A departing reader must restart a flush_to_ldisc() worker _before_
the next reader enters the read loop; this is to avoid the new reader
concluding no more i/o is available and prematurely exiting, when the
old reader simply hasn't re-started the worker yet.

Cc: sta...@kernel.org # 3.12
Signed-off-by: Peter Hurley <pe...@hurleysoftware.com>
---
 drivers/tty/n_tty.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 7a744b6..ce11cd5 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -2250,6 +2250,9 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct 
file *file,
                if (time)
                        timeout = time;
        }
+       n_tty_set_room(tty);
+       up_read(&tty->termios_rwsem);
+
        mutex_unlock(&ldata->atomic_read_lock);
        remove_wait_queue(&tty->read_wait, &wait);
 
@@ -2260,8 +2263,6 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct 
file *file,
        if (b - buf)
                retval = b - buf;
 
-       n_tty_set_room(tty);
-       up_read(&tty->termios_rwsem);
        return retval;
 }
 
-- 
1.8.1.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to