ipv6: convert addrconf list to hlist

Using hash list macros, simplifies code and helps later RCU.

This patch includes some initialization that is not strictly necessary,
since an empty hlist node/list is all zero; and list is in BSS
and node is allocated with kzalloc.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 54 insertions, 76 deletions

diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h
index 09d906460a43..498401541519 100644
--- a/include/net/if_inet6.h
+++ b/include/net/if_inet6.h
@@ -54,7 +54,7 @@ struct inet6_ifaddr {
         struct inet6_dev        *idev;
         struct rt6_info         *rt;
 
-        struct inet6_ifaddr     *lst_next;      /* next addr in addr_lst */
+        struct hlist_node       addr_lst;
         struct inet6_ifaddr     *if_next;       /* next addr in inet6_dev */
 
 #ifdef CONFIG_IPV6_PRIVACY
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index f372f895cd41..0488b9f8071d 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -126,7 +126,7 @@ static int ipv6_count_addresses(struct inet6_dev *idev);
 /*
  *      Configured unicast address hash table
  */
-static struct inet6_ifaddr              *inet6_addr_lst[IN6_ADDR_HSIZE];
+static struct hlist_head inet6_addr_lst[IN6_ADDR_HSIZE];
 static DEFINE_RWLOCK(addrconf_hash_lock);
 
 static void addrconf_verify(unsigned long);
@@ -528,7 +528,7 @@ static int addrconf_fixup_forwarding(struct ctl_table *table, int *p, int old)
 void inet6_ifa_finish_destroy(struct inet6_ifaddr *ifp)
 {
         WARN_ON(ifp->if_next != NULL);
-        WARN_ON(ifp->lst_next != NULL);
+        WARN_ON(!hlist_unhashed(&ifp->addr_lst));
 
 #ifdef NET_REFCNT_DEBUG
         printk(KERN_DEBUG "inet6_ifa_finish_destroy\n");
@@ -643,6 +643,7 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr, int pfxlen,
 
         spin_lock_init(&ifa->lock);
         init_timer(&ifa->timer);
+        INIT_HLIST_NODE(&ifa->addr_lst);
         ifa->timer.data = (unsigned long) ifa;
         ifa->scope = scope;
         ifa->prefix_len = pfxlen;
@@ -669,8 +670,7 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr, int pfxlen,
         /* Add to big hash table */
         hash = ipv6_addr_hash(addr);
 
-        ifa->lst_next = inet6_addr_lst[hash];
-        inet6_addr_lst[hash] = ifa;
+        hlist_add_head(&ifa->addr_lst, &inet6_addr_lst[hash]);
         in6_ifa_hold(ifa);
         write_unlock(&addrconf_hash_lock);
 
@@ -718,15 +718,8 @@ static void ipv6_del_addr(struct inet6_ifaddr *ifp)
         ifp->dead = 1;
 
         write_lock_bh(&addrconf_hash_lock);
-        for (ifap = &inet6_addr_lst[hash]; (ifa=*ifap) != NULL;
-             ifap = &ifa->lst_next) {
-                if (ifa == ifp) {
-                        *ifap = ifa->lst_next;
-                        __in6_ifa_put(ifp);
-                        ifa->lst_next = NULL;
-                        break;
-                }
-        }
+        hlist_del_init(&ifp->addr_lst);
+        __in6_ifa_put(ifp);
         write_unlock_bh(&addrconf_hash_lock);
 
         write_lock_bh(&idev->lock);
@@ -1277,11 +1270,12 @@ static int ipv6_count_addresses(struct inet6_dev *idev)
 int ipv6_chk_addr(struct net *net, struct in6_addr *addr,
                   struct net_device *dev, int strict)
 {
-        struct inet6_ifaddr * ifp;
+        struct inet6_ifaddr *ifp = NULL;
+        struct hlist_node *node;
         u8 hash = ipv6_addr_hash(addr);
 
         read_lock_bh(&addrconf_hash_lock);
-        for(ifp = inet6_addr_lst[hash]; ifp; ifp=ifp->lst_next) {
+        hlist_for_each_entry(ifp, node, &inet6_addr_lst[hash], addr_lst) {
                 if (!net_eq(dev_net(ifp->idev->dev), net))
                         continue;
                 if (ipv6_addr_equal(&ifp->addr, addr) &&
@@ -1300,10 +1294,11 @@ static
 int ipv6_chk_same_addr(struct net *net, const struct in6_addr *addr,
                        struct net_device *dev)
 {
-        struct inet6_ifaddr * ifp;
+        struct inet6_ifaddr *ifp;
+        struct hlist_node *node;
         u8 hash = ipv6_addr_hash(addr);
 
-        for(ifp = inet6_addr_lst[hash]; ifp; ifp=ifp->lst_next) {
+        hlist_for_each_entry(ifp, node, &inet6_addr_lst[hash], addr_lst) {
                 if (!net_eq(dev_net(ifp->idev->dev), net))
                         continue;
                 if (ipv6_addr_equal(&ifp->addr, addr)) {
@@ -1342,11 +1337,12 @@ EXPORT_SYMBOL(ipv6_chk_prefix);
 struct inet6_ifaddr *ipv6_get_ifaddr(struct net *net, const struct in6_addr *addr,
                                      struct net_device *dev, int strict)
 {
-        struct inet6_ifaddr * ifp;
+        struct inet6_ifaddr *ifp = NULL;
+        struct hlist_node *node;
         u8 hash = ipv6_addr_hash(addr);
 
         read_lock_bh(&addrconf_hash_lock);
-        for(ifp = inet6_addr_lst[hash]; ifp; ifp=ifp->lst_next) {
+        hlist_for_each_entry(ifp, node, &inet6_addr_lst[hash], addr_lst) {
                 if (!net_eq(dev_net(ifp->idev->dev), net))
                         continue;
                 if (ipv6_addr_equal(&ifp->addr, addr)) {
@@ -2612,7 +2608,6 @@ static int addrconf_ifdown(struct net_device *dev, int how)
         struct inet6_dev *idev;
         struct inet6_ifaddr *ifa, *keep_list, **bifa;
         struct net *net = dev_net(dev);
-        int i;
 
         ASSERT_RTNL();
 
@@ -2637,25 +2632,6 @@ static int addrconf_ifdown(struct net_device *dev, int how)
 
         }
 
-        /* Step 2: clear hash table */
-        for (i=0; i<IN6_ADDR_HSIZE; i++) {
-                bifa = &inet6_addr_lst[i];
-
-                write_lock_bh(&addrconf_hash_lock);
-                while ((ifa = *bifa) != NULL) {
-                        if (ifa->idev == idev &&
-                            (how || !(ifa->flags&IFA_F_PERMANENT) ||
-                             ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)) {
-                                *bifa = ifa->lst_next;
-                                ifa->lst_next = NULL;
-                                __in6_ifa_put(ifa);
-                                continue;
-                        }
-                        bifa = &ifa->lst_next;
-                }
-                write_unlock_bh(&addrconf_hash_lock);
-        }
-
         write_lock_bh(&idev->lock);
 
         /* Step 3: clear flags for stateless addrconf */
@@ -2721,6 +2697,12 @@ static int addrconf_ifdown(struct net_device *dev, int how)
                 }
                 write_unlock_bh(&idev->lock);
 
+                /* clear hash table */
+                write_lock_bh(&addrconf_hash_lock);
+                hlist_del_init(&ifa->addr_lst);
+                __in6_ifa_put(ifa);
+                write_unlock_bh(&addrconf_hash_lock);
+
                 __ipv6_ifa_notify(RTM_DELADDR, ifa);
                 atomic_notifier_call_chain(&inet6addr_chain, NETDEV_DOWN, ifa);
                 in6_ifa_put(ifa);
@@ -2963,36 +2945,37 @@ static struct inet6_ifaddr *if6_get_first(struct seq_file *seq)
         struct net *net = seq_file_net(seq);
 
         for (state->bucket = 0; state->bucket < IN6_ADDR_HSIZE; ++state->bucket) {
-                ifa = inet6_addr_lst[state->bucket];
-
-                while (ifa && !net_eq(dev_net(ifa->idev->dev), net))
-                        ifa = ifa->lst_next;
-                if (ifa)
-                        break;
+                struct hlist_node *n;
+                hlist_for_each_entry(ifa, n,
+                                     &inet6_addr_lst[state->bucket], addr_lst) {
+                        if (net_eq(dev_net(ifa->idev->dev), net))
+                                return ifa;
+                }
         }
-        return ifa;
+        return NULL;
 }
 
-static struct inet6_ifaddr *if6_get_next(struct seq_file *seq, struct inet6_ifaddr *ifa)
+static struct inet6_ifaddr *if6_get_next(struct seq_file *seq,
+                                         struct inet6_ifaddr *ifa)
 {
         struct if6_iter_state *state = seq->private;
         struct net *net = seq_file_net(seq);
+        struct hlist_node *n = &ifa->addr_lst;
 
-        ifa = ifa->lst_next;
-try_again:
-        if (ifa) {
-                if (!net_eq(dev_net(ifa->idev->dev), net)) {
-                        ifa = ifa->lst_next;
-                        goto try_again;
-                }
+        hlist_for_each_entry_continue(ifa, n, addr_lst) {
+                if (net_eq(dev_net(ifa->idev->dev), net))
+                        return ifa;
         }
 
-        if (!ifa && ++state->bucket < IN6_ADDR_HSIZE) {
-                ifa = inet6_addr_lst[state->bucket];
-                goto try_again;
+        while (++state->bucket < IN6_ADDR_HSIZE) {
+                hlist_for_each_entry(ifa, n,
+                                     &inet6_addr_lst[state->bucket], addr_lst) {
+                        if (net_eq(dev_net(ifa->idev->dev), net))
+                                return ifa;
+                }
         }
 
-        return ifa;
+        return NULL;
 }
 
 static struct inet6_ifaddr *if6_get_idx(struct seq_file *seq, loff_t pos)
@@ -3094,10 +3077,12 @@ void if6_proc_exit(void)
 int ipv6_chk_home_addr(struct net *net, struct in6_addr *addr)
 {
         int ret = 0;
-        struct inet6_ifaddr * ifp;
+        struct inet6_ifaddr *ifp = NULL;
+        struct hlist_node *n;
         u8 hash = ipv6_addr_hash(addr);
+
         read_lock_bh(&addrconf_hash_lock);
-        for (ifp = inet6_addr_lst[hash]; ifp; ifp = ifp->lst_next) {
+        hlist_for_each_entry(ifp, n, &inet6_addr_lst[hash], addr_lst) {
                 if (!net_eq(dev_net(ifp->idev->dev), net))
                         continue;
                 if (ipv6_addr_equal(&ifp->addr, addr) &&
@@ -3118,6 +3103,7 @@ int ipv6_chk_home_addr(struct net *net, struct in6_addr *addr)
 static void addrconf_verify(unsigned long foo)
 {
         struct inet6_ifaddr *ifp;
+        struct hlist_node *node;
         unsigned long now, next;
         int i;
 
@@ -3131,7 +3117,7 @@ static void addrconf_verify(unsigned long foo)
 
 restart:
                 read_lock(&addrconf_hash_lock);
-                for (ifp=inet6_addr_lst[i]; ifp; ifp=ifp->lst_next) {
+                hlist_for_each_entry(ifp, node, &inet6_addr_lst[i], addr_lst) {
                         unsigned long age;
 #ifdef CONFIG_IPV6_PRIVACY
                         unsigned long regen_advance;
@@ -4550,7 +4536,7 @@ EXPORT_SYMBOL(unregister_inet6addr_notifier);
 
 int __init addrconf_init(void)
 {
-        int err;
+        int i, err;
 
         if ((err = ipv6_addr_label_init()) < 0) {
                 printk(KERN_CRIT "IPv6 Addrconf: cannot initialize default policy table: %d.\n",
@@ -4585,6 +4571,9 @@ int __init addrconf_init(void)
         if (err)
                 goto errlo;
 
+        for (i = 0; i < IN6_ADDR_HSIZE; i++)
+                INIT_HLIST_HEAD(&inet6_addr_lst[i]);
+
         register_netdevice_notifier(&ipv6_dev_notf);
 
         addrconf_verify(0);
@@ -4613,7 +4602,6 @@ errlo:
 
 void addrconf_cleanup(void)
 {
-        struct inet6_ifaddr *ifa;
         struct net_device *dev;
         int i;
 
@@ -4634,18 +4622,8 @@ void addrconf_cleanup(void)
          *      Check hash table.
          */
         write_lock_bh(&addrconf_hash_lock);
-        for (i=0; i < IN6_ADDR_HSIZE; i++) {
-                for (ifa=inet6_addr_lst[i]; ifa; ) {
-                        struct inet6_ifaddr *bifa;
-
-                        bifa = ifa;
-                        ifa = ifa->lst_next;
-                        printk(KERN_DEBUG "bug: IPv6 address leakage detected: ifa=%p\n", bifa);
-                        /* Do not free it; something is wrong.
-                           Now we can investigate it with debugger.
-                         */
-                }
-        }
+        for (i = 0; i < IN6_ADDR_HSIZE; i++)
+                WARN_ON(!hlist_empty(&inet6_addr_lst[i]));
         write_unlock_bh(&addrconf_hash_lock);
 
         del_timer(&addr_chk_timer);