[PATCH v3 07/10] iotests/129: Actually test a commit job

[Max Reitz <mreitz@redhat.com>]

Before this patch, test_block_commit() performs an active commit, which
under the hood is a mirror job.  If we want to test various different
block jobs, we should perhaps run an actual commit job instead.

Doing so requires adding an overlay above the source node before the
commit is done (and then specifying the source node as the top node for
the commit job).

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 tests/qemu-iotests/129 | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/tests/qemu-iotests/129 b/tests/qemu-iotests/129
index 58536bc6ee..7b4b6649f0 100755
--- a/tests/qemu-iotests/129
+++ b/tests/qemu-iotests/129
@@ -26,6 +26,7 @@ class TestStopWithBlockJob(iotests.QMPTestCase):
     test_img = os.path.join(iotests.test_dir, 'test.img')
     target_img = os.path.join(iotests.test_dir, 'target.img')
     base_img = os.path.join(iotests.test_dir, 'base.img')
+    overlay_img = os.path.join(iotests.test_dir, 'overlay.img')
 
     def setUp(self):
         iotests.qemu_img('create', '-f', iotests.imgfmt, self.base_img, "1G")
@@ -36,6 +37,7 @@ class TestStopWithBlockJob(iotests.QMPTestCase):
         self.vm.add_object('throttle-group,id=tg0,x-bps-total=1024')
 
         source_drive = 'driver=throttle,' \
+                       'node-name=source,' \
                        'throttle-group=tg0,' \
                       f'file.driver={iotests.imgfmt},' \
                       f'file.file.filename={self.test_img}'
@@ -45,7 +47,8 @@ class TestStopWithBlockJob(iotests.QMPTestCase):
 
     def tearDown(self):
         self.vm.shutdown()
-        for img in (self.test_img, self.target_img, self.base_img):
+        for img in (self.test_img, self.target_img, self.base_img,
+                    self.overlay_img):
             iotests.try_remove(img)
 
     def do_test_stop(self, cmd, **args):
@@ -72,7 +75,27 @@ class TestStopWithBlockJob(iotests.QMPTestCase):
                           sync="full")
 
     def test_block_commit(self):
-        self.do_test_stop("block-commit", device="drive0")
+        # Add overlay above the source node so that we actually use a
+        # commit job instead of a mirror job
+
+        iotests.qemu_img('create', '-f', iotests.imgfmt, self.overlay_img,
+                         '1G')
+
+        result = self.vm.qmp('blockdev-add', **{
+                                 'node-name': 'overlay',
+                                 'driver': iotests.imgfmt,
+                                 'file': {
+                                     'driver': 'file',
+                                     'filename': self.overlay_img
+                                 }
+                             })
+        self.assert_qmp(result, 'return', {})
+
+        result = self.vm.qmp('blockdev-snapshot',
+                             node='source', overlay='overlay')
+        self.assert_qmp(result, 'return', {})
+
+        self.do_test_stop('block-commit', device='drive0', top_node='source')
 
 if __name__ == '__main__':
     iotests.main(supported_fmts=["qcow2"],
-- 
2.29.2