On 11/10/2014 06:45 AM, Max Reitz wrote:
> If a reference count is not representable with the current refcount
> order, the image check should point to qemu-img amend for increasing the
> refcount order. However, qemu-img amend needs write access to the image
> which cannot be provided if the image is marked corrupt; and the image
> check will not mark the image consistent unless everything actually is
> consistent.
> 
> Therefore, if an image is marked corrupt and the image check encounters
> a reference count overflow, it cannot be fixed by using qemu-img amend
> to increase the refcount order. Instead, one has to use qemu-img convert
> to create a completely new copy of the image in this case.
> 
> Alternatively, we may want to give the user a way of manually removing
> the corrupt flag, maybe through qemu-img amend, but this is not part of
> this patch.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
>  block/qcow2-refcount.c | 3 +++
>  1 file changed, 3 insertions(+)

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org