Bluetooth: Move the tty initialization and cleanup out of open/close

Move the tty_struct initialization from rfcomm_tty_open() to
rfcomm_tty_install() and do the same for the cleanup moving the code from
rfcomm_tty_close() to rfcomm_tty_cleanup().

Add also extra error handling in rfcomm_tty_install() because, unlike
.open()/.close(), .cleanup() is not called if .install() fails.

Signed-off-by: Gianluca Anzolin <gianluca@sottospazio.it>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c
index 9c0e142..73dd615 100644 (file)
--- a/net/bluetooth/rfcomm/tty.c
+++ b/net/bluetooth/rfcomm/tty.c
@@ -633,49 +633,61 @@ static void rfcomm_tty_copy_pending(struct rfcomm_dev *dev)
                tty_flip_buffer_push(&dev->port);
 }
 
-static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
+/* do the reverse of install, clearing the tty fields and releasing the
+ * reference to tty_port
+ */
+static void rfcomm_tty_cleanup(struct tty_struct *tty)
+{
+       struct rfcomm_dev *dev = tty->driver_data;
+
+       if (dev->tty_dev->parent)
+               device_move(dev->tty_dev, NULL, DPM_ORDER_DEV_LAST);
+
+       /* Close DLC and dettach TTY */
+       rfcomm_dlc_close(dev->dlc, 0);
+
+       clear_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
+
+       rfcomm_dlc_lock(dev->dlc);
+       tty->driver_data = NULL;
+       dev->port.tty = NULL;
+       rfcomm_dlc_unlock(dev->dlc);
+
+       tty_port_put(&dev->port);
+}
+
+/* we acquire the tty_port reference since it's here the tty is first used
+ * by setting the termios. We also populate the driver_data field and install
+ * the tty port
+ */
+static int rfcomm_tty_install(struct tty_driver *driver, struct tty_struct *tty)
 {
        DECLARE_WAITQUEUE(wait, current);
        struct rfcomm_dev *dev;
        struct rfcomm_dlc *dlc;
-       unsigned long flags;
-       int err, id;
-
-       id = tty->index;
+       int err;
 
-       BT_DBG("tty %p id %d", tty, id);
-
-       /* We don't leak this refcount. For reasons which are not entirely
-          clear, the TTY layer will call our ->close() method even if the
-          open fails. We decrease the refcount there, and decreasing it
-          here too would cause breakage. */
-       dev = rfcomm_dev_get(id);
+       dev = rfcomm_dev_get(tty->index);
        if (!dev)
                return -ENODEV;
 
-       BT_DBG("dev %p dst %pMR channel %d opened %d", dev, &dev->dst,
-              dev->channel, dev->port.count);
-
-       spin_lock_irqsave(&dev->port.lock, flags);
-       if (++dev->port.count > 1) {
-               spin_unlock_irqrestore(&dev->port.lock, flags);
-               return 0;
-       }
-       spin_unlock_irqrestore(&dev->port.lock, flags);
-
        dlc = dev->dlc;
 
        /* Attach TTY and open DLC */
-
        rfcomm_dlc_lock(dlc);
        tty->driver_data = dev;
        dev->port.tty = tty;
        rfcomm_dlc_unlock(dlc);
        set_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
 
+       /* install the tty_port */
+       err = tty_port_install(&dev->port, driver, tty);
+       if (err < 0)
+               goto error_no_dlc;
+
        err = rfcomm_dlc_open(dlc, &dev->src, &dev->dst, dev->channel);
        if (err < 0)
-               return err;
+               goto error_no_dlc;
 
        /* Wait for DLC to connect */
        add_wait_queue(&dev->wait, &wait);
@@ -702,15 +714,45 @@ static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
        set_current_state(TASK_RUNNING);
        remove_wait_queue(&dev->wait, &wait);
 
-       if (err == 0)
-               device_move(dev->tty_dev, rfcomm_get_device(dev),
-                           DPM_ORDER_DEV_AFTER_PARENT);
+       if (err < 0)
+               goto error_no_connection;
+
+       device_move(dev->tty_dev, rfcomm_get_device(dev),
+                   DPM_ORDER_DEV_AFTER_PARENT);
+       return 0;
+
+error_no_connection:
+       rfcomm_dlc_close(dlc, err);
+error_no_dlc:
+       clear_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
+       tty_port_put(&dev->port);
+       return err;
+}
+
+static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
+{
+       struct rfcomm_dev *dev = tty->driver_data;
+       unsigned long flags;
+
+       BT_DBG("tty %p id %d", tty, tty->index);
 
+       BT_DBG("dev %p dst %pMR channel %d opened %d", dev, &dev->dst,
+              dev->channel, dev->port.count);
+
+       spin_lock_irqsave(&dev->port.lock, flags);
+       dev->port.count++;
+       spin_unlock_irqrestore(&dev->port.lock, flags);
+
+       /*
+        * FIXME: rfcomm should use proper flow control for
+        * received data. This hack will be unnecessary and can
+        * be removed when that's implemented
+        */
        rfcomm_tty_copy_pending(dev);
 
        rfcomm_dlc_unthrottle(dev->dlc);
 
-       return err;
+       return 0;
 }
 
 static void rfcomm_tty_close(struct tty_struct *tty, struct file *filp)
@@ -727,25 +769,11 @@ static void rfcomm_tty_close(struct tty_struct *tty, struct file *filp)
        spin_lock_irqsave(&dev->port.lock, flags);
        if (!--dev->port.count) {
                spin_unlock_irqrestore(&dev->port.lock, flags);
-               if (dev->tty_dev->parent)
-                       device_move(dev->tty_dev, NULL, DPM_ORDER_DEV_LAST);
-
-               /* Close DLC and dettach TTY */
-               rfcomm_dlc_close(dev->dlc, 0);
-
-               clear_bit(RFCOMM_TTY_ATTACHED, &dev->flags);
-
-               rfcomm_dlc_lock(dev->dlc);
-               tty->driver_data = NULL;
-               dev->port.tty = NULL;
-               rfcomm_dlc_unlock(dev->dlc);
 
                if (test_bit(RFCOMM_TTY_RELEASED, &dev->flags))
                        tty_port_put(&dev->port);
        } else
                spin_unlock_irqrestore(&dev->port.lock, flags);
-
-       tty_port_put(&dev->port);
 }
 
 static int rfcomm_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
@@ -1118,6 +1146,8 @@ static const struct tty_operations rfcomm_ops = {
        .wait_until_sent        = rfcomm_tty_wait_until_sent,
        .tiocmget               = rfcomm_tty_tiocmget,
        .tiocmset               = rfcomm_tty_tiocmset,
+       .install                = rfcomm_tty_install,
+       .cleanup                = rfcomm_tty_cleanup,
 };
 
 int __init rfcomm_init_ttys(void)