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io_uring: fix req->apoll_events

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apoll_events should be set once in the beginning of poll arming just as
poll->events and not change after. However, currently io_uring resets it
on each __io_poll_execute() for no clear reason. There is also a place
in __io_arm_poll_handler() where we add EPOLLONESHOT to downgrade a
multishot, but forget to do the same thing with ->apoll_events, which is
buggy.

Fixes: 81459350d581e ("io_uring: cache req->apoll->events in req->cflags")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Hao Xu <howeyxu@tencent.com>
Link: https://lore.kernel.org/r/0aef40399ba75b1a4d2c2e85e6e8fd93c02fc6e4.1655814213.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2022-06-21 13:25:06 +01:00 committed by Jens Axboe
parent b60cac14bb
commit aacf2f9f38
1 changed files with 8 additions and 4 deletions
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12
fs/io_uring.c
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@ -6950,7 +6950,8 @@ static void io_apoll_task_func(struct io_kiocb *req, bool *locked)
io_req_complete_failed(req, ret);
}
static void __io_poll_execute(struct io_kiocb *req, int mask, __poll_t events)
static void __io_poll_execute(struct io_kiocb *req, int mask,
__poll_t __maybe_unused events)
{
req->cqe.res = mask;
/*
@ -6959,7 +6960,6 @@ static void __io_poll_execute(struct io_kiocb *req, int mask, __poll_t events)
* CPU. We want to avoid pulling in req->apoll->events for that
* case.
*/
req->apoll_events = events;
if (req->opcode == IORING_OP_POLL_ADD)
req->io_task_work.func = io_poll_task_func;
else
@ -7110,6 +7110,8 @@ static int __io_arm_poll_handler(struct io_kiocb *req,
io_init_poll_iocb(poll, mask, io_poll_wake);
poll->file = req->file;
req->apoll_events = poll->events;
ipt->pt._key = mask;
ipt->req = req;
ipt->error = 0;
@ -7140,8 +7142,10 @@ static int __io_arm_poll_handler(struct io_kiocb *req,
if (mask) {
/* can't multishot if failed, just queue the event we've got */
if (unlikely(ipt->error || !ipt->nr_entries))
if (unlikely(ipt->error || !ipt->nr_entries)) {
poll->events |= EPOLLONESHOT;
req->apoll_events |= EPOLLONESHOT;
}
__io_poll_execute(req, mask, poll->events);
return 0;
}
@ -7388,7 +7392,7 @@ static int io_poll_add_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe
return -EINVAL;
io_req_set_refcount(req);
req->apoll_events = poll->events = io_poll_parse_events(sqe, flags);
poll->events = io_poll_parse_events(sqe, flags);
return 0;
}