Unity: add option to delete attached snapshots

Add a option to delete the snapshot even if it is attached to hosts.

Closes-bug: #1798529
Change-Id: I53b7efc093f7fc5823e0543aca4ce57720b88f5b
(cherry picked from commit 547ec23bcd1fac006e0a9c6949fd34e0698e1ca1)

Author: Murray-LIANG

cinder/volume/drivers/dell_emc/unity/adapter.py

@@ -138,6 +138,7 @@ def __init__(self, version=None):
         self.storage_pools_map = None
         self._client = None
         self.allowed_ports = None
+        self.force_delete_attached_snapshots = False
 
     def do_setup(self, driver, conf):
         self.driver = driver
@@ -166,6 +167,9 @@ def do_setup(self, driver, conf):
 
         self.allowed_ports = self.validate_ports(self.config.unity_io_ports)
 
+        self.force_delete_attached_snapshots = (
+            self.config.force_delete_attached_snapshots)
+
         group_name = (self.config.config_group if self.config.config_group
                       else 'DEFAULT')
         folder_name = '%(group)s.%(sys_name)s' % {
@@ -408,7 +412,8 @@ def delete_snapshot(self, snapshot):
         :param snapshot: the snapshot to delete.
         """
         snap = self.client.get_snap(name=snapshot.name)
-        self.client.delete_snap(snap)
+        self.client.delete_snap(
+            snap, even_attached=self.force_delete_attached_snapshots)
 
     def _get_referenced_lun(self, existing_ref):
         if 'source-id' in existing_ref:

cinder/volume/drivers/dell_emc/unity/client.py

@@ -160,13 +160,13 @@ def create_snap(self, src_lun_id, name=None):
         return snap
 
     @staticmethod
-    def delete_snap(snap):
+    def delete_snap(snap, even_attached=False):
         if snap is None:
             LOG.debug("Snap to delete is None, skipping deletion.")
             return
 
         try:
-            snap.delete()
+            snap.delete(even_attached=even_attached)
         except storops_ex.UnityResourceNotFoundError as err:
             LOG.debug("Snap %(snap_name)s may be deleted already. "
                       "Message: %(err)s",

cinder/volume/drivers/dell_emc/unity/driver.py

@@ -36,7 +36,13 @@
     cfg.ListOpt('unity_io_ports',
                 default=None,
                 help='A comma-separated list of iSCSI or FC ports to be used. '
-                     'Each port can be Unix-style glob expressions.')]
+                     'Each port can be Unix-style glob expressions.'),
+    cfg.BoolOpt('force_delete_attached_snapshots',
+                default=False,
+                help='To force delete the snapshot from Unity even when it is '
+                     'attached to hosts. Be careful to set it to True. If the '
+                     'snapshot is attached, force deleting it could cause data'
+                     'unaccessble and/or data loss. By default, it is False.')]
 
 CONF.register_opts(UNITY_OPTS)
 
@@ -52,9 +58,11 @@ class UnityDriver(driver.TransferVD,
         00.05.00 - Initial version
         00.05.01 - Backport thin clone from Pike
         00.05.02 - Fixed bug 170311: temp snapshot for backup was deleted twice
+        00.05.03 - Fixed bug 1798529: add option for force deleting attached
+                   snapshots
     """
 
-    VERSION = '00.05.02'
+    VERSION = '00.05.03'
     VENDOR = 'Dell EMC'
     # ThirdPartySystems wiki page
     CI_WIKI_NAME = "EMC_UNITY_CI"