This is a note to let you know that I've just added the patch titled io_uring: simplify do_read return parsing to the 5.11-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-simplify-do_read-return-parsing.patch and it can be found in the queue-5.11 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 5dcd1a4c57f4b7346dfee295fa579ba022743bd8 Author: Pavel Begunkov <asml.silence@xxxxxxxxx> Date: Mon Feb 1 18:59:56 2021 +0000 io_uring: simplify do_read return parsing [ Upstream commit 57cd657b8272a66277c139e7bbdc8b86057cb415 ] do_read() returning 0 bytes read (not -EAGAIN/etc.) is not an important enough of a case to prioritise it. Fold it into ret < 0 check, so we get rid of an extra if and make it a bit more readable. Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/io_uring.c b/fs/io_uring.c index cab380a337e4..c18e4a334614 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3518,7 +3518,6 @@ static int io_read(struct io_kiocb *req, bool force_nonblock, else kiocb->ki_flags |= IOCB_NOWAIT; - /* If the file doesn't support async, just async punt */ no_async = force_nonblock && !io_file_supports_async(req->file, READ); if (no_async) @@ -3530,9 +3529,7 @@ static int io_read(struct io_kiocb *req, bool force_nonblock, ret = io_iter_do_read(req, iter); - if (!ret) { - goto done; - } else if (ret == -EIOCBQUEUED) { + if (ret == -EIOCBQUEUED) { ret = 0; goto out_free; } else if (ret == -EAGAIN) { @@ -3546,7 +3543,7 @@ static int io_read(struct io_kiocb *req, bool force_nonblock, iov_iter_revert(iter, io_size - iov_iter_count(iter)); ret = 0; goto copy_iov; - } else if (ret < 0) { + } else if (ret <= 0) { /* make sure -ERESTARTSYS -> -EINTR is done */ goto done; }