diff options
| -rw-r--r-- | net/batman-adv/bat_iv_ogm.c | 19 | ||||
| -rw-r--r-- | net/batman-adv/send.c | 283 | ||||
| -rw-r--r-- | net/batman-adv/send.h | 5 | ||||
| -rw-r--r-- | net/batman-adv/types.h | 2 |
4 files changed, 227 insertions, 82 deletions
diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index 36d8818..f00f666 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -717,17 +717,10 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff, if (direct_link) forw_packet_aggr->direct_link_flags |= 1; - /* add new packet to packet list */ - spin_lock_bh(&bat_priv->forw_bat_list_lock); - hlist_add_head(&forw_packet_aggr->list, &bat_priv->forw_bat_list); - spin_unlock_bh(&bat_priv->forw_bat_list_lock); - - /* start timer for this packet */ INIT_DELAYED_WORK(&forw_packet_aggr->delayed_work, batadv_iv_send_outstanding_bat_ogm_packet); - queue_delayed_work(batadv_event_workqueue, - &forw_packet_aggr->delayed_work, - send_time - jiffies); + + batadv_forw_packet_ogmv1_queue(bat_priv, forw_packet_aggr, send_time); } /* aggregate a new packet into the existing ogm packet */ @@ -1789,9 +1782,6 @@ static void batadv_iv_send_outstanding_bat_ogm_packet(struct work_struct *work) forw_packet = container_of(delayed_work, struct batadv_forw_packet, delayed_work); bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface); - spin_lock_bh(&bat_priv->forw_bat_list_lock); - hlist_del(&forw_packet->list); - spin_unlock_bh(&bat_priv->forw_bat_list_lock); if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) { dropped = true; @@ -1813,7 +1803,10 @@ static void batadv_iv_send_outstanding_bat_ogm_packet(struct work_struct *work) batadv_iv_ogm_schedule(forw_packet->if_incoming); out: - batadv_forw_packet_free(forw_packet, dropped); + /* do we get something for free()? */ + if (batadv_forw_packet_steal(forw_packet, + &bat_priv->forw_bat_list_lock)) + batadv_forw_packet_free(forw_packet, dropped); } static int batadv_iv_ogm_receive(struct sk_buff *skb, diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c index 9ea272e..49021b7 100644 --- a/net/batman-adv/send.c +++ b/net/batman-adv/send.c @@ -19,6 +19,7 @@ #include "main.h" #include <linux/atomic.h> +#include <linux/bug.h> #include <linux/byteorder/generic.h> #include <linux/errno.h> #include <linux/etherdevice.h> @@ -520,6 +521,8 @@ batadv_forw_packet_alloc(struct batadv_hard_iface *if_incoming, if (if_outgoing) kref_get(&if_outgoing->refcount); + INIT_HLIST_NODE(&forw_packet->list); + INIT_HLIST_NODE(&forw_packet->cleanup_list); forw_packet->skb = NULL; forw_packet->queue_left = queue_left; forw_packet->if_incoming = if_incoming; @@ -535,19 +538,191 @@ err: return NULL; } +/** + * batadv_forw_packet_was_stolen - check whether someone stole this packet + * @forw_packet: the forwarding packet to check + * + * This function checks whether the given forwarding packet was claimed by + * someone else for free(). + * + * Return: True if someone stole it, false otherwise. + */ +static bool +batadv_forw_packet_was_stolen(struct batadv_forw_packet *forw_packet) +{ + return !hlist_unhashed(&forw_packet->cleanup_list); +} + +/** + * batadv_forw_packet_steal - claim a forw_packet for free() + * @forw_packet: the forwarding packet to steal + * @lock: a key to the store to steal from (e.g. forw_{bat,bcast}_list_lock) + * + * This function tries to steal a specific forw_packet from global + * visibility for the purpose of getting it for free(). That means + * the caller is *not* allowed to requeue it afterwards. + * + * Return: True if stealing was successful. False if someone else stole it + * before us. + */ +bool batadv_forw_packet_steal(struct batadv_forw_packet *forw_packet, + spinlock_t *lock) +{ + /* did purging routine steal it earlier? */ + spin_lock_bh(lock); + if (batadv_forw_packet_was_stolen(forw_packet)) { + spin_unlock_bh(lock); + return false; + } + + hlist_del_init(&forw_packet->list); + + /* Just to spot misuse of this function */ + hlist_add_fake(&forw_packet->cleanup_list); + + spin_unlock_bh(lock); + return true; +} + +/** + * batadv_forw_packet_list_steal - claim a list of forward packets for free() + * @forw_list: the to be stolen forward packets + * @cleanup_list: a backup pointer, to be able to dispose the packet later + * @hard_iface: the interface to steal forward packets from + * + * This function claims responsibility to free any forw_packet queued on the + * given hard_iface. If hard_iface is NULL forwarding packets on all hard + * interfaces will be claimed. + * + * The packets are being moved from the forw_list to the cleanup_list and + * by that allows already running threads to notice the claiming. + */ static void -_batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv, - struct batadv_forw_packet *forw_packet, - unsigned long send_time) +batadv_forw_packet_list_steal(struct hlist_head *forw_list, + struct hlist_head *cleanup_list, + const struct batadv_hard_iface *hard_iface) { - /* add new packet to packet list */ - spin_lock_bh(&bat_priv->forw_bcast_list_lock); - hlist_add_head(&forw_packet->list, &bat_priv->forw_bcast_list); - spin_unlock_bh(&bat_priv->forw_bcast_list_lock); + struct batadv_forw_packet *forw_packet; + struct hlist_node *safe_tmp_node; + + hlist_for_each_entry_safe(forw_packet, safe_tmp_node, + forw_list, list) { + /* if purge_outstanding_packets() was called with an argument + * we delete only packets belonging to the given interface + */ + if (hard_iface && + (forw_packet->if_incoming != hard_iface) && + (forw_packet->if_outgoing != hard_iface)) + continue; + + hlist_del(&forw_packet->list); + hlist_add_head(&forw_packet->cleanup_list, cleanup_list); + } +} + +/** + * batadv_forw_packet_list_free - free a list of forward packets + * @head: a list of to be freed forw_packets + * + * This function cancels the scheduling of any packet in the provided list, + * waits for any possibly running packet forwarding thread to finish and + * finally, safely frees this forward packet. + * + * This function might sleep. + */ +static void batadv_forw_packet_list_free(struct hlist_head *head) +{ + struct batadv_forw_packet *forw_packet; + struct hlist_node *safe_tmp_node; + + hlist_for_each_entry_safe(forw_packet, safe_tmp_node, head, + cleanup_list) { + cancel_delayed_work_sync(&forw_packet->delayed_work); - /* start timer for this packet */ - queue_delayed_work(batadv_event_workqueue, &forw_packet->delayed_work, - send_time); + hlist_del(&forw_packet->cleanup_list); + batadv_forw_packet_free(forw_packet, true); + } +} + +/** + * batadv_forw_packet_queue - try to queue a forwarding packet + * @forw_packet: the forwarding packet to queue + * @lock: a key to the store (e.g. forw_{bat,bcast}_list_lock) + * @head: the shelve to queue it on (e.g. forw_{bat,bcast}_list) + * @send_time: timestamp (jiffies) when the packet is to be sent + * + * This function tries to (re)queue a forwarding packet. Requeuing + * is prevented if the according interface is shutting down + * (e.g. if batadv_forw_packet_list_steal() was called for this + * packet earlier). + * + * Calling batadv_forw_packet_queue() after a call to + * batadv_forw_packet_steal() is forbidden! + * + * Caller needs to ensure that forw_packet->delayed_work was initialized. + */ +static void batadv_forw_packet_queue(struct batadv_forw_packet *forw_packet, + spinlock_t *lock, struct hlist_head *head, + unsigned long send_time) +{ + spin_lock_bh(lock); + + /* did purging routine steal it from us? */ + if (batadv_forw_packet_was_stolen(forw_packet)) { + /* If you got it for free() without trouble, then + * don't get back into the queue after stealing... + */ + WARN_ONCE(hlist_fake(&forw_packet->cleanup_list), + "Requeuing after batadv_forw_packet_steal() not allowed!\n"); + + spin_unlock_bh(lock); + return; + } + + hlist_del_init(&forw_packet->list); + hlist_add_head(&forw_packet->list, head); + + queue_delayed_work(batadv_event_workqueue, + &forw_packet->delayed_work, + send_time - jiffies); + spin_unlock_bh(lock); +} + +/** + * batadv_forw_packet_bcast_queue - try to queue a broadcast packet + * @bat_priv: the bat priv with all the soft interface information + * @forw_packet: the forwarding packet to queue + * @send_time: timestamp (jiffies) when the packet is to be sent + * + * This function tries to (re)queue a broadcast packet. + * + * Caller needs to ensure that forw_packet->delayed_work was initialized. + */ +static void +batadv_forw_packet_bcast_queue(struct batadv_priv *bat_priv, + struct batadv_forw_packet *forw_packet, + unsigned long send_time) +{ + batadv_forw_packet_queue(forw_packet, &bat_priv->forw_bcast_list_lock, + &bat_priv->forw_bcast_list, send_time); +} + +/** + * batadv_forw_packet_ogmv1_queue - try to queue an OGMv1 packet + * @bat_priv: the bat priv with all the soft interface information + * @forw_packet: the forwarding packet to queue + * @send_time: timestamp (jiffies) when the packet is to be sent + * + * This function tries to (re)queue an OGMv1 packet. + * + * Caller needs to ensure that forw_packet->delayed_work was initialized. + */ +void batadv_forw_packet_ogmv1_queue(struct batadv_priv *bat_priv, + struct batadv_forw_packet *forw_packet, + unsigned long send_time) +{ + batadv_forw_packet_queue(forw_packet, &bat_priv->forw_bat_list_lock, + &bat_priv->forw_bat_list, send_time); } /** @@ -600,7 +775,7 @@ int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv, INIT_DELAYED_WORK(&forw_packet->delayed_work, batadv_send_outstanding_bcast_packet); - _batadv_add_bcast_packet_to_list(bat_priv, forw_packet, delay); + batadv_forw_packet_bcast_queue(bat_priv, forw_packet, jiffies + delay); return NETDEV_TX_OK; err_packet_free: @@ -619,6 +794,7 @@ static void batadv_send_outstanding_bcast_packet(struct work_struct *work) struct sk_buff *skb1; struct net_device *soft_iface; struct batadv_priv *bat_priv; + unsigned long send_time = jiffies + msecs_to_jiffies(5); bool dropped = false; u8 *neigh_addr; u8 *orig_neigh; @@ -630,10 +806,6 @@ static void batadv_send_outstanding_bcast_packet(struct work_struct *work) soft_iface = forw_packet->if_incoming->soft_iface; bat_priv = netdev_priv(soft_iface); - spin_lock_bh(&bat_priv->forw_bcast_list_lock); - hlist_del(&forw_packet->list); - spin_unlock_bh(&bat_priv->forw_bcast_list_lock); - if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) { dropped = true; goto out; @@ -714,22 +886,34 @@ static void batadv_send_outstanding_bcast_packet(struct work_struct *work) /* if we still have some more bcasts to send */ if (forw_packet->num_packets < BATADV_NUM_BCASTS_MAX) { - _batadv_add_bcast_packet_to_list(bat_priv, forw_packet, - msecs_to_jiffies(5)); + batadv_forw_packet_bcast_queue(bat_priv, forw_packet, + send_time); return; } out: - batadv_forw_packet_free(forw_packet, dropped); + /* do we get something for free()? */ + if (batadv_forw_packet_steal(forw_packet, + &bat_priv->forw_bcast_list_lock)) + batadv_forw_packet_free(forw_packet, dropped); } +/** + * batadv_purge_outstanding_packets - stop/purge scheduled bcast/OGMv1 packets + * @bat_priv: the bat priv with all the soft interface information + * @hard_iface: the hard interface to cancel and purge bcast/ogm packets on + * + * This method cancels and purges any broadcast and OGMv1 packet on the given + * hard_iface. If hard_iface is NULL, broadcast and OGMv1 packets on all hard + * interfaces will be canceled and purged. + * + * This function might sleep. + */ void batadv_purge_outstanding_packets(struct batadv_priv *bat_priv, const struct batadv_hard_iface *hard_iface) { - struct batadv_forw_packet *forw_packet; - struct hlist_node *safe_tmp_node; - bool pending; + struct hlist_head head = HLIST_HEAD_INIT; if (hard_iface) batadv_dbg(BATADV_DBG_BATMAN, bat_priv, @@ -739,57 +923,18 @@ batadv_purge_outstanding_packets(struct batadv_priv *bat_priv, batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "purge_outstanding_packets()\n"); - /* free bcast list */ + /* claim bcast list for free() */ spin_lock_bh(&bat_priv->forw_bcast_list_lock); - hlist_for_each_entry_safe(forw_packet, safe_tmp_node, - &bat_priv->forw_bcast_list, list) { - /* if purge_outstanding_packets() was called with an argument - * we delete only packets belonging to the given interface - */ - if ((hard_iface) && - (forw_packet->if_incoming != hard_iface) && - (forw_packet->if_outgoing != hard_iface)) - continue; - - spin_unlock_bh(&bat_priv->forw_bcast_list_lock); - - /* batadv_send_outstanding_bcast_packet() will lock the list to - * delete the item from the list - */ - pending = cancel_delayed_work_sync(&forw_packet->delayed_work); - spin_lock_bh(&bat_priv->forw_bcast_list_lock); - - if (pending) { - hlist_del(&forw_packet->list); - batadv_forw_packet_free(forw_packet, true); - } - } + batadv_forw_packet_list_steal(&bat_priv->forw_bcast_list, &head, + hard_iface); spin_unlock_bh(&bat_priv->forw_bcast_list_lock); - /* free batman packet list */ + /* claim batman packet list for free() */ spin_lock_bh(&bat_priv->forw_bat_list_lock); - hlist_for_each_entry_safe(forw_packet, safe_tmp_node, - &bat_priv->forw_bat_list, list) { - /* if purge_outstanding_packets() was called with an argument - * we delete only packets belonging to the given interface - */ - if ((hard_iface) && - (forw_packet->if_incoming != hard_iface) && - (forw_packet->if_outgoing != hard_iface)) - continue; - - spin_unlock_bh(&bat_priv->forw_bat_list_lock); - - /* send_outstanding_bat_packet() will lock the list to - * delete the item from the list - */ - pending = cancel_delayed_work_sync(&forw_packet->delayed_work); - spin_lock_bh(&bat_priv->forw_bat_list_lock); - - if (pending) { - hlist_del(&forw_packet->list); - batadv_forw_packet_free(forw_packet, true); - } - } + batadv_forw_packet_list_steal(&bat_priv->forw_bat_list, &head, + hard_iface); spin_unlock_bh(&bat_priv->forw_bat_list_lock); + + /* then cancel or wait for packet workers to finish and free */ + batadv_forw_packet_list_free(&head); } diff --git a/net/batman-adv/send.h b/net/batman-adv/send.h index c580194..a94e1e8 100644 --- a/net/batman-adv/send.h +++ b/net/batman-adv/send.h @@ -21,6 +21,7 @@ #include "main.h" #include <linux/compiler.h> +#include <linux/spinlock.h> #include <linux/types.h> #include "packet.h" @@ -34,6 +35,10 @@ batadv_forw_packet_alloc(struct batadv_hard_iface *if_incoming, struct batadv_hard_iface *if_outgoing, atomic_t *queue_left, struct batadv_priv *bat_priv); +bool batadv_forw_packet_steal(struct batadv_forw_packet *packet, spinlock_t *l); +void batadv_forw_packet_ogmv1_queue(struct batadv_priv *bat_priv, + struct batadv_forw_packet *forw_packet, + unsigned long send_time); int batadv_send_skb_to_orig(struct sk_buff *skb, struct batadv_orig_node *orig_node, diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index caa00a5..e913aee 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -1385,6 +1385,7 @@ struct batadv_skb_cb { /** * struct batadv_forw_packet - structure for bcast packets to be sent/forwarded * @list: list node for batadv_priv::forw_{bat,bcast}_list + * @cleanup_list: list node for purging functions * @send_time: execution time for delayed_work (packet sending) * @own: bool for locally generated packets (local OGMs are re-scheduled after * sending) @@ -1401,6 +1402,7 @@ struct batadv_skb_cb { */ struct batadv_forw_packet { struct hlist_node list; + struct hlist_node cleanup_list; unsigned long send_time; u8 own; struct sk_buff *skb; |
