Don't import libvirt_utils in disk api.

Updates the virt/disk/api so that we no longer import libvirt_utils.

This fixes issues when using Nova compute with compute drivers other
than libvirt. (xenapi, etc.)

Fixes LP Bug #1029501.

Change-Id: I46ece309480ce0a0941a96371a51d77712c41eb6

3 files changed, 17 insertions, 5 deletions

diff --git a/nova/virt/disk/api.py b/nova/virt/disk/api.py
index 68d83c386..e55b54fa1 100644
--- a/nova/virt/disk/api.py
+++ b/nova/virt/disk/api.py
@@ -39,7 +39,7 @@ from nova import utils
 from nova.virt.disk import guestfs
 from nova.virt.disk import loop
 from nova.virt.disk import nbd
-from nova.virt.libvirt import utils as libvirt_utils
+from nova.virt import images
 
 
 LOG = logging.getLogger(__name__)
@@ -103,9 +103,21 @@ def resize2fs(image, check_exit_code=False):
     utils.execute('resize2fs', image, check_exit_code=check_exit_code)
 
 
+def get_disk_size(path):
+    """Get the (virtual) size of a disk image
+
+    :param path: Path to the disk image
+    :returns: Size (in bytes) of the given disk image as it would be seen
+              by a virtual machine.
+    """
+    size = images.qemu_img_info(path)['virtual size']
+    size = size.split('(')[1].split()[0]
+    return int(size)
+
+
 def extend(image, size):
     """Increase image to size"""
-    virt_size = libvirt_utils.get_disk_size(image)
+    virt_size = get_disk_size(image)
     if virt_size >= size:
         return
     utils.execute('qemu-img', 'resize', image, size)
@@ -117,7 +129,7 @@ def can_resize_fs(image, size, use_cow=False):
     """Check whether we can resize contained file system."""
 
     # Check that we're increasing the size
-    virt_size = libvirt_utils.get_disk_size(image)
+    virt_size = get_disk_size(image)
     if virt_size >= size:
         return False
 
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index 761ca3e45..71454d38e 100644
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -2667,7 +2667,7 @@ class LibvirtDriver(driver.ComputeDriver):
             disk_type = driver_nodes[cnt].get('type')
             if disk_type == "qcow2":
                 backing_file = libvirt_utils.get_disk_backing_file(path)
-                virt_size = libvirt_utils.get_disk_size(path)
+                virt_size = disk.get_disk_size(path)
             else:
                 backing_file = ""
                 virt_size = 0
diff --git a/nova/virt/libvirt/imagebackend.py b/nova/virt/libvirt/imagebackend.py
index d66dbaf2c..001bf58a3 100644
--- a/nova/virt/libvirt/imagebackend.py
+++ b/nova/virt/libvirt/imagebackend.py
@@ -191,7 +191,7 @@ class Lvm(Image):
     def create_image(self, prepare_template, base, size, *args, **kwargs):
         @utils.synchronized(base)
         def create_lvm_image(base, size):
-            base_size = libvirt_utils.get_disk_size(base)
+            base_size = disk.get_disk_size(base)
             resize = size > base_size
             size = size if resize else base_size
             libvirt_utils.create_lvm_image(self.vg, self.lv,