From 35e0ee309e040a95988a433120f1eba747f6f33c 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 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 This patch also includes part of commit 65386c91910ee03d947c2b8bcc226a53c30e060a, not cherry-picked as a whole due to the fact that it is a trivial change, and to avoud the proliferation of patches needed to fix this bug. Change-Id: I78aa2f4243899db4f4941e77014a7e18e27fc63e (cherry picked from commit c69a619668b5f44e94a8fe1a23f3d887ba2834d7) Conflicts: nova/tests/test_libvirt.py nova/virt/libvirt/driver.py --- nova/tests/test_libvirt.py | 63 +++++++++++++++++++++++++++++++++++++++++++++ nova/virt/libvirt/driver.py | 31 +++++++++++++++------- 2 files changed, 85 insertions(+), 9 deletions(-) diff --git a/nova/tests/test_libvirt.py b/nova/tests/test_libvirt.py index d2ac73b..d9c7405 100644 --- a/nova/tests/test_libvirt.py +++ b/nova/tests/test_libvirt.py @@ -2346,6 +2346,69 @@ class LibvirtConnTestCase(test.TestCase): db.instance_destroy(self.context, instance_ref['uuid']) + def test_create_images_and_backing(self): + conn = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI(), False) + self.mox.StubOutWithMock(conn, '_fetch_instance_kernel_ramdisk') + self.mox.StubOutWithMock(libvirt_driver.libvirt_utils, 'create_image') + + libvirt_driver.libvirt_utils.create_image(mox.IgnoreArg(), + mox.IgnoreArg(), + mox.IgnoreArg()) + conn._fetch_instance_kernel_ramdisk(self.context, self.test_instance) + self.mox.ReplayAll() + + self.stubs.Set(os.path, 'exists', lambda *args: False) + disk_info_json = jsonutils.dumps([{'path': 'foo', 'type': None, + 'disk_size': 0, + 'backing_file': None}]) + 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, '_base') + ephemeral_target = os.path.join(base_dir, 'ephemeral_1_default') + image_target = os.path.join(base_dir, 'fake_image_backing_file') + self.test_instance.update({'name': 'fake_instance', + 'user_id': 'fake-user', + 'os_type': None, + 'project_id': 'fake-project'}) + + self.mox.StubOutWithMock(libvirt_driver.libvirt_utils, 'fetch_image') + self.mox.StubOutWithMock(conn, '_create_ephemeral') + self.mox.StubOutWithMock(conn, '_fetch_instance_kernel_ramdisk') + + conn._create_ephemeral( + target=ephemeral_target, + ephemeral_size=self.test_instance['ephemeral_gb'], + max_size=mox.IgnoreArg(), os_type=mox.IgnoreArg(), + fs_label=mox.IgnoreArg()) + libvirt_driver.libvirt_utils.fetch_image(context=self.context, + image_id=mox.IgnoreArg(), + user_id=mox.IgnoreArg(), project_id=mox.IgnoreArg(), + max_size=mox.IgnoreArg(), target=image_target) + conn._fetch_instance_kernel_ramdisk( + self.context, self.test_instance).AndReturn(None) + + self.mox.ReplayAll() + + conn._create_images_and_backing(self.context, self.test_instance, + "/fake/instance/dir", + disk_info_json) + def test_pre_live_migration_works_correctly_mocked(self): # Creating testdata vol = {'block_device_mapping': [ diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py index 0f0ea46..39191af 100755 --- a/nova/virt/libvirt/driver.py +++ b/nova/virt/libvirt/driver.py @@ -3304,19 +3304,32 @@ class LibvirtDriver(driver.ComputeDriver): elif info['backing_file']: # Creating backing file follows same way as spawning instances. cache_name = os.path.basename(info['backing_file']) - # Remove any size tags which the cache manages - cache_name = cache_name.split('_')[0] image = self.image_backend.image(instance, instance_disk, CONF.libvirt_images_type) - image.cache(fetch_func=libvirt_utils.fetch_image, - context=ctxt, - 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 * unit.Mi, + swap_mb=swap_mb) + else: + image.cache(fetch_func=libvirt_utils.fetch_image, + context=ctxt, + 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. -- 1.8.3.1