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/rds/af_rds.c b/net/rds/af_rds.c
index 7919a9e..aebfecb 100644
--- a/net/rds/af_rds.c
+++ b/net/rds/af_rds.c
@@ -158,7 +158,7 @@
 	unsigned int mask = 0;
 	unsigned long flags;
 
-	poll_wait(file, sk->sk_sleep, wait);
+	poll_wait(file, sk_sleep(sk), wait);
 
 	if (rs->rs_seen_congestion)
 		poll_wait(file, &rds_poll_waitq, wait);
diff --git a/net/rds/rds.h b/net/rds/rds.h
index 4bec6e2..c224b5b 100644
--- a/net/rds/rds.h
+++ b/net/rds/rds.h
@@ -492,7 +492,7 @@
 void rds_wake_sk_sleep(struct rds_sock *rs);
 static inline void __rds_wake_sk_sleep(struct sock *sk)
 {
-	wait_queue_head_t *waitq = sk->sk_sleep;
+	wait_queue_head_t *waitq = sk_sleep(sk);
 
 	if (!sock_flag(sk, SOCK_DEAD) && waitq)
 		wake_up(waitq);
diff --git a/net/rds/recv.c b/net/rds/recv.c
index e2a2b93..795a00b 100644
--- a/net/rds/recv.c
+++ b/net/rds/recv.c
@@ -432,7 +432,7 @@
 				break;
 			}
 
-			timeo = wait_event_interruptible_timeout(*sk->sk_sleep,
+			timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
 					(!list_empty(&rs->rs_notify_queue) ||
 					 rs->rs_cong_notify ||
 					 rds_next_incoming(rs, &inc)), timeo);
diff --git a/net/rds/send.c b/net/rds/send.c
index 53d6795..9c1c6bc 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -915,7 +915,7 @@
 			goto out;
 		}
 
-		timeo = wait_event_interruptible_timeout(*sk->sk_sleep,
+		timeo = wait_event_interruptible_timeout(*sk_sleep(sk),
 					rds_send_queue_rm(rs, conn, rm,
 							  rs->rs_bound_port,
 							  dport,