xref: /netbsd-src/sbin/newfs/mkfs.c (revision ce0bb6e8d2e560ecacbe865a848624f94498063b)
1 /*	$NetBSD: mkfs.c,v 1.21 1995/04/12 21:24:31 mycroft Exp $	*/
2 
3 /*
4  * Copyright (c) 1980, 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)mkfs.c	8.3 (Berkeley) 2/3/94";
39 #else
40 static char rcsid[] = "$NetBSD: mkfs.c,v 1.21 1995/04/12 21:24:31 mycroft Exp $";
41 #endif
42 #endif /* not lint */
43 
44 #include <sys/param.h>
45 #include <sys/time.h>
46 #include <sys/wait.h>
47 #include <sys/resource.h>
48 #include <ufs/ufs/dinode.h>
49 #include <ufs/ufs/dir.h>
50 #include <ufs/ffs/fs.h>
51 #include <sys/disklabel.h>
52 
53 #include <string.h>
54 #include <unistd.h>
55 
56 #ifndef STANDALONE
57 #include <a.out.h>
58 #include <stdio.h>
59 #endif
60 
61 /*
62  * make file system for cylinder-group style file systems
63  */
64 
65 /*
66  * We limit the size of the inode map to be no more than a
67  * third of the cylinder group space, since we must leave at
68  * least an equal amount of space for the block map.
69  *
70  * N.B.: MAXIPG must be a multiple of INOPB(fs).
71  */
72 #define MAXIPG(fs)	roundup((fs)->fs_bsize * NBBY / 3, INOPB(fs))
73 
74 #define UMASK		0755
75 #define MAXINOPB	(MAXBSIZE / sizeof(struct dinode))
76 #define POWEROF2(num)	(((num) & ((num) - 1)) == 0)
77 
78 /*
79  * variables set up by front end.
80  */
81 extern int	mfs;		/* run as the memory based filesystem */
82 extern int	Nflag;		/* run mkfs without writing file system */
83 extern int	Oflag;		/* format as an 4.3BSD file system */
84 extern int	fssize;		/* file system size */
85 extern int	ntracks;	/* # tracks/cylinder */
86 extern int	nsectors;	/* # sectors/track */
87 extern int	nphyssectors;	/* # sectors/track including spares */
88 extern int	secpercyl;	/* sectors per cylinder */
89 extern int	sectorsize;	/* bytes/sector */
90 extern int	rpm;		/* revolutions/minute of drive */
91 extern int	interleave;	/* hardware sector interleave */
92 extern int	trackskew;	/* sector 0 skew, per track */
93 extern int	headswitch;	/* head switch time, usec */
94 extern int	trackseek;	/* track-to-track seek, usec */
95 extern int	fsize;		/* fragment size */
96 extern int	bsize;		/* block size */
97 extern int	cpg;		/* cylinders/cylinder group */
98 extern int	cpgflg;		/* cylinders/cylinder group flag was given */
99 extern int	minfree;	/* free space threshold */
100 extern int	opt;		/* optimization preference (space or time) */
101 extern int	density;	/* number of bytes per inode */
102 extern int	maxcontig;	/* max contiguous blocks to allocate */
103 extern int	rotdelay;	/* rotational delay between blocks */
104 extern int	maxbpg;		/* maximum blocks per file in a cyl group */
105 extern int	nrpos;		/* # of distinguished rotational positions */
106 extern int	bbsize;		/* boot block size */
107 extern int	sbsize;		/* superblock size */
108 extern u_long	memleft;	/* virtual memory available */
109 extern caddr_t	membase;	/* start address of memory based filesystem */
110 extern caddr_t	malloc(), calloc();
111 
112 union {
113 	struct fs fs;
114 	char pad[SBSIZE];
115 } fsun;
116 #define	sblock	fsun.fs
117 struct	csum *fscs;
118 
119 union {
120 	struct cg cg;
121 	char pad[MAXBSIZE];
122 } cgun;
123 #define	acg	cgun.cg
124 
125 struct dinode zino[MAXBSIZE / sizeof(struct dinode)];
126 
127 int	fsi, fso;
128 daddr_t	alloc();
129 
130 mkfs(pp, fsys, fi, fo)
131 	struct partition *pp;
132 	char *fsys;
133 	int fi, fo;
134 {
135 	register long i, mincpc, mincpg, inospercg;
136 	long cylno, rpos, blk, j, warn = 0;
137 	long used, mincpgcnt, bpcg;
138 	long mapcramped, inodecramped;
139 	long postblsize, rotblsize, totalsbsize;
140 	int ppid, status;
141 	time_t utime;
142 	quad_t sizepb;
143 	void started();
144 
145 #ifndef STANDALONE
146 	time(&utime);
147 #endif
148 	if (mfs) {
149 		ppid = getpid();
150 		(void) signal(SIGUSR1, started);
151 		if (i = fork()) {
152 			if (i == -1) {
153 				perror("mfs");
154 				exit(10);
155 			}
156 			if (waitpid(i, &status, 0) != -1 && WIFEXITED(status))
157 				exit(WEXITSTATUS(status));
158 			exit(11);
159 			/* NOTREACHED */
160 		}
161 		(void)malloc(0);
162 		if (fssize * sectorsize > memleft)
163 			fssize = (memleft - 16384) / sectorsize;
164 		if ((membase = malloc(fssize * sectorsize)) == 0)
165 			exit(12);
166 	}
167 	fsi = fi;
168 	fso = fo;
169 	if (Oflag) {
170 		sblock.fs_inodefmt = FS_42INODEFMT;
171 		sblock.fs_maxsymlinklen = 0;
172 	} else {
173 		sblock.fs_inodefmt = FS_44INODEFMT;
174 		sblock.fs_maxsymlinklen = MAXSYMLINKLEN;
175 	}
176 	/*
177 	 * Validate the given file system size.
178 	 * Verify that its last block can actually be accessed.
179 	 */
180 	if (fssize <= 0)
181 		printf("preposterous size %d\n", fssize), exit(13);
182 	wtfs(fssize - 1, sectorsize, (char *)&sblock);
183 	/*
184 	 * collect and verify the sector and track info
185 	 */
186 	sblock.fs_nsect = nsectors;
187 	sblock.fs_ntrak = ntracks;
188 	if (sblock.fs_ntrak <= 0)
189 		printf("preposterous ntrak %d\n", sblock.fs_ntrak), exit(14);
190 	if (sblock.fs_nsect <= 0)
191 		printf("preposterous nsect %d\n", sblock.fs_nsect), exit(15);
192 	/*
193 	 * collect and verify the block and fragment sizes
194 	 */
195 	sblock.fs_bsize = bsize;
196 	sblock.fs_fsize = fsize;
197 	if (!POWEROF2(sblock.fs_bsize)) {
198 		printf("block size must be a power of 2, not %d\n",
199 		    sblock.fs_bsize);
200 		exit(16);
201 	}
202 	if (!POWEROF2(sblock.fs_fsize)) {
203 		printf("fragment size must be a power of 2, not %d\n",
204 		    sblock.fs_fsize);
205 		exit(17);
206 	}
207 	if (sblock.fs_fsize < sectorsize) {
208 		printf("fragment size %d is too small, minimum is %d\n",
209 		    sblock.fs_fsize, sectorsize);
210 		exit(18);
211 	}
212 	if (sblock.fs_bsize < MINBSIZE) {
213 		printf("block size %d is too small, minimum is %d\n",
214 		    sblock.fs_bsize, MINBSIZE);
215 		exit(19);
216 	}
217 	if (sblock.fs_bsize < sblock.fs_fsize) {
218 		printf("block size (%d) cannot be smaller than fragment size (%d)\n",
219 		    sblock.fs_bsize, sblock.fs_fsize);
220 		exit(20);
221 	}
222 	sblock.fs_bmask = ~(sblock.fs_bsize - 1);
223 	sblock.fs_fmask = ~(sblock.fs_fsize - 1);
224 	sblock.fs_qbmask = ~sblock.fs_bmask;
225 	sblock.fs_qfmask = ~sblock.fs_fmask;
226 	for (sblock.fs_bshift = 0, i = sblock.fs_bsize; i > 1; i >>= 1)
227 		sblock.fs_bshift++;
228 	for (sblock.fs_fshift = 0, i = sblock.fs_fsize; i > 1; i >>= 1)
229 		sblock.fs_fshift++;
230 	sblock.fs_frag = numfrags(&sblock, sblock.fs_bsize);
231 	for (sblock.fs_fragshift = 0, i = sblock.fs_frag; i > 1; i >>= 1)
232 		sblock.fs_fragshift++;
233 	if (sblock.fs_frag > MAXFRAG) {
234 		printf("fragment size %d is too small, minimum with block size %d is %d\n",
235 		    sblock.fs_fsize, sblock.fs_bsize,
236 		    sblock.fs_bsize / MAXFRAG);
237 		exit(21);
238 	}
239 	sblock.fs_nrpos = nrpos;
240 	sblock.fs_nindir = sblock.fs_bsize / sizeof(daddr_t);
241 	sblock.fs_inopb = sblock.fs_bsize / sizeof(struct dinode);
242 	sblock.fs_nspf = sblock.fs_fsize / sectorsize;
243 	for (sblock.fs_fsbtodb = 0, i = NSPF(&sblock); i > 1; i >>= 1)
244 		sblock.fs_fsbtodb++;
245 	sblock.fs_sblkno =
246 	    roundup(howmany(bbsize + sbsize, sblock.fs_fsize), sblock.fs_frag);
247 	sblock.fs_cblkno = (daddr_t)(sblock.fs_sblkno +
248 	    roundup(howmany(sbsize, sblock.fs_fsize), sblock.fs_frag));
249 	sblock.fs_iblkno = sblock.fs_cblkno + sblock.fs_frag;
250 	sblock.fs_cgoffset = roundup(
251 	    howmany(sblock.fs_nsect, NSPF(&sblock)), sblock.fs_frag);
252 	for (sblock.fs_cgmask = 0xffffffff, i = sblock.fs_ntrak; i > 1; i >>= 1)
253 		sblock.fs_cgmask <<= 1;
254 	if (!POWEROF2(sblock.fs_ntrak))
255 		sblock.fs_cgmask <<= 1;
256 	sblock.fs_maxfilesize = sblock.fs_bsize * NDADDR - 1;
257 	for (sizepb = sblock.fs_bsize, i = 0; i < NIADDR; i++) {
258 		sizepb *= NINDIR(&sblock);
259 		sblock.fs_maxfilesize += sizepb;
260 	}
261 	/*
262 	 * Validate specified/determined secpercyl
263 	 * and calculate minimum cylinders per group.
264 	 */
265 	sblock.fs_spc = secpercyl;
266 	for (sblock.fs_cpc = NSPB(&sblock), i = sblock.fs_spc;
267 	     sblock.fs_cpc > 1 && (i & 1) == 0;
268 	     sblock.fs_cpc >>= 1, i >>= 1)
269 		/* void */;
270 	mincpc = sblock.fs_cpc;
271 	bpcg = sblock.fs_spc * sectorsize;
272 	inospercg = roundup(bpcg / sizeof(struct dinode), INOPB(&sblock));
273 	if (inospercg > MAXIPG(&sblock))
274 		inospercg = MAXIPG(&sblock);
275 	used = (sblock.fs_iblkno + inospercg / INOPF(&sblock)) * NSPF(&sblock);
276 	mincpgcnt = howmany(sblock.fs_cgoffset * (~sblock.fs_cgmask) + used,
277 	    sblock.fs_spc);
278 	mincpg = roundup(mincpgcnt, mincpc);
279 	/*
280 	 * Ensure that cylinder group with mincpg has enough space
281 	 * for block maps.
282 	 */
283 	sblock.fs_cpg = mincpg;
284 	sblock.fs_ipg = inospercg;
285 	if (maxcontig > 1)
286 		sblock.fs_contigsumsize = MIN(maxcontig, FS_MAXCONTIG);
287 	mapcramped = 0;
288 	while (CGSIZE(&sblock) > sblock.fs_bsize) {
289 		mapcramped = 1;
290 		if (sblock.fs_bsize < MAXBSIZE) {
291 			sblock.fs_bsize <<= 1;
292 			if ((i & 1) == 0) {
293 				i >>= 1;
294 			} else {
295 				sblock.fs_cpc <<= 1;
296 				mincpc <<= 1;
297 				mincpg = roundup(mincpgcnt, mincpc);
298 				sblock.fs_cpg = mincpg;
299 			}
300 			sblock.fs_frag <<= 1;
301 			sblock.fs_fragshift += 1;
302 			if (sblock.fs_frag <= MAXFRAG)
303 				continue;
304 		}
305 		if (sblock.fs_fsize == sblock.fs_bsize) {
306 			printf("There is no block size that");
307 			printf(" can support this disk\n");
308 			exit(22);
309 		}
310 		sblock.fs_frag >>= 1;
311 		sblock.fs_fragshift -= 1;
312 		sblock.fs_fsize <<= 1;
313 		sblock.fs_nspf <<= 1;
314 	}
315 	/*
316 	 * Ensure that cylinder group with mincpg has enough space for inodes.
317 	 */
318 	inodecramped = 0;
319 	used *= sectorsize;
320 	inospercg = roundup((mincpg * bpcg - used) / density, INOPB(&sblock));
321 	sblock.fs_ipg = inospercg;
322 	while (inospercg > MAXIPG(&sblock)) {
323 		inodecramped = 1;
324 		if (mincpc == 1 || sblock.fs_frag == 1 ||
325 		    sblock.fs_bsize == MINBSIZE)
326 			break;
327 		printf("With a block size of %d %s %d\n", sblock.fs_bsize,
328 		    "minimum bytes per inode is",
329 		    (mincpg * bpcg - used) / MAXIPG(&sblock) + 1);
330 		sblock.fs_bsize >>= 1;
331 		sblock.fs_frag >>= 1;
332 		sblock.fs_fragshift -= 1;
333 		mincpc >>= 1;
334 		sblock.fs_cpg = roundup(mincpgcnt, mincpc);
335 		if (CGSIZE(&sblock) > sblock.fs_bsize) {
336 			sblock.fs_bsize <<= 1;
337 			break;
338 		}
339 		mincpg = sblock.fs_cpg;
340 		inospercg =
341 		    roundup((mincpg * bpcg - used) / density, INOPB(&sblock));
342 		sblock.fs_ipg = inospercg;
343 	}
344 	if (inodecramped) {
345 		if (inospercg > MAXIPG(&sblock)) {
346 			printf("Minimum bytes per inode is %d\n",
347 			    (mincpg * bpcg - used) / MAXIPG(&sblock) + 1);
348 		} else if (!mapcramped) {
349 			printf("With %d bytes per inode, ", density);
350 			printf("minimum cylinders per group is %d\n", mincpg);
351 		}
352 	}
353 	if (mapcramped) {
354 		printf("With %d sectors per cylinder, ", sblock.fs_spc);
355 		printf("minimum cylinders per group is %d\n", mincpg);
356 	}
357 	if (inodecramped || mapcramped) {
358 		if (sblock.fs_bsize != bsize)
359 			printf("%s to be changed from %d to %d\n",
360 			    "This requires the block size",
361 			    bsize, sblock.fs_bsize);
362 		if (sblock.fs_fsize != fsize)
363 			printf("\t%s to be changed from %d to %d\n",
364 			    "and the fragment size",
365 			    fsize, sblock.fs_fsize);
366 		exit(23);
367 	}
368 	/*
369 	 * Calculate the number of cylinders per group
370 	 */
371 	sblock.fs_cpg = cpg;
372 	if (sblock.fs_cpg % mincpc != 0) {
373 		printf("%s groups must have a multiple of %d cylinders\n",
374 			cpgflg ? "Cylinder" : "Warning: cylinder", mincpc);
375 		sblock.fs_cpg = roundup(sblock.fs_cpg, mincpc);
376 		if (!cpgflg)
377 			cpg = sblock.fs_cpg;
378 	}
379 	/*
380 	 * Must ensure there is enough space for inodes.
381 	 */
382 	sblock.fs_ipg = roundup((sblock.fs_cpg * bpcg - used) / density,
383 		INOPB(&sblock));
384 	while (sblock.fs_ipg > MAXIPG(&sblock)) {
385 		inodecramped = 1;
386 		sblock.fs_cpg -= mincpc;
387 		sblock.fs_ipg = roundup((sblock.fs_cpg * bpcg - used) / density,
388 			INOPB(&sblock));
389 	}
390 	/*
391 	 * Must ensure there is enough space to hold block map.
392 	 */
393 	while (CGSIZE(&sblock) > sblock.fs_bsize) {
394 		mapcramped = 1;
395 		sblock.fs_cpg -= mincpc;
396 		sblock.fs_ipg = roundup((sblock.fs_cpg * bpcg - used) / density,
397 			INOPB(&sblock));
398 	}
399 	sblock.fs_fpg = (sblock.fs_cpg * sblock.fs_spc) / NSPF(&sblock);
400 	if ((sblock.fs_cpg * sblock.fs_spc) % NSPB(&sblock) != 0) {
401 		printf("panic (fs_cpg * fs_spc) % NSPF != 0");
402 		exit(24);
403 	}
404 	if (sblock.fs_cpg < mincpg) {
405 		printf("cylinder groups must have at least %d cylinders\n",
406 			mincpg);
407 		exit(25);
408 	} else if (sblock.fs_cpg != cpg) {
409 		if (!cpgflg)
410 			printf("Warning: ");
411 		else if (!mapcramped && !inodecramped)
412 			exit(26);
413 		if (mapcramped && inodecramped)
414 			printf("Block size and bytes per inode restrict");
415 		else if (mapcramped)
416 			printf("Block size restricts");
417 		else
418 			printf("Bytes per inode restrict");
419 		printf(" cylinders per group to %d.\n", sblock.fs_cpg);
420 		if (cpgflg)
421 			exit(27);
422 	}
423 	sblock.fs_cgsize = fragroundup(&sblock, CGSIZE(&sblock));
424 	/*
425 	 * Now have size for file system and nsect and ntrak.
426 	 * Determine number of cylinders and blocks in the file system.
427 	 */
428 	sblock.fs_size = fssize = dbtofsb(&sblock, fssize);
429 	sblock.fs_ncyl = fssize * NSPF(&sblock) / sblock.fs_spc;
430 	if (fssize * NSPF(&sblock) > sblock.fs_ncyl * sblock.fs_spc) {
431 		sblock.fs_ncyl++;
432 		warn = 1;
433 	}
434 	if (sblock.fs_ncyl < 1) {
435 		printf("file systems must have at least one cylinder\n");
436 		exit(28);
437 	}
438 	/*
439 	 * Determine feasability/values of rotational layout tables.
440 	 *
441 	 * The size of the rotational layout tables is limited by the
442 	 * size of the superblock, SBSIZE. The amount of space available
443 	 * for tables is calculated as (SBSIZE - sizeof (struct fs)).
444 	 * The size of these tables is inversely proportional to the block
445 	 * size of the file system. The size increases if sectors per track
446 	 * are not powers of two, because more cylinders must be described
447 	 * by the tables before the rotational pattern repeats (fs_cpc).
448 	 */
449 	sblock.fs_interleave = interleave;
450 	sblock.fs_trackskew = trackskew;
451 	sblock.fs_npsect = nphyssectors;
452 	sblock.fs_postblformat = FS_DYNAMICPOSTBLFMT;
453 	sblock.fs_sbsize = fragroundup(&sblock, sizeof(struct fs));
454 	if (sblock.fs_ntrak == 1) {
455 		sblock.fs_cpc = 0;
456 		goto next;
457 	}
458 	postblsize = sblock.fs_nrpos * sblock.fs_cpc * sizeof(int16_t);
459 	rotblsize = sblock.fs_cpc * sblock.fs_spc / NSPB(&sblock);
460 	totalsbsize = sizeof(struct fs) + rotblsize;
461 	if (sblock.fs_nrpos == 8 && sblock.fs_cpc <= 16) {
462 		/* use old static table space */
463 		sblock.fs_postbloff = (char *)(&sblock.fs_opostbl[0][0]) -
464 		    (char *)(&sblock.fs_firstfield);
465 		sblock.fs_rotbloff = &sblock.fs_space[0] -
466 		    (u_char *)(&sblock.fs_firstfield);
467 	} else {
468 		/* use dynamic table space */
469 		sblock.fs_postbloff = &sblock.fs_space[0] -
470 		    (u_char *)(&sblock.fs_firstfield);
471 		sblock.fs_rotbloff = sblock.fs_postbloff + postblsize;
472 		totalsbsize += postblsize;
473 	}
474 	if (totalsbsize > SBSIZE ||
475 	    sblock.fs_nsect > (1 << NBBY) * NSPB(&sblock)) {
476 		printf("%s %s %d %s %d.%s",
477 		    "Warning: insufficient space in super block for\n",
478 		    "rotational layout tables with nsect", sblock.fs_nsect,
479 		    "and ntrak", sblock.fs_ntrak,
480 		    "\nFile system performance may be impaired.\n");
481 		sblock.fs_cpc = 0;
482 		goto next;
483 	}
484 	sblock.fs_sbsize = fragroundup(&sblock, totalsbsize);
485 	/*
486 	 * calculate the available blocks for each rotational position
487 	 */
488 	for (cylno = 0; cylno < sblock.fs_cpc; cylno++)
489 		for (rpos = 0; rpos < sblock.fs_nrpos; rpos++)
490 			fs_postbl(&sblock, cylno)[rpos] = -1;
491 	for (i = (rotblsize - 1) * sblock.fs_frag;
492 	     i >= 0; i -= sblock.fs_frag) {
493 		cylno = cbtocylno(&sblock, i);
494 		rpos = cbtorpos(&sblock, i);
495 		blk = fragstoblks(&sblock, i);
496 		if (fs_postbl(&sblock, cylno)[rpos] == -1)
497 			fs_rotbl(&sblock)[blk] = 0;
498 		else
499 			fs_rotbl(&sblock)[blk] =
500 			    fs_postbl(&sblock, cylno)[rpos] - blk;
501 		fs_postbl(&sblock, cylno)[rpos] = blk;
502 	}
503 next:
504 	/*
505 	 * Compute/validate number of cylinder groups.
506 	 */
507 	sblock.fs_ncg = sblock.fs_ncyl / sblock.fs_cpg;
508 	if (sblock.fs_ncyl % sblock.fs_cpg)
509 		sblock.fs_ncg++;
510 	sblock.fs_dblkno = sblock.fs_iblkno + sblock.fs_ipg / INOPF(&sblock);
511 	i = MIN(~sblock.fs_cgmask, sblock.fs_ncg - 1);
512 	if (cgdmin(&sblock, i) - cgbase(&sblock, i) >= sblock.fs_fpg) {
513 		printf("inode blocks/cyl group (%d) >= data blocks (%d)\n",
514 		    cgdmin(&sblock, i) - cgbase(&sblock, i) / sblock.fs_frag,
515 		    sblock.fs_fpg / sblock.fs_frag);
516 		printf("number of cylinders per cylinder group (%d) %s.\n",
517 		    sblock.fs_cpg, "must be increased");
518 		exit(29);
519 	}
520 	j = sblock.fs_ncg - 1;
521 	if ((i = fssize - j * sblock.fs_fpg) < sblock.fs_fpg &&
522 	    cgdmin(&sblock, j) - cgbase(&sblock, j) > i) {
523 		if (j == 0) {
524 			printf("Filesystem must have at least %d sectors\n",
525 			    NSPF(&sblock) *
526 			    (cgdmin(&sblock, 0) + 3 * sblock.fs_frag));
527 			exit(30);
528 		}
529 		printf("Warning: inode blocks/cyl group (%d) >= data blocks (%d) in last\n",
530 		    (cgdmin(&sblock, j) - cgbase(&sblock, j)) / sblock.fs_frag,
531 		    i / sblock.fs_frag);
532 		printf("    cylinder group. This implies %d sector(s) cannot be allocated.\n",
533 		    i * NSPF(&sblock));
534 		sblock.fs_ncg--;
535 		sblock.fs_ncyl -= sblock.fs_ncyl % sblock.fs_cpg;
536 		sblock.fs_size = fssize = sblock.fs_ncyl * sblock.fs_spc /
537 		    NSPF(&sblock);
538 		warn = 0;
539 	}
540 	if (warn && !mfs) {
541 		printf("Warning: %d sector(s) in last cylinder unallocated\n",
542 		    sblock.fs_spc -
543 		    (fssize * NSPF(&sblock) - (sblock.fs_ncyl - 1)
544 		    * sblock.fs_spc));
545 	}
546 	/*
547 	 * fill in remaining fields of the super block
548 	 */
549 	sblock.fs_csaddr = cgdmin(&sblock, 0);
550 	sblock.fs_cssize =
551 	    fragroundup(&sblock, sblock.fs_ncg * sizeof(struct csum));
552 	i = sblock.fs_bsize / sizeof(struct csum);
553 	sblock.fs_csmask = ~(i - 1);
554 	for (sblock.fs_csshift = 0; i > 1; i >>= 1)
555 		sblock.fs_csshift++;
556 	fscs = (struct csum *)calloc(1, sblock.fs_cssize);
557 	sblock.fs_magic = FS_MAGIC;
558 	sblock.fs_rotdelay = rotdelay;
559 	sblock.fs_minfree = minfree;
560 	sblock.fs_maxcontig = maxcontig;
561 	sblock.fs_headswitch = headswitch;
562 	sblock.fs_trkseek = trackseek;
563 	sblock.fs_maxbpg = maxbpg;
564 	sblock.fs_rps = rpm / 60;
565 	sblock.fs_optim = opt;
566 	sblock.fs_cgrotor = 0;
567 	sblock.fs_cstotal.cs_ndir = 0;
568 	sblock.fs_cstotal.cs_nbfree = 0;
569 	sblock.fs_cstotal.cs_nifree = 0;
570 	sblock.fs_cstotal.cs_nffree = 0;
571 	sblock.fs_fmod = 0;
572 	sblock.fs_clean = FS_ISCLEAN;
573 	sblock.fs_ronly = 0;
574 	/*
575 	 * Dump out summary information about file system.
576 	 */
577 	if (!mfs) {
578 		printf("%s:\t%d sectors in %d %s of %d tracks, %d sectors\n",
579 		    fsys, sblock.fs_size * NSPF(&sblock), sblock.fs_ncyl,
580 		    "cylinders", sblock.fs_ntrak, sblock.fs_nsect);
581 #define B2MBFACTOR (1 / (1024.0 * 1024.0))
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 * B2MBFACTOR,
584 		    sblock.fs_ncg, sblock.fs_cpg,
585 		    (float)sblock.fs_fpg * sblock.fs_fsize * B2MBFACTOR,
586 		    sblock.fs_ipg);
587 #undef B2MBFACTOR
588 	}
589 	/*
590 	 * Now build the cylinders group blocks and
591 	 * then print out indices of cylinder groups.
592 	 */
593 	if (!mfs)
594 		printf("super-block backups (for fsck -b #) at:");
595 	for (cylno = 0; cylno < sblock.fs_ncg; cylno++) {
596 		initcg(cylno, utime);
597 		if (mfs)
598 			continue;
599 		if (cylno % 8 == 0)
600 			printf("\n");
601 		printf(" %d,", fsbtodb(&sblock, cgsblock(&sblock, cylno)));
602 		fflush(stderr);
603 	}
604 	if (!mfs)
605 		printf("\n");
606 	if (Nflag && !mfs)
607 		exit(0);
608 	/*
609 	 * Now construct the initial file system,
610 	 * then write out the super-block.
611 	 */
612 	fsinit(utime);
613 	sblock.fs_time = utime;
614 	wtfs((int)SBOFF / sectorsize, sbsize, (char *)&sblock);
615 	for (i = 0; i < sblock.fs_cssize; i += sblock.fs_bsize)
616 		wtfs(fsbtodb(&sblock, sblock.fs_csaddr + numfrags(&sblock, i)),
617 			sblock.fs_cssize - i < sblock.fs_bsize ?
618 			    sblock.fs_cssize - i : sblock.fs_bsize,
619 			((char *)fscs) + i);
620 	/*
621 	 * Write out the duplicate super blocks
622 	 */
623 	for (cylno = 0; cylno < sblock.fs_ncg; cylno++)
624 		wtfs(fsbtodb(&sblock, cgsblock(&sblock, cylno)),
625 		    sbsize, (char *)&sblock);
626 	/*
627 	 * Update information about this partion in pack
628 	 * label, to that it may be updated on disk.
629 	 */
630 	pp->p_fstype = FS_BSDFFS;
631 	pp->p_fsize = sblock.fs_fsize;
632 	pp->p_frag = sblock.fs_frag;
633 	pp->p_cpg = sblock.fs_cpg;
634 	/*
635 	 * Notify parent process of success.
636 	 * Dissociate from session and tty.
637 	 */
638 	if (mfs) {
639 		kill(ppid, SIGUSR1);
640 		(void) setsid();
641 		(void) close(0);
642 		(void) close(1);
643 		(void) close(2);
644 		(void) chdir("/");
645 	}
646 }
647 
648 /*
649  * Initialize a cylinder group.
650  */
651 initcg(cylno, utime)
652 	int cylno;
653 	time_t utime;
654 {
655 	daddr_t cbase, d, dlower, dupper, dmax, blkno;
656 	long i, j, s;
657 	register struct csum *cs;
658 
659 	/*
660 	 * Determine block bounds for cylinder group.
661 	 * Allow space for super block summary information in first
662 	 * cylinder group.
663 	 */
664 	cbase = cgbase(&sblock, cylno);
665 	dmax = cbase + sblock.fs_fpg;
666 	if (dmax > sblock.fs_size)
667 		dmax = sblock.fs_size;
668 	dlower = cgsblock(&sblock, cylno) - cbase;
669 	dupper = cgdmin(&sblock, cylno) - cbase;
670 	if (cylno == 0)
671 		dupper += howmany(sblock.fs_cssize, sblock.fs_fsize);
672 	cs = fscs + cylno;
673 	memset(&acg, 0, sblock.fs_cgsize);
674 	acg.cg_time = utime;
675 	acg.cg_magic = CG_MAGIC;
676 	acg.cg_cgx = cylno;
677 	if (cylno == sblock.fs_ncg - 1)
678 		acg.cg_ncyl = sblock.fs_ncyl % sblock.fs_cpg;
679 	else
680 		acg.cg_ncyl = sblock.fs_cpg;
681 	acg.cg_niblk = sblock.fs_ipg;
682 	acg.cg_ndblk = dmax - cbase;
683 	if (sblock.fs_contigsumsize > 0)
684 		acg.cg_nclusterblks = acg.cg_ndblk / sblock.fs_frag;
685 	acg.cg_btotoff = &acg.cg_space[0] - (u_char *)(&acg.cg_firstfield);
686 	acg.cg_boff = acg.cg_btotoff + sblock.fs_cpg * sizeof(int32_t);
687 	acg.cg_iusedoff = acg.cg_boff +
688 		sblock.fs_cpg * sblock.fs_nrpos * sizeof(int16_t);
689 	acg.cg_freeoff = acg.cg_iusedoff + howmany(sblock.fs_ipg, NBBY);
690 	if (sblock.fs_contigsumsize <= 0) {
691 		acg.cg_nextfreeoff = acg.cg_freeoff +
692 		   howmany(sblock.fs_cpg * sblock.fs_spc / NSPF(&sblock), NBBY);
693 	} else {
694 		acg.cg_clustersumoff = acg.cg_freeoff + howmany
695 		    (sblock.fs_cpg * sblock.fs_spc / NSPF(&sblock), NBBY) -
696 		    sizeof(int32_t);
697 		acg.cg_clustersumoff =
698 		    roundup(acg.cg_clustersumoff, sizeof(int32_t));
699 		acg.cg_clusteroff = acg.cg_clustersumoff +
700 		    (sblock.fs_contigsumsize + 1) * sizeof(int32_t);
701 		acg.cg_nextfreeoff = acg.cg_clusteroff + howmany
702 		    (sblock.fs_cpg * sblock.fs_spc / NSPB(&sblock), NBBY);
703 	}
704 	if (acg.cg_nextfreeoff - (long)(&acg.cg_firstfield) > sblock.fs_cgsize) {
705 		printf("Panic: cylinder group too big\n");
706 		exit(37);
707 	}
708 	acg.cg_cs.cs_nifree += sblock.fs_ipg;
709 	if (cylno == 0)
710 		for (i = 0; i < ROOTINO; i++) {
711 			setbit(cg_inosused(&acg), i);
712 			acg.cg_cs.cs_nifree--;
713 		}
714 	for (i = 0; i < sblock.fs_ipg / INOPF(&sblock); i += sblock.fs_frag)
715 		wtfs(fsbtodb(&sblock, cgimin(&sblock, cylno) + i),
716 		    sblock.fs_bsize, (char *)zino);
717 	if (cylno > 0) {
718 		/*
719 		 * In cylno 0, beginning space is reserved
720 		 * for boot and super blocks.
721 		 */
722 		for (d = 0; d < dlower; d += sblock.fs_frag) {
723 			blkno = d / sblock.fs_frag;
724 			setblock(&sblock, cg_blksfree(&acg), blkno);
725 			if (sblock.fs_contigsumsize > 0)
726 				setbit(cg_clustersfree(&acg), blkno);
727 			acg.cg_cs.cs_nbfree++;
728 			cg_blktot(&acg)[cbtocylno(&sblock, d)]++;
729 			cg_blks(&sblock, &acg, cbtocylno(&sblock, d))
730 			    [cbtorpos(&sblock, d)]++;
731 		}
732 		sblock.fs_dsize += dlower;
733 	}
734 	sblock.fs_dsize += acg.cg_ndblk - dupper;
735 	if (i = dupper % sblock.fs_frag) {
736 		acg.cg_frsum[sblock.fs_frag - i]++;
737 		for (d = dupper + sblock.fs_frag - i; dupper < d; dupper++) {
738 			setbit(cg_blksfree(&acg), dupper);
739 			acg.cg_cs.cs_nffree++;
740 		}
741 	}
742 	for (d = dupper; d + sblock.fs_frag <= dmax - cbase; ) {
743 		blkno = d / sblock.fs_frag;
744 		setblock(&sblock, cg_blksfree(&acg), blkno);
745 		if (sblock.fs_contigsumsize > 0)
746 			setbit(cg_clustersfree(&acg), blkno);
747 		acg.cg_cs.cs_nbfree++;
748 		cg_blktot(&acg)[cbtocylno(&sblock, d)]++;
749 		cg_blks(&sblock, &acg, cbtocylno(&sblock, d))
750 		    [cbtorpos(&sblock, d)]++;
751 		d += sblock.fs_frag;
752 	}
753 	if (d < dmax - cbase) {
754 		acg.cg_frsum[dmax - cbase - d]++;
755 		for (; d < dmax - cbase; d++) {
756 			setbit(cg_blksfree(&acg), d);
757 			acg.cg_cs.cs_nffree++;
758 		}
759 	}
760 	if (sblock.fs_contigsumsize > 0) {
761 		int32_t *sump = cg_clustersum(&acg);
762 		u_char *mapp = cg_clustersfree(&acg);
763 		int map = *mapp++;
764 		int bit = 1;
765 		int run = 0;
766 
767 		for (i = 0; i < acg.cg_nclusterblks; i++) {
768 			if ((map & bit) != 0) {
769 				run++;
770 			} else if (run != 0) {
771 				if (run > sblock.fs_contigsumsize)
772 					run = sblock.fs_contigsumsize;
773 				sump[run]++;
774 				run = 0;
775 			}
776 			if ((i & (NBBY - 1)) != (NBBY - 1)) {
777 				bit <<= 1;
778 			} else {
779 				map = *mapp++;
780 				bit = 1;
781 			}
782 		}
783 		if (run != 0) {
784 			if (run > sblock.fs_contigsumsize)
785 				run = sblock.fs_contigsumsize;
786 			sump[run]++;
787 		}
788 	}
789 	sblock.fs_cstotal.cs_ndir += acg.cg_cs.cs_ndir;
790 	sblock.fs_cstotal.cs_nffree += acg.cg_cs.cs_nffree;
791 	sblock.fs_cstotal.cs_nbfree += acg.cg_cs.cs_nbfree;
792 	sblock.fs_cstotal.cs_nifree += acg.cg_cs.cs_nifree;
793 	*cs = acg.cg_cs;
794 	wtfs(fsbtodb(&sblock, cgtod(&sblock, cylno)),
795 		sblock.fs_bsize, (char *)&acg);
796 }
797 
798 /*
799  * initialize the file system
800  */
801 struct dinode node;
802 
803 #ifdef LOSTDIR
804 #define PREDEFDIR 3
805 #else
806 #define PREDEFDIR 2
807 #endif
808 
809 struct direct root_dir[] = {
810 	{ ROOTINO, sizeof(struct direct), DT_DIR, 1, "." },
811 	{ ROOTINO, sizeof(struct direct), DT_DIR, 2, ".." },
812 #ifdef LOSTDIR
813 	{ LOSTFOUNDINO, sizeof(struct direct), DT_DIR, 10, "lost+found" },
814 #endif
815 };
816 struct odirect {
817 	u_int32_t d_ino;
818 	u_int16_t d_reclen;
819 	u_int16_t d_namlen;
820 	u_char	d_name[MAXNAMLEN + 1];
821 } oroot_dir[] = {
822 	{ ROOTINO, sizeof(struct direct), 1, "." },
823 	{ ROOTINO, sizeof(struct direct), 2, ".." },
824 #ifdef LOSTDIR
825 	{ LOSTFOUNDINO, sizeof(struct direct), 10, "lost+found" },
826 #endif
827 };
828 #ifdef LOSTDIR
829 struct direct lost_found_dir[] = {
830 	{ LOSTFOUNDINO, sizeof(struct direct), DT_DIR, 1, "." },
831 	{ ROOTINO, sizeof(struct direct), DT_DIR, 2, ".." },
832 	{ 0, DIRBLKSIZ, 0, 0, 0 },
833 };
834 struct odirect olost_found_dir[] = {
835 	{ LOSTFOUNDINO, sizeof(struct direct), 1, "." },
836 	{ ROOTINO, sizeof(struct direct), 2, ".." },
837 	{ 0, DIRBLKSIZ, 0, 0 },
838 };
839 #endif
840 char buf[MAXBSIZE];
841 
842 fsinit(utime)
843 	time_t utime;
844 {
845 	int i;
846 
847 	/*
848 	 * initialize the node
849 	 */
850 	node.di_atime.ts_sec = utime;
851 	node.di_mtime.ts_sec = utime;
852 	node.di_ctime.ts_sec = utime;
853 #ifdef LOSTDIR
854 	/*
855 	 * create the lost+found directory
856 	 */
857 	if (Oflag) {
858 		(void)makedir((struct direct *)olost_found_dir, 2);
859 		for (i = DIRBLKSIZ; i < sblock.fs_bsize; i += DIRBLKSIZ)
860 			memcpy(&buf[i], &olost_found_dir[2],
861 			    DIRSIZ(0, &olost_found_dir[2]));
862 	} else {
863 		(void)makedir(lost_found_dir, 2);
864 		for (i = DIRBLKSIZ; i < sblock.fs_bsize; i += DIRBLKSIZ)
865 			memcpy(&buf[i], &lost_found_dir[2],
866 			    DIRSIZ(0, &lost_found_dir[2]));
867 	}
868 	node.di_mode = IFDIR | UMASK;
869 	node.di_nlink = 2;
870 	node.di_size = sblock.fs_bsize;
871 	node.di_db[0] = alloc(node.di_size, node.di_mode);
872 	node.di_blocks = btodb(fragroundup(&sblock, node.di_size));
873 	wtfs(fsbtodb(&sblock, node.di_db[0]), node.di_size, buf);
874 	iput(&node, LOSTFOUNDINO);
875 #endif
876 	/*
877 	 * create the root directory
878 	 */
879 	if (mfs)
880 		node.di_mode = IFDIR | 01777;
881 	else
882 		node.di_mode = IFDIR | UMASK;
883 	node.di_nlink = PREDEFDIR;
884 	if (Oflag)
885 		node.di_size = makedir((struct direct *)oroot_dir, PREDEFDIR);
886 	else
887 		node.di_size = makedir(root_dir, PREDEFDIR);
888 	node.di_db[0] = alloc(sblock.fs_fsize, node.di_mode);
889 	node.di_blocks = btodb(fragroundup(&sblock, node.di_size));
890 	wtfs(fsbtodb(&sblock, node.di_db[0]), sblock.fs_fsize, buf);
891 	iput(&node, ROOTINO);
892 }
893 
894 /*
895  * construct a set of directory entries in "buf".
896  * return size of directory.
897  */
898 makedir(protodir, entries)
899 	register struct direct *protodir;
900 	int entries;
901 {
902 	char *cp;
903 	int i, spcleft;
904 
905 	spcleft = DIRBLKSIZ;
906 	for (cp = buf, i = 0; i < entries - 1; i++) {
907 		protodir[i].d_reclen = DIRSIZ(0, &protodir[i]);
908 		memcpy(cp, &protodir[i], protodir[i].d_reclen);
909 		cp += protodir[i].d_reclen;
910 		spcleft -= protodir[i].d_reclen;
911 	}
912 	protodir[i].d_reclen = spcleft;
913 	memcpy(cp, &protodir[i], DIRSIZ(0, &protodir[i]));
914 	return (DIRBLKSIZ);
915 }
916 
917 /*
918  * allocate a block or frag
919  */
920 daddr_t
921 alloc(size, mode)
922 	int size;
923 	int mode;
924 {
925 	int i, frag;
926 	daddr_t d, blkno;
927 
928 	rdfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
929 	    (char *)&acg);
930 	if (acg.cg_magic != CG_MAGIC) {
931 		printf("cg 0: bad magic number\n");
932 		return (0);
933 	}
934 	if (acg.cg_cs.cs_nbfree == 0) {
935 		printf("first cylinder group ran out of space\n");
936 		return (0);
937 	}
938 	for (d = 0; d < acg.cg_ndblk; d += sblock.fs_frag)
939 		if (isblock(&sblock, cg_blksfree(&acg), d / sblock.fs_frag))
940 			goto goth;
941 	printf("internal error: can't find block in cyl 0\n");
942 	return (0);
943 goth:
944 	blkno = fragstoblks(&sblock, d);
945 	clrblock(&sblock, cg_blksfree(&acg), blkno);
946 	if (sblock.fs_contigsumsize > 0)
947 		clrbit(cg_clustersfree(&acg), blkno);
948 	acg.cg_cs.cs_nbfree--;
949 	sblock.fs_cstotal.cs_nbfree--;
950 	fscs[0].cs_nbfree--;
951 	if (mode & IFDIR) {
952 		acg.cg_cs.cs_ndir++;
953 		sblock.fs_cstotal.cs_ndir++;
954 		fscs[0].cs_ndir++;
955 	}
956 	cg_blktot(&acg)[cbtocylno(&sblock, d)]--;
957 	cg_blks(&sblock, &acg, cbtocylno(&sblock, d))[cbtorpos(&sblock, d)]--;
958 	if (size != sblock.fs_bsize) {
959 		frag = howmany(size, sblock.fs_fsize);
960 		fscs[0].cs_nffree += sblock.fs_frag - frag;
961 		sblock.fs_cstotal.cs_nffree += sblock.fs_frag - frag;
962 		acg.cg_cs.cs_nffree += sblock.fs_frag - frag;
963 		acg.cg_frsum[sblock.fs_frag - frag]++;
964 		for (i = frag; i < sblock.fs_frag; i++)
965 			setbit(cg_blksfree(&acg), d + i);
966 	}
967 	wtfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
968 	    (char *)&acg);
969 	return (d);
970 }
971 
972 /*
973  * Allocate an inode on the disk
974  */
975 iput(ip, ino)
976 	register struct dinode *ip;
977 	register ino_t ino;
978 {
979 	struct dinode buf[MAXINOPB];
980 	daddr_t d;
981 	int c;
982 
983 	c = ino_to_cg(&sblock, ino);
984 	rdfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
985 	    (char *)&acg);
986 	if (acg.cg_magic != CG_MAGIC) {
987 		printf("cg 0: bad magic number\n");
988 		exit(31);
989 	}
990 	acg.cg_cs.cs_nifree--;
991 	setbit(cg_inosused(&acg), ino);
992 	wtfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
993 	    (char *)&acg);
994 	sblock.fs_cstotal.cs_nifree--;
995 	fscs[0].cs_nifree--;
996 	if (ino >= sblock.fs_ipg * sblock.fs_ncg) {
997 		printf("fsinit: inode value out of range (%d).\n", ino);
998 		exit(32);
999 	}
1000 	d = fsbtodb(&sblock, ino_to_fsba(&sblock, ino));
1001 	rdfs(d, sblock.fs_bsize, buf);
1002 	buf[ino_to_fsbo(&sblock, ino)] = *ip;
1003 	wtfs(d, sblock.fs_bsize, buf);
1004 }
1005 
1006 /*
1007  * Notify parent process that the filesystem has created itself successfully.
1008  */
1009 void
1010 started()
1011 {
1012 
1013 	exit(0);
1014 }
1015 
1016 /*
1017  * Replace libc function with one suited to our needs.
1018  */
1019 caddr_t
1020 malloc(size)
1021 	register u_long size;
1022 {
1023 	char *base, *i;
1024 	static u_long pgsz;
1025 	struct rlimit rlp;
1026 
1027 	if (pgsz == 0) {
1028 		base = sbrk(0);
1029 		pgsz = getpagesize() - 1;
1030 		i = (char *)((u_long)(base + pgsz) &~ pgsz);
1031 		base = sbrk(i - base);
1032 		if (getrlimit(RLIMIT_DATA, &rlp) < 0)
1033 			perror("getrlimit");
1034 		rlp.rlim_cur = rlp.rlim_max;
1035 		if (setrlimit(RLIMIT_DATA, &rlp) < 0)
1036 			perror("setrlimit");
1037 		memleft = rlp.rlim_max - (u_long)base;
1038 	}
1039 	size = (size + pgsz) &~ pgsz;
1040 	if (size > memleft)
1041 		size = memleft;
1042 	memleft -= size;
1043 	if (size == 0)
1044 		return (0);
1045 	return ((caddr_t)sbrk(size));
1046 }
1047 
1048 /*
1049  * Replace libc function with one suited to our needs.
1050  */
1051 caddr_t
1052 realloc(ptr, size)
1053 	char *ptr;
1054 	u_long size;
1055 {
1056 	void *p;
1057 
1058 	if ((p = malloc(size)) == NULL)
1059 		return (NULL);
1060 	memcpy(p, ptr, size);
1061 	free(ptr);
1062 	return (p);
1063 }
1064 
1065 /*
1066  * Replace libc function with one suited to our needs.
1067  */
1068 char *
1069 calloc(size, numelm)
1070 	u_long size, numelm;
1071 {
1072 	caddr_t base;
1073 
1074 	size *= numelm;
1075 	base = malloc(size);
1076 	memset(base, 0, size);
1077 	return (base);
1078 }
1079 
1080 /*
1081  * Replace libc function with one suited to our needs.
1082  */
1083 free(ptr)
1084 	char *ptr;
1085 {
1086 
1087 	/* do not worry about it for now */
1088 }
1089 
1090 /*
1091  * read a block from the file system
1092  */
1093 rdfs(bno, size, bf)
1094 	daddr_t bno;
1095 	int size;
1096 	char *bf;
1097 {
1098 	int n;
1099 	off_t offset;
1100 
1101 	if (mfs) {
1102 		memcpy(bf, membase + bno * sectorsize, size);
1103 		return;
1104 	}
1105 	offset = bno;
1106 	offset *= sectorsize;
1107 	if (lseek(fsi, offset, SEEK_SET) < 0) {
1108 		printf("seek error: %ld\n", bno);
1109 		perror("rdfs");
1110 		exit(33);
1111 	}
1112 	n = read(fsi, bf, size);
1113 	if (n != size) {
1114 		printf("read error: %ld\n", bno);
1115 		perror("rdfs");
1116 		exit(34);
1117 	}
1118 }
1119 
1120 /*
1121  * write a block to the file system
1122  */
1123 wtfs(bno, size, bf)
1124 	daddr_t bno;
1125 	int size;
1126 	char *bf;
1127 {
1128 	int n;
1129 	off_t offset;
1130 
1131 	if (mfs) {
1132 		memcpy(membase + bno * sectorsize, bf, size);
1133 		return;
1134 	}
1135 	if (Nflag)
1136 		return;
1137 	offset = bno;
1138 	offset *= sectorsize;
1139 	if (lseek(fso, offset, SEEK_SET) < 0) {
1140 		printf("seek error: %ld\n", bno);
1141 		perror("wtfs");
1142 		exit(35);
1143 	}
1144 	n = write(fso, bf, size);
1145 	if (n != size) {
1146 		printf("write error: %ld\n", bno);
1147 		perror("wtfs");
1148 		exit(36);
1149 	}
1150 }
1151 
1152 /*
1153  * check if a block is available
1154  */
1155 isblock(fs, cp, h)
1156 	struct fs *fs;
1157 	unsigned char *cp;
1158 	int h;
1159 {
1160 	unsigned char mask;
1161 
1162 	switch (fs->fs_frag) {
1163 	case 8:
1164 		return (cp[h] == 0xff);
1165 	case 4:
1166 		mask = 0x0f << ((h & 0x1) << 2);
1167 		return ((cp[h >> 1] & mask) == mask);
1168 	case 2:
1169 		mask = 0x03 << ((h & 0x3) << 1);
1170 		return ((cp[h >> 2] & mask) == mask);
1171 	case 1:
1172 		mask = 0x01 << (h & 0x7);
1173 		return ((cp[h >> 3] & mask) == mask);
1174 	default:
1175 #ifdef STANDALONE
1176 		printf("isblock bad fs_frag %d\n", fs->fs_frag);
1177 #else
1178 		fprintf(stderr, "isblock bad fs_frag %d\n", fs->fs_frag);
1179 #endif
1180 		return (0);
1181 	}
1182 }
1183 
1184 /*
1185  * take a block out of the map
1186  */
1187 clrblock(fs, cp, h)
1188 	struct fs *fs;
1189 	unsigned char *cp;
1190 	int h;
1191 {
1192 	switch ((fs)->fs_frag) {
1193 	case 8:
1194 		cp[h] = 0;
1195 		return;
1196 	case 4:
1197 		cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
1198 		return;
1199 	case 2:
1200 		cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
1201 		return;
1202 	case 1:
1203 		cp[h >> 3] &= ~(0x01 << (h & 0x7));
1204 		return;
1205 	default:
1206 #ifdef STANDALONE
1207 		printf("clrblock bad fs_frag %d\n", fs->fs_frag);
1208 #else
1209 		fprintf(stderr, "clrblock bad fs_frag %d\n", fs->fs_frag);
1210 #endif
1211 		return;
1212 	}
1213 }
1214 
1215 /*
1216  * put a block into the map
1217  */
1218 setblock(fs, cp, h)
1219 	struct fs *fs;
1220 	unsigned char *cp;
1221 	int h;
1222 {
1223 	switch (fs->fs_frag) {
1224 	case 8:
1225 		cp[h] = 0xff;
1226 		return;
1227 	case 4:
1228 		cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
1229 		return;
1230 	case 2:
1231 		cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
1232 		return;
1233 	case 1:
1234 		cp[h >> 3] |= (0x01 << (h & 0x7));
1235 		return;
1236 	default:
1237 #ifdef STANDALONE
1238 		printf("setblock bad fs_frag %d\n", fs->fs_frag);
1239 #else
1240 		fprintf(stderr, "setblock bad fs_frag %d\n", fs->fs_frag);
1241 #endif
1242 		return;
1243 	}
1244 }
1245