diff options
| -rw-r--r-- | fs/io_uring.c | 149 | ||||
| -rw-r--r-- | include/uapi/linux/io_uring.h | 2 |
2 files changed, 146 insertions, 5 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index 05a299e80159..9d8e703bc851 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -200,6 +200,7 @@ struct io_ring_ctx { struct io_uring_sqe *sq_sqes; struct list_head defer_list; + struct list_head timeout_list; } ____cacheline_aligned_in_smp; /* IO offload */ @@ -216,6 +217,7 @@ struct io_ring_ctx { struct wait_queue_head cq_wait; struct fasync_struct *cq_fasync; struct eventfd_ctx *cq_ev_fd; + atomic_t cq_timeouts; } ____cacheline_aligned_in_smp; struct io_rings *rings; @@ -283,6 +285,11 @@ struct io_poll_iocb { struct wait_queue_entry wait; }; +struct io_timeout { + struct file *file; + struct hrtimer timer; +}; + /* * NOTE! Each of the iocb union members has the file pointer * as the first entry in their struct definition. So you can @@ -294,6 +301,7 @@ struct io_kiocb { struct file *file; struct kiocb rw; struct io_poll_iocb poll; + struct io_timeout timeout; }; struct sqe_submit submit; @@ -313,6 +321,7 @@ struct io_kiocb { #define REQ_F_LINK_DONE 128 /* linked sqes done */ #define REQ_F_FAIL_LINK 256 /* fail rest of links */ #define REQ_F_SHADOW_DRAIN 512 /* link-drain shadow req */ +#define REQ_F_TIMEOUT 1024 /* timeout request */ u64 user_data; u32 result; u32 sequence; @@ -344,6 +353,8 @@ struct io_submit_state { }; static void io_sq_wq_submit_work(struct work_struct *work); +static void io_cqring_fill_event(struct io_ring_ctx *ctx, u64 ki_user_data, + long res); static void __io_free_req(struct io_kiocb *req); static struct kmem_cache *req_cachep; @@ -400,26 +411,30 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p) INIT_LIST_HEAD(&ctx->poll_list); INIT_LIST_HEAD(&ctx->cancel_list); INIT_LIST_HEAD(&ctx->defer_list); + INIT_LIST_HEAD(&ctx->timeout_list); return ctx; } static inline bool io_sequence_defer(struct io_ring_ctx *ctx, struct io_kiocb *req) { - if ((req->flags & (REQ_F_IO_DRAIN|REQ_F_IO_DRAINED)) != REQ_F_IO_DRAIN) + /* timeout requests always honor sequence */ + if (!(req->flags & REQ_F_TIMEOUT) && + (req->flags & (REQ_F_IO_DRAIN|REQ_F_IO_DRAINED)) != REQ_F_IO_DRAIN) return false; return req->sequence != ctx->cached_cq_tail + ctx->rings->sq_dropped; } -static struct io_kiocb *io_get_deferred_req(struct io_ring_ctx *ctx) +static struct io_kiocb *__io_get_deferred_req(struct io_ring_ctx *ctx, + struct list_head *list) { struct io_kiocb *req; - if (list_empty(&ctx->defer_list)) + if (list_empty(list)) return NULL; - req = list_first_entry(&ctx->defer_list, struct io_kiocb, list); + req = list_first_entry(list, struct io_kiocb, list); if (!io_sequence_defer(ctx, req)) { list_del_init(&req->list); return req; @@ -428,6 +443,16 @@ static struct io_kiocb *io_get_deferred_req(struct io_ring_ctx *ctx) return NULL; } +static struct io_kiocb *io_get_deferred_req(struct io_ring_ctx *ctx) +{ + return __io_get_deferred_req(ctx, &ctx->defer_list); +} + +static struct io_kiocb *io_get_timeout_req(struct io_ring_ctx *ctx) +{ + return __io_get_deferred_req(ctx, &ctx->timeout_list); +} + static void __io_commit_cqring(struct io_ring_ctx *ctx) { struct io_rings *rings = ctx->rings; @@ -460,10 +485,36 @@ static inline void io_queue_async_work(struct io_ring_ctx *ctx, queue_work(ctx->sqo_wq[rw], &req->work); } +static void io_kill_timeout(struct io_kiocb *req) +{ + int ret; + + ret = hrtimer_try_to_cancel(&req->timeout.timer); + if (ret != -1) { + atomic_inc(&req->ctx->cq_timeouts); + list_del(&req->list); + io_cqring_fill_event(req->ctx, req->user_data, 0); + __io_free_req(req); + } +} + +static void io_kill_timeouts(struct io_ring_ctx *ctx) +{ + struct io_kiocb *req, *tmp; + + spin_lock_irq(&ctx->completion_lock); + list_for_each_entry_safe(req, tmp, &ctx->timeout_list, list) + io_kill_timeout(req); + spin_unlock_irq(&ctx->completion_lock); +} + static void io_commit_cqring(struct io_ring_ctx *ctx) { struct io_kiocb *req; + while ((req = io_get_timeout_req(ctx)) != NULL) + io_kill_timeout(req); + __io_commit_cqring(ctx); while ((req = io_get_deferred_req(ctx)) != NULL) { @@ -1765,6 +1816,81 @@ static int io_poll_add(struct io_kiocb *req, const struct io_uring_sqe *sqe) return ipt.error; } +static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer) +{ + struct io_ring_ctx *ctx; + struct io_kiocb *req; + unsigned long flags; + + 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); + spin_unlock_irqrestore(&ctx->completion_lock, flags); + + io_cqring_ev_posted(ctx); + + io_put_req(req); + return HRTIMER_NORESTART; +} + +static int io_timeout(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + unsigned count, req_dist, tail_index; + struct io_ring_ctx *ctx = req->ctx; + struct list_head *entry; + struct timespec ts; + + if (unlikely(ctx->flags & IORING_SETUP_IOPOLL)) + return -EINVAL; + if (sqe->flags || sqe->ioprio || sqe->buf_index || sqe->timeout_flags || + sqe->len != 1) + return -EINVAL; + if (copy_from_user(&ts, (void __user *) (unsigned long) sqe->addr, + sizeof(ts))) + return -EFAULT; + + /* + * sqe->off holds how many events that need to occur for this + * timeout event to be satisfied. + */ + count = READ_ONCE(sqe->off); + if (!count) + count = 1; + + req->sequence = ctx->cached_sq_head + count - 1; + req->flags |= REQ_F_TIMEOUT; + + /* + * Insertion sort, ensuring the first entry in the list is always + * the one we need first. + */ + tail_index = ctx->cached_cq_tail - ctx->rings->sq_dropped; + req_dist = req->sequence - tail_index; + spin_lock_irq(&ctx->completion_lock); + list_for_each_prev(entry, &ctx->timeout_list) { + struct io_kiocb *nxt = list_entry(entry, struct io_kiocb, list); + unsigned dist; + + dist = nxt->sequence - tail_index; + if (req_dist >= dist) + break; + } + list_add(&req->list, entry); + spin_unlock_irq(&ctx->completion_lock); + + hrtimer_init(&req->timeout.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + req->timeout.timer.function = io_timeout_fn; + hrtimer_start(&req->timeout.timer, timespec_to_ktime(ts), + HRTIMER_MODE_REL); + return 0; +} + static int io_req_defer(struct io_ring_ctx *ctx, struct io_kiocb *req, const struct io_uring_sqe *sqe) { @@ -1842,6 +1968,9 @@ static int __io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, case IORING_OP_RECVMSG: ret = io_recvmsg(req, s->sqe, force_nonblock); break; + case IORING_OP_TIMEOUT: + ret = io_timeout(req, s->sqe); + break; default: ret = -EINVAL; break; @@ -2599,6 +2728,7 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, const sigset_t __user *sig, size_t sigsz) { struct io_rings *rings = ctx->rings; + unsigned nr_timeouts; int ret; if (io_cqring_events(rings) >= min_events) @@ -2617,7 +2747,15 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, return ret; } - ret = wait_event_interruptible(ctx->wait, io_cqring_events(rings) >= min_events); + nr_timeouts = atomic_read(&ctx->cq_timeouts); + /* + * Return if we have enough events, or if a timeout occured since + * we started waiting. For timeouts, we always want to return to + * userspace. + */ + ret = wait_event_interruptible(ctx->wait, + io_cqring_events(rings) >= min_events || + atomic_read(&ctx->cq_timeouts) != nr_timeouts); restore_saved_sigmask_unless(ret == -ERESTARTSYS); if (ret == -ERESTARTSYS) ret = -EINTR; @@ -3288,6 +3426,7 @@ static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) percpu_ref_kill(&ctx->refs); mutex_unlock(&ctx->uring_lock); + io_kill_timeouts(ctx); io_poll_remove_all(ctx); io_iopoll_reap_events(ctx); wait_for_completion(&ctx->ctx_done); diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 96ee9d94b73e..ea57526a5b89 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -28,6 +28,7 @@ struct io_uring_sqe { __u16 poll_events; __u32 sync_range_flags; __u32 msg_flags; + __u32 timeout_flags; }; __u64 user_data; /* data to be passed back at completion time */ union { @@ -61,6 +62,7 @@ struct io_uring_sqe { #define IORING_OP_SYNC_FILE_RANGE 8 #define IORING_OP_SENDMSG 9 #define IORING_OP_RECVMSG 10 +#define IORING_OP_TIMEOUT 11 /* * sqe->fsync_flags |