include/uapi/linux/nilfs2_ondisk.h

   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
 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 */