Re: [libvirt] [PATCH] Fix deadlock in QEMU close callback APIs

On Thu, Feb 28, 2013 at 13:33:31 +0000, Daniel P. Berrange wrote: > From: "Daniel P. Berrange" <berrange(a)redhat.com&gt; > > 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?