[libvirt] [PATCH 1/2] conf: Format the "nocow" field.

[John Ferlan]

On 12/09/2016 09:52 AM, Martin Kletzander wrote:
> On Fri, Dec 09, 2016 at 03:38:09PM +0100, Michal Privoznik wrote:
>> On 07.12.2016 16:31, John Ferlan wrote:
>>> Commit id 'a9fd30e63' added a '<nocow/>' field to be parsed, but
>>> didn't Format the field on output. This patch fixes that and adds
>>> the vol-qcow2-nocow test to/for storagevolxml2xml
>>>
>>> Signed-off-by: John Ferlan <jferlan at redhat.com>
>>> ---
>>>  src/conf/storage_conf.c                        | 2 ++
>>>  tests/storagevolxml2xmlout/vol-qcow2-nocow.xml | 1 +
>>>  tests/storagevolxml2xmltest.c                  | 1 +
>>>  3 files changed, 4 insertions(+)
>>>
>>> diff --git a/src/conf/storage_conf.c b/src/conf/storage_conf.c
>>> index 7e7bb72..dc7cc25 100644
>>> --- a/src/conf/storage_conf.c
>>> +++ b/src/conf/storage_conf.c
>>> @@ -1590,6 +1590,8 @@
>>> virStorageVolTargetDefFormat(virStorageVolOptionsPtr options,
>>>              return -1;
>>>
>>>      virBufferEscapeString(buf, "<compat>%s</compat>\n", def->compat);
>>> +    if (def->nocow)
>>> +        virBufferAddLit(buf, "<nocow/>\n");
>>>
>>
>> I wonder whether we should detect this flag over a volume and set it so
>> that vol-dumpxml reports the flag even after libvirtd restart.
>>
> 
> Well, I don't think we output things we cannot detect (like
> "prealloc_metadata") which we accept on input.  So if we output it, we
> need to be able to detect it.  If we only accept it on input, then we
> should not output it (because we cannot guarantee reproducibility after
> daemon restart).
> 
> Martin
> 
>> Michal


Hmmm. detection after restart would only be possible if we can probe the
file and so far it only matters for btrfs...

Ummm.. I'll just drop this then


John