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mkfs.c revision 1.1
      1 /*
      2  * Copyright (c) 1980, 1989 The Regents of the University of California.
      3  * All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  * 3. All advertising materials mentioning features or use of this software
     14  *    must display the following acknowledgement:
     15  *	This product includes software developed by the University of
     16  *	California, Berkeley and its contributors.
     17  * 4. Neither the name of the University nor the names of its contributors
     18  *    may be used to endorse or promote products derived from this software
     19  *    without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     31  * SUCH DAMAGE.
     32  */
     33 
     34 #ifndef lint
     35 static char sccsid[] = "@(#)mkfs.c	6.18 (Berkeley) 7/3/91";
     36 #endif /* not lint */
     37 
     38 #ifndef STANDALONE
     39 #include <stdio.h>
     40 #include <a.out.h>
     41 #endif
     42 
     43 #include <sys/param.h>
     44 #include <sys/time.h>
     45 #include <sys/wait.h>
     46 #include <sys/resource.h>
     47 #include <ufs/dinode.h>
     48 #include <ufs/fs.h>
     49 #include <ufs/dir.h>
     50 #include <sys/disklabel.h>
     51 #include <machine/endian.h>
     52 
     53 /*
     54  * make file system for cylinder-group style file systems
     55  */
     56 
     57 /*
     58  * The size of a cylinder group is calculated by CGSIZE. The maximum size
     59  * is limited by the fact that cylinder groups are at most one block.
     60  * Its size is derived from the size of the maps maintained in the
     61  * cylinder group and the (struct cg) size.
     62  */
     63 #define CGSIZE(fs) \
     64     /* base cg */	(sizeof(struct cg) + \
     65     /* blktot size */	(fs)->fs_cpg * sizeof(long) + \
     66     /* blks size */	(fs)->fs_cpg * (fs)->fs_nrpos * sizeof(short) + \
     67     /* inode map */	howmany((fs)->fs_ipg, NBBY) + \
     68     /* block map */	howmany((fs)->fs_cpg * (fs)->fs_spc / NSPF(fs), NBBY))
     69 
     70 /*
     71  * We limit the size of the inode map to be no more than a
     72  * third of the cylinder group space, since we must leave at
     73  * least an equal amount of space for the block map.
     74  *
     75  * N.B.: MAXIPG must be a multiple of INOPB(fs).
     76  */
     77 #define MAXIPG(fs)	roundup((fs)->fs_bsize * NBBY / 3, INOPB(fs))
     78 
     79 #define UMASK		0755
     80 #define MAXINOPB	(MAXBSIZE / sizeof(struct dinode))
     81 #define POWEROF2(num)	(((num) & ((num) - 1)) == 0)
     82 
     83 /*
     84  * variables set up by front end.
     85  */
     86 extern int	mfs;		/* run as the memory based filesystem */
     87 extern int	Nflag;		/* run mkfs without writing file system */
     88 extern int	fssize;		/* file system size */
     89 extern int	ntracks;	/* # tracks/cylinder */
     90 extern int	nsectors;	/* # sectors/track */
     91 extern int	nphyssectors;	/* # sectors/track including spares */
     92 extern int	secpercyl;	/* sectors per cylinder */
     93 extern int	sectorsize;	/* bytes/sector */
     94 extern int	rpm;		/* revolutions/minute of drive */
     95 extern int	interleave;	/* hardware sector interleave */
     96 extern int	trackskew;	/* sector 0 skew, per track */
     97 extern int	headswitch;	/* head switch time, usec */
     98 extern int	trackseek;	/* track-to-track seek, usec */
     99 extern int	fsize;		/* fragment size */
    100 extern int	bsize;		/* block size */
    101 extern int	cpg;		/* cylinders/cylinder group */
    102 extern int	cpgflg;		/* cylinders/cylinder group flag was given */
    103 extern int	minfree;	/* free space threshold */
    104 extern int	opt;		/* optimization preference (space or time) */
    105 extern int	density;	/* number of bytes per inode */
    106 extern int	maxcontig;	/* max contiguous blocks to allocate */
    107 extern int	rotdelay;	/* rotational delay between blocks */
    108 extern int	maxbpg;		/* maximum blocks per file in a cyl group */
    109 extern int	nrpos;		/* # of distinguished rotational positions */
    110 extern int	bbsize;		/* boot block size */
    111 extern int	sbsize;		/* superblock size */
    112 extern u_long	memleft;	/* virtual memory available */
    113 extern caddr_t	membase;	/* start address of memory based filesystem */
    114 extern caddr_t	malloc(), calloc();
    115 
    116 union {
    117 	struct fs fs;
    118 	char pad[SBSIZE];
    119 } fsun;
    120 #define	sblock	fsun.fs
    121 struct	csum *fscs;
    122 
    123 union {
    124 	struct cg cg;
    125 	char pad[MAXBSIZE];
    126 } cgun;
    127 #define	acg	cgun.cg
    128 
    129 struct dinode zino[MAXBSIZE / sizeof(struct dinode)];
    130 
    131 int	fsi, fso;
    132 daddr_t	alloc();
    133 
    134 mkfs(pp, fsys, fi, fo)
    135 	struct partition *pp;
    136 	char *fsys;
    137 	int fi, fo;
    138 {
    139 	register long i, mincpc, mincpg, inospercg;
    140 	long cylno, rpos, blk, j, warn = 0;
    141 	long used, mincpgcnt, bpcg;
    142 	long mapcramped, inodecramped;
    143 	long postblsize, rotblsize, totalsbsize;
    144 	int ppid, status;
    145 	time_t utime;
    146 	void started();
    147 
    148 #ifndef STANDALONE
    149 	time(&utime);
    150 #endif
    151 	if (mfs) {
    152 		ppid = getpid();
    153 		(void) signal(SIGUSR1, started);
    154 		if (i = fork()) {
    155 			if (i == -1) {
    156 				perror("mfs");
    157 				exit(10);
    158 			}
    159 			if (waitpid(i, &status, 0) != -1 && WIFEXITED(status))
    160 				exit(WEXITSTATUS(status));
    161 			exit(11);
    162 			/* NOTREACHED */
    163 		}
    164 		(void)malloc(0);
    165 		if (fssize * sectorsize > memleft)
    166 			fssize = (memleft - 16384) / sectorsize;
    167 		if ((membase = malloc(fssize * sectorsize)) == 0)
    168 			exit(12);
    169 	}
    170 	fsi = fi;
    171 	fso = fo;
    172 	/*
    173 	 * Validate the given file system size.
    174 	 * Verify that its last block can actually be accessed.
    175 	 */
    176 	if (fssize <= 0)
    177 		printf("preposterous size %d\n", fssize), exit(13);
    178 	wtfs(fssize - 1, sectorsize, (char *)&sblock);
    179 	/*
    180 	 * collect and verify the sector and track info
    181 	 */
    182 	sblock.fs_nsect = nsectors;
    183 	sblock.fs_ntrak = ntracks;
    184 	if (sblock.fs_ntrak <= 0)
    185 		printf("preposterous ntrak %d\n", sblock.fs_ntrak), exit(14);
    186 	if (sblock.fs_nsect <= 0)
    187 		printf("preposterous nsect %d\n", sblock.fs_nsect), exit(15);
    188 	/*
    189 	 * collect and verify the block and fragment sizes
    190 	 */
    191 	sblock.fs_bsize = bsize;
    192 	sblock.fs_fsize = fsize;
    193 	if (!POWEROF2(sblock.fs_bsize)) {
    194 		printf("block size must be a power of 2, not %d\n",
    195 		    sblock.fs_bsize);
    196 		exit(16);
    197 	}
    198 	if (!POWEROF2(sblock.fs_fsize)) {
    199 		printf("fragment size must be a power of 2, not %d\n",
    200 		    sblock.fs_fsize);
    201 		exit(17);
    202 	}
    203 	if (sblock.fs_fsize < sectorsize) {
    204 		printf("fragment size %d is too small, minimum is %d\n",
    205 		    sblock.fs_fsize, sectorsize);
    206 		exit(18);
    207 	}
    208 	if (sblock.fs_bsize < MINBSIZE) {
    209 		printf("block size %d is too small, minimum is %d\n",
    210 		    sblock.fs_bsize, MINBSIZE);
    211 		exit(19);
    212 	}
    213 	if (sblock.fs_bsize < sblock.fs_fsize) {
    214 		printf("block size (%d) cannot be smaller than fragment size (%d)\n",
    215 		    sblock.fs_bsize, sblock.fs_fsize);
    216 		exit(20);
    217 	}
    218 	sblock.fs_bmask = ~(sblock.fs_bsize - 1);
    219 	sblock.fs_fmask = ~(sblock.fs_fsize - 1);
    220 	/*
    221 	 * Planning now for future expansion.
    222 	 */
    223 #	if (BYTE_ORDER == BIG_ENDIAN)
    224 		sblock.fs_qbmask.val[0] = 0;
    225 		sblock.fs_qbmask.val[1] = ~sblock.fs_bmask;
    226 		sblock.fs_qfmask.val[0] = 0;
    227 		sblock.fs_qfmask.val[1] = ~sblock.fs_fmask;
    228 #	endif /* BIG_ENDIAN */
    229 #	if (BYTE_ORDER == LITTLE_ENDIAN)
    230 		sblock.fs_qbmask.val[0] = ~sblock.fs_bmask;
    231 		sblock.fs_qbmask.val[1] = 0;
    232 		sblock.fs_qfmask.val[0] = ~sblock.fs_fmask;
    233 		sblock.fs_qfmask.val[1] = 0;
    234 #	endif /* LITTLE_ENDIAN */
    235 	for (sblock.fs_bshift = 0, i = sblock.fs_bsize; i > 1; i >>= 1)
    236 		sblock.fs_bshift++;
    237 	for (sblock.fs_fshift = 0, i = sblock.fs_fsize; i > 1; i >>= 1)
    238 		sblock.fs_fshift++;
    239 	sblock.fs_frag = numfrags(&sblock, sblock.fs_bsize);
    240 	for (sblock.fs_fragshift = 0, i = sblock.fs_frag; i > 1; i >>= 1)
    241 		sblock.fs_fragshift++;
    242 	if (sblock.fs_frag > MAXFRAG) {
    243 		printf("fragment size %d is too small, minimum with block size %d is %d\n",
    244 		    sblock.fs_fsize, sblock.fs_bsize,
    245 		    sblock.fs_bsize / MAXFRAG);
    246 		exit(21);
    247 	}
    248 	sblock.fs_nrpos = nrpos;
    249 	sblock.fs_nindir = sblock.fs_bsize / sizeof(daddr_t);
    250 	sblock.fs_inopb = sblock.fs_bsize / sizeof(struct dinode);
    251 	sblock.fs_nspf = sblock.fs_fsize / sectorsize;
    252 	for (sblock.fs_fsbtodb = 0, i = NSPF(&sblock); i > 1; i >>= 1)
    253 		sblock.fs_fsbtodb++;
    254 	sblock.fs_sblkno =
    255 	    roundup(howmany(bbsize + sbsize, sblock.fs_fsize), sblock.fs_frag);
    256 	sblock.fs_cblkno = (daddr_t)(sblock.fs_sblkno +
    257 	    roundup(howmany(sbsize, sblock.fs_fsize), sblock.fs_frag));
    258 	sblock.fs_iblkno = sblock.fs_cblkno + sblock.fs_frag;
    259 	sblock.fs_cgoffset = roundup(
    260 	    howmany(sblock.fs_nsect, NSPF(&sblock)), sblock.fs_frag);
    261 	for (sblock.fs_cgmask = 0xffffffff, i = sblock.fs_ntrak; i > 1; i >>= 1)
    262 		sblock.fs_cgmask <<= 1;
    263 	if (!POWEROF2(sblock.fs_ntrak))
    264 		sblock.fs_cgmask <<= 1;
    265 	/*
    266 	 * Validate specified/determined secpercyl
    267 	 * and calculate minimum cylinders per group.
    268 	 */
    269 	sblock.fs_spc = secpercyl;
    270 	for (sblock.fs_cpc = NSPB(&sblock), i = sblock.fs_spc;
    271 	     sblock.fs_cpc > 1 && (i & 1) == 0;
    272 	     sblock.fs_cpc >>= 1, i >>= 1)
    273 		/* void */;
    274 	mincpc = sblock.fs_cpc;
    275 	bpcg = sblock.fs_spc * sectorsize;
    276 	inospercg = roundup(bpcg / sizeof(struct dinode), INOPB(&sblock));
    277 	if (inospercg > MAXIPG(&sblock))
    278 		inospercg = MAXIPG(&sblock);
    279 	used = (sblock.fs_iblkno + inospercg / INOPF(&sblock)) * NSPF(&sblock);
    280 	mincpgcnt = howmany(sblock.fs_cgoffset * (~sblock.fs_cgmask) + used,
    281 	    sblock.fs_spc);
    282 	mincpg = roundup(mincpgcnt, mincpc);
    283 	/*
    284 	 * Insure that cylinder group with mincpg has enough space
    285 	 * for block maps
    286 	 */
    287 	sblock.fs_cpg = mincpg;
    288 	sblock.fs_ipg = inospercg;
    289 	mapcramped = 0;
    290 	while (CGSIZE(&sblock) > sblock.fs_bsize) {
    291 		mapcramped = 1;
    292 		if (sblock.fs_bsize < MAXBSIZE) {
    293 			sblock.fs_bsize <<= 1;
    294 			if ((i & 1) == 0) {
    295 				i >>= 1;
    296 			} else {
    297 				sblock.fs_cpc <<= 1;
    298 				mincpc <<= 1;
    299 				mincpg = roundup(mincpgcnt, mincpc);
    300 				sblock.fs_cpg = mincpg;
    301 			}
    302 			sblock.fs_frag <<= 1;
    303 			sblock.fs_fragshift += 1;
    304 			if (sblock.fs_frag <= MAXFRAG)
    305 				continue;
    306 		}
    307 		if (sblock.fs_fsize == sblock.fs_bsize) {
    308 			printf("There is no block size that");
    309 			printf(" can support this disk\n");
    310 			exit(22);
    311 		}
    312 		sblock.fs_frag >>= 1;
    313 		sblock.fs_fragshift -= 1;
    314 		sblock.fs_fsize <<= 1;
    315 		sblock.fs_nspf <<= 1;
    316 	}
    317 	/*
    318 	 * Insure that cylinder group with mincpg has enough space for inodes
    319 	 */
    320 	inodecramped = 0;
    321 	used *= sectorsize;
    322 	inospercg = roundup((mincpg * bpcg - used) / density, INOPB(&sblock));
    323 	sblock.fs_ipg = inospercg;
    324 	while (inospercg > MAXIPG(&sblock)) {
    325 		inodecramped = 1;
    326 		if (mincpc == 1 || sblock.fs_frag == 1 ||
    327 		    sblock.fs_bsize == MINBSIZE)
    328 			break;
    329 		printf("With a block size of %d %s %d\n", sblock.fs_bsize,
    330 		    "minimum bytes per inode is",
    331 		    (mincpg * bpcg - used) / MAXIPG(&sblock) + 1);
    332 		sblock.fs_bsize >>= 1;
    333 		sblock.fs_frag >>= 1;
    334 		sblock.fs_fragshift -= 1;
    335 		mincpc >>= 1;
    336 		sblock.fs_cpg = roundup(mincpgcnt, mincpc);
    337 		if (CGSIZE(&sblock) > sblock.fs_bsize) {
    338 			sblock.fs_bsize <<= 1;
    339 			break;
    340 		}
    341 		mincpg = sblock.fs_cpg;
    342 		inospercg =
    343 		    roundup((mincpg * bpcg - used) / density, INOPB(&sblock));
    344 		sblock.fs_ipg = inospercg;
    345 	}
    346 	if (inodecramped) {
    347 		if (inospercg > MAXIPG(&sblock)) {
    348 			printf("Minimum bytes per inode is %d\n",
    349 			    (mincpg * bpcg - used) / MAXIPG(&sblock) + 1);
    350 		} else if (!mapcramped) {
    351 			printf("With %d bytes per inode, ", density);
    352 			printf("minimum cylinders per group is %d\n", mincpg);
    353 		}
    354 	}
    355 	if (mapcramped) {
    356 		printf("With %d sectors per cylinder, ", sblock.fs_spc);
    357 		printf("minimum cylinders per group is %d\n", mincpg);
    358 	}
    359 	if (inodecramped || mapcramped) {
    360 		if (sblock.fs_bsize != bsize)
    361 			printf("%s to be changed from %d to %d\n",
    362 			    "This requires the block size",
    363 			    bsize, sblock.fs_bsize);
    364 		if (sblock.fs_fsize != fsize)
    365 			printf("\t%s to be changed from %d to %d\n",
    366 			    "and the fragment size",
    367 			    fsize, sblock.fs_fsize);
    368 		exit(23);
    369 	}
    370 	/*
    371 	 * Calculate the number of cylinders per group
    372 	 */
    373 	sblock.fs_cpg = cpg;
    374 	if (sblock.fs_cpg % mincpc != 0) {
    375 		printf("%s groups must have a multiple of %d cylinders\n",
    376 			cpgflg ? "Cylinder" : "Warning: cylinder", mincpc);
    377 		sblock.fs_cpg = roundup(sblock.fs_cpg, mincpc);
    378 		if (!cpgflg)
    379 			cpg = sblock.fs_cpg;
    380 	}
    381 	/*
    382 	 * Must insure there is enough space for inodes
    383 	 */
    384 	sblock.fs_ipg = roundup((sblock.fs_cpg * bpcg - used) / density,
    385 		INOPB(&sblock));
    386 	while (sblock.fs_ipg > MAXIPG(&sblock)) {
    387 		inodecramped = 1;
    388 		sblock.fs_cpg -= mincpc;
    389 		sblock.fs_ipg = roundup((sblock.fs_cpg * bpcg - used) / density,
    390 			INOPB(&sblock));
    391 	}
    392 	/*
    393 	 * Must insure there is enough space to hold block map
    394 	 */
    395 	while (CGSIZE(&sblock) > sblock.fs_bsize) {
    396 		mapcramped = 1;
    397 		sblock.fs_cpg -= mincpc;
    398 		sblock.fs_ipg = roundup((sblock.fs_cpg * bpcg - used) / density,
    399 			INOPB(&sblock));
    400 	}
    401 	sblock.fs_fpg = (sblock.fs_cpg * sblock.fs_spc) / NSPF(&sblock);
    402 	if ((sblock.fs_cpg * sblock.fs_spc) % NSPB(&sblock) != 0) {
    403 		printf("panic (fs_cpg * fs_spc) % NSPF != 0");
    404 		exit(24);
    405 	}
    406 	if (sblock.fs_cpg < mincpg) {
    407 		printf("cylinder groups must have at least %d cylinders\n",
    408 			mincpg);
    409 		exit(25);
    410 	} else if (sblock.fs_cpg != cpg) {
    411 		if (!cpgflg)
    412 			printf("Warning: ");
    413 		else if (!mapcramped && !inodecramped)
    414 			exit(26);
    415 		if (mapcramped && inodecramped)
    416 			printf("Block size and bytes per inode restrict");
    417 		else if (mapcramped)
    418 			printf("Block size restricts");
    419 		else
    420 			printf("Bytes per inode restrict");
    421 		printf(" cylinders per group to %d.\n", sblock.fs_cpg);
    422 		if (cpgflg)
    423 			exit(27);
    424 	}
    425 	sblock.fs_cgsize = fragroundup(&sblock, CGSIZE(&sblock));
    426 	/*
    427 	 * Now have size for file system and nsect and ntrak.
    428 	 * Determine number of cylinders and blocks in the file system.
    429 	 */
    430 	sblock.fs_size = fssize = dbtofsb(&sblock, fssize);
    431 	sblock.fs_ncyl = fssize * NSPF(&sblock) / sblock.fs_spc;
    432 	if (fssize * NSPF(&sblock) > sblock.fs_ncyl * sblock.fs_spc) {
    433 		sblock.fs_ncyl++;
    434 		warn = 1;
    435 	}
    436 	if (sblock.fs_ncyl < 1) {
    437 		printf("file systems must have at least one cylinder\n");
    438 		exit(28);
    439 	}
    440 	/*
    441 	 * Determine feasability/values of rotational layout tables.
    442 	 *
    443 	 * The size of the rotational layout tables is limited by the
    444 	 * size of the superblock, SBSIZE. The amount of space available
    445 	 * for tables is calculated as (SBSIZE - sizeof (struct fs)).
    446 	 * The size of these tables is inversely proportional to the block
    447 	 * size of the file system. The size increases if sectors per track
    448 	 * are not powers of two, because more cylinders must be described
    449 	 * by the tables before the rotational pattern repeats (fs_cpc).
    450 	 */
    451 	sblock.fs_interleave = interleave;
    452 	sblock.fs_trackskew = trackskew;
    453 	sblock.fs_npsect = nphyssectors;
    454 	sblock.fs_postblformat = FS_DYNAMICPOSTBLFMT;
    455 	sblock.fs_sbsize = fragroundup(&sblock, sizeof(struct fs));
    456 	if (sblock.fs_ntrak == 1) {
    457 		sblock.fs_cpc = 0;
    458 		goto next;
    459 	}
    460 	postblsize = sblock.fs_nrpos * sblock.fs_cpc * sizeof(short);
    461 	rotblsize = sblock.fs_cpc * sblock.fs_spc / NSPB(&sblock);
    462 	totalsbsize = sizeof(struct fs) + rotblsize;
    463 	if (sblock.fs_nrpos == 8 && sblock.fs_cpc <= 16) {
    464 		/* use old static table space */
    465 		sblock.fs_postbloff = (char *)(&sblock.fs_opostbl[0][0]) -
    466 		    (char *)(&sblock.fs_link);
    467 		sblock.fs_rotbloff = &sblock.fs_space[0] -
    468 		    (u_char *)(&sblock.fs_link);
    469 	} else {
    470 		/* use dynamic table space */
    471 		sblock.fs_postbloff = &sblock.fs_space[0] -
    472 		    (u_char *)(&sblock.fs_link);
    473 		sblock.fs_rotbloff = sblock.fs_postbloff + postblsize;
    474 		totalsbsize += postblsize;
    475 	}
    476 	if (totalsbsize > SBSIZE ||
    477 	    sblock.fs_nsect > (1 << NBBY) * NSPB(&sblock)) {
    478 		printf("%s %s %d %s %d.%s",
    479 		    "Warning: insufficient space in super block for\n",
    480 		    "rotational layout tables with nsect", sblock.fs_nsect,
    481 		    "and ntrak", sblock.fs_ntrak,
    482 		    "\nFile system performance may be impaired.\n");
    483 		sblock.fs_cpc = 0;
    484 		goto next;
    485 	}
    486 	sblock.fs_sbsize = fragroundup(&sblock, totalsbsize);
    487 	/*
    488 	 * calculate the available blocks for each rotational position
    489 	 */
    490 	for (cylno = 0; cylno < sblock.fs_cpc; cylno++)
    491 		for (rpos = 0; rpos < sblock.fs_nrpos; rpos++)
    492 			fs_postbl(&sblock, cylno)[rpos] = -1;
    493 	for (i = (rotblsize - 1) * sblock.fs_frag;
    494 	     i >= 0; i -= sblock.fs_frag) {
    495 		cylno = cbtocylno(&sblock, i);
    496 		rpos = cbtorpos(&sblock, i);
    497 		blk = fragstoblks(&sblock, i);
    498 		if (fs_postbl(&sblock, cylno)[rpos] == -1)
    499 			fs_rotbl(&sblock)[blk] = 0;
    500 		else
    501 			fs_rotbl(&sblock)[blk] =
    502 			    fs_postbl(&sblock, cylno)[rpos] - blk;
    503 		fs_postbl(&sblock, cylno)[rpos] = blk;
    504 	}
    505 next:
    506 	/*
    507 	 * Compute/validate number of cylinder groups.
    508 	 */
    509 	sblock.fs_ncg = sblock.fs_ncyl / sblock.fs_cpg;
    510 	if (sblock.fs_ncyl % sblock.fs_cpg)
    511 		sblock.fs_ncg++;
    512 	sblock.fs_dblkno = sblock.fs_iblkno + sblock.fs_ipg / INOPF(&sblock);
    513 	i = MIN(~sblock.fs_cgmask, sblock.fs_ncg - 1);
    514 	if (cgdmin(&sblock, i) - cgbase(&sblock, i) >= sblock.fs_fpg) {
    515 		printf("inode blocks/cyl group (%d) >= data blocks (%d)\n",
    516 		    cgdmin(&sblock, i) - cgbase(&sblock, i) / sblock.fs_frag,
    517 		    sblock.fs_fpg / sblock.fs_frag);
    518 		printf("number of cylinders per cylinder group (%d) %s.\n",
    519 		    sblock.fs_cpg, "must be increased");
    520 		exit(29);
    521 	}
    522 	j = sblock.fs_ncg - 1;
    523 	if ((i = fssize - j * sblock.fs_fpg) < sblock.fs_fpg &&
    524 	    cgdmin(&sblock, j) - cgbase(&sblock, j) > i) {
    525 		if (j == 0) {
    526 			printf("Filesystem must have at least %d sectors\n",
    527 			    NSPF(&sblock) *
    528 			    (cgdmin(&sblock, 0) + 3 * sblock.fs_frag));
    529 			exit(30);
    530 		}
    531 		printf("Warning: inode blocks/cyl group (%d) >= data blocks (%d) in last\n",
    532 		    (cgdmin(&sblock, j) - cgbase(&sblock, j)) / sblock.fs_frag,
    533 		    i / sblock.fs_frag);
    534 		printf("    cylinder group. This implies %d sector(s) cannot be allocated.\n",
    535 		    i * NSPF(&sblock));
    536 		sblock.fs_ncg--;
    537 		sblock.fs_ncyl -= sblock.fs_ncyl % sblock.fs_cpg;
    538 		sblock.fs_size = fssize = sblock.fs_ncyl * sblock.fs_spc /
    539 		    NSPF(&sblock);
    540 		warn = 0;
    541 	}
    542 	if (warn && !mfs) {
    543 		printf("Warning: %d sector(s) in last cylinder unallocated\n",
    544 		    sblock.fs_spc -
    545 		    (fssize * NSPF(&sblock) - (sblock.fs_ncyl - 1)
    546 		    * sblock.fs_spc));
    547 	}
    548 	/*
    549 	 * fill in remaining fields of the super block
    550 	 */
    551 	sblock.fs_csaddr = cgdmin(&sblock, 0);
    552 	sblock.fs_cssize =
    553 	    fragroundup(&sblock, sblock.fs_ncg * sizeof(struct csum));
    554 	i = sblock.fs_bsize / sizeof(struct csum);
    555 	sblock.fs_csmask = ~(i - 1);
    556 	for (sblock.fs_csshift = 0; i > 1; i >>= 1)
    557 		sblock.fs_csshift++;
    558 	fscs = (struct csum *)calloc(1, sblock.fs_cssize);
    559 	sblock.fs_magic = FS_MAGIC;
    560 	sblock.fs_rotdelay = rotdelay;
    561 	sblock.fs_minfree = minfree;
    562 	sblock.fs_maxcontig = maxcontig;
    563 	sblock.fs_headswitch = headswitch;
    564 	sblock.fs_trkseek = trackseek;
    565 	sblock.fs_maxbpg = maxbpg;
    566 	sblock.fs_rps = rpm / 60;
    567 	sblock.fs_optim = opt;
    568 	sblock.fs_cgrotor = 0;
    569 	sblock.fs_cstotal.cs_ndir = 0;
    570 	sblock.fs_cstotal.cs_nbfree = 0;
    571 	sblock.fs_cstotal.cs_nifree = 0;
    572 	sblock.fs_cstotal.cs_nffree = 0;
    573 	sblock.fs_fmod = 0;
    574 	sblock.fs_ronly = 0;
    575 	/*
    576 	 * Dump out summary information about file system.
    577 	 */
    578 	if (!mfs) {
    579 		printf("%s:\t%d sectors in %d %s of %d tracks, %d sectors\n",
    580 		    fsys, sblock.fs_size * NSPF(&sblock), sblock.fs_ncyl,
    581 		    "cylinders", sblock.fs_ntrak, sblock.fs_nsect);
    582 		printf("\t%.1fMB in %d cyl groups (%d c/g, %.2fMB/g, %d i/g)\n",
    583 		    (float)sblock.fs_size * sblock.fs_fsize * 1e-6,
    584 		    sblock.fs_ncg, sblock.fs_cpg,
    585 		    (float)sblock.fs_fpg * sblock.fs_fsize * 1e-6,
    586 		    sblock.fs_ipg);
    587 	}
    588 	/*
    589 	 * Now build the cylinders group blocks and
    590 	 * then print out indices of cylinder groups.
    591 	 */
    592 	if (!mfs)
    593 		printf("super-block backups (for fsck -b #) at:");
    594 	for (cylno = 0; cylno < sblock.fs_ncg; cylno++) {
    595 		initcg(cylno, utime);
    596 		if (mfs)
    597 			continue;
    598 		if (cylno % 9 == 0)
    599 			printf("\n");
    600 		printf(" %d,", fsbtodb(&sblock, cgsblock(&sblock, cylno)));
    601 	}
    602 	if (!mfs)
    603 		printf("\n");
    604 	if (Nflag && !mfs)
    605 		exit(0);
    606 	/*
    607 	 * Now construct the initial file system,
    608 	 * then write out the super-block.
    609 	 */
    610 	fsinit(utime);
    611 	sblock.fs_time = utime;
    612 	wtfs(SBOFF / sectorsize, sbsize, (char *)&sblock);
    613 	for (i = 0; i < sblock.fs_cssize; i += sblock.fs_bsize)
    614 		wtfs(fsbtodb(&sblock, sblock.fs_csaddr + numfrags(&sblock, i)),
    615 			sblock.fs_cssize - i < sblock.fs_bsize ?
    616 			    sblock.fs_cssize - i : sblock.fs_bsize,
    617 			((char *)fscs) + i);
    618 	/*
    619 	 * Write out the duplicate super blocks
    620 	 */
    621 	for (cylno = 0; cylno < sblock.fs_ncg; cylno++)
    622 		wtfs(fsbtodb(&sblock, cgsblock(&sblock, cylno)),
    623 		    sbsize, (char *)&sblock);
    624 	/*
    625 	 * Update information about this partion in pack
    626 	 * label, to that it may be updated on disk.
    627 	 */
    628 	pp->p_fstype = FS_BSDFFS;
    629 	pp->p_fsize = sblock.fs_fsize;
    630 	pp->p_frag = sblock.fs_frag;
    631 	pp->p_cpg = sblock.fs_cpg;
    632 	/*
    633 	 * Notify parent process of success.
    634 	 * Dissociate from session and tty.
    635 	 */
    636 	if (mfs) {
    637 		kill(ppid, SIGUSR1);
    638 		(void) setsid();
    639 		(void) close(0);
    640 		(void) close(1);
    641 		(void) close(2);
    642 		(void) chdir("/");
    643 	}
    644 }
    645 
    646 /*
    647  * Initialize a cylinder group.
    648  */
    649 initcg(cylno, utime)
    650 	int cylno;
    651 	time_t utime;
    652 {
    653 	daddr_t cbase, d, dlower, dupper, dmax;
    654 	long i, j, s;
    655 	register struct csum *cs;
    656 
    657 	/*
    658 	 * Determine block bounds for cylinder group.
    659 	 * Allow space for super block summary information in first
    660 	 * cylinder group.
    661 	 */
    662 	cbase = cgbase(&sblock, cylno);
    663 	dmax = cbase + sblock.fs_fpg;
    664 	if (dmax > sblock.fs_size)
    665 		dmax = sblock.fs_size;
    666 	dlower = cgsblock(&sblock, cylno) - cbase;
    667 	dupper = cgdmin(&sblock, cylno) - cbase;
    668 	if (cylno == 0)
    669 		dupper += howmany(sblock.fs_cssize, sblock.fs_fsize);
    670 	cs = fscs + cylno;
    671 	acg.cg_time = utime;
    672 	acg.cg_magic = CG_MAGIC;
    673 	acg.cg_cgx = cylno;
    674 	if (cylno == sblock.fs_ncg - 1)
    675 		acg.cg_ncyl = sblock.fs_ncyl % sblock.fs_cpg;
    676 	else
    677 		acg.cg_ncyl = sblock.fs_cpg;
    678 	acg.cg_niblk = sblock.fs_ipg;
    679 	acg.cg_ndblk = dmax - cbase;
    680 	acg.cg_cs.cs_ndir = 0;
    681 	acg.cg_cs.cs_nffree = 0;
    682 	acg.cg_cs.cs_nbfree = 0;
    683 	acg.cg_cs.cs_nifree = 0;
    684 	acg.cg_rotor = 0;
    685 	acg.cg_frotor = 0;
    686 	acg.cg_irotor = 0;
    687 	acg.cg_btotoff = &acg.cg_space[0] - (u_char *)(&acg.cg_link);
    688 	acg.cg_boff = acg.cg_btotoff + sblock.fs_cpg * sizeof(long);
    689 	acg.cg_iusedoff = acg.cg_boff +
    690 		sblock.fs_cpg * sblock.fs_nrpos * sizeof(short);
    691 	acg.cg_freeoff = acg.cg_iusedoff + howmany(sblock.fs_ipg, NBBY);
    692 	acg.cg_nextfreeoff = acg.cg_freeoff +
    693 		howmany(sblock.fs_cpg * sblock.fs_spc / NSPF(&sblock), NBBY);
    694 	for (i = 0; i < sblock.fs_frag; i++) {
    695 		acg.cg_frsum[i] = 0;
    696 	}
    697 	bzero((caddr_t)cg_inosused(&acg), acg.cg_freeoff - acg.cg_iusedoff);
    698 	acg.cg_cs.cs_nifree += sblock.fs_ipg;
    699 	if (cylno == 0)
    700 		for (i = 0; i < ROOTINO; i++) {
    701 			setbit(cg_inosused(&acg), i);
    702 			acg.cg_cs.cs_nifree--;
    703 		}
    704 	for (i = 0; i < sblock.fs_ipg / INOPF(&sblock); i += sblock.fs_frag)
    705 		wtfs(fsbtodb(&sblock, cgimin(&sblock, cylno) + i),
    706 		    sblock.fs_bsize, (char *)zino);
    707 	bzero((caddr_t)cg_blktot(&acg), acg.cg_boff - acg.cg_btotoff);
    708 	bzero((caddr_t)cg_blks(&sblock, &acg, 0),
    709 	    acg.cg_iusedoff - acg.cg_boff);
    710 	bzero((caddr_t)cg_blksfree(&acg), acg.cg_nextfreeoff - acg.cg_freeoff);
    711 	if (cylno > 0) {
    712 		/*
    713 		 * In cylno 0, beginning space is reserved
    714 		 * for boot and super blocks.
    715 		 */
    716 		for (d = 0; d < dlower; d += sblock.fs_frag) {
    717 			setblock(&sblock, cg_blksfree(&acg), d/sblock.fs_frag);
    718 			acg.cg_cs.cs_nbfree++;
    719 			cg_blktot(&acg)[cbtocylno(&sblock, d)]++;
    720 			cg_blks(&sblock, &acg, cbtocylno(&sblock, d))
    721 			    [cbtorpos(&sblock, d)]++;
    722 		}
    723 		sblock.fs_dsize += dlower;
    724 	}
    725 	sblock.fs_dsize += acg.cg_ndblk - dupper;
    726 	if (i = dupper % sblock.fs_frag) {
    727 		acg.cg_frsum[sblock.fs_frag - i]++;
    728 		for (d = dupper + sblock.fs_frag - i; dupper < d; dupper++) {
    729 			setbit(cg_blksfree(&acg), dupper);
    730 			acg.cg_cs.cs_nffree++;
    731 		}
    732 	}
    733 	for (d = dupper; d + sblock.fs_frag <= dmax - cbase; ) {
    734 		setblock(&sblock, cg_blksfree(&acg), d / sblock.fs_frag);
    735 		acg.cg_cs.cs_nbfree++;
    736 		cg_blktot(&acg)[cbtocylno(&sblock, d)]++;
    737 		cg_blks(&sblock, &acg, cbtocylno(&sblock, d))
    738 		    [cbtorpos(&sblock, d)]++;
    739 		d += sblock.fs_frag;
    740 	}
    741 	if (d < dmax - cbase) {
    742 		acg.cg_frsum[dmax - cbase - d]++;
    743 		for (; d < dmax - cbase; d++) {
    744 			setbit(cg_blksfree(&acg), d);
    745 			acg.cg_cs.cs_nffree++;
    746 		}
    747 	}
    748 	sblock.fs_cstotal.cs_ndir += acg.cg_cs.cs_ndir;
    749 	sblock.fs_cstotal.cs_nffree += acg.cg_cs.cs_nffree;
    750 	sblock.fs_cstotal.cs_nbfree += acg.cg_cs.cs_nbfree;
    751 	sblock.fs_cstotal.cs_nifree += acg.cg_cs.cs_nifree;
    752 	*cs = acg.cg_cs;
    753 	wtfs(fsbtodb(&sblock, cgtod(&sblock, cylno)),
    754 		sblock.fs_bsize, (char *)&acg);
    755 }
    756 
    757 /*
    758  * initialize the file system
    759  */
    760 struct dinode node;
    761 
    762 #ifdef LOSTDIR
    763 #define PREDEFDIR 3
    764 #else
    765 #define PREDEFDIR 2
    766 #endif
    767 
    768 struct direct root_dir[] = {
    769 	{ ROOTINO, sizeof(struct direct), 1, "." },
    770 	{ ROOTINO, sizeof(struct direct), 2, ".." },
    771 #ifdef LOSTDIR
    772 	{ LOSTFOUNDINO, sizeof(struct direct), 10, "lost+found" },
    773 #endif
    774 };
    775 #ifdef LOSTDIR
    776 struct direct lost_found_dir[] = {
    777 	{ LOSTFOUNDINO, sizeof(struct direct), 1, "." },
    778 	{ ROOTINO, sizeof(struct direct), 2, ".." },
    779 	{ 0, DIRBLKSIZ, 0, 0 },
    780 };
    781 #endif
    782 char buf[MAXBSIZE];
    783 
    784 fsinit(utime)
    785 	time_t utime;
    786 {
    787 	int i;
    788 
    789 	/*
    790 	 * initialize the node
    791 	 */
    792 	node.di_atime = utime;
    793 	node.di_mtime = utime;
    794 	node.di_ctime = utime;
    795 #ifdef LOSTDIR
    796 	/*
    797 	 * create the lost+found directory
    798 	 */
    799 	(void)makedir(lost_found_dir, 2);
    800 	for (i = DIRBLKSIZ; i < sblock.fs_bsize; i += DIRBLKSIZ)
    801 		bcopy(&lost_found_dir[2], &buf[i], DIRSIZ(&lost_found_dir[2]));
    802 	node.di_mode = IFDIR | UMASK;
    803 	node.di_nlink = 2;
    804 	node.di_size = sblock.fs_bsize;
    805 	node.di_db[0] = alloc(node.di_size, node.di_mode);
    806 	node.di_blocks = btodb(fragroundup(&sblock, node.di_size));
    807 	wtfs(fsbtodb(&sblock, node.di_db[0]), node.di_size, buf);
    808 	iput(&node, LOSTFOUNDINO);
    809 #endif
    810 	/*
    811 	 * create the root directory
    812 	 */
    813 	if (mfs)
    814 		node.di_mode = IFDIR | 01777;
    815 	else
    816 		node.di_mode = IFDIR | UMASK;
    817 	node.di_nlink = PREDEFDIR;
    818 	node.di_size = makedir(root_dir, PREDEFDIR);
    819 	node.di_db[0] = alloc(sblock.fs_fsize, node.di_mode);
    820 	node.di_blocks = btodb(fragroundup(&sblock, node.di_size));
    821 	wtfs(fsbtodb(&sblock, node.di_db[0]), sblock.fs_fsize, buf);
    822 	iput(&node, ROOTINO);
    823 }
    824 
    825 /*
    826  * construct a set of directory entries in "buf".
    827  * return size of directory.
    828  */
    829 makedir(protodir, entries)
    830 	register struct direct *protodir;
    831 	int entries;
    832 {
    833 	char *cp;
    834 	int i, spcleft;
    835 
    836 	spcleft = DIRBLKSIZ;
    837 	for (cp = buf, i = 0; i < entries - 1; i++) {
    838 		protodir[i].d_reclen = DIRSIZ(&protodir[i]);
    839 		bcopy(&protodir[i], cp, protodir[i].d_reclen);
    840 		cp += protodir[i].d_reclen;
    841 		spcleft -= protodir[i].d_reclen;
    842 	}
    843 	protodir[i].d_reclen = spcleft;
    844 	bcopy(&protodir[i], cp, DIRSIZ(&protodir[i]));
    845 	return (DIRBLKSIZ);
    846 }
    847 
    848 /*
    849  * allocate a block or frag
    850  */
    851 daddr_t
    852 alloc(size, mode)
    853 	int size;
    854 	int mode;
    855 {
    856 	int i, frag;
    857 	daddr_t d;
    858 
    859 	rdfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
    860 	    (char *)&acg);
    861 	if (acg.cg_magic != CG_MAGIC) {
    862 		printf("cg 0: bad magic number\n");
    863 		return (0);
    864 	}
    865 	if (acg.cg_cs.cs_nbfree == 0) {
    866 		printf("first cylinder group ran out of space\n");
    867 		return (0);
    868 	}
    869 	for (d = 0; d < acg.cg_ndblk; d += sblock.fs_frag)
    870 		if (isblock(&sblock, cg_blksfree(&acg), d / sblock.fs_frag))
    871 			goto goth;
    872 	printf("internal error: can't find block in cyl 0\n");
    873 	return (0);
    874 goth:
    875 	clrblock(&sblock, cg_blksfree(&acg), d / sblock.fs_frag);
    876 	acg.cg_cs.cs_nbfree--;
    877 	sblock.fs_cstotal.cs_nbfree--;
    878 	fscs[0].cs_nbfree--;
    879 	if (mode & IFDIR) {
    880 		acg.cg_cs.cs_ndir++;
    881 		sblock.fs_cstotal.cs_ndir++;
    882 		fscs[0].cs_ndir++;
    883 	}
    884 	cg_blktot(&acg)[cbtocylno(&sblock, d)]--;
    885 	cg_blks(&sblock, &acg, cbtocylno(&sblock, d))[cbtorpos(&sblock, d)]--;
    886 	if (size != sblock.fs_bsize) {
    887 		frag = howmany(size, sblock.fs_fsize);
    888 		fscs[0].cs_nffree += sblock.fs_frag - frag;
    889 		sblock.fs_cstotal.cs_nffree += sblock.fs_frag - frag;
    890 		acg.cg_cs.cs_nffree += sblock.fs_frag - frag;
    891 		acg.cg_frsum[sblock.fs_frag - frag]++;
    892 		for (i = frag; i < sblock.fs_frag; i++)
    893 			setbit(cg_blksfree(&acg), d + i);
    894 	}
    895 	wtfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
    896 	    (char *)&acg);
    897 	return (d);
    898 }
    899 
    900 /*
    901  * Allocate an inode on the disk
    902  */
    903 iput(ip, ino)
    904 	register struct dinode *ip;
    905 	register ino_t ino;
    906 {
    907 	struct dinode buf[MAXINOPB];
    908 	daddr_t d;
    909 	int c;
    910 
    911 	c = itog(&sblock, ino);
    912 	rdfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
    913 	    (char *)&acg);
    914 	if (acg.cg_magic != CG_MAGIC) {
    915 		printf("cg 0: bad magic number\n");
    916 		exit(31);
    917 	}
    918 	acg.cg_cs.cs_nifree--;
    919 	setbit(cg_inosused(&acg), ino);
    920 	wtfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
    921 	    (char *)&acg);
    922 	sblock.fs_cstotal.cs_nifree--;
    923 	fscs[0].cs_nifree--;
    924 	if (ino >= sblock.fs_ipg * sblock.fs_ncg) {
    925 		printf("fsinit: inode value out of range (%d).\n", ino);
    926 		exit(32);
    927 	}
    928 	d = fsbtodb(&sblock, itod(&sblock, ino));
    929 	rdfs(d, sblock.fs_bsize, buf);
    930 	buf[itoo(&sblock, ino)] = *ip;
    931 	wtfs(d, sblock.fs_bsize, buf);
    932 }
    933 
    934 /*
    935  * Notify parent process that the filesystem has created itself successfully.
    936  */
    937 void
    938 started()
    939 {
    940 
    941 	exit(0);
    942 }
    943 
    944 /*
    945  * Replace libc function with one suited to our needs.
    946  */
    947 caddr_t
    948 malloc(size)
    949 	register u_long size;
    950 {
    951 	u_long base, i;
    952 	static u_long pgsz;
    953 	struct rlimit rlp;
    954 
    955 	if (pgsz == 0) {
    956 		base = sbrk(0);
    957 		pgsz = getpagesize() - 1;
    958 		i = (base + pgsz) &~ pgsz;
    959 		base = sbrk(i - base);
    960 		if (getrlimit(RLIMIT_DATA, &rlp) < 0)
    961 			perror("getrlimit");
    962 		rlp.rlim_cur = rlp.rlim_max;
    963 		if (setrlimit(RLIMIT_DATA, &rlp) < 0)
    964 			perror("setrlimit");
    965 		memleft = rlp.rlim_max - base;
    966 	}
    967 	size = (size + pgsz) &~ pgsz;
    968 	if (size > memleft)
    969 		size = memleft;
    970 	memleft -= size;
    971 	if (size == 0)
    972 		return (0);
    973 	return ((caddr_t)sbrk(size));
    974 }
    975 
    976 /*
    977  * Replace libc function with one suited to our needs.
    978  */
    979 caddr_t
    980 realloc(ptr, size)
    981 	char *ptr;
    982 	u_long size;
    983 {
    984 
    985 	/* always fail for now */
    986 	return ((caddr_t)0);
    987 }
    988 
    989 /*
    990  * Replace libc function with one suited to our needs.
    991  */
    992 char *
    993 calloc(size, numelm)
    994 	u_long size, numelm;
    995 {
    996 	caddr_t base;
    997 
    998 	size *= numelm;
    999 	base = malloc(size);
   1000 	bzero(base, size);
   1001 	return (base);
   1002 }
   1003 
   1004 /*
   1005  * Replace libc function with one suited to our needs.
   1006  */
   1007 free(ptr)
   1008 	char *ptr;
   1009 {
   1010 
   1011 	/* do not worry about it for now */
   1012 }
   1013 
   1014 /*
   1015  * read a block from the file system
   1016  */
   1017 rdfs(bno, size, bf)
   1018 	daddr_t bno;
   1019 	int size;
   1020 	char *bf;
   1021 {
   1022 	int n;
   1023 
   1024 	if (mfs) {
   1025 		bcopy(membase + bno * sectorsize, bf, size);
   1026 		return;
   1027 	}
   1028 	if (lseek(fsi, bno * sectorsize, 0) < 0) {
   1029 		printf("seek error: %ld\n", bno);
   1030 		perror("rdfs");
   1031 		exit(33);
   1032 	}
   1033 	n = read(fsi, bf, size);
   1034 	if(n != size) {
   1035 		printf("read error: %ld\n", bno);
   1036 		perror("rdfs");
   1037 		exit(34);
   1038 	}
   1039 }
   1040 
   1041 /*
   1042  * write a block to the file system
   1043  */
   1044 wtfs(bno, size, bf)
   1045 	daddr_t bno;
   1046 	int size;
   1047 	char *bf;
   1048 {
   1049 	int n;
   1050 
   1051 	if (mfs) {
   1052 		bcopy(bf, membase + bno * sectorsize, size);
   1053 		return;
   1054 	}
   1055 	if (Nflag)
   1056 		return;
   1057 	if (lseek(fso, bno * sectorsize, 0) < 0) {
   1058 		printf("seek error: %ld\n", bno);
   1059 		perror("wtfs");
   1060 		exit(35);
   1061 	}
   1062 	n = write(fso, bf, size);
   1063 	if(n != size) {
   1064 		printf("write error: %ld\n", bno);
   1065 		perror("wtfs");
   1066 		exit(36);
   1067 	}
   1068 }
   1069 
   1070 /*
   1071  * check if a block is available
   1072  */
   1073 isblock(fs, cp, h)
   1074 	struct fs *fs;
   1075 	unsigned char *cp;
   1076 	int h;
   1077 {
   1078 	unsigned char mask;
   1079 
   1080 	switch (fs->fs_frag) {
   1081 	case 8:
   1082 		return (cp[h] == 0xff);
   1083 	case 4:
   1084 		mask = 0x0f << ((h & 0x1) << 2);
   1085 		return ((cp[h >> 1] & mask) == mask);
   1086 	case 2:
   1087 		mask = 0x03 << ((h & 0x3) << 1);
   1088 		return ((cp[h >> 2] & mask) == mask);
   1089 	case 1:
   1090 		mask = 0x01 << (h & 0x7);
   1091 		return ((cp[h >> 3] & mask) == mask);
   1092 	default:
   1093 #ifdef STANDALONE
   1094 		printf("isblock bad fs_frag %d\n", fs->fs_frag);
   1095 #else
   1096 		fprintf(stderr, "isblock bad fs_frag %d\n", fs->fs_frag);
   1097 #endif
   1098 		return (0);
   1099 	}
   1100 }
   1101 
   1102 /*
   1103  * take a block out of the map
   1104  */
   1105 clrblock(fs, cp, h)
   1106 	struct fs *fs;
   1107 	unsigned char *cp;
   1108 	int h;
   1109 {
   1110 	switch ((fs)->fs_frag) {
   1111 	case 8:
   1112 		cp[h] = 0;
   1113 		return;
   1114 	case 4:
   1115 		cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
   1116 		return;
   1117 	case 2:
   1118 		cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
   1119 		return;
   1120 	case 1:
   1121 		cp[h >> 3] &= ~(0x01 << (h & 0x7));
   1122 		return;
   1123 	default:
   1124 #ifdef STANDALONE
   1125 		printf("clrblock bad fs_frag %d\n", fs->fs_frag);
   1126 #else
   1127 		fprintf(stderr, "clrblock bad fs_frag %d\n", fs->fs_frag);
   1128 #endif
   1129 		return;
   1130 	}
   1131 }
   1132 
   1133 /*
   1134  * put a block into the map
   1135  */
   1136 setblock(fs, cp, h)
   1137 	struct fs *fs;
   1138 	unsigned char *cp;
   1139 	int h;
   1140 {
   1141 	switch (fs->fs_frag) {
   1142 	case 8:
   1143 		cp[h] = 0xff;
   1144 		return;
   1145 	case 4:
   1146 		cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
   1147 		return;
   1148 	case 2:
   1149 		cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
   1150 		return;
   1151 	case 1:
   1152 		cp[h >> 3] |= (0x01 << (h & 0x7));
   1153 		return;
   1154 	default:
   1155 #ifdef STANDALONE
   1156 		printf("setblock bad fs_frag %d\n", fs->fs_frag);
   1157 #else
   1158 		fprintf(stderr, "setblock bad fs_frag %d\n", fs->fs_frag);
   1159 #endif
   1160 		return;
   1161 	}
   1162 }
   1163