openstack
/
nova
Code Issues Proposed changes

libvirt: Fix root disk leak in live mig 

This patch makes sure that i_create_images_and_backing method of the
libvirt driver (called in several places, but most problematic one is
the call in the pre_live_migration method) creates all the files the
instance needs that are not present.

Prioir to this patch - the method would only attempt to download the
image, and if it did so with the path of the ephemeral drives, it could
expose the image to other users as an ephemeral devices. See the related
bug for more detaiis.

After this patch - we properly distinguish between image, ephemeral and
swap files, and make sure that the imagebackend does the correct thing.

Closes-bug: #1251590

Co-authored-by: Loganathan Parthipan <parthipan@hp.com>

Change-Id: I78aa2f4243899db4f4941e77014a7e18e27fc63e
This commit is contained in:
Nikola Dipanov 2013-12-10 17:43:17 +01:00
parent f579affb50
commit b0d36683fe
2 changed files with 64 additions and 7 deletions
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42
nova/tests/virt/libvirt/test_libvirt.py
View File

@ -3361,6 +3361,48 @@ class LibvirtConnTestCase(test.TestCase):
def test_create_images_and_backing_raw(self):
self._do_test_create_images_and_backing('raw')
def test_create_images_and_backing_ephemeral_gets_created(self):
conn = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
disk_info_json = jsonutils.dumps(
[{u'backing_file': u'fake_image_backing_file',
u'disk_size': 10747904,
u'path': u'disk_path',
u'type': u'qcow2',
u'virt_disk_size': 25165824},
{u'backing_file': u'ephemeral_1_default',
u'disk_size': 393216,
u'over_committed_disk_size': 1073348608,
u'path': u'disk_eph_path',
u'type': u'qcow2',
u'virt_disk_size': 1073741824}])
base_dir = os.path.join(CONF.instances_path,
CONF.image_cache_subdirectory_name)
self.test_instance.update({'name': 'fake_instance',
'user_id': 'fake-user',
'os_type': None,
'project_id': 'fake-project'})
with contextlib.nested(
mock.patch.object(conn, '_fetch_instance_kernel_ramdisk'),
mock.patch.object(libvirt_driver.libvirt_utils, 'fetch_image'),
mock.patch.object(conn, '_create_ephemeral')
) as (fetch_kernel_ramdisk_mock, fetch_image_mock,
create_ephemeral_mock):
conn._create_images_and_backing(self.context, self.test_instance,
"/fake/instance/dir",
disk_info_json)
self.assertEqual(len(create_ephemeral_mock.call_args_list), 1)
m_args, m_kwargs = create_ephemeral_mock.call_args_list[0]
self.assertEqual(
os.path.join(base_dir, 'ephemeral_1_default'),
m_kwargs['target'])
self.assertEqual(len(fetch_image_mock.call_args_list), 1)
m_args, m_kwargs = fetch_image_mock.call_args_list[0]
self.assertEqual(
os.path.join(base_dir, 'fake_image_backing_file'),
m_kwargs['target'])
def test_create_images_and_backing_disk_info_none(self):
conn = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False)
self.mox.StubOutWithMock(conn, '_fetch_instance_kernel_ramdisk')

29
nova/virt/libvirt/driver.py
View File

@ -4387,13 +4387,28 @@ class LibvirtDriver(driver.ComputeDriver):
image = self.image_backend.image(instance,
instance_disk,
CONF.libvirt.images_type)
image.cache(fetch_func=libvirt_utils.fetch_image,
context=context,
filename=cache_name,
image_id=instance['image_ref'],
user_id=instance['user_id'],
project_id=instance['project_id'],
size=info['virt_disk_size'])
if cache_name.startswith('ephemeral'):
image.cache(fetch_func=self._create_ephemeral,
fs_label=cache_name,
os_type=instance["os_type"],
filename=cache_name,
size=info['virt_disk_size'],
ephemeral_size=instance['ephemeral_gb'])
elif cache_name.startswith('swap'):
inst_type = flavors.extract_flavor(instance)
swap_mb = inst_type['swap']
image.cache(fetch_func=self._create_swap,
filename="swap_%s" % swap_mb,
size=swap_mb * units.Mi,
swap_mb=swap_mb)
else:
image.cache(fetch_func=libvirt_utils.fetch_image,
context=context,
filename=cache_name,
image_id=instance['image_ref'],
user_id=instance['user_id'],
project_id=instance['project_id'],
size=info['virt_disk_size'])
# if image has kernel and ramdisk, just download
# following normal way.