net: add sysfs helpers for netdev_adjacent logic

They clean up the code a bit and can be used further.

CC: Ding Tianhong <dingtianhong@huawei.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Nicolas Dichtel <nicolas.dichtel@6wind.com>
CC: Cong Wang <amwang@redhat.com>
Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/core/dev.c b/net/core/dev.c
index 20c834e..130d3bd 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4623,13 +4623,36 @@ struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
 }
 EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
 
+int netdev_adjacent_sysfs_add(struct net_device *dev,
+                             struct net_device *adj_dev,
+                             struct list_head *dev_list)
+{
+       char linkname[IFNAMSIZ+7];
+       sprintf(linkname, dev_list == &dev->adj_list.upper ?
+               "upper_%s" : "lower_%s", adj_dev->name);
+       return sysfs_create_link(&(dev->dev.kobj), &(adj_dev->dev.kobj),
+                                linkname);
+}
+void netdev_adjacent_sysfs_del(struct net_device *dev,
+                              char *name,
+                              struct list_head *dev_list)
+{
+       char linkname[IFNAMSIZ+7];
+       sprintf(linkname, dev_list == &dev->adj_list.upper ?
+               "upper_%s" : "lower_%s", name);
+       sysfs_remove_link(&(dev->dev.kobj), linkname);
+}
+
+#define netdev_adjacent_is_neigh_list(dev, dev_list) \
+               (dev_list == &dev->adj_list.upper || \
+                dev_list == &dev->adj_list.lower)
+
 static int __netdev_adjacent_dev_insert(struct net_device *dev,
                                        struct net_device *adj_dev,
                                        struct list_head *dev_list,
                                        void *private, bool master)
 {
        struct netdev_adjacent *adj;
-       char linkname[IFNAMSIZ+7];
        int ret;
 
        adj = __netdev_find_adj(dev, adj_dev, dev_list);
@@ -4652,16 +4675,8 @@ static int __netdev_adjacent_dev_insert(struct net_device *dev,
        pr_debug("dev_hold for %s, because of link added from %s to %s\n",
                 adj_dev->name, dev->name, adj_dev->name);
 
-       if (dev_list == &dev->adj_list.lower) {
-               sprintf(linkname, "lower_%s", adj_dev->name);
-               ret = sysfs_create_link(&(dev->dev.kobj),
-                                       &(adj_dev->dev.kobj), linkname);
-               if (ret)
-                       goto free_adj;
-       } else if (dev_list == &dev->adj_list.upper) {
-               sprintf(linkname, "upper_%s", adj_dev->name);
-               ret = sysfs_create_link(&(dev->dev.kobj),
-                                       &(adj_dev->dev.kobj), linkname);
+       if (netdev_adjacent_is_neigh_list(dev, dev_list)) {
+               ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
                if (ret)
                        goto free_adj;
        }
@@ -4681,14 +4696,8 @@ static int __netdev_adjacent_dev_insert(struct net_device *dev,
        return 0;
 
 remove_symlinks:
-       if (dev_list == &dev->adj_list.lower) {
-               sprintf(linkname, "lower_%s", adj_dev->name);
-               sysfs_remove_link(&(dev->dev.kobj), linkname);
-       } else if (dev_list == &dev->adj_list.upper) {
-               sprintf(linkname, "upper_%s", adj_dev->name);
-               sysfs_remove_link(&(dev->dev.kobj), linkname);
-       }
-
+       if (netdev_adjacent_is_neigh_list(dev, dev_list))
+               netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
 free_adj:
        kfree(adj);
        dev_put(adj_dev);
@@ -4701,7 +4710,6 @@ static void __netdev_adjacent_dev_remove(struct net_device *dev,
                                         struct list_head *dev_list)
 {
        struct netdev_adjacent *adj;
-       char linkname[IFNAMSIZ+7];
 
        adj = __netdev_find_adj(dev, adj_dev, dev_list);
 
@@ -4721,13 +4729,8 @@ static void __netdev_adjacent_dev_remove(struct net_device *dev,
        if (adj->master)
                sysfs_remove_link(&(dev->dev.kobj), "master");
 
-       if (dev_list == &dev->adj_list.lower) {
-               sprintf(linkname, "lower_%s", adj_dev->name);
-               sysfs_remove_link(&(dev->dev.kobj), linkname);
-       } else if (dev_list == &dev->adj_list.upper) {
-               sprintf(linkname, "upper_%s", adj_dev->name);
-               sysfs_remove_link(&(dev->dev.kobj), linkname);
-       }
+       if (netdev_adjacent_is_neigh_list(dev, dev_list))
+               netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
 
        list_del_rcu(&adj->list);
        pr_debug("dev_put for %s, because link removed from %s to %s\n",