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 */ 192 193/*F8*/ __le32 s_c_interval; /* Commit interval of segment */ 194 __le32 s_c_block_max; /* 195 * Threshold of data amount for 196 * the segment construction 197 */ 198/*100*/ __le64 s_feature_compat; /* Compatible feature set */ 199 __le64 s_feature_compat_ro; /* Read-only compatible feature set */ 200 __le64 s_feature_incompat; /* Incompatible feature set */ 201 __u32 s_reserved[186]; /* padding to the end of the block */ 202}; 203 204/* 205 * Codes for operating systems 206 */ 207#define NILFS_OS_LINUX 0 208/* Codes from 1 to 4 are reserved to keep compatibility with ext2 creator-OS */ 209 210/* 211 * Revision levels 212 */ 213#define NILFS_CURRENT_REV 2 /* current major revision */ 214#define NILFS_MINOR_REV 0 /* minor revision */ 215#define NILFS_MIN_SUPP_REV 2 /* minimum supported revision */ 216 217/* 218 * Feature set definitions 219 * 220 * If there is a bit set in the incompatible feature set that the kernel 221 * doesn't know about, it should refuse to mount the filesystem. 222 */ 223#define NILFS_FEATURE_COMPAT_RO_BLOCK_COUNT 0x00000001ULL 224 225#define NILFS_FEATURE_COMPAT_SUPP 0ULL 226#define NILFS_FEATURE_COMPAT_RO_SUPP NILFS_FEATURE_COMPAT_RO_BLOCK_COUNT 227#define NILFS_FEATURE_INCOMPAT_SUPP 0ULL 228 229/* 230 * Bytes count of super_block for CRC-calculation 231 */ 232#define NILFS_SB_BYTES \ 233 ((long)&((struct nilfs_super_block *)0)->s_reserved) 234 235/* 236 * Special inode number 237 */ 238#define NILFS_ROOT_INO 2 /* Root file inode */ 239#define NILFS_DAT_INO 3 /* DAT file */ 240#define NILFS_CPFILE_INO 4 /* checkpoint file */ 241#define NILFS_SUFILE_INO 5 /* segment usage file */ 242#define NILFS_IFILE_INO 6 /* ifile */ 243#define NILFS_ATIME_INO 7 /* Atime file (reserved) */ 244#define NILFS_XATTR_INO 8 /* Xattribute file (reserved) */ 245#define NILFS_SKETCH_INO 10 /* Sketch file */ 246#define NILFS_USER_INO 11 /* Fisrt user's file inode number */ 247 248#define NILFS_SB_OFFSET_BYTES 1024 /* byte offset of nilfs superblock */ 249 250#define NILFS_SEG_MIN_BLOCKS 16 /* 251 * Minimum number of blocks in 252 * a full segment 253 */ 254#define NILFS_PSEG_MIN_BLOCKS 2 /* 255 * Minimum number of blocks in 256 * a partial segment 257 */ 258#define NILFS_MIN_NRSVSEGS 8 /* 259 * Minimum number of reserved 260 * segments 261 */ 262 263/* 264 * We call DAT, cpfile, and sufile root metadata files. Inodes of 265 * these files are written in super root block instead of ifile, and 266 * garbage collector doesn't keep any past versions of these files. 267 */ 268#define NILFS_ROOT_METADATA_FILE(ino) \ 269 ((ino) >= NILFS_DAT_INO && (ino) <= NILFS_SUFILE_INO) 270 271/* 272 * bytes offset of secondary super block 273 */ 274#define NILFS_SB2_OFFSET_BYTES(devsize) ((((devsize) >> 12) - 1) << 12) 275 276/* 277 * Maximal count of links to a file 278 */ 279#define NILFS_LINK_MAX 32000 280 281/* 282 * Structure of a directory entry 283 * (Same as ext2) 284 */ 285 286#define NILFS_NAME_LEN 255 287 288/* 289 * Block size limitations 290 */ 291#define NILFS_MIN_BLOCK_SIZE 1024 292#define NILFS_MAX_BLOCK_SIZE 65536 293 294/* 295 * The new version of the directory entry. Since V0 structures are 296 * stored in intel byte order, and the name_len field could never be 297 * bigger than 255 chars, it's safe to reclaim the extra byte for the 298 * file_type field. 299 */ 300struct nilfs_dir_entry { 301 __le64 inode; /* Inode number */ 302 __le16 rec_len; /* Directory entry length */ 303 __u8 name_len; /* Name length */ 304 __u8 file_type; /* Dir entry type (file, dir, etc) */ 305 char name[NILFS_NAME_LEN]; /* File name */ 306 char pad; 307}; 308 309/* 310 * NILFS directory file types. Only the low 3 bits are used. The 311 * other bits are reserved for now. 312 */ 313enum { 314 NILFS_FT_UNKNOWN, 315 NILFS_FT_REG_FILE, 316 NILFS_FT_DIR, 317 NILFS_FT_CHRDEV, 318 NILFS_FT_BLKDEV, 319 NILFS_FT_FIFO, 320 NILFS_FT_SOCK, 321 NILFS_FT_SYMLINK, 322 NILFS_FT_MAX 323}; 324 325/* 326 * NILFS_DIR_PAD defines the directory entries boundaries 327 * 328 * NOTE: It must be a multiple of 8 329 */ 330#define NILFS_DIR_PAD 8 331#define NILFS_DIR_ROUND (NILFS_DIR_PAD - 1) 332#define NILFS_DIR_REC_LEN(name_len) (((name_len) + 12 + NILFS_DIR_ROUND) & \ 333 ~NILFS_DIR_ROUND) 334#define NILFS_MAX_REC_LEN ((1 << 16) - 1) 335 336/** 337 * struct nilfs_finfo - file information 338 * @fi_ino: inode number 339 * @fi_cno: checkpoint number 340 * @fi_nblocks: number of blocks (including intermediate blocks) 341 * @fi_ndatablk: number of file data blocks 342 */ 343struct nilfs_finfo { 344 __le64 fi_ino; 345 __le64 fi_cno; 346 __le32 fi_nblocks; 347 __le32 fi_ndatablk; 348}; 349 350/** 351 * struct nilfs_binfo_v - information on a data block (except DAT) 352 * @bi_vblocknr: virtual block number 353 * @bi_blkoff: block offset 354 */ 355struct nilfs_binfo_v { 356 __le64 bi_vblocknr; 357 __le64 bi_blkoff; 358}; 359 360/** 361 * struct nilfs_binfo_dat - information on a DAT node block 362 * @bi_blkoff: block offset 363 * @bi_level: level 364 * @bi_pad: padding 365 */ 366struct nilfs_binfo_dat { 367 __le64 bi_blkoff; 368 __u8 bi_level; 369 __u8 bi_pad[7]; 370}; 371 372/** 373 * union nilfs_binfo: block information 374 * @bi_v: nilfs_binfo_v structure 375 * @bi_dat: nilfs_binfo_dat structure 376 */ 377union nilfs_binfo { 378 struct nilfs_binfo_v bi_v; 379 struct nilfs_binfo_dat bi_dat; 380}; 381 382/** 383 * struct nilfs_segment_summary - segment summary header 384 * @ss_datasum: checksum of data 385 * @ss_sumsum: checksum of segment summary 386 * @ss_magic: magic number 387 * @ss_bytes: size of this structure in bytes 388 * @ss_flags: flags 389 * @ss_seq: sequence number 390 * @ss_create: creation timestamp 391 * @ss_next: next segment 392 * @ss_nblocks: number of blocks 393 * @ss_nfinfo: number of finfo structures 394 * @ss_sumbytes: total size of segment summary in bytes 395 * @ss_pad: padding 396 * @ss_cno: checkpoint number 397 */ 398struct nilfs_segment_summary { 399 __le32 ss_datasum; 400 __le32 ss_sumsum; 401 __le32 ss_magic; 402 __le16 ss_bytes; 403 __le16 ss_flags; 404 __le64 ss_seq; 405 __le64 ss_create; 406 __le64 ss_next; 407 __le32 ss_nblocks; 408 __le32 ss_nfinfo; 409 __le32 ss_sumbytes; 410 __le32 ss_pad; 411 __le64 ss_cno; 412 /* array of finfo structures */ 413}; 414 415#define NILFS_SEGSUM_MAGIC 0x1eaffa11 /* segment summary magic number */ 416 417/* 418 * Segment summary flags 419 */ 420#define NILFS_SS_LOGBGN 0x0001 /* begins a logical segment */ 421#define NILFS_SS_LOGEND 0x0002 /* ends a logical segment */ 422#define NILFS_SS_SR 0x0004 /* has super root */ 423#define NILFS_SS_SYNDT 0x0008 /* includes data only updates */ 424#define NILFS_SS_GC 0x0010 /* segment written for cleaner operation */ 425 426/** 427 * struct nilfs_btree_node - header of B-tree node block 428 * @bn_flags: flags 429 * @bn_level: level 430 * @bn_nchildren: number of children 431 * @bn_pad: padding 432 */ 433struct nilfs_btree_node { 434 __u8 bn_flags; 435 __u8 bn_level; 436 __le16 bn_nchildren; 437 __le32 bn_pad; 438}; 439 440/* flags */ 441#define NILFS_BTREE_NODE_ROOT 0x01 442 443/* level */ 444#define NILFS_BTREE_LEVEL_DATA 0 445#define NILFS_BTREE_LEVEL_NODE_MIN (NILFS_BTREE_LEVEL_DATA + 1) 446#define NILFS_BTREE_LEVEL_MAX 14 /* Max level (exclusive) */ 447 448/** 449 * struct nilfs_direct_node - header of built-in bmap array 450 * @dn_flags: flags 451 * @dn_pad: padding 452 */ 453struct nilfs_direct_node { 454 __u8 dn_flags; 455 __u8 pad[7]; 456}; 457 458/** 459 * struct nilfs_palloc_group_desc - block group descriptor 460 * @pg_nfrees: number of free entries in block group 461 */ 462struct nilfs_palloc_group_desc { 463 __le32 pg_nfrees; 464}; 465 466/** 467 * struct nilfs_dat_entry - disk address translation entry 468 * @de_blocknr: block number 469 * @de_start: start checkpoint number 470 * @de_end: end checkpoint number 471 * @de_rsv: reserved for future use 472 */ 473struct nilfs_dat_entry { 474 __le64 de_blocknr; 475 __le64 de_start; 476 __le64 de_end; 477 __le64 de_rsv; 478}; 479 480#define NILFS_MIN_DAT_ENTRY_SIZE 32 481 482/** 483 * struct nilfs_snapshot_list - snapshot list 484 * @ssl_next: next checkpoint number on snapshot list 485 * @ssl_prev: previous checkpoint number on snapshot list 486 */ 487struct nilfs_snapshot_list { 488 __le64 ssl_next; 489 __le64 ssl_prev; 490}; 491 492/** 493 * struct nilfs_checkpoint - checkpoint structure 494 * @cp_flags: flags 495 * @cp_checkpoints_count: checkpoints count in a block 496 * @cp_snapshot_list: snapshot list 497 * @cp_cno: checkpoint number 498 * @cp_create: creation timestamp 499 * @cp_nblk_inc: number of blocks incremented by this checkpoint 500 * @cp_inodes_count: inodes count 501 * @cp_blocks_count: blocks count 502 * @cp_ifile_inode: inode of ifile 503 */ 504struct nilfs_checkpoint { 505 __le32 cp_flags; 506 __le32 cp_checkpoints_count; 507 struct nilfs_snapshot_list cp_snapshot_list; 508 __le64 cp_cno; 509 __le64 cp_create; 510 __le64 cp_nblk_inc; 511 __le64 cp_inodes_count; 512 __le64 cp_blocks_count; 513 514 /* 515 * Do not change the byte offset of ifile inode. 516 * To keep the compatibility of the disk format, 517 * additional fields should be added behind cp_ifile_inode. 518 */ 519 struct nilfs_inode cp_ifile_inode; 520}; 521 522#define NILFS_MIN_CHECKPOINT_SIZE (64 + NILFS_MIN_INODE_SIZE) 523 524/* checkpoint flags */ 525enum { 526 NILFS_CHECKPOINT_SNAPSHOT, 527 NILFS_CHECKPOINT_INVALID, 528 NILFS_CHECKPOINT_SKETCH, 529 NILFS_CHECKPOINT_MINOR, 530}; 531 532#define NILFS_CHECKPOINT_FNS(flag, name) \ 533static inline void \ 534nilfs_checkpoint_set_##name(struct nilfs_checkpoint *cp) \ 535{ \ 536 cp->cp_flags = __cpu_to_le32(__le32_to_cpu(cp->cp_flags) | \ 537 (1UL << NILFS_CHECKPOINT_##flag)); \ 538} \ 539static inline void \ 540nilfs_checkpoint_clear_##name(struct nilfs_checkpoint *cp) \ 541{ \ 542 cp->cp_flags = __cpu_to_le32(__le32_to_cpu(cp->cp_flags) & \ 543 ~(1UL << NILFS_CHECKPOINT_##flag)); \ 544} \ 545static inline int \ 546nilfs_checkpoint_##name(const struct nilfs_checkpoint *cp) \ 547{ \ 548 return !!(__le32_to_cpu(cp->cp_flags) & \ 549 (1UL << NILFS_CHECKPOINT_##flag)); \ 550} 551 552NILFS_CHECKPOINT_FNS(SNAPSHOT, snapshot) 553NILFS_CHECKPOINT_FNS(INVALID, invalid) 554NILFS_CHECKPOINT_FNS(MINOR, minor) 555 556/** 557 * struct nilfs_cpfile_header - checkpoint file header 558 * @ch_ncheckpoints: number of checkpoints 559 * @ch_nsnapshots: number of snapshots 560 * @ch_snapshot_list: snapshot list 561 */ 562struct nilfs_cpfile_header { 563 __le64 ch_ncheckpoints; 564 __le64 ch_nsnapshots; 565 struct nilfs_snapshot_list ch_snapshot_list; 566}; 567 568#define NILFS_CPFILE_FIRST_CHECKPOINT_OFFSET \ 569 ((sizeof(struct nilfs_cpfile_header) + \ 570 sizeof(struct nilfs_checkpoint) - 1) / \ 571 sizeof(struct nilfs_checkpoint)) 572 573/** 574 * struct nilfs_segment_usage - segment usage 575 * @su_lastmod: last modified timestamp 576 * @su_nblocks: number of blocks in segment 577 * @su_flags: flags 578 */ 579struct nilfs_segment_usage { 580 __le64 su_lastmod; 581 __le32 su_nblocks; 582 __le32 su_flags; 583}; 584 585#define NILFS_MIN_SEGMENT_USAGE_SIZE 16 586 587/* segment usage flag */ 588enum { 589 NILFS_SEGMENT_USAGE_ACTIVE, 590 NILFS_SEGMENT_USAGE_DIRTY, 591 NILFS_SEGMENT_USAGE_ERROR, 592}; 593 594#define NILFS_SEGMENT_USAGE_FNS(flag, name) \ 595static inline void \ 596nilfs_segment_usage_set_##name(struct nilfs_segment_usage *su) \ 597{ \ 598 su->su_flags = __cpu_to_le32(__le32_to_cpu(su->su_flags) | \ 599 (1UL << NILFS_SEGMENT_USAGE_##flag));\ 600} \ 601static inline void \ 602nilfs_segment_usage_clear_##name(struct nilfs_segment_usage *su) \ 603{ \ 604 su->su_flags = \ 605 __cpu_to_le32(__le32_to_cpu(su->su_flags) & \ 606 ~(1UL << NILFS_SEGMENT_USAGE_##flag)); \ 607} \ 608static inline int \ 609nilfs_segment_usage_##name(const struct nilfs_segment_usage *su) \ 610{ \ 611 return !!(__le32_to_cpu(su->su_flags) & \ 612 (1UL << NILFS_SEGMENT_USAGE_##flag)); \ 613} 614 615NILFS_SEGMENT_USAGE_FNS(ACTIVE, active) 616NILFS_SEGMENT_USAGE_FNS(DIRTY, dirty) 617NILFS_SEGMENT_USAGE_FNS(ERROR, error) 618 619static inline void 620nilfs_segment_usage_set_clean(struct nilfs_segment_usage *su) 621{ 622 su->su_lastmod = __cpu_to_le64(0); 623 su->su_nblocks = __cpu_to_le32(0); 624 su->su_flags = __cpu_to_le32(0); 625} 626 627static inline int 628nilfs_segment_usage_clean(const struct nilfs_segment_usage *su) 629{ 630 return !__le32_to_cpu(su->su_flags); 631} 632 633/** 634 * struct nilfs_sufile_header - segment usage file header 635 * @sh_ncleansegs: number of clean segments 636 * @sh_ndirtysegs: number of dirty segments 637 * @sh_last_alloc: last allocated segment number 638 */ 639struct nilfs_sufile_header { 640 __le64 sh_ncleansegs; 641 __le64 sh_ndirtysegs; 642 __le64 sh_last_alloc; 643 /* ... */ 644}; 645 646#define NILFS_SUFILE_FIRST_SEGMENT_USAGE_OFFSET \ 647 ((sizeof(struct nilfs_sufile_header) + \ 648 sizeof(struct nilfs_segment_usage) - 1) / \ 649 sizeof(struct nilfs_segment_usage)) 650 651#endif /* _LINUX_NILFS2_ONDISK_H */ 652