cgroup: add/update accessors which obtain subsys specific data from css

[deliverable/linux.git] / kernel / cpuset.c

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index f7371341d42a8305292680b51e8eb19f2569278d..6e9cbdde25bd61e994ca395dd0f131c857a7aeaf 100644 (file)
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -114,18 +114,21 @@ struct cpuset {
        int relax_domain_level;
 };
 
+static inline struct cpuset *css_cs(struct cgroup_subsys_state *css)
+{
+       return css ? container_of(css, struct cpuset, css) : NULL;
+}
+
 /* Retrieve the cpuset for a cgroup */
 static inline struct cpuset *cgroup_cs(struct cgroup *cgrp)
 {
-       return container_of(cgroup_css(cgrp, cpuset_subsys_id),
-                           struct cpuset, css);
+       return css_cs(cgroup_css(cgrp, cpuset_subsys_id));
 }
 
 /* Retrieve the cpuset for a task */
 static inline struct cpuset *task_cs(struct task_struct *task)
 {
-       return container_of(task_css(task, cpuset_subsys_id),
-                           struct cpuset, css);
+       return css_cs(task_css(task, cpuset_subsys_id));
 }
 
 static inline struct cpuset *parent_cs(struct cpuset *cs)