diff options
Diffstat (limited to 'block/blk-cgroup.c')
| -rw-r--r-- | block/blk-cgroup.c | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index c15a26096038..c5dc833212e1 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -883,8 +883,8 @@ static void blkcg_css_offline(struct cgroup_subsys_state *css) /* this prevents anyone from attaching or migrating to this blkcg */ wb_blkcg_offline(blkcg); - /* put the base cgwb reference allowing step 2 to be triggered */ - blkcg_cgwb_put(blkcg); + /* put the base online pin allowing step 2 to be triggered */ + blkcg_unpin_online(blkcg); } /** @@ -983,11 +983,11 @@ blkcg_css_alloc(struct cgroup_subsys_state *parent_css) } spin_lock_init(&blkcg->lock); + refcount_set(&blkcg->online_pin, 1); INIT_RADIX_TREE(&blkcg->blkg_tree, GFP_NOWAIT | __GFP_NOWARN); INIT_HLIST_HEAD(&blkcg->blkg_list); #ifdef CONFIG_CGROUP_WRITEBACK INIT_LIST_HEAD(&blkcg->cgwb_list); - refcount_set(&blkcg->cgwb_refcnt, 1); #endif list_add_tail(&blkcg->all_blkcgs_node, &all_blkcgs); @@ -1006,6 +1006,21 @@ unlock: return ret; } +static int blkcg_css_online(struct cgroup_subsys_state *css) +{ + struct blkcg *blkcg = css_to_blkcg(css); + struct blkcg *parent = blkcg_parent(blkcg); + + /* + * blkcg_pin_online() is used to delay blkcg offline so that blkgs + * don't go offline while cgwbs are still active on them. Pin the + * parent so that offline always happens towards the root. + */ + if (parent) + blkcg_pin_online(parent); + return 0; +} + /** * blkcg_init_queue - initialize blkcg part of request queue * @q: request_queue to initialize @@ -1199,6 +1214,7 @@ static void blkcg_exit(struct task_struct *tsk) struct cgroup_subsys io_cgrp_subsys = { .css_alloc = blkcg_css_alloc, + .css_online = blkcg_css_online, .css_offline = blkcg_css_offline, .css_free = blkcg_css_free, .can_attach = blkcg_can_attach, |