cgroup: remove for_each_root_subsys()

After the previous patch which introduced for_each_css(),
for_each_root_subsys() only has two users left.  This patch replaces
it with for_each_subsys() + explicit subsys_mask testing and remove
for_each_root_subsys() along with cgroupfs_root->subsys_list handling.

This patch doesn't introduce any behavior changes.

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

1 files changed, 1 insertions, 8 deletions

diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 8b9a594f0c92..cfaf416492dd 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -319,9 +319,6 @@ struct cgroupfs_root {
         /* Unique id for this hierarchy. */
         int hierarchy_id;
 
-        /* A list running through the attached subsystems */
-        struct list_head subsys_list;
-
         /* The root cgroup for this hierarchy */
         struct cgroup top_cgroup;
 
@@ -617,12 +614,8 @@ struct cgroup_subsys {
 #define MAX_CGROUP_TYPE_NAMELEN 32
         const char *name;
 
-        /*
-         * Link to parent, and list entry in parent's children.
-         * Protected by cgroup_lock()
-         */
+        /* link to parent, protected by cgroup_lock() */
         struct cgroupfs_root *root;
-        struct list_head sibling;
 
         /* list of cftype_sets */
         struct list_head cftsets;