[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>

4 files changed, 57 insertions, 55 deletions

diff --git a/net/decnet/af_decnet.c b/net/decnet/af_decnet.c
index a205eaa87f52..9fbe87c93802 100644
--- a/net/decnet/af_decnet.c
+++ b/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;
                 }
         }
diff --git a/net/decnet/dn_dev.c b/net/decnet/dn_dev.c
index 5c2a9951b638..764a56a13e38 100644
--- a/net/decnet/dn_dev.c
+++ b/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)
diff --git a/net/decnet/dn_fib.c b/net/decnet/dn_fib.c
index 310a86268d2b..d2bc19d47950 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_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;
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index 5d7337bcf0fe..a8bf106b7a61 100644
--- a/net/decnet/dn_route.c
+++ b/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);