net: consolidate net namespace related proc files creation

index 131f9c6..421ea28 100644
@@ -22,10 +22,48 @@
 #include <linux/mount.h>
 #include <linux/nsproxy.h>
 #include <net/net_namespace.h>
+#include <linux/seq_file.h>
 
 #include "internal.h"
 
 
+int seq_open_net(struct inode *ino, struct file *f,
+		 const struct seq_operations *ops, int size)
+{
+	struct net *net;
+	struct seq_net_private *p;
+
+	BUG_ON(size < sizeof(*p));
+
+	net = get_proc_net(ino);
+	if (net == NULL)
+		return -ENXIO;
+
+	p = __seq_open_private(f, ops, size);
+	if (p == NULL) {
+		put_net(net);
+		return -ENOMEM;
+	}
+	p->net = net;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(seq_open_net);
+
+int seq_release_net(struct inode *ino, struct file *f)
+{
+	struct seq_file *seq;
+	struct seq_net_private *p;
+
+	seq = f->private_data;
+	p = seq->private;
+
+	put_net(p->net);
+	seq_release_private(ino, f);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(seq_release_net);
+
+
 struct proc_dir_entry *proc_net_fops_create(struct net *net,
 	const char *name, mode_t mode, const struct file_operations *fops)
 {

index ebbc02b..648dfeb 100644
@@ -63,5 +63,18 @@ extern struct list_head *seq_list_start_head(struct list_head *head,
 extern struct list_head *seq_list_next(void *v, struct list_head *head,
 		loff_t *ppos);
 
+struct net;
+struct seq_net_private {
+	struct net *net;
+};
+
+int seq_open_net(struct inode *, struct file *,
+		 const struct seq_operations *, int);
+int seq_release_net(struct inode *, struct file *);
+static inline struct net *seq_file_net(struct seq_file *seq)
+{
+	return ((struct seq_net_private *)seq->private)->net;
+}
+
 #endif
 #endif

index 86d6261..043e2f8 100644
@@ -2360,7 +2360,7 @@ static int dev_ifconf(struct net *net, char __user *arg)
  */
 void *dev_seq_start(struct seq_file *seq, loff_t *pos)
 {
-	struct net *net = seq->private;
+	struct net *net = seq_file_net(seq);
 	loff_t off;
 	struct net_device *dev;
 

@@ -2378,7 +2378,7 @@ void *dev_seq_start(struct seq_file *seq, loff_t *pos)
 
 void *dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
-	struct net *net = seq->private;
+	struct net *net = seq_file_net(seq);
 	++*pos;
 	return v == SEQ_START_TOKEN ?
 		first_net_device(net) : next_net_device((struct net_device *)v);

@@ -2477,26 +2477,8 @@ static const struct seq_operations dev_seq_ops = {
 
 static int dev_seq_open(struct inode *inode, struct file *file)
 {
-	struct seq_file *seq;
-	int res;
-	res =  seq_open(file, &dev_seq_ops);
-	if (!res) {
-		seq = file->private_data;
-		seq->private = get_proc_net(inode);
-		if (!seq->private) {
-			seq_release(inode, file);
-			res = -ENXIO;
-		}
-	}
-	return res;
-}
-
-static int dev_seq_release(struct inode *inode, struct file *file)
-{
-	struct seq_file *seq = file->private_data;
-	struct net *net = seq->private;
-	put_net(net);
-	return seq_release(inode, file);
+	return seq_open_net(inode, file, &dev_seq_ops,
+			    sizeof(struct seq_net_private));
 }
 
 static const struct file_operations dev_seq_fops = {

@@ -2504,7 +2486,7 @@ static const struct file_operations dev_seq_fops = {
 	.open    = dev_seq_open,
 	.read    = seq_read,
 	.llseek  = seq_lseek,
-	.release = dev_seq_release,
+	.release = seq_release_net,
 };
 
 static const struct seq_operations softnet_seq_ops = {

index 69fff16..63f0b33 100644
@@ -187,7 +187,7 @@ EXPORT_SYMBOL(dev_mc_unsync);
 #ifdef CONFIG_PROC_FS
 static void *dev_mc_seq_start(struct seq_file *seq, loff_t *pos)
 {
-	struct net *net = seq->private;
+	struct net *net = seq_file_net(seq);
 	struct net_device *dev;
 	loff_t off = 0;
 

@@ -241,26 +241,8 @@ static const struct seq_operations dev_mc_seq_ops = {
 
 static int dev_mc_seq_open(struct inode *inode, struct file *file)
 {
-	struct seq_file *seq;
-	int res;
-	res = seq_open(file, &dev_mc_seq_ops);
-	if (!res) {
-		seq = file->private_data;
-		seq->private = get_proc_net(inode);
-		if (!seq->private) {
-			seq_release(inode, file);
-			res = -ENXIO;
-		}
-	}
-	return res;
-}
-
-static int dev_mc_seq_release(struct inode *inode, struct file *file)
-{
-	struct seq_file *seq = file->private_data;
-	struct net *net = seq->private;
-	put_net(net);
-	return seq_release(inode, file);
+	return seq_open_net(inode, file, &dev_mc_seq_ops,
+			    sizeof(struct seq_net_private));
 }
 
 static const struct file_operations dev_mc_seq_fops = {

@@ -268,7 +250,7 @@ static const struct file_operations dev_mc_seq_fops = {
 	.open    = dev_mc_seq_open,
 	.read    = seq_read,
 	.llseek  = seq_lseek,
-	.release = dev_mc_seq_release,
+	.release = seq_release_net,
 };
 
 #endif

index de3988b..1518244 100644
@@ -1681,7 +1681,7 @@ int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid,
 
 #ifdef CONFIG_PROC_FS
 struct nl_seq_iter {
-	struct net *net;
+	struct seq_net_private p;
 	int link;
 	int hash_idx;
 };

@@ -1699,7 +1699,7 @@ static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos)
 
 		for (j = 0; j <= hash->mask; j++) {
 			sk_for_each(s, node, &hash->table[j]) {
-				if (iter->net != s->sk_net)
+				if (iter->p.net != s->sk_net)
 					continue;
 				if (off == pos) {
 					iter->link = i;

@@ -1734,7 +1734,7 @@ static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 	s = v;
 	do {
 		s = sk_next(s);
-	} while (s && (iter->net != s->sk_net));
+	} while (s && (iter->p.net != s->sk_net));
 	if (s)
 		return s;
 

@@ -1746,7 +1746,7 @@ static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 
 		for (; j <= hash->mask; j++) {
 			s = sk_head(&hash->table[j]);
-			while (s && (iter->net != s->sk_net))
+			while (s && (iter->p.net != s->sk_net))
 				s = sk_next(s);
 			if (s) {
 				iter->link = i;

@@ -1802,27 +1802,8 @@ static const struct seq_operations netlink_seq_ops = {
 
 static int netlink_seq_open(struct inode *inode, struct file *file)
 {
-	struct nl_seq_iter *iter;
-
-	iter = __seq_open_private(file, &netlink_seq_ops, sizeof(*iter));
-	if (!iter)
-		return -ENOMEM;
-
-	iter->net = get_proc_net(inode);
-	if (!iter->net) {
-		seq_release_private(inode, file);
-		return -ENXIO;
-	}
-
-	return 0;
-}
-
-static int netlink_seq_release(struct inode *inode, struct file *file)
-{
-	struct seq_file *seq = file->private_data;
-	struct nl_seq_iter *iter = seq->private;
-	put_net(iter->net);
-	return seq_release_private(inode, file);
+	return seq_open_net(inode, file, &netlink_seq_ops,
+				sizeof(struct nl_seq_iter));
 }
 
 static const struct file_operations netlink_seq_fops = {

@@ -1830,7 +1811,7 @@ static const struct file_operations netlink_seq_fops = {
 	.open		= netlink_seq_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
-	.release	= netlink_seq_release,
+	.release	= seq_release_net,
 };
 
 #endif

index 45e3cbc..ace29f1 100644
@@ -1871,7 +1871,7 @@ static inline struct sock *packet_seq_idx(struct net *net, loff_t off)
 
 static void *packet_seq_start(struct seq_file *seq, loff_t *pos)
 {
-	struct net *net = seq->private;
+	struct net *net = seq_file_net(seq);
 	read_lock(&net->packet_sklist_lock);
 	return *pos ? packet_seq_idx(net, *pos - 1) : SEQ_START_TOKEN;
 }

@@ -1924,26 +1924,8 @@ static const struct seq_operations packet_seq_ops = {
 
 static int packet_seq_open(struct inode *inode, struct file *file)
 {
-	struct seq_file *seq;
-	int res;
-	res = seq_open(file, &packet_seq_ops);
-	if (!res) {
-		seq = file->private_data;
-		seq->private = get_proc_net(inode);
-		if (!seq->private) {
-			seq_release(inode, file);
-			res = -ENXIO;
-		}
-	}
-	return res;
-}
-
-static int packet_seq_release(struct inode *inode, struct file *file)
-{
-	struct seq_file *seq=  file->private_data;
-	struct net *net = seq->private;
-	put_net(net);
-	return seq_release(inode, file);
+	return seq_open_net(inode, file, &packet_seq_ops,
+			    sizeof(struct seq_net_private));
 }
 
 static const struct file_operations packet_seq_fops = {

@@ -1951,7 +1933,7 @@ static const struct file_operations packet_seq_fops = {
 	.open		= packet_seq_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
-	.release	= packet_seq_release,
+	.release	= seq_release_net,
 };
 
 #endif

index 93d7e55..6be6d87 100644
@@ -2011,7 +2011,7 @@ static unsigned int unix_poll(struct file * file, struct socket *sock, poll_tabl
 
 #ifdef CONFIG_PROC_FS
 struct unix_iter_state {
-	struct net *net;
+	struct seq_net_private p;
 	int i;
 };
 static struct sock *unix_seq_idx(struct unix_iter_state *iter, loff_t pos)

@@ -2020,7 +2020,7 @@ static struct sock *unix_seq_idx(struct unix_iter_state *iter, loff_t pos)
 	struct sock *s;
 
 	for (s = first_unix_socket(&iter->i); s; s = next_unix_socket(&iter->i, s)) {
-		if (s->sk_net != iter->net)
+		if (s->sk_net != iter->p.net)
 			continue;
 		if (off == pos)
 			return s;

@@ -2047,7 +2047,7 @@ static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 		sk = first_unix_socket(&iter->i);
 	else
 		sk = next_unix_socket(&iter->i, sk);
-	while (sk && (sk->sk_net != iter->net))
+	while (sk && (sk->sk_net != iter->p.net))
 		sk = next_unix_socket(&iter->i, sk);
 	return sk;
 }

@@ -2111,27 +2111,8 @@ static const struct seq_operations unix_seq_ops = {
 
 static int unix_seq_open(struct inode *inode, struct file *file)
 {
-	struct unix_iter_state *it;
-       
-	it = __seq_open_private(file, &unix_seq_ops,
-				sizeof(struct unix_iter_state));
-	if (it == NULL)
-		return -ENOMEM;
-
-	it->net = get_proc_net(inode);
-	if (it->net == NULL) {
-		seq_release_private(inode, file);
-		return -ENXIO;
-	}
-	return 0;
-}
-
-static int unix_seq_release(struct inode *inode, struct file *file)
-{
-	struct seq_file *seq = file->private_data;
-	struct unix_iter_state *iter = seq->private;
-	put_net(iter->net);
-	return seq_release_private(inode, file);
+	return seq_open_net(inode, file, &unix_seq_ops,
+			    sizeof(struct unix_iter_state));
 }
 
 static const struct file_operations unix_seq_fops = {

@@ -2139,7 +2120,7 @@ static const struct file_operations unix_seq_fops = {
 	.open		= unix_seq_open,
 	.read		= seq_read,
 	.llseek		= seq_lseek,
-	.release	= unix_seq_release,
+	.release	= seq_release_net,
 };
 
 #endif

index 85805f2..3ffbd1b 100644
@@ -673,26 +673,8 @@ static const struct seq_operations wireless_seq_ops = {
 
 static int wireless_seq_open(struct inode *inode, struct file *file)
 {
-	struct seq_file *seq;
-	int res;
-	res = seq_open(file, &wireless_seq_ops);
-	if (!res) {
-		seq = file->private_data;
-		seq->private = get_proc_net(inode);
-		if (!seq->private) {
-			seq_release(inode, file);
-			res = -ENXIO;
-		}
-	}
-	return res;
-}
-
-static int wireless_seq_release(struct inode *inode, struct file *file)
-{
-	struct seq_file *seq = file->private_data;
-	struct net *net = seq->private;
-	put_net(net);
-	return seq_release(inode, file);
+	return seq_open_net(inode, file, &wireless_seq_ops,
+			    sizeof(struct seq_net_private));
 }
 
 static const struct file_operations wireless_seq_fops = {

@@ -700,7 +682,7 @@ static const struct file_operations wireless_seq_fops = {
 	.open    = wireless_seq_open,
 	.read    = seq_read,
 	.llseek  = seq_lseek,
-	.release = wireless_seq_release,
+	.release = seq_release_net,
 };
 
 int wext_proc_init(struct net *net)