diff mbox series

[3/3] ext4: Use bdev_getblk() to avoid memory reclaim in readahead path

Message ID 20230811161528.506437-4-willy@infradead.org (mailing list archive)
State New, archived
Headers show
Series Add and use bdev_getblk() | expand

Commit Message

Matthew Wilcox Aug. 11, 2023, 4:15 p.m. UTC
sb_getblk_gfp adds __GFP_NOFAIL, which is unnecessary for readahead;
we're quite comfortable with the possibility that we may not get a bh
back.  Switch to bdev_getblk() which does not include __GFP_NOFAIL.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: Hui Zhu <teawater@antgroup.com>
Link: https://lore.kernel.org/linux-fsdevel/20230811035705.3296-1-teawaterz@linux.alibaba.com/
---
 fs/ext4/super.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Matthew Wilcox Aug. 11, 2023, 4:17 p.m. UTC | #1
On Fri, Aug 11, 2023 at 05:15:28PM +0100, Matthew Wilcox (Oracle) wrote:
> +	struct buffer_head *bh = bdev_getblk(sb->s_bdev, block,
> +			sb->s_blocksize, GFP_NOWAIT);

Doh, I missed the __GFP_ACCOUNT from that.  Will wait a day or two
for other feedback.
diff mbox series

Patch

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index c94ebf704616..48524314be97 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -254,7 +254,8 @@  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 = sb_getblk_gfp(sb, block, 0);
+	struct buffer_head *bh = bdev_getblk(sb->s_bdev, block,
+			sb->s_blocksize, GFP_NOWAIT);
 
 	if (likely(bh)) {
 		if (trylock_buffer(bh))