[Libvir] [PATCH] avoid virsh hang due to missing virDomainFree(dom) call

[Daniel P. Berrange]

On Wed, Jan 30, 2008 at 07:00:30PM +0100, Jim Meyering wrote:
> "Daniel P. Berrange" <berrange at redhat.com> wrote:
> >
> > Not, its a bug in virUnrefDomain/Network - it calls mutex_lock() twice
> > in one codepath, instead of calling  unlock().
> >
> > Of course your patch to avoid the memory leak is still needed - so ACK
> > to that, but the locking flaw needs this patch:
> >
> > Index: src/hash.c
> > ===================================================================
> > RCS file: /data/cvs/libvirt/src/hash.c,v
> > retrieving revision 1.29
> > diff -u -p -r1.29 hash.c
> > --- src/hash.c	29 Jan 2008 18:15:54 -0000	1.29
> > +++ src/hash.c	30 Jan 2008 17:42:32 -0000
> > @@ -881,7 +881,7 @@ virUnrefDomain(virDomainPtr domain) {
> >          return (0);
> >      }
> >
> > -    pthread_mutex_lock(&domain->conn->lock);
> > +    pthread_mutex_unlock(&domain->conn->lock);
> >      return (refs);
> >  }
> >
> > @@ -1013,7 +1013,7 @@ virUnrefNetwork(virNetworkPtr network) {
> >          return (0);
> >      }
> >
> > -    pthread_mutex_lock(&network->conn->lock);
> > +    pthread_mutex_unlock(&network->conn->lock);
> >      return (refs);
> >  }
> 
> Oh!  Two locks in a row.
> Amazing that such a problem wasn't exposed sooner.

Well I only committed this flaw last week, so not much time to expose it.
Fixed in CVS now.

Dan.
-- 
|=- Red Hat, Engineering, Emerging Technologies, Boston.  +1 978 392 2496 -=|
|=-           Perl modules: http://search.cpan.org/~danberr/              -=|
|=-               Projects: http://freshmeat.net/~danielpb/               -=|
|=-  GnuPG: 7D3B9505   F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505  -=|