[PATCH 15/21] batman-adv: Convert batadv_neigh_ifinfo to kref

[Antonio Quartulli]

From: Sven Eckelmann <s...@narfation.org>

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 <s...@narfation.org>
Signed-off-by: Marek Lindner <mareklind...@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a...@unstable.cc>
---
 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 7710595ffc42..1c50abe52c6d 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 17f97ff5b4d1..81d9f8d6c54b 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;
 };
 
-- 
2.7.1