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Annotation of qemu/roms/openbios/fs/grubfs/fs.h, revision 1.1

1.1     ! root        1: /*
        !             2:  * Mach Operating System
        !             3:  * Copyright (c) 1991,1990 Carnegie Mellon University
        !             4:  * All Rights Reserved.
        !             5:  *
        !             6:  * Permission to use, copy, modify and distribute this software and its
        !             7:  * documentation is hereby granted, provided that both the copyright
        !             8:  * notice and this permission notice appear in all copies of the
        !             9:  * software, derivative works or modified versions, and any portions
        !            10:  * thereof, and that both notices appear in supporting documentation.
        !            11:  *
        !            12:  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
        !            13:  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
        !            14:  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
        !            15:  *
        !            16:  * Carnegie Mellon requests users of this software to return to
        !            17:  *
        !            18:  *  Software Distribution Coordinator  or  [email protected]
        !            19:  *  School of Computer Science
        !            20:  *  Carnegie Mellon University
        !            21:  *  Pittsburgh PA 15213-3890
        !            22:  *
        !            23:  * any improvements or extensions that they make and grant Carnegie Mellon
        !            24:  * the rights to redistribute these changes.
        !            25:  */
        !            26: /*
        !            27:  * Copyright (c) 1982, 1986 Regents of the University of California.
        !            28:  * All rights reserved.
        !            29:  *
        !            30:  * Redistribution and use in source and binary forms are permitted
        !            31:  * provided that the above copyright notice and this paragraph are
        !            32:  * duplicated in all such forms and that any documentation,
        !            33:  * advertising materials, and other materials related to such
        !            34:  * distribution and use acknowledge that the software was developed
        !            35:  * by the University of California, Berkeley.  The name of the
        !            36:  * University may not be used to endorse or promote products derived
        !            37:  * from this software without specific prior written permission.
        !            38:  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
        !            39:  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
        !            40:  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
        !            41:  *
        !            42:  *     @(#)fs.h        7.7 (Berkeley) 5/9/89
        !            43:  */
        !            44: 
        !            45: /*
        !            46:  * Each disk drive contains some number of file systems.
        !            47:  * A file system consists of a number of cylinder groups.
        !            48:  * Each cylinder group has inodes and data.
        !            49:  *
        !            50:  * A file system is described by its super-block, which in turn
        !            51:  * describes the cylinder groups.  The super-block is critical
        !            52:  * data and is replicated in each cylinder group to protect against
        !            53:  * catastrophic loss.  This is done at `newfs' time and the critical
        !            54:  * super-block data does not change, so the copies need not be
        !            55:  * referenced further unless disaster strikes.
        !            56:  *
        !            57:  * For file system fs, the offsets of the various blocks of interest
        !            58:  * are given in the super block as:
        !            59:  *     [fs->fs_sblkno]         Super-block
        !            60:  *     [fs->fs_cblkno]         Cylinder group block
        !            61:  *     [fs->fs_iblkno]         Inode blocks
        !            62:  *     [fs->fs_dblkno]         Data blocks
        !            63:  * The beginning of cylinder group cg in fs, is given by
        !            64:  * the ``cgbase(fs, cg)'' macro.
        !            65:  *
        !            66:  * The first boot and super blocks are given in absolute disk addresses.
        !            67:  * The byte-offset forms are preferred, as they don't imply a sector size.
        !            68:  */
        !            69: #define BBSIZE         8192
        !            70: #define SBSIZE         8192
        !            71: #define        BBOFF           ((mach_off_t)(0))
        !            72: #define        SBOFF           ((mach_off_t)(BBOFF + BBSIZE))
        !            73: #define        BBLOCK          ((mach_daddr_t)(0))
        !            74: #define        SBLOCK          ((mach_daddr_t)(BBLOCK + BBSIZE / DEV_BSIZE))
        !            75: 
        !            76: /*
        !            77:  * Addresses stored in inodes are capable of addressing fragments
        !            78:  * of `blocks'. File system blocks of at most size MAXBSIZE can
        !            79:  * be optionally broken into 2, 4, or 8 pieces, each of which is
        !            80:  * addressible; these pieces may be DEV_BSIZE, or some multiple of
        !            81:  * a DEV_BSIZE unit.
        !            82:  *
        !            83:  * Large files consist of exclusively large data blocks.  To avoid
        !            84:  * undue wasted disk space, the last data block of a small file may be
        !            85:  * allocated as only as many fragments of a large block as are
        !            86:  * necessary.  The file system format retains only a single pointer
        !            87:  * to such a fragment, which is a piece of a single large block that
        !            88:  * has been divided.  The size of such a fragment is determinable from
        !            89:  * information in the inode, using the ``blksize(fs, ip, lbn)'' macro.
        !            90:  *
        !            91:  * The file system records space availability at the fragment level;
        !            92:  * to determine block availability, aligned fragments are examined.
        !            93:  *
        !            94:  * The root inode is the root of the file system.
        !            95:  * Inode 0 can't be used for normal purposes and
        !            96:  * historically bad blocks were linked to inode 1,
        !            97:  * thus the root inode is 2. (inode 1 is no longer used for
        !            98:  * this purpose, however numerous dump tapes make this
        !            99:  * assumption, so we are stuck with it)
        !           100:  */
        !           101: #define        ROOTINO         ((mach_ino_t)2) /* i number of all roots */
        !           102: 
        !           103: /*
        !           104:  * MINBSIZE is the smallest allowable block size.
        !           105:  * In order to insure that it is possible to create files of size
        !           106:  * 2^32 with only two levels of indirection, MINBSIZE is set to 4096.
        !           107:  * MINBSIZE must be big enough to hold a cylinder group block,
        !           108:  * thus changes to (struct cg) must keep its size within MINBSIZE.
        !           109:  * Note that super blocks are always of size SBSIZE,
        !           110:  * and that both SBSIZE and MAXBSIZE must be >= MINBSIZE.
        !           111:  */
        !           112: #define MINBSIZE       4096
        !           113: 
        !           114: /*
        !           115:  * The path name on which the file system is mounted is maintained
        !           116:  * in fs_fsmnt. MAXMNTLEN defines the amount of space allocated in
        !           117:  * the super block for this name.
        !           118:  * The limit on the amount of summary information per file system
        !           119:  * is defined by MAXCSBUFS. It is currently parameterized for a
        !           120:  * maximum of two million cylinders.
        !           121:  */
        !           122: #define MAXMNTLEN 512
        !           123: #define MAXCSBUFS 32
        !           124: 
        !           125: /*
        !           126:  * Per cylinder group information; summarized in blocks allocated
        !           127:  * from first cylinder group data blocks.  These blocks have to be
        !           128:  * read in from fs_csaddr (size fs_cssize) in addition to the
        !           129:  * super block.
        !           130:  *
        !           131:  * N.B. sizeof(struct csum) must be a power of two in order for
        !           132:  * the ``fs_cs'' macro to work (see below).
        !           133:  */
        !           134: struct csum
        !           135:   {
        !           136:     int cs_ndir;               /* number of directories */
        !           137:     int cs_nbfree;             /* number of free blocks */
        !           138:     int cs_nifree;             /* number of free inodes */
        !           139:     int cs_nffree;             /* number of free frags */
        !           140:   };
        !           141: 
        !           142: /*
        !           143:  * Super block for a file system.
        !           144:  */
        !           145: #define        FS_MAGIC        0x011954
        !           146: struct fs
        !           147:   {
        !           148:     int xxx1;                  /* struct       fs *fs_link; */
        !           149:     int xxx2;                  /* struct       fs *fs_rlink; */
        !           150:     mach_daddr_t fs_sblkno;    /* addr of super-block in filesys */
        !           151:     mach_daddr_t fs_cblkno;    /* offset of cyl-block in filesys */
        !           152:     mach_daddr_t fs_iblkno;    /* offset of inode-blocks in filesys */
        !           153:     mach_daddr_t fs_dblkno;    /* offset of first data after cg */
        !           154:     int fs_cgoffset;           /* cylinder group offset in cylinder */
        !           155:     int fs_cgmask;             /* used to calc mod fs_ntrak */
        !           156:     mach_time_t fs_time;       /* last time written */
        !           157:     int fs_size;               /* number of blocks in fs */
        !           158:     int fs_dsize;              /* number of data blocks in fs */
        !           159:     int fs_ncg;                        /* number of cylinder groups */
        !           160:     int fs_bsize;              /* size of basic blocks in fs */
        !           161:     int fs_fsize;              /* size of frag blocks in fs */
        !           162:     int fs_frag;               /* number of frags in a block in fs */
        !           163: /* these are configuration parameters */
        !           164:     int fs_minfree;            /* minimum percentage of free blocks */
        !           165:     int fs_rotdelay;           /* num of ms for optimal next block */
        !           166:     int fs_rps;                        /* disk revolutions per second */
        !           167: /* these fields can be computed from the others */
        !           168:     int fs_bmask;              /* ``blkoff'' calc of blk offsets */
        !           169:     int fs_fmask;              /* ``fragoff'' calc of frag offsets */
        !           170:     int fs_bshift;             /* ``lblkno'' calc of logical blkno */
        !           171:     int fs_fshift;             /* ``numfrags'' calc number of frags */
        !           172: /* these are configuration parameters */
        !           173:     int fs_maxcontig;          /* max number of contiguous blks */
        !           174:     int fs_maxbpg;             /* max number of blks per cyl group */
        !           175: /* these fields can be computed from the others */
        !           176:     int fs_fragshift;          /* block to frag shift */
        !           177:     int fs_fsbtodb;            /* fsbtodb and dbtofsb shift constant */
        !           178:     int fs_sbsize;             /* actual size of super block */
        !           179:     int fs_csmask;             /* csum block offset */
        !           180:     int fs_csshift;            /* csum block number */
        !           181:     int fs_nindir;             /* value of NINDIR */
        !           182:     int fs_inopb;              /* value of INOPB */
        !           183:     int fs_nspf;               /* value of NSPF */
        !           184: /* yet another configuration parameter */
        !           185:     int fs_optim;              /* optimization preference, see below */
        !           186: /* these fields are derived from the hardware */
        !           187:     int fs_npsect;             /* # sectors/track including spares */
        !           188:     int fs_interleave;         /* hardware sector interleave */
        !           189:     int fs_trackskew;          /* sector 0 skew, per track */
        !           190:     int fs_headswitch;         /* head switch time, usec */
        !           191:     int fs_trkseek;            /* track-to-track seek, usec */
        !           192: /* sizes determined by number of cylinder groups and their sizes */
        !           193:     mach_daddr_t fs_csaddr;    /* blk addr of cyl grp summary area */
        !           194:     int fs_cssize;             /* size of cyl grp summary area */
        !           195:     int fs_cgsize;             /* cylinder group size */
        !           196: /* these fields are derived from the hardware */
        !           197:     int fs_ntrak;              /* tracks per cylinder */
        !           198:     int fs_nsect;              /* sectors per track */
        !           199:     int fs_spc;                        /* sectors per cylinder */
        !           200: /* this comes from the disk driver partitioning */
        !           201:     int fs_ncyl;               /* cylinders in file system */
        !           202: /* these fields can be computed from the others */
        !           203:     int fs_cpg;                        /* cylinders per group */
        !           204:     int fs_ipg;                        /* inodes per group */
        !           205:     int fs_fpg;                        /* blocks per group * fs_frag */
        !           206: /* this data must be re-computed after crashes */
        !           207:     struct csum fs_cstotal;    /* cylinder summary information */
        !           208: /* these fields are cleared at mount time */
        !           209:     char fs_fmod;              /* super block modified flag */
        !           210:     char fs_clean;             /* file system is clean flag */
        !           211:     char fs_ronly;             /* mounted read-only flag */
        !           212:     char fs_flags;             /* currently unused flag */
        !           213:     char fs_fsmnt[MAXMNTLEN];  /* name mounted on */
        !           214: /* these fields retain the current block allocation info */
        !           215:     int fs_cgrotor;            /* last cg searched */
        !           216: #if 1
        !           217:     int was_fs_csp[MAXCSBUFS];
        !           218: #else
        !           219:     struct csum *fs_csp[MAXCSBUFS];    /* list of fs_cs info buffers */
        !           220: #endif
        !           221:     int fs_cpc;                        /* cyl per cycle in postbl */
        !           222:     short fs_opostbl[16][8];   /* old rotation block list head */
        !           223:     long fs_sparecon[50];      /* reserved for future constants */
        !           224:     long fs_contigsumsize;     /* size of cluster summary array */
        !           225:     long fs_maxsymlinklen;     /* max length of an internal symlink */
        !           226:     long fs_inodefmt;          /* format of on-disk inodes */
        !           227:     quad fs_maxfilesize;       /* maximum representable file size */
        !           228:     quad fs_qbmask;            /* ~fs_bmask - for use with quad size */
        !           229:     quad fs_qfmask;            /* ~fs_fmask - for use with quad size */
        !           230:     long fs_state;             /* validate fs_clean field */
        !           231:     int fs_postblformat;       /* format of positional layout tables */
        !           232:     int fs_nrpos;              /* number of rotaional positions */
        !           233:     int fs_postbloff;          /* (short) rotation block list head */
        !           234:     int fs_rotbloff;           /* (char) blocks for each rotation */
        !           235:     int fs_magic;              /* magic number */
        !           236:     unsigned char fs_space[1]; /* list of blocks for each rotation */
        !           237: /* actually longer */
        !           238:   };
        !           239: /*
        !           240:  * Preference for optimization.
        !           241:  */
        !           242: #define FS_OPTTIME     0       /* minimize allocation time */
        !           243: #define FS_OPTSPACE    1       /* minimize disk fragmentation */
        !           244: 
        !           245: /*
        !           246:  * Rotational layout table format types
        !           247:  */
        !           248: #define FS_42POSTBLFMT         -1      /* 4.2BSD rotational table format */
        !           249: #define FS_DYNAMICPOSTBLFMT    1       /* dynamic rotational table format */
        !           250: /*
        !           251:  * Macros for access to superblock array structures
        !           252:  */
        !           253: #define fs_postbl(fs, cylno) \
        !           254:     (((fs)->fs_postblformat == FS_42POSTBLFMT) \
        !           255:     ? ((fs)->fs_opostbl[cylno]) \
        !           256:     : ((short *)((char *)(fs) + (fs)->fs_postbloff) + (cylno) * (fs)->fs_nrpos))
        !           257: #define fs_rotbl(fs) \
        !           258:     (((fs)->fs_postblformat == FS_42POSTBLFMT) \
        !           259:     ? ((fs)->fs_space) \
        !           260:     : ((unsigned char *)((char *)(fs) + (fs)->fs_rotbloff)))
        !           261: 
        !           262: /*
        !           263:  * Convert cylinder group to base address of its global summary info.
        !           264:  *
        !           265:  * N.B. This macro assumes that sizeof(struct csum) is a power of two.
        !           266:  */
        !           267: #define fs_cs(fs, indx) \
        !           268:        fs_csp[(indx) >> (fs)->fs_csshift][(indx) & ~(fs)->fs_csmask]
        !           269: 
        !           270: /*
        !           271:  * Cylinder group block for a file system.
        !           272:  */
        !           273: #define        CG_MAGIC        0x090255
        !           274: struct cg
        !           275:   {
        !           276:     int xxx1;                  /* struct       cg *cg_link; */
        !           277:     int cg_magic;              /* magic number */
        !           278:     mach_time_t cg_time;               /* time last written */
        !           279:     int cg_cgx;                        /* we are the cgx'th cylinder group */
        !           280:     short cg_ncyl;             /* number of cyl's this cg */
        !           281:     short cg_niblk;            /* number of inode blocks this cg */
        !           282:     int cg_ndblk;              /* number of data blocks this cg */
        !           283:     struct csum cg_cs;         /* cylinder summary information */
        !           284:     int cg_rotor;              /* position of last used block */
        !           285:     int cg_frotor;             /* position of last used frag */
        !           286:     int cg_irotor;             /* position of last used inode */
        !           287:     int cg_frsum[MAXFRAG];     /* counts of available frags */
        !           288:     int cg_btotoff;            /* (long) block totals per cylinder */
        !           289:     int cg_boff;               /* (short) free block positions */
        !           290:     int cg_iusedoff;           /* (char) used inode map */
        !           291:     int cg_freeoff;            /* (char) free block map */
        !           292:     int cg_nextfreeoff;                /* (char) next available space */
        !           293:     int cg_sparecon[16];       /* reserved for future use */
        !           294:     unsigned char cg_space[1];        /* space for cylinder group maps */
        !           295: /* actually longer */
        !           296:   };
        !           297: /*
        !           298:  * Macros for access to cylinder group array structures
        !           299:  */
        !           300: #define cg_blktot(cgp) \
        !           301:     (((cgp)->cg_magic != CG_MAGIC) \
        !           302:     ? (((struct ocg *)(cgp))->cg_btot) \
        !           303:     : ((int *)((char *)(cgp) + (cgp)->cg_btotoff)))
        !           304: #define cg_blks(fs, cgp, cylno) \
        !           305:     (((cgp)->cg_magic != CG_MAGIC) \
        !           306:     ? (((struct ocg *)(cgp))->cg_b[cylno]) \
        !           307:     : ((short *)((char *)(cgp) + (cgp)->cg_boff) + (cylno) * (fs)->fs_nrpos))
        !           308: #define cg_inosused(cgp) \
        !           309:     (((cgp)->cg_magic != CG_MAGIC) \
        !           310:     ? (((struct ocg *)(cgp))->cg_iused) \
        !           311:     : ((char *)((char *)(cgp) + (cgp)->cg_iusedoff)))
        !           312: #define cg_blksfree(cgp) \
        !           313:     (((cgp)->cg_magic != CG_MAGIC) \
        !           314:     ? (((struct ocg *)(cgp))->cg_free) \
        !           315:     : ((unsigned char *)((char *)(cgp) + (cgp)->cg_freeoff)))
        !           316: #define cg_chkmagic(cgp) \
        !           317:     ((cgp)->cg_magic == CG_MAGIC || ((struct ocg *)(cgp))->cg_magic == CG_MAGIC)
        !           318: 
        !           319: /*
        !           320:  * The following structure is defined
        !           321:  * for compatibility with old file systems.
        !           322:  */
        !           323: struct ocg
        !           324:   {
        !           325:     int xxx1;                  /* struct       ocg *cg_link; */
        !           326:     int xxx2;                  /* struct       ocg *cg_rlink; */
        !           327:     mach_time_t cg_time;       /* time last written */
        !           328:     int cg_cgx;                        /* we are the cgx'th cylinder group */
        !           329:     short cg_ncyl;             /* number of cyl's this cg */
        !           330:     short cg_niblk;            /* number of inode blocks this cg */
        !           331:     int cg_ndblk;              /* number of data blocks this cg */
        !           332:     struct csum cg_cs;         /* cylinder summary information */
        !           333:     int cg_rotor;              /* position of last used block */
        !           334:     int cg_frotor;             /* position of last used frag */
        !           335:     int cg_irotor;             /* position of last used inode */
        !           336:     int cg_frsum[8];           /* counts of available frags */
        !           337:     int cg_btot[32];           /* block totals per cylinder */
        !           338:     short cg_b[32][8];         /* positions of free blocks */
        !           339:     char cg_iused[256];                /* used inode map */
        !           340:     int cg_magic;              /* magic number */
        !           341:     unsigned char cg_free[1];  /* free block map */
        !           342: /* actually longer */
        !           343:   };
        !           344: 
        !           345: /*
        !           346:  * Turn file system block numbers into disk block addresses.
        !           347:  * This maps file system blocks to device size blocks.
        !           348:  */
        !           349: #define fsbtodb(fs, b) ((b) << (fs)->fs_fsbtodb)
        !           350: #define        dbtofsb(fs, b)  ((b) >> (fs)->fs_fsbtodb)
        !           351: 
        !           352: /*
        !           353:  * Cylinder group macros to locate things in cylinder groups.
        !           354:  * They calc file system addresses of cylinder group data structures.
        !           355:  */
        !           356: #define        cgbase(fs, c)   ((mach_daddr_t)((fs)->fs_fpg * (c)))
        !           357: #define cgstart(fs, c) \
        !           358:        (cgbase(fs, c) + (fs)->fs_cgoffset * ((c) & ~((fs)->fs_cgmask)))
        !           359: #define        cgsblock(fs, c) (cgstart(fs, c) + (fs)->fs_sblkno)      /* super blk */
        !           360: #define        cgtod(fs, c)    (cgstart(fs, c) + (fs)->fs_cblkno)      /* cg block */
        !           361: #define        cgimin(fs, c)   (cgstart(fs, c) + (fs)->fs_iblkno)      /* inode blk */
        !           362: #define        cgdmin(fs, c)   (cgstart(fs, c) + (fs)->fs_dblkno)      /* 1st data */
        !           363: 
        !           364: /*
        !           365:  * Macros for handling inode numbers:
        !           366:  *     inode number to file system block offset.
        !           367:  *     inode number to cylinder group number.
        !           368:  *     inode number to file system block address.
        !           369:  */
        !           370: #define        itoo(fs, x)     ((x) % INOPB(fs))
        !           371: #define        itog(fs, x)     ((x) / (fs)->fs_ipg)
        !           372: #define        itod(fs, x) \
        !           373:        ((mach_daddr_t)(cgimin(fs, itog(fs, x)) + \
        !           374:        (blkstofrags((fs), (((x) % (fs)->fs_ipg) / INOPB(fs))))))
        !           375: 
        !           376: /*
        !           377:  * Give cylinder group number for a file system block.
        !           378:  * Give cylinder group block number for a file system block.
        !           379:  */
        !           380: #define        dtog(fs, d)     ((d) / (fs)->fs_fpg)
        !           381: #define        dtogd(fs, d)    ((d) % (fs)->fs_fpg)
        !           382: 
        !           383: /*
        !           384:  * Extract the bits for a block from a map.
        !           385:  * Compute the cylinder and rotational position of a cyl block addr.
        !           386:  */
        !           387: #define blkmap(fs, map, loc) \
        !           388:     (((map)[(loc) / NBBY] >> ((loc) % NBBY)) & (0xff >> (NBBY - (fs)->fs_frag)))
        !           389: #define cbtocylno(fs, bno) \
        !           390:     ((bno) * NSPF(fs) / (fs)->fs_spc)
        !           391: #define cbtorpos(fs, bno) \
        !           392:     (((bno) * NSPF(fs) % (fs)->fs_spc / (fs)->fs_nsect * (fs)->fs_trackskew + \
        !           393:      (bno) * NSPF(fs) % (fs)->fs_spc % (fs)->fs_nsect * (fs)->fs_interleave) % \
        !           394:      (fs)->fs_nsect * (fs)->fs_nrpos / (fs)->fs_npsect)
        !           395: 
        !           396: /*
        !           397:  * The following macros optimize certain frequently calculated
        !           398:  * quantities by using shifts and masks in place of divisions
        !           399:  * modulos and multiplications.
        !           400:  */
        !           401: #define blkoff(fs, loc)                /* calculates (loc % fs->fs_bsize) */ \
        !           402:        ((loc) & ~(fs)->fs_bmask)
        !           403: #define fragoff(fs, loc)       /* calculates (loc % fs->fs_fsize) */ \
        !           404:        ((loc) & ~(fs)->fs_fmask)
        !           405: #define lblkno(fs, loc)                /* calculates (loc / fs->fs_bsize) */ \
        !           406:        ((loc) >> (fs)->fs_bshift)
        !           407: #define numfrags(fs, loc)      /* calculates (loc / fs->fs_fsize) */ \
        !           408:        ((loc) >> (fs)->fs_fshift)
        !           409: #define blkroundup(fs, size)   /* calculates roundup(size, fs->fs_bsize) */ \
        !           410:        (((size) + (fs)->fs_bsize - 1) & (fs)->fs_bmask)
        !           411: #define fragroundup(fs, size)  /* calculates roundup(size, fs->fs_fsize) */ \
        !           412:        (((size) + (fs)->fs_fsize - 1) & (fs)->fs_fmask)
        !           413: #define fragstoblks(fs, frags) /* calculates (frags / fs->fs_frag) */ \
        !           414:        ((frags) >> (fs)->fs_fragshift)
        !           415: #define blkstofrags(fs, blks)  /* calculates (blks * fs->fs_frag) */ \
        !           416:        ((blks) << (fs)->fs_fragshift)
        !           417: #define fragnum(fs, fsb)       /* calculates (fsb % fs->fs_frag) */ \
        !           418:        ((fsb) & ((fs)->fs_frag - 1))
        !           419: #define blknum(fs, fsb)                /* calculates rounddown(fsb, fs->fs_frag) */ \
        !           420:        ((fsb) &~ ((fs)->fs_frag - 1))
        !           421: 
        !           422: /*
        !           423:  * Determine the number of available frags given a
        !           424:  * percentage to hold in reserve
        !           425:  */
        !           426: #define freespace(fs, percentreserved) \
        !           427:        (blkstofrags((fs), (fs)->fs_cstotal.cs_nbfree) + \
        !           428:        (fs)->fs_cstotal.cs_nffree - ((fs)->fs_dsize * (percentreserved) / 100))
        !           429: 
        !           430: /*
        !           431:  * Determining the size of a file block in the file system.
        !           432:  */
        !           433: #define blksize(fs, ip, lbn) \
        !           434:        (((lbn) >= NDADDR || (ip)->i_size >= ((lbn) + 1) << (fs)->fs_bshift) \
        !           435:            ? (fs)->fs_bsize \
        !           436:            : (fragroundup(fs, blkoff(fs, (ip)->i_size))))
        !           437: #define dblksize(fs, dip, lbn) \
        !           438:        (((lbn) >= NDADDR || (dip)->di_size >= ((lbn) + 1) << (fs)->fs_bshift) \
        !           439:            ? (fs)->fs_bsize \
        !           440:            : (fragroundup(fs, blkoff(fs, (dip)->di_size))))
        !           441: 
        !           442: /*
        !           443:  * Number of disk sectors per block; assumes DEV_BSIZE byte sector size.
        !           444:  */
        !           445: #define        NSPB(fs)        ((fs)->fs_nspf << (fs)->fs_fragshift)
        !           446: #define        NSPF(fs)        ((fs)->fs_nspf)
        !           447: 
        !           448: /*
        !           449:  * INOPB is the number of inodes in a secondary storage block.
        !           450:  */
        !           451: #define        INOPB(fs)       ((fs)->fs_inopb)
        !           452: #define        INOPF(fs)       ((fs)->fs_inopb >> (fs)->fs_fragshift)
        !           453: 
        !           454: /*
        !           455:  * NINDIR is the number of indirects in a file system block.
        !           456:  */
        !           457: #define        NINDIR(fs)      ((fs)->fs_nindir)

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