var internal/oserror.ErrClosed

3 uses

	internal/oserror (current package)
		errors.go#L17: 	ErrClosed     = errors.New("file already closed")

	io/fs
		fs.go#L147: func errClosed() error     { return oserror.ErrClosed }

	os
		error.go#L31: func errClosed() error     { return oserror.ErrClosed }