[libvirt] [PATCH v3 2/2] virtlogd: add missing netserver refcount increment on reload

[Nikolay Shirokovskiy]

On 25.10.2017 12:06, John Ferlan wrote:
> 
> 
> On 10/24/2017 06:47 AM, Nikolay Shirokovskiy wrote:
>> After virNetDaemonAddServerPostExec call in virtlogd we should have
>> netserver refcount set to 2. One goes to netdaemon servers hashtable
>> and one goes to virtlogd own reference to netserver. Let's add
>> missing increment in virNetDaemonAddServerPostExec itself while holding
>> daemon lock.
>>
>> We also have to unref new extra ref after virtlockd call to virNetDaemonAddServerPostExec.
>> ---
>>  src/locking/lock_daemon.c | 1 +
>>  src/rpc/virnetdaemon.c    | 1 +
>>  2 files changed, 2 insertions(+)
>>
>> diff --git a/src/locking/lock_daemon.c b/src/locking/lock_daemon.c
>> index fe3eaf9..41a06b2 100644
>> --- a/src/locking/lock_daemon.c
>> +++ b/src/locking/lock_daemon.c
>> @@ -275,6 +275,7 @@ virLockDaemonNewPostExecRestart(virJSONValuePtr object, bool privileged)
>>                                                virLockDaemonClientFree,
>>                                                (void*)(intptr_t)(privileged ? 0x1 : 0x0))))
>>          goto error;
>> +    virObjectUnref(srv);
> 
> I need to think a bit more about this one... different model in lockd
> vs. logd over @srv usage especially w/r/t this particular path.
> 
> I see that in this path eventually something calls virNetDaemonGetServer
> instead of storing the @srv in order to add lockProgram... In any case,> I guess I'd be worried/concerned that something could remove @srv
> causing the Hash table code to unref/delete the srv... Also, in the
> cleanup: path of main() wouldn't the Unref(srv) cause problems?

But this unref only balance newly added ref. If there are other
problems with reference conting in virtlockd - its a different
concern.

> 
> Again- need to think a bit longer.
> 
> John
> 
>>  
>>      return lockd;
>>  
>> diff --git a/src/rpc/virnetdaemon.c b/src/rpc/virnetdaemon.c
>> index 495bc4b..f3e3ffe 100644
>> --- a/src/rpc/virnetdaemon.c
>> +++ b/src/rpc/virnetdaemon.c
>> @@ -312,6 +312,7 @@ virNetDaemonAddServerPostExec(virNetDaemonPtr dmn,
>>  
>>      if (virHashAddEntry(dmn->servers, serverName, srv) < 0)
>>          goto error;
>> +    virObjectRef(srv);
>>  
>>      virJSONValueFree(object);
>>      virObjectUnlock(dmn);
>>