fix https://github.com/chrislusf/seaweedfs/issues/473
@ -56,5 +56,7 @@ func (t *Topology) UnRegisterDataNode(dn *DataNode) {
dn.UpAdjustVolumeCountDelta(-dn.GetVolumeCount())
dn.UpAdjustActiveVolumeCountDelta(-dn.GetActiveVolumeCount())
dn.UpAdjustMaxVolumeCountDelta(-dn.GetMaxVolumeCount())
dn.Parent().UnlinkChildNode(dn.Id())
if dn.Parent() != nil {
}