diff options
Diffstat (limited to 'block/blk-cgroup.c')
-rw-r--r-- | block/blk-cgroup.c | 74 |
1 files changed, 38 insertions, 36 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 290792a13e3..4e491d9b529 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -235,8 +235,13 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, blkg->online = true; spin_unlock(&blkcg->lock); - if (!ret) + if (!ret) { + if (blkcg == &blkcg_root) { + q->root_blkg = blkg; + q->root_rl.blkg = blkg; + } return blkg; + } /* @blkg failed fully initialized, use the usual release path */ blkg_put(blkg); @@ -335,6 +340,15 @@ static void blkg_destroy(struct blkcg_gq *blkg) rcu_assign_pointer(blkcg->blkg_hint, NULL); /* + * If root blkg is destroyed. Just clear the pointer since root_rl + * does not take reference on root blkg. + */ + if (blkcg == &blkcg_root) { + blkg->q->root_blkg = NULL; + blkg->q->root_rl.blkg = NULL; + } + + /* * Put the reference taken at the time of creation so that when all * queues are gone, group can be destroyed. */ @@ -360,13 +374,6 @@ static void blkg_destroy_all(struct request_queue *q) blkg_destroy(blkg); spin_unlock(&blkcg->lock); } - - /* - * root blkg is destroyed. Just clear the pointer since - * root_rl does not take reference on root blkg. - */ - q->root_blkg = NULL; - q->root_rl.blkg = NULL; } /* @@ -437,10 +444,10 @@ struct request_list *__blk_queue_next_rl(struct request_list *rl, return &blkg->rl; } -static int blkcg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, - u64 val) +static int blkcg_reset_stats(struct cgroup_subsys_state *css, + struct cftype *cftype, u64 val) { - struct blkcg *blkcg = cgroup_to_blkcg(cgroup); + struct blkcg *blkcg = css_to_blkcg(css); struct blkcg_gq *blkg; int i; @@ -614,15 +621,13 @@ u64 blkg_stat_recursive_sum(struct blkg_policy_data *pd, int off) { struct blkcg_policy *pol = blkcg_policy[pd->plid]; struct blkcg_gq *pos_blkg; - struct cgroup *pos_cgrp; - u64 sum; + struct cgroup_subsys_state *pos_css; + u64 sum = 0; lockdep_assert_held(pd->blkg->q->queue_lock); - sum = blkg_stat_read((void *)pd + off); - rcu_read_lock(); - blkg_for_each_descendant_pre(pos_blkg, pos_cgrp, pd_to_blkg(pd)) { + blkg_for_each_descendant_pre(pos_blkg, pos_css, pd_to_blkg(pd)) { struct blkg_policy_data *pos_pd = blkg_to_pd(pos_blkg, pol); struct blkg_stat *stat = (void *)pos_pd + off; @@ -649,16 +654,14 @@ struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkg_policy_data *pd, { struct blkcg_policy *pol = blkcg_policy[pd->plid]; struct blkcg_gq *pos_blkg; - struct cgroup *pos_cgrp; - struct blkg_rwstat sum; + struct cgroup_subsys_state *pos_css; + struct blkg_rwstat sum = { }; int i; lockdep_assert_held(pd->blkg->q->queue_lock); - sum = blkg_rwstat_read((void *)pd + off); - rcu_read_lock(); - blkg_for_each_descendant_pre(pos_blkg, pos_cgrp, pd_to_blkg(pd)) { + blkg_for_each_descendant_pre(pos_blkg, pos_css, pd_to_blkg(pd)) { struct blkg_policy_data *pos_pd = blkg_to_pd(pos_blkg, pol); struct blkg_rwstat *rwstat = (void *)pos_pd + off; struct blkg_rwstat tmp; @@ -765,18 +768,18 @@ struct cftype blkcg_files[] = { /** * blkcg_css_offline - cgroup css_offline callback - * @cgroup: cgroup of interest + * @css: css of interest * - * This function is called when @cgroup is about to go away and responsible - * for shooting down all blkgs associated with @cgroup. blkgs should be + * This function is called when @css is about to go away and responsible + * for shooting down all blkgs associated with @css. blkgs should be * removed while holding both q and blkcg locks. As blkcg lock is nested * inside q lock, this function performs reverse double lock dancing. * * This is the blkcg counterpart of ioc_release_fn(). */ -static void blkcg_css_offline(struct cgroup *cgroup) +static void blkcg_css_offline(struct cgroup_subsys_state *css) { - struct blkcg *blkcg = cgroup_to_blkcg(cgroup); + struct blkcg *blkcg = css_to_blkcg(css); spin_lock_irq(&blkcg->lock); @@ -798,21 +801,21 @@ static void blkcg_css_offline(struct cgroup *cgroup) spin_unlock_irq(&blkcg->lock); } -static void blkcg_css_free(struct cgroup *cgroup) +static void blkcg_css_free(struct cgroup_subsys_state *css) { - struct blkcg *blkcg = cgroup_to_blkcg(cgroup); + struct blkcg *blkcg = css_to_blkcg(css); if (blkcg != &blkcg_root) kfree(blkcg); } -static struct cgroup_subsys_state *blkcg_css_alloc(struct cgroup *cgroup) +static struct cgroup_subsys_state * +blkcg_css_alloc(struct cgroup_subsys_state *parent_css) { static atomic64_t id_seq = ATOMIC64_INIT(0); struct blkcg *blkcg; - struct cgroup *parent = cgroup->parent; - if (!parent) { + if (!parent_css) { blkcg = &blkcg_root; goto done; } @@ -883,14 +886,15 @@ void blkcg_exit_queue(struct request_queue *q) * of the main cic data structures. For now we allow a task to change * its cgroup only if it's the only owner of its ioc. */ -static int blkcg_can_attach(struct cgroup *cgrp, struct cgroup_taskset *tset) +static int blkcg_can_attach(struct cgroup_subsys_state *css, + struct cgroup_taskset *tset) { struct task_struct *task; struct io_context *ioc; int ret = 0; /* task_lock() is needed to avoid races with exit_io_context() */ - cgroup_taskset_for_each(task, cgrp, tset) { + cgroup_taskset_for_each(task, css, tset) { task_lock(task); ioc = task->io_context; if (ioc && atomic_read(&ioc->nr_tasks) > 1) @@ -973,8 +977,6 @@ int blkcg_activate_policy(struct request_queue *q, ret = PTR_ERR(blkg); goto out_unlock; } - q->root_blkg = blkg; - q->root_rl.blkg = blkg; list_for_each_entry(blkg, &q->blkg_list, q_node) cnt++; @@ -1127,7 +1129,7 @@ void blkcg_policy_unregister(struct blkcg_policy *pol) /* kill the intf files first */ if (pol->cftypes) - cgroup_rm_cftypes(&blkio_subsys, pol->cftypes); + cgroup_rm_cftypes(pol->cftypes); /* unregister and update blkgs */ blkcg_policy[pol->plid] = NULL; |