[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);

net/ipv4/igmp.c

@@ -2288,9 +2288,8 @@ static inline struct ip_mc_list *igmp_mc_get_first(struct seq_file *seq)
 	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)
@@ -2316,7 +2315,7 @@ static struct ip_mc_list *igmp_mc_get_next(struct seq_file *seq, struct ip_mc_li
 			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;
@@ -2450,9 +2449,9 @@ static inline struct ip_sf_list *igmp_mcf_get_first(struct seq_file *seq)
 	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))
@@ -2488,7 +2487,7 @@ static struct ip_sf_list *igmp_mcf_get_next(struct seq_file *seq, struct ip_sf_l
 				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;

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) :

net/ipv6/addrconf.c

@@ -449,7 +449,7 @@ 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) {
@@ -911,7 +911,7 @@ int ipv6_dev_get_saddr(struct net_device *daddr_dev,
 	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;
 
@@ -2064,7 +2064,7 @@ static void sit_add_v4_addrs(struct inet6_dev *idev)
 		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;
@@ -2225,7 +2225,7 @@ static void ip6_tnl_add_linklocal(struct inet6_dev *idev)
 			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;
 	}
@@ -3257,14 +3257,15 @@ static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb,
 	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;
 		ip_idx = 0;
 		if ((idev = in6_dev_get(dev)) == NULL)
-			continue;
+			goto cont;
 		read_lock_bh(&idev->lock);
 		switch (type) {
 		case UNICAST_ADDR:
@@ -3311,6 +3312,8 @@ static int inet6_dump_addr(struct sk_buff *skb, struct netlink_callback *cb,
 		}
 		read_unlock_bh(&idev->lock);
 		in6_dev_put(idev);
+cont:
+		idx++;
 	}
 done:
 	if (err <= 0) {
@@ -3575,16 +3578,19 @@ static int inet6_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
 	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;
@@ -4247,7 +4253,7 @@ 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);

net/ipv6/anycast.c

@@ -423,14 +423,18 @@ static int ipv6_chk_acast_dev(struct net_device *dev, struct in6_addr *addr)
  */
 int ipv6_chk_acast_addr(struct net_device *dev, struct in6_addr *addr)
 {
+	int found = 0;
+
 	if (dev)
 		return ipv6_chk_acast_dev(dev, addr);
 	read_lock(&dev_base_lock);
-	for (dev=dev_base; dev; dev=dev->next)
-		if (ipv6_chk_acast_dev(dev, addr))
+	for_each_netdev(dev)
+		if (ipv6_chk_acast_dev(dev, addr)) {
+			found = 1;
 			break;
+		}
 	read_unlock(&dev_base_lock);
-	return dev != 0;
+	return found;
 }
 
 
@@ -447,9 +451,8 @@ static inline struct ifacaddr6 *ac6_get_first(struct seq_file *seq)
 	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 +479,7 @@ static struct ifacaddr6 *ac6_get_next(struct seq_file *seq, struct ifacaddr6 *im
 			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;

net/ipv6/mcast.c

@@ -2331,9 +2331,8 @@ static inline struct ifmcaddr6 *igmp6_mc_get_first(struct seq_file *seq)
 	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)
@@ -2360,7 +2359,7 @@ static struct ifmcaddr6 *igmp6_mc_get_next(struct seq_file *seq, struct ifmcaddr
 			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;
@@ -2475,9 +2474,9 @@ static inline struct ip6_sf_list *igmp6_mcf_get_first(struct seq_file *seq)
 	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))
@@ -2513,7 +2512,7 @@ static struct ip6_sf_list *igmp6_mcf_get_next(struct seq_file *seq, struct ip6_s
 				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;

net/llc/llc_core.c

@@ -160,8 +160,14 @@ static struct packet_type llc_tr_packet_type = {
 
 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);

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;
@@ -618,12 +618,13 @@ struct net_device *nr_dev_get(ax25_address *addr)
 	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;
 		}
 	}
+	dev = NULL;
 out:
 	read_unlock(&dev_base_lock);
 	return dev;

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;
@@ -614,12 +614,13 @@ struct net_device *rose_dev_get(rose_address *addr)
 	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;
 		}
 	}
+	dev = NULL;
 out:
 	read_unlock(&dev_base_lock);
 	return dev;
@@ -630,10 +631,11 @@ static int rose_dev_exists(rose_address *addr)
 	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;
 	}
+	dev = NULL;
 out:
 	read_unlock(&dev_base_lock);
 	return dev != NULL;

net/sched/sch_api.c

@@ -894,9 +894,10 @@ static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
 	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;
 		q_idx = 0;
@@ -910,6 +911,8 @@ static int tc_dump_qdisc(struct sk_buff *skb, struct netlink_callback *cb)
 				goto done;
 			q_idx++;
 		}
+cont:
+		idx++;
 	}
 
 done:

net/sctp/protocol.c

@@ -170,7 +170,7 @@ static void sctp_get_local_addr_list(void)
 	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);

net/tipc/eth_media.c

@@ -120,16 +120,18 @@ static int recv_msg(struct sk_buff *buf, struct net_device *dev,
 
 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;