On Thu, Feb 28, 2013 at 02:50:34PM +0100, Jiri Denemark wrote: > On Thu, Feb 28, 2013 at 13:33:31 +0000, Daniel P. Berrange wrote: > > From: "Daniel P. Berrange" <berrange@xxxxxxxxxx> > > > > There is a lock ordering problem in the QEMU close callback > > APIs. > > > > When starting a guest we have a lock on the VM. We then > > set a autodestroy callback, which acquires a lock on the > > close callbacks. > > > > When running auto-destroy, we obtain a lock on the close > > callbacks, then run each callbacks - which obtains a lock > > on the VM. > > > > This causes deadlock if anyone tries to start a VM, while > > autodestroy is taking place. > > > > The fix is to do autodestroy in 2 phases. First obtain > > all the callbacks and remove them from the list under > > the close callback lock. Then invoke each callback > > from outside the close callback lock. > > Looks like we can just remove 568a6cda277f04ab9baaeb97490e548b7b608aa6 > then, can't we? Quite possibly. I'll investigate that further, and test what happens. Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :| -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list