Re-using the code of os brick cinder

To avoid the errors during force delete of logical volume,
cinder library os brick is already using udevadm settle for it.
Calling the same library of cinder in nova too.

Change-Id: I092afdd0409ab27187cf74cd1514e9e0c550d52c
Closes-Bug: #1191960

nova/privsep/fs.py

@@ -75,11 +75,6 @@ def lvinfo(path):
                                 '--separator', '|', path)
 
 
-@nova.privsep.sys_admin_pctxt.entrypoint
-def lvremove(path):
-    processutils.execute('lvremove', '-f', path, attempts=3)
-
-
 @nova.privsep.sys_admin_pctxt.entrypoint
 def blockdev_size(path):
     return processutils.execute('blockdev', '--getsize64', path)

nova/tests/unit/virt/libvirt/storage/test_lvm.py

@@ -118,7 +118,7 @@ class LvmTestCase(test.NoDBTestCase):
         lvm.clear_volume('/dev/foo')
 
     @mock.patch.object(lvm, 'clear_volume')
-    @mock.patch('nova.privsep.fs.lvremove',
+    @mock.patch('os_brick.local_dev.lvm.LVM.delete',
                 side_effect=processutils.ProcessExecutionError('Error'))
     def test_fail_remove_all_logical_volumes(self, mock_clear, mock_lvremove):
         self.assertRaises(exception.VolumesNotRemoved,

nova/virt/libvirt/storage/lvm.py

@@ -21,6 +21,7 @@
 
 import os
 
+from os_brick.local_dev import lvm as brick_lvm
 from oslo_concurrency import processutils
 from oslo_log import log as logging
 from oslo_utils import units
@@ -186,7 +187,7 @@ def remove_volumes(paths):
     for path in paths:
         clear_volume(path)
         try:
-            nova.privsep.fs.lvremove(path)
+            brick_lvm.LVM.delete(path)
         except processutils.ProcessExecutionError as exp:
             errors.append(six.text_type(exp))
     if errors: