net: remove DST_NOCACHE flag

DST_NOCACHE flag check has been removed from dst_release() and
dst_hold_safe() in a previous patch because all the dst are now ref
counted properly and can be released based on refcnt only.
Looking at the rest of the DST_NOCACHE use, all of them can now be
removed or replaced with other checks.
So this patch gets rid of all the DST_NOCACHE usage and remove this flag
completely.

Signed-off-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 12 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 9a0f496f8bf4..c816cd53f7fc 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1299,7 +1299,7 @@ static struct fib_nh_exception *find_exception(struct fib_nh *nh, __be32 daddr)
 }
 
 static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
-			      __be32 daddr)
+			      __be32 daddr, const bool do_cache)
 {
 	bool ret = false;
 
@@ -1328,7 +1328,7 @@ static bool rt_bind_exception(struct rtable *rt, struct fib_nh_exception *fnhe,
 		if (!rt->rt_gateway)
 			rt->rt_gateway = daddr;
 
-		if (!(rt->dst.flags & DST_NOCACHE)) {
+		if (do_cache) {
 			dst_hold(&rt->dst);
 			rcu_assign_pointer(*porig, rt);
 			if (orig) {
@@ -1441,7 +1441,8 @@ static bool rt_cache_valid(const struct rtable *rt)
 static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
 			   const struct fib_result *res,
 			   struct fib_nh_exception *fnhe,
-			   struct fib_info *fi, u16 type, u32 itag)
+			   struct fib_info *fi, u16 type, u32 itag,
+			   const bool do_cache)
 {
 	bool cached = false;
 
@@ -1462,8 +1463,8 @@ static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
 #endif
 		rt->dst.lwtstate = lwtstate_get(nh->nh_lwtstate);
 		if (unlikely(fnhe))
-			cached = rt_bind_exception(rt, fnhe, daddr);
-		else if (!(rt->dst.flags & DST_NOCACHE))
+			cached = rt_bind_exception(rt, fnhe, daddr, do_cache);
+		else if (do_cache)
 			cached = rt_cache_route(nh, rt);
 		if (unlikely(!cached)) {
 			/* Routes we intend to cache in nexthop exception or
@@ -1471,7 +1472,6 @@ static void rt_set_nexthop(struct rtable *rt, __be32 daddr,
 			 * However, if we are unsuccessful at storing this
 			 * route into the cache we really need to set it.
 			 */
-			rt->dst.flags |= DST_NOCACHE;
 			if (!rt->rt_gateway)
 				rt->rt_gateway = daddr;
 			rt_add_uncached_list(rt);
@@ -1494,7 +1494,7 @@ struct rtable *rt_dst_alloc(struct net_device *dev,
 	struct rtable *rt;
 
 	rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
-		       (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
+		       (will_cache ? 0 : DST_HOST) |
 		       (nopolicy ? DST_NOPOLICY : 0) |
 		       (noxfrm ? DST_NOXFRM : 0));
 
@@ -1738,7 +1738,8 @@ rt_cache:
 
 	rth->dst.input = ip_forward;
 
-	rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag);
+	rt_set_nexthop(rth, daddr, res, fnhe, res->fi, res->type, itag,
+		       do_cache);
 	set_lwt_redirect(rth);
 	skb_dst_set(skb, &rth->dst);
 out:
@@ -2026,10 +2027,8 @@ local_input:
 			rth->dst.input = lwtunnel_input;
 		}
 
-		if (unlikely(!rt_cache_route(nh, rth))) {
-			rth->dst.flags |= DST_NOCACHE;
+		if (unlikely(!rt_cache_route(nh, rth)))
 			rt_add_uncached_list(rth);
-		}
 	}
 	skb_dst_set(skb, &rth->dst);
 	err = 0;
@@ -2260,7 +2259,7 @@ add:
 #endif
 	}
 
-	rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0);
+	rt_set_nexthop(rth, fl4->daddr, res, fnhe, fi, type, 0, do_cache);
 	set_lwt_redirect(rth);
 
 	return rth;