io_uring: prioritise read success path over fails

Rearrange io_read return handling so first we expect it completing
successfully and only then checking for errors, which is a colder path.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/c91c7c2da11815ec8b04b5d872f60dc4cde662c5.1634144845.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 094cd5f49214a146e5ade2613fc60b855067b585..86ef803db27a034876ec6470bb24db7e095088a0 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -3487,7 +3487,7 @@ static int io_read(struct io_kiocb *req, unsigned int issue_flags)
                ret = 0;
        } else if (ret == -EIOCBQUEUED) {
                goto out_free;
-       } else if (ret <= 0 || ret == req->result || !force_nonblock ||
+       } else if (ret == req->result || ret <= 0 || !force_nonblock ||
                   (req->flags & REQ_F_NOWAIT) || !need_read_all(req)) {
                /* read all, failed, already did sync or don't want to retry */
                goto done;