Bluetooth: Add debug logs to help track locking issues

This patch adds some extra debug logs to L2CAP related code. These are
mainly to help track locking issues but will probably be useful for
debugging other types of issues as well.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/l2cap_core.c

@@ -570,7 +570,8 @@ void l2cap_chan_del(struct l2cap_chan *chan, int err)
 
 	__clear_chan_timer(chan);
 
-	BT_DBG("chan %p, conn %p, err %d", chan, conn, err);
+	BT_DBG("chan %p, conn %p, err %d, state %s", chan, conn, err,
+	       state_to_string(chan->state));
 
 	chan->ops->teardown(chan, err);
 

net/bluetooth/l2cap_sock.c

@@ -1102,6 +1102,8 @@ static int l2cap_sock_shutdown(struct socket *sock, int how)
 	chan = l2cap_pi(sk)->chan;
 	conn = chan->conn;
 
+	BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
+
 	if (conn)
 		mutex_lock(&conn->chan_lock);
 
@@ -1159,12 +1161,16 @@ static void l2cap_sock_cleanup_listen(struct sock *parent)
 {
 	struct sock *sk;
 
-	BT_DBG("parent %p", parent);
+	BT_DBG("parent %p state %s", parent,
+	       state_to_string(parent->sk_state));
 
 	/* Close not yet accepted channels */
 	while ((sk = bt_accept_dequeue(parent, NULL))) {
 		struct l2cap_chan *chan = l2cap_pi(sk)->chan;
 
+		BT_DBG("child chan %p state %s", chan,
+		       state_to_string(chan->state));
+
 		l2cap_chan_lock(chan);
 		__clear_chan_timer(chan);
 		l2cap_chan_close(chan, ECONNRESET);
@@ -1252,6 +1258,8 @@ static void l2cap_sock_teardown_cb(struct l2cap_chan *chan, int err)
 	struct sock *sk = chan->data;
 	struct sock *parent;
 
+	BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
+
 	/* This callback can be called both for server (BT_LISTEN)
 	 * sockets as well as "normal" ones. To avoid lockdep warnings
 	 * with child socket locking (through l2cap_sock_cleanup_listen)