obj-$(CONFIG_IO_URING) += io_uring.o opdef.o kbuf.o rsrc.o notif.o \
tctx.o filetable.o rw.o poll.o \
- tw.o eventfd.o uring_cmd.o openclose.o \
- sqpoll.o xattr.o nop.o fs.o splice.o \
- sync.o msg_ring.o advise.o openclose.o \
- statx.o timeout.o cancel.o \
- waitid.o register.o truncate.o \
- memmap.o alloc_cache.o query.o
+ tw.o wait.o eventfd.o uring_cmd.o \
+ openclose.o sqpoll.o xattr.o nop.o \
+ fs.o splice.o sync.o msg_ring.o \
+ advise.o openclose.o statx.o timeout.o \
+ cancel.o waitid.o register.o \
+ truncate.o memmap.o alloc_cache.o \
+ query.o
obj-$(CONFIG_IO_URING_ZCRX) += zcrx.o
obj-$(CONFIG_IO_WQ) += io-wq.o
#include "waitid.h"
#include "futex.h"
#include "cancel.h"
+#include "wait.h"
struct io_cancel {
struct file *file;
#include "rw.h"
#include "alloc_cache.h"
#include "eventfd.h"
+#include "wait.h"
#define SQE_COMMON_FLAGS (IOSQE_FIXED_FILE | IOSQE_IO_LINK | \
IOSQE_IO_HARDLINK | IOSQE_ASYNC)
req->link = IO_URING_PTR_POISON;
}
-static inline unsigned int __io_cqring_events(struct io_ring_ctx *ctx)
-{
- return ctx->cached_cq_tail - READ_ONCE(ctx->rings->cq.head);
-}
-
-static inline unsigned int __io_cqring_events_user(struct io_ring_ctx *ctx)
-{
- return READ_ONCE(ctx->rings->cq.tail) - READ_ONCE(ctx->rings->cq.head);
-}
-
static inline void req_fail_link_node(struct io_kiocb *req, int res)
{
req_set_fail(req);
__io_cqring_overflow_flush(ctx, true);
}
-static void io_cqring_do_overflow_flush(struct io_ring_ctx *ctx)
+void io_cqring_do_overflow_flush(struct io_ring_ctx *ctx)
{
mutex_lock(&ctx->uring_lock);
__io_cqring_overflow_flush(ctx, false);
ctx->submit_state.cq_flush = false;
}
-static unsigned io_cqring_events(struct io_ring_ctx *ctx)
-{
- /* See comment at the top of this file */
- smp_rmb();
- return __io_cqring_events(ctx);
-}
-
/*
* We can't just wait for polled events to come to us, we have to actively
* find and complete them.
return ret;
}
-static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode,
- int wake_flags, void *key)
-{
- struct io_wait_queue *iowq = container_of(curr, struct io_wait_queue, wq);
-
- /*
- * Cannot safely flush overflowed CQEs from here, ensure we wake up
- * the task, and the next invocation will do it.
- */
- if (io_should_wake(iowq) || io_has_work(iowq->ctx))
- return autoremove_wake_function(curr, mode, wake_flags, key);
- return -1;
-}
-
-int io_run_task_work_sig(struct io_ring_ctx *ctx)
-{
- if (io_local_work_pending(ctx)) {
- __set_current_state(TASK_RUNNING);
- if (io_run_local_work(ctx, INT_MAX, IO_LOCAL_TW_DEFAULT_MAX) > 0)
- return 0;
- }
- if (io_run_task_work() > 0)
- return 0;
- if (task_sigpending(current))
- return -EINTR;
- return 0;
-}
-
-static bool current_pending_io(void)
-{
- struct io_uring_task *tctx = current->io_uring;
-
- if (!tctx)
- return false;
- return percpu_counter_read_positive(&tctx->inflight);
-}
-
-static enum hrtimer_restart io_cqring_timer_wakeup(struct hrtimer *timer)
-{
- struct io_wait_queue *iowq = container_of(timer, struct io_wait_queue, t);
-
- WRITE_ONCE(iowq->hit_timeout, 1);
- iowq->min_timeout = 0;
- wake_up_process(iowq->wq.private);
- return HRTIMER_NORESTART;
-}
-
-/*
- * Doing min_timeout portion. If we saw any timeouts, events, or have work,
- * wake up. If not, and we have a normal timeout, switch to that and keep
- * sleeping.
- */
-static enum hrtimer_restart io_cqring_min_timer_wakeup(struct hrtimer *timer)
-{
- struct io_wait_queue *iowq = container_of(timer, struct io_wait_queue, t);
- struct io_ring_ctx *ctx = iowq->ctx;
-
- /* no general timeout, or shorter (or equal), we are done */
- if (iowq->timeout == KTIME_MAX ||
- ktime_compare(iowq->min_timeout, iowq->timeout) >= 0)
- goto out_wake;
- /* work we may need to run, wake function will see if we need to wake */
- if (io_has_work(ctx))
- goto out_wake;
- /* got events since we started waiting, min timeout is done */
- if (iowq->cq_min_tail != READ_ONCE(ctx->rings->cq.tail))
- goto out_wake;
- /* if we have any events and min timeout expired, we're done */
- if (io_cqring_events(ctx))
- goto out_wake;
-
- /*
- * If using deferred task_work running and application is waiting on
- * more than one request, ensure we reset it now where we are switching
- * to normal sleeps. Any request completion post min_wait should wake
- * the task and return.
- */
- if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) {
- atomic_set(&ctx->cq_wait_nr, 1);
- smp_mb();
- if (!llist_empty(&ctx->work_llist))
- goto out_wake;
- }
-
- /* any generated CQE posted past this time should wake us up */
- iowq->cq_tail = iowq->cq_min_tail;
-
- hrtimer_update_function(&iowq->t, io_cqring_timer_wakeup);
- hrtimer_set_expires(timer, iowq->timeout);
- return HRTIMER_RESTART;
-out_wake:
- return io_cqring_timer_wakeup(timer);
-}
-
-static int io_cqring_schedule_timeout(struct io_wait_queue *iowq,
- clockid_t clock_id, ktime_t start_time)
-{
- ktime_t timeout;
-
- if (iowq->min_timeout) {
- timeout = ktime_add_ns(iowq->min_timeout, start_time);
- hrtimer_setup_on_stack(&iowq->t, io_cqring_min_timer_wakeup, clock_id,
- HRTIMER_MODE_ABS);
- } else {
- timeout = iowq->timeout;
- hrtimer_setup_on_stack(&iowq->t, io_cqring_timer_wakeup, clock_id,
- HRTIMER_MODE_ABS);
- }
-
- hrtimer_set_expires_range_ns(&iowq->t, timeout, 0);
- hrtimer_start_expires(&iowq->t, HRTIMER_MODE_ABS);
-
- if (!READ_ONCE(iowq->hit_timeout))
- schedule();
-
- hrtimer_cancel(&iowq->t);
- destroy_hrtimer_on_stack(&iowq->t);
- __set_current_state(TASK_RUNNING);
-
- return READ_ONCE(iowq->hit_timeout) ? -ETIME : 0;
-}
-
-struct ext_arg {
- size_t argsz;
- struct timespec64 ts;
- const sigset_t __user *sig;
- ktime_t min_time;
- bool ts_set;
- bool iowait;
-};
-
-static int __io_cqring_wait_schedule(struct io_ring_ctx *ctx,
- struct io_wait_queue *iowq,
- struct ext_arg *ext_arg,
- ktime_t start_time)
-{
- int ret = 0;
-
- /*
- * Mark us as being in io_wait if we have pending requests, so cpufreq
- * can take into account that the task is waiting for IO - turns out
- * to be important for low QD IO.
- */
- if (ext_arg->iowait && current_pending_io())
- current->in_iowait = 1;
- if (iowq->timeout != KTIME_MAX || iowq->min_timeout)
- ret = io_cqring_schedule_timeout(iowq, ctx->clockid, start_time);
- else
- schedule();
- current->in_iowait = 0;
- return ret;
-}
-
-/* If this returns > 0, the caller should retry */
-static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx,
- struct io_wait_queue *iowq,
- struct ext_arg *ext_arg,
- ktime_t start_time)
-{
- if (unlikely(READ_ONCE(ctx->check_cq)))
- return 1;
- if (unlikely(io_local_work_pending(ctx)))
- return 1;
- if (unlikely(task_work_pending(current)))
- return 1;
- if (unlikely(task_sigpending(current)))
- return -EINTR;
- if (unlikely(io_should_wake(iowq)))
- return 0;
-
- return __io_cqring_wait_schedule(ctx, iowq, ext_arg, start_time);
-}
-
-/*
- * Wait until events become available, if we don't already have some. The
- * application must reap them itself, as they reside on the shared cq ring.
- */
-static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, u32 flags,
- struct ext_arg *ext_arg)
-{
- struct io_wait_queue iowq;
- struct io_rings *rings = ctx->rings;
- ktime_t start_time;
- int ret;
-
- min_events = min_t(int, min_events, ctx->cq_entries);
-
- if (!io_allowed_run_tw(ctx))
- return -EEXIST;
- if (io_local_work_pending(ctx))
- io_run_local_work(ctx, min_events,
- max(IO_LOCAL_TW_DEFAULT_MAX, min_events));
- io_run_task_work();
-
- if (unlikely(test_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq)))
- io_cqring_do_overflow_flush(ctx);
- if (__io_cqring_events_user(ctx) >= min_events)
- return 0;
-
- init_waitqueue_func_entry(&iowq.wq, io_wake_function);
- iowq.wq.private = current;
- INIT_LIST_HEAD(&iowq.wq.entry);
- iowq.ctx = ctx;
- iowq.cq_tail = READ_ONCE(ctx->rings->cq.head) + min_events;
- iowq.cq_min_tail = READ_ONCE(ctx->rings->cq.tail);
- iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts);
- iowq.hit_timeout = 0;
- iowq.min_timeout = ext_arg->min_time;
- iowq.timeout = KTIME_MAX;
- start_time = io_get_time(ctx);
-
- if (ext_arg->ts_set) {
- iowq.timeout = timespec64_to_ktime(ext_arg->ts);
- if (!(flags & IORING_ENTER_ABS_TIMER))
- iowq.timeout = ktime_add(iowq.timeout, start_time);
- }
-
- if (ext_arg->sig) {
-#ifdef CONFIG_COMPAT
- if (in_compat_syscall())
- ret = set_compat_user_sigmask((const compat_sigset_t __user *)ext_arg->sig,
- ext_arg->argsz);
- else
-#endif
- ret = set_user_sigmask(ext_arg->sig, ext_arg->argsz);
-
- if (ret)
- return ret;
- }
-
- io_napi_busy_loop(ctx, &iowq);
-
- trace_io_uring_cqring_wait(ctx, min_events);
- do {
- unsigned long check_cq;
- int nr_wait;
-
- /* if min timeout has been hit, don't reset wait count */
- if (!iowq.hit_timeout)
- nr_wait = (int) iowq.cq_tail -
- READ_ONCE(ctx->rings->cq.tail);
- else
- nr_wait = 1;
-
- if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) {
- atomic_set(&ctx->cq_wait_nr, nr_wait);
- set_current_state(TASK_INTERRUPTIBLE);
- } else {
- prepare_to_wait_exclusive(&ctx->cq_wait, &iowq.wq,
- TASK_INTERRUPTIBLE);
- }
-
- ret = io_cqring_wait_schedule(ctx, &iowq, ext_arg, start_time);
- __set_current_state(TASK_RUNNING);
- atomic_set(&ctx->cq_wait_nr, IO_CQ_WAKE_INIT);
-
- /*
- * Run task_work after scheduling and before io_should_wake().
- * If we got woken because of task_work being processed, run it
- * now rather than let the caller do another wait loop.
- */
- if (io_local_work_pending(ctx))
- io_run_local_work(ctx, nr_wait, nr_wait);
- io_run_task_work();
-
- /*
- * Non-local task_work will be run on exit to userspace, but
- * if we're using DEFER_TASKRUN, then we could have waited
- * with a timeout for a number of requests. If the timeout
- * hits, we could have some requests ready to process. Ensure
- * this break is _after_ we have run task_work, to avoid
- * deferring running potentially pending requests until the
- * next time we wait for events.
- */
- if (ret < 0)
- break;
-
- check_cq = READ_ONCE(ctx->check_cq);
- if (unlikely(check_cq)) {
- /* let the caller flush overflows, retry */
- if (check_cq & BIT(IO_CHECK_CQ_OVERFLOW_BIT))
- io_cqring_do_overflow_flush(ctx);
- if (check_cq & BIT(IO_CHECK_CQ_DROPPED_BIT)) {
- ret = -EBADR;
- break;
- }
- }
-
- if (io_should_wake(&iowq)) {
- ret = 0;
- break;
- }
- cond_resched();
- } while (1);
-
- if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN))
- finish_wait(&ctx->cq_wait, &iowq.wq);
- restore_saved_sigmask_unless(ret == -EINTR);
-
- return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0;
-}
-
static void io_rings_free(struct io_ring_ctx *ctx)
{
io_free_region(ctx->user, &ctx->sq_region);
#include "poll.h"
#include "rw.h"
#include "eventfd.h"
+#include "wait.h"
void io_fallback_req_func(struct work_struct *work)
{
#define IO_LOCAL_TW_DEFAULT_MAX 20
-/*
- * No waiters. It's larger than any valid value of the tw counter
- * so that tests against ->cq_wait_nr would fail and skip wake_up().
- */
-#define IO_CQ_WAKE_INIT (-1U)
-/* Forced wake up if there is a waiter regardless of ->cq_wait_nr */
-#define IO_CQ_WAKE_FORCE (IO_CQ_WAKE_INIT >> 1)
-
/*
* Terminate the request if either of these conditions are true:
*
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Waiting for completion events
+ */
+#include <linux/kernel.h>
+#include <linux/sched/signal.h>
+#include <linux/io_uring.h>
+
+#include <trace/events/io_uring.h>
+
+#include <uapi/linux/io_uring.h>
+
+#include "io_uring.h"
+#include "napi.h"
+#include "wait.h"
+
+static int io_wake_function(struct wait_queue_entry *curr, unsigned int mode,
+ int wake_flags, void *key)
+{
+ struct io_wait_queue *iowq = container_of(curr, struct io_wait_queue, wq);
+
+ /*
+ * Cannot safely flush overflowed CQEs from here, ensure we wake up
+ * the task, and the next invocation will do it.
+ */
+ if (io_should_wake(iowq) || io_has_work(iowq->ctx))
+ return autoremove_wake_function(curr, mode, wake_flags, key);
+ return -1;
+}
+
+int io_run_task_work_sig(struct io_ring_ctx *ctx)
+{
+ if (io_local_work_pending(ctx)) {
+ __set_current_state(TASK_RUNNING);
+ if (io_run_local_work(ctx, INT_MAX, IO_LOCAL_TW_DEFAULT_MAX) > 0)
+ return 0;
+ }
+ if (io_run_task_work() > 0)
+ return 0;
+ if (task_sigpending(current))
+ return -EINTR;
+ return 0;
+}
+
+static bool current_pending_io(void)
+{
+ struct io_uring_task *tctx = current->io_uring;
+
+ if (!tctx)
+ return false;
+ return percpu_counter_read_positive(&tctx->inflight);
+}
+
+static enum hrtimer_restart io_cqring_timer_wakeup(struct hrtimer *timer)
+{
+ struct io_wait_queue *iowq = container_of(timer, struct io_wait_queue, t);
+
+ WRITE_ONCE(iowq->hit_timeout, 1);
+ iowq->min_timeout = 0;
+ wake_up_process(iowq->wq.private);
+ return HRTIMER_NORESTART;
+}
+
+/*
+ * Doing min_timeout portion. If we saw any timeouts, events, or have work,
+ * wake up. If not, and we have a normal timeout, switch to that and keep
+ * sleeping.
+ */
+static enum hrtimer_restart io_cqring_min_timer_wakeup(struct hrtimer *timer)
+{
+ struct io_wait_queue *iowq = container_of(timer, struct io_wait_queue, t);
+ struct io_ring_ctx *ctx = iowq->ctx;
+
+ /* no general timeout, or shorter (or equal), we are done */
+ if (iowq->timeout == KTIME_MAX ||
+ ktime_compare(iowq->min_timeout, iowq->timeout) >= 0)
+ goto out_wake;
+ /* work we may need to run, wake function will see if we need to wake */
+ if (io_has_work(ctx))
+ goto out_wake;
+ /* got events since we started waiting, min timeout is done */
+ if (iowq->cq_min_tail != READ_ONCE(ctx->rings->cq.tail))
+ goto out_wake;
+ /* if we have any events and min timeout expired, we're done */
+ if (io_cqring_events(ctx))
+ goto out_wake;
+
+ /*
+ * If using deferred task_work running and application is waiting on
+ * more than one request, ensure we reset it now where we are switching
+ * to normal sleeps. Any request completion post min_wait should wake
+ * the task and return.
+ */
+ if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) {
+ atomic_set(&ctx->cq_wait_nr, 1);
+ smp_mb();
+ if (!llist_empty(&ctx->work_llist))
+ goto out_wake;
+ }
+
+ /* any generated CQE posted past this time should wake us up */
+ iowq->cq_tail = iowq->cq_min_tail;
+
+ hrtimer_update_function(&iowq->t, io_cqring_timer_wakeup);
+ hrtimer_set_expires(timer, iowq->timeout);
+ return HRTIMER_RESTART;
+out_wake:
+ return io_cqring_timer_wakeup(timer);
+}
+
+static int io_cqring_schedule_timeout(struct io_wait_queue *iowq,
+ clockid_t clock_id, ktime_t start_time)
+{
+ ktime_t timeout;
+
+ if (iowq->min_timeout) {
+ timeout = ktime_add_ns(iowq->min_timeout, start_time);
+ hrtimer_setup_on_stack(&iowq->t, io_cqring_min_timer_wakeup, clock_id,
+ HRTIMER_MODE_ABS);
+ } else {
+ timeout = iowq->timeout;
+ hrtimer_setup_on_stack(&iowq->t, io_cqring_timer_wakeup, clock_id,
+ HRTIMER_MODE_ABS);
+ }
+
+ hrtimer_set_expires_range_ns(&iowq->t, timeout, 0);
+ hrtimer_start_expires(&iowq->t, HRTIMER_MODE_ABS);
+
+ if (!READ_ONCE(iowq->hit_timeout))
+ schedule();
+
+ hrtimer_cancel(&iowq->t);
+ destroy_hrtimer_on_stack(&iowq->t);
+ __set_current_state(TASK_RUNNING);
+
+ return READ_ONCE(iowq->hit_timeout) ? -ETIME : 0;
+}
+
+static int __io_cqring_wait_schedule(struct io_ring_ctx *ctx,
+ struct io_wait_queue *iowq,
+ struct ext_arg *ext_arg,
+ ktime_t start_time)
+{
+ int ret = 0;
+
+ /*
+ * Mark us as being in io_wait if we have pending requests, so cpufreq
+ * can take into account that the task is waiting for IO - turns out
+ * to be important for low QD IO.
+ */
+ if (ext_arg->iowait && current_pending_io())
+ current->in_iowait = 1;
+ if (iowq->timeout != KTIME_MAX || iowq->min_timeout)
+ ret = io_cqring_schedule_timeout(iowq, ctx->clockid, start_time);
+ else
+ schedule();
+ current->in_iowait = 0;
+ return ret;
+}
+
+/* If this returns > 0, the caller should retry */
+static inline int io_cqring_wait_schedule(struct io_ring_ctx *ctx,
+ struct io_wait_queue *iowq,
+ struct ext_arg *ext_arg,
+ ktime_t start_time)
+{
+ if (unlikely(READ_ONCE(ctx->check_cq)))
+ return 1;
+ if (unlikely(io_local_work_pending(ctx)))
+ return 1;
+ if (unlikely(task_work_pending(current)))
+ return 1;
+ if (unlikely(task_sigpending(current)))
+ return -EINTR;
+ if (unlikely(io_should_wake(iowq)))
+ return 0;
+
+ return __io_cqring_wait_schedule(ctx, iowq, ext_arg, start_time);
+}
+
+/*
+ * Wait until events become available, if we don't already have some. The
+ * application must reap them itself, as they reside on the shared cq ring.
+ */
+int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, u32 flags,
+ struct ext_arg *ext_arg)
+{
+ struct io_wait_queue iowq;
+ struct io_rings *rings = ctx->rings;
+ ktime_t start_time;
+ int ret;
+
+ min_events = min_t(int, min_events, ctx->cq_entries);
+
+ if (!io_allowed_run_tw(ctx))
+ return -EEXIST;
+ if (io_local_work_pending(ctx))
+ io_run_local_work(ctx, min_events,
+ max(IO_LOCAL_TW_DEFAULT_MAX, min_events));
+ io_run_task_work();
+
+ if (unlikely(test_bit(IO_CHECK_CQ_OVERFLOW_BIT, &ctx->check_cq)))
+ io_cqring_do_overflow_flush(ctx);
+ if (__io_cqring_events_user(ctx) >= min_events)
+ return 0;
+
+ init_waitqueue_func_entry(&iowq.wq, io_wake_function);
+ iowq.wq.private = current;
+ INIT_LIST_HEAD(&iowq.wq.entry);
+ iowq.ctx = ctx;
+ iowq.cq_tail = READ_ONCE(ctx->rings->cq.head) + min_events;
+ iowq.cq_min_tail = READ_ONCE(ctx->rings->cq.tail);
+ iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts);
+ iowq.hit_timeout = 0;
+ iowq.min_timeout = ext_arg->min_time;
+ iowq.timeout = KTIME_MAX;
+ start_time = io_get_time(ctx);
+
+ if (ext_arg->ts_set) {
+ iowq.timeout = timespec64_to_ktime(ext_arg->ts);
+ if (!(flags & IORING_ENTER_ABS_TIMER))
+ iowq.timeout = ktime_add(iowq.timeout, start_time);
+ }
+
+ if (ext_arg->sig) {
+#ifdef CONFIG_COMPAT
+ if (in_compat_syscall())
+ ret = set_compat_user_sigmask((const compat_sigset_t __user *)ext_arg->sig,
+ ext_arg->argsz);
+ else
+#endif
+ ret = set_user_sigmask(ext_arg->sig, ext_arg->argsz);
+
+ if (ret)
+ return ret;
+ }
+
+ io_napi_busy_loop(ctx, &iowq);
+
+ trace_io_uring_cqring_wait(ctx, min_events);
+ do {
+ unsigned long check_cq;
+ int nr_wait;
+
+ /* if min timeout has been hit, don't reset wait count */
+ if (!iowq.hit_timeout)
+ nr_wait = (int) iowq.cq_tail -
+ READ_ONCE(ctx->rings->cq.tail);
+ else
+ nr_wait = 1;
+
+ if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) {
+ atomic_set(&ctx->cq_wait_nr, nr_wait);
+ set_current_state(TASK_INTERRUPTIBLE);
+ } else {
+ prepare_to_wait_exclusive(&ctx->cq_wait, &iowq.wq,
+ TASK_INTERRUPTIBLE);
+ }
+
+ ret = io_cqring_wait_schedule(ctx, &iowq, ext_arg, start_time);
+ __set_current_state(TASK_RUNNING);
+ atomic_set(&ctx->cq_wait_nr, IO_CQ_WAKE_INIT);
+
+ /*
+ * Run task_work after scheduling and before io_should_wake().
+ * If we got woken because of task_work being processed, run it
+ * now rather than let the caller do another wait loop.
+ */
+ if (io_local_work_pending(ctx))
+ io_run_local_work(ctx, nr_wait, nr_wait);
+ io_run_task_work();
+
+ /*
+ * Non-local task_work will be run on exit to userspace, but
+ * if we're using DEFER_TASKRUN, then we could have waited
+ * with a timeout for a number of requests. If the timeout
+ * hits, we could have some requests ready to process. Ensure
+ * this break is _after_ we have run task_work, to avoid
+ * deferring running potentially pending requests until the
+ * next time we wait for events.
+ */
+ if (ret < 0)
+ break;
+
+ check_cq = READ_ONCE(ctx->check_cq);
+ if (unlikely(check_cq)) {
+ /* let the caller flush overflows, retry */
+ if (check_cq & BIT(IO_CHECK_CQ_OVERFLOW_BIT))
+ io_cqring_do_overflow_flush(ctx);
+ if (check_cq & BIT(IO_CHECK_CQ_DROPPED_BIT)) {
+ ret = -EBADR;
+ break;
+ }
+ }
+
+ if (io_should_wake(&iowq)) {
+ ret = 0;
+ break;
+ }
+ cond_resched();
+ } while (1);
+
+ if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN))
+ finish_wait(&ctx->cq_wait, &iowq.wq);
+ restore_saved_sigmask_unless(ret == -EINTR);
+
+ return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0;
+}
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+#ifndef IOU_WAIT_H
+#define IOU_WAIT_H
+
+#include <linux/io_uring_types.h>
+
+/*
+ * No waiters. It's larger than any valid value of the tw counter
+ * so that tests against ->cq_wait_nr would fail and skip wake_up().
+ */
+#define IO_CQ_WAKE_INIT (-1U)
+/* Forced wake up if there is a waiter regardless of ->cq_wait_nr */
+#define IO_CQ_WAKE_FORCE (IO_CQ_WAKE_INIT >> 1)
+
+struct ext_arg {
+ size_t argsz;
+ struct timespec64 ts;
+ const sigset_t __user *sig;
+ ktime_t min_time;
+ bool ts_set;
+ bool iowait;
+};
+
+int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, u32 flags,
+ struct ext_arg *ext_arg);
+int io_run_task_work_sig(struct io_ring_ctx *ctx);
+void io_cqring_do_overflow_flush(struct io_ring_ctx *ctx);
+
+static inline unsigned int __io_cqring_events(struct io_ring_ctx *ctx)
+{
+ return ctx->cached_cq_tail - READ_ONCE(ctx->rings->cq.head);
+}
+
+static inline unsigned int __io_cqring_events_user(struct io_ring_ctx *ctx)
+{
+ return READ_ONCE(ctx->rings->cq.tail) - READ_ONCE(ctx->rings->cq.head);
+}
+
+/*
+ * Reads the tail/head of the CQ ring while providing an acquire ordering,
+ * see comment at top of io_uring.c.
+ */
+static inline unsigned io_cqring_events(struct io_ring_ctx *ctx)
+{
+ smp_rmb();
+ return __io_cqring_events(ctx);
+}
+
+#endif
projects / thirdparty / linux.git / commitdiff
