Properly write non-raw LVM images on creation

Fixes bug 1075333

When force_raw_images=False and libvirt_images_type=lvm were set
together, selecting anything other than a RAW image would result in
an unbootable instance. This is because the downloaded image was
being directly dd'd onto the new LVM root, which will obviously not
work for any format other than RAW.

Simple change to use qemu-img to read from the image (letting it
decide the format) and write to the LVM root as raw.

Change-Id: I36494e6d0671c07f7511c10ef886c8cf84c18df7

3 files changed, 7 insertions, 8 deletions

diff --git a/nova/tests/test_imagebackend.py b/nova/tests/test_imagebackend.py
index 76fd1d5b6..87e51819d 100644
--- a/nova/tests/test_imagebackend.py
+++ b/nova/tests/test_imagebackend.py
@@ -241,8 +241,8 @@ class LvmTestCase(_ImageTestCase, test.TestCase):
                                             sparse=sparse)
         self.disk.get_disk_size(self.TEMPLATE_PATH
                                          ).AndReturn(self.TEMPLATE_SIZE)
-        cmd = ('dd', 'if=%s' % self.TEMPLATE_PATH,
-               'of=%s' % self.PATH, 'bs=4M')
+        cmd = ('qemu-img', 'convert', '-O', 'raw', self.TEMPLATE_PATH,
+               self.PATH)
         self.utils.execute(*cmd, run_as_root=True)
         self.mox.ReplayAll()
 
@@ -271,8 +271,8 @@ class LvmTestCase(_ImageTestCase, test.TestCase):
                                             self.SIZE, sparse=sparse)
         self.disk.get_disk_size(self.TEMPLATE_PATH
                                          ).AndReturn(self.TEMPLATE_SIZE)
-        cmd = ('dd', 'if=%s' % self.TEMPLATE_PATH,
-               'of=%s' % self.PATH, 'bs=4M')
+        cmd = ('qemu-img', 'convert', '-O', 'raw', self.TEMPLATE_PATH,
+               self.PATH)
         self.utils.execute(*cmd, run_as_root=True)
         self.disk.resize2fs(self.PATH, run_as_root=True)
         self.mox.ReplayAll()
diff --git a/nova/virt/images.py b/nova/virt/images.py
index 018badecf..a5c960486 100644..100755
--- a/nova/virt/images.py
+++ b/nova/virt/images.py
@@ -184,10 +184,10 @@ def qemu_img_info(path):
     return QemuImgInfo(out)
 
 
-def convert_image(source, dest, out_format):
+def convert_image(source, dest, out_format, run_as_root=False):
     """Convert image to other format."""
     cmd = ('qemu-img', 'convert', '-O', out_format, source, dest)
-    utils.execute(*cmd)
+    utils.execute(*cmd, run_as_root=run_as_root)
 
 
 def fetch(context, image_href, path, _user_id, _project_id):
diff --git a/nova/virt/libvirt/imagebackend.py b/nova/virt/libvirt/imagebackend.py
index 74148a866..7e7175865 100755
--- a/nova/virt/libvirt/imagebackend.py
+++ b/nova/virt/libvirt/imagebackend.py
@@ -248,8 +248,7 @@ class Lvm(Image):
             size = size if resize else base_size
             libvirt_utils.create_lvm_image(self.vg, self.lv,
                                            size, sparse=self.sparse)
-            cmd = ('dd', 'if=%s' % base, 'of=%s' % self.path, 'bs=4M')
-            utils.execute(*cmd, run_as_root=True)
+            images.convert_image(base, self.path, 'raw', run_as_root=True)
             if resize:
                 disk.resize2fs(self.path, run_as_root=True)