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batman-adv: Convert batadv_gw_node 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 10:29:41 +01:00 committed by Antonio Quartulli
parent 90f564dff4
commit e7aed321b8
2 changed files with 30 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

40
net/batman-adv/gateway_client.c
View File

@ -28,6 +28,7 @@
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/rculist.h>
@ -59,12 +60,29 @@
*/
#define BATADV_DHCP_CHADDR_OFFSET 28
/**
* batadv_gw_node_release - release gw_node from lists and queue for free after
* rcu grace period
* @ref: kref pointer of the gw_node
*/
static void batadv_gw_node_release(struct kref *ref)
{
struct batadv_gw_node *gw_node;
gw_node = container_of(ref, struct batadv_gw_node, refcount);
batadv_orig_node_free_ref(gw_node->orig_node);
kfree_rcu(gw_node, rcu);
}
/**
* batadv_gw_node_free_ref - decrement the gw_node refcounter and possibly
* release it
* @gw_node: gateway node to free
*/
static void batadv_gw_node_free_ref(struct batadv_gw_node *gw_node)
{
if (atomic_dec_and_test(&gw_node->refcount)) {
batadv_orig_node_free_ref(gw_node->orig_node);
kfree_rcu(gw_node, rcu);
}
kref_put(&gw_node->refcount, batadv_gw_node_release);
}
static struct batadv_gw_node *
@ -77,7 +95,7 @@ batadv_gw_get_selected_gw_node(struct batadv_priv *bat_priv)
if (!gw_node)
goto out;
if (!atomic_inc_not_zero(&gw_node->refcount))
if (!kref_get_unless_zero(&gw_node->refcount))
gw_node = NULL;
out:
@ -118,7 +136,7 @@ static void batadv_gw_select(struct batadv_priv *bat_priv,
spin_lock_bh(&bat_priv->gw.list_lock);
if (new_gw_node && !atomic_inc_not_zero(&new_gw_node->refcount))
if (new_gw_node && !kref_get_unless_zero(&new_gw_node->refcount))
new_gw_node = NULL;
curr_gw_node = rcu_dereference_protected(bat_priv->gw.curr_gw, 1);
@ -170,7 +188,7 @@ batadv_gw_get_best_gw_node(struct batadv_priv *bat_priv)
if (!router_ifinfo)
goto next;
if (!atomic_inc_not_zero(&gw_node->refcount))
if (!kref_get_unless_zero(&gw_node->refcount))
goto next;
tq_avg = router_ifinfo->bat_iv.tq_avg;
@ -188,7 +206,7 @@ batadv_gw_get_best_gw_node(struct batadv_priv *bat_priv)
if (curr_gw)
batadv_gw_node_free_ref(curr_gw);
curr_gw = gw_node;
atomic_inc(&curr_gw->refcount);
kref_get(&curr_gw->refcount);
}
break;
@ -203,7 +221,7 @@ batadv_gw_get_best_gw_node(struct batadv_priv *bat_priv)
if (curr_gw)
batadv_gw_node_free_ref(curr_gw);
curr_gw = gw_node;
atomic_inc(&curr_gw->refcount);
kref_get(&curr_gw->refcount);
}
break;
}
@ -436,7 +454,7 @@ static void batadv_gw_node_add(struct batadv_priv *bat_priv,
gw_node->orig_node = orig_node;
gw_node->bandwidth_down = ntohl(gateway->bandwidth_down);
gw_node->bandwidth_up = ntohl(gateway->bandwidth_up);
atomic_set(&gw_node->refcount, 1);
kref_init(&gw_node->refcount);
spin_lock_bh(&bat_priv->gw.list_lock);
hlist_add_head_rcu(&gw_node->list, &bat_priv->gw.list);
@ -469,7 +487,7 @@ batadv_gw_node_get(struct batadv_priv *bat_priv,
if (gw_node_tmp->orig_node != orig_node)
continue;
if (!atomic_inc_not_zero(&gw_node_tmp->refcount))
if (!kref_get_unless_zero(&gw_node_tmp->refcount))
continue;
gw_node = gw_node_tmp;

2
net/batman-adv/types.h
View File

@ -342,7 +342,7 @@ struct batadv_gw_node {
struct batadv_orig_node *orig_node;
u32 bandwidth_down;
u32 bandwidth_up;
atomic_t refcount;
struct kref refcount;
struct rcu_head rcu;
};