1 files changed, 60 insertions, 77 deletions

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 28a3065470bc..987b06d1effe 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1181,72 +1181,6 @@ err:
         return err;
 }
 
-/* should be called with rcu_read_lock */
-static int check_leaf(struct fib_table *tb, struct trie *t, struct tnode *l,
-                      t_key key,  const struct flowi4 *flp,
-                      struct fib_result *res, int fib_flags)
-{
-        struct leaf_info *li;
-        struct hlist_head *hhead = &l->list;
-
-        hlist_for_each_entry_rcu(li, hhead, hlist) {
-                struct fib_alias *fa;
-
-                if (l->key != (key & li->mask_plen))
-                        continue;
-
-                list_for_each_entry_rcu(fa, &li->falh, fa_list) {
-                        struct fib_info *fi = fa->fa_info;
-                        int nhsel, err;
-
-                        if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
-                                continue;
-                        if (fi->fib_dead)
-                                continue;
-                        if (fa->fa_info->fib_scope < flp->flowi4_scope)
-                                continue;
-                        fib_alias_accessed(fa);
-                        err = fib_props[fa->fa_type].error;
-                        if (unlikely(err < 0)) {
-#ifdef CONFIG_IP_FIB_TRIE_STATS
-                                this_cpu_inc(t->stats->semantic_match_passed);
-#endif
-                                return err;
-                        }
-                        if (fi->fib_flags & RTNH_F_DEAD)
-                                continue;
-                        for (nhsel = 0; nhsel < fi->fib_nhs; nhsel++) {
-                                const struct fib_nh *nh = &fi->fib_nh[nhsel];
-
-                                if (nh->nh_flags & RTNH_F_DEAD)
-                                        continue;
-                                if (flp->flowi4_oif && flp->flowi4_oif != nh->nh_oif)
-                                        continue;
-
-#ifdef CONFIG_IP_FIB_TRIE_STATS
-                                this_cpu_inc(t->stats->semantic_match_passed);
-#endif
-                                res->prefixlen = li->plen;
-                                res->nh_sel = nhsel;
-                                res->type = fa->fa_type;
-                                res->scope = fi->fib_scope;
-                                res->fi = fi;
-                                res->table = tb;
-                                res->fa_head = &li->falh;
-                                if (!(fib_flags & FIB_LOOKUP_NOREF))
-                                        atomic_inc(&fi->fib_clntref);
-                                return 0;
-                        }
-                }
-
-#ifdef CONFIG_IP_FIB_TRIE_STATS
-                this_cpu_inc(t->stats->semantic_match_miss);
-#endif
-        }
-
-        return 1;
-}
-
 static inline t_key prefix_mismatch(t_key key, struct tnode *n)
 {
         t_key prefix = n->key;
@@ -1254,6 +1188,7 @@ static inline t_key prefix_mismatch(t_key key, struct tnode *n)
         return (key ^ prefix) & (prefix | -prefix);
 }
 
+/* should be called with rcu_read_lock */
 int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
                      struct fib_result *res, int fib_flags)
 {
@@ -1263,14 +1198,12 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
 #endif
         const t_key key = ntohl(flp->daddr);
         struct tnode *n, *pn;
+        struct leaf_info *li;
         t_key cindex;
-        int ret = 1;
-
-        rcu_read_lock();
 
         n = rcu_dereference(t->trie);
         if (!n)
-                goto failed;
+                return -EAGAIN;
 
 #ifdef CONFIG_IP_FIB_TRIE_STATS
         this_cpu_inc(stats->gets);
@@ -1350,7 +1283,7 @@ backtrace:
 
                                 pn = node_parent_rcu(pn);
                                 if (unlikely(!pn))
-                                        goto failed;
+                                        return -EAGAIN;
 #ifdef CONFIG_IP_FIB_TRIE_STATS
                                 this_cpu_inc(stats->backtrack);
 #endif
@@ -1368,12 +1301,62 @@ backtrace:
 
 found:
         /* Step 3: Process the leaf, if that fails fall back to backtracing */
-        ret = check_leaf(tb, t, n, key, flp, res, fib_flags);
-        if (unlikely(ret > 0))
-                goto backtrace;
-failed:
-        rcu_read_unlock();
-        return ret;
+        hlist_for_each_entry_rcu(li, &n->list, hlist) {
+                struct fib_alias *fa;
+
+                if ((key ^ n->key) & li->mask_plen)
+                        continue;
+
+                list_for_each_entry_rcu(fa, &li->falh, fa_list) {
+                        struct fib_info *fi = fa->fa_info;
+                        int nhsel, err;
+
+                        if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
+                                continue;
+                        if (fi->fib_dead)
+                                continue;
+                        if (fa->fa_info->fib_scope < flp->flowi4_scope)
+                                continue;
+                        fib_alias_accessed(fa);
+                        err = fib_props[fa->fa_type].error;
+                        if (unlikely(err < 0)) {
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+                                this_cpu_inc(stats->semantic_match_passed);
+#endif
+                                return err;
+                        }
+                        if (fi->fib_flags & RTNH_F_DEAD)
+                                continue;
+                        for (nhsel = 0; nhsel < fi->fib_nhs; nhsel++) {
+                                const struct fib_nh *nh = &fi->fib_nh[nhsel];
+
+                                if (nh->nh_flags & RTNH_F_DEAD)
+                                        continue;
+                                if (flp->flowi4_oif && flp->flowi4_oif != nh->nh_oif)
+                                        continue;
+
+                                if (!(fib_flags & FIB_LOOKUP_NOREF))
+                                        atomic_inc(&fi->fib_clntref);
+
+                                res->prefixlen = li->plen;
+                                res->nh_sel = nhsel;
+                                res->type = fa->fa_type;
+                                res->scope = fi->fib_scope;
+                                res->fi = fi;
+                                res->table = tb;
+                                res->fa_head = &li->falh;
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+                                this_cpu_inc(stats->semantic_match_passed);
+#endif
+                                return err;
+                        }
+                }
+
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+                this_cpu_inc(stats->semantic_match_miss);
+#endif
+        }
+        goto backtrace;
 }
 EXPORT_SYMBOL_GPL(fib_table_lookup);