batman-adv: Convert batadv_tt_common_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 10:29:57 +01:00 committed by Antonio Quartulli
parent 7c12439115
commit 92dcdf09a1
2 changed files with 51 additions and 15 deletions

View File

@ -142,7 +142,7 @@ batadv_tt_hash_find(struct batadv_hashtable *hash, const u8 *addr,
if (tt->vid != vid)
continue;
if (!atomic_inc_not_zero(&tt->refcount))
if (!kref_get_unless_zero(&tt->refcount))
continue;
tt_tmp = tt;
@ -203,25 +203,59 @@ batadv_tt_global_hash_find(struct batadv_priv *bat_priv, const u8 *addr,
return tt_global_entry;
}
static void
batadv_tt_local_entry_free_ref(struct batadv_tt_local_entry *tt_local_entry)
/**
* batadv_tt_local_entry_release - release tt_local_entry from lists and queue
* for free after rcu grace period
* @ref: kref pointer of the nc_node
*/
static void batadv_tt_local_entry_release(struct kref *ref)
{
if (atomic_dec_and_test(&tt_local_entry->common.refcount))
kfree_rcu(tt_local_entry, common.rcu);
struct batadv_tt_local_entry *tt_local_entry;
tt_local_entry = container_of(ref, struct batadv_tt_local_entry,
common.refcount);
kfree_rcu(tt_local_entry, common.rcu);
}
/**
* batadv_tt_global_entry_free_ref - decrement the refcounter for a
* tt_global_entry and possibly free it
* @tt_global_entry: the object to free
* batadv_tt_local_entry_free_ref - decrement the tt_local_entry refcounter and
* possibly release it
* @tt_local_entry: tt_local_entry to be free'd
*/
static void
batadv_tt_local_entry_free_ref(struct batadv_tt_local_entry *tt_local_entry)
{
kref_put(&tt_local_entry->common.refcount,
batadv_tt_local_entry_release);
}
/**
* batadv_tt_global_entry_release - release tt_global_entry from lists and queue
* for free after rcu grace period
* @ref: kref pointer of the nc_node
*/
static void batadv_tt_global_entry_release(struct kref *ref)
{
struct batadv_tt_global_entry *tt_global_entry;
tt_global_entry = container_of(ref, struct batadv_tt_global_entry,
common.refcount);
batadv_tt_global_del_orig_list(tt_global_entry);
kfree_rcu(tt_global_entry, common.rcu);
}
/**
* batadv_tt_global_entry_free_ref - decrement the tt_global_entry refcounter
* and possibly release it
* @tt_global_entry: tt_global_entry to be free'd
*/
static void
batadv_tt_global_entry_free_ref(struct batadv_tt_global_entry *tt_global_entry)
{
if (atomic_dec_and_test(&tt_global_entry->common.refcount)) {
batadv_tt_global_del_orig_list(tt_global_entry);
kfree_rcu(tt_global_entry, common.rcu);
}
kref_put(&tt_global_entry->common.refcount,
batadv_tt_global_entry_release);
}
/**
@ -633,7 +667,8 @@ bool batadv_tt_local_add(struct net_device *soft_iface, const u8 *addr,
tt_local->common.vid = vid;
if (batadv_is_wifi_netdev(in_dev))
tt_local->common.flags |= BATADV_TT_CLIENT_WIFI;
atomic_set(&tt_local->common.refcount, 2);
kref_init(&tt_local->common.refcount);
kref_get(&tt_local->common.refcount);
tt_local->last_seen = jiffies;
tt_local->common.added_at = tt_local->last_seen;
@ -1415,7 +1450,8 @@ static bool batadv_tt_global_add(struct batadv_priv *bat_priv,
*/
if (flags & BATADV_TT_CLIENT_ROAM)
tt_global_entry->roam_at = jiffies;
atomic_set(&common->refcount, 2);
kref_init(&common->refcount);
kref_get(&common->refcount);
common->added_at = jiffies;
INIT_HLIST_HEAD(&tt_global_entry->orig_list);

View File

@ -972,7 +972,7 @@ struct batadv_tt_common_entry {
struct hlist_node hash_entry;
u16 flags;
unsigned long added_at;
atomic_t refcount;
struct kref refcount;
struct rcu_head rcu;
};