xref: /freebsd/usr.sbin/makefs/ffs/mkfs.c (revision b1f92fa22938fe29ab7e53692ffe0ed7a0ecc4d0)
1 /*	$NetBSD: mkfs.c,v 1.20 2004/06/24 22:30:13 lukem Exp $	*/
2 
3 /*
4  * Copyright (c) 2002 Networks Associates Technology, Inc.
5  * All rights reserved.
6  *
7  * This software was developed for the FreeBSD Project by Marshall
8  * Kirk McKusick and Network Associates Laboratories, the Security
9  * Research Division of Network Associates, Inc. under DARPA/SPAWAR
10  * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS
11  * research program
12  *
13  * Copyright (c) 1980, 1989, 1993
14  *	The Regents of the University of California.  All rights reserved.
15  *
16  * Redistribution and use in source and binary forms, with or without
17  * modification, are permitted provided that the following conditions
18  * are met:
19  * 1. Redistributions of source code must retain the above copyright
20  *    notice, this list of conditions and the following disclaimer.
21  * 2. Redistributions in binary form must reproduce the above copyright
22  *    notice, this list of conditions and the following disclaimer in the
23  *    documentation and/or other materials provided with the distribution.
24  * 3. Neither the name of the University nor the names of its contributors
25  *    may be used to endorse or promote products derived from this software
26  *    without specific prior written permission.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38  * SUCH DAMAGE.
39  */
40 
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
43 
44 #include <sys/param.h>
45 #include <sys/time.h>
46 #include <sys/resource.h>
47 
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include <errno.h>
53 
54 #include "makefs.h"
55 #include "ffs.h"
56 
57 #include <ufs/ufs/dinode.h>
58 #include <ufs/ffs/fs.h>
59 
60 #include "ffs/ufs_bswap.h"
61 #include "ffs/ufs_inode.h"
62 #include "ffs/ffs_extern.h"
63 #include "ffs/newfs_extern.h"
64 
65 #ifndef BBSIZE
66 #define	BBSIZE	8192			/* size of boot area, with label */
67 #endif
68 
69 static void initcg(int, time_t, const fsinfo_t *);
70 static int ilog2(int);
71 
72 static int count_digits(int);
73 
74 /*
75  * make file system for cylinder-group style file systems
76  */
77 #define	UMASK		0755
78 #define	POWEROF2(num)	(((num) & ((num) - 1)) == 0)
79 
80 union {
81 	struct fs fs;
82 	char pad[SBLOCKSIZE];
83 } fsun;
84 #define	sblock	fsun.fs
85 struct	csum *fscs;
86 
87 union {
88 	struct cg cg;
89 	char pad[FFS_MAXBSIZE];
90 } cgun;
91 #define	acg	cgun.cg
92 
93 char *iobuf;
94 int iobufsize;
95 
96 char writebuf[FFS_MAXBSIZE];
97 
98 static int     Oflag;	   /* format as an 4.3BSD file system */
99 static int64_t fssize;	   /* file system size */
100 static int     sectorsize;	   /* bytes/sector */
101 static int     fsize;	   /* fragment size */
102 static int     bsize;	   /* block size */
103 static int     maxbsize;   /* maximum clustering */
104 static int     maxblkspercg;
105 static int     minfree;	   /* free space threshold */
106 static int     opt;		   /* optimization preference (space or time) */
107 static int     density;	   /* number of bytes per inode */
108 static int     maxcontig;	   /* max contiguous blocks to allocate */
109 static int     maxbpg;	   /* maximum blocks per file in a cyl group */
110 static int     bbsize;	   /* boot block size */
111 static int     sbsize;	   /* superblock size */
112 static int     avgfilesize;	   /* expected average file size */
113 static int     avgfpdir;	   /* expected number of files per directory */
114 
115 struct fs *
116 ffs_mkfs(const char *fsys, const fsinfo_t *fsopts)
117 {
118 	int fragsperinode, optimalfpg, origdensity, minfpg, lastminfpg;
119 	int32_t cylno, i, csfrags;
120 	long long sizepb;
121 	void *space;
122 	int size, blks;
123 	int nprintcols, printcolwidth;
124 	ffs_opt_t	*ffs_opts = fsopts->fs_specific;
125 
126 	Oflag =		ffs_opts->version;
127 	fssize =        fsopts->size / fsopts->sectorsize;
128 	sectorsize =    fsopts->sectorsize;
129 	fsize =         ffs_opts->fsize;
130 	bsize =         ffs_opts->bsize;
131 	maxbsize =      ffs_opts->maxbsize;
132 	maxblkspercg =  ffs_opts->maxblkspercg;
133 	minfree =       ffs_opts->minfree;
134 	opt =           ffs_opts->optimization;
135 	density =       ffs_opts->density;
136 	maxcontig =     ffs_opts->maxcontig;
137 	maxbpg =        ffs_opts->maxbpg;
138 	avgfilesize =   ffs_opts->avgfilesize;
139 	avgfpdir =      ffs_opts->avgfpdir;
140 	bbsize =        BBSIZE;
141 	sbsize =        SBLOCKSIZE;
142 
143 	strlcpy(sblock.fs_volname, ffs_opts->label, sizeof(sblock.fs_volname));
144 
145 	if (Oflag == 0) {
146 		sblock.fs_old_inodefmt = FS_42INODEFMT;
147 		sblock.fs_maxsymlinklen = 0;
148 		sblock.fs_old_flags = 0;
149 	} else {
150 		sblock.fs_old_inodefmt = FS_44INODEFMT;
151 		sblock.fs_maxsymlinklen = (Oflag == 1 ? MAXSYMLINKLEN_UFS1 :
152 		    MAXSYMLINKLEN_UFS2);
153 		sblock.fs_old_flags = FS_FLAGS_UPDATED;
154 		sblock.fs_flags = 0;
155 	}
156 	/*
157 	 * Validate the given file system size.
158 	 * Verify that its last block can actually be accessed.
159 	 * Convert to file system fragment sized units.
160 	 */
161 	if (fssize <= 0) {
162 		printf("preposterous size %lld\n", (long long)fssize);
163 		exit(13);
164 	}
165 	ffs_wtfs(fssize - 1, sectorsize, (char *)&sblock, fsopts);
166 
167 	/*
168 	 * collect and verify the filesystem density info
169 	 */
170 	sblock.fs_avgfilesize = avgfilesize;
171 	sblock.fs_avgfpdir = avgfpdir;
172 	if (sblock.fs_avgfilesize <= 0)
173 		printf("illegal expected average file size %d\n",
174 		    sblock.fs_avgfilesize), exit(14);
175 	if (sblock.fs_avgfpdir <= 0)
176 		printf("illegal expected number of files per directory %d\n",
177 		    sblock.fs_avgfpdir), exit(15);
178 	/*
179 	 * collect and verify the block and fragment sizes
180 	 */
181 	sblock.fs_bsize = bsize;
182 	sblock.fs_fsize = fsize;
183 	if (!POWEROF2(sblock.fs_bsize)) {
184 		printf("block size must be a power of 2, not %d\n",
185 		    sblock.fs_bsize);
186 		exit(16);
187 	}
188 	if (!POWEROF2(sblock.fs_fsize)) {
189 		printf("fragment size must be a power of 2, not %d\n",
190 		    sblock.fs_fsize);
191 		exit(17);
192 	}
193 	if (sblock.fs_fsize < sectorsize) {
194 		printf("fragment size %d is too small, minimum is %d\n",
195 		    sblock.fs_fsize, sectorsize);
196 		exit(18);
197 	}
198 	if (sblock.fs_bsize < MINBSIZE) {
199 		printf("block size %d is too small, minimum is %d\n",
200 		    sblock.fs_bsize, MINBSIZE);
201 		exit(19);
202 	}
203 	if (sblock.fs_bsize > FFS_MAXBSIZE) {
204 		printf("block size %d is too large, maximum is %d\n",
205 		    sblock.fs_bsize, FFS_MAXBSIZE);
206 		exit(19);
207 	}
208 	if (sblock.fs_bsize < sblock.fs_fsize) {
209 		printf("block size (%d) cannot be smaller than fragment size (%d)\n",
210 		    sblock.fs_bsize, sblock.fs_fsize);
211 		exit(20);
212 	}
213 
214 	if (maxbsize < bsize || !POWEROF2(maxbsize)) {
215 		sblock.fs_maxbsize = sblock.fs_bsize;
216 		printf("Extent size set to %d\n", sblock.fs_maxbsize);
217 	} else if (sblock.fs_maxbsize > FS_MAXCONTIG * sblock.fs_bsize) {
218 		sblock.fs_maxbsize = FS_MAXCONTIG * sblock.fs_bsize;
219 		printf("Extent size reduced to %d\n", sblock.fs_maxbsize);
220 	} else {
221 		sblock.fs_maxbsize = maxbsize;
222 	}
223 	sblock.fs_maxcontig = maxcontig;
224 	if (sblock.fs_maxcontig < sblock.fs_maxbsize / sblock.fs_bsize) {
225 		sblock.fs_maxcontig = sblock.fs_maxbsize / sblock.fs_bsize;
226 		printf("Maxcontig raised to %d\n", sblock.fs_maxbsize);
227 	}
228 
229 	if (sblock.fs_maxcontig > 1)
230 		sblock.fs_contigsumsize = MIN(sblock.fs_maxcontig,FS_MAXCONTIG);
231 
232 	sblock.fs_bmask = ~(sblock.fs_bsize - 1);
233 	sblock.fs_fmask = ~(sblock.fs_fsize - 1);
234 	sblock.fs_qbmask = ~sblock.fs_bmask;
235 	sblock.fs_qfmask = ~sblock.fs_fmask;
236 	for (sblock.fs_bshift = 0, i = sblock.fs_bsize; i > 1; i >>= 1)
237 		sblock.fs_bshift++;
238 	for (sblock.fs_fshift = 0, i = sblock.fs_fsize; i > 1; i >>= 1)
239 		sblock.fs_fshift++;
240 	sblock.fs_frag = numfrags(&sblock, sblock.fs_bsize);
241 	for (sblock.fs_fragshift = 0, i = sblock.fs_frag; i > 1; i >>= 1)
242 		sblock.fs_fragshift++;
243 	if (sblock.fs_frag > MAXFRAG) {
244 		printf("fragment size %d is too small, "
245 			"minimum with block size %d is %d\n",
246 		    sblock.fs_fsize, sblock.fs_bsize,
247 		    sblock.fs_bsize / MAXFRAG);
248 		exit(21);
249 	}
250 	sblock.fs_fsbtodb = ilog2(sblock.fs_fsize / sectorsize);
251 	sblock.fs_size = sblock.fs_providersize = fssize =
252 	    dbtofsb(&sblock, fssize);
253 
254 	if (Oflag <= 1) {
255 		sblock.fs_magic = FS_UFS1_MAGIC;
256 		sblock.fs_sblockloc = SBLOCK_UFS1;
257 		sblock.fs_nindir = sblock.fs_bsize / sizeof(ufs1_daddr_t);
258 		sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs1_dinode);
259 		sblock.fs_maxsymlinklen = ((NDADDR + NIADDR) *
260 		    sizeof (ufs1_daddr_t));
261 		sblock.fs_old_inodefmt = FS_44INODEFMT;
262 		sblock.fs_old_cgoffset = 0;
263 		sblock.fs_old_cgmask = 0xffffffff;
264 		sblock.fs_old_size = sblock.fs_size;
265 		sblock.fs_old_rotdelay = 0;
266 		sblock.fs_old_rps = 60;
267 		sblock.fs_old_nspf = sblock.fs_fsize / sectorsize;
268 		sblock.fs_old_cpg = 1;
269 		sblock.fs_old_interleave = 1;
270 		sblock.fs_old_trackskew = 0;
271 		sblock.fs_old_cpc = 0;
272 		sblock.fs_old_postblformat = 1;
273 		sblock.fs_old_nrpos = 1;
274 	} else {
275 		sblock.fs_magic = FS_UFS2_MAGIC;
276 		sblock.fs_sblockloc = SBLOCK_UFS2;
277 		sblock.fs_nindir = sblock.fs_bsize / sizeof(ufs2_daddr_t);
278 		sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs2_dinode);
279 		sblock.fs_maxsymlinklen = ((NDADDR + NIADDR) *
280 		    sizeof (ufs2_daddr_t));
281 	}
282 
283 	sblock.fs_sblkno =
284 	    roundup(howmany(sblock.fs_sblockloc + SBLOCKSIZE, sblock.fs_fsize),
285 		sblock.fs_frag);
286 	sblock.fs_cblkno = (daddr_t)(sblock.fs_sblkno +
287 	    roundup(howmany(SBLOCKSIZE, sblock.fs_fsize), sblock.fs_frag));
288 	sblock.fs_iblkno = sblock.fs_cblkno + sblock.fs_frag;
289 	sblock.fs_maxfilesize = sblock.fs_bsize * NDADDR - 1;
290 	for (sizepb = sblock.fs_bsize, i = 0; i < NIADDR; i++) {
291 		sizepb *= NINDIR(&sblock);
292 		sblock.fs_maxfilesize += sizepb;
293 	}
294 
295 	/*
296 	 * Calculate the number of blocks to put into each cylinder group.
297 	 *
298 	 * This algorithm selects the number of blocks per cylinder
299 	 * group. The first goal is to have at least enough data blocks
300 	 * in each cylinder group to meet the density requirement. Once
301 	 * this goal is achieved we try to expand to have at least
302 	 * 1 cylinder group. Once this goal is achieved, we pack as
303 	 * many blocks into each cylinder group map as will fit.
304 	 *
305 	 * We start by calculating the smallest number of blocks that we
306 	 * can put into each cylinder group. If this is too big, we reduce
307 	 * the density until it fits.
308 	 */
309 	origdensity = density;
310 	for (;;) {
311 		fragsperinode = MAX(numfrags(&sblock, density), 1);
312 		minfpg = fragsperinode * INOPB(&sblock);
313 		if (minfpg > sblock.fs_size)
314 			minfpg = sblock.fs_size;
315 		sblock.fs_ipg = INOPB(&sblock);
316 		sblock.fs_fpg = roundup(sblock.fs_iblkno +
317 		    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
318 		if (sblock.fs_fpg < minfpg)
319 			sblock.fs_fpg = minfpg;
320 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
321 		    INOPB(&sblock));
322 		sblock.fs_fpg = roundup(sblock.fs_iblkno +
323 		    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
324 		if (sblock.fs_fpg < minfpg)
325 			sblock.fs_fpg = minfpg;
326 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
327 		    INOPB(&sblock));
328 		if (CGSIZE(&sblock) < (unsigned long)sblock.fs_bsize)
329 			break;
330 		density -= sblock.fs_fsize;
331 	}
332 	if (density != origdensity)
333 		printf("density reduced from %d to %d\n", origdensity, density);
334 
335 	if (maxblkspercg <= 0 || maxblkspercg >= fssize)
336 		maxblkspercg = fssize - 1;
337 	/*
338 	 * Start packing more blocks into the cylinder group until
339 	 * it cannot grow any larger, the number of cylinder groups
340 	 * drops below 1, or we reach the size requested.
341 	 */
342 	for ( ; sblock.fs_fpg < maxblkspercg; sblock.fs_fpg += sblock.fs_frag) {
343 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
344 		    INOPB(&sblock));
345 		if (sblock.fs_size / sblock.fs_fpg < 1)
346 			break;
347 		if (CGSIZE(&sblock) < (unsigned long)sblock.fs_bsize)
348 			continue;
349 		if (CGSIZE(&sblock) == (unsigned long)sblock.fs_bsize)
350 			break;
351 		sblock.fs_fpg -= sblock.fs_frag;
352 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
353 		    INOPB(&sblock));
354 		break;
355 	}
356 	/*
357 	 * Check to be sure that the last cylinder group has enough blocks
358 	 * to be viable. If it is too small, reduce the number of blocks
359 	 * per cylinder group which will have the effect of moving more
360 	 * blocks into the last cylinder group.
361 	 */
362 	optimalfpg = sblock.fs_fpg;
363 	for (;;) {
364 		sblock.fs_ncg = howmany(sblock.fs_size, sblock.fs_fpg);
365 		lastminfpg = roundup(sblock.fs_iblkno +
366 		    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
367 		if (sblock.fs_size < lastminfpg) {
368 			printf("Filesystem size %lld < minimum size of %d\n",
369 			    (long long)sblock.fs_size, lastminfpg);
370 			exit(28);
371 		}
372 		if (sblock.fs_size % sblock.fs_fpg >= lastminfpg ||
373 		    sblock.fs_size % sblock.fs_fpg == 0)
374 			break;
375 		sblock.fs_fpg -= sblock.fs_frag;
376 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
377 		    INOPB(&sblock));
378 	}
379 	if (optimalfpg != sblock.fs_fpg)
380 		printf("Reduced frags per cylinder group from %d to %d %s\n",
381 		   optimalfpg, sblock.fs_fpg, "to enlarge last cyl group");
382 	sblock.fs_cgsize = fragroundup(&sblock, CGSIZE(&sblock));
383 	sblock.fs_dblkno = sblock.fs_iblkno + sblock.fs_ipg / INOPF(&sblock);
384 	if (Oflag <= 1) {
385 		sblock.fs_old_spc = sblock.fs_fpg * sblock.fs_old_nspf;
386 		sblock.fs_old_nsect = sblock.fs_old_spc;
387 		sblock.fs_old_npsect = sblock.fs_old_spc;
388 		sblock.fs_old_ncyl = sblock.fs_ncg;
389 	}
390 
391 	/*
392 	 * fill in remaining fields of the super block
393 	 */
394 	sblock.fs_csaddr = cgdmin(&sblock, 0);
395 	sblock.fs_cssize =
396 	    fragroundup(&sblock, sblock.fs_ncg * sizeof(struct csum));
397 
398 	/*
399 	 * Setup memory for temporary in-core cylgroup summaries.
400 	 * Cribbed from ffs_mountfs().
401 	 */
402 	size = sblock.fs_cssize;
403 	blks = howmany(size, sblock.fs_fsize);
404 	if (sblock.fs_contigsumsize > 0)
405 		size += sblock.fs_ncg * sizeof(int32_t);
406 	if ((space = (char *)calloc(1, size)) == NULL)
407 		err(1, "memory allocation error for cg summaries");
408 	sblock.fs_csp = space;
409 	space = (char *)space + sblock.fs_cssize;
410 	if (sblock.fs_contigsumsize > 0) {
411 		int32_t *lp;
412 
413 		sblock.fs_maxcluster = lp = space;
414 		for (i = 0; i < sblock.fs_ncg; i++)
415 		*lp++ = sblock.fs_contigsumsize;
416 	}
417 
418 	sblock.fs_sbsize = fragroundup(&sblock, sizeof(struct fs));
419 	if (sblock.fs_sbsize > SBLOCKSIZE)
420 		sblock.fs_sbsize = SBLOCKSIZE;
421 	sblock.fs_minfree = minfree;
422 	sblock.fs_maxcontig = maxcontig;
423 	sblock.fs_maxbpg = maxbpg;
424 	sblock.fs_optim = opt;
425 	sblock.fs_cgrotor = 0;
426 	sblock.fs_pendingblocks = 0;
427 	sblock.fs_pendinginodes = 0;
428 	sblock.fs_cstotal.cs_ndir = 0;
429 	sblock.fs_cstotal.cs_nbfree = 0;
430 	sblock.fs_cstotal.cs_nifree = 0;
431 	sblock.fs_cstotal.cs_nffree = 0;
432 	sblock.fs_fmod = 0;
433 	sblock.fs_ronly = 0;
434 	sblock.fs_state = 0;
435 	sblock.fs_clean = FS_ISCLEAN;
436 	sblock.fs_ronly = 0;
437 	sblock.fs_id[0] = start_time.tv_sec;
438 	sblock.fs_id[1] = random();
439 	sblock.fs_fsmnt[0] = '\0';
440 	csfrags = howmany(sblock.fs_cssize, sblock.fs_fsize);
441 	sblock.fs_dsize = sblock.fs_size - sblock.fs_sblkno -
442 	    sblock.fs_ncg * (sblock.fs_dblkno - sblock.fs_sblkno);
443 	sblock.fs_cstotal.cs_nbfree =
444 	    fragstoblks(&sblock, sblock.fs_dsize) -
445 	    howmany(csfrags, sblock.fs_frag);
446 	sblock.fs_cstotal.cs_nffree =
447 	    fragnum(&sblock, sblock.fs_size) +
448 	    (fragnum(&sblock, csfrags) > 0 ?
449 	    sblock.fs_frag - fragnum(&sblock, csfrags) : 0);
450 	sblock.fs_cstotal.cs_nifree = sblock.fs_ncg * sblock.fs_ipg - ROOTINO;
451 	sblock.fs_cstotal.cs_ndir = 0;
452 	sblock.fs_dsize -= csfrags;
453 	sblock.fs_time = start_time.tv_sec;
454 	if (Oflag <= 1) {
455 		sblock.fs_old_time = start_time.tv_sec;
456 		sblock.fs_old_dsize = sblock.fs_dsize;
457 		sblock.fs_old_csaddr = sblock.fs_csaddr;
458 		sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
459 		sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
460 		sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
461 		sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
462 	}
463 	/*
464 	 * Dump out summary information about file system.
465 	 */
466 #define	B2MBFACTOR (1 / (1024.0 * 1024.0))
467 	printf("%s: %.1fMB (%lld sectors) block size %d, "
468 	       "fragment size %d\n",
469 	    fsys, (float)sblock.fs_size * sblock.fs_fsize * B2MBFACTOR,
470 	    (long long)fsbtodb(&sblock, sblock.fs_size),
471 	    sblock.fs_bsize, sblock.fs_fsize);
472 	printf("\tusing %d cylinder groups of %.2fMB, %d blks, "
473 	       "%d inodes.\n",
474 	    sblock.fs_ncg,
475 	    (float)sblock.fs_fpg * sblock.fs_fsize * B2MBFACTOR,
476 	    sblock.fs_fpg / sblock.fs_frag, sblock.fs_ipg);
477 #undef B2MBFACTOR
478 	/*
479 	 * Now determine how wide each column will be, and calculate how
480 	 * many columns will fit in a 76 char line. 76 is the width of the
481 	 * subwindows in sysinst.
482 	 */
483 	printcolwidth = count_digits(
484 			fsbtodb(&sblock, cgsblock(&sblock, sblock.fs_ncg -1)));
485 	nprintcols = 76 / (printcolwidth + 2);
486 
487 	/*
488 	 * allocate space for superblock, cylinder group map, and
489 	 * two sets of inode blocks.
490 	 */
491 	if (sblock.fs_bsize < SBLOCKSIZE)
492 		iobufsize = SBLOCKSIZE + 3 * sblock.fs_bsize;
493 	else
494 		iobufsize = 4 * sblock.fs_bsize;
495 	if ((iobuf = malloc(iobufsize)) == 0) {
496 		printf("Cannot allocate I/O buffer\n");
497 		exit(38);
498 	}
499 	memset(iobuf, 0, iobufsize);
500 	/*
501 	 * Make a copy of the superblock into the buffer that we will be
502 	 * writing out in each cylinder group.
503 	 */
504 	memcpy(writebuf, &sblock, sbsize);
505 	if (fsopts->needswap)
506 		ffs_sb_swap(&sblock, (struct fs*)writebuf);
507 	memcpy(iobuf, writebuf, SBLOCKSIZE);
508 
509 	printf("super-block backups (for fsck -b #) at:");
510 	for (cylno = 0; cylno < sblock.fs_ncg; cylno++) {
511 		initcg(cylno, start_time.tv_sec, fsopts);
512 		if (cylno % nprintcols == 0)
513 			printf("\n");
514 		printf(" %*lld,", printcolwidth,
515 			(long long)fsbtodb(&sblock, cgsblock(&sblock, cylno)));
516 		fflush(stdout);
517 	}
518 	printf("\n");
519 
520 	/*
521 	 * Now construct the initial file system,
522 	 * then write out the super-block.
523 	 */
524 	sblock.fs_time = start_time.tv_sec;
525 	if (Oflag <= 1) {
526 		sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
527 		sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
528 		sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
529 		sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
530 	}
531 	if (fsopts->needswap)
532 		sblock.fs_flags |= FS_SWAPPED;
533 	ffs_write_superblock(&sblock, fsopts);
534 	return (&sblock);
535 }
536 
537 /*
538  * Write out the superblock and its duplicates,
539  * and the cylinder group summaries
540  */
541 void
542 ffs_write_superblock(struct fs *fs, const fsinfo_t *fsopts)
543 {
544 	int cylno, size, blks, i, saveflag;
545 	void *space;
546 	char *wrbuf;
547 
548 	saveflag = fs->fs_flags & FS_INTERNAL;
549 	fs->fs_flags &= ~FS_INTERNAL;
550 
551         memcpy(writebuf, &sblock, sbsize);
552 	if (fsopts->needswap)
553 		ffs_sb_swap(fs, (struct fs*)writebuf);
554 	ffs_wtfs(fs->fs_sblockloc / sectorsize, sbsize, writebuf, fsopts);
555 
556 	/* Write out the duplicate super blocks */
557 	for (cylno = 0; cylno < fs->fs_ncg; cylno++)
558 		ffs_wtfs(fsbtodb(fs, cgsblock(fs, cylno)),
559 		    sbsize, writebuf, fsopts);
560 
561 	/* Write out the cylinder group summaries */
562 	size = fs->fs_cssize;
563 	blks = howmany(size, fs->fs_fsize);
564 	space = (void *)fs->fs_csp;
565 	if ((wrbuf = malloc(size)) == NULL)
566 		err(1, "ffs_write_superblock: malloc %d", size);
567 	for (i = 0; i < blks; i+= fs->fs_frag) {
568 		size = fs->fs_bsize;
569 		if (i + fs->fs_frag > blks)
570 			size = (blks - i) * fs->fs_fsize;
571 		if (fsopts->needswap)
572 			ffs_csum_swap((struct csum *)space,
573 			    (struct csum *)wrbuf, size);
574 		else
575 			memcpy(wrbuf, space, (u_int)size);
576 		ffs_wtfs(fsbtodb(fs, fs->fs_csaddr + i), size, wrbuf, fsopts);
577 		space = (char *)space + size;
578 	}
579 	free(wrbuf);
580 	fs->fs_flags |= saveflag;
581 }
582 
583 /*
584  * Initialize a cylinder group.
585  */
586 static void
587 initcg(int cylno, time_t utime, const fsinfo_t *fsopts)
588 {
589 	daddr_t cbase, dmax;
590 	int32_t i, j, d, dlower, dupper, blkno;
591 	struct ufs1_dinode *dp1;
592 	struct ufs2_dinode *dp2;
593 	int start;
594 
595 	/*
596 	 * Determine block bounds for cylinder group.
597 	 * Allow space for super block summary information in first
598 	 * cylinder group.
599 	 */
600 	cbase = cgbase(&sblock, cylno);
601 	dmax = cbase + sblock.fs_fpg;
602 	if (dmax > sblock.fs_size)
603 		dmax = sblock.fs_size;
604 	dlower = cgsblock(&sblock, cylno) - cbase;
605 	dupper = cgdmin(&sblock, cylno) - cbase;
606 	if (cylno == 0)
607 		dupper += howmany(sblock.fs_cssize, sblock.fs_fsize);
608 	memset(&acg, 0, sblock.fs_cgsize);
609 	acg.cg_time = utime;
610 	acg.cg_magic = CG_MAGIC;
611 	acg.cg_cgx = cylno;
612 	acg.cg_niblk = sblock.fs_ipg;
613 	acg.cg_initediblk = sblock.fs_ipg < 2 * INOPB(&sblock) ?
614 	    sblock.fs_ipg : 2 * INOPB(&sblock);
615 	acg.cg_ndblk = dmax - cbase;
616 	if (sblock.fs_contigsumsize > 0)
617 		acg.cg_nclusterblks = acg.cg_ndblk >> sblock.fs_fragshift;
618 	start = &acg.cg_space[0] - (u_char *)(&acg.cg_firstfield);
619 	if (Oflag == 2) {
620 		acg.cg_iusedoff = start;
621 	} else {
622 		if (cylno == sblock.fs_ncg - 1)
623 			acg.cg_old_ncyl = howmany(acg.cg_ndblk,
624 			    sblock.fs_fpg / sblock.fs_old_cpg);
625 		else
626 			acg.cg_old_ncyl = sblock.fs_old_cpg;
627 		acg.cg_old_time = acg.cg_time;
628 		acg.cg_time = 0;
629 		acg.cg_old_niblk = acg.cg_niblk;
630 		acg.cg_niblk = 0;
631 		acg.cg_initediblk = 0;
632 		acg.cg_old_btotoff = start;
633 		acg.cg_old_boff = acg.cg_old_btotoff +
634 		    sblock.fs_old_cpg * sizeof(int32_t);
635 		acg.cg_iusedoff = acg.cg_old_boff +
636 		    sblock.fs_old_cpg * sizeof(u_int16_t);
637 	}
638 	acg.cg_freeoff = acg.cg_iusedoff + howmany(sblock.fs_ipg, CHAR_BIT);
639 	if (sblock.fs_contigsumsize <= 0) {
640 		acg.cg_nextfreeoff = acg.cg_freeoff +
641 		   howmany(sblock.fs_fpg, CHAR_BIT);
642 	} else {
643 		acg.cg_clustersumoff = acg.cg_freeoff +
644 		    howmany(sblock.fs_fpg, CHAR_BIT) - sizeof(int32_t);
645 		acg.cg_clustersumoff =
646 		    roundup(acg.cg_clustersumoff, sizeof(int32_t));
647 		acg.cg_clusteroff = acg.cg_clustersumoff +
648 		    (sblock.fs_contigsumsize + 1) * sizeof(int32_t);
649 		acg.cg_nextfreeoff = acg.cg_clusteroff +
650 		    howmany(fragstoblks(&sblock, sblock.fs_fpg), CHAR_BIT);
651 	}
652 	if (acg.cg_nextfreeoff > sblock.fs_cgsize) {
653 		printf("Panic: cylinder group too big\n");
654 		exit(37);
655 	}
656 	acg.cg_cs.cs_nifree += sblock.fs_ipg;
657 	if (cylno == 0)
658 		for (i = 0; i < ROOTINO; i++) {
659 			setbit(cg_inosused_swap(&acg, 0), i);
660 			acg.cg_cs.cs_nifree--;
661 		}
662 	if (cylno > 0) {
663 		/*
664 		 * In cylno 0, beginning space is reserved
665 		 * for boot and super blocks.
666 		 */
667 		for (d = 0, blkno = 0; d < dlower;) {
668 			ffs_setblock(&sblock, cg_blksfree_swap(&acg, 0), blkno);
669 			if (sblock.fs_contigsumsize > 0)
670 				setbit(cg_clustersfree_swap(&acg, 0), blkno);
671 			acg.cg_cs.cs_nbfree++;
672 			d += sblock.fs_frag;
673 			blkno++;
674 		}
675 	}
676 	if ((i = (dupper & (sblock.fs_frag - 1))) != 0) {
677 		acg.cg_frsum[sblock.fs_frag - i]++;
678 		for (d = dupper + sblock.fs_frag - i; dupper < d; dupper++) {
679 			setbit(cg_blksfree_swap(&acg, 0), dupper);
680 			acg.cg_cs.cs_nffree++;
681 		}
682 	}
683 	for (d = dupper, blkno = dupper >> sblock.fs_fragshift;
684 	     d + sblock.fs_frag <= acg.cg_ndblk; ) {
685 		ffs_setblock(&sblock, cg_blksfree_swap(&acg, 0), blkno);
686 		if (sblock.fs_contigsumsize > 0)
687 			setbit(cg_clustersfree_swap(&acg, 0), blkno);
688 		acg.cg_cs.cs_nbfree++;
689 		d += sblock.fs_frag;
690 		blkno++;
691 	}
692 	if (d < acg.cg_ndblk) {
693 		acg.cg_frsum[acg.cg_ndblk - d]++;
694 		for (; d < acg.cg_ndblk; d++) {
695 			setbit(cg_blksfree_swap(&acg, 0), d);
696 			acg.cg_cs.cs_nffree++;
697 		}
698 	}
699 	if (sblock.fs_contigsumsize > 0) {
700 		int32_t *sump = cg_clustersum_swap(&acg, 0);
701 		u_char *mapp = cg_clustersfree_swap(&acg, 0);
702 		int map = *mapp++;
703 		int bit = 1;
704 		int run = 0;
705 
706 		for (i = 0; i < acg.cg_nclusterblks; i++) {
707 			if ((map & bit) != 0) {
708 				run++;
709 			} else if (run != 0) {
710 				if (run > sblock.fs_contigsumsize)
711 					run = sblock.fs_contigsumsize;
712 				sump[run]++;
713 				run = 0;
714 			}
715 			if ((i & (CHAR_BIT - 1)) != (CHAR_BIT - 1)) {
716 				bit <<= 1;
717 			} else {
718 				map = *mapp++;
719 				bit = 1;
720 			}
721 		}
722 		if (run != 0) {
723 			if (run > sblock.fs_contigsumsize)
724 				run = sblock.fs_contigsumsize;
725 			sump[run]++;
726 		}
727 	}
728 	sblock.fs_cs(&sblock, cylno) = acg.cg_cs;
729 	/*
730 	 * Write out the duplicate super block, the cylinder group map
731 	 * and two blocks worth of inodes in a single write.
732 	 */
733 	start = sblock.fs_bsize > SBLOCKSIZE ? sblock.fs_bsize : SBLOCKSIZE;
734 	memcpy(&iobuf[start], &acg, sblock.fs_cgsize);
735 	if (fsopts->needswap)
736 		ffs_cg_swap(&acg, (struct cg*)&iobuf[start], &sblock);
737 	start += sblock.fs_bsize;
738 	dp1 = (struct ufs1_dinode *)(&iobuf[start]);
739 	dp2 = (struct ufs2_dinode *)(&iobuf[start]);
740 	for (i = 0; i < acg.cg_initediblk; i++) {
741 		if (sblock.fs_magic == FS_UFS1_MAGIC) {
742 			/* No need to swap, it'll stay random */
743 			dp1->di_gen = random();
744 			dp1++;
745 		} else {
746 			dp2->di_gen = random();
747 			dp2++;
748 		}
749 	}
750 	ffs_wtfs(fsbtodb(&sblock, cgsblock(&sblock, cylno)), iobufsize, iobuf,
751 	    fsopts);
752 	/*
753 	 * For the old file system, we have to initialize all the inodes.
754 	 */
755 	if (Oflag <= 1) {
756 		for (i = 2 * sblock.fs_frag;
757 		     i < sblock.fs_ipg / INOPF(&sblock);
758 		     i += sblock.fs_frag) {
759 			dp1 = (struct ufs1_dinode *)(&iobuf[start]);
760 			for (j = 0; j < INOPB(&sblock); j++) {
761 				dp1->di_gen = random();
762 				dp1++;
763 			}
764 			ffs_wtfs(fsbtodb(&sblock, cgimin(&sblock, cylno) + i),
765 			    sblock.fs_bsize, &iobuf[start], fsopts);
766 		}
767 	}
768 }
769 
770 /*
771  * read a block from the file system
772  */
773 void
774 ffs_rdfs(daddr_t bno, int size, void *bf, const fsinfo_t *fsopts)
775 {
776 	int n;
777 	off_t offset;
778 
779 	offset = bno;
780 	offset *= fsopts->sectorsize;
781 	if (lseek(fsopts->fd, offset, SEEK_SET) < 0)
782 		err(1, "ffs_rdfs: seek error for sector %lld: %s\n",
783 		    (long long)bno, strerror(errno));
784 	n = read(fsopts->fd, bf, size);
785 	if (n == -1) {
786 		abort();
787 		err(1, "ffs_rdfs: read error bno %lld size %d", (long long)bno,
788 		    size);
789 	}
790 	else if (n != size)
791 		errx(1, "ffs_rdfs: read error for sector %lld: %s\n",
792 		    (long long)bno, strerror(errno));
793 }
794 
795 /*
796  * write a block to the file system
797  */
798 void
799 ffs_wtfs(daddr_t bno, int size, void *bf, const fsinfo_t *fsopts)
800 {
801 	int n;
802 	off_t offset;
803 
804 	offset = bno;
805 	offset *= fsopts->sectorsize;
806 	if (lseek(fsopts->fd, offset, SEEK_SET) < 0)
807 		err(1, "wtfs: seek error for sector %lld: %s\n",
808 		    (long long)bno, strerror(errno));
809 	n = write(fsopts->fd, bf, size);
810 	if (n == -1)
811 		err(1, "wtfs: write error for sector %lld: %s\n",
812 		    (long long)bno, strerror(errno));
813 	else if (n != size)
814 		errx(1, "wtfs: write error for sector %lld: %s\n",
815 		    (long long)bno, strerror(errno));
816 }
817 
818 
819 /* Determine how many digits are needed to print a given integer */
820 static int
821 count_digits(int num)
822 {
823 	int ndig;
824 
825 	for(ndig = 1; num > 9; num /=10, ndig++);
826 
827 	return (ndig);
828 }
829 
830 static int
831 ilog2(int val)
832 {
833 	u_int n;
834 
835 	for (n = 0; n < sizeof(n) * CHAR_BIT; n++)
836 		if (1 << n == val)
837 			return (n);
838 	errx(1, "ilog2: %d is not a power of 2\n", val);
839 }
840