[PATCH 5.11 10/31] io_uring: simplify do_read return parsing

From: Greg Kroah-Hartman
Date: Fri Mar 19 2021 - 08:21:15 EST


From: Pavel Begunkov <asml.silence@xxxxxxxxx>

[ 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>
---
fs/io_uring.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)

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;
}
--
2.30.1