From: Yahu Gao <yahugao@xxxxxxxxxxxxxx>
Some inode pinned dying memory cgroup and its parent destroyed at first.
The parent's pd of iocost won't be allocated during function
blkcg_activate_policy.
Ignore the DYING CSS to avoid kernel NULL during iocost policy data init.
Signed-off-by: Yahu Gao <yahugao@xxxxxxxxxxxxxx>
Signed-off-by: Kunhai Dai <daikunhai@xxxxxxxxxxxxxx>
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index a91f8ae18b49..32472de2e61d 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1418,6 +1418,9 @@ int blkcg_activate_policy(struct request_queue *q,
list_for_each_entry_reverse(blkg, &q->blkg_list, q_node) {
struct blkg_policy_data *pd;
+ if (blkg->blkcg->css.flags & CSS_DYING)
+ continue;
+
if (blkg->pd[pol->plid])
continue;
@@ -1459,8 +1462,11 @@ int blkcg_activate_policy(struct request_queue *q,
/* all allocated, init in the same order */
if (pol->pd_init_fn)
- list_for_each_entry_reverse(blkg, &q->blkg_list, q_node)
+ list_for_each_entry_reverse(blkg, &q->blkg_list, q_node) {
+ if (blkg->blkcg->css.flags & CSS_DYING)
+ continue;
pol->pd_init_fn(blkg->pd[pol->plid]);
+ }
__set_bit(pol->plid, q->blkcg_pols);
ret = 0;
--
2.30.1
