commit 69ae27579d7ac5fdd30efd57dbde62beff86d5ea
Author: Lee Yarwood <lyarwood@redhat.com>
Date:   Thu May 14 10:49:07 2020 +0100

    compute: Allow snapshots to be created from PAUSED volume backed instances
    
    Iabeb44f843c3c04f767c4103038fcf6c52966ff3 allowed snapshots to be
    created from PAUSED non-volume backed instances but missed the volume
    backed use case.
    
    This change simply adds PAUSED to the list of acceptable vm_states when
    creating a snapshot from a volume backed instance in addition to the
    already supported ACTIVE, STOPPED and SUSPENDED vm_states.
    
    Closes-Bug: #1878583
    Change-Id: I9f95a054de9d43ecaa50ff7ffc9343490e212d53
    (cherry picked from commit cfde53e4b402e71d7f53b6e0ab232854dba160dc)
    (cherry picked from commit a270eeeb9b1a65045c3a8bf3cfad5eee6415f63c)
    (cherry picked from commit c93ca609568bac73210f39207c821867620b2f0e)
    (cherry picked from commit 04a8399f1d0ce38bb3089c6c4cb3e11da924b2ae)
    (cherry picked from commit 35c1846d5cbdf10b08de1ffcd454a67662d32917)

diff --git a/nova/compute/api.py b/nova/compute/api.py
index 6f1ff7c..e756cdd 100644
--- a/nova/compute/api.py
+++ b/nova/compute/api.py
@@ -2938,7 +2938,7 @@ class API(base.Base):
     # NOTE(melwitt): We don't check instance lock for snapshot because lock is
     #                intended to prevent accidental change/delete of instances
     @check_instance_state(vm_state=[vm_states.ACTIVE, vm_states.STOPPED,
-                                    vm_states.SUSPENDED])
+                                    vm_states.PAUSED, vm_states.SUSPENDED])
     def snapshot_volume_backed(self, context, instance, name,
                                extra_properties=None):
         """Snapshot the given volume-backed instance.
diff --git a/nova/tests/unit/compute/test_compute_api.py b/nova/tests/unit/compute/test_compute_api.py
index a1c8de7..ed44e4b 100644
--- a/nova/tests/unit/compute/test_compute_api.py
+++ b/nova/tests/unit/compute/test_compute_api.py
@@ -3415,6 +3415,11 @@ class _ComputeAPIUnitTestMixIn(object):
                                           quiesce_unsupported=True,
                                           vm_state=vm_states.SUSPENDED)
 
+    def test_snapshot_volume_backed_with_pause(self):
+        self._test_snapshot_volume_backed(quiesce_required=False,
+                                          quiesce_unsupported=True,
+                                          vm_state=vm_states.PAUSED)
+
     @mock.patch.object(context, 'set_target_cell')
     @mock.patch.object(objects.BlockDeviceMapping, 'get_by_volume')
     def test_get_bdm_by_volume_id(self, mock_get_by_volume,