This is a note to let you know that I've just added the patch titled io_uring: fix async accept on O_NONBLOCK sockets to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: io_uring-fix-async-accept-on-o_nonblock-sockets.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit ca760f9e0df16e3351879479cdb05b61ee1789fd Author: Dylan Yudaken <dylany@xxxxxxxx> Date: Sat Jan 21 09:13:12 2023 -0700 io_uring: fix async accept on O_NONBLOCK sockets commit a73825ba70c93e1eb39a845bb3d9885a787f8ffe 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. Signed-off-by: Dylan Yudaken <dylany@xxxxxx> Link: https://lore.kernel.org/r/20220324143435.2875844-1-dylany@xxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index 997a7264e1d4..e1e15d40d758 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -5272,9 +5272,6 @@ static int io_accept(struct io_kiocb *req, unsigned int issue_flags) struct file *file; int ret, fd; - if (req->file->f_flags & O_NONBLOCK) - req->flags |= REQ_F_NOWAIT; - if (!fixed) { fd = __get_unused_fd_flags(accept->flags, accept->nofile); if (unlikely(fd < 0)) @@ -5286,6 +5283,8 @@ static int io_accept(struct io_kiocb *req, unsigned int issue_flags) if (!fixed) put_unused_fd(fd); ret = PTR_ERR(file); + /* safe to retry */ + req->flags |= REQ_F_PARTIAL_IO; if (ret == -EAGAIN && force_nonblock) return -EAGAIN; if (ret == -ERESTARTSYS)