1 // SPDX-License-Identifier: GPL-2.0
3 * Shared application/kernel submission and completion ring pairs, for
4 * supporting fast/efficient IO.
6 * A note on the read/write ordering memory barriers that are matched between
7 * the application and kernel side.
9 * After the application reads the CQ ring tail, it must use an
10 * appropriate smp_rmb() to pair with the smp_wmb() the kernel uses
11 * before writing the tail (using smp_load_acquire to read the tail will
12 * do). It also needs a smp_mb() before updating CQ head (ordering the
13 * entry load(s) with the head store), pairing with an implicit barrier
14 * through a control-dependency in io_get_cqe (smp_store_release to
15 * store head will do). Failure to do so could lead to reading invalid
18 * Likewise, the application must use an appropriate smp_wmb() before
19 * writing the SQ tail (ordering SQ entry stores with the tail store),
20 * which pairs with smp_load_acquire in io_get_sqring (smp_store_release
21 * to store the tail will do). And it needs a barrier ordering the SQ
22 * head load before writing new SQ entries (smp_load_acquire to read
25 * When using the SQ poll thread (IORING_SETUP_SQPOLL), the application
26 * needs to check the SQ flags for IORING_SQ_NEED_WAKEUP *after*
27 * updating the SQ tail; a full memory barrier smp_mb() is needed
30 * Also see the examples in the liburing library:
32 * git://git.kernel.dk/liburing
34 * io_uring also uses READ/WRITE_ONCE() for _any_ store or load that happens
35 * from data shared between the kernel and application. This is done both
36 * for ordering purposes, but also to ensure that once a value is loaded from
37 * data that the application could potentially modify, it remains stable.
39 * Copyright (C) 2018-2019 Jens Axboe
40 * Copyright (c) 2018-2019 Christoph Hellwig
42 #include <linux/kernel.h>
43 #include <linux/init.h>
44 #include <linux/errno.h>
45 #include <linux/syscalls.h>
46 #include <net/compat.h>
47 #include <linux/refcount.h>
48 #include <linux/uio.h>
49 #include <linux/bits.h>
51 #include <linux/sched/signal.h>
53 #include <linux/file.h>
54 #include <linux/fdtable.h>
56 #include <linux/mman.h>
57 #include <linux/percpu.h>
58 #include <linux/slab.h>
59 #include <linux/bvec.h>
60 #include <linux/net.h>
62 #include <net/af_unix.h>
64 #include <linux/anon_inodes.h>
65 #include <linux/sched/mm.h>
66 #include <linux/uaccess.h>
67 #include <linux/nospec.h>
68 #include <linux/highmem.h>
69 #include <linux/fsnotify.h>
70 #include <linux/fadvise.h>
71 #include <linux/task_work.h>
72 #include <linux/io_uring.h>
73 #include <linux/audit.h>
74 #include <linux/security.h>
75 #include <asm/shmparam.h>
77 #define CREATE_TRACE_POINTS
78 #include <trace/events/io_uring.h>
80 #include <uapi/linux/io_uring.h>
101 #include "alloc_cache.h"
103 #define IORING_MAX_ENTRIES 32768
104 #define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES)
106 #define IORING_MAX_RESTRICTIONS (IORING_RESTRICTION_LAST + \
107 IORING_REGISTER_LAST + IORING_OP_LAST)
109 #define SQE_COMMON_FLAGS (IOSQE_FIXED_FILE | IOSQE_IO_LINK | \
110 IOSQE_IO_HARDLINK | IOSQE_ASYNC)
112 #define SQE_VALID_FLAGS (SQE_COMMON_FLAGS | IOSQE_BUFFER_SELECT | \
113 IOSQE_IO_DRAIN | IOSQE_CQE_SKIP_SUCCESS)
115 #define IO_REQ_CLEAN_FLAGS (REQ_F_BUFFER_SELECTED | REQ_F_NEED_CLEANUP | \
116 REQ_F_POLLED | REQ_F_INFLIGHT | REQ_F_CREDS | \
119 #define IO_REQ_CLEAN_SLOW_FLAGS (REQ_F_REFCOUNT | REQ_F_LINK | REQ_F_HARDLINK |\
122 #define IO_TCTX_REFS_CACHE_NR (1U << 10)
124 #define IO_COMPL_BATCH 32
125 #define IO_REQ_ALLOC_BATCH 8
128 IO_CHECK_CQ_OVERFLOW_BIT
,
129 IO_CHECK_CQ_DROPPED_BIT
,
133 IO_EVENTFD_OP_SIGNAL_BIT
,
134 IO_EVENTFD_OP_FREE_BIT
,
137 struct io_defer_entry
{
138 struct list_head list
;
139 struct io_kiocb
*req
;
143 /* requests with any of those set should undergo io_disarm_next() */
144 #define IO_DISARM_MASK (REQ_F_ARM_LTIMEOUT | REQ_F_LINK_TIMEOUT | REQ_F_FAIL)
145 #define IO_REQ_LINK_FLAGS (REQ_F_LINK | REQ_F_HARDLINK)
147 static bool io_uring_try_cancel_requests(struct io_ring_ctx
*ctx
,
148 struct task_struct
*task
,
151 static void io_queue_sqe(struct io_kiocb
*req
);
153 struct kmem_cache
*req_cachep
;
155 static int __read_mostly sysctl_io_uring_disabled
;
156 static int __read_mostly sysctl_io_uring_group
= -1;
159 static struct ctl_table kernel_io_uring_disabled_table
[] = {
161 .procname
= "io_uring_disabled",
162 .data
= &sysctl_io_uring_disabled
,
163 .maxlen
= sizeof(sysctl_io_uring_disabled
),
165 .proc_handler
= proc_dointvec_minmax
,
166 .extra1
= SYSCTL_ZERO
,
167 .extra2
= SYSCTL_TWO
,
170 .procname
= "io_uring_group",
171 .data
= &sysctl_io_uring_group
,
172 .maxlen
= sizeof(gid_t
),
174 .proc_handler
= proc_dointvec
,
180 struct sock
*io_uring_get_socket(struct file
*file
)
182 #if defined(CONFIG_UNIX)
183 if (io_is_uring_fops(file
)) {
184 struct io_ring_ctx
*ctx
= file
->private_data
;
186 return ctx
->ring_sock
->sk
;
191 EXPORT_SYMBOL(io_uring_get_socket
);
193 static inline void io_submit_flush_completions(struct io_ring_ctx
*ctx
)
195 if (!wq_list_empty(&ctx
->submit_state
.compl_reqs
) ||
196 ctx
->submit_state
.cqes_count
)
197 __io_submit_flush_completions(ctx
);
200 static inline unsigned int __io_cqring_events(struct io_ring_ctx
*ctx
)
202 return ctx
->cached_cq_tail
- READ_ONCE(ctx
->rings
->cq
.head
);
205 static inline unsigned int __io_cqring_events_user(struct io_ring_ctx
*ctx
)
207 return READ_ONCE(ctx
->rings
->cq
.tail
) - READ_ONCE(ctx
->rings
->cq
.head
);
210 static bool io_match_linked(struct io_kiocb
*head
)
212 struct io_kiocb
*req
;
214 io_for_each_link(req
, head
) {
215 if (req
->flags
& REQ_F_INFLIGHT
)
222 * As io_match_task() but protected against racing with linked timeouts.
223 * User must not hold timeout_lock.
225 bool io_match_task_safe(struct io_kiocb
*head
, struct task_struct
*task
,
230 if (task
&& head
->task
!= task
)
235 if (head
->flags
& REQ_F_LINK_TIMEOUT
) {
236 struct io_ring_ctx
*ctx
= head
->ctx
;
238 /* protect against races with linked timeouts */
239 spin_lock_irq(&ctx
->timeout_lock
);
240 matched
= io_match_linked(head
);
241 spin_unlock_irq(&ctx
->timeout_lock
);
243 matched
= io_match_linked(head
);
248 static inline void req_fail_link_node(struct io_kiocb
*req
, int res
)
251 io_req_set_res(req
, res
, 0);
254 static inline void io_req_add_to_cache(struct io_kiocb
*req
, struct io_ring_ctx
*ctx
)
256 wq_stack_add_head(&req
->comp_list
, &ctx
->submit_state
.free_list
);
259 static __cold
void io_ring_ctx_ref_free(struct percpu_ref
*ref
)
261 struct io_ring_ctx
*ctx
= container_of(ref
, struct io_ring_ctx
, refs
);
263 complete(&ctx
->ref_comp
);
266 static __cold
void io_fallback_req_func(struct work_struct
*work
)
268 struct io_ring_ctx
*ctx
= container_of(work
, struct io_ring_ctx
,
270 struct llist_node
*node
= llist_del_all(&ctx
->fallback_llist
);
271 struct io_kiocb
*req
, *tmp
;
272 struct io_tw_state ts
= { .locked
= true, };
274 mutex_lock(&ctx
->uring_lock
);
275 llist_for_each_entry_safe(req
, tmp
, node
, io_task_work
.node
)
276 req
->io_task_work
.func(req
, &ts
);
277 if (WARN_ON_ONCE(!ts
.locked
))
279 io_submit_flush_completions(ctx
);
280 mutex_unlock(&ctx
->uring_lock
);
283 static int io_alloc_hash_table(struct io_hash_table
*table
, unsigned bits
)
285 unsigned hash_buckets
= 1U << bits
;
286 size_t hash_size
= hash_buckets
* sizeof(table
->hbs
[0]);
288 table
->hbs
= kmalloc(hash_size
, GFP_KERNEL
);
292 table
->hash_bits
= bits
;
293 init_hash_table(table
, hash_buckets
);
297 static __cold
struct io_ring_ctx
*io_ring_ctx_alloc(struct io_uring_params
*p
)
299 struct io_ring_ctx
*ctx
;
302 ctx
= kzalloc(sizeof(*ctx
), GFP_KERNEL
);
306 xa_init(&ctx
->io_bl_xa
);
309 * Use 5 bits less than the max cq entries, that should give us around
310 * 32 entries per hash list if totally full and uniformly spread, but
311 * don't keep too many buckets to not overconsume memory.
313 hash_bits
= ilog2(p
->cq_entries
) - 5;
314 hash_bits
= clamp(hash_bits
, 1, 8);
315 if (io_alloc_hash_table(&ctx
->cancel_table
, hash_bits
))
317 if (io_alloc_hash_table(&ctx
->cancel_table_locked
, hash_bits
))
319 if (percpu_ref_init(&ctx
->refs
, io_ring_ctx_ref_free
,
323 ctx
->flags
= p
->flags
;
324 init_waitqueue_head(&ctx
->sqo_sq_wait
);
325 INIT_LIST_HEAD(&ctx
->sqd_list
);
326 INIT_LIST_HEAD(&ctx
->cq_overflow_list
);
327 INIT_LIST_HEAD(&ctx
->io_buffers_cache
);
328 io_alloc_cache_init(&ctx
->rsrc_node_cache
, IO_NODE_ALLOC_CACHE_MAX
,
329 sizeof(struct io_rsrc_node
));
330 io_alloc_cache_init(&ctx
->apoll_cache
, IO_ALLOC_CACHE_MAX
,
331 sizeof(struct async_poll
));
332 io_alloc_cache_init(&ctx
->netmsg_cache
, IO_ALLOC_CACHE_MAX
,
333 sizeof(struct io_async_msghdr
));
334 io_futex_cache_init(ctx
);
335 init_completion(&ctx
->ref_comp
);
336 xa_init_flags(&ctx
->personalities
, XA_FLAGS_ALLOC1
);
337 mutex_init(&ctx
->uring_lock
);
338 init_waitqueue_head(&ctx
->cq_wait
);
339 init_waitqueue_head(&ctx
->poll_wq
);
340 init_waitqueue_head(&ctx
->rsrc_quiesce_wq
);
341 spin_lock_init(&ctx
->completion_lock
);
342 spin_lock_init(&ctx
->timeout_lock
);
343 INIT_WQ_LIST(&ctx
->iopoll_list
);
344 INIT_LIST_HEAD(&ctx
->io_buffers_comp
);
345 INIT_LIST_HEAD(&ctx
->defer_list
);
346 INIT_LIST_HEAD(&ctx
->timeout_list
);
347 INIT_LIST_HEAD(&ctx
->ltimeout_list
);
348 INIT_LIST_HEAD(&ctx
->rsrc_ref_list
);
349 init_llist_head(&ctx
->work_llist
);
350 INIT_LIST_HEAD(&ctx
->tctx_list
);
351 ctx
->submit_state
.free_list
.next
= NULL
;
352 INIT_WQ_LIST(&ctx
->locked_free_list
);
353 INIT_HLIST_HEAD(&ctx
->waitid_list
);
355 INIT_HLIST_HEAD(&ctx
->futex_list
);
357 INIT_DELAYED_WORK(&ctx
->fallback_work
, io_fallback_req_func
);
358 INIT_WQ_LIST(&ctx
->submit_state
.compl_reqs
);
359 INIT_HLIST_HEAD(&ctx
->cancelable_uring_cmd
);
362 kfree(ctx
->cancel_table
.hbs
);
363 kfree(ctx
->cancel_table_locked
.hbs
);
365 xa_destroy(&ctx
->io_bl_xa
);
370 static void io_account_cq_overflow(struct io_ring_ctx
*ctx
)
372 struct io_rings
*r
= ctx
->rings
;
374 WRITE_ONCE(r
->cq_overflow
, READ_ONCE(r
->cq_overflow
) + 1);
378 static bool req_need_defer(struct io_kiocb
*req
, u32 seq
)
380 if (unlikely(req
->flags
& REQ_F_IO_DRAIN
)) {
381 struct io_ring_ctx
*ctx
= req
->ctx
;
383 return seq
+ READ_ONCE(ctx
->cq_extra
) != ctx
->cached_cq_tail
;
389 static void io_clean_op(struct io_kiocb
*req
)
391 if (req
->flags
& REQ_F_BUFFER_SELECTED
) {
392 spin_lock(&req
->ctx
->completion_lock
);
393 io_put_kbuf_comp(req
);
394 spin_unlock(&req
->ctx
->completion_lock
);
397 if (req
->flags
& REQ_F_NEED_CLEANUP
) {
398 const struct io_cold_def
*def
= &io_cold_defs
[req
->opcode
];
403 if ((req
->flags
& REQ_F_POLLED
) && req
->apoll
) {
404 kfree(req
->apoll
->double_poll
);
408 if (req
->flags
& REQ_F_INFLIGHT
) {
409 struct io_uring_task
*tctx
= req
->task
->io_uring
;
411 atomic_dec(&tctx
->inflight_tracked
);
413 if (req
->flags
& REQ_F_CREDS
)
414 put_cred(req
->creds
);
415 if (req
->flags
& REQ_F_ASYNC_DATA
) {
416 kfree(req
->async_data
);
417 req
->async_data
= NULL
;
419 req
->flags
&= ~IO_REQ_CLEAN_FLAGS
;
422 static inline void io_req_track_inflight(struct io_kiocb
*req
)
424 if (!(req
->flags
& REQ_F_INFLIGHT
)) {
425 req
->flags
|= REQ_F_INFLIGHT
;
426 atomic_inc(&req
->task
->io_uring
->inflight_tracked
);
430 static struct io_kiocb
*__io_prep_linked_timeout(struct io_kiocb
*req
)
432 if (WARN_ON_ONCE(!req
->link
))
435 req
->flags
&= ~REQ_F_ARM_LTIMEOUT
;
436 req
->flags
|= REQ_F_LINK_TIMEOUT
;
438 /* linked timeouts should have two refs once prep'ed */
439 io_req_set_refcount(req
);
440 __io_req_set_refcount(req
->link
, 2);
444 static inline struct io_kiocb
*io_prep_linked_timeout(struct io_kiocb
*req
)
446 if (likely(!(req
->flags
& REQ_F_ARM_LTIMEOUT
)))
448 return __io_prep_linked_timeout(req
);
451 static noinline
void __io_arm_ltimeout(struct io_kiocb
*req
)
453 io_queue_linked_timeout(__io_prep_linked_timeout(req
));
456 static inline void io_arm_ltimeout(struct io_kiocb
*req
)
458 if (unlikely(req
->flags
& REQ_F_ARM_LTIMEOUT
))
459 __io_arm_ltimeout(req
);
462 static void io_prep_async_work(struct io_kiocb
*req
)
464 const struct io_issue_def
*def
= &io_issue_defs
[req
->opcode
];
465 struct io_ring_ctx
*ctx
= req
->ctx
;
467 if (!(req
->flags
& REQ_F_CREDS
)) {
468 req
->flags
|= REQ_F_CREDS
;
469 req
->creds
= get_current_cred();
472 req
->work
.list
.next
= NULL
;
474 req
->work
.cancel_seq
= atomic_read(&ctx
->cancel_seq
);
475 if (req
->flags
& REQ_F_FORCE_ASYNC
)
476 req
->work
.flags
|= IO_WQ_WORK_CONCURRENT
;
478 if (req
->file
&& !(req
->flags
& REQ_F_FIXED_FILE
))
479 req
->flags
|= io_file_get_flags(req
->file
);
481 if (req
->file
&& (req
->flags
& REQ_F_ISREG
)) {
482 bool should_hash
= def
->hash_reg_file
;
484 /* don't serialize this request if the fs doesn't need it */
485 if (should_hash
&& (req
->file
->f_flags
& O_DIRECT
) &&
486 (req
->file
->f_mode
& FMODE_DIO_PARALLEL_WRITE
))
488 if (should_hash
|| (ctx
->flags
& IORING_SETUP_IOPOLL
))
489 io_wq_hash_work(&req
->work
, file_inode(req
->file
));
490 } else if (!req
->file
|| !S_ISBLK(file_inode(req
->file
)->i_mode
)) {
491 if (def
->unbound_nonreg_file
)
492 req
->work
.flags
|= IO_WQ_WORK_UNBOUND
;
496 static void io_prep_async_link(struct io_kiocb
*req
)
498 struct io_kiocb
*cur
;
500 if (req
->flags
& REQ_F_LINK_TIMEOUT
) {
501 struct io_ring_ctx
*ctx
= req
->ctx
;
503 spin_lock_irq(&ctx
->timeout_lock
);
504 io_for_each_link(cur
, req
)
505 io_prep_async_work(cur
);
506 spin_unlock_irq(&ctx
->timeout_lock
);
508 io_for_each_link(cur
, req
)
509 io_prep_async_work(cur
);
513 void io_queue_iowq(struct io_kiocb
*req
, struct io_tw_state
*ts_dont_use
)
515 struct io_kiocb
*link
= io_prep_linked_timeout(req
);
516 struct io_uring_task
*tctx
= req
->task
->io_uring
;
519 BUG_ON(!tctx
->io_wq
);
521 /* init ->work of the whole link before punting */
522 io_prep_async_link(req
);
525 * Not expected to happen, but if we do have a bug where this _can_
526 * happen, catch it here and ensure the request is marked as
527 * canceled. That will make io-wq go through the usual work cancel
528 * procedure rather than attempt to run this request (or create a new
531 if (WARN_ON_ONCE(!same_thread_group(req
->task
, current
)))
532 req
->work
.flags
|= IO_WQ_WORK_CANCEL
;
534 trace_io_uring_queue_async_work(req
, io_wq_is_hashed(&req
->work
));
535 io_wq_enqueue(tctx
->io_wq
, &req
->work
);
537 io_queue_linked_timeout(link
);
540 static __cold
void io_queue_deferred(struct io_ring_ctx
*ctx
)
542 while (!list_empty(&ctx
->defer_list
)) {
543 struct io_defer_entry
*de
= list_first_entry(&ctx
->defer_list
,
544 struct io_defer_entry
, list
);
546 if (req_need_defer(de
->req
, de
->seq
))
548 list_del_init(&de
->list
);
549 io_req_task_queue(de
->req
);
555 static void io_eventfd_ops(struct rcu_head
*rcu
)
557 struct io_ev_fd
*ev_fd
= container_of(rcu
, struct io_ev_fd
, rcu
);
558 int ops
= atomic_xchg(&ev_fd
->ops
, 0);
560 if (ops
& BIT(IO_EVENTFD_OP_SIGNAL_BIT
))
561 eventfd_signal_mask(ev_fd
->cq_ev_fd
, 1, EPOLL_URING_WAKE
);
563 /* IO_EVENTFD_OP_FREE_BIT may not be set here depending on callback
564 * ordering in a race but if references are 0 we know we have to free
567 if (atomic_dec_and_test(&ev_fd
->refs
)) {
568 eventfd_ctx_put(ev_fd
->cq_ev_fd
);
573 static void io_eventfd_signal(struct io_ring_ctx
*ctx
)
575 struct io_ev_fd
*ev_fd
= NULL
;
579 * rcu_dereference ctx->io_ev_fd once and use it for both for checking
582 ev_fd
= rcu_dereference(ctx
->io_ev_fd
);
585 * Check again if ev_fd exists incase an io_eventfd_unregister call
586 * completed between the NULL check of ctx->io_ev_fd at the start of
587 * the function and rcu_read_lock.
589 if (unlikely(!ev_fd
))
591 if (READ_ONCE(ctx
->rings
->cq_flags
) & IORING_CQ_EVENTFD_DISABLED
)
593 if (ev_fd
->eventfd_async
&& !io_wq_current_is_worker())
596 if (likely(eventfd_signal_allowed())) {
597 eventfd_signal_mask(ev_fd
->cq_ev_fd
, 1, EPOLL_URING_WAKE
);
599 atomic_inc(&ev_fd
->refs
);
600 if (!atomic_fetch_or(BIT(IO_EVENTFD_OP_SIGNAL_BIT
), &ev_fd
->ops
))
601 call_rcu_hurry(&ev_fd
->rcu
, io_eventfd_ops
);
603 atomic_dec(&ev_fd
->refs
);
610 static void io_eventfd_flush_signal(struct io_ring_ctx
*ctx
)
614 spin_lock(&ctx
->completion_lock
);
617 * Eventfd should only get triggered when at least one event has been
618 * posted. Some applications rely on the eventfd notification count
619 * only changing IFF a new CQE has been added to the CQ ring. There's
620 * no depedency on 1:1 relationship between how many times this
621 * function is called (and hence the eventfd count) and number of CQEs
622 * posted to the CQ ring.
624 skip
= ctx
->cached_cq_tail
== ctx
->evfd_last_cq_tail
;
625 ctx
->evfd_last_cq_tail
= ctx
->cached_cq_tail
;
626 spin_unlock(&ctx
->completion_lock
);
630 io_eventfd_signal(ctx
);
633 void __io_commit_cqring_flush(struct io_ring_ctx
*ctx
)
635 if (ctx
->poll_activated
)
636 io_poll_wq_wake(ctx
);
637 if (ctx
->off_timeout_used
)
638 io_flush_timeouts(ctx
);
639 if (ctx
->drain_active
) {
640 spin_lock(&ctx
->completion_lock
);
641 io_queue_deferred(ctx
);
642 spin_unlock(&ctx
->completion_lock
);
645 io_eventfd_flush_signal(ctx
);
648 static inline void __io_cq_lock(struct io_ring_ctx
*ctx
)
650 if (!ctx
->lockless_cq
)
651 spin_lock(&ctx
->completion_lock
);
654 static inline void io_cq_lock(struct io_ring_ctx
*ctx
)
655 __acquires(ctx
->completion_lock
)
657 spin_lock(&ctx
->completion_lock
);
660 static inline void __io_cq_unlock_post(struct io_ring_ctx
*ctx
)
662 io_commit_cqring(ctx
);
663 if (!ctx
->task_complete
) {
664 if (!ctx
->lockless_cq
)
665 spin_unlock(&ctx
->completion_lock
);
666 /* IOPOLL rings only need to wake up if it's also SQPOLL */
667 if (!ctx
->syscall_iopoll
)
670 io_commit_cqring_flush(ctx
);
673 static void io_cq_unlock_post(struct io_ring_ctx
*ctx
)
674 __releases(ctx
->completion_lock
)
676 io_commit_cqring(ctx
);
677 spin_unlock(&ctx
->completion_lock
);
679 io_commit_cqring_flush(ctx
);
682 /* Returns true if there are no backlogged entries after the flush */
683 static void io_cqring_overflow_kill(struct io_ring_ctx
*ctx
)
685 struct io_overflow_cqe
*ocqe
;
688 spin_lock(&ctx
->completion_lock
);
689 list_splice_init(&ctx
->cq_overflow_list
, &list
);
690 clear_bit(IO_CHECK_CQ_OVERFLOW_BIT
, &ctx
->check_cq
);
691 spin_unlock(&ctx
->completion_lock
);
693 while (!list_empty(&list
)) {
694 ocqe
= list_first_entry(&list
, struct io_overflow_cqe
, list
);
695 list_del(&ocqe
->list
);
700 static void __io_cqring_overflow_flush(struct io_ring_ctx
*ctx
)
702 size_t cqe_size
= sizeof(struct io_uring_cqe
);
704 if (__io_cqring_events(ctx
) == ctx
->cq_entries
)
707 if (ctx
->flags
& IORING_SETUP_CQE32
)
711 while (!list_empty(&ctx
->cq_overflow_list
)) {
712 struct io_uring_cqe
*cqe
;
713 struct io_overflow_cqe
*ocqe
;
715 if (!io_get_cqe_overflow(ctx
, &cqe
, true))
717 ocqe
= list_first_entry(&ctx
->cq_overflow_list
,
718 struct io_overflow_cqe
, list
);
719 memcpy(cqe
, &ocqe
->cqe
, cqe_size
);
720 list_del(&ocqe
->list
);
724 if (list_empty(&ctx
->cq_overflow_list
)) {
725 clear_bit(IO_CHECK_CQ_OVERFLOW_BIT
, &ctx
->check_cq
);
726 atomic_andnot(IORING_SQ_CQ_OVERFLOW
, &ctx
->rings
->sq_flags
);
728 io_cq_unlock_post(ctx
);
731 static void io_cqring_do_overflow_flush(struct io_ring_ctx
*ctx
)
733 /* iopoll syncs against uring_lock, not completion_lock */
734 if (ctx
->flags
& IORING_SETUP_IOPOLL
)
735 mutex_lock(&ctx
->uring_lock
);
736 __io_cqring_overflow_flush(ctx
);
737 if (ctx
->flags
& IORING_SETUP_IOPOLL
)
738 mutex_unlock(&ctx
->uring_lock
);
741 static void io_cqring_overflow_flush(struct io_ring_ctx
*ctx
)
743 if (test_bit(IO_CHECK_CQ_OVERFLOW_BIT
, &ctx
->check_cq
))
744 io_cqring_do_overflow_flush(ctx
);
747 /* can be called by any task */
748 static void io_put_task_remote(struct task_struct
*task
)
750 struct io_uring_task
*tctx
= task
->io_uring
;
752 percpu_counter_sub(&tctx
->inflight
, 1);
753 if (unlikely(atomic_read(&tctx
->in_cancel
)))
754 wake_up(&tctx
->wait
);
755 put_task_struct(task
);
758 /* used by a task to put its own references */
759 static void io_put_task_local(struct task_struct
*task
)
761 task
->io_uring
->cached_refs
++;
764 /* must to be called somewhat shortly after putting a request */
765 static inline void io_put_task(struct task_struct
*task
)
767 if (likely(task
== current
))
768 io_put_task_local(task
);
770 io_put_task_remote(task
);
773 void io_task_refs_refill(struct io_uring_task
*tctx
)
775 unsigned int refill
= -tctx
->cached_refs
+ IO_TCTX_REFS_CACHE_NR
;
777 percpu_counter_add(&tctx
->inflight
, refill
);
778 refcount_add(refill
, ¤t
->usage
);
779 tctx
->cached_refs
+= refill
;
782 static __cold
void io_uring_drop_tctx_refs(struct task_struct
*task
)
784 struct io_uring_task
*tctx
= task
->io_uring
;
785 unsigned int refs
= tctx
->cached_refs
;
788 tctx
->cached_refs
= 0;
789 percpu_counter_sub(&tctx
->inflight
, refs
);
790 put_task_struct_many(task
, refs
);
794 static bool io_cqring_event_overflow(struct io_ring_ctx
*ctx
, u64 user_data
,
795 s32 res
, u32 cflags
, u64 extra1
, u64 extra2
)
797 struct io_overflow_cqe
*ocqe
;
798 size_t ocq_size
= sizeof(struct io_overflow_cqe
);
799 bool is_cqe32
= (ctx
->flags
& IORING_SETUP_CQE32
);
801 lockdep_assert_held(&ctx
->completion_lock
);
804 ocq_size
+= sizeof(struct io_uring_cqe
);
806 ocqe
= kmalloc(ocq_size
, GFP_ATOMIC
| __GFP_ACCOUNT
);
807 trace_io_uring_cqe_overflow(ctx
, user_data
, res
, cflags
, ocqe
);
810 * If we're in ring overflow flush mode, or in task cancel mode,
811 * or cannot allocate an overflow entry, then we need to drop it
814 io_account_cq_overflow(ctx
);
815 set_bit(IO_CHECK_CQ_DROPPED_BIT
, &ctx
->check_cq
);
818 if (list_empty(&ctx
->cq_overflow_list
)) {
819 set_bit(IO_CHECK_CQ_OVERFLOW_BIT
, &ctx
->check_cq
);
820 atomic_or(IORING_SQ_CQ_OVERFLOW
, &ctx
->rings
->sq_flags
);
823 ocqe
->cqe
.user_data
= user_data
;
825 ocqe
->cqe
.flags
= cflags
;
827 ocqe
->cqe
.big_cqe
[0] = extra1
;
828 ocqe
->cqe
.big_cqe
[1] = extra2
;
830 list_add_tail(&ocqe
->list
, &ctx
->cq_overflow_list
);
834 void io_req_cqe_overflow(struct io_kiocb
*req
)
836 io_cqring_event_overflow(req
->ctx
, req
->cqe
.user_data
,
837 req
->cqe
.res
, req
->cqe
.flags
,
838 req
->big_cqe
.extra1
, req
->big_cqe
.extra2
);
839 memset(&req
->big_cqe
, 0, sizeof(req
->big_cqe
));
843 * writes to the cq entry need to come after reading head; the
844 * control dependency is enough as we're using WRITE_ONCE to
847 bool io_cqe_cache_refill(struct io_ring_ctx
*ctx
, bool overflow
)
849 struct io_rings
*rings
= ctx
->rings
;
850 unsigned int off
= ctx
->cached_cq_tail
& (ctx
->cq_entries
- 1);
851 unsigned int free
, queued
, len
;
854 * Posting into the CQ when there are pending overflowed CQEs may break
855 * ordering guarantees, which will affect links, F_MORE users and more.
856 * Force overflow the completion.
858 if (!overflow
&& (ctx
->check_cq
& BIT(IO_CHECK_CQ_OVERFLOW_BIT
)))
861 /* userspace may cheat modifying the tail, be safe and do min */
862 queued
= min(__io_cqring_events(ctx
), ctx
->cq_entries
);
863 free
= ctx
->cq_entries
- queued
;
864 /* we need a contiguous range, limit based on the current array offset */
865 len
= min(free
, ctx
->cq_entries
- off
);
869 if (ctx
->flags
& IORING_SETUP_CQE32
) {
874 ctx
->cqe_cached
= &rings
->cqes
[off
];
875 ctx
->cqe_sentinel
= ctx
->cqe_cached
+ len
;
879 static bool io_fill_cqe_aux(struct io_ring_ctx
*ctx
, u64 user_data
, s32 res
,
882 struct io_uring_cqe
*cqe
;
887 * If we can't get a cq entry, userspace overflowed the
888 * submission (by quite a lot). Increment the overflow count in
891 if (likely(io_get_cqe(ctx
, &cqe
))) {
892 trace_io_uring_complete(ctx
, NULL
, user_data
, res
, cflags
, 0, 0);
894 WRITE_ONCE(cqe
->user_data
, user_data
);
895 WRITE_ONCE(cqe
->res
, res
);
896 WRITE_ONCE(cqe
->flags
, cflags
);
898 if (ctx
->flags
& IORING_SETUP_CQE32
) {
899 WRITE_ONCE(cqe
->big_cqe
[0], 0);
900 WRITE_ONCE(cqe
->big_cqe
[1], 0);
907 static void __io_flush_post_cqes(struct io_ring_ctx
*ctx
)
908 __must_hold(&ctx
->uring_lock
)
910 struct io_submit_state
*state
= &ctx
->submit_state
;
913 lockdep_assert_held(&ctx
->uring_lock
);
914 for (i
= 0; i
< state
->cqes_count
; i
++) {
915 struct io_uring_cqe
*cqe
= &ctx
->completion_cqes
[i
];
917 if (!io_fill_cqe_aux(ctx
, cqe
->user_data
, cqe
->res
, cqe
->flags
)) {
918 if (ctx
->lockless_cq
) {
919 spin_lock(&ctx
->completion_lock
);
920 io_cqring_event_overflow(ctx
, cqe
->user_data
,
921 cqe
->res
, cqe
->flags
, 0, 0);
922 spin_unlock(&ctx
->completion_lock
);
924 io_cqring_event_overflow(ctx
, cqe
->user_data
,
925 cqe
->res
, cqe
->flags
, 0, 0);
929 state
->cqes_count
= 0;
932 static bool __io_post_aux_cqe(struct io_ring_ctx
*ctx
, u64 user_data
, s32 res
, u32 cflags
,
938 filled
= io_fill_cqe_aux(ctx
, user_data
, res
, cflags
);
939 if (!filled
&& allow_overflow
)
940 filled
= io_cqring_event_overflow(ctx
, user_data
, res
, cflags
, 0, 0);
942 io_cq_unlock_post(ctx
);
946 bool io_post_aux_cqe(struct io_ring_ctx
*ctx
, u64 user_data
, s32 res
, u32 cflags
)
948 return __io_post_aux_cqe(ctx
, user_data
, res
, cflags
, true);
952 * A helper for multishot requests posting additional CQEs.
953 * Should only be used from a task_work including IO_URING_F_MULTISHOT.
955 bool io_fill_cqe_req_aux(struct io_kiocb
*req
, bool defer
, s32 res
, u32 cflags
)
957 struct io_ring_ctx
*ctx
= req
->ctx
;
958 u64 user_data
= req
->cqe
.user_data
;
959 struct io_uring_cqe
*cqe
;
962 return __io_post_aux_cqe(ctx
, user_data
, res
, cflags
, false);
964 lockdep_assert_held(&ctx
->uring_lock
);
966 if (ctx
->submit_state
.cqes_count
== ARRAY_SIZE(ctx
->completion_cqes
)) {
968 __io_flush_post_cqes(ctx
);
969 /* no need to flush - flush is deferred */
970 __io_cq_unlock_post(ctx
);
973 /* For defered completions this is not as strict as it is otherwise,
974 * however it's main job is to prevent unbounded posted completions,
975 * and in that it works just as well.
977 if (test_bit(IO_CHECK_CQ_OVERFLOW_BIT
, &ctx
->check_cq
))
980 cqe
= &ctx
->completion_cqes
[ctx
->submit_state
.cqes_count
++];
981 cqe
->user_data
= user_data
;
987 static void __io_req_complete_post(struct io_kiocb
*req
, unsigned issue_flags
)
989 struct io_ring_ctx
*ctx
= req
->ctx
;
990 struct io_rsrc_node
*rsrc_node
= NULL
;
993 if (!(req
->flags
& REQ_F_CQE_SKIP
)) {
994 if (!io_fill_cqe_req(ctx
, req
))
995 io_req_cqe_overflow(req
);
999 * If we're the last reference to this request, add to our locked
1002 if (req_ref_put_and_test(req
)) {
1003 if (req
->flags
& IO_REQ_LINK_FLAGS
) {
1004 if (req
->flags
& IO_DISARM_MASK
)
1005 io_disarm_next(req
);
1007 io_req_task_queue(req
->link
);
1011 io_put_kbuf_comp(req
);
1012 if (unlikely(req
->flags
& IO_REQ_CLEAN_FLAGS
))
1016 rsrc_node
= req
->rsrc_node
;
1018 * Selected buffer deallocation in io_clean_op() assumes that
1019 * we don't hold ->completion_lock. Clean them here to avoid
1022 io_put_task_remote(req
->task
);
1023 wq_list_add_head(&req
->comp_list
, &ctx
->locked_free_list
);
1024 ctx
->locked_free_nr
++;
1026 io_cq_unlock_post(ctx
);
1029 io_ring_submit_lock(ctx
, issue_flags
);
1030 io_put_rsrc_node(ctx
, rsrc_node
);
1031 io_ring_submit_unlock(ctx
, issue_flags
);
1035 void io_req_complete_post(struct io_kiocb
*req
, unsigned issue_flags
)
1037 if (req
->ctx
->task_complete
&& req
->ctx
->submitter_task
!= current
) {
1038 req
->io_task_work
.func
= io_req_task_complete
;
1039 io_req_task_work_add(req
);
1040 } else if (!(issue_flags
& IO_URING_F_UNLOCKED
) ||
1041 !(req
->ctx
->flags
& IORING_SETUP_IOPOLL
)) {
1042 __io_req_complete_post(req
, issue_flags
);
1044 struct io_ring_ctx
*ctx
= req
->ctx
;
1046 mutex_lock(&ctx
->uring_lock
);
1047 __io_req_complete_post(req
, issue_flags
& ~IO_URING_F_UNLOCKED
);
1048 mutex_unlock(&ctx
->uring_lock
);
1052 void io_req_defer_failed(struct io_kiocb
*req
, s32 res
)
1053 __must_hold(&ctx
->uring_lock
)
1055 const struct io_cold_def
*def
= &io_cold_defs
[req
->opcode
];
1057 lockdep_assert_held(&req
->ctx
->uring_lock
);
1060 io_req_set_res(req
, res
, io_put_kbuf(req
, IO_URING_F_UNLOCKED
));
1063 io_req_complete_defer(req
);
1067 * Don't initialise the fields below on every allocation, but do that in
1068 * advance and keep them valid across allocations.
1070 static void io_preinit_req(struct io_kiocb
*req
, struct io_ring_ctx
*ctx
)
1074 req
->async_data
= NULL
;
1075 /* not necessary, but safer to zero */
1076 memset(&req
->cqe
, 0, sizeof(req
->cqe
));
1077 memset(&req
->big_cqe
, 0, sizeof(req
->big_cqe
));
1080 static void io_flush_cached_locked_reqs(struct io_ring_ctx
*ctx
,
1081 struct io_submit_state
*state
)
1083 spin_lock(&ctx
->completion_lock
);
1084 wq_list_splice(&ctx
->locked_free_list
, &state
->free_list
);
1085 ctx
->locked_free_nr
= 0;
1086 spin_unlock(&ctx
->completion_lock
);
1090 * A request might get retired back into the request caches even before opcode
1091 * handlers and io_issue_sqe() are done with it, e.g. inline completion path.
1092 * Because of that, io_alloc_req() should be called only under ->uring_lock
1093 * and with extra caution to not get a request that is still worked on.
1095 __cold
bool __io_alloc_req_refill(struct io_ring_ctx
*ctx
)
1096 __must_hold(&ctx
->uring_lock
)
1098 gfp_t gfp
= GFP_KERNEL
| __GFP_NOWARN
;
1099 void *reqs
[IO_REQ_ALLOC_BATCH
];
1103 * If we have more than a batch's worth of requests in our IRQ side
1104 * locked cache, grab the lock and move them over to our submission
1107 if (data_race(ctx
->locked_free_nr
) > IO_COMPL_BATCH
) {
1108 io_flush_cached_locked_reqs(ctx
, &ctx
->submit_state
);
1109 if (!io_req_cache_empty(ctx
))
1113 ret
= kmem_cache_alloc_bulk(req_cachep
, gfp
, ARRAY_SIZE(reqs
), reqs
);
1116 * Bulk alloc is all-or-nothing. If we fail to get a batch,
1117 * retry single alloc to be on the safe side.
1119 if (unlikely(ret
<= 0)) {
1120 reqs
[0] = kmem_cache_alloc(req_cachep
, gfp
);
1126 percpu_ref_get_many(&ctx
->refs
, ret
);
1127 for (i
= 0; i
< ret
; i
++) {
1128 struct io_kiocb
*req
= reqs
[i
];
1130 io_preinit_req(req
, ctx
);
1131 io_req_add_to_cache(req
, ctx
);
1136 __cold
void io_free_req(struct io_kiocb
*req
)
1138 /* refs were already put, restore them for io_req_task_complete() */
1139 req
->flags
&= ~REQ_F_REFCOUNT
;
1140 /* we only want to free it, don't post CQEs */
1141 req
->flags
|= REQ_F_CQE_SKIP
;
1142 req
->io_task_work
.func
= io_req_task_complete
;
1143 io_req_task_work_add(req
);
1146 static void __io_req_find_next_prep(struct io_kiocb
*req
)
1148 struct io_ring_ctx
*ctx
= req
->ctx
;
1150 spin_lock(&ctx
->completion_lock
);
1151 io_disarm_next(req
);
1152 spin_unlock(&ctx
->completion_lock
);
1155 static inline struct io_kiocb
*io_req_find_next(struct io_kiocb
*req
)
1157 struct io_kiocb
*nxt
;
1160 * If LINK is set, we have dependent requests in this chain. If we
1161 * didn't fail this request, queue the first one up, moving any other
1162 * dependencies to the next request. In case of failure, fail the rest
1165 if (unlikely(req
->flags
& IO_DISARM_MASK
))
1166 __io_req_find_next_prep(req
);
1172 static void ctx_flush_and_put(struct io_ring_ctx
*ctx
, struct io_tw_state
*ts
)
1176 if (ctx
->flags
& IORING_SETUP_TASKRUN_FLAG
)
1177 atomic_andnot(IORING_SQ_TASKRUN
, &ctx
->rings
->sq_flags
);
1179 io_submit_flush_completions(ctx
);
1180 mutex_unlock(&ctx
->uring_lock
);
1183 percpu_ref_put(&ctx
->refs
);
1186 static unsigned int handle_tw_list(struct llist_node
*node
,
1187 struct io_ring_ctx
**ctx
,
1188 struct io_tw_state
*ts
,
1189 struct llist_node
*last
)
1191 unsigned int count
= 0;
1193 while (node
&& node
!= last
) {
1194 struct llist_node
*next
= node
->next
;
1195 struct io_kiocb
*req
= container_of(node
, struct io_kiocb
,
1198 prefetch(container_of(next
, struct io_kiocb
, io_task_work
.node
));
1200 if (req
->ctx
!= *ctx
) {
1201 ctx_flush_and_put(*ctx
, ts
);
1203 /* if not contended, grab and improve batching */
1204 ts
->locked
= mutex_trylock(&(*ctx
)->uring_lock
);
1205 percpu_ref_get(&(*ctx
)->refs
);
1207 INDIRECT_CALL_2(req
->io_task_work
.func
,
1208 io_poll_task_func
, io_req_rw_complete
,
1212 if (unlikely(need_resched())) {
1213 ctx_flush_and_put(*ctx
, ts
);
1223 * io_llist_xchg - swap all entries in a lock-less list
1224 * @head: the head of lock-less list to delete all entries
1225 * @new: new entry as the head of the list
1227 * If list is empty, return NULL, otherwise, return the pointer to the first entry.
1228 * The order of entries returned is from the newest to the oldest added one.
1230 static inline struct llist_node
*io_llist_xchg(struct llist_head
*head
,
1231 struct llist_node
*new)
1233 return xchg(&head
->first
, new);
1237 * io_llist_cmpxchg - possibly swap all entries in a lock-less list
1238 * @head: the head of lock-less list to delete all entries
1239 * @old: expected old value of the first entry of the list
1240 * @new: new entry as the head of the list
1242 * perform a cmpxchg on the first entry of the list.
1245 static inline struct llist_node
*io_llist_cmpxchg(struct llist_head
*head
,
1246 struct llist_node
*old
,
1247 struct llist_node
*new)
1249 return cmpxchg(&head
->first
, old
, new);
1252 static __cold
void io_fallback_tw(struct io_uring_task
*tctx
, bool sync
)
1254 struct llist_node
*node
= llist_del_all(&tctx
->task_list
);
1255 struct io_ring_ctx
*last_ctx
= NULL
;
1256 struct io_kiocb
*req
;
1259 req
= container_of(node
, struct io_kiocb
, io_task_work
.node
);
1261 if (sync
&& last_ctx
!= req
->ctx
) {
1263 flush_delayed_work(&last_ctx
->fallback_work
);
1264 percpu_ref_put(&last_ctx
->refs
);
1266 last_ctx
= req
->ctx
;
1267 percpu_ref_get(&last_ctx
->refs
);
1269 if (llist_add(&req
->io_task_work
.node
,
1270 &req
->ctx
->fallback_llist
))
1271 schedule_delayed_work(&req
->ctx
->fallback_work
, 1);
1275 flush_delayed_work(&last_ctx
->fallback_work
);
1276 percpu_ref_put(&last_ctx
->refs
);
1280 void tctx_task_work(struct callback_head
*cb
)
1282 struct io_tw_state ts
= {};
1283 struct io_ring_ctx
*ctx
= NULL
;
1284 struct io_uring_task
*tctx
= container_of(cb
, struct io_uring_task
,
1286 struct llist_node fake
= {};
1287 struct llist_node
*node
;
1288 unsigned int loops
= 0;
1289 unsigned int count
= 0;
1291 if (unlikely(current
->flags
& PF_EXITING
)) {
1292 io_fallback_tw(tctx
, true);
1298 node
= io_llist_xchg(&tctx
->task_list
, &fake
);
1299 count
+= handle_tw_list(node
, &ctx
, &ts
, &fake
);
1301 /* skip expensive cmpxchg if there are items in the list */
1302 if (READ_ONCE(tctx
->task_list
.first
) != &fake
)
1304 if (ts
.locked
&& !wq_list_empty(&ctx
->submit_state
.compl_reqs
)) {
1305 io_submit_flush_completions(ctx
);
1306 if (READ_ONCE(tctx
->task_list
.first
) != &fake
)
1309 node
= io_llist_cmpxchg(&tctx
->task_list
, &fake
, NULL
);
1310 } while (node
!= &fake
);
1312 ctx_flush_and_put(ctx
, &ts
);
1314 /* relaxed read is enough as only the task itself sets ->in_cancel */
1315 if (unlikely(atomic_read(&tctx
->in_cancel
)))
1316 io_uring_drop_tctx_refs(current
);
1318 trace_io_uring_task_work_run(tctx
, count
, loops
);
1321 static inline void io_req_local_work_add(struct io_kiocb
*req
, unsigned flags
)
1323 struct io_ring_ctx
*ctx
= req
->ctx
;
1324 unsigned nr_wait
, nr_tw
, nr_tw_prev
;
1325 struct llist_node
*first
;
1327 if (req
->flags
& (REQ_F_LINK
| REQ_F_HARDLINK
))
1328 flags
&= ~IOU_F_TWQ_LAZY_WAKE
;
1330 first
= READ_ONCE(ctx
->work_llist
.first
);
1334 struct io_kiocb
*first_req
= container_of(first
,
1338 * Might be executed at any moment, rely on
1339 * SLAB_TYPESAFE_BY_RCU to keep it alive.
1341 nr_tw_prev
= READ_ONCE(first_req
->nr_tw
);
1343 nr_tw
= nr_tw_prev
+ 1;
1344 /* Large enough to fail the nr_wait comparison below */
1345 if (!(flags
& IOU_F_TWQ_LAZY_WAKE
))
1349 req
->io_task_work
.node
.next
= first
;
1350 } while (!try_cmpxchg(&ctx
->work_llist
.first
, &first
,
1351 &req
->io_task_work
.node
));
1354 if (ctx
->flags
& IORING_SETUP_TASKRUN_FLAG
)
1355 atomic_or(IORING_SQ_TASKRUN
, &ctx
->rings
->sq_flags
);
1357 io_eventfd_signal(ctx
);
1360 nr_wait
= atomic_read(&ctx
->cq_wait_nr
);
1361 /* no one is waiting */
1364 /* either not enough or the previous add has already woken it up */
1365 if (nr_wait
> nr_tw
|| nr_tw_prev
>= nr_wait
)
1367 /* pairs with set_current_state() in io_cqring_wait() */
1368 smp_mb__after_atomic();
1369 wake_up_state(ctx
->submitter_task
, TASK_INTERRUPTIBLE
);
1372 static void io_req_normal_work_add(struct io_kiocb
*req
)
1374 struct io_uring_task
*tctx
= req
->task
->io_uring
;
1375 struct io_ring_ctx
*ctx
= req
->ctx
;
1377 /* task_work already pending, we're done */
1378 if (!llist_add(&req
->io_task_work
.node
, &tctx
->task_list
))
1381 if (ctx
->flags
& IORING_SETUP_TASKRUN_FLAG
)
1382 atomic_or(IORING_SQ_TASKRUN
, &ctx
->rings
->sq_flags
);
1384 if (likely(!task_work_add(req
->task
, &tctx
->task_work
, ctx
->notify_method
)))
1387 io_fallback_tw(tctx
, false);
1390 void __io_req_task_work_add(struct io_kiocb
*req
, unsigned flags
)
1392 if (req
->ctx
->flags
& IORING_SETUP_DEFER_TASKRUN
) {
1394 io_req_local_work_add(req
, flags
);
1397 io_req_normal_work_add(req
);
1401 static void __cold
io_move_task_work_from_local(struct io_ring_ctx
*ctx
)
1403 struct llist_node
*node
;
1405 node
= llist_del_all(&ctx
->work_llist
);
1407 struct io_kiocb
*req
= container_of(node
, struct io_kiocb
,
1411 io_req_normal_work_add(req
);
1415 static int __io_run_local_work(struct io_ring_ctx
*ctx
, struct io_tw_state
*ts
)
1417 struct llist_node
*node
;
1418 unsigned int loops
= 0;
1421 if (WARN_ON_ONCE(ctx
->submitter_task
!= current
))
1423 if (ctx
->flags
& IORING_SETUP_TASKRUN_FLAG
)
1424 atomic_andnot(IORING_SQ_TASKRUN
, &ctx
->rings
->sq_flags
);
1427 * llists are in reverse order, flip it back the right way before
1428 * running the pending items.
1430 node
= llist_reverse_order(io_llist_xchg(&ctx
->work_llist
, NULL
));
1432 struct llist_node
*next
= node
->next
;
1433 struct io_kiocb
*req
= container_of(node
, struct io_kiocb
,
1435 prefetch(container_of(next
, struct io_kiocb
, io_task_work
.node
));
1436 INDIRECT_CALL_2(req
->io_task_work
.func
,
1437 io_poll_task_func
, io_req_rw_complete
,
1444 if (!llist_empty(&ctx
->work_llist
))
1447 io_submit_flush_completions(ctx
);
1448 if (!llist_empty(&ctx
->work_llist
))
1451 trace_io_uring_local_work_run(ctx
, ret
, loops
);
1455 static inline int io_run_local_work_locked(struct io_ring_ctx
*ctx
)
1457 struct io_tw_state ts
= { .locked
= true, };
1460 if (llist_empty(&ctx
->work_llist
))
1463 ret
= __io_run_local_work(ctx
, &ts
);
1464 /* shouldn't happen! */
1465 if (WARN_ON_ONCE(!ts
.locked
))
1466 mutex_lock(&ctx
->uring_lock
);
1470 static int io_run_local_work(struct io_ring_ctx
*ctx
)
1472 struct io_tw_state ts
= {};
1475 ts
.locked
= mutex_trylock(&ctx
->uring_lock
);
1476 ret
= __io_run_local_work(ctx
, &ts
);
1478 mutex_unlock(&ctx
->uring_lock
);
1483 static void io_req_task_cancel(struct io_kiocb
*req
, struct io_tw_state
*ts
)
1485 io_tw_lock(req
->ctx
, ts
);
1486 io_req_defer_failed(req
, req
->cqe
.res
);
1489 void io_req_task_submit(struct io_kiocb
*req
, struct io_tw_state
*ts
)
1491 io_tw_lock(req
->ctx
, ts
);
1492 /* req->task == current here, checking PF_EXITING is safe */
1493 if (unlikely(req
->task
->flags
& PF_EXITING
))
1494 io_req_defer_failed(req
, -EFAULT
);
1495 else if (req
->flags
& REQ_F_FORCE_ASYNC
)
1496 io_queue_iowq(req
, ts
);
1501 void io_req_task_queue_fail(struct io_kiocb
*req
, int ret
)
1503 io_req_set_res(req
, ret
, 0);
1504 req
->io_task_work
.func
= io_req_task_cancel
;
1505 io_req_task_work_add(req
);
1508 void io_req_task_queue(struct io_kiocb
*req
)
1510 req
->io_task_work
.func
= io_req_task_submit
;
1511 io_req_task_work_add(req
);
1514 void io_queue_next(struct io_kiocb
*req
)
1516 struct io_kiocb
*nxt
= io_req_find_next(req
);
1519 io_req_task_queue(nxt
);
1522 static void io_free_batch_list(struct io_ring_ctx
*ctx
,
1523 struct io_wq_work_node
*node
)
1524 __must_hold(&ctx
->uring_lock
)
1527 struct io_kiocb
*req
= container_of(node
, struct io_kiocb
,
1530 if (unlikely(req
->flags
& IO_REQ_CLEAN_SLOW_FLAGS
)) {
1531 if (req
->flags
& REQ_F_REFCOUNT
) {
1532 node
= req
->comp_list
.next
;
1533 if (!req_ref_put_and_test(req
))
1536 if ((req
->flags
& REQ_F_POLLED
) && req
->apoll
) {
1537 struct async_poll
*apoll
= req
->apoll
;
1539 if (apoll
->double_poll
)
1540 kfree(apoll
->double_poll
);
1541 if (!io_alloc_cache_put(&ctx
->apoll_cache
, &apoll
->cache
))
1543 req
->flags
&= ~REQ_F_POLLED
;
1545 if (req
->flags
& IO_REQ_LINK_FLAGS
)
1547 if (unlikely(req
->flags
& IO_REQ_CLEAN_FLAGS
))
1552 io_req_put_rsrc_locked(req
, ctx
);
1554 io_put_task(req
->task
);
1555 node
= req
->comp_list
.next
;
1556 io_req_add_to_cache(req
, ctx
);
1560 void __io_submit_flush_completions(struct io_ring_ctx
*ctx
)
1561 __must_hold(&ctx
->uring_lock
)
1563 struct io_submit_state
*state
= &ctx
->submit_state
;
1564 struct io_wq_work_node
*node
;
1567 /* must come first to preserve CQE ordering in failure cases */
1568 if (state
->cqes_count
)
1569 __io_flush_post_cqes(ctx
);
1570 __wq_list_for_each(node
, &state
->compl_reqs
) {
1571 struct io_kiocb
*req
= container_of(node
, struct io_kiocb
,
1574 if (!(req
->flags
& REQ_F_CQE_SKIP
) &&
1575 unlikely(!io_fill_cqe_req(ctx
, req
))) {
1576 if (ctx
->lockless_cq
) {
1577 spin_lock(&ctx
->completion_lock
);
1578 io_req_cqe_overflow(req
);
1579 spin_unlock(&ctx
->completion_lock
);
1581 io_req_cqe_overflow(req
);
1585 __io_cq_unlock_post(ctx
);
1587 if (!wq_list_empty(&ctx
->submit_state
.compl_reqs
)) {
1588 io_free_batch_list(ctx
, state
->compl_reqs
.first
);
1589 INIT_WQ_LIST(&state
->compl_reqs
);
1593 static unsigned io_cqring_events(struct io_ring_ctx
*ctx
)
1595 /* See comment at the top of this file */
1597 return __io_cqring_events(ctx
);
1601 * We can't just wait for polled events to come to us, we have to actively
1602 * find and complete them.
1604 static __cold
void io_iopoll_try_reap_events(struct io_ring_ctx
*ctx
)
1606 if (!(ctx
->flags
& IORING_SETUP_IOPOLL
))
1609 mutex_lock(&ctx
->uring_lock
);
1610 while (!wq_list_empty(&ctx
->iopoll_list
)) {
1611 /* let it sleep and repeat later if can't complete a request */
1612 if (io_do_iopoll(ctx
, true) == 0)
1615 * Ensure we allow local-to-the-cpu processing to take place,
1616 * in this case we need to ensure that we reap all events.
1617 * Also let task_work, etc. to progress by releasing the mutex
1619 if (need_resched()) {
1620 mutex_unlock(&ctx
->uring_lock
);
1622 mutex_lock(&ctx
->uring_lock
);
1625 mutex_unlock(&ctx
->uring_lock
);
1628 static int io_iopoll_check(struct io_ring_ctx
*ctx
, long min
)
1630 unsigned int nr_events
= 0;
1631 unsigned long check_cq
;
1633 if (!io_allowed_run_tw(ctx
))
1636 check_cq
= READ_ONCE(ctx
->check_cq
);
1637 if (unlikely(check_cq
)) {
1638 if (check_cq
& BIT(IO_CHECK_CQ_OVERFLOW_BIT
))
1639 __io_cqring_overflow_flush(ctx
);
1641 * Similarly do not spin if we have not informed the user of any
1644 if (check_cq
& BIT(IO_CHECK_CQ_DROPPED_BIT
))
1648 * Don't enter poll loop if we already have events pending.
1649 * If we do, we can potentially be spinning for commands that
1650 * already triggered a CQE (eg in error).
1652 if (io_cqring_events(ctx
))
1659 * If a submit got punted to a workqueue, we can have the
1660 * application entering polling for a command before it gets
1661 * issued. That app will hold the uring_lock for the duration
1662 * of the poll right here, so we need to take a breather every
1663 * now and then to ensure that the issue has a chance to add
1664 * the poll to the issued list. Otherwise we can spin here
1665 * forever, while the workqueue is stuck trying to acquire the
1668 if (wq_list_empty(&ctx
->iopoll_list
) ||
1669 io_task_work_pending(ctx
)) {
1670 u32 tail
= ctx
->cached_cq_tail
;
1672 (void) io_run_local_work_locked(ctx
);
1674 if (task_work_pending(current
) ||
1675 wq_list_empty(&ctx
->iopoll_list
)) {
1676 mutex_unlock(&ctx
->uring_lock
);
1678 mutex_lock(&ctx
->uring_lock
);
1680 /* some requests don't go through iopoll_list */
1681 if (tail
!= ctx
->cached_cq_tail
||
1682 wq_list_empty(&ctx
->iopoll_list
))
1685 ret
= io_do_iopoll(ctx
, !min
);
1686 if (unlikely(ret
< 0))
1689 if (task_sigpending(current
))
1695 } while (nr_events
< min
);
1700 void io_req_task_complete(struct io_kiocb
*req
, struct io_tw_state
*ts
)
1703 io_req_complete_defer(req
);
1705 io_req_complete_post(req
, IO_URING_F_UNLOCKED
);
1709 * After the iocb has been issued, it's safe to be found on the poll list.
1710 * Adding the kiocb to the list AFTER submission ensures that we don't
1711 * find it from a io_do_iopoll() thread before the issuer is done
1712 * accessing the kiocb cookie.
1714 static void io_iopoll_req_issued(struct io_kiocb
*req
, unsigned int issue_flags
)
1716 struct io_ring_ctx
*ctx
= req
->ctx
;
1717 const bool needs_lock
= issue_flags
& IO_URING_F_UNLOCKED
;
1719 /* workqueue context doesn't hold uring_lock, grab it now */
1720 if (unlikely(needs_lock
))
1721 mutex_lock(&ctx
->uring_lock
);
1724 * Track whether we have multiple files in our lists. This will impact
1725 * how we do polling eventually, not spinning if we're on potentially
1726 * different devices.
1728 if (wq_list_empty(&ctx
->iopoll_list
)) {
1729 ctx
->poll_multi_queue
= false;
1730 } else if (!ctx
->poll_multi_queue
) {
1731 struct io_kiocb
*list_req
;
1733 list_req
= container_of(ctx
->iopoll_list
.first
, struct io_kiocb
,
1735 if (list_req
->file
!= req
->file
)
1736 ctx
->poll_multi_queue
= true;
1740 * For fast devices, IO may have already completed. If it has, add
1741 * it to the front so we find it first.
1743 if (READ_ONCE(req
->iopoll_completed
))
1744 wq_list_add_head(&req
->comp_list
, &ctx
->iopoll_list
);
1746 wq_list_add_tail(&req
->comp_list
, &ctx
->iopoll_list
);
1748 if (unlikely(needs_lock
)) {
1750 * If IORING_SETUP_SQPOLL is enabled, sqes are either handle
1751 * in sq thread task context or in io worker task context. If
1752 * current task context is sq thread, we don't need to check
1753 * whether should wake up sq thread.
1755 if ((ctx
->flags
& IORING_SETUP_SQPOLL
) &&
1756 wq_has_sleeper(&ctx
->sq_data
->wait
))
1757 wake_up(&ctx
->sq_data
->wait
);
1759 mutex_unlock(&ctx
->uring_lock
);
1763 unsigned int io_file_get_flags(struct file
*file
)
1765 unsigned int res
= 0;
1767 if (S_ISREG(file_inode(file
)->i_mode
))
1769 if ((file
->f_flags
& O_NONBLOCK
) || (file
->f_mode
& FMODE_NOWAIT
))
1770 res
|= REQ_F_SUPPORT_NOWAIT
;
1774 bool io_alloc_async_data(struct io_kiocb
*req
)
1776 WARN_ON_ONCE(!io_cold_defs
[req
->opcode
].async_size
);
1777 req
->async_data
= kmalloc(io_cold_defs
[req
->opcode
].async_size
, GFP_KERNEL
);
1778 if (req
->async_data
) {
1779 req
->flags
|= REQ_F_ASYNC_DATA
;
1785 int io_req_prep_async(struct io_kiocb
*req
)
1787 const struct io_cold_def
*cdef
= &io_cold_defs
[req
->opcode
];
1788 const struct io_issue_def
*def
= &io_issue_defs
[req
->opcode
];
1790 /* assign early for deferred execution for non-fixed file */
1791 if (def
->needs_file
&& !(req
->flags
& REQ_F_FIXED_FILE
) && !req
->file
)
1792 req
->file
= io_file_get_normal(req
, req
->cqe
.fd
);
1793 if (!cdef
->prep_async
)
1795 if (WARN_ON_ONCE(req_has_async_data(req
)))
1797 if (!def
->manual_alloc
) {
1798 if (io_alloc_async_data(req
))
1801 return cdef
->prep_async(req
);
1804 static u32
io_get_sequence(struct io_kiocb
*req
)
1806 u32 seq
= req
->ctx
->cached_sq_head
;
1807 struct io_kiocb
*cur
;
1809 /* need original cached_sq_head, but it was increased for each req */
1810 io_for_each_link(cur
, req
)
1815 static __cold
void io_drain_req(struct io_kiocb
*req
)
1816 __must_hold(&ctx
->uring_lock
)
1818 struct io_ring_ctx
*ctx
= req
->ctx
;
1819 struct io_defer_entry
*de
;
1821 u32 seq
= io_get_sequence(req
);
1823 /* Still need defer if there is pending req in defer list. */
1824 spin_lock(&ctx
->completion_lock
);
1825 if (!req_need_defer(req
, seq
) && list_empty_careful(&ctx
->defer_list
)) {
1826 spin_unlock(&ctx
->completion_lock
);
1828 ctx
->drain_active
= false;
1829 io_req_task_queue(req
);
1832 spin_unlock(&ctx
->completion_lock
);
1834 io_prep_async_link(req
);
1835 de
= kmalloc(sizeof(*de
), GFP_KERNEL
);
1838 io_req_defer_failed(req
, ret
);
1842 spin_lock(&ctx
->completion_lock
);
1843 if (!req_need_defer(req
, seq
) && list_empty(&ctx
->defer_list
)) {
1844 spin_unlock(&ctx
->completion_lock
);
1849 trace_io_uring_defer(req
);
1852 list_add_tail(&de
->list
, &ctx
->defer_list
);
1853 spin_unlock(&ctx
->completion_lock
);
1856 static bool io_assign_file(struct io_kiocb
*req
, const struct io_issue_def
*def
,
1857 unsigned int issue_flags
)
1859 if (req
->file
|| !def
->needs_file
)
1862 if (req
->flags
& REQ_F_FIXED_FILE
)
1863 req
->file
= io_file_get_fixed(req
, req
->cqe
.fd
, issue_flags
);
1865 req
->file
= io_file_get_normal(req
, req
->cqe
.fd
);
1870 static int io_issue_sqe(struct io_kiocb
*req
, unsigned int issue_flags
)
1872 const struct io_issue_def
*def
= &io_issue_defs
[req
->opcode
];
1873 const struct cred
*creds
= NULL
;
1876 if (unlikely(!io_assign_file(req
, def
, issue_flags
)))
1879 if (unlikely((req
->flags
& REQ_F_CREDS
) && req
->creds
!= current_cred()))
1880 creds
= override_creds(req
->creds
);
1882 if (!def
->audit_skip
)
1883 audit_uring_entry(req
->opcode
);
1885 ret
= def
->issue(req
, issue_flags
);
1887 if (!def
->audit_skip
)
1888 audit_uring_exit(!ret
, ret
);
1891 revert_creds(creds
);
1893 if (ret
== IOU_OK
) {
1894 if (issue_flags
& IO_URING_F_COMPLETE_DEFER
)
1895 io_req_complete_defer(req
);
1897 io_req_complete_post(req
, issue_flags
);
1898 } else if (ret
!= IOU_ISSUE_SKIP_COMPLETE
)
1901 /* If the op doesn't have a file, we're not polling for it */
1902 if ((req
->ctx
->flags
& IORING_SETUP_IOPOLL
) && def
->iopoll_queue
)
1903 io_iopoll_req_issued(req
, issue_flags
);
1908 int io_poll_issue(struct io_kiocb
*req
, struct io_tw_state
*ts
)
1910 io_tw_lock(req
->ctx
, ts
);
1911 return io_issue_sqe(req
, IO_URING_F_NONBLOCK
|IO_URING_F_MULTISHOT
|
1912 IO_URING_F_COMPLETE_DEFER
);
1915 struct io_wq_work
*io_wq_free_work(struct io_wq_work
*work
)
1917 struct io_kiocb
*req
= container_of(work
, struct io_kiocb
, work
);
1918 struct io_kiocb
*nxt
= NULL
;
1920 if (req_ref_put_and_test(req
)) {
1921 if (req
->flags
& IO_REQ_LINK_FLAGS
)
1922 nxt
= io_req_find_next(req
);
1925 return nxt
? &nxt
->work
: NULL
;
1928 void io_wq_submit_work(struct io_wq_work
*work
)
1930 struct io_kiocb
*req
= container_of(work
, struct io_kiocb
, work
);
1931 const struct io_issue_def
*def
= &io_issue_defs
[req
->opcode
];
1932 unsigned int issue_flags
= IO_URING_F_UNLOCKED
| IO_URING_F_IOWQ
;
1933 bool needs_poll
= false;
1934 int ret
= 0, err
= -ECANCELED
;
1936 /* one will be dropped by ->io_wq_free_work() after returning to io-wq */
1937 if (!(req
->flags
& REQ_F_REFCOUNT
))
1938 __io_req_set_refcount(req
, 2);
1942 io_arm_ltimeout(req
);
1944 /* either cancelled or io-wq is dying, so don't touch tctx->iowq */
1945 if (work
->flags
& IO_WQ_WORK_CANCEL
) {
1947 io_req_task_queue_fail(req
, err
);
1950 if (!io_assign_file(req
, def
, issue_flags
)) {
1952 work
->flags
|= IO_WQ_WORK_CANCEL
;
1956 if (req
->flags
& REQ_F_FORCE_ASYNC
) {
1957 bool opcode_poll
= def
->pollin
|| def
->pollout
;
1959 if (opcode_poll
&& file_can_poll(req
->file
)) {
1961 issue_flags
|= IO_URING_F_NONBLOCK
;
1966 ret
= io_issue_sqe(req
, issue_flags
);
1971 * If REQ_F_NOWAIT is set, then don't wait or retry with
1972 * poll. -EAGAIN is final for that case.
1974 if (req
->flags
& REQ_F_NOWAIT
)
1978 * We can get EAGAIN for iopolled IO even though we're
1979 * forcing a sync submission from here, since we can't
1980 * wait for request slots on the block side.
1983 if (!(req
->ctx
->flags
& IORING_SETUP_IOPOLL
))
1985 if (io_wq_worker_stopped())
1991 if (io_arm_poll_handler(req
, issue_flags
) == IO_APOLL_OK
)
1993 /* aborted or ready, in either case retry blocking */
1995 issue_flags
&= ~IO_URING_F_NONBLOCK
;
1998 /* avoid locking problems by failing it from a clean context */
2000 io_req_task_queue_fail(req
, ret
);
2003 inline struct file
*io_file_get_fixed(struct io_kiocb
*req
, int fd
,
2004 unsigned int issue_flags
)
2006 struct io_ring_ctx
*ctx
= req
->ctx
;
2007 struct io_fixed_file
*slot
;
2008 struct file
*file
= NULL
;
2010 io_ring_submit_lock(ctx
, issue_flags
);
2012 if (unlikely((unsigned int)fd
>= ctx
->nr_user_files
))
2014 fd
= array_index_nospec(fd
, ctx
->nr_user_files
);
2015 slot
= io_fixed_file_slot(&ctx
->file_table
, fd
);
2016 file
= io_slot_file(slot
);
2017 req
->flags
|= io_slot_flags(slot
);
2018 io_req_set_rsrc_node(req
, ctx
, 0);
2020 io_ring_submit_unlock(ctx
, issue_flags
);
2024 struct file
*io_file_get_normal(struct io_kiocb
*req
, int fd
)
2026 struct file
*file
= fget(fd
);
2028 trace_io_uring_file_get(req
, fd
);
2030 /* we don't allow fixed io_uring files */
2031 if (file
&& io_is_uring_fops(file
))
2032 io_req_track_inflight(req
);
2036 static void io_queue_async(struct io_kiocb
*req
, int ret
)
2037 __must_hold(&req
->ctx
->uring_lock
)
2039 struct io_kiocb
*linked_timeout
;
2041 if (ret
!= -EAGAIN
|| (req
->flags
& REQ_F_NOWAIT
)) {
2042 io_req_defer_failed(req
, ret
);
2046 linked_timeout
= io_prep_linked_timeout(req
);
2048 switch (io_arm_poll_handler(req
, 0)) {
2049 case IO_APOLL_READY
:
2050 io_kbuf_recycle(req
, 0);
2051 io_req_task_queue(req
);
2053 case IO_APOLL_ABORTED
:
2054 io_kbuf_recycle(req
, 0);
2055 io_queue_iowq(req
, NULL
);
2062 io_queue_linked_timeout(linked_timeout
);
2065 static inline void io_queue_sqe(struct io_kiocb
*req
)
2066 __must_hold(&req
->ctx
->uring_lock
)
2070 ret
= io_issue_sqe(req
, IO_URING_F_NONBLOCK
|IO_URING_F_COMPLETE_DEFER
);
2073 * We async punt it if the file wasn't marked NOWAIT, or if the file
2074 * doesn't support non-blocking read/write attempts
2077 io_arm_ltimeout(req
);
2079 io_queue_async(req
, ret
);
2082 static void io_queue_sqe_fallback(struct io_kiocb
*req
)
2083 __must_hold(&req
->ctx
->uring_lock
)
2085 if (unlikely(req
->flags
& REQ_F_FAIL
)) {
2087 * We don't submit, fail them all, for that replace hardlinks
2088 * with normal links. Extra REQ_F_LINK is tolerated.
2090 req
->flags
&= ~REQ_F_HARDLINK
;
2091 req
->flags
|= REQ_F_LINK
;
2092 io_req_defer_failed(req
, req
->cqe
.res
);
2094 int ret
= io_req_prep_async(req
);
2096 if (unlikely(ret
)) {
2097 io_req_defer_failed(req
, ret
);
2101 if (unlikely(req
->ctx
->drain_active
))
2104 io_queue_iowq(req
, NULL
);
2109 * Check SQE restrictions (opcode and flags).
2111 * Returns 'true' if SQE is allowed, 'false' otherwise.
2113 static inline bool io_check_restriction(struct io_ring_ctx
*ctx
,
2114 struct io_kiocb
*req
,
2115 unsigned int sqe_flags
)
2117 if (!test_bit(req
->opcode
, ctx
->restrictions
.sqe_op
))
2120 if ((sqe_flags
& ctx
->restrictions
.sqe_flags_required
) !=
2121 ctx
->restrictions
.sqe_flags_required
)
2124 if (sqe_flags
& ~(ctx
->restrictions
.sqe_flags_allowed
|
2125 ctx
->restrictions
.sqe_flags_required
))
2131 static void io_init_req_drain(struct io_kiocb
*req
)
2133 struct io_ring_ctx
*ctx
= req
->ctx
;
2134 struct io_kiocb
*head
= ctx
->submit_state
.link
.head
;
2136 ctx
->drain_active
= true;
2139 * If we need to drain a request in the middle of a link, drain
2140 * the head request and the next request/link after the current
2141 * link. Considering sequential execution of links,
2142 * REQ_F_IO_DRAIN will be maintained for every request of our
2145 head
->flags
|= REQ_F_IO_DRAIN
| REQ_F_FORCE_ASYNC
;
2146 ctx
->drain_next
= true;
2150 static int io_init_req(struct io_ring_ctx
*ctx
, struct io_kiocb
*req
,
2151 const struct io_uring_sqe
*sqe
)
2152 __must_hold(&ctx
->uring_lock
)
2154 const struct io_issue_def
*def
;
2155 unsigned int sqe_flags
;
2159 /* req is partially pre-initialised, see io_preinit_req() */
2160 req
->opcode
= opcode
= READ_ONCE(sqe
->opcode
);
2161 /* same numerical values with corresponding REQ_F_*, safe to copy */
2162 req
->flags
= sqe_flags
= READ_ONCE(sqe
->flags
);
2163 req
->cqe
.user_data
= READ_ONCE(sqe
->user_data
);
2165 req
->rsrc_node
= NULL
;
2166 req
->task
= current
;
2168 if (unlikely(opcode
>= IORING_OP_LAST
)) {
2172 def
= &io_issue_defs
[opcode
];
2173 if (unlikely(sqe_flags
& ~SQE_COMMON_FLAGS
)) {
2174 /* enforce forwards compatibility on users */
2175 if (sqe_flags
& ~SQE_VALID_FLAGS
)
2177 if (sqe_flags
& IOSQE_BUFFER_SELECT
) {
2178 if (!def
->buffer_select
)
2180 req
->buf_index
= READ_ONCE(sqe
->buf_group
);
2182 if (sqe_flags
& IOSQE_CQE_SKIP_SUCCESS
)
2183 ctx
->drain_disabled
= true;
2184 if (sqe_flags
& IOSQE_IO_DRAIN
) {
2185 if (ctx
->drain_disabled
)
2187 io_init_req_drain(req
);
2190 if (unlikely(ctx
->restricted
|| ctx
->drain_active
|| ctx
->drain_next
)) {
2191 if (ctx
->restricted
&& !io_check_restriction(ctx
, req
, sqe_flags
))
2193 /* knock it to the slow queue path, will be drained there */
2194 if (ctx
->drain_active
)
2195 req
->flags
|= REQ_F_FORCE_ASYNC
;
2196 /* if there is no link, we're at "next" request and need to drain */
2197 if (unlikely(ctx
->drain_next
) && !ctx
->submit_state
.link
.head
) {
2198 ctx
->drain_next
= false;
2199 ctx
->drain_active
= true;
2200 req
->flags
|= REQ_F_IO_DRAIN
| REQ_F_FORCE_ASYNC
;
2204 if (!def
->ioprio
&& sqe
->ioprio
)
2206 if (!def
->iopoll
&& (ctx
->flags
& IORING_SETUP_IOPOLL
))
2209 if (def
->needs_file
) {
2210 struct io_submit_state
*state
= &ctx
->submit_state
;
2212 req
->cqe
.fd
= READ_ONCE(sqe
->fd
);
2215 * Plug now if we have more than 2 IO left after this, and the
2216 * target is potentially a read/write to block based storage.
2218 if (state
->need_plug
&& def
->plug
) {
2219 state
->plug_started
= true;
2220 state
->need_plug
= false;
2221 blk_start_plug_nr_ios(&state
->plug
, state
->submit_nr
);
2225 personality
= READ_ONCE(sqe
->personality
);
2229 req
->creds
= xa_load(&ctx
->personalities
, personality
);
2232 get_cred(req
->creds
);
2233 ret
= security_uring_override_creds(req
->creds
);
2235 put_cred(req
->creds
);
2238 req
->flags
|= REQ_F_CREDS
;
2241 return def
->prep(req
, sqe
);
2244 static __cold
int io_submit_fail_init(const struct io_uring_sqe
*sqe
,
2245 struct io_kiocb
*req
, int ret
)
2247 struct io_ring_ctx
*ctx
= req
->ctx
;
2248 struct io_submit_link
*link
= &ctx
->submit_state
.link
;
2249 struct io_kiocb
*head
= link
->head
;
2251 trace_io_uring_req_failed(sqe
, req
, ret
);
2254 * Avoid breaking links in the middle as it renders links with SQPOLL
2255 * unusable. Instead of failing eagerly, continue assembling the link if
2256 * applicable and mark the head with REQ_F_FAIL. The link flushing code
2257 * should find the flag and handle the rest.
2259 req_fail_link_node(req
, ret
);
2260 if (head
&& !(head
->flags
& REQ_F_FAIL
))
2261 req_fail_link_node(head
, -ECANCELED
);
2263 if (!(req
->flags
& IO_REQ_LINK_FLAGS
)) {
2265 link
->last
->link
= req
;
2269 io_queue_sqe_fallback(req
);
2274 link
->last
->link
= req
;
2281 static inline int io_submit_sqe(struct io_ring_ctx
*ctx
, struct io_kiocb
*req
,
2282 const struct io_uring_sqe
*sqe
)
2283 __must_hold(&ctx
->uring_lock
)
2285 struct io_submit_link
*link
= &ctx
->submit_state
.link
;
2288 ret
= io_init_req(ctx
, req
, sqe
);
2290 return io_submit_fail_init(sqe
, req
, ret
);
2292 trace_io_uring_submit_req(req
);
2295 * If we already have a head request, queue this one for async
2296 * submittal once the head completes. If we don't have a head but
2297 * IOSQE_IO_LINK is set in the sqe, start a new head. This one will be
2298 * submitted sync once the chain is complete. If none of those
2299 * conditions are true (normal request), then just queue it.
2301 if (unlikely(link
->head
)) {
2302 ret
= io_req_prep_async(req
);
2304 return io_submit_fail_init(sqe
, req
, ret
);
2306 trace_io_uring_link(req
, link
->head
);
2307 link
->last
->link
= req
;
2310 if (req
->flags
& IO_REQ_LINK_FLAGS
)
2312 /* last request of the link, flush it */
2315 if (req
->flags
& (REQ_F_FORCE_ASYNC
| REQ_F_FAIL
))
2318 } else if (unlikely(req
->flags
& (IO_REQ_LINK_FLAGS
|
2319 REQ_F_FORCE_ASYNC
| REQ_F_FAIL
))) {
2320 if (req
->flags
& IO_REQ_LINK_FLAGS
) {
2325 io_queue_sqe_fallback(req
);
2335 * Batched submission is done, ensure local IO is flushed out.
2337 static void io_submit_state_end(struct io_ring_ctx
*ctx
)
2339 struct io_submit_state
*state
= &ctx
->submit_state
;
2341 if (unlikely(state
->link
.head
))
2342 io_queue_sqe_fallback(state
->link
.head
);
2343 /* flush only after queuing links as they can generate completions */
2344 io_submit_flush_completions(ctx
);
2345 if (state
->plug_started
)
2346 blk_finish_plug(&state
->plug
);
2350 * Start submission side cache.
2352 static void io_submit_state_start(struct io_submit_state
*state
,
2353 unsigned int max_ios
)
2355 state
->plug_started
= false;
2356 state
->need_plug
= max_ios
> 2;
2357 state
->submit_nr
= max_ios
;
2358 /* set only head, no need to init link_last in advance */
2359 state
->link
.head
= NULL
;
2362 static void io_commit_sqring(struct io_ring_ctx
*ctx
)
2364 struct io_rings
*rings
= ctx
->rings
;
2367 * Ensure any loads from the SQEs are done at this point,
2368 * since once we write the new head, the application could
2369 * write new data to them.
2371 smp_store_release(&rings
->sq
.head
, ctx
->cached_sq_head
);
2375 * Fetch an sqe, if one is available. Note this returns a pointer to memory
2376 * that is mapped by userspace. This means that care needs to be taken to
2377 * ensure that reads are stable, as we cannot rely on userspace always
2378 * being a good citizen. If members of the sqe are validated and then later
2379 * used, it's important that those reads are done through READ_ONCE() to
2380 * prevent a re-load down the line.
2382 static bool io_get_sqe(struct io_ring_ctx
*ctx
, const struct io_uring_sqe
**sqe
)
2384 unsigned mask
= ctx
->sq_entries
- 1;
2385 unsigned head
= ctx
->cached_sq_head
++ & mask
;
2387 if (!(ctx
->flags
& IORING_SETUP_NO_SQARRAY
)) {
2388 head
= READ_ONCE(ctx
->sq_array
[head
]);
2389 if (unlikely(head
>= ctx
->sq_entries
)) {
2390 /* drop invalid entries */
2391 spin_lock(&ctx
->completion_lock
);
2393 spin_unlock(&ctx
->completion_lock
);
2394 WRITE_ONCE(ctx
->rings
->sq_dropped
,
2395 READ_ONCE(ctx
->rings
->sq_dropped
) + 1);
2401 * The cached sq head (or cq tail) serves two purposes:
2403 * 1) allows us to batch the cost of updating the user visible
2405 * 2) allows the kernel side to track the head on its own, even
2406 * though the application is the one updating it.
2409 /* double index for 128-byte SQEs, twice as long */
2410 if (ctx
->flags
& IORING_SETUP_SQE128
)
2412 *sqe
= &ctx
->sq_sqes
[head
];
2416 int io_submit_sqes(struct io_ring_ctx
*ctx
, unsigned int nr
)
2417 __must_hold(&ctx
->uring_lock
)
2419 unsigned int entries
= io_sqring_entries(ctx
);
2423 if (unlikely(!entries
))
2425 /* make sure SQ entry isn't read before tail */
2426 ret
= left
= min(nr
, entries
);
2427 io_get_task_refs(left
);
2428 io_submit_state_start(&ctx
->submit_state
, left
);
2431 const struct io_uring_sqe
*sqe
;
2432 struct io_kiocb
*req
;
2434 if (unlikely(!io_alloc_req(ctx
, &req
)))
2436 if (unlikely(!io_get_sqe(ctx
, &sqe
))) {
2437 io_req_add_to_cache(req
, ctx
);
2442 * Continue submitting even for sqe failure if the
2443 * ring was setup with IORING_SETUP_SUBMIT_ALL
2445 if (unlikely(io_submit_sqe(ctx
, req
, sqe
)) &&
2446 !(ctx
->flags
& IORING_SETUP_SUBMIT_ALL
)) {
2452 if (unlikely(left
)) {
2454 /* try again if it submitted nothing and can't allocate a req */
2455 if (!ret
&& io_req_cache_empty(ctx
))
2457 current
->io_uring
->cached_refs
+= left
;
2460 io_submit_state_end(ctx
);
2461 /* Commit SQ ring head once we've consumed and submitted all SQEs */
2462 io_commit_sqring(ctx
);
2466 struct io_wait_queue
{
2467 struct wait_queue_entry wq
;
2468 struct io_ring_ctx
*ctx
;
2470 unsigned nr_timeouts
;
2474 static inline bool io_has_work(struct io_ring_ctx
*ctx
)
2476 return test_bit(IO_CHECK_CQ_OVERFLOW_BIT
, &ctx
->check_cq
) ||
2477 !llist_empty(&ctx
->work_llist
);
2480 static inline bool io_should_wake(struct io_wait_queue
*iowq
)
2482 struct io_ring_ctx
*ctx
= iowq
->ctx
;
2483 int dist
= READ_ONCE(ctx
->rings
->cq
.tail
) - (int) iowq
->cq_tail
;
2486 * Wake up if we have enough events, or if a timeout occurred since we
2487 * started waiting. For timeouts, we always want to return to userspace,
2488 * regardless of event count.
2490 return dist
>= 0 || atomic_read(&ctx
->cq_timeouts
) != iowq
->nr_timeouts
;
2493 static int io_wake_function(struct wait_queue_entry
*curr
, unsigned int mode
,
2494 int wake_flags
, void *key
)
2496 struct io_wait_queue
*iowq
= container_of(curr
, struct io_wait_queue
, wq
);
2499 * Cannot safely flush overflowed CQEs from here, ensure we wake up
2500 * the task, and the next invocation will do it.
2502 if (io_should_wake(iowq
) || io_has_work(iowq
->ctx
))
2503 return autoremove_wake_function(curr
, mode
, wake_flags
, key
);
2507 int io_run_task_work_sig(struct io_ring_ctx
*ctx
)
2509 if (!llist_empty(&ctx
->work_llist
)) {
2510 __set_current_state(TASK_RUNNING
);
2511 if (io_run_local_work(ctx
) > 0)
2514 if (io_run_task_work() > 0)
2516 if (task_sigpending(current
))
2521 static bool current_pending_io(void)
2523 struct io_uring_task
*tctx
= current
->io_uring
;
2527 return percpu_counter_read_positive(&tctx
->inflight
);
2530 /* when returns >0, the caller should retry */
2531 static inline int io_cqring_wait_schedule(struct io_ring_ctx
*ctx
,
2532 struct io_wait_queue
*iowq
)
2536 if (unlikely(READ_ONCE(ctx
->check_cq
)))
2538 if (unlikely(!llist_empty(&ctx
->work_llist
)))
2540 if (unlikely(test_thread_flag(TIF_NOTIFY_SIGNAL
)))
2542 if (unlikely(task_sigpending(current
)))
2544 if (unlikely(io_should_wake(iowq
)))
2548 * Mark us as being in io_wait if we have pending requests, so cpufreq
2549 * can take into account that the task is waiting for IO - turns out
2550 * to be important for low QD IO.
2552 io_wait
= current
->in_iowait
;
2553 if (current_pending_io())
2554 current
->in_iowait
= 1;
2556 if (iowq
->timeout
== KTIME_MAX
)
2558 else if (!schedule_hrtimeout(&iowq
->timeout
, HRTIMER_MODE_ABS
))
2560 current
->in_iowait
= io_wait
;
2565 * Wait until events become available, if we don't already have some. The
2566 * application must reap them itself, as they reside on the shared cq ring.
2568 static int io_cqring_wait(struct io_ring_ctx
*ctx
, int min_events
,
2569 const sigset_t __user
*sig
, size_t sigsz
,
2570 struct __kernel_timespec __user
*uts
)
2572 struct io_wait_queue iowq
;
2573 struct io_rings
*rings
= ctx
->rings
;
2576 if (!io_allowed_run_tw(ctx
))
2578 if (!llist_empty(&ctx
->work_llist
))
2579 io_run_local_work(ctx
);
2581 io_cqring_overflow_flush(ctx
);
2582 /* if user messes with these they will just get an early return */
2583 if (__io_cqring_events_user(ctx
) >= min_events
)
2587 #ifdef CONFIG_COMPAT
2588 if (in_compat_syscall())
2589 ret
= set_compat_user_sigmask((const compat_sigset_t __user
*)sig
,
2593 ret
= set_user_sigmask(sig
, sigsz
);
2599 init_waitqueue_func_entry(&iowq
.wq
, io_wake_function
);
2600 iowq
.wq
.private = current
;
2601 INIT_LIST_HEAD(&iowq
.wq
.entry
);
2603 iowq
.nr_timeouts
= atomic_read(&ctx
->cq_timeouts
);
2604 iowq
.cq_tail
= READ_ONCE(ctx
->rings
->cq
.head
) + min_events
;
2605 iowq
.timeout
= KTIME_MAX
;
2608 struct timespec64 ts
;
2610 if (get_timespec64(&ts
, uts
))
2612 iowq
.timeout
= ktime_add_ns(timespec64_to_ktime(ts
), ktime_get_ns());
2615 trace_io_uring_cqring_wait(ctx
, min_events
);
2617 unsigned long check_cq
;
2619 if (ctx
->flags
& IORING_SETUP_DEFER_TASKRUN
) {
2620 int nr_wait
= (int) iowq
.cq_tail
- READ_ONCE(ctx
->rings
->cq
.tail
);
2622 atomic_set(&ctx
->cq_wait_nr
, nr_wait
);
2623 set_current_state(TASK_INTERRUPTIBLE
);
2625 prepare_to_wait_exclusive(&ctx
->cq_wait
, &iowq
.wq
,
2626 TASK_INTERRUPTIBLE
);
2629 ret
= io_cqring_wait_schedule(ctx
, &iowq
);
2630 __set_current_state(TASK_RUNNING
);
2631 atomic_set(&ctx
->cq_wait_nr
, 0);
2636 * Run task_work after scheduling and before io_should_wake().
2637 * If we got woken because of task_work being processed, run it
2638 * now rather than let the caller do another wait loop.
2641 if (!llist_empty(&ctx
->work_llist
))
2642 io_run_local_work(ctx
);
2644 check_cq
= READ_ONCE(ctx
->check_cq
);
2645 if (unlikely(check_cq
)) {
2646 /* let the caller flush overflows, retry */
2647 if (check_cq
& BIT(IO_CHECK_CQ_OVERFLOW_BIT
))
2648 io_cqring_do_overflow_flush(ctx
);
2649 if (check_cq
& BIT(IO_CHECK_CQ_DROPPED_BIT
)) {
2655 if (io_should_wake(&iowq
)) {
2662 if (!(ctx
->flags
& IORING_SETUP_DEFER_TASKRUN
))
2663 finish_wait(&ctx
->cq_wait
, &iowq
.wq
);
2664 restore_saved_sigmask_unless(ret
== -EINTR
);
2666 return READ_ONCE(rings
->cq
.head
) == READ_ONCE(rings
->cq
.tail
) ? ret
: 0;
2669 static void io_mem_free(void *ptr
)
2674 folio_put(virt_to_folio(ptr
));
2677 static void io_pages_free(struct page
***pages
, int npages
)
2679 struct page
**page_array
;
2685 page_array
= *pages
;
2689 for (i
= 0; i
< npages
; i
++)
2690 unpin_user_page(page_array
[i
]);
2695 static void *__io_uaddr_map(struct page
***pages
, unsigned short *npages
,
2696 unsigned long uaddr
, size_t size
)
2698 struct page
**page_array
;
2699 unsigned int nr_pages
;
2704 if (uaddr
& (PAGE_SIZE
- 1) || !size
)
2705 return ERR_PTR(-EINVAL
);
2707 nr_pages
= (size
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
2708 if (nr_pages
> USHRT_MAX
)
2709 return ERR_PTR(-EINVAL
);
2710 page_array
= kvmalloc_array(nr_pages
, sizeof(struct page
*), GFP_KERNEL
);
2712 return ERR_PTR(-ENOMEM
);
2714 ret
= pin_user_pages_fast(uaddr
, nr_pages
, FOLL_WRITE
| FOLL_LONGTERM
,
2716 if (ret
!= nr_pages
) {
2718 io_pages_free(&page_array
, ret
> 0 ? ret
: 0);
2719 return ret
< 0 ? ERR_PTR(ret
) : ERR_PTR(-EFAULT
);
2722 * Should be a single page. If the ring is small enough that we can
2723 * use a normal page, that is fine. If we need multiple pages, then
2724 * userspace should use a huge page. That's the only way to guarantee
2725 * that we get contigious memory, outside of just being lucky or
2726 * (currently) having low memory fragmentation.
2728 if (page_array
[0] != page_array
[ret
- 1])
2732 * Can't support mapping user allocated ring memory on 32-bit archs
2733 * where it could potentially reside in highmem. Just fail those with
2734 * -EINVAL, just like we did on kernels that didn't support this
2737 for (i
= 0; i
< nr_pages
; i
++) {
2738 if (PageHighMem(page_array
[i
])) {
2744 *pages
= page_array
;
2746 return page_to_virt(page_array
[0]);
2749 static void *io_rings_map(struct io_ring_ctx
*ctx
, unsigned long uaddr
,
2752 return __io_uaddr_map(&ctx
->ring_pages
, &ctx
->n_ring_pages
, uaddr
,
2756 static void *io_sqes_map(struct io_ring_ctx
*ctx
, unsigned long uaddr
,
2759 return __io_uaddr_map(&ctx
->sqe_pages
, &ctx
->n_sqe_pages
, uaddr
,
2763 static void io_rings_free(struct io_ring_ctx
*ctx
)
2765 if (!(ctx
->flags
& IORING_SETUP_NO_MMAP
)) {
2766 io_mem_free(ctx
->rings
);
2767 io_mem_free(ctx
->sq_sqes
);
2769 ctx
->sq_sqes
= NULL
;
2771 io_pages_free(&ctx
->ring_pages
, ctx
->n_ring_pages
);
2772 ctx
->n_ring_pages
= 0;
2773 io_pages_free(&ctx
->sqe_pages
, ctx
->n_sqe_pages
);
2774 ctx
->n_sqe_pages
= 0;
2778 static void *io_mem_alloc(size_t size
)
2780 gfp_t gfp
= GFP_KERNEL_ACCOUNT
| __GFP_ZERO
| __GFP_NOWARN
| __GFP_COMP
;
2783 ret
= (void *) __get_free_pages(gfp
, get_order(size
));
2786 return ERR_PTR(-ENOMEM
);
2789 static unsigned long rings_size(struct io_ring_ctx
*ctx
, unsigned int sq_entries
,
2790 unsigned int cq_entries
, size_t *sq_offset
)
2792 struct io_rings
*rings
;
2793 size_t off
, sq_array_size
;
2795 off
= struct_size(rings
, cqes
, cq_entries
);
2796 if (off
== SIZE_MAX
)
2798 if (ctx
->flags
& IORING_SETUP_CQE32
) {
2799 if (check_shl_overflow(off
, 1, &off
))
2804 off
= ALIGN(off
, SMP_CACHE_BYTES
);
2809 if (ctx
->flags
& IORING_SETUP_NO_SQARRAY
) {
2811 *sq_offset
= SIZE_MAX
;
2818 sq_array_size
= array_size(sizeof(u32
), sq_entries
);
2819 if (sq_array_size
== SIZE_MAX
)
2822 if (check_add_overflow(off
, sq_array_size
, &off
))
2828 static int io_eventfd_register(struct io_ring_ctx
*ctx
, void __user
*arg
,
2829 unsigned int eventfd_async
)
2831 struct io_ev_fd
*ev_fd
;
2832 __s32 __user
*fds
= arg
;
2835 ev_fd
= rcu_dereference_protected(ctx
->io_ev_fd
,
2836 lockdep_is_held(&ctx
->uring_lock
));
2840 if (copy_from_user(&fd
, fds
, sizeof(*fds
)))
2843 ev_fd
= kmalloc(sizeof(*ev_fd
), GFP_KERNEL
);
2847 ev_fd
->cq_ev_fd
= eventfd_ctx_fdget(fd
);
2848 if (IS_ERR(ev_fd
->cq_ev_fd
)) {
2849 int ret
= PTR_ERR(ev_fd
->cq_ev_fd
);
2854 spin_lock(&ctx
->completion_lock
);
2855 ctx
->evfd_last_cq_tail
= ctx
->cached_cq_tail
;
2856 spin_unlock(&ctx
->completion_lock
);
2858 ev_fd
->eventfd_async
= eventfd_async
;
2859 ctx
->has_evfd
= true;
2860 rcu_assign_pointer(ctx
->io_ev_fd
, ev_fd
);
2861 atomic_set(&ev_fd
->refs
, 1);
2862 atomic_set(&ev_fd
->ops
, 0);
2866 static int io_eventfd_unregister(struct io_ring_ctx
*ctx
)
2868 struct io_ev_fd
*ev_fd
;
2870 ev_fd
= rcu_dereference_protected(ctx
->io_ev_fd
,
2871 lockdep_is_held(&ctx
->uring_lock
));
2873 ctx
->has_evfd
= false;
2874 rcu_assign_pointer(ctx
->io_ev_fd
, NULL
);
2875 if (!atomic_fetch_or(BIT(IO_EVENTFD_OP_FREE_BIT
), &ev_fd
->ops
))
2876 call_rcu(&ev_fd
->rcu
, io_eventfd_ops
);
2883 static void io_req_caches_free(struct io_ring_ctx
*ctx
)
2885 struct io_kiocb
*req
;
2888 mutex_lock(&ctx
->uring_lock
);
2889 io_flush_cached_locked_reqs(ctx
, &ctx
->submit_state
);
2891 while (!io_req_cache_empty(ctx
)) {
2892 req
= io_extract_req(ctx
);
2893 kmem_cache_free(req_cachep
, req
);
2897 percpu_ref_put_many(&ctx
->refs
, nr
);
2898 mutex_unlock(&ctx
->uring_lock
);
2901 static void io_rsrc_node_cache_free(struct io_cache_entry
*entry
)
2903 kfree(container_of(entry
, struct io_rsrc_node
, cache
));
2906 static __cold
void io_ring_ctx_free(struct io_ring_ctx
*ctx
)
2908 io_sq_thread_finish(ctx
);
2909 /* __io_rsrc_put_work() may need uring_lock to progress, wait w/o it */
2910 if (WARN_ON_ONCE(!list_empty(&ctx
->rsrc_ref_list
)))
2913 mutex_lock(&ctx
->uring_lock
);
2915 __io_sqe_buffers_unregister(ctx
);
2917 __io_sqe_files_unregister(ctx
);
2918 io_cqring_overflow_kill(ctx
);
2919 io_eventfd_unregister(ctx
);
2920 io_alloc_cache_free(&ctx
->apoll_cache
, io_apoll_cache_free
);
2921 io_alloc_cache_free(&ctx
->netmsg_cache
, io_netmsg_cache_free
);
2922 io_futex_cache_free(ctx
);
2923 io_destroy_buffers(ctx
);
2924 mutex_unlock(&ctx
->uring_lock
);
2926 put_cred(ctx
->sq_creds
);
2927 if (ctx
->submitter_task
)
2928 put_task_struct(ctx
->submitter_task
);
2930 /* there are no registered resources left, nobody uses it */
2932 io_rsrc_node_destroy(ctx
, ctx
->rsrc_node
);
2934 WARN_ON_ONCE(!list_empty(&ctx
->rsrc_ref_list
));
2936 #if defined(CONFIG_UNIX)
2937 if (ctx
->ring_sock
) {
2938 ctx
->ring_sock
->file
= NULL
; /* so that iput() is called */
2939 sock_release(ctx
->ring_sock
);
2942 WARN_ON_ONCE(!list_empty(&ctx
->ltimeout_list
));
2944 io_alloc_cache_free(&ctx
->rsrc_node_cache
, io_rsrc_node_cache_free
);
2945 if (ctx
->mm_account
) {
2946 mmdrop(ctx
->mm_account
);
2947 ctx
->mm_account
= NULL
;
2951 percpu_ref_exit(&ctx
->refs
);
2952 free_uid(ctx
->user
);
2953 io_req_caches_free(ctx
);
2955 io_wq_put_hash(ctx
->hash_map
);
2956 kfree(ctx
->cancel_table
.hbs
);
2957 kfree(ctx
->cancel_table_locked
.hbs
);
2959 xa_destroy(&ctx
->io_bl_xa
);
2963 static __cold
void io_activate_pollwq_cb(struct callback_head
*cb
)
2965 struct io_ring_ctx
*ctx
= container_of(cb
, struct io_ring_ctx
,
2968 mutex_lock(&ctx
->uring_lock
);
2969 ctx
->poll_activated
= true;
2970 mutex_unlock(&ctx
->uring_lock
);
2973 * Wake ups for some events between start of polling and activation
2974 * might've been lost due to loose synchronisation.
2976 wake_up_all(&ctx
->poll_wq
);
2977 percpu_ref_put(&ctx
->refs
);
2980 static __cold
void io_activate_pollwq(struct io_ring_ctx
*ctx
)
2982 spin_lock(&ctx
->completion_lock
);
2983 /* already activated or in progress */
2984 if (ctx
->poll_activated
|| ctx
->poll_wq_task_work
.func
)
2986 if (WARN_ON_ONCE(!ctx
->task_complete
))
2988 if (!ctx
->submitter_task
)
2991 * with ->submitter_task only the submitter task completes requests, we
2992 * only need to sync with it, which is done by injecting a tw
2994 init_task_work(&ctx
->poll_wq_task_work
, io_activate_pollwq_cb
);
2995 percpu_ref_get(&ctx
->refs
);
2996 if (task_work_add(ctx
->submitter_task
, &ctx
->poll_wq_task_work
, TWA_SIGNAL
))
2997 percpu_ref_put(&ctx
->refs
);
2999 spin_unlock(&ctx
->completion_lock
);
3002 static __poll_t
io_uring_poll(struct file
*file
, poll_table
*wait
)
3004 struct io_ring_ctx
*ctx
= file
->private_data
;
3007 if (unlikely(!ctx
->poll_activated
))
3008 io_activate_pollwq(ctx
);
3010 poll_wait(file
, &ctx
->poll_wq
, wait
);
3012 * synchronizes with barrier from wq_has_sleeper call in
3016 if (!io_sqring_full(ctx
))
3017 mask
|= EPOLLOUT
| EPOLLWRNORM
;
3020 * Don't flush cqring overflow list here, just do a simple check.
3021 * Otherwise there could possible be ABBA deadlock:
3024 * lock(&ctx->uring_lock);
3026 * lock(&ctx->uring_lock);
3029 * Users may get EPOLLIN meanwhile seeing nothing in cqring, this
3030 * pushes them to do the flush.
3033 if (__io_cqring_events_user(ctx
) || io_has_work(ctx
))
3034 mask
|= EPOLLIN
| EPOLLRDNORM
;
3039 static int io_unregister_personality(struct io_ring_ctx
*ctx
, unsigned id
)
3041 const struct cred
*creds
;
3043 creds
= xa_erase(&ctx
->personalities
, id
);
3052 struct io_tctx_exit
{
3053 struct callback_head task_work
;
3054 struct completion completion
;
3055 struct io_ring_ctx
*ctx
;
3058 static __cold
void io_tctx_exit_cb(struct callback_head
*cb
)
3060 struct io_uring_task
*tctx
= current
->io_uring
;
3061 struct io_tctx_exit
*work
;
3063 work
= container_of(cb
, struct io_tctx_exit
, task_work
);
3065 * When @in_cancel, we're in cancellation and it's racy to remove the
3066 * node. It'll be removed by the end of cancellation, just ignore it.
3067 * tctx can be NULL if the queueing of this task_work raced with
3068 * work cancelation off the exec path.
3070 if (tctx
&& !atomic_read(&tctx
->in_cancel
))
3071 io_uring_del_tctx_node((unsigned long)work
->ctx
);
3072 complete(&work
->completion
);
3075 static __cold
bool io_cancel_ctx_cb(struct io_wq_work
*work
, void *data
)
3077 struct io_kiocb
*req
= container_of(work
, struct io_kiocb
, work
);
3079 return req
->ctx
== data
;
3082 static __cold
void io_ring_exit_work(struct work_struct
*work
)
3084 struct io_ring_ctx
*ctx
= container_of(work
, struct io_ring_ctx
, exit_work
);
3085 unsigned long timeout
= jiffies
+ HZ
* 60 * 5;
3086 unsigned long interval
= HZ
/ 20;
3087 struct io_tctx_exit exit
;
3088 struct io_tctx_node
*node
;
3092 * If we're doing polled IO and end up having requests being
3093 * submitted async (out-of-line), then completions can come in while
3094 * we're waiting for refs to drop. We need to reap these manually,
3095 * as nobody else will be looking for them.
3098 if (test_bit(IO_CHECK_CQ_OVERFLOW_BIT
, &ctx
->check_cq
)) {
3099 mutex_lock(&ctx
->uring_lock
);
3100 io_cqring_overflow_kill(ctx
);
3101 mutex_unlock(&ctx
->uring_lock
);
3104 if (ctx
->flags
& IORING_SETUP_DEFER_TASKRUN
)
3105 io_move_task_work_from_local(ctx
);
3107 while (io_uring_try_cancel_requests(ctx
, NULL
, true))
3111 struct io_sq_data
*sqd
= ctx
->sq_data
;
3112 struct task_struct
*tsk
;
3114 io_sq_thread_park(sqd
);
3116 if (tsk
&& tsk
->io_uring
&& tsk
->io_uring
->io_wq
)
3117 io_wq_cancel_cb(tsk
->io_uring
->io_wq
,
3118 io_cancel_ctx_cb
, ctx
, true);
3119 io_sq_thread_unpark(sqd
);
3122 io_req_caches_free(ctx
);
3124 if (WARN_ON_ONCE(time_after(jiffies
, timeout
))) {
3125 /* there is little hope left, don't run it too often */
3129 * This is really an uninterruptible wait, as it has to be
3130 * complete. But it's also run from a kworker, which doesn't
3131 * take signals, so it's fine to make it interruptible. This
3132 * avoids scenarios where we knowingly can wait much longer
3133 * on completions, for example if someone does a SIGSTOP on
3134 * a task that needs to finish task_work to make this loop
3135 * complete. That's a synthetic situation that should not
3136 * cause a stuck task backtrace, and hence a potential panic
3137 * on stuck tasks if that is enabled.
3139 } while (!wait_for_completion_interruptible_timeout(&ctx
->ref_comp
, interval
));
3141 init_completion(&exit
.completion
);
3142 init_task_work(&exit
.task_work
, io_tctx_exit_cb
);
3145 * Some may use context even when all refs and requests have been put,
3146 * and they are free to do so while still holding uring_lock or
3147 * completion_lock, see io_req_task_submit(). Apart from other work,
3148 * this lock/unlock section also waits them to finish.
3150 mutex_lock(&ctx
->uring_lock
);
3151 while (!list_empty(&ctx
->tctx_list
)) {
3152 WARN_ON_ONCE(time_after(jiffies
, timeout
));
3154 node
= list_first_entry(&ctx
->tctx_list
, struct io_tctx_node
,
3156 /* don't spin on a single task if cancellation failed */
3157 list_rotate_left(&ctx
->tctx_list
);
3158 ret
= task_work_add(node
->task
, &exit
.task_work
, TWA_SIGNAL
);
3159 if (WARN_ON_ONCE(ret
))
3162 mutex_unlock(&ctx
->uring_lock
);
3164 * See comment above for
3165 * wait_for_completion_interruptible_timeout() on why this
3166 * wait is marked as interruptible.
3168 wait_for_completion_interruptible(&exit
.completion
);
3169 mutex_lock(&ctx
->uring_lock
);
3171 mutex_unlock(&ctx
->uring_lock
);
3172 spin_lock(&ctx
->completion_lock
);
3173 spin_unlock(&ctx
->completion_lock
);
3175 /* pairs with RCU read section in io_req_local_work_add() */
3176 if (ctx
->flags
& IORING_SETUP_DEFER_TASKRUN
)
3179 io_ring_ctx_free(ctx
);
3182 static __cold
void io_ring_ctx_wait_and_kill(struct io_ring_ctx
*ctx
)
3184 unsigned long index
;
3185 struct creds
*creds
;
3187 mutex_lock(&ctx
->uring_lock
);
3188 percpu_ref_kill(&ctx
->refs
);
3189 xa_for_each(&ctx
->personalities
, index
, creds
)
3190 io_unregister_personality(ctx
, index
);
3192 io_poll_remove_all(ctx
, NULL
, true);
3193 mutex_unlock(&ctx
->uring_lock
);
3196 * If we failed setting up the ctx, we might not have any rings
3197 * and therefore did not submit any requests
3200 io_kill_timeouts(ctx
, NULL
, true);
3202 flush_delayed_work(&ctx
->fallback_work
);
3204 INIT_WORK(&ctx
->exit_work
, io_ring_exit_work
);
3206 * Use system_unbound_wq to avoid spawning tons of event kworkers
3207 * if we're exiting a ton of rings at the same time. It just adds
3208 * noise and overhead, there's no discernable change in runtime
3209 * over using system_wq.
3211 queue_work(system_unbound_wq
, &ctx
->exit_work
);
3214 static int io_uring_release(struct inode
*inode
, struct file
*file
)
3216 struct io_ring_ctx
*ctx
= file
->private_data
;
3218 file
->private_data
= NULL
;
3219 io_ring_ctx_wait_and_kill(ctx
);
3223 struct io_task_cancel
{
3224 struct task_struct
*task
;
3228 static bool io_cancel_task_cb(struct io_wq_work
*work
, void *data
)
3230 struct io_kiocb
*req
= container_of(work
, struct io_kiocb
, work
);
3231 struct io_task_cancel
*cancel
= data
;
3233 return io_match_task_safe(req
, cancel
->task
, cancel
->all
);
3236 static __cold
bool io_cancel_defer_files(struct io_ring_ctx
*ctx
,
3237 struct task_struct
*task
,
3240 struct io_defer_entry
*de
;
3243 spin_lock(&ctx
->completion_lock
);
3244 list_for_each_entry_reverse(de
, &ctx
->defer_list
, list
) {
3245 if (io_match_task_safe(de
->req
, task
, cancel_all
)) {
3246 list_cut_position(&list
, &ctx
->defer_list
, &de
->list
);
3250 spin_unlock(&ctx
->completion_lock
);
3251 if (list_empty(&list
))
3254 while (!list_empty(&list
)) {
3255 de
= list_first_entry(&list
, struct io_defer_entry
, list
);
3256 list_del_init(&de
->list
);
3257 io_req_task_queue_fail(de
->req
, -ECANCELED
);
3263 static __cold
bool io_uring_try_cancel_iowq(struct io_ring_ctx
*ctx
)
3265 struct io_tctx_node
*node
;
3266 enum io_wq_cancel cret
;
3269 mutex_lock(&ctx
->uring_lock
);
3270 list_for_each_entry(node
, &ctx
->tctx_list
, ctx_node
) {
3271 struct io_uring_task
*tctx
= node
->task
->io_uring
;
3274 * io_wq will stay alive while we hold uring_lock, because it's
3275 * killed after ctx nodes, which requires to take the lock.
3277 if (!tctx
|| !tctx
->io_wq
)
3279 cret
= io_wq_cancel_cb(tctx
->io_wq
, io_cancel_ctx_cb
, ctx
, true);
3280 ret
|= (cret
!= IO_WQ_CANCEL_NOTFOUND
);
3282 mutex_unlock(&ctx
->uring_lock
);
3287 static bool io_uring_try_cancel_uring_cmd(struct io_ring_ctx
*ctx
,
3288 struct task_struct
*task
, bool cancel_all
)
3290 struct hlist_node
*tmp
;
3291 struct io_kiocb
*req
;
3294 lockdep_assert_held(&ctx
->uring_lock
);
3296 hlist_for_each_entry_safe(req
, tmp
, &ctx
->cancelable_uring_cmd
,
3298 struct io_uring_cmd
*cmd
= io_kiocb_to_cmd(req
,
3299 struct io_uring_cmd
);
3300 struct file
*file
= req
->file
;
3302 if (!cancel_all
&& req
->task
!= task
)
3305 if (cmd
->flags
& IORING_URING_CMD_CANCELABLE
) {
3306 /* ->sqe isn't available if no async data */
3307 if (!req_has_async_data(req
))
3309 file
->f_op
->uring_cmd(cmd
, IO_URING_F_CANCEL
);
3313 io_submit_flush_completions(ctx
);
3318 static __cold
bool io_uring_try_cancel_requests(struct io_ring_ctx
*ctx
,
3319 struct task_struct
*task
,
3322 struct io_task_cancel cancel
= { .task
= task
, .all
= cancel_all
, };
3323 struct io_uring_task
*tctx
= task
? task
->io_uring
: NULL
;
3324 enum io_wq_cancel cret
;
3327 /* set it so io_req_local_work_add() would wake us up */
3328 if (ctx
->flags
& IORING_SETUP_DEFER_TASKRUN
) {
3329 atomic_set(&ctx
->cq_wait_nr
, 1);
3333 /* failed during ring init, it couldn't have issued any requests */
3338 ret
|= io_uring_try_cancel_iowq(ctx
);
3339 } else if (tctx
&& tctx
->io_wq
) {
3341 * Cancels requests of all rings, not only @ctx, but
3342 * it's fine as the task is in exit/exec.
3344 cret
= io_wq_cancel_cb(tctx
->io_wq
, io_cancel_task_cb
,
3346 ret
|= (cret
!= IO_WQ_CANCEL_NOTFOUND
);
3349 /* SQPOLL thread does its own polling */
3350 if ((!(ctx
->flags
& IORING_SETUP_SQPOLL
) && cancel_all
) ||
3351 (ctx
->sq_data
&& ctx
->sq_data
->thread
== current
)) {
3352 while (!wq_list_empty(&ctx
->iopoll_list
)) {
3353 io_iopoll_try_reap_events(ctx
);
3359 if ((ctx
->flags
& IORING_SETUP_DEFER_TASKRUN
) &&
3360 io_allowed_defer_tw_run(ctx
))
3361 ret
|= io_run_local_work(ctx
) > 0;
3362 ret
|= io_cancel_defer_files(ctx
, task
, cancel_all
);
3363 mutex_lock(&ctx
->uring_lock
);
3364 ret
|= io_poll_remove_all(ctx
, task
, cancel_all
);
3365 ret
|= io_waitid_remove_all(ctx
, task
, cancel_all
);
3366 ret
|= io_futex_remove_all(ctx
, task
, cancel_all
);
3367 ret
|= io_uring_try_cancel_uring_cmd(ctx
, task
, cancel_all
);
3368 mutex_unlock(&ctx
->uring_lock
);
3369 ret
|= io_kill_timeouts(ctx
, task
, cancel_all
);
3371 ret
|= io_run_task_work() > 0;
3375 static s64
tctx_inflight(struct io_uring_task
*tctx
, bool tracked
)
3378 return atomic_read(&tctx
->inflight_tracked
);
3379 return percpu_counter_sum(&tctx
->inflight
);
3383 * Find any io_uring ctx that this task has registered or done IO on, and cancel
3384 * requests. @sqd should be not-null IFF it's an SQPOLL thread cancellation.
3386 __cold
void io_uring_cancel_generic(bool cancel_all
, struct io_sq_data
*sqd
)
3388 struct io_uring_task
*tctx
= current
->io_uring
;
3389 struct io_ring_ctx
*ctx
;
3390 struct io_tctx_node
*node
;
3391 unsigned long index
;
3395 WARN_ON_ONCE(sqd
&& sqd
->thread
!= current
);
3397 if (!current
->io_uring
)
3400 io_wq_exit_start(tctx
->io_wq
);
3402 atomic_inc(&tctx
->in_cancel
);
3406 io_uring_drop_tctx_refs(current
);
3407 /* read completions before cancelations */
3408 inflight
= tctx_inflight(tctx
, !cancel_all
);
3413 xa_for_each(&tctx
->xa
, index
, node
) {
3414 /* sqpoll task will cancel all its requests */
3415 if (node
->ctx
->sq_data
)
3417 loop
|= io_uring_try_cancel_requests(node
->ctx
,
3418 current
, cancel_all
);
3421 list_for_each_entry(ctx
, &sqd
->ctx_list
, sqd_list
)
3422 loop
|= io_uring_try_cancel_requests(ctx
,
3432 prepare_to_wait(&tctx
->wait
, &wait
, TASK_INTERRUPTIBLE
);
3434 io_uring_drop_tctx_refs(current
);
3435 xa_for_each(&tctx
->xa
, index
, node
) {
3436 if (!llist_empty(&node
->ctx
->work_llist
)) {
3437 WARN_ON_ONCE(node
->ctx
->submitter_task
&&
3438 node
->ctx
->submitter_task
!= current
);
3443 * If we've seen completions, retry without waiting. This
3444 * avoids a race where a completion comes in before we did
3445 * prepare_to_wait().
3447 if (inflight
== tctx_inflight(tctx
, !cancel_all
))
3450 finish_wait(&tctx
->wait
, &wait
);
3453 io_uring_clean_tctx(tctx
);
3456 * We shouldn't run task_works after cancel, so just leave
3457 * ->in_cancel set for normal exit.
3459 atomic_dec(&tctx
->in_cancel
);
3460 /* for exec all current's requests should be gone, kill tctx */
3461 __io_uring_free(current
);
3465 void __io_uring_cancel(bool cancel_all
)
3467 io_uring_cancel_generic(cancel_all
, NULL
);
3470 static void *io_uring_validate_mmap_request(struct file
*file
,
3471 loff_t pgoff
, size_t sz
)
3473 struct io_ring_ctx
*ctx
= file
->private_data
;
3474 loff_t offset
= pgoff
<< PAGE_SHIFT
;
3478 /* Don't allow mmap if the ring was setup without it */
3479 if (ctx
->flags
& IORING_SETUP_NO_MMAP
)
3480 return ERR_PTR(-EINVAL
);
3482 switch (offset
& IORING_OFF_MMAP_MASK
) {
3483 case IORING_OFF_SQ_RING
:
3484 case IORING_OFF_CQ_RING
:
3487 case IORING_OFF_SQES
:
3490 case IORING_OFF_PBUF_RING
: {
3493 bgid
= (offset
& ~IORING_OFF_MMAP_MASK
) >> IORING_OFF_PBUF_SHIFT
;
3494 mutex_lock(&ctx
->uring_lock
);
3495 ptr
= io_pbuf_get_address(ctx
, bgid
);
3496 mutex_unlock(&ctx
->uring_lock
);
3498 return ERR_PTR(-EINVAL
);
3502 return ERR_PTR(-EINVAL
);
3505 page
= virt_to_head_page(ptr
);
3506 if (sz
> page_size(page
))
3507 return ERR_PTR(-EINVAL
);
3514 static __cold
int io_uring_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3516 size_t sz
= vma
->vm_end
- vma
->vm_start
;
3520 ptr
= io_uring_validate_mmap_request(file
, vma
->vm_pgoff
, sz
);
3522 return PTR_ERR(ptr
);
3524 pfn
= virt_to_phys(ptr
) >> PAGE_SHIFT
;
3525 return remap_pfn_range(vma
, vma
->vm_start
, pfn
, sz
, vma
->vm_page_prot
);
3528 static unsigned long io_uring_mmu_get_unmapped_area(struct file
*filp
,
3529 unsigned long addr
, unsigned long len
,
3530 unsigned long pgoff
, unsigned long flags
)
3535 * Do not allow to map to user-provided address to avoid breaking the
3536 * aliasing rules. Userspace is not able to guess the offset address of
3537 * kernel kmalloc()ed memory area.
3542 ptr
= io_uring_validate_mmap_request(filp
, pgoff
, len
);
3547 * Some architectures have strong cache aliasing requirements.
3548 * For such architectures we need a coherent mapping which aliases
3549 * kernel memory *and* userspace memory. To achieve that:
3550 * - use a NULL file pointer to reference physical memory, and
3551 * - use the kernel virtual address of the shared io_uring context
3552 * (instead of the userspace-provided address, which has to be 0UL
3554 * - use the same pgoff which the get_unmapped_area() uses to
3555 * calculate the page colouring.
3556 * For architectures without such aliasing requirements, the
3557 * architecture will return any suitable mapping because addr is 0.
3560 flags
|= MAP_SHARED
;
3561 pgoff
= 0; /* has been translated to ptr above */
3563 addr
= (uintptr_t) ptr
;
3564 pgoff
= addr
>> PAGE_SHIFT
;
3568 return current
->mm
->get_unmapped_area(filp
, addr
, len
, pgoff
, flags
);
3571 #else /* !CONFIG_MMU */
3573 static int io_uring_mmap(struct file
*file
, struct vm_area_struct
*vma
)
3575 return is_nommu_shared_mapping(vma
->vm_flags
) ? 0 : -EINVAL
;
3578 static unsigned int io_uring_nommu_mmap_capabilities(struct file
*file
)
3580 return NOMMU_MAP_DIRECT
| NOMMU_MAP_READ
| NOMMU_MAP_WRITE
;
3583 static unsigned long io_uring_nommu_get_unmapped_area(struct file
*file
,
3584 unsigned long addr
, unsigned long len
,
3585 unsigned long pgoff
, unsigned long flags
)
3589 ptr
= io_uring_validate_mmap_request(file
, pgoff
, len
);
3591 return PTR_ERR(ptr
);
3593 return (unsigned long) ptr
;
3596 #endif /* !CONFIG_MMU */
3598 static int io_validate_ext_arg(unsigned flags
, const void __user
*argp
, size_t argsz
)
3600 if (flags
& IORING_ENTER_EXT_ARG
) {
3601 struct io_uring_getevents_arg arg
;
3603 if (argsz
!= sizeof(arg
))
3605 if (copy_from_user(&arg
, argp
, sizeof(arg
)))
3611 static int io_get_ext_arg(unsigned flags
, const void __user
*argp
, size_t *argsz
,
3612 struct __kernel_timespec __user
**ts
,
3613 const sigset_t __user
**sig
)
3615 struct io_uring_getevents_arg arg
;
3618 * If EXT_ARG isn't set, then we have no timespec and the argp pointer
3619 * is just a pointer to the sigset_t.
3621 if (!(flags
& IORING_ENTER_EXT_ARG
)) {
3622 *sig
= (const sigset_t __user
*) argp
;
3628 * EXT_ARG is set - ensure we agree on the size of it and copy in our
3629 * timespec and sigset_t pointers if good.
3631 if (*argsz
!= sizeof(arg
))
3633 if (copy_from_user(&arg
, argp
, sizeof(arg
)))
3637 *sig
= u64_to_user_ptr(arg
.sigmask
);
3638 *argsz
= arg
.sigmask_sz
;
3639 *ts
= u64_to_user_ptr(arg
.ts
);
3643 SYSCALL_DEFINE6(io_uring_enter
, unsigned int, fd
, u32
, to_submit
,
3644 u32
, min_complete
, u32
, flags
, const void __user
*, argp
,
3647 struct io_ring_ctx
*ctx
;
3651 if (unlikely(flags
& ~(IORING_ENTER_GETEVENTS
| IORING_ENTER_SQ_WAKEUP
|
3652 IORING_ENTER_SQ_WAIT
| IORING_ENTER_EXT_ARG
|
3653 IORING_ENTER_REGISTERED_RING
)))
3657 * Ring fd has been registered via IORING_REGISTER_RING_FDS, we
3658 * need only dereference our task private array to find it.
3660 if (flags
& IORING_ENTER_REGISTERED_RING
) {
3661 struct io_uring_task
*tctx
= current
->io_uring
;
3663 if (unlikely(!tctx
|| fd
>= IO_RINGFD_REG_MAX
))
3665 fd
= array_index_nospec(fd
, IO_RINGFD_REG_MAX
);
3666 f
.file
= tctx
->registered_rings
[fd
];
3668 if (unlikely(!f
.file
))
3672 if (unlikely(!f
.file
))
3675 if (unlikely(!io_is_uring_fops(f
.file
)))
3679 ctx
= f
.file
->private_data
;
3681 if (unlikely(ctx
->flags
& IORING_SETUP_R_DISABLED
))
3685 * For SQ polling, the thread will do all submissions and completions.
3686 * Just return the requested submit count, and wake the thread if
3690 if (ctx
->flags
& IORING_SETUP_SQPOLL
) {
3691 io_cqring_overflow_flush(ctx
);
3693 if (unlikely(ctx
->sq_data
->thread
== NULL
)) {
3697 if (flags
& IORING_ENTER_SQ_WAKEUP
)
3698 wake_up(&ctx
->sq_data
->wait
);
3699 if (flags
& IORING_ENTER_SQ_WAIT
)
3700 io_sqpoll_wait_sq(ctx
);
3703 } else if (to_submit
) {
3704 ret
= io_uring_add_tctx_node(ctx
);
3708 mutex_lock(&ctx
->uring_lock
);
3709 ret
= io_submit_sqes(ctx
, to_submit
);
3710 if (ret
!= to_submit
) {
3711 mutex_unlock(&ctx
->uring_lock
);
3714 if (flags
& IORING_ENTER_GETEVENTS
) {
3715 if (ctx
->syscall_iopoll
)
3718 * Ignore errors, we'll soon call io_cqring_wait() and
3719 * it should handle ownership problems if any.
3721 if (ctx
->flags
& IORING_SETUP_DEFER_TASKRUN
)
3722 (void)io_run_local_work_locked(ctx
);
3724 mutex_unlock(&ctx
->uring_lock
);
3727 if (flags
& IORING_ENTER_GETEVENTS
) {
3730 if (ctx
->syscall_iopoll
) {
3732 * We disallow the app entering submit/complete with
3733 * polling, but we still need to lock the ring to
3734 * prevent racing with polled issue that got punted to
3737 mutex_lock(&ctx
->uring_lock
);
3739 ret2
= io_validate_ext_arg(flags
, argp
, argsz
);
3740 if (likely(!ret2
)) {
3741 min_complete
= min(min_complete
,
3743 ret2
= io_iopoll_check(ctx
, min_complete
);
3745 mutex_unlock(&ctx
->uring_lock
);
3747 const sigset_t __user
*sig
;
3748 struct __kernel_timespec __user
*ts
;
3750 ret2
= io_get_ext_arg(flags
, argp
, &argsz
, &ts
, &sig
);
3751 if (likely(!ret2
)) {
3752 min_complete
= min(min_complete
,
3754 ret2
= io_cqring_wait(ctx
, min_complete
, sig
,
3763 * EBADR indicates that one or more CQE were dropped.
3764 * Once the user has been informed we can clear the bit
3765 * as they are obviously ok with those drops.
3767 if (unlikely(ret2
== -EBADR
))
3768 clear_bit(IO_CHECK_CQ_DROPPED_BIT
,
3777 static const struct file_operations io_uring_fops
= {
3778 .release
= io_uring_release
,
3779 .mmap
= io_uring_mmap
,
3781 .get_unmapped_area
= io_uring_nommu_get_unmapped_area
,
3782 .mmap_capabilities
= io_uring_nommu_mmap_capabilities
,
3784 .get_unmapped_area
= io_uring_mmu_get_unmapped_area
,
3786 .poll
= io_uring_poll
,
3787 #ifdef CONFIG_PROC_FS
3788 .show_fdinfo
= io_uring_show_fdinfo
,
3792 bool io_is_uring_fops(struct file
*file
)
3794 return file
->f_op
== &io_uring_fops
;
3797 static __cold
int io_allocate_scq_urings(struct io_ring_ctx
*ctx
,
3798 struct io_uring_params
*p
)
3800 struct io_rings
*rings
;
3801 size_t size
, sq_array_offset
;
3804 /* make sure these are sane, as we already accounted them */
3805 ctx
->sq_entries
= p
->sq_entries
;
3806 ctx
->cq_entries
= p
->cq_entries
;
3808 size
= rings_size(ctx
, p
->sq_entries
, p
->cq_entries
, &sq_array_offset
);
3809 if (size
== SIZE_MAX
)
3812 if (!(ctx
->flags
& IORING_SETUP_NO_MMAP
))
3813 rings
= io_mem_alloc(size
);
3815 rings
= io_rings_map(ctx
, p
->cq_off
.user_addr
, size
);
3818 return PTR_ERR(rings
);
3821 if (!(ctx
->flags
& IORING_SETUP_NO_SQARRAY
))
3822 ctx
->sq_array
= (u32
*)((char *)rings
+ sq_array_offset
);
3823 rings
->sq_ring_mask
= p
->sq_entries
- 1;
3824 rings
->cq_ring_mask
= p
->cq_entries
- 1;
3825 rings
->sq_ring_entries
= p
->sq_entries
;
3826 rings
->cq_ring_entries
= p
->cq_entries
;
3828 if (p
->flags
& IORING_SETUP_SQE128
)
3829 size
= array_size(2 * sizeof(struct io_uring_sqe
), p
->sq_entries
);
3831 size
= array_size(sizeof(struct io_uring_sqe
), p
->sq_entries
);
3832 if (size
== SIZE_MAX
) {
3837 if (!(ctx
->flags
& IORING_SETUP_NO_MMAP
))
3838 ptr
= io_mem_alloc(size
);
3840 ptr
= io_sqes_map(ctx
, p
->sq_off
.user_addr
, size
);
3844 return PTR_ERR(ptr
);
3851 static int io_uring_install_fd(struct file
*file
)
3855 fd
= get_unused_fd_flags(O_RDWR
| O_CLOEXEC
);
3858 fd_install(fd
, file
);
3863 * Allocate an anonymous fd, this is what constitutes the application
3864 * visible backing of an io_uring instance. The application mmaps this
3865 * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
3866 * we have to tie this fd to a socket for file garbage collection purposes.
3868 static struct file
*io_uring_get_file(struct io_ring_ctx
*ctx
)
3871 #if defined(CONFIG_UNIX)
3874 ret
= sock_create_kern(&init_net
, PF_UNIX
, SOCK_RAW
, IPPROTO_IP
,
3877 return ERR_PTR(ret
);
3880 file
= anon_inode_getfile_secure("[io_uring]", &io_uring_fops
, ctx
,
3881 O_RDWR
| O_CLOEXEC
, NULL
);
3882 #if defined(CONFIG_UNIX)
3884 sock_release(ctx
->ring_sock
);
3885 ctx
->ring_sock
= NULL
;
3887 ctx
->ring_sock
->file
= file
;
3893 static __cold
int io_uring_create(unsigned entries
, struct io_uring_params
*p
,
3894 struct io_uring_params __user
*params
)
3896 struct io_ring_ctx
*ctx
;
3897 struct io_uring_task
*tctx
;
3903 if (entries
> IORING_MAX_ENTRIES
) {
3904 if (!(p
->flags
& IORING_SETUP_CLAMP
))
3906 entries
= IORING_MAX_ENTRIES
;
3909 if ((p
->flags
& IORING_SETUP_REGISTERED_FD_ONLY
)
3910 && !(p
->flags
& IORING_SETUP_NO_MMAP
))
3914 * Use twice as many entries for the CQ ring. It's possible for the
3915 * application to drive a higher depth than the size of the SQ ring,
3916 * since the sqes are only used at submission time. This allows for
3917 * some flexibility in overcommitting a bit. If the application has
3918 * set IORING_SETUP_CQSIZE, it will have passed in the desired number
3919 * of CQ ring entries manually.
3921 p
->sq_entries
= roundup_pow_of_two(entries
);
3922 if (p
->flags
& IORING_SETUP_CQSIZE
) {
3924 * If IORING_SETUP_CQSIZE is set, we do the same roundup
3925 * to a power-of-two, if it isn't already. We do NOT impose
3926 * any cq vs sq ring sizing.
3930 if (p
->cq_entries
> IORING_MAX_CQ_ENTRIES
) {
3931 if (!(p
->flags
& IORING_SETUP_CLAMP
))
3933 p
->cq_entries
= IORING_MAX_CQ_ENTRIES
;
3935 p
->cq_entries
= roundup_pow_of_two(p
->cq_entries
);
3936 if (p
->cq_entries
< p
->sq_entries
)
3939 p
->cq_entries
= 2 * p
->sq_entries
;
3942 ctx
= io_ring_ctx_alloc(p
);
3946 if ((ctx
->flags
& IORING_SETUP_DEFER_TASKRUN
) &&
3947 !(ctx
->flags
& IORING_SETUP_IOPOLL
) &&
3948 !(ctx
->flags
& IORING_SETUP_SQPOLL
))
3949 ctx
->task_complete
= true;
3951 if (ctx
->task_complete
|| (ctx
->flags
& IORING_SETUP_IOPOLL
))
3952 ctx
->lockless_cq
= true;
3955 * lazy poll_wq activation relies on ->task_complete for synchronisation
3956 * purposes, see io_activate_pollwq()
3958 if (!ctx
->task_complete
)
3959 ctx
->poll_activated
= true;
3962 * When SETUP_IOPOLL and SETUP_SQPOLL are both enabled, user
3963 * space applications don't need to do io completion events
3964 * polling again, they can rely on io_sq_thread to do polling
3965 * work, which can reduce cpu usage and uring_lock contention.
3967 if (ctx
->flags
& IORING_SETUP_IOPOLL
&&
3968 !(ctx
->flags
& IORING_SETUP_SQPOLL
))
3969 ctx
->syscall_iopoll
= 1;
3971 ctx
->compat
= in_compat_syscall();
3972 if (!ns_capable_noaudit(&init_user_ns
, CAP_IPC_LOCK
))
3973 ctx
->user
= get_uid(current_user());
3976 * For SQPOLL, we just need a wakeup, always. For !SQPOLL, if
3977 * COOP_TASKRUN is set, then IPIs are never needed by the app.
3980 if (ctx
->flags
& IORING_SETUP_SQPOLL
) {
3981 /* IPI related flags don't make sense with SQPOLL */
3982 if (ctx
->flags
& (IORING_SETUP_COOP_TASKRUN
|
3983 IORING_SETUP_TASKRUN_FLAG
|
3984 IORING_SETUP_DEFER_TASKRUN
))
3986 ctx
->notify_method
= TWA_SIGNAL_NO_IPI
;
3987 } else if (ctx
->flags
& IORING_SETUP_COOP_TASKRUN
) {
3988 ctx
->notify_method
= TWA_SIGNAL_NO_IPI
;
3990 if (ctx
->flags
& IORING_SETUP_TASKRUN_FLAG
&&
3991 !(ctx
->flags
& IORING_SETUP_DEFER_TASKRUN
))
3993 ctx
->notify_method
= TWA_SIGNAL
;
3997 * For DEFER_TASKRUN we require the completion task to be the same as the
3998 * submission task. This implies that there is only one submitter, so enforce
4001 if (ctx
->flags
& IORING_SETUP_DEFER_TASKRUN
&&
4002 !(ctx
->flags
& IORING_SETUP_SINGLE_ISSUER
)) {
4007 * This is just grabbed for accounting purposes. When a process exits,
4008 * the mm is exited and dropped before the files, hence we need to hang
4009 * on to this mm purely for the purposes of being able to unaccount
4010 * memory (locked/pinned vm). It's not used for anything else.
4012 mmgrab(current
->mm
);
4013 ctx
->mm_account
= current
->mm
;
4015 ret
= io_allocate_scq_urings(ctx
, p
);
4019 ret
= io_sq_offload_create(ctx
, p
);
4023 ret
= io_rsrc_init(ctx
);
4027 p
->sq_off
.head
= offsetof(struct io_rings
, sq
.head
);
4028 p
->sq_off
.tail
= offsetof(struct io_rings
, sq
.tail
);
4029 p
->sq_off
.ring_mask
= offsetof(struct io_rings
, sq_ring_mask
);
4030 p
->sq_off
.ring_entries
= offsetof(struct io_rings
, sq_ring_entries
);
4031 p
->sq_off
.flags
= offsetof(struct io_rings
, sq_flags
);
4032 p
->sq_off
.dropped
= offsetof(struct io_rings
, sq_dropped
);
4033 if (!(ctx
->flags
& IORING_SETUP_NO_SQARRAY
))
4034 p
->sq_off
.array
= (char *)ctx
->sq_array
- (char *)ctx
->rings
;
4035 p
->sq_off
.resv1
= 0;
4036 if (!(ctx
->flags
& IORING_SETUP_NO_MMAP
))
4037 p
->sq_off
.user_addr
= 0;
4039 p
->cq_off
.head
= offsetof(struct io_rings
, cq
.head
);
4040 p
->cq_off
.tail
= offsetof(struct io_rings
, cq
.tail
);
4041 p
->cq_off
.ring_mask
= offsetof(struct io_rings
, cq_ring_mask
);
4042 p
->cq_off
.ring_entries
= offsetof(struct io_rings
, cq_ring_entries
);
4043 p
->cq_off
.overflow
= offsetof(struct io_rings
, cq_overflow
);
4044 p
->cq_off
.cqes
= offsetof(struct io_rings
, cqes
);
4045 p
->cq_off
.flags
= offsetof(struct io_rings
, cq_flags
);
4046 p
->cq_off
.resv1
= 0;
4047 if (!(ctx
->flags
& IORING_SETUP_NO_MMAP
))
4048 p
->cq_off
.user_addr
= 0;
4050 p
->features
= IORING_FEAT_SINGLE_MMAP
| IORING_FEAT_NODROP
|
4051 IORING_FEAT_SUBMIT_STABLE
| IORING_FEAT_RW_CUR_POS
|
4052 IORING_FEAT_CUR_PERSONALITY
| IORING_FEAT_FAST_POLL
|
4053 IORING_FEAT_POLL_32BITS
| IORING_FEAT_SQPOLL_NONFIXED
|
4054 IORING_FEAT_EXT_ARG
| IORING_FEAT_NATIVE_WORKERS
|
4055 IORING_FEAT_RSRC_TAGS
| IORING_FEAT_CQE_SKIP
|
4056 IORING_FEAT_LINKED_FILE
| IORING_FEAT_REG_REG_RING
;
4058 if (copy_to_user(params
, p
, sizeof(*p
))) {
4063 if (ctx
->flags
& IORING_SETUP_SINGLE_ISSUER
4064 && !(ctx
->flags
& IORING_SETUP_R_DISABLED
))
4065 WRITE_ONCE(ctx
->submitter_task
, get_task_struct(current
));
4067 file
= io_uring_get_file(ctx
);
4069 ret
= PTR_ERR(file
);
4073 ret
= __io_uring_add_tctx_node(ctx
);
4076 tctx
= current
->io_uring
;
4079 * Install ring fd as the very last thing, so we don't risk someone
4080 * having closed it before we finish setup
4082 if (p
->flags
& IORING_SETUP_REGISTERED_FD_ONLY
)
4083 ret
= io_ring_add_registered_file(tctx
, file
, 0, IO_RINGFD_REG_MAX
);
4085 ret
= io_uring_install_fd(file
);
4089 trace_io_uring_create(ret
, ctx
, p
->sq_entries
, p
->cq_entries
, p
->flags
);
4092 io_ring_ctx_wait_and_kill(ctx
);
4100 * Sets up an aio uring context, and returns the fd. Applications asks for a
4101 * ring size, we return the actual sq/cq ring sizes (among other things) in the
4102 * params structure passed in.
4104 static long io_uring_setup(u32 entries
, struct io_uring_params __user
*params
)
4106 struct io_uring_params p
;
4109 if (copy_from_user(&p
, params
, sizeof(p
)))
4111 for (i
= 0; i
< ARRAY_SIZE(p
.resv
); i
++) {
4116 if (p
.flags
& ~(IORING_SETUP_IOPOLL
| IORING_SETUP_SQPOLL
|
4117 IORING_SETUP_SQ_AFF
| IORING_SETUP_CQSIZE
|
4118 IORING_SETUP_CLAMP
| IORING_SETUP_ATTACH_WQ
|
4119 IORING_SETUP_R_DISABLED
| IORING_SETUP_SUBMIT_ALL
|
4120 IORING_SETUP_COOP_TASKRUN
| IORING_SETUP_TASKRUN_FLAG
|
4121 IORING_SETUP_SQE128
| IORING_SETUP_CQE32
|
4122 IORING_SETUP_SINGLE_ISSUER
| IORING_SETUP_DEFER_TASKRUN
|
4123 IORING_SETUP_NO_MMAP
| IORING_SETUP_REGISTERED_FD_ONLY
|
4124 IORING_SETUP_NO_SQARRAY
))
4127 return io_uring_create(entries
, &p
, params
);
4130 static inline bool io_uring_allowed(void)
4132 int disabled
= READ_ONCE(sysctl_io_uring_disabled
);
4133 kgid_t io_uring_group
;
4138 if (disabled
== 0 || capable(CAP_SYS_ADMIN
))
4141 io_uring_group
= make_kgid(&init_user_ns
, sysctl_io_uring_group
);
4142 if (!gid_valid(io_uring_group
))
4145 return in_group_p(io_uring_group
);
4148 SYSCALL_DEFINE2(io_uring_setup
, u32
, entries
,
4149 struct io_uring_params __user
*, params
)
4151 if (!io_uring_allowed())
4154 return io_uring_setup(entries
, params
);
4157 static __cold
int io_probe(struct io_ring_ctx
*ctx
, void __user
*arg
,
4160 struct io_uring_probe
*p
;
4164 size
= struct_size(p
, ops
, nr_args
);
4165 if (size
== SIZE_MAX
)
4167 p
= kzalloc(size
, GFP_KERNEL
);
4172 if (copy_from_user(p
, arg
, size
))
4175 if (memchr_inv(p
, 0, size
))
4178 p
->last_op
= IORING_OP_LAST
- 1;
4179 if (nr_args
> IORING_OP_LAST
)
4180 nr_args
= IORING_OP_LAST
;
4182 for (i
= 0; i
< nr_args
; i
++) {
4184 if (!io_issue_defs
[i
].not_supported
)
4185 p
->ops
[i
].flags
= IO_URING_OP_SUPPORTED
;
4190 if (copy_to_user(arg
, p
, size
))
4197 static int io_register_personality(struct io_ring_ctx
*ctx
)
4199 const struct cred
*creds
;
4203 creds
= get_current_cred();
4205 ret
= xa_alloc_cyclic(&ctx
->personalities
, &id
, (void *)creds
,
4206 XA_LIMIT(0, USHRT_MAX
), &ctx
->pers_next
, GFP_KERNEL
);
4214 static __cold
int io_register_restrictions(struct io_ring_ctx
*ctx
,
4215 void __user
*arg
, unsigned int nr_args
)
4217 struct io_uring_restriction
*res
;
4221 /* Restrictions allowed only if rings started disabled */
4222 if (!(ctx
->flags
& IORING_SETUP_R_DISABLED
))
4225 /* We allow only a single restrictions registration */
4226 if (ctx
->restrictions
.registered
)
4229 if (!arg
|| nr_args
> IORING_MAX_RESTRICTIONS
)
4232 size
= array_size(nr_args
, sizeof(*res
));
4233 if (size
== SIZE_MAX
)
4236 res
= memdup_user(arg
, size
);
4238 return PTR_ERR(res
);
4242 for (i
= 0; i
< nr_args
; i
++) {
4243 switch (res
[i
].opcode
) {
4244 case IORING_RESTRICTION_REGISTER_OP
:
4245 if (res
[i
].register_op
>= IORING_REGISTER_LAST
) {
4250 __set_bit(res
[i
].register_op
,
4251 ctx
->restrictions
.register_op
);
4253 case IORING_RESTRICTION_SQE_OP
:
4254 if (res
[i
].sqe_op
>= IORING_OP_LAST
) {
4259 __set_bit(res
[i
].sqe_op
, ctx
->restrictions
.sqe_op
);
4261 case IORING_RESTRICTION_SQE_FLAGS_ALLOWED
:
4262 ctx
->restrictions
.sqe_flags_allowed
= res
[i
].sqe_flags
;
4264 case IORING_RESTRICTION_SQE_FLAGS_REQUIRED
:
4265 ctx
->restrictions
.sqe_flags_required
= res
[i
].sqe_flags
;
4274 /* Reset all restrictions if an error happened */
4276 memset(&ctx
->restrictions
, 0, sizeof(ctx
->restrictions
));
4278 ctx
->restrictions
.registered
= true;
4284 static int io_register_enable_rings(struct io_ring_ctx
*ctx
)
4286 if (!(ctx
->flags
& IORING_SETUP_R_DISABLED
))
4289 if (ctx
->flags
& IORING_SETUP_SINGLE_ISSUER
&& !ctx
->submitter_task
) {
4290 WRITE_ONCE(ctx
->submitter_task
, get_task_struct(current
));
4292 * Lazy activation attempts would fail if it was polled before
4293 * submitter_task is set.
4295 if (wq_has_sleeper(&ctx
->poll_wq
))
4296 io_activate_pollwq(ctx
);
4299 if (ctx
->restrictions
.registered
)
4300 ctx
->restricted
= 1;
4302 ctx
->flags
&= ~IORING_SETUP_R_DISABLED
;
4303 if (ctx
->sq_data
&& wq_has_sleeper(&ctx
->sq_data
->wait
))
4304 wake_up(&ctx
->sq_data
->wait
);
4308 static __cold
int __io_register_iowq_aff(struct io_ring_ctx
*ctx
,
4309 cpumask_var_t new_mask
)
4313 if (!(ctx
->flags
& IORING_SETUP_SQPOLL
)) {
4314 ret
= io_wq_cpu_affinity(current
->io_uring
, new_mask
);
4316 mutex_unlock(&ctx
->uring_lock
);
4317 ret
= io_sqpoll_wq_cpu_affinity(ctx
, new_mask
);
4318 mutex_lock(&ctx
->uring_lock
);
4324 static __cold
int io_register_iowq_aff(struct io_ring_ctx
*ctx
,
4325 void __user
*arg
, unsigned len
)
4327 cpumask_var_t new_mask
;
4330 if (!alloc_cpumask_var(&new_mask
, GFP_KERNEL
))
4333 cpumask_clear(new_mask
);
4334 if (len
> cpumask_size())
4335 len
= cpumask_size();
4337 if (in_compat_syscall()) {
4338 ret
= compat_get_bitmap(cpumask_bits(new_mask
),
4339 (const compat_ulong_t __user
*)arg
,
4340 len
* 8 /* CHAR_BIT */);
4342 ret
= copy_from_user(new_mask
, arg
, len
);
4346 free_cpumask_var(new_mask
);
4350 ret
= __io_register_iowq_aff(ctx
, new_mask
);
4351 free_cpumask_var(new_mask
);
4355 static __cold
int io_unregister_iowq_aff(struct io_ring_ctx
*ctx
)
4357 return __io_register_iowq_aff(ctx
, NULL
);
4360 static __cold
int io_register_iowq_max_workers(struct io_ring_ctx
*ctx
,
4362 __must_hold(&ctx
->uring_lock
)
4364 struct io_tctx_node
*node
;
4365 struct io_uring_task
*tctx
= NULL
;
4366 struct io_sq_data
*sqd
= NULL
;
4370 if (copy_from_user(new_count
, arg
, sizeof(new_count
)))
4372 for (i
= 0; i
< ARRAY_SIZE(new_count
); i
++)
4373 if (new_count
[i
] > INT_MAX
)
4376 if (ctx
->flags
& IORING_SETUP_SQPOLL
) {
4380 * Observe the correct sqd->lock -> ctx->uring_lock
4381 * ordering. Fine to drop uring_lock here, we hold
4384 refcount_inc(&sqd
->refs
);
4385 mutex_unlock(&ctx
->uring_lock
);
4386 mutex_lock(&sqd
->lock
);
4387 mutex_lock(&ctx
->uring_lock
);
4389 tctx
= sqd
->thread
->io_uring
;
4392 tctx
= current
->io_uring
;
4395 BUILD_BUG_ON(sizeof(new_count
) != sizeof(ctx
->iowq_limits
));
4397 for (i
= 0; i
< ARRAY_SIZE(new_count
); i
++)
4399 ctx
->iowq_limits
[i
] = new_count
[i
];
4400 ctx
->iowq_limits_set
= true;
4402 if (tctx
&& tctx
->io_wq
) {
4403 ret
= io_wq_max_workers(tctx
->io_wq
, new_count
);
4407 memset(new_count
, 0, sizeof(new_count
));
4411 mutex_unlock(&sqd
->lock
);
4412 io_put_sq_data(sqd
);
4415 if (copy_to_user(arg
, new_count
, sizeof(new_count
)))
4418 /* that's it for SQPOLL, only the SQPOLL task creates requests */
4422 /* now propagate the restriction to all registered users */
4423 list_for_each_entry(node
, &ctx
->tctx_list
, ctx_node
) {
4424 struct io_uring_task
*tctx
= node
->task
->io_uring
;
4426 if (WARN_ON_ONCE(!tctx
->io_wq
))
4429 for (i
= 0; i
< ARRAY_SIZE(new_count
); i
++)
4430 new_count
[i
] = ctx
->iowq_limits
[i
];
4431 /* ignore errors, it always returns zero anyway */
4432 (void)io_wq_max_workers(tctx
->io_wq
, new_count
);
4437 mutex_unlock(&sqd
->lock
);
4438 io_put_sq_data(sqd
);
4443 static int __io_uring_register(struct io_ring_ctx
*ctx
, unsigned opcode
,
4444 void __user
*arg
, unsigned nr_args
)
4445 __releases(ctx
->uring_lock
)
4446 __acquires(ctx
->uring_lock
)
4451 * We don't quiesce the refs for register anymore and so it can't be
4452 * dying as we're holding a file ref here.
4454 if (WARN_ON_ONCE(percpu_ref_is_dying(&ctx
->refs
)))
4457 if (ctx
->submitter_task
&& ctx
->submitter_task
!= current
)
4460 if (ctx
->restricted
) {
4461 opcode
= array_index_nospec(opcode
, IORING_REGISTER_LAST
);
4462 if (!test_bit(opcode
, ctx
->restrictions
.register_op
))
4467 case IORING_REGISTER_BUFFERS
:
4471 ret
= io_sqe_buffers_register(ctx
, arg
, nr_args
, NULL
);
4473 case IORING_UNREGISTER_BUFFERS
:
4477 ret
= io_sqe_buffers_unregister(ctx
);
4479 case IORING_REGISTER_FILES
:
4483 ret
= io_sqe_files_register(ctx
, arg
, nr_args
, NULL
);
4485 case IORING_UNREGISTER_FILES
:
4489 ret
= io_sqe_files_unregister(ctx
);
4491 case IORING_REGISTER_FILES_UPDATE
:
4492 ret
= io_register_files_update(ctx
, arg
, nr_args
);
4494 case IORING_REGISTER_EVENTFD
:
4498 ret
= io_eventfd_register(ctx
, arg
, 0);
4500 case IORING_REGISTER_EVENTFD_ASYNC
:
4504 ret
= io_eventfd_register(ctx
, arg
, 1);
4506 case IORING_UNREGISTER_EVENTFD
:
4510 ret
= io_eventfd_unregister(ctx
);
4512 case IORING_REGISTER_PROBE
:
4514 if (!arg
|| nr_args
> 256)
4516 ret
= io_probe(ctx
, arg
, nr_args
);
4518 case IORING_REGISTER_PERSONALITY
:
4522 ret
= io_register_personality(ctx
);
4524 case IORING_UNREGISTER_PERSONALITY
:
4528 ret
= io_unregister_personality(ctx
, nr_args
);
4530 case IORING_REGISTER_ENABLE_RINGS
:
4534 ret
= io_register_enable_rings(ctx
);
4536 case IORING_REGISTER_RESTRICTIONS
:
4537 ret
= io_register_restrictions(ctx
, arg
, nr_args
);
4539 case IORING_REGISTER_FILES2
:
4540 ret
= io_register_rsrc(ctx
, arg
, nr_args
, IORING_RSRC_FILE
);
4542 case IORING_REGISTER_FILES_UPDATE2
:
4543 ret
= io_register_rsrc_update(ctx
, arg
, nr_args
,
4546 case IORING_REGISTER_BUFFERS2
:
4547 ret
= io_register_rsrc(ctx
, arg
, nr_args
, IORING_RSRC_BUFFER
);
4549 case IORING_REGISTER_BUFFERS_UPDATE
:
4550 ret
= io_register_rsrc_update(ctx
, arg
, nr_args
,
4551 IORING_RSRC_BUFFER
);
4553 case IORING_REGISTER_IOWQ_AFF
:
4555 if (!arg
|| !nr_args
)
4557 ret
= io_register_iowq_aff(ctx
, arg
, nr_args
);
4559 case IORING_UNREGISTER_IOWQ_AFF
:
4563 ret
= io_unregister_iowq_aff(ctx
);
4565 case IORING_REGISTER_IOWQ_MAX_WORKERS
:
4567 if (!arg
|| nr_args
!= 2)
4569 ret
= io_register_iowq_max_workers(ctx
, arg
);
4571 case IORING_REGISTER_RING_FDS
:
4572 ret
= io_ringfd_register(ctx
, arg
, nr_args
);
4574 case IORING_UNREGISTER_RING_FDS
:
4575 ret
= io_ringfd_unregister(ctx
, arg
, nr_args
);
4577 case IORING_REGISTER_PBUF_RING
:
4579 if (!arg
|| nr_args
!= 1)
4581 ret
= io_register_pbuf_ring(ctx
, arg
);
4583 case IORING_UNREGISTER_PBUF_RING
:
4585 if (!arg
|| nr_args
!= 1)
4587 ret
= io_unregister_pbuf_ring(ctx
, arg
);
4589 case IORING_REGISTER_SYNC_CANCEL
:
4591 if (!arg
|| nr_args
!= 1)
4593 ret
= io_sync_cancel(ctx
, arg
);
4595 case IORING_REGISTER_FILE_ALLOC_RANGE
:
4597 if (!arg
|| nr_args
)
4599 ret
= io_register_file_alloc_range(ctx
, arg
);
4609 SYSCALL_DEFINE4(io_uring_register
, unsigned int, fd
, unsigned int, opcode
,
4610 void __user
*, arg
, unsigned int, nr_args
)
4612 struct io_ring_ctx
*ctx
;
4615 bool use_registered_ring
;
4617 use_registered_ring
= !!(opcode
& IORING_REGISTER_USE_REGISTERED_RING
);
4618 opcode
&= ~IORING_REGISTER_USE_REGISTERED_RING
;
4620 if (opcode
>= IORING_REGISTER_LAST
)
4623 if (use_registered_ring
) {
4625 * Ring fd has been registered via IORING_REGISTER_RING_FDS, we
4626 * need only dereference our task private array to find it.
4628 struct io_uring_task
*tctx
= current
->io_uring
;
4630 if (unlikely(!tctx
|| fd
>= IO_RINGFD_REG_MAX
))
4632 fd
= array_index_nospec(fd
, IO_RINGFD_REG_MAX
);
4633 f
.file
= tctx
->registered_rings
[fd
];
4635 if (unlikely(!f
.file
))
4639 if (unlikely(!f
.file
))
4642 if (!io_is_uring_fops(f
.file
))
4646 ctx
= f
.file
->private_data
;
4648 mutex_lock(&ctx
->uring_lock
);
4649 ret
= __io_uring_register(ctx
, opcode
, arg
, nr_args
);
4650 mutex_unlock(&ctx
->uring_lock
);
4651 trace_io_uring_register(ctx
, opcode
, ctx
->nr_user_files
, ctx
->nr_user_bufs
, ret
);
4657 static int __init
io_uring_init(void)
4659 #define __BUILD_BUG_VERIFY_OFFSET_SIZE(stype, eoffset, esize, ename) do { \
4660 BUILD_BUG_ON(offsetof(stype, ename) != eoffset); \
4661 BUILD_BUG_ON(sizeof_field(stype, ename) != esize); \
4664 #define BUILD_BUG_SQE_ELEM(eoffset, etype, ename) \
4665 __BUILD_BUG_VERIFY_OFFSET_SIZE(struct io_uring_sqe, eoffset, sizeof(etype), ename)
4666 #define BUILD_BUG_SQE_ELEM_SIZE(eoffset, esize, ename) \
4667 __BUILD_BUG_VERIFY_OFFSET_SIZE(struct io_uring_sqe, eoffset, esize, ename)
4668 BUILD_BUG_ON(sizeof(struct io_uring_sqe
) != 64);
4669 BUILD_BUG_SQE_ELEM(0, __u8
, opcode
);
4670 BUILD_BUG_SQE_ELEM(1, __u8
, flags
);
4671 BUILD_BUG_SQE_ELEM(2, __u16
, ioprio
);
4672 BUILD_BUG_SQE_ELEM(4, __s32
, fd
);
4673 BUILD_BUG_SQE_ELEM(8, __u64
, off
);
4674 BUILD_BUG_SQE_ELEM(8, __u64
, addr2
);
4675 BUILD_BUG_SQE_ELEM(8, __u32
, cmd_op
);
4676 BUILD_BUG_SQE_ELEM(12, __u32
, __pad1
);
4677 BUILD_BUG_SQE_ELEM(16, __u64
, addr
);
4678 BUILD_BUG_SQE_ELEM(16, __u64
, splice_off_in
);
4679 BUILD_BUG_SQE_ELEM(24, __u32
, len
);
4680 BUILD_BUG_SQE_ELEM(28, __kernel_rwf_t
, rw_flags
);
4681 BUILD_BUG_SQE_ELEM(28, /* compat */ int, rw_flags
);
4682 BUILD_BUG_SQE_ELEM(28, /* compat */ __u32
, rw_flags
);
4683 BUILD_BUG_SQE_ELEM(28, __u32
, fsync_flags
);
4684 BUILD_BUG_SQE_ELEM(28, /* compat */ __u16
, poll_events
);
4685 BUILD_BUG_SQE_ELEM(28, __u32
, poll32_events
);
4686 BUILD_BUG_SQE_ELEM(28, __u32
, sync_range_flags
);
4687 BUILD_BUG_SQE_ELEM(28, __u32
, msg_flags
);
4688 BUILD_BUG_SQE_ELEM(28, __u32
, timeout_flags
);
4689 BUILD_BUG_SQE_ELEM(28, __u32
, accept_flags
);
4690 BUILD_BUG_SQE_ELEM(28, __u32
, cancel_flags
);
4691 BUILD_BUG_SQE_ELEM(28, __u32
, open_flags
);
4692 BUILD_BUG_SQE_ELEM(28, __u32
, statx_flags
);
4693 BUILD_BUG_SQE_ELEM(28, __u32
, fadvise_advice
);
4694 BUILD_BUG_SQE_ELEM(28, __u32
, splice_flags
);
4695 BUILD_BUG_SQE_ELEM(28, __u32
, rename_flags
);
4696 BUILD_BUG_SQE_ELEM(28, __u32
, unlink_flags
);
4697 BUILD_BUG_SQE_ELEM(28, __u32
, hardlink_flags
);
4698 BUILD_BUG_SQE_ELEM(28, __u32
, xattr_flags
);
4699 BUILD_BUG_SQE_ELEM(28, __u32
, msg_ring_flags
);
4700 BUILD_BUG_SQE_ELEM(32, __u64
, user_data
);
4701 BUILD_BUG_SQE_ELEM(40, __u16
, buf_index
);
4702 BUILD_BUG_SQE_ELEM(40, __u16
, buf_group
);
4703 BUILD_BUG_SQE_ELEM(42, __u16
, personality
);
4704 BUILD_BUG_SQE_ELEM(44, __s32
, splice_fd_in
);
4705 BUILD_BUG_SQE_ELEM(44, __u32
, file_index
);
4706 BUILD_BUG_SQE_ELEM(44, __u16
, addr_len
);
4707 BUILD_BUG_SQE_ELEM(46, __u16
, __pad3
[0]);
4708 BUILD_BUG_SQE_ELEM(48, __u64
, addr3
);
4709 BUILD_BUG_SQE_ELEM_SIZE(48, 0, cmd
);
4710 BUILD_BUG_SQE_ELEM(56, __u64
, __pad2
);
4712 BUILD_BUG_ON(sizeof(struct io_uring_files_update
) !=
4713 sizeof(struct io_uring_rsrc_update
));
4714 BUILD_BUG_ON(sizeof(struct io_uring_rsrc_update
) >
4715 sizeof(struct io_uring_rsrc_update2
));
4717 /* ->buf_index is u16 */
4718 BUILD_BUG_ON(offsetof(struct io_uring_buf_ring
, bufs
) != 0);
4719 BUILD_BUG_ON(offsetof(struct io_uring_buf
, resv
) !=
4720 offsetof(struct io_uring_buf_ring
, tail
));
4722 /* should fit into one byte */
4723 BUILD_BUG_ON(SQE_VALID_FLAGS
>= (1 << 8));
4724 BUILD_BUG_ON(SQE_COMMON_FLAGS
>= (1 << 8));
4725 BUILD_BUG_ON((SQE_VALID_FLAGS
| SQE_COMMON_FLAGS
) != SQE_VALID_FLAGS
);
4727 BUILD_BUG_ON(__REQ_F_LAST_BIT
> 8 * sizeof(int));
4729 BUILD_BUG_ON(sizeof(atomic_t
) != sizeof(u32
));
4731 /* top 8bits are for internal use */
4732 BUILD_BUG_ON((IORING_URING_CMD_MASK
& 0xff000000) != 0);
4734 io_uring_optable_init();
4737 * Allow user copy in the per-command field, which starts after the
4738 * file in io_kiocb and until the opcode field. The openat2 handling
4739 * requires copying in user memory into the io_kiocb object in that
4740 * range, and HARDENED_USERCOPY will complain if we haven't
4741 * correctly annotated this range.
4743 req_cachep
= kmem_cache_create_usercopy("io_kiocb",
4744 sizeof(struct io_kiocb
), 0,
4745 SLAB_HWCACHE_ALIGN
| SLAB_PANIC
|
4746 SLAB_ACCOUNT
| SLAB_TYPESAFE_BY_RCU
,
4747 offsetof(struct io_kiocb
, cmd
.data
),
4748 sizeof_field(struct io_kiocb
, cmd
.data
), NULL
);
4749 io_buf_cachep
= kmem_cache_create("io_buffer", sizeof(struct io_buffer
), 0,
4750 SLAB_HWCACHE_ALIGN
| SLAB_PANIC
| SLAB_ACCOUNT
,
4753 #ifdef CONFIG_SYSCTL
4754 register_sysctl_init("kernel", kernel_io_uring_disabled_table
);
4759 __initcall(io_uring_init
);