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/*      $NetBSD: fs.h,v 1.56 2011/03/06 17:08:38 bouyer Exp $   */

/*

 * 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

 */

/*

 * NOTE: COORDINATE ON-DISK FORMAT CHANGES WITH THE FREEBSD PROJECT.

 */

#ifndef _UFS_FFS_FS_H_

#define _UFS_FFS_FS_H_

/*

 * Each disk drive contains some number of file systems.

 * A file system consists of a number of cylinder groups.

 * Each cylinder group has inodes and data.

 *

 * A file system is described by its super-block, which in turn

 * describes the cylinder groups.  The super-block is critical

 * data and is replicated in each cylinder group to protect against

 * catastrophic loss.  This is done at `newfs' time and the critical

 * super-block data does not change, so the copies need not be

 * referenced further unless disaster strikes.

 *

 * For file system fs, the offsets of the various blocks of interest

 * are given in the super block as:

 *      [fs->fs_sblkno]         Super-block

 *      [fs->fs_cblkno]         Cylinder group block

 *      [fs->fs_iblkno]         Inode blocks

 *      [fs->fs_dblkno]         Data blocks

 * The beginning of cylinder group cg in fs, is given by

 * the ``cgbase(fs, cg)'' macro.

 *

 * Depending on the architecture and the media, the superblock may

 * reside in any one of four places. For tiny media where every block

 * counts, it is placed at the very front of the partition. Historically,

 * UFS1 placed it 8K from the front to leave room for the disk label and

 * a small bootstrap. For UFS2 it got moved to 64K from the front to leave

 * room for the disk label and a bigger bootstrap, and for really piggy

 * systems we check at 256K from the front if the first three fail. In

 * all cases the size of the superblock will be SBLOCKSIZE. All values are

 * given in byte-offset form, so they do not imply a sector size. The

 * SBLOCKSEARCH specifies the order in which the locations should be searched.

 *

 * Unfortunately the UFS2/FFSv2 change was done without adequate consideration

 * of backward compatibility.  In particular 'newfs' for a FFSv2 partition

 * must overwrite any old FFSv1 superblock at 8k, and preferrably as many

 * of the alternates as it can find - otherwise attempting to mount on a

 * system that only supports FFSv1 is likely to succeed!.

 * For a small FFSv1 filesystem, an old FFSv2 superblock can be left on

 * the disk, and a system that tries to find an FFSv2 filesystem in preference

 * to and FFSv1 one (as NetBSD does) can mount the old FFSv2 filesystem.

 * As a added bonus, the 'first alternate' superblock of a FFSv1 filesystem

 * with 64k blocks is at 64k - just where the code looks first when playing

 * 'hunt the superblock'.

 *

 * The ffsv2 superblock layout (which might contain an ffsv1 filesystem)

 * can be detected by checking for sb->fs_old_flags & FS_FLAGS_UPDATED.

 * This is the default superblock type for NetBSD since ffsv2 support was added.

 */

#define BBSIZE          8192

#define BBOFF           ((off_t)(0))

#define BBLOCK          ((daddr_t)(0))

#define SBLOCK_FLOPPY      0

#define SBLOCK_UFS1     8192

#define SBLOCK_UFS2    65536

#define SBLOCK_PIGGY  262144

#define SBLOCKSIZE      8192

/*

 * NB: Do not, under any circumstances, look for an ffsv1 filesystem at

 * SBLOCK_UFS2.  Doing so will find the wrong superblock for filesystems

 * with a 64k block size.

 */

#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 file system 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 file system records space availability at the fragment level;

 * to determine block availability, aligned fragments are examined.

 */

/*

 * MINBSIZE is the smallest allowable block size.

 * In order to insure that it is possible to create files of size

 * 2^32 with only two levels of indirection, MINBSIZE is set to 4096.

 * MINBSIZE must be big enough to hold a cylinder group block,

 * thus changes to (struct cg) must keep its size within MINBSIZE.

 * Note that super blocks are always of size SBSIZE,

 * and that both SBSIZE and MAXBSIZE must be >= MINBSIZE.

 */

#define MINBSIZE        4096

/*

 * The path name on which the file system 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.

 * This space used to be part of of fs_fsmnt.

 */

#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 four

 * 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;

 * the third (fs_contigdirs) points to an array that tracks the

 * creation of new directories; and the fourth (fs_active) is used

 * by snapshots.

 */

#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

/*

 * 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      ((daddr_t)(1))

#define BLK_SNAP        ((daddr_t)(2))

/*

 * MINFREE gives the minimum acceptable percentage of file system

 * 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 file system

 * 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. This value is used only

 * when creating a file system and can be overriden from the

 * command line. By default we choose to optimize for time.

 */

#define MINFREE         5

#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 */

/*

 * 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_spare[4];            /* future expansion */

};

/*

 * Super block for an FFS file system in memory.

 */

struct fs {

        int32_t  fs_firstfield;         /* historic file system linked list, */

        int32_t  fs_unused_1;           /*     used for incore super blocks */

        int32_t  fs_sblkno;             /* addr 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 */

        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 */

        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 */

/* these fields are derived from the hardware */

        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 */

/* fs_id takes the space of the unused fs_headswitch and fs_trkseek fields */

        int32_t  fs_id[2];              /* unique file system 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 */

/* these fields are derived from the hardware */

        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 file system */

        int32_t  fs_old_cpg;            /* cylinders per group */

        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 */

        uint8_t  fs_clean;              /* file system is clean flag */

        int8_t   fs_ronly;              /* mounted read-only flag */

        uint8_t  fs_old_flags;          /* see FS_ flags below */

        u_char   fs_fsmnt[MAXMNTLEN];   /* name mounted on */

        u_char   fs_volname[MAXVOLLEN]; /* volume name */

        uint64_t fs_swuid;              /* system-wide uid */

        int32_t  fs_pad;

/* these fields retain the current block allocation info */

        int32_t  fs_cgrotor;            /* last cg searched (UNUSED) */

        void    *fs_ocsp[NOCSPTRS];     /* padding; was list of fs_cs buffers */

        u_int8_t *fs_contigdirs;        /* # of contiguously allocated dirs */

        struct csum *fs_csp;            /* cg summary info buffer for fs_cs */

        int32_t *fs_maxcluster;         /* max cluster in each cyl group */

        u_char  *fs_active;             /* used by snapshots to track fs */

        int32_t  fs_old_cpc;            /* cyl per cycle in postbl */

/* this area is otherwise allocated unless fs_old_flags & FS_FLAGS_UPDATED */

        int32_t  fs_maxbsize;           /* maximum blocking factor permitted */

        uint8_t  fs_journal_version;    /* journal format version */

        uint8_t  fs_journal_location;   /* journal location type */

        uint8_t  fs_journal_reserved[2];/* reserved for future use */

        uint32_t fs_journal_flags;      /* journal flags */

        uint64_t fs_journallocs[4];     /* location info for journal */

        uint32_t fs_quota_magic;        /* see quota2.h */

        uint8_t  fs_quota_flags;        /* see quota2.h */

        uint8_t  fs_quota_reserved[3];

        uint64_t fs_quotafile[2];       /* pointer to quota inodes */

        int64_t  fs_sparecon64[9];      /* reserved for future use */

        int64_t  fs_sblockloc;          /* byte offset of standard superblock */

        struct  csum_total fs_cstotal;  /* 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;      /* blocks in process of being freed */

        int32_t  fs_pendinginodes;      /* inodes in process of being freed */

        int32_t  fs_snapinum[FSMAXSNAP];/* list of snapshot inode numbers */

/* back to stuff that has been around a while */

        int32_t  fs_avgfilesize;        /* expected average file size */

        int32_t  fs_avgfpdir;           /* expected # of files per directory */

        int32_t  fs_save_cgsize;        /* save real cg size to use fs_bsize */

        int32_t  fs_sparecon32[26];     /* reserved for future constants */

        uint32_t fs_flags;              /* see FS_ flags below */

/* back to stuff that has been around a while (again) */

        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 (UNUSED) */

        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 */

};

#define fs_old_postbloff        fs_spare5[0]

#define fs_old_rotbloff         fs_spare5[1]

#define fs_old_postbl_start     fs_maxbsize

#define fs_old_headswitch       fs_id[0]

#define fs_old_trkseek  fs_id[1]

#define fs_old_csmask   fs_spare1[0]

#define fs_old_csshift  fs_spare1[1]

#define FS_42POSTBLFMT          -1      /* 4.2BSD rotational table format */

#define FS_DYNAMICPOSTBLFMT     1       /* dynamic rotational table format */

#define old_fs_postbl(fs_, cylno, opostblsave) \

    ((((fs_)->fs_old_postblformat == FS_42POSTBLFMT) || \

     ((fs_)->fs_old_postbloff == offsetof(struct fs, fs_old_postbl_start))) \

    ? ((int16_t *)(opostblsave) + (cylno) * (fs_)->fs_old_nrpos) \

    : ((int16_t *)((uint8_t *)(fs_) + \

        (fs_)->fs_old_postbloff) + (cylno) * (fs_)->fs_old_nrpos))

#define old_fs_rotbl(fs) \

    (((fs)->fs_old_postblformat == FS_42POSTBLFMT) \

    ? ((uint8_t *)(&(fs)->fs_magic+1)) \

    : ((uint8_t *)((uint8_t *)(fs) + (fs)->fs_old_rotbloff)))

/*

 * File system identification

 */

#define FS_UFS1_MAGIC   0x011954        /* UFS1 fast file system magic number */

#define FS_UFS2_MAGIC   0x19540119      /* UFS2 fast file system magic number */

#define FS_UFS1_MAGIC_SWAPPED   0x54190100

#define FS_UFS2_MAGIC_SWAPPED   0x19015419

#define FS_OKAY         0x7c269d38      /* superblock checksum */

#define FS_42INODEFMT   -1              /* 4.2BSD inode format */

#define FS_44INODEFMT   2               /* 4.4BSD inode format */

/*

 * File system clean flags

 */

#define FS_ISCLEAN      0x01

#define FS_WASCLEAN     0x02

/*

 * Preference for optimization.

 */

#define FS_OPTTIME      0        /* minimize allocation time */

#define FS_OPTSPACE     1       /* minimize disk fragmentation */

/*

 * File system flags

 */

#define FS_UNCLEAN      0x001   /* file system not clean at mount (unused) */

#define FS_DOSOFTDEP    0x002   /* file system using soft dependencies */

#define FS_NEEDSFSCK    0x004   /* needs sync fsck (FreeBSD compat, unused) */

#define FS_INDEXDIRS    0x008   /* kernel supports indexed directories */

#define FS_ACLS         0x010   /* file system has ACLs enabled */

#define FS_MULTILABEL   0x020   /* file system is MAC multi-label */

#define FS_GJOURNAL     0x40    /* gjournaled file system */

#define FS_FLAGS_UPDATED 0x80   /* flags have been moved to new location */

#define FS_DOWAPBL      0x100   /* Write ahead physical block logging */

#define FS_DOQUOTA2     0x200   /* in-filesystem quotas */

/* File system flags that are ok for NetBSD if set in fs_flags */

#define FS_KNOWN_FLAGS  (FS_DOSOFTDEP | FS_DOWAPBL | FS_DOQUOTA2)

/*

 * File system internal flags, also in fs_flags.

 * (Pick highest number to avoid conflicts with others)

 */

#define FS_SWAPPED      0x80000000      /* file system is endian swapped */

#define FS_INTERNAL     0x80000000      /* mask for internal flags */

/*

 * Macros to access bits in the fs_active array.

 */

#define ACTIVECG_SET(fs, cg)                            \

        do {                                            \

                if ((fs)->fs_active != NULL)            \

                        setbit((fs)->fs_active, (cg));  \

        } while (/*CONSTCOND*/ 0)

#define ACTIVECG_CLR(fs, cg)                            \

        do {                                            \

                if ((fs)->fs_active != NULL)            \

                        clrbit((fs)->fs_active, (cg));  \

        } while (/*CONSTCOND*/ 0)

#define ACTIVECG_ISSET(fs, cg)                          \

        ((fs)->fs_active != NULL && isset((fs)->fs_active, (cg)))

/*

 * 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_IF(fs, ipg, fpg) \

    /* 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((ipg), NBBY) + \

    /* block map */     howmany((fpg), NBBY) +\

    /* if present */    ((fs)->fs_contigsumsize <= 0 ? 0 : \

    /* cluster sum */   (fs)->fs_contigsumsize * sizeof(int32_t) + \

    /* cluster map */   howmany(fragstoblks(fs, (fpg)), NBBY)))

#define CGSIZE(fs) CGSIZE_IF((fs), (fs)->fs_ipg, (fs)->fs_fpg)

/*

 * 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 file system.

 */

#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 */

        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 */

        int32_t  cg_ndblk;              /* number of data blocks this cg */

        struct  csum cg_cs;             /* cylinder summary information */

        int32_t  cg_rotor;              /* position of last used block */

        int32_t  cg_frotor;             /* position of last used frag */

        int32_t  cg_irotor;             /* position of last used inode */

        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 */

        int32_t  cg_iusedoff;           /* (u_int8) used inode map */

        int32_t  cg_freeoff;            /* (u_int8) free block map */

        int32_t  cg_nextfreeoff;        /* (u_int8) next available space */

        int32_t  cg_clustersumoff;      /* (u_int32) counts of avail clusters */

        int32_t  cg_clusteroff;         /* (u_int8) free cluster map */

        int32_t  cg_nclusterblks;       /* number of clusters this cg */

        int32_t  cg_niblk;              /* number of inode blocks this cg */

        int32_t  cg_initediblk;         /* last initialized inode */

        int32_t  cg_sparecon32[3];      /* reserved for future use */

        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 */

};

/*

 * The following structure is defined

 * for compatibility with old file systems.

 */

struct ocg {

        int32_t  cg_firstfield;         /* historic linked list of cyl groups */

        int32_t  cg_unused_1;           /*     used for incore cyl groups */

        int32_t  cg_time;               /* time last written */

        int32_t  cg_cgx;                /* we are the cgx'th cylinder group */

        int16_t  cg_ncyl;               /* number of cyl's this cg */

        int16_t  cg_niblk;              /* number of inode blocks this cg */

        int32_t  cg_ndblk;              /* number of data blocks this cg */

        struct  csum cg_cs;             /* cylinder summary information */

        int32_t  cg_rotor;              /* position of last used block */

        int32_t  cg_frotor;             /* position of last used frag */

        int32_t  cg_irotor;             /* position of last used inode */

        int32_t  cg_frsum[8];           /* counts of available frags */

        int32_t  cg_btot[32];           /* block totals per cylinder */

        int16_t  cg_b[32][8];           /* positions of free blocks */

        u_int8_t cg_iused[256];         /* used inode map */

        int32_t  cg_magic;              /* magic number */

        u_int8_t cg_free[1];            /* free block map */

/* actually longer */

};

/*

 * Macros for access to cylinder group array structures.

 */

#define old_cg_blktot_old(cgp, ns) \

    (((struct ocg *)(cgp))->cg_btot)

#define old_cg_blks_old(fs, cgp, cylno, ns) \

    (((struct ocg *)(cgp))->cg_b[cylno])

#define old_cg_blktot_new(cgp, ns) \

    ((int32_t *)((u_int8_t *)(cgp) + \

        ufs_rw32((cgp)->cg_old_btotoff, (ns))))

#define old_cg_blks_new(fs, cgp, cylno, ns) \

    ((int16_t *)((u_int8_t *)(cgp) + \

        ufs_rw32((cgp)->cg_old_boff, (ns))) + (cylno) * (fs)->fs_old_nrpos)

#define old_cg_blktot(cgp, ns) \

    ((ufs_rw32((cgp)->cg_magic, (ns)) != CG_MAGIC) ? \

      old_cg_blktot_old(cgp, ns) : old_cg_blktot_new(cgp, ns))

#define old_cg_blks(fs, cgp, cylno, ns) \

    ((ufs_rw32((cgp)->cg_magic, (ns)) != CG_MAGIC) ? \

      old_cg_blks_old(fs, cgp, cylno, ns) : old_cg_blks_new(fs, cgp, cylno, ns))

#define cg_inosused_new(cgp, ns) \

    ((u_int8_t *)((u_int8_t *)(cgp) + \

        ufs_rw32((cgp)->cg_iusedoff, (ns))))

#define cg_blksfree_new(cgp, ns) \

    ((u_int8_t *)((u_int8_t *)(cgp) + \

        ufs_rw32((cgp)->cg_freeoff, (ns))))

#define cg_chkmagic_new(cgp, ns) \

    (ufs_rw32((cgp)->cg_magic, (ns)) == CG_MAGIC)

#define cg_inosused_old(cgp, ns) \

    (((struct ocg *)(cgp))->cg_iused)

#define cg_blksfree_old(cgp, ns) \

    (((struct ocg *)(cgp))->cg_free)

#define cg_chkmagic_old(cgp, ns) \

    (ufs_rw32(((struct ocg *)(cgp))->cg_magic, (ns)) == CG_MAGIC)

#define cg_inosused(cgp, ns) \

    ((ufs_rw32((cgp)->cg_magic, (ns)) != CG_MAGIC) ? \

      cg_inosused_old(cgp, ns) : cg_inosused_new(cgp, ns))

#define cg_blksfree(cgp, ns) \

    ((ufs_rw32((cgp)->cg_magic, (ns)) != CG_MAGIC) ? \

      cg_blksfree_old(cgp, ns) : cg_blksfree_new(cgp, ns))

#define cg_chkmagic(cgp, ns) \

    (cg_chkmagic_new(cgp, ns) || cg_chkmagic_old(cgp, ns))

#define cg_clustersfree(cgp, ns) \

    ((u_int8_t *)((u_int8_t *)(cgp) + \

        ufs_rw32((cgp)->cg_clusteroff, (ns))))

#define cg_clustersum(cgp, ns) \

    ((int32_t *)((u_int8_t *)(cgp) + \

        ufs_rw32((cgp)->cg_clustersumoff, (ns))))

/*

 * Turn file system block numbers into disk block addresses.

 * This maps file system blocks to device size blocks.

 */

#if defined (_KERNEL)

#define fsbtodb(fs, b)  ((b) << ((fs)->fs_fshift - DEV_BSHIFT))

#define dbtofsb(fs, b)  ((b) >> ((fs)->fs_fshift - DEV_BSHIFT))

#else

#define fsbtodb(fs, b)  ((b) << (fs)->fs_fsbtodb)

#define dbtofsb(fs, b)  ((b) >> (fs)->fs_fsbtodb)

#endif

/*

 * Cylinder group macros to locate things in cylinder groups.

 * They calc file system addresses of cylinder group data structures.

 */

#define cgbase(fs, c)   (((daddr_t)(fs)->fs_fpg) * (c))

#define cgstart_ufs1(fs, c) \

    (cgbase(fs, c) + (fs)->fs_old_cgoffset * ((c) & ~((fs)->fs_old_cgmask)))

#define cgstart_ufs2(fs, c) cgbase((fs), (c))

#define cgstart(fs, c) ((fs)->fs_magic == FS_UFS2_MAGIC \

                            ? cgstart_ufs2((fs), (c)) : cgstart_ufs1((fs), (c)))

#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 */

/*

 * Macros for handling inode numbers:

 *     inode number to file system block offset.

 *     inode number to cylinder group number.

 *     inode number to file system block address.

 */

#define ino_to_cg(fs, x)        ((x) / (fs)->fs_ipg)

#define ino_to_fsba(fs, x)                                              \

        ((daddr_t)(cgimin(fs, ino_to_cg(fs, x)) +                       \

            (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs))))))

#define ino_to_fsbo(fs, x)      ((x) % INOPB(fs))

/*

 * Give cylinder group number for a file system block.

 * Give cylinder group block number for a file system 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)))

#define old_cbtocylno(fs, bno) \

    (fsbtodb(fs, bno) / (fs)->fs_old_spc)

#define old_cbtorpos(fs, bno) \

    ((fs)->fs_old_nrpos <= 1 ? 0 : \

     (fsbtodb(fs, bno) % (fs)->fs_old_spc / (fs)->fs_old_nsect * (fs)->fs_old_trackskew + \

      fsbtodb(fs, bno) % (fs)->fs_old_spc % (fs)->fs_old_nsect * (fs)->fs_old_interleave) % \

     (fs)->fs_old_nsect * (fs)->fs_old_nrpos / (fs)->fs_old_npsect)

/*

 * 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)

#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 file system.

 */

#define blksize(fs, ip, lbn) \

        (((lbn) >= NDADDR || (ip)->i_size >= lblktosize(fs, (lbn) + 1)) \

            ? (fs)->fs_bsize \

            : (fragroundup(fs, blkoff(fs, (ip)->i_size))))

#define sblksize(fs, size, lbn) \

        (((lbn) >= NDADDR || (size) >= ((lbn) + 1) << (fs)->fs_bshift) \

          ? (fs)->fs_bsize \

          : (fragroundup(fs, blkoff(fs, (size)))))

/*

 * Number of inodes in a secondary storage block/fragment.

 */

#define INOPB(fs)       ((fs)->fs_inopb)

#define INOPF(fs)       ((fs)->fs_inopb >> (fs)->fs_fragshift)

/*