diff options
Diffstat (limited to 'block/blk-cgroup.h')
| -rw-r--r-- | block/blk-cgroup.h | 128 |
1 files changed, 124 insertions, 4 deletions
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index 8ac457ce778..24597309e23 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -17,6 +17,7 @@ #include <linux/u64_stats_sync.h> #include <linux/seq_file.h> #include <linux/radix-tree.h> +#include <linux/blkdev.h> /* Max limits for throttle policy */ #define THROTL_IOPS_MAX UINT_MAX @@ -93,6 +94,8 @@ struct blkcg_gq { struct list_head q_node; struct hlist_node blkcg_node; struct blkcg *blkcg; + /* request allocation list for this blkcg-q pair */ + struct request_list rl; /* reference count */ int refcnt; @@ -120,8 +123,6 @@ struct blkcg_policy { extern struct blkcg blkcg_root; -struct blkcg *cgroup_to_blkcg(struct cgroup *cgroup); -struct blkcg *bio_blkcg(struct bio *bio); struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, struct request_queue *q); struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg, struct request_queue *q); @@ -160,6 +161,25 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, void blkg_conf_finish(struct blkg_conf_ctx *ctx); +static inline struct blkcg *cgroup_to_blkcg(struct cgroup *cgroup) +{ + return container_of(cgroup_subsys_state(cgroup, blkio_subsys_id), + struct blkcg, css); +} + +static inline struct blkcg *task_blkcg(struct task_struct *tsk) +{ + return container_of(task_subsys_state(tsk, blkio_subsys_id), + struct blkcg, css); +} + +static inline struct blkcg *bio_blkcg(struct bio *bio) +{ + if (bio && bio->bi_css) + return container_of(bio->bi_css, struct blkcg, css); + return task_blkcg(current); +} + /** * blkg_to_pdata - get policy private data * @blkg: blkg of interest @@ -234,6 +254,95 @@ static inline void blkg_put(struct blkcg_gq *blkg) } /** + * blk_get_rl - get request_list to use + * @q: request_queue of interest + * @bio: bio which will be attached to the allocated request (may be %NULL) + * + * The caller wants to allocate a request from @q to use for @bio. Find + * the request_list to use and obtain a reference on it. Should be called + * under queue_lock. This function is guaranteed to return non-%NULL + * request_list. + */ +static inline struct request_list *blk_get_rl(struct request_queue *q, + struct bio *bio) +{ + struct blkcg *blkcg; + struct blkcg_gq *blkg; + + rcu_read_lock(); + + blkcg = bio_blkcg(bio); + + /* bypass blkg lookup and use @q->root_rl directly for root */ + if (blkcg == &blkcg_root) + goto root_rl; + + /* + * Try to use blkg->rl. blkg lookup may fail under memory pressure + * or if either the blkcg or queue is going away. Fall back to + * root_rl in such cases. + */ + blkg = blkg_lookup_create(blkcg, q); + if (unlikely(IS_ERR(blkg))) + goto root_rl; + + blkg_get(blkg); + rcu_read_unlock(); + return &blkg->rl; +root_rl: + rcu_read_unlock(); + return &q->root_rl; +} + +/** + * blk_put_rl - put request_list + * @rl: request_list to put + * + * Put the reference acquired by blk_get_rl(). Should be called under + * queue_lock. + */ +static inline void blk_put_rl(struct request_list *rl) +{ + /* root_rl may not have blkg set */ + if (rl->blkg && rl->blkg->blkcg != &blkcg_root) + blkg_put(rl->blkg); +} + +/** + * blk_rq_set_rl - associate a request with a request_list + * @rq: request of interest + * @rl: target request_list + * + * Associate @rq with @rl so that accounting and freeing can know the + * request_list @rq came from. + */ +static inline void blk_rq_set_rl(struct request *rq, struct request_list *rl) +{ + rq->rl = rl; +} + +/** + * blk_rq_rl - return the request_list a request came from + * @rq: request of interest + * + * Return the request_list @rq is allocated from. + */ +static inline struct request_list *blk_rq_rl(struct request *rq) +{ + return rq->rl; +} + +struct request_list *__blk_queue_next_rl(struct request_list *rl, + struct request_queue *q); +/** + * blk_queue_for_each_rl - iterate through all request_lists of a request_queue + * + * Should be used under queue_lock. + */ +#define blk_queue_for_each_rl(rl, q) \ + for ((rl) = &(q)->root_rl; (rl); (rl) = __blk_queue_next_rl((rl), (q))) + +/** * blkg_stat_add - add a value to a blkg_stat * @stat: target blkg_stat * @val: value to add @@ -351,6 +460,7 @@ static inline void blkg_rwstat_reset(struct blkg_rwstat *rwstat) #else /* CONFIG_BLK_CGROUP */ struct cgroup; +struct blkcg; struct blkg_policy_data { }; @@ -361,8 +471,6 @@ struct blkcg_gq { struct blkcg_policy { }; -static inline struct blkcg *cgroup_to_blkcg(struct cgroup *cgroup) { return NULL; } -static inline struct blkcg *bio_blkcg(struct bio *bio) { return NULL; } static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, void *key) { return NULL; } static inline int blkcg_init_queue(struct request_queue *q) { return 0; } static inline void blkcg_drain_queue(struct request_queue *q) { } @@ -374,6 +482,9 @@ static inline int blkcg_activate_policy(struct request_queue *q, static inline void blkcg_deactivate_policy(struct request_queue *q, const struct blkcg_policy *pol) { } +static inline struct blkcg *cgroup_to_blkcg(struct cgroup *cgroup) { return NULL; } +static inline struct blkcg *bio_blkcg(struct bio *bio) { return NULL; } + static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg, struct blkcg_policy *pol) { return NULL; } static inline struct blkcg_gq *pd_to_blkg(struct blkg_policy_data *pd) { return NULL; } @@ -381,5 +492,14 @@ static inline char *blkg_path(struct blkcg_gq *blkg) { return NULL; } static inline void blkg_get(struct blkcg_gq *blkg) { } static inline void blkg_put(struct blkcg_gq *blkg) { } +static inline struct request_list *blk_get_rl(struct request_queue *q, + struct bio *bio) { return &q->root_rl; } +static inline void blk_put_rl(struct request_list *rl) { } +static inline void blk_rq_set_rl(struct request *rq, struct request_list *rl) { } +static inline struct request_list *blk_rq_rl(struct request *rq) { return &rq->q->root_rl; } + +#define blk_queue_for_each_rl(rl, q) \ + for ((rl) = &(q)->root_rl; (rl); (rl) = NULL) + #endif /* CONFIG_BLK_CGROUP */ #endif /* _BLK_CGROUP_H */ |