ipv6: don't walk node's leaf during serial number update

Cc: YOSHIFUJI Hideaki <hideaki@yoshifuji.org>
Cc: Martin Lau <kafai@fb.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 6f9beb1f286155bdab7efcfc8d8ccb50d81ce871..b2d1838897c933f6f1ceb2a6f64a2f67495ce3c9 100644 (file)
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -50,6 +50,7 @@ struct fib6_cleaner {
        struct fib6_walker w;
        struct net *net;
        int (*func)(struct rt6_info *, void *arg);
+       int sernum;
        void *arg;
 };
 
@@ -105,6 +106,10 @@ static int fib6_new_sernum(struct net *net)
        return new;
 }
 
+enum {
+       FIB6_NO_SERNUM_CHANGE = 0,
+};
+
 /*
  *     Auxiliary address test functions for the radix tree.
  *
@@ -1514,6 +1519,16 @@ static int fib6_clean_node(struct fib6_walker *w)
                .nl_net = c->net,
        };
 
+       if (c->sernum != FIB6_NO_SERNUM_CHANGE &&
+           w->node->fn_sernum != c->sernum)
+               w->node->fn_sernum = c->sernum;
+
+       if (!c->func) {
+               WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE);
+               w->leaf = NULL;
+               return 0;
+       }
+
        for (rt = w->leaf; rt; rt = rt->dst.rt6_next) {
                res = c->func(rt, c->arg);
                if (res < 0) {
@@ -1547,7 +1562,7 @@ static int fib6_clean_node(struct fib6_walker *w)
 
 static void fib6_clean_tree(struct net *net, struct fib6_node *root,
                            int (*func)(struct rt6_info *, void *arg),
-                           bool prune, void *arg)
+                           bool prune, int sernum, void *arg)
 {
        struct fib6_cleaner c;
 
@@ -1557,14 +1572,16 @@ static void fib6_clean_tree(struct net *net, struct fib6_node *root,
        c.w.count = 0;
        c.w.skip = 0;
        c.func = func;
+       c.sernum = sernum;
        c.arg = arg;
        c.net = net;
 
        fib6_walk(&c.w);
 }
 
-void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),
-                   void *arg)
+static void __fib6_clean_all(struct net *net,
+                            int (*func)(struct rt6_info *, void *),
+                            int sernum, void *arg)
 {
        struct fib6_table *table;
        struct hlist_head *head;
@@ -1576,13 +1593,19 @@ void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg),
                hlist_for_each_entry_rcu(table, head, tb6_hlist) {
                        write_lock_bh(&table->tb6_lock);
                        fib6_clean_tree(net, &table->tb6_root,
-                                       func, false, arg);
+                                       func, false, sernum, arg);
                        write_unlock_bh(&table->tb6_lock);
                }
        }
        rcu_read_unlock();
 }
 
+void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *),
+                   void *arg)
+{
+       __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg);
+}
+
 static int fib6_prune_clone(struct rt6_info *rt, void *arg)
 {
        if (rt->rt6i_flags & RTF_CACHE) {
@@ -1595,25 +1618,15 @@ static int fib6_prune_clone(struct rt6_info *rt, void *arg)
 
 static void fib6_prune_clones(struct net *net, struct fib6_node *fn)
 {
-       fib6_clean_tree(net, fn, fib6_prune_clone, true, NULL);
-}
-
-static int fib6_update_sernum(struct rt6_info *rt, void *arg)
-{
-       int sernum = *(int *)arg;
-
-       if (rt->rt6i_node &&
-           rt->rt6i_node->fn_sernum != sernum)
-               rt->rt6i_node->fn_sernum = sernum;
-
-       return 0;
+       fib6_clean_tree(net, fn, fib6_prune_clone, true,
+                       FIB6_NO_SERNUM_CHANGE, NULL);
 }
 
 static void fib6_flush_trees(struct net *net)
 {
        int new_sernum = fib6_new_sernum(net);
 
-       fib6_clean_all(net, fib6_update_sernum, &new_sernum);
+       __fib6_clean_all(net, NULL, new_sernum, NULL);
 }
 
 /*