[PATCH] ext4: add __GFP_NOWARN to GFP_NOWAIT in readahead

[Hugh Dickins <hughd@google.com>]

Since mm-hotfixes-stable commit e509ad4d77e6 ("ext4: use bdev_getblk() to
avoid memory reclaim in readahead path") rightly replaced GFP_NOFAIL
allocations by GFP_NOWAIT allocations, I've occasionally been seeing
"page allocation failure: order:0" warnings under load: all with
ext4_sb_breadahead_unmovable() in the stack.  I don't think those
warnings are of any interest: suppress them with __GFP_NOWARN.

Fixes: e509ad4d77e6 ("ext4: use bdev_getblk() to avoid memory reclaim in readahead path")
Signed-off-by: Hugh Dickins <hughd@google.com>
---
 fs/ext4/super.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index c00ec159dea5..56a08fc5c5d5 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -262,7 +262,7 @@ struct buffer_head *ext4_sb_bread_unmovable(struct super_block *sb,
 void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
 {
 	struct buffer_head *bh = bdev_getblk(sb->s_bdev, block,
-			sb->s_blocksize, GFP_NOWAIT);
+			sb->s_blocksize, GFP_NOWAIT | __GFP_NOWARN);
 
 	if (likely(bh)) {
 		if (trylock_buffer(bh))
-- 
2.35.3