From baa1e8a0da768d9b9c34b47f2cc6c6db67a265c4 Mon Sep 17 00:00:00 2001 From: Christophe JAILLET Date: Thu, 31 Oct 2019 09:52:40 +0100 Subject: [PATCH] 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 Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich --- net/batman-adv/bat_v.c | 1 - net/batman-adv/bat_v_ogm.c | 30 +++++++++++++++--------------- net/batman-adv/types.h | 3 --- 3 files changed, 15 insertions(+), 19 deletions(-) diff --git a/net/batman-adv/bat_v.c b/net/batman-adv/bat_v.c index 64054edc2e3c..4ff6cf1ecae7 100644 --- a/net/batman-adv/bat_v.c +++ b/net/batman-adv/bat_v.c @@ -1085,7 +1085,6 @@ void batadv_v_hardif_init(struct batadv_hard_iface *hard_iface) hard_iface->bat_v.aggr_len = 0; 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, batadv_v_ogm_aggr_work); } diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c index 76b732e2f31c..714ce56cfcc8 100644 --- a/net/batman-adv/bat_v_ogm.c +++ b/net/batman-adv/bat_v_ogm.c @@ -152,7 +152,7 @@ static unsigned int batadv_v_ogm_len(struct sk_buff *skb) * @skb: the OGM to check * @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. */ @@ -163,7 +163,7 @@ static bool batadv_v_ogm_queue_left(struct sk_buff *skb, BATADV_MAX_AGGREGATION_BYTES); 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; } @@ -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. * - * 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) { - 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; } @@ -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. * - * 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) { @@ -202,7 +202,7 @@ static void batadv_v_ogm_aggr_send(struct batadv_hard_iface *hard_iface) unsigned int ogm_len; 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) 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_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); ogm_len = batadv_v_ogm_len(skb); @@ -243,13 +243,13 @@ static void batadv_v_ogm_queue_on_if(struct sk_buff *skb, 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)) batadv_v_ogm_aggr_send(hard_iface); hard_iface->bat_v.aggr_len += batadv_v_ogm_len(skb); - skb_queue_tail(&hard_iface->bat_v.aggr_list, skb); - spin_unlock_bh(&hard_iface->bat_v.aggr_list_lock); + __skb_queue_tail(&hard_iface->bat_v.aggr_list, skb); + 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); 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); - 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); } @@ -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); - 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); - spin_unlock_bh(&hard_iface->bat_v.aggr_list_lock); + spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock); } /** diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 4d7f1baee7b7..47718a82eaf2 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -130,9 +130,6 @@ struct batadv_hard_iface_bat_v { /** @aggr_len: size of the OGM aggregate (excluding ethernet header) */ unsigned int aggr_len; - /** @aggr_list_lock: protects aggr_list */ - spinlock_t aggr_list_lock; - /** * @throughput_override: throughput override to disable link * auto-detection