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 (at) 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 } 613 614 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 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
