the FileChunk is created without setting ModifiedTsNs

weed/operation/upload_chunked.go

@@ -8,6 +8,7 @@ import (
 	"hash"
 	"io"
 	"sync"
+	"time"
 
 	"github.com/seaweedfs/seaweedfs/weed/glog"
 	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
@@ -167,11 +168,15 @@ func UploadReaderInChunks(ctx context.Context, reader io.Reader, opt *ChunkedUpl
 			}
 			
 		// Create chunk entry
+		// Set ModifiedTsNs to current time (nanoseconds) to track when upload completed
+		// This is critical for multipart uploads where the same part may be uploaded multiple times
+		// The part with the latest ModifiedTsNs is selected as the authoritative version
 		fid, _ := filer_pb.ToFileIdObject(assignResult.Fid)
 		chunk := &filer_pb.FileChunk{
 			FileId:       assignResult.Fid,
 			Offset:       offset,
 			Size:         uint64(uploadResult.Size),
+			ModifiedTsNs: time.Now().UnixNano(),
 			ETag:         uploadResult.ContentMd5,
 			Fid:          fid,
 			CipherKey:    uploadResult.CipherKey,