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Diffstat (limited to 'mm')
-rw-r--r--mm/memcontrol.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index f0dc076adf05..4d0ea3ceba6d 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1992,6 +1992,7 @@ static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft,
{
struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
struct mem_cgroup *parent;
+
if (val > 100)
return -EINVAL;
@@ -1999,15 +2000,22 @@ static int mem_cgroup_swappiness_write(struct cgroup *cgrp, struct cftype *cft,
return -EINVAL;
parent = mem_cgroup_from_cont(cgrp->parent);
+
+ cgroup_lock();
+
/* If under hierarchy, only empty-root can set this value */
if ((parent->use_hierarchy) ||
- (memcg->use_hierarchy && !list_empty(&cgrp->children)))
+ (memcg->use_hierarchy && !list_empty(&cgrp->children))) {
+ cgroup_unlock();
return -EINVAL;
+ }
spin_lock(&memcg->reclaim_param_lock);
memcg->swappiness = val;
spin_unlock(&memcg->reclaim_param_lock);
+ cgroup_unlock();
+
return 0;
}