Snapshot deleting of attached volume fails with remotefs volume drivers

[Dmitry Guryanov]

cinder create --image-id 3dc83685-ed82-444c-8863-1e962eb33de8 1 # ID of cirros image

nova boot qwe --flavor m1.tiny --block-device id=d62c5786-1d13-46bb-be13-3b110c144de7,source=volume,dest=volume,type=disk,bootindex=0

cinder snapshot-create --force=True 46b22595-31b0-41ca-8214-8ad6b81a06b6

cinder snapshot-delete 43fb72a4-963f-45f7-8b42-89e7c2cbd720

Then check nova-compute log:

2015-07-16 08:44:26.841 ERROR nova.virt.libvirt.driver [req-f92f3dd2-1bef-4c2c-8208-54d765592985 nova service] Error occurred during volume_snapshot_delete, sending error status to Cinder.
2015-07-16 08:44:26.841 29626 ERROR nova.virt.libvirt.driver Traceback (most recent call last):
2015-07-16 08:44:26.841 29626 ERROR nova.virt.libvirt.driver File "/opt/stack/new/nova/nova/virt/libvirt/driver.py", line 2004, in volume_snapshot_delete
2015-07-16 08:44:26.841 29626 ERROR nova.virt.libvirt.driver self._volume_snapshot_delete(context, instance, volume_id,
2015-07-16 08:44:26.841 29626 ERROR nova.virt.libvirt.driver File "/opt/stack/new/nova/nova/virt/libvirt/driver.py", line 1939, in _volume_snapshot_delete
2015-07-16 08:44:26.841 29626 ERROR nova.virt.libvirt.driver dev = guest.get_block_device(rebase_disk)
2015-07-16 08:44:26.841 29626 ERROR nova.virt.libvirt.driver File "/opt/stack/new/nova/nova/virt/libvirt/guest.py", line 302, in rebase
2015-07-16 08:44:26.841 29626 ERROR nova.virt.libvirt.driver self._disk, base, self.REBASE_DEFAULT_BANDWIDTH, flags=flags)
2015-07-16 08:44:26.841 29626 ERROR nova.virt.libvirt.driver File "/usr/lib/python2.7/site-packages/eventlet/tpool.py", line 183, in doit
2015-07-16 08:44:26.841 29626 ERROR nova.virt.libvirt.driver result = proxy_call(self._autowrap, f, *args, **kwargs)
2015-07-16 08:44:26.841 29626 ERROR nova.virt.libvirt.driver File "/usr/lib/python2.7/site-packages/eventlet/tpool.py", line 141, in proxy_call
2015-07-16 08:44:26.841 29626 ERROR nova.virt.libvirt.driver rv = execute(f, *args, **kwargs)
2015-07-16 08:44:26.841 29626 ERROR nova.virt.libvirt.driver File "/usr/lib/python2.7/site-packages/eventlet/tpool.py", line 122, in execute
2015-07-16 08:44:26.841 29626 ERROR nova.virt.libvirt.driver six.reraise(c, e, tb)
2015-07-16 08:44:26.841 29626 ERROR nova.virt.libvirt.driver File "/usr/lib/python2.7/site-packages/eventlet/tpool.py", line 80, in tworker
2015-07-16 08:44:26.841 29626 ERROR nova.virt.libvirt.driver rv = meth(*args, **kwargs)
2015-07-16 08:44:26.841 29626 ERROR nova.virt.libvirt.driver File "/usr/lib/python2.7/site-packages/libvirt.py", line 865, in blockRebase
2015-07-16 08:44:26.841 29626 ERROR nova.virt.libvirt.driver if ret == -1: raise libvirtError ('virDomainBlockRebase() failed', dom=self)
2015-07-16 08:44:26.841 29626 ERROR nova.virt.libvirt.driver libvirtError: invalid argument: flag VIR_DOMAIN_BLOCK_REBASE_RELATIVE is valid only with non-null base

[Dmitry Guryanov (dguryanov)]

Commit, that introduced the problem: e9639913294036ff94f354e9c8ea18cd816243ab

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/202442

[Deepak C Shetty (dpkshetty)]

FWIW, the recent patch @ https://review.openstack.org/#/c/190213/9 caused this regression

[Sylvain Bauza (sylvain-bauza)]

Triaging the bug as High as we only leave the Critical bugs for major feature issues.

See https://wiki.openstack.org/wiki/BugTriage#Task_2:_Prioritize_confirmed_bugs_.28bug_supervisors.29 for further details

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/202442
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=45d73c49bd2f37ff0091f10a928b2ad548256bae
Submitter: Jenkins
Branch: master

commit 45d73c49bd2f37ff0091f10a928b2ad548256bae
Author: Dmitry Guryanov <email address hidden>
Date: Thu Jul 23 02:52:31 2015 +0300

    libvirt: do relative block rebase only with non-null base

    You can't use VIR_DOMAIN_BLOCK_REBASE_RELATIVE with null
    base, libvirt reports error in this case, so check if
    base is non-null before setting this flag (relative argument
    of BlockDevice.rebase method).

    The error was introduced by commit
    e9639913294036ff94f354e9c8ea18cd816243ab

    Change-Id: Ife50f211fd54190a2665ad090f6208048b841690
    Closes-Bug: #1475202