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, 8 insertions, 14 deletions

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index fa8f26309444..1359d637831f 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -28,13 +28,10 @@ static LIST_HEAD(blkio_list);
 struct blkio_cgroup blkio_root_cgroup = { .weight = 2*BLKIO_WEIGHT_DEFAULT };
 EXPORT_SYMBOL_GPL(blkio_root_cgroup);
 
-static struct cgroup_subsys_state *blkiocg_create(struct cgroup_subsys *,
-                                                  struct cgroup *);
-static int blkiocg_can_attach(struct cgroup_subsys *, struct cgroup *,
-                              struct cgroup_taskset *);
-static void blkiocg_attach(struct cgroup_subsys *, struct cgroup *,
-                           struct cgroup_taskset *);
-static void blkiocg_destroy(struct cgroup_subsys *, struct cgroup *);
+static struct cgroup_subsys_state *blkiocg_create(struct cgroup *);
+static int blkiocg_can_attach(struct cgroup *, struct cgroup_taskset *);
+static void blkiocg_attach(struct cgroup *, struct cgroup_taskset *);
+static void blkiocg_destroy(struct cgroup *);
 static int blkiocg_populate(struct cgroup_subsys *, struct cgroup *);
 
 /* for encoding cft->private value on file */
@@ -1548,7 +1545,7 @@ static int blkiocg_populate(struct cgroup_subsys *subsys, struct cgroup *cgroup)
                                 ARRAY_SIZE(blkio_files));
 }
 
-static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup)
+static void blkiocg_destroy(struct cgroup *cgroup)
 {
         struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup);
         unsigned long flags;
@@ -1598,8 +1595,7 @@ static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup)
                 kfree(blkcg);
 }
 
-static struct cgroup_subsys_state *
-blkiocg_create(struct cgroup_subsys *subsys, struct cgroup *cgroup)
+static struct cgroup_subsys_state *blkiocg_create(struct cgroup *cgroup)
 {
         struct blkio_cgroup *blkcg;
         struct cgroup *parent = cgroup->parent;
@@ -1628,8 +1624,7 @@ done:
  * of the main cic data structures.  For now we allow a task to change
  * its cgroup only if it's the only owner of its ioc.
  */
-static int blkiocg_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
-                              struct cgroup_taskset *tset)
+static int blkiocg_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
 {
         struct task_struct *task;
         struct io_context *ioc;
@@ -1648,8 +1643,7 @@ static int blkiocg_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
         return ret;
 }
 
-static void blkiocg_attach(struct cgroup_subsys *ss, struct cgroup *cgrp,
-                           struct cgroup_taskset *tset)
+static void blkiocg_attach(struct cgroup *cgrp, struct cgroup_taskset *tset)
 {
         struct task_struct *task;
         struct io_context *ioc;