diff options
| -rw-r--r-- | include/linux/netdevice.h | 1 | ||||
| -rw-r--r-- | net/core/dev.c | 285 |
2 files changed, 259 insertions, 27 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 077363dcd86..5ccf5b73c37 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1125,6 +1125,7 @@ struct net_device { struct list_head napi_list; struct list_head unreg_list; struct list_head upper_dev_list; /* List of upper devices */ + struct list_head lower_dev_list; /* currently active device features */ diff --git a/net/core/dev.c b/net/core/dev.c index 5072e2c1a07..2aa914eee05 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4369,7 +4369,16 @@ softnet_break: struct netdev_adjacent { struct net_device *dev; + + /* upper master flag, there can only be one master device per list */ bool master; + + /* indicates that this dev is our first-level lower/upper device */ + bool neighbour; + + /* counter for the number of times this device was added to us */ + u16 ref_nr; + struct list_head list; struct rcu_head rcu; struct list_head search_list; @@ -4408,18 +4417,34 @@ static bool __netdev_search_upper_dev(struct net_device *dev, return ret; } -static struct netdev_adjacent *__netdev_find_upper(struct net_device *dev, - struct net_device *upper_dev) +static struct netdev_adjacent *__netdev_find_adj(struct net_device *dev, + struct net_device *adj_dev, + bool upper) { - struct netdev_adjacent *upper; + struct netdev_adjacent *adj; + struct list_head *dev_list; - list_for_each_entry(upper, &dev->upper_dev_list, list) { - if (upper->dev == upper_dev) - return upper; + dev_list = upper ? &dev->upper_dev_list : &dev->lower_dev_list; + + list_for_each_entry(adj, dev_list, list) { + if (adj->dev == adj_dev) + return adj; } return NULL; } +static inline struct netdev_adjacent *__netdev_find_upper(struct net_device *dev, + struct net_device *udev) +{ + return __netdev_find_adj(dev, udev, true); +} + +static inline struct netdev_adjacent *__netdev_find_lower(struct net_device *dev, + struct net_device *ldev) +{ + return __netdev_find_adj(dev, ldev, false); +} + /** * netdev_has_upper_dev - Check if device is linked to an upper device * @dev: device @@ -4496,10 +4521,149 @@ struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev) } EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu); +static int __netdev_adjacent_dev_insert(struct net_device *dev, + struct net_device *adj_dev, + bool neighbour, bool master, + bool upper) +{ + struct netdev_adjacent *adj; + + adj = __netdev_find_adj(dev, adj_dev, upper); + + if (adj) { + BUG_ON(neighbour); + adj->ref_nr++; + return 0; + } + + adj = kmalloc(sizeof(*adj), GFP_KERNEL); + if (!adj) + return -ENOMEM; + + adj->dev = adj_dev; + adj->master = master; + adj->neighbour = neighbour; + adj->ref_nr = 1; + INIT_LIST_HEAD(&adj->search_list); + + dev_hold(adj_dev); + pr_debug("dev_hold for %s, because of %s link added from %s to %s\n", + adj_dev->name, upper ? "upper" : "lower", dev->name, + adj_dev->name); + + if (!upper) { + list_add_tail_rcu(&adj->list, &dev->lower_dev_list); + return 0; + } + + /* Ensure that master upper link is always the first item in list. */ + if (master) + list_add_rcu(&adj->list, &dev->upper_dev_list); + else + list_add_tail_rcu(&adj->list, &dev->upper_dev_list); + + return 0; +} + +static inline int __netdev_upper_dev_insert(struct net_device *dev, + struct net_device *udev, + bool master, bool neighbour) +{ + return __netdev_adjacent_dev_insert(dev, udev, neighbour, master, + true); +} + +static inline int __netdev_lower_dev_insert(struct net_device *dev, + struct net_device *ldev, + bool neighbour) +{ + return __netdev_adjacent_dev_insert(dev, ldev, neighbour, false, + false); +} + +void __netdev_adjacent_dev_remove(struct net_device *dev, + struct net_device *adj_dev, bool upper) +{ + struct netdev_adjacent *adj; + + if (upper) + adj = __netdev_find_upper(dev, adj_dev); + else + adj = __netdev_find_lower(dev, adj_dev); + + if (!adj) + BUG(); + + if (adj->ref_nr > 1) { + adj->ref_nr--; + return; + } + + list_del_rcu(&adj->list); + pr_debug("dev_put for %s, because of %s link removed from %s to %s\n", + adj_dev->name, upper ? "upper" : "lower", dev->name, + adj_dev->name); + dev_put(adj_dev); + kfree_rcu(adj, rcu); +} + +static inline void __netdev_upper_dev_remove(struct net_device *dev, + struct net_device *udev) +{ + return __netdev_adjacent_dev_remove(dev, udev, true); +} + +static inline void __netdev_lower_dev_remove(struct net_device *dev, + struct net_device *ldev) +{ + return __netdev_adjacent_dev_remove(dev, ldev, false); +} + +int __netdev_adjacent_dev_insert_link(struct net_device *dev, + struct net_device *upper_dev, + bool master, bool neighbour) +{ + int ret; + + ret = __netdev_upper_dev_insert(dev, upper_dev, master, neighbour); + if (ret) + return ret; + + ret = __netdev_lower_dev_insert(upper_dev, dev, neighbour); + if (ret) { + __netdev_upper_dev_remove(dev, upper_dev); + return ret; + } + + return 0; +} + +static inline int __netdev_adjacent_dev_link(struct net_device *dev, + struct net_device *udev) +{ + return __netdev_adjacent_dev_insert_link(dev, udev, false, false); +} + +static inline int __netdev_adjacent_dev_link_neighbour(struct net_device *dev, + struct net_device *udev, + bool master) +{ + return __netdev_adjacent_dev_insert_link(dev, udev, master, true); +} + +void __netdev_adjacent_dev_unlink(struct net_device *dev, + struct net_device *upper_dev) +{ + __netdev_upper_dev_remove(dev, upper_dev); + __netdev_lower_dev_remove(upper_dev, dev); +} + + static int __netdev_upper_dev_link(struct net_device *dev, struct net_device *upper_dev, bool master) { - struct netdev_adjacent *upper; + struct netdev_adjacent *i, *j, *to_i, *to_j; + int ret = 0; ASSERT_RTNL(); @@ -4516,22 +4680,76 @@ static int __netdev_upper_dev_link(struct net_device *dev, if (master && netdev_master_upper_dev_get(dev)) return -EBUSY; - upper = kmalloc(sizeof(*upper), GFP_KERNEL); - if (!upper) - return -ENOMEM; + ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, master); + if (ret) + return ret; - upper->dev = upper_dev; - upper->master = master; - INIT_LIST_HEAD(&upper->search_list); + /* Now that we linked these devs, make all the upper_dev's + * upper_dev_list visible to every dev's lower_dev_list and vice + * versa, and don't forget the devices itself. All of these + * links are non-neighbours. + */ + list_for_each_entry(i, &upper_dev->upper_dev_list, list) { + list_for_each_entry(j, &dev->lower_dev_list, list) { + ret = __netdev_adjacent_dev_link(i->dev, j->dev); + if (ret) + goto rollback_mesh; + } + } + + /* add dev to every upper_dev's upper device */ + list_for_each_entry(i, &upper_dev->upper_dev_list, list) { + ret = __netdev_adjacent_dev_link(dev, i->dev); + if (ret) + goto rollback_upper_mesh; + } + + /* add upper_dev to every dev's lower device */ + list_for_each_entry(i, &dev->lower_dev_list, list) { + ret = __netdev_adjacent_dev_link(i->dev, upper_dev); + if (ret) + goto rollback_lower_mesh; + } - /* Ensure that master upper link is always the first item in list. */ - if (master) - list_add_rcu(&upper->list, &dev->upper_dev_list); - else - list_add_tail_rcu(&upper->list, &dev->upper_dev_list); - dev_hold(upper_dev); call_netdevice_notifiers(NETDEV_CHANGEUPPER, dev); return 0; + +rollback_lower_mesh: + to_i = i; + list_for_each_entry(i, &dev->lower_dev_list, list) { + if (i == to_i) + break; + __netdev_adjacent_dev_unlink(i->dev, upper_dev); + } + + i = NULL; + +rollback_upper_mesh: + to_i = i; + list_for_each_entry(i, &upper_dev->upper_dev_list, list) { + if (i == to_i) + break; + __netdev_adjacent_dev_unlink(dev, i->dev); + } + + i = j = NULL; + +rollback_mesh: + to_i = i; + to_j = j; + list_for_each_entry(i, &dev->lower_dev_list, list) { + list_for_each_entry(j, &upper_dev->upper_dev_list, list) { + if (i == to_i && j == to_j) + break; + __netdev_adjacent_dev_unlink(i->dev, j->dev); + } + if (i == to_i) + break; + } + + __netdev_adjacent_dev_unlink(dev, upper_dev); + + return ret; } /** @@ -4580,16 +4798,28 @@ EXPORT_SYMBOL(netdev_master_upper_dev_link); void netdev_upper_dev_unlink(struct net_device *dev, struct net_device *upper_dev) { - struct netdev_adjacent *upper; - + struct netdev_adjacent *i, *j; ASSERT_RTNL(); - upper = __netdev_find_upper(dev, upper_dev); - if (!upper) - return; - list_del_rcu(&upper->list); - dev_put(upper_dev); - kfree_rcu(upper, rcu); + __netdev_adjacent_dev_unlink(dev, upper_dev); + + /* Here is the tricky part. We must remove all dev's lower + * devices from all upper_dev's upper devices and vice + * versa, to maintain the graph relationship. + */ + list_for_each_entry(i, &dev->lower_dev_list, list) + list_for_each_entry(j, &upper_dev->upper_dev_list, list) + __netdev_adjacent_dev_unlink(i->dev, j->dev); + + /* remove also the devices itself from lower/upper device + * list + */ + list_for_each_entry(i, &dev->lower_dev_list, list) + __netdev_adjacent_dev_unlink(i->dev, upper_dev); + + list_for_each_entry(i, &upper_dev->upper_dev_list, list) + __netdev_adjacent_dev_unlink(dev, i->dev); + call_netdevice_notifiers(NETDEV_CHANGEUPPER, dev); } EXPORT_SYMBOL(netdev_upper_dev_unlink); @@ -5850,6 +6080,7 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name, INIT_LIST_HEAD(&dev->unreg_list); INIT_LIST_HEAD(&dev->link_watch_list); INIT_LIST_HEAD(&dev->upper_dev_list); + INIT_LIST_HEAD(&dev->lower_dev_list); dev->priv_flags = IFF_XMIT_DST_RELEASE; setup(dev); |