LVM: Disable multiattach for LIO iSCSI target

Multiattach does not yet work with the LIO iSCSI target.

Related-Bug: #1786327

Change-Id: I84f607de13bc17b00609ad37121d8678f7f4a920

cinder/tests/unit/volume/drivers/test_lvm_driver.py

@@ -957,6 +957,7 @@ class LVMISCSITestCase(test_driver.BaseDriverTestCase):
         # This value is set in check_for_setup_error.
         self.configuration = conf.Configuration(None)
         self.configuration.lvm_type = 'thin'
+        self.configuration.target_helper = 'lioadm'
         vg_obj = fake_lvm.FakeBrickLVM('cinder-volumes',
                                        False,
                                        None,

cinder/volume/drivers/lvm.py

@@ -242,6 +242,10 @@ class LVMVolumeDriver(driver.VolumeDriver):
         # This includes volumes and snapshots.
         total_volumes = len(self.vg.get_volumes())
 
+        supports_multiattach = True
+        if self.configuration.target_helper == 'lioadm':
+            supports_multiattach = False
+
         # Skip enabled_pools setting, treat the whole backend as one pool
         # XXX FIXME if multipool support is added to LVM driver.
         single_pool = {}
@@ -260,7 +264,7 @@ class LVMVolumeDriver(driver.VolumeDriver):
             total_volumes=total_volumes,
             filter_function=self.get_filter_function(),
             goodness_function=self.get_goodness_function(),
-            multiattach=True,
+            multiattach=supports_multiattach,
             backend_state='up'
         ))
         data["pools"].append(single_pool)

releasenotes/notes/lio-multiattach-disabled-a6ee89072fe5d032.yaml

@@ -0,0 +1,5 @@
+---
+issues:
+  - |
+    Multiattach support is disabled for the LVM driver when using the LIO iSCSI
+    target.  This functionality will be fixed in a later release.