Comment # 6 on bug 1047793 from Michael Albert

Gotcha. So, this is something that could crop up again without a rollback
because any time I trigger a reboot a rescan may be running? That's good to
know, and while I may try the live cd method (thanks for the simple
explanation!), but given that this may rear it's head again any time I reboot
the computer, I may just hold off for the patch to be incorporated into the
standard kernel.

Is there any way to check if a qgroup rescan is running? If so, then I suppose
I could run that before a reboot as a temporary fix.