1/*
2 * nilfs2_ondisk.h - NILFS2 on-disk structures
3 *
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU Lesser General Public License as published
8 * by the Free Software Foundation; either version 2.1 of the License, or
9 * (at your option) any later version.
10 */
11/*
12 *  linux/include/linux/ext2_fs.h
13 *
14 * Copyright (C) 1992, 1993, 1994, 1995
15 * Remy Card (card@masi.ibp.fr)
16 * Laboratoire MASI - Institut Blaise Pascal
17 * Universite Pierre et Marie Curie (Paris VI)
18 *
19 *  from
20 *
21 *  linux/include/linux/minix_fs.h
22 *
23 *  Copyright (C) 1991, 1992  Linus Torvalds
24 */
25
26#ifndef _LINUX_NILFS2_ONDISK_H
27#define _LINUX_NILFS2_ONDISK_H
28
29#include <linux/types.h>
30#include <linux/magic.h>
31
32
33#define NILFS_INODE_BMAP_SIZE	7
34
35/**
36 * struct nilfs_inode - structure of an inode on disk
37 * @i_blocks: blocks count
38 * @i_size: size in bytes
39 * @i_ctime: creation time (seconds)
40 * @i_mtime: modification time (seconds)
41 * @i_ctime_nsec: creation time (nano seconds)
42 * @i_mtime_nsec: modification time (nano seconds)
43 * @i_uid: user id
44 * @i_gid: group id
45 * @i_mode: file mode
46 * @i_links_count: links count
47 * @i_flags: file flags
48 * @i_bmap: block mapping
49 * @i_xattr: extended attributes
50 * @i_generation: file generation (for NFS)
51 * @i_pad: padding
52 */
53struct nilfs_inode {
54	__le64	i_blocks;
55	__le64	i_size;
56	__le64	i_ctime;
57	__le64	i_mtime;
58	__le32	i_ctime_nsec;
59	__le32	i_mtime_nsec;
60	__le32	i_uid;
61	__le32	i_gid;
62	__le16	i_mode;
63	__le16	i_links_count;
64	__le32	i_flags;
65	__le64	i_bmap[NILFS_INODE_BMAP_SIZE];
66#define i_device_code	i_bmap[0]
67	__le64	i_xattr;
68	__le32	i_generation;
69	__le32	i_pad;
70};
71
72#define NILFS_MIN_INODE_SIZE		128
73
74/**
75 * struct nilfs_super_root - structure of super root
76 * @sr_sum: check sum
77 * @sr_bytes: byte count of the structure
78 * @sr_flags: flags (reserved)
79 * @sr_nongc_ctime: write time of the last segment not for cleaner operation
80 * @sr_dat: DAT file inode
81 * @sr_cpfile: checkpoint file inode
82 * @sr_sufile: segment usage file inode
83 */
84struct nilfs_super_root {
85	__le32 sr_sum;
86	__le16 sr_bytes;
87	__le16 sr_flags;
88	__le64 sr_nongc_ctime;
89	struct nilfs_inode sr_dat;
90	struct nilfs_inode sr_cpfile;
91	struct nilfs_inode sr_sufile;
92};
93
94#define NILFS_SR_MDT_OFFSET(inode_size, i)  \
95	((unsigned long)&((struct nilfs_super_root *)0)->sr_dat + \
96			(inode_size) * (i))
97#define NILFS_SR_DAT_OFFSET(inode_size)     NILFS_SR_MDT_OFFSET(inode_size, 0)
98#define NILFS_SR_CPFILE_OFFSET(inode_size)  NILFS_SR_MDT_OFFSET(inode_size, 1)
99#define NILFS_SR_SUFILE_OFFSET(inode_size)  NILFS_SR_MDT_OFFSET(inode_size, 2)
100#define NILFS_SR_BYTES(inode_size)	    NILFS_SR_MDT_OFFSET(inode_size, 3)
101
102/*
103 * Maximal mount counts
104 */
105#define NILFS_DFL_MAX_MNT_COUNT		50      /* 50 mounts */
106
107/*
108 * File system states (sbp->s_state, nilfs->ns_mount_state)
109 */
110#define NILFS_VALID_FS			0x0001  /* Unmounted cleanly */
111#define NILFS_ERROR_FS			0x0002  /* Errors detected */
112#define NILFS_RESIZE_FS			0x0004	/* Resize required */
113
114/*
115 * Mount flags (sbi->s_mount_opt)
116 */
117#define NILFS_MOUNT_ERROR_MODE		0x0070  /* Error mode mask */
118#define NILFS_MOUNT_ERRORS_CONT		0x0010  /* Continue on errors */
119#define NILFS_MOUNT_ERRORS_RO		0x0020  /* Remount fs ro on errors */
120#define NILFS_MOUNT_ERRORS_PANIC	0x0040  /* Panic on errors */
121#define NILFS_MOUNT_BARRIER		0x1000  /* Use block barriers */
122#define NILFS_MOUNT_STRICT_ORDER	0x2000  /*
123						 * Apply strict in-order
124						 * semantics also for data
125						 */
126#define NILFS_MOUNT_NORECOVERY		0x4000  /*
127						 * Disable write access during
128						 * mount-time recovery
129						 */
130#define NILFS_MOUNT_DISCARD		0x8000  /* Issue DISCARD requests */
131
132
133/**
134 * struct nilfs_super_block - structure of super block on disk
135 */
136struct nilfs_super_block {
137/*00*/	__le32	s_rev_level;		/* Revision level */
138	__le16	s_minor_rev_level;	/* minor revision level */
139	__le16	s_magic;		/* Magic signature */
140
141	__le16  s_bytes;		/*
142					 * Bytes count of CRC calculation
143					 * for this structure. s_reserved
144					 * is excluded.
145					 */
146	__le16  s_flags;		/* flags */
147	__le32  s_crc_seed;		/* Seed value of CRC calculation */
148/*10*/	__le32	s_sum;			/* Check sum of super block */
149
150	__le32	s_log_block_size;	/*
151					 * Block size represented as follows
152					 * blocksize =
153					 *     1 << (s_log_block_size + 10)
154					 */
155	__le64  s_nsegments;		/* Number of segments in filesystem */
156/*20*/	__le64  s_dev_size;		/* block device size in bytes */
157	__le64	s_first_data_block;	/* 1st seg disk block number */
158/*30*/	__le32  s_blocks_per_segment;   /* number of blocks per full segment */
159	__le32	s_r_segments_percentage; /* Reserved segments percentage */
160
161	__le64  s_last_cno;		/* Last checkpoint number */
162/*40*/	__le64  s_last_pseg;		/* disk block addr pseg written last */
163	__le64  s_last_seq;             /* seq. number of seg written last */
164/*50*/	__le64	s_free_blocks_count;	/* Free blocks count */
165
166	__le64	s_ctime;		/*
167					 * Creation time (execution time of
168					 * newfs)
169					 */
170/*60*/	__le64	s_mtime;		/* Mount time */
171	__le64	s_wtime;		/* Write time */
172/*70*/	__le16	s_mnt_count;		/* Mount count */
173	__le16	s_max_mnt_count;	/* Maximal mount count */
174	__le16	s_state;		/* File system state */
175	__le16	s_errors;		/* Behaviour when detecting errors */
176	__le64	s_lastcheck;		/* time of last check */
177
178/*80*/	__le32	s_checkinterval;	/* max. time between checks */
179	__le32	s_creator_os;		/* OS */
180	__le16	s_def_resuid;		/* Default uid for reserved blocks */
181	__le16	s_def_resgid;		/* Default gid for reserved blocks */
182	__le32	s_first_ino;		/* First non-reserved inode */
183
184/*90*/	__le16  s_inode_size;		/* Size of an inode */
185	__le16  s_dat_entry_size;       /* Size of a dat entry */
186	__le16  s_checkpoint_size;      /* Size of a checkpoint */
187	__le16	s_segment_usage_size;	/* Size of a segment usage */
188
189/*98*/	__u8	s_uuid[16];		/* 128-bit uuid for volume */
190/*A8*/	char	s_volume_name[80];	/* volume name */
191
192/*F8*/	__le32  s_c_interval;           /* Commit interval of segment */
193	__le32  s_c_block_max;          /*
194					 * Threshold of data amount for
195					 * the segment construction
196					 */
197/*100*/	__le64  s_feature_compat;	/* Compatible feature set */
198	__le64  s_feature_compat_ro;	/* Read-only compatible feature set */
199	__le64  s_feature_incompat;	/* Incompatible feature set */
200	__u32	s_reserved[186];	/* padding to the end of the block */
201};
202
203/*
204 * Codes for operating systems
205 */
206#define NILFS_OS_LINUX		0
207/* Codes from 1 to 4 are reserved to keep compatibility with ext2 creator-OS */
208
209/*
210 * Revision levels
211 */
212#define NILFS_CURRENT_REV	2	/* current major revision */
213#define NILFS_MINOR_REV		0	/* minor revision */
214#define NILFS_MIN_SUPP_REV	2	/* minimum supported revision */
215
216/*
217 * Feature set definitions
218 *
219 * If there is a bit set in the incompatible feature set that the kernel
220 * doesn't know about, it should refuse to mount the filesystem.
221 */
222#define NILFS_FEATURE_COMPAT_RO_BLOCK_COUNT	0x00000001ULL
223
224#define NILFS_FEATURE_COMPAT_SUPP	0ULL
225#define NILFS_FEATURE_COMPAT_RO_SUPP	NILFS_FEATURE_COMPAT_RO_BLOCK_COUNT
226#define NILFS_FEATURE_INCOMPAT_SUPP	0ULL
227
228/*
229 * Bytes count of super_block for CRC-calculation
230 */
231#define NILFS_SB_BYTES  \
232	((long)&((struct nilfs_super_block *)0)->s_reserved)
233
234/*
235 * Special inode number
236 */
237#define NILFS_ROOT_INO		2	/* Root file inode */
238#define NILFS_DAT_INO		3	/* DAT file */
239#define NILFS_CPFILE_INO	4	/* checkpoint file */
240#define NILFS_SUFILE_INO	5	/* segment usage file */
241#define NILFS_IFILE_INO		6	/* ifile */
242#define NILFS_ATIME_INO		7	/* Atime file (reserved) */
243#define NILFS_XATTR_INO		8	/* Xattribute file (reserved) */
244#define NILFS_SKETCH_INO	10	/* Sketch file */
245#define NILFS_USER_INO		11	/* Fisrt user's file inode number */
246
247#define NILFS_SB_OFFSET_BYTES	1024	/* byte offset of nilfs superblock */
248
249#define NILFS_SEG_MIN_BLOCKS	16	/*
250					 * Minimum number of blocks in
251					 * a full segment
252					 */
253#define NILFS_PSEG_MIN_BLOCKS	2	/*
254					 * Minimum number of blocks in
255					 * a partial segment
256					 */
257#define NILFS_MIN_NRSVSEGS	8	/*
258					 * Minimum number of reserved
259					 * segments
260					 */
261
262/*
263 * We call DAT, cpfile, and sufile root metadata files.  Inodes of
264 * these files are written in super root block instead of ifile, and
265 * garbage collector doesn't keep any past versions of these files.
266 */
267#define NILFS_ROOT_METADATA_FILE(ino) \
268	((ino) >= NILFS_DAT_INO && (ino) <= NILFS_SUFILE_INO)
269
270/*
271 * bytes offset of secondary super block
272 */
273#define NILFS_SB2_OFFSET_BYTES(devsize)	((((devsize) >> 12) - 1) << 12)
274
275/*
276 * Maximal count of links to a file
277 */
278#define NILFS_LINK_MAX		32000
279
280/*
281 * Structure of a directory entry
282 *  (Same as ext2)
283 */
284
285#define NILFS_NAME_LEN 255
286
287/*
288 * Block size limitations
289 */
290#define NILFS_MIN_BLOCK_SIZE		1024
291#define NILFS_MAX_BLOCK_SIZE		65536
292
293/*
294 * The new version of the directory entry.  Since V0 structures are
295 * stored in intel byte order, and the name_len field could never be
296 * bigger than 255 chars, it's safe to reclaim the extra byte for the
297 * file_type field.
298 */
299struct nilfs_dir_entry {
300	__le64	inode;			/* Inode number */
301	__le16	rec_len;		/* Directory entry length */
302	__u8	name_len;		/* Name length */
303	__u8	file_type;		/* Dir entry type (file, dir, etc) */
304	char	name[NILFS_NAME_LEN];	/* File name */
305	char    pad;
306};
307
308/*
309 * NILFS directory file types.  Only the low 3 bits are used.  The
310 * other bits are reserved for now.
311 */
312enum {
313	NILFS_FT_UNKNOWN,
314	NILFS_FT_REG_FILE,
315	NILFS_FT_DIR,
316	NILFS_FT_CHRDEV,
317	NILFS_FT_BLKDEV,
318	NILFS_FT_FIFO,
319	NILFS_FT_SOCK,
320	NILFS_FT_SYMLINK,
321	NILFS_FT_MAX
322};
323
324/*
325 * NILFS_DIR_PAD defines the directory entries boundaries
326 *
327 * NOTE: It must be a multiple of 8
328 */
329#define NILFS_DIR_PAD			8
330#define NILFS_DIR_ROUND			(NILFS_DIR_PAD - 1)
331#define NILFS_DIR_REC_LEN(name_len)	(((name_len) + 12 + NILFS_DIR_ROUND) & \
332					~NILFS_DIR_ROUND)
333#define NILFS_MAX_REC_LEN		((1 << 16) - 1)
334
335/**
336 * struct nilfs_finfo - file information
337 * @fi_ino: inode number
338 * @fi_cno: checkpoint number
339 * @fi_nblocks: number of blocks (including intermediate blocks)
340 * @fi_ndatablk: number of file data blocks
341 */
342struct nilfs_finfo {
343	__le64 fi_ino;
344	__le64 fi_cno;
345	__le32 fi_nblocks;
346	__le32 fi_ndatablk;
347};
348
349/**
350 * struct nilfs_binfo_v - information on a data block (except DAT)
351 * @bi_vblocknr: virtual block number
352 * @bi_blkoff: block offset
353 */
354struct nilfs_binfo_v {
355	__le64 bi_vblocknr;
356	__le64 bi_blkoff;
357};
358
359/**
360 * struct nilfs_binfo_dat - information on a DAT node block
361 * @bi_blkoff: block offset
362 * @bi_level: level
363 * @bi_pad: padding
364 */
365struct nilfs_binfo_dat {
366	__le64 bi_blkoff;
367	__u8 bi_level;
368	__u8 bi_pad[7];
369};
370
371/**
372 * union nilfs_binfo: block information
373 * @bi_v: nilfs_binfo_v structure
374 * @bi_dat: nilfs_binfo_dat structure
375 */
376union nilfs_binfo {
377	struct nilfs_binfo_v bi_v;
378	struct nilfs_binfo_dat bi_dat;
379};
380
381/**
382 * struct nilfs_segment_summary - segment summary header
383 * @ss_datasum: checksum of data
384 * @ss_sumsum: checksum of segment summary
385 * @ss_magic: magic number
386 * @ss_bytes: size of this structure in bytes
387 * @ss_flags: flags
388 * @ss_seq: sequence number
389 * @ss_create: creation timestamp
390 * @ss_next: next segment
391 * @ss_nblocks: number of blocks
392 * @ss_nfinfo: number of finfo structures
393 * @ss_sumbytes: total size of segment summary in bytes
394 * @ss_pad: padding
395 * @ss_cno: checkpoint number
396 */
397struct nilfs_segment_summary {
398	__le32 ss_datasum;
399	__le32 ss_sumsum;
400	__le32 ss_magic;
401	__le16 ss_bytes;
402	__le16 ss_flags;
403	__le64 ss_seq;
404	__le64 ss_create;
405	__le64 ss_next;
406	__le32 ss_nblocks;
407	__le32 ss_nfinfo;
408	__le32 ss_sumbytes;
409	__le32 ss_pad;
410	__le64 ss_cno;
411	/* array of finfo structures */
412};
413
414#define NILFS_SEGSUM_MAGIC	0x1eaffa11  /* segment summary magic number */
415
416/*
417 * Segment summary flags
418 */
419#define NILFS_SS_LOGBGN 0x0001  /* begins a logical segment */
420#define NILFS_SS_LOGEND 0x0002  /* ends a logical segment */
421#define NILFS_SS_SR     0x0004  /* has super root */
422#define NILFS_SS_SYNDT  0x0008  /* includes data only updates */
423#define NILFS_SS_GC     0x0010  /* segment written for cleaner operation */
424
425/**
426 * struct nilfs_btree_node - header of B-tree node block
427 * @bn_flags: flags
428 * @bn_level: level
429 * @bn_nchildren: number of children
430 * @bn_pad: padding
431 */
432struct nilfs_btree_node {
433	__u8 bn_flags;
434	__u8 bn_level;
435	__le16 bn_nchildren;
436	__le32 bn_pad;
437};
438
439/* flags */
440#define NILFS_BTREE_NODE_ROOT   0x01
441
442/* level */
443#define NILFS_BTREE_LEVEL_DATA          0
444#define NILFS_BTREE_LEVEL_NODE_MIN      (NILFS_BTREE_LEVEL_DATA + 1)
445#define NILFS_BTREE_LEVEL_MAX           14	/* Max level (exclusive) */
446
447/**
448 * struct nilfs_direct_node - header of built-in bmap array
449 * @dn_flags: flags
450 * @dn_pad: padding
451 */
452struct nilfs_direct_node {
453	__u8 dn_flags;
454	__u8 pad[7];
455};
456
457/**
458 * struct nilfs_palloc_group_desc - block group descriptor
459 * @pg_nfrees: number of free entries in block group
460 */
461struct nilfs_palloc_group_desc {
462	__le32 pg_nfrees;
463};
464
465/**
466 * struct nilfs_dat_entry - disk address translation entry
467 * @de_blocknr: block number
468 * @de_start: start checkpoint number
469 * @de_end: end checkpoint number
470 * @de_rsv: reserved for future use
471 */
472struct nilfs_dat_entry {
473	__le64 de_blocknr;
474	__le64 de_start;
475	__le64 de_end;
476	__le64 de_rsv;
477};
478
479#define NILFS_MIN_DAT_ENTRY_SIZE	32
480
481/**
482 * struct nilfs_snapshot_list - snapshot list
483 * @ssl_next: next checkpoint number on snapshot list
484 * @ssl_prev: previous checkpoint number on snapshot list
485 */
486struct nilfs_snapshot_list {
487	__le64 ssl_next;
488	__le64 ssl_prev;
489};
490
491/**
492 * struct nilfs_checkpoint - checkpoint structure
493 * @cp_flags: flags
494 * @cp_checkpoints_count: checkpoints count in a block
495 * @cp_snapshot_list: snapshot list
496 * @cp_cno: checkpoint number
497 * @cp_create: creation timestamp
498 * @cp_nblk_inc: number of blocks incremented by this checkpoint
499 * @cp_inodes_count: inodes count
500 * @cp_blocks_count: blocks count
501 * @cp_ifile_inode: inode of ifile
502 */
503struct nilfs_checkpoint {
504	__le32 cp_flags;
505	__le32 cp_checkpoints_count;
506	struct nilfs_snapshot_list cp_snapshot_list;
507	__le64 cp_cno;
508	__le64 cp_create;
509	__le64 cp_nblk_inc;
510	__le64 cp_inodes_count;
511	__le64 cp_blocks_count;
512
513	/*
514	 * Do not change the byte offset of ifile inode.
515	 * To keep the compatibility of the disk format,
516	 * additional fields should be added behind cp_ifile_inode.
517	 */
518	struct nilfs_inode cp_ifile_inode;
519};
520
521#define NILFS_MIN_CHECKPOINT_SIZE	(64 + NILFS_MIN_INODE_SIZE)
522
523/* checkpoint flags */
524enum {
525	NILFS_CHECKPOINT_SNAPSHOT,
526	NILFS_CHECKPOINT_INVALID,
527	NILFS_CHECKPOINT_SKETCH,
528	NILFS_CHECKPOINT_MINOR,
529};
530
531#define NILFS_CHECKPOINT_FNS(flag, name)				\
532static inline void							\
533nilfs_checkpoint_set_##name(struct nilfs_checkpoint *cp)		\
534{									\
535	cp->cp_flags = cpu_to_le32(le32_to_cpu(cp->cp_flags) |		\
536				   (1UL << NILFS_CHECKPOINT_##flag));	\
537}									\
538static inline void							\
539nilfs_checkpoint_clear_##name(struct nilfs_checkpoint *cp)		\
540{									\
541	cp->cp_flags = cpu_to_le32(le32_to_cpu(cp->cp_flags) &		\
542				   ~(1UL << NILFS_CHECKPOINT_##flag));	\
543}									\
544static inline int							\
545nilfs_checkpoint_##name(const struct nilfs_checkpoint *cp)		\
546{									\
547	return !!(le32_to_cpu(cp->cp_flags) &				\
548		  (1UL << NILFS_CHECKPOINT_##flag));			\
549}
550
551NILFS_CHECKPOINT_FNS(SNAPSHOT, snapshot)
552NILFS_CHECKPOINT_FNS(INVALID, invalid)
553NILFS_CHECKPOINT_FNS(MINOR, minor)
554
555/**
556 * struct nilfs_cpfile_header - checkpoint file header
557 * @ch_ncheckpoints: number of checkpoints
558 * @ch_nsnapshots: number of snapshots
559 * @ch_snapshot_list: snapshot list
560 */
561struct nilfs_cpfile_header {
562	__le64 ch_ncheckpoints;
563	__le64 ch_nsnapshots;
564	struct nilfs_snapshot_list ch_snapshot_list;
565};
566
567#define NILFS_CPFILE_FIRST_CHECKPOINT_OFFSET				\
568	((sizeof(struct nilfs_cpfile_header) +				\
569	  sizeof(struct nilfs_checkpoint) - 1) /			\
570			sizeof(struct nilfs_checkpoint))
571
572/**
573 * struct nilfs_segment_usage - segment usage
574 * @su_lastmod: last modified timestamp
575 * @su_nblocks: number of blocks in segment
576 * @su_flags: flags
577 */
578struct nilfs_segment_usage {
579	__le64 su_lastmod;
580	__le32 su_nblocks;
581	__le32 su_flags;
582};
583
584#define NILFS_MIN_SEGMENT_USAGE_SIZE	16
585
586/* segment usage flag */
587enum {
588	NILFS_SEGMENT_USAGE_ACTIVE,
589	NILFS_SEGMENT_USAGE_DIRTY,
590	NILFS_SEGMENT_USAGE_ERROR,
591};
592
593#define NILFS_SEGMENT_USAGE_FNS(flag, name)				\
594static inline void							\
595nilfs_segment_usage_set_##name(struct nilfs_segment_usage *su)		\
596{									\
597	su->su_flags = cpu_to_le32(le32_to_cpu(su->su_flags) |		\
598				   (1UL << NILFS_SEGMENT_USAGE_##flag));\
599}									\
600static inline void							\
601nilfs_segment_usage_clear_##name(struct nilfs_segment_usage *su)	\
602{									\
603	su->su_flags =							\
604		cpu_to_le32(le32_to_cpu(su->su_flags) &			\
605			    ~(1UL << NILFS_SEGMENT_USAGE_##flag));      \
606}									\
607static inline int							\
608nilfs_segment_usage_##name(const struct nilfs_segment_usage *su)	\
609{									\
610	return !!(le32_to_cpu(su->su_flags) &				\
611		  (1UL << NILFS_SEGMENT_USAGE_##flag));			\
612}
613
614NILFS_SEGMENT_USAGE_FNS(ACTIVE, active)
615NILFS_SEGMENT_USAGE_FNS(DIRTY, dirty)
616NILFS_SEGMENT_USAGE_FNS(ERROR, error)
617
618static inline void
619nilfs_segment_usage_set_clean(struct nilfs_segment_usage *su)
620{
621	su->su_lastmod = cpu_to_le64(0);
622	su->su_nblocks = cpu_to_le32(0);
623	su->su_flags = cpu_to_le32(0);
624}
625
626static inline int
627nilfs_segment_usage_clean(const struct nilfs_segment_usage *su)
628{
629	return !le32_to_cpu(su->su_flags);
630}
631
632/**
633 * struct nilfs_sufile_header - segment usage file header
634 * @sh_ncleansegs: number of clean segments
635 * @sh_ndirtysegs: number of dirty segments
636 * @sh_last_alloc: last allocated segment number
637 */
638struct nilfs_sufile_header {
639	__le64 sh_ncleansegs;
640	__le64 sh_ndirtysegs;
641	__le64 sh_last_alloc;
642	/* ... */
643};
644
645#define NILFS_SUFILE_FIRST_SEGMENT_USAGE_OFFSET				\
646	((sizeof(struct nilfs_sufile_header) +				\
647	  sizeof(struct nilfs_segment_usage) - 1) /			\
648			 sizeof(struct nilfs_segment_usage))
649
650#endif	/* _LINUX_NILFS2_ONDISK_H */
651