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Date: Tue, 12 Jun 2012 16:39:11 +0200
From: Paolo Bonzini <pbonzini@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH] qcow2: Simplify calculation for COW area
	at the end
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To: Kevin Wolf <kwolf@redhat.com>
Cc: qemu-devel@nongnu.org

Il 12/06/2012 16:37, Kevin Wolf ha scritto:
>> >        align_offset(m->nb_available+1, s->cluster_sectors)
> Heh, yes, you're thinking about equivalence of the very formula (which
> is what I would do in unknown code as well), whereas I think about a COW
> operation that ranges from a given sector to the end of the same cluster
> (and not the next one).
> 
> It's eventually the same, because this statement is only executed when
> it's not aligned (i.e. the COW range isn't empty):
> 
>    if (m->nb_available & (s->cluster_sectors - 1)) {
>        ...
>    }

Indeed, your version is ok.

Paolo