ext4: use bdev_getblk() to avoid memory reclaim in readahead path

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.

Link: https://lkml.kernel.org/r/20230914150011.843330-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reported-by: Hui Zhu <teawater@antgroup.com>
Closes: https://lore.kernel.org/linux-fsdevel/20230811035705.3296-1-teawaterz@linux.alibaba.com/
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2023-09-14 16:00:06 +01:00 committed by Andrew Morton
parent 3ed65f04aa
commit e509ad4d77

View file

@ -255,7 +255,8 @@ 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))