io_uring: fix poll file assign deadlock

We pass "unlocked" into io_assign_file() in io_poll_check_events(),
which can lead to double locking.

Fixes: 6bf9c47a39 ("io_uring: defer file assignment")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/2476d4ae46554324b599ee4055447b105f20a75a.1649862516.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2022-04-13 16:10:34 +01:00 committed by Jens Axboe
parent e941976659
commit cce64ef013

View File

@ -5858,8 +5858,9 @@ static int io_poll_check_events(struct io_kiocb *req, bool locked)
if (!req->result) {
struct poll_table_struct pt = { ._key = req->apoll_events };
unsigned flags = locked ? 0 : IO_URING_F_UNLOCKED;
if (unlikely(!io_assign_file(req, IO_URING_F_UNLOCKED)))
if (unlikely(!io_assign_file(req, flags)))
req->result = -EBADF;
else
req->result = vfs_poll(req->file, &pt) & req->apoll_events;