net: Disambiguate kernel message

Some of our machines were reporting:

TCP: too many of orphaned sockets

even when the number of orphaned sockets was well below the
limit.

We print a different message depending on whether we're out
of TCP memory or there are too many orphaned sockets.

Also move the check out of line and cleanup the messages
that were printed.

Signed-off-by: Arun Sharma <asharma@fb.com>
Suggested-by: Mohan Srinivasan <mohan@fb.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: David Miller <davem@davemloft.net>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/tcp.h b/include/net/tcp.h
index d49db01..42c29bf 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -273,6 +273,14 @@
 	return seq3 - seq2 >= seq1 - seq2;
 }
 
+static inline bool tcp_out_of_memory(struct sock *sk)
+{
+	if (sk->sk_wmem_queued > SOCK_MIN_SNDBUF &&
+	    sk_memory_allocated(sk) > sk_prot_mem_limits(sk, 2))
+		return true;
+	return false;
+}
+
 static inline bool tcp_too_many_orphans(struct sock *sk, int shift)
 {
 	struct percpu_counter *ocp = sk->sk_prot->orphan_count;
@@ -283,13 +291,11 @@
 		if (orphans << shift > sysctl_tcp_max_orphans)
 			return true;
 	}
-
-	if (sk->sk_wmem_queued > SOCK_MIN_SNDBUF &&
-	    sk_memory_allocated(sk) > sk_prot_mem_limits(sk, 2))
-		return true;
 	return false;
 }
 
+extern bool tcp_check_oom(struct sock *sk, int shift);
+
 /* syncookies: remember time of last synqueue overflow */
 static inline void tcp_synq_overflow(struct sock *sk)
 {