Merge tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

[linux-2.6-block.git] / mm / backing-dev.c

diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index f5981e9d6ae2e73761879023584ff378ebfcb1b8..8a8bb8796c6c43cb711c0f618c488df188853623 100644 (file)
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -491,6 +491,7 @@ static void cgwb_release_workfn(struct work_struct *work)
 {
        struct bdi_writeback *wb = container_of(work, struct bdi_writeback,
                                                release_work);
+       struct blkcg *blkcg = css_to_blkcg(wb->blkcg_css);
 
        mutex_lock(&wb->bdi->cgwb_release_mutex);
        wb_shutdown(wb);
@@ -499,6 +500,9 @@ static void cgwb_release_workfn(struct work_struct *work)
        css_put(wb->blkcg_css);
        mutex_unlock(&wb->bdi->cgwb_release_mutex);
 
+       /* triggers blkg destruction if cgwb_refcnt becomes zero */
+       blkcg_cgwb_put(blkcg);
+
        fprop_local_destroy_percpu(&wb->memcg_completions);
        percpu_ref_exit(&wb->refcnt);
        wb_exit(wb);
@@ -597,6 +601,7 @@ static int cgwb_create(struct backing_dev_info *bdi,
                        list_add_tail_rcu(&wb->bdi_node, &bdi->wb_list);
                        list_add(&wb->memcg_node, memcg_cgwb_list);
                        list_add(&wb->blkcg_node, blkcg_cgwb_list);
+                       blkcg_cgwb_get(blkcg);
                        css_get(memcg_css);
                        css_get(blkcg_css);
                }