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1/* SPDX-License-Identifier: LGPL-2.1+ WITH Linux-syscall-note */
2/*
3 * nilfs2_ondisk.h - NILFS2 on-disk structures
4 *
5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU Lesser General Public License as published
9 * by the Free Software Foundation; either version 2.1 of the License, or
10 * (at your option) any later version.
11 */
12/*
13 * linux/include/linux/ext2_fs.h
14 *
15 * Copyright (C) 1992, 1993, 1994, 1995
16 * Remy Card (card@masi.ibp.fr)
17 * Laboratoire MASI - Institut Blaise Pascal
18 * Universite Pierre et Marie Curie (Paris VI)
19 *
20 * from
21 *
22 * linux/include/linux/minix_fs.h
23 *
24 * Copyright (C) 1991, 1992 Linus Torvalds
25 */
26
27#ifndef _LINUX_NILFS2_ONDISK_H
28#define _LINUX_NILFS2_ONDISK_H
29
30#include <linux/types.h>
31#include <linux/magic.h>
32#include <asm/byteorder.h>
33
34#define NILFS_INODE_BMAP_SIZE 7
35
36/**
37 * struct nilfs_inode - structure of an inode on disk
38 * @i_blocks: blocks count
39 * @i_size: size in bytes
40 * @i_ctime: creation time (seconds)
41 * @i_mtime: modification time (seconds)
42 * @i_ctime_nsec: creation time (nano seconds)
43 * @i_mtime_nsec: modification time (nano seconds)
44 * @i_uid: user id
45 * @i_gid: group id
46 * @i_mode: file mode
47 * @i_links_count: links count
48 * @i_flags: file flags
49 * @i_bmap: block mapping
50 * @i_xattr: extended attributes
51 * @i_generation: file generation (for NFS)
52 * @i_pad: padding
53 */
54struct nilfs_inode {
55 __le64 i_blocks;
56 __le64 i_size;
57 __le64 i_ctime;
58 __le64 i_mtime;
59 __le32 i_ctime_nsec;
60 __le32 i_mtime_nsec;
61 __le32 i_uid;
62 __le32 i_gid;
63 __le16 i_mode;
64 __le16 i_links_count;
65 __le32 i_flags;
66 __le64 i_bmap[NILFS_INODE_BMAP_SIZE];
67#define i_device_code i_bmap[0]
68 __le64 i_xattr;
69 __le32 i_generation;
70 __le32 i_pad;
71};
72
73#define NILFS_MIN_INODE_SIZE 128
74
75/**
76 * struct nilfs_super_root - structure of super root
77 * @sr_sum: check sum
78 * @sr_bytes: byte count of the structure
79 * @sr_flags: flags (reserved)
80 * @sr_nongc_ctime: write time of the last segment not for cleaner operation
81 * @sr_dat: DAT file inode
82 * @sr_cpfile: checkpoint file inode
83 * @sr_sufile: segment usage file inode
84 */
85struct nilfs_super_root {
86 __le32 sr_sum;
87 __le16 sr_bytes;
88 __le16 sr_flags;
89 __le64 sr_nongc_ctime;
90 struct nilfs_inode sr_dat;
91 struct nilfs_inode sr_cpfile;
92 struct nilfs_inode sr_sufile;
93};
94
95#define NILFS_SR_MDT_OFFSET(inode_size, i) \
96 ((unsigned long)&((struct nilfs_super_root *)0)->sr_dat + \
97 (inode_size) * (i))
98#define NILFS_SR_DAT_OFFSET(inode_size) NILFS_SR_MDT_OFFSET(inode_size, 0)
99#define NILFS_SR_CPFILE_OFFSET(inode_size) NILFS_SR_MDT_OFFSET(inode_size, 1)
100#define NILFS_SR_SUFILE_OFFSET(inode_size) NILFS_SR_MDT_OFFSET(inode_size, 2)
101#define NILFS_SR_BYTES(inode_size) NILFS_SR_MDT_OFFSET(inode_size, 3)
102
103/*
104 * Maximal mount counts
105 */
106#define NILFS_DFL_MAX_MNT_COUNT 50 /* 50 mounts */
107
108/*
109 * File system states (sbp->s_state, nilfs->ns_mount_state)
110 */
111#define NILFS_VALID_FS 0x0001 /* Unmounted cleanly */
112#define NILFS_ERROR_FS 0x0002 /* Errors detected */
113#define NILFS_RESIZE_FS 0x0004 /* Resize required */
114
115/*
116 * Mount flags (sbi->s_mount_opt)
117 */
118#define NILFS_MOUNT_ERROR_MODE 0x0070 /* Error mode mask */
119#define NILFS_MOUNT_ERRORS_CONT 0x0010 /* Continue on errors */
120#define NILFS_MOUNT_ERRORS_RO 0x0020 /* Remount fs ro on errors */
121#define NILFS_MOUNT_ERRORS_PANIC 0x0040 /* Panic on errors */
122#define NILFS_MOUNT_BARRIER 0x1000 /* Use block barriers */
123#define NILFS_MOUNT_STRICT_ORDER 0x2000 /*
124 * Apply strict in-order
125 * semantics also for data
126 */
127#define NILFS_MOUNT_NORECOVERY 0x4000 /*
128 * Disable write access during
129 * mount-time recovery
130 */
131#define NILFS_MOUNT_DISCARD 0x8000 /* Issue DISCARD requests */
132
133
134/**
135 * struct nilfs_super_block - structure of super block on disk
136 */
137struct nilfs_super_block {
138/*00*/ __le32 s_rev_level; /* Revision level */
139 __le16 s_minor_rev_level; /* minor revision level */
140 __le16 s_magic; /* Magic signature */
141
142 __le16 s_bytes; /*
143 * Bytes count of CRC calculation
144 * for this structure. s_reserved
145 * is excluded.
146 */
147 __le16 s_flags; /* flags */
148 __le32 s_crc_seed; /* Seed value of CRC calculation */
149/*10*/ __le32 s_sum; /* Check sum of super block */
150
151 __le32 s_log_block_size; /*
152 * Block size represented as follows
153 * blocksize =
154 * 1 << (s_log_block_size + 10)
155 */
156 __le64 s_nsegments; /* Number of segments in filesystem */
157/*20*/ __le64 s_dev_size; /* block device size in bytes */
158 __le64 s_first_data_block; /* 1st seg disk block number */
159/*30*/ __le32 s_blocks_per_segment; /* number of blocks per full segment */
160 __le32 s_r_segments_percentage; /* Reserved segments percentage */
161
162 __le64 s_last_cno; /* Last checkpoint number */
163/*40*/ __le64 s_last_pseg; /* disk block addr pseg written last */
164 __le64 s_last_seq; /* seq. number of seg written last */
165/*50*/ __le64 s_free_blocks_count; /* Free blocks count */
166
167 __le64 s_ctime; /*
168 * Creation time (execution time of
169 * newfs)
170 */
171/*60*/ __le64 s_mtime; /* Mount time */
172 __le64 s_wtime; /* Write time */
173/*70*/ __le16 s_mnt_count; /* Mount count */
174 __le16 s_max_mnt_count; /* Maximal mount count */
175 __le16 s_state; /* File system state */
176 __le16 s_errors; /* Behaviour when detecting errors */
177 __le64 s_lastcheck; /* time of last check */
178
179/*80*/ __le32 s_checkinterval; /* max. time between checks */
180 __le32 s_creator_os; /* OS */
181 __le16 s_def_resuid; /* Default uid for reserved blocks */
182 __le16 s_def_resgid; /* Default gid for reserved blocks */
183 __le32 s_first_ino; /* First non-reserved inode */
184
185/*90*/ __le16 s_inode_size; /* Size of an inode */
186 __le16 s_dat_entry_size; /* Size of a dat entry */
187 __le16 s_checkpoint_size; /* Size of a checkpoint */
188 __le16 s_segment_usage_size; /* Size of a segment usage */
189
190/*98*/ __u8 s_uuid[16]; /* 128-bit uuid for volume */
191/*A8*/ char s_volume_name[80] /* volume name */
192 __kernel_nonstring;
193
194/*F8*/ __le32 s_c_interval; /* Commit interval of segment */
195 __le32 s_c_block_max; /*
196 * Threshold of data amount for
197 * the segment construction
198 */
199/*100*/ __le64 s_feature_compat; /* Compatible feature set */
200 __le64 s_feature_compat_ro; /* Read-only compatible feature set */
201 __le64 s_feature_incompat; /* Incompatible feature set */
202 __u32 s_reserved[186]; /* padding to the end of the block */
203};
204
205/*
206 * Codes for operating systems
207 */
208#define NILFS_OS_LINUX 0
209/* Codes from 1 to 4 are reserved to keep compatibility with ext2 creator-OS */
210
211/*
212 * Revision levels
213 */
214#define NILFS_CURRENT_REV 2 /* current major revision */
215#define NILFS_MINOR_REV 0 /* minor revision */
216#define NILFS_MIN_SUPP_REV 2 /* minimum supported revision */
217
218/*
219 * Feature set definitions
220 *
221 * If there is a bit set in the incompatible feature set that the kernel
222 * doesn't know about, it should refuse to mount the filesystem.
223 */
224#define NILFS_FEATURE_COMPAT_RO_BLOCK_COUNT 0x00000001ULL
225
226#define NILFS_FEATURE_COMPAT_SUPP 0ULL
227#define NILFS_FEATURE_COMPAT_RO_SUPP NILFS_FEATURE_COMPAT_RO_BLOCK_COUNT
228#define NILFS_FEATURE_INCOMPAT_SUPP 0ULL
229
230/*
231 * Bytes count of super_block for CRC-calculation
232 */
233#define NILFS_SB_BYTES \
234 ((long)&((struct nilfs_super_block *)0)->s_reserved)
235
236/*
237 * Special inode number
238 */
239#define NILFS_ROOT_INO 2 /* Root file inode */
240#define NILFS_DAT_INO 3 /* DAT file */
241#define NILFS_CPFILE_INO 4 /* checkpoint file */
242#define NILFS_SUFILE_INO 5 /* segment usage file */
243#define NILFS_IFILE_INO 6 /* ifile */
244#define NILFS_ATIME_INO 7 /* Atime file (reserved) */
245#define NILFS_XATTR_INO 8 /* Xattribute file (reserved) */
246#define NILFS_SKETCH_INO 10 /* Sketch file */
247#define NILFS_USER_INO 11 /* Fisrt user's file inode number */
248
249#define NILFS_SB_OFFSET_BYTES 1024 /* byte offset of nilfs superblock */
250
251#define NILFS_SEG_MIN_BLOCKS 16 /*
252 * Minimum number of blocks in
253 * a full segment
254 */
255#define NILFS_PSEG_MIN_BLOCKS 2 /*
256 * Minimum number of blocks in
257 * a partial segment
258 */
259#define NILFS_MIN_NRSVSEGS 8 /*
260 * Minimum number of reserved
261 * segments
262 */
263
264/*
265 * We call DAT, cpfile, and sufile root metadata files. Inodes of
266 * these files are written in super root block instead of ifile, and
267 * garbage collector doesn't keep any past versions of these files.
268 */
269#define NILFS_ROOT_METADATA_FILE(ino) \
270 ((ino) >= NILFS_DAT_INO && (ino) <= NILFS_SUFILE_INO)
271
272/*
273 * bytes offset of secondary super block
274 */
275#define NILFS_SB2_OFFSET_BYTES(devsize) ((((devsize) >> 12) - 1) << 12)
276
277/*
278 * Maximal count of links to a file
279 */
280#define NILFS_LINK_MAX 32000
281
282/*
283 * Structure of a directory entry
284 * (Same as ext2)
285 */
286
287#define NILFS_NAME_LEN 255
288
289/*
290 * Block size limitations
291 */
292#define NILFS_MIN_BLOCK_SIZE 1024
293#define NILFS_MAX_BLOCK_SIZE 65536
294
295/*
296 * The new version of the directory entry. Since V0 structures are
297 * stored in intel byte order, and the name_len field could never be
298 * bigger than 255 chars, it's safe to reclaim the extra byte for the
299 * file_type field.
300 */
301struct nilfs_dir_entry {
302 __le64 inode; /* Inode number */
303 __le16 rec_len; /* Directory entry length */
304 __u8 name_len; /* Name length */
305 __u8 file_type; /* Dir entry type (file, dir, etc) */
306 char name[NILFS_NAME_LEN]; /* File name */
307 char pad;
308};
309
310/*
311 * NILFS directory file types. Only the low 3 bits are used. The
312 * other bits are reserved for now.
313 */
314enum {
315 NILFS_FT_UNKNOWN,
316 NILFS_FT_REG_FILE,
317 NILFS_FT_DIR,
318 NILFS_FT_CHRDEV,
319 NILFS_FT_BLKDEV,
320 NILFS_FT_FIFO,
321 NILFS_FT_SOCK,
322 NILFS_FT_SYMLINK,
323 NILFS_FT_MAX
324};
325
326/*
327 * NILFS_DIR_PAD defines the directory entries boundaries
328 *
329 * NOTE: It must be a multiple of 8
330 */
331#define NILFS_DIR_PAD 8
332#define NILFS_DIR_ROUND (NILFS_DIR_PAD - 1)
333#define NILFS_DIR_REC_LEN(name_len) (((name_len) + 12 + NILFS_DIR_ROUND) & \
334 ~NILFS_DIR_ROUND)
335#define NILFS_MAX_REC_LEN ((1 << 16) - 1)
336
337/**
338 * struct nilfs_finfo - file information
339 * @fi_ino: inode number
340 * @fi_cno: checkpoint number
341 * @fi_nblocks: number of blocks (including intermediate blocks)
342 * @fi_ndatablk: number of file data blocks
343 */
344struct nilfs_finfo {
345 __le64 fi_ino;
346 __le64 fi_cno;
347 __le32 fi_nblocks;
348 __le32 fi_ndatablk;
349};
350
351/**
352 * struct nilfs_binfo_v - information on a data block (except DAT)
353 * @bi_vblocknr: virtual block number
354 * @bi_blkoff: block offset
355 */
356struct nilfs_binfo_v {
357 __le64 bi_vblocknr;
358 __le64 bi_blkoff;
359};
360
361/**
362 * struct nilfs_binfo_dat - information on a DAT node block
363 * @bi_blkoff: block offset
364 * @bi_level: level
365 * @bi_pad: padding
366 */
367struct nilfs_binfo_dat {
368 __le64 bi_blkoff;
369 __u8 bi_level;
370 __u8 bi_pad[7];
371};
372
373/**
374 * union nilfs_binfo: block information
375 * @bi_v: nilfs_binfo_v structure
376 * @bi_dat: nilfs_binfo_dat structure
377 */
378union nilfs_binfo {
379 struct nilfs_binfo_v bi_v;
380 struct nilfs_binfo_dat bi_dat;
381};
382
383/**
384 * struct nilfs_segment_summary - segment summary header
385 * @ss_datasum: checksum of data
386 * @ss_sumsum: checksum of segment summary
387 * @ss_magic: magic number
388 * @ss_bytes: size of this structure in bytes
389 * @ss_flags: flags
390 * @ss_seq: sequence number
391 * @ss_create: creation timestamp
392 * @ss_next: next segment
393 * @ss_nblocks: number of blocks
394 * @ss_nfinfo: number of finfo structures
395 * @ss_sumbytes: total size of segment summary in bytes
396 * @ss_pad: padding
397 * @ss_cno: checkpoint number
398 */
399struct nilfs_segment_summary {
400 __le32 ss_datasum;
401 __le32 ss_sumsum;
402 __le32 ss_magic;
403 __le16 ss_bytes;
404 __le16 ss_flags;
405 __le64 ss_seq;
406 __le64 ss_create;
407 __le64 ss_next;
408 __le32 ss_nblocks;
409 __le32 ss_nfinfo;
410 __le32 ss_sumbytes;
411 __le32 ss_pad;
412 __le64 ss_cno;
413 /* array of finfo structures */
414};
415
416#define NILFS_SEGSUM_MAGIC 0x1eaffa11 /* segment summary magic number */
417
418/*
419 * Segment summary flags
420 */
421#define NILFS_SS_LOGBGN 0x0001 /* begins a logical segment */
422#define NILFS_SS_LOGEND 0x0002 /* ends a logical segment */
423#define NILFS_SS_SR 0x0004 /* has super root */
424#define NILFS_SS_SYNDT 0x0008 /* includes data only updates */
425#define NILFS_SS_GC 0x0010 /* segment written for cleaner operation */
426
427/**
428 * struct nilfs_btree_node - header of B-tree node block
429 * @bn_flags: flags
430 * @bn_level: level
431 * @bn_nchildren: number of children
432 * @bn_pad: padding
433 */
434struct nilfs_btree_node {
435 __u8 bn_flags;
436 __u8 bn_level;
437 __le16 bn_nchildren;
438 __le32 bn_pad;
439};
440
441/* flags */
442#define NILFS_BTREE_NODE_ROOT 0x01
443
444/* level */
445#define NILFS_BTREE_LEVEL_DATA 0
446#define NILFS_BTREE_LEVEL_NODE_MIN (NILFS_BTREE_LEVEL_DATA + 1)
447#define NILFS_BTREE_LEVEL_MAX 14 /* Max level (exclusive) */
448
449/**
450 * struct nilfs_direct_node - header of built-in bmap array
451 * @dn_flags: flags
452 * @dn_pad: padding
453 */
454struct nilfs_direct_node {
455 __u8 dn_flags;
456 __u8 pad[7];
457};
458
459/**
460 * struct nilfs_palloc_group_desc - block group descriptor
461 * @pg_nfrees: number of free entries in block group
462 */
463struct nilfs_palloc_group_desc {
464 __le32 pg_nfrees;
465};
466
467/**
468 * struct nilfs_dat_entry - disk address translation entry
469 * @de_blocknr: block number
470 * @de_start: start checkpoint number
471 * @de_end: end checkpoint number
472 * @de_rsv: reserved for future use
473 */
474struct nilfs_dat_entry {
475 __le64 de_blocknr;
476 __le64 de_start;
477 __le64 de_end;
478 __le64 de_rsv;
479};
480
481#define NILFS_MIN_DAT_ENTRY_SIZE 32
482
483/**
484 * struct nilfs_snapshot_list - snapshot list
485 * @ssl_next: next checkpoint number on snapshot list
486 * @ssl_prev: previous checkpoint number on snapshot list
487 */
488struct nilfs_snapshot_list {
489 __le64 ssl_next;
490 __le64 ssl_prev;
491};
492
493/**
494 * struct nilfs_checkpoint - checkpoint structure
495 * @cp_flags: flags
496 * @cp_checkpoints_count: checkpoints count in a block
497 * @cp_snapshot_list: snapshot list
498 * @cp_cno: checkpoint number
499 * @cp_create: creation timestamp
500 * @cp_nblk_inc: number of blocks incremented by this checkpoint
501 * @cp_inodes_count: inodes count
502 * @cp_blocks_count: blocks count
503 * @cp_ifile_inode: inode of ifile
504 */
505struct nilfs_checkpoint {
506 __le32 cp_flags;
507 __le32 cp_checkpoints_count;
508 struct nilfs_snapshot_list cp_snapshot_list;
509 __le64 cp_cno;
510 __le64 cp_create;
511 __le64 cp_nblk_inc;
512 __le64 cp_inodes_count;
513 __le64 cp_blocks_count;
514
515 /*
516 * Do not change the byte offset of ifile inode.
517 * To keep the compatibility of the disk format,
518 * additional fields should be added behind cp_ifile_inode.
519 */
520 struct nilfs_inode cp_ifile_inode;
521};
522
523#define NILFS_MIN_CHECKPOINT_SIZE (64 + NILFS_MIN_INODE_SIZE)
524
525/* checkpoint flags */
526enum {
527 NILFS_CHECKPOINT_SNAPSHOT,
528 NILFS_CHECKPOINT_INVALID,
529 NILFS_CHECKPOINT_SKETCH,
530 NILFS_CHECKPOINT_MINOR,
531};
532
533#define NILFS_CHECKPOINT_FNS(flag, name) \
534static __inline__ void \
535nilfs_checkpoint_set_##name(struct nilfs_checkpoint *cp) \
536{ \
537 cp->cp_flags = __cpu_to_le32(__le32_to_cpu(cp->cp_flags) | \
538 (1UL << NILFS_CHECKPOINT_##flag)); \
539} \
540static __inline__ void \
541nilfs_checkpoint_clear_##name(struct nilfs_checkpoint *cp) \
542{ \
543 cp->cp_flags = __cpu_to_le32(__le32_to_cpu(cp->cp_flags) & \
544 ~(1UL << NILFS_CHECKPOINT_##flag)); \
545} \
546static __inline__ int \
547nilfs_checkpoint_##name(const struct nilfs_checkpoint *cp) \
548{ \
549 return !!(__le32_to_cpu(cp->cp_flags) & \
550 (1UL << NILFS_CHECKPOINT_##flag)); \
551}
552
553NILFS_CHECKPOINT_FNS(SNAPSHOT, snapshot)
554NILFS_CHECKPOINT_FNS(INVALID, invalid)
555NILFS_CHECKPOINT_FNS(MINOR, minor)
556
557/**
558 * struct nilfs_cpfile_header - checkpoint file header
559 * @ch_ncheckpoints: number of checkpoints
560 * @ch_nsnapshots: number of snapshots
561 * @ch_snapshot_list: snapshot list
562 */
563struct nilfs_cpfile_header {
564 __le64 ch_ncheckpoints;
565 __le64 ch_nsnapshots;
566 struct nilfs_snapshot_list ch_snapshot_list;
567};
568
569#define NILFS_CPFILE_FIRST_CHECKPOINT_OFFSET \
570 ((sizeof(struct nilfs_cpfile_header) + \
571 sizeof(struct nilfs_checkpoint) - 1) / \
572 sizeof(struct nilfs_checkpoint))
573
574/**
575 * struct nilfs_segment_usage - segment usage
576 * @su_lastmod: last modified timestamp
577 * @su_nblocks: number of blocks in segment
578 * @su_flags: flags
579 */
580struct nilfs_segment_usage {
581 __le64 su_lastmod;
582 __le32 su_nblocks;
583 __le32 su_flags;
584};
585
586#define NILFS_MIN_SEGMENT_USAGE_SIZE 16
587
588/* segment usage flag */
589enum {
590 NILFS_SEGMENT_USAGE_ACTIVE,
591 NILFS_SEGMENT_USAGE_DIRTY,
592 NILFS_SEGMENT_USAGE_ERROR,
593};
594
595#define NILFS_SEGMENT_USAGE_FNS(flag, name) \
596static __inline__ void \
597nilfs_segment_usage_set_##name(struct nilfs_segment_usage *su) \
598{ \
599 su->su_flags = __cpu_to_le32(__le32_to_cpu(su->su_flags) | \
600 (1UL << NILFS_SEGMENT_USAGE_##flag));\
601} \
602static __inline__ void \
603nilfs_segment_usage_clear_##name(struct nilfs_segment_usage *su) \
604{ \
605 su->su_flags = \
606 __cpu_to_le32(__le32_to_cpu(su->su_flags) & \
607 ~(1UL << NILFS_SEGMENT_USAGE_##flag)); \
608} \
609static __inline__ int \
610nilfs_segment_usage_##name(const struct nilfs_segment_usage *su) \
611{ \
612 return !!(__le32_to_cpu(su->su_flags) & \
613 (1UL << NILFS_SEGMENT_USAGE_##flag)); \
614}
615
616NILFS_SEGMENT_USAGE_FNS(ACTIVE, active)
617NILFS_SEGMENT_USAGE_FNS(DIRTY, dirty)
618NILFS_SEGMENT_USAGE_FNS(ERROR, error)
619
620static __inline__ void
621nilfs_segment_usage_set_clean(struct nilfs_segment_usage *su)
622{
623 su->su_lastmod = __cpu_to_le64(0);
624 su->su_nblocks = __cpu_to_le32(0);
625 su->su_flags = __cpu_to_le32(0);
626}
627
628static __inline__ int
629nilfs_segment_usage_clean(const struct nilfs_segment_usage *su)
630{
631 return !__le32_to_cpu(su->su_flags);
632}
633
634/**
635 * struct nilfs_sufile_header - segment usage file header
636 * @sh_ncleansegs: number of clean segments
637 * @sh_ndirtysegs: number of dirty segments
638 * @sh_last_alloc: last allocated segment number
639 */
640struct nilfs_sufile_header {
641 __le64 sh_ncleansegs;
642 __le64 sh_ndirtysegs;
643 __le64 sh_last_alloc;
644 /* ... */
645};
646
647#define NILFS_SUFILE_FIRST_SEGMENT_USAGE_OFFSET \
648 ((sizeof(struct nilfs_sufile_header) + \
649 sizeof(struct nilfs_segment_usage) - 1) / \
650 sizeof(struct nilfs_segment_usage))
651
652#endif /* _LINUX_NILFS2_ONDISK_H */