[ATM]: [lec] add reference counting to lec_arp entries

Signed-off-by: Chas Williams <chas@cmf.nrl.navy.mil>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 29 insertions, 14 deletions

diff --git a/net/atm/lec.c b/net/atm/lec.c
index 29acfb0e6d04..c5d1f9e9a647 100644
--- a/net/atm/lec.c
+++ b/net/atm/lec.c
@@ -107,6 +107,19 @@ static void lec_vcc_added(struct lec_priv *priv, struct atmlec_ioc *ioc_data,
                                             struct sk_buff *skb));
 static void lec_vcc_close(struct lec_priv *priv, struct atm_vcc *vcc);
 
+/* must be done under lec_arp_lock */
+static inline void lec_arp_hold(struct lec_arp_table *entry)
+{
+        atomic_inc(&entry->usage);
+}
+
+static inline void lec_arp_put(struct lec_arp_table *entry)
+{
+        if (atomic_dec_and_test(&entry->usage))
+                kfree(entry);
+}
+
+
 static struct lane2_ops lane2_ops = {
         lane2_resolve,          /* resolve,             spec 3.1.3 */
         lane2_associate_req,    /* associate_req,       spec 3.1.4 */
@@ -795,7 +808,7 @@ static void lec_push(struct atm_vcc *vcc, struct sk_buff *skb)
                         entry = lec_arp_find(priv, src);
                         if (entry && entry->vcc != vcc) {
                                 lec_arp_remove(priv, entry);
-                                kfree(entry);
+                                lec_arp_put(entry);
                         }
                 }
                 spin_unlock_irqrestore(&priv->lec_arp_lock, flags);
@@ -1726,7 +1739,7 @@ static void lec_arp_destroy(struct lec_priv *priv)
         for (i = 0; i < LEC_ARP_TABLE_SIZE; i++) {
                 hlist_for_each_entry_safe(entry, node, next, &priv->lec_arp_tables[i], next) {
                         lec_arp_remove(priv, entry);
-                        kfree(entry);
+                        lec_arp_put(entry);
                 }
                 INIT_HLIST_HEAD(&priv->lec_arp_tables[i]);
         }
@@ -1735,7 +1748,7 @@ static void lec_arp_destroy(struct lec_priv *priv)
                 del_timer_sync(&entry->timer);
                 lec_arp_clear_vccs(entry);
                 hlist_del(&entry->next);
-                kfree(entry);
+                lec_arp_put(entry);
         }
         INIT_HLIST_HEAD(&priv->lec_arp_empty_ones);
 
@@ -1743,7 +1756,7 @@ static void lec_arp_destroy(struct lec_priv *priv)
                 del_timer_sync(&entry->timer);
                 lec_arp_clear_vccs(entry);
                 hlist_del(&entry->next);
-                kfree(entry);
+                lec_arp_put(entry);
         }
         INIT_HLIST_HEAD(&priv->lec_no_forward);
 
@@ -1751,7 +1764,7 @@ static void lec_arp_destroy(struct lec_priv *priv)
                 /* No timer, LANEv2 7.1.20 and 2.3.5.3 */
                 lec_arp_clear_vccs(entry);
                 hlist_del(&entry->next);
-                kfree(entry);
+                lec_arp_put(entry);
         }
         INIT_HLIST_HEAD(&priv->mcast_fwds);
         priv->mcast_vcc = NULL;
@@ -1799,6 +1812,7 @@ static struct lec_arp_table *make_entry(struct lec_priv *priv,
         to_return->last_used = jiffies;
         to_return->priv = priv;
         skb_queue_head_init(&to_return->tx_wait);
+        atomic_set(&to_return->usage, 1);
         return to_return;
 }
 
@@ -1843,7 +1857,7 @@ static void lec_arp_expire_vcc(unsigned long data)
         spin_unlock_irqrestore(&priv->lec_arp_lock, flags);
 
         lec_arp_clear_vccs(to_remove);
-        kfree(to_remove);
+        lec_arp_put(to_remove);
 }
 
 /*
@@ -1891,7 +1905,7 @@ static void lec_arp_check_expire(void *data)
                                 /* Remove entry */
                                 DPRINTK("LEC:Entry timed out\n");
                                 lec_arp_remove(priv, entry);
-                                kfree(entry);
+                                lec_arp_put(entry);
                         } else {
                                 /* Something else */
                                 if ((entry->status == ESI_VC_PENDING ||
@@ -2045,7 +2059,7 @@ lec_addr_delete(struct lec_priv *priv, unsigned char *atm_addr,
                             && (permanent ||
                                 !(entry->flags & LEC_PERMANENT_FLAG))) {
                                 lec_arp_remove(priv, entry);
-                                kfree(entry);
+                                lec_arp_put(entry);
                         }
                         spin_unlock_irqrestore(&priv->lec_arp_lock, flags);
                         return 0;
@@ -2094,7 +2108,7 @@ lec_arp_update(struct lec_priv *priv, unsigned char *mac_addr,
                                         tmp->old_push = entry->old_push;
                                         tmp->last_used = jiffies;
                                         del_timer(&entry->timer);
-                                        kfree(entry);
+                                        lec_arp_put(entry);
                                         entry = tmp;
                                 } else {
                                         entry->status = ESI_FORWARD_DIRECT;
@@ -2414,7 +2428,7 @@ static void lec_vcc_close(struct lec_priv *priv, struct atm_vcc *vcc)
                 hlist_for_each_entry_safe(entry, node, next, &priv->lec_arp_tables[i], next) {
                         if (vcc == entry->vcc) {
                                 lec_arp_remove(priv, entry);
-                                kfree(entry);
+                                lec_arp_put(entry);
                                 if (priv->mcast_vcc == vcc) {
                                         priv->mcast_vcc = NULL;
                                 }
@@ -2427,7 +2441,7 @@ static void lec_vcc_close(struct lec_priv *priv, struct atm_vcc *vcc)
                         lec_arp_clear_vccs(entry);
                         del_timer(&entry->timer);
                         hlist_del(&entry->next);
-                        kfree(entry);
+                        lec_arp_put(entry);
                 }
         }
 
@@ -2436,7 +2450,7 @@ static void lec_vcc_close(struct lec_priv *priv, struct atm_vcc *vcc)
                         lec_arp_clear_vccs(entry);
                         del_timer(&entry->timer);
                         hlist_del(&entry->next);
-                        kfree(entry);
+                        lec_arp_put(entry);
                 }
         }
 
@@ -2445,7 +2459,7 @@ static void lec_vcc_close(struct lec_priv *priv, struct atm_vcc *vcc)
                         lec_arp_clear_vccs(entry);
                         /* No timer, LANEv2 7.1.20 and 2.3.5.3 */
                         hlist_del(&entry->next);
-                        kfree(entry);
+                        lec_arp_put(entry);
                 }
         }
 
@@ -2481,7 +2495,7 @@ lec_arp_check_empties(struct lec_priv *priv,
                         /* We might have got an entry */
                         if ((tmp = lec_arp_find(priv, src))) {
                                 lec_arp_remove(priv, tmp);
-                                kfree(tmp);
+                                lec_arp_put(tmp);
                         }
                         hlist_del(&entry->next);
                         lec_arp_add(priv, entry);
diff --git a/net/atm/lec_arpc.h b/net/atm/lec_arpc.h
index 125df36d33b8..ec67435a40a6 100644
--- a/net/atm/lec_arpc.h
+++ b/net/atm/lec_arpc.h
@@ -47,6 +47,7 @@ struct lec_arp_table {
                                          * the length of the tlvs array
                                          */
         struct sk_buff_head tx_wait;    /* wait queue for outgoing packets */
+        atomic_t usage;                 /* usage count */
 };
 
 /*