[Qemu-devel] [2.4 PATCH v3 19/19] iotests: add incremental backup failure recovery test

[John Snow <jsnow@redhat.com>]

To test the failure case, we modify iotests.py to allow us to specify
that we'd like to allow failures when we wait for block job events.

Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
---
 tests/qemu-iotests/124        | 57 ++++++++++++++++++++++++++++++++++++++++++-
 tests/qemu-iotests/124.out    |  4 +--
 tests/qemu-iotests/iotests.py |  6 +++--
 3 files changed, 62 insertions(+), 5 deletions(-)

diff --git a/tests/qemu-iotests/124 b/tests/qemu-iotests/124
index da8f0e0..1c07387 100644
--- a/tests/qemu-iotests/124
+++ b/tests/qemu-iotests/124
@@ -135,7 +135,11 @@ class TestIncrementalBackup(iotests.QMPTestCase):
                              mode='existing')
         self.assert_qmp(result, 'return', {})
 
-        event = self.wait_until_completed(bitmap.node, check_offset=validate)
+        event = self.wait_until_completed(bitmap.node, check_offset=validate,
+                                          allow_failures=(not validate))
+        if 'error' in event['data']:
+            bitmap.del_target()
+            return False
         if validate:
             return self.check_incremental(target)
 
@@ -180,6 +184,57 @@ class TestIncrementalBackup(iotests.QMPTestCase):
         return True
 
 
+    def test_incremental_failure(self):
+        '''Test: Verify backups made after a failure are correct.
+
+        Simulate a failure during an incremental backup block job,
+        emulate additional writes, then create another incremental backup
+        afterwards and verify that the backup created is correct.
+        '''
+
+        # Create a blkdebug interface to this img as 'drive1'
+        result = self.vm.qmp('blockdev-add', options={
+            'id': 'drive1',
+            'driver': iotests.imgfmt,
+            'file': {
+                'driver': 'blkdebug',
+                'image': {
+                    'driver': 'file',
+                    'filename': self.test_img
+                },
+                'set-state': [{
+                    'event': 'flush_to_disk',
+                    'state': 1,
+                    'new_state': 2
+                }],
+                'inject-error': [{
+                    'event': 'read_aio',
+                    'errno': 5,
+                    'state': 2,
+                    'immediately': False,
+                    'once': True
+                }],
+            }
+        })
+        self.assert_qmp(result, 'return', {})
+
+        self.create_full_backup()
+        self.add_bitmap('bitmap0', 'drive1')
+        # Note: at this point, during a normal execution,
+        # Assume that the VM resumes and begins issuing IO requests here.
+
+        self.hmp_io_writes('drive1', (('0xab', 0, 512),
+                                      ('0xfe', '16M', '256k'),
+                                      ('0x64', '32736k', '64k')))
+
+        result = self.create_incremental(validate=False)
+        self.assertFalse(result)
+        self.hmp_io_writes('drive1', (('0x9a', 0, 512),
+                                      ('0x55', '8M', '352k'),
+                                      ('0x78', '15872k', '1M')))
+        self.create_incremental()
+
+
     def test_sync_dirty_bitmap_missing(self):
         self.assert_no_active_block_jobs()
         self.files.append(self.foo_img)
diff --git a/tests/qemu-iotests/124.out b/tests/qemu-iotests/124.out
index 8d7e996..89968f3 100644
--- a/tests/qemu-iotests/124.out
+++ b/tests/qemu-iotests/124.out
@@ -1,5 +1,5 @@
-...
+....
 ----------------------------------------------------------------------
-Ran 3 tests
+Ran 4 tests
 
 OK
diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index 1402854..0522501 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -273,14 +273,16 @@ class QMPTestCase(unittest.TestCase):
         self.assert_no_active_block_jobs()
         return result
 
-    def wait_until_completed(self, drive='drive0', check_offset=True):
+    def wait_until_completed(self, drive='drive0', check_offset=True,
+                             allow_failures=False):
         '''Wait for a block job to finish, returning the event'''
         completed = False
         while not completed:
             for event in self.vm.get_qmp_events(wait=True):
                 if event['event'] == 'BLOCK_JOB_COMPLETED':
                     self.assert_qmp(event, 'data/device', drive)
-                    self.assert_qmp_absent(event, 'data/error')
+                    if not allow_failures:
+                        self.assert_qmp_absent(event, 'data/error')
                     if check_offset:
                         self.assert_qmp(event, 'data/offset', event['data']['len'])
                     completed = True
-- 
1.9.3