TTY: rfcomm/tty, use count from tty_port

This means converting an atomic counter to a counter protected by
lock. This is the first step needed to convert the rest of the code to
the tty_port helpers.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 21 insertions, 9 deletions

diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c
index 0433d263233..d1820ff14ae 100644
--- a/net/bluetooth/rfcomm/tty.c
+++ b/net/bluetooth/rfcomm/tty.c
@@ -54,7 +54,6 @@ struct rfcomm_dev {
         char                    name[12];
         int                     id;
         unsigned long           flags;
-        atomic_t                opened;
         int                     err;
 
         bdaddr_t                src;
@@ -240,8 +239,6 @@ static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc)
         dev->flags = req->flags &
                 ((1 << RFCOMM_RELEASE_ONHUP) | (1 << RFCOMM_REUSE_DLC));
 
-        atomic_set(&dev->opened, 0);
-
         tty_port_init(&dev->port);
         dev->port.ops = &rfcomm_port_ops;
         init_waitqueue_head(&dev->wait);
@@ -311,12 +308,17 @@ free:
 
 static void rfcomm_dev_del(struct rfcomm_dev *dev)
 {
+        unsigned long flags;
         BT_DBG("dev %p", dev);
 
         BUG_ON(test_and_set_bit(RFCOMM_TTY_RELEASED, &dev->flags));
 
-        if (atomic_read(&dev->opened) > 0)
+        spin_lock_irqsave(&dev->port.lock, flags);
+        if (dev->port.count > 0) {
+                spin_unlock_irqrestore(&dev->port.lock, flags);
                 return;
+        }
+        spin_unlock_irqrestore(&dev->port.lock, flags);
 
         spin_lock(&rfcomm_dev_lock);
         list_del_init(&dev->list);
@@ -651,6 +653,7 @@ static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
         DECLARE_WAITQUEUE(wait, current);
         struct rfcomm_dev *dev;
         struct rfcomm_dlc *dlc;
+        unsigned long flags;
         int err, id;
 
         id = tty->index;
@@ -666,10 +669,14 @@ static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
                 return -ENODEV;
 
         BT_DBG("dev %p dst %s channel %d opened %d", dev, batostr(&dev->dst),
-                                dev->channel, atomic_read(&dev->opened));
+                                dev->channel, dev->port.count);
 
-        if (atomic_inc_return(&dev->opened) > 1)
+        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;
 
@@ -724,13 +731,17 @@ static int rfcomm_tty_open(struct tty_struct *tty, struct file *filp)
 static void rfcomm_tty_close(struct tty_struct *tty, struct file *filp)
 {
         struct rfcomm_dev *dev = (struct rfcomm_dev *) tty->driver_data;
+        unsigned long flags;
+
         if (!dev)
                 return;
 
         BT_DBG("tty %p dev %p dlc %p opened %d", tty, dev, dev->dlc,
-                                                atomic_read(&dev->opened));
+                                                dev->port.count);
 
-        if (atomic_dec_and_test(&dev->opened)) {
+        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);
 
@@ -751,7 +762,8 @@ static void rfcomm_tty_close(struct tty_struct *tty, struct file *filp)
 
                         tty_port_put(&dev->port);
                 }
-        }
+        } else
+                spin_unlock_irqrestore(&dev->port.lock, flags);
 
         tty_port_put(&dev->port);
 }