[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>

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);

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 */
 };
 
 /*