Re: [Qemu-devel] [Nbd] [PATCH v2] doc: Add NBD_CMD_BLOCK_STATUS extension

["Denis V. Lunev" <den@openvz.org>]

On 04/04/2016 11:08 PM, Alex Bligh wrote:
> On 4 Apr 2016, at 21:04, Denis V. Lunev <den@openvz.org> wrote:
>
>>> Sure, but given you can't report dirtiness without also reporting
>>> allocation, if they are are at different blocksize I'd rather they
>>> were in different commands, because otherwise the code to report
>>> block size needs to work at two different granularities.
>>>
>> 'dirty' could come after the data was 'trimmed' from the region!
>> thus we could have dirty unallocated data.
> Let me rephrase.
>
> Under the current proposal it is not possible to report whether or
> not a region is dirty without also reporting whether or not it
> is allocated. As these two concepts exist at potentially
> different block sizes, the code to support reporting on allocation
> must now be able to run both at the allocation blocksize and
> the dirtiness blocksize, which is going to be a pain.
>
> If these were two different commands, they could each run at their
> natural block size.
>
could you look into V1 of this?

As far as I remember that text we have had a number in request
specifying which bitmap to query and the server should reply with one
bitmap at a time.

Would this work for you?