net: remove DST_NOGC flag

Now that all the components have been changed to release dst based on
refcnt only and not depend on dst gc anymore, we can remove the
temporary flag DST_NOGC.

Note that we also need to remove the DST_NOCACHE check in dst_release()
and dst_hold_safe() because now all the dst are released based on refcnt
and behaves as DST_NOCACHE.

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>

6 files changed, 9 insertions, 19 deletions

diff --git a/include/net/dst.h b/include/net/dst.h
index 0c56d1fc4d7f..1be82f672c37 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -57,7 +57,6 @@ struct dst_entry {
 #define DST_XFRM_TUNNEL		0x0080
 #define DST_XFRM_QUEUE		0x0100
 #define DST_METADATA		0x0200
-#define DST_NOGC		0x0400
 
 	short			error;
 
@@ -336,10 +335,7 @@ static inline void skb_dst_force(struct sk_buff *skb)
  */
 static inline bool dst_hold_safe(struct dst_entry *dst)
 {
-	if (dst->flags & (DST_NOCACHE | DST_NOGC))
-		return atomic_inc_not_zero(&dst->__refcnt);
-	dst_hold(dst);
-	return true;
+	return atomic_inc_not_zero(&dst->__refcnt);
 }
 
 /**
diff --git a/net/core/dst.c b/net/core/dst.c
index 30bea01d2262..70543dabb797 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -179,14 +179,12 @@ void dst_release(struct dst_entry *dst)
 {
 	if (dst) {
 		int newrefcnt;
-		unsigned short destroy_after_rcu = dst->flags &
-						   (DST_NOCACHE | DST_NOGC);
 
 		newrefcnt = atomic_dec_return(&dst->__refcnt);
 		if (unlikely(newrefcnt < 0))
 			net_warn_ratelimited("%s: dst:%p refcnt:%d\n",
 					     __func__, dst, newrefcnt);
-		if (!newrefcnt && unlikely(destroy_after_rcu))
+		if (!newrefcnt)
 			call_rcu(&dst->rcu_head, dst_destroy_rcu);
 	}
 }
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index f467c4e3205b..5d17d843ac86 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -1179,8 +1179,7 @@ make_route:
 	if (dev_out->flags & IFF_LOOPBACK)
 		flags |= RTCF_LOCAL;
 
-	rt = dst_alloc(&dn_dst_ops, dev_out, 1, DST_OBSOLETE_NONE,
-		       DST_HOST | DST_NOGC);
+	rt = dst_alloc(&dn_dst_ops, dev_out, 1, DST_OBSOLETE_NONE, DST_HOST);
 	if (rt == NULL)
 		goto e_nobufs;
 
@@ -1445,8 +1444,7 @@ static int dn_route_input_slow(struct sk_buff *skb)
 	}
 
 make_route:
-	rt = dst_alloc(&dn_dst_ops, out_dev, 1, DST_OBSOLETE_NONE,
-		       DST_HOST | DST_NOGC);
+	rt = dst_alloc(&dn_dst_ops, out_dev, 1, DST_OBSOLETE_NONE, DST_HOST);
 	if (rt == NULL)
 		goto e_nobufs;
 
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 80b30c2bf47d..9a0f496f8bf4 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1496,8 +1496,7 @@ struct rtable *rt_dst_alloc(struct net_device *dev,
 	rt = dst_alloc(&ipv4_dst_ops, dev, 1, DST_OBSOLETE_FORCE_CHK,
 		       (will_cache ? 0 : (DST_HOST | DST_NOCACHE)) |
 		       (nopolicy ? DST_NOPOLICY : 0) |
-		       (noxfrm ? DST_NOXFRM : 0) |
-		       DST_NOGC);
+		       (noxfrm ? DST_NOXFRM : 0));
 
 	if (rt) {
 		rt->rt_genid = rt_genid_ipv4(dev_net(dev));
@@ -2503,7 +2502,7 @@ struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_or
 	struct rtable *ort = (struct rtable *) dst_orig;
 	struct rtable *rt;
 
-	rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, DST_NOGC);
+	rt = dst_alloc(&ipv4_dst_blackhole_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
 	if (rt) {
 		struct dst_entry *new = &rt->dst;
 
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index c88044b8fa7c..6b6528fa3292 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -354,8 +354,7 @@ static struct rt6_info *__ip6_dst_alloc(struct net *net,
 					int flags)
 {
 	struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev,
-					1, DST_OBSOLETE_FORCE_CHK,
-					flags | DST_NOGC);
+					1, DST_OBSOLETE_FORCE_CHK, flags);
 
 	if (rt)
 		rt6_info_init(rt);
@@ -1255,7 +1254,7 @@ struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_ori
 	struct dst_entry *new = NULL;
 
 	rt = dst_alloc(&ip6_dst_blackhole_ops, loopback_dev, 1,
-		       DST_OBSOLETE_NONE, DST_NOGC);
+		       DST_OBSOLETE_NONE, 0);
 	if (rt) {
 		rt6_info_init(rt);
 
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 85e1e13639cc..3f7e77f11112 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1622,7 +1622,7 @@ static inline struct xfrm_dst *xfrm_alloc_dst(struct net *net, int family)
 	default:
 		BUG();
 	}
-	xdst = dst_alloc(dst_ops, NULL, 1, DST_OBSOLETE_NONE, DST_NOGC);
+	xdst = dst_alloc(dst_ops, NULL, 1, DST_OBSOLETE_NONE, 0);
 
 	if (likely(xdst)) {
 		struct dst_entry *dst = &xdst->u.dst;