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| author | Jens Axboe <axboe@kernel.dk> | 2022-11-20 10:18:45 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-01-04 11:28:48 +0100 |
| commit | ff46a46b7a30dd59513d7f33dfdd06553843b11d (patch) | |
| tree | 72176b8dc098cee16b00c908770578c4349c313e /io_uring/poll.c | |
| parent | 3b2728881dcd4ec3549d479c4b3aa38cf15fc73d (diff) | |
| download | linux-ff46a46b7a30dd59513d7f33dfdd06553843b11d.tar.gz linux-ff46a46b7a30dd59513d7f33dfdd06553843b11d.tar.bz2 linux-ff46a46b7a30dd59513d7f33dfdd06553843b11d.zip | |
io_uring: pass in EPOLL_URING_WAKE for eventfd signaling and wakeups
[ Upstream commit 4464853277d0ccdb9914608dd1332f0fa2f9846f ]
Pass in EPOLL_URING_WAKE when signaling eventfd or doing poll related
wakups, so that we can check for a circular event dependency between
eventfd and epoll. If this flag is set when our wakeup handlers are
called, then we know we have a dependency that needs to terminate
multishot requests.
eventfd and epoll are the only such possible dependencies.
Cc: stable@vger.kernel.org # 6.0
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'io_uring/poll.c')
| -rw-r--r-- | io_uring/poll.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/io_uring/poll.c b/io_uring/poll.c index d9bf1767867e..fded1445a803 100644 --- a/io_uring/poll.c +++ b/io_uring/poll.c @@ -429,6 +429,14 @@ static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync, return 0; if (io_poll_get_ownership(req)) { + /* + * If we trigger a multishot poll off our own wakeup path, + * disable multishot as there is a circular dependency between + * CQ posting and triggering the event. + */ + if (mask & EPOLL_URING_WAKE) + poll->events |= EPOLLONESHOT; + /* optional, saves extra locking for removal in tw handler */ if (mask && poll->events & EPOLLONESHOT) { list_del_init(&poll->wait.entry); |