dev_addr_list: put the first addr on the tree

Since all netdev->dev_addr modifications go via dev_addr_mod()
we can put it on the list. When address is change remove it
and add it back.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/dev_addr_lists.c b/net/core/dev_addr_lists.c
index 9699427..bead38c 100644 (file)
--- a/net/core/dev_addr_lists.c
+++ b/net/core/dev_addr_lists.c
@@ -16,6 +16,35 @@
  * General list handling functions
  */
 
+static int __hw_addr_insert(struct netdev_hw_addr_list *list,
+                           struct netdev_hw_addr *new, int addr_len)
+{
+       struct rb_node **ins_point = &list->tree.rb_node, *parent = NULL;
+       struct netdev_hw_addr *ha;
+
+       while (*ins_point) {
+               int diff;
+
+               ha = rb_entry(*ins_point, struct netdev_hw_addr, node);
+               diff = memcmp(new->addr, ha->addr, addr_len);
+               if (diff == 0)
+                       diff = memcmp(&new->type, &ha->type, sizeof(new->type));
+
+               parent = *ins_point;
+               if (diff < 0)
+                       ins_point = &parent->rb_left;
+               else if (diff > 0)
+                       ins_point = &parent->rb_right;
+               else
+                       return -EEXIST;
+       }
+
+       rb_link_node_rcu(&new->node, parent, ins_point);
+       rb_insert_color(&new->node, &list->tree);
+
+       return 0;
+}
+
 static struct netdev_hw_addr*
 __hw_addr_create(const unsigned char *addr, int addr_len,
                 unsigned char addr_type, bool global, bool sync)
@@ -50,11 +79,6 @@ static int __hw_addr_add_ex(struct netdev_hw_addr_list *list,
        if (addr_len > MAX_ADDR_LEN)
                return -EINVAL;
 
-       ha = list_first_entry(&list->list, struct netdev_hw_addr, list);
-       if (ha && !memcmp(addr, ha->addr, addr_len) &&
-           (!addr_type || addr_type == ha->type))
-               goto found_it;
-
        while (*ins_point) {
                int diff;
 
@@ -69,7 +93,6 @@ static int __hw_addr_add_ex(struct netdev_hw_addr_list *list,
                } else if (diff > 0) {
                        ins_point = &parent->rb_right;
                } else {
-found_it:
                        if (exclusive)
                                return -EEXIST;
                        if (global) {
@@ -94,16 +117,8 @@ found_it:
        if (!ha)
                return -ENOMEM;
 
-       /* The first address in dev->dev_addrs is pointed to by dev->dev_addr
-        * and mutated freely by device drivers and netdev ops, so if we insert
-        * it into the tree we'll end up with an invalid rbtree.
-        */
-       if (list->count > 0) {
-               rb_link_node(&ha->node, parent, ins_point);
-               rb_insert_color(&ha->node, &list->tree);
-       } else {
-               RB_CLEAR_NODE(&ha->node);
-       }
+       rb_link_node(&ha->node, parent, ins_point);
+       rb_insert_color(&ha->node, &list->tree);
 
        list_add_tail_rcu(&ha->list, &list->list);
        list->count++;
@@ -138,8 +153,7 @@ static int __hw_addr_del_entry(struct netdev_hw_addr_list *list,
        if (--ha->refcount)
                return 0;
 
-       if (!RB_EMPTY_NODE(&ha->node))
-               rb_erase(&ha->node, &list->tree);
+       rb_erase(&ha->node, &list->tree);
 
        list_del_rcu(&ha->list);
        kfree_rcu(ha, rcu_head);
@@ -151,18 +165,8 @@ static struct netdev_hw_addr *__hw_addr_lookup(struct netdev_hw_addr_list *list,
                                               const unsigned char *addr, int addr_len,
                                               unsigned char addr_type)
 {
-       struct netdev_hw_addr *ha;
        struct rb_node *node;
 
-       /* The first address isn't inserted into the tree because in the dev->dev_addrs
-        * list it's the address pointed to by dev->dev_addr which is freely mutated
-        * in place, so we need to check it separately.
-        */
-       ha = list_first_entry(&list->list, struct netdev_hw_addr, list);
-       if (ha && !memcmp(addr, ha->addr, addr_len) &&
-           (!addr_type || addr_type == ha->type))
-               return ha;
-
        node = list->tree.rb_node;
 
        while (node) {
@@ -571,8 +575,10 @@ void dev_addr_mod(struct net_device *dev, unsigned int offset,
        dev_addr_check(dev);
 
        ha = container_of(dev->dev_addr, struct netdev_hw_addr, addr[0]);
+       rb_erase(&ha->node, &dev->dev_addrs.tree);
        memcpy(&ha->addr[offset], addr, len);
        memcpy(&dev->dev_addr_shadow[offset], addr, len);
+       WARN_ON(__hw_addr_insert(&dev->dev_addrs, ha, dev->addr_len));
 }
 EXPORT_SYMBOL(dev_addr_mod);