net: sk_sleep() helper

Define a new function to return the waitqueue of a "struct sock".

static inline wait_queue_head_t *sk_sleep(struct sock *sk)
{
	return sk->sk_sleep;
}

Change all read occurrences of sk_sleep by a call to this function.

Needed for a future RCU conversion. sk_sleep wont be a field directly
available.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/datagram.c b/net/core/datagram.c
index 2dccd4e..5574a5d 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -86,7 +86,7 @@
 	int error;
 	DEFINE_WAIT_FUNC(wait, receiver_wake_function);
 
-	prepare_to_wait_exclusive(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
+	prepare_to_wait_exclusive(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 
 	/* Socket errors? */
 	error = sock_error(sk);
@@ -115,7 +115,7 @@
 	error = 0;
 	*timeo_p = schedule_timeout(*timeo_p);
 out:
-	finish_wait(sk->sk_sleep, &wait);
+	finish_wait(sk_sleep(sk), &wait);
 	return error;
 interrupted:
 	error = sock_intr_errno(*timeo_p);
@@ -726,7 +726,7 @@
 	struct sock *sk = sock->sk;
 	unsigned int mask;
 
-	sock_poll_wait(file, sk->sk_sleep, wait);
+	sock_poll_wait(file, sk_sleep(sk), wait);
 	mask = 0;
 
 	/* exceptional events? */
diff --git a/net/core/sock.c b/net/core/sock.c
index 7effa1e..58ebd14 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1395,7 +1395,7 @@
 		if (signal_pending(current))
 			break;
 		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
-		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
+		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
 			break;
 		if (sk->sk_shutdown & SEND_SHUTDOWN)
@@ -1404,7 +1404,7 @@
 			break;
 		timeo = schedule_timeout(timeo);
 	}
-	finish_wait(sk->sk_sleep, &wait);
+	finish_wait(sk_sleep(sk), &wait);
 	return timeo;
 }
 
@@ -1570,11 +1570,11 @@
 	int rc;
 	DEFINE_WAIT(wait);
 
-	prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
+	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 	set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
 	rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
 	clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
-	finish_wait(sk->sk_sleep, &wait);
+	finish_wait(sk_sleep(sk), &wait);
 	return rc;
 }
 EXPORT_SYMBOL(sk_wait_data);
@@ -1798,7 +1798,7 @@
 {
 	read_lock(&sk->sk_callback_lock);
 	if (sk_has_sleeper(sk))
-		wake_up_interruptible_all(sk->sk_sleep);
+		wake_up_interruptible_all(sk_sleep(sk));
 	read_unlock(&sk->sk_callback_lock);
 }
 
@@ -1806,7 +1806,7 @@
 {
 	read_lock(&sk->sk_callback_lock);
 	if (sk_has_sleeper(sk))
-		wake_up_interruptible_poll(sk->sk_sleep, POLLERR);
+		wake_up_interruptible_poll(sk_sleep(sk), POLLERR);
 	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
 	read_unlock(&sk->sk_callback_lock);
 }
@@ -1815,7 +1815,7 @@
 {
 	read_lock(&sk->sk_callback_lock);
 	if (sk_has_sleeper(sk))
-		wake_up_interruptible_sync_poll(sk->sk_sleep, POLLIN |
+		wake_up_interruptible_sync_poll(sk_sleep(sk), POLLIN |
 						POLLRDNORM | POLLRDBAND);
 	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
 	read_unlock(&sk->sk_callback_lock);
@@ -1830,7 +1830,7 @@
 	 */
 	if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
 		if (sk_has_sleeper(sk))
-			wake_up_interruptible_sync_poll(sk->sk_sleep, POLLOUT |
+			wake_up_interruptible_sync_poll(sk_sleep(sk), POLLOUT |
 						POLLWRNORM | POLLWRBAND);
 
 		/* Should agree with poll, otherwise some programs break */
diff --git a/net/core/stream.c b/net/core/stream.c
index a37debf..7b3c3f3 100644
--- a/net/core/stream.c
+++ b/net/core/stream.c
@@ -32,8 +32,8 @@
 	if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) && sock) {
 		clear_bit(SOCK_NOSPACE, &sock->flags);
 
-		if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
-			wake_up_interruptible_poll(sk->sk_sleep, POLLOUT |
+		if (sk_sleep(sk) && waitqueue_active(sk_sleep(sk)))
+			wake_up_interruptible_poll(sk_sleep(sk), POLLOUT |
 						POLLWRNORM | POLLWRBAND);
 		if (sock->fasync_list && !(sk->sk_shutdown & SEND_SHUTDOWN))
 			sock_wake_async(sock, SOCK_WAKE_SPACE, POLL_OUT);
@@ -66,13 +66,13 @@
 		if (signal_pending(tsk))
 			return sock_intr_errno(*timeo_p);
 
-		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
+		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 		sk->sk_write_pending++;
 		done = sk_wait_event(sk, timeo_p,
 				     !sk->sk_err &&
 				     !((1 << sk->sk_state) &
 				       ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)));
-		finish_wait(sk->sk_sleep, &wait);
+		finish_wait(sk_sleep(sk), &wait);
 		sk->sk_write_pending--;
 	} while (!done);
 	return 0;
@@ -96,13 +96,13 @@
 		DEFINE_WAIT(wait);
 
 		do {
-			prepare_to_wait(sk->sk_sleep, &wait,
+			prepare_to_wait(sk_sleep(sk), &wait,
 					TASK_INTERRUPTIBLE);
 			if (sk_wait_event(sk, &timeout, !sk_stream_closing(sk)))
 				break;
 		} while (!signal_pending(current) && timeout);
 
-		finish_wait(sk->sk_sleep, &wait);
+		finish_wait(sk_sleep(sk), &wait);
 	}
 }
 
@@ -126,7 +126,7 @@
 	while (1) {
 		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
 
-		prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
+		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 
 		if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
 			goto do_error;
@@ -157,7 +157,7 @@
 		*timeo_p = current_timeo;
 	}
 out:
-	finish_wait(sk->sk_sleep, &wait);
+	finish_wait(sk_sleep(sk), &wait);
 	return err;
 
 do_error: