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// SPDX-License-Identifier: GPL-2.0#include <linux/kernel.h>#include <linux/errno.h>#include <linux/file.h>#include <linux/io_uring.h> #include <trace/events/io_uring.h> #include <uapi/linux/io_uring.h> #include "io_uring.h"#include "refs.h"#include "cancel.h"#include "timeout.h" struct io_timeout {	struct file			*file;	u32				off;	u32				target_seq;	struct list_head		list;	/* head of the link, used by linked timeouts only */	struct io_kiocb			*head;	/* for linked completions */	struct io_kiocb			*prev;}; struct io_timeout_rem {	struct file			*file;	u64				addr; 	/* timeout update */	struct timespec64		ts;	u32				flags;	bool				ltimeout;}; static inline bool io_is_timeout_noseq(struct io_kiocb *req){	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout); 	return !timeout->off;} static inline void io_put_req(struct io_kiocb *req){	if (req_ref_put_and_test(req)) {		io_queue_next(req);		io_free_req(req);	}} static bool io_kill_timeout(struct io_kiocb *req, int status)	__must_hold(&req->ctx->completion_lock)	__must_hold(&req->ctx->timeout_lock){	struct io_timeout_data *io = req->async_data; 	if (hrtimer_try_to_cancel(&io->timer) != -1) {		struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout); 		if (status)			req_set_fail(req);		atomic_set(&req->ctx->cq_timeouts,			atomic_read(&req->ctx->cq_timeouts) + 1);		list_del_init(&timeout->list);		io_req_tw_post_queue(req, status, 0);		return true;	}	return false;} __cold void io_flush_timeouts(struct io_ring_ctx *ctx)	__must_hold(&ctx->completion_lock){	u32 seq = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);	struct io_timeout *timeout, *tmp; 	spin_lock_irq(&ctx->timeout_lock);	list_for_each_entry_safe(timeout, tmp, &ctx->timeout_list, list) {		struct io_kiocb *req = cmd_to_io_kiocb(timeout);		u32 events_needed, events_got; 		if (io_is_timeout_noseq(req))			break; 		/*		 * Since seq can easily wrap around over time, subtract		 * the last seq at which timeouts were flushed before comparing.		 * Assuming not more than 2^31-1 events have happened since,		 * these subtractions won't have wrapped, so we can check if		 * target is in [last_seq, current_seq] by comparing the two.		 */		events_needed = timeout->target_seq - ctx->cq_last_tm_flush;		events_got = seq - ctx->cq_last_tm_flush;		if (events_got < events_needed)			break; 		io_kill_timeout(req, 0);	}	ctx->cq_last_tm_flush = seq;	spin_unlock_irq(&ctx->timeout_lock);} static void io_req_tw_fail_links(struct io_kiocb *link, bool *locked){	io_tw_lock(link->ctx, locked);	while (link) {		struct io_kiocb *nxt = link->link;		long res = -ECANCELED; 		if (link->flags & REQ_F_FAIL)			res = link->cqe.res;		link->link = NULL;		io_req_set_res(link, res, 0);		io_req_task_complete(link, locked);		link = nxt;	}} static void io_fail_links(struct io_kiocb *req)	__must_hold(&req->ctx->completion_lock){	struct io_kiocb *link = req->link;	bool ignore_cqes = req->flags & REQ_F_SKIP_LINK_CQES; 	if (!link)		return; 	while (link) {		if (ignore_cqes)			link->flags |= REQ_F_CQE_SKIP;		else			link->flags &= ~REQ_F_CQE_SKIP;		trace_io_uring_fail_link(req, link);		link = link->link;	} 	link = req->link;	link->io_task_work.func = io_req_tw_fail_links;	io_req_task_work_add(link);	req->link = NULL;} static inline void io_remove_next_linked(struct io_kiocb *req){	struct io_kiocb *nxt = req->link; 	req->link = nxt->link;	nxt->link = NULL;} bool io_disarm_next(struct io_kiocb *req)	__must_hold(&req->ctx->completion_lock){	struct io_kiocb *link = NULL;	bool posted = false; 	if (req->flags & REQ_F_ARM_LTIMEOUT) {		link = req->link;		req->flags &= ~REQ_F_ARM_LTIMEOUT;		if (link && link->opcode == IORING_OP_LINK_TIMEOUT) {			io_remove_next_linked(req);			io_req_tw_post_queue(link, -ECANCELED, 0);			posted = true;		}	} else if (req->flags & REQ_F_LINK_TIMEOUT) {		struct io_ring_ctx *ctx = req->ctx; 		spin_lock_irq(&ctx->timeout_lock);		link = io_disarm_linked_timeout(req);		spin_unlock_irq(&ctx->timeout_lock);		if (link) {			posted = true;			io_req_tw_post_queue(link, -ECANCELED, 0);		}	}	if (unlikely((req->flags & REQ_F_FAIL) &&		     !(req->flags & REQ_F_HARDLINK))) {		posted |= (req->link != NULL);		io_fail_links(req);	}	return posted;} struct io_kiocb *__io_disarm_linked_timeout(struct io_kiocb *req,					    struct io_kiocb *link)	__must_hold(&req->ctx->completion_lock)	__must_hold(&req->ctx->timeout_lock){	struct io_timeout_data *io = link->async_data;	struct io_timeout *timeout = io_kiocb_to_cmd(link, struct io_timeout); 	io_remove_next_linked(req);	timeout->head = NULL;	if (hrtimer_try_to_cancel(&io->timer) != -1) {		list_del(&timeout->list);		return link;	} 	return NULL;} static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer){	struct io_timeout_data *data = container_of(timer,						struct io_timeout_data, timer);	struct io_kiocb *req = data->req;	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);	struct io_ring_ctx *ctx = req->ctx;	unsigned long flags; 	spin_lock_irqsave(&ctx->timeout_lock, flags);	list_del_init(&timeout->list);	atomic_set(&req->ctx->cq_timeouts,		atomic_read(&req->ctx->cq_timeouts) + 1);	spin_unlock_irqrestore(&ctx->timeout_lock, flags); 	if (!(data->flags & IORING_TIMEOUT_ETIME_SUCCESS))		req_set_fail(req); 	io_req_set_res(req, -ETIME, 0);	req->io_task_work.func = io_req_task_complete;	io_req_task_work_add(req);	return HRTIMER_NORESTART;} static struct io_kiocb *io_timeout_extract(struct io_ring_ctx *ctx,					   struct io_cancel_data *cd)	__must_hold(&ctx->timeout_lock){	struct io_timeout *timeout;	struct io_timeout_data *io;	struct io_kiocb *req = NULL; 	list_for_each_entry(timeout, &ctx->timeout_list, list) {		struct io_kiocb *tmp = cmd_to_io_kiocb(timeout); 		if (!(cd->flags & IORING_ASYNC_CANCEL_ANY) &&		    cd->data != tmp->cqe.user_data)			continue;		if (cd->flags & (IORING_ASYNC_CANCEL_ALL|IORING_ASYNC_CANCEL_ANY)) {			if (cd->seq == tmp->work.cancel_seq)				continue;			tmp->work.cancel_seq = cd->seq;		}		req = tmp;		break;	}	if (!req)		return ERR_PTR(-ENOENT); 	io = req->async_data;	if (hrtimer_try_to_cancel(&io->timer) == -1)		return ERR_PTR(-EALREADY);	timeout = io_kiocb_to_cmd(req, struct io_timeout);	list_del_init(&timeout->list);	return req;} int io_timeout_cancel(struct io_ring_ctx *ctx, struct io_cancel_data *cd)	__must_hold(&ctx->completion_lock){	struct io_kiocb *req; 	spin_lock_irq(&ctx->timeout_lock);	req = io_timeout_extract(ctx, cd);	spin_unlock_irq(&ctx->timeout_lock); 	if (IS_ERR(req))		return PTR_ERR(req);	io_req_task_queue_fail(req, -ECANCELED);	return 0;} static void io_req_task_link_timeout(struct io_kiocb *req, bool *locked){	unsigned issue_flags = *locked ? 0 : IO_URING_F_UNLOCKED;	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);	struct io_kiocb *prev = timeout->prev;	int ret = -ENOENT; 	if (prev) {		if (!(req->task->flags & PF_EXITING)) {			struct io_cancel_data cd = {				.ctx		= req->ctx,				.data		= prev->cqe.user_data,			}; 			ret = io_try_cancel(req->task->io_uring, &cd, issue_flags);		}		io_req_set_res(req, ret ?: -ETIME, 0);		io_req_complete_post(req);		io_put_req(prev);	} else {		io_req_set_res(req, -ETIME, 0);		io_req_complete_post(req);	}} static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer){	struct io_timeout_data *data = container_of(timer,						struct io_timeout_data, timer);	struct io_kiocb *prev, *req = data->req;	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);	struct io_ring_ctx *ctx = req->ctx;	unsigned long flags; 	spin_lock_irqsave(&ctx->timeout_lock, flags);	prev = timeout->head;	timeout->head = NULL; 	/*	 * We don't expect the list to be empty, that will only happen if we	 * race with the completion of the linked work.	 */	if (prev) {		io_remove_next_linked(prev);		if (!req_ref_inc_not_zero(prev))			prev = NULL;	}	list_del(&timeout->list);	timeout->prev = prev;	spin_unlock_irqrestore(&ctx->timeout_lock, flags); 	req->io_task_work.func = io_req_task_link_timeout;	io_req_task_work_add(req);	return HRTIMER_NORESTART;} static clockid_t io_timeout_get_clock(struct io_timeout_data *data){	switch (data->flags & IORING_TIMEOUT_CLOCK_MASK) {	case IORING_TIMEOUT_BOOTTIME:		return CLOCK_BOOTTIME;	case IORING_TIMEOUT_REALTIME:		return CLOCK_REALTIME;	default:		/* can't happen, vetted at prep time */		WARN_ON_ONCE(1);		fallthrough;	case 0:		return CLOCK_MONOTONIC;	}} static int io_linked_timeout_update(struct io_ring_ctx *ctx, __u64 user_data,				    struct timespec64 *ts, enum hrtimer_mode mode)	__must_hold(&ctx->timeout_lock){	struct io_timeout_data *io;	struct io_timeout *timeout;	struct io_kiocb *req = NULL; 	list_for_each_entry(timeout, &ctx->ltimeout_list, list) {		struct io_kiocb *tmp = cmd_to_io_kiocb(timeout); 		if (user_data == tmp->cqe.user_data) {			req = tmp;			break;		}	}	if (!req)		return -ENOENT; 	io = req->async_data;	if (hrtimer_try_to_cancel(&io->timer) == -1)		return -EALREADY;	hrtimer_init(&io->timer, io_timeout_get_clock(io), mode);	io->timer.function = io_link_timeout_fn;	hrtimer_start(&io->timer, timespec64_to_ktime(*ts), mode);	return 0;} static int io_timeout_update(struct io_ring_ctx *ctx, __u64 user_data,			     struct timespec64 *ts, enum hrtimer_mode mode)	__must_hold(&ctx->timeout_lock){	struct io_cancel_data cd = { .data = user_data, };	struct io_kiocb *req = io_timeout_extract(ctx, &cd);	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);	struct io_timeout_data *data; 	if (IS_ERR(req))		return PTR_ERR(req); 	timeout->off = 0; /* noseq */	data = req->async_data;	list_add_tail(&timeout->list, &ctx->timeout_list);	hrtimer_init(&data->timer, io_timeout_get_clock(data), mode);	data->timer.function = io_timeout_fn;	hrtimer_start(&data->timer, timespec64_to_ktime(*ts), mode);	return 0;} int io_timeout_remove_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe){	struct io_timeout_rem *tr = io_kiocb_to_cmd(req, struct io_timeout_rem); 	if (unlikely(req->flags & (REQ_F_FIXED_FILE | REQ_F_BUFFER_SELECT)))		return -EINVAL;	if (sqe->buf_index || sqe->len || sqe->splice_fd_in)		return -EINVAL; 	tr->ltimeout = false;	tr->addr = READ_ONCE(sqe->addr);	tr->flags = READ_ONCE(sqe->timeout_flags);	if (tr->flags & IORING_TIMEOUT_UPDATE_MASK) {		if (hweight32(tr->flags & IORING_TIMEOUT_CLOCK_MASK) > 1)			return -EINVAL;		if (tr->flags & IORING_LINK_TIMEOUT_UPDATE)			tr->ltimeout = true;		if (tr->flags & ~(IORING_TIMEOUT_UPDATE_MASK|IORING_TIMEOUT_ABS))			return -EINVAL;		if (get_timespec64(&tr->ts, u64_to_user_ptr(sqe->addr2)))			return -EFAULT;		if (tr->ts.tv_sec < 0 || tr->ts.tv_nsec < 0)			return -EINVAL;	} else if (tr->flags) {		/* timeout removal doesn't support flags */		return -EINVAL;	} 	return 0;} static inline enum hrtimer_mode io_translate_timeout_mode(unsigned int flags){	return (flags & IORING_TIMEOUT_ABS) ? HRTIMER_MODE_ABS					    : HRTIMER_MODE_REL;} /* * Remove or update an existing timeout command */int io_timeout_remove(struct io_kiocb *req, unsigned int issue_flags){	struct io_timeout_rem *tr = io_kiocb_to_cmd(req, struct io_timeout_rem);	struct io_ring_ctx *ctx = req->ctx;	int ret; 	if (!(tr->flags & IORING_TIMEOUT_UPDATE)) {		struct io_cancel_data cd = { .data = tr->addr, }; 		spin_lock(&ctx->completion_lock);		ret = io_timeout_cancel(ctx, &cd);		spin_unlock(&ctx->completion_lock);	} else {		enum hrtimer_mode mode = io_translate_timeout_mode(tr->flags); 		spin_lock_irq(&ctx->timeout_lock);		if (tr->ltimeout)			ret = io_linked_timeout_update(ctx, tr->addr, &tr->ts, mode);		else			ret = io_timeout_update(ctx, tr->addr, &tr->ts, mode);		spin_unlock_irq(&ctx->timeout_lock);	} 	if (ret < 0)		req_set_fail(req);	io_req_set_res(req, ret, 0);	return IOU_OK;} static int __io_timeout_prep(struct io_kiocb *req,			     const struct io_uring_sqe *sqe,			     bool is_timeout_link){	struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);	struct io_timeout_data *data;	unsigned flags;	u32 off = READ_ONCE(sqe->off); 	if (sqe->buf_index || sqe->len != 1 || sqe->splice_fd_in)		return -EINVAL;	if (off && is_timeout_link)		return -EINVAL;	flags = READ_ONCE(sqe->timeout_flags);	if (flags & ~(IORING_TIMEOUT_ABS | IORING_TIMEOUT_CLOCK_MASK |		      IORING_TIMEOUT_ETIME_SUCCESS))		return -EINVAL;	/* more than one clock specified is invalid, obviously */	if (hweight32(flags & IORING_TIMEOUT_CLOCK_MASK) > 1)		return -EINVAL; 	INIT_LIST_HEAD(&timeout->list);	timeout->off = off;	if (unlikely(off && !req->ctx->off_timeout_used))		req->ctx->off_timeout_used = true; 	if (WARN_ON_ONCE(req_has_async_data(req)))		return -EFAULT;	if (io_alloc_async_data(req))		return -ENOMEM; 	data = req->async_data;	data->req = req;	data->flags = flags; 	if (get_timespec64(&data->ts, u64_to_user_ptr(sqe->addr)))

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