net: expose the master link to sysfs, and remove it from bond

Currently, we can have only one master upper neighbour, so it would be
useful to create a symlink to it in the sysfs device directory, the way
that bonding now does it, for every device. Lower devices from
bridge/team/etc will automagically get it, so we could rely on it.

Also, remove the same functionality from bonding.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jiri@resnulli.us>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/bonding/bond_sysfs.c b/drivers/net/bonding/bond_sysfs.c
index 04d95d6..1c57246 100644 (file)
--- a/drivers/net/bonding/bond_sysfs.c
+++ b/drivers/net/bonding/bond_sysfs.c
@@ -172,24 +172,11 @@ int bond_create_slave_symlinks(struct net_device *master,
                               struct net_device *slave)
 {
        char linkname[IFNAMSIZ+7];
-       int ret = 0;
 
-       /* first, create a link from the slave back to the master */
-       ret = sysfs_create_link(&(slave->dev.kobj), &(master->dev.kobj),
-                               "master");
-       if (ret)
-               return ret;
-       /* next, create a link from the master to the slave */
+       /* create a link from the master to the slave */
        sprintf(linkname, "slave_%s", slave->name);
-       ret = sysfs_create_link(&(master->dev.kobj), &(slave->dev.kobj),
-                               linkname);
-
-       /* free the master link created earlier in case of error */
-       if (ret)
-               sysfs_remove_link(&(slave->dev.kobj), "master");
-
-       return ret;
-
+       return sysfs_create_link(&(master->dev.kobj), &(slave->dev.kobj),
+                                linkname);
 }
 
 void bond_destroy_slave_symlinks(struct net_device *master,
@@ -197,7 +184,6 @@ void bond_destroy_slave_symlinks(struct net_device *master,
 {
        char linkname[IFNAMSIZ+7];
 
-       sysfs_remove_link(&(slave->dev.kobj), "master");
        sprintf(linkname, "slave_%s", slave->name);
        sysfs_remove_link(&(master->dev.kobj), linkname);
 }

diff --git a/net/core/dev.c b/net/core/dev.c
index acc1181..de443ee 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4584,6 +4584,7 @@ static int __netdev_adjacent_dev_insert(struct net_device *dev,
                                        void *private, bool master)
 {
        struct netdev_adjacent *adj;
+       int ret;
 
        adj = __netdev_find_adj(dev, adj_dev, dev_list);
 
@@ -4606,12 +4607,23 @@ static int __netdev_adjacent_dev_insert(struct net_device *dev,
                 adj_dev->name, dev->name, adj_dev->name);
 
        /* Ensure that master link is always the first item in list. */
-       if (master)
+       if (master) {
+               ret = sysfs_create_link(&(dev->dev.kobj),
+                                       &(adj_dev->dev.kobj), "master");
+               if (ret)
+                       goto free_adj;
+
                list_add_rcu(&adj->list, dev_list);
-       else
+       } else {
                list_add_tail_rcu(&adj->list, dev_list);
+       }
 
        return 0;
+
+free_adj:
+       kfree(adj);
+
+       return ret;
 }
 
 void __netdev_adjacent_dev_remove(struct net_device *dev,
@@ -4635,6 +4647,9 @@ void __netdev_adjacent_dev_remove(struct net_device *dev,
                return;
        }
 
+       if (adj->master)
+               sysfs_remove_link(&(dev->dev.kobj), "master");
+
        list_del_rcu(&adj->list);
        pr_debug("dev_put for %s, because link removed from %s to %s\n",
                 adj_dev->name, dev->name, adj_dev->name);