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/bridge_loop_avoidance.c | 19 ++++++++++++------- net/batman-adv/types.h | 2 +- 2 files changed, 13 insertions(+), 8 deletions(-)
diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c index 22fe700..2988890 100644 --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -172,22 +172,26 @@ batadv_backbone_gw_free_ref(struct batadv_bla_backbone_gw *backbone_gw) /** * batadv_claim_release - release claim from lists and queue for free after rcu * grace period - * @claim: claim to be free'd + * @ref: kref pointer of the claim */ -static void batadv_claim_release(struct batadv_bla_claim *claim) +static void batadv_claim_release(struct kref *ref) { + struct batadv_bla_claim *claim; + + claim = container_of(ref, struct batadv_bla_claim, refcount); + batadv_backbone_gw_free_ref(claim->backbone_gw); kfree_rcu(claim, rcu); }
/** - * batadv_claim_free_rcu - free a claim + * batadv_claim_free_ref - decrement the claim refcounter and possibly + * release it * @claim: claim to be free'd */ static void batadv_claim_free_ref(struct batadv_bla_claim *claim) { - if (atomic_dec_and_test(&claim->refcount)) - batadv_claim_release(claim); + kref_put(&claim->refcount, batadv_claim_release); }
/** @@ -218,7 +222,7 @@ static struct batadv_bla_claim if (!batadv_compare_claim(&claim->hash_entry, data)) continue;
- if (!atomic_inc_not_zero(&claim->refcount)) + if (!kref_get_unless_zero(&claim->refcount)) continue;
claim_tmp = claim; @@ -650,7 +654,8 @@ static void batadv_bla_add_claim(struct batadv_priv *bat_priv, claim->lasttime = jiffies; claim->backbone_gw = backbone_gw;
- atomic_set(&claim->refcount, 2); + kref_init(&claim->refcount); + kref_get(&claim->refcount); batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla_add_claim(): adding new entry %pM, vid %d to hash ...\n", mac, BATADV_PRINT_VID(vid)); diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 098ec7f..c56b99c 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -951,7 +951,7 @@ struct batadv_bla_claim { unsigned long lasttime; struct hlist_node hash_entry; struct rcu_head rcu; - atomic_t refcount; + struct kref refcount; }; #endif