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 <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>
This commit is contained in:
Sven Eckelmann 2016-01-16 10:29:47 +01:00 committed by Antonio Quartulli
parent 727e0cd59e
commit 68a6722cc4
2 changed files with 22 additions and 7 deletions

View file

@ -30,6 +30,7 @@
#include <linux/in.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/rculist.h>
#include <linux/rcupdate.h>
@ -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,

View file

@ -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;
};