Bluetooth: Make __l2cap_wait_ack more efficient (f65468f6) · Commits · 戴 / test

Use chan->state instead of chan->conn because waiting for ACK's is only possible in the BT_CONNECTED state. Also avoids reference to the conn structure so makes locking easier. Only call __l2cap_wait_ack() when the needed condition of chan->unacked_frames > 0 && chan->state == BT_CONNECTED is true and convert the while loop to a do while loop. __l2cap_wait_ack() change the function prototype to pass in the chan variable as chan is already available in the calling function l2cap_sock_shutdown(). Avoids locking issues. Signed-off-by:

Dean Jenkins <Dean_Jenkins@mentor.com> Signed-off-by:

Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/l2cap_sock.c

+10 −6

Original line number	Diff line number	Diff line
		@@ -1054,16 +1054,15 @@ static void l2cap_sock_kill(struct sock *sk)
		sock_put(sk);
		}

		static int __l2cap_wait_ack(struct sock *sk)
		static int __l2cap_wait_ack(struct sock sk, struct l2cap_chan chan)
		{
		struct l2cap_chan *chan = l2cap_pi(sk)->chan;
		DECLARE_WAITQUEUE(wait, current);
		int err = 0;
		int timeo = HZ/5;

		add_wait_queue(sk_sleep(sk), &wait);
		set_current_state(TASK_INTERRUPTIBLE);
		while (chan->unacked_frames > 0 && chan->conn) {
		do {
		if (!timeo)
		timeo = HZ/5;

		@@ -1080,7 +1079,10 @@ static int __l2cap_wait_ack(struct sock *sk)
		err = sock_error(sk);
		if (err)
		break;
		}

		} while (chan->unacked_frames > 0 &&
		chan->state == BT_CONNECTED);

		set_current_state(TASK_RUNNING);
		remove_wait_queue(sk_sleep(sk), &wait);
		return err;
		@@ -1115,8 +1117,10 @@ static int l2cap_sock_shutdown(struct socket *sock, int how)
		lock_sock(sk);

		if (!sk->sk_shutdown) {
		if (chan->mode == L2CAP_MODE_ERTM)
		err = __l2cap_wait_ack(sk);
		if (chan->mode == L2CAP_MODE_ERTM &&
		chan->unacked_frames > 0 &&
		chan->state == BT_CONNECTED)
		err = __l2cap_wait_ack(sk, chan);

		sk->sk_shutdown = SHUTDOWN_MASK;

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