summaryrefslogtreecommitdiff
path: root/io_uring/timeout.c
diff options
context:
space:
mode:
authorJens Axboe <axboe@kernel.dk>2022-05-25 08:57:27 -0600
committerJens Axboe <axboe@kernel.dk>2022-07-24 18:39:12 -0600
commit59915143e89fb8dc7b5bd9dcaf628d8181fd54ac (patch)
treeaa1d77dce0cc12a0ca04ab3fb2a0e036ead6719e /io_uring/timeout.c
parente418bbc97bffda868934acfdf8a1173ab044be69 (diff)
io_uring: move timeout opcodes and handling into its own file
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring/timeout.c')
-rw-r--r--io_uring/timeout.c634
1 files changed, 634 insertions, 0 deletions
diff --git a/io_uring/timeout.c b/io_uring/timeout.c
new file mode 100644
index 000000000000..5e42bfcd683e
--- /dev/null
+++ b/io_uring/timeout.c
@@ -0,0 +1,634 @@
+// 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_types.h"
+#include "io_uring.h"
+#include "refs.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);
+
+ 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 void 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);
+
+ 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);
+ }
+}
+
+__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_fail_links(struct io_kiocb *req)
+ __must_hold(&req->ctx->completion_lock)
+{
+ struct io_kiocb *nxt, *link = req->link;
+ bool ignore_cqes = req->flags & REQ_F_SKIP_LINK_CQES;
+
+ req->link = NULL;
+ while (link) {
+ long res = -ECANCELED;
+
+ if (link->flags & REQ_F_FAIL)
+ res = link->cqe.res;
+
+ nxt = link->link;
+ link->link = NULL;
+
+ trace_io_uring_fail_link(req->ctx, req, req->cqe.user_data,
+ req->opcode, link);
+
+ if (ignore_cqes)
+ link->flags |= REQ_F_CQE_SKIP;
+ else
+ link->flags &= ~REQ_F_CQE_SKIP;
+ io_req_set_res(link, res, 0);
+ __io_req_complete_post(link);
+ link = nxt;
+ }
+}
+
+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);
+
+ 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_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);
+ 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)
+{
+ struct io_timeout *timeout = io_kiocb_to_cmd(req);
+ 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, &cd);
+ }
+ 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_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_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);
+
+ 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_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_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)))
+ return -EFAULT;
+
+ if (data->ts.tv_sec < 0 || data->ts.tv_nsec < 0)
+ return -EINVAL;
+
+ INIT_LIST_HEAD(&timeout->list);
+ data->mode = io_translate_timeout_mode(flags);
+ hrtimer_init(&data->timer, io_timeout_get_clock(data), data->mode);
+
+ if (is_timeout_link) {
+ struct io_submit_link *link = &req->ctx->submit_state.link;
+
+ if (!link->head)
+ return -EINVAL;
+ if (link->last->opcode == IORING_OP_LINK_TIMEOUT)
+ return -EINVAL;
+ timeout->head = link->last;
+ link->last->flags |= REQ_F_ARM_LTIMEOUT;
+ }
+ return 0;
+}
+
+int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ return __io_timeout_prep(req, sqe, false);
+}
+
+int io_link_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ return __io_timeout_prep(req, sqe, true);
+}
+
+int io_timeout(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_timeout *timeout = io_kiocb_to_cmd(req);
+ struct io_ring_ctx *ctx = req->ctx;
+ struct io_timeout_data *data = req->async_data;
+ struct list_head *entry;
+ u32 tail, off = timeout->off;
+
+ spin_lock_irq(&ctx->timeout_lock);
+
+ /*
+ * sqe->off holds how many events that need to occur for this
+ * timeout event to be satisfied. If it isn't set, then this is
+ * a pure timeout request, sequence isn't used.
+ */
+ if (io_is_timeout_noseq(req)) {
+ entry = ctx->timeout_list.prev;
+ goto add;
+ }
+
+ tail = ctx->cached_cq_tail - atomic_read(&ctx->cq_timeouts);
+ timeout->target_seq = tail + off;
+
+ /* Update the last seq here in case io_flush_timeouts() hasn't.
+ * This is safe because ->completion_lock is held, and submissions
+ * and completions are never mixed in the same ->completion_lock section.
+ */
+ ctx->cq_last_tm_flush = tail;
+
+ /*
+ * Insertion sort, ensuring the first entry in the list is always
+ * the one we need first.
+ */
+ list_for_each_prev(entry, &ctx->timeout_list) {
+ struct io_timeout *nextt = list_entry(entry, struct io_timeout, list);
+ struct io_kiocb *nxt = cmd_to_io_kiocb(nextt);
+
+ if (io_is_timeout_noseq(nxt))
+ continue;
+ /* nxt.seq is behind @tail, otherwise would've been completed */
+ if (off >= nextt->target_seq - tail)
+ break;
+ }
+add:
+ list_add(&timeout->list, entry);
+ data->timer.function = io_timeout_fn;
+ hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode);
+ spin_unlock_irq(&ctx->timeout_lock);
+ return IOU_ISSUE_SKIP_COMPLETE;
+}
+
+void io_queue_linked_timeout(struct io_kiocb *req)
+{
+ struct io_timeout *timeout = io_kiocb_to_cmd(req);
+ struct io_ring_ctx *ctx = req->ctx;
+
+ spin_lock_irq(&ctx->timeout_lock);
+ /*
+ * If the back reference is NULL, then our linked request finished
+ * before we got a chance to setup the timer
+ */
+ if (timeout->head) {
+ struct io_timeout_data *data = req->async_data;
+
+ data->timer.function = io_link_timeout_fn;
+ hrtimer_start(&data->timer, timespec64_to_ktime(data->ts),
+ data->mode);
+ list_add_tail(&timeout->list, &ctx->ltimeout_list);
+ }
+ spin_unlock_irq(&ctx->timeout_lock);
+ /* drop submission reference */
+ io_put_req(req);
+}
+
+static bool io_match_task(struct io_kiocb *head, struct task_struct *task,
+ bool cancel_all)
+ __must_hold(&req->ctx->timeout_lock)
+{
+ struct io_kiocb *req;
+
+ if (task && head->task != task)
+ return false;
+ if (cancel_all)
+ return true;
+
+ io_for_each_link(req, head) {
+ if (req->flags & REQ_F_INFLIGHT)
+ return true;
+ }
+ return false;
+}
+
+/* Returns true if we found and killed one or more timeouts */
+__cold bool io_kill_timeouts(struct io_ring_ctx *ctx, struct task_struct *tsk,
+ bool cancel_all)
+{
+ struct io_timeout *timeout, *tmp;
+ int canceled = 0;
+
+ spin_lock(&ctx->completion_lock);
+ 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);
+
+ if (io_match_task(req, tsk, cancel_all)) {
+ io_kill_timeout(req, -ECANCELED);
+ canceled++;
+ }
+ }
+ spin_unlock_irq(&ctx->timeout_lock);
+ io_commit_cqring(ctx);
+ spin_unlock(&ctx->completion_lock);
+ if (canceled != 0)
+ io_cqring_ev_posted(ctx);
+ return canceled != 0;
+}