On 04/26/2018 12:40 PM, Marc Hartmayer wrote:
> On Thu, Apr 26, 2018 at 05:08 PM +0200, John Ferlan <jferlan@xxxxxxxxxx> wrote:
>> On 04/12/2018 08:41 AM, Marc Hartmayer wrote:
>>> No lock is required to access 'priv->conn' therefore we can shrink the
>>> critical sections.
>>>
>>> Signed-off-by: Marc Hartmayer <mhartmay@xxxxxxxxxxxxxxxxxx>
>>> Reviewed-by: Boris Fiuczynski <fiuczy@xxxxxxxxxxxxx>
>>> ---
>>> src/remote/remote_daemon_dispatch.c | 8 ++++----
>>> 1 file changed, 4 insertions(+), 4 deletions(-)
>>>
>>
>> While this follows other usages, that means virMutexUnlock in cleanup:
>> may be called without holding the lock.
>
> Yep. I saw it… another patch was in planning :)
>
>>
>> Perhaps this and other *Register/*Deregister API's should take the lock
>> around anything that could end up in cleanup - perhaps even the same
>> history as the previous patch
>
> This may lead to locking issues and it would increase the critical
> sections for “no reason”.
>
> What’s about:
> Add another goto-label? Not beautiful but it would work.
>
That option could work too... I was thinking more about how to avoid the
call Unlock when we don't have the lock. Probably doesn't matter how
it's done.
John
>>
>> John
>>
>>> diff --git a/src/remote/remote_daemon_dispatch.c b/src/remote/remote_daemon_dispatch.c
>>> index 041e7c7440bf..d6699418392e 100644
>>> --- a/src/remote/remote_daemon_dispatch.c
>>> +++ b/src/remote/remote_daemon_dispatch.c
>>> @@ -3841,8 +3841,6 @@ remoteDispatchConnectRegisterCloseCallback(virNetServerPtr server,
>>> virNetServerClientGetPrivateData(client);
>>> virNetServerProgramPtr program;
>>>
>>> - virMutexLock(&priv->lock);
>>> -
>>> if (!priv->conn) {
>>> virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("connection not open"));
>>> goto cleanup;
>>> @@ -3853,6 +3851,8 @@ remoteDispatchConnectRegisterCloseCallback(virNetServerPtr server,
>>> goto cleanup;
>>> }
>>>
>>> + virMutexLock(&priv->lock);
>>> +
>>> if (VIR_ALLOC(callback) < 0)
>>> goto cleanup;
>>> callback->client = virObjectRef(client);
>>> @@ -3887,13 +3887,13 @@ remoteDispatchConnectUnregisterCloseCallback(virNetServerPtr server ATTRIBUTE_UN
>>> struct daemonClientPrivate *priv =
>>> virNetServerClientGetPrivateData(client);
>>>
>>> - virMutexLock(&priv->lock);
>>> -
>>> if (!priv->conn) {
>>> virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("connection not open"));
>>> goto cleanup;
>>> }
>>>
>>> + virMutexLock(&priv->lock);
>>> +
>>> if (virConnectUnregisterCloseCallback(priv->conn,
>>> remoteRelayConnectionClosedEvent) < 0)
>>> goto cleanup;
>>>
>>
> --
> Beste Grüße / Kind regards
> Marc Hartmayer
>
> IBM Deutschland Research & Development GmbH
> Vorsitzende des Aufsichtsrats: Martina Koederitz
> Geschäftsführung: Dirk Wittkopp
> Sitz der Gesellschaft: Böblingen
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>
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