mm: list_lru: fix the return value of list_lru_count_one()

Since commit 2788cf0c401c ("memcg: reparent list_lrus and free kmemcg_id
on css offline"), ->nr_items can be negative during memory cgroup
reparenting.  In this case, list_lru_count_one() will return an unusual
and huge value, which can surprise users.  At least for now it hasn't
affected any users.  But it is better to let list_lru_count_ont()
returns zero when ->nr_items is negative.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Muchun Song <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Shakeel Butt <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions