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/main.c | 20 ++++++++++++++++---- net/batman-adv/types.h | 2 +- 2 files changed, 17 insertions(+), 5 deletions(-)
diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c index 9d34be6..d6c12a7 100644 --- a/net/batman-adv/main.c +++ b/net/batman-adv/main.c @@ -29,6 +29,7 @@ #include <linux/ip.h> #include <linux/ipv6.h> #include <linux/kernel.h> +#include <linux/kref.h> #include <linux/list.h> #include <linux/lockdep.h> #include <linux/module.h> @@ -670,14 +671,25 @@ static struct batadv_tvlv_handler }
/** + * batadv_tvlv_container_release - release tvlv from lists and free + * @ref: kref pointer of the tvlv + */ +static void batadv_tvlv_container_release(struct kref *ref) +{ + struct batadv_tvlv_container *tvlv; + + tvlv = container_of(ref, struct batadv_tvlv_container, refcount); + kfree(tvlv); +} + +/** * batadv_tvlv_container_free_ref - decrement the tvlv container refcounter and * possibly free it * @tvlv: the tvlv container to free */ static void batadv_tvlv_container_free_ref(struct batadv_tvlv_container *tvlv) { - if (atomic_dec_and_test(&tvlv->refcount)) - kfree(tvlv); + kref_put(&tvlv->refcount, batadv_tvlv_container_release); }
/** @@ -704,7 +716,7 @@ static struct batadv_tvlv_container if (tvlv_tmp->tvlv_hdr.version != version) continue;
- if (!atomic_inc_not_zero(&tvlv_tmp->refcount)) + if (!kref_get_unless_zero(&tvlv_tmp->refcount)) continue;
tvlv = tvlv_tmp; @@ -810,7 +822,7 @@ void batadv_tvlv_container_register(struct batadv_priv *bat_priv,
memcpy(tvlv_new + 1, tvlv_value, ntohs(tvlv_new->tvlv_hdr.len)); INIT_HLIST_NODE(&tvlv_new->list); - atomic_set(&tvlv_new->refcount, 1); + kref_init(&tvlv_new->refcount);
spin_lock_bh(&bat_priv->tvlv.container_list_lock); tvlv_old = batadv_tvlv_container_get(bat_priv, type, version); diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index a6ba6c0..0ebd5a4 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -1266,7 +1266,7 @@ struct batadv_dat_candidate { struct batadv_tvlv_container { struct hlist_node list; struct batadv_tvlv_hdr tvlv_hdr; - atomic_t refcount; + struct kref refcount; };
/**