blkcg: implement blkio_policy_type->cftypes

Add blkiop->cftypes which is added and removed together with the
policy.  This will be used to move conf/stat handling to the policies.

Signed-off-by: Tejun Heo <tj@kernel.org>

2 files changed, 7 insertions, 0 deletions

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 53976f2704a5..4e714f8ddcd2 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1538,6 +1538,9 @@ void blkio_policy_register(struct blkio_policy_type *blkiop)
         list_for_each_entry(q, &all_q_list, all_q_node)
                 update_root_blkg_pd(q, blkiop->plid);
         blkcg_bypass_end();
+
+        if (blkiop->cftypes)
+                WARN_ON(cgroup_add_cftypes(&blkio_subsys, blkiop->cftypes));
 }
 EXPORT_SYMBOL_GPL(blkio_policy_register);
 
@@ -1545,6 +1548,9 @@ void blkio_policy_unregister(struct blkio_policy_type *blkiop)
 {
         struct request_queue *q;
 
+        if (blkiop->cftypes)
+                cgroup_rm_cftypes(&blkio_subsys, blkiop->cftypes);
+
         blkcg_bypass_start();
         spin_lock(&blkio_list_lock);
 
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 361ecfa4d28d..fa744d57bebb 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -181,6 +181,7 @@ struct blkio_policy_type {
         struct blkio_policy_ops ops;
         enum blkio_policy_id plid;
         size_t pdata_size;              /* policy specific private data size */
+        struct cftype *cftypes;         /* cgroup files for the policy */
 };
 
 extern int blkcg_init_queue(struct request_queue *q);