proc: introduce proc_create_single{,_data}

Variants of proc_create{,_data} that directly take a seq_file show
callback and drastically reduces the boilerplate code in the callers.

All trivial callers converted over.

Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/proc/cmdline.c b/fs/proc/cmdline.c
index 8233e7a..fa762c5 100644
--- a/fs/proc/cmdline.c
+++ b/fs/proc/cmdline.c
@@ -11,21 +11,9 @@ static int cmdline_proc_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static int cmdline_proc_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, cmdline_proc_show, NULL);
-}
-
-static const struct file_operations cmdline_proc_fops = {
-	.open		= cmdline_proc_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
-
 static int __init proc_cmdline_init(void)
 {
-	proc_create("cmdline", 0, NULL, &cmdline_proc_fops);
+	proc_create_single("cmdline", 0, NULL, cmdline_proc_show);
 	return 0;
 }
 fs_initcall(proc_cmdline_init);
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index f87cb00..02bb191 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -588,6 +588,35 @@ struct proc_dir_entry *proc_create_seq_private(const char *name, umode_t mode,
 }
 EXPORT_SYMBOL(proc_create_seq_private);
 
+static int proc_single_open(struct inode *inode, struct file *file)
+{
+	struct proc_dir_entry *de = PDE(inode);
+
+	return single_open(file, de->single_show, de->data);
+}
+
+static const struct file_operations proc_single_fops = {
+	.open		= proc_single_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+struct proc_dir_entry *proc_create_single_data(const char *name, umode_t mode,
+		struct proc_dir_entry *parent,
+		int (*show)(struct seq_file *, void *), void *data)
+{
+	struct proc_dir_entry *p;
+
+	p = proc_create_reg(name, mode, &parent, data);
+	if (!p)
+		return NULL;
+	p->proc_fops = &proc_single_fops;
+	p->single_show = show;
+	return proc_register(parent, p);
+}
+EXPORT_SYMBOL(proc_create_single_data);
+
 void proc_set_size(struct proc_dir_entry *de, loff_t size)
 {
 	de->size = size;
diff --git a/fs/proc/internal.h b/fs/proc/internal.h
index bcfe830..84c6850 100644
--- a/fs/proc/internal.h
+++ b/fs/proc/internal.h
@@ -44,7 +44,10 @@ struct proc_dir_entry {
 	struct completion *pde_unload_completion;
 	const struct inode_operations *proc_iops;
 	const struct file_operations *proc_fops;
-	const struct seq_operations *seq_ops;
+	union {
+		const struct seq_operations *seq_ops;
+		int (*single_show)(struct seq_file *, void *);
+	};
 	void *data;
 	unsigned int state_size;
 	unsigned int low_ino;
diff --git a/fs/proc/loadavg.c b/fs/proc/loadavg.c
index b572cc8..d066947 100644
--- a/fs/proc/loadavg.c
+++ b/fs/proc/loadavg.c
@@ -28,21 +28,9 @@ static int loadavg_proc_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static int loadavg_proc_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, loadavg_proc_show, NULL);
-}
-
-static const struct file_operations loadavg_proc_fops = {
-	.open		= loadavg_proc_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
-
 static int __init proc_loadavg_init(void)
 {
-	proc_create("loadavg", 0, NULL, &loadavg_proc_fops);
+	proc_create_single("loadavg", 0, NULL, loadavg_proc_show);
 	return 0;
 }
 fs_initcall(proc_loadavg_init);
diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c
index 65a72ab..2fb0484 100644
--- a/fs/proc/meminfo.c
+++ b/fs/proc/meminfo.c
@@ -149,21 +149,9 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static int meminfo_proc_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, meminfo_proc_show, NULL);
-}
-
-static const struct file_operations meminfo_proc_fops = {
-	.open		= meminfo_proc_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
-
 static int __init proc_meminfo_init(void)
 {
-	proc_create("meminfo", 0, NULL, &meminfo_proc_fops);
+	proc_create_single("meminfo", 0, NULL, meminfo_proc_show);
 	return 0;
 }
 fs_initcall(proc_meminfo_init);
diff --git a/fs/proc/softirqs.c b/fs/proc/softirqs.c
index 24072cc..12901dc 100644
--- a/fs/proc/softirqs.c
+++ b/fs/proc/softirqs.c
@@ -25,21 +25,9 @@ static int show_softirqs(struct seq_file *p, void *v)
 	return 0;
 }
 
-static int softirqs_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, show_softirqs, NULL);
-}
-
-static const struct file_operations proc_softirqs_operations = {
-	.open		= softirqs_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
-
 static int __init proc_softirqs_init(void)
 {
-	proc_create("softirqs", 0, NULL, &proc_softirqs_operations);
+	proc_create_single("softirqs", 0, NULL, show_softirqs);
 	return 0;
 }
 fs_initcall(proc_softirqs_init);
diff --git a/fs/proc/uptime.c b/fs/proc/uptime.c
index 95a708d..3bd12f9 100644
--- a/fs/proc/uptime.c
+++ b/fs/proc/uptime.c
@@ -30,21 +30,9 @@ static int uptime_proc_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static int uptime_proc_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, uptime_proc_show, NULL);
-}
-
-static const struct file_operations uptime_proc_fops = {
-	.open		= uptime_proc_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
-
 static int __init proc_uptime_init(void)
 {
-	proc_create("uptime", 0, NULL, &uptime_proc_fops);
+	proc_create_single("uptime", 0, NULL, uptime_proc_show);
 	return 0;
 }
 fs_initcall(proc_uptime_init);
diff --git a/fs/proc/version.c b/fs/proc/version.c
index 94901e8..b449f18 100644
--- a/fs/proc/version.c
+++ b/fs/proc/version.c
@@ -15,21 +15,9 @@ static int version_proc_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static int version_proc_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, version_proc_show, NULL);
-}
-
-static const struct file_operations version_proc_fops = {
-	.open		= version_proc_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
-
 static int __init proc_version_init(void)
 {
-	proc_create("version", 0, NULL, &version_proc_fops);
+	proc_create_single("version", 0, NULL, version_proc_show);
 	return 0;
 }
 fs_initcall(proc_version_init);