iotests: Check that @replaces can replace filters

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200218103454.296704-20-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

tests/qemu-iotests/041

@@ -1190,6 +1190,52 @@ class TestOrphanedSource(iotests.QMPTestCase):
         self.assertFalse('mirror-filter' in nodes,
                          'Mirror filter node did not disappear')
 
+# Test cases for @replaces that do not necessarily involve Quorum
+class TestReplaces(iotests.QMPTestCase):
+    # Each of these test cases needs their own block graph, so do not
+    # create any nodes here
+    def setUp(self):
+        self.vm = iotests.VM()
+        self.vm.launch()
+
+    def tearDown(self):
+        self.vm.shutdown()
+        for img in (test_img, target_img):
+            try:
+                os.remove(img)
+            except OSError:
+                pass
+
+    @iotests.skip_if_unsupported(['copy-on-read'])
+    def test_replace_filter(self):
+        """
+        Check that we can replace filter nodes.
+        """
+        result = self.vm.qmp('blockdev-add', **{
+                                 'driver': 'copy-on-read',
+                                 'node-name': 'filter0',
+                                 'file': {
+                                     'driver': 'copy-on-read',
+                                     'node-name': 'filter1',
+                                     'file': {
+                                         'driver': 'null-co'
+                                     }
+                                 }
+                             })
+        self.assert_qmp(result, 'return', {})
+
+        result = self.vm.qmp('blockdev-add',
+                             node_name='target', driver='null-co')
+        self.assert_qmp(result, 'return', {})
+
+        result = self.vm.qmp('blockdev-mirror', job_id='mirror', device='filter0',
+                             target='target', sync='full', replaces='filter1')
+        self.assert_qmp(result, 'return', {})
+
+        self.complete_and_wait('mirror')
+
+        self.vm.assert_block_path('filter0', '/file', 'target')
+
 if __name__ == '__main__':
     iotests.main(supported_fmts=['qcow2', 'qed'],
                  supported_protocols=['file'],

tests/qemu-iotests/041.out

@@ -1,5 +1,5 @@
-.............................................................................................
+..............................................................................................
 ----------------------------------------------------------------------
-Ran 93 tests
+Ran 94 tests
 
 OK