From eeecbd1971517103e06f11750dd1a9a1dc37e4e6 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 18 Nov 2014 02:49:52 -0500 Subject: cgroup: implement cgroup_get_e_css() Implement cgroup_get_e_css() which finds and gets the effective css for the specified cgroup and subsystem combination. This function always returns a valid pinned css. This will be used by cgroup writeback support. While at it, add comment to cgroup_e_css() to explain why that function is different from cgroup_get_e_css() and has to test cgrp->child_subsys_mask instead of cgroup_css(cgrp, ss). Signed-off-by: Tejun Heo Acked-by: Zefan Li --- include/linux/cgroup.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index 3a04aeb8b5a1..9fd99f5e699f 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -910,6 +910,8 @@ void css_task_iter_end(struct css_task_iter *it); int cgroup_attach_task_all(struct task_struct *from, struct task_struct *); int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from); +struct cgroup_subsys_state *cgroup_get_e_css(struct cgroup *cgroup, + struct cgroup_subsys *ss); struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry, struct cgroup_subsys *ss); -- cgit v1.2.3