net: use helpers to change sk_ack_backlog

Writers are holding a lock, but many readers do not.

Following patch will add appropriate barriers in
sk_acceptq_removed() and sk_acceptq_added().
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/atm/signaling.c

@@ -109,7 +109,7 @@ static int sigd_send(struct atm_vcc *vcc, struct sk_buff *skb)
 			dev_kfree_skb(skb);
 			goto as_indicate_complete;
 		}
-		sk->sk_ack_backlog++;
+		sk_acceptq_added(sk);
 		skb_queue_tail(&sk->sk_receive_queue, skb);
 		pr_debug("waking sk_sleep(sk) 0x%p\n", sk_sleep(sk));
 		sk->sk_state_change(sk);

net/atm/svc.c

@@ -381,7 +381,7 @@ static int svc_accept(struct socket *sock, struct socket *newsock, int flags,
 				    msg->pvc.sap_addr.vpi,
 				    msg->pvc.sap_addr.vci);
 		dev_kfree_skb(skb);
-		sk->sk_ack_backlog--;
+		sk_acceptq_removed(sk);
 		if (error) {
 			sigd_enq2(NULL, as_reject, old_vcc, NULL, NULL,
 				  &old_vcc->qos, error);

net/ax25/af_ax25.c

@@ -1384,7 +1384,7 @@ static int ax25_accept(struct socket *sock, struct socket *newsock, int flags,
 
 	/* Now attach up the new socket */
 	kfree_skb(skb);
-	sk->sk_ack_backlog--;
+	sk_acceptq_removed(sk);
 	newsock->state = SS_CONNECTED;
 
 out:

net/ax25/ax25_in.c

@@ -356,7 +356,7 @@ static int ax25_rcv(struct sk_buff *skb, struct net_device *dev,
 
 		make->sk_state = TCP_ESTABLISHED;
 
-		sk->sk_ack_backlog++;
+		sk_acceptq_added(sk);
 		bh_unlock_sock(sk);
 	} else {
 		if (!mine)

net/bluetooth/af_bluetooth.c

@@ -173,7 +173,7 @@ void bt_accept_enqueue(struct sock *parent, struct sock *sk, bool bh)
 	else
 		release_sock(sk);
 
-	parent->sk_ack_backlog++;
+	sk_acceptq_added(parent);
 }
 EXPORT_SYMBOL(bt_accept_enqueue);
 
@@ -185,7 +185,7 @@ void bt_accept_unlink(struct sock *sk)
 	BT_DBG("sk %p state %d", sk, sk->sk_state);
 
 	list_del_init(&bt_sk(sk)->accept_q);
-	bt_sk(sk)->parent->sk_ack_backlog--;
+	sk_acceptq_removed(bt_sk(sk)->parent);
 	bt_sk(sk)->parent = NULL;
 	sock_put(sk);
 }

net/decnet/af_decnet.c

@@ -1091,7 +1091,7 @@ static int dn_accept(struct socket *sock, struct socket *newsock, int flags,
 	}
 
 	cb = DN_SKB_CB(skb);
-	sk->sk_ack_backlog--;
+	sk_acceptq_removed(sk);
 	newsk = dn_alloc_sock(sock_net(sk), newsock, sk->sk_allocation, kern);
 	if (newsk == NULL) {
 		release_sock(sk);

net/decnet/dn_nsp_in.c

@@ -328,7 +328,7 @@ static void dn_nsp_conn_init(struct sock *sk, struct sk_buff *skb)
 		return;
 	}
 
-	sk->sk_ack_backlog++;
+	sk_acceptq_added(sk);
 	skb_queue_tail(&sk->sk_receive_queue, skb);
 	sk->sk_state_change(sk);
 }

net/llc/af_llc.c

@@ -705,7 +705,7 @@ static int llc_ui_accept(struct socket *sock, struct socket *newsock, int flags,
 
 	/* put original socket back into a clean listen state. */
 	sk->sk_state = TCP_LISTEN;
-	sk->sk_ack_backlog--;
+	sk_acceptq_removed(sk);
 	dprintk("%s: ok success on %02X, client on %02X\n", __func__,
 		llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap);
 frees:

net/rose/af_rose.c

@@ -906,7 +906,7 @@ static int rose_accept(struct socket *sock, struct socket *newsock, int flags,
 	/* Now attach up the new socket */
 	skb->sk = NULL;
 	kfree_skb(skb);
-	sk->sk_ack_backlog--;
+	sk_acceptq_removed(sk);
 
 out_release:
 	release_sock(sk);
@@ -1011,7 +1011,7 @@ int rose_rx_call_request(struct sk_buff *skb, struct net_device *dev, struct ros
 	make_rose->va        = 0;
 	make_rose->vr        = 0;
 	make_rose->vl        = 0;
-	sk->sk_ack_backlog++;
+	sk_acceptq_added(sk);
 
 	rose_insert_socket(make);
 

net/sctp/associola.c

@@ -324,7 +324,7 @@ void sctp_association_free(struct sctp_association *asoc)
 		 * socket.
 		 */
 		if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
-			sk->sk_ack_backlog--;
+			sk_acceptq_removed(sk);
 	}
 
 	/* Mark as dead, so other users can know this structure is
@@ -1073,7 +1073,7 @@ void sctp_assoc_migrate(struct sctp_association *assoc, struct sock *newsk)
 
 	/* Decrement the backlog value for a TCP-style socket. */
 	if (sctp_style(oldsk, TCP))
-		oldsk->sk_ack_backlog--;
+		sk_acceptq_removed(oldsk);
 
 	/* Release references to the old endpoint and the sock.  */
 	sctp_endpoint_put(assoc->ep);

net/sctp/endpointola.c

@@ -164,7 +164,7 @@ void sctp_endpoint_add_asoc(struct sctp_endpoint *ep,
 
 	/* Increment the backlog value for a TCP-style listening socket. */
 	if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
-		sk->sk_ack_backlog++;
+		sk_acceptq_added(sk);
 }
 
 /* Free the endpoint structure.  Delay cleanup until

net/vmw_vsock/af_vsock.c

@@ -439,7 +439,7 @@ static void vsock_pending_work(struct work_struct *work)
 	if (vsock_is_pending(sk)) {
 		vsock_remove_pending(listener, sk);
 
-		listener->sk_ack_backlog--;
+		sk_acceptq_removed(listener);
 	} else if (!vsk->rejected) {
 		/* We are not on the pending list and accept() did not reject
 		 * us, so we must have been accepted by our user process.  We
@@ -1299,7 +1299,7 @@ static int vsock_accept(struct socket *sock, struct socket *newsock, int flags,
 		err = -listener->sk_err;
 
 	if (connected) {
-		listener->sk_ack_backlog--;
+		sk_acceptq_removed(listener);
 
 		lock_sock_nested(connected, SINGLE_DEPTH_NESTING);
 		vconnected = vsock_sk(connected);

net/vmw_vsock/hyperv_transport.c

@@ -428,7 +428,7 @@ static void hvs_open_connection(struct vmbus_channel *chan)
 
 	if (conn_from_host) {
 		new->sk_state = TCP_ESTABLISHED;
-		sk->sk_ack_backlog++;
+		sk_acceptq_added(sk);
 
 		hvs_addr_init(&vnew->local_addr, if_type);
 		hvs_remote_addr_init(&vnew->remote_addr, &vnew->local_addr);

net/vmw_vsock/virtio_transport_common.c

@@ -1066,7 +1066,7 @@ virtio_transport_recv_listen(struct sock *sk, struct virtio_vsock_pkt *pkt)
 		return -ENOMEM;
 	}
 
-	sk->sk_ack_backlog++;
+	sk_acceptq_added(sk);
 
 	lock_sock_nested(child, SINGLE_DEPTH_NESTING);
 

net/vmw_vsock/vmci_transport.c

@@ -1098,7 +1098,7 @@ static int vmci_transport_recv_listen(struct sock *sk,
 	}
 
 	vsock_add_pending(sk, pending);
-	sk->sk_ack_backlog++;
+	sk_acceptq_added(sk);
 
 	pending->sk_state = TCP_SYN_SENT;
 	vmci_trans(vpending)->produce_size =

net/x25/af_x25.c

@@ -891,7 +891,7 @@ static int x25_accept(struct socket *sock, struct socket *newsock, int flags,
 	/* Now attach up the new socket */
 	skb->sk = NULL;
 	kfree_skb(skb);
-	sk->sk_ack_backlog--;
+	sk_acceptq_removed(sk);
 	newsock->state = SS_CONNECTED;
 	rc = 0;
 out2:
@@ -1062,7 +1062,7 @@ int x25_rx_call_request(struct sk_buff *skb, struct x25_neigh *nb,
 	skb_copy_from_linear_data(skb, makex25->calluserdata.cuddata, skb->len);
 	makex25->calluserdata.cudlength = skb->len;
 
-	sk->sk_ack_backlog++;
+	sk_acceptq_added(sk);
 
 	x25_insert_socket(make);