tree 700bd0b0f325e9eebf4b0c91ae31d1872f471e39
parent eb95419b023abacb415e2a18fea899023ce7624d
author Tejun Heo <tj@kernel.org> 1376007083 -0400
committer Tejun Heo <tj@kernel.org> 1376007083 -0400

cgroup: add subsys backlink pointer to cftype

cgroup is transitioning to using css (cgroup_subsys_state) instead of
cgroup as the primary subsystem handle.  The cgroupfs file interface
will be converted to use css's which requires finding out the
subsystem from cftype so that the matching css can be determined from
the cgroup.

This patch adds cftype->ss which points to the subsystem the file
belongs to.  The field is initialized while a cftype is being
registered.  This makes it unnecessary to explicitly specify the
subsystem for other cftype handling functions.  @ss argument dropped
from various cftype handling functions.

This patch shouldn't introduce any behavior differences.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>