Ensure device node exists before wiping during volume deletion

If the LVM device node is missing when a Cinder volume is deleted,
a large amount of data will be written to /dev/.  Check that the
device node exists before performing a _copy_volume('/dev/zero'...)
to wipe it.  Fixes bug 1070023.

Change-Id: I77a0a5545a54a4adc905a781ed8120db7adccc27

diff --git a/cinder/volume/driver.py b/cinder/volume/driver.py
index 1f540d15996fa83c0b7ab0b43a196a5614459ac5..69c9d5ae76060e8aacc7815b21bb377581c2f736 100644 (file)
--- a/cinder/volume/driver.py
+++ b/cinder/volume/driver.py
@@ -147,9 +147,9 @@ class VolumeDriver(object):
         """Deletes a logical volume."""
         # zero out old volumes to prevent data leaking between users
         # TODO(ja): reclaiming space should be done lazy and low priority
-        self._copy_volume('/dev/zero', self.local_path(volume), size_in_g)
         dev_path = self.local_path(volume)
         if os.path.exists(dev_path):
+            self._copy_volume('/dev/zero', dev_path, size_in_g)
             self._try_execute('dmsetup', 'remove', '-f', dev_path,
                               run_as_root=True)
         self._try_execute('lvremove', '-f', "%s/%s" %