proc: introduce proc_create_net{,_data}

Variants of proc_create{,_data} that directly take a struct seq_operations
and deal with network namespaces in ->open and ->release.  All callers of
proc_create + seq_open_net converted over, and seq_{open,release}_net are
removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>

2 files changed, 44 insertions, 60 deletions

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index b9129e2befea..bbc91d7ca1bd 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -1067,7 +1067,6 @@ void nfs_clients_init(struct net *net)
 }
 
 #ifdef CONFIG_PROC_FS
-static int nfs_server_list_open(struct inode *inode, struct file *file);
 static void *nfs_server_list_start(struct seq_file *p, loff_t *pos);
 static void *nfs_server_list_next(struct seq_file *p, void *v, loff_t *pos);
 static void nfs_server_list_stop(struct seq_file *p, void *v);
@@ -1080,14 +1079,6 @@ static const struct seq_operations nfs_server_list_ops = {
 	.show	= nfs_server_list_show,
 };
 
-static const struct file_operations nfs_server_list_fops = {
-	.open		= nfs_server_list_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= seq_release_net,
-};
-
-static int nfs_volume_list_open(struct inode *inode, struct file *file);
 static void *nfs_volume_list_start(struct seq_file *p, loff_t *pos);
 static void *nfs_volume_list_next(struct seq_file *p, void *v, loff_t *pos);
 static void nfs_volume_list_stop(struct seq_file *p, void *v);
@@ -1100,23 +1091,6 @@ static const struct seq_operations nfs_volume_list_ops = {
 	.show	= nfs_volume_list_show,
 };
 
-static const struct file_operations nfs_volume_list_fops = {
-	.open		= nfs_volume_list_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= seq_release_net,
-};
-
-/*
- * open "/proc/fs/nfsfs/servers" which provides a summary of servers with which
- * we're dealing
- */
-static int nfs_server_list_open(struct inode *inode, struct file *file)
-{
-	return seq_open_net(inode, file, &nfs_server_list_ops,
-			   sizeof(struct seq_net_private));
-}
-
 /*
  * set up the iterator to start reading from the server list and return the first item
  */
@@ -1185,15 +1159,6 @@ static int nfs_server_list_show(struct seq_file *m, void *v)
 }
 
 /*
- * open "/proc/fs/nfsfs/volumes" which provides a summary of extant volumes
- */
-static int nfs_volume_list_open(struct inode *inode, struct file *file)
-{
-	return seq_open_net(inode, file, &nfs_volume_list_ops,
-			   sizeof(struct seq_net_private));
-}
-
-/*
  * set up the iterator to start reading from the volume list and return the first item
  */
 static void *nfs_volume_list_start(struct seq_file *m, loff_t *_pos)
@@ -1278,14 +1243,14 @@ int nfs_fs_proc_net_init(struct net *net)
 		goto error_0;
 
 	/* a file of servers with which we're dealing */
-	p = proc_create("servers", S_IFREG|S_IRUGO,
-			nn->proc_nfsfs, &nfs_server_list_fops);
+	p = proc_create_net("servers", S_IFREG|S_IRUGO, nn->proc_nfsfs,
+			&nfs_server_list_ops, sizeof(struct seq_net_private));
 	if (!p)
 		goto error_1;
 
 	/* a file of volumes that we have mounted */
-	p = proc_create("volumes", S_IFREG|S_IRUGO,
-			nn->proc_nfsfs, &nfs_volume_list_fops);
+	p = proc_create_net("volumes", S_IFREG|S_IRUGO, nn->proc_nfsfs,
+			&nfs_volume_list_ops, sizeof(struct seq_net_private));
 	if (!p)
 		goto error_1;
 	return 0;
diff --git a/fs/proc/proc_net.c b/fs/proc/proc_net.c
index 1763f370489d..c99fd183f034 100644
--- a/fs/proc/proc_net.c
+++ b/fs/proc/proc_net.c
@@ -38,20 +38,20 @@ static struct net *get_proc_net(const struct inode *inode)
 	return maybe_get_net(PDE_NET(PDE(inode)));
 }
 
-int seq_open_net(struct inode *ino, struct file *f,
-		 const struct seq_operations *ops, int size)
+static int seq_open_net(struct inode *inode, struct file *file)
 {
-	struct net *net;
+	unsigned int state_size = PDE(inode)->state_size;
 	struct seq_net_private *p;
+	struct net *net;
 
-	BUG_ON(size < sizeof(*p));
+	WARN_ON_ONCE(state_size < sizeof(*p));
 
-	net = get_proc_net(ino);
-	if (net == NULL)
+	net = get_proc_net(inode);
+	if (!net)
 		return -ENXIO;
 
-	p = __seq_open_private(f, ops, size);
-	if (p == NULL) {
+	p = __seq_open_private(file, PDE(inode)->seq_ops, state_size);
+	if (!p) {
 		put_net(net);
 		return -ENOMEM;
 	}
@@ -60,7 +60,38 @@ int seq_open_net(struct inode *ino, struct file *f,
 #endif
 	return 0;
 }
-EXPORT_SYMBOL_GPL(seq_open_net);
+
+static int seq_release_net(struct inode *ino, struct file *f)
+{
+	struct seq_file *seq = f->private_data;
+
+	put_net(seq_file_net(seq));
+	seq_release_private(ino, f);
+	return 0;
+}
+
+static const struct file_operations proc_net_seq_fops = {
+	.open		= seq_open_net,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release_net,
+};
+
+struct proc_dir_entry *proc_create_net_data(const char *name, umode_t mode,
+		struct proc_dir_entry *parent, const struct seq_operations *ops,
+		unsigned int state_size, void *data)
+{
+	struct proc_dir_entry *p;
+
+	p = proc_create_reg(name, mode, &parent, data);
+	if (!p)
+		return NULL;
+	p->proc_fops = &proc_net_seq_fops;
+	p->seq_ops = ops;
+	p->state_size = state_size;
+	return proc_register(parent, p);
+}
+EXPORT_SYMBOL_GPL(proc_create_net_data);
 
 int single_open_net(struct inode *inode, struct file *file,
 		int (*show)(struct seq_file *, void *))
@@ -86,18 +117,6 @@ err_net:
 }
 EXPORT_SYMBOL_GPL(single_open_net);
 
-int seq_release_net(struct inode *ino, struct file *f)
-{
-	struct seq_file *seq;
-
-	seq = f->private_data;
-
-	put_net(seq_file_net(seq));
-	seq_release_private(ino, f);
-	return 0;
-}
-EXPORT_SYMBOL_GPL(seq_release_net);
-
 int single_release_net(struct inode *ino, struct file *f)
 {
 	struct seq_file *seq = f->private_data;