Merge branch 'rt6_pmtu'

Martin KaFai Lau says:

====================
ipv6: Stop /128 route from disappearing after pmtu update

The series is separated from another patch series,
'ipv6: Only create RTF_CACHE route after encountering pmtu exception',
which can be found here:
http://thread.gmane.org/gmane.linux.network/359140

This series focus on fixing the /128 route issues.  It is currently targeted
for net-next due to the number of code churn but it is also applicable
to net (should be without conflict).  The original reported problem can be
found here:
http://thread.gmane.org/gmane.linux.network/348138

Patch 01 and 02 are to prepare the fib6 search to expect both the
RTF_CACHE clone and its original route exist at the same fib6_node.

Patch 03 fixes the /128 route disappearing bug.

Patch 04 and 05 stop rt6_info from using the inet_peer's metrics to
avoid the /128 routes (like the /128 clone and its original route)
from stepping on each others' metrics.

The second patch is by 'Steffen Klassert <steffen.klassert@secunet.com>'
which I pulled off from netdev.  The third patch is also mostly by
Steffen with one minor optimization.

Many thanks to Hannes Frederic Sowa <hannes@stressinduktion.org> on
reviewing the patches and giving advice.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/dst.h

@@ -109,7 +109,6 @@ u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old);
 extern const u32 dst_default_metrics[];
 
 #define DST_METRICS_READ_ONLY		0x1UL
-#define DST_METRICS_FORCE_OVERWRITE	0x2UL
 #define DST_METRICS_FLAGS		0x3UL
 #define __DST_METRICS_PTR(Y)	\
 	((u32 *)((Y) & ~DST_METRICS_FLAGS))
@@ -120,11 +119,6 @@ static inline bool dst_metrics_read_only(const struct dst_entry *dst)
 	return dst->_metrics & DST_METRICS_READ_ONLY;
 }
 
-static inline void dst_metrics_set_force_overwrite(struct dst_entry *dst)
-{
-	dst->_metrics |= DST_METRICS_FORCE_OVERWRITE;
-}
-
 void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
 
 static inline void dst_destroy_metrics_generic(struct dst_entry *dst)

include/net/ip6_fib.h

@@ -121,44 +121,14 @@ struct rt6_info {
 	struct rt6key			rt6i_prefsrc;
 
 	struct inet6_dev		*rt6i_idev;
-	unsigned long			_rt6i_peer;
 
 	u32				rt6i_metric;
+	u32				rt6i_pmtu;
 	/* more non-fragment space at head required */
 	unsigned short			rt6i_nfheader_len;
 	u8				rt6i_protocol;
 };
 
-static inline struct inet_peer *rt6_peer_ptr(struct rt6_info *rt)
-{
-	return inetpeer_ptr(rt->_rt6i_peer);
-}
-
-static inline bool rt6_has_peer(struct rt6_info *rt)
-{
-	return inetpeer_ptr_is_peer(rt->_rt6i_peer);
-}
-
-static inline void __rt6_set_peer(struct rt6_info *rt, struct inet_peer *peer)
-{
-	__inetpeer_ptr_set_peer(&rt->_rt6i_peer, peer);
-}
-
-static inline bool rt6_set_peer(struct rt6_info *rt, struct inet_peer *peer)
-{
-	return inetpeer_ptr_set_peer(&rt->_rt6i_peer, peer);
-}
-
-static inline void rt6_init_peer(struct rt6_info *rt, struct inet_peer_base *base)
-{
-	inetpeer_init_ptr(&rt->_rt6i_peer, base);
-}
-
-static inline void rt6_transfer_peer(struct rt6_info *rt, struct rt6_info *ort)
-{
-	inetpeer_transfer_peer(&rt->_rt6i_peer, &ort->_rt6i_peer);
-}
-
 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
 {
 	return ((struct rt6_info *)dst)->rt6i_idev;
@@ -189,15 +159,6 @@ static inline void rt6_update_expires(struct rt6_info *rt0, int timeout)
 	rt0->rt6i_flags |= RTF_EXPIRES;
 }
 
-static inline void rt6_set_from(struct rt6_info *rt, struct rt6_info *from)
-{
-	struct dst_entry *new = (struct dst_entry *) from;
-
-	rt->rt6i_flags &= ~RTF_EXPIRES;
-	dst_hold(new);
-	rt->dst.from = new;
-}
-
 static inline void ip6_rt_put(struct rt6_info *rt)
 {
 	/* dst_release() accepts a NULL parameter.

net/ipv6/addrconf.c

@@ -2121,6 +2121,8 @@ static struct rt6_info *addrconf_get_prefix_route(const struct in6_addr *pfx,
 	fn = fib6_locate(&table->tb6_root, pfx, plen, NULL, 0);
 	if (!fn)
 		goto out;
+
+	noflags |= RTF_CACHE;
 	for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) {
 		if (rt->dst.dev->ifindex != dev->ifindex)
 			continue;

net/ipv6/xfrm6_policy.c

@@ -71,13 +71,6 @@ static int xfrm6_get_tos(const struct flowi *fl)
 	return 0;
 }
 
-static void xfrm6_init_dst(struct net *net, struct xfrm_dst *xdst)
-{
-	struct rt6_info *rt = (struct rt6_info *)xdst;
-
-	rt6_init_peer(rt, net->ipv6.peers);
-}
-
 static int xfrm6_init_path(struct xfrm_dst *path, struct dst_entry *dst,
 			   int nfheader_len)
 {
@@ -106,8 +99,6 @@ static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
 		return -ENODEV;
 	}
 
-	rt6_transfer_peer(&xdst->u.rt6, rt);
-
 	/* Sheit... I remember I did this right. Apparently,
 	 * it was magically lost, so this code needs audit */
 	xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST |
@@ -255,10 +246,6 @@ static void xfrm6_dst_destroy(struct dst_entry *dst)
 	if (likely(xdst->u.rt6.rt6i_idev))
 		in6_dev_put(xdst->u.rt6.rt6i_idev);
 	dst_destroy_metrics_generic(dst);
-	if (rt6_has_peer(&xdst->u.rt6)) {
-		struct inet_peer *peer = rt6_peer_ptr(&xdst->u.rt6);
-		inet_putpeer(peer);
-	}
 	xfrm_dst_destroy(xdst);
 }
 
@@ -308,7 +295,6 @@ static struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
 	.get_saddr =		xfrm6_get_saddr,
 	.decode_session =	_decode_session6,
 	.get_tos =		xfrm6_get_tos,
-	.init_dst =		xfrm6_init_dst,
 	.init_path =		xfrm6_init_path,
 	.fill_dst =		xfrm6_fill_dst,
 	.blackhole_route =	ip6_blackhole_route,