From 45f9c298c2a6ba3b182ce3c225d09a0bfcb7dd2d Mon Sep 17 00:00:00 2001
From: Johannes Erdfelt <johannes.erdfelt@rackspace.com>
Date: Mon, 2 Jul 2012 20:48:30 +0000
Subject: Properly track VBD and VDI connections in xenapi fake

The fake xenapi module correctly destroys VBDs when destroying a VM
but it won't destroy VBDs when destroying a VDI. If an exception
occurs during a spawn when running test_xenapi, then another exception
can occur which obscures the original (and likely more important)
exception. This can make troubleshooting test suite failures more
difficult.

Change-Id: I19aad7f39b0707893a04784faef90815f7b0effb
---
 nova/tests/xenapi/stubs.py |  6 ------
 nova/virt/xenapi/fake.py   | 48 ++++++++++++++++++++++++++++++++++++++++------
 2 files changed, 42 insertions(+), 12 deletions(-)

diff --git a/nova/tests/xenapi/stubs.py b/nova/tests/xenapi/stubs.py
index 275e3ce63..1b9366761 100644
--- a/nova/tests/xenapi/stubs.py
+++ b/nova/tests/xenapi/stubs.py
@@ -211,12 +211,6 @@ class FakeSessionForVMTests(fake.SessionBase):
         template_vbd_ref = fake.create_vbd(template_vm_ref, template_vdi_ref)
         return template_vm_ref
 
-    def VDI_destroy(self, session_ref, vdi_ref):
-        fake.destroy_vdi(vdi_ref)
-
-    def VM_destroy(self, session_ref, vm_ref):
-        fake.destroy_vm(vm_ref)
-
     def SR_scan(self, session_ref, sr_ref):
         pass
 
diff --git a/nova/virt/xenapi/fake.py b/nova/virt/xenapi/fake.py
index 48c9c1083..e835abb57 100644
--- a/nova/virt/xenapi/fake.py
+++ b/nova/virt/xenapi/fake.py
@@ -127,17 +127,37 @@ def destroy_vm(vm_ref):
     vm_rec = _db_content['VM'][vm_ref]
 
     vbd_refs = vm_rec['VBDs']
-    for vbd_ref in vbd_refs:
+    # NOTE(johannes): Shallow copy since destroy_vbd will remove itself
+    # from the list
+    for vbd_ref in vbd_refs[:]:
         destroy_vbd(vbd_ref)
 
     del _db_content['VM'][vm_ref]
 
 
 def destroy_vbd(vbd_ref):
+    vbd_rec = _db_content['VBD'][vbd_ref]
+
+    vm_ref = vbd_rec['VM']
+    vm_rec = _db_content['VM'][vm_ref]
+    vm_rec['VBDs'].remove(vbd_ref)
+
+    vdi_ref = vbd_rec['VDI']
+    vdi_rec = _db_content['VDI'][vdi_ref]
+    vdi_rec['VBDs'].remove(vbd_ref)
+
     del _db_content['VBD'][vbd_ref]
 
 
 def destroy_vdi(vdi_ref):
+    vdi_rec = _db_content['VDI'][vdi_ref]
+
+    vbd_refs = vdi_rec['VBDs']
+    # NOTE(johannes): Shallow copy since destroy_vbd will remove itself
+    # from the list
+    for vbd_ref in vbd_refs[:]:
+        destroy_vbd(vbd_ref)
+
     del _db_content['VDI'][vdi_ref]
 
 
@@ -155,10 +175,15 @@ def create_vdi(name_label, sr_ref, **kwargs):
         'sm_config': {},
         'physical_utilisation': '123',
         'managed': True,
-        'VBDs': {},
     }
     vdi_rec.update(kwargs)
-    return _create_object('VDI', vdi_rec)
+    vdi_ref = _create_object('VDI', vdi_rec)
+    after_VDI_create(vdi_ref, vdi_rec)
+    return vdi_ref
+
+
+def after_VDI_create(vdi_ref, vdi_rec):
+    vdi_rec.setdefault('VBDs', [])
 
 
 def create_vbd(vm_ref, vdi_ref, userdevice=0):
@@ -172,14 +197,19 @@ def create_vbd(vm_ref, vdi_ref, userdevice=0):
 
 
 def after_VBD_create(vbd_ref, vbd_rec):
-    """Create read-only fields and backref from VM to VBD when VBD is
-    created."""
+    """Create read-only fields and backref from VM and VDI to VBD when VBD
+    is created."""
     vbd_rec['currently_attached'] = False
     vbd_rec['device'] = ''
+
     vm_ref = vbd_rec['VM']
     vm_rec = _db_content['VM'][vm_ref]
     vm_rec['VBDs'].append(vbd_ref)
 
+    vdi_ref = vbd_rec['VDI']
+    vdi_rec = _db_content['VDI'][vdi_ref]
+    vdi_rec['VBDs'].append(vbd_ref)
+
     vm_name_label = _db_content['VM'][vm_ref]['name_label']
     vbd_rec['vm_name_label'] = vm_name_label
 
@@ -725,7 +755,13 @@ class SessionBase(object):
         ref = params[1]
         if ref not in _db_content[table]:
             raise Failure(['HANDLE_INVALID', table, ref])
-        del _db_content[table][ref]
+
+        # Call destroy function (if exists)
+        destroy_func = globals().get('destroy_%s' % table.lower())
+        if destroy_func:
+            destroy_func(ref)
+        else:
+            del _db_content[table][ref]
 
     def _async(self, name, params):
         task_ref = create_task(name)
-- 
cgit