Re: libvirt: Using rbd_create3 to create format 2 images

[Josh Durgin <josh.durgin@inktank.com>]

On 09/02/2013 07:58 AM, Wido den Hollander wrote:
> On 08/30/2013 08:38 PM, Wido den Hollander wrote:
>> On 08/30/2013 05:26 PM, Josh Durgin wrote:
>>> On 08/30/2013 02:42 AM, Wido den Hollander wrote:
>>>> Hi,
>>>>
>>>> I created the attached patch to have libvirt create images with
>>>> format 2
>>>> by default, this would simplify the CloudStack code and could also help
>>>> other projects.
>>>>
>>>> The problem with libvirt is that there is no mechanism to supply
>>>> information like order, features, stripe unit and count to the
>>>> rbd_create3 method, so it's now hardcoded in libvirt.
>>>>
>>>> Any comments on this patch before I fire it of to the libvirt guys?
>>>
>>> Seems ok to me. They might want you to detect whether the function is
>>> there and compile without it if librbd doesn't support it (rbd_create3
>>> first appeared in bobtail).
>>>
>>
>> Good one. Although I don't think anybody is still running Argonaut I'll
>> do a version check of librbd and switch to rbd_create if needed.
>>
>>
> What do you think of the attached patch Josh?

It be a bit cleaner to make a helper to call the rbd_create() or
rbd_create3() so you only need one check of LIBRBD_VERSION_CODE.

It looks like v0.55 was the first release which contained rbd_create3(),
and the version code for that is 261, so the version code check is off
by one.

Josh