-+ io_fixed_file_set(file_slot, file);
-+ err = io_sqe_file_register(ctx, file, i);
-+ if (err) {
-+ file_slot->file_ptr = 0;
-+ fput(file);
-+ break;
-+ }
-+ }
-+ }
-+
-+ if (needs_switch)
-+ io_rsrc_node_switch(ctx, data);
-+ return done ? done : err;
-+}
-+
-+static struct io_wq *io_init_wq_offload(struct io_ring_ctx *ctx,
-+ struct task_struct *task)
-+{
-+ struct io_wq_hash *hash;
-+ struct io_wq_data data;
-+ unsigned int concurrency;
-+
-+ mutex_lock(&ctx->uring_lock);
-+ hash = ctx->hash_map;
-+ if (!hash) {
-+ hash = kzalloc(sizeof(*hash), GFP_KERNEL);
-+ if (!hash) {
-+ mutex_unlock(&ctx->uring_lock);
-+ return ERR_PTR(-ENOMEM);
-+ }
-+ refcount_set(&hash->refs, 1);
-+ init_waitqueue_head(&hash->wait);
-+ ctx->hash_map = hash;
-+ }
-+ mutex_unlock(&ctx->uring_lock);
-+
-+ data.hash = hash;
-+ data.task = task;
-+ data.free_work = io_wq_free_work;
-+ data.do_work = io_wq_submit_work;
-+
-+ /* Do QD, or 4 * CPUS, whatever is smallest */
-+ concurrency = min(ctx->sq_entries, 4 * num_online_cpus());
-+
-+ return io_wq_create(concurrency, &data);
-+}
-+
-+static int io_uring_alloc_task_context(struct task_struct *task,
-+ struct io_ring_ctx *ctx)
-+{
-+ struct io_uring_task *tctx;
-+ int ret;
-+
-+ tctx = kzalloc(sizeof(*tctx), GFP_KERNEL);
-+ if (unlikely(!tctx))
-+ return -ENOMEM;
-+
-+ ret = percpu_counter_init(&tctx->inflight, 0, GFP_KERNEL);
-+ if (unlikely(ret)) {
-+ kfree(tctx);
-+ return ret;
-+ }
-+
-+ tctx->io_wq = io_init_wq_offload(ctx, task);
-+ if (IS_ERR(tctx->io_wq)) {
-+ ret = PTR_ERR(tctx->io_wq);
-+ percpu_counter_destroy(&tctx->inflight);
-+ kfree(tctx);
-+ return ret;
-+ }
-+
-+ xa_init(&tctx->xa);
-+ init_waitqueue_head(&tctx->wait);
-+ atomic_set(&tctx->in_idle, 0);
-+ atomic_set(&tctx->inflight_tracked, 0);
-+ task->io_uring = tctx;
-+ spin_lock_init(&tctx->task_lock);
-+ INIT_WQ_LIST(&tctx->task_list);
-+ init_task_work(&tctx->task_work, tctx_task_work);
-+ return 0;
-+}
-+
-+void __io_uring_free(struct task_struct *tsk)
-+{
-+ struct io_uring_task *tctx = tsk->io_uring;
-+
-+ WARN_ON_ONCE(!xa_empty(&tctx->xa));
-+ WARN_ON_ONCE(tctx->io_wq);
-+ WARN_ON_ONCE(tctx->cached_refs);
-+
-+ percpu_counter_destroy(&tctx->inflight);
-+ kfree(tctx);
-+ tsk->io_uring = NULL;
-+}
-+
-+static int io_sq_offload_create(struct io_ring_ctx *ctx,
-+ struct io_uring_params *p)
-+{
-+ int ret;
-+
-+ /* Retain compatibility with failing for an invalid attach attempt */
-+ if ((ctx->flags & (IORING_SETUP_ATTACH_WQ | IORING_SETUP_SQPOLL)) ==
-+ IORING_SETUP_ATTACH_WQ) {
-+ struct fd f;
-+
-+ f = fdget(p->wq_fd);
-+ if (!f.file)
-+ return -ENXIO;
-+ if (f.file->f_op != &io_uring_fops) {
-+ fdput(f);
-+ return -EINVAL;
-+ }
-+ fdput(f);
-+ }
-+ if (ctx->flags & IORING_SETUP_SQPOLL) {
-+ struct task_struct *tsk;
-+ struct io_sq_data *sqd;
-+ bool attached;
-+
-+ sqd = io_get_sq_data(p, &attached);
-+ if (IS_ERR(sqd)) {
-+ ret = PTR_ERR(sqd);
-+ goto err;
-+ }
-+
-+ ctx->sq_creds = get_current_cred();
-+ ctx->sq_data = sqd;
-+ ctx->sq_thread_idle = msecs_to_jiffies(p->sq_thread_idle);
-+ if (!ctx->sq_thread_idle)
-+ ctx->sq_thread_idle = HZ;
-+
-+ io_sq_thread_park(sqd);
-+ list_add(&ctx->sqd_list, &sqd->ctx_list);
-+ io_sqd_update_thread_idle(sqd);
-+ /* don't attach to a dying SQPOLL thread, would be racy */
-+ ret = (attached && !sqd->thread) ? -ENXIO : 0;
-+ io_sq_thread_unpark(sqd);
-+
-+ if (ret < 0)
-+ goto err;
-+ if (attached)
-+ return 0;
-+
-+ if (p->flags & IORING_SETUP_SQ_AFF) {
-+ int cpu = p->sq_thread_cpu;
-+
-+ ret = -EINVAL;
-+ if (cpu >= nr_cpu_ids || !cpu_online(cpu))
-+ goto err_sqpoll;
-+ sqd->sq_cpu = cpu;
-+ } else {
-+ sqd->sq_cpu = -1;
-+ }
-+
-+ sqd->task_pid = current->pid;
-+ sqd->task_tgid = current->tgid;
-+ tsk = create_io_thread(io_sq_thread, sqd, NUMA_NO_NODE);
-+ if (IS_ERR(tsk)) {
-+ ret = PTR_ERR(tsk);
-+ goto err_sqpoll;
-+ }
-+
-+ sqd->thread = tsk;
-+ ret = io_uring_alloc_task_context(tsk, ctx);
-+ wake_up_new_task(tsk);
-+ if (ret)
-+ goto err;
-+ } else if (p->flags & IORING_SETUP_SQ_AFF) {
-+ /* Can't have SQ_AFF without SQPOLL */
-+ ret = -EINVAL;
-+ goto err;
-+ }
-+
-+ return 0;
-+err_sqpoll:
-+ complete(&ctx->sq_data->exited);
-+err:
-+ io_sq_thread_finish(ctx);
-+ return ret;
-+}
-+
-+static inline void __io_unaccount_mem(struct user_struct *user,
-+ unsigned long nr_pages)
-+{
-+ atomic_long_sub(nr_pages, &user->locked_vm);
-+}
-+
-+static inline int __io_account_mem(struct user_struct *user,
-+ unsigned long nr_pages)
-+{
-+ unsigned long page_limit, cur_pages, new_pages;
-+
-+ /* Don't allow more pages than we can safely lock */
-+ page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
-+
-+ do {
-+ cur_pages = atomic_long_read(&user->locked_vm);
-+ new_pages = cur_pages + nr_pages;
-+ if (new_pages > page_limit)
-+ return -ENOMEM;
-+ } while (atomic_long_cmpxchg(&user->locked_vm, cur_pages,
-+ new_pages) != cur_pages);
-+
-+ return 0;
-+}
-+
-+static void io_unaccount_mem(struct io_ring_ctx *ctx, unsigned long nr_pages)
-+{
-+ if (ctx->user)
-+ __io_unaccount_mem(ctx->user, nr_pages);
-+
-+ if (ctx->mm_account)
-+ atomic64_sub(nr_pages, &ctx->mm_account->pinned_vm);
-+}
-+
-+static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages)
-+{
-+ int ret;
-+
-+ if (ctx->user) {
-+ ret = __io_account_mem(ctx->user, nr_pages);
-+ if (ret)
-+ return ret;
-+ }
-+
-+ if (ctx->mm_account)
-+ atomic64_add(nr_pages, &ctx->mm_account->pinned_vm);
-+
-+ return 0;
-+}
-+
-+static void io_mem_free(void *ptr)
-+{
-+ struct page *page;
-+
-+ if (!ptr)
-+ return;
-+
-+ page = virt_to_head_page(ptr);
-+ if (put_page_testzero(page))
-+ free_compound_page(page);
-+}
-+
-+static void *io_mem_alloc(size_t size)
-+{
-+ gfp_t gfp = GFP_KERNEL_ACCOUNT | __GFP_ZERO | __GFP_NOWARN | __GFP_COMP;
-+
-+ return (void *) __get_free_pages(gfp, get_order(size));
-+}
-+
-+static unsigned long rings_size(unsigned sq_entries, unsigned cq_entries,
-+ size_t *sq_offset)
-+{
-+ struct io_rings *rings;
-+ size_t off, sq_array_size;
-+
-+ off = struct_size(rings, cqes, cq_entries);
-+ if (off == SIZE_MAX)
-+ return SIZE_MAX;
-+
-+#ifdef CONFIG_SMP
-+ off = ALIGN(off, SMP_CACHE_BYTES);
-+ if (off == 0)
-+ return SIZE_MAX;
-+#endif
-+
-+ if (sq_offset)
-+ *sq_offset = off;
-+
-+ sq_array_size = array_size(sizeof(u32), sq_entries);
-+ if (sq_array_size == SIZE_MAX)
-+ return SIZE_MAX;
-+
-+ if (check_add_overflow(off, sq_array_size, &off))
-+ return SIZE_MAX;
-+
-+ return off;
-+}
-+
-+static void io_buffer_unmap(struct io_ring_ctx *ctx, struct io_mapped_ubuf **slot)
-+{
-+ struct io_mapped_ubuf *imu = *slot;
-+ unsigned int i;
-+
-+ if (imu != ctx->dummy_ubuf) {
-+ for (i = 0; i < imu->nr_bvecs; i++)
-+ unpin_user_page(imu->bvec[i].bv_page);
-+ if (imu->acct_pages)
-+ io_unaccount_mem(ctx, imu->acct_pages);
-+ kvfree(imu);
-+ }
-+ *slot = NULL;
-+}
-+
-+static void io_rsrc_buf_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
-+{
-+ io_buffer_unmap(ctx, &prsrc->buf);
-+ prsrc->buf = NULL;
-+}
-+
-+static void __io_sqe_buffers_unregister(struct io_ring_ctx *ctx)
-+{
-+ unsigned int i;
-+
-+ for (i = 0; i < ctx->nr_user_bufs; i++)
-+ io_buffer_unmap(ctx, &ctx->user_bufs[i]);
-+ kfree(ctx->user_bufs);
-+ io_rsrc_data_free(ctx->buf_data);
-+ ctx->user_bufs = NULL;
-+ ctx->buf_data = NULL;
-+ ctx->nr_user_bufs = 0;
-+}
-+
-+static int io_sqe_buffers_unregister(struct io_ring_ctx *ctx)
-+{
-+ unsigned nr = ctx->nr_user_bufs;
-+ int ret;
-+
-+ if (!ctx->buf_data)
-+ return -ENXIO;
-+
-+ /*
-+ * Quiesce may unlock ->uring_lock, and while it's not held
-+ * prevent new requests using the table.
-+ */
-+ ctx->nr_user_bufs = 0;
-+ ret = io_rsrc_ref_quiesce(ctx->buf_data, ctx);
-+ ctx->nr_user_bufs = nr;
-+ if (!ret)
-+ __io_sqe_buffers_unregister(ctx);
-+ return ret;
-+}
-+
-+static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst,
-+ void __user *arg, unsigned index)
-+{
-+ struct iovec __user *src;
-+
-+#ifdef CONFIG_COMPAT
-+ if (ctx->compat) {
-+ struct compat_iovec __user *ciovs;
-+ struct compat_iovec ciov;
-+
-+ ciovs = (struct compat_iovec __user *) arg;
-+ if (copy_from_user(&ciov, &ciovs[index], sizeof(ciov)))
-+ return -EFAULT;
-+
-+ dst->iov_base = u64_to_user_ptr((u64)ciov.iov_base);
-+ dst->iov_len = ciov.iov_len;
-+ return 0;
-+ }
-+#endif
-+ src = (struct iovec __user *) arg;
-+ if (copy_from_user(dst, &src[index], sizeof(*dst)))
-+ return -EFAULT;
-+ return 0;
-+}
-+
-+/*
-+ * Not super efficient, but this is just a registration time. And we do cache
-+ * the last compound head, so generally we'll only do a full search if we don't
-+ * match that one.
-+ *
-+ * We check if the given compound head page has already been accounted, to
-+ * avoid double accounting it. This allows us to account the full size of the
-+ * page, not just the constituent pages of a huge page.
-+ */
-+static bool headpage_already_acct(struct io_ring_ctx *ctx, struct page **pages,
-+ int nr_pages, struct page *hpage)
-+{
-+ int i, j;
-+
-+ /* check current page array */
-+ for (i = 0; i < nr_pages; i++) {
-+ if (!PageCompound(pages[i]))
-+ continue;
-+ if (compound_head(pages[i]) == hpage)
-+ return true;
-+ }
-+
-+ /* check previously registered pages */
-+ for (i = 0; i < ctx->nr_user_bufs; i++) {
-+ struct io_mapped_ubuf *imu = ctx->user_bufs[i];
-+
-+ for (j = 0; j < imu->nr_bvecs; j++) {
-+ if (!PageCompound(imu->bvec[j].bv_page))
-+ continue;
-+ if (compound_head(imu->bvec[j].bv_page) == hpage)
-+ return true;
-+ }
-+ }
-+
-+ return false;
-+}
-+
-+static int io_buffer_account_pin(struct io_ring_ctx *ctx, struct page **pages,
-+ int nr_pages, struct io_mapped_ubuf *imu,
-+ struct page **last_hpage)
-+{
-+ int i, ret;
-+
-+ imu->acct_pages = 0;
-+ for (i = 0; i < nr_pages; i++) {
-+ if (!PageCompound(pages[i])) {
-+ imu->acct_pages++;
-+ } else {
-+ struct page *hpage;
-+
-+ hpage = compound_head(pages[i]);
-+ if (hpage == *last_hpage)
-+ continue;
-+ *last_hpage = hpage;
-+ if (headpage_already_acct(ctx, pages, i, hpage))
-+ continue;
-+ imu->acct_pages += page_size(hpage) >> PAGE_SHIFT;
-+ }
-+ }
-+
-+ if (!imu->acct_pages)
-+ return 0;
-+
-+ ret = io_account_mem(ctx, imu->acct_pages);
-+ if (ret)
-+ imu->acct_pages = 0;
-+ return ret;
-+}
-+
-+static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov,
-+ struct io_mapped_ubuf **pimu,
-+ struct page **last_hpage)
-+{
-+ struct io_mapped_ubuf *imu = NULL;
-+ struct vm_area_struct **vmas = NULL;
-+ struct page **pages = NULL;
-+ unsigned long off, start, end, ubuf;
-+ size_t size;
-+ int ret, pret, nr_pages, i;
-+
-+ if (!iov->iov_base) {
-+ *pimu = ctx->dummy_ubuf;
-+ return 0;
-+ }
-+
-+ ubuf = (unsigned long) iov->iov_base;
-+ end = (ubuf + iov->iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
-+ start = ubuf >> PAGE_SHIFT;
-+ nr_pages = end - start;
-+
-+ *pimu = NULL;
-+ ret = -ENOMEM;
-+
-+ pages = kvmalloc_array(nr_pages, sizeof(struct page *), GFP_KERNEL);
-+ if (!pages)
-+ goto done;
-+
-+ vmas = kvmalloc_array(nr_pages, sizeof(struct vm_area_struct *),
-+ GFP_KERNEL);
-+ if (!vmas)
-+ goto done;
-+
-+ imu = kvmalloc(struct_size(imu, bvec, nr_pages), GFP_KERNEL);
-+ if (!imu)
-+ goto done;
-+
-+ ret = 0;
-+ mmap_read_lock(current->mm);
-+ pret = pin_user_pages(ubuf, nr_pages, FOLL_WRITE | FOLL_LONGTERM,
-+ pages, vmas);
-+ if (pret == nr_pages) {
-+ /* don't support file backed memory */
-+ for (i = 0; i < nr_pages; i++) {
-+ struct vm_area_struct *vma = vmas[i];
-+
-+ if (vma_is_shmem(vma))
-+ continue;
-+ if (vma->vm_file &&
-+ !is_file_hugepages(vma->vm_file)) {
-+ ret = -EOPNOTSUPP;
-+ break;
-+ }
-+ }
-+ } else {
-+ ret = pret < 0 ? pret : -EFAULT;
-+ }
-+ mmap_read_unlock(current->mm);
-+ if (ret) {
-+ /*
-+ * if we did partial map, or found file backed vmas,
-+ * release any pages we did get
-+ */
-+ if (pret > 0)
-+ unpin_user_pages(pages, pret);
-+ goto done;
-+ }
-+
-+ ret = io_buffer_account_pin(ctx, pages, pret, imu, last_hpage);
-+ if (ret) {
-+ unpin_user_pages(pages, pret);
-+ goto done;
-+ }
-+
-+ off = ubuf & ~PAGE_MASK;
-+ size = iov->iov_len;
-+ for (i = 0; i < nr_pages; i++) {
-+ size_t vec_len;
-+
-+ vec_len = min_t(size_t, size, PAGE_SIZE - off);
-+ imu->bvec[i].bv_page = pages[i];
-+ imu->bvec[i].bv_len = vec_len;
-+ imu->bvec[i].bv_offset = off;
-+ off = 0;
-+ size -= vec_len;
-+ }
-+ /* store original address for later verification */
-+ imu->ubuf = ubuf;
-+ imu->ubuf_end = ubuf + iov->iov_len;
-+ imu->nr_bvecs = nr_pages;
-+ *pimu = imu;
-+ ret = 0;
-+done:
-+ if (ret)
-+ kvfree(imu);
-+ kvfree(pages);
-+ kvfree(vmas);
-+ return ret;
-+}
-+
-+static int io_buffers_map_alloc(struct io_ring_ctx *ctx, unsigned int nr_args)
-+{
-+ ctx->user_bufs = kcalloc(nr_args, sizeof(*ctx->user_bufs), GFP_KERNEL);
-+ return ctx->user_bufs ? 0 : -ENOMEM;
-+}
-+
-+static int io_buffer_validate(struct iovec *iov)
-+{
-+ unsigned long tmp, acct_len = iov->iov_len + (PAGE_SIZE - 1);
-+
-+ /*
-+ * Don't impose further limits on the size and buffer
-+ * constraints here, we'll -EINVAL later when IO is
-+ * submitted if they are wrong.
-+ */
-+ if (!iov->iov_base)
-+ return iov->iov_len ? -EFAULT : 0;
-+ if (!iov->iov_len)
-+ return -EFAULT;
-+
-+ /* arbitrary limit, but we need something */
-+ if (iov->iov_len > SZ_1G)
-+ return -EFAULT;
-+
-+ if (check_add_overflow((unsigned long)iov->iov_base, acct_len, &tmp))
-+ return -EOVERFLOW;
-+
-+ return 0;
-+}
-+
-+static int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg,
-+ unsigned int nr_args, u64 __user *tags)
-+{
-+ struct page *last_hpage = NULL;
-+ struct io_rsrc_data *data;
-+ int i, ret;
-+ struct iovec iov;
-+
-+ if (ctx->user_bufs)
-+ return -EBUSY;
-+ if (!nr_args || nr_args > IORING_MAX_REG_BUFFERS)
-+ return -EINVAL;
-+ ret = io_rsrc_node_switch_start(ctx);
-+ if (ret)
-+ return ret;
-+ ret = io_rsrc_data_alloc(ctx, io_rsrc_buf_put, tags, nr_args, &data);
-+ if (ret)
-+ return ret;
-+ ret = io_buffers_map_alloc(ctx, nr_args);
-+ if (ret) {
-+ io_rsrc_data_free(data);
-+ return ret;
-+ }
-+
-+ for (i = 0; i < nr_args; i++, ctx->nr_user_bufs++) {
-+ ret = io_copy_iov(ctx, &iov, arg, i);
-+ if (ret)
-+ break;
-+ ret = io_buffer_validate(&iov);
-+ if (ret)
-+ break;
-+ if (!iov.iov_base && *io_get_tag_slot(data, i)) {
-+ ret = -EINVAL;
-+ break;
-+ }
-+
-+ ret = io_sqe_buffer_register(ctx, &iov, &ctx->user_bufs[i],
-+ &last_hpage);
-+ if (ret)
-+ break;
-+ }
-+
-+ WARN_ON_ONCE(ctx->buf_data);
-+
-+ ctx->buf_data = data;
-+ if (ret)
-+ __io_sqe_buffers_unregister(ctx);
-+ else
-+ io_rsrc_node_switch(ctx, NULL);
-+ return ret;
-+}
-+
-+static int __io_sqe_buffers_update(struct io_ring_ctx *ctx,
-+ struct io_uring_rsrc_update2 *up,
-+ unsigned int nr_args)
-+{
-+ u64 __user *tags = u64_to_user_ptr(up->tags);
-+ struct iovec iov, __user *iovs = u64_to_user_ptr(up->data);
-+ struct page *last_hpage = NULL;
-+ bool needs_switch = false;
-+ __u32 done;
-+ int i, err;
-+
-+ if (!ctx->buf_data)
-+ return -ENXIO;
-+ if (up->offset + nr_args > ctx->nr_user_bufs)
-+ return -EINVAL;
-+
-+ for (done = 0; done < nr_args; done++) {
-+ struct io_mapped_ubuf *imu;
-+ int offset = up->offset + done;
-+ u64 tag = 0;
-+
-+ err = io_copy_iov(ctx, &iov, iovs, done);
-+ if (err)
-+ break;
-+ if (tags && copy_from_user(&tag, &tags[done], sizeof(tag))) {
-+ err = -EFAULT;
-+ break;
-+ }
-+ err = io_buffer_validate(&iov);
-+ if (err)
-+ break;
-+ if (!iov.iov_base && tag) {
-+ err = -EINVAL;
-+ break;
-+ }
-+ err = io_sqe_buffer_register(ctx, &iov, &imu, &last_hpage);
-+ if (err)
-+ break;
-+
-+ i = array_index_nospec(offset, ctx->nr_user_bufs);
-+ if (ctx->user_bufs[i] != ctx->dummy_ubuf) {
-+ err = io_queue_rsrc_removal(ctx->buf_data, i,
-+ ctx->rsrc_node, ctx->user_bufs[i]);
-+ if (unlikely(err)) {
-+ io_buffer_unmap(ctx, &imu);
-+ break;
-+ }
-+ ctx->user_bufs[i] = NULL;
-+ needs_switch = true;
-+ }
-+
-+ ctx->user_bufs[i] = imu;
-+ *io_get_tag_slot(ctx->buf_data, offset) = tag;
-+ }
-+
-+ if (needs_switch)
-+ io_rsrc_node_switch(ctx, ctx->buf_data);
-+ return done ? done : err;
-+}
-+
-+static int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg)
-+{
-+ __s32 __user *fds = arg;
-+ int fd;
-+
-+ if (ctx->cq_ev_fd)
-+ return -EBUSY;
-+
-+ if (copy_from_user(&fd, fds, sizeof(*fds)))
-+ return -EFAULT;
-+
-+ ctx->cq_ev_fd = eventfd_ctx_fdget(fd);
-+ if (IS_ERR(ctx->cq_ev_fd)) {
-+ int ret = PTR_ERR(ctx->cq_ev_fd);
-+
-+ ctx->cq_ev_fd = NULL;
-+ return ret;
-+ }
-+
-+ return 0;
-+}
-+
-+static int io_eventfd_unregister(struct io_ring_ctx *ctx)
-+{
-+ if (ctx->cq_ev_fd) {
-+ eventfd_ctx_put(ctx->cq_ev_fd);
-+ ctx->cq_ev_fd = NULL;
-+ return 0;
-+ }
-+
-+ return -ENXIO;
-+}
-+
-+static void io_destroy_buffers(struct io_ring_ctx *ctx)
-+{
-+ struct io_buffer *buf;
-+ unsigned long index;
-+
-+ xa_for_each(&ctx->io_buffers, index, buf)
-+ __io_remove_buffers(ctx, buf, index, -1U);
-+}
-+
-+static void io_req_cache_free(struct list_head *list)
-+{
-+ struct io_kiocb *req, *nxt;
-+
-+ list_for_each_entry_safe(req, nxt, list, inflight_entry) {
-+ list_del(&req->inflight_entry);
-+ kmem_cache_free(req_cachep, req);
-+ }
-+}
-+
-+static void io_req_caches_free(struct io_ring_ctx *ctx)
-+{
-+ struct io_submit_state *state = &ctx->submit_state;
-+
-+ mutex_lock(&ctx->uring_lock);
-+
-+ if (state->free_reqs) {
-+ kmem_cache_free_bulk(req_cachep, state->free_reqs, state->reqs);
-+ state->free_reqs = 0;
-+ }
-+
-+ io_flush_cached_locked_reqs(ctx, state);
-+ io_req_cache_free(&state->free_list);
-+ mutex_unlock(&ctx->uring_lock);
-+}
-+
-+static void io_wait_rsrc_data(struct io_rsrc_data *data)
-+{
-+ if (data && !atomic_dec_and_test(&data->refs))
-+ wait_for_completion(&data->done);
-+}
-+
-+static void io_ring_ctx_free(struct io_ring_ctx *ctx)
-+{
-+ io_sq_thread_finish(ctx);
-+
-+ /* __io_rsrc_put_work() may need uring_lock to progress, wait w/o it */
-+ io_wait_rsrc_data(ctx->buf_data);
-+ io_wait_rsrc_data(ctx->file_data);
-+
-+ mutex_lock(&ctx->uring_lock);
-+ if (ctx->buf_data)
-+ __io_sqe_buffers_unregister(ctx);
-+ if (ctx->file_data)
-+ __io_sqe_files_unregister(ctx);
-+ if (ctx->rings)
-+ __io_cqring_overflow_flush(ctx, true);
-+ mutex_unlock(&ctx->uring_lock);
-+ io_eventfd_unregister(ctx);
-+ io_destroy_buffers(ctx);
-+ if (ctx->sq_creds)
-+ put_cred(ctx->sq_creds);
-+
-+ /* there are no registered resources left, nobody uses it */
-+ if (ctx->rsrc_node)
-+ io_rsrc_node_destroy(ctx->rsrc_node);
-+ if (ctx->rsrc_backup_node)
-+ io_rsrc_node_destroy(ctx->rsrc_backup_node);
-+ flush_delayed_work(&ctx->rsrc_put_work);
-+
-+ WARN_ON_ONCE(!list_empty(&ctx->rsrc_ref_list));
-+ WARN_ON_ONCE(!llist_empty(&ctx->rsrc_put_llist));
-+
-+#if defined(CONFIG_UNIX)
-+ if (ctx->ring_sock) {
-+ ctx->ring_sock->file = NULL; /* so that iput() is called */
-+ sock_release(ctx->ring_sock);
-+ }
-+#endif
-+ WARN_ON_ONCE(!list_empty(&ctx->ltimeout_list));
-+
-+ if (ctx->mm_account) {
-+ mmdrop(ctx->mm_account);
-+ ctx->mm_account = NULL;
-+ }
-+
-+ io_mem_free(ctx->rings);
-+ io_mem_free(ctx->sq_sqes);
-+
-+ percpu_ref_exit(&ctx->refs);
-+ free_uid(ctx->user);
-+ io_req_caches_free(ctx);
-+ if (ctx->hash_map)
-+ io_wq_put_hash(ctx->hash_map);
-+ kfree(ctx->cancel_hash);
-+ kfree(ctx->dummy_ubuf);
-+ kfree(ctx);
-+}
-+
-+static __poll_t io_uring_poll(struct file *file, poll_table *wait)
-+{
-+ struct io_ring_ctx *ctx = file->private_data;
-+ __poll_t mask = 0;
-+
-+ poll_wait(file, &ctx->poll_wait, wait);
-+ /*
-+ * synchronizes with barrier from wq_has_sleeper call in
-+ * io_commit_cqring
-+ */
-+ smp_rmb();
-+ if (!io_sqring_full(ctx))
-+ mask |= EPOLLOUT | EPOLLWRNORM;
-+
-+ /*
-+ * Don't flush cqring overflow list here, just do a simple check.
-+ * Otherwise there could possible be ABBA deadlock:
-+ * CPU0 CPU1
-+ * ---- ----
-+ * lock(&ctx->uring_lock);
-+ * lock(&ep->mtx);
-+ * lock(&ctx->uring_lock);
-+ * lock(&ep->mtx);
-+ *
-+ * Users may get EPOLLIN meanwhile seeing nothing in cqring, this
-+ * pushs them to do the flush.
-+ */
-+ if (io_cqring_events(ctx) || test_bit(0, &ctx->check_cq_overflow))
-+ mask |= EPOLLIN | EPOLLRDNORM;
-+
-+ return mask;
-+}
-+
-+static int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id)
-+{
-+ const struct cred *creds;
-+
-+ creds = xa_erase(&ctx->personalities, id);
-+ if (creds) {
-+ put_cred(creds);
-+ return 0;
-+ }
-+
-+ return -EINVAL;
-+}
-+
-+struct io_tctx_exit {
-+ struct callback_head task_work;
-+ struct completion completion;
-+ struct io_ring_ctx *ctx;
-+};
-+
-+static void io_tctx_exit_cb(struct callback_head *cb)
-+{
-+ struct io_uring_task *tctx = current->io_uring;
-+ struct io_tctx_exit *work;
-+
-+ work = container_of(cb, struct io_tctx_exit, task_work);
-+ /*
-+ * When @in_idle, we're in cancellation and it's racy to remove the
-+ * node. It'll be removed by the end of cancellation, just ignore it.
-+ * tctx can be NULL if the queueing of this task_work raced with
-+ * work cancelation off the exec path.
-+ */
-+ if (tctx && !atomic_read(&tctx->in_idle))
-+ io_uring_del_tctx_node((unsigned long)work->ctx);
-+ complete(&work->completion);
-+}
-+
-+static bool io_cancel_ctx_cb(struct io_wq_work *work, void *data)
-+{
-+ struct io_kiocb *req = container_of(work, struct io_kiocb, work);
-+
-+ return req->ctx == data;
-+}
-+
-+static void io_ring_exit_work(struct work_struct *work)
-+{
-+ struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx, exit_work);
-+ unsigned long timeout = jiffies + HZ * 60 * 5;
-+ unsigned long interval = HZ / 20;
-+ struct io_tctx_exit exit;
-+ struct io_tctx_node *node;
-+ int ret;
-+
-+ /*
-+ * If we're doing polled IO and end up having requests being
-+ * submitted async (out-of-line), then completions can come in while
-+ * we're waiting for refs to drop. We need to reap these manually,
-+ * as nobody else will be looking for them.
-+ */
-+ do {
-+ io_uring_try_cancel_requests(ctx, NULL, true);
-+ if (ctx->sq_data) {
-+ struct io_sq_data *sqd = ctx->sq_data;
-+ struct task_struct *tsk;
-+
-+ io_sq_thread_park(sqd);
-+ tsk = sqd->thread;
-+ if (tsk && tsk->io_uring && tsk->io_uring->io_wq)
-+ io_wq_cancel_cb(tsk->io_uring->io_wq,
-+ io_cancel_ctx_cb, ctx, true);
-+ io_sq_thread_unpark(sqd);
-+ }
-+
-+ if (WARN_ON_ONCE(time_after(jiffies, timeout))) {
-+ /* there is little hope left, don't run it too often */
-+ interval = HZ * 60;
-+ }
-+ } while (!wait_for_completion_timeout(&ctx->ref_comp, interval));
-+
-+ init_completion(&exit.completion);
-+ init_task_work(&exit.task_work, io_tctx_exit_cb);
-+ exit.ctx = ctx;
-+ /*
-+ * Some may use context even when all refs and requests have been put,
-+ * and they are free to do so while still holding uring_lock or
-+ * completion_lock, see io_req_task_submit(). Apart from other work,
-+ * this lock/unlock section also waits them to finish.
-+ */
-+ mutex_lock(&ctx->uring_lock);
-+ while (!list_empty(&ctx->tctx_list)) {
-+ WARN_ON_ONCE(time_after(jiffies, timeout));
-+
-+ node = list_first_entry(&ctx->tctx_list, struct io_tctx_node,
-+ ctx_node);
-+ /* don't spin on a single task if cancellation failed */
-+ list_rotate_left(&ctx->tctx_list);
-+ ret = task_work_add(node->task, &exit.task_work, TWA_SIGNAL);
-+ if (WARN_ON_ONCE(ret))
-+ continue;
-+ wake_up_process(node->task);
-+
-+ mutex_unlock(&ctx->uring_lock);
-+ wait_for_completion(&exit.completion);
-+ mutex_lock(&ctx->uring_lock);
-+ }
-+ mutex_unlock(&ctx->uring_lock);
-+ spin_lock(&ctx->completion_lock);
-+ spin_unlock(&ctx->completion_lock);
-+
-+ io_ring_ctx_free(ctx);
-+}
-+
-+/* Returns true if we found and killed one or more timeouts */
-+static bool io_kill_timeouts(struct io_ring_ctx *ctx, struct task_struct *tsk,
-+ bool cancel_all)
-+{
-+ struct io_kiocb *req, *tmp;
-+ int canceled = 0;
-+
-+ spin_lock(&ctx->completion_lock);
-+ spin_lock_irq(&ctx->timeout_lock);
-+ list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list) {
-+ if (io_match_task(req, tsk, cancel_all)) {
-+ io_kill_timeout(req, -ECANCELED);
-+ canceled++;
-+ }
-+ }
-+ spin_unlock_irq(&ctx->timeout_lock);
-+ if (canceled != 0)
-+ io_commit_cqring(ctx);
-+ spin_unlock(&ctx->completion_lock);
-+ if (canceled != 0)
-+ io_cqring_ev_posted(ctx);
-+ return canceled != 0;
-+}
-+
-+static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
-+{
-+ unsigned long index;
-+ struct creds *creds;
-+
-+ mutex_lock(&ctx->uring_lock);
-+ percpu_ref_kill(&ctx->refs);
-+ if (ctx->rings)
-+ __io_cqring_overflow_flush(ctx, true);
-+ xa_for_each(&ctx->personalities, index, creds)
-+ io_unregister_personality(ctx, index);
-+ mutex_unlock(&ctx->uring_lock);
-+
-+ io_kill_timeouts(ctx, NULL, true);
-+ io_poll_remove_all(ctx, NULL, true);
-+
-+ /* if we failed setting up the ctx, we might not have any rings */
-+ io_iopoll_try_reap_events(ctx);
-+
-+ INIT_WORK(&ctx->exit_work, io_ring_exit_work);
-+ /*
-+ * Use system_unbound_wq to avoid spawning tons of event kworkers
-+ * if we're exiting a ton of rings at the same time. It just adds
-+ * noise and overhead, there's no discernable change in runtime
-+ * over using system_wq.
-+ */
-+ queue_work(system_unbound_wq, &ctx->exit_work);
-+}
-+
-+static int io_uring_release(struct inode *inode, struct file *file)
-+{
-+ struct io_ring_ctx *ctx = file->private_data;
-+
-+ file->private_data = NULL;
-+ io_ring_ctx_wait_and_kill(ctx);
-+ return 0;
-+}
-+
-+struct io_task_cancel {
-+ struct task_struct *task;
-+ bool all;
-+};
-+
-+static bool io_cancel_task_cb(struct io_wq_work *work, void *data)
-+{
-+ struct io_kiocb *req = container_of(work, struct io_kiocb, work);
-+ struct io_task_cancel *cancel = data;
-+
-+ return io_match_task_safe(req, cancel->task, cancel->all);
-+}
-+
-+static bool io_cancel_defer_files(struct io_ring_ctx *ctx,
-+ struct task_struct *task, bool cancel_all)
-+{
-+ struct io_defer_entry *de;
-+ LIST_HEAD(list);
-+
-+ spin_lock(&ctx->completion_lock);
-+ list_for_each_entry_reverse(de, &ctx->defer_list, list) {
-+ if (io_match_task_safe(de->req, task, cancel_all)) {
-+ list_cut_position(&list, &ctx->defer_list, &de->list);
-+ break;
-+ }
-+ }
-+ spin_unlock(&ctx->completion_lock);
-+ if (list_empty(&list))
-+ return false;
-+
-+ while (!list_empty(&list)) {
-+ de = list_first_entry(&list, struct io_defer_entry, list);
-+ list_del_init(&de->list);
-+ io_req_complete_failed(de->req, -ECANCELED);
-+ kfree(de);
-+ }
-+ return true;
-+}
-+
-+static bool io_uring_try_cancel_iowq(struct io_ring_ctx *ctx)
-+{
-+ struct io_tctx_node *node;
-+ enum io_wq_cancel cret;
-+ bool ret = false;
-+
-+ mutex_lock(&ctx->uring_lock);
-+ list_for_each_entry(node, &ctx->tctx_list, ctx_node) {
-+ struct io_uring_task *tctx = node->task->io_uring;
-+
-+ /*
-+ * io_wq will stay alive while we hold uring_lock, because it's
-+ * killed after ctx nodes, which requires to take the lock.
-+ */
-+ if (!tctx || !tctx->io_wq)
-+ continue;
-+ cret = io_wq_cancel_cb(tctx->io_wq, io_cancel_ctx_cb, ctx, true);
-+ ret |= (cret != IO_WQ_CANCEL_NOTFOUND);
-+ }
-+ mutex_unlock(&ctx->uring_lock);
-+
-+ return ret;
-+}
-+
-+static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
-+ struct task_struct *task,
-+ bool cancel_all)
-+{
-+ struct io_task_cancel cancel = { .task = task, .all = cancel_all, };
-+ struct io_uring_task *tctx = task ? task->io_uring : NULL;
-+
-+ while (1) {
-+ enum io_wq_cancel cret;
-+ bool ret = false;
-+
-+ if (!task) {
-+ ret |= io_uring_try_cancel_iowq(ctx);
-+ } else if (tctx && tctx->io_wq) {
-+ /*
-+ * Cancels requests of all rings, not only @ctx, but
-+ * it's fine as the task is in exit/exec.
-+ */
-+ cret = io_wq_cancel_cb(tctx->io_wq, io_cancel_task_cb,
-+ &cancel, true);
-+ ret |= (cret != IO_WQ_CANCEL_NOTFOUND);
-+ }
-+
-+ /* SQPOLL thread does its own polling */
-+ if ((!(ctx->flags & IORING_SETUP_SQPOLL) && cancel_all) ||
-+ (ctx->sq_data && ctx->sq_data->thread == current)) {
-+ while (!list_empty_careful(&ctx->iopoll_list)) {
-+ io_iopoll_try_reap_events(ctx);
-+ ret = true;
-+ }
-+ }
-+
-+ ret |= io_cancel_defer_files(ctx, task, cancel_all);
-+ ret |= io_poll_remove_all(ctx, task, cancel_all);
-+ ret |= io_kill_timeouts(ctx, task, cancel_all);
-+ if (task)
-+ ret |= io_run_task_work();
-+ if (!ret)
-+ break;
-+ cond_resched();
-+ }
-+}
-+
-+static int __io_uring_add_tctx_node(struct io_ring_ctx *ctx)
-+{
-+ struct io_uring_task *tctx = current->io_uring;
-+ struct io_tctx_node *node;
-+ int ret;
-+
-+ if (unlikely(!tctx)) {
-+ ret = io_uring_alloc_task_context(current, ctx);
-+ if (unlikely(ret))
-+ return ret;
-+
-+ tctx = current->io_uring;
-+ if (ctx->iowq_limits_set) {
-+ unsigned int limits[2] = { ctx->iowq_limits[0],
-+ ctx->iowq_limits[1], };
-+
-+ ret = io_wq_max_workers(tctx->io_wq, limits);
-+ if (ret)
-+ return ret;
-+ }
-+ }
-+ if (!xa_load(&tctx->xa, (unsigned long)ctx)) {
-+ node = kmalloc(sizeof(*node), GFP_KERNEL);
-+ if (!node)
-+ return -ENOMEM;
-+ node->ctx = ctx;
-+ node->task = current;
-+
-+ ret = xa_err(xa_store(&tctx->xa, (unsigned long)ctx,
-+ node, GFP_KERNEL));
-+ if (ret) {
-+ kfree(node);
-+ return ret;
-+ }
-+
-+ mutex_lock(&ctx->uring_lock);
-+ list_add(&node->ctx_node, &ctx->tctx_list);
-+ mutex_unlock(&ctx->uring_lock);
-+ }
-+ tctx->last = ctx;
-+ return 0;
-+}
-+
-+/*
-+ * Note that this task has used io_uring. We use it for cancelation purposes.
-+ */
-+static inline int io_uring_add_tctx_node(struct io_ring_ctx *ctx)
-+{
-+ struct io_uring_task *tctx = current->io_uring;
-+
-+ if (likely(tctx && tctx->last == ctx))
-+ return 0;
-+ return __io_uring_add_tctx_node(ctx);
-+}
-+
-+/*
-+ * Remove this io_uring_file -> task mapping.
-+ */
-+static void io_uring_del_tctx_node(unsigned long index)
-+{
-+ struct io_uring_task *tctx = current->io_uring;
-+ struct io_tctx_node *node;
-+
-+ if (!tctx)
-+ return;
-+ node = xa_erase(&tctx->xa, index);
-+ if (!node)
-+ return;
-+
-+ WARN_ON_ONCE(current != node->task);
-+ WARN_ON_ONCE(list_empty(&node->ctx_node));
-+
-+ mutex_lock(&node->ctx->uring_lock);
-+ list_del(&node->ctx_node);
-+ mutex_unlock(&node->ctx->uring_lock);
-+
-+ if (tctx->last == node->ctx)
-+ tctx->last = NULL;
-+ kfree(node);
-+}
-+
-+static void io_uring_clean_tctx(struct io_uring_task *tctx)
-+{
-+ struct io_wq *wq = tctx->io_wq;
-+ struct io_tctx_node *node;
-+ unsigned long index;
-+
-+ xa_for_each(&tctx->xa, index, node) {
-+ io_uring_del_tctx_node(index);
-+ cond_resched();
-+ }
-+ if (wq) {
-+ /*
-+ * Must be after io_uring_del_task_file() (removes nodes under
-+ * uring_lock) to avoid race with io_uring_try_cancel_iowq().
-+ */
-+ io_wq_put_and_exit(wq);
-+ tctx->io_wq = NULL;
-+ }
-+}
-+
-+static s64 tctx_inflight(struct io_uring_task *tctx, bool tracked)
-+{
-+ if (tracked)
-+ return atomic_read(&tctx->inflight_tracked);
-+ return percpu_counter_sum(&tctx->inflight);
-+}
-+
-+/*
-+ * Find any io_uring ctx that this task has registered or done IO on, and cancel
-+ * requests. @sqd should be not-null IFF it's an SQPOLL thread cancellation.
-+ */
-+static void io_uring_cancel_generic(bool cancel_all, struct io_sq_data *sqd)
-+{
-+ struct io_uring_task *tctx = current->io_uring;
-+ struct io_ring_ctx *ctx;
-+ s64 inflight;
-+ DEFINE_WAIT(wait);
-+
-+ WARN_ON_ONCE(sqd && sqd->thread != current);
-+
-+ if (!current->io_uring)
-+ return;
-+ if (tctx->io_wq)
-+ io_wq_exit_start(tctx->io_wq);
-+
-+ atomic_inc(&tctx->in_idle);
-+ do {
-+ io_uring_drop_tctx_refs(current);
-+ /* read completions before cancelations */
-+ inflight = tctx_inflight(tctx, !cancel_all);
-+ if (!inflight)
-+ break;
-+
-+ if (!sqd) {
-+ struct io_tctx_node *node;
-+ unsigned long index;
-+
-+ xa_for_each(&tctx->xa, index, node) {
-+ /* sqpoll task will cancel all its requests */
-+ if (node->ctx->sq_data)
-+ continue;
-+ io_uring_try_cancel_requests(node->ctx, current,
-+ cancel_all);
-+ }
-+ } else {
-+ list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
-+ io_uring_try_cancel_requests(ctx, current,
-+ cancel_all);
-+ }
-+
-+ prepare_to_wait(&tctx->wait, &wait, TASK_INTERRUPTIBLE);
-+ io_run_task_work();
-+ io_uring_drop_tctx_refs(current);
-+
-+ /*
-+ * If we've seen completions, retry without waiting. This
-+ * avoids a race where a completion comes in before we did
-+ * prepare_to_wait().
-+ */
-+ if (inflight == tctx_inflight(tctx, !cancel_all))
-+ schedule();
-+ finish_wait(&tctx->wait, &wait);
-+ } while (1);
-+
-+ io_uring_clean_tctx(tctx);
-+ if (cancel_all) {
-+ /*
-+ * We shouldn't run task_works after cancel, so just leave
-+ * ->in_idle set for normal exit.
-+ */
-+ atomic_dec(&tctx->in_idle);
-+ /* for exec all current's requests should be gone, kill tctx */
-+ __io_uring_free(current);
-+ }
-+}
-+
-+void __io_uring_cancel(bool cancel_all)
-+{
-+ io_uring_cancel_generic(cancel_all, NULL);
-+}
-+
-+static void *io_uring_validate_mmap_request(struct file *file,
-+ loff_t pgoff, size_t sz)
-+{
-+ struct io_ring_ctx *ctx = file->private_data;
-+ loff_t offset = pgoff << PAGE_SHIFT;
-+ struct page *page;
-+ void *ptr;
-+
-+ switch (offset) {
-+ case IORING_OFF_SQ_RING:
-+ case IORING_OFF_CQ_RING:
-+ ptr = ctx->rings;
-+ break;
-+ case IORING_OFF_SQES:
-+ ptr = ctx->sq_sqes;
-+ break;
-+ default:
-+ return ERR_PTR(-EINVAL);
-+ }
-+
-+ page = virt_to_head_page(ptr);
-+ if (sz > page_size(page))
-+ return ERR_PTR(-EINVAL);
-+
-+ return ptr;
-+}
-+
-+#ifdef CONFIG_MMU
-+
-+static int io_uring_mmap(struct file *file, struct vm_area_struct *vma)
-+{
-+ size_t sz = vma->vm_end - vma->vm_start;
-+ unsigned long pfn;
-+ void *ptr;
-+
-+ ptr = io_uring_validate_mmap_request(file, vma->vm_pgoff, sz);
-+ if (IS_ERR(ptr))
-+ return PTR_ERR(ptr);
-+
-+ pfn = virt_to_phys(ptr) >> PAGE_SHIFT;
-+ return remap_pfn_range(vma, vma->vm_start, pfn, sz, vma->vm_page_prot);
-+}
-+
-+#else /* !CONFIG_MMU */
-+
-+static int io_uring_mmap(struct file *file, struct vm_area_struct *vma)
-+{
-+ return vma->vm_flags & (VM_SHARED | VM_MAYSHARE) ? 0 : -EINVAL;
-+}
-+
-+static unsigned int io_uring_nommu_mmap_capabilities(struct file *file)
-+{
-+ return NOMMU_MAP_DIRECT | NOMMU_MAP_READ | NOMMU_MAP_WRITE;
-+}
-+
-+static unsigned long io_uring_nommu_get_unmapped_area(struct file *file,
-+ unsigned long addr, unsigned long len,
-+ unsigned long pgoff, unsigned long flags)
-+{
-+ void *ptr;
-+
-+ ptr = io_uring_validate_mmap_request(file, pgoff, len);
-+ if (IS_ERR(ptr))
-+ return PTR_ERR(ptr);
-+
-+ return (unsigned long) ptr;
-+}
-+
-+#endif /* !CONFIG_MMU */
-+
-+static int io_sqpoll_wait_sq(struct io_ring_ctx *ctx)
-+{
-+ DEFINE_WAIT(wait);
-+
-+ do {
-+ if (!io_sqring_full(ctx))
-+ break;
-+ prepare_to_wait(&ctx->sqo_sq_wait, &wait, TASK_INTERRUPTIBLE);
-+
-+ if (!io_sqring_full(ctx))
-+ break;
-+ schedule();
-+ } while (!signal_pending(current));
-+
-+ finish_wait(&ctx->sqo_sq_wait, &wait);
-+ return 0;
-+}
-+
-+static int io_get_ext_arg(unsigned flags, const void __user *argp, size_t *argsz,
-+ struct __kernel_timespec __user **ts,
-+ const sigset_t __user **sig)
-+{
-+ struct io_uring_getevents_arg arg;
-+
-+ /*
-+ * If EXT_ARG isn't set, then we have no timespec and the argp pointer
-+ * is just a pointer to the sigset_t.
-+ */
-+ if (!(flags & IORING_ENTER_EXT_ARG)) {
-+ *sig = (const sigset_t __user *) argp;
-+ *ts = NULL;
-+ return 0;
-+ }
-+
-+ /*
-+ * EXT_ARG is set - ensure we agree on the size of it and copy in our
-+ * timespec and sigset_t pointers if good.
-+ */
-+ if (*argsz != sizeof(arg))
-+ return -EINVAL;
-+ if (copy_from_user(&arg, argp, sizeof(arg)))
-+ return -EFAULT;
-+ if (arg.pad)
-+ return -EINVAL;
-+ *sig = u64_to_user_ptr(arg.sigmask);
-+ *argsz = arg.sigmask_sz;
-+ *ts = u64_to_user_ptr(arg.ts);
-+ return 0;
-+}
-+
-+SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit,
-+ u32, min_complete, u32, flags, const void __user *, argp,
-+ size_t, argsz)
-+{
-+ struct io_ring_ctx *ctx;
-+ int submitted = 0;
-+ struct fd f;
-+ long ret;
-+
-+ io_run_task_work();
-+
-+ if (unlikely(flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP |
-+ IORING_ENTER_SQ_WAIT | IORING_ENTER_EXT_ARG)))
-+ return -EINVAL;
-+
-+ f = fdget(fd);
-+ if (unlikely(!f.file))
-+ return -EBADF;
-+
-+ ret = -EOPNOTSUPP;
-+ if (unlikely(f.file->f_op != &io_uring_fops))
-+ goto out_fput;
-+
-+ ret = -ENXIO;
-+ ctx = f.file->private_data;
-+ if (unlikely(!percpu_ref_tryget(&ctx->refs)))
-+ goto out_fput;
-+
-+ ret = -EBADFD;
-+ if (unlikely(ctx->flags & IORING_SETUP_R_DISABLED))
-+ goto out;
-+
-+ /*
-+ * For SQ polling, the thread will do all submissions and completions.
-+ * Just return the requested submit count, and wake the thread if
-+ * we were asked to.
-+ */
-+ ret = 0;
-+ if (ctx->flags & IORING_SETUP_SQPOLL) {
-+ io_cqring_overflow_flush(ctx);
-+
-+ if (unlikely(ctx->sq_data->thread == NULL)) {
-+ ret = -EOWNERDEAD;
-+ goto out;
-+ }
-+ if (flags & IORING_ENTER_SQ_WAKEUP)
-+ wake_up(&ctx->sq_data->wait);
-+ if (flags & IORING_ENTER_SQ_WAIT) {
-+ ret = io_sqpoll_wait_sq(ctx);
-+ if (ret)
-+ goto out;
-+ }
-+ submitted = to_submit;
-+ } else if (to_submit) {
-+ ret = io_uring_add_tctx_node(ctx);
-+ if (unlikely(ret))
-+ goto out;
-+ mutex_lock(&ctx->uring_lock);
-+ submitted = io_submit_sqes(ctx, to_submit);
-+ mutex_unlock(&ctx->uring_lock);
-+
-+ if (submitted != to_submit)
-+ goto out;
-+ }
-+ if (flags & IORING_ENTER_GETEVENTS) {
-+ const sigset_t __user *sig;
-+ struct __kernel_timespec __user *ts;
-+
-+ ret = io_get_ext_arg(flags, argp, &argsz, &ts, &sig);
-+ if (unlikely(ret))
-+ goto out;
-+
-+ min_complete = min(min_complete, ctx->cq_entries);
-+
-+ /*
-+ * When SETUP_IOPOLL and SETUP_SQPOLL are both enabled, user
-+ * space applications don't need to do io completion events
-+ * polling again, they can rely on io_sq_thread to do polling
-+ * work, which can reduce cpu usage and uring_lock contention.
-+ */
-+ if (ctx->flags & IORING_SETUP_IOPOLL &&
-+ !(ctx->flags & IORING_SETUP_SQPOLL)) {
-+ ret = io_iopoll_check(ctx, min_complete);
-+ } else {
-+ ret = io_cqring_wait(ctx, min_complete, sig, argsz, ts);
-+ }
-+ }
-+
-+out:
-+ percpu_ref_put(&ctx->refs);
-+out_fput:
-+ fdput(f);
-+ return submitted ? submitted : ret;
-+}
-+
-+#ifdef CONFIG_PROC_FS
-+static int io_uring_show_cred(struct seq_file *m, unsigned int id,
-+ const struct cred *cred)
-+{
-+ struct user_namespace *uns = seq_user_ns(m);
-+ struct group_info *gi;
-+ kernel_cap_t cap;
-+ unsigned __capi;
-+ int g;
-+
-+ seq_printf(m, "%5d\n", id);
-+ seq_put_decimal_ull(m, "\tUid:\t", from_kuid_munged(uns, cred->uid));
-+ seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->euid));
-+ seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->suid));
-+ seq_put_decimal_ull(m, "\t\t", from_kuid_munged(uns, cred->fsuid));
-+ seq_put_decimal_ull(m, "\n\tGid:\t", from_kgid_munged(uns, cred->gid));
-+ seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->egid));
-+ seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->sgid));
-+ seq_put_decimal_ull(m, "\t\t", from_kgid_munged(uns, cred->fsgid));
-+ seq_puts(m, "\n\tGroups:\t");
-+ gi = cred->group_info;
-+ for (g = 0; g < gi->ngroups; g++) {
-+ seq_put_decimal_ull(m, g ? " " : "",
-+ from_kgid_munged(uns, gi->gid[g]));
-+ }
-+ seq_puts(m, "\n\tCapEff:\t");
-+ cap = cred->cap_effective;
-+ CAP_FOR_EACH_U32(__capi)
-+ seq_put_hex_ll(m, NULL, cap.cap[CAP_LAST_U32 - __capi], 8);
-+ seq_putc(m, '\n');
-+ return 0;
-+}
-+
-+static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m)
-+{
-+ struct io_sq_data *sq = NULL;
-+ bool has_lock;
-+ int i;
-+
-+ /*
-+ * Avoid ABBA deadlock between the seq lock and the io_uring mutex,
-+ * since fdinfo case grabs it in the opposite direction of normal use
-+ * cases. If we fail to get the lock, we just don't iterate any
-+ * structures that could be going away outside the io_uring mutex.
-+ */
-+ has_lock = mutex_trylock(&ctx->uring_lock);
-+
-+ if (has_lock && (ctx->flags & IORING_SETUP_SQPOLL)) {
-+ sq = ctx->sq_data;
-+ if (!sq->thread)
-+ sq = NULL;
-+ }
-+
-+ seq_printf(m, "SqThread:\t%d\n", sq ? task_pid_nr(sq->thread) : -1);
-+ seq_printf(m, "SqThreadCpu:\t%d\n", sq ? task_cpu(sq->thread) : -1);
-+ seq_printf(m, "UserFiles:\t%u\n", ctx->nr_user_files);
-+ for (i = 0; has_lock && i < ctx->nr_user_files; i++) {
-+ struct file *f = io_file_from_index(ctx, i);
-+
-+ if (f)
-+ seq_printf(m, "%5u: %s\n", i, file_dentry(f)->d_iname);
-+ else
-+ seq_printf(m, "%5u: <none>\n", i);
-+ }
-+ seq_printf(m, "UserBufs:\t%u\n", ctx->nr_user_bufs);
-+ for (i = 0; has_lock && i < ctx->nr_user_bufs; i++) {
-+ struct io_mapped_ubuf *buf = ctx->user_bufs[i];
-+ unsigned int len = buf->ubuf_end - buf->ubuf;
-+
-+ seq_printf(m, "%5u: 0x%llx/%u\n", i, buf->ubuf, len);
-+ }
-+ if (has_lock && !xa_empty(&ctx->personalities)) {
-+ unsigned long index;
-+ const struct cred *cred;
-+
-+ seq_printf(m, "Personalities:\n");
-+ xa_for_each(&ctx->personalities, index, cred)
-+ io_uring_show_cred(m, index, cred);
-+ }
-+ seq_printf(m, "PollList:\n");
-+ spin_lock(&ctx->completion_lock);
-+ for (i = 0; i < (1U << ctx->cancel_hash_bits); i++) {
-+ struct hlist_head *list = &ctx->cancel_hash[i];
-+ struct io_kiocb *req;
-+
-+ hlist_for_each_entry(req, list, hash_node)
-+ seq_printf(m, " op=%d, task_works=%d\n", req->opcode,
-+ req->task->task_works != NULL);
-+ }
-+ spin_unlock(&ctx->completion_lock);
-+ if (has_lock)
-+ mutex_unlock(&ctx->uring_lock);
-+}
-+
-+static void io_uring_show_fdinfo(struct seq_file *m, struct file *f)
-+{
-+ struct io_ring_ctx *ctx = f->private_data;
-+
-+ if (percpu_ref_tryget(&ctx->refs)) {
-+ __io_uring_show_fdinfo(ctx, m);
-+ percpu_ref_put(&ctx->refs);
-+ }
-+}
-+#endif
-+
-+static const struct file_operations io_uring_fops = {
-+ .release = io_uring_release,
-+ .mmap = io_uring_mmap,
-+#ifndef CONFIG_MMU
-+ .get_unmapped_area = io_uring_nommu_get_unmapped_area,
-+ .mmap_capabilities = io_uring_nommu_mmap_capabilities,
-+#endif
-+ .poll = io_uring_poll,
-+#ifdef CONFIG_PROC_FS
-+ .show_fdinfo = io_uring_show_fdinfo,
-+#endif
-+};
-+
-+static int io_allocate_scq_urings(struct io_ring_ctx *ctx,
-+ struct io_uring_params *p)
-+{
-+ struct io_rings *rings;
-+ size_t size, sq_array_offset;
-+
-+ /* make sure these are sane, as we already accounted them */
-+ ctx->sq_entries = p->sq_entries;
-+ ctx->cq_entries = p->cq_entries;
-+
-+ size = rings_size(p->sq_entries, p->cq_entries, &sq_array_offset);
-+ if (size == SIZE_MAX)
-+ return -EOVERFLOW;
-+
-+ rings = io_mem_alloc(size);
-+ if (!rings)
-+ return -ENOMEM;
-+
-+ ctx->rings = rings;
-+ ctx->sq_array = (u32 *)((char *)rings + sq_array_offset);
-+ rings->sq_ring_mask = p->sq_entries - 1;
-+ rings->cq_ring_mask = p->cq_entries - 1;
-+ rings->sq_ring_entries = p->sq_entries;
-+ rings->cq_ring_entries = p->cq_entries;
-+
-+ size = array_size(sizeof(struct io_uring_sqe), p->sq_entries);
-+ if (size == SIZE_MAX) {
-+ io_mem_free(ctx->rings);
-+ ctx->rings = NULL;
-+ return -EOVERFLOW;
-+ }
-+
-+ ctx->sq_sqes = io_mem_alloc(size);
-+ if (!ctx->sq_sqes) {
-+ io_mem_free(ctx->rings);
-+ ctx->rings = NULL;
-+ return -ENOMEM;
-+ }
-+
-+ return 0;
-+}
-+
-+static int io_uring_install_fd(struct io_ring_ctx *ctx, struct file *file)
-+{
-+ int ret, fd;
-+
-+ fd = get_unused_fd_flags(O_RDWR | O_CLOEXEC);
-+ if (fd < 0)
-+ return fd;
-+
-+ ret = io_uring_add_tctx_node(ctx);
-+ if (ret) {
-+ put_unused_fd(fd);
-+ return ret;
-+ }
-+ fd_install(fd, file);
-+ return fd;
-+}
-+
-+/*
-+ * Allocate an anonymous fd, this is what constitutes the application
-+ * visible backing of an io_uring instance. The application mmaps this
-+ * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
-+ * we have to tie this fd to a socket for file garbage collection purposes.
-+ */
-+static struct file *io_uring_get_file(struct io_ring_ctx *ctx)
-+{
-+ struct file *file;
-+#if defined(CONFIG_UNIX)
-+ int ret;
-+
-+ ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
-+ &ctx->ring_sock);
-+ if (ret)
-+ return ERR_PTR(ret);
-+#endif
-+
-+ file = anon_inode_getfile("[io_uring]", &io_uring_fops, ctx,
-+ O_RDWR | O_CLOEXEC);
-+#if defined(CONFIG_UNIX)
-+ if (IS_ERR(file)) {
-+ sock_release(ctx->ring_sock);
-+ ctx->ring_sock = NULL;
-+ } else {
-+ ctx->ring_sock->file = file;
-+ }
-+#endif
-+ return file;
-+}
-+
-+static int io_uring_create(unsigned entries, struct io_uring_params *p,
-+ struct io_uring_params __user *params)
-+{
-+ struct io_ring_ctx *ctx;
-+ struct file *file;
-+ int ret;
-+
-+ if (!entries)
-+ return -EINVAL;
-+ if (entries > IORING_MAX_ENTRIES) {
-+ if (!(p->flags & IORING_SETUP_CLAMP))
-+ return -EINVAL;
-+ entries = IORING_MAX_ENTRIES;
-+ }
-+
-+ /*
-+ * Use twice as many entries for the CQ ring. It's possible for the
-+ * application to drive a higher depth than the size of the SQ ring,
-+ * since the sqes are only used at submission time. This allows for
-+ * some flexibility in overcommitting a bit. If the application has
-+ * set IORING_SETUP_CQSIZE, it will have passed in the desired number
-+ * of CQ ring entries manually.
-+ */
-+ p->sq_entries = roundup_pow_of_two(entries);
-+ if (p->flags & IORING_SETUP_CQSIZE) {
-+ /*
-+ * If IORING_SETUP_CQSIZE is set, we do the same roundup
-+ * to a power-of-two, if it isn't already. We do NOT impose
-+ * any cq vs sq ring sizing.
-+ */
-+ if (!p->cq_entries)
-+ return -EINVAL;
-+ if (p->cq_entries > IORING_MAX_CQ_ENTRIES) {
-+ if (!(p->flags & IORING_SETUP_CLAMP))
-+ return -EINVAL;
-+ p->cq_entries = IORING_MAX_CQ_ENTRIES;
-+ }
-+ p->cq_entries = roundup_pow_of_two(p->cq_entries);
-+ if (p->cq_entries < p->sq_entries)
-+ return -EINVAL;
-+ } else {
-+ p->cq_entries = 2 * p->sq_entries;
-+ }
-+
-+ ctx = io_ring_ctx_alloc(p);
-+ if (!ctx)
-+ return -ENOMEM;
-+ ctx->compat = in_compat_syscall();
-+ if (!capable(CAP_IPC_LOCK))
-+ ctx->user = get_uid(current_user());
-+
-+ /*
-+ * This is just grabbed for accounting purposes. When a process exits,
-+ * the mm is exited and dropped before the files, hence we need to hang
-+ * on to this mm purely for the purposes of being able to unaccount
-+ * memory (locked/pinned vm). It's not used for anything else.
-+ */
-+ mmgrab(current->mm);
-+ ctx->mm_account = current->mm;
-+
-+ ret = io_allocate_scq_urings(ctx, p);
-+ if (ret)
-+ goto err;
-+
-+ ret = io_sq_offload_create(ctx, p);
-+ if (ret)
-+ goto err;
-+ /* always set a rsrc node */
-+ ret = io_rsrc_node_switch_start(ctx);
-+ if (ret)
-+ goto err;
-+ io_rsrc_node_switch(ctx, NULL);
-+
-+ memset(&p->sq_off, 0, sizeof(p->sq_off));
-+ p->sq_off.head = offsetof(struct io_rings, sq.head);
-+ p->sq_off.tail = offsetof(struct io_rings, sq.tail);
-+ p->sq_off.ring_mask = offsetof(struct io_rings, sq_ring_mask);
-+ p->sq_off.ring_entries = offsetof(struct io_rings, sq_ring_entries);
-+ p->sq_off.flags = offsetof(struct io_rings, sq_flags);
-+ p->sq_off.dropped = offsetof(struct io_rings, sq_dropped);
-+ p->sq_off.array = (char *)ctx->sq_array - (char *)ctx->rings;
-+
-+ memset(&p->cq_off, 0, sizeof(p->cq_off));
-+ p->cq_off.head = offsetof(struct io_rings, cq.head);
-+ p->cq_off.tail = offsetof(struct io_rings, cq.tail);
-+ p->cq_off.ring_mask = offsetof(struct io_rings, cq_ring_mask);
-+ p->cq_off.ring_entries = offsetof(struct io_rings, cq_ring_entries);
-+ p->cq_off.overflow = offsetof(struct io_rings, cq_overflow);
-+ p->cq_off.cqes = offsetof(struct io_rings, cqes);
-+ p->cq_off.flags = offsetof(struct io_rings, cq_flags);
-+
-+ p->features = IORING_FEAT_SINGLE_MMAP | IORING_FEAT_NODROP |
-+ IORING_FEAT_SUBMIT_STABLE | IORING_FEAT_RW_CUR_POS |
-+ IORING_FEAT_CUR_PERSONALITY | IORING_FEAT_FAST_POLL |
-+ IORING_FEAT_POLL_32BITS | IORING_FEAT_SQPOLL_NONFIXED |
-+ IORING_FEAT_EXT_ARG | IORING_FEAT_NATIVE_WORKERS |
-+ IORING_FEAT_RSRC_TAGS;
-+
-+ if (copy_to_user(params, p, sizeof(*p))) {
-+ ret = -EFAULT;
-+ goto err;
-+ }
-+
-+ file = io_uring_get_file(ctx);
-+ if (IS_ERR(file)) {
-+ ret = PTR_ERR(file);
-+ goto err;
-+ }
-+
-+ /*
-+ * Install ring fd as the very last thing, so we don't risk someone
-+ * having closed it before we finish setup
-+ */
-+ ret = io_uring_install_fd(ctx, file);
-+ if (ret < 0) {
-+ /* fput will clean it up */
-+ fput(file);
-+ return ret;
-+ }
-+
-+ trace_io_uring_create(ret, ctx, p->sq_entries, p->cq_entries, p->flags);
-+ return ret;
-+err:
-+ io_ring_ctx_wait_and_kill(ctx);
-+ return ret;
-+}
-+
-+/*
-+ * Sets up an aio uring context, and returns the fd. Applications asks for a
-+ * ring size, we return the actual sq/cq ring sizes (among other things) in the
-+ * params structure passed in.
-+ */
-+static long io_uring_setup(u32 entries, struct io_uring_params __user *params)
-+{
-+ struct io_uring_params p;
-+ int i;
-+
-+ if (copy_from_user(&p, params, sizeof(p)))
-+ return -EFAULT;
-+ for (i = 0; i < ARRAY_SIZE(p.resv); i++) {
-+ if (p.resv[i])
-+ return -EINVAL;
-+ }
-+
-+ if (p.flags & ~(IORING_SETUP_IOPOLL | IORING_SETUP_SQPOLL |
-+ IORING_SETUP_SQ_AFF | IORING_SETUP_CQSIZE |
-+ IORING_SETUP_CLAMP | IORING_SETUP_ATTACH_WQ |
-+ IORING_SETUP_R_DISABLED))
-+ return -EINVAL;
-+
-+ return io_uring_create(entries, &p, params);
-+}
-+
-+SYSCALL_DEFINE2(io_uring_setup, u32, entries,
-+ struct io_uring_params __user *, params)
-+{
-+ return io_uring_setup(entries, params);
-+}
-+
-+static int io_probe(struct io_ring_ctx *ctx, void __user *arg, unsigned nr_args)
-+{
-+ struct io_uring_probe *p;
-+ size_t size;
-+ int i, ret;
-+
-+ size = struct_size(p, ops, nr_args);
-+ if (size == SIZE_MAX)
-+ return -EOVERFLOW;
-+ p = kzalloc(size, GFP_KERNEL);
-+ if (!p)
-+ return -ENOMEM;
-+
-+ ret = -EFAULT;
-+ if (copy_from_user(p, arg, size))
-+ goto out;
-+ ret = -EINVAL;
-+ if (memchr_inv(p, 0, size))
-+ goto out;
-+
-+ p->last_op = IORING_OP_LAST - 1;
-+ if (nr_args > IORING_OP_LAST)
-+ nr_args = IORING_OP_LAST;
-+
-+ for (i = 0; i < nr_args; i++) {
-+ p->ops[i].op = i;
-+ if (!io_op_defs[i].not_supported)
-+ p->ops[i].flags = IO_URING_OP_SUPPORTED;
-+ }
-+ p->ops_len = i;
-+
-+ ret = 0;
-+ if (copy_to_user(arg, p, size))
-+ ret = -EFAULT;
-+out:
-+ kfree(p);
-+ return ret;
-+}
-+
-+static int io_register_personality(struct io_ring_ctx *ctx)
-+{
-+ const struct cred *creds;
-+ u32 id;
-+ int ret;
-+
-+ creds = get_current_cred();
-+
-+ ret = xa_alloc_cyclic(&ctx->personalities, &id, (void *)creds,
-+ XA_LIMIT(0, USHRT_MAX), &ctx->pers_next, GFP_KERNEL);
-+ if (ret < 0) {
-+ put_cred(creds);
-+ return ret;
-+ }
-+ return id;
-+}
-+
-+static int io_register_restrictions(struct io_ring_ctx *ctx, void __user *arg,
-+ unsigned int nr_args)
-+{
-+ struct io_uring_restriction *res;
-+ size_t size;
-+ int i, ret;
-+
-+ /* Restrictions allowed only if rings started disabled */
-+ if (!(ctx->flags & IORING_SETUP_R_DISABLED))
-+ return -EBADFD;
-+
-+ /* We allow only a single restrictions registration */
-+ if (ctx->restrictions.registered)
-+ return -EBUSY;
-+
-+ if (!arg || nr_args > IORING_MAX_RESTRICTIONS)
-+ return -EINVAL;
-+
-+ size = array_size(nr_args, sizeof(*res));
-+ if (size == SIZE_MAX)
-+ return -EOVERFLOW;
-+
-+ res = memdup_user(arg, size);
-+ if (IS_ERR(res))
-+ return PTR_ERR(res);
-+
-+ ret = 0;
-+
-+ for (i = 0; i < nr_args; i++) {
-+ switch (res[i].opcode) {
-+ case IORING_RESTRICTION_REGISTER_OP:
-+ if (res[i].register_op >= IORING_REGISTER_LAST) {
-+ ret = -EINVAL;
-+ goto out;
-+ }
-+
-+ __set_bit(res[i].register_op,
-+ ctx->restrictions.register_op);
-+ break;
-+ case IORING_RESTRICTION_SQE_OP:
-+ if (res[i].sqe_op >= IORING_OP_LAST) {
-+ ret = -EINVAL;
-+ goto out;
-+ }
-+
-+ __set_bit(res[i].sqe_op, ctx->restrictions.sqe_op);
-+ break;
-+ case IORING_RESTRICTION_SQE_FLAGS_ALLOWED:
-+ ctx->restrictions.sqe_flags_allowed = res[i].sqe_flags;
-+ break;
-+ case IORING_RESTRICTION_SQE_FLAGS_REQUIRED:
-+ ctx->restrictions.sqe_flags_required = res[i].sqe_flags;
-+ break;
-+ default:
-+ ret = -EINVAL;
-+ goto out;
-+ }
-+ }
-+
-+out:
-+ /* Reset all restrictions if an error happened */
-+ if (ret != 0)
-+ memset(&ctx->restrictions, 0, sizeof(ctx->restrictions));
-+ else
-+ ctx->restrictions.registered = true;
-+
-+ kfree(res);
-+ return ret;
-+}
-+
-+static int io_register_enable_rings(struct io_ring_ctx *ctx)
-+{
-+ if (!(ctx->flags & IORING_SETUP_R_DISABLED))
-+ return -EBADFD;
-+
-+ if (ctx->restrictions.registered)
-+ ctx->restricted = 1;
-+
-+ ctx->flags &= ~IORING_SETUP_R_DISABLED;
-+ if (ctx->sq_data && wq_has_sleeper(&ctx->sq_data->wait))
-+ wake_up(&ctx->sq_data->wait);
-+ return 0;
-+}
-+
-+static int __io_register_rsrc_update(struct io_ring_ctx *ctx, unsigned type,
-+ struct io_uring_rsrc_update2 *up,
-+ unsigned nr_args)
-+{
-+ __u32 tmp;
-+ int err;
-+
-+ if (check_add_overflow(up->offset, nr_args, &tmp))
-+ return -EOVERFLOW;
-+ err = io_rsrc_node_switch_start(ctx);
-+ if (err)
-+ return err;
-+
-+ switch (type) {
-+ case IORING_RSRC_FILE:
-+ return __io_sqe_files_update(ctx, up, nr_args);
-+ case IORING_RSRC_BUFFER:
-+ return __io_sqe_buffers_update(ctx, up, nr_args);
-+ }
-+ return -EINVAL;
-+}
-+
-+static int io_register_files_update(struct io_ring_ctx *ctx, void __user *arg,
-+ unsigned nr_args)
-+{
-+ struct io_uring_rsrc_update2 up;
-+
-+ if (!nr_args)
-+ return -EINVAL;
-+ memset(&up, 0, sizeof(up));
-+ if (copy_from_user(&up, arg, sizeof(struct io_uring_rsrc_update)))
-+ return -EFAULT;
-+ if (up.resv || up.resv2)
-+ return -EINVAL;
-+ return __io_register_rsrc_update(ctx, IORING_RSRC_FILE, &up, nr_args);
-+}
-+
-+static int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg,
-+ unsigned size, unsigned type)
-+{
-+ struct io_uring_rsrc_update2 up;
-+
-+ if (size != sizeof(up))
-+ return -EINVAL;
-+ if (copy_from_user(&up, arg, sizeof(up)))
-+ return -EFAULT;
-+ if (!up.nr || up.resv || up.resv2)
-+ return -EINVAL;
-+ return __io_register_rsrc_update(ctx, type, &up, up.nr);
-+}
-+
-+static int io_register_rsrc(struct io_ring_ctx *ctx, void __user *arg,
-+ unsigned int size, unsigned int type)
-+{
-+ struct io_uring_rsrc_register rr;
-+
-+ /* keep it extendible */
-+ if (size != sizeof(rr))
-+ return -EINVAL;
-+
-+ memset(&rr, 0, sizeof(rr));
-+ if (copy_from_user(&rr, arg, size))
-+ return -EFAULT;
-+ if (!rr.nr || rr.resv || rr.resv2)
-+ return -EINVAL;
-+
-+ switch (type) {
-+ case IORING_RSRC_FILE:
-+ return io_sqe_files_register(ctx, u64_to_user_ptr(rr.data),
-+ rr.nr, u64_to_user_ptr(rr.tags));
-+ case IORING_RSRC_BUFFER:
-+ return io_sqe_buffers_register(ctx, u64_to_user_ptr(rr.data),
-+ rr.nr, u64_to_user_ptr(rr.tags));
-+ }
-+ return -EINVAL;
-+}
-+
-+static int io_register_iowq_aff(struct io_ring_ctx *ctx, void __user *arg,
-+ unsigned len)
-+{
-+ struct io_uring_task *tctx = current->io_uring;
-+ cpumask_var_t new_mask;
-+ int ret;
-+
-+ if (!tctx || !tctx->io_wq)
-+ return -EINVAL;
-+
-+ if (!alloc_cpumask_var(&new_mask, GFP_KERNEL))
-+ return -ENOMEM;
-+
-+ cpumask_clear(new_mask);
-+ if (len > cpumask_size())
-+ len = cpumask_size();
-+
-+#ifdef CONFIG_COMPAT
-+ if (in_compat_syscall()) {
-+ ret = compat_get_bitmap(cpumask_bits(new_mask),
-+ (const compat_ulong_t __user *)arg,
-+ len * 8 /* CHAR_BIT */);
-+ } else {
-+ ret = copy_from_user(new_mask, arg, len);
-+ }
-+#else
-+ ret = copy_from_user(new_mask, arg, len);
-+#endif
-+
-+ if (ret) {
-+ free_cpumask_var(new_mask);
-+ return -EFAULT;
-+ }
-+
-+ ret = io_wq_cpu_affinity(tctx->io_wq, new_mask);
-+ free_cpumask_var(new_mask);
-+ return ret;
-+}
-+
-+static int io_unregister_iowq_aff(struct io_ring_ctx *ctx)
-+{
-+ struct io_uring_task *tctx = current->io_uring;
-+
-+ if (!tctx || !tctx->io_wq)
-+ return -EINVAL;
-+
-+ return io_wq_cpu_affinity(tctx->io_wq, NULL);
-+}
-+
-+static int io_register_iowq_max_workers(struct io_ring_ctx *ctx,
-+ void __user *arg)
-+ __must_hold(&ctx->uring_lock)
-+{
-+ struct io_tctx_node *node;
-+ struct io_uring_task *tctx = NULL;
-+ struct io_sq_data *sqd = NULL;
-+ __u32 new_count[2];
-+ int i, ret;
-+
-+ if (copy_from_user(new_count, arg, sizeof(new_count)))
-+ return -EFAULT;
-+ for (i = 0; i < ARRAY_SIZE(new_count); i++)
-+ if (new_count[i] > INT_MAX)
-+ return -EINVAL;
-+
-+ if (ctx->flags & IORING_SETUP_SQPOLL) {
-+ sqd = ctx->sq_data;
-+ if (sqd) {
-+ /*
-+ * Observe the correct sqd->lock -> ctx->uring_lock
-+ * ordering. Fine to drop uring_lock here, we hold
-+ * a ref to the ctx.
-+ */
-+ refcount_inc(&sqd->refs);
-+ mutex_unlock(&ctx->uring_lock);
-+ mutex_lock(&sqd->lock);
-+ mutex_lock(&ctx->uring_lock);
-+ if (sqd->thread)
-+ tctx = sqd->thread->io_uring;
-+ }
-+ } else {
-+ tctx = current->io_uring;
-+ }
-+
-+ BUILD_BUG_ON(sizeof(new_count) != sizeof(ctx->iowq_limits));
-+
-+ for (i = 0; i < ARRAY_SIZE(new_count); i++)
-+ if (new_count[i])
-+ ctx->iowq_limits[i] = new_count[i];
-+ ctx->iowq_limits_set = true;
-+
-+ ret = -EINVAL;
-+ if (tctx && tctx->io_wq) {
-+ ret = io_wq_max_workers(tctx->io_wq, new_count);
-+ if (ret)
-+ goto err;
-+ } else {
-+ memset(new_count, 0, sizeof(new_count));
-+ }
-+
-+ if (sqd) {
-+ mutex_unlock(&sqd->lock);
-+ io_put_sq_data(sqd);
-+ }
-+
-+ if (copy_to_user(arg, new_count, sizeof(new_count)))
-+ return -EFAULT;
-+
-+ /* that's it for SQPOLL, only the SQPOLL task creates requests */
-+ if (sqd)
-+ return 0;
-+
-+ /* now propagate the restriction to all registered users */
-+ list_for_each_entry(node, &ctx->tctx_list, ctx_node) {
-+ struct io_uring_task *tctx = node->task->io_uring;
-+
-+ if (WARN_ON_ONCE(!tctx->io_wq))
-+ continue;
-+
-+ for (i = 0; i < ARRAY_SIZE(new_count); i++)
-+ new_count[i] = ctx->iowq_limits[i];
-+ /* ignore errors, it always returns zero anyway */
-+ (void)io_wq_max_workers(tctx->io_wq, new_count);
-+ }
-+ return 0;
-+err:
-+ if (sqd) {
-+ mutex_unlock(&sqd->lock);
-+ io_put_sq_data(sqd);
-+ }
-+ return ret;
-+}
-+
-+static bool io_register_op_must_quiesce(int op)
-+{
-+ switch (op) {
-+ case IORING_REGISTER_BUFFERS:
-+ case IORING_UNREGISTER_BUFFERS:
-+ case IORING_REGISTER_FILES:
-+ case IORING_UNREGISTER_FILES:
-+ case IORING_REGISTER_FILES_UPDATE:
-+ case IORING_REGISTER_PROBE:
-+ case IORING_REGISTER_PERSONALITY:
-+ case IORING_UNREGISTER_PERSONALITY:
-+ case IORING_REGISTER_FILES2:
-+ case IORING_REGISTER_FILES_UPDATE2:
-+ case IORING_REGISTER_BUFFERS2:
-+ case IORING_REGISTER_BUFFERS_UPDATE:
-+ case IORING_REGISTER_IOWQ_AFF:
-+ case IORING_UNREGISTER_IOWQ_AFF:
-+ case IORING_REGISTER_IOWQ_MAX_WORKERS:
-+ return false;
-+ default:
-+ return true;
-+ }
-+}
-+
-+static int io_ctx_quiesce(struct io_ring_ctx *ctx)
-+{
-+ long ret;
-+
-+ percpu_ref_kill(&ctx->refs);
-+
-+ /*
-+ * Drop uring mutex before waiting for references to exit. If another
-+ * thread is currently inside io_uring_enter() it might need to grab the
-+ * uring_lock to make progress. If we hold it here across the drain
-+ * wait, then we can deadlock. It's safe to drop the mutex here, since
-+ * no new references will come in after we've killed the percpu ref.
-+ */
-+ mutex_unlock(&ctx->uring_lock);
-+ do {
-+ ret = wait_for_completion_interruptible(&ctx->ref_comp);
-+ if (!ret)
-+ break;
-+ ret = io_run_task_work_sig();
-+ } while (ret >= 0);
-+ mutex_lock(&ctx->uring_lock);
-+
-+ if (ret)
-+ io_refs_resurrect(&ctx->refs, &ctx->ref_comp);
-+ return ret;
-+}
-+
-+static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
-+ void __user *arg, unsigned nr_args)
-+ __releases(ctx->uring_lock)
-+ __acquires(ctx->uring_lock)
-+{
-+ int ret;
-+
-+ /*
-+ * We're inside the ring mutex, if the ref is already dying, then
-+ * someone else killed the ctx or is already going through
-+ * io_uring_register().
-+ */
-+ if (percpu_ref_is_dying(&ctx->refs))
-+ return -ENXIO;
-+
-+ if (ctx->restricted) {
-+ if (opcode >= IORING_REGISTER_LAST)
-+ return -EINVAL;
-+ opcode = array_index_nospec(opcode, IORING_REGISTER_LAST);
-+ if (!test_bit(opcode, ctx->restrictions.register_op))
-+ return -EACCES;
-+ }
-+
-+ if (io_register_op_must_quiesce(opcode)) {
-+ ret = io_ctx_quiesce(ctx);
-+ if (ret)
-+ return ret;
-+ }
-+
-+ switch (opcode) {
-+ case IORING_REGISTER_BUFFERS:
-+ ret = io_sqe_buffers_register(ctx, arg, nr_args, NULL);
-+ break;
-+ case IORING_UNREGISTER_BUFFERS:
-+ ret = -EINVAL;
-+ if (arg || nr_args)
-+ break;
-+ ret = io_sqe_buffers_unregister(ctx);
-+ break;
-+ case IORING_REGISTER_FILES:
-+ ret = io_sqe_files_register(ctx, arg, nr_args, NULL);
-+ break;
-+ case IORING_UNREGISTER_FILES:
-+ ret = -EINVAL;
-+ if (arg || nr_args)
-+ break;
-+ ret = io_sqe_files_unregister(ctx);
-+ break;
-+ case IORING_REGISTER_FILES_UPDATE:
-+ ret = io_register_files_update(ctx, arg, nr_args);
-+ break;
-+ case IORING_REGISTER_EVENTFD:
-+ case IORING_REGISTER_EVENTFD_ASYNC:
-+ ret = -EINVAL;
-+ if (nr_args != 1)
-+ break;
-+ ret = io_eventfd_register(ctx, arg);
-+ if (ret)
-+ break;
-+ if (opcode == IORING_REGISTER_EVENTFD_ASYNC)
-+ ctx->eventfd_async = 1;
-+ else
-+ ctx->eventfd_async = 0;
-+ break;
-+ case IORING_UNREGISTER_EVENTFD:
-+ ret = -EINVAL;
-+ if (arg || nr_args)
-+ break;
-+ ret = io_eventfd_unregister(ctx);
-+ break;
-+ case IORING_REGISTER_PROBE:
-+ ret = -EINVAL;
-+ if (!arg || nr_args > 256)
-+ break;
-+ ret = io_probe(ctx, arg, nr_args);
-+ break;
-+ case IORING_REGISTER_PERSONALITY:
-+ ret = -EINVAL;
-+ if (arg || nr_args)
-+ break;
-+ ret = io_register_personality(ctx);
-+ break;
-+ case IORING_UNREGISTER_PERSONALITY:
-+ ret = -EINVAL;
-+ if (arg)
-+ break;
-+ ret = io_unregister_personality(ctx, nr_args);
-+ break;
-+ case IORING_REGISTER_ENABLE_RINGS:
-+ ret = -EINVAL;
-+ if (arg || nr_args)
-+ break;
-+ ret = io_register_enable_rings(ctx);
-+ break;
-+ case IORING_REGISTER_RESTRICTIONS:
-+ ret = io_register_restrictions(ctx, arg, nr_args);
-+ break;
-+ case IORING_REGISTER_FILES2:
-+ ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_FILE);
-+ break;
-+ case IORING_REGISTER_FILES_UPDATE2:
-+ ret = io_register_rsrc_update(ctx, arg, nr_args,
-+ IORING_RSRC_FILE);
-+ break;
-+ case IORING_REGISTER_BUFFERS2:
-+ ret = io_register_rsrc(ctx, arg, nr_args, IORING_RSRC_BUFFER);
-+ break;
-+ case IORING_REGISTER_BUFFERS_UPDATE:
-+ ret = io_register_rsrc_update(ctx, arg, nr_args,
-+ IORING_RSRC_BUFFER);
-+ break;
-+ case IORING_REGISTER_IOWQ_AFF:
-+ ret = -EINVAL;
-+ if (!arg || !nr_args)
-+ break;
-+ ret = io_register_iowq_aff(ctx, arg, nr_args);
-+ break;
-+ case IORING_UNREGISTER_IOWQ_AFF:
-+ ret = -EINVAL;
-+ if (arg || nr_args)
-+ break;
-+ ret = io_unregister_iowq_aff(ctx);
-+ break;
-+ case IORING_REGISTER_IOWQ_MAX_WORKERS:
-+ ret = -EINVAL;
-+ if (!arg || nr_args != 2)
-+ break;
-+ ret = io_register_iowq_max_workers(ctx, arg);
-+ break;
-+ default:
-+ ret = -EINVAL;
-+ break;
-+ }
-+
-+ if (io_register_op_must_quiesce(opcode)) {
-+ /* bring the ctx back to life */
-+ percpu_ref_reinit(&ctx->refs);
-+ reinit_completion(&ctx->ref_comp);
-+ }
-+ return ret;
-+}
-+
-+SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode,
-+ void __user *, arg, unsigned int, nr_args)
-+{
-+ struct io_ring_ctx *ctx;
-+ long ret = -EBADF;
-+ struct fd f;
-+
-+ f = fdget(fd);
-+ if (!f.file)
-+ return -EBADF;
-+
-+ ret = -EOPNOTSUPP;
-+ if (f.file->f_op != &io_uring_fops)
-+ goto out_fput;
-+
-+ ctx = f.file->private_data;
-+
-+ io_run_task_work();
-+
-+ mutex_lock(&ctx->uring_lock);
-+ ret = __io_uring_register(ctx, opcode, arg, nr_args);
-+ mutex_unlock(&ctx->uring_lock);
-+ trace_io_uring_register(ctx, opcode, ctx->nr_user_files, ctx->nr_user_bufs,
-+ ctx->cq_ev_fd != NULL, ret);
-+out_fput:
-+ fdput(f);
-+ return ret;
-+}
-+
-+static int __init io_uring_init(void)
-+{
-+#define __BUILD_BUG_VERIFY_ELEMENT(stype, eoffset, etype, ename) do { \
-+ BUILD_BUG_ON(offsetof(stype, ename) != eoffset); \
-+ BUILD_BUG_ON(sizeof(etype) != sizeof_field(stype, ename)); \
-+} while (0)
-+
-+#define BUILD_BUG_SQE_ELEM(eoffset, etype, ename) \
-+ __BUILD_BUG_VERIFY_ELEMENT(struct io_uring_sqe, eoffset, etype, ename)
-+ BUILD_BUG_ON(sizeof(struct io_uring_sqe) != 64);
-+ BUILD_BUG_SQE_ELEM(0, __u8, opcode);
-+ BUILD_BUG_SQE_ELEM(1, __u8, flags);
-+ BUILD_BUG_SQE_ELEM(2, __u16, ioprio);
-+ BUILD_BUG_SQE_ELEM(4, __s32, fd);
-+ BUILD_BUG_SQE_ELEM(8, __u64, off);
-+ BUILD_BUG_SQE_ELEM(8, __u64, addr2);
-+ BUILD_BUG_SQE_ELEM(16, __u64, addr);
-+ BUILD_BUG_SQE_ELEM(16, __u64, splice_off_in);
-+ BUILD_BUG_SQE_ELEM(24, __u32, len);
-+ BUILD_BUG_SQE_ELEM(28, __kernel_rwf_t, rw_flags);
-+ BUILD_BUG_SQE_ELEM(28, /* compat */ int, rw_flags);
-+ BUILD_BUG_SQE_ELEM(28, /* compat */ __u32, rw_flags);
-+ BUILD_BUG_SQE_ELEM(28, __u32, fsync_flags);
-+ BUILD_BUG_SQE_ELEM(28, /* compat */ __u16, poll_events);
-+ BUILD_BUG_SQE_ELEM(28, __u32, poll32_events);
-+ BUILD_BUG_SQE_ELEM(28, __u32, sync_range_flags);
-+ BUILD_BUG_SQE_ELEM(28, __u32, msg_flags);
-+ BUILD_BUG_SQE_ELEM(28, __u32, timeout_flags);
-+ BUILD_BUG_SQE_ELEM(28, __u32, accept_flags);
-+ BUILD_BUG_SQE_ELEM(28, __u32, cancel_flags);
-+ BUILD_BUG_SQE_ELEM(28, __u32, open_flags);
-+ BUILD_BUG_SQE_ELEM(28, __u32, statx_flags);
-+ BUILD_BUG_SQE_ELEM(28, __u32, fadvise_advice);
-+ BUILD_BUG_SQE_ELEM(28, __u32, splice_flags);
-+ BUILD_BUG_SQE_ELEM(32, __u64, user_data);
-+ BUILD_BUG_SQE_ELEM(40, __u16, buf_index);
-+ BUILD_BUG_SQE_ELEM(40, __u16, buf_group);
-+ BUILD_BUG_SQE_ELEM(42, __u16, personality);
-+ BUILD_BUG_SQE_ELEM(44, __s32, splice_fd_in);
-+ BUILD_BUG_SQE_ELEM(44, __u32, file_index);
-+
-+ BUILD_BUG_ON(sizeof(struct io_uring_files_update) !=
-+ sizeof(struct io_uring_rsrc_update));
-+ BUILD_BUG_ON(sizeof(struct io_uring_rsrc_update) >
-+ sizeof(struct io_uring_rsrc_update2));
-+
-+ /* ->buf_index is u16 */
-+ BUILD_BUG_ON(IORING_MAX_REG_BUFFERS >= (1u << 16));
-+
-+ /* should fit into one byte */
-+ BUILD_BUG_ON(SQE_VALID_FLAGS >= (1 << 8));
-+
-+ BUILD_BUG_ON(ARRAY_SIZE(io_op_defs) != IORING_OP_LAST);
-+ BUILD_BUG_ON(__REQ_F_LAST_BIT > 8 * sizeof(int));
-+
-+ req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC |
-+ SLAB_ACCOUNT);
-+ return 0;
-+};
-+__initcall(io_uring_init);
---- a/kernel/exit.c
-+++ b/kernel/exit.c
-@@ -763,7 +763,7 @@ void __noreturn do_exit(long code)
- schedule();
- }
-
-- io_uring_files_cancel(tsk->files);
-+ io_uring_files_cancel();
- exit_signals(tsk); /* sets PF_EXITING */
-
- /* sync mm's RSS info before statistics gathering */
---- a/kernel/fork.c
-+++ b/kernel/fork.c
-@@ -926,6 +926,7 @@ static struct task_struct *dup_task_stru
- tsk->splice_pipe = NULL;
- tsk->task_frag.page = NULL;
- tsk->wake_q.next = NULL;
-+ tsk->pf_io_worker = NULL;
-
- account_kernel_stack(tsk, 1);
-
---- a/kernel/sched/core.c
-+++ b/kernel/sched/core.c
-@@ -21,7 +21,7 @@
- #include <asm/tlb.h>
-
- #include "../workqueue_internal.h"
--#include "../../fs/io-wq.h"
-+#include "../../io_uring/io-wq.h"
- #include "../smpboot.h"
-
- #include "pelt.h"
projects / thirdparty / kernel / stable-queue.git / commitdiff
