[NETNS]: Show routing information from correct namespace (fib_trie.c)

This is the second part (for the CONFIG_IP_FIB_TRIE case) of the patch
#4, where we have created proc files in namespaces.

Now we can dump correct info in them.
Acked-by: NBenjamin Thery <benjamin.thery@bull.net>
Acked-by: NDaniel Lezcano <dlezcano@fr.ibm.com>
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/fib_trie.c

@@ -1995,6 +1995,7 @@ struct fib_table *fib_hash_init(u32 id)
 #ifdef CONFIG_PROC_FS
 /* Depth first Trie walk iterator */
 struct fib_trie_iter {
+	struct seq_net_private p;
 	struct trie *trie_local, *trie_main;
 	struct tnode *tnode;
 	struct trie *trie;
@@ -2162,17 +2163,18 @@ static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat)
 
 static int fib_triestat_seq_show(struct seq_file *seq, void *v)
 {
+	struct net *net = (struct net *)seq->private;
 	struct trie *trie_local, *trie_main;
 	struct trie_stat *stat;
 	struct fib_table *tb;
 
 	trie_local = NULL;
-	tb = fib_get_table(&init_net, RT_TABLE_LOCAL);
+	tb = fib_get_table(net, RT_TABLE_LOCAL);
 	if (tb)
 		trie_local = (struct trie *) tb->tb_data;
 
 	trie_main = NULL;
-	tb = fib_get_table(&init_net, RT_TABLE_MAIN);
+	tb = fib_get_table(net, RT_TABLE_MAIN);
 	if (tb)
 		trie_main = (struct trie *) tb->tb_data;
 
@@ -2202,7 +2204,25 @@ static int fib_triestat_seq_show(struct seq_file *seq, void *v)
 
 static int fib_triestat_seq_open(struct inode *inode, struct file *file)
 {
-	return single_open(file, fib_triestat_seq_show, NULL);
+	int err;
+	struct net *net;
+
+	net = get_proc_net(inode);
+	if (net == NULL)
+		return -ENXIO;
+	err = single_open(file, fib_triestat_seq_show, net);
+	if (err < 0) {
+		put_net(net);
+		return err;
+	}
+	return 0;
+}
+
+static int fib_triestat_seq_release(struct inode *ino, struct file *f)
+{
+	struct seq_file *seq = f->private_data;
+	put_net(seq->private);
+	return single_release(ino, f);
 }
 
 static const struct file_operations fib_triestat_fops = {
@@ -2210,7 +2230,7 @@ static const struct file_operations fib_triestat_fops = {
 	.open	= fib_triestat_seq_open,
 	.read	= seq_read,
 	.llseek	= seq_lseek,
-	.release = single_release,
+	.release = fib_triestat_seq_release,
 };
 
 static struct node *fib_trie_get_idx(struct fib_trie_iter *iter,
@@ -2239,12 +2259,12 @@ static void *fib_trie_seq_start(struct seq_file *seq, loff_t *pos)
 	struct fib_table *tb;
 
 	if (!iter->trie_local) {
-		tb = fib_get_table(&init_net, RT_TABLE_LOCAL);
+		tb = fib_get_table(iter->p.net, RT_TABLE_LOCAL);
 		if (tb)
 			iter->trie_local = (struct trie *) tb->tb_data;
 	}
 	if (!iter->trie_main) {
-		tb = fib_get_table(&init_net, RT_TABLE_MAIN);
+		tb = fib_get_table(iter->p.net, RT_TABLE_MAIN);
 		if (tb)
 			iter->trie_main = (struct trie *) tb->tb_data;
 	}
@@ -2388,8 +2408,8 @@ static const struct seq_operations fib_trie_seq_ops = {
 
 static int fib_trie_seq_open(struct inode *inode, struct file *file)
 {
-	return seq_open_private(file, &fib_trie_seq_ops,
-			sizeof(struct fib_trie_iter));
+	return seq_open_net(inode, file, &fib_trie_seq_ops,
+			    sizeof(struct fib_trie_iter));
 }
 
 static const struct file_operations fib_trie_fops = {
@@ -2397,7 +2417,7 @@ static const struct file_operations fib_trie_fops = {
 	.open   = fib_trie_seq_open,
 	.read   = seq_read,
 	.llseek = seq_lseek,
-	.release = seq_release_private,
+	.release = seq_release_net,
 };
 
 static unsigned fib_flag_trans(int type, __be32 mask, const struct fib_info *fi)
@@ -2492,8 +2512,8 @@ static const struct seq_operations fib_route_seq_ops = {
 
 static int fib_route_seq_open(struct inode *inode, struct file *file)
 {
-	return seq_open_private(file, &fib_route_seq_ops,
-			sizeof(struct fib_trie_iter));
+	return seq_open_net(inode, file, &fib_route_seq_ops,
+			    sizeof(struct fib_trie_iter));
 }
 
 static const struct file_operations fib_route_fops = {
@@ -2501,7 +2521,7 @@ static const struct file_operations fib_route_fops = {
 	.open   = fib_route_seq_open,
 	.read   = seq_read,
 	.llseek = seq_lseek,
-	.release = seq_release_private,
+	.release = seq_release_net,
 };
 
 int __net_init fib_proc_init(struct net *net)