cgroup: implement cgroup_rm_cftypes()

Implement cgroup_rm_cftypes() which removes an array of cftypes from a
subsystem.  It can be called whether the target subsys is attached or
not.  cgroup core will remove the specified file from all existing
cgroups.

This will be used to improve sub-subsys modularity and will be helpful
for unified hierarchy.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 87b034ed0c3..028478c6e0c 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -406,6 +406,7 @@ struct cgroup_scanner {
 };
 
 int cgroup_add_cftypes(struct cgroup_subsys *ss, const struct cftype *cfts);
+int cgroup_rm_cftypes(struct cgroup_subsys *ss, const struct cftype *cfts);
 
 int cgroup_is_removed(const struct cgroup *cgrp);