[libvirt] [PATCH] nwfilter: re-order lock grabbed by IP addr. learn thread

[Stefan Berger]

On 11/19/2010 02:49 PM, Eric Blake wrote:
> On 11/18/2010 05:16 AM, Stefan Berger wrote:
>> The IP address learning thread was causing a deadlock when it
>> instantiated a filter while a filter update/change was ongoing. The
>> reason for this was the ordering of locks due to the following calls
>>
>> virNWFilterUnlockFilterUpdates()
>> virNWFilterPoolObjFindByName()
>>
>> + * Call this function while holding the NWFilter filter update lock
>>   static int
>>   __virNWFilterInstantiateFilter(virConnectPtr conn,
> I'm assuming that's a bogus line in your patch,
Yes, incomplete conversion from // to /* style comment. Fixed.
>>                                  bool teardownOld,
>> @@ -823,23 +822,30 @@ _virNWFilterInstantiateFilter(virConnect
>>                             ? net->data.direct.linkdev
>>                             : NULL;
>>       int ifindex;
>> +    int rc;
>>
>>       if (ifaceGetIndex(true, net->ifname,&ifindex))
>>           return 1;
> ...
>> +    virNWFilterLockFilterUpdates();
>> +
>> +    rc = __virNWFilterInstantiateFilter(conn,
> ...especially given the fact that you grab the lock here, so
> __virNWFilterInstantiateFilter should NOT have the filter update lock in
> the caller.
>
> ACK, once you fix that compilation error due to the stray line.
>
Pushed.

    Stefan