Use VIR_DOMAIN_BLOCK_REBASE_COPY_DEV when rebasing

Previously, in swap_volume, the VIR_DOMAIN_BLOCK_REBASE_COPY_DEV flag
was not passed to virDomainBlockRebase. In the case of iSCSI-backed
disks, this caused the XML to change from <source dev=/dev/iscsi/lun>
to <source file=/dev/iscsi/lun>. This was a problem because
/dev/iscsi/lun is not a regular file. This patch passes the
VIR_DOMAIN_BLOCK_REBASE_COPY_DEV flag to virDomainBlockRebase, causing
the correct <source dev=/dev/iscsi/lun> to be generated upon
volume-update.

Conflicts:
      nova/tests/unit/virt/libvirt/test_driver.py
      nova/virt/libvirt/driver.py
      nova/virt/libvirt/guest.py

NOTE(mriedem): The conflicts are due to
fbcf8d6733 needing to translate
the exception message in driver.py and for passing instance
to disconnect_volume in test_driver, which was added in Pike with
b66b7d4f9d.

NOTE(artom): In stable/newton, the conflict in guest.py is due to a
different docstring for the rebase() method.

NOTE(artom): This backport squashes
5d5c5a5d92 to guard againt older libvirt
versions that don't have the VIR_DOMAIN_BLOCK_REBASE_COPY_DEV flag.

Change-Id: I868a0dae0baf8cded9c7c5807ea63ffc5eec0c5e
Closes-bug: 1691195
(cherry picked from commit a8a4a8ea7b)
(cherry picked from commit ef853e038d)
This commit is contained in:
Artom Lifshitz 2017-05-17 00:22:34 +00:00
parent bcc88d4cad
commit 8b9aa3e001
5 changed files with 124 additions and 13 deletions

View File

@ -52,6 +52,7 @@ VIR_DOMAIN_XML_MIGRATABLE = 8
VIR_DOMAIN_BLOCK_REBASE_SHALLOW = 1
VIR_DOMAIN_BLOCK_REBASE_REUSE_EXT = 2
VIR_DOMAIN_BLOCK_REBASE_COPY = 8
VIR_DOMAIN_BLOCK_REBASE_COPY_DEV = 32
VIR_DOMAIN_BLOCK_JOB_ABORT_ASYNC = 1
VIR_DOMAIN_BLOCK_JOB_ABORT_PIVOT = 2

View File

@ -14653,7 +14653,7 @@ class LibvirtConnTestCase(test.NoDBTestCase):
save.assert_called_once_with()
@mock.patch('nova.virt.libvirt.guest.BlockDevice.is_job_complete')
def test_swap_volume(self, mock_is_job_complete):
def test_swap_volume_file(self, mock_is_job_complete):
drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI())
mock_dom = mock.MagicMock()
@ -14669,7 +14669,93 @@ class LibvirtConnTestCase(test.NoDBTestCase):
mock_dom.isPersistent.return_value = True
mock_is_job_complete.return_value = True
drvr._swap_volume(guest, srcfile, dstfile, 1)
drvr._swap_volume(guest, srcfile,
mock.MagicMock(source_type='file',
source_path=dstfile),
1)
mock_dom.XMLDesc.assert_called_once_with(
flags=(fakelibvirt.VIR_DOMAIN_XML_INACTIVE |
fakelibvirt.VIR_DOMAIN_XML_SECURE))
mock_dom.blockRebase.assert_called_once_with(
srcfile, dstfile, 0, flags=(
fakelibvirt.VIR_DOMAIN_BLOCK_REBASE_COPY |
fakelibvirt.VIR_DOMAIN_BLOCK_REBASE_REUSE_EXT))
mock_dom.blockResize.assert_called_once_with(
srcfile, 1 * units.Gi / units.Ki)
mock_define.assert_called_once_with(xmldoc)
@mock.patch('nova.virt.libvirt.guest.BlockDevice.is_job_complete')
def test_swap_volume_block(self, mock_is_job_complete):
"""If the swapped volume is type="block", make sure that we give
libvirt the correct VIR_DOMAIN_BLOCK_REBASE_COPY_DEV flag to ensure the
correct type="block" XML is generated (bug 1691195)
"""
drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI())
mock_dom = mock.MagicMock()
guest = libvirt_guest.Guest(mock_dom)
with mock.patch.object(drvr._conn, 'defineXML',
create=True) as mock_define:
xmldoc = "<domain/>"
srcfile = "/first/path"
dstfile = "/second/path"
mock_dom.XMLDesc.return_value = xmldoc
mock_dom.isPersistent.return_value = True
mock_is_job_complete.return_value = True
drvr._swap_volume(guest, srcfile,
mock.MagicMock(source_type='block',
source_path=dstfile),
1)
mock_dom.XMLDesc.assert_called_once_with(
flags=(fakelibvirt.VIR_DOMAIN_XML_INACTIVE |
fakelibvirt.VIR_DOMAIN_XML_SECURE))
mock_dom.blockRebase.assert_called_once_with(
srcfile, dstfile, 0, flags=(
fakelibvirt.VIR_DOMAIN_BLOCK_REBASE_COPY |
fakelibvirt.VIR_DOMAIN_BLOCK_REBASE_COPY_DEV |
fakelibvirt.VIR_DOMAIN_BLOCK_REBASE_REUSE_EXT))
mock_dom.blockResize.assert_called_once_with(
srcfile, 1 * units.Gi / units.Ki)
mock_define.assert_called_once_with(xmldoc)
@mock.patch('nova.virt.libvirt.guest.BlockDevice.is_job_complete')
def test_swap_volume_block_old_libvirt(self, mock_is_job_complete):
"""If the swapped volume is type="block", make sure that we don't give
libvirt the VIR_DOMAIN_BLOCK_REBASE_COPY_DEV flag if the version
of libvirt is so old that it doesn't have that flag (bug 1724039)
"""
drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI())
mock_dom = mock.MagicMock()
guest = libvirt_guest.Guest(mock_dom)
with mock.patch.object(drvr._conn, 'defineXML',
create=True) as mock_define:
xmldoc = "<domain/>"
srcfile = "/first/path"
dstfile = "/second/path"
mock_dom.XMLDesc.return_value = xmldoc
mock_dom.isPersistent.return_value = True
mock_is_job_complete.return_value = True
# Temporarily remove the global.
copy_dev = libvirt_driver.libvirt.VIR_DOMAIN_BLOCK_REBASE_COPY_DEV
delattr(libvirt_driver.libvirt, 'VIR_DOMAIN_BLOCK_REBASE_COPY_DEV')
try:
drvr._swap_volume(guest, srcfile,
mock.MagicMock(source_type='block',
source_path=dstfile),
1)
finally:
# Reset the global.
libvirt_driver.libvirt.VIR_DOMAIN_BLOCK_REBASE_COPY_DEV = \
copy_dev
mock_dom.XMLDesc.assert_called_once_with(
flags=(fakelibvirt.VIR_DOMAIN_XML_INACTIVE |
@ -14715,8 +14801,8 @@ class LibvirtConnTestCase(test.NoDBTestCase):
mock_dom.UUIDString.return_value = 'uuid'
get_guest.return_value = guest
disk_info = {'bus': 'virtio', 'type': 'disk', 'dev': 'vdb'}
get_volume_config.return_value = mock.MagicMock(
source_path='/fake-new-volume')
conf = mock.MagicMock(source_path='/fake-new-volume')
get_volume_config.return_value = conf
conn.swap_volume(old_connection_info, new_connection_info, instance,
'/dev/vdb', 1)
@ -14724,8 +14810,7 @@ class LibvirtConnTestCase(test.NoDBTestCase):
get_guest.assert_called_once_with(instance)
connect_volume.assert_called_once_with(new_connection_info, disk_info)
swap_volume.assert_called_once_with(guest, 'vdb',
'/fake-new-volume', 1)
swap_volume.assert_called_once_with(guest, 'vdb', conf, 1)
disconnect_volume.assert_called_once_with(old_connection_info, 'vdb')
def test_swap_volume_driver_source_is_volume(self):

View File

@ -734,6 +734,12 @@ class GuestBlockTestCase(test.NoDBTestCase):
'vda', "foo", 0,
flags=fakelibvirt.VIR_DOMAIN_BLOCK_REBASE_RELATIVE)
def test_rebase_copy_dev(self):
self.gblock.rebase("foo", copy_dev=True)
self.domain.blockRebase.assert_called_once_with(
'vda', "foo", 0,
flags=fakelibvirt.VIR_DOMAIN_BLOCK_REBASE_COPY_DEV)
def test_commit(self):
self.gblock.commit("foo", "top")
self.domain.blockCommit.assert_called_once_with(

View File

@ -1185,7 +1185,7 @@ class LibvirtDriver(driver.ComputeDriver):
with excutils.save_and_reraise_exception():
self._disconnect_volume(connection_info, disk_dev)
def _swap_volume(self, guest, disk_path, new_path, resize_to):
def _swap_volume(self, guest, disk_path, conf, resize_to):
"""Swap existing disk with a new block device."""
dev = guest.get_block_device(disk_path)
@ -1209,9 +1209,26 @@ class LibvirtDriver(driver.ComputeDriver):
guest.delete_configuration(support_uefi)
try:
# Start copy with VIR_DOMAIN_REBASE_REUSE_EXT flag to
# allow writing to existing external volume file
dev.rebase(new_path, copy=True, reuse_ext=True)
# Start copy with VIR_DOMAIN_BLOCK_REBASE_REUSE_EXT flag to
# allow writing to existing external volume file. Use
# VIR_DOMAIN_BLOCK_REBASE_COPY_DEV if it's a block device to
# make sure XML is generated correctly (bug 1691195)
# NOTE(mriedem): VIR_DOMAIN_BLOCK_REBASE_COPY_DEV was
# introduced in libvirt 1.2.9 and since we support >= 1.2.1
# we have to guard against the flag not being available.
if hasattr(libvirt, 'VIR_DOMAIN_BLOCK_REBASE_COPY_DEV'):
copy_dev = conf.source_type == 'block'
else:
copy_dev = False
# Leave a breadcrumb.
if conf.source_type == 'block':
LOG.warning(_LW(
'Rebasing a block device using libvirt < 1.2.9 '
'where the VIR_DOMAIN_BLOCK_REBASE_COPY_DEV '
'flag is not available. This may lead to failures '
'later if the volume is swapped again.'))
dev.rebase(conf.source_path, copy=True, reuse_ext=True,
copy_dev=copy_dev)
while not dev.is_job_complete():
time.sleep(0.5)
@ -1224,7 +1241,7 @@ class LibvirtDriver(driver.ComputeDriver):
except Exception as exc:
LOG.exception(_LE("Failure rebasing volume %(new_path)s on "
"%(new_path)s."), {'new_path': new_path,
"%(new_path)s."), {'new_path': conf.source_path,
'old_path': disk_path})
raise exception.VolumeRebaseFailed(reason=six.text_type(exc))
@ -1261,7 +1278,7 @@ class LibvirtDriver(driver.ComputeDriver):
raise NotImplementedError(_("Swap only supports host devices"))
try:
self._swap_volume(guest, disk_dev, conf.source_path, resize_to)
self._swap_volume(guest, disk_dev, conf, resize_to)
except exception.VolumeRebaseFailed:
with excutils.save_and_reraise_exception():
self._disconnect_volume(new_connection_info, disk_dev)

View File

@ -735,17 +735,19 @@ class BlockDevice(object):
end=status['end'])
def rebase(self, base, shallow=False, reuse_ext=False,
copy=False, relative=False):
copy=False, relative=False, copy_dev=False):
"""Rebases block to new base
:param shallow: Limit copy to top of source backing chain
:param reuse_ext: Reuse existing external file of a copy
:param copy: Start a copy job
:param relative: Keep backing chain referenced using relative names
:param copy_dev: Treat the destination as type="block"
"""
flags = shallow and libvirt.VIR_DOMAIN_BLOCK_REBASE_SHALLOW or 0
flags |= reuse_ext and libvirt.VIR_DOMAIN_BLOCK_REBASE_REUSE_EXT or 0
flags |= copy and libvirt.VIR_DOMAIN_BLOCK_REBASE_COPY or 0
flags |= copy_dev and libvirt.VIR_DOMAIN_BLOCK_REBASE_COPY_DEV or 0
flags |= relative and libvirt.VIR_DOMAIN_BLOCK_REBASE_RELATIVE or 0
return self._guest._domain.blockRebase(
self._disk, base, self.REBASE_DEFAULT_BANDWIDTH, flags=flags)