From: Nora Schiffer <[email protected]> batman-adv is using netdev notifiers to create a hard_iface struct for every Ethernet-like netdev in the system. These hardifs are tracked in a global linked list, which results in a few performance issues:
Lookups in this list are O(n) in the total number of netdevs. As a hardif is looked up when a netdev is removed, this also takes O(n) in the number of netdevs, and removing n netdevs may take O(n^2). This slowdown will always happen when the batman-adv module is loaded, no mesh needs to be active. With the hardif being referenced as iflink private data, the global list is only needed for hardifs that are *not* part of a mesh (that is, the hardif is unused). To prepare for removing the global list, only create a hardif struct when an interface is added to a mesh and destroy it on removal. As adding/removing and enabling/disabling a hardif become one and the same, batadv_hardif_add_interface() is merged into batadv_hardif_enable_interface(), and batadv_hardif_remove_interface() can be dropped altogether. Signed-off-by: Nora Schiffer <[email protected]> Signed-off-by: Sven Eckelmann <[email protected]> Signed-off-by: Simon Wunderlich <[email protected]> --- net/batman-adv/hard-interface.c | 120 +++++++++++--------------------- net/batman-adv/hard-interface.h | 2 +- net/batman-adv/mesh-interface.c | 13 +--- 3 files changed, 44 insertions(+), 91 deletions(-) diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c index 03d01c20a9548..9c9a892d22c6b 100644 --- a/net/batman-adv/hard-interface.c +++ b/net/batman-adv/hard-interface.c @@ -723,33 +723,58 @@ batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface) } /** - * batadv_hardif_enable_interface() - Enslave hard interface to mesh interface - * @hard_iface: hard interface to add to mesh interface + * batadv_hardif_enable_interface() - Enslave interface to mesh interface + * @net_dev: netdev struct of the interface to add to mesh interface * @mesh_iface: netdev struct of the mesh interface * * Return: 0 on success or negative error number in case of failure */ -int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface, +int batadv_hardif_enable_interface(struct net_device *net_dev, struct net_device *mesh_iface) { struct batadv_priv *bat_priv; __be16 ethertype = htons(ETH_P_BATMAN); int max_header_len = batadv_max_header_len(); + struct batadv_hard_iface *hard_iface; unsigned int required_mtu; unsigned int hardif_mtu; bool fragmentation; int ret; - hardif_mtu = READ_ONCE(hard_iface->net_dev->mtu); + ASSERT_RTNL(); + + if (!batadv_is_valid_iface(net_dev)) + return -EINVAL; + + hardif_mtu = READ_ONCE(net_dev->mtu); required_mtu = READ_ONCE(mesh_iface->mtu) + max_header_len; if (hardif_mtu < ETH_MIN_MTU + max_header_len) return -EINVAL; - if (hard_iface->if_status != BATADV_IF_NOT_IN_USE) - goto out; + hard_iface = kzalloc_obj(*hard_iface, GFP_ATOMIC); + if (!hard_iface) + return -ENOMEM; + + netdev_hold(net_dev, &hard_iface->dev_tracker, GFP_ATOMIC); + hard_iface->net_dev = net_dev; + + hard_iface->if_status = BATADV_IF_INACTIVE; + + INIT_LIST_HEAD(&hard_iface->list); + INIT_HLIST_HEAD(&hard_iface->neigh_list); - kref_get(&hard_iface->refcount); + mutex_init(&hard_iface->bat_iv.ogm_buff_mutex); + spin_lock_init(&hard_iface->neigh_list_lock); + kref_init(&hard_iface->refcount); + + hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT; + if (batadv_is_wifi_hardif(hard_iface)) + hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS; + + WRITE_ONCE(hard_iface->hop_penalty, 0); + + batadv_v_hardif_init(hard_iface); netdev_hold(mesh_iface, &hard_iface->meshif_dev_tracker, GFP_ATOMIC); hard_iface->mesh_iface = mesh_iface; @@ -764,9 +789,6 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface, if (ret < 0) goto err_upper; - hard_iface->if_status = BATADV_IF_INACTIVE; - - kref_get(&hard_iface->refcount); hard_iface->batman_adv_ptype.type = ethertype; hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv; hard_iface->batman_adv_ptype.dev = hard_iface->net_dev; @@ -802,7 +824,9 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface, if (bat_priv->algo_ops->iface.enabled) bat_priv->algo_ops->iface.enabled(hard_iface); -out: + list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list); + batadv_hardif_generation++; + return 0; err_upper: @@ -823,15 +847,19 @@ void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface) struct batadv_priv *bat_priv = netdev_priv(hard_iface->mesh_iface); struct batadv_hard_iface *primary_if = NULL; + ASSERT_RTNL(); + batadv_hardif_deactivate_interface(hard_iface); if (hard_iface->if_status != BATADV_IF_INACTIVE) goto out; + list_del_rcu(&hard_iface->list); + batadv_hardif_generation++; + batadv_info(hard_iface->mesh_iface, "Removing interface: %s\n", hard_iface->net_dev->name); dev_remove_pack(&hard_iface->batman_adv_ptype); - batadv_hardif_put(hard_iface); primary_if = batadv_primary_if_get_selected(bat_priv); if (hard_iface == primary_if) { @@ -844,7 +872,7 @@ void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface) } bat_priv->algo_ops->iface.disable(hard_iface); - hard_iface->if_status = BATADV_IF_NOT_IN_USE; + hard_iface->if_status = BATADV_IF_TO_BE_REMOVED; /* delete all references to this hard_iface */ batadv_purge_orig_ref(bat_priv); @@ -865,63 +893,6 @@ void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface) batadv_hardif_put(primary_if); } -static struct batadv_hard_iface * -batadv_hardif_add_interface(struct net_device *net_dev) -{ - struct batadv_hard_iface *hard_iface; - - ASSERT_RTNL(); - - if (!batadv_is_valid_iface(net_dev)) - return NULL; - - hard_iface = kzalloc_obj(*hard_iface, GFP_ATOMIC); - if (!hard_iface) - return NULL; - - netdev_hold(net_dev, &hard_iface->dev_tracker, GFP_ATOMIC); - hard_iface->net_dev = net_dev; - - hard_iface->mesh_iface = NULL; - hard_iface->if_status = BATADV_IF_NOT_IN_USE; - - INIT_LIST_HEAD(&hard_iface->list); - INIT_HLIST_HEAD(&hard_iface->neigh_list); - - mutex_init(&hard_iface->bat_iv.ogm_buff_mutex); - spin_lock_init(&hard_iface->neigh_list_lock); - kref_init(&hard_iface->refcount); - - hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT; - if (batadv_is_wifi_hardif(hard_iface)) - hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS; - - WRITE_ONCE(hard_iface->hop_penalty, 0); - - batadv_v_hardif_init(hard_iface); - - kref_get(&hard_iface->refcount); - list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list); - batadv_hardif_generation++; - - return hard_iface; -} - -static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface) -{ - ASSERT_RTNL(); - - /* first deactivate interface */ - if (hard_iface->if_status != BATADV_IF_NOT_IN_USE) - batadv_hardif_disable_interface(hard_iface); - - if (hard_iface->if_status != BATADV_IF_NOT_IN_USE) - return; - - hard_iface->if_status = BATADV_IF_TO_BE_REMOVED; - batadv_hardif_put(hard_iface); -} - /** * batadv_hard_if_event_meshif() - Handle events for mesh interfaces * @event: NETDEV_* event to handle @@ -1082,10 +1053,6 @@ static int batadv_hard_if_event(struct notifier_block *this, batadv_wifi_net_device_event(event, net_dev); hard_iface = batadv_hardif_get_by_netdev(net_dev); - if (!hard_iface && (event == NETDEV_REGISTER || - event == NETDEV_POST_TYPE_CHANGE)) - hard_iface = batadv_hardif_add_interface(net_dev); - if (!hard_iface) goto out; @@ -1099,10 +1066,7 @@ static int batadv_hard_if_event(struct notifier_block *this, break; case NETDEV_UNREGISTER: case NETDEV_PRE_TYPE_CHANGE: - list_del_rcu(&hard_iface->list); - batadv_hardif_generation++; - - batadv_hardif_remove_interface(hard_iface); + batadv_hardif_disable_interface(hard_iface); break; case NETDEV_CHANGEMTU: if (hard_iface->mesh_iface) diff --git a/net/batman-adv/hard-interface.h b/net/batman-adv/hard-interface.h index af31696c39780..6d72dbdd5c203 100644 --- a/net/batman-adv/hard-interface.h +++ b/net/batman-adv/hard-interface.h @@ -75,7 +75,7 @@ u32 batadv_hardif_get_wifi_flags(struct batadv_hard_iface *hard_iface); bool batadv_is_wifi_hardif(struct batadv_hard_iface *hard_iface); struct batadv_hard_iface* batadv_hardif_get_by_netdev(const struct net_device *net_dev); -int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface, +int batadv_hardif_enable_interface(struct net_device *net_dev, struct net_device *mesh_iface); void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface); int batadv_hardif_min_mtu(struct net_device *mesh_iface); diff --git a/net/batman-adv/mesh-interface.c b/net/batman-adv/mesh-interface.c index 44026810b99ce..a37368c1f5b55 100644 --- a/net/batman-adv/mesh-interface.c +++ b/net/batman-adv/mesh-interface.c @@ -836,18 +836,7 @@ static int batadv_meshif_slave_add(struct net_device *dev, struct net_device *slave_dev, struct netlink_ext_ack *extack) { - struct batadv_hard_iface *hard_iface; - int ret = -EINVAL; - - hard_iface = batadv_hardif_get_by_netdev(slave_dev); - if (!hard_iface || hard_iface->mesh_iface) - goto out; - - ret = batadv_hardif_enable_interface(hard_iface, dev); - -out: - batadv_hardif_put(hard_iface); - return ret; + return batadv_hardif_enable_interface(slave_dev, dev); } /** -- 2.47.3
