clone volume locations in case they are changed

fix https://github.com/seaweedfs/seaweedfs/issues/4642

weed/shell/command_ec_encode.go

@@ -98,7 +98,7 @@ func doEcEncode(commandEnv *CommandEnv, collection string, vid needle.VolumeId,
 	}
 
 	// find volume location
-	locations, found := commandEnv.MasterClient.GetLocations(uint32(vid))
+	locations, found := commandEnv.MasterClient.GetLocationsClone(uint32(vid))
 	if !found {
 		return fmt.Errorf("volume %d not found", vid)
 	}

weed/shell/command_volume_tier_download.go

@@ -105,7 +105,7 @@ func collectRemoteVolumes(topoInfo *master_pb.TopologyInfo, selectedCollection s
 
 func doVolumeTierDownload(commandEnv *CommandEnv, writer io.Writer, collection string, vid needle.VolumeId) (err error) {
 	// find volume location
-	locations, found := commandEnv.MasterClient.GetLocations(uint32(vid))
+	locations, found := commandEnv.MasterClient.GetLocationsClone(uint32(vid))
 	if !found {
 		return fmt.Errorf("volume %d not found", vid)
 	}

weed/shell/command_volume_tier_move.go

@@ -116,7 +116,7 @@ func (c *commandVolumeTierMove) Do(args []string, commandEnv *CommandEnv, writer
 			for job := range jobs {
 				fmt.Fprintf(writer, "moving volume %d from %s to %s with disk type %s ...\n", job.vid, job.src, dst.dataNode.Id, toDiskType.ReadableString())
 
-				locations, found := commandEnv.MasterClient.GetLocations(uint32(job.vid))
+				locations, found := commandEnv.MasterClient.GetLocationsClone(uint32(job.vid))
 				if !found {
 					fmt.Printf("volume %d not found", job.vid)
 					continue
@@ -186,7 +186,7 @@ func isOneOf(server string, locations []wdclient.Location) bool {
 
 func (c *commandVolumeTierMove) doVolumeTierMove(commandEnv *CommandEnv, writer io.Writer, vid needle.VolumeId, toDiskType types.DiskType, allLocations []location) (err error) {
 	// find volume location
-	locations, found := commandEnv.MasterClient.GetLocations(uint32(vid))
+	locations, found := commandEnv.MasterClient.GetLocationsClone(uint32(vid))
 	if !found {
 		return fmt.Errorf("volume %d not found", vid)
 	}

weed/shell/command_volume_tier_upload.go

@@ -97,7 +97,7 @@ func (c *commandVolumeTierUpload) Do(args []string, commandEnv *CommandEnv, writ
 
 func doVolumeTierUpload(commandEnv *CommandEnv, writer io.Writer, collection string, vid needle.VolumeId, dest string, keepLocalDatFile bool) (err error) {
 	// find volume location
-	existingLocations, found := commandEnv.MasterClient.GetLocations(uint32(vid))
+	existingLocations, found := commandEnv.MasterClient.GetLocationsClone(uint32(vid))
 	if !found {
 		return fmt.Errorf("volume %d not found", vid)
 	}

weed/wdclient/vid_map.go

@@ -141,6 +141,19 @@ func (vc *vidMap) GetLocations(vid uint32) (locations []Location, found bool) {
 	return nil, false
 }
 
+func (vc *vidMap) GetLocationsClone(vid uint32) (locations []Location, found bool) {
+	locations, found = vc.GetLocations(vid)
+
+	if found {
+		// clone the locations in case the volume locations are changed below
+		existingLocations := make([]Location, len(locations))
+		copy(existingLocations, locations)
+		return existingLocations, found
+	}
+
+	return nil, false
+}
+
 func (vc *vidMap) getLocations(vid uint32) (locations []Location, found bool) {
 	vc.RLock()
 	defer vc.RUnlock()