net: introduce lockdep_is_held and update various places to use it

The socket is either locked if we hold the slock spin_lock for
lock_sock_fast and unlock_sock_fast or we own the lock (sk_lock.owned
!= 0). Check for this and at the same time improve that the current
thread/cpu is really holding the lock.

Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 1b7c077..89b5f3b 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -642,7 +642,7 @@
 		if (err)
 			break;
 		old = rcu_dereference_protected(inet->inet_opt,
-						sock_owned_by_user(sk));
+						lockdep_sock_is_held(sk));
 		if (inet->is_icsk) {
 			struct inet_connection_sock *icsk = inet_csk(sk);
 #if IS_ENABLED(CONFIG_IPV6)
@@ -1302,7 +1302,7 @@
 		struct ip_options_rcu *inet_opt;
 
 		inet_opt = rcu_dereference_protected(inet->inet_opt,
-						     sock_owned_by_user(sk));
+						     lockdep_sock_is_held(sk));
 		opt->optlen = 0;
 		if (inet_opt)
 			memcpy(optbuf, &inet_opt->opt,