diff options
| -rw-r--r-- | block/blk-cgroup.c | 43 | ||||
| -rw-r--r-- | block/blk-cgroup.h | 2 | ||||
| -rw-r--r-- | block/blk-throttle.c | 3 | ||||
| -rw-r--r-- | block/cfq-iosched.c | 4 |
4 files changed, 32 insertions, 20 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 76942360872..d42d826ece3 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -37,6 +37,7 @@ static int blkiocg_can_attach(struct cgroup_subsys *, struct cgroup *, struct cgroup_taskset *); static void blkiocg_attach(struct cgroup_subsys *, struct cgroup *, struct cgroup_taskset *); +static int blkiocg_pre_destroy(struct cgroup_subsys *, struct cgroup *); static void blkiocg_destroy(struct cgroup_subsys *, struct cgroup *); static int blkiocg_populate(struct cgroup_subsys *, struct cgroup *); @@ -51,10 +52,10 @@ struct cgroup_subsys blkio_subsys = { .create = blkiocg_create, .can_attach = blkiocg_can_attach, .attach = blkiocg_attach, + .pre_destroy = blkiocg_pre_destroy, .destroy = blkiocg_destroy, .populate = blkiocg_populate, .subsys_id = blkio_subsys_id, - .use_id = 1, .module = THIS_MODULE, }; EXPORT_SYMBOL_GPL(blkio_subsys); @@ -442,6 +443,7 @@ struct blkio_group *blkg_lookup_create(struct blkio_cgroup *blkcg, if (blkg) return blkg; + /* blkg holds a reference to blkcg */ if (!css_tryget(&blkcg->css)) return ERR_PTR(-EINVAL); @@ -463,15 +465,16 @@ struct blkio_group *blkg_lookup_create(struct blkio_cgroup *blkcg, spin_lock_init(&new_blkg->stats_lock); rcu_assign_pointer(new_blkg->q, q); - new_blkg->blkcg_id = css_id(&blkcg->css); + new_blkg->blkcg = blkcg; new_blkg->plid = plid; cgroup_path(blkcg->css.cgroup, new_blkg->path, sizeof(new_blkg->path)); + } else { + css_put(&blkcg->css); } rcu_read_lock(); spin_lock_irq(q->queue_lock); - css_put(&blkcg->css); /* did bypass get turned on inbetween? */ if (unlikely(blk_queue_bypass(q)) && !for_root) { @@ -500,6 +503,7 @@ out: if (new_blkg) { free_percpu(new_blkg->stats_cpu); kfree(new_blkg); + css_put(&blkcg->css); } return blkg; } @@ -508,7 +512,6 @@ EXPORT_SYMBOL_GPL(blkg_lookup_create); static void __blkiocg_del_blkio_group(struct blkio_group *blkg) { hlist_del_init_rcu(&blkg->blkcg_node); - blkg->blkcg_id = 0; } /* @@ -517,24 +520,17 @@ static void __blkiocg_del_blkio_group(struct blkio_group *blkg) */ int blkiocg_del_blkio_group(struct blkio_group *blkg) { - struct blkio_cgroup *blkcg; + struct blkio_cgroup *blkcg = blkg->blkcg; unsigned long flags; - struct cgroup_subsys_state *css; int ret = 1; - rcu_read_lock(); - css = css_lookup(&blkio_subsys, blkg->blkcg_id); - if (css) { - blkcg = container_of(css, struct blkio_cgroup, css); - spin_lock_irqsave(&blkcg->lock, flags); - if (!hlist_unhashed(&blkg->blkcg_node)) { - __blkiocg_del_blkio_group(blkg); - ret = 0; - } - spin_unlock_irqrestore(&blkcg->lock, flags); + spin_lock_irqsave(&blkcg->lock, flags); + if (!hlist_unhashed(&blkg->blkcg_node)) { + __blkiocg_del_blkio_group(blkg); + ret = 0; } + spin_unlock_irqrestore(&blkcg->lock, flags); - rcu_read_unlock(); return ret; } EXPORT_SYMBOL_GPL(blkiocg_del_blkio_group); @@ -1387,7 +1383,8 @@ static int blkiocg_populate(struct cgroup_subsys *subsys, struct cgroup *cgroup) ARRAY_SIZE(blkio_files)); } -static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup) +static int blkiocg_pre_destroy(struct cgroup_subsys *subsys, + struct cgroup *cgroup) { struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup); unsigned long flags; @@ -1396,6 +1393,7 @@ static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup) struct blkio_policy_type *blkiop; rcu_read_lock(); + do { spin_lock_irqsave(&blkcg->lock, flags); @@ -1425,8 +1423,15 @@ static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup) spin_unlock(&blkio_list_lock); } while (1); - free_css_id(&blkio_subsys, &blkcg->css); rcu_read_unlock(); + + return 0; +} + +static void blkiocg_destroy(struct cgroup_subsys *subsys, struct cgroup *cgroup) +{ + struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup); + if (blkcg != &blkio_root_cgroup) kfree(blkcg); } diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h index 7ebecf6ea8f..ca1fc637bd6 100644 --- a/block/blk-cgroup.h +++ b/block/blk-cgroup.h @@ -163,7 +163,7 @@ struct blkio_group { /* Pointer to the associated request_queue, RCU protected */ struct request_queue __rcu *q; struct hlist_node blkcg_node; - unsigned short blkcg_id; + struct blkio_cgroup *blkcg; /* Store cgroup path */ char path[128]; /* policy which owns this blk group */ diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 52a429397d3..fe6a442b848 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -169,6 +169,9 @@ static void throtl_put_tg(struct throtl_grp *tg) if (!atomic_dec_and_test(&tg->ref)) return; + /* release the extra blkcg reference this blkg has been holding */ + css_put(&tg->blkg.blkcg->css); + /* * A group is freed in rcu manner. But having an rcu lock does not * mean that one can access all the fields of blkg and assume these diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index f67d109eb97..9ef86fbfc9a 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -1133,6 +1133,10 @@ static void cfq_put_cfqg(struct cfq_group *cfqg) cfqg->ref--; if (cfqg->ref) return; + + /* release the extra blkcg reference this blkg has been holding */ + css_put(&cfqg->blkg.blkcg->css); + for_each_cfqg_st(cfqg, i, j, st) BUG_ON(!RB_EMPTY_ROOT(&st->rb)); free_percpu(cfqg->blkg.stats_cpu); |