erasure coding: fix cases where there are no .ecj files

weed/server/volume_grpc_erasure_coding.go

@@ -201,9 +201,7 @@ func (vs *VolumeServer) VolumeEcShardsDelete(ctx context.Context, req *volume_se
 		if err := os.Remove(baseFilename + ".ecx"); err != nil {
 			return nil, err
 		}
-		if err := os.Remove(baseFilename + ".ecj"); err != nil {
-			return nil, err
-		}
+		os.Remove(baseFilename + ".ecj")
 	}
 	if !hasIdxFile {
 		// .vif is used for ec volumes and normal volumes

weed/shell/command_ec_encode.go

@@ -123,6 +123,8 @@ func markVolumeReadonly(grpcDialOption grpc.DialOption, volumeId needle.VolumeId
 
 	for _, location := range locations {
 
+		fmt.Printf("markVolumeReadonly %d on %s ...\n", volumeId, location.Url)
+
 		err := operation.WithVolumeServerClient(location.Url, grpcDialOption, func(volumeServerClient volume_server_pb.VolumeServerClient) error {
 			_, markErr := volumeServerClient.VolumeMarkReadonly(context.Background(), &volume_server_pb.VolumeMarkReadonlyRequest{
 				VolumeId: uint32(volumeId),
@@ -141,6 +143,8 @@ func markVolumeReadonly(grpcDialOption grpc.DialOption, volumeId needle.VolumeId
 
 func generateEcShards(grpcDialOption grpc.DialOption, volumeId needle.VolumeId, collection string, sourceVolumeServer string) error {
 
+	fmt.Printf("generateEcShards %s %d on %s ...\n", collection, volumeId, sourceVolumeServer)
+
 	err := operation.WithVolumeServerClient(sourceVolumeServer, grpcDialOption, func(volumeServerClient volume_server_pb.VolumeServerClient) error {
 		_, genErr := volumeServerClient.VolumeEcShardsGenerate(context.Background(), &volume_server_pb.VolumeEcShardsGenerateRequest{
 			VolumeId:   uint32(volumeId),
@@ -204,6 +208,8 @@ func spreadEcShards(commandEnv *CommandEnv, volumeId needle.VolumeId, collection
 
 func parallelCopyEcShardsFromSource(grpcDialOption grpc.DialOption, targetServers []*EcNode, allocatedEcIds [][]uint32, volumeId needle.VolumeId, collection string, existingLocation wdclient.Location) (actuallyCopied []uint32, err error) {
 
+	fmt.Printf("parallelCopyEcShardsFromSource %d %s\n", volumeId, existingLocation.Url)
+
 	// parallelize
 	shardIdChan := make(chan []uint32, len(targetServers))
 	var wg sync.WaitGroup

weed/shell/command_volume_fix_replication.go

@@ -121,7 +121,10 @@ func (c *commandVolumeFixReplication) Do(args []string, commandEnv *CommandEnv,
 						VolumeId:       volumeInfo.Id,
 						SourceDataNode: sourceNode.dataNode.Id,
 					})
-					return fmt.Errorf("copying from %s => %s : %v", sourceNode.dataNode.Id, dst.dataNode.Id, replicateErr)
+					if replicateErr != nil {
+						return fmt.Errorf("copying from %s => %s : %v", sourceNode.dataNode.Id, dst.dataNode.Id, replicateErr)
+					}
+					return nil
 				})
 
 				if err != nil {

weed/storage/erasure_coding/ec_decoder.go

@@ -11,6 +11,7 @@ import (
 	"github.com/chrislusf/seaweedfs/weed/storage/needle_map"
 	"github.com/chrislusf/seaweedfs/weed/storage/super_block"
 	"github.com/chrislusf/seaweedfs/weed/storage/types"
+	"github.com/chrislusf/seaweedfs/weed/util"
 )
 
 // write .idx file from .ecx and .ecj files
@@ -118,9 +119,12 @@ func iterateEcxFile(baseFileName string, processNeedleFn func(key types.NeedleId
 }
 
 func iterateEcjFile(baseFileName string, processNeedleFn func(key types.NeedleId) error) error {
+	if !util.FileExists(baseFileName+".ecj") {
+		return nil
+	}
 	ecjFile, openErr := os.OpenFile(baseFileName+".ecj", os.O_RDONLY, 0644)
 	if openErr != nil {
-		return fmt.Errorf("cannot open ec index %s.ecx: %v", baseFileName, openErr)
+		return fmt.Errorf("cannot open ec index %s.ecj: %v", baseFileName, openErr)
 	}
 	defer ecjFile.Close()