From 68a6722cc41f92ceffa8915bfe6a9c0307f2abeb Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Sat, 16 Jan 2016 10:29:47 +0100 Subject: [PATCH] batman-adv: Convert batadv_dat_entry to kref 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 Signed-off-by: Marek Lindner Signed-off-by: Antonio Quartulli --- net/batman-adv/distributed-arp-table.c | 27 ++++++++++++++++++++------ net/batman-adv/types.h | 2 +- 2 files changed, 22 insertions(+), 7 deletions(-) diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index 017fffe9a5b8..921e25255cab 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include #include @@ -61,15 +62,28 @@ static void batadv_dat_start_timer(struct batadv_priv *bat_priv) msecs_to_jiffies(10000)); } +/** + * batadv_dat_entry_release - release dat_entry from lists and queue for free + * after rcu grace period + * @ref: kref pointer of the dat_entry + */ +static void batadv_dat_entry_release(struct kref *ref) +{ + struct batadv_dat_entry *dat_entry; + + dat_entry = container_of(ref, struct batadv_dat_entry, refcount); + + kfree_rcu(dat_entry, rcu); +} + /** * batadv_dat_entry_free_ref - decrement the dat_entry refcounter and possibly - * free it - * @dat_entry: the entry to free + * release it + * @dat_entry: dat_entry to be free'd */ static void batadv_dat_entry_free_ref(struct batadv_dat_entry *dat_entry) { - if (atomic_dec_and_test(&dat_entry->refcount)) - kfree_rcu(dat_entry, rcu); + kref_put(&dat_entry->refcount, batadv_dat_entry_release); } /** @@ -281,7 +295,7 @@ batadv_dat_entry_hash_find(struct batadv_priv *bat_priv, __be32 ip, if (dat_entry->ip != ip) continue; - if (!atomic_inc_not_zero(&dat_entry->refcount)) + if (!kref_get_unless_zero(&dat_entry->refcount)) continue; dat_entry_tmp = dat_entry; @@ -326,7 +340,8 @@ static void batadv_dat_entry_add(struct batadv_priv *bat_priv, __be32 ip, dat_entry->vid = vid; ether_addr_copy(dat_entry->mac_addr, mac_addr); dat_entry->last_update = jiffies; - atomic_set(&dat_entry->refcount, 2); + kref_init(&dat_entry->refcount); + kref_get(&dat_entry->refcount); hash_added = batadv_hash_add(bat_priv->dat.hash, batadv_compare_dat, batadv_hash_dat, dat_entry, diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index b3d9b5b566a2..9df8f39e4785 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -1230,7 +1230,7 @@ struct batadv_dat_entry { unsigned short vid; unsigned long last_update; struct hlist_node hash_entry; - atomic_t refcount; + struct kref refcount; struct rcu_head rcu; };