tty: Make core responsible for synchronizing its work
The tty core relies on the ldisc layer for synchronizing destruction
of the tty. Instead, the final tty release must wait for any pending tty
work to complete prior to tty destruction.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index cbb945b..7f7e1a3 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -499,18 +499,6 @@
}
/**
- * tty_ldisc_flush_works - flush all works of a tty
- * @tty: tty device to flush works for
- *
- * Sync flush all works belonging to @tty.
- */
-static void tty_ldisc_flush_works(struct tty_struct *tty)
-{
- flush_work(&tty->SAK_work);
- flush_work(&tty->hangup_work);
-}
-
-/**
* tty_ldisc_wait_idle - wait for the ldisc to become idle
* @tty: tty to wait for
* @timeout: for how long to wait at most
@@ -698,13 +686,13 @@
retval = tty_ldisc_halt(tty, o_tty, 5 * HZ);
/*
- * Wait for ->hangup_work and ->buf.work handlers to terminate.
+ * Wait for hangup to complete, if pending.
* We must drop the mutex here in case a hangup is also in process.
*/
mutex_unlock(&tty->ldisc_mutex);
- tty_ldisc_flush_works(tty);
+ flush_work(&tty->hangup_work);
tty_lock(tty);
mutex_lock(&tty->ldisc_mutex);
@@ -951,15 +939,11 @@
void tty_ldisc_release(struct tty_struct *tty, struct tty_struct *o_tty)
{
/*
- * Prevent flush_to_ldisc() from rescheduling the work for later. Then
- * kill any delayed work. As this is the final close it does not
- * race with the set_ldisc code path.
+ * Shutdown this line discipline. As this is the final close,
+ * it does not race with the set_ldisc code path.
*/
tty_ldisc_halt(tty, o_tty, MAX_SCHEDULE_TIMEOUT);
- tty_ldisc_flush_works(tty);
- if (o_tty)
- tty_ldisc_flush_works(o_tty);
tty_lock_pair(tty, o_tty);
/* This will need doing differently if we need to lock */