xref: /openbmc/linux/io_uring/timeout.c (revision 3b73c45e) 
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
3 #include <linux/errno.h>
4 #include <linux/file.h>
5 #include <linux/io_uring.h>
6 
7 #include <trace/events/io_uring.h>
8 
9 #include <uapi/linux/io_uring.h>
10 
11 #include "io_uring.h"
12 #include "refs.h"
13 #include "cancel.h"
14 #include "timeout.h"
15 
16 struct io_timeout {
17 	struct file			*file;
18 	u32				off;
19 	u32				target_seq;
20 	struct list_head		list;
21 	/* head of the link, used by linked timeouts only */
22 	struct io_kiocb			*head;
23 	/* for linked completions */
24 	struct io_kiocb			*prev;
25 };
26 
27 struct io_timeout_rem {
28 	struct file			*file;
29 	u64				addr;
30 
31 	/* timeout update */
32 	struct timespec64		ts;
33 	u32				flags;
34 	bool				ltimeout;
35 };
36 
37 static inline bool io_is_timeout_noseq(struct io_kiocb *req)
38 {
39 	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
40 
41 	return !timeout->off;
42 }
43 
44 static inline void io_put_req(struct io_kiocb *req)
45 {
46 	if (req_ref_put_and_test(req)) {
47 		io_queue_next(req);
48 		io_free_req(req);
49 	}
50 }
51 
52 static bool io_kill_timeout(struct io_kiocb *req, int status)
53 	__must_hold(&req->ctx->completion_lock)
54 	__must_hold(&req->ctx->timeout_lock)
55 {
56 	struct io_timeout_data *io = req->async_data;
57 
58 	if (hrtimer_try_to_cancel(&io->timer) != -1) {
59 		struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
60 
61 		if (status)
62 			req_set_fail(req);
63 		atomic_set(&req->ctx->cq_timeouts,
64 			atomic_read(&req->ctx->cq_timeouts) + 1);
65 		list_del_init(&timeout->list);
66 		io_req_tw_post_queue(req, status, 0);
67 		return true;
68 	}
69 	return false;
70 }
71 
72 __cold void io_flush_timeouts(struct io_ring_ctx *ctx)
73 	__must_hold(&ctx->completion_lock)
74 {
75 	u32 seq = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);
76 	struct io_timeout *timeout, *tmp;
77 
78 	spin_lock_irq(&ctx->timeout_lock);
79 	list_for_each_entry_safe(timeout, tmp, &ctx->timeout_list, list) {
80 		struct io_kiocb *req = cmd_to_io_kiocb(timeout);
81 		u32 events_needed, events_got;
82 
83 		if (io_is_timeout_noseq(req))
84 			break;
85 
86 		/*
87 		 * Since seq can easily wrap around over time, subtract
88 		 * the last seq at which timeouts were flushed before comparing.
89 		 * Assuming not more than 2^31-1 events have happened since,
90 		 * these subtractions won't have wrapped, so we can check if
91 		 * target is in [last_seq, current_seq] by comparing the two.
92 		 */
93 		events_needed = timeout->target_seq - ctx->cq_last_tm_flush;
94 		events_got = seq - ctx->cq_last_tm_flush;
95 		if (events_got < events_needed)
96 			break;
97 
98 		io_kill_timeout(req, 0);
99 	}
100 	ctx->cq_last_tm_flush = seq;
101 	spin_unlock_irq(&ctx->timeout_lock);
102 }
103 
104 static void io_req_tw_fail_links(struct io_kiocb *link, bool *locked)
105 {
106 	io_tw_lock(link->ctx, locked);
107 	while (link) {
108 		struct io_kiocb *nxt = link->link;
109 		long res = -ECANCELED;
110 
111 		if (link->flags & REQ_F_FAIL)
112 			res = link->cqe.res;
113 		link->link = NULL;
114 		io_req_set_res(link, res, 0);
115 		io_req_task_complete(link, locked);
116 		link = nxt;
117 	}
118 }
119 
120 static void io_fail_links(struct io_kiocb *req)
121 	__must_hold(&req->ctx->completion_lock)
122 {
123 	struct io_kiocb *link = req->link;
124 	bool ignore_cqes = req->flags & REQ_F_SKIP_LINK_CQES;
125 
126 	if (!link)
127 		return;
128 
129 	while (link) {
130 		if (ignore_cqes)
131 			link->flags |= REQ_F_CQE_SKIP;
132 		else
133 			link->flags &= ~REQ_F_CQE_SKIP;
134 		trace_io_uring_fail_link(req, link);
135 		link = link->link;
136 	}
137 
138 	link = req->link;
139 	link->io_task_work.func = io_req_tw_fail_links;
140 	io_req_task_work_add(link);
141 	req->link = NULL;
142 }
143 
144 static inline void io_remove_next_linked(struct io_kiocb *req)
145 {
146 	struct io_kiocb *nxt = req->link;
147 
148 	req->link = nxt->link;
149 	nxt->link = NULL;
150 }
151 
152 bool io_disarm_next(struct io_kiocb *req)
153 	__must_hold(&req->ctx->completion_lock)
154 {
155 	struct io_kiocb *link = NULL;
156 	bool posted = false;
157 
158 	if (req->flags & REQ_F_ARM_LTIMEOUT) {
159 		link = req->link;
160 		req->flags &= ~REQ_F_ARM_LTIMEOUT;
161 		if (link && link->opcode == IORING_OP_LINK_TIMEOUT) {
162 			io_remove_next_linked(req);
163 			io_req_tw_post_queue(link, -ECANCELED, 0);
164 			posted = true;
165 		}
166 	} else if (req->flags & REQ_F_LINK_TIMEOUT) {
167 		struct io_ring_ctx *ctx = req->ctx;
168 
169 		spin_lock_irq(&ctx->timeout_lock);
170 		link = io_disarm_linked_timeout(req);
171 		spin_unlock_irq(&ctx->timeout_lock);
172 		if (link) {
173 			posted = true;
174 			io_req_tw_post_queue(link, -ECANCELED, 0);
175 		}
176 	}
177 	if (unlikely((req->flags & REQ_F_FAIL) &&
178 		     !(req->flags & REQ_F_HARDLINK))) {
179 		posted |= (req->link != NULL);
180 		io_fail_links(req);
181 	}
182 	return posted;
183 }
184 
185 struct io_kiocb *__io_disarm_linked_timeout(struct io_kiocb *req,
186 					    struct io_kiocb *link)
187 	__must_hold(&req->ctx->completion_lock)
188 	__must_hold(&req->ctx->timeout_lock)
189 {
190 	struct io_timeout_data *io = link->async_data;
191 	struct io_timeout *timeout = io_kiocb_to_cmd(link, struct io_timeout);
192 
193 	io_remove_next_linked(req);
194 	timeout->head = NULL;
195 	if (hrtimer_try_to_cancel(&io->timer) != -1) {
196 		list_del(&timeout->list);
197 		return link;
198 	}
199 
200 	return NULL;
201 }
202 
203 static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer)
204 {
205 	struct io_timeout_data *data = container_of(timer,
206 						struct io_timeout_data, timer);
207 	struct io_kiocb *req = data->req;
208 	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
209 	struct io_ring_ctx *ctx = req->ctx;
210 	unsigned long flags;
211 
212 	spin_lock_irqsave(&ctx->timeout_lock, flags);
213 	list_del_init(&timeout->list);
214 	atomic_set(&req->ctx->cq_timeouts,
215 		atomic_read(&req->ctx->cq_timeouts) + 1);
216 	spin_unlock_irqrestore(&ctx->timeout_lock, flags);
217 
218 	if (!(data->flags & IORING_TIMEOUT_ETIME_SUCCESS))
219 		req_set_fail(req);
220 
221 	io_req_set_res(req, -ETIME, 0);
222 	req->io_task_work.func = io_req_task_complete;
223 	io_req_task_work_add(req);
224 	return HRTIMER_NORESTART;
225 }
226 
227 static struct io_kiocb *io_timeout_extract(struct io_ring_ctx *ctx,
228 					   struct io_cancel_data *cd)
229 	__must_hold(&ctx->timeout_lock)
230 {
231 	struct io_timeout *timeout;
232 	struct io_timeout_data *io;
233 	struct io_kiocb *req = NULL;
234 
235 	list_for_each_entry(timeout, &ctx->timeout_list, list) {
236 		struct io_kiocb *tmp = cmd_to_io_kiocb(timeout);
237 
238 		if (!(cd->flags & IORING_ASYNC_CANCEL_ANY) &&
239 		    cd->data != tmp->cqe.user_data)
240 			continue;
241 		if (cd->flags & (IORING_ASYNC_CANCEL_ALL|IORING_ASYNC_CANCEL_ANY)) {
242 			if (cd->seq == tmp->work.cancel_seq)
243 				continue;
244 			tmp->work.cancel_seq = cd->seq;
245 		}
246 		req = tmp;
247 		break;
248 	}
249 	if (!req)
250 		return ERR_PTR(-ENOENT);
251 
252 	io = req->async_data;
253 	if (hrtimer_try_to_cancel(&io->timer) == -1)
254 		return ERR_PTR(-EALREADY);
255 	timeout = io_kiocb_to_cmd(req, struct io_timeout);
256 	list_del_init(&timeout->list);
257 	return req;
258 }
259 
260 int io_timeout_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd)
261 	__must_hold(&ctx->completion_lock)
262 {
263 	struct io_kiocb *req;
264 
265 	spin_lock_irq(&ctx->timeout_lock);
266 	req = io_timeout_extract(ctx, cd);
267 	spin_unlock_irq(&ctx->timeout_lock);
268 
269 	if (IS_ERR(req))
270 		return PTR_ERR(req);
271 	io_req_task_queue_fail(req, -ECANCELED);
272 	return 0;
273 }
274 
275 static void io_req_task_link_timeout(struct io_kiocb *req, bool *locked)
276 {
277 	unsigned issue_flags = *locked ? 0 : IO_URING_F_UNLOCKED;
278 	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
279 	struct io_kiocb *prev = timeout->prev;
280 	int ret = -ENOENT;
281 
282 	if (prev) {
283 		if (!(req->task->flags & PF_EXITING)) {
284 			struct io_cancel_data cd = {
285 				.ctx		= req->ctx,
286 				.data		= prev->cqe.user_data,
287 			};
288 
289 			ret = io_try_cancel(req->task->io_uring, &cd, issue_flags);
290 		}
291 		io_req_set_res(req, ret ?: -ETIME, 0);
292 		io_req_complete_post(req);
293 		io_put_req(prev);
294 	} else {
295 		io_req_set_res(req, -ETIME, 0);
296 		io_req_complete_post(req);
297 	}
298 }
299 
300 static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer)
301 {
302 	struct io_timeout_data *data = container_of(timer,
303 						struct io_timeout_data, timer);
304 	struct io_kiocb *prev, *req = data->req;
305 	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
306 	struct io_ring_ctx *ctx = req->ctx;
307 	unsigned long flags;
308 
309 	spin_lock_irqsave(&ctx->timeout_lock, flags);
310 	prev = timeout->head;
311 	timeout->head = NULL;
312 
313 	/*
314 	 * We don't expect the list to be empty, that will only happen if we
315 	 * race with the completion of the linked work.
316 	 */
317 	if (prev) {
318 		io_remove_next_linked(prev);
319 		if (!req_ref_inc_not_zero(prev))
320 			prev = NULL;
321 	}
322 	list_del(&timeout->list);
323 	timeout->prev = prev;
324 	spin_unlock_irqrestore(&ctx->timeout_lock, flags);
325 
326 	req->io_task_work.func = io_req_task_link_timeout;
327 	io_req_task_work_add(req);
328 	return HRTIMER_NORESTART;
329 }
330 
331 static clockid_t io_timeout_get_clock(struct io_timeout_data *data)
332 {
333 	switch (data->flags & IORING_TIMEOUT_CLOCK_MASK) {
334 	case IORING_TIMEOUT_BOOTTIME:
335 		return CLOCK_BOOTTIME;
336 	case IORING_TIMEOUT_REALTIME:
337 		return CLOCK_REALTIME;
338 	default:
339 		/* can't happen, vetted at prep time */
340 		WARN_ON_ONCE(1);
341 		fallthrough;
342 	case 0:
343 		return CLOCK_MONOTONIC;
344 	}
345 }
346 
347 static int io_linked_timeout_update(struct io_ring_ctx *ctx, __u64 user_data,
348 				    struct timespec64 *ts, enum hrtimer_mode mode)
349 	__must_hold(&ctx->timeout_lock)
350 {
351 	struct io_timeout_data *io;
352 	struct io_timeout *timeout;
353 	struct io_kiocb *req = NULL;
354 
355 	list_for_each_entry(timeout, &ctx->ltimeout_list, list) {
356 		struct io_kiocb *tmp = cmd_to_io_kiocb(timeout);
357 
358 		if (user_data == tmp->cqe.user_data) {
359 			req = tmp;
360 			break;
361 		}
362 	}
363 	if (!req)
364 		return -ENOENT;
365 
366 	io = req->async_data;
367 	if (hrtimer_try_to_cancel(&io->timer) == -1)
368 		return -EALREADY;
369 	hrtimer_init(&io->timer, io_timeout_get_clock(io), mode);
370 	io->timer.function = io_link_timeout_fn;
371 	hrtimer_start(&io->timer, timespec64_to_ktime(*ts), mode);
372 	return 0;
373 }
374 
375 static int io_timeout_update(struct io_ring_ctx *ctx, __u64 user_data,
376 			     struct timespec64 *ts, enum hrtimer_mode mode)
377 	__must_hold(&ctx->timeout_lock)
378 {
379 	struct io_cancel_data cd = { .data = user_data, };
380 	struct io_kiocb *req = io_timeout_extract(ctx, &cd);
381 	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
382 	struct io_timeout_data *data;
383 
384 	if (IS_ERR(req))
385 		return PTR_ERR(req);
386 
387 	timeout->off = 0; /* noseq */
388 	data = req->async_data;
389 	list_add_tail(&timeout->list, &ctx->timeout_list);
390 	hrtimer_init(&data->timer, io_timeout_get_clock(data), mode);
391 	data->timer.function = io_timeout_fn;
392 	hrtimer_start(&data->timer, timespec64_to_ktime(*ts), mode);
393 	return 0;
394 }
395 
396 int io_timeout_remove_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
397 {
398 	struct io_timeout_rem *tr = io_kiocb_to_cmd(req, struct io_timeout_rem);
399 
400 	if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
401 		return -EINVAL;
402 	if (sqe->buf_index || sqe->len || sqe->splice_fd_in)
403 		return -EINVAL;
404 
405 	tr->ltimeout = false;
406 	tr->addr = READ_ONCE(sqe->addr);
407 	tr->flags = READ_ONCE(sqe->timeout_flags);
408 	if (tr->flags & IORING_TIMEOUT_UPDATE_MASK) {
409 		if (hweight32(tr->flags & IORING_TIMEOUT_CLOCK_MASK) > 1)
410 			return -EINVAL;
411 		if (tr->flags & IORING_LINK_TIMEOUT_UPDATE)
412 			tr->ltimeout = true;
413 		if (tr->flags & ~(IORING_TIMEOUT_UPDATE_MASK|IORING_TIMEOUT_ABS))
414 			return -EINVAL;
415 		if (get_timespec64(&tr->ts, u64_to_user_ptr(sqe->addr2)))
416 			return -EFAULT;
417 		if (tr->ts.tv_sec < 0 || tr->ts.tv_nsec < 0)
418 			return -EINVAL;
419 	} else if (tr->flags) {
420 		/* timeout removal doesn't support flags */
421 		return -EINVAL;
422 	}
423 
424 	return 0;
425 }
426 
427 static inline enum hrtimer_mode io_translate_timeout_mode(unsigned int flags)
428 {
429 	return (flags & IORING_TIMEOUT_ABS) ? HRTIMER_MODE_ABS
430 					    : HRTIMER_MODE_REL;
431 }
432 
433 /*
434  * Remove or update an existing timeout command
435  */
436 int io_timeout_remove(struct io_kiocb *req, unsigned int issue_flags)
437 {
438 	struct io_timeout_rem *tr = io_kiocb_to_cmd(req, struct io_timeout_rem);
439 	struct io_ring_ctx *ctx = req->ctx;
440 	int ret;
441 
442 	if (!(tr->flags & IORING_TIMEOUT_UPDATE)) {
443 		struct io_cancel_data cd = { .data = tr->addr, };
444 
445 		spin_lock(&ctx->completion_lock);
446 		ret = io_timeout_cancel(ctx, &cd);
447 		spin_unlock(&ctx->completion_lock);
448 	} else {
449 		enum hrtimer_mode mode = io_translate_timeout_mode(tr->flags);
450 
451 		spin_lock_irq(&ctx->timeout_lock);
452 		if (tr->ltimeout)
453 			ret = io_linked_timeout_update(ctx, tr->addr, &tr->ts, mode);
454 		else
455 			ret = io_timeout_update(ctx, tr->addr, &tr->ts, mode);
456 		spin_unlock_irq(&ctx->timeout_lock);
457 	}
458 
459 	if (ret < 0)
460 		req_set_fail(req);
461 	io_req_set_res(req, ret, 0);
462 	return IOU_OK;
463 }
464 
465 static int __io_timeout_prep(struct io_kiocb *req,
466 			     const struct io_uring_sqe *sqe,
467 			     bool is_timeout_link)
468 {
469 	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
470 	struct io_timeout_data *data;
471 	unsigned flags;
472 	u32 off = READ_ONCE(sqe->off);
473 
474 	if (sqe->buf_index || sqe->len != 1 || sqe->splice_fd_in)
475 		return -EINVAL;
476 	if (off && is_timeout_link)
477 		return -EINVAL;
478 	flags = READ_ONCE(sqe->timeout_flags);
479 	if (flags & ~(IORING_TIMEOUT_ABS | IORING_TIMEOUT_CLOCK_MASK |
480 		      IORING_TIMEOUT_ETIME_SUCCESS))
481 		return -EINVAL;
482 	/* more than one clock specified is invalid, obviously */
483 	if (hweight32(flags & IORING_TIMEOUT_CLOCK_MASK) > 1)
484 		return -EINVAL;
485 
486 	INIT_LIST_HEAD(&timeout->list);
487 	timeout->off = off;
488 	if (unlikely(off && !req->ctx->off_timeout_used))
489 		req->ctx->off_timeout_used = true;
490 
491 	if (WARN_ON_ONCE(req_has_async_data(req)))
492 		return -EFAULT;
493 	if (io_alloc_async_data(req))
494 		return -ENOMEM;
495 
496 	data = req->async_data;
497 	data->req = req;
498 	data->flags = flags;
499 
500 	if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr)))
501 		return -EFAULT;
502 
503 	if (data->ts.tv_sec < 0 || data->ts.tv_nsec < 0)
504 		return -EINVAL;
505 
506 	INIT_LIST_HEAD(&timeout->list);
507 	data->mode = io_translate_timeout_mode(flags);
508 	hrtimer_init(&data->timer, io_timeout_get_clock(data), data->mode);
509 
510 	if (is_timeout_link) {
511 		struct io_submit_link *link = &req->ctx->submit_state.link;
512 
513 		if (!link->head)
514 			return -EINVAL;
515 		if (link->last->opcode == IORING_OP_LINK_TIMEOUT)
516 			return -EINVAL;
517 		timeout->head = link->last;
518 		link->last->flags |= REQ_F_ARM_LTIMEOUT;
519 	}
520 	return 0;
521 }
522 
523 int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
524 {
525 	return __io_timeout_prep(req, sqe, false);
526 }
527 
528 int io_link_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
529 {
530 	return __io_timeout_prep(req, sqe, true);
531 }
532 
533 int io_timeout(struct io_kiocb *req, unsigned int issue_flags)
534 {
535 	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
536 	struct io_ring_ctx *ctx = req->ctx;
537 	struct io_timeout_data *data = req->async_data;
538 	struct list_head *entry;
539 	u32 tail, off = timeout->off;
540 
541 	spin_lock_irq(&ctx->timeout_lock);
542 
543 	/*
544 	 * sqe->off holds how many events that need to occur for this
545 	 * timeout event to be satisfied. If it isn't set, then this is
546 	 * a pure timeout request, sequence isn't used.
547 	 */
548 	if (io_is_timeout_noseq(req)) {
549 		entry = ctx->timeout_list.prev;
550 		goto add;
551 	}
552 
553 	tail = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);
554 	timeout->target_seq = tail + off;
555 
556 	/* Update the last seq here in case io_flush_timeouts() hasn't.
557 	 * This is safe because ->completion_lock is held, and submissions
558 	 * and completions are never mixed in the same ->completion_lock section.
559 	 */
560 	ctx->cq_last_tm_flush = tail;
561 
562 	/*
563 	 * Insertion sort, ensuring the first entry in the list is always
564 	 * the one we need first.
565 	 */
566 	list_for_each_prev(entry, &ctx->timeout_list) {
567 		struct io_timeout *nextt = list_entry(entry, struct io_timeout, list);
568 		struct io_kiocb *nxt = cmd_to_io_kiocb(nextt);
569 
570 		if (io_is_timeout_noseq(nxt))
571 			continue;
572 		/* nxt.seq is behind @tail, otherwise would've been completed */
573 		if (off >= nextt->target_seq - tail)
574 			break;
575 	}
576 add:
577 	list_add(&timeout->list, entry);
578 	data->timer.function = io_timeout_fn;
579 	hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode);
580 	spin_unlock_irq(&ctx->timeout_lock);
581 	return IOU_ISSUE_SKIP_COMPLETE;
582 }
583 
584 void io_queue_linked_timeout(struct io_kiocb *req)
585 {
586 	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
587 	struct io_ring_ctx *ctx = req->ctx;
588 
589 	spin_lock_irq(&ctx->timeout_lock);
590 	/*
591 	 * If the back reference is NULL, then our linked request finished
592 	 * before we got a chance to setup the timer
593 	 */
594 	if (timeout->head) {
595 		struct io_timeout_data *data = req->async_data;
596 
597 		data->timer.function = io_link_timeout_fn;
598 		hrtimer_start(&data->timer, timespec64_to_ktime(data->ts),
599 				data->mode);
600 		list_add_tail(&timeout->list, &ctx->ltimeout_list);
601 	}
602 	spin_unlock_irq(&ctx->timeout_lock);
603 	/* drop submission reference */
604 	io_put_req(req);
605 }
606 
607 static bool io_match_task(struct io_kiocb *head, struct task_struct *task,
608 			  bool cancel_all)
609 	__must_hold(&req->ctx->timeout_lock)
610 {
611 	struct io_kiocb *req;
612 
613 	if (task && head->task != task)
614 		return false;
615 	if (cancel_all)
616 		return true;
617 
618 	io_for_each_link(req, head) {
619 		if (req->flags & REQ_F_INFLIGHT)
620 			return true;
621 	}
622 	return false;
623 }
624 
625 /* Returns true if we found and killed one or more timeouts */
626 __cold bool io_kill_timeouts(struct io_ring_ctx *ctx, struct task_struct *tsk,
627 			     bool cancel_all)
628 {
629 	struct io_timeout *timeout, *tmp;
630 	int canceled = 0;
631 
632 	io_cq_lock(ctx);
633 	spin_lock_irq(&ctx->timeout_lock);
634 	list_for_each_entry_safe(timeout, tmp, &ctx->timeout_list, list) {
635 		struct io_kiocb *req = cmd_to_io_kiocb(timeout);
636 
637 		if (io_match_task(req, tsk, cancel_all) &&
638 		    io_kill_timeout(req, -ECANCELED))
639 			canceled++;
640 	}
641 	spin_unlock_irq(&ctx->timeout_lock);
642 	io_cq_unlock_post(ctx);
643 	return canceled != 0;
644 }
645