ipv6: take care of rt6_stats

Currently, most of the rt6_stats are not hooked up correctly. As the
last part of this patch series, hook up all existing rt6_stats and add
one new stat fib_rt_uncache to indicate the number of routes in the
uncached list.
For details of the stats, please refer to the comments added in
include/net/ip6_fib.h.

Note: fib_rt_alloc and fib_rt_uncache are not guaranteed to be modified
under a lock. So atomic_t is used for them.

Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 0b438b9..10c9138 100644 (file)
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -297,12 +297,15 @@ struct fib6_walker {
 };
 
 struct rt6_statistics {
-       __u32           fib_nodes;
-       __u32           fib_route_nodes;
-       __u32           fib_rt_alloc;           /* permanent routes     */
-       __u32           fib_rt_entries;         /* rt entries in table  */
-       __u32           fib_rt_cache;           /* cache routes         */
-       __u32           fib_discarded_routes;
+       __u32           fib_nodes;              /* all fib6 nodes */
+       __u32           fib_route_nodes;        /* intermediate nodes */
+       __u32           fib_rt_entries;         /* rt entries in fib table */
+       __u32           fib_rt_cache;           /* cached rt entries in exception table */
+       __u32           fib_discarded_routes;   /* total number of routes delete */
+
+       /* The following stats are not protected by any lock */
+       atomic_t        fib_rt_alloc;           /* total number of routes alloced */
+       atomic_t        fib_rt_uncache;         /* rt entries in uncached list */
 };
 
 #define RTN_TL_ROOT    0x0001

diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 3f95908..52a29ba 100644 (file)
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -149,18 +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)
@@ -170,9 +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)
@@ -583,7 +587,8 @@ out:
  *     node.
  */
 
-static struct fib6_node *fib6_add_1(struct fib6_table *table,
+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,
@@ -675,7 +680,7 @@ static struct fib6_node *fib6_add_1(struct fib6_table *table,
         *      Create new leaf node without children.
         */
 
-       ln = node_alloc();
+       ln = node_alloc(net);
 
        if (!ln)
                return ERR_PTR(-ENOMEM);
@@ -716,14 +721,14 @@ 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);
                }
 
@@ -768,7 +773,7 @@ insert_above:
                 *           (old node)[fn] NULL
                 */
 
-               ln = node_alloc();
+               ln = node_alloc(net);
 
                if (!ln)
                        return ERR_PTR(-ENOMEM);
@@ -1065,6 +1070,7 @@ add:
                                                fn->rr_ptr = NULL;
                                        rt6_release(iter);
                                        nsiblings--;
+                                       info->nl_net->ipv6.rt6_stats->fib_rt_entries--;
                                } else {
                                        ins = &iter->dst.rt6_next;
                                }
@@ -1140,7 +1146,7 @@ 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(table, root,
+       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, extack);
@@ -1170,7 +1176,7 @@ 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;
 
@@ -1181,8 +1187,8 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt,
 
                        /* Now add the first leaf node to new subtree */
 
-                       sn = fib6_add_1(table, 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, extack);
 
@@ -1191,7 +1197,7 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt,
                                   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;
                        }
@@ -1200,8 +1206,8 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt,
                        rcu_assign_pointer(sfn->parent, fn);
                        rcu_assign_pointer(fn->subtree, sfn);
                } else {
-                       sn = fib6_add_1(table, FIB6_SUBTREE(fn), &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, extack);
 
@@ -1609,7 +1615,7 @@ 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;
 

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index cf44d09..399d1bc 100644 (file)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -143,9 +143,11 @@ static void rt6_uncached_list_del(struct rt6_info *rt)
 {
        if (!list_empty(&rt->rt6i_uncached)) {
                struct uncached_list *ul = rt->rt6i_uncached_list;
+               struct net *net = dev_net(rt->dst.dev);
 
                spin_lock_bh(&ul->lock);
                list_del(&rt->rt6i_uncached);
+               atomic_dec(&net->ipv6.rt6_stats->fib_rt_uncache);
                spin_unlock_bh(&ul->lock);
        }
 }
@@ -359,8 +361,10 @@ static struct rt6_info *__ip6_dst_alloc(struct net *net,
        struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev,
                                        1, DST_OBSOLETE_FORCE_CHK, flags);
 
-       if (rt)
+       if (rt) {
                rt6_info_init(rt);
+               atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
+       }
 
        return rt;
 }
@@ -1156,6 +1160,8 @@ static DEFINE_SPINLOCK(rt6_exception_lock);
 static void rt6_remove_exception(struct rt6_exception_bucket *bucket,
                                 struct rt6_exception *rt6_ex)
 {
+       struct net *net = dev_net(rt6_ex->rt6i->dst.dev);
+
        if (!bucket || !rt6_ex)
                return;
        rt6_ex->rt6i->rt6i_node = NULL;
@@ -1164,6 +1170,7 @@ static void rt6_remove_exception(struct rt6_exception_bucket *bucket,
        kfree_rcu(rt6_ex, rcu);
        WARN_ON_ONCE(!bucket->depth);
        bucket->depth--;
+       net->ipv6.rt6_stats->fib_rt_cache--;
 }
 
 /* Remove oldest rt6_ex in bucket and free the memory
@@ -1270,6 +1277,7 @@ __rt6_find_exception_rcu(struct rt6_exception_bucket **bucket,
 static int rt6_insert_exception(struct rt6_info *nrt,
                                struct rt6_info *ort)
 {
+       struct net *net = dev_net(ort->dst.dev);
        struct rt6_exception_bucket *bucket;
        struct in6_addr *src_key = NULL;
        struct rt6_exception *rt6_ex;
@@ -1339,6 +1347,7 @@ static int rt6_insert_exception(struct rt6_info *nrt,
        nrt->rt6i_node = ort->rt6i_node;
        hlist_add_head_rcu(&rt6_ex->hlist, &bucket->chain);
        bucket->depth++;
+       net->ipv6.rt6_stats->fib_rt_cache++;
 
        if (bucket->depth > FIB6_MAX_DEPTH)
                rt6_exception_remove_oldest(bucket);
@@ -1714,6 +1723,7 @@ redo_rt6_select:
                         * No need for another dst_hold()
                         */
                        rt6_uncached_list_add(uncached_rt);
+                       atomic_inc(&net->ipv6.rt6_stats->fib_rt_uncache);
                } else {
                        uncached_rt = net->ipv6.ip6_null_entry;
                        dst_hold(&uncached_rt->dst);
@@ -1894,6 +1904,7 @@ struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_ori
                       DST_OBSOLETE_NONE, 0);
        if (rt) {
                rt6_info_init(rt);
+               atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
 
                new = &rt->dst;
                new->__use = 1;
@@ -2341,6 +2352,7 @@ struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
         * do proper release of the net_device
         */
        rt6_uncached_list_add(rt);
+       atomic_inc(&net->ipv6.rt6_stats->fib_rt_uncache);
 
        dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0);
 
@@ -4422,7 +4434,7 @@ static int rt6_stats_seq_show(struct seq_file *seq, void *v)
        seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
                   net->ipv6.rt6_stats->fib_nodes,
                   net->ipv6.rt6_stats->fib_route_nodes,
-                  net->ipv6.rt6_stats->fib_rt_alloc,
+                  atomic_read(&net->ipv6.rt6_stats->fib_rt_alloc),
                   net->ipv6.rt6_stats->fib_rt_entries,
                   net->ipv6.rt6_stats->fib_rt_cache,
                   dst_entries_get_slow(&net->ipv6.ip6_dst_ops),