From: Ming Lei ming.lei@redhat.com
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@huawei.com Cc: xiaoli feng xifeng@redhat.com Cc: Chunyu Hu chuhu@redhat.com Cc: Mike Snitzer snitzer@kernel.org Cc: Tejun Heo tj@kernel.org Signed-off-by: Ming Lei ming.lei@redhat.com Acked-by: Tejun Heo tj@kernel.org Link: https://lore.kernel.org/r/20230817141751.1128970-1-ming.lei@redhat.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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);