cgroup: remove css_parent()
cgroup in general is moving towards using cgroup_subsys_state as the
fundamental structural component and css_parent() was introduced to
convert from using cgroup->parent to css->parent. It was quite some
time ago and we're moving forward with making css more prominent.
This patch drops the trivial wrapper css_parent() and let the users
dereference css->parent. While at it, explicitly mark fields of css
which are public and immutable.
v2: New usage from device_cgroup.c converted.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: "David S. Miller" <davem@davemloft.net>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Johannes Weiner <hannes@cmpxchg.org>
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index 6b4e60e..a79e40f 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -59,7 +59,7 @@
static struct freezer *parent_freezer(struct freezer *freezer)
{
- return css_freezer(css_parent(&freezer->css));
+ return css_freezer(freezer->css.parent);
}
bool cgroup_freezing(struct task_struct *task)