Re: [Qemu-devel] [PATCH v2 11/11] qmp: add command 'blockdev-backup'

[Wenchao Xia <xiawenc@linux.vnet.ibm.com>]

于 2013-7-18 12:41, Fam Zheng 写道:
> On Wed, 07/17 06:44, Eric Blake wrote:
>> On 07/17/2013 03:42 AM, Fam Zheng wrote:
>>> Similar to drive-backup, but this command uses a device id as target
>>> instead of creating/opening an image file.
>>>
>>> Signed-off-by: Fam Zheng <famz@redhat.com>
>>> ---
>>>   blockdev.c       | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>>   qapi-schema.json | 49 ++++++++++++++++++++++++++++++++++++++
>>>   qmp-commands.hx  | 22 ++++++++++++++++++
>>>   3 files changed, 142 insertions(+)
>>>
>>
>>> +++ b/qapi-schema.json
>>> @@ -1665,6 +1665,40 @@
>>>               '*on-target-error': 'BlockdevOnError' } }
>>>
>>>   ##
>>> +# @BlockdevBackup
>>> +#
>>
>>> +{ 'type': 'BlockdevBackup',
>>> +  'data': { 'device': 'str', 'target': 'str',
>>> +            'sync': 'MirrorSyncMode',
>>> +            '*speed': 'int',
>>> +            '*on-source-error': 'BlockdevOnError',
>>> +            '*on-target-error': 'BlockdevOnError' } }
>>
>> Seems okay.  But what is missing is the addition of this type into the
>> union used for 'transaction' - shouldn't it be possible to mix this with
>> other transaction capabilities?
>>
>
> Should be possible, as users may want point-in-time snapshot of multiple
> disks. If this API looks OK, I will include it into transaction in the
> next version.
>
   Instead of add this new API, how about extend Driver-backup API? This
patch is basically doing similar things with driver-backup, extension
of old API will save trouble to do same things driver-backup already
does, such as support qmp_transaction.

-- 
Best Regards

Wenchao Xia