diff options
Diffstat (limited to 'block/blk-cgroup.h')
| -rw-r--r-- | block/blk-cgroup.h | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index 9537819c29c..7da106843f0 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -177,6 +177,8 @@ struct blkio_group { char path[128]; /* policy which owns this blk group */ enum blkio_policy_id plid; + /* reference count */ + int refcnt; /* Configuration */ struct blkio_group_conf conf; @@ -188,6 +190,8 @@ struct blkio_group { struct blkio_group_stats_cpu __percpu *stats_cpu; struct blkg_policy_data *pd; + + struct rcu_head rcu_head; }; typedef void (blkio_init_group_fn)(struct blkio_group *blkg); @@ -272,6 +276,35 @@ static inline char *blkg_path(struct blkio_group *blkg) return blkg->path; } +/** + * blkg_get - get a blkg reference + * @blkg: blkg to get + * + * The caller should be holding queue_lock and an existing reference. + */ +static inline void blkg_get(struct blkio_group *blkg) +{ + lockdep_assert_held(blkg->q->queue_lock); + WARN_ON_ONCE(!blkg->refcnt); + blkg->refcnt++; +} + +void __blkg_release(struct blkio_group *blkg); + +/** + * blkg_put - put a blkg reference + * @blkg: blkg to put + * + * The caller should be holding queue_lock. + */ +static inline void blkg_put(struct blkio_group *blkg) +{ + lockdep_assert_held(blkg->q->queue_lock); + WARN_ON_ONCE(blkg->refcnt <= 0); + if (!--blkg->refcnt) + __blkg_release(blkg); +} + #else struct blkio_group { @@ -292,6 +325,8 @@ static inline void *blkg_to_pdata(struct blkio_group *blkg, static inline struct blkio_group *pdata_to_blkg(void *pdata, struct blkio_policy_type *pol) { return NULL; } static inline char *blkg_path(struct blkio_group *blkg) { return NULL; } +static inline void blkg_get(struct blkio_group *blkg) { } +static inline void blkg_put(struct blkio_group *blkg) { } #endif |