[B.A.T.M.A.N.] [PATCH 23/28] batman-adv: increase refcount in create_neighbor to be consistent

Sven Eckelmann
2011-03-05T12:28:37Z

net/batman-adv/originator.c | 4 ++-
net/batman-adv/routing.c | 63 ++++++++++++++++++------------------------
2 files changed, 30 insertions(+), 37 deletions(-)

diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c
index a70debe..69e27a24 100644
--- a/net/batman-adv/originator.c
+++ b/net/batman-adv/originator.c
@@ -94,7 +94,9 @@ struct neigh_node *create_neighbor(struct orig_node *orig_node,
memcpy(neigh_node->addr, neigh, ETH_ALEN);
neigh_node->orig_node = orig_neigh_node;
neigh_node->if_incoming = if_incoming;
- atomic_set(&neigh_node->refcount, 1);
+
+ /* extra reference for return */
+ atomic_set(&neigh_node->refcount, 2);

spin_lock_bh(&orig_node->neigh_list_lock);
hlist_add_head_rcu(&neigh_node->list, &orig_node->neigh_list);
diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index 9863c03..c4b7ae9 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -150,7 +150,7 @@ static int is_bidirectional_neigh(struct orig_node *orig_node,
struct batman_if *if_incoming)
{
struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
- struct neigh_node *neigh_node = NULL, *tmp_neigh_node = NULL;
+ struct neigh_node *neigh_node = NULL, *tmp_neigh_node;
struct hlist_node *node;
unsigned char total_count;
uint8_t orig_eq_count, neigh_rq_count, tq_own;
@@ -161,27 +161,27 @@ static int is_bidirectional_neigh(struct orig_node *orig_node,
hlist_for_each_entry_rcu(tmp_neigh_node, node,
&orig_node->neigh_list, list) {

- if (compare_eth(tmp_neigh_node->addr,
- orig_neigh_node->orig) &&
- (tmp_neigh_node->if_incoming == if_incoming))
- neigh_node = tmp_neigh_node;
+ if (!compare_eth(tmp_neigh_node->addr,
+ orig_neigh_node->orig))
+ continue;
+
+ if (tmp_neigh_node->if_incoming != if_incoming)
+ continue;
+
+ if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
+ continue;
+
+ neigh_node = tmp_neigh_node;
}
+ rcu_read_unlock();

if (!neigh_node)
neigh_node = create_neighbor(orig_node,
orig_neigh_node,
orig_neigh_node->orig,
if_incoming);
- /* create_neighbor failed, return 0 */
if (!neigh_node)
- goto unlock;
-
- if (!atomic_inc_not_zero(&neigh_node->refcount)) {
- neigh_node = NULL;
- goto unlock;
- }
-
- rcu_read_unlock();
+ goto out;

neigh_node->last_valid = jiffies;
} else {
@@ -190,27 +190,27 @@ static int is_bidirectional_neigh(struct orig_node *orig_node,
hlist_for_each_entry_rcu(tmp_neigh_node, node,
&orig_neigh_node->neigh_list, list) {

- if (compare_eth(tmp_neigh_node->addr,
- orig_neigh_node->orig) &&
- (tmp_neigh_node->if_incoming == if_incoming))
- neigh_node = tmp_neigh_node;
+ if (!compare_eth(tmp_neigh_node->addr,
+ orig_neigh_node->orig))
+ continue;
+
+ if (tmp_neigh_node->if_incoming != if_incoming)
+ continue;
+
+ if (!atomic_inc_not_zero(&tmp_neigh_node->refcount))
+ continue;
+
+ neigh_node = tmp_neigh_node;
}
+ rcu_read_unlock();

if (!neigh_node)
neigh_node = create_neighbor(orig_neigh_node,
orig_neigh_node,
orig_neigh_node->orig,
if_incoming);
- /* create_neighbor failed, return 0 */
if (!neigh_node)
- goto unlock;
-
- if (!atomic_inc_not_zero(&neigh_node->refcount)) {
- neigh_node = NULL;
- goto unlock;
- }
-
- rcu_read_unlock();
+ goto out;
}

orig_node->last_valid = jiffies;
@@ -265,10 +265,6 @@ static int is_bidirectional_neigh(struct orig_node *orig_node,
if (batman_packet->tq >= TQ_TOTAL_BIDRECT_LIMIT)
ret = 1;

- goto out;
-
-unlock:
- rcu_read_unlock();
out:
if (neigh_node)
neigh_node_free_ref(neigh_node);
@@ -423,11 +419,6 @@ static void update_orig(struct bat_priv *bat_priv,
orig_node_free_ref(orig_tmp);
if (!neigh_node)
goto unlock;
-
- if (!atomic_inc_not_zero(&neigh_node->refcount)) {
- neigh_node = NULL;
- goto unlock;
- }
} else
bat_dbg(DBG_BATMAN, bat_priv,
"Updating existing last-hop neighbor of originator\n");
--
1.7.2.3