[PATCHv3 5/6] tty: Simplify tty->count math in tty_reopen()

Dmitry Safonov
2018-09-11T01:48:44Z

As notted by Jiri, tty_ldisc_reinit() shouldn't rely on tty counter.
Simplify math by increasing the counter after reinit success.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Link: lkml.kernel.org/r/<20180829022353.23568-2-dima@arista.com>
Suggested-by: Jiri Slaby <jslaby@suse.com>
Reviewed-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Dmitry Safonov <dima@arista.com>
---
drivers/tty/tty_io.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index a947719b4626..7f968ac14bbd 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -1268,17 +1268,13 @@ static int tty_reopen(struct tty_struct *tty)
return -EBUSY;

tty_ldisc_lock(tty, MAX_SCHEDULE_TIMEOUT);
+ if (!tty->ldisc)
+ retval = tty_ldisc_reinit(tty, tty->termios.c_line);
+ tty_ldisc_unlock(tty);

- tty->count++;
- if (tty->ldisc)
- goto out_unlock;
+ if (retval == 0)
+ tty->count++;

- retval = tty_ldisc_reinit(tty, tty->termios.c_line);
- if (retval)
- tty->count--;
-
-out_unlock:
- tty_ldisc_unlock(tty);
return retval;
}

--
2.13.6