1 files changed, 19 insertions, 19 deletions

diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index b924941b96a3..92bc56028b8b 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -112,7 +112,7 @@ void fib6_update_sernum(struct net *net, struct fib6_info *f6i)
 	fn = rcu_dereference_protected(f6i->fib6_node,
 			lockdep_is_held(&f6i->fib6_table->tb6_lock));
 	if (fn)
-		fn->fn_sernum = fib6_new_sernum(net);
+		WRITE_ONCE(fn->fn_sernum, fib6_new_sernum(net));
 }
 
 /*
@@ -544,12 +544,13 @@ static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
 		spin_unlock_bh(&table->tb6_lock);
 		if (res > 0) {
 			cb->args[4] = 1;
-			cb->args[5] = w->root->fn_sernum;
+			cb->args[5] = READ_ONCE(w->root->fn_sernum);
 		}
 	} else {
-		if (cb->args[5] != w->root->fn_sernum) {
+		int sernum = READ_ONCE(w->root->fn_sernum);
+		if (cb->args[5] != sernum) {
 			/* Begin at the root if the tree changed */
-			cb->args[5] = w->root->fn_sernum;
+			cb->args[5] = sernum;
 			w->state = FWS_INIT;
 			w->node = w->root;
 			w->skip = w->count;
@@ -906,6 +907,8 @@ static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn,
 {
 	struct fib6_table *table = rt->fib6_table;
 
+	/* Flush all cached dst in exception table */
+	rt6_flush_exceptions(rt);
 	if (rt->rt6i_pcpu)
 		fib6_drop_pcpu_from(rt, table);
 
@@ -1201,7 +1204,7 @@ static void __fib6_update_sernum_upto_root(struct fib6_info *rt,
 	/* paired with smp_rmb() in rt6_get_cookie_safe() */
 	smp_wmb();
 	while (fn) {
-		fn->fn_sernum = sernum;
+		WRITE_ONCE(fn->fn_sernum, sernum);
 		fn = rcu_dereference_protected(fn->parent,
 				lockdep_is_held(&rt->fib6_table->tb6_lock));
 	}
@@ -1348,13 +1351,9 @@ out:
 			if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) {
 				pn_leaf = fib6_find_prefix(info->nl_net, table,
 							   pn);
-#if RT6_DEBUG >= 2
-				if (!pn_leaf) {
-					WARN_ON(!pn_leaf);
+				if (!pn_leaf)
 					pn_leaf =
 					    info->nl_net->ipv6.fib6_null_entry;
-				}
-#endif
 				fib6_info_hold(pn_leaf);
 				rcu_assign_pointer(pn->leaf, pn_leaf);
 			}
@@ -1756,9 +1755,6 @@ static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn,
 	net->ipv6.rt6_stats->fib_rt_entries--;
 	net->ipv6.rt6_stats->fib_discarded_routes++;
 
-	/* Flush all cached dst in exception table */
-	rt6_flush_exceptions(rt);
-
 	/* Reset round-robin state, if necessary */
 	if (rcu_access_pointer(fn->rr_ptr) == rt)
 		fn->rr_ptr = NULL;
@@ -1984,8 +1980,8 @@ static int fib6_clean_node(struct fib6_walker *w)
 	};
 
 	if (c->sernum != FIB6_NO_SERNUM_CHANGE &&
-	    w->node->fn_sernum != c->sernum)
-		w->node->fn_sernum = c->sernum;
+	    READ_ONCE(w->node->fn_sernum) != c->sernum)
+		WRITE_ONCE(w->node->fn_sernum, c->sernum);
 
 	if (!c->func) {
 		WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE);
@@ -2333,7 +2329,7 @@ static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter,
 	iter->w.state = FWS_INIT;
 	iter->w.node = iter->w.root;
 	iter->w.args = iter;
-	iter->sernum = iter->w.root->fn_sernum;
+	iter->sernum = READ_ONCE(iter->w.root->fn_sernum);
 	INIT_LIST_HEAD(&iter->w.lh);
 	fib6_walker_link(net, &iter->w);
 }
@@ -2361,8 +2357,10 @@ static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl,
 
 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter)
 {
-	if (iter->sernum != iter->w.root->fn_sernum) {
-		iter->sernum = iter->w.root->fn_sernum;
+	int sernum = READ_ONCE(iter->w.root->fn_sernum);
+
+	if (iter->sernum != sernum) {
+		iter->sernum = sernum;
 		iter->w.state = FWS_INIT;
 		iter->w.node = iter->w.root;
 		WARN_ON(iter->w.skip);
@@ -2417,8 +2415,10 @@ static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos)
 	iter->skip = *pos;
 
 	if (iter->tbl) {
+		loff_t p = 0;
+
 		ipv6_route_seq_setup_walk(iter, net);
-		return ipv6_route_seq_next(seq, NULL, pos);
+		return ipv6_route_seq_next(seq, NULL, &p);
 	} else {
 		return NULL;
 	}