netlink: fix for too early rmmod

[safe/jmp/linux-2.6] / drivers / char / tty_port.c

diff --git a/drivers/char/tty_port.c b/drivers/char/tty_port.c
index 41b314c..be492dd 100644 (file)
--- a/drivers/char/tty_port.c
+++ b/drivers/char/tty_port.c
@@ -25,19 +25,21 @@ void tty_port_init(struct tty_port *port)
        init_waitqueue_head(&port->close_wait);
        init_waitqueue_head(&port->delta_msr_wait);
        mutex_init(&port->mutex);
+       mutex_init(&port->buf_mutex);
        spin_lock_init(&port->lock);
        port->close_delay = (50 * HZ) / 100;
        port->closing_wait = (3000 * HZ) / 100;
+       kref_init(&port->kref);
 }
 EXPORT_SYMBOL(tty_port_init);
 
 int tty_port_alloc_xmit_buf(struct tty_port *port)
 {
        /* We may sleep in get_zeroed_page() */
-       mutex_lock(&port->mutex);
+       mutex_lock(&port->buf_mutex);
        if (port->xmit_buf == NULL)
                port->xmit_buf = (unsigned char *)get_zeroed_page(GFP_KERNEL);
-       mutex_unlock(&port->mutex);
+       mutex_unlock(&port->buf_mutex);
        if (port->xmit_buf == NULL)
                return -ENOMEM;
        return 0;
@@ -46,15 +48,32 @@ EXPORT_SYMBOL(tty_port_alloc_xmit_buf);
 
 void tty_port_free_xmit_buf(struct tty_port *port)
 {
-       mutex_lock(&port->mutex);
+       mutex_lock(&port->buf_mutex);
        if (port->xmit_buf != NULL) {
                free_page((unsigned long)port->xmit_buf);
                port->xmit_buf = NULL;
        }
-       mutex_unlock(&port->mutex);
+       mutex_unlock(&port->buf_mutex);
 }
 EXPORT_SYMBOL(tty_port_free_xmit_buf);
 
+static void tty_port_destructor(struct kref *kref)
+{
+       struct tty_port *port = container_of(kref, struct tty_port, kref);
+       if (port->xmit_buf)
+               free_page((unsigned long)port->xmit_buf);
+       if (port->ops->destruct)
+               port->ops->destruct(port);
+       else
+               kfree(port);
+}
+
+void tty_port_put(struct tty_port *port)
+{
+       if (port)
+               kref_put(&port->kref, tty_port_destructor);
+}
+EXPORT_SYMBOL(tty_port_put);
 
 /**
  *     tty_port_tty_get        -       get a tty reference
@@ -121,8 +140,10 @@ void tty_port_hangup(struct tty_port *port)
        spin_lock_irqsave(&port->lock, flags);
        port->count = 0;
        port->flags &= ~ASYNC_NORMAL_ACTIVE;
-       if (port->tty)
+       if (port->tty) {
+               set_bit(TTY_IO_ERROR, &port->tty->flags);
                tty_kref_put(port->tty);
+       }
        port->tty = NULL;
        spin_unlock_irqrestore(&port->lock, flags);
        wake_up_interruptible(&port->open_wait);
@@ -339,6 +360,14 @@ int tty_port_close_start(struct tty_port *port,
                        timeout = 2 * HZ;
                schedule_timeout_interruptible(timeout);
        }
+       /* Flush the ldisc buffering */
+       tty_ldisc_flush(tty);
+
+       /* Drop DTR/RTS if HUPCL is set. This causes any attached modem to
+          hang up the line */
+       if (tty->termios->c_cflag & HUPCL)
+               tty_port_lower_dtr_rts(port);
+
        /* Don't call port->drop for the last reference. Callers will want
           to drop the last active reference in ->shutdown() or the tty
           shutdown path */
@@ -350,11 +379,6 @@ void tty_port_close_end(struct tty_port *port, struct tty_struct *tty)
 {
        unsigned long flags;
 
-       tty_ldisc_flush(tty);
-
-       if (tty->termios->c_cflag & HUPCL)
-               tty_port_lower_dtr_rts(port);
-
        spin_lock_irqsave(&port->lock, flags);
        tty->closing = 0;
 
@@ -379,6 +403,7 @@ void tty_port_close(struct tty_port *port, struct tty_struct *tty,
        if (tty_port_close_start(port, tty, filp) == 0)
                return;
        tty_port_shutdown(port);
+       set_bit(TTY_IO_ERROR, &tty->flags);
        tty_port_close_end(port, tty);
        tty_port_tty_set(port, NULL);
 }
@@ -402,6 +427,7 @@ int tty_port_open(struct tty_port *port, struct tty_struct *tty,
        mutex_lock(&port->mutex);
 
        if (!test_bit(ASYNCB_INITIALIZED, &port->flags)) {
+               clear_bit(TTY_IO_ERROR, &tty->flags);
                if (port->ops->activate) {
                        int retval = port->ops->activate(port, tty);
                        if (retval) {