linux/fs/xfs/libxfs/xfs_format.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
   4 * All Rights Reserved.
   5 */
   6#ifndef __XFS_FORMAT_H__
   7#define __XFS_FORMAT_H__
   8
   9/*
  10 * XFS On Disk Format Definitions
  11 *
  12 * This header file defines all the on-disk format definitions for 
  13 * general XFS objects. Directory and attribute related objects are defined in
  14 * xfs_da_format.h, which log and log item formats are defined in
  15 * xfs_log_format.h. Everything else goes here.
  16 */
  17
  18struct xfs_mount;
  19struct xfs_trans;
  20struct xfs_inode;
  21struct xfs_buf;
  22struct xfs_ifork;
  23
  24/*
  25 * Super block
  26 * Fits into a sector-sized buffer at address 0 of each allocation group.
  27 * Only the first of these is ever updated except during growfs.
  28 */
  29#define XFS_SB_MAGIC            0x58465342      /* 'XFSB' */
  30#define XFS_SB_VERSION_1        1               /* 5.3, 6.0.1, 6.1 */
  31#define XFS_SB_VERSION_2        2               /* 6.2 - attributes */
  32#define XFS_SB_VERSION_3        3               /* 6.2 - new inode version */
  33#define XFS_SB_VERSION_4        4               /* 6.2+ - bitmask version */
  34#define XFS_SB_VERSION_5        5               /* CRC enabled filesystem */
  35#define XFS_SB_VERSION_NUMBITS          0x000f
  36#define XFS_SB_VERSION_ALLFBITS         0xfff0
  37#define XFS_SB_VERSION_ATTRBIT          0x0010
  38#define XFS_SB_VERSION_NLINKBIT         0x0020
  39#define XFS_SB_VERSION_QUOTABIT         0x0040
  40#define XFS_SB_VERSION_ALIGNBIT         0x0080
  41#define XFS_SB_VERSION_DALIGNBIT        0x0100
  42#define XFS_SB_VERSION_SHAREDBIT        0x0200
  43#define XFS_SB_VERSION_LOGV2BIT         0x0400
  44#define XFS_SB_VERSION_SECTORBIT        0x0800
  45#define XFS_SB_VERSION_EXTFLGBIT        0x1000
  46#define XFS_SB_VERSION_DIRV2BIT         0x2000
  47#define XFS_SB_VERSION_BORGBIT          0x4000  /* ASCII only case-insens. */
  48#define XFS_SB_VERSION_MOREBITSBIT      0x8000
  49
  50/*
  51 * The size of a single extended attribute on disk is limited by
  52 * the size of index values within the attribute entries themselves.
  53 * These are be16 fields, so we can only support attribute data
  54 * sizes up to 2^16 bytes in length.
  55 */
  56#define XFS_XATTR_SIZE_MAX (1 << 16)
  57
  58/*
  59 * Supported feature bit list is just all bits in the versionnum field because
  60 * we've used them all up and understand them all. Except, of course, for the
  61 * shared superblock bit, which nobody knows what it does and so is unsupported.
  62 */
  63#define XFS_SB_VERSION_OKBITS           \
  64        ((XFS_SB_VERSION_NUMBITS | XFS_SB_VERSION_ALLFBITS) & \
  65                ~XFS_SB_VERSION_SHAREDBIT)
  66
  67/*
  68 * There are two words to hold XFS "feature" bits: the original
  69 * word, sb_versionnum, and sb_features2.  Whenever a bit is set in
  70 * sb_features2, the feature bit XFS_SB_VERSION_MOREBITSBIT must be set.
  71 *
  72 * These defines represent bits in sb_features2.
  73 */
  74#define XFS_SB_VERSION2_RESERVED1BIT    0x00000001
  75#define XFS_SB_VERSION2_LAZYSBCOUNTBIT  0x00000002      /* Superblk counters */
  76#define XFS_SB_VERSION2_RESERVED4BIT    0x00000004
  77#define XFS_SB_VERSION2_ATTR2BIT        0x00000008      /* Inline attr rework */
  78#define XFS_SB_VERSION2_PARENTBIT       0x00000010      /* parent pointers */
  79#define XFS_SB_VERSION2_PROJID32BIT     0x00000080      /* 32 bit project id */
  80#define XFS_SB_VERSION2_CRCBIT          0x00000100      /* metadata CRCs */
  81#define XFS_SB_VERSION2_FTYPE           0x00000200      /* inode type in dir */
  82
  83#define XFS_SB_VERSION2_OKBITS          \
  84        (XFS_SB_VERSION2_LAZYSBCOUNTBIT | \
  85         XFS_SB_VERSION2_ATTR2BIT       | \
  86         XFS_SB_VERSION2_PROJID32BIT    | \
  87         XFS_SB_VERSION2_FTYPE)
  88
  89/* Maximum size of the xfs filesystem label, no terminating NULL */
  90#define XFSLABEL_MAX                    12
  91
  92/*
  93 * Superblock - in core version.  Must match the ondisk version below.
  94 * Must be padded to 64 bit alignment.
  95 */
  96typedef struct xfs_sb {
  97        uint32_t        sb_magicnum;    /* magic number == XFS_SB_MAGIC */
  98        uint32_t        sb_blocksize;   /* logical block size, bytes */
  99        xfs_rfsblock_t  sb_dblocks;     /* number of data blocks */
 100        xfs_rfsblock_t  sb_rblocks;     /* number of realtime blocks */
 101        xfs_rtblock_t   sb_rextents;    /* number of realtime extents */
 102        uuid_t          sb_uuid;        /* user-visible file system unique id */
 103        xfs_fsblock_t   sb_logstart;    /* starting block of log if internal */
 104        xfs_ino_t       sb_rootino;     /* root inode number */
 105        xfs_ino_t       sb_rbmino;      /* bitmap inode for realtime extents */
 106        xfs_ino_t       sb_rsumino;     /* summary inode for rt bitmap */
 107        xfs_agblock_t   sb_rextsize;    /* realtime extent size, blocks */
 108        xfs_agblock_t   sb_agblocks;    /* size of an allocation group */
 109        xfs_agnumber_t  sb_agcount;     /* number of allocation groups */
 110        xfs_extlen_t    sb_rbmblocks;   /* number of rt bitmap blocks */
 111        xfs_extlen_t    sb_logblocks;   /* number of log blocks */
 112        uint16_t        sb_versionnum;  /* header version == XFS_SB_VERSION */
 113        uint16_t        sb_sectsize;    /* volume sector size, bytes */
 114        uint16_t        sb_inodesize;   /* inode size, bytes */
 115        uint16_t        sb_inopblock;   /* inodes per block */
 116        char            sb_fname[XFSLABEL_MAX]; /* file system name */
 117        uint8_t         sb_blocklog;    /* log2 of sb_blocksize */
 118        uint8_t         sb_sectlog;     /* log2 of sb_sectsize */
 119        uint8_t         sb_inodelog;    /* log2 of sb_inodesize */
 120        uint8_t         sb_inopblog;    /* log2 of sb_inopblock */
 121        uint8_t         sb_agblklog;    /* log2 of sb_agblocks (rounded up) */
 122        uint8_t         sb_rextslog;    /* log2 of sb_rextents */
 123        uint8_t         sb_inprogress;  /* mkfs is in progress, don't mount */
 124        uint8_t         sb_imax_pct;    /* max % of fs for inode space */
 125                                        /* statistics */
 126        /*
 127         * These fields must remain contiguous.  If you really
 128         * want to change their layout, make sure you fix the
 129         * code in xfs_trans_apply_sb_deltas().
 130         */
 131        uint64_t        sb_icount;      /* allocated inodes */
 132        uint64_t        sb_ifree;       /* free inodes */
 133        uint64_t        sb_fdblocks;    /* free data blocks */
 134        uint64_t        sb_frextents;   /* free realtime extents */
 135        /*
 136         * End contiguous fields.
 137         */
 138        xfs_ino_t       sb_uquotino;    /* user quota inode */
 139        xfs_ino_t       sb_gquotino;    /* group quota inode */
 140        uint16_t        sb_qflags;      /* quota flags */
 141        uint8_t         sb_flags;       /* misc. flags */
 142        uint8_t         sb_shared_vn;   /* shared version number */
 143        xfs_extlen_t    sb_inoalignmt;  /* inode chunk alignment, fsblocks */
 144        uint32_t        sb_unit;        /* stripe or raid unit */
 145        uint32_t        sb_width;       /* stripe or raid width */
 146        uint8_t         sb_dirblklog;   /* log2 of dir block size (fsbs) */
 147        uint8_t         sb_logsectlog;  /* log2 of the log sector size */
 148        uint16_t        sb_logsectsize; /* sector size for the log, bytes */
 149        uint32_t        sb_logsunit;    /* stripe unit size for the log */
 150        uint32_t        sb_features2;   /* additional feature bits */
 151
 152        /*
 153         * bad features2 field as a result of failing to pad the sb structure to
 154         * 64 bits. Some machines will be using this field for features2 bits.
 155         * Easiest just to mark it bad and not use it for anything else.
 156         *
 157         * This is not kept up to date in memory; it is always overwritten by
 158         * the value in sb_features2 when formatting the incore superblock to
 159         * the disk buffer.
 160         */
 161        uint32_t        sb_bad_features2;
 162
 163        /* version 5 superblock fields start here */
 164
 165        /* feature masks */
 166        uint32_t        sb_features_compat;
 167        uint32_t        sb_features_ro_compat;
 168        uint32_t        sb_features_incompat;
 169        uint32_t        sb_features_log_incompat;
 170
 171        uint32_t        sb_crc;         /* superblock crc */
 172        xfs_extlen_t    sb_spino_align; /* sparse inode chunk alignment */
 173
 174        xfs_ino_t       sb_pquotino;    /* project quota inode */
 175        xfs_lsn_t       sb_lsn;         /* last write sequence */
 176        uuid_t          sb_meta_uuid;   /* metadata file system unique id */
 177
 178        /* must be padded to 64 bit alignment */
 179} xfs_sb_t;
 180
 181#define XFS_SB_CRC_OFF          offsetof(struct xfs_sb, sb_crc)
 182
 183/*
 184 * Superblock - on disk version.  Must match the in core version above.
 185 * Must be padded to 64 bit alignment.
 186 */
 187typedef struct xfs_dsb {
 188        __be32          sb_magicnum;    /* magic number == XFS_SB_MAGIC */
 189        __be32          sb_blocksize;   /* logical block size, bytes */
 190        __be64          sb_dblocks;     /* number of data blocks */
 191        __be64          sb_rblocks;     /* number of realtime blocks */
 192        __be64          sb_rextents;    /* number of realtime extents */
 193        uuid_t          sb_uuid;        /* user-visible file system unique id */
 194        __be64          sb_logstart;    /* starting block of log if internal */
 195        __be64          sb_rootino;     /* root inode number */
 196        __be64          sb_rbmino;      /* bitmap inode for realtime extents */
 197        __be64          sb_rsumino;     /* summary inode for rt bitmap */
 198        __be32          sb_rextsize;    /* realtime extent size, blocks */
 199        __be32          sb_agblocks;    /* size of an allocation group */
 200        __be32          sb_agcount;     /* number of allocation groups */
 201        __be32          sb_rbmblocks;   /* number of rt bitmap blocks */
 202        __be32          sb_logblocks;   /* number of log blocks */
 203        __be16          sb_versionnum;  /* header version == XFS_SB_VERSION */
 204        __be16          sb_sectsize;    /* volume sector size, bytes */
 205        __be16          sb_inodesize;   /* inode size, bytes */
 206        __be16          sb_inopblock;   /* inodes per block */
 207        char            sb_fname[XFSLABEL_MAX]; /* file system name */
 208        __u8            sb_blocklog;    /* log2 of sb_blocksize */
 209        __u8            sb_sectlog;     /* log2 of sb_sectsize */
 210        __u8            sb_inodelog;    /* log2 of sb_inodesize */
 211        __u8            sb_inopblog;    /* log2 of sb_inopblock */
 212        __u8            sb_agblklog;    /* log2 of sb_agblocks (rounded up) */
 213        __u8            sb_rextslog;    /* log2 of sb_rextents */
 214        __u8            sb_inprogress;  /* mkfs is in progress, don't mount */
 215        __u8            sb_imax_pct;    /* max % of fs for inode space */
 216                                        /* statistics */
 217        /*
 218         * These fields must remain contiguous.  If you really
 219         * want to change their layout, make sure you fix the
 220         * code in xfs_trans_apply_sb_deltas().
 221         */
 222        __be64          sb_icount;      /* allocated inodes */
 223        __be64          sb_ifree;       /* free inodes */
 224        __be64          sb_fdblocks;    /* free data blocks */
 225        __be64          sb_frextents;   /* free realtime extents */
 226        /*
 227         * End contiguous fields.
 228         */
 229        __be64          sb_uquotino;    /* user quota inode */
 230        __be64          sb_gquotino;    /* group quota inode */
 231        __be16          sb_qflags;      /* quota flags */
 232        __u8            sb_flags;       /* misc. flags */
 233        __u8            sb_shared_vn;   /* shared version number */
 234        __be32          sb_inoalignmt;  /* inode chunk alignment, fsblocks */
 235        __be32          sb_unit;        /* stripe or raid unit */
 236        __be32          sb_width;       /* stripe or raid width */
 237        __u8            sb_dirblklog;   /* log2 of dir block size (fsbs) */
 238        __u8            sb_logsectlog;  /* log2 of the log sector size */
 239        __be16          sb_logsectsize; /* sector size for the log, bytes */
 240        __be32          sb_logsunit;    /* stripe unit size for the log */
 241        __be32          sb_features2;   /* additional feature bits */
 242        /*
 243         * bad features2 field as a result of failing to pad the sb
 244         * structure to 64 bits. Some machines will be using this field
 245         * for features2 bits. Easiest just to mark it bad and not use
 246         * it for anything else.
 247         */
 248        __be32          sb_bad_features2;
 249
 250        /* version 5 superblock fields start here */
 251
 252        /* feature masks */
 253        __be32          sb_features_compat;
 254        __be32          sb_features_ro_compat;
 255        __be32          sb_features_incompat;
 256        __be32          sb_features_log_incompat;
 257
 258        __le32          sb_crc;         /* superblock crc */
 259        __be32          sb_spino_align; /* sparse inode chunk alignment */
 260
 261        __be64          sb_pquotino;    /* project quota inode */
 262        __be64          sb_lsn;         /* last write sequence */
 263        uuid_t          sb_meta_uuid;   /* metadata file system unique id */
 264
 265        /* must be padded to 64 bit alignment */
 266} xfs_dsb_t;
 267
 268
 269/*
 270 * Misc. Flags - warning - these will be cleared by xfs_repair unless
 271 * a feature bit is set when the flag is used.
 272 */
 273#define XFS_SBF_NOFLAGS         0x00    /* no flags set */
 274#define XFS_SBF_READONLY        0x01    /* only read-only mounts allowed */
 275
 276/*
 277 * define max. shared version we can interoperate with
 278 */
 279#define XFS_SB_MAX_SHARED_VN    0
 280
 281#define XFS_SB_VERSION_NUM(sbp) ((sbp)->sb_versionnum & XFS_SB_VERSION_NUMBITS)
 282
 283/*
 284 * The first XFS version we support is a v4 superblock with V2 directories.
 285 */
 286static inline bool xfs_sb_good_v4_features(struct xfs_sb *sbp)
 287{
 288        if (!(sbp->sb_versionnum & XFS_SB_VERSION_DIRV2BIT))
 289                return false;
 290        if (!(sbp->sb_versionnum & XFS_SB_VERSION_EXTFLGBIT))
 291                return false;
 292
 293        /* check for unknown features in the fs */
 294        if ((sbp->sb_versionnum & ~XFS_SB_VERSION_OKBITS) ||
 295            ((sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT) &&
 296             (sbp->sb_features2 & ~XFS_SB_VERSION2_OKBITS)))
 297                return false;
 298
 299        return true;
 300}
 301
 302static inline bool xfs_sb_good_version(struct xfs_sb *sbp)
 303{
 304        if (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5)
 305                return true;
 306        if (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4)
 307                return xfs_sb_good_v4_features(sbp);
 308        return false;
 309}
 310
 311static inline bool xfs_sb_version_hasrealtime(struct xfs_sb *sbp)
 312{
 313        return sbp->sb_rblocks > 0;
 314}
 315
 316/*
 317 * Detect a mismatched features2 field.  Older kernels read/wrote
 318 * this into the wrong slot, so to be safe we keep them in sync.
 319 */
 320static inline bool xfs_sb_has_mismatched_features2(struct xfs_sb *sbp)
 321{
 322        return sbp->sb_bad_features2 != sbp->sb_features2;
 323}
 324
 325static inline bool xfs_sb_version_hasattr(struct xfs_sb *sbp)
 326{
 327        return (sbp->sb_versionnum & XFS_SB_VERSION_ATTRBIT);
 328}
 329
 330static inline void xfs_sb_version_addattr(struct xfs_sb *sbp)
 331{
 332        sbp->sb_versionnum |= XFS_SB_VERSION_ATTRBIT;
 333}
 334
 335static inline bool xfs_sb_version_hasquota(struct xfs_sb *sbp)
 336{
 337        return (sbp->sb_versionnum & XFS_SB_VERSION_QUOTABIT);
 338}
 339
 340static inline void xfs_sb_version_addquota(struct xfs_sb *sbp)
 341{
 342        sbp->sb_versionnum |= XFS_SB_VERSION_QUOTABIT;
 343}
 344
 345static inline bool xfs_sb_version_hasalign(struct xfs_sb *sbp)
 346{
 347        return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5 ||
 348                (sbp->sb_versionnum & XFS_SB_VERSION_ALIGNBIT));
 349}
 350
 351static inline bool xfs_sb_version_hasdalign(struct xfs_sb *sbp)
 352{
 353        return (sbp->sb_versionnum & XFS_SB_VERSION_DALIGNBIT);
 354}
 355
 356static inline bool xfs_sb_version_haslogv2(struct xfs_sb *sbp)
 357{
 358        return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5 ||
 359               (sbp->sb_versionnum & XFS_SB_VERSION_LOGV2BIT);
 360}
 361
 362static inline bool xfs_sb_version_hassector(struct xfs_sb *sbp)
 363{
 364        return (sbp->sb_versionnum & XFS_SB_VERSION_SECTORBIT);
 365}
 366
 367static inline bool xfs_sb_version_hasasciici(struct xfs_sb *sbp)
 368{
 369        return (sbp->sb_versionnum & XFS_SB_VERSION_BORGBIT);
 370}
 371
 372static inline bool xfs_sb_version_hasmorebits(struct xfs_sb *sbp)
 373{
 374        return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5 ||
 375               (sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT);
 376}
 377
 378/*
 379 * sb_features2 bit version macros.
 380 */
 381static inline bool xfs_sb_version_haslazysbcount(struct xfs_sb *sbp)
 382{
 383        return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) ||
 384               (xfs_sb_version_hasmorebits(sbp) &&
 385                (sbp->sb_features2 & XFS_SB_VERSION2_LAZYSBCOUNTBIT));
 386}
 387
 388static inline bool xfs_sb_version_hasattr2(struct xfs_sb *sbp)
 389{
 390        return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) ||
 391               (xfs_sb_version_hasmorebits(sbp) &&
 392                (sbp->sb_features2 & XFS_SB_VERSION2_ATTR2BIT));
 393}
 394
 395static inline void xfs_sb_version_addattr2(struct xfs_sb *sbp)
 396{
 397        sbp->sb_versionnum |= XFS_SB_VERSION_MOREBITSBIT;
 398        sbp->sb_features2 |= XFS_SB_VERSION2_ATTR2BIT;
 399}
 400
 401static inline void xfs_sb_version_removeattr2(struct xfs_sb *sbp)
 402{
 403        sbp->sb_features2 &= ~XFS_SB_VERSION2_ATTR2BIT;
 404        if (!sbp->sb_features2)
 405                sbp->sb_versionnum &= ~XFS_SB_VERSION_MOREBITSBIT;
 406}
 407
 408static inline bool xfs_sb_version_hasprojid32bit(struct xfs_sb *sbp)
 409{
 410        return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) ||
 411               (xfs_sb_version_hasmorebits(sbp) &&
 412                (sbp->sb_features2 & XFS_SB_VERSION2_PROJID32BIT));
 413}
 414
 415static inline void xfs_sb_version_addprojid32bit(struct xfs_sb *sbp)
 416{
 417        sbp->sb_versionnum |= XFS_SB_VERSION_MOREBITSBIT;
 418        sbp->sb_features2 |= XFS_SB_VERSION2_PROJID32BIT;
 419}
 420
 421/*
 422 * Extended v5 superblock feature masks. These are to be used for new v5
 423 * superblock features only.
 424 *
 425 * Compat features are new features that old kernels will not notice or affect
 426 * and so can mount read-write without issues.
 427 *
 428 * RO-Compat (read only) are features that old kernels can read but will break
 429 * if they write. Hence only read-only mounts of such filesystems are allowed on
 430 * kernels that don't support the feature bit.
 431 *
 432 * InCompat features are features which old kernels will not understand and so
 433 * must not mount.
 434 *
 435 * Log-InCompat features are for changes to log formats or new transactions that
 436 * can't be replayed on older kernels. The fields are set when the filesystem is
 437 * mounted, and a clean unmount clears the fields.
 438 */
 439#define XFS_SB_FEAT_COMPAT_ALL 0
 440#define XFS_SB_FEAT_COMPAT_UNKNOWN      ~XFS_SB_FEAT_COMPAT_ALL
 441static inline bool
 442xfs_sb_has_compat_feature(
 443        struct xfs_sb   *sbp,
 444        uint32_t        feature)
 445{
 446        return (sbp->sb_features_compat & feature) != 0;
 447}
 448
 449#define XFS_SB_FEAT_RO_COMPAT_FINOBT   (1 << 0)         /* free inode btree */
 450#define XFS_SB_FEAT_RO_COMPAT_RMAPBT   (1 << 1)         /* reverse map btree */
 451#define XFS_SB_FEAT_RO_COMPAT_REFLINK  (1 << 2)         /* reflinked files */
 452#define XFS_SB_FEAT_RO_COMPAT_INOBTCNT (1 << 3)         /* inobt block counts */
 453#define XFS_SB_FEAT_RO_COMPAT_ALL \
 454                (XFS_SB_FEAT_RO_COMPAT_FINOBT | \
 455                 XFS_SB_FEAT_RO_COMPAT_RMAPBT | \
 456                 XFS_SB_FEAT_RO_COMPAT_REFLINK)
 457#define XFS_SB_FEAT_RO_COMPAT_UNKNOWN   ~XFS_SB_FEAT_RO_COMPAT_ALL
 458static inline bool
 459xfs_sb_has_ro_compat_feature(
 460        struct xfs_sb   *sbp,
 461        uint32_t        feature)
 462{
 463        return (sbp->sb_features_ro_compat & feature) != 0;
 464}
 465
 466#define XFS_SB_FEAT_INCOMPAT_FTYPE      (1 << 0)        /* filetype in dirent */
 467#define XFS_SB_FEAT_INCOMPAT_SPINODES   (1 << 1)        /* sparse inode chunks */
 468#define XFS_SB_FEAT_INCOMPAT_META_UUID  (1 << 2)        /* metadata UUID */
 469#define XFS_SB_FEAT_INCOMPAT_BIGTIME    (1 << 3)        /* large timestamps */
 470#define XFS_SB_FEAT_INCOMPAT_ALL \
 471                (XFS_SB_FEAT_INCOMPAT_FTYPE|    \
 472                 XFS_SB_FEAT_INCOMPAT_SPINODES| \
 473                 XFS_SB_FEAT_INCOMPAT_META_UUID)
 474
 475#define XFS_SB_FEAT_INCOMPAT_UNKNOWN    ~XFS_SB_FEAT_INCOMPAT_ALL
 476static inline bool
 477xfs_sb_has_incompat_feature(
 478        struct xfs_sb   *sbp,
 479        uint32_t        feature)
 480{
 481        return (sbp->sb_features_incompat & feature) != 0;
 482}
 483
 484#define XFS_SB_FEAT_INCOMPAT_LOG_ALL 0
 485#define XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN        ~XFS_SB_FEAT_INCOMPAT_LOG_ALL
 486static inline bool
 487xfs_sb_has_incompat_log_feature(
 488        struct xfs_sb   *sbp,
 489        uint32_t        feature)
 490{
 491        return (sbp->sb_features_log_incompat & feature) != 0;
 492}
 493
 494/*
 495 * V5 superblock specific feature checks
 496 */
 497static inline bool xfs_sb_version_hascrc(struct xfs_sb *sbp)
 498{
 499        return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5;
 500}
 501
 502/*
 503 * v5 file systems support V3 inodes only, earlier file systems support
 504 * v2 and v1 inodes.
 505 */
 506static inline bool xfs_sb_version_has_v3inode(struct xfs_sb *sbp)
 507{
 508        return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5;
 509}
 510
 511static inline bool xfs_dinode_good_version(struct xfs_sb *sbp,
 512                uint8_t version)
 513{
 514        if (xfs_sb_version_has_v3inode(sbp))
 515                return version == 3;
 516        return version == 1 || version == 2;
 517}
 518
 519static inline bool xfs_sb_version_has_pquotino(struct xfs_sb *sbp)
 520{
 521        return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5;
 522}
 523
 524static inline int xfs_sb_version_hasftype(struct xfs_sb *sbp)
 525{
 526        return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5 &&
 527                xfs_sb_has_incompat_feature(sbp, XFS_SB_FEAT_INCOMPAT_FTYPE)) ||
 528               (xfs_sb_version_hasmorebits(sbp) &&
 529                 (sbp->sb_features2 & XFS_SB_VERSION2_FTYPE));
 530}
 531
 532static inline bool xfs_sb_version_hasfinobt(xfs_sb_t *sbp)
 533{
 534        return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) &&
 535                (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_FINOBT);
 536}
 537
 538static inline bool xfs_sb_version_hassparseinodes(struct xfs_sb *sbp)
 539{
 540        return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5 &&
 541                xfs_sb_has_incompat_feature(sbp, XFS_SB_FEAT_INCOMPAT_SPINODES);
 542}
 543
 544/*
 545 * XFS_SB_FEAT_INCOMPAT_META_UUID indicates that the metadata UUID
 546 * is stored separately from the user-visible UUID; this allows the
 547 * user-visible UUID to be changed on V5 filesystems which have a
 548 * filesystem UUID stamped into every piece of metadata.
 549 */
 550static inline bool xfs_sb_version_hasmetauuid(struct xfs_sb *sbp)
 551{
 552        return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) &&
 553                (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_META_UUID);
 554}
 555
 556static inline bool xfs_sb_version_hasrmapbt(struct xfs_sb *sbp)
 557{
 558        return (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5) &&
 559                (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_RMAPBT);
 560}
 561
 562static inline bool xfs_sb_version_hasreflink(struct xfs_sb *sbp)
 563{
 564        return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5 &&
 565                (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_REFLINK);
 566}
 567
 568static inline bool xfs_sb_version_hasbigtime(struct xfs_sb *sbp)
 569{
 570        return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5 &&
 571                (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_BIGTIME);
 572}
 573
 574/*
 575 * Inode btree block counter.  We record the number of inobt and finobt blocks
 576 * in the AGI header so that we can skip the finobt walk at mount time when
 577 * setting up per-AG reservations.
 578 */
 579static inline bool xfs_sb_version_hasinobtcounts(struct xfs_sb *sbp)
 580{
 581        return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5 &&
 582                (sbp->sb_features_ro_compat & XFS_SB_FEAT_RO_COMPAT_INOBTCNT);
 583}
 584
 585/*
 586 * end of superblock version macros
 587 */
 588
 589static inline bool
 590xfs_is_quota_inode(struct xfs_sb *sbp, xfs_ino_t ino)
 591{
 592        return (ino == sbp->sb_uquotino ||
 593                ino == sbp->sb_gquotino ||
 594                ino == sbp->sb_pquotino);
 595}
 596
 597#define XFS_SB_DADDR            ((xfs_daddr_t)0) /* daddr in filesystem/ag */
 598#define XFS_SB_BLOCK(mp)        XFS_HDR_BLOCK(mp, XFS_SB_DADDR)
 599
 600#define XFS_HDR_BLOCK(mp,d)     ((xfs_agblock_t)XFS_BB_TO_FSBT(mp,d))
 601#define XFS_DADDR_TO_FSB(mp,d)  XFS_AGB_TO_FSB(mp, \
 602                        xfs_daddr_to_agno(mp,d), xfs_daddr_to_agbno(mp,d))
 603#define XFS_FSB_TO_DADDR(mp,fsbno)      XFS_AGB_TO_DADDR(mp, \
 604                        XFS_FSB_TO_AGNO(mp,fsbno), XFS_FSB_TO_AGBNO(mp,fsbno))
 605
 606/*
 607 * File system sector to basic block conversions.
 608 */
 609#define XFS_FSS_TO_BB(mp,sec)   ((sec) << (mp)->m_sectbb_log)
 610
 611/*
 612 * File system block to basic block conversions.
 613 */
 614#define XFS_FSB_TO_BB(mp,fsbno) ((fsbno) << (mp)->m_blkbb_log)
 615#define XFS_BB_TO_FSB(mp,bb)    \
 616        (((bb) + (XFS_FSB_TO_BB(mp,1) - 1)) >> (mp)->m_blkbb_log)
 617#define XFS_BB_TO_FSBT(mp,bb)   ((bb) >> (mp)->m_blkbb_log)
 618
 619/*
 620 * File system block to byte conversions.
 621 */
 622#define XFS_FSB_TO_B(mp,fsbno)  ((xfs_fsize_t)(fsbno) << (mp)->m_sb.sb_blocklog)
 623#define XFS_B_TO_FSB(mp,b)      \
 624        ((((uint64_t)(b)) + (mp)->m_blockmask) >> (mp)->m_sb.sb_blocklog)
 625#define XFS_B_TO_FSBT(mp,b)     (((uint64_t)(b)) >> (mp)->m_sb.sb_blocklog)
 626#define XFS_B_FSB_OFFSET(mp,b)  ((b) & (mp)->m_blockmask)
 627
 628/*
 629 * Allocation group header
 630 *
 631 * This is divided into three structures, placed in sequential 512-byte
 632 * buffers after a copy of the superblock (also in a 512-byte buffer).
 633 */
 634#define XFS_AGF_MAGIC   0x58414746      /* 'XAGF' */
 635#define XFS_AGI_MAGIC   0x58414749      /* 'XAGI' */
 636#define XFS_AGFL_MAGIC  0x5841464c      /* 'XAFL' */
 637#define XFS_AGF_VERSION 1
 638#define XFS_AGI_VERSION 1
 639
 640#define XFS_AGF_GOOD_VERSION(v) ((v) == XFS_AGF_VERSION)
 641#define XFS_AGI_GOOD_VERSION(v) ((v) == XFS_AGI_VERSION)
 642
 643/*
 644 * Btree number 0 is bno, 1 is cnt, 2 is rmap. This value gives the size of the
 645 * arrays below.
 646 */
 647#define XFS_BTNUM_AGF   ((int)XFS_BTNUM_RMAPi + 1)
 648
 649/*
 650 * The second word of agf_levels in the first a.g. overlaps the EFS
 651 * superblock's magic number.  Since the magic numbers valid for EFS
 652 * are > 64k, our value cannot be confused for an EFS superblock's.
 653 */
 654
 655typedef struct xfs_agf {
 656        /*
 657         * Common allocation group header information
 658         */
 659        __be32          agf_magicnum;   /* magic number == XFS_AGF_MAGIC */
 660        __be32          agf_versionnum; /* header version == XFS_AGF_VERSION */
 661        __be32          agf_seqno;      /* sequence # starting from 0 */
 662        __be32          agf_length;     /* size in blocks of a.g. */
 663        /*
 664         * Freespace and rmap information
 665         */
 666        __be32          agf_roots[XFS_BTNUM_AGF];       /* root blocks */
 667        __be32          agf_levels[XFS_BTNUM_AGF];      /* btree levels */
 668
 669        __be32          agf_flfirst;    /* first freelist block's index */
 670        __be32          agf_fllast;     /* last freelist block's index */
 671        __be32          agf_flcount;    /* count of blocks in freelist */
 672        __be32          agf_freeblks;   /* total free blocks */
 673
 674        __be32          agf_longest;    /* longest free space */
 675        __be32          agf_btreeblks;  /* # of blocks held in AGF btrees */
 676        uuid_t          agf_uuid;       /* uuid of filesystem */
 677
 678        __be32          agf_rmap_blocks;        /* rmapbt blocks used */
 679        __be32          agf_refcount_blocks;    /* refcountbt blocks used */
 680
 681        __be32          agf_refcount_root;      /* refcount tree root block */
 682        __be32          agf_refcount_level;     /* refcount btree levels */
 683
 684        /*
 685         * reserve some contiguous space for future logged fields before we add
 686         * the unlogged fields. This makes the range logging via flags and
 687         * structure offsets much simpler.
 688         */
 689        __be64          agf_spare64[14];
 690
 691        /* unlogged fields, written during buffer writeback. */
 692        __be64          agf_lsn;        /* last write sequence */
 693        __be32          agf_crc;        /* crc of agf sector */
 694        __be32          agf_spare2;
 695
 696        /* structure must be padded to 64 bit alignment */
 697} xfs_agf_t;
 698
 699#define XFS_AGF_CRC_OFF         offsetof(struct xfs_agf, agf_crc)
 700
 701#define XFS_AGF_MAGICNUM        0x00000001
 702#define XFS_AGF_VERSIONNUM      0x00000002
 703#define XFS_AGF_SEQNO           0x00000004
 704#define XFS_AGF_LENGTH          0x00000008
 705#define XFS_AGF_ROOTS           0x00000010
 706#define XFS_AGF_LEVELS          0x00000020
 707#define XFS_AGF_FLFIRST         0x00000040
 708#define XFS_AGF_FLLAST          0x00000080
 709#define XFS_AGF_FLCOUNT         0x00000100
 710#define XFS_AGF_FREEBLKS        0x00000200
 711#define XFS_AGF_LONGEST         0x00000400
 712#define XFS_AGF_BTREEBLKS       0x00000800
 713#define XFS_AGF_UUID            0x00001000
 714#define XFS_AGF_RMAP_BLOCKS     0x00002000
 715#define XFS_AGF_REFCOUNT_BLOCKS 0x00004000
 716#define XFS_AGF_REFCOUNT_ROOT   0x00008000
 717#define XFS_AGF_REFCOUNT_LEVEL  0x00010000
 718#define XFS_AGF_SPARE64         0x00020000
 719#define XFS_AGF_NUM_BITS        18
 720#define XFS_AGF_ALL_BITS        ((1 << XFS_AGF_NUM_BITS) - 1)
 721
 722#define XFS_AGF_FLAGS \
 723        { XFS_AGF_MAGICNUM,     "MAGICNUM" }, \
 724        { XFS_AGF_VERSIONNUM,   "VERSIONNUM" }, \
 725        { XFS_AGF_SEQNO,        "SEQNO" }, \
 726        { XFS_AGF_LENGTH,       "LENGTH" }, \
 727        { XFS_AGF_ROOTS,        "ROOTS" }, \
 728        { XFS_AGF_LEVELS,       "LEVELS" }, \
 729        { XFS_AGF_FLFIRST,      "FLFIRST" }, \
 730        { XFS_AGF_FLLAST,       "FLLAST" }, \
 731        { XFS_AGF_FLCOUNT,      "FLCOUNT" }, \
 732        { XFS_AGF_FREEBLKS,     "FREEBLKS" }, \
 733        { XFS_AGF_LONGEST,      "LONGEST" }, \
 734        { XFS_AGF_BTREEBLKS,    "BTREEBLKS" }, \
 735        { XFS_AGF_UUID,         "UUID" }, \
 736        { XFS_AGF_RMAP_BLOCKS,  "RMAP_BLOCKS" }, \
 737        { XFS_AGF_REFCOUNT_BLOCKS,      "REFCOUNT_BLOCKS" }, \
 738        { XFS_AGF_REFCOUNT_ROOT,        "REFCOUNT_ROOT" }, \
 739        { XFS_AGF_REFCOUNT_LEVEL,       "REFCOUNT_LEVEL" }, \
 740        { XFS_AGF_SPARE64,      "SPARE64" }
 741
 742/* disk block (xfs_daddr_t) in the AG */
 743#define XFS_AGF_DADDR(mp)       ((xfs_daddr_t)(1 << (mp)->m_sectbb_log))
 744#define XFS_AGF_BLOCK(mp)       XFS_HDR_BLOCK(mp, XFS_AGF_DADDR(mp))
 745
 746/*
 747 * Size of the unlinked inode hash table in the agi.
 748 */
 749#define XFS_AGI_UNLINKED_BUCKETS        64
 750
 751typedef struct xfs_agi {
 752        /*
 753         * Common allocation group header information
 754         */
 755        __be32          agi_magicnum;   /* magic number == XFS_AGI_MAGIC */
 756        __be32          agi_versionnum; /* header version == XFS_AGI_VERSION */
 757        __be32          agi_seqno;      /* sequence # starting from 0 */
 758        __be32          agi_length;     /* size in blocks of a.g. */
 759        /*
 760         * Inode information
 761         * Inodes are mapped by interpreting the inode number, so no
 762         * mapping data is needed here.
 763         */
 764        __be32          agi_count;      /* count of allocated inodes */
 765        __be32          agi_root;       /* root of inode btree */
 766        __be32          agi_level;      /* levels in inode btree */
 767        __be32          agi_freecount;  /* number of free inodes */
 768
 769        __be32          agi_newino;     /* new inode just allocated */
 770        __be32          agi_dirino;     /* last directory inode chunk */
 771        /*
 772         * Hash table of inodes which have been unlinked but are
 773         * still being referenced.
 774         */
 775        __be32          agi_unlinked[XFS_AGI_UNLINKED_BUCKETS];
 776        /*
 777         * This marks the end of logging region 1 and start of logging region 2.
 778         */
 779        uuid_t          agi_uuid;       /* uuid of filesystem */
 780        __be32          agi_crc;        /* crc of agi sector */
 781        __be32          agi_pad32;
 782        __be64          agi_lsn;        /* last write sequence */
 783
 784        __be32          agi_free_root; /* root of the free inode btree */
 785        __be32          agi_free_level;/* levels in free inode btree */
 786
 787        __be32          agi_iblocks;    /* inobt blocks used */
 788        __be32          agi_fblocks;    /* finobt blocks used */
 789
 790        /* structure must be padded to 64 bit alignment */
 791} xfs_agi_t;
 792
 793#define XFS_AGI_CRC_OFF         offsetof(struct xfs_agi, agi_crc)
 794
 795#define XFS_AGI_MAGICNUM        (1 << 0)
 796#define XFS_AGI_VERSIONNUM      (1 << 1)
 797#define XFS_AGI_SEQNO           (1 << 2)
 798#define XFS_AGI_LENGTH          (1 << 3)
 799#define XFS_AGI_COUNT           (1 << 4)
 800#define XFS_AGI_ROOT            (1 << 5)
 801#define XFS_AGI_LEVEL           (1 << 6)
 802#define XFS_AGI_FREECOUNT       (1 << 7)
 803#define XFS_AGI_NEWINO          (1 << 8)
 804#define XFS_AGI_DIRINO          (1 << 9)
 805#define XFS_AGI_UNLINKED        (1 << 10)
 806#define XFS_AGI_NUM_BITS_R1     11      /* end of the 1st agi logging region */
 807#define XFS_AGI_ALL_BITS_R1     ((1 << XFS_AGI_NUM_BITS_R1) - 1)
 808#define XFS_AGI_FREE_ROOT       (1 << 11)
 809#define XFS_AGI_FREE_LEVEL      (1 << 12)
 810#define XFS_AGI_IBLOCKS         (1 << 13) /* both inobt/finobt block counters */
 811#define XFS_AGI_NUM_BITS_R2     14
 812
 813/* disk block (xfs_daddr_t) in the AG */
 814#define XFS_AGI_DADDR(mp)       ((xfs_daddr_t)(2 << (mp)->m_sectbb_log))
 815#define XFS_AGI_BLOCK(mp)       XFS_HDR_BLOCK(mp, XFS_AGI_DADDR(mp))
 816
 817/*
 818 * The third a.g. block contains the a.g. freelist, an array
 819 * of block pointers to blocks owned by the allocation btree code.
 820 */
 821#define XFS_AGFL_DADDR(mp)      ((xfs_daddr_t)(3 << (mp)->m_sectbb_log))
 822#define XFS_AGFL_BLOCK(mp)      XFS_HDR_BLOCK(mp, XFS_AGFL_DADDR(mp))
 823#define XFS_BUF_TO_AGFL(bp)     ((struct xfs_agfl *)((bp)->b_addr))
 824
 825struct xfs_agfl {
 826        __be32          agfl_magicnum;
 827        __be32          agfl_seqno;
 828        uuid_t          agfl_uuid;
 829        __be64          agfl_lsn;
 830        __be32          agfl_crc;
 831} __attribute__((packed));
 832
 833#define XFS_AGFL_CRC_OFF        offsetof(struct xfs_agfl, agfl_crc)
 834
 835#define XFS_AGB_TO_FSB(mp,agno,agbno)   \
 836        (((xfs_fsblock_t)(agno) << (mp)->m_sb.sb_agblklog) | (agbno))
 837#define XFS_FSB_TO_AGNO(mp,fsbno)       \
 838        ((xfs_agnumber_t)((fsbno) >> (mp)->m_sb.sb_agblklog))
 839#define XFS_FSB_TO_AGBNO(mp,fsbno)      \
 840        ((xfs_agblock_t)((fsbno) & xfs_mask32lo((mp)->m_sb.sb_agblklog)))
 841#define XFS_AGB_TO_DADDR(mp,agno,agbno) \
 842        ((xfs_daddr_t)XFS_FSB_TO_BB(mp, \
 843                (xfs_fsblock_t)(agno) * (mp)->m_sb.sb_agblocks + (agbno)))
 844#define XFS_AG_DADDR(mp,agno,d)         (XFS_AGB_TO_DADDR(mp, agno, 0) + (d))
 845
 846/*
 847 * For checking for bad ranges of xfs_daddr_t's, covering multiple
 848 * allocation groups or a single xfs_daddr_t that's a superblock copy.
 849 */
 850#define XFS_AG_CHECK_DADDR(mp,d,len)    \
 851        ((len) == 1 ? \
 852            ASSERT((d) == XFS_SB_DADDR || \
 853                   xfs_daddr_to_agbno(mp, d) != XFS_SB_DADDR) : \
 854            ASSERT(xfs_daddr_to_agno(mp, d) == \
 855                   xfs_daddr_to_agno(mp, (d) + (len) - 1)))
 856
 857/*
 858 * XFS Timestamps
 859 * ==============
 860 *
 861 * Traditional ondisk inode timestamps consist of signed 32-bit counters for
 862 * seconds and nanoseconds; time zero is the Unix epoch, Jan  1 00:00:00 UTC
 863 * 1970, which means that the timestamp epoch is the same as the Unix epoch.
 864 * Therefore, the ondisk min and max defined here can be used directly to
 865 * constrain the incore timestamps on a Unix system.  Note that we actually
 866 * encode a __be64 value on disk.
 867 *
 868 * When the bigtime feature is enabled, ondisk inode timestamps become an
 869 * unsigned 64-bit nanoseconds counter.  This means that the bigtime inode
 870 * timestamp epoch is the start of the classic timestamp range, which is
 871 * Dec 31 20:45:52 UTC 1901.  Because the epochs are not the same, callers
 872 * /must/ use the bigtime conversion functions when encoding and decoding raw
 873 * timestamps.
 874 */
 875typedef __be64 xfs_timestamp_t;
 876
 877/* Legacy timestamp encoding format. */
 878struct xfs_legacy_timestamp {
 879        __be32          t_sec;          /* timestamp seconds */
 880        __be32          t_nsec;         /* timestamp nanoseconds */
 881};
 882
 883/*
 884 * Smallest possible ondisk seconds value with traditional timestamps.  This
 885 * corresponds exactly with the incore timestamp Dec 13 20:45:52 UTC 1901.
 886 */
 887#define XFS_LEGACY_TIME_MIN     ((int64_t)S32_MIN)
 888
 889/*
 890 * Largest possible ondisk seconds value with traditional timestamps.  This
 891 * corresponds exactly with the incore timestamp Jan 19 03:14:07 UTC 2038.
 892 */
 893#define XFS_LEGACY_TIME_MAX     ((int64_t)S32_MAX)
 894
 895/*
 896 * Smallest possible ondisk seconds value with bigtime timestamps.  This
 897 * corresponds (after conversion to a Unix timestamp) with the traditional
 898 * minimum timestamp of Dec 13 20:45:52 UTC 1901.
 899 */
 900#define XFS_BIGTIME_TIME_MIN    ((int64_t)0)
 901
 902/*
 903 * Largest supported ondisk seconds value with bigtime timestamps.  This
 904 * corresponds (after conversion to a Unix timestamp) with an incore timestamp
 905 * of Jul  2 20:20:24 UTC 2486.
 906 *
 907 * We round down the ondisk limit so that the bigtime quota and inode max
 908 * timestamps will be the same.
 909 */
 910#define XFS_BIGTIME_TIME_MAX    ((int64_t)((-1ULL / NSEC_PER_SEC) & ~0x3ULL))
 911
 912/*
 913 * Bigtime epoch is set exactly to the minimum time value that a traditional
 914 * 32-bit timestamp can represent when using the Unix epoch as a reference.
 915 * Hence the Unix epoch is at a fixed offset into the supported bigtime
 916 * timestamp range.
 917 *
 918 * The bigtime epoch also matches the minimum value an on-disk 32-bit XFS
 919 * timestamp can represent so we will not lose any fidelity in converting
 920 * to/from unix and bigtime timestamps.
 921 *
 922 * The following conversion factor converts a seconds counter from the Unix
 923 * epoch to the bigtime epoch.
 924 */
 925#define XFS_BIGTIME_EPOCH_OFFSET        (-(int64_t)S32_MIN)
 926
 927/* Convert a timestamp from the Unix epoch to the bigtime epoch. */
 928static inline uint64_t xfs_unix_to_bigtime(time64_t unix_seconds)
 929{
 930        return (uint64_t)unix_seconds + XFS_BIGTIME_EPOCH_OFFSET;
 931}
 932
 933/* Convert a timestamp from the bigtime epoch to the Unix epoch. */
 934static inline time64_t xfs_bigtime_to_unix(uint64_t ondisk_seconds)
 935{
 936        return (time64_t)ondisk_seconds - XFS_BIGTIME_EPOCH_OFFSET;
 937}
 938
 939/*
 940 * On-disk inode structure.
 941 *
 942 * This is just the header or "dinode core", the inode is expanded to fill a
 943 * variable size the leftover area split into a data and an attribute fork.
 944 * The format of the data and attribute fork depends on the format of the
 945 * inode as indicated by di_format and di_aformat.  To access the data and
 946 * attribute use the XFS_DFORK_DPTR, XFS_DFORK_APTR, and XFS_DFORK_PTR macros
 947 * below.
 948 *
 949 * There is a very similar struct icdinode in xfs_inode which matches the
 950 * layout of the first 96 bytes of this structure, but is kept in native
 951 * format instead of big endian.
 952 *
 953 * Note: di_flushiter is only used by v1/2 inodes - it's effectively a zeroed
 954 * padding field for v3 inodes.
 955 */
 956#define XFS_DINODE_MAGIC                0x494e  /* 'IN' */
 957typedef struct xfs_dinode {
 958        __be16          di_magic;       /* inode magic # = XFS_DINODE_MAGIC */
 959        __be16          di_mode;        /* mode and type of file */
 960        __u8            di_version;     /* inode version */
 961        __u8            di_format;      /* format of di_c data */
 962        __be16          di_onlink;      /* old number of links to file */
 963        __be32          di_uid;         /* owner's user id */
 964        __be32          di_gid;         /* owner's group id */
 965        __be32          di_nlink;       /* number of links to file */
 966        __be16          di_projid_lo;   /* lower part of owner's project id */
 967        __be16          di_projid_hi;   /* higher part owner's project id */
 968        __u8            di_pad[6];      /* unused, zeroed space */
 969        __be16          di_flushiter;   /* incremented on flush */
 970        xfs_timestamp_t di_atime;       /* time last accessed */
 971        xfs_timestamp_t di_mtime;       /* time last modified */
 972        xfs_timestamp_t di_ctime;       /* time created/inode modified */
 973        __be64          di_size;        /* number of bytes in file */
 974        __be64          di_nblocks;     /* # of direct & btree blocks used */
 975        __be32          di_extsize;     /* basic/minimum extent size for file */
 976        __be32          di_nextents;    /* number of extents in data fork */
 977        __be16          di_anextents;   /* number of extents in attribute fork*/
 978        __u8            di_forkoff;     /* attr fork offs, <<3 for 64b align */
 979        __s8            di_aformat;     /* format of attr fork's data */
 980        __be32          di_dmevmask;    /* DMIG event mask */
 981        __be16          di_dmstate;     /* DMIG state info */
 982        __be16          di_flags;       /* random flags, XFS_DIFLAG_... */
 983        __be32          di_gen;         /* generation number */
 984
 985        /* di_next_unlinked is the only non-core field in the old dinode */
 986        __be32          di_next_unlinked;/* agi unlinked list ptr */
 987
 988        /* start of the extended dinode, writable fields */
 989        __le32          di_crc;         /* CRC of the inode */
 990        __be64          di_changecount; /* number of attribute changes */
 991        __be64          di_lsn;         /* flush sequence */
 992        __be64          di_flags2;      /* more random flags */
 993        __be32          di_cowextsize;  /* basic cow extent size for file */
 994        __u8            di_pad2[12];    /* more padding for future expansion */
 995
 996        /* fields only written to during inode creation */
 997        xfs_timestamp_t di_crtime;      /* time created */
 998        __be64          di_ino;         /* inode number */
 999        uuid_t          di_uuid;        /* UUID of the filesystem */
1000
1001        /* structure must be padded to 64 bit alignment */
1002} xfs_dinode_t;
1003
1004#define XFS_DINODE_CRC_OFF      offsetof(struct xfs_dinode, di_crc)
1005
1006#define DI_MAX_FLUSH 0xffff
1007
1008/*
1009 * Size of the core inode on disk.  Version 1 and 2 inodes have
1010 * the same size, but version 3 has grown a few additional fields.
1011 */
1012static inline uint xfs_dinode_size(int version)
1013{
1014        if (version == 3)
1015                return sizeof(struct xfs_dinode);
1016        return offsetof(struct xfs_dinode, di_crc);
1017}
1018
1019/*
1020 * The 32 bit link count in the inode theoretically maxes out at UINT_MAX.
1021 * Since the pathconf interface is signed, we use 2^31 - 1 instead.
1022 */
1023#define XFS_MAXLINK             ((1U << 31) - 1U)
1024
1025/*
1026 * Values for di_format
1027 *
1028 * This enum is used in string mapping in xfs_trace.h; please keep the
1029 * TRACE_DEFINE_ENUMs for it up to date.
1030 */
1031enum xfs_dinode_fmt {
1032        XFS_DINODE_FMT_DEV,             /* xfs_dev_t */
1033        XFS_DINODE_FMT_LOCAL,           /* bulk data */
1034        XFS_DINODE_FMT_EXTENTS,         /* struct xfs_bmbt_rec */
1035        XFS_DINODE_FMT_BTREE,           /* struct xfs_bmdr_block */
1036        XFS_DINODE_FMT_UUID             /* added long ago, but never used */
1037};
1038
1039#define XFS_INODE_FORMAT_STR \
1040        { XFS_DINODE_FMT_DEV,           "dev" }, \
1041        { XFS_DINODE_FMT_LOCAL,         "local" }, \
1042        { XFS_DINODE_FMT_EXTENTS,       "extent" }, \
1043        { XFS_DINODE_FMT_BTREE,         "btree" }, \
1044        { XFS_DINODE_FMT_UUID,          "uuid" }
1045
1046/*
1047 * Inode minimum and maximum sizes.
1048 */
1049#define XFS_DINODE_MIN_LOG      8
1050#define XFS_DINODE_MAX_LOG      11
1051#define XFS_DINODE_MIN_SIZE     (1 << XFS_DINODE_MIN_LOG)
1052#define XFS_DINODE_MAX_SIZE     (1 << XFS_DINODE_MAX_LOG)
1053
1054/*
1055 * Inode size for given fs.
1056 */
1057#define XFS_DINODE_SIZE(sbp) \
1058        (xfs_sb_version_has_v3inode(sbp) ? \
1059                sizeof(struct xfs_dinode) : \
1060                offsetof(struct xfs_dinode, di_crc))
1061#define XFS_LITINO(mp) \
1062        ((mp)->m_sb.sb_inodesize - XFS_DINODE_SIZE(&(mp)->m_sb))
1063
1064/*
1065 * Inode data & attribute fork sizes, per inode.
1066 */
1067#define XFS_DFORK_BOFF(dip)             ((int)((dip)->di_forkoff << 3))
1068
1069#define XFS_DFORK_DSIZE(dip,mp) \
1070        ((dip)->di_forkoff ? XFS_DFORK_BOFF(dip) : XFS_LITINO(mp))
1071#define XFS_DFORK_ASIZE(dip,mp) \
1072        ((dip)->di_forkoff ? XFS_LITINO(mp) - XFS_DFORK_BOFF(dip) : 0)
1073#define XFS_DFORK_SIZE(dip,mp,w) \
1074        ((w) == XFS_DATA_FORK ? \
1075                XFS_DFORK_DSIZE(dip, mp) : \
1076                XFS_DFORK_ASIZE(dip, mp))
1077
1078#define XFS_DFORK_MAXEXT(dip, mp, w) \
1079        (XFS_DFORK_SIZE(dip, mp, w) / sizeof(struct xfs_bmbt_rec))
1080
1081/*
1082 * Return pointers to the data or attribute forks.
1083 */
1084#define XFS_DFORK_DPTR(dip) \
1085        ((char *)dip + xfs_dinode_size(dip->di_version))
1086#define XFS_DFORK_APTR(dip)     \
1087        (XFS_DFORK_DPTR(dip) + XFS_DFORK_BOFF(dip))
1088#define XFS_DFORK_PTR(dip,w)    \
1089        ((w) == XFS_DATA_FORK ? XFS_DFORK_DPTR(dip) : XFS_DFORK_APTR(dip))
1090
1091#define XFS_DFORK_FORMAT(dip,w) \
1092        ((w) == XFS_DATA_FORK ? \
1093                (dip)->di_format : \
1094                (dip)->di_aformat)
1095#define XFS_DFORK_NEXTENTS(dip,w) \
1096        ((w) == XFS_DATA_FORK ? \
1097                be32_to_cpu((dip)->di_nextents) : \
1098                be16_to_cpu((dip)->di_anextents))
1099
1100/*
1101 * For block and character special files the 32bit dev_t is stored at the
1102 * beginning of the data fork.
1103 */
1104static inline xfs_dev_t xfs_dinode_get_rdev(struct xfs_dinode *dip)
1105{
1106        return be32_to_cpu(*(__be32 *)XFS_DFORK_DPTR(dip));
1107}
1108
1109static inline void xfs_dinode_put_rdev(struct xfs_dinode *dip, xfs_dev_t rdev)
1110{
1111        *(__be32 *)XFS_DFORK_DPTR(dip) = cpu_to_be32(rdev);
1112}
1113
1114/*
1115 * Values for di_flags
1116 */
1117#define XFS_DIFLAG_REALTIME_BIT  0      /* file's blocks come from rt area */
1118#define XFS_DIFLAG_PREALLOC_BIT  1      /* file space has been preallocated */
1119#define XFS_DIFLAG_NEWRTBM_BIT   2      /* for rtbitmap inode, new format */
1120#define XFS_DIFLAG_IMMUTABLE_BIT 3      /* inode is immutable */
1121#define XFS_DIFLAG_APPEND_BIT    4      /* inode is append-only */
1122#define XFS_DIFLAG_SYNC_BIT      5      /* inode is written synchronously */
1123#define XFS_DIFLAG_NOATIME_BIT   6      /* do not update atime */
1124#define XFS_DIFLAG_NODUMP_BIT    7      /* do not dump */
1125#define XFS_DIFLAG_RTINHERIT_BIT 8      /* create with realtime bit set */
1126#define XFS_DIFLAG_PROJINHERIT_BIT   9  /* create with parents projid */
1127#define XFS_DIFLAG_NOSYMLINKS_BIT   10  /* disallow symlink creation */
1128#define XFS_DIFLAG_EXTSIZE_BIT      11  /* inode extent size allocator hint */
1129#define XFS_DIFLAG_EXTSZINHERIT_BIT 12  /* inherit inode extent size */
1130#define XFS_DIFLAG_NODEFRAG_BIT     13  /* do not reorganize/defragment */
1131#define XFS_DIFLAG_FILESTREAM_BIT   14  /* use filestream allocator */
1132/* Do not use bit 15, di_flags is legacy and unchanging now */
1133
1134#define XFS_DIFLAG_REALTIME      (1 << XFS_DIFLAG_REALTIME_BIT)
1135#define XFS_DIFLAG_PREALLOC      (1 << XFS_DIFLAG_PREALLOC_BIT)
1136#define XFS_DIFLAG_NEWRTBM       (1 << XFS_DIFLAG_NEWRTBM_BIT)
1137#define XFS_DIFLAG_IMMUTABLE     (1 << XFS_DIFLAG_IMMUTABLE_BIT)
1138#define XFS_DIFLAG_APPEND        (1 << XFS_DIFLAG_APPEND_BIT)
1139#define XFS_DIFLAG_SYNC          (1 << XFS_DIFLAG_SYNC_BIT)
1140#define XFS_DIFLAG_NOATIME       (1 << XFS_DIFLAG_NOATIME_BIT)
1141#define XFS_DIFLAG_NODUMP        (1 << XFS_DIFLAG_NODUMP_BIT)
1142#define XFS_DIFLAG_RTINHERIT     (1 << XFS_DIFLAG_RTINHERIT_BIT)
1143#define XFS_DIFLAG_PROJINHERIT   (1 << XFS_DIFLAG_PROJINHERIT_BIT)
1144#define XFS_DIFLAG_NOSYMLINKS    (1 << XFS_DIFLAG_NOSYMLINKS_BIT)
1145#define XFS_DIFLAG_EXTSIZE       (1 << XFS_DIFLAG_EXTSIZE_BIT)
1146#define XFS_DIFLAG_EXTSZINHERIT  (1 << XFS_DIFLAG_EXTSZINHERIT_BIT)
1147#define XFS_DIFLAG_NODEFRAG      (1 << XFS_DIFLAG_NODEFRAG_BIT)
1148#define XFS_DIFLAG_FILESTREAM    (1 << XFS_DIFLAG_FILESTREAM_BIT)
1149
1150#define XFS_DIFLAG_ANY \
1151        (XFS_DIFLAG_REALTIME | XFS_DIFLAG_PREALLOC | XFS_DIFLAG_NEWRTBM | \
1152         XFS_DIFLAG_IMMUTABLE | XFS_DIFLAG_APPEND | XFS_DIFLAG_SYNC | \
1153         XFS_DIFLAG_NOATIME | XFS_DIFLAG_NODUMP | XFS_DIFLAG_RTINHERIT | \
1154         XFS_DIFLAG_PROJINHERIT | XFS_DIFLAG_NOSYMLINKS | XFS_DIFLAG_EXTSIZE | \
1155         XFS_DIFLAG_EXTSZINHERIT | XFS_DIFLAG_NODEFRAG | XFS_DIFLAG_FILESTREAM)
1156
1157/*
1158 * Values for di_flags2 These start by being exposed to userspace in the upper
1159 * 16 bits of the XFS_XFLAG_s range.
1160 */
1161#define XFS_DIFLAG2_DAX_BIT     0       /* use DAX for this inode */
1162#define XFS_DIFLAG2_REFLINK_BIT 1       /* file's blocks may be shared */
1163#define XFS_DIFLAG2_COWEXTSIZE_BIT   2  /* copy on write extent size hint */
1164#define XFS_DIFLAG2_BIGTIME_BIT 3       /* big timestamps */
1165
1166#define XFS_DIFLAG2_DAX         (1 << XFS_DIFLAG2_DAX_BIT)
1167#define XFS_DIFLAG2_REFLINK     (1 << XFS_DIFLAG2_REFLINK_BIT)
1168#define XFS_DIFLAG2_COWEXTSIZE  (1 << XFS_DIFLAG2_COWEXTSIZE_BIT)
1169#define XFS_DIFLAG2_BIGTIME     (1 << XFS_DIFLAG2_BIGTIME_BIT)
1170
1171#define XFS_DIFLAG2_ANY \
1172        (XFS_DIFLAG2_DAX | XFS_DIFLAG2_REFLINK | XFS_DIFLAG2_COWEXTSIZE | \
1173         XFS_DIFLAG2_BIGTIME)
1174
1175static inline bool xfs_dinode_has_bigtime(const struct xfs_dinode *dip)
1176{
1177        return dip->di_version >= 3 &&
1178               (dip->di_flags2 & cpu_to_be64(XFS_DIFLAG2_BIGTIME));
1179}
1180
1181/*
1182 * Inode number format:
1183 * low inopblog bits - offset in block
1184 * next agblklog bits - block number in ag
1185 * next agno_log bits - ag number
1186 * high agno_log-agblklog-inopblog bits - 0
1187 */
1188#define XFS_INO_MASK(k)                 (uint32_t)((1ULL << (k)) - 1)
1189#define XFS_INO_OFFSET_BITS(mp)         (mp)->m_sb.sb_inopblog
1190#define XFS_INO_AGBNO_BITS(mp)          (mp)->m_sb.sb_agblklog
1191#define XFS_INO_AGINO_BITS(mp)          ((mp)->m_ino_geo.agino_log)
1192#define XFS_INO_AGNO_BITS(mp)           (mp)->m_agno_log
1193#define XFS_INO_BITS(mp)                \
1194        XFS_INO_AGNO_BITS(mp) + XFS_INO_AGINO_BITS(mp)
1195#define XFS_INO_TO_AGNO(mp,i)           \
1196        ((xfs_agnumber_t)((i) >> XFS_INO_AGINO_BITS(mp)))
1197#define XFS_INO_TO_AGINO(mp,i)          \
1198        ((xfs_agino_t)(i) & XFS_INO_MASK(XFS_INO_AGINO_BITS(mp)))
1199#define XFS_INO_TO_AGBNO(mp,i)          \
1200        (((xfs_agblock_t)(i) >> XFS_INO_OFFSET_BITS(mp)) & \
1201                XFS_INO_MASK(XFS_INO_AGBNO_BITS(mp)))
1202#define XFS_INO_TO_OFFSET(mp,i)         \
1203        ((int)(i) & XFS_INO_MASK(XFS_INO_OFFSET_BITS(mp)))
1204#define XFS_INO_TO_FSB(mp,i)            \
1205        XFS_AGB_TO_FSB(mp, XFS_INO_TO_AGNO(mp,i), XFS_INO_TO_AGBNO(mp,i))
1206#define XFS_AGINO_TO_INO(mp,a,i)        \
1207        (((xfs_ino_t)(a) << XFS_INO_AGINO_BITS(mp)) | (i))
1208#define XFS_AGINO_TO_AGBNO(mp,i)        ((i) >> XFS_INO_OFFSET_BITS(mp))
1209#define XFS_AGINO_TO_OFFSET(mp,i)       \
1210        ((i) & XFS_INO_MASK(XFS_INO_OFFSET_BITS(mp)))
1211#define XFS_OFFBNO_TO_AGINO(mp,b,o)     \
1212        ((xfs_agino_t)(((b) << XFS_INO_OFFSET_BITS(mp)) | (o)))
1213#define XFS_FSB_TO_INO(mp, b)   ((xfs_ino_t)((b) << XFS_INO_OFFSET_BITS(mp)))
1214#define XFS_AGB_TO_AGINO(mp, b) ((xfs_agino_t)((b) << XFS_INO_OFFSET_BITS(mp)))
1215
1216#define XFS_MAXINUMBER          ((xfs_ino_t)((1ULL << 56) - 1ULL))
1217#define XFS_MAXINUMBER_32       ((xfs_ino_t)((1ULL << 32) - 1ULL))
1218
1219/*
1220 * RealTime Device format definitions
1221 */
1222
1223/* Min and max rt extent sizes, specified in bytes */
1224#define XFS_MAX_RTEXTSIZE       (1024 * 1024 * 1024)    /* 1GB */
1225#define XFS_DFL_RTEXTSIZE       (64 * 1024)             /* 64kB */
1226#define XFS_MIN_RTEXTSIZE       (4 * 1024)              /* 4kB */
1227
1228#define XFS_BLOCKSIZE(mp)       ((mp)->m_sb.sb_blocksize)
1229#define XFS_BLOCKMASK(mp)       ((mp)->m_blockmask)
1230#define XFS_BLOCKWSIZE(mp)      ((mp)->m_blockwsize)
1231#define XFS_BLOCKWMASK(mp)      ((mp)->m_blockwmask)
1232
1233/*
1234 * RT Summary and bit manipulation macros.
1235 */
1236#define XFS_SUMOFFS(mp,ls,bb)   ((int)((ls) * (mp)->m_sb.sb_rbmblocks + (bb)))
1237#define XFS_SUMOFFSTOBLOCK(mp,s)        \
1238        (((s) * (uint)sizeof(xfs_suminfo_t)) >> (mp)->m_sb.sb_blocklog)
1239#define XFS_SUMPTR(mp,bp,so)    \
1240        ((xfs_suminfo_t *)((bp)->b_addr + \
1241                (((so) * (uint)sizeof(xfs_suminfo_t)) & XFS_BLOCKMASK(mp))))
1242
1243#define XFS_BITTOBLOCK(mp,bi)   ((bi) >> (mp)->m_blkbit_log)
1244#define XFS_BLOCKTOBIT(mp,bb)   ((bb) << (mp)->m_blkbit_log)
1245#define XFS_BITTOWORD(mp,bi)    \
1246        ((int)(((bi) >> XFS_NBWORDLOG) & XFS_BLOCKWMASK(mp)))
1247
1248#define XFS_RTMIN(a,b)  ((a) < (b) ? (a) : (b))
1249#define XFS_RTMAX(a,b)  ((a) > (b) ? (a) : (b))
1250
1251#define XFS_RTLOBIT(w)  xfs_lowbit32(w)
1252#define XFS_RTHIBIT(w)  xfs_highbit32(w)
1253
1254#define XFS_RTBLOCKLOG(b)       xfs_highbit64(b)
1255
1256/*
1257 * Dquot and dquot block format definitions
1258 */
1259#define XFS_DQUOT_MAGIC         0x4451          /* 'DQ' */
1260#define XFS_DQUOT_VERSION       (uint8_t)0x01   /* latest version number */
1261
1262#define XFS_DQTYPE_USER         0x01            /* user dquot record */
1263#define XFS_DQTYPE_PROJ         0x02            /* project dquot record */
1264#define XFS_DQTYPE_GROUP        0x04            /* group dquot record */
1265#define XFS_DQTYPE_BIGTIME      0x80            /* large expiry timestamps */
1266
1267/* bitmask to determine if this is a user/group/project dquot */
1268#define XFS_DQTYPE_REC_MASK     (XFS_DQTYPE_USER | \
1269                                 XFS_DQTYPE_PROJ | \
1270                                 XFS_DQTYPE_GROUP)
1271
1272#define XFS_DQTYPE_ANY          (XFS_DQTYPE_REC_MASK | \
1273                                 XFS_DQTYPE_BIGTIME)
1274
1275/*
1276 * XFS Quota Timers
1277 * ================
1278 *
1279 * Traditional quota grace period expiration timers are an unsigned 32-bit
1280 * seconds counter; time zero is the Unix epoch, Jan  1 00:00:01 UTC 1970.
1281 * Note that an expiration value of zero means that the quota limit has not
1282 * been reached, and therefore no expiration has been set.  Therefore, the
1283 * ondisk min and max defined here can be used directly to constrain the incore
1284 * quota expiration timestamps on a Unix system.
1285 *
1286 * When bigtime is enabled, we trade two bits of precision to expand the
1287 * expiration timeout range to match that of big inode timestamps.  The min and
1288 * max recorded here are the on-disk limits, not a Unix timestamp.
1289 *
1290 * The grace period for each quota type is stored in the root dquot (id = 0)
1291 * and is applied to a non-root dquot when it exceeds the soft or hard limits.
1292 * The length of quota grace periods are unsigned 32-bit quantities measured in
1293 * units of seconds.  A value of zero means to use the default period.
1294 */
1295
1296/*
1297 * Smallest possible ondisk quota expiration value with traditional timestamps.
1298 * This corresponds exactly with the incore expiration Jan  1 00:00:01 UTC 1970.
1299 */
1300#define XFS_DQ_LEGACY_EXPIRY_MIN        ((int64_t)1)
1301
1302/*
1303 * Largest possible ondisk quota expiration value with traditional timestamps.
1304 * This corresponds exactly with the incore expiration Feb  7 06:28:15 UTC 2106.
1305 */
1306#define XFS_DQ_LEGACY_EXPIRY_MAX        ((int64_t)U32_MAX)
1307
1308/*
1309 * Smallest possible ondisk quota expiration value with bigtime timestamps.
1310 * This corresponds (after conversion to a Unix timestamp) with the incore
1311 * expiration of Jan  1 00:00:04 UTC 1970.
1312 */
1313#define XFS_DQ_BIGTIME_EXPIRY_MIN       (XFS_DQ_LEGACY_EXPIRY_MIN)
1314
1315/*
1316 * Largest supported ondisk quota expiration value with bigtime timestamps.
1317 * This corresponds (after conversion to a Unix timestamp) with an incore
1318 * expiration of Jul  2 20:20:24 UTC 2486.
1319 *
1320 * The ondisk field supports values up to -1U, which corresponds to an incore
1321 * expiration in 2514.  This is beyond the maximum the bigtime inode timestamp,
1322 * so we cap the maximum bigtime quota expiration to the max inode timestamp.
1323 */
1324#define XFS_DQ_BIGTIME_EXPIRY_MAX       ((int64_t)4074815106U)
1325
1326/*
1327 * The following conversion factors assist in converting a quota expiration
1328 * timestamp between the incore and ondisk formats.
1329 */
1330#define XFS_DQ_BIGTIME_SHIFT    (2)
1331#define XFS_DQ_BIGTIME_SLACK    ((int64_t)(1ULL << XFS_DQ_BIGTIME_SHIFT) - 1)
1332
1333/* Convert an incore quota expiration timestamp to an ondisk bigtime value. */
1334static inline uint32_t xfs_dq_unix_to_bigtime(time64_t unix_seconds)
1335{
1336        /*
1337         * Round the expiration timestamp up to the nearest bigtime timestamp
1338         * that we can store, to give users the most time to fix problems.
1339         */
1340        return ((uint64_t)unix_seconds + XFS_DQ_BIGTIME_SLACK) >>
1341                        XFS_DQ_BIGTIME_SHIFT;
1342}
1343
1344/* Convert an ondisk bigtime quota expiration value to an incore timestamp. */
1345static inline time64_t xfs_dq_bigtime_to_unix(uint32_t ondisk_seconds)
1346{
1347        return (time64_t)ondisk_seconds << XFS_DQ_BIGTIME_SHIFT;
1348}
1349
1350/*
1351 * Default quota grace periods, ranging from zero (use the compiled defaults)
1352 * to ~136 years.  These are applied to a non-root dquot that has exceeded
1353 * either limit.
1354 */
1355#define XFS_DQ_GRACE_MIN                ((int64_t)0)
1356#define XFS_DQ_GRACE_MAX                ((int64_t)U32_MAX)
1357
1358/*
1359 * This is the main portion of the on-disk representation of quota information
1360 * for a user.  We pad this with some more expansion room to construct the on
1361 * disk structure.
1362 */
1363struct xfs_disk_dquot {
1364        __be16          d_magic;        /* dquot magic = XFS_DQUOT_MAGIC */
1365        __u8            d_version;      /* dquot version */
1366        __u8            d_type;         /* XFS_DQTYPE_USER/PROJ/GROUP */
1367        __be32          d_id;           /* user,project,group id */
1368        __be64          d_blk_hardlimit;/* absolute limit on disk blks */
1369        __be64          d_blk_softlimit;/* preferred limit on disk blks */
1370        __be64          d_ino_hardlimit;/* maximum # allocated inodes */
1371        __be64          d_ino_softlimit;/* preferred inode limit */
1372        __be64          d_bcount;       /* disk blocks owned by the user */
1373        __be64          d_icount;       /* inodes owned by the user */
1374        __be32          d_itimer;       /* zero if within inode limits if not,
1375                                           this is when we refuse service */
1376        __be32          d_btimer;       /* similar to above; for disk blocks */
1377        __be16          d_iwarns;       /* warnings issued wrt num inodes */
1378        __be16          d_bwarns;       /* warnings issued wrt disk blocks */
1379        __be32          d_pad0;         /* 64 bit align */
1380        __be64          d_rtb_hardlimit;/* absolute limit on realtime blks */
1381        __be64          d_rtb_softlimit;/* preferred limit on RT disk blks */
1382        __be64          d_rtbcount;     /* realtime blocks owned */
1383        __be32          d_rtbtimer;     /* similar to above; for RT disk blocks */
1384        __be16          d_rtbwarns;     /* warnings issued wrt RT disk blocks */
1385        __be16          d_pad;
1386};
1387
1388/*
1389 * This is what goes on disk. This is separated from the xfs_disk_dquot because
1390 * carrying the unnecessary padding would be a waste of memory.
1391 */
1392typedef struct xfs_dqblk {
1393        struct xfs_disk_dquot   dd_diskdq; /* portion living incore as well */
1394        char                    dd_fill[4];/* filling for posterity */
1395
1396        /*
1397         * These two are only present on filesystems with the CRC bits set.
1398         */
1399        __be32            dd_crc;       /* checksum */
1400        __be64            dd_lsn;       /* last modification in log */
1401        uuid_t            dd_uuid;      /* location information */
1402} xfs_dqblk_t;
1403
1404#define XFS_DQUOT_CRC_OFF       offsetof(struct xfs_dqblk, dd_crc)
1405
1406/*
1407 * This defines the unit of allocation of dquots.
1408 *
1409 * Currently, it is just one file system block, and a 4K blk contains 30
1410 * (136 * 30 = 4080) dquots. It's probably not worth trying to make
1411 * this more dynamic.
1412 *
1413 * However, if this number is changed, we have to make sure that we don't
1414 * implicitly assume that we do allocations in chunks of a single filesystem
1415 * block in the dquot/xqm code.
1416 *
1417 * This is part of the ondisk format because the structure size is not a power
1418 * of two, which leaves slack at the end of the disk block.
1419 */
1420#define XFS_DQUOT_CLUSTER_SIZE_FSB      (xfs_filblks_t)1
1421
1422/*
1423 * Remote symlink format and access functions.
1424 */
1425#define XFS_SYMLINK_MAGIC       0x58534c4d      /* XSLM */
1426
1427struct xfs_dsymlink_hdr {
1428        __be32  sl_magic;
1429        __be32  sl_offset;
1430        __be32  sl_bytes;
1431        __be32  sl_crc;
1432        uuid_t  sl_uuid;
1433        __be64  sl_owner;
1434        __be64  sl_blkno;
1435        __be64  sl_lsn;
1436};
1437
1438#define XFS_SYMLINK_CRC_OFF     offsetof(struct xfs_dsymlink_hdr, sl_crc)
1439
1440#define XFS_SYMLINK_MAXLEN      1024
1441/*
1442 * The maximum pathlen is 1024 bytes. Since the minimum file system
1443 * blocksize is 512 bytes, we can get a max of 3 extents back from
1444 * bmapi when crc headers are taken into account.
1445 */
1446#define XFS_SYMLINK_MAPS 3
1447
1448#define XFS_SYMLINK_BUF_SPACE(mp, bufsize)      \
1449        ((bufsize) - (xfs_sb_version_hascrc(&(mp)->m_sb) ? \
1450                        sizeof(struct xfs_dsymlink_hdr) : 0))
1451
1452
1453/*
1454 * Allocation Btree format definitions
1455 *
1456 * There are two on-disk btrees, one sorted by blockno and one sorted
1457 * by blockcount and blockno.  All blocks look the same to make the code
1458 * simpler; if we have time later, we'll make the optimizations.
1459 */
1460#define XFS_ABTB_MAGIC          0x41425442      /* 'ABTB' for bno tree */
1461#define XFS_ABTB_CRC_MAGIC      0x41423342      /* 'AB3B' */
1462#define XFS_ABTC_MAGIC          0x41425443      /* 'ABTC' for cnt tree */
1463#define XFS_ABTC_CRC_MAGIC      0x41423343      /* 'AB3C' */
1464
1465/*
1466 * Data record/key structure
1467 */
1468typedef struct xfs_alloc_rec {
1469        __be32          ar_startblock;  /* starting block number */
1470        __be32          ar_blockcount;  /* count of free blocks */
1471} xfs_alloc_rec_t, xfs_alloc_key_t;
1472
1473typedef struct xfs_alloc_rec_incore {
1474        xfs_agblock_t   ar_startblock;  /* starting block number */
1475        xfs_extlen_t    ar_blockcount;  /* count of free blocks */
1476} xfs_alloc_rec_incore_t;
1477
1478/* btree pointer type */
1479typedef __be32 xfs_alloc_ptr_t;
1480
1481/*
1482 * Block numbers in the AG:
1483 * SB is sector 0, AGF is sector 1, AGI is sector 2, AGFL is sector 3.
1484 */
1485#define XFS_BNO_BLOCK(mp)       ((xfs_agblock_t)(XFS_AGFL_BLOCK(mp) + 1))
1486#define XFS_CNT_BLOCK(mp)       ((xfs_agblock_t)(XFS_BNO_BLOCK(mp) + 1))
1487
1488
1489/*
1490 * Inode Allocation Btree format definitions
1491 *
1492 * There is a btree for the inode map per allocation group.
1493 */
1494#define XFS_IBT_MAGIC           0x49414254      /* 'IABT' */
1495#define XFS_IBT_CRC_MAGIC       0x49414233      /* 'IAB3' */
1496#define XFS_FIBT_MAGIC          0x46494254      /* 'FIBT' */
1497#define XFS_FIBT_CRC_MAGIC      0x46494233      /* 'FIB3' */
1498
1499typedef uint64_t        xfs_inofree_t;
1500#define XFS_INODES_PER_CHUNK            (NBBY * sizeof(xfs_inofree_t))
1501#define XFS_INODES_PER_CHUNK_LOG        (XFS_NBBYLOG + 3)
1502#define XFS_INOBT_ALL_FREE              ((xfs_inofree_t)-1)
1503#define XFS_INOBT_MASK(i)               ((xfs_inofree_t)1 << (i))
1504
1505#define XFS_INOBT_HOLEMASK_FULL         0       /* holemask for full chunk */
1506#define XFS_INOBT_HOLEMASK_BITS         (NBBY * sizeof(uint16_t))
1507#define XFS_INODES_PER_HOLEMASK_BIT     \
1508        (XFS_INODES_PER_CHUNK / (NBBY * sizeof(uint16_t)))
1509
1510static inline xfs_inofree_t xfs_inobt_maskn(int i, int n)
1511{
1512        return ((n >= XFS_INODES_PER_CHUNK ? 0 : XFS_INOBT_MASK(n)) - 1) << i;
1513}
1514
1515/*
1516 * The on-disk inode record structure has two formats. The original "full"
1517 * format uses a 4-byte freecount. The "sparse" format uses a 1-byte freecount
1518 * and replaces the 3 high-order freecount bytes wth the holemask and inode
1519 * count.
1520 *
1521 * The holemask of the sparse record format allows an inode chunk to have holes
1522 * that refer to blocks not owned by the inode record. This facilitates inode
1523 * allocation in the event of severe free space fragmentation.
1524 */
1525typedef struct xfs_inobt_rec {
1526        __be32          ir_startino;    /* starting inode number */
1527        union {
1528                struct {
1529                        __be32  ir_freecount;   /* count of free inodes */
1530                } f;
1531                struct {
1532                        __be16  ir_holemask;/* hole mask for sparse chunks */
1533                        __u8    ir_count;       /* total inode count */
1534                        __u8    ir_freecount;   /* count of free inodes */
1535                } sp;
1536        } ir_u;
1537        __be64          ir_free;        /* free inode mask */
1538} xfs_inobt_rec_t;
1539
1540typedef struct xfs_inobt_rec_incore {
1541        xfs_agino_t     ir_startino;    /* starting inode number */
1542        uint16_t        ir_holemask;    /* hole mask for sparse chunks */
1543        uint8_t         ir_count;       /* total inode count */
1544        uint8_t         ir_freecount;   /* count of free inodes (set bits) */
1545        xfs_inofree_t   ir_free;        /* free inode mask */
1546} xfs_inobt_rec_incore_t;
1547
1548static inline bool xfs_inobt_issparse(uint16_t holemask)
1549{
1550        /* non-zero holemask represents a sparse rec. */
1551        return holemask;
1552}
1553
1554/*
1555 * Key structure
1556 */
1557typedef struct xfs_inobt_key {
1558        __be32          ir_startino;    /* starting inode number */
1559} xfs_inobt_key_t;
1560
1561/* btree pointer type */
1562typedef __be32 xfs_inobt_ptr_t;
1563
1564/*
1565 * block numbers in the AG.
1566 */
1567#define XFS_IBT_BLOCK(mp)               ((xfs_agblock_t)(XFS_CNT_BLOCK(mp) + 1))
1568#define XFS_FIBT_BLOCK(mp)              ((xfs_agblock_t)(XFS_IBT_BLOCK(mp) + 1))
1569
1570/*
1571 * Reverse mapping btree format definitions
1572 *
1573 * There is a btree for the reverse map per allocation group
1574 */
1575#define XFS_RMAP_CRC_MAGIC      0x524d4233      /* 'RMB3' */
1576
1577/*
1578 * Ownership info for an extent.  This is used to create reverse-mapping
1579 * entries.
1580 */
1581#define XFS_OWNER_INFO_ATTR_FORK        (1 << 0)
1582#define XFS_OWNER_INFO_BMBT_BLOCK       (1 << 1)
1583struct xfs_owner_info {
1584        uint64_t                oi_owner;
1585        xfs_fileoff_t           oi_offset;
1586        unsigned int            oi_flags;
1587};
1588
1589/*
1590 * Special owner types.
1591 *
1592 * Seeing as we only support up to 8EB, we have the upper bit of the owner field
1593 * to tell us we have a special owner value. We use these for static metadata
1594 * allocated at mkfs/growfs time, as well as for freespace management metadata.
1595 */
1596#define XFS_RMAP_OWN_NULL       (-1ULL) /* No owner, for growfs */
1597#define XFS_RMAP_OWN_UNKNOWN    (-2ULL) /* Unknown owner, for EFI recovery */
1598#define XFS_RMAP_OWN_FS         (-3ULL) /* static fs metadata */
1599#define XFS_RMAP_OWN_LOG        (-4ULL) /* static fs metadata */
1600#define XFS_RMAP_OWN_AG         (-5ULL) /* AG freespace btree blocks */
1601#define XFS_RMAP_OWN_INOBT      (-6ULL) /* Inode btree blocks */
1602#define XFS_RMAP_OWN_INODES     (-7ULL) /* Inode chunk */
1603#define XFS_RMAP_OWN_REFC       (-8ULL) /* refcount tree */
1604#define XFS_RMAP_OWN_COW        (-9ULL) /* cow allocations */
1605#define XFS_RMAP_OWN_MIN        (-10ULL) /* guard */
1606
1607#define XFS_RMAP_NON_INODE_OWNER(owner) (!!((owner) & (1ULL << 63)))
1608
1609/*
1610 * Data record structure
1611 */
1612struct xfs_rmap_rec {
1613        __be32          rm_startblock;  /* extent start block */
1614        __be32          rm_blockcount;  /* extent length */
1615        __be64          rm_owner;       /* extent owner */
1616        __be64          rm_offset;      /* offset within the owner */
1617};
1618
1619/*
1620 * rmap btree record
1621 *  rm_offset:63 is the attribute fork flag
1622 *  rm_offset:62 is the bmbt block flag
1623 *  rm_offset:61 is the unwritten extent flag (same as l0:63 in bmbt)
1624 *  rm_offset:54-60 aren't used and should be zero
1625 *  rm_offset:0-53 is the block offset within the inode
1626 */
1627#define XFS_RMAP_OFF_ATTR_FORK  ((uint64_t)1ULL << 63)
1628#define XFS_RMAP_OFF_BMBT_BLOCK ((uint64_t)1ULL << 62)
1629#define XFS_RMAP_OFF_UNWRITTEN  ((uint64_t)1ULL << 61)
1630
1631#define XFS_RMAP_LEN_MAX        ((uint32_t)~0U)
1632#define XFS_RMAP_OFF_FLAGS      (XFS_RMAP_OFF_ATTR_FORK | \
1633                                 XFS_RMAP_OFF_BMBT_BLOCK | \
1634                                 XFS_RMAP_OFF_UNWRITTEN)
1635#define XFS_RMAP_OFF_MASK       ((uint64_t)0x3FFFFFFFFFFFFFULL)
1636
1637#define XFS_RMAP_OFF(off)               ((off) & XFS_RMAP_OFF_MASK)
1638
1639#define XFS_RMAP_IS_BMBT_BLOCK(off)     (!!((off) & XFS_RMAP_OFF_BMBT_BLOCK))
1640#define XFS_RMAP_IS_ATTR_FORK(off)      (!!((off) & XFS_RMAP_OFF_ATTR_FORK))
1641#define XFS_RMAP_IS_UNWRITTEN(len)      (!!((off) & XFS_RMAP_OFF_UNWRITTEN))
1642
1643#define RMAPBT_STARTBLOCK_BITLEN        32
1644#define RMAPBT_BLOCKCOUNT_BITLEN        32
1645#define RMAPBT_OWNER_BITLEN             64
1646#define RMAPBT_ATTRFLAG_BITLEN          1
1647#define RMAPBT_BMBTFLAG_BITLEN          1
1648#define RMAPBT_EXNTFLAG_BITLEN          1
1649#define RMAPBT_UNUSED_OFFSET_BITLEN     7
1650#define RMAPBT_OFFSET_BITLEN            54
1651
1652#define XFS_RMAP_ATTR_FORK              (1 << 0)
1653#define XFS_RMAP_BMBT_BLOCK             (1 << 1)
1654#define XFS_RMAP_UNWRITTEN              (1 << 2)
1655#define XFS_RMAP_KEY_FLAGS              (XFS_RMAP_ATTR_FORK | \
1656                                         XFS_RMAP_BMBT_BLOCK)
1657#define XFS_RMAP_REC_FLAGS              (XFS_RMAP_UNWRITTEN)
1658struct xfs_rmap_irec {
1659        xfs_agblock_t   rm_startblock;  /* extent start block */
1660        xfs_extlen_t    rm_blockcount;  /* extent length */
1661        uint64_t        rm_owner;       /* extent owner */
1662        uint64_t        rm_offset;      /* offset within the owner */
1663        unsigned int    rm_flags;       /* state flags */
1664};
1665
1666/*
1667 * Key structure
1668 *
1669 * We don't use the length for lookups
1670 */
1671struct xfs_rmap_key {
1672        __be32          rm_startblock;  /* extent start block */
1673        __be64          rm_owner;       /* extent owner */
1674        __be64          rm_offset;      /* offset within the owner */
1675} __attribute__((packed));
1676
1677/* btree pointer type */
1678typedef __be32 xfs_rmap_ptr_t;
1679
1680#define XFS_RMAP_BLOCK(mp) \
1681        (xfs_sb_version_hasfinobt(&((mp)->m_sb)) ? \
1682         XFS_FIBT_BLOCK(mp) + 1 : \
1683         XFS_IBT_BLOCK(mp) + 1)
1684
1685/*
1686 * Reference Count Btree format definitions
1687 *
1688 */
1689#define XFS_REFC_CRC_MAGIC      0x52334643      /* 'R3FC' */
1690
1691unsigned int xfs_refc_block(struct xfs_mount *mp);
1692
1693/*
1694 * Data record/key structure
1695 *
1696 * Each record associates a range of physical blocks (starting at
1697 * rc_startblock and ending rc_blockcount blocks later) with a reference
1698 * count (rc_refcount).  Extents that are being used to stage a copy on
1699 * write (CoW) operation are recorded in the refcount btree with a
1700 * refcount of 1.  All other records must have a refcount > 1 and must
1701 * track an extent mapped only by file data forks.
1702 *
1703 * Extents with a single owner (attributes, metadata, non-shared file
1704 * data) are not tracked here.  Free space is also not tracked here.
1705 * This is consistent with pre-reflink XFS.
1706 */
1707
1708/*
1709 * Extents that are being used to stage a copy on write are stored
1710 * in the refcount btree with a refcount of 1 and the upper bit set
1711 * on the startblock.  This speeds up mount time deletion of stale
1712 * staging extents because they're all at the right side of the tree.
1713 */
1714#define XFS_REFC_COW_START              ((xfs_agblock_t)(1U << 31))
1715#define REFCNTBT_COWFLAG_BITLEN         1
1716#define REFCNTBT_AGBLOCK_BITLEN         31
1717
1718struct xfs_refcount_rec {
1719        __be32          rc_startblock;  /* starting block number */
1720        __be32          rc_blockcount;  /* count of blocks */
1721        __be32          rc_refcount;    /* number of inodes linked here */
1722};
1723
1724struct xfs_refcount_key {
1725        __be32          rc_startblock;  /* starting block number */
1726};
1727
1728struct xfs_refcount_irec {
1729        xfs_agblock_t   rc_startblock;  /* starting block number */
1730        xfs_extlen_t    rc_blockcount;  /* count of free blocks */
1731        xfs_nlink_t     rc_refcount;    /* number of inodes linked here */
1732};
1733
1734#define MAXREFCOUNT     ((xfs_nlink_t)~0U)
1735#define MAXREFCEXTLEN   ((xfs_extlen_t)~0U)
1736
1737/* btree pointer type */
1738typedef __be32 xfs_refcount_ptr_t;
1739
1740
1741/*
1742 * BMAP Btree format definitions
1743 *
1744 * This includes both the root block definition that sits inside an inode fork
1745 * and the record/pointer formats for the leaf/node in the blocks.
1746 */
1747#define XFS_BMAP_MAGIC          0x424d4150      /* 'BMAP' */
1748#define XFS_BMAP_CRC_MAGIC      0x424d4133      /* 'BMA3' */
1749
1750/*
1751 * Bmap root header, on-disk form only.
1752 */
1753typedef struct xfs_bmdr_block {
1754        __be16          bb_level;       /* 0 is a leaf */
1755        __be16          bb_numrecs;     /* current # of data records */
1756} xfs_bmdr_block_t;
1757
1758/*
1759 * Bmap btree record and extent descriptor.
1760 *  l0:63 is an extent flag (value 1 indicates non-normal).
1761 *  l0:9-62 are startoff.
1762 *  l0:0-8 and l1:21-63 are startblock.
1763 *  l1:0-20 are blockcount.
1764 */
1765#define BMBT_EXNTFLAG_BITLEN    1
1766#define BMBT_STARTOFF_BITLEN    54
1767#define BMBT_STARTBLOCK_BITLEN  52
1768#define BMBT_BLOCKCOUNT_BITLEN  21
1769
1770#define BMBT_STARTOFF_MASK      ((1ULL << BMBT_STARTOFF_BITLEN) - 1)
1771#define BMBT_BLOCKCOUNT_MASK    ((1ULL << BMBT_BLOCKCOUNT_BITLEN) - 1)
1772
1773/*
1774 * bmbt records have a file offset (block) field that is 54 bits wide, so this
1775 * is the largest xfs_fileoff_t that we ever expect to see.
1776 */
1777#define XFS_MAX_FILEOFF         (BMBT_STARTOFF_MASK + BMBT_BLOCKCOUNT_MASK)
1778
1779typedef struct xfs_bmbt_rec {
1780        __be64                  l0, l1;
1781} xfs_bmbt_rec_t;
1782
1783typedef uint64_t        xfs_bmbt_rec_base_t;    /* use this for casts */
1784typedef xfs_bmbt_rec_t xfs_bmdr_rec_t;
1785
1786/*
1787 * Values and macros for delayed-allocation startblock fields.
1788 */
1789#define STARTBLOCKVALBITS       17
1790#define STARTBLOCKMASKBITS      (15 + 20)
1791#define STARTBLOCKMASK          \
1792        (((((xfs_fsblock_t)1) << STARTBLOCKMASKBITS) - 1) << STARTBLOCKVALBITS)
1793
1794static inline int isnullstartblock(xfs_fsblock_t x)
1795{
1796        return ((x) & STARTBLOCKMASK) == STARTBLOCKMASK;
1797}
1798
1799static inline xfs_fsblock_t nullstartblock(int k)
1800{
1801        ASSERT(k < (1 << STARTBLOCKVALBITS));
1802        return STARTBLOCKMASK | (k);
1803}
1804
1805static inline xfs_filblks_t startblockval(xfs_fsblock_t x)
1806{
1807        return (xfs_filblks_t)((x) & ~STARTBLOCKMASK);
1808}
1809
1810/*
1811 * Key structure for non-leaf levels of the tree.
1812 */
1813typedef struct xfs_bmbt_key {
1814        __be64          br_startoff;    /* starting file offset */
1815} xfs_bmbt_key_t, xfs_bmdr_key_t;
1816
1817/* btree pointer type */
1818typedef __be64 xfs_bmbt_ptr_t, xfs_bmdr_ptr_t;
1819
1820
1821/*
1822 * Generic Btree block format definitions
1823 *
1824 * This is a combination of the actual format used on disk for short and long
1825 * format btrees.  The first three fields are shared by both format, but the
1826 * pointers are different and should be used with care.
1827 *
1828 * To get the size of the actual short or long form headers please use the size
1829 * macros below.  Never use sizeof(xfs_btree_block).
1830 *
1831 * The blkno, crc, lsn, owner and uuid fields are only available in filesystems
1832 * with the crc feature bit, and all accesses to them must be conditional on
1833 * that flag.
1834 */
1835/* short form block header */
1836struct xfs_btree_block_shdr {
1837        __be32          bb_leftsib;
1838        __be32          bb_rightsib;
1839
1840        __be64          bb_blkno;
1841        __be64          bb_lsn;
1842        uuid_t          bb_uuid;
1843        __be32          bb_owner;
1844        __le32          bb_crc;
1845};
1846
1847/* long form block header */
1848struct xfs_btree_block_lhdr {
1849        __be64          bb_leftsib;
1850        __be64          bb_rightsib;
1851
1852        __be64          bb_blkno;
1853        __be64          bb_lsn;
1854        uuid_t          bb_uuid;
1855        __be64          bb_owner;
1856        __le32          bb_crc;
1857        __be32          bb_pad; /* padding for alignment */
1858};
1859
1860struct xfs_btree_block {
1861        __be32          bb_magic;       /* magic number for block type */
1862        __be16          bb_level;       /* 0 is a leaf */
1863        __be16          bb_numrecs;     /* current # of data records */
1864        union {
1865                struct xfs_btree_block_shdr s;
1866                struct xfs_btree_block_lhdr l;
1867        } bb_u;                         /* rest */
1868};
1869
1870/* size of a short form block */
1871#define XFS_BTREE_SBLOCK_LEN \
1872        (offsetof(struct xfs_btree_block, bb_u) + \
1873         offsetof(struct xfs_btree_block_shdr, bb_blkno))
1874/* size of a long form block */
1875#define XFS_BTREE_LBLOCK_LEN \
1876        (offsetof(struct xfs_btree_block, bb_u) + \
1877         offsetof(struct xfs_btree_block_lhdr, bb_blkno))
1878
1879/* sizes of CRC enabled btree blocks */
1880#define XFS_BTREE_SBLOCK_CRC_LEN \
1881        (offsetof(struct xfs_btree_block, bb_u) + \
1882         sizeof(struct xfs_btree_block_shdr))
1883#define XFS_BTREE_LBLOCK_CRC_LEN \
1884        (offsetof(struct xfs_btree_block, bb_u) + \
1885         sizeof(struct xfs_btree_block_lhdr))
1886
1887#define XFS_BTREE_SBLOCK_CRC_OFF \
1888        offsetof(struct xfs_btree_block, bb_u.s.bb_crc)
1889#define XFS_BTREE_LBLOCK_CRC_OFF \
1890        offsetof(struct xfs_btree_block, bb_u.l.bb_crc)
1891
1892/*
1893 * On-disk XFS access control list structure.
1894 */
1895struct xfs_acl_entry {
1896        __be32  ae_tag;
1897        __be32  ae_id;
1898        __be16  ae_perm;
1899        __be16  ae_pad;         /* fill the implicit hole in the structure */
1900};
1901
1902struct xfs_acl {
1903        __be32                  acl_cnt;
1904        struct xfs_acl_entry    acl_entry[];
1905};
1906
1907/*
1908 * The number of ACL entries allowed is defined by the on-disk format.
1909 * For v4 superblocks, that is limited to 25 entries. For v5 superblocks, it is
1910 * limited only by the maximum size of the xattr that stores the information.
1911 */
1912#define XFS_ACL_MAX_ENTRIES(mp) \
1913        (xfs_sb_version_hascrc(&mp->m_sb) \
1914                ?  (XFS_XATTR_SIZE_MAX - sizeof(struct xfs_acl)) / \
1915                                                sizeof(struct xfs_acl_entry) \
1916                : 25)
1917
1918#define XFS_ACL_SIZE(cnt) \
1919        (sizeof(struct xfs_acl) + \
1920                sizeof(struct xfs_acl_entry) * cnt)
1921
1922#define XFS_ACL_MAX_SIZE(mp) \
1923        XFS_ACL_SIZE(XFS_ACL_MAX_ENTRIES((mp)))
1924
1925
1926/* On-disk XFS extended attribute names */
1927#define SGI_ACL_FILE            "SGI_ACL_FILE"
1928#define SGI_ACL_DEFAULT         "SGI_ACL_DEFAULT"
1929#define SGI_ACL_FILE_SIZE       (sizeof(SGI_ACL_FILE)-1)
1930#define SGI_ACL_DEFAULT_SIZE    (sizeof(SGI_ACL_DEFAULT)-1)
1931
1932#endif /* __XFS_FORMAT_H__ */
1933