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;