FreeBSD/Linux Kernel Cross Reference
sys/ufs/ffs/fs.h

     /*
      * 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. All advertising materials mentioning features or use of this software
     *    must display the following acknowledgement:
     *      This product includes software developed by the University of
     *      California, Berkeley and its contributors.
     * 4. 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        8.7 (Berkeley) 4/19/94
     * $FreeBSD: src/sys/ufs/ffs/fs.h,v 1.7.2.2 1999/09/05 08:23:38 peter Exp $
     */
    
    #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.
     *
     * The first boot and super blocks are given in absolute disk addresses.
     * The byte-offset forms are preferred, as they don't imply a sector size.
     */
    #define BBSIZE          8192
    #define SBSIZE          8192
    #define BBOFF           ((off_t)(0))
    #define SBOFF           ((off_t)(BBOFF + BBSIZE))
    #define BBLOCK          ((daddr_t)(0))
    #define SBLOCK          ((daddr_t)(BBLOCK + BBSIZE / DEV_BSIZE))
    
    /*
     * 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.
    * The limit on the amount of summary information per file system
    * is defined by MAXCSBUFS. It is currently parameterized for a
    * maximum of two million cylinders.
    */
   #define MAXMNTLEN 512
   #define MAXCSBUFS 32
   
   /*
    * 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 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. 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
   
   /*
    * 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.
    *
    * N.B. sizeof(struct csum) must be a power of two in order for
    * the ``fs_cs'' macro to work (see below).
    */
   struct csum {
           long    cs_ndir;        /* number of directories */
           long    cs_nbfree;      /* number of free blocks */
           long    cs_nifree;      /* number of free inodes */
           long    cs_nffree;      /* number of free frags */
   };
   
   /*
    * Super block for a file system.
    */
   struct fs {
           struct  fs *fs_link;            /* linked list of file systems */
           struct  fs *fs_rlink;           /*     used for incore super blocks */
           daddr_t fs_sblkno;              /* addr of super-block in filesys */
           daddr_t fs_cblkno;              /* offset of cyl-block in filesys */
           daddr_t fs_iblkno;              /* offset of inode-blocks in filesys */
           daddr_t fs_dblkno;              /* offset of first data after cg */
           long    fs_cgoffset;            /* cylinder group offset in cylinder */
           long    fs_cgmask;              /* used to calc mod fs_ntrak */
           time_t  fs_time;                /* last time written */
           long    fs_size;                /* number of blocks in fs */
           long    fs_dsize;               /* number of data blocks in fs */
           long    fs_ncg;                 /* number of cylinder groups */
           long    fs_bsize;               /* size of basic blocks in fs */
           long    fs_fsize;               /* size of frag blocks in fs */
           long    fs_frag;                /* number of frags in a block in fs */
   /* these are configuration parameters */
           long    fs_minfree;             /* minimum percentage of free blocks */
           long    fs_rotdelay;            /* num of ms for optimal next block */
           long    fs_rps;                 /* disk revolutions per second */
   /* these fields can be computed from the others */
           long    fs_bmask;               /* ``blkoff'' calc of blk offsets */
           long    fs_fmask;               /* ``fragoff'' calc of frag offsets */
           long    fs_bshift;              /* ``lblkno'' calc of logical blkno */
           long    fs_fshift;              /* ``numfrags'' calc number of frags */
   /* these are configuration parameters */
           long    fs_maxcontig;           /* max number of contiguous blks */
           long    fs_maxbpg;              /* max number of blks per cyl group */
   /* these fields can be computed from the others */
           long    fs_fragshift;           /* block to frag shift */
           long    fs_fsbtodb;             /* fsbtodb and dbtofsb shift constant */
           long    fs_sbsize;              /* actual size of super block */
           long    fs_csmask;              /* csum block offset */
           long    fs_csshift;             /* csum block number */
           long    fs_nindir;              /* value of NINDIR */
           long    fs_inopb;               /* value of INOPB */
           long    fs_nspf;                /* value of NSPF */
   /* yet another configuration parameter */
           long    fs_optim;               /* optimization preference, see below */
   /* these fields are derived from the hardware */
           long    fs_npsect;              /* # sectors/track including spares */
           long    fs_interleave;          /* hardware sector interleave */
           long    fs_trackskew;           /* sector 0 skew, per track */
   /* fs_id takes the space of the unused fs_headswitch and fs_trkseek fields */
           long    fs_id[2];               /* unique filesystem id */ 
   /* sizes determined by number of cylinder groups and their sizes */
           daddr_t fs_csaddr;              /* blk addr of cyl grp summary area */
           long    fs_cssize;              /* size of cyl grp summary area */
           long    fs_cgsize;              /* cylinder group size */
   /* these fields are derived from the hardware */
           long    fs_ntrak;               /* tracks per cylinder */
           long    fs_nsect;               /* sectors per track */
           long    fs_spc;                 /* sectors per cylinder */
   /* this comes from the disk driver partitioning */
           long    fs_ncyl;                /* cylinders in file system */
   /* these fields can be computed from the others */
           long    fs_cpg;                 /* cylinders per group */
           long    fs_ipg;                 /* inodes per group */
           long    fs_fpg;                 /* blocks per group * fs_frag */
   /* this data must be re-computed after crashes */
           struct  csum fs_cstotal;        /* cylinder summary information */
   /* these fields are cleared at mount time */
           char    fs_fmod;                /* super block modified flag */
           char    fs_clean;               /* file system is clean flag */
           char    fs_ronly;               /* mounted read-only flag */
           char    fs_flags;               /* currently unused flag */
           char    fs_fsmnt[MAXMNTLEN];    /* name mounted on */
   /* these fields retain the current block allocation info */
           long    fs_cgrotor;             /* last cg searched */
           struct  csum *fs_csp[MAXCSBUFS];/* list of fs_cs info buffers */
           long    fs_cpc;                 /* cyl per cycle in postbl */
           short   fs_opostbl[16][8];      /* old rotation block list head */
           long    fs_sparecon[50];        /* reserved for future constants */
           long    fs_contigsumsize;       /* size of cluster summary array */
           long    fs_maxsymlinklen;       /* max length of an internal symlink */
           long    fs_inodefmt;            /* format of on-disk inodes */
           u_quad_t fs_maxfilesize;        /* maximum representable file size */
           quad_t  fs_qbmask;              /* ~fs_bmask - for use with quad size */
           quad_t  fs_qfmask;              /* ~fs_fmask - for use with quad size */
           long    fs_state;               /* validate fs_clean field */
           long    fs_postblformat;        /* format of positional layout tables */
           long    fs_nrpos;               /* number of rotational positions */
           long    fs_postbloff;           /* (short) rotation block list head */
           long    fs_rotbloff;            /* (u_char) blocks for each rotation */
           long    fs_magic;               /* magic number */
           u_char  fs_space[1];            /* list of blocks for each rotation */
   /* actually longer */
   };
   /*
    * Filesystem identification
    */
   #define FS_MAGIC        0x011954        /* the fast filesystem magic number */
   #define FS_OKAY         0x7c269d38      /* superblock checksum */
   #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 */
   
   /*
    * Rotational layout table format types
    */
   #define FS_42POSTBLFMT          -1      /* 4.2BSD rotational table format */
   #define FS_DYNAMICPOSTBLFMT     1       /* dynamic rotational table format */
   /*
    * Macros for access to superblock array structures
    */
   #define fs_postbl(fs, cylno) \
       (((fs)->fs_postblformat == FS_42POSTBLFMT) \
       ? ((fs)->fs_opostbl[cylno]) \
       : ((short *)((char *)(fs) + (fs)->fs_postbloff) + (cylno) * (fs)->fs_nrpos))
   #define fs_rotbl(fs) \
       (((fs)->fs_postblformat == FS_42POSTBLFMT) \
       ? ((fs)->fs_space) \
       : ((u_char *)((char *)(fs) + (fs)->fs_rotbloff)))
   
   /*
    * 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(long) + \
       /* blktot size */   (fs)->fs_cpg * sizeof(long) + \
       /* blks size */     (fs)->fs_cpg * (fs)->fs_nrpos * sizeof(short) + \
       /* inode map */     howmany((fs)->fs_ipg, NBBY) + \
       /* block map */     howmany((fs)->fs_cpg * (fs)->fs_spc / NSPF(fs), NBBY) +\
       /* if present */    ((fs)->fs_contigsumsize <= 0 ? 0 : \
       /* cluster sum */   (fs)->fs_contigsumsize * sizeof(long) + \
       /* cluster map */   howmany((fs)->fs_cpg * (fs)->fs_spc / NSPB(fs), NBBY)))
   
   /*
    * Convert cylinder group to base address of its global summary info.
    *
    * N.B. This macro assumes that sizeof(struct csum) is a power of two.
    */
   #define fs_cs(fs, indx) \
           fs_csp[(indx) >> (fs)->fs_csshift][(indx) & ~(fs)->fs_csmask]
   
   /*
    * Cylinder group block for a file system.
    */
   #define CG_MAGIC        0x090255
   struct  cg {
           struct  cg *cg_link;            /* linked list of cyl groups */
           long    cg_magic;               /* magic number */
           time_t  cg_time;                /* time last written */
           long    cg_cgx;                 /* we are the cgx'th cylinder group */
           short   cg_ncyl;                /* number of cyl's this cg */
           short   cg_niblk;               /* number of inode blocks this cg */
           long    cg_ndblk;               /* number of data blocks this cg */
           struct  csum cg_cs;             /* cylinder summary information */
           long    cg_rotor;               /* position of last used block */
           long    cg_frotor;              /* position of last used frag */
           long    cg_irotor;              /* position of last used inode */
           long    cg_frsum[MAXFRAG];      /* counts of available frags */
           long    cg_btotoff;             /* (long) block totals per cylinder */
           long    cg_boff;                /* (short) free block positions */
           long    cg_iusedoff;            /* (char) used inode map */
           long    cg_freeoff;             /* (u_char) free block map */
           long    cg_nextfreeoff;         /* (u_char) next available space */
           long    cg_clustersumoff;       /* (long) counts of avail clusters */
           long    cg_clusteroff;          /* (char) free cluster map */
           long    cg_nclusterblks;        /* number of clusters this cg */
           long    cg_sparecon[13];        /* reserved for future use */
           u_char  cg_space[1];            /* space for cylinder group maps */
   /* actually longer */
   };
   /*
    * Macros for access to cylinder group array structures
    */
   #define cg_blktot(cgp) \
       (((cgp)->cg_magic != CG_MAGIC) \
       ? (((struct ocg *)(cgp))->cg_btot) \
       : ((long *)((char *)(cgp) + (cgp)->cg_btotoff)))
   #define cg_blks(fs, cgp, cylno) \
       (((cgp)->cg_magic != CG_MAGIC) \
       ? (((struct ocg *)(cgp))->cg_b[cylno]) \
       : ((short *)((char *)(cgp) + (cgp)->cg_boff) + (cylno) * (fs)->fs_nrpos))
   #define cg_inosused(cgp) \
       (((cgp)->cg_magic != CG_MAGIC) \
       ? (((struct ocg *)(cgp))->cg_iused) \
       : ((char *)((char *)(cgp) + (cgp)->cg_iusedoff)))
   #define cg_blksfree(cgp) \
       (((cgp)->cg_magic != CG_MAGIC) \
       ? (((struct ocg *)(cgp))->cg_free) \
       : ((u_char *)((char *)(cgp) + (cgp)->cg_freeoff)))
   #define cg_chkmagic(cgp) \
       ((cgp)->cg_magic == CG_MAGIC || ((struct ocg *)(cgp))->cg_magic == CG_MAGIC)
   #define cg_clustersfree(cgp) \
       ((u_char *)((char *)(cgp) + (cgp)->cg_clusteroff))
   #define cg_clustersum(cgp) \
       ((long *)((char *)(cgp) + (cgp)->cg_clustersumoff))
   
   /*
    * The following structure is defined
    * for compatibility with old file systems.
    */
   struct  ocg {
           struct  ocg *cg_link;           /* linked list of cyl groups */
           struct  ocg *cg_rlink;          /*     used for incore cyl groups */
           time_t  cg_time;                /* time last written */
           long    cg_cgx;                 /* we are the cgx'th cylinder group */
           short   cg_ncyl;                /* number of cyl's this cg */
           short   cg_niblk;               /* number of inode blocks this cg */
           long    cg_ndblk;               /* number of data blocks this cg */
           struct  csum cg_cs;             /* cylinder summary information */
           long    cg_rotor;               /* position of last used block */
           long    cg_frotor;              /* position of last used frag */
           long    cg_irotor;              /* position of last used inode */
           long    cg_frsum[8];            /* counts of available frags */
           long    cg_btot[32];            /* block totals per cylinder */
           short   cg_b[32][8];            /* positions of free blocks */
           char    cg_iused[256];          /* used inode map */
           long    cg_magic;               /* magic number */
           u_char  cg_free[1];             /* free block map */
   /* actually longer */
   };
   
   /*
    * Turn file system block numbers into disk block addresses.
    * This maps file system blocks to device size blocks.
    */
   #define fsbtodb(fs, b)  ((b) << (fs)->fs_fsbtodb)
   #define dbtofsb(fs, b)  ((b) >> (fs)->fs_fsbtodb)
   
   /*
    * 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 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)                                                  \
           (cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask)))
   
   /*
    * 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 cbtocylno(fs, bno) \
       ((bno) * NSPF(fs) / (fs)->fs_spc)
   #define cbtorpos(fs, bno) \
       (((bno) * NSPF(fs) % (fs)->fs_spc / (fs)->fs_nsect * (fs)->fs_trackskew + \
        (bno) * NSPF(fs) % (fs)->fs_spc % (fs)->fs_nsect * (fs)->fs_interleave) % \
        (fs)->fs_nsect * (fs)->fs_nrpos / (fs)->fs_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 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., < 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 - ((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 >= smalllblktosize(fs, (lbn) + 1)) \
               ? (fs)->fs_bsize \
               : (fragroundup(fs, blkoff(fs, (ip)->i_size))))
   #define dblksize(fs, dip, lbn) \
           (((lbn) >= NDADDR || (dip)->di_size >= smalllblktosize(fs, (lbn) + 1)) \
               ? (fs)->fs_bsize \
               : (fragroundup(fs, blkoff(fs, (dip)->di_size))))
   
   /*
    * Number of disk sectors per block; assumes DEV_BSIZE byte sector size.
    */
   #define NSPB(fs)        ((fs)->fs_nspf << (fs)->fs_fragshift)
   #define NSPF(fs)        ((fs)->fs_nspf)
   
   /*
    * INOPB is the number of inodes in a secondary storage block.
    */
   #define INOPB(fs)       ((fs)->fs_inopb)
   #define INOPF(fs)       ((fs)->fs_inopb >> (fs)->fs_fragshift)
   
   /*
    * NINDIR is the number of indirects in a file system block.
    */
   #define NINDIR(fs)      ((fs)->fs_nindir)
   
   extern int inside[], around[];
   extern u_char *fragtbl[];
   
   #endif

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