3 files changed, 96 insertions, 119 deletions

diff --git a/net/can/af_can.c b/net/can/af_can.c
index 51adc4c..bc18b08 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -77,8 +77,8 @@ static int stats_timer __read_mostly = 1;
 module_param(stats_timer, int, S_IRUGO);
 MODULE_PARM_DESC(stats_timer, "enable timer for statistics (default:on)");
 
-HLIST_HEAD(can_rx_dev_list);
-static struct dev_rcv_lists can_rx_alldev_list;
+/* receive filters subscribed for 'all' CAN devices */
+struct dev_rcv_lists can_rx_alldev_list;
 static DEFINE_SPINLOCK(can_rcvlists_lock);
 
 static struct kmem_cache *rcv_cache __read_mostly;
@@ -292,28 +292,10 @@ EXPORT_SYMBOL(can_send);
 
 static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev)
 {
-	struct dev_rcv_lists *d = NULL;
-	struct hlist_node *n;
-
-	/*
-	 * find receive list for this device
-	 *
-	 * The hlist_for_each_entry*() macros curse through the list
-	 * using the pointer variable n and set d to the containing
-	 * struct in each list iteration.  Therefore, after list
-	 * iteration, d is unmodified when the list is empty, and it
-	 * points to last list element, when the list is non-empty
-	 * but no match in the loop body is found.  I.e. d is *not*
-	 * NULL when no match is found.  We can, however, use the
-	 * cursor variable n to decide if a match was found.
-	 */
-
-	hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) {
-		if (d->dev == dev)
-			break;
-	}
-
-	return n ? d : NULL;
+	if (!dev)
+		return &can_rx_alldev_list;
+	else
+		return (struct dev_rcv_lists *)dev->ml_priv;
 }
 
 /**
@@ -468,16 +450,6 @@ int can_rx_register(struct net_device *dev, canid_t can_id, canid_t mask,
 EXPORT_SYMBOL(can_rx_register);
 
 /*
- * can_rx_delete_device - rcu callback for dev_rcv_lists structure removal
- */
-static void can_rx_delete_device(struct rcu_head *rp)
-{
-	struct dev_rcv_lists *d = container_of(rp, struct dev_rcv_lists, rcu);
-
-	kfree(d);
-}
-
-/*
  * can_rx_delete_receiver - rcu callback for single receiver entry removal
  */
 static void can_rx_delete_receiver(struct rcu_head *rp)
@@ -541,7 +513,6 @@ void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask,
 		       "dev %s, id %03X, mask %03X\n",
 		       DNAME(dev), can_id, mask);
 		r = NULL;
-		d = NULL;
 		goto out;
 	}
 
@@ -552,10 +523,10 @@ void can_rx_unregister(struct net_device *dev, canid_t can_id, canid_t mask,
 		can_pstats.rcv_entries--;
 
 	/* remove device structure requested by NETDEV_UNREGISTER */
-	if (d->remove_on_zero_entries && !d->entries)
-		hlist_del_rcu(&d->list);
-	else
-		d = NULL;
+	if (d->remove_on_zero_entries && !d->entries) {
+		kfree(d);
+		dev->ml_priv = NULL;
+	}
 
  out:
 	spin_unlock(&can_rcvlists_lock);
@@ -563,10 +534,6 @@ void 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_receiver);
-
-	/* schedule the device structure for deletion */
-	if (d)
-		call_rcu(&d->rcu, can_rx_delete_device);
 }
 EXPORT_SYMBOL(can_rx_unregister);
 
@@ -780,48 +747,35 @@ static int can_notifier(struct notifier_block *nb, unsigned long msg,
 
 	case NETDEV_REGISTER:
 
-		/*
-		 * create new dev_rcv_lists for this device
-		 *
-		 * N.B. zeroing the struct is the correct initialization
-		 * for the embedded hlist_head structs.
-		 * Another list type, e.g. list_head, would require
-		 * explicit initialization.
-		 */
-
+		/* create new dev_rcv_lists for this device */
 		d = kzalloc(sizeof(*d), GFP_KERNEL);
 		if (!d) {
 			printk(KERN_ERR
 			       "can: allocation of receive list failed\n");
 			return NOTIFY_DONE;
 		}
-		d->dev = dev;
-
-		spin_lock(&can_rcvlists_lock);
-		hlist_add_head_rcu(&d->list, &can_rx_dev_list);
-		spin_unlock(&can_rcvlists_lock);
+		BUG_ON(dev->ml_priv);
+		dev->ml_priv = d;
 
 		break;
 
 	case NETDEV_UNREGISTER:
 		spin_lock(&can_rcvlists_lock);
 
-		d = find_dev_rcv_lists(dev);
+		d = dev->ml_priv;
 		if (d) {
-			if (d->entries) {
+			if (d->entries)
 				d->remove_on_zero_entries = 1;
-				d = NULL;
-			} else
-				hlist_del_rcu(&d->list);
+			else {
+				kfree(d);
+				dev->ml_priv = NULL;
+			}
 		} else
 			printk(KERN_ERR "can: notifier: receive list not "
 			       "found for dev %s\n", dev->name);
 
 		spin_unlock(&can_rcvlists_lock);
 
-		if (d)
-			call_rcu(&d->rcu, can_rx_delete_device);
-
 		break;
 	}
 
@@ -853,21 +807,13 @@ static __init int can_init(void)
 {
 	printk(banner);
 
+	memset(&can_rx_alldev_list, 0, sizeof(can_rx_alldev_list));
+
 	rcv_cache = kmem_cache_create("can_receiver", sizeof(struct receiver),
 				      0, 0, NULL);
 	if (!rcv_cache)
 		return -ENOMEM;
 
-	/*
-	 * Insert can_rx_alldev_list for reception on all devices.
-	 * This struct is zero initialized which is correct for the
-	 * embedded hlist heads, the dev pointer, and the entries counter.
-	 */
-
-	spin_lock(&can_rcvlists_lock);
-	hlist_add_head_rcu(&can_rx_alldev_list.list, &can_rx_dev_list);
-	spin_unlock(&can_rcvlists_lock);
-
 	if (stats_timer) {
 		/* the statistics are updated every second (timer triggered) */
 		setup_timer(&can_stattimer, can_stat_update, 0);
@@ -887,8 +833,7 @@ static __init int can_init(void)
 
 static __exit void can_exit(void)
 {
-	struct dev_rcv_lists *d;
-	struct hlist_node *n, *next;
+	struct net_device *dev;
 
 	if (stats_timer)
 		del_timer(&can_stattimer);
@@ -900,14 +845,19 @@ static __exit void can_exit(void)
 	unregister_netdevice_notifier(&can_netdev_notifier);
 	sock_unregister(PF_CAN);
 
-	/* remove can_rx_dev_list */
-	spin_lock(&can_rcvlists_lock);
-	hlist_del(&can_rx_alldev_list.list);
-	hlist_for_each_entry_safe(d, n, next, &can_rx_dev_list, list) {
-		hlist_del(&d->list);
-		kfree(d);
+	/* remove created dev_rcv_lists from still registered CAN devices */
+	rcu_read_lock();
+	for_each_netdev_rcu(&init_net, dev) {
+		if (dev->type == ARPHRD_CAN && dev->ml_priv){
+
+			struct dev_rcv_lists *d = dev->ml_priv;
+
+			BUG_ON(d->entries);
+			kfree(d);
+			dev->ml_priv = NULL;
+		}
 	}
-	spin_unlock(&can_rcvlists_lock);
+	rcu_read_unlock();
 
 	rcu_barrier(); /* Wait for completion of call_rcu()'s */
 
diff --git a/net/can/af_can.h b/net/can/af_can.h
index 18f91e3..34253b8 100644
--- a/net/can/af_can.h
+++ b/net/can/af_can.h
@@ -63,10 +63,8 @@ struct receiver {
 
 enum { RX_ERR, RX_ALL, RX_FIL, RX_INV, RX_EFF, RX_MAX };
 
+/* per device receive filters linked at dev->ml_priv */
 struct dev_rcv_lists {
-	struct hlist_node list;
-	struct rcu_head rcu;
-	struct net_device *dev;
 	struct hlist_head rx[RX_MAX];
 	struct hlist_head rx_sff[0x800];
 	int remove_on_zero_entries;
diff --git a/net/can/proc.c b/net/can/proc.c
index 9b9ad29..f4265cc 100644
--- a/net/can/proc.c
+++ b/net/can/proc.c
@@ -45,6 +45,7 @@
 #include <linux/proc_fs.h>
 #include <linux/list.h>
 #include <linux/rcupdate.h>
+#include <linux/if_arp.h>
 #include <linux/can/core.h>
 
 #include "af_can.h"
@@ -84,6 +85,9 @@ static const char rx_list_name[][8] = {
 	[RX_EFF] = "rx_eff",
 };
 
+/* receive filters subscribed for 'all' CAN devices */
+extern struct dev_rcv_lists can_rx_alldev_list;
+
 /*
  * af_can statistics stuff
  */
@@ -190,10 +194,6 @@ void can_stat_update(unsigned long data)
 
 /*
  * proc read functions
- *
- * From known use-cases we expect about 10 entries in a receive list to be
- * printed in the proc_fs. So PAGE_SIZE is definitely enough space here.
- *
  */
 
 static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
@@ -202,7 +202,6 @@ static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
 	struct receiver *r;
 	struct hlist_node *n;
 
-	rcu_read_lock();
 	hlist_for_each_entry_rcu(r, n, rx_list, list) {
 		char *fmt = (r->can_id & CAN_EFF_FLAG)?
 			"   %-5s  %08X  %08x  %08x  %08x  %8ld  %s\n" :
@@ -212,7 +211,6 @@ static void can_print_rcvlist(struct seq_file *m, struct hlist_head *rx_list,
 				(unsigned long)r->func, (unsigned long)r->data,
 				r->matches, r->ident);
 	}
-	rcu_read_unlock();
 }
 
 static void can_print_recv_banner(struct seq_file *m)
@@ -346,24 +344,39 @@ static const struct file_operations can_version_proc_fops = {
 	.release	= single_release,
 };
 
+static inline void can_rcvlist_proc_show_one(struct seq_file *m, int idx,
+					     struct net_device *dev,
+					     struct dev_rcv_lists *d)
+{
+	if (!hlist_empty(&d->rx[idx])) {
+		can_print_recv_banner(m);
+		can_print_rcvlist(m, &d->rx[idx], dev);
+	} else
+		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
+
+}
+
 static int can_rcvlist_proc_show(struct seq_file *m, void *v)
 {
 	/* double cast to prevent GCC warning */
 	int idx = (int)(long)m->private;
+	struct net_device *dev;
 	struct dev_rcv_lists *d;
-	struct hlist_node *n;
 
 	seq_printf(m, "\nreceive list '%s':\n", rx_list_name[idx]);
 
 	rcu_read_lock();
-	hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) {
 
-		if (!hlist_empty(&d->rx[idx])) {
-			can_print_recv_banner(m);
-			can_print_rcvlist(m, &d->rx[idx], d->dev);
-		} else
-			seq_printf(m, "  (%s: no entry)\n", DNAME(d->dev));
+	/* receive list for 'all' CAN devices (dev == NULL) */
+	d = &can_rx_alldev_list;
+	can_rcvlist_proc_show_one(m, idx, NULL, d);
+
+	/* receive list for registered CAN devices */
+	for_each_netdev_rcu(&init_net, dev) {
+		if (dev->type == ARPHRD_CAN && dev->ml_priv)
+			can_rcvlist_proc_show_one(m, idx, dev, dev->ml_priv);
 	}
+
 	rcu_read_unlock();
 
 	seq_putc(m, '\n');
@@ -383,34 +396,50 @@ static const struct file_operations can_rcvlist_proc_fops = {
 	.release	= single_release,
 };
 
+static inline void can_rcvlist_sff_proc_show_one(struct seq_file *m,
+						 struct net_device *dev,
+						 struct dev_rcv_lists *d)
+{
+	int i;
+	int all_empty = 1;
+
+	/* check wether at least one list is non-empty */
+	for (i = 0; i < 0x800; i++)
+		if (!hlist_empty(&d->rx_sff[i])) {
+			all_empty = 0;
+			break;
+		}
+
+	if (!all_empty) {
+		can_print_recv_banner(m);
+		for (i = 0; i < 0x800; i++) {
+			if (!hlist_empty(&d->rx_sff[i]))
+				can_print_rcvlist(m, &d->rx_sff[i], dev);
+		}
+	} else
+		seq_printf(m, "  (%s: no entry)\n", DNAME(dev));
+}
+
 static int can_rcvlist_sff_proc_show(struct seq_file *m, void *v)
 {
+	struct net_device *dev;
 	struct dev_rcv_lists *d;
-	struct hlist_node *n;
 
 	/* RX_SFF */
 	seq_puts(m, "\nreceive list 'rx_sff':\n");
 
 	rcu_read_lock();
-	hlist_for_each_entry_rcu(d, n, &can_rx_dev_list, list) {
-		int i, all_empty = 1;
-		/* check wether at least one list is non-empty */
-		for (i = 0; i < 0x800; i++)
-			if (!hlist_empty(&d->rx_sff[i])) {
-				all_empty = 0;
-				break;
-			}
-
-		if (!all_empty) {
-			can_print_recv_banner(m);
-			for (i = 0; i < 0x800; i++) {
-				if (!hlist_empty(&d->rx_sff[i]))
-					can_print_rcvlist(m, &d->rx_sff[i],
-							  d->dev);
-			}
-		} else
-			seq_printf(m, "  (%s: no entry)\n", DNAME(d->dev));
+
+	/* sff receive list for 'all' CAN devices (dev == NULL) */
+	d = &can_rx_alldev_list;
+	can_rcvlist_sff_proc_show_one(m, NULL, d);
+
+	/* sff receive list for registered CAN devices */
+	for_each_netdev_rcu(&init_net, dev) {
+		if (dev->type == ARPHRD_CAN && dev->ml_priv)
+			can_rcvlist_sff_proc_show_one(m, dev, dev->ml_priv);
 	}
+
 	rcu_read_unlock();
 
 	seq_putc(m, '\n');