[RFC PATCH net-next 03/10] ipv6: Combine rt6_alloc_cow and rt6_alloc_clone

[Martin KaFai Lau <kafai@fb.com>]

A prep work for creating RTF_CACHE on exception only.  After this
patch, the same condition (rt->rt6i_flags & (RTF_NONEXTHOP | RTF_GATEWAY))
is checked twice. This redundancy will be removed in the later patch.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
---
 net/ipv6/route.c | 40 +++++++++++++++-------------------------
 1 file changed, 15 insertions(+), 25 deletions(-)

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 0ccb8ec..f753a67 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -872,9 +872,9 @@ int ip6_ins_rt(struct rt6_info *rt)
 	return __ip6_ins_rt(rt, &info, &mxc);
 }
 
-static struct rt6_info *rt6_alloc_cow(struct rt6_info *ort,
-				      const struct in6_addr *daddr,
-				      const struct in6_addr *saddr)
+static struct rt6_info *ip6_pmtu_rt_cache_alloc(struct rt6_info *ort,
+						const struct in6_addr *daddr,
+						const struct in6_addr *saddr)
 {
 	struct rt6_info *rt;
 
@@ -885,33 +885,24 @@ static struct rt6_info *rt6_alloc_cow(struct rt6_info *ort,
 	rt = ip6_rt_copy(ort, daddr);
 
 	if (rt) {
-		if (ort->rt6i_dst.plen != 128 &&
-		    ipv6_addr_equal(&ort->rt6i_dst.addr, daddr))
-			rt->rt6i_flags |= RTF_ANYCAST;
-
 		rt->rt6i_flags |= RTF_CACHE;
 
+		if (!(ort->rt6i_flags & (RTF_NONEXTHOP | RTF_GATEWAY))) {
+			if (ort->rt6i_dst.plen != 128 &&
+			    ipv6_addr_equal(&ort->rt6i_dst.addr, daddr))
+				rt->rt6i_flags |= RTF_ANYCAST;
 #ifdef CONFIG_IPV6_SUBTREES
-		if (rt->rt6i_src.plen && saddr) {
-			rt->rt6i_src.addr = *saddr;
-			rt->rt6i_src.plen = 128;
-		}
+			if (rt->rt6i_src.plen && saddr) {
+				rt->rt6i_src.addr = *saddr;
+				rt->rt6i_src.plen = 128;
+			}
 #endif
+		}
 	}
 
 	return rt;
 }
 
-static struct rt6_info *rt6_alloc_clone(struct rt6_info *ort,
-					const struct in6_addr *daddr)
-{
-	struct rt6_info *rt = ip6_rt_copy(ort, daddr);
-
-	if (rt)
-		rt->rt6i_flags |= RTF_CACHE;
-	return rt;
-}
-
 static struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, int oif,
 				      struct flowi6 *fl6, int flags)
 {
@@ -957,10 +948,9 @@ redo_rt6_select:
 	if (rt->rt6i_flags & RTF_CACHE)
 		goto out2;
 
-	if (!(rt->rt6i_flags & (RTF_NONEXTHOP | RTF_GATEWAY)))
-		nrt = rt6_alloc_cow(rt, &fl6->daddr, &fl6->saddr);
-	else if (!(rt->dst.flags & DST_HOST))
-		nrt = rt6_alloc_clone(rt, &fl6->daddr);
+	if (!(rt->rt6i_flags & (RTF_NONEXTHOP | RTF_GATEWAY)) ||
+	    !(rt->dst.flags & DST_HOST))
+		nrt = ip6_pmtu_rt_cache_alloc(rt, &fl6->daddr, &fl6->saddr);
 	else
 		goto out2;
 
-- 
1.8.1