From f427d909648aa592c9588d0f66b5b457752a0cd1 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 9 Jan 2013 08:05:12 -0800 Subject: blkcg: implement blkcg_policy->on/offline_pd_fn() and blkcg_gq->online Add two blkcg_policy methods, ->online_pd_fn() and ->offline_pd_fn(), which are invoked as the policy_data gets activated and deactivated while holding both blkcg and q locks. Also, add blkcg_gq->online bool, which is set and cleared as the blkcg_gq gets activated and deactivated. This flag also is toggled while holding both blkcg and q locks. These will be used to implement hierarchical stats. Signed-off-by: Tejun Heo Acked-by: Vivek Goyal --- block/blk-cgroup.c | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) (limited to 'block/blk-cgroup.c') diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 3a8de321d1f6..4d625d28e070 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -182,7 +182,7 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, struct blkcg_gq *new_blkg) { struct blkcg_gq *blkg; - int ret; + int i, ret; WARN_ON_ONCE(!rcu_read_lock_held()); lockdep_assert_held(q->queue_lock); @@ -218,7 +218,15 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, if (likely(!ret)) { hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list); list_add(&blkg->q_node, &q->blkg_list); + + for (i = 0; i < BLKCG_MAX_POLS; i++) { + struct blkcg_policy *pol = blkcg_policy[i]; + + if (blkg->pd[i] && pol->pd_online_fn) + pol->pd_online_fn(blkg); + } } + blkg->online = true; spin_unlock(&blkcg->lock); if (!ret) @@ -291,6 +299,7 @@ EXPORT_SYMBOL_GPL(blkg_lookup_create); static void blkg_destroy(struct blkcg_gq *blkg) { struct blkcg *blkcg = blkg->blkcg; + int i; lockdep_assert_held(blkg->q->queue_lock); lockdep_assert_held(&blkcg->lock); @@ -299,6 +308,14 @@ static void blkg_destroy(struct blkcg_gq *blkg) WARN_ON_ONCE(list_empty(&blkg->q_node)); WARN_ON_ONCE(hlist_unhashed(&blkg->blkcg_node)); + for (i = 0; i < BLKCG_MAX_POLS; i++) { + struct blkcg_policy *pol = blkcg_policy[i]; + + if (blkg->pd[i] && pol->pd_offline_fn) + pol->pd_offline_fn(blkg); + } + blkg->online = false; + radix_tree_delete(&blkcg->blkg_tree, blkg->q->id); list_del_init(&blkg->q_node); hlist_del_init_rcu(&blkg->blkcg_node); @@ -956,6 +973,8 @@ void blkcg_deactivate_policy(struct request_queue *q, /* grab blkcg lock too while removing @pd from @blkg */ spin_lock(&blkg->blkcg->lock); + if (pol->pd_offline_fn) + pol->pd_offline_fn(blkg); if (pol->pd_exit_fn) pol->pd_exit_fn(blkg); -- cgit v1.2.3