batadv_hardif_neigh_node perfectly resamples the examples for the kernel reference counter kref. So switch to kref instead of using the self-made, atomic_t-based implementation.
Signed-off-by: Sven Eckelmann <[email protected]> --- compat-include/linux/kref.h | 39 ++++++++++++++++++ net/batman-adv/bat_iv_ogm.c | 2 +- net/batman-adv/originator.c | 96 +++++++++++++++++++++++++++++++-------------- net/batman-adv/originator.h | 2 +- net/batman-adv/types.h | 3 +- 5 files changed, 109 insertions(+), 33 deletions(-) create mode 100644 compat-include/linux/kref.h diff --git a/compat-include/linux/kref.h b/compat-include/linux/kref.h new file mode 100644 index 0000000..08b6328 --- /dev/null +++ b/compat-include/linux/kref.h @@ -0,0 +1,39 @@ +/* Copyright (C) 2007-2015 B.A.T.M.A.N. contributors: + * + * Marek Lindner, Simon Wunderlich + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + * + * This file contains macros for maintaining compatibility with older versions + * of the Linux kernel. + */ + +#ifndef _NET_BATMAN_ADV_COMPAT_LINUX_KREF_H_ +#define _NET_BATMAN_ADV_COMPAT_LINUX_KREF_H_ + +#include <linux/version.h> +#include_next <linux/kref.h> + +#include <linux/atomic.h> +#include <linux/kernel.h> + +#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 8, 0) + +static inline int __must_check kref_get_unless_zero(struct kref *kref) +{ + return atomic_add_unless(&kref->refcount, 1, 0); +} + +#endif /* < KERNEL_VERSION(3, 8, 0) */ + +#endif /* _NET_BATMAN_ADV_COMPAT_LINUX_KREF_H_ */ diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index 12bdffa..b9db667 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -1571,7 +1571,7 @@ out: if (orig_neigh_router) batadv_neigh_node_free_ref(orig_neigh_router); if (hardif_neigh) - batadv_hardif_neigh_free_ref(hardif_neigh); + batadv_hardif_neigh_put(hardif_neigh); kfree_skb(skb_priv); } diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c index 2681c7d..24c62a8 100644 --- a/net/batman-adv/originator.c +++ b/net/batman-adv/originator.c @@ -23,6 +23,7 @@ #include <linux/fs.h> #include <linux/jiffies.h> #include <linux/kernel.h> +#include <linux/kref.h> #include <linux/list.h> #include <linux/lockdep.h> #include <linux/netdevice.h> @@ -208,6 +209,47 @@ void batadv_neigh_ifinfo_free_ref(struct batadv_neigh_ifinfo *neigh_ifinfo) } /** + * batadv_hardif_neigh_free - remove unreferenced hardif neighbor + * @hardif_neigh: hardif neigh neighbor to free + */ +static void +batadv_hardif_neigh_free(struct batadv_hardif_neigh_node *hardif_neigh) +{ + batadv_hardif_free_ref_now(hardif_neigh->if_incoming); + kfree(hardif_neigh); +} + +/** + * batadv_hardif_neigh_release_now - release hardif neigh node from lists and + * free without waiting for rcu grace period + * @ref: kref pointer of the neigh_node + */ +static void batadv_hardif_neigh_release_now(struct kref *ref) +{ + struct batadv_hardif_neigh_node *hardif_neigh; + + hardif_neigh = container_of(ref, struct batadv_hardif_neigh_node, + refcount); + + spin_lock_bh(&hardif_neigh->if_incoming->neigh_list_lock); + hlist_del_init_rcu(&hardif_neigh->list); + spin_unlock_bh(&hardif_neigh->if_incoming->neigh_list_lock); + + batadv_hardif_neigh_free(hardif_neigh); +} + +/** + * batadv_hardif_neigh_put_now - decrement the hardif neighbors refcounter + * and possibly release it (without rcu callback) + * @hardif_neigh: hardif neigh neighbor to free + */ +static void +batadv_hardif_neigh_put_now(struct batadv_hardif_neigh_node *hardif_neigh) +{ + kref_put(&hardif_neigh->refcount, batadv_hardif_neigh_release_now); +} + +/** * batadv_hardif_neigh_free_rcu - free the hardif neigh_node * @rcu: rcu pointer of the neigh_node */ @@ -216,42 +258,36 @@ static void batadv_hardif_neigh_free_rcu(struct rcu_head *rcu) struct batadv_hardif_neigh_node *hardif_neigh; hardif_neigh = container_of(rcu, struct batadv_hardif_neigh_node, rcu); - - batadv_hardif_free_ref_now(hardif_neigh->if_incoming); - kfree(hardif_neigh); + batadv_hardif_neigh_free(hardif_neigh); } /** - * batadv_hardif_neigh_free_now - decrement the hardif neighbors refcounter - * and possibly free it (without rcu callback) - * @hardif_neigh: hardif neigh neighbor to free + * batadv_hardif_neigh_release_rcu - release hardif neigh node from lists and + * queue for free after rcu grace period + * * @ref: kref pointer of the neigh_node */ -static void -batadv_hardif_neigh_free_now(struct batadv_hardif_neigh_node *hardif_neigh) +static void batadv_hardif_neigh_release_rcu(struct kref *ref) { - if (atomic_dec_and_test(&hardif_neigh->refcount)) { - spin_lock_bh(&hardif_neigh->if_incoming->neigh_list_lock); - hlist_del_init_rcu(&hardif_neigh->list); - spin_unlock_bh(&hardif_neigh->if_incoming->neigh_list_lock); + struct batadv_hardif_neigh_node *hardif_neigh; - batadv_hardif_neigh_free_rcu(&hardif_neigh->rcu); - } + hardif_neigh = container_of(ref, struct batadv_hardif_neigh_node, + refcount); + + spin_lock_bh(&hardif_neigh->if_incoming->neigh_list_lock); + hlist_del_init_rcu(&hardif_neigh->list); + spin_unlock_bh(&hardif_neigh->if_incoming->neigh_list_lock); + + call_rcu(&hardif_neigh->rcu, batadv_hardif_neigh_free_rcu); } /** - * batadv_hardif_neigh_free_ref - decrement the hardif neighbors refcounter - * and possibly free it + * batadv_hardif_neigh_put - decrement the hardif neighbors refcounter + * and possibly release it * @hardif_neigh: hardif neigh neighbor to free */ -void batadv_hardif_neigh_free_ref(struct batadv_hardif_neigh_node *hardif_neigh) +void batadv_hardif_neigh_put(struct batadv_hardif_neigh_node *hardif_neigh) { - if (atomic_dec_and_test(&hardif_neigh->refcount)) { - spin_lock_bh(&hardif_neigh->if_incoming->neigh_list_lock); - hlist_del_init_rcu(&hardif_neigh->list); - spin_unlock_bh(&hardif_neigh->if_incoming->neigh_list_lock); - - call_rcu(&hardif_neigh->rcu, batadv_hardif_neigh_free_rcu); - } + kref_put(&hardif_neigh->refcount, batadv_hardif_neigh_release_rcu); } /** @@ -278,8 +314,8 @@ static void batadv_neigh_node_free_rcu(struct rcu_head *rcu) neigh_node->addr); if (hardif_neigh) { /* batadv_hardif_neigh_get() increases refcount too */ - batadv_hardif_neigh_free_now(hardif_neigh); - batadv_hardif_neigh_free_now(hardif_neigh); + batadv_hardif_neigh_put_now(hardif_neigh); + batadv_hardif_neigh_put_now(hardif_neigh); } if (bao->bat_neigh_free) @@ -576,7 +612,7 @@ batadv_hardif_neigh_create(struct batadv_hard_iface *hard_iface, hardif_neigh->if_incoming = hard_iface; hardif_neigh->last_seen = jiffies; - atomic_set(&hardif_neigh->refcount, 1); + kref_init(&hardif_neigh->refcount); if (bat_priv->bat_algo_ops->bat_hardif_neigh_init) bat_priv->bat_algo_ops->bat_hardif_neigh_init(hardif_neigh); @@ -631,7 +667,7 @@ batadv_hardif_neigh_get(const struct batadv_hard_iface *hard_iface, if (!batadv_compare_eth(tmp_hardif_neigh->addr, neigh_addr)) continue; - if (!atomic_inc_not_zero(&tmp_hardif_neigh->refcount)) + if (!kref_get_unless_zero(&tmp_hardif_neigh->refcount)) continue; hardif_neigh = tmp_hardif_neigh; @@ -695,7 +731,7 @@ batadv_neigh_node_new(struct batadv_orig_node *orig_node, spin_unlock_bh(&orig_node->neigh_list_lock); /* increment unique neighbor refcount */ - atomic_inc(&hardif_neigh->refcount); + kref_get(&hardif_neigh->refcount); batadv_dbg(BATADV_DBG_BATMAN, orig_node->bat_priv, "Creating new neighbor %pM for orig_node %pM on interface %s\n", @@ -703,7 +739,7 @@ batadv_neigh_node_new(struct batadv_orig_node *orig_node, out: if (hardif_neigh) - batadv_hardif_neigh_free_ref(hardif_neigh); + batadv_hardif_neigh_put(hardif_neigh); return neigh_node; } diff --git a/net/batman-adv/originator.h b/net/batman-adv/originator.h index 2955775..0dd1beb 100644 --- a/net/batman-adv/originator.h +++ b/net/batman-adv/originator.h @@ -45,7 +45,7 @@ struct batadv_hardif_neigh_node * batadv_hardif_neigh_get(const struct batadv_hard_iface *hard_iface, const u8 *neigh_addr); void -batadv_hardif_neigh_free_ref(struct batadv_hardif_neigh_node *hardif_neigh); +batadv_hardif_neigh_put(struct batadv_hardif_neigh_node *hardif_neigh); struct batadv_neigh_node * batadv_neigh_node_new(struct batadv_orig_node *orig_node, struct batadv_hard_iface *hard_iface, diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 5e8c8df..091ad76 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -25,6 +25,7 @@ #include <linux/bitops.h> #include <linux/compiler.h> #include <linux/if_ether.h> +#include <linux/kref.h> #include <linux/netdevice.h> #include <linux/sched.h> /* for linux/wait.h */ #include <linux/spinlock.h> @@ -359,7 +360,7 @@ struct batadv_hardif_neigh_node { u8 addr[ETH_ALEN]; struct batadv_hard_iface *if_incoming; unsigned long last_seen; - atomic_t refcount; + struct kref refcount; struct rcu_head rcu; }; -- 2.6.4
