f2fs: move sysfs code from super.c to fs/f2fs/sysfs.c

Codes related to sysfs and procfs are dispersive and mixed with sb
related codes, but actually these codes are independent from others,
so split them from super.c, and reorgnize and manger them in sysfs.c.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/Makefile

@@ -2,7 +2,7 @@ obj-$(CONFIG_F2FS_FS) += f2fs.o
 
 f2fs-y		:= dir.o file.o inode.o namei.o hash.o super.o inline.o
 f2fs-y		+= checkpoint.o gc.o data.o node.o segment.o recovery.o
-f2fs-y		+= shrinker.o extent_cache.o
+f2fs-y		+= shrinker.o extent_cache.o sysfs.o
 f2fs-$(CONFIG_F2FS_STAT_FS) += debug.o
 f2fs-$(CONFIG_F2FS_FS_XATTR) += xattr.o
 f2fs-$(CONFIG_F2FS_FS_POSIX_ACL) += acl.o

fs/f2fs/f2fs.h

@@ -2673,6 +2673,14 @@ void init_extent_cache_info(struct f2fs_sb_info *sbi);
 int __init create_extent_cache(void);
 void destroy_extent_cache(void);
 
+/*
+ * sysfs.c
+ */
+int __init f2fs_register_sysfs(void);
+void f2fs_unregister_sysfs(void);
+int f2fs_init_sysfs(struct f2fs_sb_info *sbi);
+void f2fs_exit_sysfs(struct f2fs_sb_info *sbi);
+
 /*
  * crypto support
  */