diff options
Diffstat (limited to 'block/blk-cgroup.h')
| -rw-r--r-- | block/blk-cgroup.h | 140 |
1 files changed, 94 insertions, 46 deletions
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index 47e1e38390c9..d4de0a35e066 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -15,13 +15,101 @@ */ #include <linux/blk-cgroup.h> +#include <linux/cgroup.h> +#include <linux/kthread.h> #include <linux/blk-mq.h> +struct blkcg_gq; +struct blkg_policy_data; + + /* percpu_counter batch for blkg_[rw]stats, per-cpu drift doesn't matter */ #define BLKG_STAT_CPU_BATCH (INT_MAX / 2) #ifdef CONFIG_BLK_CGROUP +enum blkg_iostat_type { + BLKG_IOSTAT_READ, + BLKG_IOSTAT_WRITE, + BLKG_IOSTAT_DISCARD, + + BLKG_IOSTAT_NR, +}; + +struct blkg_iostat { + u64 bytes[BLKG_IOSTAT_NR]; + u64 ios[BLKG_IOSTAT_NR]; +}; + +struct blkg_iostat_set { + struct u64_stats_sync sync; + struct blkg_iostat cur; + struct blkg_iostat last; +}; + +/* association between a blk cgroup and a request queue */ +struct blkcg_gq { + /* Pointer to the associated request_queue */ + struct request_queue *q; + 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; + + /* reference count */ + struct percpu_ref refcnt; + + /* is this blkg online? protected by both blkcg and q locks */ + bool online; + + struct blkg_iostat_set __percpu *iostat_cpu; + struct blkg_iostat_set iostat; + + struct blkg_policy_data *pd[BLKCG_MAX_POLS]; + + spinlock_t async_bio_lock; + struct bio_list async_bios; + union { + struct work_struct async_bio_work; + struct work_struct free_work; + }; + + atomic_t use_delay; + atomic64_t delay_nsec; + atomic64_t delay_start; + u64 last_delay; + int last_use; + + struct rcu_head rcu_head; +}; + +struct blkcg { + struct cgroup_subsys_state css; + spinlock_t lock; + refcount_t online_pin; + + struct radix_tree_root blkg_tree; + struct blkcg_gq __rcu *blkg_hint; + struct hlist_head blkg_list; + + struct blkcg_policy_data *cpd[BLKCG_MAX_POLS]; + + struct list_head all_blkcgs_node; +#ifdef CONFIG_BLK_CGROUP_FC_APPID + char fc_app_id[FC_APPID_LEN]; +#endif +#ifdef CONFIG_CGROUP_WRITEBACK + struct list_head cgwb_list; +#endif +}; + +static inline struct blkcg *css_to_blkcg(struct cgroup_subsys_state *css) +{ + return css ? container_of(css, struct blkcg, css) : NULL; +} + /* * A blkcg_gq (blkg) is association between a block cgroup (blkcg) and a * request_queue (q). This is used by blkcg policies which need to track @@ -63,7 +151,7 @@ typedef void (blkcg_pol_online_pd_fn)(struct blkg_policy_data *pd); typedef void (blkcg_pol_offline_pd_fn)(struct blkg_policy_data *pd); typedef void (blkcg_pol_free_pd_fn)(struct blkg_policy_data *pd); typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkg_policy_data *pd); -typedef bool (blkcg_pol_stat_pd_fn)(struct blkg_policy_data *pd, +typedef void (blkcg_pol_stat_pd_fn)(struct blkg_policy_data *pd, struct seq_file *s); struct blkcg_policy { @@ -123,52 +211,14 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, void blkg_conf_finish(struct blkg_conf_ctx *ctx); /** - * blkcg_css - find the current css - * - * Find the css associated with either the kthread or the current task. - * This may return a dying css, so it is up to the caller to use tryget logic - * to confirm it is alive and well. - */ -static inline struct cgroup_subsys_state *blkcg_css(void) -{ - struct cgroup_subsys_state *css; - - css = kthread_blkcg(); - if (css) - return css; - return task_css(current, io_cgrp_id); -} - -/** - * __bio_blkcg - internal, inconsistent version to get blkcg - * - * DO NOT USE. - * This function is inconsistent and consequently is dangerous to use. The - * first part of the function returns a blkcg where a reference is owned by the - * bio. This means it does not need to be rcu protected as it cannot go away - * with the bio owning a reference to it. However, the latter potentially gets - * it from task_css(). This can race against task migration and the cgroup - * dying. It is also semantically different as it must be called rcu protected - * and is susceptible to failure when trying to get a reference to it. - * Therefore, it is not ok to assume that *_get() will always succeed on the - * blkcg returned here. - */ -static inline struct blkcg *__bio_blkcg(struct bio *bio) -{ - if (bio && bio->bi_blkg) - return bio->bi_blkg->blkcg; - return css_to_blkcg(blkcg_css()); -} - -/** * bio_issue_as_root_blkg - see if this bio needs to be issued as root blkg * @return: true if this bio needs to be submitted with the root blkg context. * * In order to avoid priority inversions we sometimes need to issue a bio as if * it were attached to the root blkg, and then backcharge to the actual owning - * blkg. The idea is we do bio_blkcg() to look up the actual context for the - * bio and attach the appropriate blkg to the bio. Then we call this helper and - * if it is true run with the root blkg for that queue and then do any + * blkg. The idea is we do bio_blkcg_css() to look up the actual context for + * the bio and attach the appropriate blkg to the bio. Then we call this helper + * and if it is true run with the root blkg for that queue and then do any * backcharging to the originating cgroup once the io is complete. */ static inline bool bio_issue_as_root_blkg(struct bio *bio) @@ -457,7 +507,8 @@ struct blkcg_policy_data { struct blkcg_policy { }; -#ifdef CONFIG_BLOCK +struct blkcg { +}; static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg, void *key) { return NULL; } static inline struct blkcg_gq *blk_queue_root_blkg(struct request_queue *q) @@ -471,8 +522,6 @@ 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 *__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; } @@ -488,7 +537,6 @@ static inline bool blk_cgroup_mergeable(struct request *rq, struct bio *bio) { r #define blk_queue_for_each_rl(rl, q) \ for ((rl) = &(q)->root_rl; (rl); (rl) = NULL) -#endif /* CONFIG_BLOCK */ #endif /* CONFIG_BLK_CGROUP */ #endif /* _BLK_CGROUP_PRIVATE_H */ |