/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 */
#ifndef __XFS_FORMAT_H__
#define __XFS_FORMAT_H__

/*
 * XFS On Disk Format Definitions
 *
 * This header file defines all the on-disk format definitions for
 * general XFS objects. Directory and attribute related objects are defined in
 * xfs_da_format.h, which log and log item formats are defined in
 * xfs_log_format.h. Everything else goes here.
 */

struct xfs_mount;
struct xfs_trans;
struct xfs_inode;
struct xfs_buf;
struct xfs_ifork;

/*
 * Super block
 * Fits into a sector-sized buffer at address 0 of each allocation group.
 * Only the first of these is ever updated except during growfs.
 */
#define XFS_SB_MAGIC            0x58465342      /* 'XFSB' */
#define XFS_SB_VERSION_1        1               /* 5.3, 6.0.1, 6.1 */
#define XFS_SB_VERSION_2        2               /* 6.2 - attributes */
#define XFS_SB_VERSION_3        3               /* 6.2 - new inode version */
#define XFS_SB_VERSION_4        4               /* 6.2+ - bitmask version */
#define XFS_SB_VERSION_5        5               /* CRC enabled filesystem */
#define XFS_SB_VERSION_NUMBITS          0x000f
#define XFS_SB_VERSION_ALLFBITS         0xfff0
#define XFS_SB_VERSION_ATTRBIT          0x0010
#define XFS_SB_VERSION_NLINKBIT         0x0020
#define XFS_SB_VERSION_QUOTABIT         0x0040
#define XFS_SB_VERSION_ALIGNBIT         0x0080
#define XFS_SB_VERSION_DALIGNBIT        0x0100
#define XFS_SB_VERSION_SHAREDBIT        0x0200
#define XFS_SB_VERSION_LOGV2BIT         0x0400
#define XFS_SB_VERSION_SECTORBIT        0x0800
#define XFS_SB_VERSION_EXTFLGBIT        0x1000
#define XFS_SB_VERSION_DIRV2BIT         0x2000
#define XFS_SB_VERSION_BORGBIT          0x4000  /* ASCII only case-insens. */
#define XFS_SB_VERSION_MOREBITSBIT      0x8000

/*
 * The size of a single extended attribute on disk is limited by
 * the size of index values within the attribute entries themselves.
 * These are be16 fields, so we can only support attribute data
 * sizes up to 2^16 bytes in length.
 */
#define XFS_XATTR_SIZE_MAX (1 << 16)

/*
 * Supported feature bit list is just all bits in the versionnum field because
 * we've used them all up and understand them all. Except, of course, for the
 * shared superblock bit, which nobody knows what it does and so is unsupported.
 */
#define XFS_SB_VERSION_OKBITS           \
        ((XFS_SB_VERSION_NUMBITS | XFS_SB_VERSION_ALLFBITS) & \
                ~XFS_SB_VERSION_SHAREDBIT)

/*
 * There are two words to hold XFS "feature" bits: the original
 * word, sb_versionnum, and sb_features2.  Whenever a bit is set in
 * sb_features2, the feature bit XFS_SB_VERSION_MOREBITSBIT must be set.
 *
 * These defines represent bits in sb_features2.
 */
#define XFS_SB_VERSION2_RESERVED1BIT    0x00000001
#define XFS_SB_VERSION2_LAZYSBCOUNTBIT  0x00000002      /* Superblk counters */
#define XFS_SB_VERSION2_RESERVED4BIT    0x00000004
#define XFS_SB_VERSION2_ATTR2BIT        0x00000008      /* Inline attr rework */
#define XFS_SB_VERSION2_PARENTBIT       0x00000010      /* parent pointers */
#define XFS_SB_VERSION2_PROJID32BIT     0x00000080      /* 32 bit project id */
#define XFS_SB_VERSION2_CRCBIT          0x00000100      /* metadata CRCs */
#define XFS_SB_VERSION2_FTYPE           0x00000200      /* inode type in dir */

#define XFS_SB_VERSION2_OKBITS          \
        (XFS_SB_VERSION2_LAZYSBCOUNTBIT | \
         XFS_SB_VERSION2_ATTR2BIT       | \
         XFS_SB_VERSION2_PROJID32BIT    | \
         XFS_SB_VERSION2_FTYPE)

/* Maximum size of the xfs filesystem label, no terminating NULL */
#define XFSLABEL_MAX                    12

/*
 * Superblock - in core version.  Must be padded to 64 bit alignment.
 */
typedef struct xfs_sb {
        uint32_t        sb_magicnum;    /* magic number == XFS_SB_MAGIC */
        uint32_t        sb_blocksize;   /* logical block size, bytes */
        xfs_rfsblock_t  sb_dblocks;     /* number of data blocks */
        xfs_rfsblock_t  sb_rblocks;     /* number of realtime blocks */
        xfs_rtbxlen_t   sb_rextents;    /* number of realtime extents */
        uuid_t          sb_uuid;        /* user-visible file system unique id */
        xfs_fsblock_t   sb_logstart;    /* starting block of log if internal */
        xfs_ino_t       sb_rootino;     /* root inode number */
        xfs_ino_t       sb_rbmino;      /* bitmap inode for realtime extents */
        xfs_ino_t       sb_rsumino;     /* summary inode for rt bitmap */
        xfs_agblock_t   sb_rextsize;    /* realtime extent size, blocks */
        xfs_agblock_t   sb_agblocks;    /* size of an allocation group */
        xfs_agnumber_t  sb_agcount;     /* number of allocation groups */
        xfs_extlen_t    sb_rbmblocks;   /* number of rt bitmap blocks */
        xfs_extlen_t    sb_logblocks;   /* number of log blocks */
        uint16_t        sb_versionnum;  /* header version == XFS_SB_VERSION */
        uint16_t        sb_sectsize;    /* volume sector size, bytes */
        uint16_t        sb_inodesize;   /* inode size, bytes */
        uint16_t        sb_inopblock;   /* inodes per block */
        char            sb_fname[XFSLABEL_MAX] __nonstring; /* file system name */
        uint8_t         sb_blocklog;    /* log2 of sb_blocksize */
        uint8_t         sb_sectlog;     /* log2 of sb_sectsize */
        uint8_t         sb_inodelog;    /* log2 of sb_inodesize */
        uint8_t         sb_inopblog;    /* log2 of sb_inopblock */
        uint8_t         sb_agblklog;    /* log2 of sb_agblocks (rounded up) */
        uint8_t         sb_rextslog;    /* log2 of sb_rextents */
        uint8_t         sb_inprogress;  /* mkfs is in progress, don't mount */
        uint8_t         sb_imax_pct;    /* max % of fs for inode space */
                                        /* statistics */
        /*
         * These fields must remain contiguous.  If you really
         * want to change their layout, make sure you fix the
         * code in xfs_trans_apply_sb_deltas().
         */
        uint64_t        sb_icount;      /* allocated inodes */
        uint64_t        sb_ifree;       /* free inodes */
        uint64_t        sb_fdblocks;    /* free data blocks */
        uint64_t        sb_frextents;   /* free realtime extents */
        /*
         * End contiguous fields.
         */
        xfs_ino_t       sb_uquotino;    /* user quota inode */
        xfs_ino_t       sb_gquotino;    /* group quota inode */
        uint16_t        sb_qflags;      /* quota flags */
        uint8_t         sb_flags;       /* misc. flags */
        uint8_t         sb_shared_vn;   /* shared version number */
        xfs_extlen_t    sb_inoalignmt;  /* inode chunk alignment, fsblocks */
        uint32_t        sb_unit;        /* stripe or raid unit */
        uint32_t        sb_width;       /* stripe or raid width */
        uint8_t         sb_dirblklog;   /* log2 of dir block size (fsbs) */
        uint8_t         sb_logsectlog;  /* log2 of the log sector size */
        uint16_t        sb_logsectsize; /* sector size for the log, bytes */
        uint32_t        sb_logsunit;    /* stripe unit size for the log */
        uint32_t        sb_features2;   /* additional feature bits */

        /*
         * bad features2 field as a result of failing to pad the sb structure to
         * 64 bits. Some machines will be using this field for features2 bits.
         * Easiest just to mark it bad and not use it for anything else.
         *
         * This is not kept up to date in memory; it is always overwritten by
         * the value in sb_features2 when formatting the incore superblock to
         * the disk buffer.
         */
        uint32_t        sb_bad_features2;

        /* version 5 superblock fields start here */

        /* feature masks */
        uint32_t        sb_features_compat;
        uint32_t        sb_features_ro_compat;
        uint32_t        sb_features_incompat;
        uint32_t        sb_features_log_incompat;

        uint32_t        sb_crc;         /* superblock crc */
        xfs_extlen_t    sb_spino_align; /* sparse inode chunk alignment */

        xfs_ino_t       sb_pquotino;    /* project quota inode */
        xfs_lsn_t       sb_lsn;         /* last write sequence */
        uuid_t          sb_meta_uuid;   /* metadata file system unique id */

        xfs_ino_t       sb_metadirino;  /* metadata directory tree root */

        xfs_rgnumber_t  sb_rgcount;     /* number of realtime groups */
        xfs_rtxlen_t    sb_rgextents;   /* size of a realtime group in rtx */
        uint8_t         sb_rgblklog;    /* rt group number shift */
        uint8_t         sb_pad[7];      /* zeroes */
        xfs_rfsblock_t  sb_rtstart;     /* start of internal RT section (FSB) */
        xfs_filblks_t   sb_rtreserved;  /* reserved (zoned) RT blocks */

        /* must be padded to 64 bit alignment */
} xfs_sb_t;

/*
 * Superblock - on disk version.
 * Must be padded to 64 bit alignment.
 */
struct xfs_dsb {
        __be32          sb_magicnum;    /* magic number == XFS_SB_MAGIC */
        __be32          sb_blocksize;   /* logical block size, bytes */
        __be64          sb_dblocks;     /* number of data blocks */
        __be64          sb_rblocks;     /* number of realtime blocks */
        __be64          sb_rextents;    /* number of realtime extents */
        uuid_t          sb_uuid;        /* user-visible file system unique id */
        __be64          sb_logstart;    /* starting block of log if internal */
        __be64          sb_rootino;     /* root inode number */
        __be64          sb_rbmino;      /* bitmap inode for realtime extents */
        __be64          sb_rsumino;     /* summary inode for rt bitmap */
        __be32          sb_rextsize;    /* realtime extent size, blocks */
        __be32          sb_agblocks;    /* size of an allocation group */
        __be32          sb_agcount;     /* number of allocation groups */
        __be32          sb_rbmblocks;   /* number of rt bitmap blocks */
        __be32          sb_logblocks;   /* number of log blocks */
        __be16          sb_versionnum;  /* header version == XFS_SB_VERSION */
        __be16          sb_sectsize;    /* volume sector size, bytes */
        __be16          sb_inodesize;   /* inode size, bytes */
        __be16          sb_inopblock;   /* inodes per block */
        char            sb_fname[XFSLABEL_MAX]; /* file system name */
        __u8            sb_blocklog;    /* log2 of sb_blocksize */
        __u8            sb_sectlog;     /* log2 of sb_sectsize */
        __u8            sb_inodelog;    /* log2 of sb_inodesize */
        __u8            sb_inopblog;    /* log2 of sb_inopblock */
        __u8            sb_agblklog;    /* log2 of sb_agblocks (rounded up) */
        __u8            sb_rextslog;    /* log2 of sb_rextents */
        __u8            sb_inprogress;  /* mkfs is in progress, don't mount */
        __u8            sb_imax_pct;    /* max % of fs for inode space */
                                        /* statistics */
        /*
         * These fields must remain contiguous.  If you really
         * want to change their layout, make sure you fix the
         * code in xfs_trans_apply_sb_deltas().
         */
        __be64          sb_icount;      /* allocated inodes */
        __be64          sb_ifree;       /* free inodes */
        __be64          sb_fdblocks;    /* free data blocks */
        __be64          sb_frextents;   /* free realtime extents */
        /*
         * End contiguous fields.
         */
        __be64          sb_uquotino;    /* user quota inode */
        __be64          sb_gquotino;    /* group quota inode */
        __be16          sb_qflags;      /* quota flags */
        __u8            sb_flags;       /* misc. flags */
        __u8            sb_shared_vn;   /* shared version number */
        __be32          sb_inoalignmt;  /* inode chunk alignment, fsblocks */
        __be32          sb_unit;        /* stripe or raid unit */
        __be32          sb_width;       /* stripe or raid width */
        __u8            sb_dirblklog;   /* log2 of dir block size (fsbs) */
        __u8            sb_logsectlog;  /* log2 of the log sector size */
        __be16          sb_logsectsize; /* sector size for the log, bytes */
        __be32          sb_logsunit;    /* stripe unit size for the log */
        __be32          sb_features2;   /* additional feature bits */
        /*
         * bad features2 field as a result of failing to pad the sb
         * structure to 64 bits. Some machines will be using this field
         * for features2 bits. Easiest just to mark it bad and not use
         * it for anything else.
         */
        __be32          sb_bad_features2;

        /* version 5 superblock fields start here */

        /* feature masks */
        __be32          sb_features_compat;
        __be32          sb_features_ro_compat;
        __be32          sb_features_incompat;
        __be32          sb_features_log_incompat;

        __le32          sb_crc;         /* superblock crc */
        __be32          sb_spino_align; /* sparse inode chunk alignment */

        __be64          sb_pquotino;    /* project quota inode */
        __be64          sb_lsn;         /* last write sequence */
        uuid_t          sb_meta_uuid;   /* metadata file system unique id */

        __be64          sb_metadirino;  /* metadata directory tree root */
        __be32          sb_rgcount;     /* # of realtime groups */
        __be32          sb_rgextents;   /* size of rtgroup in rtx */
        __u8            sb_rgblklog;    /* rt group number shift */
        __u8            sb_pad[7];      /* zeroes */
        __be64          sb_rtstart;     /* start of internal RT section (FSB) */
        __be64          sb_rtreserved;  /* reserved (zoned) RT blocks */

        /*
         * The size of this structure must be padded to 64 bit alignment.
         *
         * NOTE: Don't forget to update secondary_sb_whack in xfs_repair when
         * adding new fields here.
         */
};

#define XFS_SB_CRC_OFF          offsetof(struct xfs_dsb, sb_crc)

/*
 * Misc. Flags - warning - these will be cleared by xfs_repair unless
 * a feature bit is set when the flag is used.
 */
#define XFS_SBF_NOFLAGS         0x00    /* no flags set */
#define XFS_SBF_READONLY        0x01    /* only read-only mounts allowed */

/*
 * define max. shared version we can interoperate with
 */
#define XFS_SB_MAX_SHARED_VN    0

#define XFS_SB_VERSION_NUM(sbp) ((sbp)->sb_versionnum & XFS_SB_VERSION_NUMBITS)

static inline bool xfs_sb_is_v5(const struct xfs_sb *sbp)
{
        return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5;
}

/*
 * Detect a mismatched features2 field.  Older kernels read/wrote
 * this into the wrong slot, so to be safe we keep them in sync.
 */
static inline bool xfs_sb_has_mismatched_features2(const struct xfs_sb *sbp)
{
        return sbp->sb_bad_features2 != sbp->sb_features2;
}

static inline bool xfs_sb_version_hasmorebits(const struct xfs_sb *sbp)
{
        return xfs_sb_is_v5(sbp) ||
               (sbp->sb_versionnum & XFS_SB_VERSION_MOREBITSBIT);
}

static inline void xfs_sb_version_addattr(struct xfs_sb *sbp)
{
        sbp->sb_versionnum |= XFS_SB_VERSION_ATTRBIT;
}

static inline void xfs_sb_version_addquota(struct xfs_sb *sbp)
{
        sbp->sb_versionnum |= XFS_SB_VERSION_QUOTABIT;
}

static inline void xfs_sb_version_addattr2(struct xfs_sb *sbp)
{
        sbp->sb_versionnum |= XFS_SB_VERSION_MOREBITSBIT;
        sbp->sb_features2 |= XFS_SB_VERSION2_ATTR2BIT;
}

static inline void xfs_sb_version_addprojid32(struct xfs_sb *sbp)
{
        sbp->sb_versionnum |= XFS_SB_VERSION_MOREBITSBIT;
        sbp->sb_features2 |= XFS_SB_VERSION2_PROJID32BIT;
}

/*
 * Extended v5 superblock feature masks. These are to be used for new v5
 * superblock features only.
 *
 * Compat features are new features that old kernels will not notice or affect
 * and so can mount read-write without issues.
 *
 * RO-Compat (read only) are features that old kernels can read but will break
 * if they write. Hence only read-only mounts of such filesystems are allowed on
 * kernels that don't support the feature bit.
 *
 * InCompat features are features which old kernels will not understand and so
 * must not mount.
 *
 * Log-InCompat features are for changes to log formats or new transactions that
 * can't be replayed on older kernels. The fields are set when the filesystem is
 * mounted, and a clean unmount clears the fields.
 */
#define XFS_SB_FEAT_COMPAT_ALL 0
#define XFS_SB_FEAT_COMPAT_UNKNOWN      ~XFS_SB_FEAT_COMPAT_ALL
static inline bool
xfs_sb_has_compat_feature(
        const struct xfs_sb     *sbp,
        uint32_t                feature)
{
        return (sbp->sb_features_compat & feature) != 0;
}

#define XFS_SB_FEAT_RO_COMPAT_FINOBT   (1 << 0)         /* free inode btree */
#define XFS_SB_FEAT_RO_COMPAT_RMAPBT   (1 << 1)         /* reverse map btree */
#define XFS_SB_FEAT_RO_COMPAT_REFLINK  (1 << 2)         /* reflinked files */
#define XFS_SB_FEAT_RO_COMPAT_INOBTCNT (1 << 3)         /* inobt block counts */
#define XFS_SB_FEAT_RO_COMPAT_ALL \
                (XFS_SB_FEAT_RO_COMPAT_FINOBT | \
                 XFS_SB_FEAT_RO_COMPAT_RMAPBT | \
                 XFS_SB_FEAT_RO_COMPAT_REFLINK| \
                 XFS_SB_FEAT_RO_COMPAT_INOBTCNT)
#define XFS_SB_FEAT_RO_COMPAT_UNKNOWN   ~XFS_SB_FEAT_RO_COMPAT_ALL
static inline bool
xfs_sb_has_ro_compat_feature(
        const struct xfs_sb     *sbp,
        uint32_t                feature)
{
        return (sbp->sb_features_ro_compat & feature) != 0;
}

#define XFS_SB_FEAT_INCOMPAT_FTYPE      (1 << 0)  /* filetype in dirent */
#define XFS_SB_FEAT_INCOMPAT_SPINODES   (1 << 1)  /* sparse inode chunks */
#define XFS_SB_FEAT_INCOMPAT_META_UUID  (1 << 2)  /* metadata UUID */
#define XFS_SB_FEAT_INCOMPAT_BIGTIME    (1 << 3)  /* large timestamps */
#define XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR (1 << 4) /* needs xfs_repair */
#define XFS_SB_FEAT_INCOMPAT_NREXT64    (1 << 5)  /* large extent counters */
#define XFS_SB_FEAT_INCOMPAT_EXCHRANGE  (1 << 6)  /* exchangerange supported */
#define XFS_SB_FEAT_INCOMPAT_PARENT     (1 << 7)  /* parent pointers */
#define XFS_SB_FEAT_INCOMPAT_METADIR    (1 << 8)  /* metadata dir tree */
#define XFS_SB_FEAT_INCOMPAT_ZONED      (1 << 9)  /* zoned RT allocator */
#define XFS_SB_FEAT_INCOMPAT_ZONE_GAPS  (1 << 10) /* RTGs have LBA gaps */

#define XFS_SB_FEAT_INCOMPAT_ALL \
                (XFS_SB_FEAT_INCOMPAT_FTYPE | \
                 XFS_SB_FEAT_INCOMPAT_SPINODES | \
                 XFS_SB_FEAT_INCOMPAT_META_UUID | \
                 XFS_SB_FEAT_INCOMPAT_BIGTIME | \
                 XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR | \
                 XFS_SB_FEAT_INCOMPAT_NREXT64 | \
                 XFS_SB_FEAT_INCOMPAT_EXCHRANGE | \
                 XFS_SB_FEAT_INCOMPAT_PARENT | \
                 XFS_SB_FEAT_INCOMPAT_METADIR | \
                 XFS_SB_FEAT_INCOMPAT_ZONED | \
                 XFS_SB_FEAT_INCOMPAT_ZONE_GAPS)

#define XFS_SB_FEAT_INCOMPAT_UNKNOWN    ~XFS_SB_FEAT_INCOMPAT_ALL
static inline bool
xfs_sb_has_incompat_feature(
        const struct xfs_sb     *sbp,
        uint32_t                feature)
{
        return (sbp->sb_features_incompat & feature) != 0;
}

#define XFS_SB_FEAT_INCOMPAT_LOG_XATTRS   (1 << 0)      /* Delayed Attributes */
#define XFS_SB_FEAT_INCOMPAT_LOG_ALL \
        (XFS_SB_FEAT_INCOMPAT_LOG_XATTRS)
#define XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN        ~XFS_SB_FEAT_INCOMPAT_LOG_ALL
static inline bool
xfs_sb_has_incompat_log_feature(
        const struct xfs_sb     *sbp,
        uint32_t                feature)
{
        return (sbp->sb_features_log_incompat & feature) != 0;
}

static inline void
xfs_sb_remove_incompat_log_features(
        struct xfs_sb   *sbp)
{
        sbp->sb_features_log_incompat &= ~XFS_SB_FEAT_INCOMPAT_LOG_ALL;
}

static inline void
xfs_sb_add_incompat_log_features(
        struct xfs_sb   *sbp,
        unsigned int    features)
{
        sbp->sb_features_log_incompat |= features;
}

static inline bool xfs_sb_version_haslogxattrs(const struct xfs_sb *sbp)
{
        return xfs_sb_is_v5(sbp) && (sbp->sb_features_log_incompat &
                 XFS_SB_FEAT_INCOMPAT_LOG_XATTRS);
}

static inline bool
xfs_is_quota_inode(struct xfs_sb *sbp, xfs_ino_t ino)
{
        return (ino == sbp->sb_uquotino ||
                ino == sbp->sb_gquotino ||
                ino == sbp->sb_pquotino);
}

#define XFS_SB_DADDR            ((xfs_daddr_t)0) /* daddr in filesystem/ag */
#define XFS_SB_BLOCK(mp)        XFS_HDR_BLOCK(mp, XFS_SB_DADDR)

#define XFS_HDR_BLOCK(mp,d)     ((xfs_agblock_t)XFS_BB_TO_FSBT(mp,d))
#define XFS_DADDR_TO_FSB(mp,d)  XFS_AGB_TO_FSB(mp, \
                        xfs_daddr_to_agno(mp,d), xfs_daddr_to_agbno(mp,d))
#define XFS_FSB_TO_DADDR(mp,fsbno)      XFS_AGB_TO_DADDR(mp, \
                        XFS_FSB_TO_AGNO(mp,fsbno), XFS_FSB_TO_AGBNO(mp,fsbno))

/*
 * File system sector to basic block conversions.
 */
#define XFS_FSS_TO_BB(mp,sec)   ((sec) << (mp)->m_sectbb_log)

/*
 * File system block to basic block conversions.
 */
#define XFS_FSB_TO_BB(mp,fsbno) ((fsbno) << (mp)->m_blkbb_log)
#define XFS_BB_TO_FSB(mp,bb)    \
        (((bb) + (XFS_FSB_TO_BB(mp,1) - 1)) >> (mp)->m_blkbb_log)
#define XFS_BB_TO_FSBT(mp,bb)   ((bb) >> (mp)->m_blkbb_log)

/*
 * File system block to byte conversions.
 */
#define XFS_FSB_TO_B(mp,fsbno)  ((xfs_fsize_t)(fsbno) << (mp)->m_sb.sb_blocklog)
#define XFS_B_TO_FSB(mp,b)      \
        ((((uint64_t)(b)) + (mp)->m_blockmask) >> (mp)->m_sb.sb_blocklog)
#define XFS_B_TO_FSBT(mp,b)     (((uint64_t)(b)) >> (mp)->m_sb.sb_blocklog)

/*
 * Allocation group header
 *
 * This is divided into three structures, placed in sequential 512-byte
 * buffers after a copy of the superblock (also in a 512-byte buffer).
 */
#define XFS_AGF_MAGIC   0x58414746      /* 'XAGF' */
#define XFS_AGI_MAGIC   0x58414749      /* 'XAGI' */
#define XFS_AGFL_MAGIC  0x5841464c      /* 'XAFL' */
#define XFS_AGF_VERSION 1
#define XFS_AGI_VERSION 1

#define XFS_AGF_GOOD_VERSION(v) ((v) == XFS_AGF_VERSION)
#define XFS_AGI_GOOD_VERSION(v) ((v) == XFS_AGI_VERSION)

/*
 * agf_cnt_level in the first AGF overlaps the EFS superblock's magic number.
 * Since the magic numbers valid for EFS are > 64k, our value cannot be confused
 * for an EFS superblock.
 */

typedef struct xfs_agf {
        /*
         * Common allocation group header information
         */
        __be32          agf_magicnum;   /* magic number == XFS_AGF_MAGIC */
        __be32          agf_versionnum; /* header version == XFS_AGF_VERSION */
        __be32          agf_seqno;      /* sequence # starting from 0 */
        __be32          agf_length;     /* size in blocks of a.g. */
        /*
         * Freespace and rmap information
         */
        __be32          agf_bno_root;   /* bnobt root block */
        __be32          agf_cnt_root;   /* cntbt root block */
        __be32          agf_rmap_root;  /* rmapbt root block */

        __be32          agf_bno_level;  /* bnobt btree levels */
        __be32          agf_cnt_level;  /* cntbt btree levels */
        __be32          agf_rmap_level; /* rmapbt btree levels */

        __be32          agf_flfirst;    /* first freelist block's index */
        __be32          agf_fllast;     /* last freelist block's index */
        __be32          agf_flcount;    /* count of blocks in freelist */
        __be32          agf_freeblks;   /* total free blocks */

        __be32          agf_longest;    /* longest free space */
        __be32          agf_btreeblks;  /* # of blocks held in AGF btrees */
        uuid_t          agf_uuid;       /* uuid of filesystem */

        __be32          agf_rmap_blocks;        /* rmapbt blocks used */
        __be32          agf_refcount_blocks;    /* refcountbt blocks used */

        __be32          agf_refcount_root;      /* refcount tree root block */
        __be32          agf_refcount_level;     /* refcount btree levels */

        /*
         * reserve some contiguous space for future logged fields before we add
         * the unlogged fields. This makes the range logging via flags and
         * structure offsets much simpler.
         */
        __be64          agf_spare64[14];

        /* unlogged fields, written during buffer writeback. */
        __be64          agf_lsn;        /* last write sequence */
        __be32          agf_crc;        /* crc of agf sector */
        __be32          agf_spare2;

        /* structure must be padded to 64 bit alignment */
} xfs_agf_t;

#define XFS_AGF_CRC_OFF         offsetof(struct xfs_agf, agf_crc)

#define XFS_AGF_MAGICNUM        (1u << 0)
#define XFS_AGF_VERSIONNUM      (1u << 1)
#define XFS_AGF_SEQNO           (1u << 2)
#define XFS_AGF_LENGTH          (1u << 3)
#define XFS_AGF_ROOTS           (1u << 4)
#define XFS_AGF_LEVELS          (1u << 5)
#define XFS_AGF_FLFIRST         (1u << 6)
#define XFS_AGF_FLLAST          (1u << 7)
#define XFS_AGF_FLCOUNT         (1u << 8)
#define XFS_AGF_FREEBLKS        (1u << 9)
#define XFS_AGF_LONGEST         (1u << 10)
#define XFS_AGF_BTREEBLKS       (1u << 11)
#define XFS_AGF_UUID            (1u << 12)
#define XFS_AGF_RMAP_BLOCKS     (1u << 13)
#define XFS_AGF_REFCOUNT_BLOCKS (1u << 14)
#define XFS_AGF_REFCOUNT_ROOT   (1u << 15)
#define XFS_AGF_REFCOUNT_LEVEL  (1u << 16)
#define XFS_AGF_SPARE64         (1u << 17)
#define XFS_AGF_NUM_BITS        18
#define XFS_AGF_ALL_BITS        ((1u << XFS_AGF_NUM_BITS) - 1)

#define XFS_AGF_FLAGS \
        { XFS_AGF_MAGICNUM,     "MAGICNUM" }, \
        { XFS_AGF_VERSIONNUM,   "VERSIONNUM" }, \
        { XFS_AGF_SEQNO,        "SEQNO" }, \
        { XFS_AGF_LENGTH,       "LENGTH" }, \
        { XFS_AGF_ROOTS,        "ROOTS" }, \
        { XFS_AGF_LEVELS,       "LEVELS" }, \
        { XFS_AGF_FLFIRST,      "FLFIRST" }, \
        { XFS_AGF_FLLAST,       "FLLAST" }, \
        { XFS_AGF_FLCOUNT,      "FLCOUNT" }, \
        { XFS_AGF_FREEBLKS,     "FREEBLKS" }, \
        { XFS_AGF_LONGEST,      "LONGEST" }, \
        { XFS_AGF_BTREEBLKS,    "BTREEBLKS" }, \
        { XFS_AGF_UUID,         "UUID" }, \
        { XFS_AGF_RMAP_BLOCKS,  "RMAP_BLOCKS" }, \
        { XFS_AGF_REFCOUNT_BLOCKS,      "REFCOUNT_BLOCKS" }, \
        { XFS_AGF_REFCOUNT_ROOT,        "REFCOUNT_ROOT" }, \
        { XFS_AGF_REFCOUNT_LEVEL,       "REFCOUNT_LEVEL" }, \
        { XFS_AGF_SPARE64,      "SPARE64" }

/* disk block (xfs_daddr_t) in the AG */
#define XFS_AGF_DADDR(mp)       ((xfs_daddr_t)(1 << (mp)->m_sectbb_log))
#define XFS_AGF_BLOCK(mp)       XFS_HDR_BLOCK(mp, XFS_AGF_DADDR(mp))

/*
 * Size of the unlinked inode hash table in the agi.
 */
#define XFS_AGI_UNLINKED_BUCKETS        64

typedef struct xfs_agi {
        /*
         * Common allocation group header information
         */
        __be32          agi_magicnum;   /* magic number == XFS_AGI_MAGIC */
        __be32          agi_versionnum; /* header version == XFS_AGI_VERSION */
        __be32          agi_seqno;      /* sequence # starting from 0 */
        __be32          agi_length;     /* size in blocks of a.g. */
        /*
         * Inode information
         * Inodes are mapped by interpreting the inode number, so no
         * mapping data is needed here.
         */
        __be32          agi_count;      /* count of allocated inodes */
        __be32          agi_root;       /* root of inode btree */
        __be32          agi_level;      /* levels in inode btree */
        __be32          agi_freecount;  /* number of free inodes */

        __be32          agi_newino;     /* new inode just allocated */
        __be32          agi_dirino;     /* last directory inode chunk */
        /*
         * Hash table of inodes which have been unlinked but are
         * still being referenced.
         */
        __be32          agi_unlinked[XFS_AGI_UNLINKED_BUCKETS];
        /*
         * This marks the end of logging region 1 and start of logging region 2.
         */
        uuid_t          agi_uuid;       /* uuid of filesystem */
        __be32          agi_crc;        /* crc of agi sector */
        __be32          agi_pad32;
        __be64          agi_lsn;        /* last write sequence */

        __be32          agi_free_root; /* root of the free inode btree */
        __be32          agi_free_level;/* levels in free inode btree */

        __be32          agi_iblocks;    /* inobt blocks used */
        __be32          agi_fblocks;    /* finobt blocks used */

        /* structure must be padded to 64 bit alignment */
} xfs_agi_t;

#define XFS_AGI_CRC_OFF         offsetof(struct xfs_agi, agi_crc)

#define XFS_AGI_MAGICNUM        (1u << 0)
#define XFS_AGI_VERSIONNUM      (1u << 1)
#define XFS_AGI_SEQNO           (1u << 2)
#define XFS_AGI_LENGTH          (1u << 3)
#define XFS_AGI_COUNT           (1u << 4)
#define XFS_AGI_ROOT            (1u << 5)
#define XFS_AGI_LEVEL           (1u << 6)
#define XFS_AGI_FREECOUNT       (1u << 7)
#define XFS_AGI_NEWINO          (1u << 8)
#define XFS_AGI_DIRINO          (1u << 9)
#define XFS_AGI_UNLINKED        (1u << 10)
#define XFS_AGI_NUM_BITS_R1     11      /* end of the 1st agi logging region */
#define XFS_AGI_ALL_BITS_R1     ((1u << XFS_AGI_NUM_BITS_R1) - 1)
#define XFS_AGI_FREE_ROOT       (1u << 11)
#define XFS_AGI_FREE_LEVEL      (1u << 12)
#define XFS_AGI_IBLOCKS         (1u << 13) /* both inobt/finobt block counters */
#define XFS_AGI_NUM_BITS_R2     14

/* disk block (xfs_daddr_t) in the AG */
#define XFS_AGI_DADDR(mp)       ((xfs_daddr_t)(2 << (mp)->m_sectbb_log))
#define XFS_AGI_BLOCK(mp)       XFS_HDR_BLOCK(mp, XFS_AGI_DADDR(mp))

/*
 * The third a.g. block contains the a.g. freelist, an array
 * of block pointers to blocks owned by the allocation btree code.
 */
#define XFS_AGFL_DADDR(mp)      ((xfs_daddr_t)(3 << (mp)->m_sectbb_log))
#define XFS_AGFL_BLOCK(mp)      XFS_HDR_BLOCK(mp, XFS_AGFL_DADDR(mp))
#define XFS_BUF_TO_AGFL(bp)     ((struct xfs_agfl *)((bp)->b_addr))

struct xfs_agfl {
        __be32          agfl_magicnum;
        __be32          agfl_seqno;
        uuid_t          agfl_uuid;
        __be64          agfl_lsn;
        __be32          agfl_crc;
} __attribute__((packed));

#define XFS_AGFL_CRC_OFF        offsetof(struct xfs_agfl, agfl_crc)

#define XFS_AGB_TO_FSB(mp,agno,agbno)   \
        (((xfs_fsblock_t)(agno) << (mp)->m_sb.sb_agblklog) | (agbno))
#define XFS_FSB_TO_AGNO(mp,fsbno)       \
        ((xfs_agnumber_t)((fsbno) >> (mp)->m_sb.sb_agblklog))
#define XFS_FSB_TO_AGBNO(mp,fsbno)      \
        ((xfs_agblock_t)((fsbno) & xfs_mask32lo((mp)->m_sb.sb_agblklog)))
#define XFS_AGB_TO_DADDR(mp,agno,agbno) \
        ((xfs_daddr_t)XFS_FSB_TO_BB(mp, \
                (xfs_fsblock_t)(agno) * (mp)->m_sb.sb_agblocks + (agbno)))
#define XFS_AG_DADDR(mp,agno,d)         (XFS_AGB_TO_DADDR(mp, agno, 0) + (d))

/*
 * For checking for bad ranges of xfs_daddr_t's, covering multiple
 * allocation groups or a single xfs_daddr_t that's a superblock copy.
 */
#define XFS_AG_CHECK_DADDR(mp,d,len)    \
        ((len) == 1 ? \
            ASSERT((d) == XFS_SB_DADDR || \
                   xfs_daddr_to_agbno(mp, d) != XFS_SB_DADDR) : \
            ASSERT(xfs_daddr_to_agno(mp, d) == \
                   xfs_daddr_to_agno(mp, (d) + (len) - 1)))

/*
 * Realtime bitmap information is accessed by the word, which is currently
 * stored in host-endian format.  Starting with the realtime groups feature,
 * the words are stored in be32 ondisk.
 */
union xfs_rtword_raw {
        __u32           old;
        __be32          rtg;
};

/*
 * Realtime summary counts are accessed by the word, which is currently
 * stored in host-endian format.  Starting with the realtime groups feature,
 * the words are stored in be32 ondisk.
 */
union xfs_suminfo_raw {
        __u32           old;
        __be32          rtg;
};

/*
 * Realtime allocation groups break the rt section into multiple pieces that
 * could be locked independently.  Realtime block group numbers are 32-bit
 * quantities.  Block numbers within a group are also 32-bit quantities, but
 * the upper bit must never be set.  rtgroup 0 might have a superblock in it,
 * so the minimum size of an rtgroup is 2 rtx.
 */
#define XFS_MAX_RGBLOCKS        ((xfs_rgblock_t)(1U << 31) - 1)
#define XFS_MIN_RGEXTENTS       ((xfs_rtxlen_t)2)
#define XFS_MAX_RGNUMBER        ((xfs_rgnumber_t)(-1U))

#define XFS_RTSB_MAGIC  0x46726F67      /* 'Frog' */

/*
 * Realtime superblock - on disk version.  Must be padded to 64 bit alignment.
 * The first block of the realtime volume contains this superblock.
 */
struct xfs_rtsb {
        __be32          rsb_magicnum;   /* magic number == XFS_RTSB_MAGIC */
        __le32          rsb_crc;        /* superblock crc */

        __be32          rsb_pad;        /* zero */
        unsigned char   rsb_fname[XFSLABEL_MAX]; /* file system name */

        uuid_t          rsb_uuid;       /* user-visible file system unique id */
        uuid_t          rsb_meta_uuid;  /* metadata file system unique id */

        /* must be padded to 64 bit alignment */
};

#define XFS_RTSB_CRC_OFF        offsetof(struct xfs_rtsb, rsb_crc)
#define XFS_RTSB_DADDR          ((xfs_daddr_t)0) /* daddr in rt section */

/*
 * XFS Timestamps
 * ==============
 *
 * Traditional ondisk inode timestamps consist of signed 32-bit counters for
 * seconds and nanoseconds; time zero is the Unix epoch, Jan  1 00:00:00 UTC
 * 1970, which means that the timestamp epoch is the same as the Unix epoch.
 * Therefore, the ondisk min and max defined here can be used directly to
 * constrain the incore timestamps on a Unix system.  Note that we actually
 * encode a __be64 value on disk.
 *
 * When the bigtime feature is enabled, ondisk inode timestamps become an
 * unsigned 64-bit nanoseconds counter.  This means that the bigtime inode
 * timestamp epoch is the start of the classic timestamp range, which is
 * Dec 13 20:45:52 UTC 1901.  Because the epochs are not the same, callers
 * /must/ use the bigtime conversion functions when encoding and decoding raw
 * timestamps.
 */
typedef __be64 xfs_timestamp_t;

/* Legacy timestamp encoding format. */
struct xfs_legacy_timestamp {
        __be32          t_sec;          /* timestamp seconds */
        __be32          t_nsec;         /* timestamp nanoseconds */
};

/*
 * Smallest possible ondisk seconds value with traditional timestamps.  This
 * corresponds exactly with the incore timestamp Dec 13 20:45:52 UTC 1901.
 */
#define XFS_LEGACY_TIME_MIN     ((int64_t)S32_MIN)

/*
 * Largest possible ondisk seconds value with traditional timestamps.  This
 * corresponds exactly with the incore timestamp Jan 19 03:14:07 UTC 2038.
 */
#define XFS_LEGACY_TIME_MAX     ((int64_t)S32_MAX)

/*
 * Smallest possible ondisk seconds value with bigtime timestamps.  This
 * corresponds (after conversion to a Unix timestamp) with the traditional
 * minimum timestamp of Dec 13 20:45:52 UTC 1901.
 */
#define XFS_BIGTIME_TIME_MIN    ((int64_t)0)

/*
 * Largest supported ondisk seconds value with bigtime timestamps.  This
 * corresponds (after conversion to a Unix timestamp) with an incore timestamp
 * of Jul  2 20:20:24 UTC 2486.
 *
 * We round down the ondisk limit so that the bigtime quota and inode max
 * timestamps will be the same.
 */
#define XFS_BIGTIME_TIME_MAX    ((int64_t)((-1ULL / NSEC_PER_SEC) & ~0x3ULL))

/*
 * Bigtime epoch is set exactly to the minimum time value that a traditional
 * 32-bit timestamp can represent when using the Unix epoch as a reference.
 * Hence the Unix epoch is at a fixed offset into the supported bigtime
 * timestamp range.
 *
 * The bigtime epoch also matches the minimum value an on-disk 32-bit XFS
 * timestamp can represent so we will not lose any fidelity in converting
 * to/from unix and bigtime timestamps.
 *
 * The following conversion factor converts a seconds counter from the Unix
 * epoch to the bigtime epoch.
 */
#define XFS_BIGTIME_EPOCH_OFFSET        (-(int64_t)S32_MIN)

/* Convert a timestamp from the Unix epoch to the bigtime epoch. */
static inline uint64_t xfs_unix_to_bigtime(time64_t unix_seconds)
{
        return (uint64_t)unix_seconds + XFS_BIGTIME_EPOCH_OFFSET;
}

/* Convert a timestamp from the bigtime epoch to the Unix epoch. */
static inline time64_t xfs_bigtime_to_unix(uint64_t ondisk_seconds)
{
        return (time64_t)ondisk_seconds - XFS_BIGTIME_EPOCH_OFFSET;
}

enum xfs_metafile_type {
        XFS_METAFILE_UNKNOWN,           /* unknown */
        XFS_METAFILE_DIR,               /* metadir directory */
        XFS_METAFILE_USRQUOTA,          /* user quota */
        XFS_METAFILE_GRPQUOTA,          /* group quota */
        XFS_METAFILE_PRJQUOTA,          /* project quota */
        XFS_METAFILE_RTBITMAP,          /* rt bitmap */
        XFS_METAFILE_RTSUMMARY,         /* rt summary */
        XFS_METAFILE_RTRMAP,            /* rt rmap */
        XFS_METAFILE_RTREFCOUNT,        /* rt refcount */

        XFS_METAFILE_MAX
} __packed;

#define XFS_METAFILE_TYPE_STR \
        { XFS_METAFILE_UNKNOWN,         "unknown" }, \
        { XFS_METAFILE_DIR,             "dir" }, \
        { XFS_METAFILE_USRQUOTA,        "usrquota" }, \
        { XFS_METAFILE_GRPQUOTA,        "grpquota" }, \
        { XFS_METAFILE_PRJQUOTA,        "prjquota" }, \
        { XFS_METAFILE_RTBITMAP,        "rtbitmap" }, \
        { XFS_METAFILE_RTSUMMARY,       "rtsummary" }, \
        { XFS_METAFILE_RTRMAP,          "rtrmap" }, \
        { XFS_METAFILE_RTREFCOUNT,      "rtrefcount" }

/*
 * On-disk inode structure.
 *
 * This is just the header or "dinode core", the inode is expanded to fill a
 * variable size the leftover area split into a data and an attribute fork.
 * The format of the data and attribute fork depends on the format of the
 * inode as indicated by di_format and di_aformat.  To access the data and
 * attribute use the XFS_DFORK_DPTR, XFS_DFORK_APTR, and XFS_DFORK_PTR macros
 * below.
 *
 * There is a very similar struct xfs_log_dinode which matches the layout of
 * this structure, but is kept in native format instead of big endian.
 *
 * Note: di_flushiter is only used by v1/2 inodes - it's effectively a zeroed
 * padding field for v3 inodes.
 */
#define XFS_DINODE_MAGIC                0x494e  /* 'IN' */
struct xfs_dinode {
        __be16          di_magic;       /* inode magic # = XFS_DINODE_MAGIC */
        __be16          di_mode;        /* mode and type of file */
        __u8            di_version;     /* inode version */
        __u8            di_format;      /* format of di_c data */
        __be16          di_metatype;    /* XFS_METAFILE_*; was di_onlink */
        __be32          di_uid;         /* owner's user id */
        __be32          di_gid;         /* owner's group id */
        __be32          di_nlink;       /* number of links to file */
        __be16          di_projid_lo;   /* lower part of owner's project id */
        __be16          di_projid_hi;   /* higher part owner's project id */
        union {
                /* Number of data fork extents if NREXT64 is set */
                __be64  di_big_nextents;

                /* Padding for V3 inodes without NREXT64 set. */
                __be64  di_v3_pad;

                /* Padding and inode flush counter for V2 inodes. */
                struct {
                        __u8    di_v2_pad[6];
                        __be16  di_flushiter;
                };
        };
        xfs_timestamp_t di_atime;       /* time last accessed */
        xfs_timestamp_t di_mtime;       /* time last modified */
        xfs_timestamp_t di_ctime;       /* time created/inode modified */
        __be64          di_size;        /* number of bytes in file */
        __be64          di_nblocks;     /* # of direct & btree blocks used */
        __be32          di_extsize;     /* basic/minimum extent size for file */
        union {
                /*
                 * For V2 inodes and V3 inodes without NREXT64 set, this
                 * is the number of data and attr fork extents.
                 */
                struct {
                        __be32  di_nextents;
                        __be16  di_anextents;
                } __packed;

                /* Number of attr fork extents if NREXT64 is set. */
                struct {
                        __be32  di_big_anextents;
                        __be16  di_nrext64_pad;
                } __packed;
        } __packed;
        __u8            di_forkoff;     /* attr fork offs, <<3 for 64b align */
        __s8            di_aformat;     /* format of attr fork's data */
        __be32          di_dmevmask;    /* DMIG event mask */
        __be16          di_dmstate;     /* DMIG state info */
        __be16          di_flags;       /* random flags, XFS_DIFLAG_... */
        __be32          di_gen;         /* generation number */

        /* di_next_unlinked is the only non-core field in the old dinode */
        __be32          di_next_unlinked;/* agi unlinked list ptr */

        /* start of the extended dinode, writable fields */
        __le32          di_crc;         /* CRC of the inode */
        __be64          di_changecount; /* number of attribute changes */
        __be64          di_lsn;         /* flush sequence */
        __be64          di_flags2;      /* more random flags */
        union {
                /* basic cow extent size for (regular) file */
                __be32          di_cowextsize;
                /* used blocks in RTG for (zoned) rtrmap inode */
                __be32          di_used_blocks;
        };
        __u8            di_pad2[12];    /* more padding for future expansion */

        /* fields only written to during inode creation */
        xfs_timestamp_t di_crtime;      /* time created */
        __be64          di_ino;         /* inode number */
        uuid_t          di_uuid;        /* UUID of the filesystem */

        /* structure must be padded to 64 bit alignment */
};

#define XFS_DINODE_CRC_OFF      offsetof(struct xfs_dinode, di_crc)

#define DI_MAX_FLUSH 0xffff

/*
 * Size of the core inode on disk.  Version 1 and 2 inodes have
 * the same size, but version 3 has grown a few additional fields.
 */
static inline uint xfs_dinode_size(int version)
{
        if (version == 3)
                return sizeof(struct xfs_dinode);
        return offsetof(struct xfs_dinode, di_crc);
}

/*
 * The 32 bit link count in the inode theoretically maxes out at UINT_MAX.
 * Since the pathconf interface is signed, we use 2^31 - 1 instead.
 */
#define XFS_MAXLINK             ((1U << 31) - 1U)

/*
 * Any file that hits the maximum ondisk link count should be pinned to avoid
 * a use-after-free situation.
 */
#define XFS_NLINK_PINNED        (~0U)

/*
 * Values for di_format
 *
 * This enum is used in string mapping in xfs_trace.h; please keep the
 * TRACE_DEFINE_ENUMs for it up to date.
 */
enum xfs_dinode_fmt {
        XFS_DINODE_FMT_DEV,             /* xfs_dev_t */
        XFS_DINODE_FMT_LOCAL,           /* bulk data */
        XFS_DINODE_FMT_EXTENTS,         /* struct xfs_bmbt_rec */
        XFS_DINODE_FMT_BTREE,           /* struct xfs_bmdr_block */
        XFS_DINODE_FMT_UUID,            /* added long ago, but never used */
        XFS_DINODE_FMT_META_BTREE,      /* metadata btree */
};

#define XFS_INODE_FORMAT_STR \
        { XFS_DINODE_FMT_DEV,           "dev" }, \
        { XFS_DINODE_FMT_LOCAL,         "local" }, \
        { XFS_DINODE_FMT_EXTENTS,       "extent" }, \
        { XFS_DINODE_FMT_BTREE,         "btree" }, \
        { XFS_DINODE_FMT_UUID,          "uuid" }, \
        { XFS_DINODE_FMT_META_BTREE,    "meta_btree" }

/*
 * Max values for extnum and aextnum.
 *
 * The original on-disk extent counts were held in signed fields, resulting in
 * maximum extent counts of 2^31 and 2^15 for the data and attr forks
 * respectively. Similarly the maximum extent length is limited to 2^21 blocks
 * by the 21-bit wide blockcount field of a BMBT extent record.
 *
 * The newly introduced data fork extent counter can hold a 64-bit value,
 * however the maximum number of extents in a file is also limited to 2^54
 * extents by the 54-bit wide startoff field of a BMBT extent record.
 *
 * It is further limited by the maximum supported file size of 2^63
 * *bytes*. This leads to a maximum extent count for maximally sized filesystem
 * blocks (64kB) of:
 *
 * 2^63 bytes / 2^16 bytes per block = 2^47 blocks
 *
 * Rounding up 47 to the nearest multiple of bits-per-byte results in 48. Hence
 * 2^48 was chosen as the maximum data fork extent count.
 *
 * The maximum file size that can be represented by the data fork extent counter
 * in the worst case occurs when all extents are 1 block in length and each
 * block is 1KB in size.
 *
 * With XFS_MAX_EXTCNT_DATA_FORK_SMALL representing maximum extent count and
 * with 1KB sized blocks, a file can reach upto,
 * 1KB * (2^31) = 2TB
 *
 * This is much larger than the theoretical maximum size of a directory
 * i.e. XFS_DIR2_SPACE_SIZE * XFS_DIR2_MAX_SPACES = ~96GB.
 *
 * Hence, a directory inode can never overflow its data fork extent counter.
 */
#define XFS_MAX_EXTCNT_DATA_FORK_LARGE  ((xfs_extnum_t)((1ULL << 48) - 1))
#define XFS_MAX_EXTCNT_ATTR_FORK_LARGE  ((xfs_extnum_t)((1ULL << 32) - 1))
#define XFS_MAX_EXTCNT_DATA_FORK_SMALL  ((xfs_extnum_t)((1ULL << 31) - 1))
#define XFS_MAX_EXTCNT_ATTR_FORK_SMALL  ((xfs_extnum_t)((1ULL << 15) - 1))

/*
 * When we upgrade an inode to the large extent counts, the maximum value by
 * which the extent count can increase is bound by the change in size of the
 * on-disk field. No upgrade operation should ever be adding more than a few
 * tens of extents, so if we get a really large value it is a sign of a code bug
 * or corruption.
 */
#define XFS_MAX_EXTCNT_UPGRADE_NR       \
        min(XFS_MAX_EXTCNT_ATTR_FORK_LARGE - XFS_MAX_EXTCNT_ATTR_FORK_SMALL,    \
            XFS_MAX_EXTCNT_DATA_FORK_LARGE - XFS_MAX_EXTCNT_DATA_FORK_SMALL)

/*
 * Inode minimum and maximum sizes.
 */
#define XFS_DINODE_MIN_LOG      8
#define XFS_DINODE_MAX_LOG      11
#define XFS_DINODE_MIN_SIZE     (1 << XFS_DINODE_MIN_LOG)
#define XFS_DINODE_MAX_SIZE     (1 << XFS_DINODE_MAX_LOG)

/*
 * Inode size for given fs.
 */
#define XFS_DINODE_SIZE(mp) \
        (xfs_has_v3inodes(mp) ? \
                sizeof(struct xfs_dinode) : \
                offsetof(struct xfs_dinode, di_crc))
#define XFS_LITINO(mp) \
        ((mp)->m_sb.sb_inodesize - XFS_DINODE_SIZE(mp))

/*
 * Inode data & attribute fork sizes, per inode.
 */
#define XFS_DFORK_BOFF(dip)             ((int)((dip)->di_forkoff << 3))

#define XFS_DFORK_DSIZE(dip,mp) \
        ((dip)->di_forkoff ? XFS_DFORK_BOFF(dip) : XFS_LITINO(mp))
#define XFS_DFORK_ASIZE(dip,mp) \
        ((dip)->di_forkoff ? XFS_LITINO(mp) - XFS_DFORK_BOFF(dip) : 0)
#define XFS_DFORK_SIZE(dip,mp,w) \
        ((w) == XFS_DATA_FORK ? \
                XFS_DFORK_DSIZE(dip, mp) : \
                XFS_DFORK_ASIZE(dip, mp))

#define XFS_DFORK_MAXEXT(dip, mp, w) \
        (XFS_DFORK_SIZE(dip, mp, w) / sizeof(struct xfs_bmbt_rec))

/*
 * Return pointers to the data or attribute forks.
 */
#define XFS_DFORK_DPTR(dip) \
        ((void *)dip + xfs_dinode_size(dip->di_version))
#define XFS_DFORK_APTR(dip)     \
        (XFS_DFORK_DPTR(dip) + XFS_DFORK_BOFF(dip))
#define XFS_DFORK_PTR(dip,w)    \
        ((w) == XFS_DATA_FORK ? XFS_DFORK_DPTR(dip) : XFS_DFORK_APTR(dip))

#define XFS_DFORK_FORMAT(dip,w) \
        ((w) == XFS_DATA_FORK ? \
                (dip)->di_format : \
                (dip)->di_aformat)

/*
 * For block and character special files the 32bit dev_t is stored at the
 * beginning of the data fork.
 */
static inline xfs_dev_t xfs_dinode_get_rdev(struct xfs_dinode *dip)
{
        return be32_to_cpu(*(__be32 *)XFS_DFORK_DPTR(dip));
}

static inline void xfs_dinode_put_rdev(struct xfs_dinode *dip, xfs_dev_t rdev)
{
        *(__be32 *)XFS_DFORK_DPTR(dip) = cpu_to_be32(rdev);
}

/*
 * Values for di_flags
 */
#define XFS_DIFLAG_REALTIME_BIT  0      /* file's blocks come from rt area */
#define XFS_DIFLAG_PREALLOC_BIT  1      /* file space has been preallocated */
#define XFS_DIFLAG_NEWRTBM_BIT   2      /* for rtbitmap inode, new format */
#define XFS_DIFLAG_IMMUTABLE_BIT 3      /* inode is immutable */
#define XFS_DIFLAG_APPEND_BIT    4      /* inode is append-only */
#define XFS_DIFLAG_SYNC_BIT      5      /* inode is written synchronously */
#define XFS_DIFLAG_NOATIME_BIT   6      /* do not update atime */
#define XFS_DIFLAG_NODUMP_BIT    7      /* do not dump */
#define XFS_DIFLAG_RTINHERIT_BIT 8      /* create with realtime bit set */
#define XFS_DIFLAG_PROJINHERIT_BIT   9  /* create with parents projid */
#define XFS_DIFLAG_NOSYMLINKS_BIT   10  /* disallow symlink creation */
#define XFS_DIFLAG_EXTSIZE_BIT      11  /* inode extent size allocator hint */
#define XFS_DIFLAG_EXTSZINHERIT_BIT 12  /* inherit inode extent size */
#define XFS_DIFLAG_NODEFRAG_BIT     13  /* do not reorganize/defragment */
#define XFS_DIFLAG_FILESTREAM_BIT   14  /* use filestream allocator */
/* Do not use bit 15, di_flags is legacy and unchanging now */

#define XFS_DIFLAG_REALTIME      (1 << XFS_DIFLAG_REALTIME_BIT)
#define XFS_DIFLAG_PREALLOC      (1 << XFS_DIFLAG_PREALLOC_BIT)
#define XFS_DIFLAG_NEWRTBM       (1 << XFS_DIFLAG_NEWRTBM_BIT)
#define XFS_DIFLAG_IMMUTABLE     (1 << XFS_DIFLAG_IMMUTABLE_BIT)
#define XFS_DIFLAG_APPEND        (1 << XFS_DIFLAG_APPEND_BIT)
#define XFS_DIFLAG_SYNC          (1 << XFS_DIFLAG_SYNC_BIT)
#define XFS_DIFLAG_NOATIME       (1 << XFS_DIFLAG_NOATIME_BIT)
#define XFS_DIFLAG_NODUMP        (1 << XFS_DIFLAG_NODUMP_BIT)
#define XFS_DIFLAG_RTINHERIT     (1 << XFS_DIFLAG_RTINHERIT_BIT)
#define XFS_DIFLAG_PROJINHERIT   (1 << XFS_DIFLAG_PROJINHERIT_BIT)
#define XFS_DIFLAG_NOSYMLINKS    (1 << XFS_DIFLAG_NOSYMLINKS_BIT)
#define XFS_DIFLAG_EXTSIZE       (1 << XFS_DIFLAG_EXTSIZE_BIT)
#define XFS_DIFLAG_EXTSZINHERIT  (1 << XFS_DIFLAG_EXTSZINHERIT_BIT)
#define XFS_DIFLAG_NODEFRAG      (1 << XFS_DIFLAG_NODEFRAG_BIT)
#define XFS_DIFLAG_FILESTREAM    (1 << XFS_DIFLAG_FILESTREAM_BIT)

#define XFS_DIFLAG_ANY \
        (XFS_DIFLAG_REALTIME | XFS_DIFLAG_PREALLOC | XFS_DIFLAG_NEWRTBM | \
         XFS_DIFLAG_IMMUTABLE | XFS_DIFLAG_APPEND | XFS_DIFLAG_SYNC | \
         XFS_DIFLAG_NOATIME | XFS_DIFLAG_NODUMP | XFS_DIFLAG_RTINHERIT | \
         XFS_DIFLAG_PROJINHERIT | XFS_DIFLAG_NOSYMLINKS | XFS_DIFLAG_EXTSIZE | \
         XFS_DIFLAG_EXTSZINHERIT | XFS_DIFLAG_NODEFRAG | XFS_DIFLAG_FILESTREAM)

/*
 * Values for di_flags2 These start by being exposed to userspace in the upper
 * 16 bits of the XFS_XFLAG_s range.
 */
/* use DAX for this inode */
#define XFS_DIFLAG2_DAX_BIT             0

/* file's blocks may be shared */
#define XFS_DIFLAG2_REFLINK_BIT         1

/* copy on write extent size hint */
#define XFS_DIFLAG2_COWEXTSIZE_BIT      2

/* big timestamps */
#define XFS_DIFLAG2_BIGTIME_BIT         3

/* large extent counters */
#define XFS_DIFLAG2_NREXT64_BIT         4

/*
 * The inode contains filesystem metadata and can be found through the metadata
 * directory tree.  Metadata inodes must satisfy the following constraints:
 *
 * - V5 filesystem (and ftype) are enabled;
 * - The only valid modes are regular files and directories;
 * - The access bits must be zero;
 * - DMAPI event and state masks are zero;
 * - The user and group IDs must be zero;
 * - The project ID can be used as a u32 annotation;
 * - The immutable, sync, noatime, nodump, nodefrag flags must be set.
 * - The dax flag must not be set.
 * - Directories must have nosymlinks set.
 *
 * These requirements are chosen defensively to minimize the ability of
 * userspace to read or modify the contents, should a metadata file ever
 * escape to userspace.
 *
 * There are further constraints on the directory tree itself:
 *
 * - Metadata inodes must never be resolvable through the root directory;
 * - They must never be accessed by userspace;
 * - Metadata directory entries must have correct ftype.
 *
 * Superblock-rooted metadata files must have the METADATA iflag set even
 * though they do not have a parent directory.
 */
#define XFS_DIFLAG2_METADATA_BIT        5

#define XFS_DIFLAG2_DAX         (1ULL << XFS_DIFLAG2_DAX_BIT)
#define XFS_DIFLAG2_REFLINK     (1ULL << XFS_DIFLAG2_REFLINK_BIT)
#define XFS_DIFLAG2_COWEXTSIZE  (1ULL << XFS_DIFLAG2_COWEXTSIZE_BIT)
#define XFS_DIFLAG2_BIGTIME     (1ULL << XFS_DIFLAG2_BIGTIME_BIT)
#define XFS_DIFLAG2_NREXT64     (1ULL << XFS_DIFLAG2_NREXT64_BIT)
#define XFS_DIFLAG2_METADATA    (1ULL << XFS_DIFLAG2_METADATA_BIT)

#define XFS_DIFLAG2_ANY \
        (XFS_DIFLAG2_DAX | XFS_DIFLAG2_REFLINK | XFS_DIFLAG2_COWEXTSIZE | \
         XFS_DIFLAG2_BIGTIME | XFS_DIFLAG2_NREXT64 | XFS_DIFLAG2_METADATA)

static inline bool xfs_dinode_has_bigtime(const struct xfs_dinode *dip)
{
        return dip->di_version >= 3 &&
               (dip->di_flags2 & cpu_to_be64(XFS_DIFLAG2_BIGTIME));
}

static inline bool xfs_dinode_has_large_extent_counts(
        const struct xfs_dinode *dip)
{
        return dip->di_version >= 3 &&
               (dip->di_flags2 & cpu_to_be64(XFS_DIFLAG2_NREXT64));
}

static inline bool xfs_dinode_is_metadir(const struct xfs_dinode *dip)
{
        return dip->di_version >= 3 &&
               (dip->di_flags2 & cpu_to_be64(XFS_DIFLAG2_METADATA));
}

/*
 * Inode number format:
 * low inopblog bits - offset in block
 * next agblklog bits - block number in ag
 * next agno_log bits - ag number
 * high agno_log-agblklog-inopblog bits - 0
 */
#define XFS_INO_MASK(k)                 (uint32_t)((1ULL << (k)) - 1)
#define XFS_INO_OFFSET_BITS(mp)         (mp)->m_sb.sb_inopblog
#define XFS_INO_AGBNO_BITS(mp)          (mp)->m_sb.sb_agblklog
#define XFS_INO_AGINO_BITS(mp)          ((mp)->m_ino_geo.agino_log)
#define XFS_INO_AGNO_BITS(mp)           (mp)->m_agno_log
#define XFS_INO_BITS(mp)                \
        XFS_INO_AGNO_BITS(mp) + XFS_INO_AGINO_BITS(mp)
#define XFS_INO_TO_AGNO(mp,i)           \
        ((xfs_agnumber_t)((i) >> XFS_INO_AGINO_BITS(mp)))
#define XFS_INO_TO_AGINO(mp,i)          \
        ((xfs_agino_t)(i) & XFS_INO_MASK(XFS_INO_AGINO_BITS(mp)))
#define XFS_INO_TO_AGBNO(mp,i)          \
        (((xfs_agblock_t)(i) >> XFS_INO_OFFSET_BITS(mp)) & \
                XFS_INO_MASK(XFS_INO_AGBNO_BITS(mp)))
#define XFS_INO_TO_OFFSET(mp,i)         \
        ((int)(i) & XFS_INO_MASK(XFS_INO_OFFSET_BITS(mp)))
#define XFS_INO_TO_FSB(mp,i)            \
        XFS_AGB_TO_FSB(mp, XFS_INO_TO_AGNO(mp,i), XFS_INO_TO_AGBNO(mp,i))
#define XFS_AGINO_TO_INO(mp,a,i)        \
        (((xfs_ino_t)(a) << XFS_INO_AGINO_BITS(mp)) | (i))
#define XFS_AGINO_TO_AGBNO(mp,i)        ((i) >> XFS_INO_OFFSET_BITS(mp))
#define XFS_AGINO_TO_OFFSET(mp,i)       \
        ((i) & XFS_INO_MASK(XFS_INO_OFFSET_BITS(mp)))
#define XFS_OFFBNO_TO_AGINO(mp,b,o)     \
        ((xfs_agino_t)(((b) << XFS_INO_OFFSET_BITS(mp)) | (o)))
#define XFS_FSB_TO_INO(mp, b)   ((xfs_ino_t)((b) << XFS_INO_OFFSET_BITS(mp)))
#define XFS_AGB_TO_AGINO(mp, b) ((xfs_agino_t)((b) << XFS_INO_OFFSET_BITS(mp)))

#define XFS_MAXINUMBER          ((xfs_ino_t)((1ULL << 56) - 1ULL))
#define XFS_MAXINUMBER_32       ((xfs_ino_t)((1ULL << 32) - 1ULL))

/*
 * RealTime Device format definitions
 */

/* Min and max rt extent sizes, specified in bytes */
#define XFS_MAX_RTEXTSIZE       (1024 * 1024 * 1024)    /* 1GB */
#define XFS_DFL_RTEXTSIZE       (64 * 1024)             /* 64kB */
#define XFS_MIN_RTEXTSIZE       (4 * 1024)              /* 4kB */

/*
 * RT bit manipulation macros.
 */
#define XFS_RTBITMAP_MAGIC      0x424D505A      /* BMPZ */
#define XFS_RTSUMMARY_MAGIC     0x53554D59      /* SUMY */

struct xfs_rtbuf_blkinfo {
        __be32          rt_magic;       /* validity check on block */
        __be32          rt_crc;         /* CRC of block */
        __be64          rt_owner;       /* inode that owns the block */
        __be64          rt_blkno;       /* first block of the buffer */
        __be64          rt_lsn;         /* sequence number of last write */
        uuid_t          rt_uuid;        /* filesystem we belong to */
};

#define XFS_RTBUF_CRC_OFF \
        offsetof(struct xfs_rtbuf_blkinfo, rt_crc)

/*
 * Dquot and dquot block format definitions
 */
#define XFS_DQUOT_MAGIC         0x4451          /* 'DQ' */
#define XFS_DQUOT_VERSION       (uint8_t)0x01   /* latest version number */

#define XFS_DQTYPE_USER         (1u << 0)       /* user dquot record */
#define XFS_DQTYPE_PROJ         (1u << 1)       /* project dquot record */
#define XFS_DQTYPE_GROUP        (1u << 2)       /* group dquot record */
#define XFS_DQTYPE_BIGTIME      (1u << 7)       /* large expiry timestamps */

/* bitmask to determine if this is a user/group/project dquot */
#define XFS_DQTYPE_REC_MASK     (XFS_DQTYPE_USER | \
                                 XFS_DQTYPE_PROJ | \
                                 XFS_DQTYPE_GROUP)

#define XFS_DQTYPE_ANY          (XFS_DQTYPE_REC_MASK | \
                                 XFS_DQTYPE_BIGTIME)

/*
 * XFS Quota Timers
 * ================
 *
 * Traditional quota grace period expiration timers are an unsigned 32-bit
 * seconds counter; time zero is the Unix epoch, Jan  1 00:00:01 UTC 1970.
 * Note that an expiration value of zero means that the quota limit has not
 * been reached, and therefore no expiration has been set.  Therefore, the
 * ondisk min and max defined here can be used directly to constrain the incore
 * quota expiration timestamps on a Unix system.
 *
 * When bigtime is enabled, we trade two bits of precision to expand the
 * expiration timeout range to match that of big inode timestamps.  The min and
 * max recorded here are the on-disk limits, not a Unix timestamp.
 *
 * The grace period for each quota type is stored in the root dquot (id = 0)
 * and is applied to a non-root dquot when it exceeds the soft or hard limits.
 * The length of quota grace periods are unsigned 32-bit quantities measured in
 * units of seconds.  A value of zero means to use the default period.
 */

/*
 * Smallest possible ondisk quota expiration value with traditional timestamps.
 * This corresponds exactly with the incore expiration Jan  1 00:00:01 UTC 1970.
 */
#define XFS_DQ_LEGACY_EXPIRY_MIN        ((int64_t)1)

/*
 * Largest possible ondisk quota expiration value with traditional timestamps.
 * This corresponds exactly with the incore expiration Feb  7 06:28:15 UTC 2106.
 */
#define XFS_DQ_LEGACY_EXPIRY_MAX        ((int64_t)U32_MAX)

/*
 * Smallest possible ondisk quota expiration value with bigtime timestamps.
 * This corresponds (after conversion to a Unix timestamp) with the incore
 * expiration of Jan  1 00:00:04 UTC 1970.
 */
#define XFS_DQ_BIGTIME_EXPIRY_MIN       (XFS_DQ_LEGACY_EXPIRY_MIN)

/*
 * Largest supported ondisk quota expiration value with bigtime timestamps.
 * This corresponds (after conversion to a Unix timestamp) with an incore
 * expiration of Jul  2 20:20:24 UTC 2486.
 *
 * The ondisk field supports values up to -1U, which corresponds to an incore
 * expiration in 2514.  This is beyond the maximum the bigtime inode timestamp,
 * so we cap the maximum bigtime quota expiration to the max inode timestamp.
 */
#define XFS_DQ_BIGTIME_EXPIRY_MAX       ((int64_t)4074815106U)

/*
 * The following conversion factors assist in converting a quota expiration
 * timestamp between the incore and ondisk formats.
 */
#define XFS_DQ_BIGTIME_SHIFT    (2)
#define XFS_DQ_BIGTIME_SLACK    ((int64_t)(1ULL << XFS_DQ_BIGTIME_SHIFT) - 1)

/* Convert an incore quota expiration timestamp to an ondisk bigtime value. */
static inline uint32_t xfs_dq_unix_to_bigtime(time64_t unix_seconds)
{
        /*
         * Round the expiration timestamp up to the nearest bigtime timestamp
         * that we can store, to give users the most time to fix problems.
         */
        return ((uint64_t)unix_seconds + XFS_DQ_BIGTIME_SLACK) >>
                        XFS_DQ_BIGTIME_SHIFT;
}

/* Convert an ondisk bigtime quota expiration value to an incore timestamp. */
static inline time64_t xfs_dq_bigtime_to_unix(uint32_t ondisk_seconds)
{
        return (time64_t)ondisk_seconds << XFS_DQ_BIGTIME_SHIFT;
}

/*
 * Default quota grace periods, ranging from zero (use the compiled defaults)
 * to ~136 years.  These are applied to a non-root dquot that has exceeded
 * either limit.
 */
#define XFS_DQ_GRACE_MIN                ((int64_t)0)
#define XFS_DQ_GRACE_MAX                ((int64_t)U32_MAX)

/* Maximum id value for a quota record */
#define XFS_DQ_ID_MAX                   (U32_MAX)

/*
 * This is the main portion of the on-disk representation of quota information
 * for a user.  We pad this with some more expansion room to construct the on
 * disk structure.
 */
struct xfs_disk_dquot {
        __be16          d_magic;        /* dquot magic = XFS_DQUOT_MAGIC */
        __u8            d_version;      /* dquot version */
        __u8            d_type;         /* XFS_DQTYPE_USER/PROJ/GROUP */
        __be32          d_id;           /* user,project,group id */
        __be64          d_blk_hardlimit;/* absolute limit on disk blks */
        __be64          d_blk_softlimit;/* preferred limit on disk blks */
        __be64          d_ino_hardlimit;/* maximum # allocated inodes */
        __be64          d_ino_softlimit;/* preferred inode limit */
        __be64          d_bcount;       /* disk blocks owned by the user */
        __be64          d_icount;       /* inodes owned by the user */
        __be32          d_itimer;       /* zero if within inode limits if not,
                                           this is when we refuse service */
        __be32          d_btimer;       /* similar to above; for disk blocks */
        __be16          d_iwarns;       /* warnings issued wrt num inodes */
        __be16          d_bwarns;       /* warnings issued wrt disk blocks */
        __be32          d_pad0;         /* 64 bit align */
        __be64          d_rtb_hardlimit;/* absolute limit on realtime blks */
        __be64          d_rtb_softlimit;/* preferred limit on RT disk blks */
        __be64          d_rtbcount;     /* realtime blocks owned */
        __be32          d_rtbtimer;     /* similar to above; for RT disk blocks */
        __be16          d_rtbwarns;     /* warnings issued wrt RT disk blocks */
        __be16          d_pad;
};

/*
 * This is what goes on disk. This is separated from the xfs_disk_dquot because
 * carrying the unnecessary padding would be a waste of memory.
 */
struct xfs_dqblk {
        struct xfs_disk_dquot   dd_diskdq; /* portion living incore as well */
        char                    dd_fill[4];/* filling for posterity */

        /*
         * These two are only present on filesystems with the CRC bits set.
         */
        __be32            dd_crc;       /* checksum */
        __be64            dd_lsn;       /* last modification in log */
        uuid_t            dd_uuid;      /* location information */
};

#define XFS_DQUOT_CRC_OFF       offsetof(struct xfs_dqblk, dd_crc)

/*
 * This defines the unit of allocation of dquots.
 *
 * Currently, it is just one file system block, and a 4K blk contains 30
 * (136 * 30 = 4080) dquots. It's probably not worth trying to make
 * this more dynamic.
 *
 * However, if this number is changed, we have to make sure that we don't
 * implicitly assume that we do allocations in chunks of a single filesystem
 * block in the dquot/xqm code.
 *
 * This is part of the ondisk format because the structure size is not a power
 * of two, which leaves slack at the end of the disk block.
 */
#define XFS_DQUOT_CLUSTER_SIZE_FSB      (xfs_filblks_t)1

/*
 * Remote symlink format and access functions.
 */
#define XFS_SYMLINK_MAGIC       0x58534c4d      /* XSLM */

struct xfs_dsymlink_hdr {
        __be32  sl_magic;
        __be32  sl_offset;
        __be32  sl_bytes;
        __be32  sl_crc;
        uuid_t  sl_uuid;
        __be64  sl_owner;
        __be64  sl_blkno;
        __be64  sl_lsn;
};

#define XFS_SYMLINK_CRC_OFF     offsetof(struct xfs_dsymlink_hdr, sl_crc)

#define XFS_SYMLINK_MAXLEN      1024
/*
 * The maximum pathlen is 1024 bytes. Since the minimum file system
 * blocksize is 512 bytes, we can get a max of 3 extents back from
 * bmapi when crc headers are taken into account.
 */
#define XFS_SYMLINK_MAPS 3

#define XFS_SYMLINK_BUF_SPACE(mp, bufsize)      \
        ((bufsize) - (xfs_has_crc((mp)) ? \
                        sizeof(struct xfs_dsymlink_hdr) : 0))


/*
 * Allocation Btree format definitions
 *
 * There are two on-disk btrees, one sorted by blockno and one sorted
 * by blockcount and blockno.  All blocks look the same to make the code
 * simpler; if we have time later, we'll make the optimizations.
 */
#define XFS_ABTB_MAGIC          0x41425442      /* 'ABTB' for bno tree */
#define XFS_ABTB_CRC_MAGIC      0x41423342      /* 'AB3B' */
#define XFS_ABTC_MAGIC          0x41425443      /* 'ABTC' for cnt tree */
#define XFS_ABTC_CRC_MAGIC      0x41423343      /* 'AB3C' */

/*
 * Data record/key structure
 */
typedef struct xfs_alloc_rec {
        __be32          ar_startblock;  /* starting block number */
        __be32          ar_blockcount;  /* count of free blocks */
} xfs_alloc_rec_t, xfs_alloc_key_t;

typedef struct xfs_alloc_rec_incore {
        xfs_agblock_t   ar_startblock;  /* starting block number */
        xfs_extlen_t    ar_blockcount;  /* count of free blocks */
} xfs_alloc_rec_incore_t;

/* btree pointer type */
typedef __be32 xfs_alloc_ptr_t;

/*
 * Block numbers in the AG:
 * SB is sector 0, AGF is sector 1, AGI is sector 2, AGFL is sector 3.
 */
#define XFS_BNO_BLOCK(mp)       ((xfs_agblock_t)(XFS_AGFL_BLOCK(mp) + 1))
#define XFS_CNT_BLOCK(mp)       ((xfs_agblock_t)(XFS_BNO_BLOCK(mp) + 1))


/*
 * Inode Allocation Btree format definitions
 *
 * There is a btree for the inode map per allocation group.
 */
#define XFS_IBT_MAGIC           0x49414254      /* 'IABT' */
#define XFS_IBT_CRC_MAGIC       0x49414233      /* 'IAB3' */
#define XFS_FIBT_MAGIC          0x46494254      /* 'FIBT' */
#define XFS_FIBT_CRC_MAGIC      0x46494233      /* 'FIB3' */

typedef uint64_t        xfs_inofree_t;
#define XFS_INODES_PER_CHUNK            (NBBY * sizeof(xfs_inofree_t))
#define XFS_INODES_PER_CHUNK_LOG        (XFS_NBBYLOG + 3)
#define XFS_INOBT_ALL_FREE              ((xfs_inofree_t)-1)
#define XFS_INOBT_MASK(i)               ((xfs_inofree_t)1 << (i))

#define XFS_INOBT_HOLEMASK_FULL         0       /* holemask for full chunk */
#define XFS_INOBT_HOLEMASK_BITS         (NBBY * sizeof(uint16_t))
#define XFS_INODES_PER_HOLEMASK_BIT     \
        (XFS_INODES_PER_CHUNK / (NBBY * sizeof(uint16_t)))

static inline xfs_inofree_t xfs_inobt_maskn(int i, int n)
{
        return ((n >= XFS_INODES_PER_CHUNK ? 0 : XFS_INOBT_MASK(n)) - 1) << i;
}

/*
 * The on-disk inode record structure has two formats. The original "full"
 * format uses a 4-byte freecount. The "sparse" format uses a 1-byte freecount
 * and replaces the 3 high-order freecount bytes wth the holemask and inode
 * count.
 *
 * The holemask of the sparse record format allows an inode chunk to have holes
 * that refer to blocks not owned by the inode record. This facilitates inode
 * allocation in the event of severe free space fragmentation.
 */
typedef struct xfs_inobt_rec {
        __be32          ir_startino;    /* starting inode number */
        union {
                struct {
                        __be32  ir_freecount;   /* count of free inodes */
                } f;
                struct {
                        __be16  ir_holemask;/* hole mask for sparse chunks */
                        __u8    ir_count;       /* total inode count */
                        __u8    ir_freecount;   /* count of free inodes */
                } sp;
        } ir_u;
        __be64          ir_free;        /* free inode mask */
} xfs_inobt_rec_t;

typedef struct xfs_inobt_rec_incore {
        xfs_agino_t     ir_startino;    /* starting inode number */
        uint16_t        ir_holemask;    /* hole mask for sparse chunks */
        uint8_t         ir_count;       /* total inode count */
        uint8_t         ir_freecount;   /* count of free inodes (set bits) */
        xfs_inofree_t   ir_free;        /* free inode mask */
} xfs_inobt_rec_incore_t;

static inline bool xfs_inobt_issparse(uint16_t holemask)
{
        /* non-zero holemask represents a sparse rec. */
        return holemask;
}

/*
 * Key structure
 */
typedef struct xfs_inobt_key {
        __be32          ir_startino;    /* starting inode number */
} xfs_inobt_key_t;

/* btree pointer type */
typedef __be32 xfs_inobt_ptr_t;

/*
 * block numbers in the AG.
 */
#define XFS_IBT_BLOCK(mp)               ((xfs_agblock_t)(XFS_CNT_BLOCK(mp) + 1))
#define XFS_FIBT_BLOCK(mp)              ((xfs_agblock_t)(XFS_IBT_BLOCK(mp) + 1))

/*
 * Reverse mapping btree format definitions
 *
 * There is a btree for the reverse map per allocation group
 */
#define XFS_RMAP_CRC_MAGIC      0x524d4233      /* 'RMB3' */

/*
 * Ownership info for an extent.  This is used to create reverse-mapping
 * entries.
 */
#define XFS_OWNER_INFO_ATTR_FORK        (1 << 0)
#define XFS_OWNER_INFO_BMBT_BLOCK       (1 << 1)
struct xfs_owner_info {
        uint64_t                oi_owner;
        xfs_fileoff_t           oi_offset;
        unsigned int            oi_flags;
};

/*
 * Special owner types.
 *
 * Seeing as we only support up to 8EB, we have the upper bit of the owner field
 * to tell us we have a special owner value. We use these for static metadata
 * allocated at mkfs/growfs time, as well as for freespace management metadata.
 */
#define XFS_RMAP_OWN_NULL       (-1ULL) /* No owner, for growfs */
#define XFS_RMAP_OWN_UNKNOWN    (-2ULL) /* Unknown owner, for EFI recovery */
#define XFS_RMAP_OWN_FS         (-3ULL) /* static fs metadata */
#define XFS_RMAP_OWN_LOG        (-4ULL) /* static fs metadata */
#define XFS_RMAP_OWN_AG         (-5ULL) /* AG freespace btree blocks */
#define XFS_RMAP_OWN_INOBT      (-6ULL) /* Inode btree blocks */
#define XFS_RMAP_OWN_INODES     (-7ULL) /* Inode chunk */
#define XFS_RMAP_OWN_REFC       (-8ULL) /* refcount tree */
#define XFS_RMAP_OWN_COW        (-9ULL) /* cow allocations */
#define XFS_RMAP_OWN_MIN        (-10ULL) /* guard */

#define XFS_RMAP_NON_INODE_OWNER(owner) (!!((owner) & (1ULL << 63)))

/*
 * Data record structure
 */
struct xfs_rmap_rec {
        __be32          rm_startblock;  /* extent start block */
        __be32          rm_blockcount;  /* extent length */
        __be64          rm_owner;       /* extent owner */
        __be64          rm_offset;      /* offset within the owner */
};

/*
 * rmap btree record
 *  rm_offset:63 is the attribute fork flag
 *  rm_offset:62 is the bmbt block flag
 *  rm_offset:61 is the unwritten extent flag (same as l0:63 in bmbt)
 *  rm_offset:54-60 aren't used and should be zero
 *  rm_offset:0-53 is the block offset within the inode
 */
#define XFS_RMAP_OFF_ATTR_FORK  ((uint64_t)1ULL << 63)
#define XFS_RMAP_OFF_BMBT_BLOCK ((uint64_t)1ULL << 62)
#define XFS_RMAP_OFF_UNWRITTEN  ((uint64_t)1ULL << 61)

#define XFS_RMAP_LEN_MAX        ((uint32_t)~0U)
#define XFS_RMAP_OFF_FLAGS      (XFS_RMAP_OFF_ATTR_FORK | \
                                 XFS_RMAP_OFF_BMBT_BLOCK | \
                                 XFS_RMAP_OFF_UNWRITTEN)
#define XFS_RMAP_OFF_MASK       ((uint64_t)0x3FFFFFFFFFFFFFULL)

#define XFS_RMAP_OFF(off)               ((off) & XFS_RMAP_OFF_MASK)

#define XFS_RMAP_IS_BMBT_BLOCK(off)     (!!((off) & XFS_RMAP_OFF_BMBT_BLOCK))
#define XFS_RMAP_IS_ATTR_FORK(off)      (!!((off) & XFS_RMAP_OFF_ATTR_FORK))
#define XFS_RMAP_IS_UNWRITTEN(len)      (!!((off) & XFS_RMAP_OFF_UNWRITTEN))

#define RMAPBT_STARTBLOCK_BITLEN        32
#define RMAPBT_BLOCKCOUNT_BITLEN        32
#define RMAPBT_OWNER_BITLEN             64
#define RMAPBT_ATTRFLAG_BITLEN          1
#define RMAPBT_BMBTFLAG_BITLEN          1
#define RMAPBT_EXNTFLAG_BITLEN          1
#define RMAPBT_UNUSED_OFFSET_BITLEN     7
#define RMAPBT_OFFSET_BITLEN            54

/*
 * Key structure
 *
 * We don't use the length for lookups
 */
struct xfs_rmap_key {
        __be32          rm_startblock;  /* extent start block */
        __be64          rm_owner;       /* extent owner */
        __be64          rm_offset;      /* offset within the owner */
} __attribute__((packed));

/* btree pointer type */
typedef __be32 xfs_rmap_ptr_t;

#define XFS_RMAP_BLOCK(mp) \
        (xfs_has_finobt(((mp))) ? \
         XFS_FIBT_BLOCK(mp) + 1 : \
         XFS_IBT_BLOCK(mp) + 1)

/*
 * Realtime Reverse mapping btree format definitions
 *
 * This is a btree for reverse mapping records for realtime volumes
 */
#define XFS_RTRMAP_CRC_MAGIC    0x4d415052      /* 'MAPR' */

/*
 * rtrmap root header, on-disk form only.
 */
struct xfs_rtrmap_root {
        __be16          bb_level;       /* 0 is a leaf */
        __be16          bb_numrecs;     /* current # of data records */
};

/* inode-based btree pointer type */
typedef __be64 xfs_rtrmap_ptr_t;

/*
 * Reference Count Btree format definitions
 *
 */
#define XFS_REFC_CRC_MAGIC      0x52334643      /* 'R3FC' */

unsigned int xfs_refc_block(struct xfs_mount *mp);

/*
 * Data record/key structure
 *
 * Each record associates a range of physical blocks (starting at
 * rc_startblock and ending rc_blockcount blocks later) with a reference
 * count (rc_refcount).  Extents that are being used to stage a copy on
 * write (CoW) operation are recorded in the refcount btree with a
 * refcount of 1.  All other records must have a refcount > 1 and must
 * track an extent mapped only by file data forks.
 *
 * Extents with a single owner (attributes, metadata, non-shared file
 * data) are not tracked here.  Free space is also not tracked here.
 * This is consistent with pre-reflink XFS.
 */

/*
 * Extents that are being used to stage a copy on write are stored
 * in the refcount btree with a refcount of 1 and the upper bit set
 * on the startblock.  This speeds up mount time deletion of stale
 * staging extents because they're all at the right side of the tree.
 */
#define XFS_REFC_COWFLAG                (1U << 31)
#define REFCNTBT_COWFLAG_BITLEN         1
#define REFCNTBT_AGBLOCK_BITLEN         31

struct xfs_refcount_rec {
        __be32          rc_startblock;  /* starting block number */
        __be32          rc_blockcount;  /* count of blocks */
        __be32          rc_refcount;    /* number of inodes linked here */
};

struct xfs_refcount_key {
        __be32          rc_startblock;  /* starting block number */
};

#define XFS_REFC_REFCOUNT_MAX   ((xfs_nlink_t)~0U)
#define XFS_REFC_LEN_MAX        ((xfs_extlen_t)~0U)

/* btree pointer type */
typedef __be32 xfs_refcount_ptr_t;

/*
 * Realtime Reference Count btree format definitions
 *
 * This is a btree for reference count records for realtime volumes
 */
#define XFS_RTREFC_CRC_MAGIC    0x52434e54      /* 'RCNT' */

/*
 * rt refcount root header, on-disk form only.
 */
struct xfs_rtrefcount_root {
        __be16          bb_level;       /* 0 is a leaf */
        __be16          bb_numrecs;     /* current # of data records */
};

/* inode-rooted btree pointer type */
typedef __be64 xfs_rtrefcount_ptr_t;

/*
 * BMAP Btree format definitions
 *
 * This includes both the root block definition that sits inside an inode fork
 * and the record/pointer formats for the leaf/node in the blocks.
 */
#define XFS_BMAP_MAGIC          0x424d4150      /* 'BMAP' */
#define XFS_BMAP_CRC_MAGIC      0x424d4133      /* 'BMA3' */

/*
 * Bmap root header, on-disk form only.
 */
typedef struct xfs_bmdr_block {
        __be16          bb_level;       /* 0 is a leaf */
        __be16          bb_numrecs;     /* current # of data records */
} xfs_bmdr_block_t;

/*
 * Bmap btree record and extent descriptor.
 *  l0:63 is an extent flag (value 1 indicates non-normal).
 *  l0:9-62 are startoff.
 *  l0:0-8 and l1:21-63 are startblock.
 *  l1:0-20 are blockcount.
 */
#define BMBT_EXNTFLAG_BITLEN    1
#define BMBT_STARTOFF_BITLEN    54
#define BMBT_STARTBLOCK_BITLEN  52
#define BMBT_BLOCKCOUNT_BITLEN  21

#define BMBT_STARTOFF_MASK      ((1ULL << BMBT_STARTOFF_BITLEN) - 1)
#define BMBT_BLOCKCOUNT_MASK    ((1ULL << BMBT_BLOCKCOUNT_BITLEN) - 1)

#define XFS_MAX_BMBT_EXTLEN     ((xfs_extlen_t)(BMBT_BLOCKCOUNT_MASK))

/*
 * bmbt records have a file offset (block) field that is 54 bits wide, so this
 * is the largest xfs_fileoff_t that we ever expect to see.
 */
#define XFS_MAX_FILEOFF         (BMBT_STARTOFF_MASK + BMBT_BLOCKCOUNT_MASK)

typedef struct xfs_bmbt_rec {
        __be64                  l0, l1;
} xfs_bmbt_rec_t;

typedef uint64_t        xfs_bmbt_rec_base_t;    /* use this for casts */
typedef xfs_bmbt_rec_t xfs_bmdr_rec_t;

/*
 * Values and macros for delayed-allocation startblock fields.
 */
#define STARTBLOCKVALBITS       17
#define STARTBLOCKMASKBITS      (15 + 20)
#define STARTBLOCKMASK          \
        (((((xfs_fsblock_t)1) << STARTBLOCKMASKBITS) - 1) << STARTBLOCKVALBITS)

static inline int isnullstartblock(xfs_fsblock_t x)
{
        return ((x) & STARTBLOCKMASK) == STARTBLOCKMASK;
}

static inline xfs_fsblock_t nullstartblock(int k)
{
        ASSERT(k < (1 << STARTBLOCKVALBITS));
        return STARTBLOCKMASK | (k);
}

static inline xfs_filblks_t startblockval(xfs_fsblock_t x)
{
        return (xfs_filblks_t)((x) & ~STARTBLOCKMASK);
}

/*
 * Key structure for non-leaf levels of the tree.
 */
typedef struct xfs_bmbt_key {
        __be64          br_startoff;    /* starting file offset */
} xfs_bmbt_key_t, xfs_bmdr_key_t;

/* btree pointer type */
typedef __be64 xfs_bmbt_ptr_t, xfs_bmdr_ptr_t;


/*
 * Generic Btree block format definitions
 *
 * This is a combination of the actual format used on disk for short and long
 * format btrees.  The first three fields are shared by both format, but the
 * pointers are different and should be used with care.
 *
 * To get the size of the actual short or long form headers please use the size
 * macros below.  Never use sizeof(xfs_btree_block).
 *
 * The blkno, crc, lsn, owner and uuid fields are only available in filesystems
 * with the crc feature bit, and all accesses to them must be conditional on
 * that flag.
 */
/* short form block header */
struct xfs_btree_block_shdr {
        __be32          bb_leftsib;
        __be32          bb_rightsib;

        __be64          bb_blkno;
        __be64          bb_lsn;
        uuid_t          bb_uuid;
        __be32          bb_owner;
        __le32          bb_crc;
};

/* long form block header */
struct xfs_btree_block_lhdr {
        __be64          bb_leftsib;
        __be64          bb_rightsib;

        __be64          bb_blkno;
        __be64          bb_lsn;
        uuid_t          bb_uuid;
        __be64          bb_owner;
        __le32          bb_crc;
        __be32          bb_pad; /* padding for alignment */
};

struct xfs_btree_block {
        __be32          bb_magic;       /* magic number for block type */
        __be16          bb_level;       /* 0 is a leaf */
        __be16          bb_numrecs;     /* current # of data records */
        union {
                struct xfs_btree_block_shdr s;
                struct xfs_btree_block_lhdr l;
        } bb_u;                         /* rest */
};

/* size of a short form block */
#define XFS_BTREE_SBLOCK_LEN \
        (offsetof(struct xfs_btree_block, bb_u) + \
         offsetof(struct xfs_btree_block_shdr, bb_blkno))
/* size of a long form block */
#define XFS_BTREE_LBLOCK_LEN \
        (offsetof(struct xfs_btree_block, bb_u) + \
         offsetof(struct xfs_btree_block_lhdr, bb_blkno))

/* sizes of CRC enabled btree blocks */
#define XFS_BTREE_SBLOCK_CRC_LEN \
        (offsetof(struct xfs_btree_block, bb_u) + \
         sizeof(struct xfs_btree_block_shdr))
#define XFS_BTREE_LBLOCK_CRC_LEN \
        (offsetof(struct xfs_btree_block, bb_u) + \
         sizeof(struct xfs_btree_block_lhdr))

#define XFS_BTREE_SBLOCK_CRC_OFF \
        offsetof(struct xfs_btree_block, bb_u.s.bb_crc)
#define XFS_BTREE_LBLOCK_CRC_OFF \
        offsetof(struct xfs_btree_block, bb_u.l.bb_crc)

/*
 * On-disk XFS access control list structure.
 */
struct xfs_acl_entry {
        __be32  ae_tag;
        __be32  ae_id;
        __be16  ae_perm;
        __be16  ae_pad;         /* fill the implicit hole in the structure */
};

struct xfs_acl {
        __be32                  acl_cnt;
        struct xfs_acl_entry    acl_entry[];
};

/*
 * The number of ACL entries allowed is defined by the on-disk format.
 * For v4 superblocks, that is limited to 25 entries. For v5 superblocks, it is
 * limited only by the maximum size of the xattr that stores the information.
 */
#define XFS_ACL_MAX_ENTRIES(mp) \
        (xfs_has_crc(mp) \
                ?  (XFS_XATTR_SIZE_MAX - sizeof(struct xfs_acl)) / \
                                                sizeof(struct xfs_acl_entry) \
                : 25)

#define XFS_ACL_SIZE(cnt) \
        (sizeof(struct xfs_acl) + \
                sizeof(struct xfs_acl_entry) * cnt)

#define XFS_ACL_MAX_SIZE(mp) \
        XFS_ACL_SIZE(XFS_ACL_MAX_ENTRIES((mp)))


/* On-disk XFS extended attribute names */
#define SGI_ACL_FILE            "SGI_ACL_FILE"
#define SGI_ACL_DEFAULT         "SGI_ACL_DEFAULT"
#define SGI_ACL_FILE_SIZE       (sizeof(SGI_ACL_FILE)-1)
#define SGI_ACL_DEFAULT_SIZE    (sizeof(SGI_ACL_DEFAULT)-1)

#endif /* __XFS_FORMAT_H__ */