tree 1daf4d9fc8d03ebbc88ceedb7abeec46d8c71df3
parent 92616b5b3a7c7fa8148df82e7ff6183056f2bfc8
author Tejun Heo <tj@kernel.org> 1330982111 -0800
committer Jens Axboe <axboe@kernel.dk> 1331065643 +0100

blkcg: let blkio_group point to blkio_cgroup directly

Currently, blkg points to the associated blkcg via its css_id.  This
unnecessarily complicates dereferencing blkcg.  Let blkg hold a
reference to the associated blkcg and point directly to it and disable
css_id on blkio_subsys.

This change requires splitting blkiocg_destroy() into
blkiocg_pre_destroy() and blkiocg_destroy() so that all blkg's can be
destroyed and all the blkcg references held by them dropped during
cgroup removal.

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