Commit 40315ce5 authored by Jiri Slaby (SUSE)'s avatar Jiri Slaby (SUSE) Committed by Greg Kroah-Hartman
Browse files

tty: n_tty: extract n_tty_wait_for_input() 



n_tty_read() is a very long function doing too much of different stuff.
Extract the "wait for input" to a separate function:
n_tty_wait_for_input(). It returns an error (< 0), no input (0), or has
potential input (1).

Signed-off-by: default avatarJiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-11-jirislaby@kernel.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent aa1ebc9c

drivers/tty/n_tty.c

+31 −26
Original line number Diff line number Diff line
@@ -2145,6 +2145,33 @@ static ssize_t n_tty_continue_cookie(struct tty_struct *tty, u8 *kbuf, 
	return kb - kbuf;

}



static int n_tty_wait_for_input(struct tty_struct *tty, struct file *file,

				struct wait_queue_entry *wait, long *timeout)

{

	if (test_bit(TTY_OTHER_CLOSED, &tty->flags))

		return -EIO;

	if (tty_hung_up_p(file))

		return 0;

	/*

	 * Abort readers for ttys which never actually get hung up.

	 * See __tty_hangup().

	 */

	if (test_bit(TTY_HUPPING, &tty->flags))

		return 0;

	if (!*timeout)

		return 0;

	if (tty_io_nonblock(tty, file))

		return -EAGAIN;

	if (signal_pending(current))

		return -ERESTARTSYS;



	up_read(&tty->termios_rwsem);

	*timeout = wait_woken(wait, TASK_INTERRUPTIBLE, *timeout);

	down_read(&tty->termios_rwsem);



	return 1;

}



/**

 * n_tty_read		-	read function for tty

 * @tty: tty device
@@ -2234,34 +2261,12 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, u8 *kbuf, 
			tty_buffer_flush_work(tty->port);

			down_read(&tty->termios_rwsem);

			if (!input_available_p(tty, 0)) {

				if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {

					retval = -EIO;

				int ret = n_tty_wait_for_input(tty, file, &wait,

							       &timeout);

				if (ret <= 0) {

					retval = ret;

					break;

				}

				if (tty_hung_up_p(file))

					break;

				/*

				 * Abort readers for ttys which never actually

				 * get hung up.  See __tty_hangup().

				 */

				if (test_bit(TTY_HUPPING, &tty->flags))

					break;

				if (!timeout)

					break;

				if (tty_io_nonblock(tty, file)) {

					retval = -EAGAIN;

					break;

				}

				if (signal_pending(current)) {

					retval = -ERESTARTSYS;

					break;

				}

				up_read(&tty->termios_rwsem);



				timeout = wait_woken(&wait, TASK_INTERRUPTIBLE,

						timeout);



				down_read(&tty->termios_rwsem);

				continue;

			}

		}