On Mon, Aug 16, 2021 at 09:21:58AM +0200, Christoph Hellwig wrote:
> On Sun, Aug 15, 2021 at 07:27:37AM -0700, Guenter Roeck wrote:
> > [ 14.467748][ T1] Possible unsafe locking scenario:
> > [ 14.467748][ T1]
> > [ 14.467928][ T1] CPU0 CPU1
> > [ 14.468058][ T1] ---- ----
> > [ 14.468187][ T1] lock(&disk->open_mutex);
> > [ 14.468317][ T1] lock(mtd_table_mutex);
> > [ 14.468493][ T1] lock(&disk->open_mutex);
> > [ 14.468671][ T1] lock(mtd_table_mutex);
>
> Oh, that ooks like a really old one, fixed by
> b7abb0516822 ("mtd: fix lock hierarchy in deregister_mtd_blktrans")
> in linux-next.
I have seen the problem in next-20210813 and that patch is there,
so that is somewhat unlikely.
Guenter
