From fc628957d03365552dbf094ca143d3ae998ed154 Mon Sep 17 00:00:00 2001
From: Chris M <cinder@tristero.net>
Date: Sun, 21 Jul 2019 18:54:11 +0000
Subject: [PATCH] Fix dothill multiattach support

Report multiattach support correctly, and avoid attempts to mount a
volume more than once to the same host.

Change-Id: Ibff3dda47d0891606e07187624dde700b01eb869
---
 .../tests/unit/volume/drivers/test_dothill.py |  4 +--
 .../volume/drivers/dothill/dothill_client.py  | 26 +++++++++++++++++++
 .../volume/drivers/dothill/dothill_common.py  |  3 +--
 3 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/cinder/tests/unit/volume/drivers/test_dothill.py b/cinder/tests/unit/volume/drivers/test_dothill.py
index 77ebc581e8b..02cabe12887 100644
--- a/cinder/tests/unit/volume/drivers/test_dothill.py
+++ b/cinder/tests/unit/volume/drivers/test_dothill.py
@@ -400,6 +400,7 @@ class TestFCDotHillCommon(test.TestCase):
         self.assertIsNone(ret)
         self.assertEqual({'driver_version': self.common.VERSION,
                           'pools': [{'QoS_support': False,
+                                     'multiattach': True,
                                      'free_capacity_gb': 90,
                                      'location_info':
                                      'DotHillVolumeDriver:xxxxx:OpenStack:A',
@@ -407,7 +408,6 @@ class TestFCDotHillCommon(test.TestCase):
                                      'total_capacity_gb': 100}],
                           'storage_protocol': None,
                           'vendor_name': 'DotHill',
-                          'multiattach': True,
                           'volume_backend_name': None}, self.common.stats)
 
     @mock.patch.object(dothill.DotHillClient, 'create_volume')
@@ -716,11 +716,11 @@ class TestDotHillFC(test.TestCase):
                  'driver_version': self.driver.VERSION,
                  'volume_backend_name': None,
                  'vendor_name': self.vendor_name,
-                 'multiattach': True,
                  'pools': [{'free_capacity_gb': 90,
                             'reserved_percentage': 0,
                             'total_capacity_gb': 100,
                             'QoS_support': False,
+                            'multiattach': True,
                             'location_info': 'xx:xx:xx:xx',
                             'pool_name': 'x'}]}
         mock_stats.side_effect = [exception.Invalid, stats, stats]
diff --git a/cinder/volume/drivers/dothill/dothill_client.py b/cinder/volume/drivers/dothill/dothill_client.py
index 1a1a3e9e166..7a14fc1bd9b 100644
--- a/cinder/volume/drivers/dothill/dothill_client.py
+++ b/cinder/volume/drivers/dothill/dothill_client.py
@@ -23,6 +23,7 @@ from defusedxml import lxml as etree
 from oslo_log import log as logging
 from oslo_utils import strutils
 from oslo_utils import units
+import pprint
 import requests
 import six
 
@@ -380,8 +381,33 @@ class DotHillClient(object):
         raise dh_exception.DotHillRequestError(
             message=_("No LUNs available for mapping to host %s.") % host)
 
+    def _is_mapped(self, volume_name, ids):
+        if not isinstance(ids, list):
+            ids = [ids]
+        try:
+            xml = self._request('/show/volume-maps', volume_name)
+
+            for obj in xml.xpath("//OBJECT[@basetype='volume-view-mappings']"):
+                lun = obj.findtext("PROPERTY[@name='lun']")
+                iid = obj.findtext("PROPERTY[@name='identifier']")
+                if iid in ids:
+                    LOG.debug("volume '{}' is already mapped to {} at lun {}".
+                              format(volume_name, iid, lun))
+                    return lun
+        except Exception as e:
+            LOG.exception("failed to look up mappings for volume '%s'",
+                          volume_name)
+            raise
+        return None
+
     @coordination.synchronized('{self._driver_name}-{self._array_name}-map')
     def map_volume(self, volume_name, connector, connector_element):
+        # If multiattach enabled, its possible the volume is already mapped
+        LOG.debug("map_volume(%s, %s, %s)", volume_name,
+                  pprint.pformat(connector), connector_element)
+        lun = self._is_mapped(volume_name, connector[connector_element])
+        if lun:
+            return lun
         if connector_element == 'wwpns':
             lun = self._get_first_available_lun_for_host(connector['wwpns'][0])
             host = ",".join(connector['wwpns'])
diff --git a/cinder/volume/drivers/dothill/dothill_common.py b/cinder/volume/drivers/dothill/dothill_common.py
index bca02950e14..4e96f9d93ee 100644
--- a/cinder/volume/drivers/dothill/dothill_common.py
+++ b/cinder/volume/drivers/dothill/dothill_common.py
@@ -264,10 +264,9 @@ class DotHillCommon(object):
                  'storage_protocol': None,
                  'vendor_name': self.vendor_name,
                  'volume_backend_name': None,
-                 'multiattach': True,
                  'pools': []}
 
-        pool = {'QoS_support': False}
+        pool = {'QoS_support': False, 'multiattach': True}
         try:
             src_type = "%sVolumeDriver" % self.vendor_name
             backend_stats = self.client.backend_stats(self.backend_name,