batman-adv uses a self-written reference implementation which is just based on atomic_t. This is less obvious when reading the code than kref and therefore increases the change that the reference counting will be missed.
Signed-off-by: Sven Eckelmann sven@narfation.org --- v2: - split patchset into fixes and kref migration to make it easier when the decision is made where each patch will be applied
net/batman-adv/originator.c | 22 +++++++++++++--------- net/batman-adv/types.h | 3 ++- 2 files changed, 15 insertions(+), 10 deletions(-)
diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c index ef82614..7e5c207 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> @@ -196,11 +197,15 @@ void batadv_neigh_ifinfo_free_ref(struct batadv_neigh_ifinfo *neigh_ifinfo) /** * batadv_hardif_neigh_release - release hardif neigh node from lists and * queue for free after rcu grace period - * @hardif_neigh: hardif neigh neighbor to free + * @ref: kref pointer of the neigh_node */ -static void -batadv_hardif_neigh_release(struct batadv_hardif_neigh_node *hardif_neigh) +static void batadv_hardif_neigh_release(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); @@ -211,13 +216,12 @@ batadv_hardif_neigh_release(struct batadv_hardif_neigh_node *hardif_neigh)
/** * batadv_hardif_neigh_free_ref - decrement the hardif neighbors refcounter - * and possibly free it + * and possibly release it * @hardif_neigh: hardif neigh neighbor to free */ void batadv_hardif_neigh_free_ref(struct batadv_hardif_neigh_node *hardif_neigh) { - if (atomic_dec_and_test(&hardif_neigh->refcount)) - batadv_hardif_neigh_release(hardif_neigh); + kref_put(&hardif_neigh->refcount, batadv_hardif_neigh_release); }
/** @@ -529,7 +533,7 @@ 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); @@ -584,7 +588,7 @@ 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; @@ -648,7 +652,7 @@ 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", 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; };