Re: [RFC][PATCH 0/3] configfs: Make nested default groups lockdep-friendly

[Peter Zijlstra <a.p.zijlstra@chello.nl>]

On Tue, 2008-05-20 at 16:51 -0700, Joel Becker wrote:
> On Tue, May 20, 2008 at 03:35:43PM -0700, Arjan van de Ven wrote:
> > not quite what I meant; what I meant is more like how sched.c deals
> > with per cpu queues:
> > 
> > (from sched.c)
> > 
> >                 spin_lock_init(&rq->lock);
> >                 lockdep_set_class(&rq->lock, &rq->rq_lock_key); 
> 
> 	Looking at this, it's taking the address of the struct
> lock_class_key as the actual key.  Thus, if we tie one of these guys to
> the structure we're representing, we get lock safety...except that we're
> talking about i_mutex here, and we want to interact with the VFS's use
> thereof.

Also bear in mind that the lock_class_key structure must be in static
storage.