nilfs2: move ioctl interface and disk layout to uapi separately

The header file "include/linux/nilfs2_fs.h" is composed of parts for
ioctl and disk format, and both are intended to be shared with user
space programs.

This moves them to the uapi directory "include/uapi/linux" splitting the
file to "nilfs2_api.h" and "nilfs2_ondisk.h". The following minor
changes are accompanied by this migration:

- nilfs_direct_node struct in nilfs2/direct.h is converged to
nilfs2_ondisk.h because it's an on-disk structure.
- inline functions nilfs_rec_len_from_disk() and
nilfs_rec_len_to_disk() are moved to nilfs2/dir.c.

Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Ryusuke Konishi <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

Documentation/filesystems/nilfs2.txt

···
                                   `-- file (ino=yy)
                                     ( regular file, directory, or symlink )
 
-For detail on the format of each file, please see include/linux/nilfs2_fs.h.
+For detail on the format of each file, please see nilfs2_ondisk.h
+located at include/uapi/linux directory.
 
 There are no patents or other intellectual property that we protect
 with regard to the design of NILFS2.  It is allowed to replicate the

Documentation/ioctl/ioctl-number.txt

···
 'm'	00	drivers/scsi/megaraid/megaraid_ioctl.h	conflict!
 'm'	00-1F	net/irda/irmod.h	conflict!
 'n'	00-7F	linux/ncp_fs.h and fs/ncpfs/ioctl.c
-'n'	80-8F	linux/nilfs2_fs.h	NILFS2
+'n'	80-8F	uapi/linux/nilfs2_api.h	NILFS2
 'n'	E0-FF	linux/matroxfb.h	matroxfb
 'o'	00-1F	fs/ocfs2/ocfs2_fs.h	OCFS2
 'o'     00-03   mtd/ubi-user.h		conflict! (OCFS2 and UBI overlaps)

MAINTAINERS

···
 S:	Supported
 F:	Documentation/filesystems/nilfs2.txt
 F:	fs/nilfs2/
-F:	include/linux/nilfs2_fs.h
 F:	include/trace/events/nilfs2.h
+F:	include/uapi/linux/nilfs2_api.h
+F:	include/uapi/linux/nilfs2_ondisk.h
 
 NINJA SCSI-3 / NINJA SCSI-32Bi (16bit/CardBus) PCMCIA SCSI HOST ADAPTER DRIVER
 M:	YOKOTA Hiroshi <[e-mail]>

fs/nilfs2/bmap.h

···
 #include <linux/types.h>
 #include <linux/fs.h>
 #include <linux/buffer_head.h>
-#include <linux/nilfs2_fs.h>
+#include <linux/nilfs2_ondisk.h>	/* nilfs_binfo, nilfs_inode, etc */
 #include "alloc.h"
 #include "dat.h"
 

fs/nilfs2/btree.h

···
 #include <linux/types.h>
 #include <linux/buffer_head.h>
 #include <linux/list.h>
-#include <linux/nilfs2_fs.h>
+#include <linux/nilfs2_ondisk.h>	/* nilfs_btree_node */
 #include "btnode.h"
 #include "bmap.h"
 

fs/nilfs2/cpfile.c

···
 #include <linux/string.h>
 #include <linux/buffer_head.h>
 #include <linux/errno.h>
-#include <linux/nilfs2_fs.h>
 #include "mdt.h"
 #include "cpfile.h"
 

fs/nilfs2/cpfile.h

···
 
 #include <linux/fs.h>
 #include <linux/buffer_head.h>
-#include <linux/nilfs2_fs.h>
+#include <linux/nilfs2_api.h>		/* nilfs_cpstat */
+#include <linux/nilfs2_ondisk.h>	/* nilfs_inode, nilfs_checkpoint */
 
 
 int nilfs_cpfile_get_checkpoint(struct inode *, __u64, int,

fs/nilfs2/dat.h

···
 #include <linux/types.h>
 #include <linux/buffer_head.h>
 #include <linux/fs.h>
+#include <linux/nilfs2_ondisk.h>	/* nilfs_inode, nilfs_checkpoint */
 
 
 struct nilfs_palloc_req;

fs/nilfs2/dir.c

···
 #include "nilfs.h"
 #include "page.h"
 
+static inline unsigned int nilfs_rec_len_from_disk(__le16 dlen)
+{
+	unsigned int len = le16_to_cpu(dlen);
+
+#if (PAGE_SIZE >= 65536)
+	if (len == NILFS_MAX_REC_LEN)
+		return 1 << 16;
+#endif
+	return len;
+}
+
+static inline __le16 nilfs_rec_len_to_disk(unsigned int len)
+{
+#if (PAGE_SIZE >= 65536)
+	if (len == (1 << 16))
+		return cpu_to_le16(NILFS_MAX_REC_LEN);
+
+	BUG_ON(len > (1 << 16));
+#endif
+	return cpu_to_le16(len);
+}
+
 /*
  * nilfs uses block-sized chunks. Arguably, sector-sized ones would be
  * more robust, but we have what we have

fs/nilfs2/direct.h

···
 #include "bmap.h"
 
 
-/**
- * struct nilfs_direct_node - direct node
- * @dn_flags: flags
- * @dn_pad: padding
- */
-struct nilfs_direct_node {
-	__u8 dn_flags;
-	__u8 pad[7];
-};
-
 #define NILFS_DIRECT_NBLOCKS	(NILFS_BMAP_SIZE / sizeof(__le64) - 1)
 #define NILFS_DIRECT_KEY_MIN	0
 #define NILFS_DIRECT_KEY_MAX	(NILFS_DIRECT_NBLOCKS - 1)

fs/nilfs2/ifile.h

···
 
 #include <linux/fs.h>
 #include <linux/buffer_head.h>
-#include <linux/nilfs2_fs.h>
 #include "mdt.h"
 #include "alloc.h"
 

fs/nilfs2/ioctl.c

···
 #include <linux/compat.h>	/* compat_ptr() */
 #include <linux/mount.h>	/* mnt_want_write_file(), mnt_drop_write_file() */
 #include <linux/buffer_head.h>
-#include <linux/nilfs2_fs.h>
 #include "nilfs.h"
 #include "segment.h"
 #include "bmap.h"

fs/nilfs2/nilfs.h

···
 #include <linux/buffer_head.h>
 #include <linux/spinlock.h>
 #include <linux/blkdev.h>
-#include <linux/nilfs2_fs.h>
+#include <linux/nilfs2_api.h>
+#include <linux/nilfs2_ondisk.h>
 #include "the_nilfs.h"
 #include "bmap.h"
 

fs/nilfs2/segment.h

···
 #include <linux/fs.h>
 #include <linux/buffer_head.h>
 #include <linux/workqueue.h>
-#include <linux/nilfs2_fs.h>
 #include "nilfs.h"
 
 struct nilfs_root;

fs/nilfs2/sufile.c

···
 #include <linux/string.h>
 #include <linux/buffer_head.h>
 #include <linux/errno.h>
-#include <linux/nilfs2_fs.h>
 #include "mdt.h"
 #include "sufile.h"
 

fs/nilfs2/sufile.h

···
 
 #include <linux/fs.h>
 #include <linux/buffer_head.h>
-#include <linux/nilfs2_fs.h>
 #include "mdt.h"
 
 

include/linux/nilfs2_fs.h include/uapi/linux/nilfs2_ondisk.h

···
 /*
- * nilfs2_fs.h - NILFS2 on-disk structures and common declarations.
+ * nilfs2_ondisk.h - NILFS2 on-disk structures
  *
  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
  *
···
  * it under the terms of the GNU Lesser General Public License as published
  * by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
- *
- * Written by Koji Sato and Ryusuke Konishi.
  */
 /*
  *  linux/include/linux/ext2_fs.h
···
  *  Copyright (C) 1991, 1992  Linus Torvalds
  */
 
-#ifndef _LINUX_NILFS_FS_H
-#define _LINUX_NILFS_FS_H
+#ifndef _LINUX_NILFS2_ONDISK_H
+#define _LINUX_NILFS2_ONDISK_H
 
 #include <linux/types.h>
-#include <linux/ioctl.h>
 #include <linux/magic.h>
-#include <linux/bug.h>
 
 
 #define NILFS_INODE_BMAP_SIZE	7
+
 /**
  * struct nilfs_inode - structure of an inode on disk
  * @i_blocks: blocks count
···
  * @i_bmap: block mapping
  * @i_xattr: extended attributes
  * @i_generation: file generation (for NFS)
- * @i_pad:	padding
+ * @i_pad: padding
  */
 struct nilfs_inode {
 	__le64	i_blocks;
···
 #define NILFS_DIR_ROUND			(NILFS_DIR_PAD - 1)
 #define NILFS_DIR_REC_LEN(name_len)	(((name_len) + 12 + NILFS_DIR_ROUND) & \
 					~NILFS_DIR_ROUND)
-#define NILFS_MAX_REC_LEN		((1<<16)-1)
-
-static inline unsigned int nilfs_rec_len_from_disk(__le16 dlen)
-{
-	unsigned int len = le16_to_cpu(dlen);
-
-#if !defined(__KERNEL__) || (PAGE_SIZE >= 65536)
-	if (len == NILFS_MAX_REC_LEN)
-		return 1 << 16;
-#endif
-	return len;
-}
-
-static inline __le16 nilfs_rec_len_to_disk(unsigned int len)
-{
-#if !defined(__KERNEL__) || (PAGE_SIZE >= 65536)
-	if (len == (1 << 16))
-		return cpu_to_le16(NILFS_MAX_REC_LEN);
-	else if (len > (1 << 16))
-		BUG();
-#endif
-	return cpu_to_le16(len);
-}
+#define NILFS_MAX_REC_LEN		((1 << 16) - 1)
 
 /**
  * struct nilfs_finfo - file information
···
 	__le64 fi_cno;
 	__le32 fi_nblocks;
 	__le32 fi_ndatablk;
-	/* array of virtual block numbers */
 };
 
 /**
- * struct nilfs_binfo_v - information for the block to which a virtual block number is assigned
+ * struct nilfs_binfo_v - information on a data block (except DAT)
  * @bi_vblocknr: virtual block number
  * @bi_blkoff: block offset
  */
···
 };
 
 /**
- * struct nilfs_binfo_dat - information for the block which belongs to the DAT file
+ * struct nilfs_binfo_dat - information on a DAT node block
  * @bi_blkoff: block offset
  * @bi_level: level
  * @bi_pad: padding
···
 #define NILFS_SS_GC     0x0010  /* segment written for cleaner operation */
 
 /**
- * struct nilfs_btree_node - B-tree node
+ * struct nilfs_btree_node - header of B-tree node block
  * @bn_flags: flags
  * @bn_level: level
  * @bn_nchildren: number of children
···
 #define NILFS_BTREE_LEVEL_DATA          0
 #define NILFS_BTREE_LEVEL_NODE_MIN      (NILFS_BTREE_LEVEL_DATA + 1)
 #define NILFS_BTREE_LEVEL_MAX           14	/* Max level (exclusive) */
+
+/**
+ * struct nilfs_direct_node - header of built-in bmap array
+ * @dn_flags: flags
+ * @dn_pad: padding
+ */
+struct nilfs_direct_node {
+	__u8 dn_flags;
+	__u8 pad[7];
+};
 
 /**
  * struct nilfs_palloc_group_desc - block group descriptor
···
 NILFS_CHECKPOINT_FNS(MINOR, minor)
 
 /**
- * struct nilfs_cpinfo - checkpoint information
- * @ci_flags: flags
- * @ci_pad: padding
- * @ci_cno: checkpoint number
- * @ci_create: creation timestamp
- * @ci_nblk_inc: number of blocks incremented by this checkpoint
- * @ci_inodes_count: inodes count
- * @ci_blocks_count: blocks count
- * @ci_next: next checkpoint number in snapshot list
- */
-struct nilfs_cpinfo {
-	__u32 ci_flags;
-	__u32 ci_pad;
-	__u64 ci_cno;
-	__u64 ci_create;
-	__u64 ci_nblk_inc;
-	__u64 ci_inodes_count;
-	__u64 ci_blocks_count;
-	__u64 ci_next;
-};
-
-#define NILFS_CPINFO_FNS(flag, name)					\
-static inline int							\
-nilfs_cpinfo_##name(const struct nilfs_cpinfo *cpinfo)			\
-{									\
-	return !!(cpinfo->ci_flags & (1UL << NILFS_CHECKPOINT_##flag));	\
-}
-
-NILFS_CPINFO_FNS(SNAPSHOT, snapshot)
-NILFS_CPINFO_FNS(INVALID, invalid)
-NILFS_CPINFO_FNS(MINOR, minor)
-
-
-/**
  * struct nilfs_cpfile_header - checkpoint file header
  * @ch_ncheckpoints: number of checkpoints
  * @ch_nsnapshots: number of snapshots
···
 	struct nilfs_snapshot_list ch_snapshot_list;
 };
 
-#define NILFS_CPFILE_FIRST_CHECKPOINT_OFFSET	\
+#define NILFS_CPFILE_FIRST_CHECKPOINT_OFFSET				\
 	((sizeof(struct nilfs_cpfile_header) +				\
 	  sizeof(struct nilfs_checkpoint) - 1) /			\
 			sizeof(struct nilfs_checkpoint))
···
 	NILFS_SEGMENT_USAGE_ACTIVE,
 	NILFS_SEGMENT_USAGE_DIRTY,
 	NILFS_SEGMENT_USAGE_ERROR,
-
-	/* ... */
 };
 
 #define NILFS_SEGMENT_USAGE_FNS(flag, name)				\
···
 	/* ... */
 };
 
-#define NILFS_SUFILE_FIRST_SEGMENT_USAGE_OFFSET	\
+#define NILFS_SUFILE_FIRST_SEGMENT_USAGE_OFFSET				\
 	((sizeof(struct nilfs_sufile_header) +				\
 	  sizeof(struct nilfs_segment_usage) - 1) /			\
 			 sizeof(struct nilfs_segment_usage))
 
-/**
- * nilfs_suinfo - segment usage information
- * @sui_lastmod: timestamp of last modification
- * @sui_nblocks: number of written blocks in segment
- * @sui_flags: segment usage flags
- */
-struct nilfs_suinfo {
-	__u64 sui_lastmod;
-	__u32 sui_nblocks;
-	__u32 sui_flags;
-};
-
-#define NILFS_SUINFO_FNS(flag, name)					\
-static inline int							\
-nilfs_suinfo_##name(const struct nilfs_suinfo *si)			\
-{									\
-	return si->sui_flags & (1UL << NILFS_SEGMENT_USAGE_##flag);	\
-}
-
-NILFS_SUINFO_FNS(ACTIVE, active)
-NILFS_SUINFO_FNS(DIRTY, dirty)
-NILFS_SUINFO_FNS(ERROR, error)
-
-static inline int nilfs_suinfo_clean(const struct nilfs_suinfo *si)
-{
-	return !si->sui_flags;
-}
-
-/* ioctl */
-/**
- * nilfs_suinfo_update - segment usage information update
- * @sup_segnum: segment number
- * @sup_flags: flags for which fields are active in sup_sui
- * @sup_reserved: reserved necessary for alignment
- * @sup_sui: segment usage information
- */
-struct nilfs_suinfo_update {
-	__u64 sup_segnum;
-	__u32 sup_flags;
-	__u32 sup_reserved;
-	struct nilfs_suinfo sup_sui;
-};
-
-enum {
-	NILFS_SUINFO_UPDATE_LASTMOD,
-	NILFS_SUINFO_UPDATE_NBLOCKS,
-	NILFS_SUINFO_UPDATE_FLAGS,
-	__NR_NILFS_SUINFO_UPDATE_FIELDS,
-};
-
-#define NILFS_SUINFO_UPDATE_FNS(flag, name)				\
-static inline void							\
-nilfs_suinfo_update_set_##name(struct nilfs_suinfo_update *sup)		\
-{									\
-	sup->sup_flags |= 1UL << NILFS_SUINFO_UPDATE_##flag;		\
-}									\
-static inline void							\
-nilfs_suinfo_update_clear_##name(struct nilfs_suinfo_update *sup)	\
-{									\
-	sup->sup_flags &= ~(1UL << NILFS_SUINFO_UPDATE_##flag);		\
-}									\
-static inline int							\
-nilfs_suinfo_update_##name(const struct nilfs_suinfo_update *sup)	\
-{									\
-	return !!(sup->sup_flags & (1UL << NILFS_SUINFO_UPDATE_##flag));\
-}
-
-NILFS_SUINFO_UPDATE_FNS(LASTMOD, lastmod)
-NILFS_SUINFO_UPDATE_FNS(NBLOCKS, nblocks)
-NILFS_SUINFO_UPDATE_FNS(FLAGS, flags)
-
-enum {
-	NILFS_CHECKPOINT,
-	NILFS_SNAPSHOT,
-};
-
-/**
- * struct nilfs_cpmode - change checkpoint mode structure
- * @cm_cno: checkpoint number
- * @cm_mode: mode of checkpoint
- * @cm_pad: padding
- */
-struct nilfs_cpmode {
-	__u64 cm_cno;
-	__u32 cm_mode;
-	__u32 cm_pad;
-};
-
-/**
- * struct nilfs_argv - argument vector
- * @v_base: pointer on data array from userspace
- * @v_nmembs: number of members in data array
- * @v_size: size of data array in bytes
- * @v_flags: flags
- * @v_index: start number of target data items
- */
-struct nilfs_argv {
-	__u64 v_base;
-	__u32 v_nmembs;	/* number of members */
-	__u16 v_size;	/* size of members */
-	__u16 v_flags;
-	__u64 v_index;
-};
-
-/**
- * struct nilfs_period - period of checkpoint numbers
- * @p_start: start checkpoint number (inclusive)
- * @p_end: end checkpoint number (exclusive)
- */
-struct nilfs_period {
-	__u64 p_start;
-	__u64 p_end;
-};
-
-/**
- * struct nilfs_cpstat - checkpoint statistics
- * @cs_cno: checkpoint number
- * @cs_ncps: number of checkpoints
- * @cs_nsss: number of snapshots
- */
-struct nilfs_cpstat {
-	__u64 cs_cno;
-	__u64 cs_ncps;
-	__u64 cs_nsss;
-};
-
-/**
- * struct nilfs_sustat - segment usage statistics
- * @ss_nsegs: number of segments
- * @ss_ncleansegs: number of clean segments
- * @ss_ndirtysegs: number of dirty segments
- * @ss_ctime: creation time of the last segment
- * @ss_nongc_ctime: creation time of the last segment not for GC
- * @ss_prot_seq: least sequence number of segments which must not be reclaimed
- */
-struct nilfs_sustat {
-	__u64 ss_nsegs;
-	__u64 ss_ncleansegs;
-	__u64 ss_ndirtysegs;
-	__u64 ss_ctime;
-	__u64 ss_nongc_ctime;
-	__u64 ss_prot_seq;
-};
-
-/**
- * struct nilfs_vinfo - virtual block number information
- * @vi_vblocknr: virtual block number
- * @vi_start: start checkpoint number (inclusive)
- * @vi_end: end checkpoint number (exclusive)
- * @vi_blocknr: disk block number
- */
-struct nilfs_vinfo {
-	__u64 vi_vblocknr;
-	__u64 vi_start;
-	__u64 vi_end;
-	__u64 vi_blocknr;
-};
-
-/**
- * struct nilfs_vdesc - descriptor of virtual block number
- * @vd_ino: inode number
- * @vd_cno: checkpoint number
- * @vd_vblocknr: virtual block number
- * @vd_period: period of checkpoint numbers
- * @vd_blocknr: disk block number
- * @vd_offset: logical block offset inside a file
- * @vd_flags: flags (data or node block)
- * @vd_pad: padding
- */
-struct nilfs_vdesc {
-	__u64 vd_ino;
-	__u64 vd_cno;
-	__u64 vd_vblocknr;
-	struct nilfs_period vd_period;
-	__u64 vd_blocknr;
-	__u64 vd_offset;
-	__u32 vd_flags;
-	__u32 vd_pad;
-};
-
-/**
- * struct nilfs_bdesc - descriptor of disk block number
- * @bd_ino: inode number
- * @bd_oblocknr: disk block address (for skipping dead blocks)
- * @bd_blocknr: disk block address
- * @bd_offset: logical block offset inside a file
- * @bd_level: level in the b-tree organization
- * @bd_pad: padding
- */
-struct nilfs_bdesc {
-	__u64 bd_ino;
-	__u64 bd_oblocknr;
-	__u64 bd_blocknr;
-	__u64 bd_offset;
-	__u32 bd_level;
-	__u32 bd_pad;
-};
-
-#define NILFS_IOCTL_IDENT		'n'
-
-#define NILFS_IOCTL_CHANGE_CPMODE  \
-	_IOW(NILFS_IOCTL_IDENT, 0x80, struct nilfs_cpmode)
-#define NILFS_IOCTL_DELETE_CHECKPOINT  \
-	_IOW(NILFS_IOCTL_IDENT, 0x81, __u64)
-#define NILFS_IOCTL_GET_CPINFO  \
-	_IOR(NILFS_IOCTL_IDENT, 0x82, struct nilfs_argv)
-#define NILFS_IOCTL_GET_CPSTAT  \
-	_IOR(NILFS_IOCTL_IDENT, 0x83, struct nilfs_cpstat)
-#define NILFS_IOCTL_GET_SUINFO  \
-	_IOR(NILFS_IOCTL_IDENT, 0x84, struct nilfs_argv)
-#define NILFS_IOCTL_GET_SUSTAT  \
-	_IOR(NILFS_IOCTL_IDENT, 0x85, struct nilfs_sustat)
-#define NILFS_IOCTL_GET_VINFO  \
-	_IOWR(NILFS_IOCTL_IDENT, 0x86, struct nilfs_argv)
-#define NILFS_IOCTL_GET_BDESCS  \
-	_IOWR(NILFS_IOCTL_IDENT, 0x87, struct nilfs_argv)
-#define NILFS_IOCTL_CLEAN_SEGMENTS  \
-	_IOW(NILFS_IOCTL_IDENT, 0x88, struct nilfs_argv[5])
-#define NILFS_IOCTL_SYNC  \
-	_IOR(NILFS_IOCTL_IDENT, 0x8A, __u64)
-#define NILFS_IOCTL_RESIZE  \
-	_IOW(NILFS_IOCTL_IDENT, 0x8B, __u64)
-#define NILFS_IOCTL_SET_ALLOC_RANGE  \
-	_IOW(NILFS_IOCTL_IDENT, 0x8C, __u64[2])
-#define NILFS_IOCTL_SET_SUINFO  \
-	_IOW(NILFS_IOCTL_IDENT, 0x8D, struct nilfs_argv)
-
-#endif	/* _LINUX_NILFS_FS_H */
+#endif	/* _LINUX_NILFS2_ONDISK_H */

include/uapi/linux/nilfs2_api.h

···
+/*
+ * nilfs2_api.h - NILFS2 user space API
+ *
+ * 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 Lesser General Public License as published
+ * by the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef _LINUX_NILFS2_API_H
+#define _LINUX_NILFS2_API_H
+
+#include <linux/types.h>
+#include <linux/ioctl.h>
+
+/**
+ * struct nilfs_cpinfo - checkpoint information
+ * @ci_flags: flags
+ * @ci_pad: padding
+ * @ci_cno: checkpoint number
+ * @ci_create: creation timestamp
+ * @ci_nblk_inc: number of blocks incremented by this checkpoint
+ * @ci_inodes_count: inodes count
+ * @ci_blocks_count: blocks count
+ * @ci_next: next checkpoint number in snapshot list
+ */
+struct nilfs_cpinfo {
+	__u32 ci_flags;
+	__u32 ci_pad;
+	__u64 ci_cno;
+	__u64 ci_create;
+	__u64 ci_nblk_inc;
+	__u64 ci_inodes_count;
+	__u64 ci_blocks_count;
+	__u64 ci_next;
+};
+
+/* checkpoint flags */
+enum {
+	NILFS_CPINFO_SNAPSHOT,
+	NILFS_CPINFO_INVALID,
+	NILFS_CPINFO_SKETCH,
+	NILFS_CPINFO_MINOR,
+};
+
+#define NILFS_CPINFO_FNS(flag, name)					\
+static inline int							\
+nilfs_cpinfo_##name(const struct nilfs_cpinfo *cpinfo)			\
+{									\
+	return !!(cpinfo->ci_flags & (1UL << NILFS_CPINFO_##flag));	\
+}
+
+NILFS_CPINFO_FNS(SNAPSHOT, snapshot)
+NILFS_CPINFO_FNS(INVALID, invalid)
+NILFS_CPINFO_FNS(MINOR, minor)
+
+/**
+ * nilfs_suinfo - segment usage information
+ * @sui_lastmod: timestamp of last modification
+ * @sui_nblocks: number of written blocks in segment
+ * @sui_flags: segment usage flags
+ */
+struct nilfs_suinfo {
+	__u64 sui_lastmod;
+	__u32 sui_nblocks;
+	__u32 sui_flags;
+};
+
+/* segment usage flags */
+enum {
+	NILFS_SUINFO_ACTIVE,
+	NILFS_SUINFO_DIRTY,
+	NILFS_SUINFO_ERROR,
+};
+
+#define NILFS_SUINFO_FNS(flag, name)					\
+static inline int							\
+nilfs_suinfo_##name(const struct nilfs_suinfo *si)			\
+{									\
+	return si->sui_flags & (1UL << NILFS_SUINFO_##flag);		\
+}
+
+NILFS_SUINFO_FNS(ACTIVE, active)
+NILFS_SUINFO_FNS(DIRTY, dirty)
+NILFS_SUINFO_FNS(ERROR, error)
+
+static inline int nilfs_suinfo_clean(const struct nilfs_suinfo *si)
+{
+	return !si->sui_flags;
+}
+
+/**
+ * nilfs_suinfo_update - segment usage information update
+ * @sup_segnum: segment number
+ * @sup_flags: flags for which fields are active in sup_sui
+ * @sup_reserved: reserved necessary for alignment
+ * @sup_sui: segment usage information
+ */
+struct nilfs_suinfo_update {
+	__u64 sup_segnum;
+	__u32 sup_flags;
+	__u32 sup_reserved;
+	struct nilfs_suinfo sup_sui;
+};
+
+enum {
+	NILFS_SUINFO_UPDATE_LASTMOD,
+	NILFS_SUINFO_UPDATE_NBLOCKS,
+	NILFS_SUINFO_UPDATE_FLAGS,
+	__NR_NILFS_SUINFO_UPDATE_FIELDS,
+};
+
+#define NILFS_SUINFO_UPDATE_FNS(flag, name)				\
+static inline void							\
+nilfs_suinfo_update_set_##name(struct nilfs_suinfo_update *sup)		\
+{									\
+	sup->sup_flags |= 1UL << NILFS_SUINFO_UPDATE_##flag;		\
+}									\
+static inline void							\
+nilfs_suinfo_update_clear_##name(struct nilfs_suinfo_update *sup)	\
+{									\
+	sup->sup_flags &= ~(1UL << NILFS_SUINFO_UPDATE_##flag);		\
+}									\
+static inline int							\
+nilfs_suinfo_update_##name(const struct nilfs_suinfo_update *sup)	\
+{									\
+	return !!(sup->sup_flags & (1UL << NILFS_SUINFO_UPDATE_##flag));\
+}
+
+NILFS_SUINFO_UPDATE_FNS(LASTMOD, lastmod)
+NILFS_SUINFO_UPDATE_FNS(NBLOCKS, nblocks)
+NILFS_SUINFO_UPDATE_FNS(FLAGS, flags)
+
+enum {
+	NILFS_CHECKPOINT,
+	NILFS_SNAPSHOT,
+};
+
+/**
+ * struct nilfs_cpmode - change checkpoint mode structure
+ * @cm_cno: checkpoint number
+ * @cm_mode: mode of checkpoint
+ * @cm_pad: padding
+ */
+struct nilfs_cpmode {
+	__u64 cm_cno;
+	__u32 cm_mode;
+	__u32 cm_pad;
+};
+
+/**
+ * struct nilfs_argv - argument vector
+ * @v_base: pointer on data array from userspace
+ * @v_nmembs: number of members in data array
+ * @v_size: size of data array in bytes
+ * @v_flags: flags
+ * @v_index: start number of target data items
+ */
+struct nilfs_argv {
+	__u64 v_base;
+	__u32 v_nmembs;	/* number of members */
+	__u16 v_size;	/* size of members */
+	__u16 v_flags;
+	__u64 v_index;
+};
+
+/**
+ * struct nilfs_period - period of checkpoint numbers
+ * @p_start: start checkpoint number (inclusive)
+ * @p_end: end checkpoint number (exclusive)
+ */
+struct nilfs_period {
+	__u64 p_start;
+	__u64 p_end;
+};
+
+/**
+ * struct nilfs_cpstat - checkpoint statistics
+ * @cs_cno: checkpoint number
+ * @cs_ncps: number of checkpoints
+ * @cs_nsss: number of snapshots
+ */
+struct nilfs_cpstat {
+	__u64 cs_cno;
+	__u64 cs_ncps;
+	__u64 cs_nsss;
+};
+
+/**
+ * struct nilfs_sustat - segment usage statistics
+ * @ss_nsegs: number of segments
+ * @ss_ncleansegs: number of clean segments
+ * @ss_ndirtysegs: number of dirty segments
+ * @ss_ctime: creation time of the last segment
+ * @ss_nongc_ctime: creation time of the last segment not for GC
+ * @ss_prot_seq: least sequence number of segments which must not be reclaimed
+ */
+struct nilfs_sustat {
+	__u64 ss_nsegs;
+	__u64 ss_ncleansegs;
+	__u64 ss_ndirtysegs;
+	__u64 ss_ctime;
+	__u64 ss_nongc_ctime;
+	__u64 ss_prot_seq;
+};
+
+/**
+ * struct nilfs_vinfo - virtual block number information
+ * @vi_vblocknr: virtual block number
+ * @vi_start: start checkpoint number (inclusive)
+ * @vi_end: end checkpoint number (exclusive)
+ * @vi_blocknr: disk block number
+ */
+struct nilfs_vinfo {
+	__u64 vi_vblocknr;
+	__u64 vi_start;
+	__u64 vi_end;
+	__u64 vi_blocknr;
+};
+
+/**
+ * struct nilfs_vdesc - descriptor of virtual block number
+ * @vd_ino: inode number
+ * @vd_cno: checkpoint number
+ * @vd_vblocknr: virtual block number
+ * @vd_period: period of checkpoint numbers
+ * @vd_blocknr: disk block number
+ * @vd_offset: logical block offset inside a file
+ * @vd_flags: flags (data or node block)
+ * @vd_pad: padding
+ */
+struct nilfs_vdesc {
+	__u64 vd_ino;
+	__u64 vd_cno;
+	__u64 vd_vblocknr;
+	struct nilfs_period vd_period;
+	__u64 vd_blocknr;
+	__u64 vd_offset;
+	__u32 vd_flags;
+	__u32 vd_pad;
+};
+
+/**
+ * struct nilfs_bdesc - descriptor of disk block number
+ * @bd_ino: inode number
+ * @bd_oblocknr: disk block address (for skipping dead blocks)
+ * @bd_blocknr: disk block address
+ * @bd_offset: logical block offset inside a file
+ * @bd_level: level in the b-tree organization
+ * @bd_pad: padding
+ */
+struct nilfs_bdesc {
+	__u64 bd_ino;
+	__u64 bd_oblocknr;
+	__u64 bd_blocknr;
+	__u64 bd_offset;
+	__u32 bd_level;
+	__u32 bd_pad;
+};
+
+#define NILFS_IOCTL_IDENT	'n'
+
+#define NILFS_IOCTL_CHANGE_CPMODE					\
+	_IOW(NILFS_IOCTL_IDENT, 0x80, struct nilfs_cpmode)
+#define NILFS_IOCTL_DELETE_CHECKPOINT					\
+	_IOW(NILFS_IOCTL_IDENT, 0x81, __u64)
+#define NILFS_IOCTL_GET_CPINFO						\
+	_IOR(NILFS_IOCTL_IDENT, 0x82, struct nilfs_argv)
+#define NILFS_IOCTL_GET_CPSTAT						\
+	_IOR(NILFS_IOCTL_IDENT, 0x83, struct nilfs_cpstat)
+#define NILFS_IOCTL_GET_SUINFO						\
+	_IOR(NILFS_IOCTL_IDENT, 0x84, struct nilfs_argv)
+#define NILFS_IOCTL_GET_SUSTAT						\
+	_IOR(NILFS_IOCTL_IDENT, 0x85, struct nilfs_sustat)
+#define NILFS_IOCTL_GET_VINFO						\
+	_IOWR(NILFS_IOCTL_IDENT, 0x86, struct nilfs_argv)
+#define NILFS_IOCTL_GET_BDESCS						\
+	_IOWR(NILFS_IOCTL_IDENT, 0x87, struct nilfs_argv)
+#define NILFS_IOCTL_CLEAN_SEGMENTS					\
+	_IOW(NILFS_IOCTL_IDENT, 0x88, struct nilfs_argv[5])
+#define NILFS_IOCTL_SYNC						\
+	_IOR(NILFS_IOCTL_IDENT, 0x8A, __u64)
+#define NILFS_IOCTL_RESIZE						\
+	_IOW(NILFS_IOCTL_IDENT, 0x8B, __u64)
+#define NILFS_IOCTL_SET_ALLOC_RANGE					\
+	_IOW(NILFS_IOCTL_IDENT, 0x8C, __u64[2])
+#define NILFS_IOCTL_SET_SUINFO						\
+	_IOW(NILFS_IOCTL_IDENT, 0x8D, struct nilfs_argv)
+
+#endif /* _LINUX_NILFS2_API_H */