Merge branch 'for-4.5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup fixes from Tejun Heo:

 - The destruction path of cgroup objects are asynchronous and
   multi-staged and some of them ended up destroying parents before
   children leading to failures in cpu and memory controllers.  Ensure
   that parents are always destroyed after children.

 - cpuset mm node migration was performed synchronously while holding
   threadgroup and cgroup mutexes and the recent threadgroup locking
   update resulted in a possible deadlock.  The migration is best effort
   and shouldn't have been performed under those locks to begin with.
   Made asynchronous.

 - Minor documentation fix.

* 'for-4.5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  Documentation: cgroup: Fix 'cgroup-legacy' -> 'cgroup-v1'
  cgroup: make sure a parent css isn't freed before its children
  cgroup: make sure a parent css isn't offlined before its children
  cpuset: make mm migration asynchronous

1 files changed, 6 insertions, 0 deletions

diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h
index 7f540f7f588d..789471dba6fb 100644
--- 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;