Re: [libvirt] [PATCH] qemu: call endjob in RevertToSnapshot

On 08/27/2014 03:20 AM, Jincheng Miao wrote: > On 08/27/2014 11:02 AM, Eric Blake wrote: >> On 08/26/2014 08:10 PM, Jincheng Miao wrote: >>> In qemuDomainRevertToSnapshot(), it will check snap->def->state. >>> But when the state is PMSUSPENDED/NOSTATE/BLOCKED, it forgets to >>> call qemuDomainObjEndJob. >>> >>> Signed-off-by: Jincheng Miao <jmiao(a)redhat.com&gt; >>> --- >>> src/qemu/qemu_driver.c | 4 ++-- >>> 1 files changed, 2 insertions(+), 2 deletions(-) >> This looks like the fix for >> https://bugzilla.redhat.com/show_bug.cgi?id=1134154 - thanks for chasing >> that! > This patch fix the part of that bug, but it doesn't touch the race > condition: > Why the snap->def->state is NOSTATE? It should be RUNNING. > The only reasonable explanation is that snapshot object is free()ed. > > IMHO, the SnapshotObjList should be clocked during snapshot job running. Okay, I see what you are saying; we need to make sure two parallel snapshot operations can't stomp on one another (probably by making them all guarded by the vm job lock).

I hope to have time to look into a fix before 1.2.8; but as it has been a long-standing issue, it's not a new regression in this release if I miss that goal (my priority today is getting 1.2.8 APIs to be feature-complete).