Re: [Qemu-devel] [PATCH v2 7/7] qemu-iotests: add 039 qcow2 lazy refcounts test

[Kevin Wolf]

Am 27.07.2012 09:56, schrieb Stefan Hajnoczi:
> On Thu, Jul 26, 2012 at 2:28 PM, Kevin Wolf <address@hidden> wrote:
>> Am 25.07.2012 14:21, schrieb Stefan Hajnoczi:
>>> +== Read-only access must still work ==
>>> +read 512/512 bytes at offset 0
>>> +512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
>>> +incompatible_features     0x1
>>> +
>>> +== Repairing the image file must succeed ==
>>> +ERROR OFLAG_COPIED: offset=8000000000050000 refcount=0
>>> +Repairing cluster 5 refcount=0 reference=1
>>> +No errors were found on the image.
>>> +incompatible_features     0x0
>>
>> I wonder what happened to the "The following inconsistencies were found
>> and repaired" message. Most likely not a problem with qemu-iotests,
>> though, but something unexpected in qemu-img.
> 
> It's because opening a qcow2 image read/write when the dirty flag is
> set causes a repair.  This accounts for the "Repairing cluster 5 ..."
> message.
> 
> Then qemu-img check -r all calls bdrv_check() on an already repaired
> image file and we get the "No errors were found on the image".

I see. Not exactly how it was intended... Do we need a BDRV_O_CHECK flag
that prevents the automatic repair or should we just live with the
suboptimal output when lazy refcounting is enabled?

Kevin