nilfs2: checkpoint file

This adds a meta data file which holds checkpoint entries in its data
blocks.
Signed-off-by: Koji Sato <sato.koji@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/nilfs2/cpfile.h

+/*
+ * cpfile.h - NILFS checkpoint file.
+ *
+ * Copyright (C) 2006-2008 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 Koji Sato <koji@osrg.net>.
+ */
+
+#ifndef _NILFS_CPFILE_H
+#define _NILFS_CPFILE_H
+
+#include <linux/fs.h>
+#include <linux/buffer_head.h>
+#include <linux/nilfs2_fs.h>
+
+#define NILFS_CPFILE_GFP	NILFS_MDT_GFP
+
+
+int nilfs_cpfile_get_checkpoint(struct inode *, __u64, int,
+				struct nilfs_checkpoint **,
+				struct buffer_head **);
+void nilfs_cpfile_put_checkpoint(struct inode *, __u64, struct buffer_head *);
+int nilfs_cpfile_delete_checkpoints(struct inode *, __u64, __u64);
+int nilfs_cpfile_delete_checkpoint(struct inode *, __u64);
+int nilfs_cpfile_change_cpmode(struct inode *, __u64, int);
+int nilfs_cpfile_is_snapshot(struct inode *, __u64);
+int nilfs_cpfile_get_stat(struct inode *, struct nilfs_cpstat *);
+ssize_t nilfs_cpfile_get_cpinfo(struct inode *, __u64, int,
+				struct nilfs_cpinfo *, size_t);
+
+#endif	/* _NILFS_CPFILE_H */