This patch abstracts the forward packet creation and destruction in the functions batadv_forw_packet_alloc() and batadv_forw_packet_free().
That way there is less complexity to wrap the head around when freeing a forward packet.
For instance broadcast/ogm queue left counting will not need to be done with "manual" atomic_inc/dec calls anymore, which should greatly reduce the risk of having or reintroducing another queue-left-miscounting again.
Signed-off-by: Linus Lüssing linus.luessing@web.de --- bat_iv_ogm.c | 32 ++++-------------- send.c | 103 +++++++++++++++++++++++++++++++++++++++++----------------- send.h | 5 +++ types.h | 1 + 4 files changed, 86 insertions(+), 55 deletions(-)
diff --git a/bat_iv_ogm.c b/bat_iv_ogm.c index 42b7a94..c113627 100644 --- a/bat_iv_ogm.c +++ b/bat_iv_ogm.c @@ -427,26 +427,13 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff, struct batadv_forw_packet *forw_packet_aggr; unsigned char *skb_buff; unsigned int skb_size; + atomic_t *queue_left = own_packet ? NULL : &bat_priv->batman_queue_left;
- if (!atomic_inc_not_zero(&if_incoming->refcount)) + forw_packet_aggr = batadv_forw_packet_alloc(if_incoming, queue_left, + bat_priv); + if (!forw_packet_aggr) return;
- /* own packet should always be scheduled */ - if (!own_packet) { - if (!batadv_atomic_dec_not_zero(&bat_priv->batman_queue_left)) { - batadv_dbg(BATADV_DBG_BATMAN, bat_priv, - "batman packet queue full\n"); - goto out; - } - } - - forw_packet_aggr = kmalloc(sizeof(*forw_packet_aggr), GFP_ATOMIC); - if (!forw_packet_aggr) { - if (!own_packet) - atomic_inc(&bat_priv->batman_queue_left); - goto out; - } - if ((atomic_read(&bat_priv->aggregated_ogms)) && (packet_len < BATADV_MAX_AGGREGATION_BYTES)) skb_size = BATADV_MAX_AGGREGATION_BYTES; @@ -457,10 +444,8 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff,
forw_packet_aggr->skb = dev_alloc_skb(skb_size); if (!forw_packet_aggr->skb) { - if (!own_packet) - atomic_inc(&bat_priv->batman_queue_left); - kfree(forw_packet_aggr); - goto out; + batadv_forw_packet_free(forw_packet_aggr); + return; } skb_reserve(forw_packet_aggr->skb, ETH_HLEN + NET_IP_ALIGN);
@@ -471,7 +456,6 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff, memcpy(skb_buff, packet_buff, packet_len);
forw_packet_aggr->own = own_packet; - forw_packet_aggr->if_incoming = if_incoming; forw_packet_aggr->num_packets = 0; forw_packet_aggr->direct_link_flags = BATADV_NO_FLAGS; forw_packet_aggr->send_time = send_time; @@ -491,10 +475,6 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff, queue_delayed_work(batadv_event_workqueue, &forw_packet_aggr->delayed_work, send_time - jiffies); - - return; -out: - batadv_hardif_free_ref(if_incoming); }
/* aggregate a new packet into the existing ogm packet */ diff --git a/send.c b/send.c index 2d539d6..36a1c4c 100644 --- a/send.c +++ b/send.c @@ -138,12 +138,77 @@ void batadv_schedule_bat_ogm(struct batadv_hard_iface *hard_iface) bat_priv->bat_algo_ops->bat_ogm_schedule(hard_iface); }
-static void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet) +/** + * batadv_forw_packet_alloc - Allocates a forwarding packet + * @if_incoming: The (optional) if_incoming to be grabbed + * @queue_left: The (optional) queue counter to decrease + * @bat_priv: The bat_priv for the mesh of this forw_packet + * + * Allocates a forwarding packet and tries to get a reference to the + * (optional) if_incoming and queue_left. If queue_left is NULL then + * bat_priv is optional, too. + * + * On success, returns the allocated forwarding packet. Otherwise returns + * NULL. + */ +struct batadv_forw_packet * +batadv_forw_packet_alloc(struct batadv_hard_iface *if_incoming, + atomic_t *queue_left, + struct batadv_priv *bat_priv) +{ + struct batadv_forw_packet *forw_packet = NULL; + + if (if_incoming && !atomic_inc_not_zero(&if_incoming->refcount)) + goto out; + + if (queue_left && !batadv_atomic_dec_not_zero(queue_left)) { + if (queue_left == &bat_priv->bcast_queue_left) + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "bcast queue full\n"); + else if (queue_left == &bat_priv->batman_queue_left) + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "batman queue full\n"); + else + batadv_dbg(BATADV_DBG_BATMAN, bat_priv, + "a mysterious queue is full\n"); + goto err; + } + + forw_packet = kmalloc(sizeof(struct batadv_forw_packet), GFP_ATOMIC); + if (!forw_packet) + goto err2; + + forw_packet->skb = NULL; + forw_packet->if_incoming = if_incoming; + forw_packet->queue_left = queue_left; + + goto out; + +err2: + if (queue_left) + atomic_inc(queue_left); +err: + if (if_incoming) + batadv_hardif_free_ref(if_incoming); +out: + return forw_packet; +} + +/** + * batadv_forw_packet_free - Frees a forwarding packet + * @forw_packet: The packet to free + * + * This frees a forwarding packet and releases any ressources it might + * have claimed. + */ +void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet) { if (forw_packet->skb) kfree_skb(forw_packet->skb); if (forw_packet->if_incoming) batadv_hardif_free_ref(forw_packet->if_incoming); + if (forw_packet->queue_left) + atomic_inc(forw_packet->queue_left); kfree(forw_packet); }
@@ -177,25 +242,21 @@ int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv, const struct sk_buff *skb, unsigned long delay) { - struct batadv_hard_iface *primary_if = NULL; + struct batadv_hard_iface *primary_if; struct batadv_forw_packet *forw_packet; struct batadv_bcast_packet *bcast_packet; struct sk_buff *newskb;
- if (!batadv_atomic_dec_not_zero(&bat_priv->bcast_queue_left)) { - batadv_dbg(BATADV_DBG_BATMAN, bat_priv, - "bcast packet queue full\n"); - goto out; - } - primary_if = batadv_primary_if_get_selected(bat_priv); if (!primary_if) - goto out_and_inc; - - forw_packet = kmalloc(sizeof(*forw_packet), GFP_ATOMIC); + goto out;
+ forw_packet = batadv_forw_packet_alloc(primary_if, + &bat_priv->bcast_queue_left, + bat_priv); + batadv_hardif_free_ref(primary_if); if (!forw_packet) - goto out_and_inc; + goto out;
newskb = skb_copy(skb, GFP_ATOMIC); if (!newskb) @@ -208,7 +269,6 @@ int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv, skb_reset_mac_header(newskb);
forw_packet->skb = newskb; - forw_packet->if_incoming = primary_if;
/* how often did we send the bcast packet ? */ forw_packet->num_packets = 0; @@ -220,12 +280,8 @@ int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv, return NETDEV_TX_OK;
packet_free: - kfree(forw_packet); -out_and_inc: - atomic_inc(&bat_priv->bcast_queue_left); + batadv_forw_packet_free(forw_packet); out: - if (primary_if) - batadv_hardif_free_ref(primary_if); return NETDEV_TX_BUSY; }
@@ -282,7 +338,6 @@ static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
out: batadv_forw_packet_free(forw_packet); - atomic_inc(&bat_priv->bcast_queue_left); }
void batadv_send_outstanding_bat_ogm_packet(struct work_struct *work) @@ -312,10 +367,6 @@ void batadv_send_outstanding_bat_ogm_packet(struct work_struct *work) batadv_schedule_bat_ogm(forw_packet->if_incoming);
out: - /* don't count own packet */ - if (!forw_packet->own) - atomic_inc(&bat_priv->batman_queue_left); - batadv_forw_packet_free(forw_packet); }
@@ -356,9 +407,6 @@ batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
if (pending) { hlist_del(&forw_packet->list); - if (!forw_packet->own) - atomic_inc(&bat_priv->bcast_queue_left); - batadv_forw_packet_free(forw_packet); } } @@ -385,9 +433,6 @@ batadv_purge_outstanding_packets(struct batadv_priv *bat_priv,
if (pending) { hlist_del(&forw_packet->list); - if (!forw_packet->own) - atomic_inc(&bat_priv->batman_queue_left); - batadv_forw_packet_free(forw_packet); } } diff --git a/send.h b/send.h index 38e662f..7004486 100644 --- a/send.h +++ b/send.h @@ -27,6 +27,11 @@ bool batadv_send_skb_to_orig(struct sk_buff *skb, struct batadv_orig_node *orig_node, struct batadv_hard_iface *recv_if); void batadv_schedule_bat_ogm(struct batadv_hard_iface *hard_iface); +struct batadv_forw_packet *batadv_forw_packet_alloc( + struct batadv_hard_iface *if_incoming, + atomic_t *queue_left, + struct batadv_priv *bat_priv); +void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet); int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv, const struct sk_buff *skb, unsigned long delay); diff --git a/types.h b/types.h index 5f542bd..8c28142 100644 --- a/types.h +++ b/types.h @@ -863,6 +863,7 @@ struct batadv_forw_packet { uint8_t num_packets; struct delayed_work delayed_work; struct batadv_hard_iface *if_incoming; + atomic_t *queue_left; };
/**