cgroup: make sure a parent css isn't offlined before its children

[karo-tx-linux.git] / include / linux / cgroup-defs.h

diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h
index 7f540f7f588d8c8461af975a5ebd21a08e6cf14b..789471dba6fb30f15c752fbca46ddbefe5bfe850 100644 (file)
--- a/include/linux/cgroup-defs.h
+++ b/include/linux/cgroup-defs.h
@@ -127,6 +127,12 @@ struct cgroup_subsys_state {
         */
        u64 serial_nr;
 
+       /*
+        * Incremented by online self and children.  Used to guarantee that
+        * parents are not offlined before their children.
+        */
+       atomic_t online_cnt;
+
        /* percpu_ref killing and RCU release */
        struct rcu_head rcu_head;
        struct work_struct destroy_work;