}

	if j > 1 {
		// Create parent.
		if err := osMkdirAll(dirPath[:j-1], perm, baseDir); err != nil {
			return err
		}
	}

	// Parent now exists; invoke Mkdir and use its result.
	if err := Mkdir(dirPath, perm); err != nil {
		if osIsExist(err) {
			return nil
		}
		return err
	}

	return nil
}

// The buffer must be at least a block long.
// refer https://github.com/golang/go/issues/24015