From: Hugh Dickins <hugh@veritas.com>

mem_cgroup_shrink_usage makes no charge: balance its css_get with a css_put.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Balbir Singh <balbir@in.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/memcontrol.c |    1 +
 1 file changed, 1 insertion(+)

diff -puN mm/memcontrol.c~memcg-helper-function-for-relcaim-from-shmem-memcg-mem_cgroup_shrink_usage-css_put mm/memcontrol.c
--- a/mm/memcontrol.c~memcg-helper-function-for-relcaim-from-shmem-memcg-mem_cgroup_shrink_usage-css_put
+++ a/mm/memcontrol.c
@@ -801,6 +801,7 @@ int mem_cgroup_shrink_usage(struct mm_st
 		progress = try_to_free_mem_cgroup_pages(mem, gfp_mask);
 	} while (!progress && --retry);
 
+	css_put(&mem->css);
 	if (!retry)
 		return -ENOMEM;
 	return 0;
_