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-rw-r--r--net/ipv6/ip6_fib.c38
1 files changed, 29 insertions, 9 deletions
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index d11a5578e4f8..9dcc3924a975 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -640,6 +640,11 @@ static struct fib6_node *fib6_add_1(struct net *net,
if (!(fn->fn_flags & RTN_RTINFO)) {
RCU_INIT_POINTER(fn->leaf, NULL);
rt6_release(leaf);
+ /* remove null_entry in the root node */
+ } else if (fn->fn_flags & RTN_TL_ROOT &&
+ rcu_access_pointer(fn->leaf) ==
+ net->ipv6.ip6_null_entry) {
+ RCU_INIT_POINTER(fn->leaf, NULL);
}
return fn;
@@ -1270,13 +1275,17 @@ out:
return err;
failure:
- /* fn->leaf could be NULL if fn is an intermediate node and we
- * failed to add the new route to it in both subtree creation
- * failure and fib6_add_rt2node() failure case.
- * In both cases, fib6_repair_tree() should be called to fix
- * fn->leaf.
+ /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if:
+ * 1. fn is an intermediate node and we failed to add the new
+ * route to it in both subtree creation failure and fib6_add_rt2node()
+ * failure case.
+ * 2. fn is the root node in the table and we fail to add the first
+ * default route to it.
*/
- if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)))
+ if (fn &&
+ (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) ||
+ (fn->fn_flags & RTN_TL_ROOT &&
+ !rcu_access_pointer(fn->leaf))))
fib6_repair_tree(info->nl_net, table, fn);
/* Always release dst as dst->__refcnt is guaranteed
* to be taken before entering this function
@@ -1531,6 +1540,12 @@ static struct fib6_node *fib6_repair_tree(struct net *net,
struct fib6_walker *w;
int iter = 0;
+ /* Set fn->leaf to null_entry for root node. */
+ if (fn->fn_flags & RTN_TL_ROOT) {
+ rcu_assign_pointer(fn->leaf, net->ipv6.ip6_null_entry);
+ return fn;
+ }
+
for (;;) {
struct fib6_node *fn_r = rcu_dereference_protected(fn->right,
lockdep_is_held(&table->tb6_lock));
@@ -1685,10 +1700,15 @@ static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn,
}
read_unlock(&net->ipv6.fib6_walker_lock);
- /* If it was last route, expunge its radix tree node */
+ /* If it was last route, call fib6_repair_tree() to:
+ * 1. For root node, put back null_entry as how the table was created.
+ * 2. For other nodes, expunge its radix tree node.
+ */
if (!rcu_access_pointer(fn->leaf)) {
- fn->fn_flags &= ~RTN_RTINFO;
- net->ipv6.rt6_stats->fib_route_nodes--;
+ if (!(fn->fn_flags & RTN_TL_ROOT)) {
+ fn->fn_flags &= ~RTN_RTINFO;
+ net->ipv6.rt6_stats->fib_route_nodes--;
+ }
fn = fib6_repair_tree(net, table, fn);
}