tests: Update clean up session to serial session

As this guest performance will get worse when the disk is filled up,
and may influence the normal session. Use serial session instead.
Signed-off-by: NYiqiao Pu <ypu@redhat.com>

tests/fillup_disk.py

@@ -9,14 +9,15 @@ def run_fillup_disk(test, params, env):
 
     Suggest to test rebooting vm after this test.
 
-    @param test: kvm test object
+    @param test: QEMU test object
     @param params: Dictionary with the test parameters
     @param env: Dictionary with test environment.
     """
     vm = env.get_vm(params["main_vm"])
     vm.verify_alive()
-    timeout = int(params.get("login_timeout", 360))
-    session = vm.wait_for_login(timeout=timeout)
+    login_timeout = int(params.get("login_timeout", 360))
+    session = vm.wait_for_login(timeout=login_timeout)
+    session2 = vm.wait_for_serial_login(timeout=login_timeout)
 
     fillup_timeout = int(params.get("fillup_timeout"))
     fillup_size = int(params.get("fillup_size"))
@@ -43,7 +44,7 @@ def run_fillup_disk(test, params, env):
         while number >= 0:
             cmd = "rm -f /%s/fillup.%d" % (fill_dir, number)
             logging.debug(cmd)
-            s, o = session.cmd_status_output(cmd)
+            s, o = session2.cmd_status_output(cmd)
             if s != 0:
                 logging.error(o)
                 raise error.TestFail("Failed to remove file %s: %s;"
@@ -51,3 +52,4 @@ def run_fillup_disk(test, params, env):
                                      "command timeout" % (number, o))
             number -= 1
         session.close()
+        session2.close()