fs: Migrate object metadata to objects directory. (#4195)

Fixes #3352

cmd/fs-v1-helpers.go

@@ -230,7 +230,7 @@ func fsOpenFile(readPath string, offset int64) (io.ReadCloser, int64, error) {
 
 // Creates a file and copies data from incoming reader. Staging buffer is used by io.CopyBuffer.
 func fsCreateFile(filePath string, reader io.Reader, buf []byte, fallocSize int64) (int64, error) {
-	if filePath == "" || reader == nil || buf == nil {
+	if filePath == "" || reader == nil {
 		return 0, traceError(errInvalidArgument)
 	}
 
@@ -263,11 +263,18 @@ func fsCreateFile(filePath string, reader io.Reader, buf []byte, fallocSize int6
 		}
 	}
 
-	bytesWritten, err := io.CopyBuffer(writer, reader, buf)
-	if err != nil {
-		return 0, traceError(err)
+	var bytesWritten int64
+	if buf != nil {
+		bytesWritten, err = io.CopyBuffer(writer, reader, buf)
+		if err != nil {
+			return 0, traceError(err)
+		}
+	} else {
+		bytesWritten, err = io.Copy(writer, reader)
+		if err != nil {
+			return 0, traceError(err)
+		}
 	}
-
 	return bytesWritten, nil
 }
 
@@ -276,6 +283,12 @@ func fsRemoveUploadIDPath(basePath, uploadIDPath string) error {
 	if basePath == "" || uploadIDPath == "" {
 		return traceError(errInvalidArgument)
 	}
+	if err := checkPathLength(basePath); err != nil {
+		return traceError(err)
+	}
+	if err := checkPathLength(uploadIDPath); err != nil {
+		return traceError(err)
+	}
 
 	// List all the entries in uploadID.
 	entries, err := readDir(uploadIDPath)
@@ -319,6 +332,26 @@ func fsFAllocate(fd int, offset int64, len int64) (err error) {
 // Renames source path to destination path, creates all the
 // missing parents if they don't exist.
 func fsRenameFile(sourcePath, destPath string) error {
+	if err := checkPathLength(sourcePath); err != nil {
+		return traceError(err)
+	}
+	if err := checkPathLength(destPath); err != nil {
+		return traceError(err)
+	}
+	// Verify if source path exists.
+	if _, err := os.Stat(preparePath(sourcePath)); err != nil {
+		if os.IsNotExist(err) {
+			return traceError(errFileNotFound)
+		} else if os.IsPermission(err) {
+			return traceError(errFileAccessDenied)
+		} else if isSysErrPathNotFound(err) {
+			return traceError(errFileNotFound)
+		} else if isSysErrNotDir(err) {
+			// File path cannot be verified since one of the parents is a file.
+			return traceError(errFileAccessDenied)
+		}
+		return traceError(err)
+	}
 	if err := mkdirAll(pathutil.Dir(destPath), 0777); err != nil {
 		return traceError(err)
 	}