From 77664b256856980cfaf35173d59d463c16562673 Mon Sep 17 00:00:00 2001
From: MotoKen <motokentsai@gmail.com>
Date: Thu, 8 Mar 2012 15:37:53 +0800
Subject: Checks image virtual size before qemu-img resize.

Checks virtual size instead of file size. Fixes bug 905350.

Change-Id: I1772b0996b7c9a2e07d3e298b156f777df67ef5f
---
 nova/virt/disk/api.py | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

(limited to 'nova')

diff --git a/nova/virt/disk/api.py b/nova/virt/disk/api.py
index a9b1067c2..f74c70bf4 100644
--- a/nova/virt/disk/api.py
+++ b/nova/virt/disk/api.py
@@ -29,6 +29,7 @@ import crypt
 import json
 import os
 import random
+import re
 import tempfile
 
 from nova import exception
@@ -90,6 +91,10 @@ for s in FLAGS.virt_mkfs:
         _DEFAULT_MKFS_COMMAND = mkfs_command
 
 
+_QEMU_VIRT_SIZE_REGEX = re.compile('^virtual size: (.*) \(([0-9]+) bytes\)',
+                                   re.MULTILINE)
+
+
 def mkfs(os_type, fs_label, target):
     mkfs_command = (_MKFS_COMMAND.get(os_type, _DEFAULT_MKFS_COMMAND) or
                     '') % locals()
@@ -97,10 +102,17 @@ def mkfs(os_type, fs_label, target):
         utils.execute(*mkfs_command.split())
 
 
+def get_image_virtual_size(image):
+    out, _err = utils.execute('qemu-img', 'info', image)
+    m = _QEMU_VIRT_SIZE_REGEX.search(out)
+    return int(m.group(2))
+
+
 def extend(image, size):
     """Increase image to size"""
-    file_size = os.path.getsize(image)
-    if file_size >= size:
+    # NOTE(MotoKen): check image virtual size before resize
+    virt_size = get_image_virtual_size(image)
+    if virt_size >= size:
         return
     utils.execute('qemu-img', 'resize', image, size)
     # NOTE(vish): attempts to resize filesystem
-- 
cgit