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io_uring: correct poll cancel and linked timeout expiration completion

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Currently a poll request fills a completion entry of 0, even if it got
cancelled. This is odd, and it makes it harder to support with chains.
Ensure that it returns -ECANCELED in the completions events if it got
cancelled, and furthermore ensure that the linked timeout that triggered
it completes with -ETIME if we did indeed trigger the completions
through a timeout.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2019-11-18 12:14:54 -07:00
parent e0e328c4b3
commit b0dd8a4126
1 changed files with 22 additions and 11 deletions
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33
fs/io_uring.c
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@ -2066,12 +2066,15 @@ static int io_poll_remove(struct io_kiocb *req, const struct io_uring_sqe *sqe)
return 0;
}
static void io_poll_complete(struct io_kiocb *req, __poll_t mask)
static void io_poll_complete(struct io_kiocb *req, __poll_t mask, int error)
{
struct io_ring_ctx *ctx = req->ctx;
req->poll.done = true;
io_cqring_fill_event(req, mangle_poll(mask));
if (error)
io_cqring_fill_event(req, error);
else
io_cqring_fill_event(req, mangle_poll(mask));
io_commit_cqring(ctx);
}
@ -2084,11 +2087,16 @@ static void io_poll_complete_work(struct io_wq_work **workptr)
struct io_ring_ctx *ctx = req->ctx;
struct io_kiocb *nxt = NULL;
__poll_t mask = 0;
int ret = 0;
if (work->flags & IO_WQ_WORK_CANCEL)
if (work->flags & IO_WQ_WORK_CANCEL) {
WRITE_ONCE(poll->canceled, true);
ret = -ECANCELED;
} else if (READ_ONCE(poll->canceled)) {
ret = -ECANCELED;
}
if (!READ_ONCE(poll->canceled))
if (ret != -ECANCELED)
mask = vfs_poll(poll->file, &pt) & poll->events;
/*
@ -2099,13 +2107,13 @@ static void io_poll_complete_work(struct io_wq_work **workptr)
* avoid further branches in the fast path.
*/
spin_lock_irq(&ctx->completion_lock);
if (!mask && !READ_ONCE(poll->canceled)) {
if (!mask && ret != -ECANCELED) {
add_wait_queue(poll->head, &poll->wait);
spin_unlock_irq(&ctx->completion_lock);
return;
}
io_poll_remove_req(req);
io_poll_complete(req, mask);
io_poll_complete(req, mask, ret);
spin_unlock_irq(&ctx->completion_lock);
io_cqring_ev_posted(ctx);
@ -2139,7 +2147,7 @@ static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
*/
if (mask && spin_trylock_irqsave(&ctx->completion_lock, flags)) {
io_poll_remove_req(req);
io_poll_complete(req, mask);
io_poll_complete(req, mask, 0);
req->flags |= REQ_F_COMP_LOCKED;
io_put_req(req);
spin_unlock_irqrestore(&ctx->completion_lock, flags);
@ -2251,7 +2259,7 @@ static int io_poll_add(struct io_kiocb *req, const struct io_uring_sqe *sqe,
}
if (mask) { /* no async, we'd stolen it */
ipt.error = 0;
io_poll_complete(req, mask);
io_poll_complete(req, mask, 0);
}
spin_unlock_irq(&ctx->completion_lock);
@ -2503,7 +2511,7 @@ static int io_async_cancel_one(struct io_ring_ctx *ctx, void *sqe_addr)
static void io_async_find_and_cancel(struct io_ring_ctx *ctx,
struct io_kiocb *req, __u64 sqe_addr,
struct io_kiocb **nxt)
struct io_kiocb **nxt, int success_ret)
{
unsigned long flags;
int ret;
@ -2520,6 +2528,8 @@ static void io_async_find_and_cancel(struct io_ring_ctx *ctx,
goto done;
ret = io_poll_cancel(ctx, sqe_addr);
done:
if (!ret)
ret = success_ret;
io_cqring_fill_event(req, ret);
io_commit_cqring(ctx);
spin_unlock_irqrestore(&ctx->completion_lock, flags);
@ -2541,7 +2551,7 @@ static int io_async_cancel(struct io_kiocb *req, const struct io_uring_sqe *sqe,
sqe->cancel_flags)
return -EINVAL;
io_async_find_and_cancel(ctx, req, READ_ONCE(sqe->addr), nxt);
io_async_find_and_cancel(ctx, req, READ_ONCE(sqe->addr), nxt, 0);
return 0;
}
@ -2831,7 +2841,8 @@ static enum hrtimer_restart io_link_timeout_fn(struct hrtimer *timer)
spin_unlock_irqrestore(&ctx->completion_lock, flags);
if (prev) {
io_async_find_and_cancel(ctx, req, prev->user_data, NULL);
io_async_find_and_cancel(ctx, req, prev->user_data, NULL,
-ETIME);
io_put_req(prev);
} else {
io_cqring_add_event(req, -ETIME);