redirected_tty_write
if (file->f_op->write_iter == redirected_tty_write)
if (L_TOSTOP(tty) && file->f_op->write_iter != redirected_tty_write) {
ssize_t redirected_tty_write(struct kiocb *, struct iov_iter *);
if (file->f_op->write_iter == redirected_tty_write) {
.write_iter = redirected_tty_write,
if (filp->f_op->write_iter == redirected_tty_write)