[PATCH slab/for-next 04/14] fs/buffer: specify SLAB_MAY_ACCOUNT for buffer_head cache

[Harry Yoo (Meta)]

Buffer heads are allocated with __GFP_ACCOUNT to charge them to the
memcg of the folio they are attached to. Specify SLAB_MAY_ACCOUNT when
the object may be charged to a memcg. __GFP_ACCOUNT without
SLAB_MAY_ACCOUNT will not be allowed.

Path: ext4_getblk() -> folio_alloc_buffers(GFP_NOFS | __GFP_ACCOUNT)
  -> alloc_buffer_head() -> kmem_cache_zalloc(bh_cachep)

Assisted-by: LLM
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Christian Brauner <brauner@xxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: linux-fsdevel@xxxxxxxxxxxxxxx
Signed-off-by: Harry Yoo (Meta) <harry@xxxxxxxxxx>
---
 fs/buffer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/buffer.c b/fs/buffer.c
index ed966fa73b1b..1cbbd065cab6 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2993,7 +2993,7 @@ void __init buffer_init(void)
 	int ret;
 
 	bh_cachep = KMEM_CACHE(buffer_head,
-				SLAB_RECLAIM_ACCOUNT|SLAB_PANIC);
+				SLAB_RECLAIM_ACCOUNT|SLAB_PANIC|SLAB_MAY_ACCOUNT);
 	/*
 	 * Limit the bh occupancy to 10% of ZONE_NORMAL
 	 */

-- 
2.54.0