Bluetooth: Add l2cap_chan_lock

Channel lock will be used to lock L2CAP channels which are locked
currently by socket locks.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Reviewed-by: Ulisses Furquim <ulisses@profusion.mobi>
Acked-by: Gustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index bbb0e21..d6d8ec8 100644
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -497,6 +497,7 @@
 
 	void		*data;
 	struct l2cap_ops *ops;
+	struct mutex		lock;
 };
 
 struct l2cap_ops {
@@ -609,6 +610,16 @@
 		kfree(c);
 }
 
+static inline void l2cap_chan_lock(struct l2cap_chan *chan)
+{
+	mutex_lock(&chan->lock);
+}
+
+static inline void l2cap_chan_unlock(struct l2cap_chan *chan)
+{
+	mutex_unlock(&chan->lock);
+}
+
 static inline void l2cap_set_timer(struct l2cap_chan *chan,
 					struct delayed_work *work, long timeout)
 {
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 8e8e9e9..e39eba1 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -247,6 +247,8 @@
 	if (!chan)
 		return NULL;
 
+	mutex_init(&chan->lock);
+
 	chan->sk = sk;
 
 	write_lock(&chan_list_lock);