Added locking on the filer move operation
Added locking on the filer move operation

chrislusf/seaweedfs,chrislusf/seaweedfs,k85169336/seaweedfs,chrislusf/seaweedfs,hxiaodon/seaweedfs,hxiaodon/seaweedfs,k85169336/seaweedfs,chrislusf/seaweedfs