The patch titled Subject: ext4: use bdev_getblk() to avoid memory reclaim in readahead path has been added to the -mm mm-unstable branch. Its filename is ext4-use-bdev_getblk-to-avoid-memory-reclaim-in-readahead-path.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/ext4-use-bdev_getblk-to-avoid-memory-reclaim-in-readahead-path.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Subject: ext4: use bdev_getblk() to avoid memory reclaim in readahead path Date: Thu, 14 Sep 2023 16:00:06 +0100 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@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Reported-by: Hui Zhu <teawater@xxxxxxxxxxxx> Closes: https://lore.kernel.org/linux-fsdevel/20230811035705.3296-1-teawaterz@xxxxxxxxxxxxxxxxx/ Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/ext4/super.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/ext4/super.c~ext4-use-bdev_getblk-to-avoid-memory-reclaim-in-readahead-path +++ a/fs/ext4/super.c @@ -255,7 +255,8 @@ struct buffer_head *ext4_sb_bread_unmova 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)) _ Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are mm-convert-dax-lock-unlock-page-to-lock-unlock-folio.patch buffer-pass-gfp-flags-to-folio_alloc_buffers.patch buffer-hoist-gfp-flags-from-grow_dev_page-to-__getblk_gfp.patch ext4-use-bdev_getblk-to-avoid-memory-reclaim-in-readahead-path.patch buffer-use-bdev_getblk-to-avoid-memory-reclaim-in-readahead-path.patch buffer-convert-getblk_unmovable-and-__getblk-to-use-bdev_getblk.patch buffer-convert-sb_getblk-to-call-__getblk.patch ext4-call-bdev_getblk-from-sb_getblk_gfp.patch buffer-remove-__getblk_gfp.patch