1 files changed, 67 insertions, 37 deletions

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index f2f47033f31f..35851c96bdfb 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1205,20 +1205,45 @@ static int fn_trie_insert(struct fib_table *tb, struct fib_config *cfg)
          * and we need to allocate a new one of those as well.
          */
 
-        if (fa && fa->fa_info->fib_priority == fi->fib_priority) {
-                struct fib_alias *fa_orig;
+        if (fa && fa->fa_tos == tos &&
+            fa->fa_info->fib_priority == fi->fib_priority) {
+                struct fib_alias *fa_first, *fa_match;
 
                 err = -EEXIST;
                 if (cfg->fc_nlflags & NLM_F_EXCL)
                         goto out;
 
+                /* We have 2 goals:
+                 * 1. Find exact match for type, scope, fib_info to avoid
+                 * duplicate routes
+                 * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it
+                 */
+                fa_match = NULL;
+                fa_first = fa;
+                fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
+                list_for_each_entry_continue(fa, fa_head, fa_list) {
+                        if (fa->fa_tos != tos)
+                                break;
+                        if (fa->fa_info->fib_priority != fi->fib_priority)
+                                break;
+                        if (fa->fa_type == cfg->fc_type &&
+                            fa->fa_scope == cfg->fc_scope &&
+                            fa->fa_info == fi) {
+                                fa_match = fa;
+                                break;
+                        }
+                }
+
                 if (cfg->fc_nlflags & NLM_F_REPLACE) {
                         struct fib_info *fi_drop;
                         u8 state;
 
-                        if (fi->fib_treeref > 1)
+                        fa = fa_first;
+                        if (fa_match) {
+                                if (fa == fa_match)
+                                        err = 0;
                                 goto out;
-
+                        }
                         err = -ENOBUFS;
                         new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL);
                         if (new_fa == NULL)
@@ -1230,7 +1255,7 @@ static int fn_trie_insert(struct fib_table *tb, struct fib_config *cfg)
                         new_fa->fa_type = cfg->fc_type;
                         new_fa->fa_scope = cfg->fc_scope;
                         state = fa->fa_state;
-                        new_fa->fa_state &= ~FA_S_ACCESSED;
+                        new_fa->fa_state = state & ~FA_S_ACCESSED;
 
                         list_replace_rcu(&fa->fa_list, &new_fa->fa_list);
                         alias_free_mem_rcu(fa);
@@ -1247,20 +1272,11 @@ static int fn_trie_insert(struct fib_table *tb, struct fib_config *cfg)
                  * uses the same scope, type, and nexthop
                  * information.
                  */
-                fa_orig = fa;
-                list_for_each_entry(fa, fa_orig->fa_list.prev, fa_list) {
-                        if (fa->fa_tos != tos)
-                                break;
-                        if (fa->fa_info->fib_priority != fi->fib_priority)
-                                break;
-                        if (fa->fa_type == cfg->fc_type &&
-                            fa->fa_scope == cfg->fc_scope &&
-                            fa->fa_info == fi)
-                                goto out;
-                }
+                if (fa_match)
+                        goto out;
 
                 if (!(cfg->fc_nlflags & NLM_F_APPEND))
-                        fa = fa_orig;
+                        fa = fa_first;
         }
         err = -ENOENT;
         if (!(cfg->fc_nlflags & NLM_F_CREATE))
@@ -1600,9 +1616,8 @@ static int fn_trie_delete(struct fib_table *tb, struct fib_config *cfg)
         pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t);
 
         fa_to_delete = NULL;
-        fa_head = fa->fa_list.prev;
-
-        list_for_each_entry(fa, fa_head, fa_list) {
+        fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
+        list_for_each_entry_continue(fa, fa_head, fa_list) {
                 struct fib_info *fi = fa->fa_info;
 
                 if (fa->fa_tos != tos)
@@ -1743,6 +1758,19 @@ static struct leaf *trie_nextleaf(struct leaf *l)
         return leaf_walk_rcu(p, c);
 }
 
+static struct leaf *trie_leafindex(struct trie *t, int index)
+{
+        struct leaf *l = trie_firstleaf(t);
+
+        while (index-- > 0) {
+                l = trie_nextleaf(l);
+                if (!l)
+                        break;
+        }
+        return l;
+}
+
+
 /*
  * Caller must hold RTNL.
  */
@@ -1848,7 +1876,7 @@ static int fn_trie_dump_fa(t_key key, int plen, struct list_head *fah,
         struct fib_alias *fa;
         __be32 xkey = htonl(key);
 
-        s_i = cb->args[4];
+        s_i = cb->args[5];
         i = 0;
 
         /* rcu_read_lock is hold by caller */
@@ -1869,12 +1897,12 @@ static int fn_trie_dump_fa(t_key key, int plen, struct list_head *fah,
                                   plen,
                                   fa->fa_tos,
                                   fa->fa_info, NLM_F_MULTI) < 0) {
-                        cb->args[4] = i;
+                        cb->args[5] = i;
                         return -1;
                 }
                 i++;
         }
-        cb->args[4] = i;
+        cb->args[5] = i;
         return skb->len;
 }
 
@@ -1885,7 +1913,7 @@ static int fn_trie_dump_leaf(struct leaf *l, struct fib_table *tb,
         struct hlist_node *node;
         int i, s_i;
 
-        s_i = cb->args[3];
+        s_i = cb->args[4];
         i = 0;
 
         /* rcu_read_lock is hold by caller */
@@ -1896,19 +1924,19 @@ static int fn_trie_dump_leaf(struct leaf *l, struct fib_table *tb,
                 }
 
                 if (i > s_i)
-                        cb->args[4] = 0;
+                        cb->args[5] = 0;
 
                 if (list_empty(&li->falh))
                         continue;
 
                 if (fn_trie_dump_fa(l->key, li->plen, &li->falh, tb, skb, cb) < 0) {
-                        cb->args[3] = i;
+                        cb->args[4] = i;
                         return -1;
                 }
                 i++;
         }
 
-        cb->args[3] = i;
+        cb->args[4] = i;
         return skb->len;
 }
 
@@ -1918,35 +1946,37 @@ static int fn_trie_dump(struct fib_table *tb, struct sk_buff *skb,
         struct leaf *l;
         struct trie *t = (struct trie *) tb->tb_data;
         t_key key = cb->args[2];
+        int count = cb->args[3];
 
         rcu_read_lock();
         /* Dump starting at last key.
          * Note: 0.0.0.0/0 (ie default) is first key.
          */
-        if (!key)
+        if (count == 0)
                 l = trie_firstleaf(t);
         else {
+                /* Normally, continue from last key, but if that is missing
+                 * fallback to using slow rescan
+                 */
                 l = fib_find_node(t, key);
-                if (!l) {
-                        /* The table changed during the dump, rather than
-                         * giving partial data, just make application retry.
-                         */
-                        rcu_read_unlock();
-                        return -EBUSY;
-                }
+                if (!l)
+                        l = trie_leafindex(t, count);
         }
 
         while (l) {
                 cb->args[2] = l->key;
                 if (fn_trie_dump_leaf(l, tb, skb, cb) < 0) {
+                        cb->args[3] = count;
                         rcu_read_unlock();
                         return -1;
                 }
 
+                ++count;
                 l = trie_nextleaf(l);
-                memset(&cb->args[3], 0,
-                       sizeof(cb->args) - 3*sizeof(cb->args[0]));
+                memset(&cb->args[4], 0,
+                       sizeof(cb->args) - 4*sizeof(cb->args[0]));
         }
+        cb->args[3] = count;
         rcu_read_unlock();
 
         return skb->len;