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 */
53 struct 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 */
84 struct 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 */
136 struct 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 */
299 struct 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 */
312 enum {
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 */
342 struct 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 */
354 struct 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 */
365 struct 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 */
376 union 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 */
397 struct 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 */
432 struct 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 */
452 struct 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 */
461 struct 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 */
472 struct 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 */
486 struct 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 */
503 struct 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 */
524 enum {
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) \
532 static inline void \
533 nilfs_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 } \
538 static inline void \
539 nilfs_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 } \
544 static inline int \
545 nilfs_checkpoint_##name(const struct nilfs_checkpoint *cp) \
546 { \
547 return !!(le32_to_cpu(cp->cp_flags) & \
548 (1UL << NILFS_CHECKPOINT_##flag)); \
549 }
550
551 NILFS_CHECKPOINT_FNS(SNAPSHOT, snapshot)
552 NILFS_CHECKPOINT_FNS(INVALID, invalid)
553 NILFS_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 */
561 struct 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 */
578 struct 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 */
587 enum {
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) \
594 static inline void \
595 nilfs_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 } \
600 static inline void \
601 nilfs_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 } \
607 static inline int \
608 nilfs_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
NILFS_SEGMENT_USAGE_FNS(ACTIVE,active)614 NILFS_SEGMENT_USAGE_FNS(ACTIVE, active)
615 NILFS_SEGMENT_USAGE_FNS(DIRTY, dirty)
616 NILFS_SEGMENT_USAGE_FNS(ERROR, error)
617
618 static inline void
619 nilfs_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
626 static inline int
nilfs_segment_usage_clean(const struct nilfs_segment_usage * su)627 nilfs_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 */
638 struct 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