Re: [RFC PATCH v3 07/27] qcow2: Add subcluster-related fields to BDRVQcow2State

[Eric Blake]

On 2/20/20 10:34 AM, Alberto Garcia wrote:
> On Thu 20 Feb 2020 04:28:07 PM CET, Eric Blake wrote:
> > > Images without subclusters are treated as if they had exactly one,
> > > with subcluster_size = cluster_size.
> >
> > The qcow2 spec changes earlier in the series made it sound like your
> > choices are exactly 1 or 32,
>
> > > +#define QCOW_MAX_SUBCLUSTERS_PER_CLUSTER 32
> > > +
> >
> > ...but this name sounds like other values (2, 4, 8, 16) might be
> > possible?
>
> I guess I didn't want to call it QCOW_SUBCLUSTERS_PER_CLUSTER because
> there's already BDRVQcow2State.subclusters_per_cluster. And that one can
> have two possible values (1 and 32) so 32 would be the maximum.
>
> I get your point, however, and I'm open to suggestions.

Maybe QCOW_EXTL2_SUBCLUSTERS_PER_CLUSTER

since it is a hard-coded property of the EXTL2 feature.

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
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