Re: [Qemu-devel] [PATCH 2/3] block: Add QMP support for streaming to an intermediate layer

[Kevin Wolf]

Am 23.02.2015 um 13:23 hat Alberto Garcia geschrieben:
> On Fri, Feb 20, 2015 at 03:38:04PM -0700, Eric Blake wrote:
> 
> > > +    if (has_top) {
> > > +        top_bs = bdrv_find_backing_image(bs, top);
> > > +        if (top_bs == NULL) {
> > > +            error_set(errp, QERR_TOP_NOT_FOUND, top);
> > > +            goto out;
> > > +        }
> > 
> > If I understand correctly, bdrv_find_backing_image has problems for
> > backing nodes that don't have a file name.  Given our shift towards
> > node names, I think we really want to target node names rather than
> > file names when specifying which node we will use as the top bound
> > receiving the stream operations.
> 
> Sure I can change that, but note that the 'base' parameter also
> receives a file name and uses bdrv_find_backing_image, so I guess it
> makes sense to change it in both sides.

Yes, using the file name for identifying nodes was a mistake. We're
going to replace all occurrences of it sooner or later. Not sure if
someone is actively working on this currently - Markus?

For your patch series, I think it's good enough to use node names for
the new parameter. Converting old parameters is a separate issue.

Kevin