UPSTREAM: io_uring: fix async accept on O_NONBLOCK sockets

commit a73825ba upstream.

Do not set REQ_F_NOWAIT if the socket is non blocking. When enabled this
causes the accept to immediately post a CQE with EAGAIN, which means you
cannot perform an accept SQE on a NONBLOCK socket asynchronously.

By removing the flag if there is no pending accept then poll is armed as
usual and when a connection comes in the CQE is posted.

Change-Id: I0fae3f75c7fbbf44f85da7d83f48c4cfed1fcae9
Signed-off-by: Dylan Yudaken <dylany@fb.com>
Link: https://lore.kernel.org/r/20220324143435.2875844-1-dylany@fb.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Bug: 268174392
(cherry picked from commit aa4c9b3e)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>