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

[mirror_ubuntu-zesty-kernel.git] / kernel / sched / cpuacct.c

diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index dbb7e2cd95eba592f6b7878238ff12979e4c1aa0..8ccfa10cc89ff4af0f9b4692b6f6d19129f1d4ec 100644 (file)
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -33,18 +33,21 @@ struct cpuacct {
        struct kernel_cpustat __percpu *cpustat;
 };
 
+static inline struct cpuacct *css_ca(struct cgroup_subsys_state *css)
+{
+       return css ? container_of(css, struct cpuacct, css) : NULL;
+}
+
 /* return cpu accounting group corresponding to this container */
 static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp)
 {
-       return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id),
-                           struct cpuacct, css);
+       return css_ca(cgroup_css(cgrp, cpuacct_subsys_id));
 }
 
 /* return cpu accounting group to which this task belongs */
 static inline struct cpuacct *task_ca(struct task_struct *tsk)
 {
-       return container_of(task_subsys_state(tsk, cpuacct_subsys_id),
-                           struct cpuacct, css);
+       return css_ca(task_css(tsk, cpuacct_subsys_id));
 }
 
 static inline struct cpuacct *__parent_ca(struct cpuacct *ca)