sysfs: Basic support for multiple super blocks

Add all of the necessary bioler plate to support
multiple superblocks in sysfs.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index 30f5a44..030a39d 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -114,6 +114,9 @@
 /*
  * mount.c
  */
+struct sysfs_super_info {
+};
+#define sysfs_info(SB) ((struct sysfs_super_info *)(SB->s_fs_info))
 extern struct sysfs_dirent sysfs_root;
 extern struct kmem_cache *sysfs_dir_cachep;