Re: [PATCH v2 4/4] lockdep: Assign a lock_class per gendisk used for wait_for_completion()

[Christoph Hellwig <hch@infradead.org>]

On Mon, Oct 23, 2017 at 08:53:35AM +0900, Byungchul Park wrote:
> On Fri, Oct 20, 2017 at 07:44:51AM -0700, Christoph Hellwig wrote:
> > The Subject prefix for this should be "block:".
> > 
> > > @@ -945,7 +945,7 @@ int submit_bio_wait(struct bio *bio)
> > >  {
> > >  	struct submit_bio_ret ret;
> > >  
> > > -	init_completion(&ret.event);
> > > +	init_completion_with_map(&ret.event, &bio->bi_disk->lockdep_map);
> > 
> > FYI, I have an outstanding patch to simplify this a lot, which
> > switches this to DECLARE_COMPLETION_ONSTACK.  I can delay this or let
> > you pick it up with your series, but we'll need a variant of
> > DECLARE_COMPLETION_ONSTACK with the lockdep annotations.
> 
> Hello,
> 
> I'm sorry for late.
> 
> I think your patch makes block code simpler and better. I like it.
> 
> But, I just wonder if it's related to my series.

Because it shows that we also need a version of DECLARE_COMPLETION_ONSTACK
the gets passed an explicit lockdep map.  And because if it was merged
through a different tree it would create a conflict.

> Is it proper to add
> your patch into my series?

Sure.