[PATCH 20/22] iotests: Add tests for invalid Quorum @replaces

[Max Reitz <mreitz@redhat.com>]

Add two tests to see that you cannot replace a Quorum child with the
mirror job while the child is in use by a different parent.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 tests/qemu-iotests/041     | 57 +++++++++++++++++++++++++++++++++++++-
 tests/qemu-iotests/041.out |  4 +--
 2 files changed, 58 insertions(+), 3 deletions(-)

diff --git a/tests/qemu-iotests/041 b/tests/qemu-iotests/041
index 20ae9750b7..148dc47ce4 100755
--- a/tests/qemu-iotests/041
+++ b/tests/qemu-iotests/041
@@ -34,6 +34,8 @@ quorum_img3 = os.path.join(iotests.test_dir, 'quorum3.img')
 quorum_repair_img = os.path.join(iotests.test_dir, 'quorum_repair.img')
 quorum_snapshot_file = os.path.join(iotests.test_dir, 'quorum_snapshot.img')
 
+nbd_sock_path = os.path.join(iotests.test_dir, 'nbd.sock')
+
 class TestSingleDrive(iotests.QMPTestCase):
     image_len = 1 * 1024 * 1024 # MB
     qmp_cmd = 'drive-mirror'
@@ -901,7 +903,8 @@ class TestRepairQuorum(iotests.QMPTestCase):
 
     def tearDown(self):
         self.vm.shutdown()
-        for i in self.IMAGES + [ quorum_repair_img, quorum_snapshot_file ]:
+        for i in self.IMAGES + [ quorum_repair_img, quorum_snapshot_file,
+                                 nbd_sock_path ]:
             # Do a try/except because the test may have deleted some images
             try:
                 os.remove(i)
@@ -1075,6 +1078,58 @@ class TestRepairQuorum(iotests.QMPTestCase):
         self.assert_has_block_node("repair0", quorum_repair_img)
         self.vm.assert_block_path('quorum0/children.1', 'repair0')
 
+    '''
+    Check that we cannot replace a Quorum child when it has other
+    parents.
+    '''
+    def test_with_other_parent(self):
+        result = self.vm.qmp('nbd-server-start',
+                             addr={
+                                 'type': 'unix',
+                                 'data': {'path': nbd_sock_path}
+                             })
+        self.assert_qmp(result, 'return', {})
+
+        result = self.vm.qmp('nbd-server-add', device='img1')
+        self.assert_qmp(result, 'return', {})
+
+        result = self.vm.qmp('drive-mirror', job_id='mirror', device='quorum0',
+                             sync='full', node_name='repair0', replaces='img1',
+                             target=quorum_repair_img, format=iotests.imgfmt)
+        self.assert_qmp(result, 'error/desc',
+                        "Cannot replace 'img1' by a node mirrored from "
+                        "'quorum0', because it cannot be guaranteed that doing "
+                        "so would not lead to an abrupt change of visible data")
+
+    '''
+    The same as test_with_other_parent(), but add the NBD server only
+    when the mirror job is already running.
+    '''
+    def test_with_other_parents_after_mirror_start(self):
+        result = self.vm.qmp('nbd-server-start',
+                             addr={
+                                 'type': 'unix',
+                                 'data': {'path': nbd_sock_path}
+                             })
+        self.assert_qmp(result, 'return', {})
+
+        result = self.vm.qmp('drive-mirror', job_id='mirror', device='quorum0',
+                             sync='full', node_name='repair0', replaces='img1',
+                             target=quorum_repair_img, format=iotests.imgfmt)
+        self.assert_qmp(result, 'return', {})
+
+        result = self.vm.qmp('nbd-server-add', device='img1')
+        self.assert_qmp(result, 'return', {})
+
+        # The full error message goes to stderr, so we unfortunately
+        # cannot check it here
+        self.complete_and_wait('mirror',
+                               completion_error='Operation not permitted')
+
+        # Should not have been replaced
+        self.vm.assert_block_path('quorum0/children.1', 'img1')
+
+
 # Test mirroring with a source that does not have any parents (not even a
 # BlockBackend)
 class TestOrphanedSource(iotests.QMPTestCase):
diff --git a/tests/qemu-iotests/041.out b/tests/qemu-iotests/041.out
index f496be9197..ffc779b4d1 100644
--- a/tests/qemu-iotests/041.out
+++ b/tests/qemu-iotests/041.out
@@ -1,5 +1,5 @@
-...........................................................................................
+.............................................................................................
 ----------------------------------------------------------------------
-Ran 91 tests
+Ran 93 tests
 
 OK
-- 
2.21.0