From 70e83bd3b0e434ee9fa8e0010f76080aa4320725 Mon Sep 17 00:00:00 2001 From: Vlad Buslov Date: Tue, 12 Jun 2018 11:59:43 +0300 Subject: net/mlx5e: Refactor mlx5e_neigh_update_table->encap_lock To remove dependency on rtnl lock, always take neigh update encap lock when modifying neigh update hash table and list. Originally, this lock was only used to synchronize with netevent handler function, which is called from bh context and cannot use rtnl lock for synchronization. Take lock in encap entry attach function to prevent concurrent modifications of neigh update hash table and list. Taking the encap lock when creating new nhe introduces a problem that we need to allocate new entry with sleeping GFP_KERNEL flag while holding a spinlock. However, since previous patch in this series has already converted lookup in netevent handler function to user rcu read lock instead of encap lock, we can safely convert the lock type to mutex. Signed-off-by: Vlad Buslov Reviewed-by: Jianbo Liu Reviewed-by: Roi Dayan Signed-off-by: Saeed Mahameed --- drivers/net/ethernet/mellanox/mlx5/core/en_rep.c | 17 ++++++++++++----- drivers/net/ethernet/mellanox/mlx5/core/en_rep.h | 3 ++- 2 files changed, 14 insertions(+), 6 deletions(-) (limited to 'drivers/net/ethernet') diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c index a294dc6b5a0c..218772d5c062 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c @@ -973,7 +973,7 @@ static int mlx5e_rep_neigh_init(struct mlx5e_rep_priv *rpriv) return err; INIT_LIST_HEAD(&neigh_update->neigh_list); - spin_lock_init(&neigh_update->encap_lock); + mutex_init(&neigh_update->encap_lock); INIT_DELAYED_WORK(&neigh_update->neigh_stats_work, mlx5e_rep_neigh_stats_work); mlx5e_rep_neigh_update_init_interval(rpriv); @@ -1000,6 +1000,7 @@ static void mlx5e_rep_neigh_cleanup(struct mlx5e_rep_priv *rpriv) cancel_delayed_work_sync(&rpriv->neigh_update.neigh_stats_work); + mutex_destroy(&neigh_update->encap_lock); rhashtable_destroy(&neigh_update->neigh_ht); } @@ -1024,18 +1025,18 @@ static void mlx5e_rep_neigh_entry_remove(struct mlx5e_neigh_hash_entry *nhe) { struct mlx5e_rep_priv *rpriv = nhe->priv->ppriv; - spin_lock_bh(&rpriv->neigh_update.encap_lock); + mutex_lock(&rpriv->neigh_update.encap_lock); list_del_rcu(&nhe->neigh_list); rhashtable_remove_fast(&rpriv->neigh_update.neigh_ht, &nhe->rhash_node, mlx5e_neigh_ht_params); - spin_unlock_bh(&rpriv->neigh_update.encap_lock); + mutex_unlock(&rpriv->neigh_update.encap_lock); } -/* This function must only be called under RTNL lock or under the - * representor's encap_lock in case RTNL mutex can't be held. +/* This function must only be called under the representor's encap_lock or + * inside rcu read lock section. */ static struct mlx5e_neigh_hash_entry * mlx5e_rep_neigh_entry_lookup(struct mlx5e_priv *priv, @@ -1088,17 +1089,23 @@ int mlx5e_rep_encap_entry_attach(struct mlx5e_priv *priv, err = mlx5_tun_entropy_refcount_inc(tun_entropy, e->reformat_type); if (err) return err; + + mutex_lock(&rpriv->neigh_update.encap_lock); nhe = mlx5e_rep_neigh_entry_lookup(priv, &e->m_neigh); if (!nhe) { err = mlx5e_rep_neigh_entry_create(priv, e, &nhe); if (err) { + mutex_unlock(&rpriv->neigh_update.encap_lock); mlx5_tun_entropy_refcount_dec(tun_entropy, e->reformat_type); return err; } } + e->nhe = nhe; list_add(&e->encap_list, &nhe->encap_list); + mutex_unlock(&rpriv->neigh_update.encap_lock); + return 0; } diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rep.h b/drivers/net/ethernet/mellanox/mlx5/core/en_rep.h index d057e401b0de..8fa27832bd81 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_rep.h +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rep.h @@ -35,6 +35,7 @@ #include #include +#include #include "eswitch.h" #include "en.h" #include "lib/port_tun.h" @@ -48,7 +49,7 @@ struct mlx5e_neigh_update_table { */ struct list_head neigh_list; /* protect lookup/remove operations */ - spinlock_t encap_lock; + struct mutex encap_lock; struct notifier_block netevent_nb; struct delayed_work neigh_stats_work; unsigned long min_interval; /* jiffies */ -- cgit v1.2.3