xref: /netbsd-src/usr.sbin/makefs/ffs/mkfs.c (revision 9fbd88883c38d0c0fbfcbe66d76fe6b0fab3f9de)
1 /*	$NetBSD: mkfs.c,v 1.9 2002/01/31 22:44:04 tv Exp $	*/
2 /* From NetBSD: mkfs.c,v 1.59 2001/12/31 07:07:58 lukem Exp $	*/
3 
4 /*
5  * Copyright (c) 1980, 1989, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *	This product includes software developed by the University of
19  *	California, Berkeley and its contributors.
20  * 4. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #include <sys/cdefs.h>
38 #if defined(__RCSID) && !defined(lint)
39 #if 0
40 static char sccsid[] = "@(#)mkfs.c	8.11 (Berkeley) 5/3/95";
41 #else
42 __RCSID("$NetBSD: mkfs.c,v 1.9 2002/01/31 22:44:04 tv Exp $");
43 #endif
44 #endif /* not lint */
45 
46 #include <sys/param.h>
47 #include <sys/time.h>
48 #include <sys/resource.h>
49 
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <unistd.h>
54 
55 #include "makefs.h"
56 
57 #include <ufs/ufs/dinode.h>
58 #include <ufs/ufs/dir.h>
59 #include <ufs/ufs/ufs_bswap.h>
60 #include <ufs/ffs/fs.h>
61 
62 #include "ffs/ufs_inode.h"
63 #include "ffs/ffs_extern.h"
64 #include "ffs/newfs_extern.h"
65 
66 static void initcg(int, time_t, const fsinfo_t *);
67 static int32_t calcipg(int32_t, int32_t, off_t *);
68 static void swap_cg(struct cg *, struct cg *);
69 
70 static int count_digits(int);
71 
72 /*
73  * make file system for cylinder-group style file systems
74  */
75 
76 /*
77  * We limit the size of the inode map to be no more than a
78  * third of the cylinder group space, since we must leave at
79  * least an equal amount of space for the block map.
80  *
81  * N.B.: MAXIPG must be a multiple of INOPB(fs).
82  */
83 #define MAXIPG(fs)	roundup((fs)->fs_bsize * NBBY / 3, INOPB(fs))
84 
85 #define UMASK		0755
86 #define POWEROF2(num)	(((num) & ((num) - 1)) == 0)
87 
88 union {
89 	struct fs fs;
90 	char pad[SBSIZE];
91 } fsun;
92 #define	sblock	fsun.fs
93 
94 union {
95 	struct cg cg;
96 	char pad[MAXBSIZE];
97 } cgun;
98 #define	acg	cgun.cg
99 
100 struct dinode zino[MAXBSIZE / DINODE_SIZE];
101 
102 char writebuf[MAXBSIZE];
103 
104 static	int	Oflag;		/* format as an 4.3BSD file system */
105 static	int	fssize;		/* file system size */
106 static	int	ntracks;	/* # tracks/cylinder */
107 static	int	nsectors;	/* # sectors/track */
108 static	int	nphyssectors;	/* # sectors/track including spares */
109 static	int	secpercyl;	/* sectors per cylinder */
110 static	int	sectorsize;	/* bytes/sector */
111 static	int	rpm;		/* revolutions/minute of drive */
112 static	int	interleave;	/* hardware sector interleave */
113 static	int	trackskew;	/* sector 0 skew, per track */
114 static	int	fsize;		/* fragment size */
115 static	int	bsize;		/* block size */
116 static	int	cpg;		/* cylinders/cylinder group */
117 static	int	cpgflg;		/* cylinders/cylinder group flag was given */
118 static	int	minfree;	/* free space threshold */
119 static	int	opt;		/* optimization preference (space or time) */
120 static	int	density;	/* number of bytes per inode */
121 static	int	maxcontig;	/* max contiguous blocks to allocate */
122 static	int	rotdelay;	/* rotational delay between blocks */
123 static	int	maxbpg;		/* maximum blocks per file in a cyl group */
124 static	int	nrpos;		/* # of distinguished rotational positions */
125 static	int	bbsize;		/* boot block size */
126 static	int	sbsize;		/* superblock size */
127 static	int	avgfilesize;	/* expected average file size */
128 static	int	avgfpdir;	/* expected number of files per directory */
129 
130 
131 struct fs *
132 ffs_mkfs(const char *fsys, const fsinfo_t *fsopts)
133 {
134 	int32_t i, mincpc, mincpg, inospercg;
135 	int32_t cylno, rpos, blk, j, warned = 0;
136 	int32_t used, mincpgcnt, bpcg;
137 	off_t usedb;
138 	int32_t mapcramped, inodecramped;
139 	int32_t postblsize, rotblsize, totalsbsize;
140 	long long sizepb;
141 	void *space;
142 	int size, blks;
143 	int nprintcols, printcolwidth;
144 
145 	Oflag = 0;
146 	fssize =	fsopts->size / fsopts->sectorsize;
147 	ntracks =	fsopts->ntracks;
148 	nsectors =	fsopts->nsectors;
149 	nphyssectors =	fsopts->nsectors;	/* XXX: no trackspares */
150 	secpercyl =	nsectors * ntracks;
151 	sectorsize =	fsopts->sectorsize;
152 	rpm =		fsopts->rpm;
153 	interleave =	1;
154 	trackskew =	0;
155 	fsize =		fsopts->fsize;
156 	bsize =		fsopts->bsize;
157 	cpg =		fsopts->cpg;
158 	cpgflg =	fsopts->cpgflg;
159 	minfree =	fsopts->minfree;
160 	opt =		fsopts->optimization;
161 	density =	fsopts->density;
162 	maxcontig =	fsopts->maxcontig;
163 	rotdelay =	fsopts->rotdelay;
164 	maxbpg =	fsopts->maxbpg;
165 	nrpos =		fsopts->nrpos;
166 	bbsize =	BBSIZE;
167 	sbsize =	SBSIZE;
168 	avgfilesize = 	fsopts->avgfilesize;
169 	avgfpdir = 	fsopts->avgfpdir;
170 
171 	if (Oflag) {
172 		sblock.fs_inodefmt = FS_42INODEFMT;
173 		sblock.fs_maxsymlinklen = 0;
174 	} else {
175 		sblock.fs_inodefmt = FS_44INODEFMT;
176 		sblock.fs_maxsymlinklen = MAXSYMLINKLEN;
177 	}
178 	/*
179 	 * Validate the given file system size.
180 	 * Verify that its last block can actually be accessed.
181 	 */
182 	if (fssize <= 0)
183 		printf("preposterous size %d\n", fssize), exit(13);
184 	ffs_wtfs(fssize - 1, sectorsize, (char *)&sblock, fsopts);
185 
186 	/*
187 	 * collect and verify the sector and track info
188 	 */
189 	sblock.fs_nsect = nsectors;
190 	sblock.fs_ntrak = ntracks;
191 	if (sblock.fs_ntrak <= 0)
192 		printf("preposterous ntrak %d\n", sblock.fs_ntrak), exit(14);
193 	if (sblock.fs_nsect <= 0)
194 		printf("preposterous nsect %d\n", sblock.fs_nsect), exit(15);
195 	/*
196 	 * collect and verify the filesystem density info
197 	 */
198 	sblock.fs_avgfilesize = avgfilesize;
199 	sblock.fs_avgfpdir = avgfpdir;
200 	if (sblock.fs_avgfilesize <= 0)
201 		printf("illegal expected average file size %d\n",
202 		    sblock.fs_avgfilesize), exit(14);
203 	if (sblock.fs_avgfpdir <= 0)
204 		printf("illegal expected number of files per directory %d\n",
205 		    sblock.fs_avgfpdir), exit(15);
206 	/*
207 	 * collect and verify the block and fragment sizes
208 	 */
209 	sblock.fs_bsize = bsize;
210 	sblock.fs_fsize = fsize;
211 	if (!POWEROF2(sblock.fs_bsize)) {
212 		printf("block size must be a power of 2, not %d\n",
213 		    sblock.fs_bsize);
214 		exit(16);
215 	}
216 	if (!POWEROF2(sblock.fs_fsize)) {
217 		printf("fragment size must be a power of 2, not %d\n",
218 		    sblock.fs_fsize);
219 		exit(17);
220 	}
221 	if (sblock.fs_fsize < sectorsize) {
222 		printf("fragment size %d is too small, minimum is %d\n",
223 		    sblock.fs_fsize, sectorsize);
224 		exit(18);
225 	}
226 	if (sblock.fs_bsize > MAXBSIZE) {
227 		printf("block size %d is too large, maximum is %d\n",
228 		    sblock.fs_bsize, MAXBSIZE);
229 		exit(19);
230 	}
231 	if (sblock.fs_bsize < MINBSIZE) {
232 		printf("block size %d is too small, minimum is %d\n",
233 		    sblock.fs_bsize, MINBSIZE);
234 		exit(19);
235 	}
236 	if (sblock.fs_bsize < sblock.fs_fsize) {
237 		printf("block size (%d) cannot be smaller than fragment size (%d)\n",
238 		    sblock.fs_bsize, sblock.fs_fsize);
239 		exit(20);
240 	}
241 	sblock.fs_bmask = ~(sblock.fs_bsize - 1);
242 	sblock.fs_fmask = ~(sblock.fs_fsize - 1);
243 	sblock.fs_qbmask = ~sblock.fs_bmask;
244 	sblock.fs_qfmask = ~sblock.fs_fmask;
245 	for (sblock.fs_bshift = 0, i = sblock.fs_bsize; i > 1; i >>= 1)
246 		sblock.fs_bshift++;
247 	for (sblock.fs_fshift = 0, i = sblock.fs_fsize; i > 1; i >>= 1)
248 		sblock.fs_fshift++;
249 	sblock.fs_frag = numfrags(&sblock, sblock.fs_bsize);
250 	for (sblock.fs_fragshift = 0, i = sblock.fs_frag; i > 1; i >>= 1)
251 		sblock.fs_fragshift++;
252 	if (sblock.fs_frag > MAXFRAG) {
253 		printf("fragment size %d is too small, "
254 			"minimum with block size %d is %d\n",
255 		    sblock.fs_fsize, sblock.fs_bsize,
256 		    sblock.fs_bsize / MAXFRAG);
257 		exit(21);
258 	}
259 	sblock.fs_nrpos = nrpos;
260 	sblock.fs_nindir = sblock.fs_bsize / sizeof(daddr_t);
261 	sblock.fs_inopb = sblock.fs_bsize / DINODE_SIZE;
262 	sblock.fs_nspf = sblock.fs_fsize / sectorsize;
263 	for (sblock.fs_fsbtodb = 0, i = NSPF(&sblock); i > 1; i >>= 1)
264 		sblock.fs_fsbtodb++;
265 	sblock.fs_sblkno =
266 	    roundup(howmany(bbsize + sbsize, sblock.fs_fsize), sblock.fs_frag);
267 	sblock.fs_cblkno = (daddr_t)(sblock.fs_sblkno +
268 	    roundup(howmany(sbsize, sblock.fs_fsize), sblock.fs_frag));
269 	sblock.fs_iblkno = sblock.fs_cblkno + sblock.fs_frag;
270 	sblock.fs_cgoffset = roundup(
271 	    howmany(sblock.fs_nsect, NSPF(&sblock)), sblock.fs_frag);
272 	for (sblock.fs_cgmask = 0xffffffff, i = sblock.fs_ntrak; i > 1; i >>= 1)
273 		sblock.fs_cgmask <<= 1;
274 	if (!POWEROF2(sblock.fs_ntrak))
275 		sblock.fs_cgmask <<= 1;
276 	sblock.fs_maxfilesize = sblock.fs_bsize * NDADDR - 1;
277 	for (sizepb = sblock.fs_bsize, i = 0; i < NIADDR; i++) {
278 		sizepb *= NINDIR(&sblock);
279 		sblock.fs_maxfilesize += sizepb;
280 	}
281 	/*
282 	 * Validate specified/determined secpercyl
283 	 * and calculate minimum cylinders per group.
284 	 */
285 	sblock.fs_spc = secpercyl;
286 	for (sblock.fs_cpc = NSPB(&sblock), i = sblock.fs_spc;
287 	     sblock.fs_cpc > 1 && (i & 1) == 0;
288 	     sblock.fs_cpc >>= 1, i >>= 1)
289 		/* void */;
290 	mincpc = sblock.fs_cpc;
291 	bpcg = sblock.fs_spc * sectorsize;
292 	inospercg = roundup(bpcg / DINODE_SIZE, INOPB(&sblock));
293 	if (inospercg > MAXIPG(&sblock))
294 		inospercg = MAXIPG(&sblock);
295 	used = (sblock.fs_iblkno + inospercg / INOPF(&sblock)) * NSPF(&sblock);
296 	mincpgcnt = howmany(sblock.fs_cgoffset * (~sblock.fs_cgmask) + used,
297 	    sblock.fs_spc);
298 	mincpg = roundup(mincpgcnt, mincpc);
299 	/*
300 	 * Ensure that cylinder group with mincpg has enough space
301 	 * for block maps.
302 	 */
303 	sblock.fs_cpg = mincpg;
304 	sblock.fs_ipg = inospercg;
305 	if (maxcontig > 1)
306 		sblock.fs_contigsumsize = MIN(maxcontig, FS_MAXCONTIG);
307 	mapcramped = 0;
308 	while (CGSIZE(&sblock) > sblock.fs_bsize) {
309 		mapcramped = 1;
310 		if (sblock.fs_bsize < MAXBSIZE) {
311 			sblock.fs_bsize <<= 1;
312 			if ((i & 1) == 0) {
313 				i >>= 1;
314 			} else {
315 				sblock.fs_cpc <<= 1;
316 				mincpc <<= 1;
317 				mincpg = roundup(mincpgcnt, mincpc);
318 				sblock.fs_cpg = mincpg;
319 			}
320 			sblock.fs_frag <<= 1;
321 			sblock.fs_fragshift += 1;
322 			if (sblock.fs_frag <= MAXFRAG)
323 				continue;
324 		}
325 		if (sblock.fs_fsize == sblock.fs_bsize) {
326 			printf("There is no block size that");
327 			printf(" can support this disk\n");
328 			exit(22);
329 		}
330 		sblock.fs_frag >>= 1;
331 		sblock.fs_fragshift -= 1;
332 		sblock.fs_fsize <<= 1;
333 		sblock.fs_nspf <<= 1;
334 	}
335 	/*
336 	 * Ensure that cylinder group with mincpg has enough space for inodes.
337 	 */
338 	inodecramped = 0;
339 	inospercg = calcipg(mincpg, bpcg, &usedb);
340 	sblock.fs_ipg = inospercg;
341 	while (inospercg > MAXIPG(&sblock)) {
342 		inodecramped = 1;
343 		if (mincpc == 1 || sblock.fs_frag == 1 ||
344 		    sblock.fs_bsize == MINBSIZE)
345 			break;
346 		printf("With a block size of %d %s %d\n", sblock.fs_bsize,
347 		       "minimum bytes per inode is",
348 		       (int)((mincpg * (off_t)bpcg - usedb)
349 			     / MAXIPG(&sblock) + 1));
350 		sblock.fs_bsize >>= 1;
351 		sblock.fs_frag >>= 1;
352 		sblock.fs_fragshift -= 1;
353 		mincpc >>= 1;
354 		sblock.fs_cpg = roundup(mincpgcnt, mincpc);
355 		if (CGSIZE(&sblock) > sblock.fs_bsize) {
356 			sblock.fs_bsize <<= 1;
357 			break;
358 		}
359 		mincpg = sblock.fs_cpg;
360 		inospercg = calcipg(mincpg, bpcg, &usedb);
361 		sblock.fs_ipg = inospercg;
362 	}
363 	if (inodecramped) {
364 		if (inospercg > MAXIPG(&sblock)) {
365 			printf("Minimum bytes per inode is %d\n",
366 			       (int)((mincpg * (off_t)bpcg - usedb)
367 				     / MAXIPG(&sblock) + 1));
368 		} else if (!mapcramped) {
369 			printf("With %d bytes per inode, ", density);
370 			printf("minimum cylinders per group is %d\n", mincpg);
371 		}
372 	}
373 	if (mapcramped) {
374 		printf("With %d sectors per cylinder, ", sblock.fs_spc);
375 		printf("minimum cylinders per group is %d\n", mincpg);
376 	}
377 	if (inodecramped || mapcramped) {
378 		if (sblock.fs_bsize != bsize)
379 			printf("%s to be changed from %d to %d\n",
380 			    "This requires the block size",
381 			    bsize, sblock.fs_bsize);
382 		if (sblock.fs_fsize != fsize)
383 			printf("\t%s to be changed from %d to %d\n",
384 			    "and the fragment size",
385 			    fsize, sblock.fs_fsize);
386 		exit(23);
387 	}
388 	/*
389 	 * Calculate the number of cylinders per group
390 	 */
391 	sblock.fs_cpg = cpg;
392 	if (sblock.fs_cpg % mincpc != 0) {
393 		printf("%s groups must have a multiple of %d cylinders\n",
394 			cpgflg ? "Cylinder" : "Warning: cylinder", mincpc);
395 		sblock.fs_cpg = roundup(sblock.fs_cpg, mincpc);
396 		if (!cpgflg)
397 			cpg = sblock.fs_cpg;
398 	}
399 	/*
400 	 * Must ensure there is enough space for inodes.
401 	 */
402 	sblock.fs_ipg = calcipg(sblock.fs_cpg, bpcg, &usedb);
403 	while (sblock.fs_ipg > MAXIPG(&sblock)) {
404 		inodecramped = 1;
405 		sblock.fs_cpg -= mincpc;
406 		sblock.fs_ipg = calcipg(sblock.fs_cpg, bpcg, &usedb);
407 	}
408 	/*
409 	 * Must ensure there is enough space to hold block map.
410 	 */
411 	while (CGSIZE(&sblock) > sblock.fs_bsize) {
412 		mapcramped = 1;
413 		sblock.fs_cpg -= mincpc;
414 		sblock.fs_ipg = calcipg(sblock.fs_cpg, bpcg, &usedb);
415 	}
416 	sblock.fs_fpg = (sblock.fs_cpg * sblock.fs_spc) / NSPF(&sblock);
417 	if ((sblock.fs_cpg * sblock.fs_spc) % NSPB(&sblock) != 0) {
418 		printf("panic (fs_cpg * fs_spc) %% NSPF != 0");
419 		exit(24);
420 	}
421 	if (sblock.fs_cpg < mincpg) {
422 		printf("cylinder groups must have at least %d cylinders\n",
423 			mincpg);
424 		exit(25);
425 	} else if (sblock.fs_cpg != cpg && cpgflg) {
426 		if (!mapcramped && !inodecramped)
427 			exit(26);
428 		if (mapcramped && inodecramped)
429 			printf("Block size and bytes per inode restrict");
430 		else if (mapcramped)
431 			printf("Block size restricts");
432 		else
433 			printf("Bytes per inode restrict");
434 		printf(" cylinders per group to %d.\n", sblock.fs_cpg);
435 		exit(27);
436 	}
437 	sblock.fs_cgsize = fragroundup(&sblock, CGSIZE(&sblock));
438 	/*
439 	 * Now have size for file system and nsect and ntrak.
440 	 * Determine number of cylinders and blocks in the file system.
441 	 */
442 	sblock.fs_size = fssize = dbtofsb(&sblock, fssize);
443 	sblock.fs_ncyl = fssize * NSPF(&sblock) / sblock.fs_spc;
444 	if (fssize * NSPF(&sblock) > sblock.fs_ncyl * sblock.fs_spc) {
445 		sblock.fs_ncyl++;
446 		warned = 1;
447 	}
448 	if (sblock.fs_ncyl < 1) {
449 		printf("file systems must have at least one cylinder\n");
450 		exit(28);
451 	}
452 	/*
453 	 * Determine feasability/values of rotational layout tables.
454 	 *
455 	 * The size of the rotational layout tables is limited by the
456 	 * size of the superblock, SBSIZE. The amount of space available
457 	 * for tables is calculated as (SBSIZE - sizeof (struct fs)).
458 	 * The size of these tables is inversely proportional to the block
459 	 * size of the file system. The size increases if sectors per track
460 	 * are not powers of two, because more cylinders must be described
461 	 * by the tables before the rotational pattern repeats (fs_cpc).
462 	 */
463 	sblock.fs_interleave = interleave;
464 	sblock.fs_trackskew = trackskew;
465 	sblock.fs_npsect = nphyssectors;
466 	sblock.fs_postblformat = FS_DYNAMICPOSTBLFMT;
467 	sblock.fs_sbsize = fragroundup(&sblock, sizeof(struct fs));
468 	if (sblock.fs_ntrak == 1) {
469 		sblock.fs_cpc = 0;
470 		goto next;
471 	}
472 	postblsize = sblock.fs_nrpos * sblock.fs_cpc * sizeof(int16_t);
473 	rotblsize = sblock.fs_cpc * sblock.fs_spc / NSPB(&sblock);
474 	totalsbsize = sizeof(struct fs) + rotblsize;
475 	if (sblock.fs_nrpos == 8 && sblock.fs_cpc <= 16) {
476 		/* use old static table space */
477 		sblock.fs_postbloff = (char *)(&sblock.fs_opostbl[0][0]) -
478 		    (char *)(&sblock.fs_firstfield);
479 		sblock.fs_rotbloff = &sblock.fs_space[0] -
480 		    (u_char *)(&sblock.fs_firstfield);
481 	} else {
482 		/* use dynamic table space */
483 		sblock.fs_postbloff = &sblock.fs_space[0] -
484 		    (u_char *)(&sblock.fs_firstfield);
485 		sblock.fs_rotbloff = sblock.fs_postbloff + postblsize;
486 		totalsbsize += postblsize;
487 	}
488 	if (totalsbsize > SBSIZE ||
489 	    sblock.fs_nsect > (1 << NBBY) * NSPB(&sblock)) {
490 		printf("%s %s %d %s %d.%s",
491 		    "Warning: insufficient space in super block for\n",
492 		    "rotational layout tables with nsect", sblock.fs_nsect,
493 		    "and ntrak", sblock.fs_ntrak,
494 		    "\nFile system performance may be impaired.\n");
495 		sblock.fs_cpc = 0;
496 		goto next;
497 	}
498 	sblock.fs_sbsize = fragroundup(&sblock, totalsbsize);
499 	/*
500 	 * calculate the available blocks for each rotational position
501 	 */
502 	for (cylno = 0; cylno < sblock.fs_cpc; cylno++)
503 		for (rpos = 0; rpos < sblock.fs_nrpos; rpos++)
504 			fs_postbl(&sblock, cylno)[rpos] = -1;
505 	for (i = (rotblsize - 1) * sblock.fs_frag;
506 	     i >= 0; i -= sblock.fs_frag) {
507 		cylno = cbtocylno(&sblock, i);
508 		rpos = cbtorpos(&sblock, i);
509 		blk = fragstoblks(&sblock, i);
510 		if (fs_postbl(&sblock, cylno)[rpos] == -1)
511 			fs_rotbl(&sblock)[blk] = 0;
512 		else
513 			fs_rotbl(&sblock)[blk] = fs_postbl(&sblock, cylno)[rpos] - blk;
514 		fs_postbl(&sblock, cylno)[rpos] = blk;
515 	}
516 next:
517 	/*
518 	 * Compute/validate number of cylinder groups.
519 	 */
520 	sblock.fs_ncg = sblock.fs_ncyl / sblock.fs_cpg;
521 	if (sblock.fs_ncyl % sblock.fs_cpg)
522 		sblock.fs_ncg++;
523 	sblock.fs_dblkno = sblock.fs_iblkno + sblock.fs_ipg / INOPF(&sblock);
524 	i = MIN(~sblock.fs_cgmask, sblock.fs_ncg - 1);
525 	if (cgdmin(&sblock, i) - cgbase(&sblock, i) >= sblock.fs_fpg) {
526 		printf("inode blocks/cyl group (%d) >= data blocks (%d)\n",
527 		    cgdmin(&sblock, i) - cgbase(&sblock, i) / sblock.fs_frag,
528 		    sblock.fs_fpg / sblock.fs_frag);
529 		printf("number of cylinders per cylinder group (%d) %s.\n",
530 		    sblock.fs_cpg, "must be increased");
531 		exit(29);
532 	}
533 	j = sblock.fs_ncg - 1;
534 	if ((i = fssize - j * sblock.fs_fpg) < sblock.fs_fpg &&
535 	    cgdmin(&sblock, j) - cgbase(&sblock, j) > i) {
536 		if (j == 0) {
537 			printf("File system must have at least %d sectors\n",
538 			    NSPF(&sblock) *
539 			    (cgdmin(&sblock, 0) + 3 * sblock.fs_frag));
540 			exit(30);
541 		}
542 		printf("Warning: inode blocks/cyl group (%d) >= "
543 			"data blocks (%d) in last\n",
544 		    (cgdmin(&sblock, j) - cgbase(&sblock, j)) / sblock.fs_frag,
545 		    i / sblock.fs_frag);
546 		printf("    cylinder group. This implies %d sector(s) "
547 			"cannot be allocated.\n",
548 		    i * NSPF(&sblock));
549 		sblock.fs_ncg--;
550 		sblock.fs_ncyl -= sblock.fs_ncyl % sblock.fs_cpg;
551 		sblock.fs_size = fssize = sblock.fs_ncyl * sblock.fs_spc /
552 		    NSPF(&sblock);
553 		warned = 0;
554 	}
555 	if (warned) {
556 		printf("Warning: %d sector(s) in last cylinder unallocated\n",
557 		    sblock.fs_spc -
558 		    (fssize * NSPF(&sblock) - (sblock.fs_ncyl - 1)
559 		    * sblock.fs_spc));
560 	}
561 	/*
562 	 * fill in remaining fields of the super block
563 	 */
564 	sblock.fs_csaddr = cgdmin(&sblock, 0);
565 	sblock.fs_cssize =
566 	    fragroundup(&sblock, sblock.fs_ncg * sizeof(struct csum));
567 	/*
568 	 * The superblock fields 'fs_csmask' and 'fs_csshift' are no
569 	 * longer used. However, we still initialise them so that the
570 	 * filesystem remains compatible with old kernels.
571 	 */
572 	i = sblock.fs_bsize / sizeof(struct csum);
573 	sblock.fs_csmask = ~(i - 1);
574 	for (sblock.fs_csshift = 0; i > 1; i >>= 1)
575 		sblock.fs_csshift++;
576 
577 	/*
578 	 * Setup memory for temporary in-core cylgroup summaries.
579 	 * Cribbed from ffs_mountfs().
580 	 */
581 	size = sblock.fs_cssize;
582 	blks = howmany(size, sblock.fs_fsize);
583 	if (sblock.fs_contigsumsize > 0)
584 		size += sblock.fs_ncg * sizeof(int32_t);
585 	if ((space = (char *)calloc(1, size)) == NULL)
586 		err(1, "memory allocation error for cg summaries");
587 	sblock.fs_csp = space;
588 	space = (char *)space + sblock.fs_cssize;
589 	if (sblock.fs_contigsumsize > 0) {
590 		int32_t *lp;
591 
592 		sblock.fs_maxcluster = lp = space;
593 		for (i = 0; i < sblock.fs_ncg; i++)
594 			*lp++ = sblock.fs_contigsumsize;
595 	}
596 
597 	sblock.fs_magic = FS_MAGIC;
598 	sblock.fs_rotdelay = rotdelay;
599 	sblock.fs_minfree = minfree;
600 	sblock.fs_maxcontig = maxcontig;
601 	sblock.fs_maxbpg = maxbpg;
602 	sblock.fs_rps = rpm / 60;
603 	sblock.fs_optim = opt;
604 	sblock.fs_cgrotor = 0;
605 	sblock.fs_cstotal.cs_ndir = 0;
606 	sblock.fs_cstotal.cs_nbfree = 0;
607 	sblock.fs_cstotal.cs_nifree = 0;
608 	sblock.fs_cstotal.cs_nffree = 0;
609 	sblock.fs_fmod = 0;
610 	sblock.fs_clean = FS_ISCLEAN;
611 	sblock.fs_ronly = 0;
612 
613 	/*
614 	 * Dump out summary information about file system.
615 	 */
616 	printf("%s:\t%d sectors in %d %s of %d tracks, %d sectors\n",
617 		    fsys, sblock.fs_size * NSPF(&sblock), sblock.fs_ncyl,
618 		    "cylinders", sblock.fs_ntrak, sblock.fs_nsect);
619 #define B2MBFACTOR (1 / (1024.0 * 1024.0))
620 	printf("\t%.1fMB in %d cyl groups (%d c/g, %.2fMB/g, %d i/g)\n",
621 		    (float)sblock.fs_size * sblock.fs_fsize * B2MBFACTOR,
622 		    sblock.fs_ncg, sblock.fs_cpg,
623 		    (float)sblock.fs_fpg * sblock.fs_fsize * B2MBFACTOR,
624 		    sblock.fs_ipg);
625 #undef B2MBFACTOR
626 	/*
627 	 * Now determine how wide each column will be, and calculate how
628 	 * many columns will fit in a 76 char line. 76 is the width of the
629 	 * subwindows in sysinst.
630 	 */
631 	printcolwidth = count_digits(
632 			fsbtodb(&sblock, cgsblock(&sblock, sblock.fs_ncg -1)));
633 	nprintcols = 76 / (printcolwidth + 2);
634 	/*
635 	 * Now build the cylinders group blocks and
636 	 * then print out indices of cylinder groups.
637 	 */
638 		printf("super-block backups (for fsck -b #) at:");
639 	for (cylno = 0; cylno < sblock.fs_ncg; cylno++) {
640 		initcg(cylno, start_time.tv_sec, fsopts);
641 		if (cylno % nprintcols == 0)
642 			printf("\n");
643 		printf(" %*d,", printcolwidth,
644 				fsbtodb(&sblock, cgsblock(&sblock, cylno)));
645 		fflush(stdout);
646 	}
647 	printf("\n");
648 
649 	/*
650 	 * Now construct the initial file system,
651 	 * then write out the super-block.
652 	 */
653 	sblock.fs_time = start_time.tv_sec;
654 	if (fsopts->needswap)
655 		sblock.fs_flags |= FS_SWAPPED;
656 	ffs_write_superblock(&sblock, fsopts);
657 	return (&sblock);
658 }
659 
660 /*
661  * Write out the superblock and its duplicates,
662  * and the cylinder group summaries
663  */
664 void
665 ffs_write_superblock(struct fs *fs, const fsinfo_t *fsopts)
666 {
667 	int	cylno, size, blks, i, saveflag;
668 	void	*space;
669 	char	*wrbuf;
670 
671 	saveflag = fs->fs_flags & FS_INTERNAL;
672 	fs->fs_flags &= ~FS_INTERNAL;
673 
674 			/* Write out the master super block */
675 	memcpy(writebuf, fs, sbsize);
676 	if (fsopts->needswap)
677 		ffs_sb_swap(fs, (struct fs*)writebuf);
678 	ffs_wtfs((int)SBOFF / sectorsize, sbsize, writebuf, fsopts);
679 
680 			/* Write out the duplicate super blocks */
681 	for (cylno = 0; cylno < sblock.fs_ncg; cylno++)
682 		ffs_wtfs(fsbtodb(fs, cgsblock(fs, cylno)),
683 		    sbsize, writebuf, fsopts);
684 
685 			/* Write out the cylinder group summaries */
686 	size = fs->fs_cssize;
687 	blks = howmany(size, fs->fs_fsize);
688 	space = (void *)fs->fs_csp;
689 	if ((wrbuf = malloc(size)) == NULL)
690 		err(1, "ffs_write_superblock: malloc %d", size);
691 	for (i = 0; i < blks; i+= fs->fs_frag) {
692 		size = fs->fs_bsize;
693 		if (i + fs->fs_frag > blks)
694 			size = (blks - i) * fs->fs_fsize;
695 		if (fsopts->needswap)
696 			ffs_csum_swap((struct csum *)space,
697 			    (struct csum *)wrbuf, size);
698 		else
699 			memcpy(wrbuf, space, (u_int)size);
700 		ffs_wtfs(fsbtodb(fs, fs->fs_csaddr + i), size, wrbuf, fsopts);
701 		space = (char *)space + size;
702 	}
703 	free(wrbuf);
704 	fs->fs_flags |= saveflag;
705 }
706 
707 
708 /*
709  * Initialize a cylinder group.
710  */
711 static void
712 initcg(int cylno, time_t utime, const fsinfo_t *fsopts)
713 {
714 	daddr_t cbase, d, dlower, dupper, dmax, blkno;
715 	int32_t i;
716 
717 	/*
718 	 * Determine block bounds for cylinder group.
719 	 * Allow space for super block summary information in first
720 	 * cylinder group.
721 	 */
722 	cbase = cgbase(&sblock, cylno);
723 	dmax = cbase + sblock.fs_fpg;
724 	if (dmax > sblock.fs_size)
725 		dmax = sblock.fs_size;
726 	dlower = cgsblock(&sblock, cylno) - cbase;
727 	dupper = cgdmin(&sblock, cylno) - cbase;
728 	if (cylno == 0)
729 		dupper += howmany(sblock.fs_cssize, sblock.fs_fsize);
730 	memset(&acg, 0, sblock.fs_cgsize);
731 	acg.cg_time = utime;
732 	acg.cg_magic = CG_MAGIC;
733 	acg.cg_cgx = cylno;
734 	if (cylno == sblock.fs_ncg - 1)
735 		acg.cg_ncyl = sblock.fs_ncyl % sblock.fs_cpg;
736 	else
737 		acg.cg_ncyl = sblock.fs_cpg;
738 	acg.cg_niblk = sblock.fs_ipg;
739 	acg.cg_ndblk = dmax - cbase;
740 	if (sblock.fs_contigsumsize > 0)
741 		acg.cg_nclusterblks = acg.cg_ndblk / sblock.fs_frag;
742 	acg.cg_btotoff = &acg.cg_space[0] - (u_char *)(&acg.cg_firstfield);
743 	acg.cg_boff = acg.cg_btotoff + sblock.fs_cpg * sizeof(int32_t);
744 	acg.cg_iusedoff = acg.cg_boff +
745 		sblock.fs_cpg * sblock.fs_nrpos * sizeof(int16_t);
746 	acg.cg_freeoff = acg.cg_iusedoff + howmany(sblock.fs_ipg, NBBY);
747 	if (sblock.fs_contigsumsize <= 0) {
748 		acg.cg_nextfreeoff = acg.cg_freeoff +
749 		   howmany(sblock.fs_cpg * sblock.fs_spc / NSPF(&sblock), NBBY);
750 	} else {
751 		acg.cg_clustersumoff = acg.cg_freeoff + howmany
752 		    (sblock.fs_cpg * sblock.fs_spc / NSPF(&sblock), NBBY) -
753 		    sizeof(int32_t);
754 		acg.cg_clustersumoff =
755 		    roundup(acg.cg_clustersumoff, sizeof(int32_t));
756 		acg.cg_clusteroff = acg.cg_clustersumoff +
757 		    (sblock.fs_contigsumsize + 1) * sizeof(int32_t);
758 		acg.cg_nextfreeoff = acg.cg_clusteroff + howmany
759 		    (sblock.fs_cpg * sblock.fs_spc / NSPB(&sblock), NBBY);
760 	}
761 	if (acg.cg_nextfreeoff > sblock.fs_cgsize) {
762 		printf("Panic: cylinder group too big\n");
763 		exit(37);
764 	}
765 	acg.cg_cs.cs_nifree += sblock.fs_ipg;
766 	if (cylno == 0)
767 		for (i = 0; i < ROOTINO; i++) {
768 			setbit(cg_inosused(&acg, 0), i);
769 			acg.cg_cs.cs_nifree--;
770 		}
771 	for (i = 0; i < sblock.fs_ipg / INOPF(&sblock); i += sblock.fs_frag)
772 		ffs_wtfs(fsbtodb(&sblock, cgimin(&sblock, cylno) + i),
773 		    sblock.fs_bsize, (char *)zino, fsopts);
774 	if (cylno > 0) {
775 		/*
776 		 * In cylno 0, beginning space is reserved
777 		 * for boot and super blocks.
778 		 */
779 		for (d = 0; d < dlower; d += sblock.fs_frag) {
780 			blkno = d / sblock.fs_frag;
781 			ffs_setblock(&sblock, cg_blksfree(&acg, 0), blkno);
782 			if (sblock.fs_contigsumsize > 0)
783 				setbit(cg_clustersfree(&acg, 0), blkno);
784 			acg.cg_cs.cs_nbfree++;
785 			cg_blktot(&acg, 0)[cbtocylno(&sblock, d)]++;
786 			cg_blks(&sblock, &acg, cbtocylno(&sblock, d), 0)
787 			    [cbtorpos(&sblock, d)]++;
788 		}
789 		sblock.fs_dsize += dlower;
790 	}
791 	sblock.fs_dsize += acg.cg_ndblk - dupper;
792 	if ((i = (dupper % sblock.fs_frag)) != 0) {
793 		acg.cg_frsum[sblock.fs_frag - i]++;
794 		for (d = dupper + sblock.fs_frag - i; dupper < d; dupper++) {
795 			setbit(cg_blksfree(&acg, 0), dupper);
796 			acg.cg_cs.cs_nffree++;
797 		}
798 	}
799 	for (d = dupper; d + sblock.fs_frag <= dmax - cbase; ) {
800 		blkno = d / sblock.fs_frag;
801 		ffs_setblock(&sblock, cg_blksfree(&acg, 0), blkno);
802 		if (sblock.fs_contigsumsize > 0)
803 			setbit(cg_clustersfree(&acg, 0), blkno);
804 		acg.cg_cs.cs_nbfree++;
805 		cg_blktot(&acg, 0)[cbtocylno(&sblock, d)]++;
806 		cg_blks(&sblock, &acg, cbtocylno(&sblock, d), 0)
807 		    [cbtorpos(&sblock, d)]++;
808 		d += sblock.fs_frag;
809 	}
810 	if (d < dmax - cbase) {
811 		acg.cg_frsum[dmax - cbase - d]++;
812 		for (; d < dmax - cbase; d++) {
813 			setbit(cg_blksfree(&acg, 0), d);
814 			acg.cg_cs.cs_nffree++;
815 		}
816 	}
817 	if (sblock.fs_contigsumsize > 0) {
818 		int32_t *sump = cg_clustersum(&acg, 0);
819 		u_char *mapp = cg_clustersfree(&acg, 0);
820 		int map = *mapp++;
821 		int bit = 1;
822 		int run = 0;
823 
824 		for (i = 0; i < acg.cg_nclusterblks; i++) {
825 			if ((map & bit) != 0) {
826 				run++;
827 			} else if (run != 0) {
828 				if (run > sblock.fs_contigsumsize)
829 					run = sblock.fs_contigsumsize;
830 				sump[run]++;
831 				run = 0;
832 			}
833 			if ((i & (NBBY - 1)) != (NBBY - 1)) {
834 				bit <<= 1;
835 			} else {
836 				map = *mapp++;
837 				bit = 1;
838 			}
839 		}
840 		if (run != 0) {
841 			if (run > sblock.fs_contigsumsize)
842 				run = sblock.fs_contigsumsize;
843 			sump[run]++;
844 		}
845 	}
846 	sblock.fs_cstotal.cs_ndir += acg.cg_cs.cs_ndir;
847 	sblock.fs_cstotal.cs_nffree += acg.cg_cs.cs_nffree;
848 	sblock.fs_cstotal.cs_nbfree += acg.cg_cs.cs_nbfree;
849 	sblock.fs_cstotal.cs_nifree += acg.cg_cs.cs_nifree;
850 	sblock.fs_cs(&sblock, cylno) = acg.cg_cs;
851 	memcpy(writebuf, &acg, sblock.fs_bsize);
852 	if (fsopts->needswap)
853 		swap_cg(&acg, (struct cg*)writebuf);
854 	ffs_wtfs(fsbtodb(&sblock, cgtod(&sblock, cylno)),
855 		sblock.fs_bsize,
856 		writebuf, fsopts);
857 }
858 
859 /*
860  * Calculate number of inodes per group.
861  */
862 static int32_t
863 calcipg(int32_t cylpg, int32_t bpcg, off_t *usedbp)
864 {
865 	int i;
866 	int32_t ipg, new_ipg, ncg, ncyl;
867 	off_t usedb;
868 
869 	/*
870 	 * Prepare to scale by fssize / (number of sectors in cylinder groups).
871 	 * Note that fssize is still in sectors, not file system blocks.
872 	 */
873 	ncyl = howmany(fssize, secpercyl);
874 	ncg = howmany(ncyl, cylpg);
875 	/*
876 	 * Iterate a few times to allow for ipg depending on itself.
877 	 */
878 	ipg = 0;
879 	for (i = 0; i < 10; i++) {
880 		usedb = (sblock.fs_iblkno + ipg / INOPF(&sblock))
881 			* NSPF(&sblock) * (off_t)sectorsize;
882 		if (cylpg * (long long)bpcg < usedb) {
883 			warnx("Too many inodes per cyl group!");
884 			return (MAXIPG(&sblock)+1);
885 		}
886 		new_ipg = (cylpg * (long long)bpcg - usedb) /
887 		    (long long)density * fssize / (ncg * secpercyl * cylpg);
888 		if (new_ipg <= 0)
889 			new_ipg = 1;		/* ensure ipg > 0 */
890 		new_ipg = roundup(new_ipg, INOPB(&sblock));
891 		if (new_ipg == ipg)
892 			break;
893 		ipg = new_ipg;
894 	}
895 	*usedbp = usedb;
896 	return (ipg);
897 }
898 
899 
900 /*
901  * read a block from the file system
902  */
903 void
904 ffs_rdfs(daddr_t bno, int size, void *bf, const fsinfo_t *fsopts)
905 {
906 	int n;
907 	off_t offset;
908 
909 	offset = bno;
910 	offset *= fsopts->sectorsize;
911 	if (lseek(fsopts->fd, offset, SEEK_SET) < 0)
912 		err(1, "ffs_rdfs: seek error: %d\n", bno);
913 	n = read(fsopts->fd, bf, size);
914 	if (n == -1)
915 		err(1, "ffs_rdfs: read error bno %d size %d\n", bno, size);
916 	else if (n != size)
917 		errx(1,
918 		    "ffs_rdfs: read error bno %d size %d: short read of %d\n",
919 		    bno, size, n);
920 }
921 
922 /*
923  * write a block to the file system
924  */
925 void
926 ffs_wtfs(daddr_t bno, int size, void *bf, const fsinfo_t *fsopts)
927 {
928 	int n;
929 	off_t offset;
930 
931 	offset = bno;
932 	offset *= fsopts->sectorsize;
933 	if (lseek(fsopts->fd, offset, SEEK_SET) < 0)
934 		err(1, "ffs_wtfs: seek error: %d\n", bno);
935 	n = write(fsopts->fd, bf, size);
936 	if (n == -1)
937 		err(1, "ffs_wtfs: write error bno %d size %d\n", bno, size);
938 	else if (n != size)
939 		errx(1,
940 		    "ffs_wtfs: write error bno %d size %d: short write of %d\n",
941 		    bno, size, n);
942 }
943 
944 /* swap byte order of cylinder group */
945 static void
946 swap_cg(struct cg *o, struct cg *n)
947 {
948 	int i, btotsize, fbsize;
949 	u_int32_t *n32, *o32;
950 	u_int16_t *n16, *o16;
951 
952 	n->cg_firstfield = bswap32(o->cg_firstfield);
953 	n->cg_magic = bswap32(o->cg_magic);
954 	n->cg_time = bswap32(o->cg_time);
955 	n->cg_cgx = bswap32(o->cg_cgx);
956 	n->cg_ncyl = bswap16(o->cg_ncyl);
957 	n->cg_niblk = bswap16(o->cg_niblk);
958 	n->cg_ndblk = bswap32(o->cg_ndblk);
959 	n->cg_cs.cs_ndir = bswap32(o->cg_cs.cs_ndir);
960 	n->cg_cs.cs_nbfree = bswap32(o->cg_cs.cs_nbfree);
961 	n->cg_cs.cs_nifree = bswap32(o->cg_cs.cs_nifree);
962 	n->cg_cs.cs_nffree = bswap32(o->cg_cs.cs_nffree);
963 	n->cg_rotor = bswap32(o->cg_rotor);
964 	n->cg_frotor = bswap32(o->cg_frotor);
965 	n->cg_irotor = bswap32(o->cg_irotor);
966 	n->cg_btotoff = bswap32(o->cg_btotoff);
967 	n->cg_boff = bswap32(o->cg_boff);
968 	n->cg_iusedoff = bswap32(o->cg_iusedoff);
969 	n->cg_freeoff = bswap32(o->cg_freeoff);
970 	n->cg_nextfreeoff = bswap32(o->cg_nextfreeoff);
971 	n->cg_clustersumoff = bswap32(o->cg_clustersumoff);
972 	n->cg_clusteroff = bswap32(o->cg_clusteroff);
973 	n->cg_nclusterblks = bswap32(o->cg_nclusterblks);
974 	for (i=0; i < MAXFRAG; i++)
975 		n->cg_frsum[i] = bswap32(o->cg_frsum[i]);
976 
977 	/* alays new format */
978 	if (n->cg_magic == CG_MAGIC) {
979 		btotsize = n->cg_boff - n->cg_btotoff;
980 		fbsize = n->cg_iusedoff - n->cg_boff;
981 		n32 = (u_int32_t*)((u_int8_t*)n + n->cg_btotoff);
982 		o32 = (u_int32_t*)((u_int8_t*)o + n->cg_btotoff);
983 		n16 = (u_int16_t*)((u_int8_t*)n + n->cg_boff);
984 		o16 = (u_int16_t*)((u_int8_t*)o + n->cg_boff);
985 	} else {
986 		btotsize = bswap32(n->cg_boff) - bswap32(n->cg_btotoff);
987 		fbsize = bswap32(n->cg_iusedoff) - bswap32(n->cg_boff);
988 		n32 = (u_int32_t*)((u_int8_t*)n + bswap32(n->cg_btotoff));
989 		o32 = (u_int32_t*)((u_int8_t*)o + bswap32(n->cg_btotoff));
990 		n16 = (u_int16_t*)((u_int8_t*)n + bswap32(n->cg_boff));
991 		o16 = (u_int16_t*)((u_int8_t*)o + bswap32(n->cg_boff));
992 	}
993 	for (i=0; i < btotsize / sizeof(u_int32_t); i++)
994 		n32[i] = bswap32(o32[i]);
995 
996 	for (i=0; i < fbsize/sizeof(u_int16_t); i++)
997 		n16[i] = bswap16(o16[i]);
998 
999 	if (n->cg_magic == CG_MAGIC) {
1000 		n32 = (u_int32_t*)((u_int8_t*)n + n->cg_clustersumoff);
1001 		o32 = (u_int32_t*)((u_int8_t*)o + n->cg_clustersumoff);
1002 	} else {
1003 		n32 = (u_int32_t*)((u_int8_t*)n + bswap32(n->cg_clustersumoff));
1004 		o32 = (u_int32_t*)((u_int8_t*)o + bswap32(n->cg_clustersumoff));
1005 	}
1006 	for (i = 1; i < sblock.fs_contigsumsize + 1; i++)
1007 		n32[i] = bswap32(o32[i]);
1008 }
1009 
1010 /* Determine how many digits are needed to print a given integer */
1011 static int
1012 count_digits(int num)
1013 {
1014 	int ndig;
1015 
1016 	for(ndig = 1; num > 9; num /=10, ndig++);
1017 
1018 	return (ndig);
1019 }
1020