batman-adv: Convert batadv_hard_iface 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>

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index affcbb5..bf0e7d6 100644 (file)
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -644,10 +644,10 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff,
        unsigned char *skb_buff;
        unsigned int skb_size;
 
-       if (!atomic_inc_not_zero(&if_incoming->refcount))
+       if (!kref_get_unless_zero(&if_incoming->refcount))
                return;
 
-       if (!atomic_inc_not_zero(&if_outgoing->refcount))
+       if (!kref_get_unless_zero(&if_outgoing->refcount))
                goto out_free_incoming;
 
        /* own packet should always be scheduled */

diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index b17e272..fb2d9c0 100644 (file)
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -18,6 +18,7 @@
 #include "hard-interface.h"
 #include "main.h"
 
+#include <linux/atomic.h>
 #include <linux/bug.h>
 #include <linux/byteorder/generic.h>
 #include <linux/errno.h>
@@ -26,6 +27,7 @@
 #include <linux/if_ether.h>
 #include <linux/if.h>
 #include <linux/kernel.h>
+#include <linux/kref.h>
 #include <linux/list.h>
 #include <linux/netdevice.h>
 #include <linux/printk.h>
@@ -50,10 +52,13 @@
 /**
  * batadv_hardif_release - release hard interface from lists and queue for
  *  free after rcu grace period
- * @hard_iface: the hard interface to free
+ * @ref: kref pointer of the hard interface
  */
-void batadv_hardif_release(struct batadv_hard_iface *hard_iface)
+void batadv_hardif_release(struct kref *ref)
 {
+       struct batadv_hard_iface *hard_iface;
+
+       hard_iface = container_of(ref, struct batadv_hard_iface, refcount);
        dev_put(hard_iface->net_dev);
 
        kfree_rcu(hard_iface, rcu);
@@ -67,7 +72,7 @@ batadv_hardif_get_by_netdev(const struct net_device *net_dev)
        rcu_read_lock();
        list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
                if (hard_iface->net_dev == net_dev &&
-                   atomic_inc_not_zero(&hard_iface->refcount))
+                   kref_get_unless_zero(&hard_iface->refcount))
                        goto out;
        }
 
@@ -172,7 +177,7 @@ batadv_hardif_get_active(const struct net_device *soft_iface)
                        continue;
 
                if (hard_iface->if_status == BATADV_IF_ACTIVE &&
-                   atomic_inc_not_zero(&hard_iface->refcount))
+                   kref_get_unless_zero(&hard_iface->refcount))
                        goto out;
        }
 
@@ -206,7 +211,7 @@ static void batadv_primary_if_select(struct batadv_priv *bat_priv,
 
        ASSERT_RTNL();
 
-       if (new_hard_iface && !atomic_inc_not_zero(&new_hard_iface->refcount))
+       if (new_hard_iface && !kref_get_unless_zero(&new_hard_iface->refcount))
                new_hard_iface = NULL;
 
        curr_hard_iface = rcu_dereference_protected(bat_priv->primary_if, 1);
@@ -434,7 +439,7 @@ int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
        if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
                goto out;
 
-       if (!atomic_inc_not_zero(&hard_iface->refcount))
+       if (!kref_get_unless_zero(&hard_iface->refcount))
                goto out;
 
        soft_iface = dev_get_by_name(&init_net, iface_name);
@@ -655,7 +660,8 @@ batadv_hardif_add_interface(struct net_device *net_dev)
                hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
 
        /* extra reference for return */
-       atomic_set(&hard_iface->refcount, 2);
+       kref_init(&hard_iface->refcount);
+       kref_get(&hard_iface->refcount);
 
        batadv_check_known_mac_addr(hard_iface->net_dev);
        list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);

diff --git a/net/batman-adv/hard-interface.h b/net/batman-adv/hard-interface.h
index 9eb08ad..5cecc6b 100644 (file)
--- a/net/batman-adv/hard-interface.h
+++ b/net/batman-adv/hard-interface.h
@@ -20,8 +20,8 @@
 
 #include "main.h"
 
-#include <linux/atomic.h>
 #include <linux/compiler.h>
+#include <linux/kref.h>
 #include <linux/notifier.h>
 #include <linux/rcupdate.h>
 #include <linux/stddef.h>
@@ -61,18 +61,16 @@ void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
 void batadv_hardif_remove_interfaces(void);
 int batadv_hardif_min_mtu(struct net_device *soft_iface);
 void batadv_update_min_mtu(struct net_device *soft_iface);
-void batadv_hardif_release(struct batadv_hard_iface *hard_iface);
+void batadv_hardif_release(struct kref *ref);
 
 /**
- * batadv_hardif_free_ref - decrement the hard interface refcounter and
- *  possibly release it
+ * batadv_hardif_free_ref - decrement the hard interface refcounter and possibly
+ *  release it
  * @hard_iface: the hard interface to free
  */
-static inline void
-batadv_hardif_free_ref(struct batadv_hard_iface *hard_iface)
+static inline void batadv_hardif_free_ref(struct batadv_hard_iface *hard_iface)
 {
-       if (atomic_dec_and_test(&hard_iface->refcount))
-               batadv_hardif_release(hard_iface);
+       kref_put(&hard_iface->refcount, batadv_hardif_release);
 }
 
 static inline struct batadv_hard_iface *
@@ -85,7 +83,7 @@ batadv_primary_if_get_selected(struct batadv_priv *bat_priv)
        if (!hard_iface)
                goto out;
 
-       if (!atomic_inc_not_zero(&hard_iface->refcount))
+       if (!kref_get_unless_zero(&hard_iface->refcount))
                hard_iface = NULL;
 
 out:

diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c
index 9e3dbd8..bf27007 100644 (file)
--- a/net/batman-adv/originator.c
+++ b/net/batman-adv/originator.c
@@ -367,7 +367,7 @@ batadv_orig_ifinfo_new(struct batadv_orig_node *orig_node,
                goto out;
 
        if (if_outgoing != BATADV_IF_DEFAULT &&
-           !atomic_inc_not_zero(&if_outgoing->refcount)) {
+           !kref_get_unless_zero(&if_outgoing->refcount)) {
                kfree(orig_ifinfo);
                orig_ifinfo = NULL;
                goto out;
@@ -447,7 +447,7 @@ batadv_neigh_ifinfo_new(struct batadv_neigh_node *neigh,
        if (!neigh_ifinfo)
                goto out;
 
-       if (if_outgoing && !atomic_inc_not_zero(&if_outgoing->refcount)) {
+       if (if_outgoing && !kref_get_unless_zero(&if_outgoing->refcount)) {
                kfree(neigh_ifinfo);
                neigh_ifinfo = NULL;
                goto out;
@@ -524,7 +524,7 @@ batadv_hardif_neigh_create(struct batadv_hard_iface *hard_iface,
        if (hardif_neigh)
                goto out;
 
-       if (!atomic_inc_not_zero(&hard_iface->refcount))
+       if (!kref_get_unless_zero(&hard_iface->refcount))
                goto out;
 
        hardif_neigh = kzalloc(sizeof(*hardif_neigh), GFP_ATOMIC);
@@ -635,7 +635,7 @@ batadv_neigh_node_new(struct batadv_orig_node *orig_node,
        if (!neigh_node)
                goto out;
 
-       if (!atomic_inc_not_zero(&hard_iface->refcount)) {
+       if (!kref_get_unless_zero(&hard_iface->refcount)) {
                kfree(neigh_node);
                neigh_node = NULL;
                goto out;

diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h
index 68ca39e..74cb263 100644 (file)
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -111,7 +111,7 @@ struct batadv_hard_iface {
        struct net_device *net_dev;
        u8 num_bcasts;
        struct kobject *hardif_obj;
-       atomic_t refcount;
+       struct kref refcount;
        struct packet_type batman_adv_ptype;
        struct net_device *soft_iface;
        struct rcu_head rcu;