We might have cases where the need for a specific timeout is gone, add support for canceling an existing timeout operation. This works like the POLL_REMOVE command, where the application passes in the user_data of the timeout it wishes to cancel in the sqe->addr field.
Signed-off-by: Jens Axboe <[email protected]> --- fs/io_uring.c | 92 ++++++++++++++++++++++++++++++----- include/uapi/linux/io_uring.h | 1 + 2 files changed, 82 insertions(+), 11 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index e48e0854bc1e..635856023fdf 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1914,22 +1914,88 @@ static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer) struct io_ring_ctx *ctx; struct io_kiocb *req; unsigned long flags; + bool comp; req = container_of(timer, struct io_kiocb, timeout.timer); ctx = req->ctx; atomic_inc(&ctx->cq_timeouts); spin_lock_irqsave(&ctx->completion_lock, flags); - list_del(&req->list); - - io_cqring_fill_event(ctx, req->user_data, -ETIME); - io_commit_cqring(ctx); + /* + * We could be racing with timeout deletion. If the list is empty, + * then timeout lookup already found it and will be handling it. + */ + comp = !list_empty(&req->list); + if (comp) { + list_del_init(&req->list); + io_cqring_fill_event(ctx, req->user_data, -ETIME); + io_commit_cqring(ctx); + } spin_unlock_irqrestore(&ctx->completion_lock, flags); + if (comp) { + io_cqring_ev_posted(ctx); + io_put_req(req, NULL); + } + return HRTIMER_NORESTART; +} + +/* + * Remove or update an existing timeout command + */ +static int io_timeout_remove(struct io_kiocb *req, + const struct io_uring_sqe *sqe) +{ + struct io_ring_ctx *ctx = req->ctx; + struct io_kiocb *treq; + int ret = -ENOENT; + __u64 user_data; + unsigned flags; + + if (unlikely(ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; + if (sqe->flags || sqe->ioprio || sqe->buf_index || sqe->len) + return -EINVAL; + flags = READ_ONCE(sqe->timeout_flags); + if (flags) + return -EINVAL; + + user_data = READ_ONCE(sqe->addr); + spin_lock_irq(&ctx->completion_lock); + list_for_each_entry(treq, &ctx->timeout_list, list) { + if (user_data == treq->user_data) { + list_del_init(&treq->list); + ret = 0; + break; + } + } + + /* didn't find timeout */ + if (ret) { +fill_ev: + io_cqring_fill_event(ctx, req->user_data, ret); + io_commit_cqring(ctx); + spin_unlock_irq(&ctx->completion_lock); + io_cqring_ev_posted(ctx); + io_put_req(req, NULL); + return 0; + } + + ret = hrtimer_try_to_cancel(&treq->timeout.timer); + if (ret == -1) { + ret = -EBUSY; + goto fill_ev; + } + + io_cqring_fill_event(ctx, req->user_data, 0); + io_cqring_fill_event(ctx, treq->user_data, -ECANCELED); + io_commit_cqring(ctx); + spin_unlock_irq(&ctx->completion_lock); io_cqring_ev_posted(ctx); + io_put_req(treq, NULL); io_put_req(req, NULL); - return HRTIMER_NORESTART; + return 0; } static int io_timeout(struct io_kiocb *req, const struct io_uring_sqe *sqe) @@ -1952,6 +2018,13 @@ static int io_timeout(struct io_kiocb *req, const struct io_uring_sqe *sqe) if (get_timespec64(&ts, u64_to_user_ptr(sqe->addr))) return -EFAULT; + if (flags & IORING_TIMEOUT_ABS) + mode = HRTIMER_MODE_ABS; + else + mode = HRTIMER_MODE_REL; + + hrtimer_init(&req->timeout.timer, CLOCK_MONOTONIC, mode); + /* * sqe->off holds how many events that need to occur for this * timeout event to be satisfied. @@ -1980,12 +2053,6 @@ static int io_timeout(struct io_kiocb *req, const struct io_uring_sqe *sqe) } list_add(&req->list, entry); spin_unlock_irq(&ctx->completion_lock); - - if (flags & IORING_TIMEOUT_ABS) - mode = HRTIMER_MODE_ABS; - else - mode = HRTIMER_MODE_REL; - hrtimer_init(&req->timeout.timer, CLOCK_MONOTONIC, mode); req->timeout.timer.function = io_timeout_fn; hrtimer_start(&req->timeout.timer, timespec64_to_ktime(ts), mode); return 0; @@ -2072,6 +2139,9 @@ static int __io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, case IORING_OP_TIMEOUT: ret = io_timeout(req, s->sqe); break; + case IORING_OP_TIMEOUT_REMOVE: + ret = io_timeout_remove(req, s->sqe); + break; default: ret = -EINVAL; break; diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index b402dfee5e15..6dc5ced1c37a 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -64,6 +64,7 @@ struct io_uring_sqe { #define IORING_OP_SENDMSG 9 #define IORING_OP_RECVMSG 10 #define IORING_OP_TIMEOUT 11 +#define IORING_OP_TIMEOUT_REMOVE 12 /* * sqe->fsync_flags -- 2.17.1 -- Jens Axboe
