treewide: setup_timer() -> timer_setup() (2 field)
[linux-2.6-block.git] / net / ipv6 / ip6_fib.c
index e5308d7cbd75c4fb67861082382122d445cf5b74..f5285f4e1d08acb60d42fb6fd10a0c38a239324f 100644 (file)
 #include <net/ip6_fib.h>
 #include <net/ip6_route.h>
 
-#define RT6_DEBUG 2
-
-#if RT6_DEBUG >= 3
-#define RT6_TRACE(x...) pr_debug(x)
-#else
-#define RT6_TRACE(x...) do { ; } while (0)
-#endif
-
 static struct kmem_cache *fib6_node_kmem __read_mostly;
 
 struct fib6_cleaner {
@@ -62,9 +54,12 @@ struct fib6_cleaner {
 #define FWS_INIT FWS_L
 #endif
 
-static void fib6_prune_clones(struct net *net, struct fib6_node *fn);
-static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn);
-static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_node *fn);
+static struct rt6_info *fib6_find_prefix(struct net *net,
+                                        struct fib6_table *table,
+                                        struct fib6_node *fn);
+static struct fib6_node *fib6_repair_tree(struct net *net,
+                                         struct fib6_table *table,
+                                         struct fib6_node *fn);
 static int fib6_walk(struct net *net, struct fib6_walker *w);
 static int fib6_walk_continue(struct fib6_walker *w);
 
@@ -75,7 +70,7 @@ static int fib6_walk_continue(struct fib6_walker *w);
  *     result of redirects, path MTU changes, etc.
  */
 
-static void fib6_gc_timer_cb(unsigned long arg);
+static void fib6_gc_timer_cb(struct timer_list *t);
 
 #define FOR_WALKERS(net, w) \
        list_for_each_entry(w, &(net)->ipv6.fib6_walkers, lh)
@@ -110,6 +105,20 @@ enum {
        FIB6_NO_SERNUM_CHANGE = 0,
 };
 
+void fib6_update_sernum(struct rt6_info *rt)
+{
+       struct fib6_table *table = rt->rt6i_table;
+       struct net *net = dev_net(rt->dst.dev);
+       struct fib6_node *fn;
+
+       spin_lock_bh(&table->tb6_lock);
+       fn = rcu_dereference_protected(rt->rt6i_node,
+                       lockdep_is_held(&table->tb6_lock));
+       if (fn)
+               fn->fn_sernum = fib6_new_sernum(net);
+       spin_unlock_bh(&table->tb6_lock);
+}
+
 /*
  *     Auxiliary address test functions for the radix tree.
  *
@@ -140,18 +149,21 @@ static __be32 addr_bit_set(const void *token, int fn_bit)
               addr[fn_bit >> 5];
 }
 
-static struct fib6_node *node_alloc(void)
+static struct fib6_node *node_alloc(struct net *net)
 {
        struct fib6_node *fn;
 
        fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC);
+       if (fn)
+               net->ipv6.rt6_stats->fib_nodes++;
 
        return fn;
 }
 
-static void node_free_immediate(struct fib6_node *fn)
+static void node_free_immediate(struct net *net, struct fib6_node *fn)
 {
        kmem_cache_free(fib6_node_kmem, fn);
+       net->ipv6.rt6_stats->fib_nodes--;
 }
 
 static void node_free_rcu(struct rcu_head *head)
@@ -161,9 +173,10 @@ static void node_free_rcu(struct rcu_head *head)
        kmem_cache_free(fib6_node_kmem, fn);
 }
 
-static void node_free(struct fib6_node *fn)
+static void node_free(struct net *net, struct fib6_node *fn)
 {
        call_rcu(&fn->rcu, node_free_rcu);
+       net->ipv6.rt6_stats->fib_nodes--;
 }
 
 void rt6_free_pcpu(struct rt6_info *non_pcpu_rt)
@@ -185,9 +198,6 @@ void rt6_free_pcpu(struct rt6_info *non_pcpu_rt)
                        *ppcpu_rt = NULL;
                }
        }
-
-       free_percpu(non_pcpu_rt->rt6i_pcpu);
-       non_pcpu_rt->rt6i_pcpu = NULL;
 }
 EXPORT_SYMBOL_GPL(rt6_free_pcpu);
 
@@ -205,8 +215,7 @@ static void fib6_link_table(struct net *net, struct fib6_table *tb)
         * Initialize table lock at a single place to give lockdep a key,
         * tables aren't visible prior to being linked to the list.
         */
-       rwlock_init(&tb->tb6_lock);
-
+       spin_lock_init(&tb->tb6_lock);
        h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1);
 
        /*
@@ -225,7 +234,8 @@ static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
        table = kzalloc(sizeof(*table), GFP_ATOMIC);
        if (table) {
                table->tb6_id = id;
-               table->tb6_root.leaf = net->ipv6.ip6_null_entry;
+               rcu_assign_pointer(table->tb6_root.leaf,
+                                  net->ipv6.ip6_null_entry);
                table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
                inet_peer_base_init(&table->tb6_peers);
        }
@@ -322,11 +332,8 @@ unsigned int fib6_tables_seq_read(struct net *net)
                struct hlist_head *head = &net->ipv6.fib_table_hash[h];
                struct fib6_table *tb;
 
-               hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
-                       read_lock_bh(&tb->tb6_lock);
+               hlist_for_each_entry_rcu(tb, head, tb6_hlist)
                        fib_seq += tb->fib_seq;
-                       read_unlock_bh(&tb->tb6_lock);
-               }
        }
        rcu_read_unlock();
 
@@ -346,9 +353,11 @@ static int call_fib6_entry_notifier(struct notifier_block *nb, struct net *net,
 
 static int call_fib6_entry_notifiers(struct net *net,
                                     enum fib_event_type event_type,
-                                    struct rt6_info *rt)
+                                    struct rt6_info *rt,
+                                    struct netlink_ext_ack *extack)
 {
        struct fib6_entry_notifier_info info = {
+               .info.extack = extack,
                .rt = rt,
        };
 
@@ -372,7 +381,7 @@ static int fib6_node_dump(struct fib6_walker *w)
 {
        struct rt6_info *rt;
 
-       for (rt = w->leaf; rt; rt = rt->dst.rt6_next)
+       for_each_fib6_walker_rt(w)
                fib6_rt_dump(rt, w->args);
        w->leaf = NULL;
        return 0;
@@ -382,9 +391,9 @@ static void fib6_table_dump(struct net *net, struct fib6_table *tb,
                            struct fib6_walker *w)
 {
        w->root = &tb->tb6_root;
-       read_lock_bh(&tb->tb6_lock);
+       spin_lock_bh(&tb->tb6_lock);
        fib6_walk(net, w);
-       read_unlock_bh(&tb->tb6_lock);
+       spin_unlock_bh(&tb->tb6_lock);
 }
 
 /* Called with rcu_read_lock() */
@@ -421,7 +430,7 @@ static int fib6_dump_node(struct fib6_walker *w)
        int res;
        struct rt6_info *rt;
 
-       for (rt = w->leaf; rt; rt = rt->dst.rt6_next) {
+       for_each_fib6_walker_rt(w) {
                res = rt6_dump_route(rt, w->args);
                if (res < 0) {
                        /* Frame is full, suspend walking */
@@ -480,9 +489,9 @@ static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
                w->count = 0;
                w->skip = 0;
 
-               read_lock_bh(&table->tb6_lock);
+               spin_lock_bh(&table->tb6_lock);
                res = fib6_walk(net, w);
-               read_unlock_bh(&table->tb6_lock);
+               spin_unlock_bh(&table->tb6_lock);
                if (res > 0) {
                        cb->args[4] = 1;
                        cb->args[5] = w->root->fn_sernum;
@@ -497,9 +506,9 @@ static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
                } else
                        w->skip = 0;
 
-               read_lock_bh(&table->tb6_lock);
+               spin_lock_bh(&table->tb6_lock);
                res = fib6_walk_continue(w);
-               read_unlock_bh(&table->tb6_lock);
+               spin_unlock_bh(&table->tb6_lock);
                if (res <= 0) {
                        fib6_walker_unlink(net, w);
                        cb->args[4] = 0;
@@ -580,11 +589,13 @@ out:
  *     node.
  */
 
-static struct fib6_node *fib6_add_1(struct fib6_node *root,
-                                    struct in6_addr *addr, int plen,
-                                    int offset, int allow_create,
-                                    int replace_required, int sernum,
-                                    struct netlink_ext_ack *extack)
+static struct fib6_node *fib6_add_1(struct net *net,
+                                   struct fib6_table *table,
+                                   struct fib6_node *root,
+                                   struct in6_addr *addr, int plen,
+                                   int offset, int allow_create,
+                                   int replace_required,
+                                   struct netlink_ext_ack *extack)
 {
        struct fib6_node *fn, *in, *ln;
        struct fib6_node *pn = NULL;
@@ -599,7 +610,9 @@ static struct fib6_node *fib6_add_1(struct fib6_node *root,
        fn = root;
 
        do {
-               key = (struct rt6key *)((u8 *)fn->leaf + offset);
+               struct rt6_info *leaf = rcu_dereference_protected(fn->leaf,
+                                           lockdep_is_held(&table->tb6_lock));
+               key = (struct rt6key *)((u8 *)leaf + offset);
 
                /*
                 *      Prefix match
@@ -625,12 +638,10 @@ static struct fib6_node *fib6_add_1(struct fib6_node *root,
                if (plen == fn->fn_bit) {
                        /* clean up an intermediate node */
                        if (!(fn->fn_flags & RTN_RTINFO)) {
-                               rt6_release(fn->leaf);
-                               fn->leaf = NULL;
+                               RCU_INIT_POINTER(fn->leaf, NULL);
+                               rt6_release(leaf);
                        }
 
-                       fn->fn_sernum = sernum;
-
                        return fn;
                }
 
@@ -639,10 +650,13 @@ static struct fib6_node *fib6_add_1(struct fib6_node *root,
                 */
 
                /* Try to walk down on tree. */
-               fn->fn_sernum = sernum;
                dir = addr_bit_set(addr, fn->fn_bit);
                pn = fn;
-               fn = dir ? fn->right : fn->left;
+               fn = dir ?
+                    rcu_dereference_protected(fn->right,
+                                       lockdep_is_held(&table->tb6_lock)) :
+                    rcu_dereference_protected(fn->left,
+                                       lockdep_is_held(&table->tb6_lock));
        } while (fn);
 
        if (!allow_create) {
@@ -668,19 +682,17 @@ static struct fib6_node *fib6_add_1(struct fib6_node *root,
         *      Create new leaf node without children.
         */
 
-       ln = node_alloc();
+       ln = node_alloc(net);
 
        if (!ln)
                return ERR_PTR(-ENOMEM);
        ln->fn_bit = plen;
-
-       ln->parent = pn;
-       ln->fn_sernum = sernum;
+       RCU_INIT_POINTER(ln->parent, pn);
 
        if (dir)
-               pn->right = ln;
+               rcu_assign_pointer(pn->right, ln);
        else
-               pn->left  = ln;
+               rcu_assign_pointer(pn->left, ln);
 
        return ln;
 
@@ -694,7 +706,8 @@ insert_above:
         * and the current
         */
 
-       pn = fn->parent;
+       pn = rcu_dereference_protected(fn->parent,
+                                      lockdep_is_held(&table->tb6_lock));
 
        /* find 1st bit in difference between the 2 addrs.
 
@@ -710,14 +723,14 @@ insert_above:
         *      (new leaf node)[ln] (old node)[fn]
         */
        if (plen > bit) {
-               in = node_alloc();
-               ln = node_alloc();
+               in = node_alloc(net);
+               ln = node_alloc(net);
 
                if (!in || !ln) {
                        if (in)
-                               node_free_immediate(in);
+                               node_free_immediate(net, in);
                        if (ln)
-                               node_free_immediate(ln);
+                               node_free_immediate(net, ln);
                        return ERR_PTR(-ENOMEM);
                }
 
@@ -731,31 +744,28 @@ insert_above:
 
                in->fn_bit = bit;
 
-               in->parent = pn;
+               RCU_INIT_POINTER(in->parent, pn);
                in->leaf = fn->leaf;
-               atomic_inc(&in->leaf->rt6i_ref);
-
-               in->fn_sernum = sernum;
+               atomic_inc(&rcu_dereference_protected(in->leaf,
+                               lockdep_is_held(&table->tb6_lock))->rt6i_ref);
 
                /* update parent pointer */
                if (dir)
-                       pn->right = in;
+                       rcu_assign_pointer(pn->right, in);
                else
-                       pn->left  = in;
+                       rcu_assign_pointer(pn->left, in);
 
                ln->fn_bit = plen;
 
-               ln->parent = in;
-               fn->parent = in;
-
-               ln->fn_sernum = sernum;
+               RCU_INIT_POINTER(ln->parent, in);
+               rcu_assign_pointer(fn->parent, in);
 
                if (addr_bit_set(addr, bit)) {
-                       in->right = ln;
-                       in->left  = fn;
+                       rcu_assign_pointer(in->right, ln);
+                       rcu_assign_pointer(in->left, fn);
                } else {
-                       in->left  = ln;
-                       in->right = fn;
+                       rcu_assign_pointer(in->left, ln);
+                       rcu_assign_pointer(in->right, fn);
                }
        } else { /* plen <= bit */
 
@@ -765,28 +775,26 @@ insert_above:
                 *           (old node)[fn] NULL
                 */
 
-               ln = node_alloc();
+               ln = node_alloc(net);
 
                if (!ln)
                        return ERR_PTR(-ENOMEM);
 
                ln->fn_bit = plen;
 
-               ln->parent = pn;
-
-               ln->fn_sernum = sernum;
-
-               if (dir)
-                       pn->right = ln;
-               else
-                       pn->left  = ln;
+               RCU_INIT_POINTER(ln->parent, pn);
 
                if (addr_bit_set(&key->addr, plen))
-                       ln->right = fn;
+                       RCU_INIT_POINTER(ln->right, fn);
                else
-                       ln->left  = fn;
+                       RCU_INIT_POINTER(ln->left, fn);
+
+               rcu_assign_pointer(fn->parent, ln);
 
-               fn->parent = ln;
+               if (dir)
+                       rcu_assign_pointer(pn->right, ln);
+               else
+                       rcu_assign_pointer(pn->left, ln);
        }
        return ln;
 }
@@ -832,6 +840,8 @@ static int fib6_commit_metrics(struct dst_entry *dst, struct mx6_config *mxc)
 static void fib6_purge_rt(struct rt6_info *rt, struct fib6_node *fn,
                          struct net *net)
 {
+       struct fib6_table *table = rt->rt6i_table;
+
        if (atomic_read(&rt->rt6i_ref) != 1) {
                /* This route is used as dummy address holder in some split
                 * nodes. It is not leaked, but it still holds other resources,
@@ -840,12 +850,17 @@ static void fib6_purge_rt(struct rt6_info *rt, struct fib6_node *fn,
                 * to still alive ones.
                 */
                while (fn) {
-                       if (!(fn->fn_flags & RTN_RTINFO) && fn->leaf == rt) {
-                               fn->leaf = fib6_find_prefix(net, fn);
-                               atomic_inc(&fn->leaf->rt6i_ref);
+                       struct rt6_info *leaf = rcu_dereference_protected(fn->leaf,
+                                           lockdep_is_held(&table->tb6_lock));
+                       struct rt6_info *new_leaf;
+                       if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) {
+                               new_leaf = fib6_find_prefix(net, table, fn);
+                               atomic_inc(&new_leaf->rt6i_ref);
+                               rcu_assign_pointer(fn->leaf, new_leaf);
                                rt6_release(rt);
                        }
-                       fn = fn->parent;
+                       fn = rcu_dereference_protected(fn->parent,
+                                   lockdep_is_held(&table->tb6_lock));
                }
        }
 }
@@ -855,11 +870,14 @@ static void fib6_purge_rt(struct rt6_info *rt, struct fib6_node *fn,
  */
 
 static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
-                           struct nl_info *info, struct mx6_config *mxc)
+                           struct nl_info *info, struct mx6_config *mxc,
+                           struct netlink_ext_ack *extack)
 {
+       struct rt6_info *leaf = rcu_dereference_protected(fn->leaf,
+                                   lockdep_is_held(&rt->rt6i_table->tb6_lock));
        struct rt6_info *iter = NULL;
-       struct rt6_info **ins;
-       struct rt6_info **fallback_ins = NULL;
+       struct rt6_info __rcu **ins;
+       struct rt6_info __rcu **fallback_ins = NULL;
        int replace = (info->nlh &&
                       (info->nlh->nlmsg_flags & NLM_F_REPLACE));
        int add = (!info->nlh ||
@@ -874,7 +892,9 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
 
        ins = &fn->leaf;
 
-       for (iter = fn->leaf; iter; iter = iter->dst.rt6_next) {
+       for (iter = leaf; iter;
+            iter = rcu_dereference_protected(iter->dst.rt6_next,
+                               lockdep_is_held(&rt->rt6i_table->tb6_lock))) {
                /*
                 *      Search for duplicates
                 */
@@ -936,7 +956,8 @@ next_iter:
        if (fallback_ins && !found) {
                /* No ECMP-able route found, replace first non-ECMP one */
                ins = fallback_ins;
-               iter = *ins;
+               iter = rcu_dereference_protected(*ins,
+                                   lockdep_is_held(&rt->rt6i_table->tb6_lock));
                found++;
        }
 
@@ -950,7 +971,7 @@ next_iter:
                struct rt6_info *sibling, *temp_sibling;
 
                /* Find the first route that have the same metric */
-               sibling = fn->leaf;
+               sibling = leaf;
                while (sibling) {
                        if (sibling->rt6i_metric == rt->rt6i_metric &&
                            rt6_qualify_for_ecmp(sibling)) {
@@ -958,7 +979,8 @@ next_iter:
                                              &sibling->rt6i_siblings);
                                break;
                        }
-                       sibling = sibling->dst.rt6_next;
+                       sibling = rcu_dereference_protected(sibling->dst.rt6_next,
+                                   lockdep_is_held(&rt->rt6i_table->tb6_lock));
                }
                /* For each sibling in the list, increment the counter of
                 * siblings. BUG() if counters does not match, list of siblings
@@ -987,12 +1009,12 @@ add:
                if (err)
                        return err;
 
-               rt->dst.rt6_next = iter;
-               *ins = rt;
-               rcu_assign_pointer(rt->rt6i_node, fn);
+               rcu_assign_pointer(rt->dst.rt6_next, iter);
                atomic_inc(&rt->rt6i_ref);
+               rcu_assign_pointer(rt->rt6i_node, fn);
+               rcu_assign_pointer(*ins, rt);
                call_fib6_entry_notifiers(info->nl_net, FIB_EVENT_ENTRY_ADD,
-                                         rt);
+                                         rt, extack);
                if (!info->skip_notify)
                        inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
                info->nl_net->ipv6.rt6_stats->fib_rt_entries++;
@@ -1016,12 +1038,12 @@ add:
                if (err)
                        return err;
 
-               *ins = rt;
+               atomic_inc(&rt->rt6i_ref);
                rcu_assign_pointer(rt->rt6i_node, fn);
                rt->dst.rt6_next = iter->dst.rt6_next;
-               atomic_inc(&rt->rt6i_ref);
+               rcu_assign_pointer(*ins, rt);
                call_fib6_entry_notifiers(info->nl_net, FIB_EVENT_ENTRY_REPLACE,
-                                         rt);
+                                         rt, extack);
                if (!info->skip_notify)
                        inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE);
                if (!(fn->fn_flags & RTN_RTINFO)) {
@@ -1031,14 +1053,15 @@ add:
                nsiblings = iter->rt6i_nsiblings;
                iter->rt6i_node = NULL;
                fib6_purge_rt(iter, fn, info->nl_net);
-               if (fn->rr_ptr == iter)
+               if (rcu_access_pointer(fn->rr_ptr) == iter)
                        fn->rr_ptr = NULL;
                rt6_release(iter);
 
                if (nsiblings) {
                        /* Replacing an ECMP route, remove all siblings */
                        ins = &rt->dst.rt6_next;
-                       iter = *ins;
+                       iter = rcu_dereference_protected(*ins,
+                                   lockdep_is_held(&rt->rt6i_table->tb6_lock));
                        while (iter) {
                                if (iter->rt6i_metric > rt->rt6i_metric)
                                        break;
@@ -1046,14 +1069,16 @@ add:
                                        *ins = iter->dst.rt6_next;
                                        iter->rt6i_node = NULL;
                                        fib6_purge_rt(iter, fn, info->nl_net);
-                                       if (fn->rr_ptr == iter)
+                                       if (rcu_access_pointer(fn->rr_ptr) == iter)
                                                fn->rr_ptr = NULL;
                                        rt6_release(iter);
                                        nsiblings--;
+                                       info->nl_net->ipv6.rt6_stats->fib_rt_entries--;
                                } else {
                                        ins = &iter->dst.rt6_next;
                                }
-                               iter = *ins;
+                               iter = rcu_dereference_protected(*ins,
+                                       lockdep_is_held(&rt->rt6i_table->tb6_lock));
                        }
                        WARN_ON(nsiblings != 0);
                }
@@ -1077,16 +1102,33 @@ void fib6_force_start_gc(struct net *net)
                          jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
 }
 
+static void fib6_update_sernum_upto_root(struct rt6_info *rt,
+                                        int sernum)
+{
+       struct fib6_node *fn = rcu_dereference_protected(rt->rt6i_node,
+                               lockdep_is_held(&rt->rt6i_table->tb6_lock));
+
+       /* paired with smp_rmb() in rt6_get_cookie_safe() */
+       smp_wmb();
+       while (fn) {
+               fn->fn_sernum = sernum;
+               fn = rcu_dereference_protected(fn->parent,
+                               lockdep_is_held(&rt->rt6i_table->tb6_lock));
+       }
+}
+
 /*
  *     Add routing information to the routing tree.
  *     <destination addr>/<source addr>
  *     with source addr info in sub-trees
+ *     Need to own table->tb6_lock
  */
 
 int fib6_add(struct fib6_node *root, struct rt6_info *rt,
             struct nl_info *info, struct mx6_config *mxc,
             struct netlink_ext_ack *extack)
 {
+       struct fib6_table *table = rt->rt6i_table;
        struct fib6_node *fn, *pn = NULL;
        int err = -ENOMEM;
        int allow_create = 1;
@@ -1095,6 +1137,8 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt,
 
        if (WARN_ON_ONCE(!atomic_read(&rt->dst.__refcnt)))
                return -EINVAL;
+       if (WARN_ON_ONCE(rt->rt6i_flags & RTF_CACHE))
+               return -EINVAL;
 
        if (info->nlh) {
                if (!(info->nlh->nlmsg_flags & NLM_F_CREATE))
@@ -1105,9 +1149,10 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt,
        if (!allow_create && !replace_required)
                pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n");
 
-       fn = fib6_add_1(root, &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
+       fn = fib6_add_1(info->nl_net, table, root,
+                       &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
                        offsetof(struct rt6_info, rt6i_dst), allow_create,
-                       replace_required, sernum, extack);
+                       replace_required, extack);
        if (IS_ERR(fn)) {
                err = PTR_ERR(fn);
                fn = NULL;
@@ -1120,7 +1165,7 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt,
        if (rt->rt6i_src.plen) {
                struct fib6_node *sn;
 
-               if (!fn->subtree) {
+               if (!rcu_access_pointer(fn->subtree)) {
                        struct fib6_node *sfn;
 
                        /*
@@ -1134,42 +1179,40 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt,
                         */
 
                        /* Create subtree root node */
-                       sfn = node_alloc();
+                       sfn = node_alloc(info->nl_net);
                        if (!sfn)
                                goto failure;
 
-                       sfn->leaf = info->nl_net->ipv6.ip6_null_entry;
                        atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref);
+                       rcu_assign_pointer(sfn->leaf,
+                                          info->nl_net->ipv6.ip6_null_entry);
                        sfn->fn_flags = RTN_ROOT;
-                       sfn->fn_sernum = sernum;
 
                        /* Now add the first leaf node to new subtree */
 
-                       sn = fib6_add_1(sfn, &rt->rt6i_src.addr,
-                                       rt->rt6i_src.plen,
+                       sn = fib6_add_1(info->nl_net, table, sfn,
+                                       &rt->rt6i_src.addr, rt->rt6i_src.plen,
                                        offsetof(struct rt6_info, rt6i_src),
-                                       allow_create, replace_required, sernum,
-                                       extack);
+                                       allow_create, replace_required, extack);
 
                        if (IS_ERR(sn)) {
                                /* If it is failed, discard just allocated
                                   root, and then (in failure) stale node
                                   in main tree.
                                 */
-                               node_free_immediate(sfn);
+                               node_free_immediate(info->nl_net, sfn);
                                err = PTR_ERR(sn);
                                goto failure;
                        }
 
                        /* Now link new subtree to main tree */
-                       sfn->parent = fn;
-                       fn->subtree = sfn;
+                       rcu_assign_pointer(sfn->parent, fn);
+                       rcu_assign_pointer(fn->subtree, sfn);
                } else {
-                       sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr,
-                                       rt->rt6i_src.plen,
+                       sn = fib6_add_1(info->nl_net, table, FIB6_SUBTREE(fn),
+                                       &rt->rt6i_src.addr, rt->rt6i_src.plen,
                                        offsetof(struct rt6_info, rt6i_src),
-                                       allow_create, replace_required, sernum,
-                                       extack);
+                                       allow_create, replace_required, extack);
 
                        if (IS_ERR(sn)) {
                                err = PTR_ERR(sn);
@@ -1177,19 +1220,18 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt,
                        }
                }
 
-               if (!fn->leaf) {
-                       fn->leaf = rt;
+               if (!rcu_access_pointer(fn->leaf)) {
                        atomic_inc(&rt->rt6i_ref);
+                       rcu_assign_pointer(fn->leaf, rt);
                }
                fn = sn;
        }
 #endif
 
-       err = fib6_add_rt2node(fn, rt, info, mxc);
+       err = fib6_add_rt2node(fn, rt, info, mxc, extack);
        if (!err) {
+               fib6_update_sernum_upto_root(rt, sernum);
                fib6_start_gc(info->nl_net, rt);
-               if (!(rt->rt6i_flags & RTF_CACHE))
-                       fib6_prune_clones(info->nl_net, pn);
        }
 
 out:
@@ -1199,19 +1241,23 @@ out:
                 * If fib6_add_1 has cleared the old leaf pointer in the
                 * super-tree leaf node we have to find a new one for it.
                 */
-               if (pn != fn && pn->leaf == rt) {
-                       pn->leaf = NULL;
+               struct rt6_info *pn_leaf = rcu_dereference_protected(pn->leaf,
+                                           lockdep_is_held(&table->tb6_lock));
+               if (pn != fn && pn_leaf == rt) {
+                       pn_leaf = NULL;
+                       RCU_INIT_POINTER(pn->leaf, NULL);
                        atomic_dec(&rt->rt6i_ref);
                }
-               if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) {
-                       pn->leaf = fib6_find_prefix(info->nl_net, pn);
+               if (pn != fn && !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 == NULL);
-                               pn->leaf = info->nl_net->ipv6.ip6_null_entry;
+                       if (!pn_leaf) {
+                               WARN_ON(!pn_leaf);
+                               pn_leaf = info->nl_net->ipv6.ip6_null_entry;
                        }
 #endif
-                       atomic_inc(&pn->leaf->rt6i_ref);
+                       atomic_inc(&pn_leaf->rt6i_ref);
+                       rcu_assign_pointer(pn->leaf, pn_leaf);
                }
 #endif
                goto failure;
@@ -1226,7 +1272,7 @@ failure:
         * fn->leaf.
         */
        if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)))
-               fib6_repair_tree(info->nl_net, fn);
+               fib6_repair_tree(info->nl_net, table, fn);
        /* Always release dst as dst->__refcnt is guaranteed
         * to be taken before entering this function
         */
@@ -1264,7 +1310,8 @@ static struct fib6_node *fib6_lookup_1(struct fib6_node *root,
 
                dir = addr_bit_set(args->addr, fn->fn_bit);
 
-               next = dir ? fn->right : fn->left;
+               next = dir ? rcu_dereference(fn->right) :
+                            rcu_dereference(fn->left);
 
                if (next) {
                        fn = next;
@@ -1274,18 +1321,22 @@ static struct fib6_node *fib6_lookup_1(struct fib6_node *root,
        }
 
        while (fn) {
-               if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) {
+               struct fib6_node *subtree = FIB6_SUBTREE(fn);
+
+               if (subtree || fn->fn_flags & RTN_RTINFO) {
+                       struct rt6_info *leaf = rcu_dereference(fn->leaf);
                        struct rt6key *key;
 
-                       key = (struct rt6key *) ((u8 *) fn->leaf +
-                                                args->offset);
+                       if (!leaf)
+                               goto backtrack;
+
+                       key = (struct rt6key *) ((u8 *)leaf + args->offset);
 
                        if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
 #ifdef CONFIG_IPV6_SUBTREES
-                               if (fn->subtree) {
+                               if (subtree) {
                                        struct fib6_node *sfn;
-                                       sfn = fib6_lookup_1(fn->subtree,
-                                                           args + 1);
+                                       sfn = fib6_lookup_1(subtree, args + 1);
                                        if (!sfn)
                                                goto backtrack;
                                        fn = sfn;
@@ -1295,18 +1346,18 @@ static struct fib6_node *fib6_lookup_1(struct fib6_node *root,
                                        return fn;
                        }
                }
-#ifdef CONFIG_IPV6_SUBTREES
 backtrack:
-#endif
                if (fn->fn_flags & RTN_ROOT)
                        break;
 
-               fn = fn->parent;
+               fn = rcu_dereference(fn->parent);
        }
 
        return NULL;
 }
 
+/* called with rcu_read_lock() held
+ */
 struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr,
                              const struct in6_addr *saddr)
 {
@@ -1337,54 +1388,87 @@ struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *dad
 /*
  *     Get node with specified destination prefix (and source prefix,
  *     if subtrees are used)
+ *     exact_match == true means we try to find fn with exact match of
+ *     the passed in prefix addr
+ *     exact_match == false means we try to find fn with longest prefix
+ *     match of the passed in prefix addr. This is useful for finding fn
+ *     for cached route as it will be stored in the exception table under
+ *     the node with longest prefix length.
  */
 
 
 static struct fib6_node *fib6_locate_1(struct fib6_node *root,
                                       const struct in6_addr *addr,
-                                      int plen, int offset)
+                                      int plen, int offset,
+                                      bool exact_match)
 {
-       struct fib6_node *fn;
+       struct fib6_node *fn, *prev = NULL;
 
        for (fn = root; fn ; ) {
-               struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset);
+               struct rt6_info *leaf = rcu_dereference(fn->leaf);
+               struct rt6key *key;
+
+               /* This node is being deleted */
+               if (!leaf) {
+                       if (plen <= fn->fn_bit)
+                               goto out;
+                       else
+                               goto next;
+               }
+
+               key = (struct rt6key *)((u8 *)leaf + offset);
 
                /*
                 *      Prefix match
                 */
                if (plen < fn->fn_bit ||
                    !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
-                       return NULL;
+                       goto out;
 
                if (plen == fn->fn_bit)
                        return fn;
 
+               prev = fn;
+
+next:
                /*
                 *      We have more bits to go
                 */
                if (addr_bit_set(addr, fn->fn_bit))
-                       fn = fn->right;
+                       fn = rcu_dereference(fn->right);
                else
-                       fn = fn->left;
+                       fn = rcu_dereference(fn->left);
        }
-       return NULL;
+out:
+       if (exact_match)
+               return NULL;
+       else
+               return prev;
 }
 
 struct fib6_node *fib6_locate(struct fib6_node *root,
                              const struct in6_addr *daddr, int dst_len,
-                             const struct in6_addr *saddr, int src_len)
+                             const struct in6_addr *saddr, int src_len,
+                             bool exact_match)
 {
        struct fib6_node *fn;
 
        fn = fib6_locate_1(root, daddr, dst_len,
-                          offsetof(struct rt6_info, rt6i_dst));
+                          offsetof(struct rt6_info, rt6i_dst),
+                          exact_match);
 
 #ifdef CONFIG_IPV6_SUBTREES
        if (src_len) {
                WARN_ON(saddr == NULL);
-               if (fn && fn->subtree)
-                       fn = fib6_locate_1(fn->subtree, saddr, src_len,
-                                          offsetof(struct rt6_info, rt6i_src));
+               if (fn) {
+                       struct fib6_node *subtree = FIB6_SUBTREE(fn);
+
+                       if (subtree) {
+                               fn = fib6_locate_1(subtree, saddr, src_len,
+                                          offsetof(struct rt6_info, rt6i_src),
+                                          exact_match);
+                       }
+               }
        }
 #endif
 
@@ -1400,16 +1484,26 @@ struct fib6_node *fib6_locate(struct fib6_node *root,
  *
  */
 
-static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn)
+static struct rt6_info *fib6_find_prefix(struct net *net,
+                                        struct fib6_table *table,
+                                        struct fib6_node *fn)
 {
+       struct fib6_node *child_left, *child_right;
+
        if (fn->fn_flags & RTN_ROOT)
                return net->ipv6.ip6_null_entry;
 
        while (fn) {
-               if (fn->left)
-                       return fn->left->leaf;
-               if (fn->right)
-                       return fn->right->leaf;
+               child_left = rcu_dereference_protected(fn->left,
+                                   lockdep_is_held(&table->tb6_lock));
+               child_right = rcu_dereference_protected(fn->right,
+                                   lockdep_is_held(&table->tb6_lock));
+               if (child_left)
+                       return rcu_dereference_protected(child_left->leaf,
+                                       lockdep_is_held(&table->tb6_lock));
+               if (child_right)
+                       return rcu_dereference_protected(child_right->leaf,
+                                       lockdep_is_held(&table->tb6_lock));
 
                fn = FIB6_SUBTREE(fn);
        }
@@ -1419,31 +1513,49 @@ static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn)
 /*
  *     Called to trim the tree of intermediate nodes when possible. "fn"
  *     is the node we want to try and remove.
+ *     Need to own table->tb6_lock
  */
 
 static struct fib6_node *fib6_repair_tree(struct net *net,
-                                          struct fib6_node *fn)
+                                         struct fib6_table *table,
+                                         struct fib6_node *fn)
 {
        int children;
        int nstate;
-       struct fib6_node *child, *pn;
+       struct fib6_node *child;
        struct fib6_walker *w;
        int iter = 0;
 
        for (;;) {
+               struct fib6_node *fn_r = rcu_dereference_protected(fn->right,
+                                           lockdep_is_held(&table->tb6_lock));
+               struct fib6_node *fn_l = rcu_dereference_protected(fn->left,
+                                           lockdep_is_held(&table->tb6_lock));
+               struct fib6_node *pn = rcu_dereference_protected(fn->parent,
+                                           lockdep_is_held(&table->tb6_lock));
+               struct fib6_node *pn_r = rcu_dereference_protected(pn->right,
+                                           lockdep_is_held(&table->tb6_lock));
+               struct fib6_node *pn_l = rcu_dereference_protected(pn->left,
+                                           lockdep_is_held(&table->tb6_lock));
+               struct rt6_info *fn_leaf = rcu_dereference_protected(fn->leaf,
+                                           lockdep_is_held(&table->tb6_lock));
+               struct rt6_info *pn_leaf = rcu_dereference_protected(pn->leaf,
+                                           lockdep_is_held(&table->tb6_lock));
+               struct rt6_info *new_fn_leaf;
+
                RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
                iter++;
 
                WARN_ON(fn->fn_flags & RTN_RTINFO);
                WARN_ON(fn->fn_flags & RTN_TL_ROOT);
-               WARN_ON(fn->leaf);
+               WARN_ON(fn_leaf);
 
                children = 0;
                child = NULL;
-               if (fn->right)
-                       child = fn->right, children |= 1;
-               if (fn->left)
-                       child = fn->left, children |= 2;
+               if (fn_r)
+                       child = fn_r, children |= 1;
+               if (fn_l)
+                       child = fn_l, children |= 2;
 
                if (children == 3 || FIB6_SUBTREE(fn)
 #ifdef CONFIG_IPV6_SUBTREES
@@ -1451,36 +1563,36 @@ static struct fib6_node *fib6_repair_tree(struct net *net,
                    || (children && fn->fn_flags & RTN_ROOT)
 #endif
                    ) {
-                       fn->leaf = fib6_find_prefix(net, fn);
+                       new_fn_leaf = fib6_find_prefix(net, table, fn);
 #if RT6_DEBUG >= 2
-                       if (!fn->leaf) {
-                               WARN_ON(!fn->leaf);
-                               fn->leaf = net->ipv6.ip6_null_entry;
+                       if (!new_fn_leaf) {
+                               WARN_ON(!new_fn_leaf);
+                               new_fn_leaf = net->ipv6.ip6_null_entry;
                        }
 #endif
-                       atomic_inc(&fn->leaf->rt6i_ref);
-                       return fn->parent;
+                       atomic_inc(&new_fn_leaf->rt6i_ref);
+                       rcu_assign_pointer(fn->leaf, new_fn_leaf);
+                       return pn;
                }
 
-               pn = fn->parent;
 #ifdef CONFIG_IPV6_SUBTREES
                if (FIB6_SUBTREE(pn) == fn) {
                        WARN_ON(!(fn->fn_flags & RTN_ROOT));
-                       FIB6_SUBTREE(pn) = NULL;
+                       RCU_INIT_POINTER(pn->subtree, NULL);
                        nstate = FWS_L;
                } else {
                        WARN_ON(fn->fn_flags & RTN_ROOT);
 #endif
-                       if (pn->right == fn)
-                               pn->right = child;
-                       else if (pn->left == fn)
-                               pn->left = child;
+                       if (pn_r == fn)
+                               rcu_assign_pointer(pn->right, child);
+                       else if (pn_l == fn)
+                               rcu_assign_pointer(pn->left, child);
 #if RT6_DEBUG >= 2
                        else
                                WARN_ON(1);
 #endif
                        if (child)
-                               child->parent = pn;
+                               rcu_assign_pointer(child->parent, pn);
                        nstate = FWS_R;
 #ifdef CONFIG_IPV6_SUBTREES
                }
@@ -1489,19 +1601,12 @@ static struct fib6_node *fib6_repair_tree(struct net *net,
                read_lock(&net->ipv6.fib6_walker_lock);
                FOR_WALKERS(net, w) {
                        if (!child) {
-                               if (w->root == fn) {
-                                       w->root = w->node = NULL;
-                                       RT6_TRACE("W %p adjusted by delroot 1\n", w);
-                               } else if (w->node == fn) {
+                               if (w->node == fn) {
                                        RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate);
                                        w->node = pn;
                                        w->state = nstate;
                                }
                        } else {
-                               if (w->root == fn) {
-                                       w->root = child;
-                                       RT6_TRACE("W %p adjusted by delroot 2\n", w);
-                               }
                                if (w->node == fn) {
                                        w->node = child;
                                        if (children&2) {
@@ -1516,33 +1621,39 @@ static struct fib6_node *fib6_repair_tree(struct net *net,
                }
                read_unlock(&net->ipv6.fib6_walker_lock);
 
-               node_free(fn);
+               node_free(net, fn);
                if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn))
                        return pn;
 
-               rt6_release(pn->leaf);
-               pn->leaf = NULL;
+               RCU_INIT_POINTER(pn->leaf, NULL);
+               rt6_release(pn_leaf);
                fn = pn;
        }
 }
 
-static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp,
-                          struct nl_info *info)
+static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn,
+                          struct rt6_info __rcu **rtp, struct nl_info *info)
 {
        struct fib6_walker *w;
-       struct rt6_info *rt = *rtp;
+       struct rt6_info *rt = rcu_dereference_protected(*rtp,
+                                   lockdep_is_held(&table->tb6_lock));
        struct net *net = info->nl_net;
 
        RT6_TRACE("fib6_del_route\n");
 
+       WARN_ON_ONCE(rt->rt6i_flags & RTF_CACHE);
+
        /* Unlink it */
        *rtp = rt->dst.rt6_next;
        rt->rt6i_node = NULL;
        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 (fn->rr_ptr == rt)
+       if (rcu_access_pointer(fn->rr_ptr) == rt)
                fn->rr_ptr = NULL;
 
        /* Remove this entry from other siblings */
@@ -1561,36 +1672,38 @@ static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp,
        FOR_WALKERS(net, w) {
                if (w->state == FWS_C && w->leaf == rt) {
                        RT6_TRACE("walker %p adjusted by delroute\n", w);
-                       w->leaf = rt->dst.rt6_next;
+                       w->leaf = rcu_dereference_protected(rt->dst.rt6_next,
+                                           lockdep_is_held(&table->tb6_lock));
                        if (!w->leaf)
                                w->state = FWS_U;
                }
        }
        read_unlock(&net->ipv6.fib6_walker_lock);
 
-       rt->dst.rt6_next = NULL;
-
        /* If it was last route, expunge its radix tree node */
-       if (!fn->leaf) {
+       if (!rcu_access_pointer(fn->leaf)) {
                fn->fn_flags &= ~RTN_RTINFO;
                net->ipv6.rt6_stats->fib_route_nodes--;
-               fn = fib6_repair_tree(net, fn);
+               fn = fib6_repair_tree(net, table, fn);
        }
 
        fib6_purge_rt(rt, fn, net);
 
-       call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt);
+       call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt, NULL);
        if (!info->skip_notify)
                inet6_rt_notify(RTM_DELROUTE, rt, info, 0);
        rt6_release(rt);
 }
 
+/* Need to own table->tb6_lock */
 int fib6_del(struct rt6_info *rt, struct nl_info *info)
 {
        struct fib6_node *fn = rcu_dereference_protected(rt->rt6i_node,
                                    lockdep_is_held(&rt->rt6i_table->tb6_lock));
+       struct fib6_table *table = rt->rt6i_table;
        struct net *net = info->nl_net;
-       struct rt6_info **rtp;
+       struct rt6_info __rcu **rtp;
+       struct rt6_info __rcu **rtp_next;
 
 #if RT6_DEBUG >= 2
        if (rt->dst.obsolete > 0) {
@@ -1603,28 +1716,22 @@ int fib6_del(struct rt6_info *rt, struct nl_info *info)
 
        WARN_ON(!(fn->fn_flags & RTN_RTINFO));
 
-       if (!(rt->rt6i_flags & RTF_CACHE)) {
-               struct fib6_node *pn = fn;
-#ifdef CONFIG_IPV6_SUBTREES
-               /* clones of this route might be in another subtree */
-               if (rt->rt6i_src.plen) {
-                       while (!(pn->fn_flags & RTN_ROOT))
-                               pn = pn->parent;
-                       pn = pn->parent;
-               }
-#endif
-               fib6_prune_clones(info->nl_net, pn);
-       }
+       /* remove cached dst from exception table */
+       if (rt->rt6i_flags & RTF_CACHE)
+               return rt6_remove_exception_rt(rt);
 
        /*
         *      Walk the leaf entries looking for ourself
         */
 
-       for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->dst.rt6_next) {
-               if (*rtp == rt) {
-                       fib6_del_route(fn, rtp, info);
+       for (rtp = &fn->leaf; *rtp; rtp = rtp_next) {
+               struct rt6_info *cur = rcu_dereference_protected(*rtp,
+                                       lockdep_is_held(&table->tb6_lock));
+               if (rt == cur) {
+                       fib6_del_route(table, fn, rtp, info);
                        return 0;
                }
+               rtp_next = &cur->dst.rt6_next;
        }
        return -ENOENT;
 }
@@ -1651,22 +1758,22 @@ int fib6_del(struct rt6_info *rt, struct nl_info *info)
  *     0   -> walk is complete.
  *     >0  -> walk is incomplete (i.e. suspended)
  *     <0  -> walk is terminated by an error.
+ *
+ *     This function is called with tb6_lock held.
  */
 
 static int fib6_walk_continue(struct fib6_walker *w)
 {
-       struct fib6_node *fn, *pn;
+       struct fib6_node *fn, *pn, *left, *right;
+
+       /* w->root should always be table->tb6_root */
+       WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT));
 
        for (;;) {
                fn = w->node;
                if (!fn)
                        return 0;
 
-               if (w->prune && fn != w->root &&
-                   fn->fn_flags & RTN_RTINFO && w->state < FWS_C) {
-                       w->state = FWS_C;
-                       w->leaf = fn->leaf;
-               }
                switch (w->state) {
 #ifdef CONFIG_IPV6_SUBTREES
                case FWS_S:
@@ -1676,21 +1783,26 @@ static int fib6_walk_continue(struct fib6_walker *w)
                        }
                        w->state = FWS_L;
 #endif
+                       /* fall through */
                case FWS_L:
-                       if (fn->left) {
-                               w->node = fn->left;
+                       left = rcu_dereference_protected(fn->left, 1);
+                       if (left) {
+                               w->node = left;
                                w->state = FWS_INIT;
                                continue;
                        }
                        w->state = FWS_R;
+                       /* fall through */
                case FWS_R:
-                       if (fn->right) {
-                               w->node = fn->right;
+                       right = rcu_dereference_protected(fn->right, 1);
+                       if (right) {
+                               w->node = right;
                                w->state = FWS_INIT;
                                continue;
                        }
                        w->state = FWS_C;
-                       w->leaf = fn->leaf;
+                       w->leaf = rcu_dereference_protected(fn->leaf, 1);
+                       /* fall through */
                case FWS_C:
                        if (w->leaf && fn->fn_flags & RTN_RTINFO) {
                                int err;
@@ -1709,10 +1821,13 @@ static int fib6_walk_continue(struct fib6_walker *w)
                        }
 skip:
                        w->state = FWS_U;
+                       /* fall through */
                case FWS_U:
                        if (fn == w->root)
                                return 0;
-                       pn = fn->parent;
+                       pn = rcu_dereference_protected(fn->parent, 1);
+                       left = rcu_dereference_protected(pn->left, 1);
+                       right = rcu_dereference_protected(pn->right, 1);
                        w->node = pn;
 #ifdef CONFIG_IPV6_SUBTREES
                        if (FIB6_SUBTREE(pn) == fn) {
@@ -1721,13 +1836,13 @@ skip:
                                continue;
                        }
 #endif
-                       if (pn->left == fn) {
+                       if (left == fn) {
                                w->state = FWS_R;
                                continue;
                        }
-                       if (pn->right == fn) {
+                       if (right == fn) {
                                w->state = FWS_C;
-                               w->leaf = w->node->leaf;
+                               w->leaf = rcu_dereference_protected(w->node->leaf, 1);
                                continue;
                        }
 #if RT6_DEBUG >= 2
@@ -1770,7 +1885,7 @@ static int fib6_clean_node(struct fib6_walker *w)
                return 0;
        }
 
-       for (rt = w->leaf; rt; rt = rt->dst.rt6_next) {
+       for_each_fib6_walker_rt(w) {
                res = c->func(rt, c->arg);
                if (res < 0) {
                        w->leaf = rt;
@@ -1798,20 +1913,16 @@ static int fib6_clean_node(struct fib6_walker *w)
  *     func is called on each route.
  *             It may return -1 -> delete this route.
  *                           0  -> continue walking
- *
- *     prune==1 -> only immediate children of node (certainly,
- *     ignoring pure split nodes) will be scanned.
  */
 
 static void fib6_clean_tree(struct net *net, struct fib6_node *root,
                            int (*func)(struct rt6_info *, void *arg),
-                           bool prune, int sernum, void *arg)
+                           int sernum, void *arg)
 {
        struct fib6_cleaner c;
 
        c.w.root = root;
        c.w.func = fib6_clean_node;
-       c.w.prune = prune;
        c.w.count = 0;
        c.w.skip = 0;
        c.func = func;
@@ -1834,10 +1945,10 @@ static void __fib6_clean_all(struct net *net,
        for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
                head = &net->ipv6.fib_table_hash[h];
                hlist_for_each_entry_rcu(table, head, tb6_hlist) {
-                       write_lock_bh(&table->tb6_lock);
+                       spin_lock_bh(&table->tb6_lock);
                        fib6_clean_tree(net, &table->tb6_root,
-                                       func, false, sernum, arg);
-                       write_unlock_bh(&table->tb6_lock);
+                                       func, sernum, arg);
+                       spin_unlock_bh(&table->tb6_lock);
                }
        }
        rcu_read_unlock();
@@ -1849,22 +1960,6 @@ void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *),
        __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) {
-               RT6_TRACE("pruning clone %p\n", rt);
-               return -1;
-       }
-
-       return 0;
-}
-
-static void fib6_prune_clones(struct net *net, struct fib6_node *fn)
-{
-       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);
@@ -1876,12 +1971,6 @@ static void fib6_flush_trees(struct net *net)
  *     Garbage collection
  */
 
-struct fib6_gc_args
-{
-       int                     timeout;
-       int                     more;
-};
-
 static int fib6_age(struct rt6_info *rt, void *arg)
 {
        struct fib6_gc_args *gc_args = arg;
@@ -1890,9 +1979,6 @@ static int fib6_age(struct rt6_info *rt, void *arg)
        /*
         *      check addrconf expiration here.
         *      Routes are expired even if they are in use.
-        *
-        *      Also age clones. Note, that clones are aged out
-        *      only if they are not in use now.
         */
 
        if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) {
@@ -1901,31 +1987,14 @@ static int fib6_age(struct rt6_info *rt, void *arg)
                        return -1;
                }
                gc_args->more++;
-       } else if (rt->rt6i_flags & RTF_CACHE) {
-               if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout))
-                       rt->dst.obsolete = DST_OBSOLETE_KILL;
-               if (atomic_read(&rt->dst.__refcnt) == 1 &&
-                   rt->dst.obsolete == DST_OBSOLETE_KILL) {
-                       RT6_TRACE("aging clone %p\n", rt);
-                       return -1;
-               } else if (rt->rt6i_flags & RTF_GATEWAY) {
-                       struct neighbour *neigh;
-                       __u8 neigh_flags = 0;
-
-                       neigh = dst_neigh_lookup(&rt->dst, &rt->rt6i_gateway);
-                       if (neigh) {
-                               neigh_flags = neigh->flags;
-                               neigh_release(neigh);
-                       }
-                       if (!(neigh_flags & NTF_ROUTER)) {
-                               RT6_TRACE("purging route %p via non-router but gateway\n",
-                                         rt);
-                               return -1;
-                       }
-               }
-               gc_args->more++;
        }
 
+       /*      Also age clones in the exception table.
+        *      Note, that clones are aged out
+        *      only if they are not in use now.
+        */
+       rt6_age_exceptions(rt, gc_args, now);
+
        return 0;
 }
 
@@ -1957,9 +2026,11 @@ void fib6_run_gc(unsigned long expires, struct net *net, bool force)
        spin_unlock_bh(&net->ipv6.fib6_gc_lock);
 }
 
-static void fib6_gc_timer_cb(unsigned long arg)
+static void fib6_gc_timer_cb(struct timer_list *t)
 {
-       fib6_run_gc(0, (struct net *)arg, true);
+       struct net *arg = from_timer(arg, t, ipv6.ip6_fib_timer);
+
+       fib6_run_gc(0, arg, true);
 }
 
 static int __net_init fib6_net_init(struct net *net)
@@ -1974,7 +2045,7 @@ static int __net_init fib6_net_init(struct net *net)
        spin_lock_init(&net->ipv6.fib6_gc_lock);
        rwlock_init(&net->ipv6.fib6_walker_lock);
        INIT_LIST_HEAD(&net->ipv6.fib6_walkers);
-       setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net);
+       timer_setup(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, 0);
 
        net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL);
        if (!net->ipv6.rt6_stats)
@@ -1993,7 +2064,8 @@ static int __net_init fib6_net_init(struct net *net)
                goto out_fib_table_hash;
 
        net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
-       net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
+       rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf,
+                          net->ipv6.ip6_null_entry);
        net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
                RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
        inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers);
@@ -2004,7 +2076,8 @@ static int __net_init fib6_net_init(struct net *net)
        if (!net->ipv6.fib6_local_tbl)
                goto out_fib6_main_tbl;
        net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
-       net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_null_entry;
+       rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf,
+                          net->ipv6.ip6_null_entry);
        net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
                RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
        inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers);
@@ -2134,7 +2207,9 @@ static int ipv6_route_yield(struct fib6_walker *w)
                return 1;
 
        do {
-               iter->w.leaf = iter->w.leaf->dst.rt6_next;
+               iter->w.leaf = rcu_dereference_protected(
+                               iter->w.leaf->dst.rt6_next,
+                               lockdep_is_held(&iter->tbl->tb6_lock));
                iter->skip--;
                if (!iter->skip && iter->w.leaf)
                        return 1;
@@ -2199,7 +2274,7 @@ static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
        if (!v)
                goto iter_table;
 
-       n = ((struct rt6_info *)v)->dst.rt6_next;
+       n = rcu_dereference_bh(((struct rt6_info *)v)->dst.rt6_next);
        if (n) {
                ++*pos;
                return n;
@@ -2207,9 +2282,9 @@ static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 
 iter_table:
        ipv6_route_check_sernum(iter);
-       read_lock(&iter->tbl->tb6_lock);
+       spin_lock_bh(&iter->tbl->tb6_lock);
        r = fib6_walk_continue(&iter->w);
-       read_unlock(&iter->tbl->tb6_lock);
+       spin_unlock_bh(&iter->tbl->tb6_lock);
        if (r > 0) {
                if (v)
                        ++*pos;