diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-cgroup.c | 59 | ||||
| -rw-r--r-- | block/blk-cgroup.h | 15 | ||||
| -rw-r--r-- | block/blk-throttle.c | 4 | ||||
| -rw-r--r-- | block/cfq-iosched.c | 25 |
4 files changed, 63 insertions, 40 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index b1231524a097..2d4d7d6d9ae9 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -31,7 +31,7 @@ static LIST_HEAD(all_q_list); struct blkio_cgroup blkio_root_cgroup = { .cfq_weight = 2 * CFQ_WEIGHT_DEFAULT }; EXPORT_SYMBOL_GPL(blkio_root_cgroup); -static struct blkio_policy_type *blkio_policy[BLKIO_NR_POLICIES]; +static struct blkio_policy_type *blkio_policy[BLKCG_MAX_POLS]; struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup) { @@ -67,7 +67,7 @@ static void blkg_free(struct blkio_group *blkg) if (!blkg) return; - for (i = 0; i < BLKIO_NR_POLICIES; i++) { + for (i = 0; i < BLKCG_MAX_POLS; i++) { struct blkio_policy_type *pol = blkio_policy[i]; struct blkg_policy_data *pd = blkg->pd[i]; @@ -107,7 +107,7 @@ static struct blkio_group *blkg_alloc(struct blkio_cgroup *blkcg, blkg->refcnt = 1; cgroup_path(blkcg->css.cgroup, blkg->path, sizeof(blkg->path)); - for (i = 0; i < BLKIO_NR_POLICIES; i++) { + for (i = 0; i < BLKCG_MAX_POLS; i++) { struct blkio_policy_type *pol = blkio_policy[i]; struct blkg_policy_data *pd; @@ -127,7 +127,7 @@ static struct blkio_group *blkg_alloc(struct blkio_cgroup *blkcg, } /* invoke per-policy init */ - for (i = 0; i < BLKIO_NR_POLICIES; i++) { + for (i = 0; i < BLKCG_MAX_POLS; i++) { struct blkio_policy_type *pol = blkio_policy[i]; if (pol) @@ -320,7 +320,7 @@ blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val) * anyway. If you get hit by a race, retry. */ hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) { - for (i = 0; i < BLKIO_NR_POLICIES; i++) { + for (i = 0; i < BLKCG_MAX_POLS; i++) { struct blkio_policy_type *pol = blkio_policy[i]; if (pol && pol->ops.blkio_reset_group_stats_fn) @@ -729,46 +729,75 @@ struct cgroup_subsys blkio_subsys = { }; EXPORT_SYMBOL_GPL(blkio_subsys); -void blkio_policy_register(struct blkio_policy_type *blkiop) +/** + * blkio_policy_register - register a blkcg policy + * @blkiop: blkcg policy to register + * + * Register @blkiop with blkcg core. Might sleep and @blkiop may be + * modified on successful registration. Returns 0 on success and -errno on + * failure. + */ +int blkio_policy_register(struct blkio_policy_type *blkiop) { struct request_queue *q; + int i, ret; mutex_lock(&blkcg_pol_mutex); - blkcg_bypass_start(); + /* find an empty slot */ + ret = -ENOSPC; + for (i = 0; i < BLKCG_MAX_POLS; i++) + if (!blkio_policy[i]) + break; + if (i >= BLKCG_MAX_POLS) + goto out_unlock; - BUG_ON(blkio_policy[blkiop->plid]); - blkio_policy[blkiop->plid] = blkiop; + /* register and update blkgs */ + blkiop->plid = i; + blkio_policy[i] = blkiop; + + blkcg_bypass_start(); list_for_each_entry(q, &all_q_list, all_q_node) update_root_blkg_pd(q, blkiop); - blkcg_bypass_end(); + /* everything is in place, add intf files for the new policy */ if (blkiop->cftypes) WARN_ON(cgroup_add_cftypes(&blkio_subsys, blkiop->cftypes)); - + ret = 0; +out_unlock: mutex_unlock(&blkcg_pol_mutex); + return ret; } EXPORT_SYMBOL_GPL(blkio_policy_register); +/** + * blkiop_policy_unregister - unregister a blkcg policy + * @blkiop: blkcg policy to unregister + * + * Undo blkio_policy_register(@blkiop). Might sleep. + */ void blkio_policy_unregister(struct blkio_policy_type *blkiop) { struct request_queue *q; mutex_lock(&blkcg_pol_mutex); + if (WARN_ON(blkio_policy[blkiop->plid] != blkiop)) + goto out_unlock; + + /* kill the intf files first */ if (blkiop->cftypes) cgroup_rm_cftypes(&blkio_subsys, blkiop->cftypes); - blkcg_bypass_start(); - - BUG_ON(blkio_policy[blkiop->plid] != blkiop); + /* unregister and update blkgs */ blkio_policy[blkiop->plid] = NULL; + blkcg_bypass_start(); list_for_each_entry(q, &all_q_list, all_q_node) update_root_blkg_pd(q, blkiop); blkcg_bypass_end(); - +out_unlock: mutex_unlock(&blkcg_pol_mutex); } EXPORT_SYMBOL_GPL(blkio_policy_unregister); diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index 26949731108f..be80d6eb6531 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -17,13 +17,6 @@ #include <linux/u64_stats_sync.h> #include <linux/seq_file.h> -enum blkio_policy_id { - BLKIO_POLICY_PROP = 0, /* Proportional Bandwidth division */ - BLKIO_POLICY_THROTL, /* Throttling */ - - BLKIO_NR_POLICIES, -}; - /* Max limits for throttle policy */ #define THROTL_IOPS_MAX UINT_MAX @@ -86,7 +79,7 @@ struct blkio_group { /* reference count */ int refcnt; - struct blkg_policy_data *pd[BLKIO_NR_POLICIES]; + struct blkg_policy_data *pd[BLKCG_MAX_POLS]; struct rcu_head rcu_head; }; @@ -103,7 +96,7 @@ struct blkio_policy_ops { struct blkio_policy_type { struct blkio_policy_ops ops; - enum blkio_policy_id plid; + int plid; size_t pdata_size; /* policy specific private data size */ struct cftype *cftypes; /* cgroup files for the policy */ }; @@ -113,7 +106,7 @@ extern void blkcg_drain_queue(struct request_queue *q); extern void blkcg_exit_queue(struct request_queue *q); /* Blkio controller policy registration */ -extern void blkio_policy_register(struct blkio_policy_type *); +extern int blkio_policy_register(struct blkio_policy_type *); extern void blkio_policy_unregister(struct blkio_policy_type *); extern void blkg_destroy_all(struct request_queue *q, bool destroy_root); extern void update_root_blkg_pd(struct request_queue *q, @@ -329,7 +322,7 @@ struct blkio_policy_type { static inline int blkcg_init_queue(struct request_queue *q) { return 0; } static inline void blkcg_drain_queue(struct request_queue *q) { } static inline void blkcg_exit_queue(struct request_queue *q) { } -static inline void blkio_policy_register(struct blkio_policy_type *blkiop) { } +static inline int blkio_policy_register(struct blkio_policy_type *blkiop) { return 0; } static inline void blkio_policy_unregister(struct blkio_policy_type *blkiop) { } static inline void blkg_destroy_all(struct request_queue *q, bool destory_root) { } diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 07c17c27a628..0dc4645aa7fe 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -1089,7 +1089,6 @@ static struct blkio_policy_type blkio_policy_throtl = { .blkio_exit_group_fn = throtl_exit_blkio_group, .blkio_reset_group_stats_fn = throtl_reset_group_stats, }, - .plid = BLKIO_POLICY_THROTL, .pdata_size = sizeof(struct throtl_grp), .cftypes = throtl_files, }; @@ -1271,8 +1270,7 @@ static int __init throtl_init(void) if (!kthrotld_workqueue) panic("Failed to create kthrotld\n"); - blkio_policy_register(&blkio_policy_throtl); - return 0; + return blkio_policy_register(&blkio_policy_throtl); } module_init(throtl_init); diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index d02f0ae9637f..08db2fc70c29 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -4157,7 +4157,6 @@ static struct blkio_policy_type blkio_policy_cfq = { .blkio_init_group_fn = cfq_init_blkio_group, .blkio_reset_group_stats_fn = cfqg_stats_reset, }, - .plid = BLKIO_POLICY_PROP, .pdata_size = sizeof(struct cfq_group), .cftypes = cfq_blkcg_files, }; @@ -4181,27 +4180,31 @@ static int __init cfq_init(void) #else cfq_group_idle = 0; #endif + + ret = blkio_policy_register(&blkio_policy_cfq); + if (ret) + return ret; + cfq_pool = KMEM_CACHE(cfq_queue, 0); if (!cfq_pool) - return -ENOMEM; + goto err_pol_unreg; ret = elv_register(&iosched_cfq); - if (ret) { - kmem_cache_destroy(cfq_pool); - return ret; - } + if (ret) + goto err_free_pool; -#ifdef CONFIG_CFQ_GROUP_IOSCHED - blkio_policy_register(&blkio_policy_cfq); -#endif return 0; + +err_free_pool: + kmem_cache_destroy(cfq_pool); +err_pol_unreg: + blkio_policy_unregister(&blkio_policy_cfq); + return ret; } static void __exit cfq_exit(void) { -#ifdef CONFIG_CFQ_GROUP_IOSCHED blkio_policy_unregister(&blkio_policy_cfq); -#endif elv_unregister(&iosched_cfq); kmem_cache_destroy(cfq_pool); } |