Commit a6ab9c82 authored by Baolin Wang's avatar Baolin Wang Committed by Andrew Morton
Browse files

mm: memcontrol: add VM_BUG_ON_FOLIO() to catch lru folio in mem_cgroup_migrate() 

mem_cgroup_migrate() will clear the memcg data of the old folio,
therefore, the callers must make sure the old folio is no longer on the
LRU list, otherwise the old folio can not get the correct lruvec object
without the memcg data, which could lead to potential problems [1].

Thus adding a VM_BUG_ON_FOLIO() to catch this issue.

[1] https://lore.kernel.org/all/5ab860d8ee987955e917748f9d6da525d3b52690.1718326003.git.baolin.wang@linux.alibaba.com/

Link: https://lkml.kernel.org/r/66d181c41b7ced35dbd39ffd3f5774a11aef266a.1718327124.git.baolin.wang@linux.alibaba.com


Signed-off-by: default avatarBaolin Wang <baolin.wang@linux.alibaba.com>
Suggested-by: default avatarShakeel Butt <shakeel.butt@linux.dev>
Acked-by: default avatarShakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 83d0d46a

mm/memcontrol.c

+1 −0
Original line number Diff line number Diff line
@@ -7807,6 +7807,7 @@ void mem_cgroup_migrate(struct folio *old, struct folio *new) 
	VM_BUG_ON_FOLIO(!folio_test_locked(new), new);

	VM_BUG_ON_FOLIO(folio_test_anon(old) != folio_test_anon(new), new);

	VM_BUG_ON_FOLIO(folio_nr_pages(old) != folio_nr_pages(new), new);

	VM_BUG_ON_FOLIO(folio_test_lru(old), old);



	if (mem_cgroup_disabled())

		return;