When blkg is removed from q->blkg_list from blkg_free_workfn(), queue_lock
has to be held, otherwise, all kinds of bugs(list corruption, hard lockup,
..) can be triggered from blkg_destroy_all().
Fixes: f1c006f1c685 ("blk-cgroup: synchronize pd_free_fn() from blkg_free_workfn() and blkcg_deactivate_policy()")
Cc: Yu Kuai <yukuai3@xxxxxxxxxx>
Cc: xiaoli feng <xifeng@xxxxxxxxxx>
Cc: Chunyu Hu <chuhu@xxxxxxxxxx>
Cc: Mike Snitzer <snitzer@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
block/blk-cgroup.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index fc49be622e05..9faafcd10e17 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -136,7 +136,9 @@ static void blkg_free_workfn(struct work_struct *work)
blkcg_policy[i]->pd_free_fn(blkg->pd[i]);
if (blkg->parent)
blkg_put(blkg->parent);
+ spin_lock_irq(&q->queue_lock);
list_del_init(&blkg->q_node);
+ spin_unlock_irq(&q->queue_lock);
mutex_unlock(&q->blkcg_mutex);
blk_put_queue(q);
--
2.40.1
