[B.A.T.M.A.N.] [PATCH v2 28/30] batman-adv: Convert batadv_orig_node to kref

Sven Eckelmann
2015-12-20T13:18:08Z

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/distributed-arp-table.c | 2 +-
net/batman-adv/gateway_client.c | 4 ++--
net/batman-adv/multicast.c | 7 ++++---
net/batman-adv/network-coding.c | 2 +-
net/batman-adv/originator.c | 14 +++++++++-----
net/batman-adv/originator.h | 4 ++--
net/batman-adv/translation-table.c | 4 ++--
net/batman-adv/types.h | 2 +-
8 files changed, 22 insertions(+), 17 deletions(-)

diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c
index ffbc45d..549f2ea 100644
--- a/net/batman-adv/distributed-arp-table.c
+++ b/net/batman-adv/distributed-arp-table.c
@@ -542,7 +542,7 @@ static void batadv_choose_next_candidate(struct batadv_priv *bat_priv,
max_orig_node))
continue;

- if (!atomic_inc_not_zero(&orig_node->refcount))
+ if (!kref_get_unless_zero(&orig_node->refcount))
continue;

max = tmp_max;
diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c
index bf5a6ef..17858f2 100644
--- a/net/batman-adv/gateway_client.c
+++ b/net/batman-adv/gateway_client.c
@@ -118,7 +118,7 @@ batadv_gw_get_selected_orig(struct batadv_priv *bat_priv)
if (!orig_node)
goto unlock;

- if (!atomic_inc_not_zero(&orig_node->refcount))
+ if (!kref_get_unless_zero(&orig_node->refcount))
orig_node = NULL;

unlock:
@@ -441,7 +441,7 @@ static void batadv_gw_node_add(struct batadv_priv *bat_priv,
if (gateway->bandwidth_down == 0)
return;

- if (!atomic_inc_not_zero(&orig_node->refcount))
+ if (!kref_get_unless_zero(&orig_node->refcount))
return;

gw_node = kzalloc(sizeof(*gw_node), GFP_ATOMIC);
diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c
index 8abf488..288844f 100644
--- a/net/batman-adv/multicast.c
+++ b/net/batman-adv/multicast.c
@@ -30,6 +30,7 @@
#include <linux/in.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
+#include <linux/kref.h>
#include <linux/list.h>
#include <linux/lockdep.h>
#include <linux/netdevice.h>
@@ -447,7 +448,7 @@ batadv_mcast_forw_ipv4_node_get(struct batadv_priv *bat_priv)
hlist_for_each_entry_rcu(tmp_orig_node,
&bat_priv->mcast.want_all_ipv4_list,
mcast_want_all_ipv4_node) {
- if (!atomic_inc_not_zero(&tmp_orig_node->refcount))
+ if (!kref_get_unless_zero(&tmp_orig_node->refcount))
continue;

orig_node = tmp_orig_node;
@@ -474,7 +475,7 @@ batadv_mcast_forw_ipv6_node_get(struct batadv_priv *bat_priv)
hlist_for_each_entry_rcu(tmp_orig_node,
&bat_priv->mcast.want_all_ipv6_list,
mcast_want_all_ipv6_node) {
- if (!atomic_inc_not_zero(&tmp_orig_node->refcount))
+ if (!kref_get_unless_zero(&tmp_orig_node->refcount))
continue;

orig_node = tmp_orig_node;
@@ -525,7 +526,7 @@ batadv_mcast_forw_unsnoop_node_get(struct batadv_priv *bat_priv)
hlist_for_each_entry_rcu(tmp_orig_node,
&bat_priv->mcast.want_all_unsnoopables_list,
mcast_want_all_unsnoopables_node) {
- if (!atomic_inc_not_zero(&tmp_orig_node->refcount))
+ if (!kref_get_unless_zero(&tmp_orig_node->refcount))
continue;

orig_node = tmp_orig_node;
diff --git a/net/batman-adv/network-coding.c b/net/batman-adv/network-coding.c
index 0ad2cc1..42206c4 100644
--- a/net/batman-adv/network-coding.c
+++ b/net/batman-adv/network-coding.c
@@ -858,7 +858,7 @@ static struct batadv_nc_node
if (!nc_node)
return NULL;

- if (!atomic_inc_not_zero(&orig_neigh_node->refcount))
+ if (!kref_get_unless_zero(&orig_neigh_node->refcount))
goto free;

/* Initialize nc_node */
diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c
index ae78844..6716d9a 100644
--- a/net/batman-adv/originator.c
+++ b/net/batman-adv/originator.c
@@ -18,6 +18,7 @@
#include "originator.h"
#include "main.h"

+#include <linux/atomic.h>
#include <linux/errno.h>
#include <linux/etherdevice.h>
#include <linux/fs.h>
@@ -775,14 +776,17 @@ static void batadv_orig_node_free_rcu(struct rcu_head *rcu)
/**
* batadv_orig_node_release - release orig_node from lists and queue for
* free after rcu grace period
- * @orig_node: the orig node to free
+ * @ref: kref pointer of the orig_node
*/
-static void batadv_orig_node_release(struct batadv_orig_node *orig_node)
+static void batadv_orig_node_release(struct kref *ref)
{
struct hlist_node *node_tmp;
struct batadv_neigh_node *neigh_node;
+ struct batadv_orig_node *orig_node;
struct batadv_orig_ifinfo *orig_ifinfo;

+ orig_node = container_of(ref, struct batadv_orig_node, refcount);
+
spin_lock_bh(&orig_node->neigh_list_lock);

/* for all neighbors towards this originator ... */
@@ -812,8 +816,7 @@ static void batadv_orig_node_release(struct batadv_orig_node *orig_node)
*/
void batadv_orig_node_free_ref(struct batadv_orig_node *orig_node)
{
- if (atomic_dec_and_test(&orig_node->refcount))
- batadv_orig_node_release(orig_node);
+ kref_put(&orig_node->refcount, batadv_orig_node_release);
}

void batadv_originator_free(struct batadv_priv *bat_priv)
@@ -885,7 +888,8 @@ struct batadv_orig_node *batadv_orig_node_new(struct batadv_priv *bat_priv,
batadv_nc_init_orig(orig_node);

/* extra reference for return */
- atomic_set(&orig_node->refcount, 2);
+ kref_init(&orig_node->refcount);
+ kref_get(&orig_node->refcount);

orig_node->bat_priv = bat_priv;
ether_addr_copy(orig_node->orig, addr);
diff --git a/net/batman-adv/originator.h b/net/batman-adv/originator.h
index cf07304..6ad7bf3 100644
--- a/net/batman-adv/originator.h
+++ b/net/batman-adv/originator.h
@@ -20,10 +20,10 @@

#include "main.h"

-#include <linux/atomic.h>
#include <linux/compiler.h>
#include <linux/if_ether.h>
#include <linux/jhash.h>
+#include <linux/kref.h>
#include <linux/rculist.h>
#include <linux/rcupdate.h>
#include <linux/stddef.h>
@@ -115,7 +115,7 @@ batadv_orig_hash_find(struct batadv_priv *bat_priv, const void *data)
if (!batadv_compare_eth(orig_node, data))
continue;

- if (!atomic_inc_not_zero(&orig_node->refcount))
+ if (!kref_get_unless_zero(&orig_node->refcount))
continue;

orig_node_tmp = orig_node;
diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c
index bc18ab5..7d395b6 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -1334,7 +1334,7 @@ batadv_tt_global_orig_entry_add(struct batadv_tt_global_entry *tt_global,
goto out;

INIT_HLIST_NODE(&orig_entry->list);
- atomic_inc(&orig_node->refcount);
+ kref_get(&orig_node->refcount);
batadv_tt_global_size_inc(orig_node, tt_global->common.vid);
orig_entry->orig_node = orig_node;
orig_entry->ttvn = ttvn;
@@ -2097,7 +2097,7 @@ struct batadv_orig_node *batadv_transtable_search(struct batadv_priv *bat_priv,
/* found anything? */
if (best_entry)
orig_node = best_entry->orig_node;
- if (orig_node && !atomic_inc_not_zero(&orig_node->refcount))
+ if (orig_node && !kref_get_unless_zero(&orig_node->refcount))
orig_node = NULL;
rcu_read_unlock();

diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index 441ebd9..c8c7ab8 100644
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -299,7 +299,7 @@ struct batadv_orig_node {
struct batadv_priv *bat_priv;
/* bcast_seqno_lock protects: bcast_bits & last_bcast_seqno */
spinlock_t bcast_seqno_lock;
- atomic_t refcount;
+ struct kref refcount;
struct rcu_head rcu;
#ifdef CONFIG_BATMAN_ADV_NC
struct list_head in_coding_list;
--
2.6.4