ipv4: FIB Local/MAIN table collapse

This patch is meant to collapse local and main into one by converting
tb_data from an array to a pointer.  Doing this allows us to point the
local table into the main while maintaining the same variables in the
table.

As such the tb_data was converted from an array to a pointer, and a new
array called data is added in order to still provide an object for tb_data
to point to.

In order to track the origin of the fib aliases a tb_id value was added in
a hole that existed on 64b systems.  Using this we can also reverse the
merge in the event that custom FIB rules are enabled.

With this patch I am seeing an improvement of 20ns to 30ns for routing
lookups as long as custom rules are not enabled, with custom rules enabled
we fall back to split tables and the original behavior.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 2 deletions

diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c
index 44706e81b2e0..b55677fed1c8 100644
--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c
@@ -492,6 +492,12 @@ static int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr* nlh)
 			goto errout;
 		}
 
+		if (ops->delete) {
+			err = ops->delete(rule);
+			if (err)
+				goto errout;
+		}
+
 		list_del_rcu(&rule->list);
 
 		if (rule->action == FR_ACT_GOTO) {
@@ -517,8 +523,6 @@ static int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr* nlh)
 
 		notify_rule_change(RTM_DELRULE, rule, ops, nlh,
 				   NETLINK_CB(skb).portid);
-		if (ops->delete)
-			ops->delete(rule);
 		fib_rule_put(rule);
 		flush_route_cache(ops);
 		rules_ops_put(ops);