cgroup: remove cgroup_subsys argument from callbacks

The argument is not used at all, and it's not necessary, because
a specific callback handler of course knows which subsys it
belongs to.

Now only ->pupulate() takes this argument, because the handlers of
this callback always call cgroup_add_file()/cgroup_add_files().

So we reduce a few lines of code, though the shrinking of object size
is minimal.

 16 files changed, 113 insertions(+), 162 deletions(-)

   text    data     bss     dec     hex filename
5486240  656987 7039960 13183187         c928d3 vmlinux.o.orig
5486170  656987 7039960 13183117         c9288d vmlinux.o

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

1 files changed, 4 insertions, 7 deletions

diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index fc0646b78a6..f86e93920b6 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -128,8 +128,7 @@ struct cgroup_subsys freezer_subsys;
  *    task->alloc_lock (inside __thaw_task(), prevents race with refrigerator())
  *     sighand->siglock
  */
-static struct cgroup_subsys_state *freezer_create(struct cgroup_subsys *ss,
-						  struct cgroup *cgroup)
+static struct cgroup_subsys_state *freezer_create(struct cgroup *cgroup)
 {
 	struct freezer *freezer;
 
@@ -142,8 +141,7 @@ static struct cgroup_subsys_state *freezer_create(struct cgroup_subsys *ss,
 	return &freezer->css;
 }
 
-static void freezer_destroy(struct cgroup_subsys *ss,
-			    struct cgroup *cgroup)
+static void freezer_destroy(struct cgroup *cgroup)
 {
 	struct freezer *freezer = cgroup_freezer(cgroup);
 
@@ -164,8 +162,7 @@ static bool is_task_frozen_enough(struct task_struct *task)
  * a write to that file racing against an attach, and hence the
  * can_attach() result will remain valid until the attach completes.
  */
-static int freezer_can_attach(struct cgroup_subsys *ss,
-			      struct cgroup *new_cgroup,
+static int freezer_can_attach(struct cgroup *new_cgroup,
 			      struct cgroup_taskset *tset)
 {
 	struct freezer *freezer;
@@ -185,7 +182,7 @@ static int freezer_can_attach(struct cgroup_subsys *ss,
 	return 0;
 }
 
-static void freezer_fork(struct cgroup_subsys *ss, struct task_struct *task)
+static void freezer_fork(struct task_struct *task)
 {
 	struct freezer *freezer;