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authorDavid Wei <davidhwei@meta.com>2023-04-18 15:58:18 -0700
committerJens Axboe <axboe@kernel.dk>2023-04-18 19:38:36 -0600
commitea97f6c8558e83cb457c3b5f53351e4fd8519ab1 (patch)
treee294b2a17ce99a18af919302ea590eb91e01c24d /io_uring
parent2236b3905b4d4e9cd4d149ab35767858c02bb79b (diff)
io_uring: add support for multishot timeouts
A multishot timeout submission will repeatedly generate completions with the IORING_CQE_F_MORE cflag set. Depending on the value of the `off' field in the submission, these timeouts can either repeat indefinitely until cancelled (`off' = 0) or for a fixed number of times (`off' > 0). Only noseq timeouts (i.e. not dependent on the number of I/O completions) are supported. An indefinite timer will be cancelled if the CQ ever overflows. Signed-off-by: David Wei <davidhwei@meta.com> Link: https://lore.kernel.org/r/20230418225817.1905027-1-davidhwei@meta.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring')
-rw-r--r--io_uring/timeout.c57
1 files changed, 54 insertions, 3 deletions
diff --git a/io_uring/timeout.c b/io_uring/timeout.c
index 5c6c6f720809..fc950177e2e1 100644
--- a/io_uring/timeout.c
+++ b/io_uring/timeout.c
@@ -17,6 +17,7 @@ struct io_timeout {
struct file *file;
u32 off;
u32 target_seq;
+ u32 repeats;
struct list_head list;
/* head of the link, used by linked timeouts only */
struct io_kiocb *head;
@@ -37,8 +38,9 @@ struct io_timeout_rem {
static inline bool io_is_timeout_noseq(struct io_kiocb *req)
{
struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
+ struct io_timeout_data *data = req->async_data;
- return !timeout->off;
+ return !timeout->off || data->flags & IORING_TIMEOUT_MULTISHOT;
}
static inline void io_put_req(struct io_kiocb *req)
@@ -49,6 +51,44 @@ static inline void io_put_req(struct io_kiocb *req)
}
}
+static inline bool io_timeout_finish(struct io_timeout *timeout,
+ struct io_timeout_data *data)
+{
+ if (!(data->flags & IORING_TIMEOUT_MULTISHOT))
+ return true;
+
+ if (!timeout->off || (timeout->repeats && --timeout->repeats))
+ return false;
+
+ return true;
+}
+
+static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer);
+
+static void io_timeout_complete(struct io_kiocb *req, struct io_tw_state *ts)
+{
+ struct io_timeout *timeout = io_kiocb_to_cmd(req, struct io_timeout);
+ struct io_timeout_data *data = req->async_data;
+ struct io_ring_ctx *ctx = req->ctx;
+
+ if (!io_timeout_finish(timeout, data)) {
+ bool filled;
+ filled = io_aux_cqe(ctx, ts->locked, req->cqe.user_data, -ETIME,
+ IORING_CQE_F_MORE, false);
+ if (filled) {
+ /* re-arm timer */
+ spin_lock_irq(&ctx->timeout_lock);
+ list_add(&timeout->list, ctx->timeout_list.prev);
+ data->timer.function = io_timeout_fn;
+ hrtimer_start(&data->timer, timespec64_to_ktime(data->ts), data->mode);
+ spin_unlock_irq(&ctx->timeout_lock);
+ return;
+ }
+ }
+
+ io_req_task_complete(req, ts);
+}
+
static bool io_kill_timeout(struct io_kiocb *req, int status)
__must_hold(&req->ctx->timeout_lock)
{
@@ -212,7 +252,7 @@ static enum hrtimer_restart io_timeout_fn(struct hrtimer *timer)
req_set_fail(req);
io_req_set_res(req, -ETIME, 0);
- req->io_task_work.func = io_req_task_complete;
+ req->io_task_work.func = io_timeout_complete;
io_req_task_work_add(req);
return HRTIMER_NORESTART;
}
@@ -470,16 +510,27 @@ static int __io_timeout_prep(struct io_kiocb *req,
return -EINVAL;
flags = READ_ONCE(sqe->timeout_flags);
if (flags & ~(IORING_TIMEOUT_ABS | IORING_TIMEOUT_CLOCK_MASK |
- IORING_TIMEOUT_ETIME_SUCCESS))
+ IORING_TIMEOUT_ETIME_SUCCESS |
+ IORING_TIMEOUT_MULTISHOT))
return -EINVAL;
/* more than one clock specified is invalid, obviously */
if (hweight32(flags & IORING_TIMEOUT_CLOCK_MASK) > 1)
return -EINVAL;
+ /* multishot requests only make sense with rel values */
+ if (!(~flags & (IORING_TIMEOUT_MULTISHOT | IORING_TIMEOUT_ABS)))
+ return -EINVAL;
INIT_LIST_HEAD(&timeout->list);
timeout->off = off;
if (unlikely(off && !req->ctx->off_timeout_used))
req->ctx->off_timeout_used = true;
+ /*
+ * for multishot reqs w/ fixed nr of repeats, repeats tracks the
+ * remaining nr
+ */
+ timeout->repeats = 0;
+ if ((flags & IORING_TIMEOUT_MULTISHOT) && off > 0)
+ timeout->repeats = off;
if (WARN_ON_ONCE(req_has_async_data(req)))
return -EFAULT;