From 15ee7e17f63f5583307a546ecf28952c364c88f9 Mon Sep 17 00:00:00 2001 From: Nikola Dipanov Date: Tue, 10 Dec 2013 17:43:17 +0100 Subject: [PATCH] libvirt: Fix root disk leak in live mig This patch makes sure that _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 (cherry picked from commit c69a619668b5f44e94a8fe1a23f3d887ba2834d7) Conflicts: nova/virt/libvirt/driver.py Change-Id: I78aa2f4243899db4f4941e77014a7e18e27fc63e --- nova/tests/virt/libvirt/test_libvirt.py | 42 +++++++++++++++++++++++++ nova/virt/libvirt/driver.py | 29 ++++++++++++----- 2 files changed, 64 insertions(+), 7 deletions(-) diff --git a/nova/tests/virt/libvirt/test_libvirt.py b/nova/tests/virt/libvirt/test_libvirt.py index c17698502a6..ea2aacde757 100644 --- a/nova/tests/virt/libvirt/test_libvirt.py +++ b/nova/tests/virt/libvirt/test_libvirt.py @@ -3047,6 +3047,48 @@ def test_create_images_and_backing(self): conn._create_images_and_backing(self.context, self.test_instance, "/fake/instance/dir", disk_info_json) + 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.base_dir_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') diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py index 500ce516f0d..19875fe2392 100644 --- a/nova/virt/libvirt/driver.py +++ b/nova/virt/libvirt/driver.py @@ -4210,13 +4210,28 @@ def _create_images_and_backing(self, context, instance, instance_dir, 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 * (1024 ** 2), + 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.