net: add __rcu annotations to sk_wq and wq

Add proper RCU annotations/verbs to sk_wq and wq members

Fix __sctp_write_space() sk_sleep() abuse (and sock->wq access)

Fix sunrpc sk_sleep() abuse too

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/net.h b/include/linux/net.h
index 16faa13..94de83c 100644
--- a/include/linux/net.h
+++ b/include/linux/net.h
@@ -118,6 +118,7 @@
 };
 
 struct socket_wq {
+	/* Note: wait MUST be first field of socket_wq */
 	wait_queue_head_t	wait;
 	struct fasync_struct	*fasync_list;
 	struct rcu_head		rcu;
@@ -142,7 +143,7 @@
 
 	unsigned long		flags;
 
-	struct socket_wq	*wq;
+	struct socket_wq __rcu	*wq;
 
 	struct file		*file;
 	struct sock		*sk;