diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 42ff436ffaf4..9da02c021ebe 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -1048,10 +1048,8 @@ int blkcg_activate_policy(struct request_queue *q, const struct blkcg_policy *pol) { LIST_HEAD(pds); - LIST_HEAD(cpds); struct blkcg_gq *blkg; struct blkg_policy_data *pd, *nd; - struct blkcg_policy_data *cpd, *cnd; int cnt = 0, ret; if (blkcg_policy_enabled(q, pol)) @@ -1064,10 +1062,7 @@ int blkcg_activate_policy(struct request_queue *q, cnt++; spin_unlock_irq(q->queue_lock); - /* - * Allocate per-blkg and per-blkcg policy data - * for all existing blkgs. - */ + /* allocate per-blkg policy data for all existing blkgs */ while (cnt--) { pd = kzalloc_node(pol->pd_size, GFP_KERNEL, q->node); if (!pd) { @@ -1075,15 +1070,6 @@ int blkcg_activate_policy(struct request_queue *q, goto out_free; } list_add_tail(&pd->alloc_node, &pds); - - if (!pol->cpd_size) - continue; - cpd = kzalloc_node(pol->cpd_size, GFP_KERNEL, q->node); - if (!cpd) { - ret = -ENOMEM; - goto out_free; - } - list_add_tail(&cpd->alloc_node, &cpds); } /* @@ -1093,32 +1079,17 @@ int blkcg_activate_policy(struct request_queue *q, spin_lock_irq(q->queue_lock); list_for_each_entry(blkg, &q->blkg_list, q_node) { - if (WARN_ON(list_empty(&pds)) || - WARN_ON(pol->cpd_size && list_empty(&cpds))) { + if (WARN_ON(list_empty(&pds))) { /* umm... this shouldn't happen, just abort */ ret = -ENOMEM; goto out_unlock; } - cpd = list_first_entry(&cpds, struct blkcg_policy_data, - alloc_node); - list_del_init(&cpd->alloc_node); pd = list_first_entry(&pds, struct blkg_policy_data, alloc_node); list_del_init(&pd->alloc_node); /* grab blkcg lock too while installing @pd on @blkg */ spin_lock(&blkg->blkcg->lock); - if (!pol->cpd_size) - goto no_cpd; - if (!blkg->blkcg->pd[pol->plid]) { - /* Per-policy per-blkcg data */ - blkg->blkcg->pd[pol->plid] = cpd; - cpd->plid = pol->plid; - pol->cpd_init_fn(blkg->blkcg); - } else { /* must free it as it has already been extracted */ - kfree(cpd); - } -no_cpd: blkg->pd[pol->plid] = pd; pd->blkg = blkg; pd->plid = pol->plid; @@ -1135,8 +1106,6 @@ out_free: blk_queue_bypass_end(q); list_for_each_entry_safe(pd, nd, &pds, alloc_node) kfree(pd); - list_for_each_entry_safe(cpd, cnd, &cpds, alloc_node) - kfree(cpd); return ret; } EXPORT_SYMBOL_GPL(blkcg_activate_policy); @@ -1191,6 +1160,7 @@ EXPORT_SYMBOL_GPL(blkcg_deactivate_policy); */ int blkcg_policy_register(struct blkcg_policy *pol) { + struct blkcg *blkcg; int i, ret; if (WARN_ON(pol->pd_size < sizeof(struct blkg_policy_data))) @@ -1207,9 +1177,27 @@ int blkcg_policy_register(struct blkcg_policy *pol) if (i >= BLKCG_MAX_POLS) goto err_unlock; - /* register and update blkgs */ + /* register @pol */ pol->plid = i; - blkcg_policy[i] = pol; + blkcg_policy[pol->plid] = pol; + + /* allocate and install cpd's */ + if (pol->cpd_size) { + list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) { + struct blkcg_policy_data *cpd; + + cpd = kzalloc(pol->cpd_size, GFP_KERNEL); + if (!cpd) { + mutex_unlock(&blkcg_pol_mutex); + goto err_free_cpds; + } + + blkcg->pd[pol->plid] = cpd; + cpd->plid = pol->plid; + pol->cpd_init_fn(blkcg); + } + } + mutex_unlock(&blkcg_pol_mutex); /* everything is in place, add intf files for the new policy */ @@ -1219,6 +1207,14 @@ int blkcg_policy_register(struct blkcg_policy *pol) mutex_unlock(&blkcg_pol_register_mutex); return 0; +err_free_cpds: + if (pol->cpd_size) { + list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) { + kfree(blkcg->pd[pol->plid]); + blkcg->pd[pol->plid] = NULL; + } + } + blkcg_policy[pol->plid] = NULL; err_unlock: mutex_unlock(&blkcg_pol_mutex); mutex_unlock(&blkcg_pol_register_mutex); @@ -1234,6 +1230,8 @@ EXPORT_SYMBOL_GPL(blkcg_policy_register); */ void blkcg_policy_unregister(struct blkcg_policy *pol) { + struct blkcg *blkcg; + mutex_lock(&blkcg_pol_register_mutex); if (WARN_ON(blkcg_policy[pol->plid] != pol)) @@ -1243,9 +1241,17 @@ void blkcg_policy_unregister(struct blkcg_policy *pol) if (pol->cftypes) cgroup_rm_cftypes(pol->cftypes); - /* unregister and update blkgs */ + /* remove cpds and unregister */ mutex_lock(&blkcg_pol_mutex); + + if (pol->cpd_size) { + list_for_each_entry(blkcg, &all_blkcgs, all_blkcgs_node) { + kfree(blkcg->pd[pol->plid]); + blkcg->pd[pol->plid] = NULL; + } + } blkcg_policy[pol->plid] = NULL; + mutex_unlock(&blkcg_pol_mutex); out_unlock: mutex_unlock(&blkcg_pol_register_mutex); diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h index cf3e7bc22ef3..1b62d768c7df 100644 --- a/include/linux/blk-cgroup.h +++ b/include/linux/blk-cgroup.h @@ -89,18 +89,12 @@ struct blkg_policy_data { * Policies that need to keep per-blkcg data which is independent * from any request_queue associated to it must specify its size * with the cpd_size field of the blkcg_policy structure and - * embed a blkcg_policy_data in it. blkcg core allocates - * policy-specific per-blkcg structures lazily the first time - * they are actually needed, so it handles them together with - * blkgs. cpd_init() is invoked to let each policy handle - * per-blkcg data. + * embed a blkcg_policy_data in it. cpd_init() is invoked to let + * each policy handle per-blkcg data. */ struct blkcg_policy_data { /* the policy id this per-policy data belongs to */ int plid; - - /* used during policy activation */ - struct list_head alloc_node; }; /* association between a blk cgroup and a request queue */