[NET]: Dynamically allocate the loopback device, part 1.

This patch replaces all occurences to the static variable
loopback_dev to a pointer loopback_dev. That provides the
mindless, trivial, uninteressting change part for the dynamic
allocation for the loopback.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
Acked-By: Kirill Korotaev <dev@sw.ru>
Acked-by: Benjamin Thery <benjamin.thery@bull.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

16 files changed, 55 insertions, 53 deletions

diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index 0e2252fd71ab..588092e13186 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -202,7 +202,7 @@ static const struct ethtool_ops loopback_ethtool_ops = {
  * The loopback device is special. There is only one instance and
  * it is statically allocated. Don't do this for other devices.
  */
-struct net_device loopback_dev = {
+struct net_device __loopback_dev = {
         .name                   = "lo",
         .get_stats              = &get_stats,
         .mtu                    = (16 * 1024) + 20 + 20 + 12,
@@ -227,10 +227,12 @@ struct net_device loopback_dev = {
         .nd_net                 = &init_net,
 };
 
+struct net_device *loopback_dev = &__loopback_dev;
+
 /* Setup and register the loopback device. */
 static int __init loopback_init(void)
 {
-        int err = register_netdev(&loopback_dev);
+        int err = register_netdev(loopback_dev);
 
         if (err)
                 panic("loopback: Failed to register netdevice: %d\n", err);
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index cf89ce677e41..baa915f0d285 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -741,7 +741,7 @@ struct packet_type {
 #include <linux/interrupt.h>
 #include <linux/notifier.h>
 
-extern struct net_device                loopback_dev;           /* The loopback */
+extern struct net_device                *loopback_dev;          /* The loopback */
 extern rwlock_t                         dev_base_lock;          /* Device list lock */
 
 
diff --git a/net/core/dst.c b/net/core/dst.c
index 38c741ac5d08..ad5ffa19d809 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -278,13 +278,13 @@ static inline void dst_ifdown(struct dst_entry *dst, struct net_device *dev,
         if (!unregister) {
                 dst->input = dst->output = dst_discard;
         } else {
-                dst->dev = &loopback_dev;
-                dev_hold(&loopback_dev);
+                dst->dev = loopback_dev;
+                dev_hold(dst->dev);
                 dev_put(dev);
                 if (dst->neighbour && dst->neighbour->dev == dev) {
-                        dst->neighbour->dev = &loopback_dev;
+                        dst->neighbour->dev = loopback_dev;
                         dev_put(dev);
-                        dev_hold(&loopback_dev);
+                        dev_hold(dst->neighbour->dev);
                 }
         }
 }
diff --git a/net/decnet/dn_dev.c b/net/decnet/dn_dev.c
index fa24614b5a37..bcaf4c5aa68e 100644
--- a/net/decnet/dn_dev.c
+++ b/net/decnet/dn_dev.c
@@ -869,10 +869,10 @@ last_chance:
                 rv = dn_dev_get_first(dev, addr);
                 read_unlock(&dev_base_lock);
                 dev_put(dev);
-                if (rv == 0 || dev == &loopback_dev)
+                if (rv == 0 || dev == loopback_dev)
                         return rv;
         }
-        dev = &loopback_dev;
+        dev = loopback_dev;
         dev_hold(dev);
         goto last_chance;
 }
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c
index 70b1c3fa00f3..96fe0aa1638e 100644
--- a/net/decnet/dn_route.c
+++ b/net/decnet/dn_route.c
@@ -887,7 +887,7 @@ static int dn_route_output_slow(struct dst_entry **pprt, const struct flowi *old
                                         .scope = RT_SCOPE_UNIVERSE,
                                      } },
                             .mark = oldflp->mark,
-                            .iif = loopback_dev.ifindex,
+                            .iif = loopback_dev->ifindex,
                             .oif = oldflp->oif };
         struct dn_route *rt = NULL;
         struct net_device *dev_out = NULL, *dev;
@@ -904,7 +904,7 @@ static int dn_route_output_slow(struct dst_entry **pprt, const struct flowi *old
                        "dn_route_output_slow: dst=%04x src=%04x mark=%d"
                        " iif=%d oif=%d\n", dn_ntohs(oldflp->fld_dst),
                        dn_ntohs(oldflp->fld_src),
-                       oldflp->mark, loopback_dev.ifindex, oldflp->oif);
+                       oldflp->mark, loopback_dev->ifindex, oldflp->oif);
 
         /* If we have an output interface, verify its a DECnet device */
         if (oldflp->oif) {
@@ -957,7 +957,7 @@ source_ok:
                 err = -EADDRNOTAVAIL;
                 if (dev_out)
                         dev_put(dev_out);
-                dev_out = &loopback_dev;
+                dev_out = loopback_dev;
                 dev_hold(dev_out);
                 if (!fl.fld_dst) {
                         fl.fld_dst =
@@ -966,7 +966,7 @@ source_ok:
                         if (!fl.fld_dst)
                                 goto out;
                 }
-                fl.oif = loopback_dev.ifindex;
+                fl.oif = loopback_dev->ifindex;
                 res.type = RTN_LOCAL;
                 goto make_route;
         }
@@ -1012,7 +1012,7 @@ source_ok:
                                         if (dev_out)
                                                 dev_put(dev_out);
                                         if (dn_dev_islocal(neigh->dev, fl.fld_dst)) {
-                                                dev_out = &loopback_dev;
+                                                dev_out = loopback_dev;
                                                 res.type = RTN_LOCAL;
                                         } else {
                                                 dev_out = neigh->dev;
@@ -1033,7 +1033,7 @@ source_ok:
                 /* Possible improvement - check all devices for local addr */
                 if (dn_dev_islocal(dev_out, fl.fld_dst)) {
                         dev_put(dev_out);
-                        dev_out = &loopback_dev;
+                        dev_out = loopback_dev;
                         dev_hold(dev_out);
                         res.type = RTN_LOCAL;
                         goto select_source;
@@ -1069,7 +1069,7 @@ select_source:
                         fl.fld_src = fl.fld_dst;
                 if (dev_out)
                         dev_put(dev_out);
-                dev_out = &loopback_dev;
+                dev_out = loopback_dev;
                 dev_hold(dev_out);
                 fl.oif = dev_out->ifindex;
                 if (res.fi)
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index 721b89b60963..affea9b121fc 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -203,7 +203,7 @@ static void inetdev_destroy(struct in_device *in_dev)
         ASSERT_RTNL();
 
         dev = in_dev->dev;
-        if (dev == &loopback_dev)
+        if (dev == loopback_dev)
                 return;
 
         in_dev->dead = 1;
@@ -1061,7 +1061,7 @@ static int inetdev_event(struct notifier_block *this, unsigned long event,
                         in_dev = inetdev_init(dev);
                         if (!in_dev)
                                 return notifier_from_errno(-ENOMEM);
-                        if (dev == &loopback_dev) {
+                        if (dev == loopback_dev) {
                                 IN_DEV_CONF_SET(in_dev, NOXFRM, 1);
                                 IN_DEV_CONF_SET(in_dev, NOPOLICY, 1);
                         }
@@ -1077,7 +1077,7 @@ static int inetdev_event(struct notifier_block *this, unsigned long event,
         case NETDEV_UP:
                 if (dev->mtu < 68)
                         break;
-                if (dev == &loopback_dev) {
+                if (dev == loopback_dev) {
                         struct in_ifaddr *ifa;
                         if ((ifa = inet_alloc_ifa()) != NULL) {
                                 ifa->ifa_local =
diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c
index 4303851749f6..2d2e0cda0470 100644
--- a/net/ipv4/ipconfig.c
+++ b/net/ipv4/ipconfig.c
@@ -190,11 +190,11 @@ static int __init ic_open_devs(void)
         rtnl_lock();
 
         /* bring loopback device up first */
-        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);
+        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_each_netdev(&init_net, dev) {
-                if (dev == &loopback_dev)
+                if (dev == loopback_dev)
                         continue;
                 if (user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
                     (!(dev->flags & IFF_LOOPBACK) &&
diff --git a/net/ipv4/ipvs/ip_vs_core.c b/net/ipv4/ipvs/ip_vs_core.c
index f005a2f929f4..74503267e5d4 100644
--- a/net/ipv4/ipvs/ip_vs_core.c
+++ b/net/ipv4/ipvs/ip_vs_core.c
@@ -961,7 +961,7 @@ ip_vs_in(unsigned int hooknum, struct sk_buff **pskb,
          *      ... don't know why 1st test DOES NOT include 2nd (?)
          */
         if (unlikely(skb->pkt_type != PACKET_HOST
-                     || skb->dev == &loopback_dev || skb->sk)) {
+                     || skb->dev == loopback_dev || skb->sk)) {
                 IP_VS_DBG(12, "packet type=%d proto=%d daddr=%d.%d.%d.%d ignored\n",
                           skb->pkt_type,
                           ip_hdr(skb)->protocol,
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 006d6058a806..ca2878dc6188 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1402,8 +1402,8 @@ static void ipv4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
 {
         struct rtable *rt = (struct rtable *) dst;
         struct in_device *idev = rt->idev;
-        if (dev != &loopback_dev && idev && idev->dev == dev) {
-                struct in_device *loopback_idev = in_dev_get(&loopback_dev);
+        if (dev != loopback_dev && idev && idev->dev == dev) {
+                struct in_device *loopback_idev = in_dev_get(loopback_dev);
                 if (loopback_idev) {
                         rt->idev = loopback_idev;
                         in_dev_put(idev);
@@ -1555,7 +1555,7 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 #endif
         rth->rt_iif     =
         rth->fl.iif     = dev->ifindex;
-        rth->u.dst.dev  = &loopback_dev;
+        rth->u.dst.dev  = loopback_dev;
         dev_hold(rth->u.dst.dev);
         rth->idev       = in_dev_get(rth->u.dst.dev);
         rth->fl.oif     = 0;
@@ -1812,7 +1812,7 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
         if (res.type == RTN_LOCAL) {
                 int result;
                 result = fib_validate_source(saddr, daddr, tos,
-                                             loopback_dev.ifindex,
+                                             loopback_dev->ifindex,
                                              dev, &spec_dst, &itag);
                 if (result < 0)
                         goto martian_source;
@@ -1879,7 +1879,7 @@ local_input:
 #endif
         rth->rt_iif     =
         rth->fl.iif     = dev->ifindex;
-        rth->u.dst.dev  = &loopback_dev;
+        rth->u.dst.dev  = loopback_dev;
         dev_hold(rth->u.dst.dev);
         rth->idev       = in_dev_get(rth->u.dst.dev);
         rth->rt_gateway = daddr;
@@ -2149,7 +2149,7 @@ static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
                                                   RT_SCOPE_UNIVERSE),
                                       } },
                             .mark = oldflp->mark,
-                            .iif = loopback_dev.ifindex,
+                            .iif = loopback_dev->ifindex,
                             .oif = oldflp->oif };
         struct fib_result res;
         unsigned flags = 0;
@@ -2243,9 +2243,9 @@ static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
                         fl.fl4_dst = fl.fl4_src = htonl(INADDR_LOOPBACK);
                 if (dev_out)
                         dev_put(dev_out);
-                dev_out = &loopback_dev;
+                dev_out = loopback_dev;
                 dev_hold(dev_out);
-                fl.oif = loopback_dev.ifindex;
+                fl.oif = loopback_dev->ifindex;
                 res.type = RTN_LOCAL;
                 flags |= RTCF_LOCAL;
                 goto make_route;
@@ -2290,7 +2290,7 @@ static int ip_route_output_slow(struct rtable **rp, const struct flowi *oldflp)
                         fl.fl4_src = fl.fl4_dst;
                 if (dev_out)
                         dev_put(dev_out);
-                dev_out = &loopback_dev;
+                dev_out = loopback_dev;
                 dev_hold(dev_out);
                 fl.oif = dev_out->ifindex;
                 if (res.fi)
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 4ff8ed30024f..29ab3de8c47f 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -306,7 +306,7 @@ static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
 
         xdst = (struct xfrm_dst *)dst;
         if (xdst->u.rt.idev->dev == dev) {
-                struct in_device *loopback_idev = in_dev_get(&loopback_dev);
+                struct in_device *loopback_idev = in_dev_get(loopback_dev);
                 BUG_ON(!loopback_idev);
 
                 do {
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 9c2e94f1c637..b43574f73375 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -2410,7 +2410,7 @@ static int addrconf_ifdown(struct net_device *dev, int how)
 
         ASSERT_RTNL();
 
-        if (dev == &loopback_dev && how == 1)
+        if (dev == loopback_dev && how == 1)
                 how = 0;
 
         rt6_ifdown(dev);
@@ -4212,16 +4212,19 @@ int __init addrconf_init(void)
          * device and it being up should be removed.
          */
         rtnl_lock();
-        if (!ipv6_add_dev(&loopback_dev))
+        if (!ipv6_add_dev(loopback_dev))
                 err = -ENOMEM;
         rtnl_unlock();
         if (err)
                 return err;
 
-        ip6_null_entry.rt6i_idev = in6_dev_get(&loopback_dev);
+        ip6_null_entry.u.dst.dev = loopback_dev;
+        ip6_null_entry.rt6i_idev = in6_dev_get(loopback_dev);
 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
-        ip6_prohibit_entry.rt6i_idev = in6_dev_get(&loopback_dev);
-        ip6_blk_hole_entry.rt6i_idev = in6_dev_get(&loopback_dev);
+        ip6_prohibit_entry.u.dst.dev = loopback_dev;
+        ip6_prohibit_entry.rt6i_idev = in6_dev_get(loopback_dev);
+        ip6_blk_hole_entry.u.dst.dev = loopback_dev;
+        ip6_blk_hole_entry.rt6i_idev = in6_dev_get(loopback_dev);
 #endif
 
         register_netdevice_notifier(&ipv6_dev_notf);
@@ -4276,7 +4279,7 @@ void __exit addrconf_cleanup(void)
                         continue;
                 addrconf_ifdown(dev, 1);
         }
-        addrconf_ifdown(&loopback_dev, 2);
+        addrconf_ifdown(loopback_dev, 2);
 
         /*
          *      Check hash table.
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 7d18cac3f110..9149fc239759 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -91,7 +91,7 @@ int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt
          *
          * BTW, when we send a packet for our own local address on a
          * non-loopback interface (e.g. ethX), it is being delivered
-         * via the loopback interface (lo) here; skb->dev = &loopback_dev.
+         * via the loopback interface (lo) here; skb->dev = loopback_dev.
          * It, however, should be considered as if it is being
          * arrived via the sending interface (ethX), because of the
          * nature of scoping architecture. --yoshfuji
diff --git a/net/ipv6/netfilter/ip6t_REJECT.c b/net/ipv6/netfilter/ip6t_REJECT.c
index 2f487cda3b6b..50860531cd3c 100644
--- a/net/ipv6/netfilter/ip6t_REJECT.c
+++ b/net/ipv6/netfilter/ip6t_REJECT.c
@@ -167,7 +167,7 @@ static inline void
 send_unreach(struct sk_buff *skb_in, unsigned char code, unsigned int hooknum)
 {
         if (hooknum == NF_IP6_LOCAL_OUT && skb_in->dev == NULL)
-                skb_in->dev = &loopback_dev;
+                skb_in->dev = loopback_dev;
 
         icmpv6_send(skb_in, ICMPV6_DEST_UNREACH, code, 0, NULL);
 }
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 104070e92cea..a7a21a7ba790 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -138,7 +138,6 @@ struct rt6_info ip6_null_entry = {
                 .dst = {
                         .__refcnt       = ATOMIC_INIT(1),
                         .__use          = 1,
-                        .dev            = &loopback_dev,
                         .obsolete       = -1,
                         .error          = -ENETUNREACH,
                         .metrics        = { [RTAX_HOPLIMIT - 1] = 255, },
@@ -164,7 +163,6 @@ struct rt6_info ip6_prohibit_entry = {
                 .dst = {
                         .__refcnt       = ATOMIC_INIT(1),
                         .__use          = 1,
-                        .dev            = &loopback_dev,
                         .obsolete       = -1,
                         .error          = -EACCES,
                         .metrics        = { [RTAX_HOPLIMIT - 1] = 255, },
@@ -184,7 +182,6 @@ struct rt6_info ip6_blk_hole_entry = {
                 .dst = {
                         .__refcnt       = ATOMIC_INIT(1),
                         .__use          = 1,
-                        .dev            = &loopback_dev,
                         .obsolete       = -1,
                         .error          = -EINVAL,
                         .metrics        = { [RTAX_HOPLIMIT - 1] = 255, },
@@ -224,8 +221,8 @@ static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
         struct rt6_info *rt = (struct rt6_info *)dst;
         struct inet6_dev *idev = rt->rt6i_idev;
 
-        if (dev != &loopback_dev && idev != NULL && idev->dev == dev) {
-                struct inet6_dev *loopback_idev = in6_dev_get(&loopback_dev);
+        if (dev != loopback_dev && idev != NULL && idev->dev == dev) {
+                struct inet6_dev *loopback_idev = in6_dev_get(loopback_dev);
                 if (loopback_idev != NULL) {
                         rt->rt6i_idev = loopback_idev;
                         in6_dev_put(idev);
@@ -1188,12 +1185,12 @@ int ip6_route_add(struct fib6_config *cfg)
         if ((cfg->fc_flags & RTF_REJECT) ||
             (dev && (dev->flags&IFF_LOOPBACK) && !(addr_type&IPV6_ADDR_LOOPBACK))) {
                 /* hold loopback dev/idev if we haven't done so. */
-                if (dev != &loopback_dev) {
+                if (dev != loopback_dev) {
                         if (dev) {
                                 dev_put(dev);
                                 in6_dev_put(idev);
                         }
-                        dev = &loopback_dev;
+                        dev = loopback_dev;
                         dev_hold(dev);
                         idev = in6_dev_get(dev);
                         if (!idev) {
@@ -1897,13 +1894,13 @@ struct rt6_info *addrconf_dst_alloc(struct inet6_dev *idev,
         if (rt == NULL)
                 return ERR_PTR(-ENOMEM);
 
-        dev_hold(&loopback_dev);
+        dev_hold(loopback_dev);
         in6_dev_hold(idev);
 
         rt->u.dst.flags = DST_HOST;
         rt->u.dst.input = ip6_input;
         rt->u.dst.output = ip6_output;
-        rt->rt6i_dev = &loopback_dev;
+        rt->rt6i_dev = loopback_dev;
         rt->rt6i_idev = idev;
         rt->u.dst.metrics[RTAX_MTU-1] = ipv6_get_mtu(rt->rt6i_dev);
         rt->u.dst.metrics[RTAX_ADVMSS-1] = ipv6_advmss(dst_mtu(&rt->u.dst));
diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index 3ec0c4770ee3..cc07216cfd59 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -375,7 +375,7 @@ static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
 
         xdst = (struct xfrm_dst *)dst;
         if (xdst->u.rt6.rt6i_idev->dev == dev) {
-                struct inet6_dev *loopback_idev = in6_dev_get(&loopback_dev);
+                struct inet6_dev *loopback_idev = in6_dev_get(loopback_dev);
                 BUG_ON(!loopback_idev);
 
                 do {
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 50682d3cd7a9..d6dfd7d1948f 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1949,8 +1949,8 @@ static int stale_bundle(struct dst_entry *dst)
 void xfrm_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
 {
         while ((dst = dst->child) && dst->xfrm && dst->dev == dev) {
-                dst->dev = &loopback_dev;
-                dev_hold(&loopback_dev);
+                dst->dev = loopback_dev;
+                dev_hold(dst->dev);
                 dev_put(dev);
         }
 }