io_uring: put the flag changing code in the same spot

mainline inclusion
from mainline-5.6-rc1
commit 3e577dcd
category: feature
bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=27
CVE: NA
---------------------------

Both iocb_flags() and kiocb_set_rw_flags() are inline and modify
kiocb->ki_flags. Place them close, so they can be potentially better
optimised.
Signed-off-by: NPavel Begunkov <asml.silence@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: Nyangerkun <yangerkun@huawei.com>
Reviewed-by: Nzhangyi (F) <yi.zhang@huawei.com>
Signed-off-by: NCheng Jian <cj.chengjian@huawei.com>

fs/io_uring.c

@@ -1862,8 +1862,11 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 		req->flags |= REQ_F_CUR_POS;
 		kiocb->ki_pos = req->file->f_pos;
 	}
-	kiocb->ki_flags = iocb_flags(kiocb->ki_filp);
 	kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp));
+	kiocb->ki_flags = iocb_flags(kiocb->ki_filp);
+	ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags));
+	if (unlikely(ret))
+		return ret;
 
 	ioprio = READ_ONCE(sqe->ioprio);
 	if (ioprio) {
@@ -1875,10 +1878,6 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 	} else
 		kiocb->ki_ioprio = get_current_ioprio();
 
-	ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags));
-	if (unlikely(ret))
-		return ret;
-
 	/* don't allow async punt if RWF_NOWAIT was requested */
 	if ((kiocb->ki_flags & IOCB_NOWAIT) ||
 	    (req->file->f_flags & O_NONBLOCK))