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fs.h

/**   $MirOS: src/sys/ufs/ffs/fs.h,v 1.6 2007/03/18 04:08:45 tg Exp $   */
/*    $OpenBSD: fs.h,v 1.17 2005/03/01 13:30:50 aaron Exp $ */
/*    $NetBSD: fs.h,v 1.6 1995/04/12 21:21:02 mycroft 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    8.10 (Berkeley) 10/27/94
 */

#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))
#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 }

/*
 * 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
 * addressible; 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 512

/*
 * 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 three
 * 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.
 */
#define           NOCSPTRS    ((128 / sizeof(void *)) - 3)

/*
 * 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         5
#define DEFAULTOPT      FS_OPTTIME

/*
 * The directory preference algorithm(dirpref) 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 sqiud 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 */
};

/*
 * Super block for an FFS file system.
 */
struct fs {
      int32_t      fs_firstfield;         /* historic file system linked list, */
      int32_t      fs_unused_1;           /*     used for incore super blocks */
      /* MirOS actually uses the two fields above to store a little entropy */
      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_cgoffset;           /* cylinder group offset in cylinder */
      int32_t      fs_cgmask;       /* used to calc mod fs_ntrak */
      int32_t      fs_time;         /* last time written XXX was time_t */
      int32_t      fs_size;         /* number of blocks in fs */
      int32_t      fs_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_rotdelay;           /* num of ms for optimal next block */
      int32_t      fs_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_csmask;       /* csum block offset (now unused) */
      int32_t      fs_csshift;            /* csum block number (now unused) */
      int32_t      fs_nindir;       /* value of NINDIR */
      int32_t      fs_inopb;        /* value of INOPB */
      int32_t      fs_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_npsect;       /* # sectors/track including spares */
      int32_t      fs_interleave;         /* hardware sector interleave */
      int32_t      fs_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 filesystem id */
/* sizes determined by number of cylinder groups and their sizes */
      int32_t  fs_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_ntrak;        /* tracks per cylinder */
      int32_t      fs_nsect;        /* sectors per track */
      int32_t      fs_spc;          /* sectors per cylinder */
/* this comes from the disk driver partitioning */
      int32_t      fs_ncyl;         /* cylinders in file system */
/* these fields can be computed from the others */
      int32_t      fs_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_cstotal;  /* cylinder summary information */
/* these fields are cleared at mount time */
      int8_t       fs_fmod;         /* super block modified flag */
      int8_t       fs_clean;        /* file system is clean flag */
      int8_t       fs_ronly;        /* mounted read-only flag */
      int8_t       fs_flags;        /* see FS_ below */
      u_char       fs_fsmnt[MAXMNTLEN];   /* name mounted on */
/* 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;      /* # 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 */
      int32_t      fs_cpc;          /* cyl per cycle in postbl */
      int16_t      fs_opostbl[16][8];     /* old rotation block list head */
      int32_t  fs_snapinum[20];     /* reserved for snapshot inode nums */
      int32_t      fs_avgfilesize;  /* expected average file size */
      int32_t      fs_avgfpdir;           /* expected # of files per directory */
      int32_t      fs_sparecon[27]; /* reserved for future constants */
      int32_t      fs_fscktime;           /* last time fsck(8)ed XXX was time_t */
      int32_t      fs_contigsumsize;      /* size of cluster summary array */
      int32_t      fs_maxsymlinklen;      /* max length of an internal symlink */
      int32_t      fs_inodefmt;           /* format of on-disk inodes */
      u_int64_t fs_maxfilesize;     /* maximum representable file size */
      int64_t      fs_qbmask;       /* ~fs_bmask - for use with quad size */
      int64_t      fs_qfmask;       /* ~fs_fmask - for use with quad size */
      int32_t      fs_state;        /* validate fs_clean field */
      int32_t      fs_postblformat; /* format of positional layout tables */
      int32_t      fs_nrpos;        /* number of rotational positions */
      int32_t      fs_postbloff;          /* (u_int16) rotation block list head */
      int32_t      fs_rotbloff;           /* (u_int8) blocks for each rotation */
      int32_t      fs_magic;        /* magic number */
      u_int8_t fs_space[1];         /* list of blocks for each rotation */
/* actually longer */
};

#define     fs_opostbl_start  fs_opostbl[0][0]

/*
 * Filesystem identification
 */
#define     FS_MAGIC    0x011954    /* the fast filesystem magic number */
#define     FS_UFS1_MAGIC     0x011954    /* the fast filesystem magic number */
#define     FS_UFS2_MAGIC     0x19540119  /* UFS 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 */

/*
 * Filesystem 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 */

/*
 * Filesystem flags.
 */
#define FS_UNCLEAN    0x01   /* filesystem not clean at mount */
#define FS_DOSOFTDEP  0x02   /* filesystem using soft dependencies */

/*
 * 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]) \
    : ((int16_t *)((u_int8_t *)(fs) + \
      (fs)->fs_postbloff) + (cylno) * (fs)->fs_nrpos))
#define fs_rotbl(fs) \
    (((fs)->fs_postblformat == FS_42POSTBLFMT) \
    ? ((fs)->fs_space) \
    : ((u_int8_t *)((u_int8_t *)(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(int32_t) + \
    /* blktot size */   (fs)->fs_cpg * sizeof(int32_t) + \
    /* blks size */     (fs)->fs_cpg * (fs)->fs_nrpos * sizeof(int16_t) + \
    /* 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(int32_t) + \
    /* cluster map */   howmany((fs)->fs_cpg * (fs)->fs_spc / NSPB(fs), NBBY)))

/*
 * 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_time;         /* time last written XXX was time_t */
      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[MAXFRAG];     /* counts of available frags */
      int32_t      cg_btotoff;            /* (int32) block totals per cylinder */
      int32_t      cg_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_ffs2_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_ffs2_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_blktot(cgp) \
    (((cgp)->cg_magic != CG_MAGIC) \
    ? (((struct ocg *)(cgp))->cg_btot) \
    : ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_btotoff)))
#define cg_blks(fs, cgp, cylno) \
    (((cgp)->cg_magic != CG_MAGIC) \
    ? (((struct ocg *)(cgp))->cg_b[cylno]) \
    : ((int16_t *)((u_int8_t *)(cgp) + \
      (cgp)->cg_boff) + (cylno) * (fs)->fs_nrpos))
#define cg_inosused(cgp) \
    (((cgp)->cg_magic != CG_MAGIC) \
    ? (((struct ocg *)(cgp))->cg_iused) \
    : ((u_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_iusedoff)))
#define cg_blksfree(cgp) \
    (((cgp)->cg_magic != CG_MAGIC) \
    ? (((struct ocg *)(cgp))->cg_free) \
    : ((u_int8_t *)((u_int8_t *)(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_int8_t *)((u_int8_t *)(cgp) + (cgp)->cg_clusteroff))
#define cg_clustersum(cgp) \
    ((int32_t *)((u_int8_t *)(cgp) + (cgp)->cg_clustersumoff))

/*
 * 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 XXX was time_t */
      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 */
};

/*
 * 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)
#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_ffs_size >= ((lbn) + 1) << (fs)->fs_bshift) \
          ? (fs)->fs_bsize \
          : (fragroundup(fs, blkoff(fs, (ip)->i_ffs_size))))
#define dblksize(fs, dip, lbn) \
      (((lbn) >= NDADDR || (dip)->di_size >= ((lbn) + 1) << (fs)->fs_bshift) \
          ? (fs)->fs_bsize \
          : (fragroundup(fs, blkoff(fs, (dip)->di_size))))

#define sblksize(fs, size, lbn) \
        (((lbn) >= NDADDR || (size) >= ((lbn) + 1) << (fs)->fs_bshift) \
            ? (fs)->fs_bsize \
            : (fragroundup(fs, blkoff(fs, (size)))))


/*
 * Number of disk sectors per block/fragment; assumes DEV_BSIZE byte
 * sector size.
 */
#define     NSPB(fs)    ((fs)->fs_nspf << (fs)->fs_fragshift)
#define     NSPF(fs)    ((fs)->fs_nspf)

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

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

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

#endif /* notdef UFS_FFS_FS_H */

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