[Bluetooth] Dynamic allocation of the RFCOMM TTY devices

Only allocate the RFCOMM TTY devices when they are really in use. This
prevents the system from calling hotplug and udev 256 times to create or
remove every device node. In fact this makes the loading and unloading
of the RFCOMM module much faster.

net/bluetooth/rfcomm/core.c

@@ -52,7 +52,7 @@
 #include <net/bluetooth/l2cap.h>
 #include <net/bluetooth/rfcomm.h>
 
-#define VERSION "1.1"
+#define VERSION "1.2"
 
 #ifndef CONFIG_BT_RFCOMM_DEBUG
 #undef  BT_DBG

net/bluetooth/rfcomm/tty.c

@@ -50,6 +50,8 @@
 #define RFCOMM_TTY_MAJOR 216		/* device node major id of the usb/bluetooth.c driver */
 #define RFCOMM_TTY_MINOR 0
 
+static struct tty_driver *rfcomm_tty_driver;
+
 struct rfcomm_dev {
 	struct list_head	list;
 	atomic_t		refcnt;
@@ -98,6 +100,8 @@ static void rfcomm_dev_destruct(struct rfcomm_dev *dev)
 
 	rfcomm_dlc_put(dlc);
 
+	tty_unregister_device(rfcomm_tty_driver, dev->id);
+
 	/* Refcount should only hit zero when called from rfcomm_dev_del()
 	   which will have taken us off the list. Everything else are
 	   refcounting bugs. */
@@ -239,7 +243,10 @@ static int rfcomm_dev_add(struct rfcomm_dev_req *req, struct rfcomm_dlc *dlc)
 	if (err) {
 		kfree(dev);
 		return err;
-	} else
+	}
+
+	tty_register_device(rfcomm_tty_driver, dev->id, NULL);
+
 	return dev->id;
 }
 
@@ -871,8 +878,6 @@ static int rfcomm_tty_tiocmset(struct tty_struct *tty, struct file *filp, unsign
 
 /* ---- TTY structure ---- */
 
-static struct tty_driver *rfcomm_tty_driver;
-
 static struct tty_operations rfcomm_ops = {
 	.open			= rfcomm_tty_open,
 	.close			= rfcomm_tty_close,
@@ -906,7 +911,7 @@ int rfcomm_init_ttys(void)
 	rfcomm_tty_driver->minor_start	= RFCOMM_TTY_MINOR;
 	rfcomm_tty_driver->type		= TTY_DRIVER_TYPE_SERIAL;
 	rfcomm_tty_driver->subtype	= SERIAL_TYPE_NORMAL;
-	rfcomm_tty_driver->flags	= TTY_DRIVER_REAL_RAW;
+	rfcomm_tty_driver->flags	= TTY_DRIVER_REAL_RAW | TTY_DRIVER_NO_DEVFS;
 	rfcomm_tty_driver->init_termios	= tty_std_termios;
 	rfcomm_tty_driver->init_termios.c_cflag	= B9600 | CS8 | CREAD | HUPCL | CLOCAL;
 	tty_set_operations(rfcomm_tty_driver, &rfcomm_ops);