libvirt: live migration stopped working after shared storage pacthes

[Vladik Romanovsky]

Live migration has stopped working with NFS shared storage, after this patch has been submitted:
https://review.openstack.org/#/c/91722, as one of the new checks doesn't take into account the file based shared storage.

2014-07-17 16:14:14.276 50785 ERROR oslo.messaging.rpc.dispatcher [-] Exception during message handling: local variable 'instance_dir' referenced before assignment
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher Traceback (most recent call last):
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher File "/usr/lib/python2.7/dist-packages/oslo/messaging/rpc/dispatcher.py", line 133, in _dispatch_and_reply
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher incoming.message))
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher File "/usr/lib/python2.7/dist-packages/oslo/messaging/rpc/dispatcher.py", line 176, in _dispatch
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher return self._do_dispatch(endpoint, method, ctxt, args)
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher File "/usr/lib/python2.7/dist-packages/oslo/messaging/rpc/dispatcher.py", line 122, in _do_dispatch
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher result = getattr(endpoint, method)(ctxt, **new_args)
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 393, in decorated_function
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher return function(self, context, *args, **kwargs)
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher File "/usr/lib/python2.7/dist-packages/nova/exception.py", line 88, in wrapped
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher payload)
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher File "/usr/lib/python2.7/dist-packages/nova/openstack/common/excutils.py", line 68, in __exit__
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher six.reraise(self.type_, self.value, self.tb)
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher File "/usr/lib/python2.7/dist-packages/nova/exception.py", line 71, in wrapped
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher return f(self, context, *args, **kw)
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 303, in decorated_function
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher e, sys.exc_info())
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher File "/usr/lib/python2.7/dist-packages/nova/openstack/common/excutils.py", line 68, in __exit__
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher six.reraise(self.type_, self.value, self.tb)
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 290, in decorated_function
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher return function(self, context, *args, **kwargs)
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 4465, in pre_live_migration
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher migrate_data)
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/driver.py", line 4585, in pre_live_migration
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher self._create_images_and_backing(context, instance, instance_dir,
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher UnboundLocalError: local variable 'instance_dir' referenced before assignment
2014-07-17 16:14:14.276 50785 TRACE oslo.messaging.rpc.dispatcher
2014-07-17 16:14:14.280 50785 ERROR oslo.messaging._drivers.common [-] Returning exception local variable 'instance_dir' referenced before assignment to caller
2014-07-17 16:14:14.280 50785 ERROR oslo.messaging._drivers.common [-] ['Traceback (most recent call last):\n', ' File "/usr/lib/python2.7/dist-packages/oslo/messaging/rpc/dispatcher.py", line

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/108468

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/108468
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=48905ac087e1de922e9230d52cc53250b17fb580
Submitter: Jenkins
Branch: master

commit 48905ac087e1de922e9230d52cc53250b17fb580
Author: Vladik Romanovsky <email address hidden>
Date: Mon Jul 21 08:35:22 2014 -0400

    Live migration is broken for NFS shared storage

    One of the new checks, introduced in
    I2755c59b4db736151000dae351fd776d3c15ca39
    is missing a check against filebased shared storage,
    leading to live migration being broken.

    Closes-Bug: #1346385
    Change-Id: I096ecd6eadc3b13ef918ca1e6c98acdd01556c0d