Commit dc26097b authored by Luiz Augusto von Dentz's avatar Luiz Augusto von Dentz
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Bluetooth: ISO: Use kref to track lifetime of iso_conn 



This make use of kref to keep track of reference of iso_conn which
allows better tracking of its lifetime with usage of things like
kref_get_unless_zero in a similar way as used in l2cap_chan.

In addition to it remove call to iso_sock_set_timer on iso_sock_disconn
since at that point it is useless to set a timer as the sk will be freed
there is nothing to be done in iso_sock_timeout.

Fixes: ccf74f23 ("Bluetooth: Add BTPROTO_ISO socket type")
Signed-off-by: default avatarLuiz Augusto von Dentz <luiz.von.dentz@intel.com>
parent e6720779

net/bluetooth/iso.c

+71 −17
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ struct iso_conn { 
	struct sk_buff	*rx_skb;

	__u32		rx_len;

	__u16		tx_sn;

	struct kref	ref;

};



#define iso_conn_lock(c)	spin_lock(&(c)->lock)
@@ -93,6 +94,49 @@ static struct sock *iso_get_sock(bdaddr_t *src, bdaddr_t *dst, 
#define ISO_CONN_TIMEOUT	(HZ * 40)

#define ISO_DISCONN_TIMEOUT	(HZ * 2)



static void iso_conn_free(struct kref *ref)

{

	struct iso_conn *conn = container_of(ref, struct iso_conn, ref);



	BT_DBG("conn %p", conn);



	if (conn->sk)

		iso_pi(conn->sk)->conn = NULL;



	if (conn->hcon) {

		conn->hcon->iso_data = NULL;

		hci_conn_drop(conn->hcon);

	}



	/* Ensure no more work items will run since hci_conn has been dropped */

	disable_delayed_work_sync(&conn->timeout_work);



	kfree(conn);

}



static void iso_conn_put(struct iso_conn *conn)

{

	if (!conn)

		return;



	BT_DBG("conn %p refcnt %d", conn, kref_read(&conn->ref));



	kref_put(&conn->ref, iso_conn_free);

}



static struct iso_conn *iso_conn_hold_unless_zero(struct iso_conn *conn)

{

	if (!conn)

		return NULL;



	BT_DBG("conn %p refcnt %u", conn, kref_read(&conn->ref));



	if (!kref_get_unless_zero(&conn->ref))

		return NULL;



	return conn;

}



static struct sock *iso_sock_hold(struct iso_conn *conn)

{

	if (!conn || !bt_sock_linked(&iso_sk_list, conn->sk))
@@ -109,9 +153,14 @@ static void iso_sock_timeout(struct work_struct *work) 
					     timeout_work.work);

	struct sock *sk;



	conn = iso_conn_hold_unless_zero(conn);

	if (!conn)

		return;



	iso_conn_lock(conn);

	sk = iso_sock_hold(conn);

	iso_conn_unlock(conn);

	iso_conn_put(conn);



	if (!sk)

		return;
@@ -149,9 +198,14 @@ static struct iso_conn *iso_conn_add(struct hci_conn *hcon) 
{

	struct iso_conn *conn = hcon->iso_data;



	conn = iso_conn_hold_unless_zero(conn);

	if (conn) {

		if (!conn->hcon)

		if (!conn->hcon) {

			iso_conn_lock(conn);

			conn->hcon = hcon;

			iso_conn_unlock(conn);

		}

		iso_conn_put(conn);

		return conn;

	}
@@ -159,6 +213,7 @@ static struct iso_conn *iso_conn_add(struct hci_conn *hcon) 
	if (!conn)

		return NULL;



	kref_init(&conn->ref);

	spin_lock_init(&conn->lock);

	INIT_DELAYED_WORK(&conn->timeout_work, iso_sock_timeout);
@@ -178,17 +233,15 @@ static void iso_chan_del(struct sock *sk, int err) 
	struct sock *parent;



	conn = iso_pi(sk)->conn;

	iso_pi(sk)->conn = NULL;



	BT_DBG("sk %p, conn %p, err %d", sk, conn, err);



	if (conn) {

		iso_conn_lock(conn);

		conn->sk = NULL;

		iso_pi(sk)->conn = NULL;

		iso_conn_unlock(conn);



		if (conn->hcon)

			hci_conn_drop(conn->hcon);

		iso_conn_put(conn);

	}



	sk->sk_state = BT_CLOSED;
@@ -210,6 +263,7 @@ static void iso_conn_del(struct hci_conn *hcon, int err) 
	struct iso_conn *conn = hcon->iso_data;

	struct sock *sk;



	conn = iso_conn_hold_unless_zero(conn);

	if (!conn)

		return;
@@ -219,8 +273,13 @@ static void iso_conn_del(struct hci_conn *hcon, int err) 
	iso_conn_lock(conn);

	sk = iso_sock_hold(conn);

	iso_conn_unlock(conn);

	iso_conn_put(conn);



	if (!sk) {

		iso_conn_put(conn);

		return;

	}



	if (sk) {

	lock_sock(sk);

	iso_sock_clear_timer(sk);

	iso_chan_del(sk, err);
@@ -228,13 +287,6 @@ static void iso_conn_del(struct hci_conn *hcon, int err) 
	sock_put(sk);

}



	/* Ensure no more work items will run before freeing conn. */

	cancel_delayed_work_sync(&conn->timeout_work);



	hcon->iso_data = NULL;

	kfree(conn);

}



static int __iso_chan_add(struct iso_conn *conn, struct sock *sk,

			  struct sock *parent)

{
@@ -652,6 +704,8 @@ static void iso_sock_destruct(struct sock *sk) 
{

	BT_DBG("sk %p", sk);



	iso_conn_put(iso_pi(sk)->conn);



	skb_queue_purge(&sk->sk_receive_queue);

	skb_queue_purge(&sk->sk_write_queue);

}
@@ -711,6 +765,7 @@ static void iso_sock_disconn(struct sock *sk) 
		 */

		if (bis_sk) {

			hcon->state = BT_OPEN;

			hcon->iso_data = NULL;

			iso_pi(sk)->conn->hcon = NULL;

			iso_sock_clear_timer(sk);

			iso_chan_del(sk, bt_to_errno(hcon->abort_reason));
@@ -720,7 +775,6 @@ static void iso_sock_disconn(struct sock *sk) 
	}



	sk->sk_state = BT_DISCONN;

	iso_sock_set_timer(sk, ISO_DISCONN_TIMEOUT);

	iso_conn_lock(iso_pi(sk)->conn);

	hci_conn_drop(iso_pi(sk)->conn->hcon);

	iso_pi(sk)->conn->hcon = NULL;