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v6.13.7
  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
 16struct io_timeout {
 17	struct file			*file;
 18	u32				off;
 19	u32				target_seq;
 20	u32				repeats;
 21	struct list_head		list;
 22	/* head of the link, used by linked timeouts only */
 23	struct io_kiocb			*head;
 24	/* for linked completions */
 25	struct io_kiocb			*prev;
 26};
 27
 28struct io_timeout_rem {
 29	struct file			*file;
 30	u64				addr;
 31
 32	/* timeout update */
 33	struct timespec64		ts;
 34	u32				flags;
 35	bool				ltimeout;
 36};
 37
 38static inline bool io_is_timeout_noseq(struct io_kiocb *req)
 39{
 40	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
 41	struct io_timeout_data *data = req->async_data;
 42
 43	return !timeout->off || data->flags & IORING_TIMEOUT_MULTISHOT;
 44}
 45
 46static inline void io_put_req(struct io_kiocb *req)
 47{
 48	if (req_ref_put_and_test(req)) {
 49		io_queue_next(req);
 50		io_free_req(req);
 51	}
 52}
 53
 54static inline bool io_timeout_finish(struct io_timeout *timeout,
 55				     struct io_timeout_data *data)
 56{
 57	if (!(data->flags & IORING_TIMEOUT_MULTISHOT))
 58		return true;
 59
 60	if (!timeout->off || (timeout->repeats && --timeout->repeats))
 61		return false;
 62
 63	return true;
 64}
 65
 66static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer);
 67
 68static void io_timeout_complete(struct io_kiocb *req, struct io_tw_state *ts)
 69{
 70	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
 71	struct io_timeout_data *data = req->async_data;
 72	struct io_ring_ctx *ctx = req->ctx;
 73
 74	if (!io_timeout_finish(timeout, data)) {
 75		if (io_req_post_cqe(req, -ETIME, IORING_CQE_F_MORE)) {
 
 
 
 76			/* re-arm timer */
 77			raw_spin_lock_irq(&ctx->timeout_lock);
 78			list_add(&timeout->list, ctx->timeout_list.prev);
 
 79			hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode);
 80			raw_spin_unlock_irq(&ctx->timeout_lock);
 81			return;
 82		}
 83	}
 84
 85	io_req_task_complete(req, ts);
 86}
 87
 88static __cold bool io_flush_killed_timeouts(struct list_head *list, int err)
 89{
 90	if (list_empty(list))
 91		return false;
 92
 93	while (!list_empty(list)) {
 94		struct io_timeout *timeout;
 95		struct io_kiocb *req;
 96
 97		timeout = list_first_entry(list, struct io_timeout, list);
 98		list_del_init(&timeout->list);
 99		req = cmd_to_io_kiocb(timeout);
100		if (err)
101			req_set_fail(req);
102		io_req_queue_tw_complete(req, err);
103	}
104
105	return true;
106}
107
108static void io_kill_timeout(struct io_kiocb *req, struct list_head *list)
109	__must_hold(&req->ctx->timeout_lock)
110{
111	struct io_timeout_data *io = req->async_data;
112
113	if (hrtimer_try_to_cancel(&io->timer) != -1) {
114		struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
115
 
 
116		atomic_set(&req->ctx->cq_timeouts,
117			atomic_read(&req->ctx->cq_timeouts) + 1);
118		list_move_tail(&timeout->list, list);
 
 
119	}
 
120}
121
122__cold void io_flush_timeouts(struct io_ring_ctx *ctx)
123{
124	struct io_timeout *timeout, *tmp;
125	LIST_HEAD(list);
126	u32 seq;
 
127
128	raw_spin_lock_irq(&ctx->timeout_lock);
129	seq = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);
130
131	list_for_each_entry_safe(timeout, tmp, &ctx->timeout_list, list) {
132		struct io_kiocb *req = cmd_to_io_kiocb(timeout);
133		u32 events_needed, events_got;
134
135		if (io_is_timeout_noseq(req))
136			break;
137
138		/*
139		 * Since seq can easily wrap around over time, subtract
140		 * the last seq at which timeouts were flushed before comparing.
141		 * Assuming not more than 2^31-1 events have happened since,
142		 * these subtractions won't have wrapped, so we can check if
143		 * target is in [last_seq, current_seq] by comparing the two.
144		 */
145		events_needed = timeout->target_seq - ctx->cq_last_tm_flush;
146		events_got = seq - ctx->cq_last_tm_flush;
147		if (events_got < events_needed)
148			break;
149
150		io_kill_timeout(req, &list);
151	}
152	ctx->cq_last_tm_flush = seq;
153	raw_spin_unlock_irq(&ctx->timeout_lock);
154	io_flush_killed_timeouts(&list, 0);
155}
156
157static void io_req_tw_fail_links(struct io_kiocb *link, struct io_tw_state *ts)
158{
159	io_tw_lock(link->ctx, ts);
160	while (link) {
161		struct io_kiocb *nxt = link->link;
162		long res = -ECANCELED;
163
164		if (link->flags & REQ_F_FAIL)
165			res = link->cqe.res;
166		link->link = NULL;
167		io_req_set_res(link, res, 0);
168		io_req_task_complete(link, ts);
169		link = nxt;
170	}
171}
172
173static void io_fail_links(struct io_kiocb *req)
174	__must_hold(&req->ctx->completion_lock)
175{
176	struct io_kiocb *link = req->link;
177	bool ignore_cqes = req->flags & REQ_F_SKIP_LINK_CQES;
178
179	if (!link)
180		return;
181
182	while (link) {
183		if (ignore_cqes)
184			link->flags |= REQ_F_CQE_SKIP;
185		else
186			link->flags &= ~REQ_F_CQE_SKIP;
187		trace_io_uring_fail_link(req, link);
188		link = link->link;
189	}
190
191	link = req->link;
192	link->io_task_work.func = io_req_tw_fail_links;
193	io_req_task_work_add(link);
194	req->link = NULL;
195}
196
197static inline void io_remove_next_linked(struct io_kiocb *req)
198{
199	struct io_kiocb *nxt = req->link;
200
201	req->link = nxt->link;
202	nxt->link = NULL;
203}
204
205void io_disarm_next(struct io_kiocb *req)
206	__must_hold(&req->ctx->completion_lock)
207{
208	struct io_kiocb *link = NULL;
209
210	if (req->flags & REQ_F_ARM_LTIMEOUT) {
211		link = req->link;
212		req->flags &= ~REQ_F_ARM_LTIMEOUT;
213		if (link && link->opcode == IORING_OP_LINK_TIMEOUT) {
214			io_remove_next_linked(req);
215			io_req_queue_tw_complete(link, -ECANCELED);
216		}
217	} else if (req->flags & REQ_F_LINK_TIMEOUT) {
218		struct io_ring_ctx *ctx = req->ctx;
219
220		raw_spin_lock_irq(&ctx->timeout_lock);
221		link = io_disarm_linked_timeout(req);
222		raw_spin_unlock_irq(&ctx->timeout_lock);
223		if (link)
224			io_req_queue_tw_complete(link, -ECANCELED);
225	}
226	if (unlikely((req->flags & REQ_F_FAIL) &&
227		     !(req->flags & REQ_F_HARDLINK)))
228		io_fail_links(req);
229}
230
231struct io_kiocb *__io_disarm_linked_timeout(struct io_kiocb *req,
232					    struct io_kiocb *link)
233	__must_hold(&req->ctx->completion_lock)
234	__must_hold(&req->ctx->timeout_lock)
235{
236	struct io_timeout_data *io = link->async_data;
237	struct io_timeout *timeout = io_kiocb_to_cmd(link, struct io_timeout);
238
239	io_remove_next_linked(req);
240	timeout->head = NULL;
241	if (hrtimer_try_to_cancel(&io->timer) != -1) {
242		list_del(&timeout->list);
243		return link;
244	}
245
246	return NULL;
247}
248
249static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer)
250{
251	struct io_timeout_data *data = container_of(timer,
252						struct io_timeout_data, timer);
253	struct io_kiocb *req = data->req;
254	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
255	struct io_ring_ctx *ctx = req->ctx;
256	unsigned long flags;
257
258	raw_spin_lock_irqsave(&ctx->timeout_lock, flags);
259	list_del_init(&timeout->list);
260	atomic_set(&req->ctx->cq_timeouts,
261		atomic_read(&req->ctx->cq_timeouts) + 1);
262	raw_spin_unlock_irqrestore(&ctx->timeout_lock, flags);
263
264	if (!(data->flags & IORING_TIMEOUT_ETIME_SUCCESS))
265		req_set_fail(req);
266
267	io_req_set_res(req, -ETIME, 0);
268	req->io_task_work.func = io_timeout_complete;
269	io_req_task_work_add(req);
270	return HRTIMER_NORESTART;
271}
272
273static struct io_kiocb *io_timeout_extract(struct io_ring_ctx *ctx,
274					   struct io_cancel_data *cd)
275	__must_hold(&ctx->timeout_lock)
276{
277	struct io_timeout *timeout;
278	struct io_timeout_data *io;
279	struct io_kiocb *req = NULL;
280
281	list_for_each_entry(timeout, &ctx->timeout_list, list) {
282		struct io_kiocb *tmp = cmd_to_io_kiocb(timeout);
283
284		if (io_cancel_req_match(tmp, cd)) {
285			req = tmp;
286			break;
287		}
288	}
289	if (!req)
290		return ERR_PTR(-ENOENT);
291
292	io = req->async_data;
293	if (hrtimer_try_to_cancel(&io->timer) == -1)
294		return ERR_PTR(-EALREADY);
295	timeout = io_kiocb_to_cmd(req, struct io_timeout);
296	list_del_init(&timeout->list);
297	return req;
298}
299
300int io_timeout_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd)
301	__must_hold(&ctx->completion_lock)
302{
303	struct io_kiocb *req;
304
305	raw_spin_lock_irq(&ctx->timeout_lock);
306	req = io_timeout_extract(ctx, cd);
307	raw_spin_unlock_irq(&ctx->timeout_lock);
308
309	if (IS_ERR(req))
310		return PTR_ERR(req);
311	io_req_task_queue_fail(req, -ECANCELED);
312	return 0;
313}
314
315static void io_req_task_link_timeout(struct io_kiocb *req, struct io_tw_state *ts)
316{
 
317	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
318	struct io_kiocb *prev = timeout->prev;
319	int ret;
320
321	if (prev) {
322		if (!io_should_terminate_tw()) {
323			struct io_cancel_data cd = {
324				.ctx		= req->ctx,
325				.data		= prev->cqe.user_data,
326			};
327
328			ret = io_try_cancel(req->tctx, &cd, 0);
329		} else {
330			ret = -ECANCELED;
331		}
332		io_req_set_res(req, ret ?: -ETIME, 0);
333		io_req_task_complete(req, ts);
334		io_put_req(prev);
335	} else {
336		io_req_set_res(req, -ETIME, 0);
337		io_req_task_complete(req, ts);
338	}
339}
340
341static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer)
342{
343	struct io_timeout_data *data = container_of(timer,
344						struct io_timeout_data, timer);
345	struct io_kiocb *prev, *req = data->req;
346	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
347	struct io_ring_ctx *ctx = req->ctx;
348	unsigned long flags;
349
350	raw_spin_lock_irqsave(&ctx->timeout_lock, flags);
351	prev = timeout->head;
352	timeout->head = NULL;
353
354	/*
355	 * We don't expect the list to be empty, that will only happen if we
356	 * race with the completion of the linked work.
357	 */
358	if (prev) {
359		io_remove_next_linked(prev);
360		if (!req_ref_inc_not_zero(prev))
361			prev = NULL;
362	}
363	list_del(&timeout->list);
364	timeout->prev = prev;
365	raw_spin_unlock_irqrestore(&ctx->timeout_lock, flags);
366
367	req->io_task_work.func = io_req_task_link_timeout;
368	io_req_task_work_add(req);
369	return HRTIMER_NORESTART;
370}
371
372static clockid_t io_timeout_get_clock(struct io_timeout_data *data)
373{
374	switch (data->flags & IORING_TIMEOUT_CLOCK_MASK) {
375	case IORING_TIMEOUT_BOOTTIME:
376		return CLOCK_BOOTTIME;
377	case IORING_TIMEOUT_REALTIME:
378		return CLOCK_REALTIME;
379	default:
380		/* can't happen, vetted at prep time */
381		WARN_ON_ONCE(1);
382		fallthrough;
383	case 0:
384		return CLOCK_MONOTONIC;
385	}
386}
387
388static int io_linked_timeout_update(struct io_ring_ctx *ctx, __u64 user_data,
389				    struct timespec64 *ts, enum hrtimer_mode mode)
390	__must_hold(&ctx->timeout_lock)
391{
392	struct io_timeout_data *io;
393	struct io_timeout *timeout;
394	struct io_kiocb *req = NULL;
395
396	list_for_each_entry(timeout, &ctx->ltimeout_list, list) {
397		struct io_kiocb *tmp = cmd_to_io_kiocb(timeout);
398
399		if (user_data == tmp->cqe.user_data) {
400			req = tmp;
401			break;
402		}
403	}
404	if (!req)
405		return -ENOENT;
406
407	io = req->async_data;
408	if (hrtimer_try_to_cancel(&io->timer) == -1)
409		return -EALREADY;
410	hrtimer_init(&io->timer, io_timeout_get_clock(io), mode);
411	io->timer.function = io_link_timeout_fn;
412	hrtimer_start(&io->timer, timespec64_to_ktime(*ts), mode);
413	return 0;
414}
415
416static int io_timeout_update(struct io_ring_ctx *ctx, __u64 user_data,
417			     struct timespec64 *ts, enum hrtimer_mode mode)
418	__must_hold(&ctx->timeout_lock)
419{
420	struct io_cancel_data cd = { .ctx = ctx, .data = user_data, };
421	struct io_kiocb *req = io_timeout_extract(ctx, &cd);
422	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
423	struct io_timeout_data *data;
424
425	if (IS_ERR(req))
426		return PTR_ERR(req);
427
428	timeout->off = 0; /* noseq */
429	data = req->async_data;
430	data->ts = *ts;
431
432	list_add_tail(&timeout->list, &ctx->timeout_list);
433	hrtimer_init(&data->timer, io_timeout_get_clock(data), mode);
434	data->timer.function = io_timeout_fn;
435	hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), mode);
436	return 0;
437}
438
439int io_timeout_remove_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
440{
441	struct io_timeout_rem *tr = io_kiocb_to_cmd(req, struct io_timeout_rem);
442
443	if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
444		return -EINVAL;
445	if (sqe->buf_index || sqe->len || sqe->splice_fd_in)
446		return -EINVAL;
447
448	tr->ltimeout = false;
449	tr->addr = READ_ONCE(sqe->addr);
450	tr->flags = READ_ONCE(sqe->timeout_flags);
451	if (tr->flags & IORING_TIMEOUT_UPDATE_MASK) {
452		if (hweight32(tr->flags & IORING_TIMEOUT_CLOCK_MASK) > 1)
453			return -EINVAL;
454		if (tr->flags & IORING_LINK_TIMEOUT_UPDATE)
455			tr->ltimeout = true;
456		if (tr->flags & ~(IORING_TIMEOUT_UPDATE_MASK|IORING_TIMEOUT_ABS))
457			return -EINVAL;
458		if (get_timespec64(&tr->ts, u64_to_user_ptr(sqe->addr2)))
459			return -EFAULT;
460		if (tr->ts.tv_sec < 0 || tr->ts.tv_nsec < 0)
461			return -EINVAL;
462	} else if (tr->flags) {
463		/* timeout removal doesn't support flags */
464		return -EINVAL;
465	}
466
467	return 0;
468}
469
470static inline enum hrtimer_mode io_translate_timeout_mode(unsigned int flags)
471{
472	return (flags & IORING_TIMEOUT_ABS) ? HRTIMER_MODE_ABS
473					    : HRTIMER_MODE_REL;
474}
475
476/*
477 * Remove or update an existing timeout command
478 */
479int io_timeout_remove(struct io_kiocb *req, unsigned int issue_flags)
480{
481	struct io_timeout_rem *tr = io_kiocb_to_cmd(req, struct io_timeout_rem);
482	struct io_ring_ctx *ctx = req->ctx;
483	int ret;
484
485	if (!(tr->flags & IORING_TIMEOUT_UPDATE)) {
486		struct io_cancel_data cd = { .ctx = ctx, .data = tr->addr, };
487
488		spin_lock(&ctx->completion_lock);
489		ret = io_timeout_cancel(ctx, &cd);
490		spin_unlock(&ctx->completion_lock);
491	} else {
492		enum hrtimer_mode mode = io_translate_timeout_mode(tr->flags);
493
494		raw_spin_lock_irq(&ctx->timeout_lock);
495		if (tr->ltimeout)
496			ret = io_linked_timeout_update(ctx, tr->addr, &tr->ts, mode);
497		else
498			ret = io_timeout_update(ctx, tr->addr, &tr->ts, mode);
499		raw_spin_unlock_irq(&ctx->timeout_lock);
500	}
501
502	if (ret < 0)
503		req_set_fail(req);
504	io_req_set_res(req, ret, 0);
505	return IOU_OK;
506}
507
508static int __io_timeout_prep(struct io_kiocb *req,
509			     const struct io_uring_sqe *sqe,
510			     bool is_timeout_link)
511{
512	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
513	struct io_timeout_data *data;
514	unsigned flags;
515	u32 off = READ_ONCE(sqe->off);
516
517	if (sqe->buf_index || sqe->len != 1 || sqe->splice_fd_in)
518		return -EINVAL;
519	if (off && is_timeout_link)
520		return -EINVAL;
521	flags = READ_ONCE(sqe->timeout_flags);
522	if (flags & ~(IORING_TIMEOUT_ABS | IORING_TIMEOUT_CLOCK_MASK |
523		      IORING_TIMEOUT_ETIME_SUCCESS |
524		      IORING_TIMEOUT_MULTISHOT))
525		return -EINVAL;
526	/* more than one clock specified is invalid, obviously */
527	if (hweight32(flags & IORING_TIMEOUT_CLOCK_MASK) > 1)
528		return -EINVAL;
529	/* multishot requests only make sense with rel values */
530	if (!(~flags & (IORING_TIMEOUT_MULTISHOT | IORING_TIMEOUT_ABS)))
531		return -EINVAL;
532
533	INIT_LIST_HEAD(&timeout->list);
534	timeout->off = off;
535	if (unlikely(off && !req->ctx->off_timeout_used))
536		req->ctx->off_timeout_used = true;
537	/*
538	 * for multishot reqs w/ fixed nr of repeats, repeats tracks the
539	 * remaining nr
540	 */
541	timeout->repeats = 0;
542	if ((flags & IORING_TIMEOUT_MULTISHOT) && off > 0)
543		timeout->repeats = off;
544
545	if (WARN_ON_ONCE(req_has_async_data(req)))
546		return -EFAULT;
547	if (io_alloc_async_data(req))
548		return -ENOMEM;
549
550	data = req->async_data;
551	data->req = req;
552	data->flags = flags;
553
554	if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr)))
555		return -EFAULT;
556
557	if (data->ts.tv_sec < 0 || data->ts.tv_nsec < 0)
558		return -EINVAL;
559
 
560	data->mode = io_translate_timeout_mode(flags);
561	hrtimer_init(&data->timer, io_timeout_get_clock(data), data->mode);
562
563	if (is_timeout_link) {
564		struct io_submit_link *link = &req->ctx->submit_state.link;
565
566		if (!link->head)
567			return -EINVAL;
568		if (link->last->opcode == IORING_OP_LINK_TIMEOUT)
569			return -EINVAL;
570		timeout->head = link->last;
571		link->last->flags |= REQ_F_ARM_LTIMEOUT;
572	}
573	return 0;
574}
575
576int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
577{
578	return __io_timeout_prep(req, sqe, false);
579}
580
581int io_link_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
582{
583	return __io_timeout_prep(req, sqe, true);
584}
585
586int io_timeout(struct io_kiocb *req, unsigned int issue_flags)
587{
588	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
589	struct io_ring_ctx *ctx = req->ctx;
590	struct io_timeout_data *data = req->async_data;
591	struct list_head *entry;
592	u32 tail, off = timeout->off;
593
594	raw_spin_lock_irq(&ctx->timeout_lock);
595
596	/*
597	 * sqe->off holds how many events that need to occur for this
598	 * timeout event to be satisfied. If it isn't set, then this is
599	 * a pure timeout request, sequence isn't used.
600	 */
601	if (io_is_timeout_noseq(req)) {
602		entry = ctx->timeout_list.prev;
603		goto add;
604	}
605
606	tail = data_race(ctx->cached_cq_tail) - atomic_read(&ctx->cq_timeouts);
607	timeout->target_seq = tail + off;
608
609	/* Update the last seq here in case io_flush_timeouts() hasn't.
610	 * This is safe because ->completion_lock is held, and submissions
611	 * and completions are never mixed in the same ->completion_lock section.
612	 */
613	ctx->cq_last_tm_flush = tail;
614
615	/*
616	 * Insertion sort, ensuring the first entry in the list is always
617	 * the one we need first.
618	 */
619	list_for_each_prev(entry, &ctx->timeout_list) {
620		struct io_timeout *nextt = list_entry(entry, struct io_timeout, list);
621		struct io_kiocb *nxt = cmd_to_io_kiocb(nextt);
622
623		if (io_is_timeout_noseq(nxt))
624			continue;
625		/* nxt.seq is behind @tail, otherwise would've been completed */
626		if (off >= nextt->target_seq - tail)
627			break;
628	}
629add:
630	list_add(&timeout->list, entry);
631	data->timer.function = io_timeout_fn;
632	hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode);
633	raw_spin_unlock_irq(&ctx->timeout_lock);
634	return IOU_ISSUE_SKIP_COMPLETE;
635}
636
637void io_queue_linked_timeout(struct io_kiocb *req)
638{
639	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
640	struct io_ring_ctx *ctx = req->ctx;
641
642	raw_spin_lock_irq(&ctx->timeout_lock);
643	/*
644	 * If the back reference is NULL, then our linked request finished
645	 * before we got a chance to setup the timer
646	 */
647	if (timeout->head) {
648		struct io_timeout_data *data = req->async_data;
649
650		data->timer.function = io_link_timeout_fn;
651		hrtimer_start(&data->timer, timespec64_to_ktime(data->ts),
652				data->mode);
653		list_add_tail(&timeout->list, &ctx->ltimeout_list);
654	}
655	raw_spin_unlock_irq(&ctx->timeout_lock);
656	/* drop submission reference */
657	io_put_req(req);
658}
659
660static bool io_match_task(struct io_kiocb *head, struct io_uring_task *tctx,
661			  bool cancel_all)
662	__must_hold(&head->ctx->timeout_lock)
663{
664	struct io_kiocb *req;
665
666	if (tctx && head->tctx != tctx)
667		return false;
668	if (cancel_all)
669		return true;
670
671	io_for_each_link(req, head) {
672		if (req->flags & REQ_F_INFLIGHT)
673			return true;
674	}
675	return false;
676}
677
678/* Returns true if we found and killed one or more timeouts */
679__cold bool io_kill_timeouts(struct io_ring_ctx *ctx, struct io_uring_task *tctx,
680			     bool cancel_all)
681{
682	struct io_timeout *timeout, *tmp;
683	LIST_HEAD(list);
684
685	/*
686	 * completion_lock is needed for io_match_task(). Take it before
687	 * timeout_lockfirst to keep locking ordering.
688	 */
689	spin_lock(&ctx->completion_lock);
690	raw_spin_lock_irq(&ctx->timeout_lock);
691	list_for_each_entry_safe(timeout, tmp, &ctx->timeout_list, list) {
692		struct io_kiocb *req = cmd_to_io_kiocb(timeout);
693
694		if (io_match_task(req, tctx, cancel_all))
695			io_kill_timeout(req, &list);
 
696	}
697	raw_spin_unlock_irq(&ctx->timeout_lock);
698	spin_unlock(&ctx->completion_lock);
699
700	return io_flush_killed_timeouts(&list, -ECANCELED);
701}
v6.8
  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
 16struct io_timeout {
 17	struct file			*file;
 18	u32				off;
 19	u32				target_seq;
 20	u32				repeats;
 21	struct list_head		list;
 22	/* head of the link, used by linked timeouts only */
 23	struct io_kiocb			*head;
 24	/* for linked completions */
 25	struct io_kiocb			*prev;
 26};
 27
 28struct io_timeout_rem {
 29	struct file			*file;
 30	u64				addr;
 31
 32	/* timeout update */
 33	struct timespec64		ts;
 34	u32				flags;
 35	bool				ltimeout;
 36};
 37
 38static inline bool io_is_timeout_noseq(struct io_kiocb *req)
 39{
 40	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
 41	struct io_timeout_data *data = req->async_data;
 42
 43	return !timeout->off || data->flags & IORING_TIMEOUT_MULTISHOT;
 44}
 45
 46static inline void io_put_req(struct io_kiocb *req)
 47{
 48	if (req_ref_put_and_test(req)) {
 49		io_queue_next(req);
 50		io_free_req(req);
 51	}
 52}
 53
 54static inline bool io_timeout_finish(struct io_timeout *timeout,
 55				     struct io_timeout_data *data)
 56{
 57	if (!(data->flags & IORING_TIMEOUT_MULTISHOT))
 58		return true;
 59
 60	if (!timeout->off || (timeout->repeats && --timeout->repeats))
 61		return false;
 62
 63	return true;
 64}
 65
 66static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer);
 67
 68static void io_timeout_complete(struct io_kiocb *req, struct io_tw_state *ts)
 69{
 70	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
 71	struct io_timeout_data *data = req->async_data;
 72	struct io_ring_ctx *ctx = req->ctx;
 73
 74	if (!io_timeout_finish(timeout, data)) {
 75		bool filled;
 76		filled = io_fill_cqe_req_aux(req, ts->locked, -ETIME,
 77					     IORING_CQE_F_MORE);
 78		if (filled) {
 79			/* re-arm timer */
 80			spin_lock_irq(&ctx->timeout_lock);
 81			list_add(&timeout->list, ctx->timeout_list.prev);
 82			data->timer.function = io_timeout_fn;
 83			hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode);
 84			spin_unlock_irq(&ctx->timeout_lock);
 85			return;
 86		}
 87	}
 88
 89	io_req_task_complete(req, ts);
 90}
 91
 92static bool io_kill_timeout(struct io_kiocb *req, int status)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 93	__must_hold(&req->ctx->timeout_lock)
 94{
 95	struct io_timeout_data *io = req->async_data;
 96
 97	if (hrtimer_try_to_cancel(&io->timer) != -1) {
 98		struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
 99
100		if (status)
101			req_set_fail(req);
102		atomic_set(&req->ctx->cq_timeouts,
103			atomic_read(&req->ctx->cq_timeouts) + 1);
104		list_del_init(&timeout->list);
105		io_req_queue_tw_complete(req, status);
106		return true;
107	}
108	return false;
109}
110
111__cold void io_flush_timeouts(struct io_ring_ctx *ctx)
112{
 
 
113	u32 seq;
114	struct io_timeout *timeout, *tmp;
115
116	spin_lock_irq(&ctx->timeout_lock);
117	seq = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);
118
119	list_for_each_entry_safe(timeout, tmp, &ctx->timeout_list, list) {
120		struct io_kiocb *req = cmd_to_io_kiocb(timeout);
121		u32 events_needed, events_got;
122
123		if (io_is_timeout_noseq(req))
124			break;
125
126		/*
127		 * Since seq can easily wrap around over time, subtract
128		 * the last seq at which timeouts were flushed before comparing.
129		 * Assuming not more than 2^31-1 events have happened since,
130		 * these subtractions won't have wrapped, so we can check if
131		 * target is in [last_seq, current_seq] by comparing the two.
132		 */
133		events_needed = timeout->target_seq - ctx->cq_last_tm_flush;
134		events_got = seq - ctx->cq_last_tm_flush;
135		if (events_got < events_needed)
136			break;
137
138		io_kill_timeout(req, 0);
139	}
140	ctx->cq_last_tm_flush = seq;
141	spin_unlock_irq(&ctx->timeout_lock);
 
142}
143
144static void io_req_tw_fail_links(struct io_kiocb *link, struct io_tw_state *ts)
145{
146	io_tw_lock(link->ctx, ts);
147	while (link) {
148		struct io_kiocb *nxt = link->link;
149		long res = -ECANCELED;
150
151		if (link->flags & REQ_F_FAIL)
152			res = link->cqe.res;
153		link->link = NULL;
154		io_req_set_res(link, res, 0);
155		io_req_task_complete(link, ts);
156		link = nxt;
157	}
158}
159
160static void io_fail_links(struct io_kiocb *req)
161	__must_hold(&req->ctx->completion_lock)
162{
163	struct io_kiocb *link = req->link;
164	bool ignore_cqes = req->flags & REQ_F_SKIP_LINK_CQES;
165
166	if (!link)
167		return;
168
169	while (link) {
170		if (ignore_cqes)
171			link->flags |= REQ_F_CQE_SKIP;
172		else
173			link->flags &= ~REQ_F_CQE_SKIP;
174		trace_io_uring_fail_link(req, link);
175		link = link->link;
176	}
177
178	link = req->link;
179	link->io_task_work.func = io_req_tw_fail_links;
180	io_req_task_work_add(link);
181	req->link = NULL;
182}
183
184static inline void io_remove_next_linked(struct io_kiocb *req)
185{
186	struct io_kiocb *nxt = req->link;
187
188	req->link = nxt->link;
189	nxt->link = NULL;
190}
191
192void io_disarm_next(struct io_kiocb *req)
193	__must_hold(&req->ctx->completion_lock)
194{
195	struct io_kiocb *link = NULL;
196
197	if (req->flags & REQ_F_ARM_LTIMEOUT) {
198		link = req->link;
199		req->flags &= ~REQ_F_ARM_LTIMEOUT;
200		if (link && link->opcode == IORING_OP_LINK_TIMEOUT) {
201			io_remove_next_linked(req);
202			io_req_queue_tw_complete(link, -ECANCELED);
203		}
204	} else if (req->flags & REQ_F_LINK_TIMEOUT) {
205		struct io_ring_ctx *ctx = req->ctx;
206
207		spin_lock_irq(&ctx->timeout_lock);
208		link = io_disarm_linked_timeout(req);
209		spin_unlock_irq(&ctx->timeout_lock);
210		if (link)
211			io_req_queue_tw_complete(link, -ECANCELED);
212	}
213	if (unlikely((req->flags & REQ_F_FAIL) &&
214		     !(req->flags & REQ_F_HARDLINK)))
215		io_fail_links(req);
216}
217
218struct io_kiocb *__io_disarm_linked_timeout(struct io_kiocb *req,
219					    struct io_kiocb *link)
220	__must_hold(&req->ctx->completion_lock)
221	__must_hold(&req->ctx->timeout_lock)
222{
223	struct io_timeout_data *io = link->async_data;
224	struct io_timeout *timeout = io_kiocb_to_cmd(link, struct io_timeout);
225
226	io_remove_next_linked(req);
227	timeout->head = NULL;
228	if (hrtimer_try_to_cancel(&io->timer) != -1) {
229		list_del(&timeout->list);
230		return link;
231	}
232
233	return NULL;
234}
235
236static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer)
237{
238	struct io_timeout_data *data = container_of(timer,
239						struct io_timeout_data, timer);
240	struct io_kiocb *req = data->req;
241	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
242	struct io_ring_ctx *ctx = req->ctx;
243	unsigned long flags;
244
245	spin_lock_irqsave(&ctx->timeout_lock, flags);
246	list_del_init(&timeout->list);
247	atomic_set(&req->ctx->cq_timeouts,
248		atomic_read(&req->ctx->cq_timeouts) + 1);
249	spin_unlock_irqrestore(&ctx->timeout_lock, flags);
250
251	if (!(data->flags & IORING_TIMEOUT_ETIME_SUCCESS))
252		req_set_fail(req);
253
254	io_req_set_res(req, -ETIME, 0);
255	req->io_task_work.func = io_timeout_complete;
256	io_req_task_work_add(req);
257	return HRTIMER_NORESTART;
258}
259
260static struct io_kiocb *io_timeout_extract(struct io_ring_ctx *ctx,
261					   struct io_cancel_data *cd)
262	__must_hold(&ctx->timeout_lock)
263{
264	struct io_timeout *timeout;
265	struct io_timeout_data *io;
266	struct io_kiocb *req = NULL;
267
268	list_for_each_entry(timeout, &ctx->timeout_list, list) {
269		struct io_kiocb *tmp = cmd_to_io_kiocb(timeout);
270
271		if (io_cancel_req_match(tmp, cd)) {
272			req = tmp;
273			break;
274		}
275	}
276	if (!req)
277		return ERR_PTR(-ENOENT);
278
279	io = req->async_data;
280	if (hrtimer_try_to_cancel(&io->timer) == -1)
281		return ERR_PTR(-EALREADY);
282	timeout = io_kiocb_to_cmd(req, struct io_timeout);
283	list_del_init(&timeout->list);
284	return req;
285}
286
287int io_timeout_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd)
288	__must_hold(&ctx->completion_lock)
289{
290	struct io_kiocb *req;
291
292	spin_lock_irq(&ctx->timeout_lock);
293	req = io_timeout_extract(ctx, cd);
294	spin_unlock_irq(&ctx->timeout_lock);
295
296	if (IS_ERR(req))
297		return PTR_ERR(req);
298	io_req_task_queue_fail(req, -ECANCELED);
299	return 0;
300}
301
302static void io_req_task_link_timeout(struct io_kiocb *req, struct io_tw_state *ts)
303{
304	unsigned issue_flags = ts->locked ? 0 : IO_URING_F_UNLOCKED;
305	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
306	struct io_kiocb *prev = timeout->prev;
307	int ret = -ENOENT;
308
309	if (prev) {
310		if (!(req->task->flags & PF_EXITING)) {
311			struct io_cancel_data cd = {
312				.ctx		= req->ctx,
313				.data		= prev->cqe.user_data,
314			};
315
316			ret = io_try_cancel(req->task->io_uring, &cd, issue_flags);
 
 
317		}
318		io_req_set_res(req, ret ?: -ETIME, 0);
319		io_req_task_complete(req, ts);
320		io_put_req(prev);
321	} else {
322		io_req_set_res(req, -ETIME, 0);
323		io_req_task_complete(req, ts);
324	}
325}
326
327static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer)
328{
329	struct io_timeout_data *data = container_of(timer,
330						struct io_timeout_data, timer);
331	struct io_kiocb *prev, *req = data->req;
332	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
333	struct io_ring_ctx *ctx = req->ctx;
334	unsigned long flags;
335
336	spin_lock_irqsave(&ctx->timeout_lock, flags);
337	prev = timeout->head;
338	timeout->head = NULL;
339
340	/*
341	 * We don't expect the list to be empty, that will only happen if we
342	 * race with the completion of the linked work.
343	 */
344	if (prev) {
345		io_remove_next_linked(prev);
346		if (!req_ref_inc_not_zero(prev))
347			prev = NULL;
348	}
349	list_del(&timeout->list);
350	timeout->prev = prev;
351	spin_unlock_irqrestore(&ctx->timeout_lock, flags);
352
353	req->io_task_work.func = io_req_task_link_timeout;
354	io_req_task_work_add(req);
355	return HRTIMER_NORESTART;
356}
357
358static clockid_t io_timeout_get_clock(struct io_timeout_data *data)
359{
360	switch (data->flags & IORING_TIMEOUT_CLOCK_MASK) {
361	case IORING_TIMEOUT_BOOTTIME:
362		return CLOCK_BOOTTIME;
363	case IORING_TIMEOUT_REALTIME:
364		return CLOCK_REALTIME;
365	default:
366		/* can't happen, vetted at prep time */
367		WARN_ON_ONCE(1);
368		fallthrough;
369	case 0:
370		return CLOCK_MONOTONIC;
371	}
372}
373
374static int io_linked_timeout_update(struct io_ring_ctx *ctx, __u64 user_data,
375				    struct timespec64 *ts, enum hrtimer_mode mode)
376	__must_hold(&ctx->timeout_lock)
377{
378	struct io_timeout_data *io;
379	struct io_timeout *timeout;
380	struct io_kiocb *req = NULL;
381
382	list_for_each_entry(timeout, &ctx->ltimeout_list, list) {
383		struct io_kiocb *tmp = cmd_to_io_kiocb(timeout);
384
385		if (user_data == tmp->cqe.user_data) {
386			req = tmp;
387			break;
388		}
389	}
390	if (!req)
391		return -ENOENT;
392
393	io = req->async_data;
394	if (hrtimer_try_to_cancel(&io->timer) == -1)
395		return -EALREADY;
396	hrtimer_init(&io->timer, io_timeout_get_clock(io), mode);
397	io->timer.function = io_link_timeout_fn;
398	hrtimer_start(&io->timer, timespec64_to_ktime(*ts), mode);
399	return 0;
400}
401
402static int io_timeout_update(struct io_ring_ctx *ctx, __u64 user_data,
403			     struct timespec64 *ts, enum hrtimer_mode mode)
404	__must_hold(&ctx->timeout_lock)
405{
406	struct io_cancel_data cd = { .ctx = ctx, .data = user_data, };
407	struct io_kiocb *req = io_timeout_extract(ctx, &cd);
408	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
409	struct io_timeout_data *data;
410
411	if (IS_ERR(req))
412		return PTR_ERR(req);
413
414	timeout->off = 0; /* noseq */
415	data = req->async_data;
 
 
416	list_add_tail(&timeout->list, &ctx->timeout_list);
417	hrtimer_init(&data->timer, io_timeout_get_clock(data), mode);
418	data->timer.function = io_timeout_fn;
419	hrtimer_start(&data->timer, timespec64_to_ktime(*ts), mode);
420	return 0;
421}
422
423int io_timeout_remove_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
424{
425	struct io_timeout_rem *tr = io_kiocb_to_cmd(req, struct io_timeout_rem);
426
427	if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))
428		return -EINVAL;
429	if (sqe->buf_index || sqe->len || sqe->splice_fd_in)
430		return -EINVAL;
431
432	tr->ltimeout = false;
433	tr->addr = READ_ONCE(sqe->addr);
434	tr->flags = READ_ONCE(sqe->timeout_flags);
435	if (tr->flags & IORING_TIMEOUT_UPDATE_MASK) {
436		if (hweight32(tr->flags & IORING_TIMEOUT_CLOCK_MASK) > 1)
437			return -EINVAL;
438		if (tr->flags & IORING_LINK_TIMEOUT_UPDATE)
439			tr->ltimeout = true;
440		if (tr->flags & ~(IORING_TIMEOUT_UPDATE_MASK|IORING_TIMEOUT_ABS))
441			return -EINVAL;
442		if (get_timespec64(&tr->ts, u64_to_user_ptr(sqe->addr2)))
443			return -EFAULT;
444		if (tr->ts.tv_sec < 0 || tr->ts.tv_nsec < 0)
445			return -EINVAL;
446	} else if (tr->flags) {
447		/* timeout removal doesn't support flags */
448		return -EINVAL;
449	}
450
451	return 0;
452}
453
454static inline enum hrtimer_mode io_translate_timeout_mode(unsigned int flags)
455{
456	return (flags & IORING_TIMEOUT_ABS) ? HRTIMER_MODE_ABS
457					    : HRTIMER_MODE_REL;
458}
459
460/*
461 * Remove or update an existing timeout command
462 */
463int io_timeout_remove(struct io_kiocb *req, unsigned int issue_flags)
464{
465	struct io_timeout_rem *tr = io_kiocb_to_cmd(req, struct io_timeout_rem);
466	struct io_ring_ctx *ctx = req->ctx;
467	int ret;
468
469	if (!(tr->flags & IORING_TIMEOUT_UPDATE)) {
470		struct io_cancel_data cd = { .ctx = ctx, .data = tr->addr, };
471
472		spin_lock(&ctx->completion_lock);
473		ret = io_timeout_cancel(ctx, &cd);
474		spin_unlock(&ctx->completion_lock);
475	} else {
476		enum hrtimer_mode mode = io_translate_timeout_mode(tr->flags);
477
478		spin_lock_irq(&ctx->timeout_lock);
479		if (tr->ltimeout)
480			ret = io_linked_timeout_update(ctx, tr->addr, &tr->ts, mode);
481		else
482			ret = io_timeout_update(ctx, tr->addr, &tr->ts, mode);
483		spin_unlock_irq(&ctx->timeout_lock);
484	}
485
486	if (ret < 0)
487		req_set_fail(req);
488	io_req_set_res(req, ret, 0);
489	return IOU_OK;
490}
491
492static int __io_timeout_prep(struct io_kiocb *req,
493			     const struct io_uring_sqe *sqe,
494			     bool is_timeout_link)
495{
496	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
497	struct io_timeout_data *data;
498	unsigned flags;
499	u32 off = READ_ONCE(sqe->off);
500
501	if (sqe->buf_index || sqe->len != 1 || sqe->splice_fd_in)
502		return -EINVAL;
503	if (off && is_timeout_link)
504		return -EINVAL;
505	flags = READ_ONCE(sqe->timeout_flags);
506	if (flags & ~(IORING_TIMEOUT_ABS | IORING_TIMEOUT_CLOCK_MASK |
507		      IORING_TIMEOUT_ETIME_SUCCESS |
508		      IORING_TIMEOUT_MULTISHOT))
509		return -EINVAL;
510	/* more than one clock specified is invalid, obviously */
511	if (hweight32(flags & IORING_TIMEOUT_CLOCK_MASK) > 1)
512		return -EINVAL;
513	/* multishot requests only make sense with rel values */
514	if (!(~flags & (IORING_TIMEOUT_MULTISHOT | IORING_TIMEOUT_ABS)))
515		return -EINVAL;
516
517	INIT_LIST_HEAD(&timeout->list);
518	timeout->off = off;
519	if (unlikely(off && !req->ctx->off_timeout_used))
520		req->ctx->off_timeout_used = true;
521	/*
522	 * for multishot reqs w/ fixed nr of repeats, repeats tracks the
523	 * remaining nr
524	 */
525	timeout->repeats = 0;
526	if ((flags & IORING_TIMEOUT_MULTISHOT) && off > 0)
527		timeout->repeats = off;
528
529	if (WARN_ON_ONCE(req_has_async_data(req)))
530		return -EFAULT;
531	if (io_alloc_async_data(req))
532		return -ENOMEM;
533
534	data = req->async_data;
535	data->req = req;
536	data->flags = flags;
537
538	if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr)))
539		return -EFAULT;
540
541	if (data->ts.tv_sec < 0 || data->ts.tv_nsec < 0)
542		return -EINVAL;
543
544	INIT_LIST_HEAD(&timeout->list);
545	data->mode = io_translate_timeout_mode(flags);
546	hrtimer_init(&data->timer, io_timeout_get_clock(data), data->mode);
547
548	if (is_timeout_link) {
549		struct io_submit_link *link = &req->ctx->submit_state.link;
550
551		if (!link->head)
552			return -EINVAL;
553		if (link->last->opcode == IORING_OP_LINK_TIMEOUT)
554			return -EINVAL;
555		timeout->head = link->last;
556		link->last->flags |= REQ_F_ARM_LTIMEOUT;
557	}
558	return 0;
559}
560
561int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
562{
563	return __io_timeout_prep(req, sqe, false);
564}
565
566int io_link_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
567{
568	return __io_timeout_prep(req, sqe, true);
569}
570
571int io_timeout(struct io_kiocb *req, unsigned int issue_flags)
572{
573	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
574	struct io_ring_ctx *ctx = req->ctx;
575	struct io_timeout_data *data = req->async_data;
576	struct list_head *entry;
577	u32 tail, off = timeout->off;
578
579	spin_lock_irq(&ctx->timeout_lock);
580
581	/*
582	 * sqe->off holds how many events that need to occur for this
583	 * timeout event to be satisfied. If it isn't set, then this is
584	 * a pure timeout request, sequence isn't used.
585	 */
586	if (io_is_timeout_noseq(req)) {
587		entry = ctx->timeout_list.prev;
588		goto add;
589	}
590
591	tail = data_race(ctx->cached_cq_tail) - atomic_read(&ctx->cq_timeouts);
592	timeout->target_seq = tail + off;
593
594	/* Update the last seq here in case io_flush_timeouts() hasn't.
595	 * This is safe because ->completion_lock is held, and submissions
596	 * and completions are never mixed in the same ->completion_lock section.
597	 */
598	ctx->cq_last_tm_flush = tail;
599
600	/*
601	 * Insertion sort, ensuring the first entry in the list is always
602	 * the one we need first.
603	 */
604	list_for_each_prev(entry, &ctx->timeout_list) {
605		struct io_timeout *nextt = list_entry(entry, struct io_timeout, list);
606		struct io_kiocb *nxt = cmd_to_io_kiocb(nextt);
607
608		if (io_is_timeout_noseq(nxt))
609			continue;
610		/* nxt.seq is behind @tail, otherwise would've been completed */
611		if (off >= nextt->target_seq - tail)
612			break;
613	}
614add:
615	list_add(&timeout->list, entry);
616	data->timer.function = io_timeout_fn;
617	hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode);
618	spin_unlock_irq(&ctx->timeout_lock);
619	return IOU_ISSUE_SKIP_COMPLETE;
620}
621
622void io_queue_linked_timeout(struct io_kiocb *req)
623{
624	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
625	struct io_ring_ctx *ctx = req->ctx;
626
627	spin_lock_irq(&ctx->timeout_lock);
628	/*
629	 * If the back reference is NULL, then our linked request finished
630	 * before we got a chance to setup the timer
631	 */
632	if (timeout->head) {
633		struct io_timeout_data *data = req->async_data;
634
635		data->timer.function = io_link_timeout_fn;
636		hrtimer_start(&data->timer, timespec64_to_ktime(data->ts),
637				data->mode);
638		list_add_tail(&timeout->list, &ctx->ltimeout_list);
639	}
640	spin_unlock_irq(&ctx->timeout_lock);
641	/* drop submission reference */
642	io_put_req(req);
643}
644
645static bool io_match_task(struct io_kiocb *head, struct task_struct *task,
646			  bool cancel_all)
647	__must_hold(&req->ctx->timeout_lock)
648{
649	struct io_kiocb *req;
650
651	if (task && head->task != task)
652		return false;
653	if (cancel_all)
654		return true;
655
656	io_for_each_link(req, head) {
657		if (req->flags & REQ_F_INFLIGHT)
658			return true;
659	}
660	return false;
661}
662
663/* Returns true if we found and killed one or more timeouts */
664__cold bool io_kill_timeouts(struct io_ring_ctx *ctx, struct task_struct *tsk,
665			     bool cancel_all)
666{
667	struct io_timeout *timeout, *tmp;
668	int canceled = 0;
669
670	/*
671	 * completion_lock is needed for io_match_task(). Take it before
672	 * timeout_lockfirst to keep locking ordering.
673	 */
674	spin_lock(&ctx->completion_lock);
675	spin_lock_irq(&ctx->timeout_lock);
676	list_for_each_entry_safe(timeout, tmp, &ctx->timeout_list, list) {
677		struct io_kiocb *req = cmd_to_io_kiocb(timeout);
678
679		if (io_match_task(req, tsk, cancel_all) &&
680		    io_kill_timeout(req, -ECANCELED))
681			canceled++;
682	}
683	spin_unlock_irq(&ctx->timeout_lock);
684	spin_unlock(&ctx->completion_lock);
685	return canceled != 0;
 
686}