io_uring: simplify do_read return parsing

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@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 7787827..24ad36d 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -3526,7 +3526,6 @@ 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)
@@ -3538,9 +3537,7 @@ 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) {
@@ -3554,7 +3551,7 @@ 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;
        }