net: Abstract away all dst_entry metrics accesses.

Use helper functions to hide all direct accesses, especially writes,
to dst_entry metrics values.

This will allow us to:

1) More easily change how the metrics are stored.

2) Implement COW for metrics.

In particular this will help us put metrics into the inetpeer
cache if that is what we end up doing.  We can make the _metrics
member a pointer instead of an array, initially have it point
at the read-only metrics in the FIB, and then on the first set
grab an inetpeer entry and point the _metrics member there.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>

2 files changed, 2 insertions, 2 deletions

diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index 17cb0b633576..556443566e9c 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -141,7 +141,7 @@ static int br_change_mtu(struct net_device *dev, int new_mtu)
 
 #ifdef CONFIG_BRIDGE_NETFILTER
         /* remember the MTU in the rtable for PMTU */
-        br->fake_rtable.dst.metrics[RTAX_MTU - 1] = new_mtu;
+        dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 #endif
 
         return 0;
diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
index 6e1392093911..16f5c333596a 100644
--- a/net/bridge/br_netfilter.c
+++ b/net/bridge/br_netfilter.c
@@ -124,7 +124,7 @@ void br_netfilter_rtable_init(struct net_bridge *br)
         atomic_set(&rt->dst.__refcnt, 1);
         rt->dst.dev = br->dev;
         rt->dst.path = &rt->dst;
-        rt->dst.metrics[RTAX_MTU - 1] = 1500;
+        dst_metric_set(&rt->dst, RTAX_MTU, 1500);
         rt->dst.flags   = DST_NOXFRM;
         rt->dst.ops = &fake_dst_ops;
 }