proc: move /proc/filesystems to fs/filesystems.c

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>

fs/filesystems.c

@@ -8,6 +8,8 @@
 
 #include <linux/syscalls.h>
 #include <linux/fs.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
 #include <linux/slab.h>
 #include <linux/kmod.h>
 #include <linux/init.h>
@@ -214,6 +216,43 @@ int get_filesystem_list(char * buf)
 	return len;
 }
 
+#ifdef CONFIG_PROC_FS
+static int filesystems_proc_show(struct seq_file *m, void *v)
+{
+	struct file_system_type * tmp;
+
+	read_lock(&file_systems_lock);
+	tmp = file_systems;
+	while (tmp) {
+		seq_printf(m, "%s\t%s\n",
+			(tmp->fs_flags & FS_REQUIRES_DEV) ? "" : "nodev",
+			tmp->name);
+		tmp = tmp->next;
+	}
+	read_unlock(&file_systems_lock);
+	return 0;
+}
+
+static int filesystems_proc_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, filesystems_proc_show, NULL);
+}
+
+static const struct file_operations filesystems_proc_fops = {
+	.open		= filesystems_proc_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static int __init proc_filesystems_init(void)
+{
+	proc_create("filesystems", 0, NULL, &filesystems_proc_fops);
+	return 0;
+}
+module_init(proc_filesystems_init);
+#endif
+
 struct file_system_type *get_fs_type(const char *name)
 {
 	struct file_system_type *fs;

fs/proc/proc_misc.c

@@ -472,13 +472,6 @@ static const struct file_operations proc_interrupts_operations = {
 	.release	= seq_release,
 };
 
-static int filesystems_read_proc(char *page, char **start, off_t off,
-				 int count, int *eof, void *data)
-{
-	int len = get_filesystem_list(page);
-	return proc_calc_metrics(page, start, off, count, eof, len);
-}
-
 static int cmdline_read_proc(char *page, char **start, off_t off,
 				 int count, int *eof, void *data)
 {
@@ -648,7 +641,6 @@ void __init proc_misc_init(void)
 		char *name;
 		int (*read_proc)(char*,char**,off_t,int,int*,void*);
 	} *p, simple_ones[] = {
-		{"filesystems",	filesystems_read_proc},
 		{"cmdline",	cmdline_read_proc},
 		{"execdomains",	execdomains_read_proc},
 		{NULL,}