Re: [Qemu-devel] quorum: validate vote threshold against num_children even if read-pattern is fifo

[Wen Congyang <wency@cn.fujitsu.com>]

On 07/03/2015 04:41 PM, Alberto Garcia wrote:
> On Fri 03 Jul 2015 08:45:06 AM CEST, Wen Congyang wrote:
> 
>> We need to use threshold to check if too many write operation fails.
>> If threshold is larger than num children, we always get write error
>> event even if all write operations success.
>>
>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
>> ---
>>  block/quorum.c | 12 ++++++------
>>  1 file changed, 6 insertions(+), 6 deletions(-)
>>
>> diff --git a/block/quorum.c b/block/quorum.c
>> index a7df17c..b0eead0 100644
>> --- a/block/quorum.c
>> +++ b/block/quorum.c
>> @@ -894,6 +894,12 @@ static int quorum_open(BlockDriverState *bs, QDict *options, int flags,
>>      }
>>  
>>      s->threshold = qemu_opt_get_number(opts, QUORUM_OPT_VOTE_THRESHOLD, 0);
>> +    /* and validate it against s->num_children */
>> +    ret = quorum_valid_threshold(s->threshold, s->num_children, &local_err);
>> +    if (ret < 0) {
>> +        goto exit;
>> +    }
>> +
> 
> I wonder why this check was moved inside the (s->read_pattern ==
> QUORUM_READ_PATTERN_QUORUM) block when the fifo mode was introduced
> (adding Liu Yuan to Cc).
> 
> I assume that you are not going to allow removing children under the
> vote_threshold limit as we discussed, right?

Yes.

Thanks
Wen Congyang

> 
> Reviewed-by: Alberto Garcia <berto@igalia.com>
> 
> Berto
> .
>