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batman-adv: Axe 'aggr_list_lock' 

'aggr_list.lock' can safely be used in place of another explicit spinlock
when access to 'aggr_list' has to be guarded.

This avoids to take 2 locks, knowing that the 2nd one is always successful.

Now that the 'aggr_list.lock' is handled explicitly, the lock-free
__sbk_something() variants should be used when dealing with 'aggr_list'.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
This commit is contained in:
Christophe JAILLET 2019-10-31 09:52:40 +01:00 committed by Simon Wunderlich
parent 9044854e4b
commit baa1e8a0da
3 changed files with 15 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
net/batman-adv/bat_v.c
View File

@ -1085,7 +1085,6 @@ void batadv_v_hardif_init(struct batadv_hard_iface *hard_iface)
hard_iface->bat_v.aggr_len = 0; hard_iface->bat_v.aggr_len = 0;
skb_queue_head_init(&hard_iface->bat_v.aggr_list); skb_queue_head_init(&hard_iface->bat_v.aggr_list);
spin_lock_init(&hard_iface->bat_v.aggr_list_lock);
INIT_DELAYED_WORK(&hard_iface->bat_v.aggr_wq, INIT_DELAYED_WORK(&hard_iface->bat_v.aggr_wq,
batadv_v_ogm_aggr_work); batadv_v_ogm_aggr_work);
} }

30
net/batman-adv/bat_v_ogm.c
View File

@ -152,7 +152,7 @@ static unsigned int batadv_v_ogm_len(struct sk_buff *skb)
* @skb: the OGM to check * @skb: the OGM to check
* @hard_iface: the interface to use to send the OGM * @hard_iface: the interface to use to send the OGM
* *
* Caller needs to hold the hard_iface->bat_v.aggr_list_lock. * Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
* *
* Return: True, if the given OGMv2 packet still fits, false otherwise. * Return: True, if the given OGMv2 packet still fits, false otherwise.
*/ */
@ -163,7 +163,7 @@ static bool batadv_v_ogm_queue_left(struct sk_buff *skb,
BATADV_MAX_AGGREGATION_BYTES); BATADV_MAX_AGGREGATION_BYTES);
unsigned int ogm_len = batadv_v_ogm_len(skb); unsigned int ogm_len = batadv_v_ogm_len(skb);
lockdep_assert_held(&hard_iface->bat_v.aggr_list_lock); lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
return hard_iface->bat_v.aggr_len + ogm_len <= max; return hard_iface->bat_v.aggr_len + ogm_len <= max;
} }
@ -174,13 +174,13 @@ static bool batadv_v_ogm_queue_left(struct sk_buff *skb,
* *
* Empties the OGMv2 aggregation queue and frees all the skbs it contained. * Empties the OGMv2 aggregation queue and frees all the skbs it contained.
* *
* Caller needs to hold the hard_iface->bat_v.aggr_list_lock. * Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
*/ */
static void batadv_v_ogm_aggr_list_free(struct batadv_hard_iface *hard_iface) static void batadv_v_ogm_aggr_list_free(struct batadv_hard_iface *hard_iface)
{ {
lockdep_assert_held(&hard_iface->bat_v.aggr_list_lock); lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
skb_queue_purge(&hard_iface->bat_v.aggr_list); __skb_queue_purge(&hard_iface->bat_v.aggr_list);
hard_iface->bat_v.aggr_len = 0; hard_iface->bat_v.aggr_len = 0;
} }
@ -193,7 +193,7 @@ static void batadv_v_ogm_aggr_list_free(struct batadv_hard_iface *hard_iface)
* *
* The aggregation queue is empty after this call. * The aggregation queue is empty after this call.
* *
* Caller needs to hold the hard_iface->bat_v.aggr_list_lock. * Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
*/ */
static void batadv_v_ogm_aggr_send(struct batadv_hard_iface *hard_iface) static void batadv_v_ogm_aggr_send(struct batadv_hard_iface *hard_iface)
{ {
@ -202,7 +202,7 @@ static void batadv_v_ogm_aggr_send(struct batadv_hard_iface *hard_iface)
unsigned int ogm_len; unsigned int ogm_len;
struct sk_buff *skb; struct sk_buff *skb;
lockdep_assert_held(&hard_iface->bat_v.aggr_list_lock); lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
if (!aggr_len) if (!aggr_len)
return; return;
@ -216,7 +216,7 @@ static void batadv_v_ogm_aggr_send(struct batadv_hard_iface *hard_iface)
skb_reserve(skb_aggr, ETH_HLEN + NET_IP_ALIGN); skb_reserve(skb_aggr, ETH_HLEN + NET_IP_ALIGN);
skb_reset_network_header(skb_aggr); skb_reset_network_header(skb_aggr);
while ((skb = skb_dequeue(&hard_iface->bat_v.aggr_list))) { while ((skb = __skb_dequeue(&hard_iface->bat_v.aggr_list))) {
hard_iface->bat_v.aggr_len -= batadv_v_ogm_len(skb); hard_iface->bat_v.aggr_len -= batadv_v_ogm_len(skb);
ogm_len = batadv_v_ogm_len(skb); ogm_len = batadv_v_ogm_len(skb);
@ -243,13 +243,13 @@ static void batadv_v_ogm_queue_on_if(struct sk_buff *skb,
return; return;
} }
spin_lock_bh(&hard_iface->bat_v.aggr_list_lock); spin_lock_bh(&hard_iface->bat_v.aggr_list.lock);
if (!batadv_v_ogm_queue_left(skb, hard_iface)) if (!batadv_v_ogm_queue_left(skb, hard_iface))
batadv_v_ogm_aggr_send(hard_iface); batadv_v_ogm_aggr_send(hard_iface);
hard_iface->bat_v.aggr_len += batadv_v_ogm_len(skb); hard_iface->bat_v.aggr_len += batadv_v_ogm_len(skb);
skb_queue_tail(&hard_iface->bat_v.aggr_list, skb); __skb_queue_tail(&hard_iface->bat_v.aggr_list, skb);
spin_unlock_bh(&hard_iface->bat_v.aggr_list_lock); spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock);
} }
/** /**
@ -388,9 +388,9 @@ void batadv_v_ogm_aggr_work(struct work_struct *work)
batv = container_of(work, struct batadv_hard_iface_bat_v, aggr_wq.work); batv = container_of(work, struct batadv_hard_iface_bat_v, aggr_wq.work);
hard_iface = container_of(batv, struct batadv_hard_iface, bat_v); hard_iface = container_of(batv, struct batadv_hard_iface, bat_v);
spin_lock_bh(&hard_iface->bat_v.aggr_list_lock); spin_lock_bh(&hard_iface->bat_v.aggr_list.lock);
batadv_v_ogm_aggr_send(hard_iface); batadv_v_ogm_aggr_send(hard_iface);
spin_unlock_bh(&hard_iface->bat_v.aggr_list_lock); spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock);
batadv_v_ogm_start_queue_timer(hard_iface); batadv_v_ogm_start_queue_timer(hard_iface);
} }
@ -421,9 +421,9 @@ void batadv_v_ogm_iface_disable(struct batadv_hard_iface *hard_iface)
{ {
cancel_delayed_work_sync(&hard_iface->bat_v.aggr_wq); cancel_delayed_work_sync(&hard_iface->bat_v.aggr_wq);
spin_lock_bh(&hard_iface->bat_v.aggr_list_lock); spin_lock_bh(&hard_iface->bat_v.aggr_list.lock);
batadv_v_ogm_aggr_list_free(hard_iface); batadv_v_ogm_aggr_list_free(hard_iface);
spin_unlock_bh(&hard_iface->bat_v.aggr_list_lock); spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock);
} }
/** /**

3
net/batman-adv/types.h
View File

@ -130,9 +130,6 @@ struct batadv_hard_iface_bat_v {
/** @aggr_len: size of the OGM aggregate (excluding ethernet header) */ /** @aggr_len: size of the OGM aggregate (excluding ethernet header) */
unsigned int aggr_len; unsigned int aggr_len;
/** @aggr_list_lock: protects aggr_list */
spinlock_t aggr_list_lock;
/** /**
* @throughput_override: throughput override to disable link * @throughput_override: throughput override to disable link
* auto-detection * auto-detection