Re: [PATCH] block: prevent deadlock in del_gendisk()

[Yu Kuai <yukuai1@xxxxxxxxxxxxxxx>]

在 2025/08/05 19:59, Hillf Danton 写道:
> On Mon, 4 Aug 2025 15:51:48 +0800 Yu Kuai wrote:
> > �� 2025/08/03 21:41, Ujwal Kundur �:
> > > A potential unsafe locking scenario presents itself when
> > > mutex_lock(&disk->open_mutex) is called with reader's lock held on
> > > update_nr_hwq_lock:
> > >          CPU0                    CPU1
> > >          ----                    ----
> > > rlock(&set->update_nr_hwq_lock)
> > >                                  lock(&nbd->config_lock);
> > >                                  lock(&set->update_nr_hwq_lock);
> > > lock(&disk->open_mutex)
> > This problem is already fixed inside nbd by:
> > 8b428f42f3ed ("nbd: fix lockdep deadlock warning")
> Deadlock still exists [1].
This deadlock is a different problem, not what you claimed to fix in
this patch.

Thanks,
Kuai

> [1] https://lore.kernel.org/lkml/6891742c.050a0220.7f033.001a.GAE@xxxxxxxxxx/
> .