Updated RCU removal of dev_rcv_lists structures in the case of CAN-interfaces

going down (in can_notifier). Thanks to Paul E. McKenny (IBM) who gave this
hint on netdev kernel mailinglist.

git-svn-id: svn://svn.berlios.de//socketcan/trunk@311 030b6a49-0b11-0410-94ab-b0dab22257f2

diff --git a/kernel/2.6/net/can/af_can.c b/kernel/2.6/net/can/af_can.c
index 307b831ca77dde7108a1b22516988b08cc3ff5be..05cbb4aa1dfb04ff2005f6c913855c14890706d0 100644 (file)
--- a/kernel/2.6/net/can/af_can.c
+++ b/kernel/2.6/net/can/af_can.c
@@ -454,29 +454,46 @@ int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask,
 }
 EXPORT_SYMBOL(can_rx_register);
 
-static void can_rcv_lists_delete(struct rcu_head *rp)
+static void can_rx_delete_list(struct hlist_head *rl)
 {
-       struct dev_rcv_lists *d = container_of(rp, struct dev_rcv_lists, rcu);
+       struct receiver *r;
+       struct hlist_node *n;
 
-       kfree(d);
+       hlist_for_each_entry_rcu(r, n, rl, list) {
+               hlist_del_rcu(&r->list);
+               kmem_cache_free(rcv_cache, r);
+       }
 }
 
-static void can_rx_delete(struct rcu_head *rp)
+/*
+ * can_rx_delete_device - rcu callback for dev_rcv_lists structure removal
+ */
+static void can_rx_delete_device(struct rcu_head *rp)
 {
-       struct receiver *r = container_of(rp, struct receiver, rcu);
+       struct dev_rcv_lists *d = container_of(rp, struct dev_rcv_lists, rcu);
+       int i;
 
-       kmem_cache_free(rcv_cache, r);
+       /* remove all receivers hooked at this netdevice */
+       can_rx_delete_list(&d->rx_err);
+       can_rx_delete_list(&d->rx_all);
+       can_rx_delete_list(&d->rx_fil);
+       can_rx_delete_list(&d->rx_inv);
+       can_rx_delete_list(&d->rx_eff);
+
+       for (i = 0; i < 2048; i++)
+               can_rx_delete_list(&d->rx_sff[i]);
+
+       kfree(d);
 }
 
-static void can_rx_delete_all(struct hlist_head *rl)
+/*
+ * can_rx_delete_receiver - rcu callback for single receiver entry removal
+ */
+static void can_rx_delete_receiver(struct rcu_head *rp)
 {
-       struct receiver *r;
-       struct hlist_node *n;
+       struct receiver *r = container_of(rp, struct receiver, rcu);
 
-       hlist_for_each_entry_rcu(r, n, rl, list) {
-               hlist_del_rcu(&r->list);
-               call_rcu(&r->rcu, can_rx_delete);
-       }
+       kmem_cache_free(rcv_cache, r);
 }
 
 /**
@@ -556,7 +573,7 @@ int can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask,
 
        /* schedule the receiver item for deletion */
        if (r)
-               call_rcu(&r->rcu, can_rx_delete);
+               call_rcu(&r->rcu, can_rx_delete_receiver);
 
        return ret;
 }
@@ -945,7 +962,6 @@ static int can_notifier(struct notifier_block *nb,
        struct net_device *dev = (struct net_device *)data;
        struct notifier *n;
        struct dev_rcv_lists *d;
-       int i;
 
        DBG("called for %s, msg = %lu\n", dev->name, msg);
 
@@ -986,25 +1002,16 @@ static int can_notifier(struct notifier_block *nb,
                spin_lock_bh(&rcv_lists_lock);
 
                d = find_dev_rcv_lists(dev);
-               if (d) {
+               if (d)
                        hlist_del_rcu(&d->list);
-
-                       /* remove all receivers hooked at this netdevice */
-                       can_rx_delete_all(&d->rx_err);
-                       can_rx_delete_all(&d->rx_all);
-                       can_rx_delete_all(&d->rx_fil);
-                       can_rx_delete_all(&d->rx_inv);
-                       can_rx_delete_all(&d->rx_eff);
-                       for (i = 0; i < 2048; i++)
-                               can_rx_delete_all(&d->rx_sff[i]);
-               } else
+               else
                        printk(KERN_ERR "can: notifier: receive list not "
                               "found for dev %s\n", dev->name);
 
                spin_unlock_bh(&rcv_lists_lock);
 
                if (d)
-                       call_rcu(&d->rcu, can_rcv_lists_delete);
+                       call_rcu(&d->rcu, can_rx_delete_device);
 
                break;
        }