[PATCH 2/3] /proc/net/if_inet6 may drop some data (Re: /proc/net/* read drops data)

[YOSHIFUJI Hideaki / 吉藤英明 <yoshfuji@xxxxxxxxxxxxxx>]

[2/3] /proc/net/if_inet6 may drop some data

Index: linux-2.6/net/ipv6/addrconf.c
===================================================================
RCS file: /home/cvs/linux-2.5/net/ipv6/addrconf.c,v
retrieving revision 1.52
diff -u -r1.52 addrconf.c
--- linux-2.6/net/ipv6/addrconf.c       4 Sep 2003 15:47:07 -0000       1.52
+++ linux-2.6/net/ipv6/addrconf.c       6 Sep 2003 04:23:07 -0000
@@ -2149,59 +2149,65 @@
        int bucket;
 };
 
-static inline struct inet6_ifaddr *if6_get_bucket(struct seq_file *seq, loff_t 
*pos)
+static struct inet6_ifaddr *if6_get_first(struct seq_file *seq)
 {
-       int i;
        struct inet6_ifaddr *ifa = NULL;
-       loff_t l = *pos;
        struct if6_iter_state *state = seq->private;
 
-       for (; state->bucket < IN6_ADDR_HSIZE; ++state->bucket)
-               for (i = 0, ifa = inet6_addr_lst[state->bucket]; ifa; ++i, 
ifa=ifa->lst_next) {
-                       if (l--)
-                               continue;
-                       *pos = i;
-                       goto out;
-               }
-out:
+       for (state->bucket = 0; state->bucket < IN6_ADDR_HSIZE; 
++state->bucket) {
+               ifa = inet6_addr_lst[state->bucket];
+               if (ifa)
+                       break;
+       }
+       return ifa;
+}
+
+static struct inet6_ifaddr *if6_get_next(struct seq_file *seq, struct 
inet6_ifaddr *ifa)
+{
+       struct if6_iter_state *state = seq->private;
+
+       ifa = ifa->lst_next;
+try_again:
+       if (!ifa && ++state->bucket < IN6_ADDR_HSIZE) {
+               ifa = inet6_addr_lst[state->bucket];
+               goto try_again;
+       }
        return ifa;
 }
 
+static struct inet6_ifaddr *if6_get_idx(struct seq_file *seq, loff_t pos)
+{
+       struct inet6_ifaddr *ifa = if6_get_first(seq);
+
+       if (ifa)
+               while(pos && (ifa = if6_get_next(seq, ifa)) != NULL)
+                       --pos;
+       return pos ? NULL : ifa;
+}
+
 static void *if6_seq_start(struct seq_file *seq, loff_t *pos)
 {
        read_lock_bh(&addrconf_hash_lock);
-       return *pos ? if6_get_bucket(seq, pos) : (void *)1;
+       return if6_get_idx(seq, *pos);
 }
 
 static void *if6_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
        struct inet6_ifaddr *ifa;
-       struct if6_iter_state *state;
-
-       if (v == (void *)1) {
-               ifa = if6_get_bucket(seq, pos);
-               goto out;
-       }
-
-       state = seq->private;
-
-       ifa = v;
-       ifa = ifa->lst_next;
-       if (ifa)
-               goto out;
-
-       if (++state->bucket >= IN6_ADDR_HSIZE)
-               goto out;
 
-       *pos = 0;
-       ifa = if6_get_bucket(seq, pos);
-out:
+       ifa = if6_get_next(seq, v);
        ++*pos;
        return ifa;
 }
 
-static inline void if6_iface_seq_show(struct seq_file *seq, struct 
inet6_ifaddr *ifp)
+static void if6_seq_stop(struct seq_file *seq, void *v)
+{
+       read_unlock_bh(&addrconf_hash_lock);
+}
+
+static int if6_seq_show(struct seq_file *seq, void *v)
 {
+       struct inet6_ifaddr *ifp = (struct inet6_ifaddr *)v;
        seq_printf(seq,
                   "%04x%04x%04x%04x%04x%04x%04x%04x %02x %02x %02x %02x %8s\n",
                   NIP6(ifp->addr),
@@ -2210,20 +2216,7 @@
                   ifp->scope,
                   ifp->flags,
                   ifp->idev->dev->name);
-}
-
-static int if6_seq_show(struct seq_file *seq, void *v)
-{
-       if (v == (void *)1)
-               return 0;
-       else
-               if6_iface_seq_show(seq, v);
        return 0;
-}
-
-static void if6_seq_stop(struct seq_file *seq, void *v)
-{
-       read_unlock_bh(&addrconf_hash_lock);
 }
 
 static struct seq_operations if6_seq_ops = {

-- 
Hideaki YOSHIFUJI @ USAGI Project <yoshfuji@xxxxxxxxxxxxxx>
GPG FP: 9022 65EB 1ECF 3AD1 0BDF  80D8 4807 F894 E062 0EEA