diff mbox series

blk-cgroup: hold queue_lock when removing blkg->q_node

Message ID 20230817141751.1128970-1-ming.lei@redhat.com (mailing list archive)
State New, archived
Headers show
Series blk-cgroup: hold queue_lock when removing blkg->q_node | expand

Commit Message

Ming Lei Aug. 17, 2023, 2:17 p.m. UTC 
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>
---
 block/blk-cgroup.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Tejun Heo Aug. 17, 2023, 4:42 p.m. UTC | #1 
On Thu, Aug 17, 2023 at 10:17:51PM +0800, Ming Lei wrote:
> 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>

Thanks.
Jens Axboe Aug. 18, 2023, 1:16 a.m. UTC | #2 
On Thu, 17 Aug 2023 22:17:51 +0800, Ming Lei wrote:
> 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().
> 
> 

Applied, thanks!

[1/1] blk-cgroup: hold queue_lock when removing blkg->q_node
      commit: 94254d59c0d22ecf9fdd1a18dd03652fc6be19e5

Best regards,
diff mbox series

Patch

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);