diff options
| author | Muchun Song <songmuchun@bytedance.com> | 2025-03-06 10:31:33 +0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-03-16 17:40:24 -0700 |
| commit | 73f839b6d2ed75f281bd75aeb68e81bce373bdee (patch) | |
| tree | c16eddc1ff554a9a869796f0b81c86d0ed704703 /include | |
| parent | 8c6ff7f181786d0b296bb0f1bf269ca8770632c9 (diff) | |
mm: memcontrol: fix swap counter leak from offline cgroup
Commit 6769183166b3 removed the parameter of id from swap_cgroup_record()
and get the memcg id from mem_cgroup_id(folio_memcg(folio)). However, the
caller of it may update a different memcg's counter instead of
folio_memcg(folio).
E.g. in the caller of mem_cgroup_swapout(), @swap_memcg could be
different with @memcg and update the counter of @swap_memcg, but
swap_cgroup_record() records the wrong memcg's ID. When it is uncharged
from __mem_cgroup_uncharge_swap(), the swap counter will leak since the
wrong recorded ID.
Fix it by bringing the parameter of id back.
Link: https://lkml.kernel.org/r/20250306023133.44838-1-songmuchun@bytedance.com
Fixes: 6769183166b3 ("mm/swap_cgroup: decouple swap cgroup recording and clearing")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Kairui Song <kasong@tencent.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/swap_cgroup.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/swap_cgroup.h b/include/linux/swap_cgroup.h index b5ec038069da..91cdf12190a0 100644 --- a/include/linux/swap_cgroup.h +++ b/include/linux/swap_cgroup.h @@ -6,7 +6,7 @@ #if defined(CONFIG_MEMCG) && defined(CONFIG_SWAP) -extern void swap_cgroup_record(struct folio *folio, swp_entry_t ent); +extern void swap_cgroup_record(struct folio *folio, unsigned short id, swp_entry_t ent); extern unsigned short swap_cgroup_clear(swp_entry_t ent, unsigned int nr_ents); extern unsigned short lookup_swap_cgroup_id(swp_entry_t ent); extern int swap_cgroup_swapon(int type, unsigned long max_pages); @@ -15,7 +15,7 @@ extern void swap_cgroup_swapoff(int type); #else static inline -void swap_cgroup_record(struct folio *folio, swp_entry_t ent) +void swap_cgroup_record(struct folio *folio, unsigned short id, swp_entry_t ent) { } |