ceph: close out mds, osd connections before stopping auth

The auth module (part of the mon_client) is needed to free any
ceph_authorizer(s) used by the mds and osd connections.  Flush the msgr
workqueue before stopping monc to ensure that the destroy_authorizer
auth op is available when those connections are closed out.

Signed-off-by: Sage Weil <sage@newdream.net>

fs/ceph/messenger.c

@@ -120,6 +120,12 @@ void ceph_msgr_exit(void)
 	destroy_workqueue(ceph_msgr_wq);
 }
 
+void ceph_msgr_flush()
+{
+	flush_workqueue(ceph_msgr_wq);
+}
+
+
 /*
  * socket callback functions
  */