// This is a special case should be handled only for
			// windows, because windows API does not return "not a
			// directory" error message. Handle this specifically here.
			return errFileAccessDenied
		}
		return osErrToFileErr(err)
	}

	return nil
}

// Reliably retries os.MkdirAll if for some reason os.MkdirAll returns
// syscall.ENOENT (parent does not exist).

// Is a one place function which converts all os.PathError
// into a more FS object layer friendly form, converts
// known errors into their typed form for top level
// interpretation.
func osErrToFileErr(err error) error {
	if err == nil {
		return nil
	}
	if osIsNotExist(err) {
		return errFileNotFound
	}
	if osIsPermission(err) {
		return errFileAccessDenied
	}