Upstream patch fixed in Grizzly 2013.1.5, Havana 2013.2.1, Icehouse

commit 135faa7b5d9855312bedc19e5e1ecebae34d3d18
Author: Pádraig Brady <[email protected]>
Date:   Fri Sep 27 04:07:14 2013 +0100

    ensure we don't boot oversized images
    
    Since we can't generally shrink incoming images, add extra checks
    to ensure oversized images are not allowed through.
    All cases when populating the libvirt image cache are now handled,
    including the initial download from glance, where we avoid
    converting to raw, as that could generate non sparse images
    much larger than the downloaded image.
    
    * nova/virt/libvirt/utils.py (fetch_image): Allow passing through
    of the max_size parameter.
    * nova/virt/images.py (fetch_to_raw): Accept the max_size parameter,
    and use it to discard images with larger (virtual) sizes.
    * nova/virt/libvirt/imagebackend.py (verify_base_size): A new
    refactored function to identify and raise exception to oversized images.
    (Raw.create_image): Pass the max_size to the fetch function.
    Also enforce virtual image size checking for already fetched images,
    as this class (despite the name) can be handling qcow files.
    (Qcow2.create_image): Pass the max_size to the fetch function,
    or verify the virtual size for the instance as done previously.
    (Lvm.create_image): Pass the max_size to the fetch function.
    Also check the size before transferring to the volume to improve
    efficiency by not even attempting the transfer of oversized images.
    (Rbd.create_image): Likewise.
    * nova/tests/fake_libvirt_utils.py: Support max_size arg.
    * nova/tests/test_libvirt.py (test_fetch_raw_image):
    Add a case to check oversized images are discarded.
    * nova/tests/test_imagebackend.py (test_create_image_too_small):
    Adjust to avoid the fetch size check.
    
    Fixes bug: 1177830
    Fixes bug: 1206081
    
    Conflicts:
    
    	nova/tests/test_imagebackend.py
    	nova/virt/libvirt/imagebackend.py
    
    Change-Id: Idc35fce580be4f74e23883d1b4bea6475c3f6e30

diff --git a/nova/tests/fake_libvirt_utils.py b/nova/tests/fake_libvirt_utils.py
index 23b758e..ecf357a 100644
--- a/nova/tests/fake_libvirt_utils.py
+++ b/nova/tests/fake_libvirt_utils.py
@@ -193,7 +193,7 @@ def get_fs_info(path):
             'free': 84 * (1024 ** 3)}
 
 
-def fetch_image(context, target, image_id, user_id, project_id):
+def fetch_image(context, target, image_id, user_id, project_id, max_size=0):
     pass
 
 
diff --git a/nova/tests/test_imagebackend.py b/nova/tests/test_imagebackend.py
index 77446e8..93ed23d 100644
--- a/nova/tests/test_imagebackend.py
+++ b/nova/tests/test_imagebackend.py
@@ -189,7 +189,7 @@ class RawTestCase(_ImageTestCase, test.TestCase):
 
     def test_create_image(self):
         fn = self.prepare_mocks()
-        fn(target=self.TEMPLATE_PATH, image_id=None)
+        fn(target=self.TEMPLATE_PATH, max_size=None, image_id=None)
         imagebackend.libvirt_utils.copy_image(self.TEMPLATE_PATH, self.PATH)
         self.mox.ReplayAll()
 
@@ -210,7 +210,7 @@ class RawTestCase(_ImageTestCase, test.TestCase):
 
     def test_create_image_extend(self):
         fn = self.prepare_mocks()
-        fn(target=self.TEMPLATE_PATH, image_id=None)
+        fn(max_size=self.SIZE, target=self.TEMPLATE_PATH, image_id=None)
         imagebackend.libvirt_utils.copy_image(self.TEMPLATE_PATH, self.PATH)
         imagebackend.disk.extend(self.PATH, self.SIZE)
         self.mox.ReplayAll()
@@ -260,7 +260,7 @@ class Qcow2TestCase(_ImageTestCase, test.TestCase):
 
     def test_create_image(self):
         fn = self.prepare_mocks()
-        fn(target=self.TEMPLATE_PATH)
+        fn(max_size=None, target=self.TEMPLATE_PATH)
         imagebackend.libvirt_utils.create_cow_image(self.TEMPLATE_PATH,
                                                     self.PATH)
         self.mox.ReplayAll()
@@ -272,15 +272,12 @@ class Qcow2TestCase(_ImageTestCase, test.TestCase):
 
     def test_create_image_with_size(self):
         fn = self.prepare_mocks()
-        fn(target=self.TEMPLATE_PATH)
+        fn(max_size=self.SIZE, target=self.TEMPLATE_PATH)
         self.mox.StubOutWithMock(os.path, 'exists')
-        self.mox.StubOutWithMock(imagebackend.disk, 'get_disk_size')
         if self.OLD_STYLE_INSTANCE_PATH:
             os.path.exists(self.OLD_STYLE_INSTANCE_PATH).AndReturn(False)
         os.path.exists(self.TEMPLATE_PATH).AndReturn(False)
         os.path.exists(self.PATH).AndReturn(False)
-        imagebackend.disk.get_disk_size(self.TEMPLATE_PATH
-                                       ).AndReturn(self.SIZE)
         os.path.exists(self.PATH).AndReturn(False)
         imagebackend.libvirt_utils.create_cow_image(self.TEMPLATE_PATH,
                                                     self.PATH)
@@ -294,27 +291,24 @@ class Qcow2TestCase(_ImageTestCase, test.TestCase):
 
     def test_create_image_too_small(self):
         fn = self.prepare_mocks()
-        fn(target=self.TEMPLATE_PATH)
         self.mox.StubOutWithMock(os.path, 'exists')
         self.mox.StubOutWithMock(imagebackend.disk, 'get_disk_size')
         if self.OLD_STYLE_INSTANCE_PATH:
             os.path.exists(self.OLD_STYLE_INSTANCE_PATH).AndReturn(False)
-        os.path.exists(self.TEMPLATE_PATH).AndReturn(False)
-        os.path.exists(self.PATH).AndReturn(False)
+        os.path.exists(self.TEMPLATE_PATH).AndReturn(True)
         imagebackend.disk.get_disk_size(self.TEMPLATE_PATH
                                        ).AndReturn(self.SIZE)
         self.mox.ReplayAll()
 
         image = self.image_class(self.INSTANCE, self.NAME)
-        self.assertRaises(exception.ImageTooLarge, image.create_image, fn,
-                          self.TEMPLATE_PATH, 1)
+        self.assertRaises(exception.InstanceTypeDiskTooSmall,
+                          image.create_image, fn, self.TEMPLATE_PATH, 1)
         self.mox.VerifyAll()
 
     def test_generate_resized_backing_files(self):
         fn = self.prepare_mocks()
-        fn(target=self.TEMPLATE_PATH)
+        fn(max_size=self.SIZE, target=self.TEMPLATE_PATH)
         self.mox.StubOutWithMock(os.path, 'exists')
-        self.mox.StubOutWithMock(imagebackend.disk, 'get_disk_size')
         self.mox.StubOutWithMock(imagebackend.libvirt_utils,
                                  'get_disk_backing_file')
         if self.OLD_STYLE_INSTANCE_PATH:
@@ -329,8 +323,6 @@ class Qcow2TestCase(_ImageTestCase, test.TestCase):
                                               self.QCOW2_BASE)
         imagebackend.disk.extend(self.QCOW2_BASE, self.SIZE)
 
-        imagebackend.disk.get_disk_size(self.TEMPLATE_PATH
-                                       ).AndReturn(self.SIZE)
         os.path.exists(self.PATH).AndReturn(True)
         self.mox.ReplayAll()
 
@@ -341,9 +333,8 @@ class Qcow2TestCase(_ImageTestCase, test.TestCase):
 
     def test_qcow2_exists_and_has_no_backing_file(self):
         fn = self.prepare_mocks()
-        fn(target=self.TEMPLATE_PATH)
+        fn(max_size=self.SIZE, target=self.TEMPLATE_PATH)
         self.mox.StubOutWithMock(os.path, 'exists')
-        self.mox.StubOutWithMock(imagebackend.disk, 'get_disk_size')
         self.mox.StubOutWithMock(imagebackend.libvirt_utils,
                                  'get_disk_backing_file')
         if self.OLD_STYLE_INSTANCE_PATH:
@@ -353,8 +344,6 @@ class Qcow2TestCase(_ImageTestCase, test.TestCase):
 
         imagebackend.libvirt_utils.get_disk_backing_file(self.PATH)\
             .AndReturn(None)
-        imagebackend.disk.get_disk_size(self.TEMPLATE_PATH
-                                       ).AndReturn(self.SIZE)
         os.path.exists(self.PATH).AndReturn(True)
         self.mox.ReplayAll()
 
@@ -391,7 +380,7 @@ class LvmTestCase(_ImageTestCase, test.TestCase):
 
     def _create_image(self, sparse):
         fn = self.prepare_mocks()
-        fn(target=self.TEMPLATE_PATH)
+        fn(max_size=None, target=self.TEMPLATE_PATH)
         self.libvirt_utils.create_lvm_image(self.VG,
                                             self.LV,
                                             self.TEMPLATE_SIZE,
@@ -423,7 +412,7 @@ class LvmTestCase(_ImageTestCase, test.TestCase):
 
     def _create_image_resize(self, sparse):
         fn = self.prepare_mocks()
-        fn(target=self.TEMPLATE_PATH)
+        fn(max_size=self.SIZE, target=self.TEMPLATE_PATH)
         self.libvirt_utils.create_lvm_image(self.VG, self.LV,
                                             self.SIZE, sparse=sparse)
         self.disk.get_disk_size(self.TEMPLATE_PATH
@@ -462,7 +451,7 @@ class LvmTestCase(_ImageTestCase, test.TestCase):
 
     def test_create_image_negative(self):
         fn = self.prepare_mocks()
-        fn(target=self.TEMPLATE_PATH)
+        fn(max_size=self.SIZE, target=self.TEMPLATE_PATH)
         self.libvirt_utils.create_lvm_image(self.VG,
                                             self.LV,
                                             self.SIZE,
diff --git a/nova/tests/test_libvirt.py b/nova/tests/test_libvirt.py
index d8c4cf2..e422ec7 100644
--- a/nova/tests/test_libvirt.py
+++ b/nova/tests/test_libvirt.py
@@ -4826,7 +4826,8 @@ disk size: 4.4M''', ''))
         image_id = '4'
         user_id = 'fake'
         project_id = 'fake'
-        images.fetch_to_raw(context, image_id, target, user_id, project_id)
+        images.fetch_to_raw(context, image_id, target, user_id, project_id,
+                            max_size=0)
 
         self.mox.ReplayAll()
         libvirt_utils.fetch_image(context, target, image_id,
@@ -4856,20 +4857,27 @@ disk size: 4.4M''', ''))
                 file_format = path.split('.')[-2]
             elif file_format == 'converted':
                 file_format = 'raw'
+
             if 'backing' in path:
                 backing_file = 'backing'
             else:
                 backing_file = None
 
+            if 'big' in path:
+                virtual_size = 2
+            else:
+                virtual_size = 1
+
             FakeImgInfo.file_format = file_format
             FakeImgInfo.backing_file = backing_file
+            FakeImgInfo.virtual_size = virtual_size
 
             return FakeImgInfo()
 
         self.stubs.Set(utils, 'execute', fake_execute)
         self.stubs.Set(os, 'rename', fake_rename)
         self.stubs.Set(os, 'unlink', fake_unlink)
-        self.stubs.Set(images, 'fetch', lambda *_: None)
+        self.stubs.Set(images, 'fetch', lambda *_, **__: None)
         self.stubs.Set(images, 'qemu_img_info', fake_qemu_img_info)
         self.stubs.Set(utils, 'delete_if_exists', fake_rm_on_errror)
 
@@ -4884,7 +4892,8 @@ disk size: 4.4M''', ''))
                               't.qcow2.part', 't.qcow2.converted'),
                              ('rm', 't.qcow2.part'),
                              ('mv', 't.qcow2.converted', 't.qcow2')]
-        images.fetch_to_raw(context, image_id, target, user_id, project_id)
+        images.fetch_to_raw(context, image_id, target, user_id, project_id,
+                            max_size=1)
         self.assertEqual(self.executes, expected_commands)
 
         target = 't.raw'
@@ -4901,6 +4910,15 @@ disk size: 4.4M''', ''))
                           context, image_id, target, user_id, project_id)
         self.assertEqual(self.executes, expected_commands)
 
+        target = 'big.qcow2'
+        self.executes = []
+        expected_commands = [('rm', '-f', 'big.qcow2.part')]
+        self.assertRaises(exception.InstanceTypeDiskTooSmall,
+                          images.fetch_to_raw,
+                          context, image_id, target, user_id, project_id,
+                          max_size=1)
+        self.assertEqual(self.executes, expected_commands)
+
         del self.executes
 
     def test_get_disk_backing_file(self):
diff --git a/nova/virt/images.py b/nova/virt/images.py
index b40f566..541779a 100755
--- a/nova/virt/images.py
+++ b/nova/virt/images.py
@@ -190,7 +190,7 @@ def convert_image(source, dest, out_format, run_as_root=False):
     utils.execute(*cmd, run_as_root=run_as_root)
 
 
-def fetch(context, image_href, path, _user_id, _project_id):
+def fetch(context, image_href, path, _user_id, _project_id, max_size=0):
     # TODO(vish): Improve context handling and add owner and auth data
     #             when it is added to glance.  Right now there is no
     #             auth checking in glance, so we assume that access was
@@ -202,9 +202,10 @@ def fetch(context, image_href, path, _user_id, _project_id):
             image_service.download(context, image_id, image_file)
 
 
-def fetch_to_raw(context, image_href, path, user_id, project_id):
+def fetch_to_raw(context, image_href, path, user_id, project_id, max_size=0):
     path_tmp = "%s.part" % path
-    fetch(context, image_href, path_tmp, user_id, project_id)
+    fetch(context, image_href, path_tmp, user_id, project_id,
+          max_size=max_size)
 
     with utils.remove_path_on_error(path_tmp):
         data = qemu_img_info(path_tmp)
@@ -220,6 +221,23 @@ def fetch_to_raw(context, image_href, path, user_id, project_id):
             raise exception.ImageUnacceptable(image_id=image_href,
                 reason=_("fmt=%(fmt)s backed by: %(backing_file)s") % locals())
 
+        # We can't generally shrink incoming images, so disallow
+        # images > size of the flavor we're booting.  Checking here avoids
+        # an immediate DoS where we convert large qcow images to raw
+        # (which may compress well but not be sparse).
+        # TODO(p-draigbrady): loop through all flavor sizes, so that
+        # we might continue here and not discard the download.
+        # If we did that we'd have to do the higher level size checks
+        # irrespective of whether the base image was prepared or not.
+        disk_size = data.virtual_size
+        if max_size and max_size < disk_size:
+            msg = _('%(base)s virtual size %(disk_size)s '
+                    'larger than flavor root disk size %(size)s')
+            LOG.error(msg % {'base': path,
+                             'disk_size': disk_size,
+                             'size': max_size})
+            raise exception.InstanceTypeDiskTooSmall()
+
         if fmt != "raw" and CONF.force_raw_images:
             staged = "%s.converted" % path
             LOG.debug("%s was %s, converting to raw" % (image_href, fmt))
diff --git a/nova/virt/libvirt/imagebackend.py b/nova/virt/libvirt/imagebackend.py
index e2c7ccf..dc85c97 100755
--- a/nova/virt/libvirt/imagebackend.py
+++ b/nova/virt/libvirt/imagebackend.py
@@ -177,6 +177,36 @@ class Image(object):
                           (CONF.preallocate_images, self.path))
         return can_fallocate
 
+    @staticmethod
+    def verify_base_size(base, size, base_size=0):
+        """Check that the base image is not larger than size.
+           Since images can't be generally shrunk, enforce this
+           constraint taking account of virtual image size.
+        """
+
+        # Note(pbrady): The size and min_disk parameters of a glance
+        #  image are checked against the instance size before the image
+        #  is even downloaded from glance, but currently min_disk is
+        #  adjustable and doesn't currently account for virtual disk size,
+        #  so we need this extra check here.
+        # NOTE(cfb): Having a flavor that sets the root size to 0 and having
+        #  nova effectively ignore that size and use the size of the
+        #  image is considered a feature at this time, not a bug.
+
+        if size is None:
+            return
+
+        if size and not base_size:
+            base_size = disk.get_disk_size(base)
+
+        if size < base_size:
+            msg = _('%(base)s virtual size %(base_size)s '
+                    'larger than flavor root disk size %(size)s')
+            LOG.error(msg % {'base': base,
+                              'base_size': base_size,
+                              'size': size})
+            raise exception.InstanceTypeDiskTooSmall()
+
     def snapshot_create(self):
         raise NotImplementedError
 
@@ -217,7 +247,8 @@ class Raw(Image):
             #Generating image in place
             prepare_template(target=self.path, *args, **kwargs)
         else:
-            prepare_template(target=base, *args, **kwargs)
+            prepare_template(target=base, max_size=size, *args, **kwargs)
+            self.verify_base_size(base, size)
             if not os.path.exists(self.path):
                 with utils.remove_path_on_error(self.path):
                     copy_raw_image(base, self.path, size)
@@ -257,7 +288,9 @@ class Qcow2(Image):
 
         # Download the unmodified base image unless we already have a copy.
         if not os.path.exists(base):
-            prepare_template(target=base, *args, **kwargs)
+            prepare_template(target=base, max_size=size, *args, **kwargs)
+        else:
+            self.verify_base_size(base, size)
 
         legacy_backing_size = None
         legacy_base = base
@@ -283,13 +316,6 @@ class Qcow2(Image):
                     libvirt_utils.copy_image(base, legacy_base)
                     disk.extend(legacy_base, legacy_backing_size)
 
-        # NOTE(cfb): Having a flavor that sets the root size to 0 and having
-        #            nova effectively ignore that size and use the size of the
-        #            image is considered a feature at this time, not a bug.
-        if size and size < disk.get_disk_size(base):
-            LOG.error('%s virtual size larger than flavor root disk size %s' %
-                      (base, size))
-            raise exception.ImageTooLarge()
         if not os.path.exists(self.path):
             with utils.remove_path_on_error(self.path):
                 copy_qcow2_image(base, self.path, size)
@@ -348,6 +374,7 @@ class Lvm(Image):
                                 lock_path=self.lock_path)
         def create_lvm_image(base, size):
             base_size = disk.get_disk_size(base)
+            self.verify_base_size(base, size, base_size=base_size)
             resize = size > base_size
             size = size if resize else base_size
             libvirt_utils.create_lvm_image(self.vg, self.lv,
@@ -365,7 +392,7 @@ class Lvm(Image):
             with self.remove_volume_on_error(self.path):
                 prepare_template(target=self.path, *args, **kwargs)
         else:
-            prepare_template(target=base, *args, **kwargs)
+            prepare_template(target=base, max_size=size, *args, **kwargs)
             with self.remove_volume_on_error(self.path):
                 create_lvm_image(base, size)
 
diff --git a/nova/virt/libvirt/utils.py b/nova/virt/libvirt/utils.py
index 6972243..4c31fcb 100755
--- a/nova/virt/libvirt/utils.py
+++ b/nova/virt/libvirt/utils.py
@@ -592,9 +592,10 @@ def get_fs_info(path):
             'used': used}
 
 
-def fetch_image(context, target, image_id, user_id, project_id):
+def fetch_image(context, target, image_id, user_id, project_id, max_size=0):
     """Grab image."""
-    images.fetch_to_raw(context, image_id, target, user_id, project_id)
+    images.fetch_to_raw(context, image_id, target, user_id, project_id,
+                        max_size=max_size)
 
 
 def get_instance_path(instance, forceold=False, relative=False):