iotests: copy-before-write: add cases for cbw-timeout option

Add two simple test-cases: timeout failure with
break-snapshot-on-cbw-error behavior and similar with
break-guest-write-on-cbw-error behavior.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>

tests/qemu-iotests/tests/copy-before-write

@@ -129,6 +129,87 @@ read 1048576/1048576 bytes at offset 0
 1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 """)
 
+    def do_cbw_timeout(self, on_cbw_error):
+        result = self.vm.qmp('object-add', {
+            'qom-type': 'throttle-group',
+            'id': 'group0',
+            'limits': {'bps-write': 300 * 1024}
+        })
+        self.assert_qmp(result, 'return', {})
+
+        result = self.vm.qmp('blockdev-add', {
+            'node-name': 'cbw',
+            'driver': 'copy-before-write',
+            'on-cbw-error': on_cbw_error,
+            'cbw-timeout': 1,
+            'file': {
+                'driver': iotests.imgfmt,
+                'file': {
+                    'driver': 'file',
+                    'filename': source_img,
+                }
+            },
+            'target': {
+                'driver': 'throttle',
+                'throttle-group': 'group0',
+                'file': {
+                    'driver': 'qcow2',
+                    'file': {
+                        'driver': 'file',
+                        'filename': temp_img
+                    }
+                }
+            }
+        })
+        self.assert_qmp(result, 'return', {})
+
+        result = self.vm.qmp('blockdev-add', {
+            'node-name': 'access',
+            'driver': 'snapshot-access',
+            'file': 'cbw'
+        })
+        self.assert_qmp(result, 'return', {})
+
+        result = self.vm.qmp('human-monitor-command',
+                             command_line='qemu-io cbw "write 0 512K"')
+        self.assert_qmp(result, 'return', '')
+
+        # We need second write to trigger throttling
+        result = self.vm.qmp('human-monitor-command',
+                             command_line='qemu-io cbw "write 512K 512K"')
+        self.assert_qmp(result, 'return', '')
+
+        result = self.vm.qmp('human-monitor-command',
+                             command_line='qemu-io access "read 0 1M"')
+        self.assert_qmp(result, 'return', '')
+
+        self.vm.shutdown()
+        log = self.vm.get_log()
+        log = re.sub(r'^\[I \d+\.\d+\] OPENED\n', '', log)
+        log = re.sub(r'\[I \+\d+\.\d+\] CLOSED\n?$', '', log)
+        log = iotests.filter_qemu_io(log)
+        return log
+
+    def test_timeout_break_guest(self):
+        log = self.do_cbw_timeout('break-guest-write')
+        self.assertEqual(log, """\
+wrote 524288/524288 bytes at offset 0
+512 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+write failed: Connection timed out
+read 1048576/1048576 bytes at offset 0
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+""")
+
+    def test_timeout_break_snapshot(self):
+        log = self.do_cbw_timeout('break-snapshot')
+        self.assertEqual(log, """\
+wrote 524288/524288 bytes at offset 0
+512 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 524288/524288 bytes at offset 524288
+512 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read failed: Permission denied
+""")
+
 
 if __name__ == '__main__':
     iotests.main(supported_fmts=['qcow2'],

tests/qemu-iotests/tests/copy-before-write.out

@@ -1,5 +1,5 @@
-..
+....
 ----------------------------------------------------------------------
-Ran 2 tests
+Ran 4 tests
 
 OK