Perform common exit for both successful and error exit handling in tty_set_ldisc(). Fixes unlikely possibility of failing to restart input kworker when switching to the same line discipline (noop case).
Signed-off-by: Peter Hurley <[email protected]> --- Requires: "tty: Fix direct use of tty buffer work" drivers/tty/tty_ldisc.c | 42 +++++++++++++----------------------------- 1 file changed, 13 insertions(+), 29 deletions(-) diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c index 2cf6826..b776f2e 100644 --- a/drivers/tty/tty_ldisc.c +++ b/drivers/tty/tty_ldisc.c @@ -527,34 +527,21 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc) tty_lock(tty); retval = tty_ldisc_lock(tty, 5 * HZ); - if (retval) { - tty_ldisc_put(new_ldisc); - tty_unlock(tty); - return retval; - } + if (retval) + goto err; - /* - * Check the no-op case - */ + /* Check the no-op case */ + if (tty->ldisc->ops->num == ldisc) + goto out; - if (tty->ldisc->ops->num == ldisc) { - tty_ldisc_unlock(tty); - tty_ldisc_put(new_ldisc); - tty_unlock(tty); - return 0; + if (test_bit(TTY_HUPPED, &tty->flags)) { + /* We were raced by hangup */ + retval = -EIO; + goto out; } old_ldisc = tty->ldisc; - if (test_bit(TTY_HUPPED, &tty->flags)) { - /* We were raced by the hangup method. It will have stomped - the ldisc data and closed the ldisc down */ - tty_ldisc_unlock(tty); - tty_ldisc_put(new_ldisc); - tty_unlock(tty); - return -EIO; - } - /* Shutdown the old discipline. */ tty_ldisc_close(tty, old_ldisc); @@ -580,18 +567,15 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc) the old ldisc (if it was restored as part of error cleanup above). In either case, releasing a single reference from the old ldisc is correct. */ - - tty_ldisc_put(old_ldisc); - - /* - * Allow ldisc referencing to occur again - */ + new_ldisc = old_ldisc; +out: tty_ldisc_unlock(tty); /* Restart the work queue in case no characters kick it off. Safe if already running */ tty_buffer_restart_work(tty->port); - +err: + tty_ldisc_put(new_ldisc); /* drop the extra reference */ tty_unlock(tty); return retval; } -- 2.6.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
