volume copying: clean up stale volume data files

fix https://github.com/chrislusf/seaweedfs/issues/2250

weed/server/volume_grpc_copy.go

@@ -69,16 +69,25 @@ func (vs *VolumeServer) VolumeCopy(ctx context.Context, req *volume_server_pb.Vo
 
 		ioutil.WriteFile(dataBaseFileName+".note", []byte(fmt.Sprintf("copying from %s", req.SourceDataNode)), 0755)
 
+		defer func() {
+			if err != nil {
+				os.Remove(dataBaseFileName + ".dat")
+				os.Remove(indexBaseFileName + ".idx")
+				os.Remove(dataBaseFileName + ".vif")
+				os.Remove(dataBaseFileName + ".note")
+			}
+		}()
+
 		// println("source:", volFileInfoResp.String())
-		if err := vs.doCopyFile(client, false, req.Collection, req.VolumeId, volFileInfoResp.CompactionRevision, volFileInfoResp.DatFileSize, dataBaseFileName, ".dat", false, true); err != nil {
+		if err = vs.doCopyFile(client, false, req.Collection, req.VolumeId, volFileInfoResp.CompactionRevision, volFileInfoResp.DatFileSize, dataBaseFileName, ".dat", false, true); err != nil {
 			return err
 		}
 
-		if err := vs.doCopyFile(client, false, req.Collection, req.VolumeId, volFileInfoResp.CompactionRevision, volFileInfoResp.IdxFileSize, indexBaseFileName, ".idx", false, false); err != nil {
+		if err = vs.doCopyFile(client, false, req.Collection, req.VolumeId, volFileInfoResp.CompactionRevision, volFileInfoResp.IdxFileSize, indexBaseFileName, ".idx", false, false); err != nil {
 			return err
 		}
 
-		if err := vs.doCopyFile(client, false, req.Collection, req.VolumeId, volFileInfoResp.CompactionRevision, volFileInfoResp.DatFileSize, dataBaseFileName, ".vif", false, true); err != nil {
+		if err = vs.doCopyFile(client, false, req.Collection, req.VolumeId, volFileInfoResp.CompactionRevision, volFileInfoResp.DatFileSize, dataBaseFileName, ".vif", false, true); err != nil {
 			return err
 		}