root/src/add-ons/kernel/file_systems/ufs2/ufs2.h
/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1982, 1986, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)fs.h        8.13 (Berkeley) 3/21/95
 * $FreeBSD$
 */

#ifndef UFS2_H
#define UFS2_H

#include "system_dependencies.h"

typedef uint32 cluster_t;
typedef uint64_t ufs2_daddr_t;

#define SBLOCK_FLOPPY           0
#define SBLOCK_UFS1                     8192
#define SBLOCK_UFS2                     65536
#define SBLOCK_PIGGY            262144
#define SBLOCKSIZE                      8192
#define SBLOCKSEARCH \
        { SBLOCK_UFS2, SBLOCK_UFS1, SBLOCK_FLOPPY, SBLOCK_PIGGY, -1 }

/*
 * Max number of fragments per block. This value is NOT tweakable.
 */
#define MAXFRAG                         8

/*
 * Addresses stored in inodes are capable of addressing fragments
 * of `blocks'. File system blocks of at most size MAXBSIZE can
 * be optionally broken into 2, 4, or 8 pieces, each of which is
 * addressable; these pieces may be DEV_BSIZE, or some multiple of
 * a DEV_BSIZE unit.
 *
 * Large files consist of exclusively large data blocks.  To avoid
 * undue wasted disk space, the last data block of a small file may be
 * allocated as only as many fragments of a large block as are
 * necessary.  The filesystem format retains only a single pointer
 * to such a fragment, which is a piece of a single large block that
 * has been divided.  The size of such a fragment is determinable from
 * information in the inode, using the ``blksize(fs, ip, lbn)'' macro.
 *
 * The filesystem records space availability at the fragment level;
 * to determine block availability, aligned fragments are examined.
 */

/*
 * The path name on which the filesystem is mounted is maintained
 * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
 * the super block for this name.
 */
#define MAXMNTLEN                       468

/*
 * The volume name for this filesystem is maintained in fs_volname.
 * MAXVOLLEN defines the length of the buffer allocated.
 */
#define MAXVOLLEN                       32

/*
 * There is a 128-byte region in the superblock reserved for in-core
 * pointers to summary information. Originally this included an array
 * of pointers to blocks of struct csum; now there are just a few
 * pointers and the remaining space is padded with fs_ocsp[].
 *
* NOCSPTRS determines the size of this padding. One pointer (fs_csp)
 * is taken away to point to a contiguous array of struct csum for
 * all cylinder groups; a second (fs_maxcluster) points to an array
 * of cluster sizes that is computed as cylinder groups are inspected,
 * and the third points to an array that tracks the creation of new
 * directories. A fourth pointer, fs_active, is used when creating
 * snapshots; it points to a bitmap of cylinder groups for which the
 * free-block bitmap has changed since the snapshot operation began.
 */
#define NOCSPTRS                        ((128 / sizeof(void *)) - 4)

/*
 * A summary of contiguous blocks of various sizes is maintained
 * in each cylinder group. Normally this is set by the initial
 * value of fs_maxcontig. To conserve space, a maximum summary size
 * is set by FS_MAXCONTIG.
 */
#define FS_MAXCONTIG            16

/*
 * MINFREE gives the minimum acceptable percentage of filesystem
 * blocks which may be free. If the freelist drops below this level
 * only the superuser may continue to allocate blocks. This may
 * be set to 0 if no reserve of free blocks is deemed necessary,
 * however throughput drops by fifty percent if the filesystem
 * is run at between 95% and 100% full; thus the minimum default
 * value of fs_minfree is 5%. However, to get good clustering
 * performance, 10% is a better choice. hence we use 10% as our
 * default value. With 10% free space, fragmentation is not a
 * problem, so we choose to optimize for time.
 */
#define MINFREE                         8
#define DEFAULTOPT                      FS_OPTTIME

/*
 * Grigoriy Orlov <gluk@ptci.ru> has done some extensive work to fine
 * tune the layout preferences for directories within a filesystem.
 * His algorithm can be tuned by adjusting the following parameters
 * which tell the system the average file size and the average number
 * of files per directory. These defaults are well selected for typical
 * filesystems, but may need to be tuned for odd cases like filesystems
 * being used for squid caches or news spools.
 */
#define AVFILESIZ                       16384   /* expected average file size */
#define AFPDIR                          64      /* expected number of files per directory */

/*
 * The maximum number of snapshot nodes that can be associated
 * with each filesystem. This limit affects only the number of
 * snapshot files that can be recorded within the superblock so
 * that they can be found when the filesystem is mounted. However,
 * maintaining too many will slow the filesystem performance, so
 * having this limit is a good idea.
 */
#define FSMAXSNAP                       20

/*
 * Used to identify special blocks in snapshots:
 *
 * BLK_NOCOPY - A block that was unallocated at the time the snapshot
 *      was taken, hence does not need to be copied when written.
 * BLK_SNAP - A block held by another snapshot that is not needed by this
 *      snapshot. When the other snapshot is freed, the BLK_SNAP entries
 *      are converted to BLK_NOCOPY. These are needed to allow fsck to
 *      identify blocks that are in use by other snapshots (which are
 *      expunged from this snapshot).
 */
#define BLK_NOCOPY                      ((ufs2_daddr_t)(1))
#define BLK_SNAP                        ((ufs2_daddr_t)(2))

/*
 * Sysctl values for the fast filesystem.
 */
#define FFS_ADJ_REFCNT           1      /* adjust inode reference count */
#define FFS_ADJ_BLKCNT           2      /* adjust inode used block count */
#define FFS_BLK_FREE             3      /* free range of blocks in map */
#define FFS_DIR_FREE             4      /* free specified dir inodes in map */
#define FFS_FILE_FREE            5      /* free specified file inodes in map */
#define FFS_SET_FLAGS            6      /* set filesystem flags */
#define FFS_ADJ_NDIR             7      /* adjust number of directories */
#define FFS_ADJ_NBFREE           8      /* adjust number of free blocks */
#define FFS_ADJ_NIFREE           9      /* adjust number of free inodes */
#define FFS_ADJ_NFFREE          10      /* adjust number of free frags */
#define FFS_ADJ_NUMCLUSTERS     11      /* adjust number of free clusters */
#define FFS_SET_CWD                     12      /* set current directory */
#define FFS_SET_DOTDOT          13      /* set inode number for ".." */
#define FFS_UNLINK                      14      /* remove a name in the filesystem */
/* Was FFS_SET_INODE            15 */
/* Was FFS_SET_BUFOUTPUT        16 */
#define FFS_SET_SIZE            17      /* set inode size */
#define FFS_MAXID                       17      /* number of valid ffs ids */

/*
 * Command structure passed in to the filesystem to adjust filesystem values.
 */
#define FFS_CMD_VERSION         0x19790518      /* version ID */
struct fsck_cmd {
        int32_t version;        /* version of command structure */
        int32_t handle;         /* reference to filesystem to be changed */
        int64_t value;          /* inode or block number to be affected */
        int64_t size;           /* amount or range to be adjusted */
        int64_t spare;          /* reserved for future use */
};

/*
 * A recovery structure placed at the end of the boot block area by newfs
 * that can be used by fsck to search for alternate superblocks.
 */
struct fsrecovery {
        int32_t fsr_magic;      /* magic number */
        int32_t fsr_fsbtodb;    /* fsbtodb and dbtofsb shift constant */
        int32_t fsr_sblkno;     /* offset of super-block in filesys */
        int32_t fsr_fpg;        /* blocks per group * fs_frag */
        u_int32_t fsr_ncg;      /* number of cylinder groups */
};

/*
 * Per cylinder group information; summarized in blocks allocated
 * from first cylinder group data blocks.  These blocks have to be
 * read in from fs_csaddr (size fs_cssize) in addition to the
 * super block.
 */
struct csum {
        int32_t cs_ndir;                /* number of directories */
        int32_t cs_nbfree;              /* number of free blocks */
        int32_t cs_nifree;              /* number of free inodes */
        int32_t cs_nffree;              /* number of free frags */
};
struct csum_total {
        int64_t cs_ndir;                /* number of directories */
        int64_t cs_nbfree;              /* number of free blocks */
        int64_t cs_nifree;              /* number of free inodes */
        int64_t cs_nffree;              /* number of free frags */
        int64_t cs_numclusters;         /* number of free clusters */
        int64_t cs_spare[3];            /* future expansion */
};

/*
 * Super block for an FFS filesystem.
 */
struct ufs2_super_block {
        int32_t         fs_firstfield;          /* historic filesystem linked list, */
        int32_t         fs_unused_1;            /*     used for incore super blocks */
        int32_t         fs_sblkno;              /* offset of super-block in filesys */
        int32_t         fs_cblkno;              /* offset of cyl-block in filesys */
        int32_t         fs_iblkno;              /* offset of inode-blocks in filesys */
        int32_t         fs_dblkno;              /* offset of first data after cg */
        int32_t         fs_old_cgoffset;        /* cylinder group offset in cylinder */
        int32_t         fs_old_cgmask;          /* used to calc mod fs_ntrak */
        int32_t         fs_old_time;            /* last time written */
        int32_t         fs_old_size;            /* number of blocks in fs */
        int32_t         fs_old_dsize;           /* number of data blocks in fs */
        u_int32_t       fs_ncg;         /* number of cylinder groups */
        int32_t         fs_bsize;               /* size of basic blocks in fs */
        int32_t         fs_fsize;               /* size of frag blocks in fs */
        int32_t         fs_frag;                /* number of frags in a block in fs */
/* these are configuration parameters */
        int32_t         fs_minfree;             /* minimum percentage of free blocks */
        int32_t         fs_old_rotdelay;        /* num of ms for optimal next block */
        int32_t         fs_old_rps;             /* disk revolutions per second */
/* these fields can be computed from the others */
        int32_t         fs_bmask;               /* ``blkoff'' calc of blk offsets */
        int32_t         fs_fmask;               /* ``fragoff'' calc of frag offsets */
        int32_t         fs_bshift;              /* ``lblkno'' calc of logical blkno */
        int32_t         fs_fshift;              /* ``numfrags'' calc number of frags */
/* these are configuration parameters */
        int32_t         fs_maxcontig;           /* max number of contiguous blks */
        int32_t         fs_maxbpg;              /* max number of blks per cyl group */
/* these fields can be computed from the others */
        int32_t         fs_fragshift;           /* block to frag shift */
        int32_t         fs_fsbtodb;             /* fsbtodb and dbtofsb shift constant */
        int32_t         fs_sbsize;              /* actual size of super block */
        int32_t         fs_spare1[2];           /* old fs_csmask */
                                        /* old fs_csshift */
        int32_t         fs_nindir;              /* value of NINDIR */
        u_int32_t       fs_inopb;               /* value of INOPB */
        int32_t         fs_old_nspf;            /* value of NSPF */
/* yet another configuration parameter */
        int32_t         fs_optim;               /* optimization preference, see below */
        int32_t         fs_old_npsect;          /* # sectors/track including spares */
        int32_t         fs_old_interleave;      /* hardware sector interleave */
        int32_t         fs_old_trackskew;       /* sector 0 skew, per track */
        int32_t         fs_id[2];               /* unique filesystem id */
/* sizes determined by number of cylinder groups and their sizes */
        int32_t         fs_old_csaddr;          /* blk addr of cyl grp summary area */
        int32_t         fs_cssize;              /* size of cyl grp summary area */
        int32_t         fs_cgsize;              /* cylinder group size */
        int32_t         fs_spare2;              /* old fs_ntrak */
        int32_t         fs_old_nsect;           /* sectors per track */
        int32_t         fs_old_spc;             /* sectors per cylinder */
        int32_t         fs_old_ncyl;            /* cylinders in filesystem */
        int32_t         fs_old_cpg;             /* cylinders per group */
        u_int32_t       fs_ipg;         /* inodes per group */
        int32_t         fs_fpg;         /* blocks per group * fs_frag */
/* this data must be re-computed after crashes */
        struct          csum fs_old_cstotal;    /* cylinder summary information */
/* these fields are cleared at mount time */
        int8_t          fs_fmod;                /* super block modified flag */
        int8_t          fs_clean;               /* filesystem is clean flag */
        int8_t          fs_ronly;               /* mounted read-only flag */
        int8_t          fs_old_flags;           /* old FS_ flags */
        u_char          fs_fsmnt[MAXMNTLEN];    /* name mounted on */
        char            fs_volname[MAXVOLLEN];  /* volume name */
        u_int64_t       fs_swuid;               /* system-wide uid */
        int32_t         fs_pad;         /* due to alignment of fs_swuid */
/* these fields retain the current block allocation info */
        int32_t         fs_cgrotor;             /* last cg searched */
        void            *fs_ocsp[NOCSPTRS];     /* padding; was list of fs_cs buffers */
        u_int8_t        *fs_contigdirs; /* (u) # of contig. allocated dirs */
        struct          csum *fs_csp;           /* (u) cg summary info buffer */
        int32_t         *fs_maxcluster;         /* (u) max cluster in each cyl group */
        u_int           *fs_active;             /* (u) used by snapshots to track fs */
        int32_t         fs_old_cpc;             /* cyl per cycle in postbl */
        int32_t         fs_maxbsize;            /* maximum blocking factor permitted */
        int64_t         fs_unrefs;              /* number of unreferenced inodes */
        int64_t         fs_providersize;        /* size of underlying GEOM provider */
        int64_t         fs_metaspace;           /* size of area reserved for metadata */
        int64_t         fs_sparecon64[13];      /* old rotation block list head */
        int64_t         fs_sblockactualloc;     /* byte offset of this superblock */
        int64_t         fs_sblockloc;           /* byte offset of standard superblock */
        struct          csum_total fs_cstotal;  /* (u) cylinder summary information */
        int64_t         fs_time;                /* last time written */
        int64_t         fs_size;                /* number of blocks in fs */
        int64_t         fs_dsize;               /* number of data blocks in fs */
        int64_t         fs_csaddr;              /* blk addr of cyl grp summary area */
        int64_t         fs_pendingblocks;       /* (u) blocks being freed */
        u_int32_t       fs_pendinginodes;       /* (u) inodes being freed */
        uint32_t        fs_snapinum[FSMAXSNAP];/* list of snapshot inode numbers */
        u_int32_t       fs_avgfilesize; /* expected average file size */
        u_int32_t       fs_avgfpdir;            /* expected # of files per directory */
        int32_t         fs_save_cgsize; /* save real cg size to use fs_bsize */
        int64_t         fs_mtime;               /* Last mount or fsck time. */
        int32_t         fs_sujfree;             /* SUJ free list */
        int32_t         fs_sparecon32[21];      /* reserved for future constants */
        u_int32_t       fs_ckhash;              /* if CK_SUPERBLOCK, its check-hash */
        u_int32_t       fs_metackhash;  /* metadata check-hash, see CK_ below */
        int32_t         fs_flags;               /* see FS_ flags below */
        int32_t         fs_contigsumsize;       /* size of cluster summary array */ 
        int32_t         fs_maxsymlinklen;       /* max length of an internal symlink */
        int32_t         fs_old_inodefmt;        /* format of on-disk inodes */
        u_int64_t       fs_maxfilesize; /* maximum representable file size */
        int64_t         fs_qbmask;              /* ~fs_bmask for use with 64-bit size */
        int64_t         fs_qfmask;              /* ~fs_fmask for use with 64-bit size */
        int32_t         fs_state;               /* validate fs_clean field */
        int32_t         fs_old_postblformat;    /* format of positional layout tables */
        int32_t         fs_old_nrpos;           /* number of rotational positions */
        int32_t         fs_spare5[2];           /* old fs_postbloff */
                                        /* old fs_rotbloff */
        int32_t         fs_magic;               /* magic number */

        bool            IsMagicValid();
        bool            IsValid();
};

/* Sanity checking. */
#ifdef CTASSERT
CTASSERT(sizeof(struct fs) == 1376);
#endif


struct file_cookie {
        bigtime_t       last_notification;
        off_t           last_size;
        int             open_mode;
};


/*
 * Filesystem identification
 */
#define FS_UFS1_MAGIC           0x011954        /* UFS1 fast filesystem magic number */
#define FS_UFS2_MAGIC           0x19540119      /* UFS2 fast filesystem magic number */
#define FS_BAD_MAGIC            0x19960408      /* UFS incomplete newfs magic number */
#define FS_42INODEFMT           -1              /* 4.2BSD inode format */
#define FS_44INODEFMT           2               /* 4.4BSD inode format */

/*
 * Preference for optimization.
 */
#define FS_OPTTIME                      0       /* minimize allocation time */
#define FS_OPTSPACE                     1       /* minimize disk fragmentation */

/*
 * Filesystem flags.
 *
 * The FS_UNCLEAN flag is set by the kernel when the filesystem was
 * mounted with fs_clean set to zero. The FS_DOSOFTDEP flag indicates
 * that the filesystem should be managed by the soft updates code.
 * Note that the FS_NEEDSFSCK flag is set and cleared by the fsck
 * utility. It is set when background fsck finds an unexpected
 * inconsistency which requires a traditional foreground fsck to be
 * run. Such inconsistencies should only be found after an uncorrectable
 * disk error. The FS_NEEDSFSCK can also be set when a mounted filesystem
 * discovers an internal inconsistency such as freeing a freed inode.
 * A foreground fsck will clear the FS_NEEDSFSCK flag when it has
 * successfully cleaned up the filesystem. The kernel uses this
 * flag to enforce that inconsistent filesystems be mounted read-only.
 *
 * The FS_METACKHASH flag when set indicates that the kernel maintains
 * one or more check hashes. The actual set of supported check hashes
 * is stored in the fs_metackhash field. Kernels that do not support
 * check hashes clear the FS_METACKHASH flag to indicate that the
 * check hashes need to be rebuilt (by fsck) before they can be used.
 *
 * When a filesystem is mounted, any flags not included in FS_SUPPORTED
 * are cleared. This lets newer features know that the filesystem has
 * been run on an older version of the filesystem and thus that data
 * structures associated with those features are out-of-date and need
 * to be rebuilt.
 *
 * FS_ACLS indicates that POSIX.1e ACLs are administratively enabled
 * for the file system, so they should be loaded from extended attributes,
 * observed for access control purposes, and be administered by object
 * owners.  FS_NFS4ACLS indicates that NFSv4 ACLs are administratively
 * enabled.  This flag is mutually exclusive with FS_ACLS.  FS_MULTILABEL
 * indicates that the TrustedBSD MAC Framework should attempt to back MAC
 * labels into extended attributes on the file system rather than maintain
 * a single mount label for all objects.
 */
#define FS_UNCLEAN                      0x00000001 /* filesystem not clean at mount */
#define FS_DOSOFTDEP            0x00000002 /* filesystem using soft dependencies */
/* filesystem needs sync fsck before mount */
#define FS_NEEDSFSCK            0x00000004
#define FS_SUJ                          0x00000008 /* Filesystem using softupdate journal */
/* file system has POSIX.1e ACLs enabled */
#define FS_ACLS                         0x00000010
#define FS_MULTILABEL           0x00000020 /* file system is MAC multi-label */
#define FS_GJOURNAL                     0x00000040 /* gjournaled file system */
/* flags have been moved to new location */
#define FS_FLAGS_UPDATED        0x0000080
#define FS_NFS4ACLS                     0x00000100 /* file system has NFSv4 ACLs enabled */
/* kernel supports metadata check hashes */
#define FS_METACKHASH           0x00000200
#define FS_TRIM                         0x00000400 /* issue BIO_DELETE for deleted blocks */
/* supported flags, others cleared at mount */
#define FS_SUPPORTED            0x00FFFFFF
/*
 * Things that we may someday support, but currently do not.
 * These flags are all cleared so we know if we ran on a kernel
 * that does not support them.
 */
#define FS_INDEXDIRS            0x01000000 /* kernel supports indexed directories */
/* kernel supports variable block sizes */
#define FS_VARBLKSIZE           0x02000000
#define FS_COOLOPT1                     0x04000000 /* kernel supports cool option 1 */
#define FS_COOLOPT2                     0x08000000 /* kernel supports cool option 2 */
#define FS_COOLOPT3                     0x10000000 /* kernel supports cool option 3 */
#define FS_COOLOPT4                     0x20000000 /* kernel supports cool option 4 */
#define FS_COOLOPT5                     0x40000000 /* kernel supports cool option 5 */
#define FS_COOLOPT6                     0x80000000 /* kernel supports cool option 6 */

/*
 * The fs_metackhash field indicates the types of metadata check-hash
 * that are maintained for a filesystem. Not all filesystems check-hash
 * all metadata.
 */
#define CK_SUPERBLOCK           0x0001  /* the superblock */
#define CK_CYLGRP                       0x0002  /* the cylinder groups */
#define CK_INODE                        0x0004  /* inodes */
#define CK_INDIR                        0x0008  /* indirect blocks */
#define CK_DIR                          0x0010  /* directory contents */
/*
 * The BX_FSPRIV buffer b_xflags are used to track types of data in buffers.
 */
#define BX_SUPERBLOCK           0x00010000      /* superblock */
#define BX_CYLGRP                       0x00020000      /* cylinder groups */
#define BX_INODE                        0x00040000      /* inodes */
#define BX_INDIR                        0x00080000      /* indirect blocks */
#define BX_DIR                          0x00100000      /* directory contents */

/*
#define PRINT_UFS_BUF_XFLAGS "\20\25dir\24indir\23inode\22cylgrp\21superblock"
*/

/*
 * Macros to access bits in the fs_active array.
 */
#define ACTIVECGNUM(fs, cg)     ((fs)->fs_active[(cg) / (NBBY * sizeof(int))])
#define ACTIVECGOFF(cg)         (1 << ((cg) % (NBBY * sizeof(int))))
#define ACTIVESET(fs, cg)       do {                                    \
        if ((fs)->fs_active)                                            \
                ACTIVECGNUM((fs), (cg)) |= ACTIVECGOFF((cg));           \
} while (0)
#define ACTIVECLEAR(fs, cg)     do {                                    \
        if ((fs)->fs_active)                                            \
                ACTIVECGNUM((fs), (cg)) &= ~ACTIVECGOFF((cg));          \
} while (0)

/*
 * The size of a cylinder group is calculated by CGSIZE. The maximum size
 * is limited by the fact that cylinder groups are at most one block.
 * Its size is derived from the size of the maps maintained in the
 * cylinder group and the (struct cg) size.
 */
#define CGSIZE(fs) \
    /* base cg */       (sizeof(struct cg) + sizeof(int32_t) + \
    /* old btotoff */   (fs)->fs_old_cpg * sizeof(int32_t) + \
    /* old boff */      (fs)->fs_old_cpg * sizeof(u_int16_t) + \
    /* inode map */     howmany((fs)->fs_ipg, NBBY) + \
    /* block map */     howmany((fs)->fs_fpg, NBBY) +\
    /* if present */    ((fs)->fs_contigsumsize <= 0 ? 0 : \
    /* cluster sum */   (fs)->fs_contigsumsize * sizeof(int32_t) + \
    /* cluster map */   howmany(fragstoblks(fs, (fs)->fs_fpg), NBBY)))

/*
 * The minimal number of cylinder groups that should be created.
 */
#define MINCYLGRPS      4

/*
 * Convert cylinder group to base address of its global summary info.
 */
#define fs_cs(fs, indx) fs_csp[indx]

/*
 * Cylinder group block for a filesystem.
 */
#define CG_MAGIC        0x090255
struct cg {
        int32_t         cg_firstfield;          /* historic cyl groups linked list */
        int32_t         cg_magic;               /* magic number */
        int32_t         cg_old_time;            /* time last written */
        u_int32_t       cg_cgx;         /* we are the cgx'th cylinder group */
        int16_t         cg_old_ncyl;            /* number of cyl's this cg */
        int16_t         cg_old_niblk;           /* number of inode blocks this cg */
        u_int32_t       cg_ndblk;               /* number of data blocks this cg */
        struct          csum cg_cs;             /* cylinder summary information */
        u_int32_t       cg_rotor;               /* position of last used block */
        u_int32_t       cg_frotor;              /* position of last used frag */
        u_int32_t       cg_irotor;              /* position of last used inode */
        u_int32_t       cg_frsum[MAXFRAG];      /* counts of available frags */
        int32_t         cg_old_btotoff; /* (int32) block totals per cylinder */
        int32_t         cg_old_boff;            /* (u_int16) free block positions */
        u_int32_t       cg_iusedoff;            /* (u_int8) used inode map */
        u_int32_t       cg_freeoff;             /* (u_int8) free block map */
        u_int32_t       cg_nextfreeoff; /* (u_int8) next available space */
        u_int32_t       cg_clustersumoff;       /* (u_int32) counts of avail clusters */
        u_int32_t       cg_clusteroff;          /* (u_int8) free cluster map */
        u_int32_t       cg_nclusterblks;        /* number of clusters this cg */
        u_int32_t       cg_niblk;               /* number of inode blocks this cg */
        u_int32_t       cg_initediblk;          /* last initialized inode */
        u_int32_t       cg_unrefs;              /* number of unreferenced inodes */
        int32_t         cg_sparecon32[1];       /* reserved for future use */
        u_int32_t       cg_ckhash;              /* check-hash of this cg */
        int64_t         cg_time;                /* time last written */
        int64_t         cg_sparecon64[3];       /* reserved for future use */
        u_int8_t        cg_space[1];            /* space for cylinder group maps */
/* actually longer */
};

/*
 * Macros for access to cylinder group array structures
 */
#define cg_chkmagic(cgp) ((cgp)->cg_magic == CG_MAGIC)
#define cg_inosused(cgp) \
    ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_iusedoff))
#define cg_blksfree(cgp) \
    ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_freeoff))
#define cg_clustersfree(cgp) \
    ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_clusteroff))
#define cg_clustersum(cgp) \
    ((int32_t *)((uintptr_t)(cgp) + (cgp)->cg_clustersumoff))

/*
 * Turn filesystem block numbers into disk block addresses.
 * This maps filesystem blocks to device size blocks.
 */
#define fsbtodb(fs, b)  ((daddr_t)(b) << (fs)->fs_fsbtodb)
#define dbtofsb(fs, b)  ((b) >> (fs)->fs_fsbtodb)

/*
 * Cylinder group macros to locate things in cylinder groups.
 * They calc filesystem addresses of cylinder group data structures.
 */
#define cgbase(fs, c)   (((ufs2_daddr_t)(fs)->fs_fpg) * (c))
#define cgdata(fs, c)   (cgdmin(fs, c) + (fs)->fs_metaspace)    /* data zone */
#define cgmeta(fs, c)   (cgdmin(fs, c))                         /* meta data */
#define cgdmin(fs, c)   (cgstart(fs, c) + (fs)->fs_dblkno)      /* 1st data */
#define cgimin(fs, c)   (cgstart(fs, c) + (fs)->fs_iblkno)      /* inode blk */
#define cgsblock(fs, c) (cgstart(fs, c) + (fs)->fs_sblkno)      /* super blk */
#define cgtod(fs, c)    (cgstart(fs, c) + (fs)->fs_cblkno)      /* cg block */
#define cgstart(fs, c)                                                  \
       ((fs)->fs_magic == FS_UFS2_MAGIC ? cgbase(fs, c) :               \
       (cgbase(fs, c) + (fs)->fs_old_cgoffset * ((c) & ~((fs)->fs_old_cgmask))))

/*
 * Macros for handling inode numbers:
 *     inode number to filesystem block offset.
 *     inode number to cylinder group number.
 *     inode number to filesystem block address.
 */
#define ino_to_cg(fs, x)        (((ino_t)(x)) / (fs)->fs_ipg)
#define ino_to_fsba(fs, x)                                              \
        ((ufs2_daddr_t)(cgimin(fs, ino_to_cg(fs, (ino_t)(x))) +         \
            (blkstofrags((fs), ((((ino_t)(x)) % (fs)->fs_ipg) / INOPB(fs))))))
#define ino_to_fsbo(fs, x)      (((ino_t)(x)) % INOPB(fs))

/*
 * Give cylinder group number for a filesystem block.
 * Give cylinder group block number for a filesystem block.
 */
#define dtog(fs, d)     ((d) / (fs)->fs_fpg)
#define dtogd(fs, d)    ((d) % (fs)->fs_fpg)

/*
 * Extract the bits for a block from a map.
 * Compute the cylinder and rotational position of a cyl block addr.
 */
#define blkmap(fs, map, loc) \
    (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag)))

/*
 * The following macros optimize certain frequently calculated
 * quantities by using shifts and masks in place of divisions
 * modulos and multiplications.
 */
#define blkoff(fs, loc)         /* calculates (loc % fs->fs_bsize) */ \
        ((loc) & (fs)->fs_qbmask)
#define fragoff(fs, loc)        /* calculates (loc % fs->fs_fsize) */ \
        ((loc) & (fs)->fs_qfmask)
#define lfragtosize(fs, frag)   /* calculates ((off_t)frag * fs->fs_fsize) */ \
        (((off_t)(frag)) << (fs)->fs_fshift)
#define lblktosize(fs, blk)     /* calculates ((off_t)blk * fs->fs_bsize) */ \
        (((off_t)(blk)) << (fs)->fs_bshift)
/* Use this only when `blk' is known to be small, e.g., < UFS_NDADDR. */
#define smalllblktosize(fs, blk)    /* calculates (blk * fs->fs_bsize) */ \
        ((blk) << (fs)->fs_bshift)
#define lblkno(fs, loc)         /* calculates (loc / fs->fs_bsize) */ \
        ((loc) >> (fs)->fs_bshift)
#define numfrags(fs, loc)       /* calculates (loc / fs->fs_fsize) */ \
        ((loc) >> (fs)->fs_fshift)
#define blkroundup(fs, size)    /* calculates roundup(size, fs->fs_bsize) */ \
        (((size) + (fs)->fs_qbmask) & (fs)->fs_bmask)
#define fragroundup(fs, size)   /* calculates roundup(size, fs->fs_fsize) */ \
        (((size) + (fs)->fs_qfmask) & (fs)->fs_fmask)
#define fragstoblks(fs, frags)  /* calculates (frags / fs->fs_frag) */ \
        ((frags) >> (fs)->fs_fragshift)
#define blkstofrags(fs, blks)   /* calculates (blks * fs->fs_frag) */ \
        ((blks) << (fs)->fs_fragshift)
#define fragnum(fs, fsb)        /* calculates (fsb % fs->fs_frag) */ \
        ((fsb) & ((fs)->fs_frag - 1))
#define blknum(fs, fsb)         /* calculates rounddown(fsb, fs->fs_frag) */ \
        ((fsb) &~ ((fs)->fs_frag - 1))

/*
 * Determine the number of available frags given a
 * percentage to hold in reserve.
 */
#define freespace(fs, percentreserved) \
        (blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \
        (fs)->fs_cstotal.cs_nffree - \
        (((off_t)((fs)->fs_dsize)) * (percentreserved) / 100))

/*
 * Determining the size of a file block in the filesystem.
 */
#define blksize(fs, ip, lbn) \
        (((lbn) >= UFS_NDADDR || (ip)->i_size >= \
            (uint64_t)smalllblktosize(fs, (lbn) + 1)) \
            ? (fs)->fs_bsize \
            : (fragroundup(fs, blkoff(fs, (ip)->i_size))))
#define sblksize(fs, size, lbn) \
        (((lbn) >= UFS_NDADDR || (size) >= ((lbn) + 1) << (fs)->fs_bshift) \
          ? (fs)->fs_bsize \
          : (fragroundup(fs, blkoff(fs, (size)))))

/*
 * Number of indirects in a filesystem block.
 */
#define NINDIR(fs)      ((fs)->fs_nindir)

/*
 * Indirect lbns are aligned on UFS_NDADDR addresses where single indirects
 * are the negated address of the lowest lbn reachable, double indirects
 * are this lbn - 1 and triple indirects are this lbn - 2.  This yields
 * an unusual bit order to determine level.
 */
/*static inline int
lbn_level(ufs_lbn_t lbn)
{
        if (lbn >= 0)
                return 0;
        switch (lbn & 0x3) {
        case 0:
                return (0);
        case 1:
                break;
        case 2:
                return (2);
        case 3:
                return (1);
        default:
                break;
        }
        return (-1);
}

static inline ufs_lbn_t
lbn_offset(struct fs *fs, int level)
{
        ufs_lbn_t res;

        for (res = 1; level > 0; level--)
                res *= NINDIR(fs);
        return (res);
}*/

/*
 * Number of inodes in a secondary storage block/fragment.
 */
#define INOPB(fs)       ((fs)->fs_inopb)
#define INOPF(fs)       ((fs)->fs_inopb >> (fs)->fs_fragshift)

/*
 * Softdep journal record format.
 */

#define JOP_ADDREF      1       /* Add a reference to an inode. */
#define JOP_REMREF      2       /* Remove a reference from an inode. */
#define JOP_NEWBLK      3       /* Allocate a block. */
#define JOP_FREEBLK     4       /* Free a block or a tree of blocks. */
#define JOP_MVREF       5       /* Move a reference from one off to another. */
#define JOP_TRUNC       6       /* Partial truncation record. */
#define JOP_SYNC        7       /* fsync() complete record. */

#define JREC_SIZE       32      /* Record and segment header size. */

#define SUJ_MIN         (4 * 1024 * 1024)       /* Minimum journal size */
#define SUJ_MAX         (32 * 1024 * 1024)      /* Maximum journal size */
#define SUJ_FILE        ".sujournal"            /* Journal file name */

/*
 * Size of the segment record header.  There is at most one for each disk
 * block in the journal.  The segment header is followed by an array of
 * records.  fsck depends on the first element in each record being 'op'
 * and the second being 'ino'.  Segments may span multiple disk blocks but
 * the header is present on each.
 */
struct jsegrec {
        uint64_t        jsr_seq;        /* Our sequence number */
        uint64_t        jsr_oldest;     /* Oldest valid sequence number */
        uint16_t        jsr_cnt;        /* Count of valid records */
        uint16_t        jsr_blocks;     /* Count of device bsize blocks. */
        uint32_t        jsr_crc;        /* 32bit crc of the valid space */
        int64_t         jsr_time;       /* timestamp for mount instance */
};

/*
 * Reference record.  Records a single link count modification.
 */
struct jrefrec {
        uint32_t        jr_op;
        uint32_t        jr_ino;
        uint32_t        jr_parent;
        uint16_t        jr_nlink;
        uint16_t        jr_mode;
        int64_t         jr_diroff;
        uint64_t        jr_unused;
};

/*
 * Move record.  Records a reference moving within a directory block.  The
 * nlink is unchanged but we must search both locations.
 */
struct jmvrec {
        uint32_t        jm_op;
        uint32_t        jm_ino;
        uint32_t        jm_parent;
        uint16_t        jm_unused;
        int64_t         jm_oldoff;
        int64_t         jm_newoff;
};

/*
 * Block record.  A set of frags or tree of blocks starting at an indirect are
 * freed or a set of frags are allocated.
 */
struct jblkrec {
        uint32_t        jb_op;
        uint32_t        jb_ino;
        int64_t         jb_blkno;
        int64_t         jb_lbn;
        uint16_t        jb_frags;
        uint16_t        jb_oldfrags;
        uint32_t        jb_unused;
};

/*
 * Truncation record.  Records a partial truncation so that it may be
 * completed at check time.  Also used for sync records.
 */
struct jtrncrec {
        uint32_t        jt_op;
        uint32_t        jt_ino;
        int64_t         jt_size;
        uint32_t        jt_extsize;
        uint32_t        jt_pad[3];
};

union jrec {
        struct  jsegrec         rec_jsegrec;
        struct  jrefrec         rec_jrefrec;
        struct  jmvrec          rec_jmvrec;
        struct  jblkrec         rec_jblkrec;
        struct  jtrncrec        rec_jtrncrec;
};

#ifdef CTASSERT
CTASSERT(sizeof(struct jsegrec) == JREC_SIZE);
CTASSERT(sizeof(struct jrefrec) == JREC_SIZE);
CTASSERT(sizeof(struct jmvrec) == JREC_SIZE);
CTASSERT(sizeof(struct jblkrec) == JREC_SIZE);
CTASSERT(sizeof(struct jtrncrec) == JREC_SIZE);
CTASSERT(sizeof(union jrec) == JREC_SIZE);
#endif

extern int inside[], around[];
extern u_char *fragtbl[];

/*
 * IOCTLs used for filesystem write suspension.
 */
#define UFSSUSPEND      _IOW('U', 1, fsid_t)
#define UFSRESUME       _IO('U', 2)

#endif