[CRIU] [PATCH 4/7] btrfs: Introduce BTRFS engine

[Cyrill Gorcunov]

On Wed, Dec 04, 2013 at 05:47:06PM +0400, Pavel Emelyanov wrote:
> 
> > +	BUG_ON(m->private);
> > +	m->private = (void *)result;
> > +	btrfs_show_subvolumes(r);
> 
> That's the only place where mi->private is used. IOW -- it's now write-only field.

Yes, but I would like to keep it because btrfs engine replies on mount-info entities,
so treat it as "used" flag kept on mount-info, also BUG_ON(m->private) makes sense
here as well and protects us from occasional seond attempt to re-parse same entry.