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/bat_iv_ogm.c | 5 +++-- net/batman-adv/originator.c | 22 ++++++++++++---------- net/batman-adv/routing.c | 8 ++++---- net/batman-adv/types.h | 2 +- 4 files changed, 20 insertions(+), 17 deletions(-)
diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index 12bdffa..895e697 100644 --- a/net/batman-adv/bat_iv_ogm.c +++ b/net/batman-adv/bat_iv_ogm.c @@ -31,6 +31,7 @@ #include <linux/init.h> #include <linux/jiffies.h> #include <linux/list.h> +#include <linux/kref.h> #include <linux/netdevice.h> #include <linux/pkt_sched.h> #include <linux/printk.h> @@ -1000,7 +1001,7 @@ batadv_iv_ogm_orig_update(struct batadv_priv *bat_priv, neigh_addr = tmp_neigh_node->addr; if (batadv_compare_eth(neigh_addr, ethhdr->h_source) && tmp_neigh_node->if_incoming == if_incoming && - atomic_inc_not_zero(&tmp_neigh_node->refcount)) { + kref_get_unless_zero(&tmp_neigh_node->refcount)) { if (WARN(neigh_node, "too many matching neigh_nodes")) batadv_neigh_node_free_ref(neigh_node); neigh_node = tmp_neigh_node; @@ -1159,7 +1160,7 @@ static int batadv_iv_ogm_calc_tq(struct batadv_orig_node *orig_node, if (tmp_neigh_node->if_incoming != if_incoming) continue;
- if (!atomic_inc_not_zero(&tmp_neigh_node->refcount)) + if (!kref_get_unless_zero(&tmp_neigh_node->refcount)) continue;
neigh_node = tmp_neigh_node; diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c index 0463fbd..90eb5e3 100644 --- a/net/batman-adv/originator.c +++ b/net/batman-adv/originator.c @@ -229,15 +229,17 @@ void batadv_hardif_neigh_free_ref(struct batadv_hardif_neigh_node *hardif_neigh) /** * batadv_neigh_node_release - release neigh_node from lists and queue for * free after rcu grace period - * @neigh_node: neigh neighbor to free + * @ref: kref pointer of the neigh_node */ -static void batadv_neigh_node_release(struct batadv_neigh_node *neigh_node) +static void batadv_neigh_node_release(struct kref *ref) { struct hlist_node *node_tmp; + struct batadv_neigh_node *neigh_node; struct batadv_hardif_neigh_node *hardif_neigh; struct batadv_neigh_ifinfo *neigh_ifinfo; struct batadv_algo_ops *bao;
+ neigh_node = container_of(ref, struct batadv_neigh_node, refcount); bao = neigh_node->orig_node->bat_priv->bat_algo_ops;
hlist_for_each_entry_safe(neigh_ifinfo, node_tmp, @@ -262,14 +264,13 @@ static void batadv_neigh_node_release(struct batadv_neigh_node *neigh_node) }
/** - * batadv_neigh_node_free_ref - decrement the neighbors refcounter - * and possibly free it + * batadv_neigh_node_free_ref - decrement the neighbors refcounter and possibly + * free * @neigh_node: neigh neighbor to free */ void batadv_neigh_node_free_ref(struct batadv_neigh_node *neigh_node) { - if (atomic_dec_and_test(&neigh_node->refcount)) - batadv_neigh_node_release(neigh_node); + kref_put(&neigh_node->refcount, batadv_neigh_node_release); }
/** @@ -298,7 +299,7 @@ batadv_orig_router_get(struct batadv_orig_node *orig_node, break; }
- if (router && !atomic_inc_not_zero(&router->refcount)) + if (router && !kref_get_unless_zero(&router->refcount)) router = NULL;
rcu_read_unlock(); @@ -491,7 +492,7 @@ batadv_neigh_node_get(const struct batadv_orig_node *orig_node, if (tmp_neigh_node->if_incoming != hard_iface) continue;
- if (!atomic_inc_not_zero(&tmp_neigh_node->refcount)) + if (!kref_get_unless_zero(&tmp_neigh_node->refcount)) continue;
res = tmp_neigh_node; @@ -649,7 +650,8 @@ batadv_neigh_node_new(struct batadv_orig_node *orig_node, neigh_node->orig_node = orig_node;
/* extra reference for return */ - atomic_set(&neigh_node->refcount, 2); + kref_init(&neigh_node->refcount); + kref_get(&neigh_node->refcount);
spin_lock_bh(&orig_node->neigh_list_lock); hlist_add_head_rcu(&neigh_node->list, &orig_node->neigh_list); @@ -1084,7 +1086,7 @@ batadv_find_best_neighbor(struct batadv_priv *bat_priv, best, if_outgoing) <= 0)) continue;
- if (!atomic_inc_not_zero(&neigh->refcount)) + if (!kref_get_unless_zero(&neigh->refcount)) continue;
if (best) diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c index 99fd1df..f2410ba 100644 --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -73,7 +73,7 @@ static void _batadv_update_route(struct batadv_priv *bat_priv,
rcu_read_lock(); curr_router = rcu_dereference(orig_ifinfo->router); - if (curr_router && !atomic_inc_not_zero(&curr_router->refcount)) + if (curr_router && !kref_get_unless_zero(&curr_router->refcount)) curr_router = NULL; rcu_read_unlock();
@@ -101,7 +101,7 @@ static void _batadv_update_route(struct batadv_priv *bat_priv, batadv_neigh_node_free_ref(curr_router);
/* increase refcount of new best neighbor */ - if (neigh_node && !atomic_inc_not_zero(&neigh_node->refcount)) + if (neigh_node && !kref_get_unless_zero(&neigh_node->refcount)) neigh_node = NULL;
spin_lock_bh(&orig_node->neigh_list_lock); @@ -505,7 +505,7 @@ batadv_find_router(struct batadv_priv *bat_priv, if (!cand_router) goto next;
- if (!atomic_inc_not_zero(&cand_router->refcount)) { + if (!kref_get_unless_zero(&cand_router->refcount)) { cand_router = NULL; goto next; } @@ -524,7 +524,7 @@ batadv_find_router(struct batadv_priv *bat_priv,
/* mark the first possible candidate */ if (!first_candidate) { - atomic_inc(&cand_router->refcount); + kref_get(&cand_router->refcount); kref_get(&cand->refcount); first_candidate = cand; first_candidate_router = cand_router; diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index a5e4310..75e1b45 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -384,7 +384,7 @@ struct batadv_neigh_node { spinlock_t ifinfo_lock; /* protects ifinfo_list and its members */ struct batadv_hard_iface *if_incoming; unsigned long last_seen; - atomic_t refcount; + struct kref refcount; struct rcu_head rcu; };