Re: [PATCHv2 01/19] Bluetooth: Add unlink to L2CAP channel ops

[Mat Martineau <mathewm@codeaurora.org>]

Andrei -

On Wed, 23 May 2012, Andrei Emeltchenko wrote:

> From: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
>
> This helps to separate socket and socketless code. Now socket related
> operations moved to l2cap_sock in unlink callback for channels with sk.
>
> Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
> ---
> include/net/bluetooth/l2cap.h |    1 +
> net/bluetooth/l2cap_core.c    |   19 ++-----------------
> net/bluetooth/l2cap_sock.c    |   25 +++++++++++++++++++++++++
> 3 files changed, 28 insertions(+), 17 deletions(-)
>
> diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
> index 0142257..a017249 100644
> --- a/include/net/bluetooth/l2cap.h
> +++ b/include/net/bluetooth/l2cap.h
> @@ -529,6 +529,7 @@ struct l2cap_ops {
> 	void			(*state_change) (void *data, int state);
> 	struct sk_buff		*(*alloc_skb) (struct l2cap_chan *chan,
> 					       unsigned long len, int nb);
> +	void			(*unlink) (struct l2cap_chan *chan, int err);
> };
>
> struct l2cap_conn {
> diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
> index e31b005..c81b828 100644
> --- a/net/bluetooth/l2cap_core.c
> +++ b/net/bluetooth/l2cap_core.c
> @@ -493,9 +493,7 @@ static void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
>
> static void l2cap_chan_del(struct l2cap_chan *chan, int err)
> {
> -	struct sock *sk = chan->sk;
> 	struct l2cap_conn *conn = chan->conn;
> -	struct sock *parent = bt_sk(sk)->parent;
>
> 	__clear_chan_timer(chan);
>
> @@ -511,21 +509,8 @@ static void l2cap_chan_del(struct l2cap_chan *chan, int err)
> 		hci_conn_put(conn->hcon);
> 	}
>
> -	lock_sock(sk);
> -
> -	__l2cap_state_change(chan, BT_CLOSED);
> -	sock_set_flag(sk, SOCK_ZAPPED);
> -
> -	if (err)
> -		__l2cap_chan_set_err(chan, err);
> -
> -	if (parent) {
> -		bt_accept_unlink(sk);
> -		parent->sk_data_ready(parent, 0);
> -	} else
> -		sk->sk_state_change(sk);
> -
> -	release_sock(sk);
> +	if (chan->ops->unlink)
> +		chan->ops->unlink(chan, err);
>
> 	if (test_bit(CONF_NOT_COMPLETE, &chan->conf_state))
> 		return;
> diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
> index 4d36605..6749d11 100644
> --- a/net/bluetooth/l2cap_sock.c
> +++ b/net/bluetooth/l2cap_sock.c
> @@ -954,6 +954,30 @@ static struct sk_buff *l2cap_sock_alloc_skb_cb(struct l2cap_chan *chan,
> 	return skb;
> }
>
> +static void l2cap_sock_unlink_cb(struct l2cap_chan *chan, int err)
> +{
> +	struct sock *sk = chan->sk;
> +	struct sock *parent = bt_sk(sk)->parent;
> +
> +	lock_sock(sk);
> +
> +	chan->state = BT_CLOSED;

I think this line had better stay in l2cap_chan_del - otherwise every 
unlink callback has to do it.  It's also the only modification to chan 
in here.  Since the channel must be locked before l2cap_chan_del is 
called anyway, I don't think it matters if chan->state is modified 
before or after the call to chan->ops->unlink.

> +	sk->sk_state = BT_CLOSED;
> +	sock_set_flag(sk, SOCK_ZAPPED);
> +
> +	if (err)
> +		sk->sk_err = err;
> +
> +	parent = bt_sk(sk)->parent;
> +	if (parent) {
> +		bt_accept_unlink(sk);
> +		parent->sk_data_ready(parent, 0);
> +	} else
> +		sk->sk_state_change(sk);
> +
> +	release_sock(sk);
> +}
> +
> static struct l2cap_ops l2cap_chan_ops = {
> 	.name		= "L2CAP Socket Interface",
> 	.new_connection	= l2cap_sock_new_connection_cb,
> @@ -961,6 +985,7 @@ static struct l2cap_ops l2cap_chan_ops = {
> 	.close		= l2cap_sock_close_cb,
> 	.state_change	= l2cap_sock_state_change_cb,
> 	.alloc_skb	= l2cap_sock_alloc_skb_cb,
> +	.unlink		= l2cap_sock_unlink_cb,
> };
>
> static void l2cap_sock_destruct(struct sock *sk)
> -- 
> 1.7.9.5



--
Mat Martineau
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum