inetpeer: Invalidate the inetpeer tree along with the routing cache

We initialize the routing metrics with the values cached on the
inetpeer in rt_init_metrics(). So if we have the metrics cached on the
inetpeer, we ignore the user configured fib_metrics.

To fix this issue, we replace the old tree with a fresh initialized
inet_peer_base. The old tree is removed later with a delayed work queue.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/inetpeer.h b/include/net/inetpeer.h
index 06b795d..ff04a33 100644
--- a/include/net/inetpeer.h
+++ b/include/net/inetpeer.h
@@ -41,6 +41,7 @@
 	u32			pmtu_orig;
 	u32			pmtu_learned;
 	struct inetpeer_addr_base redirect_learned;
+	struct list_head	gc_list;
 	/*
 	 * Once inet_peer is queued for deletion (refcnt == -1), following fields
 	 * are not available: rid, ip_id_count, tcp_ts, tcp_ts_stamp
@@ -96,6 +97,8 @@
 extern void inet_putpeer(struct inet_peer *p);
 extern bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout);
 
+extern void inetpeer_invalidate_tree(int family);
+
 /*
  * temporary check to make sure we dont access rid, ip_id_count, tcp_ts,
  * tcp_ts_stamp if no refcount is taken on inet_peer