cgroup: convert cgroup_has_live_children() into css_has_online_children()

Now that cgroup liveliness and css onliness are the same state,
convert cgroup_has_live_children() into css_has_online_children() so
that it can be used for actual csses too.  The function now uses
css_for_each_child() for iteration and is published.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 51a339c99eb6..b76999954beb 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -873,6 +873,8 @@ css_next_descendant_post(struct cgroup_subsys_state *pos,
 	for ((pos) = css_next_descendant_post(NULL, (css)); (pos);	\
 	     (pos) = css_next_descendant_post((pos), (css)))
 
+bool css_has_online_children(struct cgroup_subsys_state *css);
+
 /* A css_task_iter should be treated as an opaque object */
 struct css_task_iter {
 	struct cgroup_subsys		*ss;