diff options
Diffstat (limited to 'block/blk-cgroup.h')
| -rw-r--r-- | block/blk-cgroup.h | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index 24597309e23..b26ed58899f 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -94,8 +94,13 @@ struct blkcg_gq { struct list_head q_node; struct hlist_node blkcg_node; struct blkcg *blkcg; + + /* all non-root blkcg_gq's are guaranteed to have access to parent */ + struct blkcg_gq *parent; + /* request allocation list for this blkcg-q pair */ struct request_list rl; + /* reference count */ int refcnt; @@ -181,6 +186,19 @@ static inline struct blkcg *bio_blkcg(struct bio *bio) } /** + * blkcg_parent - get the parent of a blkcg + * @blkcg: blkcg of interest + * + * Return the parent blkcg of @blkcg. Can be called anytime. + */ +static inline struct blkcg *blkcg_parent(struct blkcg *blkcg) +{ + struct cgroup *pcg = blkcg->css.cgroup->parent; + + return pcg ? cgroup_to_blkcg(pcg) : NULL; +} + +/** * blkg_to_pdata - get policy private data * @blkg: blkg of interest * @pol: policy of interest |