openstack/nova
Code Issues Proposed changes

Merge "Make _rebase_with_qemu_img() generic"

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Zuul 2020-07-31 14:01:12 +00:00 committed by Gerrit Code Review
commit 587912d0af
2 changed files with 36 additions and 23 deletions
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19
nova/tests/unit/virt/libvirt/test_driver.py
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@ -25313,6 +25313,25 @@ class LibvirtDriverTestCase(test.NoDBTestCase, TraitsComparisonMixin):
mock_et.assert_not_called()
mock_isdir.assert_not_called()
@mock.patch('nova.virt.images.qemu_img_info',
return_value=mock.Mock(file_format="fake_fmt"))
@mock.patch('oslo_concurrency.processutils.execute')
def test_rebase_with_qemu_img(self, mock_execute, mock_qemu_img_info):
"""rebasing disk image to another backing file"""
self.drvr._rebase_with_qemu_img("disk", "backing_file")
mock_qemu_img_info.assert_called_once_with("backing_file")
mock_execute.assert_called_once_with('qemu-img', 'rebase',
'-b', 'backing_file', '-F',
'fake_fmt', 'disk')
# Flatten disk image when no backing file is given.
mock_qemu_img_info.reset_mock()
mock_execute.reset_mock()
self.drvr._rebase_with_qemu_img("disk", None)
self.assertEqual(0, mock_qemu_img_info.call_count)
mock_execute.assert_called_once_with('qemu-img', 'rebase',
'-b', '', 'disk')
class LibvirtVolumeUsageTestCase(test.NoDBTestCase):
"""Test for LibvirtDriver.get_all_volume_usage."""

40
nova/virt/libvirt/driver.py
View File

@ -2894,32 +2894,15 @@ class LibvirtDriver(driver.ComputeDriver):
timer.start(interval=0.5).wait()
@staticmethod
def _rebase_with_qemu_img(guest, device, active_disk_object,
rebase_base):
"""Rebase a device tied to a guest using qemu-img.
def _rebase_with_qemu_img(source_path, rebase_base):
"""Rebase a disk using qemu-img.
:param guest:the Guest which owns the device being rebased
:type guest: nova.virt.libvirt.guest.Guest
:param device: the guest block device to rebase
:type device: nova.virt.libvirt.guest.BlockDevice
:param active_disk_object: the guest block device to rebase
:type active_disk_object: nova.virt.libvirt.config.\
LibvirtConfigGuestDisk
:param source_path: the disk source path to rebase
:type source_path: string
:param rebase_base: the new parent in the backing chain
:type rebase_base: None or string
"""
# It's unsure how well qemu-img handles network disks for
# every protocol. So let's be safe.
active_protocol = active_disk_object.source_protocol
if active_protocol is not None:
msg = _("Something went wrong when deleting a volume snapshot: "
"rebasing a %(protocol)s network disk using qemu-img "
"has not been fully tested") % {'protocol':
active_protocol}
LOG.error(msg)
raise exception.InternalError(msg)
if rebase_base is None:
# If backing_file is specified as "" (the empty string), then
# the image is rebased onto no backing file (i.e. it will exist
@ -2934,7 +2917,7 @@ class LibvirtDriver(driver.ComputeDriver):
b_file_fmt = images.qemu_img_info(backing_file).file_format
qemu_img_extra_arg = ['-F', b_file_fmt]
qemu_img_extra_arg.append(active_disk_object.source_path)
qemu_img_extra_arg.append(source_path)
# execute operation with disk concurrency semaphore
with compute_utils.disk_ops_semaphore:
processutils.execute("qemu-img", "rebase", "-b", backing_file,
@ -3082,7 +3065,18 @@ class LibvirtDriver(driver.ComputeDriver):
else:
LOG.debug('Guest is not running so doing a block rebase '
'using "qemu-img rebase"', instance=instance)
self._rebase_with_qemu_img(guest, dev, active_disk_object,
# It's unsure how well qemu-img handles network disks for
# every protocol. So let's be safe.
active_protocol = active_disk_object.source_protocol
if active_protocol is not None:
msg = _("Something went wrong when deleting a volume "
"snapshot: rebasing a %(protocol)s network disk "
"using qemu-img has not been fully tested"
) % {'protocol': active_protocol}
LOG.error(msg)
raise exception.InternalError(msg)
self._rebase_with_qemu_img(active_disk_object.source_path,
rebase_base)
else: