nilfs2: get rid of nilfs_sb_info structure

This directly uses sb->s_fs_info to keep a nilfs filesystem object and
fully removes the intermediate nilfs_sb_info structure.  With this
change, the hierarchy of on-memory structures of nilfs will be
simplified as follows:

Before:
  super_block
       -> nilfs_sb_info
             -> the_nilfs
                   -> cptree --+-> nilfs_root (current file system)
                               +-> nilfs_root (snapshot A)
                               +-> nilfs_root (snapshot B)
                               :
             -> nilfs_sc_info (log writer structure)
After:
  super_block
       -> the_nilfs
             -> cptree --+-> nilfs_root (current file system)
                         +-> nilfs_root (snapshot A)
                         +-> nilfs_root (snapshot B)
                         :
             -> nilfs_sc_info (log writer structure)

The reason why we didn't design so from the beginning is because the
initial shape also differed from the above.  The early hierachy was
composed of "per-mount-point" super_block -> nilfs_sb_info pairs and a
shared nilfs object.  On the kernel 2.6.37, it was changed to the
current shape in order to unify super block instances into one per
device, and this cleanup became applicable as the result.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

1 files changed, 0 insertions, 46 deletions

diff --git a/fs/nilfs2/sb.h b/fs/nilfs2/sb.h
deleted file mode 100644
index 44553f4..0000000
--- a/fs/nilfs2/sb.h
+++ /dev/null
@@ -1,46 +0,0 @@
-/*
- * sb.h - NILFS on-memory super block structure.
- *
- * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
- *
- * Written by Ryusuke Konishi <ryusuke@osrg.net>
- *
- */
-
-#ifndef _NILFS_SB
-#define _NILFS_SB
-
-#include <linux/types.h>
-#include <linux/fs.h>
-
-struct the_nilfs;
-
-/*
- * NILFS super-block data in memory
- */
-struct nilfs_sb_info {
-	/* Fundamental members */
-	struct super_block *s_super;	/* reverse pointer to super_block */
-	struct the_nilfs *s_nilfs;
-};
-
-static inline struct nilfs_sb_info *NILFS_SB(struct super_block *sb)
-{
-	return sb->s_fs_info;
-}
-
-#endif /* _NILFS_SB */