[NET]: Name magic constants in sock_wake_async()

The sock_wake_async() performs a bit different actions
depending on "how" argument. Unfortunately this argument
ony has numerical magic values.

I propose to give names to their constants to help people
reading this function callers understand what's going on
without looking into this function all the time.

I suppose this is 2.6.25 material, but if it's not (or the
naming seems poor/bad/awful), I can rework it against the
current net-2.6 tree.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/net.h

@@ -186,6 +186,13 @@ struct net_proto_family {
 struct iovec;
 struct kvec;
 
+enum {
+	SOCK_WAKE_IO,
+	SOCK_WAKE_WAITD,
+	SOCK_WAKE_SPACE,
+	SOCK_WAKE_URG,
+};
+
 extern int	     sock_wake_async(struct socket *sk, int how, int band);
 extern int	     sock_register(const struct net_proto_family *fam);
 extern void	     sock_unregister(int family);

net/atm/common.c

@@ -113,7 +113,7 @@ static void vcc_write_space(struct sock *sk)
 		if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
 			wake_up_interruptible(sk->sk_sleep);
 
-		sk_wake_async(sk, 2, POLL_OUT);
+		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
 	}
 
 	read_unlock(&sk->sk_callback_lock);

net/core/sock.c

@@ -1498,7 +1498,7 @@ static void sock_def_error_report(struct sock *sk)
 	read_lock(&sk->sk_callback_lock);
 	if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
 		wake_up_interruptible(sk->sk_sleep);
-	sk_wake_async(sk,0,POLL_ERR);
+	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
 	read_unlock(&sk->sk_callback_lock);
 }
 
@@ -1507,7 +1507,7 @@ static void sock_def_readable(struct sock *sk, int len)
 	read_lock(&sk->sk_callback_lock);
 	if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
 		wake_up_interruptible(sk->sk_sleep);
-	sk_wake_async(sk,1,POLL_IN);
+	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
 	read_unlock(&sk->sk_callback_lock);
 }
 
@@ -1524,7 +1524,7 @@ static void sock_def_write_space(struct sock *sk)
 
 		/* Should agree with poll, otherwise some programs break */
 		if (sock_writeable(sk))
-			sk_wake_async(sk, 2, POLL_OUT);
+			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
 	}
 
 	read_unlock(&sk->sk_callback_lock);
@@ -1539,7 +1539,7 @@ void sk_send_sigurg(struct sock *sk)
 {
 	if (sk->sk_socket && sk->sk_socket->file)
 		if (send_sigurg(&sk->sk_socket->file->f_owner))
-			sk_wake_async(sk, 3, POLL_PRI);
+			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
 }
 
 void sk_reset_timer(struct sock *sk, struct timer_list* timer,

net/core/stream.c

@@ -35,7 +35,7 @@ void sk_stream_write_space(struct sock *sk)
 		if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
 			wake_up_interruptible(sk->sk_sleep);
 		if (sock->fasync_list && !(sk->sk_shutdown & SEND_SHUTDOWN))
-			sock_wake_async(sock, 2, POLL_OUT);
+			sock_wake_async(sock, SOCK_WAKE_SPACE, POLL_OUT);
 	}
 }
 

net/dccp/input.c

@@ -37,7 +37,7 @@ static void dccp_rcv_close(struct sock *sk, struct sk_buff *skb)
 	dccp_send_reset(sk, DCCP_RESET_CODE_CLOSED);
 	dccp_fin(sk, skb);
 	dccp_set_state(sk, DCCP_CLOSED);
-	sk_wake_async(sk, 1, POLL_HUP);
+	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP);
 }
 
 static void dccp_rcv_closereq(struct sock *sk, struct sk_buff *skb)
@@ -90,7 +90,7 @@ static void dccp_rcv_reset(struct sock *sk, struct sk_buff *skb)
 	dccp_fin(sk, skb);
 
 	if (err && !sock_flag(sk, SOCK_DEAD))
-		sk_wake_async(sk, 0, POLL_ERR);
+		sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
 	dccp_time_wait(sk, DCCP_TIME_WAIT, 0);
 }
 
@@ -416,7 +416,7 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk,
 
 		if (!sock_flag(sk, SOCK_DEAD)) {
 			sk->sk_state_change(sk);
-			sk_wake_async(sk, 0, POLL_OUT);
+			sk_wake_async(sk, SOCK_WAKE_IO, POLL_OUT);
 		}
 
 		if (sk->sk_write_pending || icsk->icsk_ack.pingpong ||
@@ -624,7 +624,7 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
 		switch (old_state) {
 		case DCCP_PARTOPEN:
 			sk->sk_state_change(sk);
-			sk_wake_async(sk, 0, POLL_OUT);
+			sk_wake_async(sk, SOCK_WAKE_IO, POLL_OUT);
 			break;
 		}
 	} else if (unlikely(dh->dccph_type == DCCP_PKT_SYNC)) {

net/dccp/output.c

@@ -170,7 +170,7 @@ void dccp_write_space(struct sock *sk)
 		wake_up_interruptible(sk->sk_sleep);
 	/* Should agree with poll, otherwise some programs break */
 	if (sock_writeable(sk))
-		sk_wake_async(sk, 2, POLL_OUT);
+		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
 
 	read_unlock(&sk->sk_callback_lock);
 }

net/ipv4/tcp_input.c

@@ -3595,9 +3595,9 @@ static void tcp_fin(struct sk_buff *skb, struct sock *sk, struct tcphdr *th)
 		/* Do not send POLL_HUP for half duplex close. */
 		if (sk->sk_shutdown == SHUTDOWN_MASK ||
 		    sk->sk_state == TCP_CLOSE)
-			sk_wake_async(sk, 1, POLL_HUP);
+			sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP);
 		else
-			sk_wake_async(sk, 1, POLL_IN);
+			sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
 	}
 }
 
@@ -4956,7 +4956,7 @@ static int tcp_rcv_synsent_state_process(struct sock *sk, struct sk_buff *skb,
 
 		if (!sock_flag(sk, SOCK_DEAD)) {
 			sk->sk_state_change(sk);
-			sk_wake_async(sk, 0, POLL_OUT);
+			sk_wake_async(sk, SOCK_WAKE_IO, POLL_OUT);
 		}
 
 		if (sk->sk_write_pending ||
@@ -5186,9 +5186,9 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
 				 * are not waked up, because sk->sk_sleep ==
 				 * NULL and sk->sk_socket == NULL.
 				 */
-				if (sk->sk_socket) {
-					sk_wake_async(sk,0,POLL_OUT);
-				}
+				if (sk->sk_socket)
+					sk_wake_async(sk,
+							SOCK_WAKE_IO, POLL_OUT);
 
 				tp->snd_una = TCP_SKB_CB(skb)->ack_seq;
 				tp->snd_wnd = ntohs(th->window) <<

net/rxrpc/af_rxrpc.c

@@ -65,7 +65,7 @@ static void rxrpc_write_space(struct sock *sk)
 	if (rxrpc_writable(sk)) {
 		if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
 			wake_up_interruptible(sk->sk_sleep);
-		sk_wake_async(sk, 2, POLL_OUT);
+		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
 	}
 	read_unlock(&sk->sk_callback_lock);
 }

net/sctp/socket.c

@@ -6008,7 +6008,8 @@ static void __sctp_write_space(struct sctp_association *asoc)
 			 */
 			if (sock->fasync_list &&
 			    !(sk->sk_shutdown & SEND_SHUTDOWN))
-				sock_wake_async(sock, 2, POLL_OUT);
+				sock_wake_async(sock,
+						SOCK_WAKE_SPACE, POLL_OUT);
 		}
 	}
 }

net/socket.c

@@ -1070,20 +1070,19 @@ int sock_wake_async(struct socket *sock, int how, int band)
 	if (!sock || !sock->fasync_list)
 		return -1;
 	switch (how) {
-	case 1:
-
+	case SOCK_WAKE_WAITD:
 		if (test_bit(SOCK_ASYNC_WAITDATA, &sock->flags))
 			break;
 		goto call_kill;
-	case 2:
+	case SOCK_WAKE_SPACE:
 		if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags))
 			break;
 		/* fall through */
-	case 0:
+	case SOCK_WAKE_IO:
 call_kill:
 		__kill_fasync(sock->fasync_list, SIGIO, band);
 		break;
-	case 3:
+	case SOCK_WAKE_URG:
 		__kill_fasync(sock->fasync_list, SIGURG, band);
 	}
 	return 0;

net/unix/af_unix.c

@@ -317,7 +317,7 @@ static void unix_write_space(struct sock *sk)
 	if (unix_writable(sk)) {
 		if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
 			wake_up_interruptible_sync(sk->sk_sleep);
-		sk_wake_async(sk, 2, POLL_OUT);
+		sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
 	}
 	read_unlock(&sk->sk_callback_lock);
 }
@@ -403,7 +403,7 @@ static int unix_release_sock (struct sock *sk, int embrion)
 			unix_state_unlock(skpair);
 			skpair->sk_state_change(skpair);
 			read_lock(&skpair->sk_callback_lock);
-			sk_wake_async(skpair,1,POLL_HUP);
+			sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP);
 			read_unlock(&skpair->sk_callback_lock);
 		}
 		sock_put(skpair); /* It may now die */
@@ -1900,9 +1900,9 @@ static int unix_shutdown(struct socket *sock, int mode)
 			other->sk_state_change(other);
 			read_lock(&other->sk_callback_lock);
 			if (peer_mode == SHUTDOWN_MASK)
-				sk_wake_async(other,1,POLL_HUP);
+				sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP);
 			else if (peer_mode & RCV_SHUTDOWN)
-				sk_wake_async(other,1,POLL_IN);
+				sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN);
 			read_unlock(&other->sk_callback_lock);
 		}
 		if (other)