lvmdbustest: Add test for wipefs

Ensure that if an external program or user calles wipefs on a PV that we
correctly update the state of the daemon.

test/dbus/lvmdbustest.py

@@ -2385,6 +2385,40 @@ class TestDbusService(unittest.TestCase):
 		finally:
 			set_exec_mode(g_lvm_shell)
 
+	@staticmethod
+	def _wipe_it(block_device):
+		cmd = ["/usr/sbin/wipefs", '-a', block_device]
+		config = Popen(cmd, stdout=PIPE, stderr=PIPE, close_fds=True, env=os.environ)
+		config.communicate()
+		if config.returncode != 0:
+			return False
+		return True
+
+	def test_wipefs(self):
+		# Ensure we update the status of the daemon if an external process clears a PV
+		pv = self.objs[PV_INT][0]
+		pv_device_path = pv.Pv.Name
+
+		wipe_result = TestDbusService._wipe_it(pv_device_path)
+		self.assertTrue(wipe_result)
+
+		if wipe_result:
+			# Need to wait a bit before the daemon will reflect the change
+			start = time.time()
+			found = True
+			while found and time.time() < start + 10:
+				if (self._lookup(pv_device_path) == "/"):
+					found = False
+
+			print("Note: Time for udev update = %f" % (time.time() - start))
+			# Make sure that the service no longer has it
+			rc = self._lookup(pv_device_path)
+			self.assertEqual(rc, '/')
+
+			# Put it back
+			pv_object_path = self._pv_create(pv_device_path)
+			self.assertNotEqual(pv_object_path, '/')
+
 
 class AggregateResults(object):