[NET]: Rework dev_base via list_head (v3)

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().
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Acked-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/s390/appldata/appldata_net_sum.c

@@ -107,7 +107,7 @@ static void appldata_get_net_sum_data(void *data)
 	tx_dropped = 0;
 	collisions = 0;
 	read_lock(&dev_base_lock);
-	for (dev = dev_base; dev != NULL; dev = dev->next) {
+	for_each_netdev(dev) {
 		stats = dev->get_stats(dev);
 		rx_packets += stats->rx_packets;
 		tx_packets += stats->tx_packets;

arch/sparc64/solaris/ioctl.c

@@ -686,7 +686,8 @@ static inline int solaris_i(unsigned int fd, unsigned int cmd, u32 arg)
 			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)))

drivers/block/aoe/aoecmd.c

@@ -194,15 +194,15 @@ aoecmd_cfg_pkts(ushort aoemajor, unsigned char aoeminor, struct sk_buff **tail)
 	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;
@@ -221,6 +221,8 @@ aoecmd_cfg_pkts(ushort aoemajor, unsigned char aoeminor, struct sk_buff **tail)
 
 		skb->next = sl;
 		sl = skb;
+cont:
+		dev_put(ifp);
 	}
 	read_unlock(&dev_base_lock);
 

drivers/net/wireless/strip.c

@@ -1971,8 +1971,7 @@ static struct net_device *get_strip_dev(struct strip *strip_info)
 		      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(struct strip *strip_info)
 				read_unlock_bh(&dev_base_lock);
 				return (dev);
 			}
-			dev = dev->next;
 		}
 		read_unlock_bh(&dev_base_lock);
 	}

drivers/parisc/led.c

@@ -365,7 +365,7 @@ static __inline__ int led_get_net_activity(void)
 	 * 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)

fs/afs/netdevices.c

@@ -47,7 +47,7 @@ int afs_get_ipv4_interfaces(struct afs_interface *bufs, size_t maxbufs,
 	ASSERT(maxbufs > 0);
 
 	rtnl_lock();
-	for (dev = dev_base; dev; dev = dev->next) {
+	for_each_netdev(dev) {
 		if (dev->type == ARPHRD_LOOPBACK && !wantloopback)
 			continue;
 		idev = __in_dev_get_rtnl(dev);

include/linux/netdevice.h

@@ -304,7 +304,7 @@ 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);
@@ -575,9 +575,31 @@ 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);

net/8021q/vlan.c

@@ -117,8 +117,7 @@ static void __exit vlan_cleanup_devices(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_802_1Q_VLAN) {
 			unregister_vlan_dev(VLAN_DEV_INFO(dev)->real_dev,
 					    VLAN_DEV_INFO(dev)->vlan_id);

net/8021q/vlanproc.c

@@ -237,13 +237,9 @@ int vlan_proc_rem_dev(struct net_device *vlandev)
  * 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_file *seq, loff_t *pos)
 	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)

net/bridge/br_if.c

@@ -475,11 +475,9 @@ 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();
 
 }

net/bridge/br_ioctl.c

@@ -27,7 +27,9 @@ static int get_bridge_ifindices(int *indices, int num)
 	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;
 	}

net/bridge/br_netlink.c

@@ -109,7 +109,8 @@ static int br_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
 	struct net_device *dev;
 	int idx;
 
-	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;

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
@@ -567,11 +566,12 @@ struct net_device *dev_getbyhwaddr(unsigned short type, char *ha)
 
 	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;
-	return dev;
+			return dev;
+
+	return NULL;
 }
 
 EXPORT_SYMBOL(dev_getbyhwaddr);
@@ -581,11 +581,11 @@ struct net_device *__dev_getfirstbyhwtype(unsigned short type)
 	struct net_device *dev;
 
 	ASSERT_RTNL();
-	for (dev = dev_base; dev; dev = dev->next) {
+	for_each_netdev(dev)
 		if (dev->type == type)
-			break;
-	}
-	return dev;
+			return dev;
+
+	return NULL;
 }
 
 EXPORT_SYMBOL(__dev_getfirstbyhwtype);
@@ -617,17 +617,19 @@ EXPORT_SYMBOL(dev_getfirstbyhwtype);
 
 struct net_device * dev_get_by_flags(unsigned short if_flags, unsigned short mask)
 {
-	struct net_device *dev;
+	struct net_device *dev, *ret;
 
+	ret = NULL;
 	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);
+			ret = dev;
 			break;
 		}
 	}
 	read_unlock(&dev_base_lock);
-	return dev;
+	return ret;
 }
 
 /**
@@ -693,7 +695,7 @@ int dev_alloc_name(struct net_device *dev, const char *name)
 		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)
@@ -975,7 +977,7 @@ int register_netdevice_notifier(struct notifier_block *nb)
 	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)
@@ -2049,7 +2051,7 @@ 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;
@@ -2081,26 +2083,28 @@ static int dev_ifconf(char __user *arg)
  *	This is invoked by the /proc filesystem handler to display a device
  *	in detail.
  */
-static 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)
@@ -3082,11 +3086,9 @@ int register_netdevice(struct net_device *dev)
 
 	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);
@@ -3360,8 +3362,6 @@ void synchronize_net(void)
 
 void unregister_netdevice(struct net_device *dev)
 {
-	struct net_device *d, **dp;
-
 	BUG_ON(dev_boot_phase);
 	ASSERT_RTNL();
 
@@ -3381,19 +3381,11 @@ void unregister_netdevice(struct net_device *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;
 

net/core/dev_mcast.c

@@ -223,7 +223,7 @@ static void *dev_mc_seq_start(struct seq_file *seq, loff_t *pos)
 	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_file *seq, loff_t *pos)
 
 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)

net/core/rtnetlink.c

@@ -539,13 +539,16 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
 	int s_idx = cb->args[0];
 	struct net_device *dev;
 
-	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++;
 	}
 	cb->args[0] = idx;
 

net/decnet/af_decnet.c

@@ -721,7 +721,7 @@ static int dn_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 	struct sock *sk = sock->sk;
 	struct dn_scp *scp = DN_SK(sk);
 	struct sockaddr_dn *saddr = (struct sockaddr_dn *)uaddr;
-	struct net_device *dev;
+	struct net_device *dev, *ldev;
 	int rv;
 
 	if (addr_len != sizeof(struct sockaddr_dn))
@@ -746,14 +746,17 @@ static int dn_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 	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) {
+			ldev = NULL;
+			for_each_netdev(dev) {
 				if (!dev->dn_ptr)
 					continue;
-				if (dn_dev_islocal(dev, dn_saddr2dn(saddr)))
+				if (dn_dev_islocal(dev, dn_saddr2dn(saddr))) {
+					ldev = dev;
 					break;
+				}
 			}
 			read_unlock(&dev_base_lock);
-			if (dev == NULL)
+			if (ldev == NULL)
 				return -EADDRNOTAVAIL;
 		}
 	}

net/decnet/dn_dev.c

@@ -799,9 +799,10 @@ static int dn_nl_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
 	skip_ndevs = cb->args[0];
 	skip_naddr = cb->args[1];
 
-	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) */
@@ -809,18 +810,20 @@ static int dn_nl_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
 		}
 
 		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:
 	cb->args[0] = idx;
@@ -1296,7 +1299,7 @@ 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();
 
@@ -1307,7 +1310,7 @@ 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);
 	}
@@ -1325,62 +1328,56 @@ int unregister_dnaddr_notifier(struct notifier_block *nb)
 }
 
 #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)

net/decnet/dn_fib.c

@@ -602,7 +602,7 @@ static void dn_fib_del_ifaddr(struct dn_ifaddr *ifa)
 
 	/* 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;

net/decnet/dn_route.c

@@ -886,7 +886,7 @@ static int dn_route_output_slow(struct dst_entry **pprt, const struct flowi *old
 			    .iif = loopback_dev.ifindex,
 			    .oif = oldflp->oif };
 	struct dn_route *rt = NULL;
-	struct net_device *dev_out = NULL;
+	struct net_device *dev_out = NULL, *dev;
 	struct neighbour *neigh = NULL;
 	unsigned hash;
 	unsigned flags = 0;
@@ -925,15 +925,17 @@ static int dn_route_output_slow(struct dst_entry **pprt, const struct flowi *old
 			goto out;
 		}
 		read_lock(&dev_base_lock);
-		for(dev_out = dev_base; dev_out; dev_out = dev_out->next) {
-			if (!dev_out->dn_ptr)
+		for_each_netdev(dev) {
+			if (!dev->dn_ptr)
 				continue;
-			if (!dn_dev_islocal(dev_out, oldflp->fld_src))
+			if (!dn_dev_islocal(dev, oldflp->fld_src))
 				continue;
-			if ((dev_out->flags & IFF_LOOPBACK) &&
+			if ((dev->flags & IFF_LOOPBACK) &&
 			    oldflp->fld_dst &&
-			    !dn_dev_islocal(dev_out, oldflp->fld_dst))
+			    !dn_dev_islocal(dev, oldflp->fld_dst))
 				continue;
+
+			dev_out = dev;
 			break;
 		}
 		read_unlock(&dev_base_lock);

net/ipv4/devinet.c

@@ -910,7 +910,7 @@ 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;
 
@@ -989,7 +989,7 @@ __be32 inet_confirm_addr(const struct net_device *dev, __be32 dst, __be32 local,
 
 	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)
@@ -1182,23 +1182,26 @@ static int inet_dump_ifaddr(struct sk_buff *skb, struct netlink_callback *cb)
 	int s_ip_idx, s_idx = cb->args[0];
 
 	s_ip_idx = ip_idx = cb->args[1];
-	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;
 		if ((in_dev = __in_dev_get_rtnl(dev)) == NULL)
-			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)
 				goto done;
 		}
+cont:
+		idx++;
 	}
 
 done:
@@ -1243,7 +1246,7 @@ 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);