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 | 17 ++++++++++------- net/batman-adv/types.h | 2 +- 2 files changed, 11 insertions(+), 8 deletions(-)
diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c index 7e5c207..cae7528 100644 --- a/net/batman-adv/originator.c +++ b/net/batman-adv/originator.c @@ -172,11 +172,14 @@ err: /** * batadv_neigh_ifinfo_release - release neigh_ifinfo from lists and queue for * free after rcu grace period - * @neigh_ifinfo: the neigh_ifinfo object to release + * @ref: kref pointer of the neigh_ifinfo */ -static void -batadv_neigh_ifinfo_release(struct batadv_neigh_ifinfo *neigh_ifinfo) +static void batadv_neigh_ifinfo_release(struct kref *ref) { + struct batadv_neigh_ifinfo *neigh_ifinfo; + + neigh_ifinfo = container_of(ref, struct batadv_neigh_ifinfo, refcount); + if (neigh_ifinfo->if_outgoing != BATADV_IF_DEFAULT) batadv_hardif_free_ref(neigh_ifinfo->if_outgoing);
@@ -190,8 +193,7 @@ batadv_neigh_ifinfo_release(struct batadv_neigh_ifinfo *neigh_ifinfo) */ void batadv_neigh_ifinfo_free_ref(struct batadv_neigh_ifinfo *neigh_ifinfo) { - if (atomic_dec_and_test(&neigh_ifinfo->refcount)) - batadv_neigh_ifinfo_release(neigh_ifinfo); + kref_put(&neigh_ifinfo->refcount, batadv_neigh_ifinfo_release); }
/** @@ -405,7 +407,7 @@ batadv_neigh_ifinfo_get(struct batadv_neigh_node *neigh, if (tmp_neigh_ifinfo->if_outgoing != if_outgoing) continue;
- if (!atomic_inc_not_zero(&tmp_neigh_ifinfo->refcount)) + if (!kref_get_unless_zero(&tmp_neigh_ifinfo->refcount)) continue;
neigh_ifinfo = tmp_neigh_ifinfo; @@ -450,7 +452,8 @@ batadv_neigh_ifinfo_new(struct batadv_neigh_node *neigh, }
INIT_HLIST_NODE(&neigh_ifinfo->list); - atomic_set(&neigh_ifinfo->refcount, 2); + kref_init(&neigh_ifinfo->refcount); + kref_get(&neigh_ifinfo->refcount); neigh_ifinfo->if_outgoing = if_outgoing;
hlist_add_head_rcu(&neigh_ifinfo->list, &neigh->ifinfo_list); diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 58ae09e..7831bf0 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -420,7 +420,7 @@ struct batadv_neigh_ifinfo { struct batadv_hard_iface *if_outgoing; struct batadv_neigh_ifinfo_bat_iv bat_iv; u8 last_ttl; - atomic_t refcount; + struct kref refcount; struct rcu_head rcu; };