Signed-off-by: Max Reitz
---
tests/qemu-iotests/040 | 61 ++
tests/qemu-iotests/040.out | 4 +--
2 files changed, 63 insertions(+), 2 deletions(-)
diff --git a/tests/qemu-iotests/040 b/tests/qemu-iotests/040
index a0a0db8889..558fdb9a09 100755
--- a/tests/qemu-iotests/040
+++ b/tests/qemu-iotests/040
@@ -605,5 +605,66 @@ class TestCommitWithFilters(iotests.QMPTestCase):
# 3 has been comitted into 2
self.pattern_files[3] = self.img2
+class TestCommitWithOverriddenBacking(iotests.QMPTestCase):
+img_base_a = os.path.join(iotests.test_dir, 'base_a.img')
+img_base_b = os.path.join(iotests.test_dir, 'base_b.img')
+img_top = os.path.join(iotests.test_dir, 'top.img')
+
+def setUp(self):
+qemu_img('create', '-f', iotests.imgfmt, self.img_base_a, '1M')
+qemu_img('create', '-f', iotests.imgfmt, self.img_base_b, '1M')
+qemu_img('create', '-f', iotests.imgfmt, '-b', self.img_base_a, \
+ self.img_top)
+
+self.vm = iotests.VM()
+self.vm.launch()
+
+# Use base_b instead of base_a as the backing of top
+result = self.vm.qmp('blockdev-add', **{
+'node-name': 'top',
+'driver': iotests.imgfmt,
+'file': {
+'driver': 'file',
+'filename': self.img_top
+},
+'backing': {
+'node-name': 'base',
+'driver': iotests.imgfmt,
+'file': {
+'driver': 'file',
+'filename': self.img_base_b
+}
+}
+})
+self.assert_qmp(result, 'return', {})
+
+def tearDown(self):
+self.vm.shutdown()
+os.remove(self.img_top)
+os.remove(self.img_base_a)
+os.remove(self.img_base_b)
+
+def test_commit_to_a(self):
+# Try committing to base_a (which should fail, as top's
+# backing image is base_b instead)
+result = self.vm.qmp('block-commit',
+ job_id='commit',
+ device='top',
+ base=self.img_base_a)
+self.assert_qmp(result, 'error/class', 'GenericError')
+
+def test_commit_to_b(self):
+# Try committing to base_b (which should work, since that is
+# actually top's backing image)
+result = self.vm.qmp('block-commit',
+ job_id='commit',
+ device='top',
+ base=self.img_base_b)
+self.assert_qmp(result, 'return', {})
+
+self.vm.event_wait('BLOCK_JOB_READY')
+self.vm.qmp('block-job-complete', device='commit')
+self.vm.event_wait('BLOCK_JOB_COMPLETED')
+
if __name__ == '__main__':
iotests.main(supported_fmts=['qcow2', 'qed'])
diff --git a/tests/qemu-iotests/040.out b/tests/qemu-iotests/040.out
index fe58934d7a..499af0e2ff 100644
--- a/tests/qemu-iotests/040.out
+++ b/tests/qemu-iotests/040.out
@@ -1,5 +1,5 @@
-...
+.
--
-Ran 51 tests
+Ran 53 tests
OK
--
2.21.0
