[PATCH] mm/filemap.c: minor optimization in write_iter file operation

[Yafang Shao]

This little adjustment on bitwise operation could make the code a little
faster.
As write_iter is used in lots of critical path, so this code change is
useful for performance.

Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx>
---
 mm/filemap.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index 81adec8..a65056ea 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2881,7 +2881,8 @@ inline ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from)
 	if (iocb->ki_flags & IOCB_APPEND)
 		iocb->ki_pos = i_size_read(inode);
 
-	if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT))
+	if ((iocb->ki_flags & (IOCB_NOWAIT | IOCB_DIRECT)) ==
+	    IOCB_NOWAIT)
 		return -EINVAL;
 
 	count = iov_iter_count(from);
-- 
1.8.3.1