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Commit 06e56ded authored by Sven Eckelmann's avatar Sven Eckelmann Committed by Antonio Quartulli
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batman-adv: Convert batadv_bla_backbone_gw 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: default avatarSven Eckelmann <sven@narfation.org>
Signed-off-by: default avatarMarek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: default avatarAntonio Quartulli <a@unstable.cc>
parent 6be4d30c

net/batman-adv/bridge_loop_avoidance.c

+23 −6
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ 
#include <linux/jhash.h>

#include <linux/jiffies.h>

#include <linux/kernel.h>

#include <linux/kref.h>

#include <linux/list.h>

#include <linux/lockdep.h>

#include <linux/netdevice.h>
@@ -143,14 +144,29 @@ static int batadv_compare_claim(const struct hlist_node *node, 
}



/**

 * batadv_compare_backbone_gw - free backbone gw

 * batadv_backbone_gw_release - release backbone gw from lists and queue for

 *  free after rcu grace period

 * @ref: kref pointer of the backbone gw

 */

static void batadv_backbone_gw_release(struct kref *ref)

{

	struct batadv_bla_backbone_gw *backbone_gw;



	backbone_gw = container_of(ref, struct batadv_bla_backbone_gw,

				   refcount);



	kfree_rcu(backbone_gw, rcu);

}



/**

 * batadv_backbone_gw_free_ref - decrement the backbone gw refcounter and

 *  possibly release it

 * @backbone_gw: backbone gateway to be free'd

 */

static void

batadv_backbone_gw_free_ref(struct batadv_bla_backbone_gw *backbone_gw)

{

	if (atomic_dec_and_test(&backbone_gw->refcount))

		kfree_rcu(backbone_gw, rcu);

	kref_put(&backbone_gw->refcount, batadv_backbone_gw_release);

}



/**
@@ -247,7 +263,7 @@ batadv_backbone_hash_find(struct batadv_priv *bat_priv, u8 *addr, 
						&search_entry))

			continue;



		if (!atomic_inc_not_zero(&backbone_gw->refcount))

		if (!kref_get_unless_zero(&backbone_gw->refcount))

			continue;



		backbone_gw_tmp = backbone_gw;
@@ -448,7 +464,8 @@ batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, u8 *orig, 
	ether_addr_copy(entry->orig, orig);



	/* one for the hash, one for returning */

	atomic_set(&entry->refcount, 2);

	kref_init(&entry->refcount);

	kref_get(&entry->refcount);



	hash_added = batadv_hash_add(bat_priv->bla.backbone_hash,

				     batadv_compare_backbone_gw,
@@ -664,7 +681,7 @@ static void batadv_bla_add_claim(struct batadv_priv *bat_priv, 
		batadv_backbone_gw_free_ref(claim->backbone_gw);

	}

	/* set (new) backbone gw */

	atomic_inc(&backbone_gw->refcount);

	kref_get(&backbone_gw->refcount);

	claim->backbone_gw = backbone_gw;



	spin_lock_bh(&backbone_gw->crc_lock);

net/batman-adv/types.h

+1 −1
Original line number Diff line number Diff line
@@ -930,7 +930,7 @@ struct batadv_bla_backbone_gw { 
	atomic_t request_sent;

	u16 crc;

	spinlock_t crc_lock; /* protects crc */

	atomic_t refcount;

	struct kref refcount;

	struct rcu_head rcu;

};