Am 11.09.2019 um 13:00 hat Max Reitz geschrieben:
> On 11.09.19 12:31, Kevin Wolf wrote:
> > Am 11.09.2019 um 12:00 hat Max Reitz geschrieben:
> >> So all in all I think it’s best to make the callback mandatory and add
> >> two global helper functions.  That’s simple enough and should prevent
> >> us from making mistakes by forgetting to adjust something in the
> >> future.
> > 
> > Yes, that should work.
> > 
> > We should probably still figure out what the relationship between the
> > child access functions and child roles is, even if we don't need it for
> > this solution. But it feels like an important part of the design.
> 
> Hm.  It feels like something that should be done before this series,
> actually.
> 
> So I think we should add at least a child role per child access function
> so that they match?  And then maybe in bdrv_attach_child() assert that a
> BDS never has more than one primary or filtered child (a filtered child
> acts as a primary child, too), or more than one COW child.  (And that
> these are always in bs->file or bs->backing so the child access
> functions do work.)

Makes sense to me.

Kevin