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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
| commit | f4cdf7ca9a1fdcca413157df19753f388a5a224e (patch) | |
| tree | 60a31895b2446cd7fa27514e8c2843534a0de0da /io_uring/wait.c | |
| download | linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip | |
Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab:
- v4l2-core: added ISP statistics support and per-block validation
- v4l2-core: Allow unknown HDR10 white point and luminance
- New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor
- New codec: Milos: VPU v2.0 codec support
- isp driver: gained support for Dreamchip RPPX1 ISP framework
- vsp1 driver: gained support for RZ/T2H and RZ/N2H
- Novalake driver: gained CVS support for new NVL hardware
- dvb-core: fix feed leak on failed DMX_ADD_PID
- several driver fixes, cleanups and minor improvements
* tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits)
media: ipu-bridge: check all DMI entries when overriding sensor rotation
media: v4l2-async: avoid deleting unlinked ASC entry on link error
media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement
media: intel/ipu6: fix async notifier cleanup leak on parse error
media: staging/ipu7: fix async notifier UAF on probe error path
media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path
media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem()
media: rcar-isp: Fix VSPX reference leaks
media: rcar-isp: Release ISPCORE resources
media: i2c: imx415: Release runtime PM reference on VBLANK error
media: i2c: imx415: Return test pattern write errors
media: renesas: vsp1: Declare index variables in for loop statement
media: renesas: vsp1: Make reset control optional to support platforms without a reset line
media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs
media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs
media: nxp: imx8-isi: Add additional 32-bit RGB format support
media: nxp: imx8-isi: Add 16-bit raw Bayer format support
media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams
media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks
media: nxp: imx8-isi: Correct color map between V4L2 and ISI
...
Diffstat (limited to 'io_uring/wait.c')
| -rw-r--r-- | io_uring/wait.c | 324 |
1 files changed, 324 insertions, 0 deletions
diff --git a/io_uring/wait.c b/io_uring/wait.c new file mode 100644 index 000000000..a48523c2f --- /dev/null +++ b/io_uring/wait.c @@ -0,0 +1,324 @@ +// 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 <linux/time_namespace.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 */ + scoped_guard(rcu) { + struct io_rings *rings = io_get_rings(ctx); + + if (iowq->cq_min_tail != READ_ONCE(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 (io_local_work_pending(ctx)) + goto out_wake; + } + + /* any generated CQE posted past this time should wake us up */ + iowq->cq_tail = iowq->cq_min_tail + 1; + + 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; + ktime_t start_time; + int ret, nr_wait; + + 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); + + rcu_read_lock(); + rings = io_get_rings(ctx); + if (__io_cqring_events_user(ctx) >= min_events) { + rcu_read_unlock(); + 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(rings->cq.head) + min_events; + iowq.cq_min_tail = READ_ONCE(rings->cq.tail); + nr_wait = (int) iowq.cq_tail - READ_ONCE(rings->cq.tail); + rcu_read_unlock(); + rings = NULL; + 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 = timens_ktime_to_host(ctx->clockid, + iowq.timeout); + else + 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; + + 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(); + + /* if min timeout has been hit, don't reset wait count */ + if (!iowq.hit_timeout) + scoped_guard(rcu) + nr_wait = (int) iowq.cq_tail - + READ_ONCE(io_get_rings(ctx)->cq.tail); + else + nr_wait = 1; + } while (1); + + if (!(ctx->flags & IORING_SETUP_DEFER_TASKRUN)) + finish_wait(&ctx->cq_wait, &iowq.wq); + restore_saved_sigmask_unless(ret == -EINTR); + + guard(rcu)(); + return READ_ONCE(io_get_rings(ctx)->cq.head) == READ_ONCE(io_get_rings(ctx)->cq.tail) ? ret : 0; +} |
