improve stale libvirt images handling fix. Bug 801412

If the unlink fails (because the path wasn't
even created for example), then that will shroud
the original failure.  Instead log failure to
remove the stale image, and raise the original exception.

Change-Id: I36c6968823bcf81d704319739b3a992dae75266a

1 files changed, 8 insertions, 2 deletions

diff --git a/nova/virt/images.py b/nova/virt/images.py
index 9a5a9e1b2c..463c5417e3 100644
--- a/nova/virt/images.py
+++ b/nova/virt/images.py
@@ -21,6 +21,7 @@
 Handling of VM disk images.
 """
 
+import errno
 import os
 
 from nova import exception
@@ -45,8 +46,13 @@ def fetch(context, image_href, path, _user_id, _project_id):
         with open(path, "wb") as image_file:
             metadata = image_service.get(context, image_id, image_file)
     except Exception:
-        os.unlink(path)
-        raise
+        with utils.save_and_reraise_exception():
+            try:
+                os.unlink(path)
+            except OSError, e:
+                if e.errno != errno.ENOENT:
+                    LOG.warn("unable to remove stale image '%s': %s" %
+                             (path, e.strerror))
     return metadata