netlink: add symbolic value for congested state

Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/netlink/af_netlink.c

@@ -68,6 +68,10 @@ struct listeners {
 	unsigned long		masks[0];
 };
 
+/* state bits */
+#define NETLINK_CONGESTED	0x0
+
+/* flags */
 #define NETLINK_KERNEL_SOCKET	0x1
 #define NETLINK_RECV_PKTINFO	0x2
 #define NETLINK_BROADCAST_SEND_ERROR	0x4
@@ -727,7 +731,7 @@ static void netlink_overrun(struct sock *sk)
 	struct netlink_sock *nlk = nlk_sk(sk);
 
 	if (!(nlk->flags & NETLINK_RECV_NO_ENOBUFS)) {
-		if (!test_and_set_bit(0, &nlk_sk(sk)->state)) {
+		if (!test_and_set_bit(NETLINK_CONGESTED, &nlk_sk(sk)->state)) {
 			sk->sk_err = ENOBUFS;
 			sk->sk_error_report(sk);
 		}
@@ -788,7 +792,7 @@ int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
 	nlk = nlk_sk(sk);
 
 	if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
-	    test_bit(0, &nlk->state)) {
+	    test_bit(NETLINK_CONGESTED, &nlk->state)) {
 		DECLARE_WAITQUEUE(wait, current);
 		if (!*timeo) {
 			if (!ssk || netlink_is_kernel(ssk))
@@ -802,7 +806,7 @@ int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
 		add_wait_queue(&nlk->wait, &wait);
 
 		if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
-		     test_bit(0, &nlk->state)) &&
+		     test_bit(NETLINK_CONGESTED, &nlk->state)) &&
 		    !sock_flag(sk, SOCK_DEAD))
 			*timeo = schedule_timeout(*timeo);
 
@@ -872,8 +876,8 @@ static void netlink_rcv_wake(struct sock *sk)
 	struct netlink_sock *nlk = nlk_sk(sk);
 
 	if (skb_queue_empty(&sk->sk_receive_queue))
-		clear_bit(0, &nlk->state);
-	if (!test_bit(0, &nlk->state))
+		clear_bit(NETLINK_CONGESTED, &nlk->state);
+	if (!test_bit(NETLINK_CONGESTED, &nlk->state))
 		wake_up_interruptible(&nlk->wait);
 }
 
@@ -957,7 +961,7 @@ static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb)
 	struct netlink_sock *nlk = nlk_sk(sk);
 
 	if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
-	    !test_bit(0, &nlk->state)) {
+	    !test_bit(NETLINK_CONGESTED, &nlk->state)) {
 		skb_set_owner_r(skb, sk);
 		__netlink_sendskb(sk, skb);
 		return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1);
@@ -1235,7 +1239,7 @@ static int netlink_setsockopt(struct socket *sock, int level, int optname,
 	case NETLINK_NO_ENOBUFS:
 		if (val) {
 			nlk->flags |= NETLINK_RECV_NO_ENOBUFS;
-			clear_bit(0, &nlk->state);
+			clear_bit(NETLINK_CONGESTED, &nlk->state);
 			wake_up_interruptible(&nlk->wait);
 		} else {
 			nlk->flags &= ~NETLINK_RECV_NO_ENOBUFS;