Re: [Qemu-devel] [PATCH v9 2/3] quorum: implement bdrv_add_child() and bdrv_del_child()

[Wen Congyang]

On 01/20/2016 11:43 PM, Alberto Garcia wrote:
> On Fri 25 Dec 2015 10:22:55 AM CET, Changlong Xie wrote:
>> @@ -875,9 +878,9 @@ static int quorum_open(BlockDriverState *bs, QDict 
>> *options, int flags,
>>          ret = -EINVAL;
>>          goto exit;
>>      }
>> -    if (s->num_children < 2) {
>> +    if (s->num_children < 1) {
>>          error_setg(&local_err,
>> -                   "Number of provided children must be greater than 1");
>> +                   "Number of provided children must be 1 or more");
>>          ret = -EINVAL;
>>          goto exit;
>>      }
> 
> I have a question: if you have a Quorum with just one member and you add
> a new one, how do you know if it has the same data as the existing one?
> 
> In general, what do you do to make sure that the data in a new Quorum
> child is consistent with that of the rest of the array?

Quorum can have more than one child when it starts. But we don't do the
similar check. So I don't think we should do such check here.

Thanks
Wen Congyang

> 
> Berto
> 
> 
> .
>