Subject: [PATCH] Rework dev_base via list_head

From: Pavel Emelianov <[email-masked]>
Date: Wed, 02 May 2007 17:40:56 +0400

Cleanup of dev_base list use, with the aim to simplify making
device list per-namespace. In almost every occasion, use of
dev_base variable and dev->next pointer could be easily replaced
by  for_each_netdev loop. A few most complicated places were
converted to using first_netdev()/next_netdev().

Fits 2.6.21-rc7 tree.

Signed-off-by: Pavel Emelianov <[email-masked]>
Acked-by: Kirill Korotaev <[email-masked]>

---

diff --git a/arch/s390/appldata/appldata_net_sum.c b/arch/s390/appldata/appldata_net_sum.c
index f64b8c8..c271c9e 100644
--- a/arch/s390/appldata/appldata_net_sum.c
+++ b/arch/s390/appldata/appldata_net_sum.c
@@ -107,7 +107,7 @@ static void appldata_get_net_sum_data(vo
 	tx_dropped = 0;
 	collisions = 0;
 	read_lock(&dev_base_lock);
-	for (dev = dev_base; dev != NULL; dev = dev->next) {
+	for_each_netdev(dev) {
 		if (dev->get_stats == NULL) {
 			continue;
 		}
diff --git a/arch/sparc64/solaris/ioctl.c b/arch/sparc64/solaris/ioctl.c
index 330743c..18352a4 100644
--- a/arch/sparc64/solaris/ioctl.c
+++ b/arch/sparc64/solaris/ioctl.c
@@ -686,7 +686,8 @@ static inline int solaris_i(unsigned int
 			int i = 0;
 			
 			read_lock_bh(&dev_base_lock);
-			for (d = dev_base; d; d = d->next) i++;
+			for_each_netdev(d)
+				i++;
 			read_unlock_bh(&dev_base_lock);
 
 			if (put_user (i, (int __user *)A(arg)))
diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index 8d17d8d..236ec10 100644
--- a/drivers/block/aoe/aoecmd.c
+++ b/drivers/block/aoe/aoecmd.c
@@ -193,15 +193,15 @@ aoecmd_cfg_pkts(ushort aoemajor, unsigne
 	sl = sl_tail = NULL;
 
 	read_lock(&dev_base_lock);
-	for (ifp = dev_base; ifp; dev_put(ifp), ifp = ifp->next) {
+	for_each_netdev(ifp) {
 		dev_hold(ifp);
 		if (!is_aoe_netif(ifp))
-			continue;
+			goto cont;
 
 		skb = new_skb(sizeof *h + sizeof *ch);
 		if (skb == NULL) {
 			printk(KERN_INFO "aoe: skb alloc failure\n");
-			continue;
+			goto cont;
 		}
 		skb_put(skb, sizeof *h + sizeof *ch);
 		skb->dev = ifp;
@@ -220,6 +220,8 @@ aoecmd_cfg_pkts(ushort aoemajor, unsigne
 
 		skb->next = sl;
 		sl = skb;
+cont:
+		dev_put(ifp);
 	}
 	read_unlock(&dev_base_lock);
 
diff --git a/drivers/net/wireless/strip.c b/drivers/net/wireless/strip.c
index f5ce1c6..200d131 100644
--- a/drivers/net/wireless/strip.c
+++ b/drivers/net/wireless/strip.c
@@ -1971,8 +1971,7 @@ static struct net_device *get_strip_dev(
 		      sizeof(zero_address))) {
 		struct net_device *dev;
 		read_lock_bh(&dev_base_lock);
-		dev = dev_base;
-		while (dev) {
+		for_each_netdev(dev) {
 			if (dev->type == strip_info->dev->type &&
 			    !memcmp(dev->dev_addr,
 				    &strip_info->true_dev_addr,
@@ -1983,7 +1982,6 @@ static struct net_device *get_strip_dev(
 				read_unlock_bh(&dev_base_lock);
 				return (dev);
 			}
-			dev = dev->next;
 		}
 		read_unlock_bh(&dev_base_lock);
 	}
diff --git a/drivers/parisc/led.c b/drivers/parisc/led.c
index d190c05..5db0526 100644
--- a/drivers/parisc/led.c
+++ b/drivers/parisc/led.c
@@ -365,7 +365,7 @@ static __inline__ int led_get_net_activi
 	 * for reading should be OK */
 	read_lock(&dev_base_lock);
 	rcu_read_lock();
-	for (dev = dev_base; dev; dev = dev->next) {
+	for_each_netdev(dev) {
 	    struct net_device_stats *stats;
 	    struct in_device *in_dev = __in_dev_get_rcu(dev);
 	    if (!in_dev || !in_dev->ifa_list)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 1a52854..7038e43 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -302,7 +302,7 @@ struct net_device
 
 	unsigned long		state;
 
-	struct net_device	*next;
+	struct list_head	dev_list;
 	
 	/* The device initialization function. Called only once. */
 	int			(*init)(struct net_device *dev);
@@ -569,9 +569,31 @@ struct packet_type {
 #include <linux/notifier.h>
 
 extern struct net_device		loopback_dev;		/* The loopback */
-extern struct net_device		*dev_base;		/* All devices */
+extern struct list_head			dev_base_head;		/* All devices */
 extern rwlock_t				dev_base_lock;		/* Device list lock */
 
+#define for_each_netdev(d)		\
+		list_for_each_entry(d, &dev_base_head, dev_list)
+#define for_each_netdev_safe(d, n)	\
+		list_for_each_entry_safe(d, n, &dev_base_head, dev_list)
+#define for_each_netdev_continue(d)		\
+		list_for_each_entry_continue(d, &dev_base_head, dev_list)
+#define net_device_entry(lh)	list_entry(lh, struct net_device, dev_list)
+
+static inline struct net_device *next_net_device(struct net_device *dev)
+{
+	struct list_head *lh;
+
+	lh = dev->dev_list.next;
+	return lh == &dev_base_head ? NULL : net_device_entry(lh);
+}
+
+static inline struct net_device *first_net_device(void)
+{
+	return list_empty(&dev_base_head) ? NULL :
+		net_device_entry(dev_base_head.next);
+}
+
 extern int 			netdev_boot_setup_check(struct net_device *dev);
 extern unsigned long		netdev_boot_base(const char *prefix, int unit);
 extern struct net_device    *dev_getbyhwaddr(unsigned short type, char *hwaddr);
diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index eb1c71e..8e5e84e 100644
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -117,8 +117,7 @@ static void __exit vlan_cleanup_devices(
 	struct net_device *dev, *nxt;
 
 	rtnl_lock();
-	for (dev = dev_base; dev; dev = nxt) {
-		nxt = dev->next;
+	for_each_netdev_safe(dev, nxt) {
 		if (dev->priv_flags & IFF_802_1Q_VLAN) {
 			unregister_vlan_dev(VLAN_DEV_INFO(dev)->real_dev,
 					    VLAN_DEV_INFO(dev)->vlan_id);
diff --git a/net/8021q/vlanproc.c b/net/8021q/vlanproc.c
index 5e24f72..d216a64 100644
--- a/net/8021q/vlanproc.c
+++ b/net/8021q/vlanproc.c
@@ -237,13 +237,9 @@ int vlan_proc_rem_dev(struct net_device 
  * The following few functions build the content of /proc/net/vlan/config
  */
 
-/* starting at dev, find a VLAN device */
-static struct net_device *vlan_skip(struct net_device *dev)
+static inline int is_vlan_dev(struct net_device *dev)
 {
-	while (dev && !(dev->priv_flags & IFF_802_1Q_VLAN))
-		dev = dev->next;
-
-	return dev;
+	return dev->priv_flags & IFF_802_1Q_VLAN;
 }
 
 /* start read of /proc/net/vlan/config */
@@ -257,19 +253,35 @@ static void *vlan_seq_start(struct seq_f
 	if (*pos == 0)
 		return SEQ_START_TOKEN;
 
-	for (dev = vlan_skip(dev_base); dev && i < *pos;
-	     dev = vlan_skip(dev->next), ++i);
+	for_each_netdev(dev) {
+		if (!is_vlan_dev(dev))
+			continue;
+
+		if (i++ == *pos)
+			return dev;
+	}
 
-	return  (i == *pos) ? dev : NULL;
+	return  NULL;
 }
 
 static void *vlan_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
+	struct net_device *dev;
+
 	++*pos;
 
-	return vlan_skip((v == SEQ_START_TOKEN)
-			    ? dev_base
-			    : ((struct net_device *)v)->next);
+	dev = (struct net_device *)v;
+	if (v == SEQ_START_TOKEN)
+		dev = net_device_entry(&dev_base_head);
+
+	for_each_netdev_continue(dev) {
+		if (!is_vlan_dev(dev))
+			continue;
+
+		return dev;
+	}
+
+	return NULL;
 }
 
 static void vlan_seq_stop(struct seq_file *seq, void *v)
diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
index f3a2e29..60b8f90 100644
--- a/net/bridge/br_if.c
+++ b/net/bridge/br_if.c
@@ -471,11 +471,9 @@ void __exit br_cleanup_bridges(void)
 	struct net_device *dev, *nxt;
 
 	rtnl_lock();
-	for (dev = dev_base; dev; dev = nxt) {
-		nxt = dev->next;
+	for_each_netdev_safe(dev, nxt)
 		if (dev->priv_flags & IFF_EBRIDGE)
 			del_br(dev->priv);
-	}
 	rtnl_unlock();
 
 }
diff --git a/net/bridge/br_ioctl.c b/net/bridge/br_ioctl.c
index 147015f..4274e5d 100644
--- a/net/bridge/br_ioctl.c
+++ b/net/bridge/br_ioctl.c
@@ -27,7 +27,9 @@ static int get_bridge_ifindices(int *ind
 	struct net_device *dev;
 	int i = 0;
 
-	for (dev = dev_base; dev && i < num; dev = dev->next) {
+	for_each_netdev(dev) {
+		if (i >= num)
+			break;
 		if (dev->priv_flags & IFF_EBRIDGE)
 			indices[i++] = dev->ifindex;
 	}
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
index 7d68b24..4c13d3a 100644
--- a/net/bridge/br_netlink.c
+++ b/net/bridge/br_netlink.c
@@ -111,7 +111,8 @@ static int br_dump_ifinfo(struct sk_buff
 	int idx;
 
 	read_lock(&dev_base_lock);
-	for (dev = dev_base, idx = 0; dev; dev = dev->next) {
+	idx = 0;
+	for_each_netdev(dev) {
 		/* not a bridge port */
 		if (dev->br_port == NULL || idx < cb->args[0])
 			goto skip;
diff --git a/net/core/dev.c b/net/core/dev.c
index 4dc93cc..df7836f 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -156,13 +156,13 @@ static spinlock_t net_dma_event_lock;
 #endif
 
 /*
- * The @dev_base list is protected by @dev_base_lock and the rtnl
+ * The @dev_base_head list is protected by @dev_base_lock and the rtnl
  * semaphore.
  *
  * Pure readers hold dev_base_lock for reading.
  *
  * Writers must hold the rtnl semaphore while they loop through the
- * dev_base list, and hold dev_base_lock for writing when they do the
+ * dev_base_head list, and hold dev_base_lock for writing when they do the
  * actual updates.  This allows pure readers to access the list even
  * while a writer is preparing to update it.
  *
@@ -174,11 +174,10 @@ static spinlock_t net_dma_event_lock;
  * unregister_netdevice(), which must be called with the rtnl
  * semaphore held.
  */
-struct net_device *dev_base;
-static struct net_device **dev_tail = &dev_base;
+LIST_HEAD(dev_base_head);
 DEFINE_RWLOCK(dev_base_lock);
 
-EXPORT_SYMBOL(dev_base);
+EXPORT_SYMBOL(dev_base_head);
 EXPORT_SYMBOL(dev_base_lock);
 
 #define NETDEV_HASHBITS	8
@@ -575,7 +574,7 @@ struct net_device *dev_getbyhwaddr(unsig
 
 	ASSERT_RTNL();
 
-	for (dev = dev_base; dev; dev = dev->next)
+	for_each_netdev(dev)
 		if (dev->type == type &&
 		    !memcmp(dev->dev_addr, ha, dev->addr_len))
 			break;
@@ -589,7 +588,7 @@ struct net_device *dev_getfirstbyhwtype(
 	struct net_device *dev;
 
 	rtnl_lock();
-	for (dev = dev_base; dev; dev = dev->next) {
+	for_each_netdev(dev) {
 		if (dev->type == type) {
 			dev_hold(dev);
 			break;
@@ -617,7 +616,7 @@ struct net_device * dev_get_by_flags(uns
 	struct net_device *dev;
 
 	read_lock(&dev_base_lock);
-	for (dev = dev_base; dev != NULL; dev = dev->next) {
+	for_each_netdev(dev) {
 		if (((dev->flags ^ if_flags) & mask) == 0) {
 			dev_hold(dev);
 			break;
@@ -690,7 +689,7 @@ int dev_alloc_name(struct net_device *de
 		if (!inuse)
 			return -ENOMEM;
 
-		for (d = dev_base; d; d = d->next) {
+		for_each_netdev(d) {
 			if (!sscanf(d->name, name, &i))
 				continue;
 			if (i < 0 || i >= max_netdevices)
@@ -973,7 +972,7 @@ int register_netdevice_notifier(struct n
 	rtnl_lock();
 	err = raw_notifier_chain_register(&netdev_chain, nb);
 	if (!err) {
-		for (dev = dev_base; dev; dev = dev->next) {
+		for_each_netdev(dev) {
 			nb->notifier_call(nb, NETDEV_REGISTER, dev);
 
 			if (dev->flags & IFF_UP)
@@ -2044,7 +2043,7 @@ static int dev_ifconf(char __user *arg)
 	 */
 
 	total = 0;
-	for (dev = dev_base; dev; dev = dev->next) {
+	for_each_netdev(dev) {
 		for (i = 0; i < NPROTO; i++) {
 			if (gifconf_list[i]) {
 				int done;
@@ -2076,26 +2075,28 @@ static int dev_ifconf(char __user *arg)
  *	This is invoked by the /proc filesystem handler to display a device
  *	in detail.
  */
-static __inline__ struct net_device *dev_get_idx(loff_t pos)
+void *dev_seq_start(struct seq_file *seq, loff_t *pos)
 {
+	loff_t off;
 	struct net_device *dev;
-	loff_t i;
 
-	for (i = 0, dev = dev_base; dev && i < pos; ++i, dev = dev->next);
+	read_lock(&dev_base_lock);
+	if (!*pos)
+		return SEQ_START_TOKEN;
 
-	return i == pos ? dev : NULL;
-}
+	off = 1;
+	for_each_netdev(dev)
+		if (off++ == *pos)
+			return dev;
 
-void *dev_seq_start(struct seq_file *seq, loff_t *pos)
-{
-	read_lock(&dev_base_lock);
-	return *pos ? dev_get_idx(*pos - 1) : SEQ_START_TOKEN;
+	return NULL;
 }
 
 void *dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
 	++*pos;
-	return v == SEQ_START_TOKEN ? dev_base : ((struct net_device *)v)->next;
+	return v == SEQ_START_TOKEN ?
+		first_net_device() : next_net_device((struct net_device *)v);
 }
 
 void dev_seq_stop(struct seq_file *seq, void *v)
@@ -2974,11 +2975,9 @@ int register_netdevice(struct net_device
 
 	set_bit(__LINK_STATE_PRESENT, &dev->state);
 
-	dev->next = NULL;
 	dev_init_scheduler(dev);
 	write_lock_bh(&dev_base_lock);
-	*dev_tail = dev;
-	dev_tail = &dev->next;
+	list_add_tail(&dev->dev_list, &dev_base_head);
 	hlist_add_head(&dev->name_hlist, head);
 	hlist_add_head(&dev->index_hlist, dev_index_hash(dev->ifindex));
 	dev_hold(dev);
@@ -3246,8 +3245,6 @@ void synchronize_net(void)
 
 void unregister_netdevice(struct net_device *dev)
 {
-	struct net_device *d, **dp;
-
 	BUG_ON(dev_boot_phase);
 	ASSERT_RTNL();
 
@@ -3267,19 +3264,11 @@ void unregister_netdevice(struct net_dev
 		dev_close(dev);
 
 	/* And unlink it from device chain. */
-	for (dp = &dev_base; (d = *dp) != NULL; dp = &d->next) {
-		if (d == dev) {
-			write_lock_bh(&dev_base_lock);
-			hlist_del(&dev->name_hlist);
-			hlist_del(&dev->index_hlist);
-			if (dev_tail == &dev->next)
-				dev_tail = dp;
-			*dp = d->next;
-			write_unlock_bh(&dev_base_lock);
-			break;
-		}
-	}
-	BUG_ON(!d);
+	write_lock_bh(&dev_base_lock);
+	list_del(&dev->dev_list);
+	hlist_del(&dev->name_hlist);
+	hlist_del(&dev->index_hlist);
+	write_unlock_bh(&dev_base_lock);
 
 	dev->reg_state = NETREG_UNREGISTERING;
 
diff --git a/net/core/dev_mcast.c b/net/core/dev_mcast.c
index 56b310c..9d49f5c 100644
--- a/net/core/dev_mcast.c
+++ b/net/core/dev_mcast.c
@@ -223,7 +223,7 @@ static void *dev_mc_seq_start(struct seq
 	loff_t off = 0;
 
 	read_lock(&dev_base_lock);
-	for (dev = dev_base; dev; dev = dev->next) {
+	for_each_netdev(dev) {
 		if (off++ == *pos)
 			return dev;
 	}
@@ -232,9 +232,8 @@ static void *dev_mc_seq_start(struct seq
 
 static void *dev_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
-	struct net_device *dev = v;
 	++*pos;
-	return dev->next;
+	return next_net_device((struct net_device *)v);
 }
 
 static void dev_mc_seq_stop(struct seq_file *seq, void *v)
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 33ea8ea..070a34c 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -394,13 +394,16 @@ static int rtnl_dump_ifinfo(struct sk_bu
 	struct net_device *dev;
 
 	read_lock(&dev_base_lock);
-	for (dev=dev_base, idx=0; dev; dev = dev->next, idx++) {
+	idx = 0;
+	for_each_netdev(dev) {
 		if (idx < s_idx)
-			continue;
+			goto cont;
 		if (rtnl_fill_ifinfo(skb, dev, NULL, 0, RTM_NEWLINK,
 				     NETLINK_CB(cb->skb).pid,
 				     cb->nlh->nlmsg_seq, 0, NLM_F_MULTI) <= 0)
 			break;
+cont:
+		idx++;
 	}
 	read_unlock(&dev_base_lock);
 	cb->args[0] = idx;
diff --git a/net/decnet/af_decnet.c b/net/decnet/af_decnet.c
index c6568d6..36c8c66 100644
--- a/net/decnet/af_decnet.c
+++ b/net/decnet/af_decnet.c
@@ -746,7 +746,7 @@ static int dn_bind(struct socket *sock, 
 	if (!(saddr->sdn_flags & SDF_WILD)) {
 		if (dn_ntohs(saddr->sdn_nodeaddrl)) {
 			read_lock(&dev_base_lock);
-			for(dev = dev_base; dev; dev = dev->next) {
+			for_each_netdev(dev) {
 				if (!dev->dn_ptr)
 					continue;
 				if (dn_dev_islocal(dev, dn_saddr2dn(saddr)))
diff --git a/net/decnet/dn_dev.c b/net/decnet/dn_dev.c
index 060d725..91ae9d6 100644
--- a/net/decnet/dn_dev.c
+++ b/net/decnet/dn_dev.c
@@ -800,9 +800,10 @@ static int dn_nl_dump_ifaddr(struct sk_b
 	skip_naddr = cb->args[1];
 
 	read_lock(&dev_base_lock);
-	for (dev = dev_base, idx = 0; dev; dev = dev->next, idx++) {
+	idx = 0;
+	for_each_netdev(dev) {
 		if (idx < skip_ndevs)
-			continue;
+			goto cont;
 		else if (idx > skip_ndevs) {
 			/* Only skip over addresses for first dev dumped
 			 * in this iteration (idx == skip_ndevs) */
@@ -810,18 +811,20 @@ static int dn_nl_dump_ifaddr(struct sk_b
 		}
 
 		if ((dn_db = dev->dn_ptr) == NULL)
-			continue;
+			goto cont;
 
 		for (ifa = dn_db->ifa_list, dn_idx = 0; ifa;
 		     ifa = ifa->ifa_next, dn_idx++) {
 			if (dn_idx < skip_naddr)
-				continue;
+				goto cont;
 
 			if (dn_nl_fill_ifaddr(skb, ifa, NETLINK_CB(cb->skb).pid,
 					      cb->nlh->nlmsg_seq, RTM_NEWADDR,
 					      NLM_F_MULTI) < 0)
 				goto done;
 		}
+cont:
+		idx++;
 	}
 done:
 	read_unlock(&dev_base_lock);
@@ -1299,7 +1302,7 @@ void dn_dev_devices_off(void)
 	struct net_device *dev;
 
 	rtnl_lock();
-	for(dev = dev_base; dev; dev = dev->next)
+	for_each_netdev(dev)
 		dn_dev_down(dev);
 	rtnl_unlock();
 
@@ -1310,7 +1313,7 @@ void dn_dev_devices_on(void)
 	struct net_device *dev;
 
 	rtnl_lock();
-	for(dev = dev_base; dev; dev = dev->next) {
+	for_each_netdev(dev) {
 		if (dev->flags & IFF_UP)
 			dn_dev_up(dev);
 	}
@@ -1328,62 +1331,56 @@ int unregister_dnaddr_notifier(struct no
 }
 
 #ifdef CONFIG_PROC_FS
-static inline struct net_device *dn_dev_get_next(struct seq_file *seq, struct net_device *dev)
+static inline int is_dn_dev(struct net_device *dev)
 {
-	do {
-		dev = dev->next;
-	} while(dev && !dev->dn_ptr);
-
-	return dev;
+	return dev->dn_ptr != NULL;
 }
 
-static struct net_device *dn_dev_get_idx(struct seq_file *seq, loff_t pos)
+static void *dn_dev_seq_start(struct seq_file *seq, loff_t *pos)
 {
+	int i;
 	struct net_device *dev;
 
-	dev = dev_base;
-	if (dev && !dev->dn_ptr)
-		dev = dn_dev_get_next(seq, dev);
-	if (pos) {
-		while(dev && (dev = dn_dev_get_next(seq, dev)))
-			--pos;
-	}
-	return dev;
-}
+	read_lock(&dev_base_lock);
 
-static void *dn_dev_seq_start(struct seq_file *seq, loff_t *pos)
-{
-	if (*pos) {
-		struct net_device *dev;
-		read_lock(&dev_base_lock);
-		dev = dn_dev_get_idx(seq, *pos - 1);
-		if (dev == NULL)
-			read_unlock(&dev_base_lock);
-		return dev;
+	if (*pos == 0)
+		return SEQ_START_TOKEN;
+
+	i = 1;
+	for_each_netdev(dev) {
+		if (!is_dn_dev(dev))
+			continue;
+
+		if (i++ == *pos)
+			return dev;
 	}
-	return SEQ_START_TOKEN;
+
+	return NULL;
 }
 
 static void *dn_dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
-	struct net_device *dev = v;
-	loff_t one = 1;
+	struct net_device *dev;
 
-	if (v == SEQ_START_TOKEN) {
-		dev = dn_dev_seq_start(seq, &one);
-	} else {
-		dev = dn_dev_get_next(seq, dev);
-		if (dev == NULL)
-			read_unlock(&dev_base_lock);
-	}
 	++*pos;
-	return dev;
+
+	dev = (struct net_device *)v;
+	if (v == SEQ_START_TOKEN)
+		dev = net_device_entry(&dev_base_head);
+
+	for_each_netdev_continue(dev) {
+		if (!is_dn_dev(dev))
+			continue;
+
+		return dev;
+	}
+
+	return NULL;
 }
 
 static void dn_dev_seq_stop(struct seq_file *seq, void *v)
 {
-	if (v && v != SEQ_START_TOKEN)
-		read_unlock(&dev_base_lock);
+	read_unlock(&dev_base_lock);
 }
 
 static char *dn_type2asc(char type)
diff --git a/net/decnet/dn_fib.c b/net/decnet/dn_fib.c
index 82d58a9..68352ad 100644
--- a/net/decnet/dn_fib.c
+++ b/net/decnet/dn_fib.c
@@ -602,7 +602,7 @@ static void dn_fib_del_ifaddr(struct dn_
 
 	/* Scan device list */
 	read_lock(&dev_base_lock);
-	for(dev = dev_base; dev; dev = dev->next) {
+	for_each_netdev(dev) {
 		dn_db = dev->dn_ptr;
 		if (dn_db == NULL)
 			continue;
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index c1b5502..394f009 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -924,7 +924,7 @@ static int dn_route_output_slow(struct d
 			goto out;
 		}
 		read_lock(&dev_base_lock);
-		for(dev_out = dev_base; dev_out; dev_out = dev_out->next) {
+		for_each_netdev(dev_out) {
 			if (!dev_out->dn_ptr)
 				continue;
 			if (!dn_dev_islocal(dev_out, oldflp->fld_src))
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 98a00d0..fb6ea96 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -911,7 +911,7 @@ no_in_dev:
 	 */
 	read_lock(&dev_base_lock);
 	rcu_read_lock();
-	for (dev = dev_base; dev; dev = dev->next) {
+	for_each_netdev(dev) {
 		if ((in_dev = __in_dev_get_rcu(dev)) == NULL)
 			continue;
 
@@ -990,7 +990,7 @@ __be32 inet_confirm_addr(const struct ne
 
 	read_lock(&dev_base_lock);
 	rcu_read_lock();
-	for (dev = dev_base; dev; dev = dev->next) {
+	for_each_netdev(dev) {
 		if ((in_dev = __in_dev_get_rcu(dev))) {
 			addr = confirm_addr_indev(in_dev, dst, local, scope);
 			if (addr)
@@ -1184,21 +1184,22 @@ static int inet_dump_ifaddr(struct sk_bu
 
 	s_ip_idx = ip_idx = cb->args[1];
 	read_lock(&dev_base_lock);
-	for (dev = dev_base, idx = 0; dev; dev = dev->next, idx++) {
+	idx = 0;
+	for_each_netdev(dev) {
 		if (idx < s_idx)
-			continue;
+			goto cont;
 		if (idx > s_idx)
 			s_ip_idx = 0;
 		rcu_read_lock();
 		if ((in_dev = __in_dev_get_rcu(dev)) == NULL) {
 			rcu_read_unlock();
-			continue;
+			goto cont;
 		}
 
 		for (ifa = in_dev->ifa_list, ip_idx = 0; ifa;
 		     ifa = ifa->ifa_next, ip_idx++) {
 			if (ip_idx < s_ip_idx)
-				continue;
+				goto cont;
 			if (inet_fill_ifaddr(skb, ifa, NETLINK_CB(cb->skb).pid,
 					     cb->nlh->nlmsg_seq,
 					     RTM_NEWADDR, NLM_F_MULTI) <= 0) {
@@ -1207,6 +1208,8 @@ static int inet_dump_ifaddr(struct sk_bu
 			}
 		}
 		rcu_read_unlock();
+cont:
+		idx++;
 	}
 
 done:
@@ -1265,7 +1268,7 @@ void inet_forward_change(void)
 	ipv4_devconf_dflt.forwarding = on;
 
 	read_lock(&dev_base_lock);
-	for (dev = dev_base; dev; dev = dev->next) {
+	for_each_netdev(dev) {
 		struct in_device *in_dev;
 		rcu_read_lock();
 		in_dev = __in_dev_get_rcu(dev);
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 8cedb2a..884cbab 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -2285,9 +2285,8 @@ static inline struct ip_mc_list *igmp_mc
 	struct ip_mc_list *im = NULL;
 	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
 
-	for (state->dev = dev_base, state->in_dev = NULL;
-	     state->dev;
-	     state->dev = state->dev->next) {
+	state->in_dev = NULL;
+	for_each_netdev(state->dev) {
 		struct in_device *in_dev;
 		in_dev = in_dev_get(state->dev);
 		if (!in_dev)
@@ -2313,7 +2312,7 @@ static struct ip_mc_list *igmp_mc_get_ne
 			read_unlock(&state->in_dev->mc_list_lock);
 			in_dev_put(state->in_dev);
 		}
-		state->dev = state->dev->next;
+		state->dev = next_net_device(state->dev);
 		if (!state->dev) {
 			state->in_dev = NULL;
 			break;
@@ -2447,9 +2446,9 @@ static inline struct ip_sf_list *igmp_mc
 	struct ip_mc_list *im = NULL;
 	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
 
-	for (state->dev = dev_base, state->idev = NULL, state->im = NULL;
-	     state->dev;
-	     state->dev = state->dev->next) {
+	state->idev = NULL;
+	state->im = NULL;
+	for_each_netdev(state->dev) {
 		struct in_device *idev;
 		idev = in_dev_get(state->dev);
 		if (unlikely(idev == NULL))
@@ -2485,7 +2484,7 @@ static struct ip_sf_list *igmp_mcf_get_n
 				read_unlock(&state->idev->mc_list_lock);
 				in_dev_put(state->idev);
 			}
-			state->dev = state->dev->next;
+			state->dev = next_net_device(state->dev);
 			if (!state->dev) {
 				state->idev = NULL;
 				goto out;
diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c
index cf49de1..b049b5c 100644
--- a/net/ipv4/ipconfig.c
+++ b/net/ipv4/ipconfig.c
@@ -192,7 +192,7 @@ static int __init ic_open_devs(void)
 	if (dev_change_flags(&loopback_dev, loopback_dev.flags | IFF_UP) < 0)
 		printk(KERN_ERR "IP-Config: Failed to open %s\n", loopback_dev.name);
 
-	for (dev = dev_base; dev; dev = dev->next) {
+	for_each_netdev(dev) {
 		if (dev == &loopback_dev)
 			continue;
 		if (user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 7552663..76c5edb 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -415,7 +415,7 @@ static void addrconf_forward_change(void
 	struct inet6_dev *idev;
 
 	read_lock(&dev_base_lock);
-	for (dev=dev_base; dev; dev=dev->next) {
+	for_each_netdev(dev) {
 		rcu_read_lock();
 		idev = __in6_dev_get(dev);
 		if (idev) {
@@ -859,7 +859,7 @@ int ipv6_dev_get_saddr(struct net_device
 	read_lock(&dev_base_lock);
 	rcu_read_lock();
 
-	for (dev = dev_base; dev; dev=dev->next) {
+	for_each_netdev(dev) {
 		struct inet6_dev *idev;
 		struct inet6_ifaddr *ifa;
 
@@ -1992,7 +1992,7 @@ static void sit_add_v4_addrs(struct inet
 		return;
 	}
 
-	for (dev = dev_base; dev != NULL; dev = dev->next) {
+	for_each_netdev(dev) {
 		struct in_device * in_dev = __in_dev_get_rtnl(dev);
 		if (in_dev && (dev->flags & IFF_UP)) {
 			struct in_ifaddr * ifa;
@@ -2145,7 +2145,7 @@ static void ip6_tnl_add_linklocal(struct
 			return;
 	}
 	/* then try to inherit it from any device */
-	for (link_dev = dev_base; link_dev; link_dev = link_dev->next) {
+	for_each_netdev(link_dev) {
 		if (!ipv6_inherit_linklocal(idev, link_dev))
 			return;
 	}
@@ -3164,14 +3164,15 @@ static int inet6_dump_addr(struct sk_buf
 	s_ip_idx = ip_idx = cb->args[1];
 	read_lock(&dev_base_lock);
 
-	for (dev = dev_base, idx = 0; dev; dev = dev->next, idx++) {
+	idx = 0;
+	for_each_netdev(dev) {
 		if (idx < s_idx)
-			continue;
+			goto cont;
 		if (idx > s_idx)
 			s_ip_idx = 0;
 		ip_idx = 0;
 		if ((idev = in6_dev_get(dev)) == NULL)
-			continue;
+			goto cont;
 		read_lock_bh(&idev->lock);
 		switch (type) {
 		case UNICAST_ADDR:
@@ -3218,6 +3219,8 @@ static int inet6_dump_addr(struct sk_buf
 		}
 		read_unlock_bh(&idev->lock);
 		in6_dev_put(idev);
+cont:
+		idx++;
 	}
 done:
 	if (err <= 0) {
@@ -3439,16 +3442,19 @@ static int inet6_dump_ifinfo(struct sk_b
 	struct inet6_dev *idev;
 
 	read_lock(&dev_base_lock);
-	for (dev=dev_base, idx=0; dev; dev = dev->next, idx++) {
+	idx = 0;
+	for_each_netdev(dev) {
 		if (idx < s_idx)
-			continue;
+			goto cont;
 		if ((idev = in6_dev_get(dev)) == NULL)
-			continue;
+			goto cont;
 		err = inet6_fill_ifinfo(skb, idev, NETLINK_CB(cb->skb).pid,
 				cb->nlh->nlmsg_seq, RTM_NEWLINK, NLM_F_MULTI);
 		in6_dev_put(idev);
 		if (err <= 0)
 			break;
+cont:
+		idx++;
 	}
 	read_unlock(&dev_base_lock);
 	cb->args[0] = idx;
@@ -4084,7 +4090,7 @@ void __exit addrconf_cleanup(void)
 	 *	clean dev list.
 	 */
 
-	for (dev=dev_base; dev; dev=dev->next) {
+	for_each_netdev(dev) {
 		if ((idev = __in6_dev_get(dev)) == NULL)
 			continue;
 		addrconf_ifdown(dev, 1);
diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c
index 09117d6..f873ef6 100644
--- a/net/ipv6/anycast.c
+++ b/net/ipv6/anycast.c
@@ -426,7 +426,7 @@ int ipv6_chk_acast_addr(struct net_devic
 	if (dev)
 		return ipv6_chk_acast_dev(dev, addr);
 	read_lock(&dev_base_lock);
-	for (dev=dev_base; dev; dev=dev->next)
+	for_each_netdev(dev)
 		if (ipv6_chk_acast_dev(dev, addr))
 			break;
 	read_unlock(&dev_base_lock);
@@ -447,9 +447,8 @@ static inline struct ifacaddr6 *ac6_get_
 	struct ifacaddr6 *im = NULL;
 	struct ac6_iter_state *state = ac6_seq_private(seq);
 
-	for (state->dev = dev_base, state->idev = NULL;
-	     state->dev;
-	     state->dev = state->dev->next) {
+	state->idev = NULL;
+	for_each_netdev(state->dev) {
 		struct inet6_dev *idev;
 		idev = in6_dev_get(state->dev);
 		if (!idev)
@@ -476,7 +475,7 @@ static struct ifacaddr6 *ac6_get_next(st
 			read_unlock_bh(&state->idev->lock);
 			in6_dev_put(state->idev);
 		}
-		state->dev = state->dev->next;
+		state->dev = next_net_device(state->dev);
 		if (!state->dev) {
 			state->idev = NULL;
 			break;
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index a8d6625..abe0a60 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -2329,9 +2329,8 @@ static inline struct ifmcaddr6 *igmp6_mc
 	struct ifmcaddr6 *im = NULL;
 	struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq);
 
-	for (state->dev = dev_base, state->idev = NULL;
-	     state->dev;
-	     state->dev = state->dev->next) {
+	state->idev = NULL;
+	for_each_netdev(state->dev) {
 		struct inet6_dev *idev;
 		idev = in6_dev_get(state->dev);
 		if (!idev)
@@ -2358,7 +2357,7 @@ static struct ifmcaddr6 *igmp6_mc_get_ne
 			read_unlock_bh(&state->idev->lock);
 			in6_dev_put(state->idev);
 		}
-		state->dev = state->dev->next;
+		state->dev = next_net_device(state->dev);
 		if (!state->dev) {
 			state->idev = NULL;
 			break;
@@ -2473,9 +2472,9 @@ static inline struct ip6_sf_list *igmp6_
 	struct ifmcaddr6 *im = NULL;
 	struct igmp6_mcf_iter_state *state = igmp6_mcf_seq_private(seq);
 
-	for (state->dev = dev_base, state->idev = NULL, state->im = NULL;
-	     state->dev;
-	     state->dev = state->dev->next) {
+	state->idev = NULL;
+	state->im = NULL;
+	for_each_netdev(state->dev) {
 		struct inet6_dev *idev;
 		idev = in6_dev_get(state->dev);
 		if (unlikely(idev == NULL))
@@ -2511,7 +2510,7 @@ static struct ip6_sf_list *igmp6_mcf_get
 				read_unlock_bh(&state->idev->lock);
 				in6_dev_put(state->idev);
 			}
-			state->dev = state->dev->next;
+			state->dev = next_net_device(state->dev);
 			if (!state->dev) {
 				state->idev = NULL;
 				goto out;
diff --git a/net/llc/llc_core.c b/net/llc/llc_core.c
index d12413c..d4b13a0 100644
--- a/net/llc/llc_core.c
+++ b/net/llc/llc_core.c
@@ -160,8 +160,14 @@ static struct packet_type llc_tr_packet_
 
 static int __init llc_init(void)
 {
-	if (dev_base->next)
-		memcpy(llc_station_mac_sa, dev_base->next->dev_addr, ETH_ALEN);
+	struct net_device *dev;
+
+	dev = first_net_device();
+	if (dev != NULL)
+		dev = next_net_device(dev);
+
+	if (dev != NULL)
+		memcpy(llc_station_mac_sa, dev->dev_addr, ETH_ALEN);
 	else
 		memset(llc_station_mac_sa, 0, ETH_ALEN);
 	dev_add_pack(&llc_packet_type);
diff --git a/net/netrom/nr_route.c b/net/netrom/nr_route.c
index 8e6bd4e..d1e8d5b 100644
--- a/net/netrom/nr_route.c
+++ b/net/netrom/nr_route.c
@@ -598,7 +598,7 @@ struct net_device *nr_dev_first(void)
 	struct net_device *dev, *first = NULL;
 
 	read_lock(&dev_base_lock);
-	for (dev = dev_base; dev != NULL; dev = dev->next) {
+	for_each_netdev(dev) {
 		if ((dev->flags & IFF_UP) && dev->type == ARPHRD_NETROM)
 			if (first == NULL || strncmp(dev->name, first->name, 3) < 0)
 				first = dev;
@@ -618,7 +618,7 @@ struct net_device *nr_dev_get(ax25_addre
 	struct net_device *dev;
 
 	read_lock(&dev_base_lock);
-	for (dev = dev_base; dev != NULL; dev = dev->next) {
+	for_each_netdev(dev) {
 		if ((dev->flags & IFF_UP) && dev->type == ARPHRD_NETROM && ax25cmp(addr, (ax25_address *)dev->dev_addr) == 0) {
 			dev_hold(dev);
 			goto out;
diff --git a/net/rose/rose_route.c b/net/rose/rose_route.c
index a1233e1..def0ffc 100644
--- a/net/rose/rose_route.c
+++ b/net/rose/rose_route.c
@@ -596,7 +596,7 @@ struct net_device *rose_dev_first(void)
 	struct net_device *dev, *first = NULL;
 
 	read_lock(&dev_base_lock);
-	for (dev = dev_base; dev != NULL; dev = dev->next) {
+	for_each_netdev(dev) {
 		if ((dev->flags & IFF_UP) && dev->type == ARPHRD_ROSE)
 			if (first == NULL || strncmp(dev->name, first->name, 3) < 0)
 				first = dev;
@@ -614,7 +614,7 @@ struct net_device *rose_dev_get(rose_add
 	struct net_device *dev;
 
 	read_lock(&dev_base_lock);
-	for (dev = dev_base; dev != NULL; dev = dev->next) {
+	for_each_netdev(dev) {
 		if ((dev->flags & IFF_UP) && dev->type == ARPHRD_ROSE && rosecmp(addr, (rose_address *)dev->dev_addr) == 0) {
 			dev_hold(dev);
 			goto out;
@@ -630,7 +630,7 @@ static int rose_dev_exists(rose_address 
 	struct net_device *dev;
 
 	read_lock(&dev_base_lock);
-	for (dev = dev_base; dev != NULL; dev = dev->next) {
+	for_each_netdev(dev) {
 		if ((dev->flags & IFF_UP) && dev->type == ARPHRD_ROSE && rosecmp(addr, (rose_address *)dev->dev_addr) == 0)
 			goto out;
 	}
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index ecc988a..6c73ae6 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -857,9 +857,10 @@ static int tc_dump_qdisc(struct sk_buff 
 	s_idx = cb->args[0];
 	s_q_idx = q_idx = cb->args[1];
 	read_lock(&dev_base_lock);
-	for (dev=dev_base, idx=0; dev; dev = dev->next, idx++) {
+	idx = 0;
+	for_each_netdev(dev) {
 		if (idx < s_idx)
-			continue;
+			goto cont;
 		if (idx > s_idx)
 			s_q_idx = 0;
 		read_lock(&qdisc_tree_lock);
@@ -877,6 +878,8 @@ static int tc_dump_qdisc(struct sk_buff 
 			q_idx++;
 		}
 		read_unlock(&qdisc_tree_lock);
+cont:
+		idx++;
 	}
 
 done:
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index e17a823..82aef01 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -170,7 +170,7 @@ static void sctp_get_local_addr_list(voi
 	struct sctp_af *af;
 
 	read_lock(&dev_base_lock);
-	for (dev = dev_base; dev; dev = dev->next) {
+	for_each_netdev(dev) {
 		__list_for_each(pos, &sctp_address_families) {
 			af = list_entry(pos, struct sctp_af, list);
 			af->copy_addrlist(&sctp_local_addr_list, dev);
diff --git a/net/tipc/eth_media.c b/net/tipc/eth_media.c
index 9be4839..218a101 100644
--- a/net/tipc/eth_media.c
+++ b/net/tipc/eth_media.c
@@ -120,16 +120,18 @@ static int recv_msg(struct sk_buff *buf,
 
 static int enable_bearer(struct tipc_bearer *tb_ptr)
 {
-	struct net_device *dev = dev_base;
+	struct net_device *dev, *pdev;
 	struct eth_bearer *eb_ptr = &eth_bearers[0];
 	struct eth_bearer *stop = &eth_bearers[MAX_ETH_BEARERS];
 	char *driver_name = strchr((const char *)tb_ptr->name, ':') + 1;
 
 	/* Find device with specified name */
-
-	while (dev && dev->name && strncmp(dev->name, driver_name, IFNAMSIZ)) {
-		dev = dev->next;
-	}
+	dev = NULL;
+	for_each_netdev(pdev)
+		if (!strncmp(dev->name, driver_name, IFNAMSIZ)) {
+			dev = pdev;
+			break;
+		}
 	if (!dev)
 		return -ENODEV;