From: Ming Lei <ming.lei@xxxxxxxxxx>
commit c164c7bc9775be7bcc68754bb3431fce5823822e upstream.
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>
Acked-by: Tejun Heo <tj@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230817141751.1128970-1-ming.lei@xxxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
block/blk-cgroup.c | 2 ++
1 file changed, 2 insertions(+)
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -136,7 +136,9 @@ static void blkg_free_workfn(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);
