Re: [Qemu-devel] [PATCH 18/21] qcow2: Add function for refcount order amendment

[Max Reitz]

On 2014-11-12 at 15:19, Eric Blake wrote:
> On 11/10/2014 06:45 AM, Max Reitz wrote:
> > Add a function qcow2_change_refcount_order() which allows changing the
> > refcount order of a qcow2 image.
> A thought: didn't you just submit a patch that marked the image as
> dirty, nuked the on-disk refcount, then rebuilt one using the in-memory
> refcounts?  Would reusing THAT code be any better than writing this patch?

Yes, I thought about that, too... The problem is that that patch 
requires all refcount blocks to fit in memory at the same time (or 
generally, the qcow2 check function requires that, for now). I'd really 
like to avoid that, if possible, but maybe it isn't possible after all.

But if you say it like that ("nuke"), I guess I'll give it a try. Maybe 
it looks funny enough.

Max