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 --- v4: - fix function names in commit messages - fix double whitespace in batadv_tt_orig_list_entry_release kerneldoc - add extra patch for batadv_claim_free_ref kerneldoc fix - change the phrase "free it" in all *_free_ref/*_put functions to "release it" v3: - update copyright year 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 | 24 ++++++++++++++++++------ net/batman-adv/types.h | 2 +- 2 files changed, 19 insertions(+), 7 deletions(-)
diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c index 476890e..2777372 100644 --- a/net/batman-adv/main.c +++ b/net/batman-adv/main.c @@ -625,15 +625,27 @@ __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr) }
/** - * batadv_tvlv_handler_free_ref - decrement the tvlv handler refcounter and - * possibly free it + * batadv_tvlv_handler_release - release tvlv handler from lists and queue for + * free after rcu grace period + * @ref: kref pointer of the tvlv + */ +static void batadv_tvlv_handler_release(struct kref *ref) +{ + struct batadv_tvlv_handler *tvlv_handler; + + tvlv_handler = container_of(ref, struct batadv_tvlv_handler, refcount); + kfree_rcu(tvlv_handler, rcu); +} + +/** + * batadv_tvlv_handler_free_ref - decrement the tvlv container refcounter and + * possibly release it * @tvlv_handler: the tvlv handler to free */ static void batadv_tvlv_handler_free_ref(struct batadv_tvlv_handler *tvlv_handler) { - if (atomic_dec_and_test(&tvlv_handler->refcount)) - kfree_rcu(tvlv_handler, rcu); + kref_put(&tvlv_handler->refcount, batadv_tvlv_handler_release); }
/** @@ -659,7 +671,7 @@ static struct batadv_tvlv_handler if (tvlv_handler_tmp->version != version) continue;
- if (!atomic_inc_not_zero(&tvlv_handler_tmp->refcount)) + if (!kref_get_unless_zero(&tvlv_handler_tmp->refcount)) continue;
tvlv_handler = tvlv_handler_tmp; @@ -1108,7 +1120,7 @@ void batadv_tvlv_handler_register(struct batadv_priv *bat_priv, tvlv_handler->type = type; tvlv_handler->version = version; tvlv_handler->flags = flags; - atomic_set(&tvlv_handler->refcount, 1); + kref_init(&tvlv_handler->refcount); INIT_HLIST_NODE(&tvlv_handler->list);
spin_lock_bh(&bat_priv->tvlv.handler_list_lock); diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 0ebd5a4..60d304b 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -1293,7 +1293,7 @@ struct batadv_tvlv_handler { u8 type; u8 version; u8 flags; - atomic_t refcount; + struct kref refcount; struct rcu_head rcu; };