Re: [Qemu-devel] [PATCH] migration: fix small leaks

[Peter Xu <peterx@redhat.com>]

On Tue, Jan 02, 2018 at 03:19:38PM +0000, Dr. David Alan Gilbert wrote:
> * Vladimir Sementsov-Ogievskiy (vsementsov@virtuozzo.com) wrote:
> > 28.12.2017 05:19, Peter Xu wrote:
> > > On Wed, Dec 27, 2017 at 03:25:23PM +0300, Vladimir Sementsov-Ogievskiy wrote:
> > > > Hi all!
> > > > 
> > > > Hmm, looks like leak is not fixed here: I've checked it while running iotest
> > > > 181, that
> > > > migration_instance_finalize is not called.
> > > > 
> > > > If I understand correct, to call it we need unref current_migration object
> > > > somewhere.
> > > > 
> > > > Or, may be I'm missing something..
> > > I think you are right.
> > > 
> > > It does not matter much though since we don't dynamically allocate
> > > migration object (there is only one and it lives forever).  Do you
> > > want to post a patch?  I guess the safest place to unref it is at the
> > > end of main() to make sure no one will be using it any more.
> > > 
> > > (Hmm, the incoming migration state is still static)
> > > 
> > > Thanks,
> > 
> > Ok, I'll send a patch.
> 
> Be very very careful that it doesn't crash in cases like quit in the main thread
> while a migration is still running.

Agree.

> 
> I have no problem with this object living forever and letting it just
> die with exit().

Yes.  But if better, I am thinking whether we should always make sure
migration is completed/failed/cancelled before that point.  If we quit
QEMU with a working migration stream, logically we should stop it
before leaving, as part of QEMU's cleanup path.

-- 
Peter Xu