xref: /freebsd/usr.sbin/makefs/ffs/mkfs.c (revision aa0a1e58)
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 	if (Oflag == 0) {
144 		sblock.fs_old_inodefmt = FS_42INODEFMT;
145 		sblock.fs_maxsymlinklen = 0;
146 		sblock.fs_old_flags = 0;
147 	} else {
148 		sblock.fs_old_inodefmt = FS_44INODEFMT;
149 		sblock.fs_maxsymlinklen = (Oflag == 1 ? MAXSYMLINKLEN_UFS1 :
150 		    MAXSYMLINKLEN_UFS2);
151 		sblock.fs_old_flags = FS_FLAGS_UPDATED;
152 		sblock.fs_flags = 0;
153 	}
154 	/*
155 	 * Validate the given file system size.
156 	 * Verify that its last block can actually be accessed.
157 	 * Convert to file system fragment sized units.
158 	 */
159 	if (fssize <= 0) {
160 		printf("preposterous size %lld\n", (long long)fssize);
161 		exit(13);
162 	}
163 	ffs_wtfs(fssize - 1, sectorsize, (char *)&sblock, fsopts);
164 
165 	/*
166 	 * collect and verify the filesystem density info
167 	 */
168 	sblock.fs_avgfilesize = avgfilesize;
169 	sblock.fs_avgfpdir = avgfpdir;
170 	if (sblock.fs_avgfilesize <= 0)
171 		printf("illegal expected average file size %d\n",
172 		    sblock.fs_avgfilesize), exit(14);
173 	if (sblock.fs_avgfpdir <= 0)
174 		printf("illegal expected number of files per directory %d\n",
175 		    sblock.fs_avgfpdir), exit(15);
176 	/*
177 	 * collect and verify the block and fragment sizes
178 	 */
179 	sblock.fs_bsize = bsize;
180 	sblock.fs_fsize = fsize;
181 	if (!POWEROF2(sblock.fs_bsize)) {
182 		printf("block size must be a power of 2, not %d\n",
183 		    sblock.fs_bsize);
184 		exit(16);
185 	}
186 	if (!POWEROF2(sblock.fs_fsize)) {
187 		printf("fragment size must be a power of 2, not %d\n",
188 		    sblock.fs_fsize);
189 		exit(17);
190 	}
191 	if (sblock.fs_fsize < sectorsize) {
192 		printf("fragment size %d is too small, minimum is %d\n",
193 		    sblock.fs_fsize, sectorsize);
194 		exit(18);
195 	}
196 	if (sblock.fs_bsize < MINBSIZE) {
197 		printf("block size %d is too small, minimum is %d\n",
198 		    sblock.fs_bsize, MINBSIZE);
199 		exit(19);
200 	}
201 	if (sblock.fs_bsize > FFS_MAXBSIZE) {
202 		printf("block size %d is too large, maximum is %d\n",
203 		    sblock.fs_bsize, FFS_MAXBSIZE);
204 		exit(19);
205 	}
206 	if (sblock.fs_bsize < sblock.fs_fsize) {
207 		printf("block size (%d) cannot be smaller than fragment size (%d)\n",
208 		    sblock.fs_bsize, sblock.fs_fsize);
209 		exit(20);
210 	}
211 
212 	if (maxbsize < bsize || !POWEROF2(maxbsize)) {
213 		sblock.fs_maxbsize = sblock.fs_bsize;
214 		printf("Extent size set to %d\n", sblock.fs_maxbsize);
215 	} else if (sblock.fs_maxbsize > FS_MAXCONTIG * sblock.fs_bsize) {
216 		sblock.fs_maxbsize = FS_MAXCONTIG * sblock.fs_bsize;
217 		printf("Extent size reduced to %d\n", sblock.fs_maxbsize);
218 	} else {
219 		sblock.fs_maxbsize = maxbsize;
220 	}
221 	sblock.fs_maxcontig = maxcontig;
222 	if (sblock.fs_maxcontig < sblock.fs_maxbsize / sblock.fs_bsize) {
223 		sblock.fs_maxcontig = sblock.fs_maxbsize / sblock.fs_bsize;
224 		printf("Maxcontig raised to %d\n", sblock.fs_maxbsize);
225 	}
226 
227 	if (sblock.fs_maxcontig > 1)
228 		sblock.fs_contigsumsize = MIN(sblock.fs_maxcontig,FS_MAXCONTIG);
229 
230 	sblock.fs_bmask = ~(sblock.fs_bsize - 1);
231 	sblock.fs_fmask = ~(sblock.fs_fsize - 1);
232 	sblock.fs_qbmask = ~sblock.fs_bmask;
233 	sblock.fs_qfmask = ~sblock.fs_fmask;
234 	for (sblock.fs_bshift = 0, i = sblock.fs_bsize; i > 1; i >>= 1)
235 		sblock.fs_bshift++;
236 	for (sblock.fs_fshift = 0, i = sblock.fs_fsize; i > 1; i >>= 1)
237 		sblock.fs_fshift++;
238 	sblock.fs_frag = numfrags(&sblock, sblock.fs_bsize);
239 	for (sblock.fs_fragshift = 0, i = sblock.fs_frag; i > 1; i >>= 1)
240 		sblock.fs_fragshift++;
241 	if (sblock.fs_frag > MAXFRAG) {
242 		printf("fragment size %d is too small, "
243 			"minimum with block size %d is %d\n",
244 		    sblock.fs_fsize, sblock.fs_bsize,
245 		    sblock.fs_bsize / MAXFRAG);
246 		exit(21);
247 	}
248 	sblock.fs_fsbtodb = ilog2(sblock.fs_fsize / sectorsize);
249 	sblock.fs_size = fssize = dbtofsb(&sblock, fssize);
250 
251 	if (Oflag <= 1) {
252 		sblock.fs_magic = FS_UFS1_MAGIC;
253 		sblock.fs_sblockloc = SBLOCK_UFS1;
254 		sblock.fs_nindir = sblock.fs_bsize / sizeof(int32_t);
255 		sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs1_dinode);
256 		sblock.fs_maxsymlinklen = ((NDADDR + NIADDR) *
257 		    sizeof (int32_t));
258 		sblock.fs_old_inodefmt = FS_44INODEFMT;
259 		sblock.fs_old_cgoffset = 0;
260 		sblock.fs_old_cgmask = 0xffffffff;
261 		sblock.fs_old_size = sblock.fs_size;
262 		sblock.fs_old_rotdelay = 0;
263 		sblock.fs_old_rps = 60;
264 		sblock.fs_old_nspf = sblock.fs_fsize / sectorsize;
265 		sblock.fs_old_cpg = 1;
266 		sblock.fs_old_interleave = 1;
267 		sblock.fs_old_trackskew = 0;
268 		sblock.fs_old_cpc = 0;
269 		sblock.fs_old_postblformat = 1;
270 		sblock.fs_old_nrpos = 1;
271 	} else {
272 		sblock.fs_magic = FS_UFS2_MAGIC;
273 #if 0 /* XXX makefs is used for small filesystems. */
274 		sblock.fs_sblockloc = SBLOCK_UFS2;
275 #else
276 		sblock.fs_sblockloc = SBLOCK_UFS1;
277 #endif
278 		sblock.fs_nindir = sblock.fs_bsize / sizeof(int64_t);
279 		sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs2_dinode);
280 		sblock.fs_maxsymlinklen = ((NDADDR + NIADDR) *
281 		    sizeof (int64_t));
282 	}
283 
284 	sblock.fs_sblkno =
285 	    roundup(howmany(sblock.fs_sblockloc + SBLOCKSIZE, sblock.fs_fsize),
286 		sblock.fs_frag);
287 	sblock.fs_cblkno = (daddr_t)(sblock.fs_sblkno +
288 	    roundup(howmany(SBLOCKSIZE, sblock.fs_fsize), sblock.fs_frag));
289 	sblock.fs_iblkno = sblock.fs_cblkno + sblock.fs_frag;
290 	sblock.fs_maxfilesize = sblock.fs_bsize * NDADDR - 1;
291 	for (sizepb = sblock.fs_bsize, i = 0; i < NIADDR; i++) {
292 		sizepb *= NINDIR(&sblock);
293 		sblock.fs_maxfilesize += sizepb;
294 	}
295 
296 	/*
297 	 * Calculate the number of blocks to put into each cylinder group.
298 	 *
299 	 * This algorithm selects the number of blocks per cylinder
300 	 * group. The first goal is to have at least enough data blocks
301 	 * in each cylinder group to meet the density requirement. Once
302 	 * this goal is achieved we try to expand to have at least
303 	 * 1 cylinder group. Once this goal is achieved, we pack as
304 	 * many blocks into each cylinder group map as will fit.
305 	 *
306 	 * We start by calculating the smallest number of blocks that we
307 	 * can put into each cylinder group. If this is too big, we reduce
308 	 * the density until it fits.
309 	 */
310 	origdensity = density;
311 	for (;;) {
312 		fragsperinode = MAX(numfrags(&sblock, density), 1);
313 		minfpg = fragsperinode * INOPB(&sblock);
314 		if (minfpg > sblock.fs_size)
315 			minfpg = sblock.fs_size;
316 		sblock.fs_ipg = INOPB(&sblock);
317 		sblock.fs_fpg = roundup(sblock.fs_iblkno +
318 		    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
319 		if (sblock.fs_fpg < minfpg)
320 			sblock.fs_fpg = minfpg;
321 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
322 		    INOPB(&sblock));
323 		sblock.fs_fpg = roundup(sblock.fs_iblkno +
324 		    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
325 		if (sblock.fs_fpg < minfpg)
326 			sblock.fs_fpg = minfpg;
327 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
328 		    INOPB(&sblock));
329 		if (CGSIZE(&sblock) < (unsigned long)sblock.fs_bsize)
330 			break;
331 		density -= sblock.fs_fsize;
332 	}
333 	if (density != origdensity)
334 		printf("density reduced from %d to %d\n", origdensity, density);
335 
336 	if (maxblkspercg <= 0 || maxblkspercg >= fssize)
337 		maxblkspercg = fssize - 1;
338 	/*
339 	 * Start packing more blocks into the cylinder group until
340 	 * it cannot grow any larger, the number of cylinder groups
341 	 * drops below 1, or we reach the size requested.
342 	 */
343 	for ( ; sblock.fs_fpg < maxblkspercg; sblock.fs_fpg += sblock.fs_frag) {
344 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
345 		    INOPB(&sblock));
346 		if (sblock.fs_size / sblock.fs_fpg < 1)
347 			break;
348 		if (CGSIZE(&sblock) < (unsigned long)sblock.fs_bsize)
349 			continue;
350 		if (CGSIZE(&sblock) == (unsigned long)sblock.fs_bsize)
351 			break;
352 		sblock.fs_fpg -= sblock.fs_frag;
353 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
354 		    INOPB(&sblock));
355 		break;
356 	}
357 	/*
358 	 * Check to be sure that the last cylinder group has enough blocks
359 	 * to be viable. If it is too small, reduce the number of blocks
360 	 * per cylinder group which will have the effect of moving more
361 	 * blocks into the last cylinder group.
362 	 */
363 	optimalfpg = sblock.fs_fpg;
364 	for (;;) {
365 		sblock.fs_ncg = howmany(sblock.fs_size, sblock.fs_fpg);
366 		lastminfpg = roundup(sblock.fs_iblkno +
367 		    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
368 		if (sblock.fs_size < lastminfpg) {
369 			printf("Filesystem size %lld < minimum size of %d\n",
370 			    (long long)sblock.fs_size, lastminfpg);
371 			exit(28);
372 		}
373 		if (sblock.fs_size % sblock.fs_fpg >= lastminfpg ||
374 		    sblock.fs_size % sblock.fs_fpg == 0)
375 			break;
376 		sblock.fs_fpg -= sblock.fs_frag;
377 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
378 		    INOPB(&sblock));
379 	}
380 	if (optimalfpg != sblock.fs_fpg)
381 		printf("Reduced frags per cylinder group from %d to %d %s\n",
382 		   optimalfpg, sblock.fs_fpg, "to enlarge last cyl group");
383 	sblock.fs_cgsize = fragroundup(&sblock, CGSIZE(&sblock));
384 	sblock.fs_dblkno = sblock.fs_iblkno + sblock.fs_ipg / INOPF(&sblock);
385 	if (Oflag <= 1) {
386 		sblock.fs_old_spc = sblock.fs_fpg * sblock.fs_old_nspf;
387 		sblock.fs_old_nsect = sblock.fs_old_spc;
388 		sblock.fs_old_npsect = sblock.fs_old_spc;
389 		sblock.fs_old_ncyl = sblock.fs_ncg;
390 	}
391 
392 	/*
393 	 * fill in remaining fields of the super block
394 	 */
395 	sblock.fs_csaddr = cgdmin(&sblock, 0);
396 	sblock.fs_cssize =
397 	    fragroundup(&sblock, sblock.fs_ncg * sizeof(struct csum));
398 
399 	/*
400 	 * Setup memory for temporary in-core cylgroup summaries.
401 	 * Cribbed from ffs_mountfs().
402 	 */
403 	size = sblock.fs_cssize;
404 	blks = howmany(size, sblock.fs_fsize);
405 	if (sblock.fs_contigsumsize > 0)
406 		size += sblock.fs_ncg * sizeof(int32_t);
407 	if ((space = (char *)calloc(1, size)) == NULL)
408 		err(1, "memory allocation error for cg summaries");
409 	sblock.fs_csp = space;
410 	space = (char *)space + sblock.fs_cssize;
411 	if (sblock.fs_contigsumsize > 0) {
412 		int32_t *lp;
413 
414 		sblock.fs_maxcluster = lp = space;
415 		for (i = 0; i < sblock.fs_ncg; i++)
416 		*lp++ = sblock.fs_contigsumsize;
417 	}
418 
419 	sblock.fs_sbsize = fragroundup(&sblock, sizeof(struct fs));
420 	if (sblock.fs_sbsize > SBLOCKSIZE)
421 		sblock.fs_sbsize = SBLOCKSIZE;
422 	sblock.fs_minfree = minfree;
423 	sblock.fs_maxcontig = maxcontig;
424 	sblock.fs_maxbpg = maxbpg;
425 	sblock.fs_optim = opt;
426 	sblock.fs_cgrotor = 0;
427 	sblock.fs_pendingblocks = 0;
428 	sblock.fs_pendinginodes = 0;
429 	sblock.fs_cstotal.cs_ndir = 0;
430 	sblock.fs_cstotal.cs_nbfree = 0;
431 	sblock.fs_cstotal.cs_nifree = 0;
432 	sblock.fs_cstotal.cs_nffree = 0;
433 	sblock.fs_fmod = 0;
434 	sblock.fs_ronly = 0;
435 	sblock.fs_state = 0;
436 	sblock.fs_clean = FS_ISCLEAN;
437 	sblock.fs_ronly = 0;
438 	sblock.fs_id[0] = start_time.tv_sec;
439 	sblock.fs_id[1] = random();
440 	sblock.fs_fsmnt[0] = '\0';
441 	csfrags = howmany(sblock.fs_cssize, sblock.fs_fsize);
442 	sblock.fs_dsize = sblock.fs_size - sblock.fs_sblkno -
443 	    sblock.fs_ncg * (sblock.fs_dblkno - sblock.fs_sblkno);
444 	sblock.fs_cstotal.cs_nbfree =
445 	    fragstoblks(&sblock, sblock.fs_dsize) -
446 	    howmany(csfrags, sblock.fs_frag);
447 	sblock.fs_cstotal.cs_nffree =
448 	    fragnum(&sblock, sblock.fs_size) +
449 	    (fragnum(&sblock, csfrags) > 0 ?
450 	    sblock.fs_frag - fragnum(&sblock, csfrags) : 0);
451 	sblock.fs_cstotal.cs_nifree = sblock.fs_ncg * sblock.fs_ipg - ROOTINO;
452 	sblock.fs_cstotal.cs_ndir = 0;
453 	sblock.fs_dsize -= csfrags;
454 	sblock.fs_time = start_time.tv_sec;
455 	if (Oflag <= 1) {
456 		sblock.fs_old_time = start_time.tv_sec;
457 		sblock.fs_old_dsize = sblock.fs_dsize;
458 		sblock.fs_old_csaddr = sblock.fs_csaddr;
459 		sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
460 		sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
461 		sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
462 		sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
463 	}
464 	/*
465 	 * Dump out summary information about file system.
466 	 */
467 #define	B2MBFACTOR (1 / (1024.0 * 1024.0))
468 	printf("%s: %.1fMB (%lld sectors) block size %d, "
469 	       "fragment size %d\n",
470 	    fsys, (float)sblock.fs_size * sblock.fs_fsize * B2MBFACTOR,
471 	    (long long)fsbtodb(&sblock, sblock.fs_size),
472 	    sblock.fs_bsize, sblock.fs_fsize);
473 	printf("\tusing %d cylinder groups of %.2fMB, %d blks, "
474 	       "%d inodes.\n",
475 	    sblock.fs_ncg,
476 	    (float)sblock.fs_fpg * sblock.fs_fsize * B2MBFACTOR,
477 	    sblock.fs_fpg / sblock.fs_frag, sblock.fs_ipg);
478 #undef B2MBFACTOR
479 	/*
480 	 * Now determine how wide each column will be, and calculate how
481 	 * many columns will fit in a 76 char line. 76 is the width of the
482 	 * subwindows in sysinst.
483 	 */
484 	printcolwidth = count_digits(
485 			fsbtodb(&sblock, cgsblock(&sblock, sblock.fs_ncg -1)));
486 	nprintcols = 76 / (printcolwidth + 2);
487 
488 	/*
489 	 * allocate space for superblock, cylinder group map, and
490 	 * two sets of inode blocks.
491 	 */
492 	if (sblock.fs_bsize < SBLOCKSIZE)
493 		iobufsize = SBLOCKSIZE + 3 * sblock.fs_bsize;
494 	else
495 		iobufsize = 4 * sblock.fs_bsize;
496 	if ((iobuf = malloc(iobufsize)) == 0) {
497 		printf("Cannot allocate I/O buffer\n");
498 		exit(38);
499 	}
500 	memset(iobuf, 0, iobufsize);
501 	/*
502 	 * Make a copy of the superblock into the buffer that we will be
503 	 * writing out in each cylinder group.
504 	 */
505 	memcpy(writebuf, &sblock, sbsize);
506 	if (fsopts->needswap)
507 		ffs_sb_swap(&sblock, (struct fs*)writebuf);
508 	memcpy(iobuf, writebuf, SBLOCKSIZE);
509 
510 	printf("super-block backups (for fsck -b #) at:");
511 	for (cylno = 0; cylno < sblock.fs_ncg; cylno++) {
512 		initcg(cylno, start_time.tv_sec, fsopts);
513 		if (cylno % nprintcols == 0)
514 			printf("\n");
515 		printf(" %*lld,", printcolwidth,
516 			(long long)fsbtodb(&sblock, cgsblock(&sblock, cylno)));
517 		fflush(stdout);
518 	}
519 	printf("\n");
520 
521 	/*
522 	 * Now construct the initial file system,
523 	 * then write out the super-block.
524 	 */
525 	sblock.fs_time = start_time.tv_sec;
526 	if (Oflag <= 1) {
527 		sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
528 		sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
529 		sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
530 		sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
531 	}
532 	if (fsopts->needswap)
533 		sblock.fs_flags |= FS_SWAPPED;
534 	ffs_write_superblock(&sblock, fsopts);
535 	return (&sblock);
536 }
537 
538 /*
539  * Write out the superblock and its duplicates,
540  * and the cylinder group summaries
541  */
542 void
543 ffs_write_superblock(struct fs *fs, const fsinfo_t *fsopts)
544 {
545 	int cylno, size, blks, i, saveflag;
546 	void *space;
547 	char *wrbuf;
548 
549 	saveflag = fs->fs_flags & FS_INTERNAL;
550 	fs->fs_flags &= ~FS_INTERNAL;
551 
552         memcpy(writebuf, &sblock, sbsize);
553 	if (fsopts->needswap)
554 		ffs_sb_swap(fs, (struct fs*)writebuf);
555 	ffs_wtfs(fs->fs_sblockloc / sectorsize, sbsize, writebuf, fsopts);
556 
557 	/* Write out the duplicate super blocks */
558 	for (cylno = 0; cylno < fs->fs_ncg; cylno++)
559 		ffs_wtfs(fsbtodb(fs, cgsblock(fs, cylno)),
560 		    sbsize, writebuf, fsopts);
561 
562 	/* Write out the cylinder group summaries */
563 	size = fs->fs_cssize;
564 	blks = howmany(size, fs->fs_fsize);
565 	space = (void *)fs->fs_csp;
566 	if ((wrbuf = malloc(size)) == NULL)
567 		err(1, "ffs_write_superblock: malloc %d", size);
568 	for (i = 0; i < blks; i+= fs->fs_frag) {
569 		size = fs->fs_bsize;
570 		if (i + fs->fs_frag > blks)
571 			size = (blks - i) * fs->fs_fsize;
572 		if (fsopts->needswap)
573 			ffs_csum_swap((struct csum *)space,
574 			    (struct csum *)wrbuf, size);
575 		else
576 			memcpy(wrbuf, space, (u_int)size);
577 		ffs_wtfs(fsbtodb(fs, fs->fs_csaddr + i), size, wrbuf, fsopts);
578 		space = (char *)space + size;
579 	}
580 	free(wrbuf);
581 	fs->fs_flags |= saveflag;
582 }
583 
584 /*
585  * Initialize a cylinder group.
586  */
587 static void
588 initcg(int cylno, time_t utime, const fsinfo_t *fsopts)
589 {
590 	daddr_t cbase, dmax;
591 	int32_t i, j, d, dlower, dupper, blkno;
592 	struct ufs1_dinode *dp1;
593 	struct ufs2_dinode *dp2;
594 	int start;
595 
596 	/*
597 	 * Determine block bounds for cylinder group.
598 	 * Allow space for super block summary information in first
599 	 * cylinder group.
600 	 */
601 	cbase = cgbase(&sblock, cylno);
602 	dmax = cbase + sblock.fs_fpg;
603 	if (dmax > sblock.fs_size)
604 		dmax = sblock.fs_size;
605 	dlower = cgsblock(&sblock, cylno) - cbase;
606 	dupper = cgdmin(&sblock, cylno) - cbase;
607 	if (cylno == 0)
608 		dupper += howmany(sblock.fs_cssize, sblock.fs_fsize);
609 	memset(&acg, 0, sblock.fs_cgsize);
610 	acg.cg_time = utime;
611 	acg.cg_magic = CG_MAGIC;
612 	acg.cg_cgx = cylno;
613 	acg.cg_niblk = sblock.fs_ipg;
614 	acg.cg_initediblk = sblock.fs_ipg < 2 * INOPB(&sblock) ?
615 	    sblock.fs_ipg : 2 * INOPB(&sblock);
616 	acg.cg_ndblk = dmax - cbase;
617 	if (sblock.fs_contigsumsize > 0)
618 		acg.cg_nclusterblks = acg.cg_ndblk >> sblock.fs_fragshift;
619 	start = &acg.cg_space[0] - (u_char *)(&acg.cg_firstfield);
620 	if (Oflag == 2) {
621 		acg.cg_iusedoff = start;
622 	} else {
623 		if (cylno == sblock.fs_ncg - 1)
624 			acg.cg_old_ncyl = howmany(acg.cg_ndblk,
625 			    sblock.fs_fpg / sblock.fs_old_cpg);
626 		else
627 			acg.cg_old_ncyl = sblock.fs_old_cpg;
628 		acg.cg_old_time = acg.cg_time;
629 		acg.cg_time = 0;
630 		acg.cg_old_niblk = acg.cg_niblk;
631 		acg.cg_niblk = 0;
632 		acg.cg_initediblk = 0;
633 		acg.cg_old_btotoff = start;
634 		acg.cg_old_boff = acg.cg_old_btotoff +
635 		    sblock.fs_old_cpg * sizeof(int32_t);
636 		acg.cg_iusedoff = acg.cg_old_boff +
637 		    sblock.fs_old_cpg * sizeof(u_int16_t);
638 	}
639 	acg.cg_freeoff = acg.cg_iusedoff + howmany(sblock.fs_ipg, CHAR_BIT);
640 	if (sblock.fs_contigsumsize <= 0) {
641 		acg.cg_nextfreeoff = acg.cg_freeoff +
642 		   howmany(sblock.fs_fpg, CHAR_BIT);
643 	} else {
644 		acg.cg_clustersumoff = acg.cg_freeoff +
645 		    howmany(sblock.fs_fpg, CHAR_BIT) - sizeof(int32_t);
646 		acg.cg_clustersumoff =
647 		    roundup(acg.cg_clustersumoff, sizeof(int32_t));
648 		acg.cg_clusteroff = acg.cg_clustersumoff +
649 		    (sblock.fs_contigsumsize + 1) * sizeof(int32_t);
650 		acg.cg_nextfreeoff = acg.cg_clusteroff +
651 		    howmany(fragstoblks(&sblock, sblock.fs_fpg), CHAR_BIT);
652 	}
653 	if (acg.cg_nextfreeoff > sblock.fs_cgsize) {
654 		printf("Panic: cylinder group too big\n");
655 		exit(37);
656 	}
657 	acg.cg_cs.cs_nifree += sblock.fs_ipg;
658 	if (cylno == 0)
659 		for (i = 0; i < ROOTINO; i++) {
660 			setbit(cg_inosused_swap(&acg, 0), i);
661 			acg.cg_cs.cs_nifree--;
662 		}
663 	if (cylno > 0) {
664 		/*
665 		 * In cylno 0, beginning space is reserved
666 		 * for boot and super blocks.
667 		 */
668 		for (d = 0, blkno = 0; d < dlower;) {
669 			ffs_setblock(&sblock, cg_blksfree_swap(&acg, 0), blkno);
670 			if (sblock.fs_contigsumsize > 0)
671 				setbit(cg_clustersfree_swap(&acg, 0), blkno);
672 			acg.cg_cs.cs_nbfree++;
673 			d += sblock.fs_frag;
674 			blkno++;
675 		}
676 	}
677 	if ((i = (dupper & (sblock.fs_frag - 1))) != 0) {
678 		acg.cg_frsum[sblock.fs_frag - i]++;
679 		for (d = dupper + sblock.fs_frag - i; dupper < d; dupper++) {
680 			setbit(cg_blksfree_swap(&acg, 0), dupper);
681 			acg.cg_cs.cs_nffree++;
682 		}
683 	}
684 	for (d = dupper, blkno = dupper >> sblock.fs_fragshift;
685 	     d + sblock.fs_frag <= acg.cg_ndblk; ) {
686 		ffs_setblock(&sblock, cg_blksfree_swap(&acg, 0), blkno);
687 		if (sblock.fs_contigsumsize > 0)
688 			setbit(cg_clustersfree_swap(&acg, 0), blkno);
689 		acg.cg_cs.cs_nbfree++;
690 		d += sblock.fs_frag;
691 		blkno++;
692 	}
693 	if (d < acg.cg_ndblk) {
694 		acg.cg_frsum[acg.cg_ndblk - d]++;
695 		for (; d < acg.cg_ndblk; d++) {
696 			setbit(cg_blksfree_swap(&acg, 0), d);
697 			acg.cg_cs.cs_nffree++;
698 		}
699 	}
700 	if (sblock.fs_contigsumsize > 0) {
701 		int32_t *sump = cg_clustersum_swap(&acg, 0);
702 		u_char *mapp = cg_clustersfree_swap(&acg, 0);
703 		int map = *mapp++;
704 		int bit = 1;
705 		int run = 0;
706 
707 		for (i = 0; i < acg.cg_nclusterblks; i++) {
708 			if ((map & bit) != 0) {
709 				run++;
710 			} else if (run != 0) {
711 				if (run > sblock.fs_contigsumsize)
712 					run = sblock.fs_contigsumsize;
713 				sump[run]++;
714 				run = 0;
715 			}
716 			if ((i & (CHAR_BIT - 1)) != (CHAR_BIT - 1)) {
717 				bit <<= 1;
718 			} else {
719 				map = *mapp++;
720 				bit = 1;
721 			}
722 		}
723 		if (run != 0) {
724 			if (run > sblock.fs_contigsumsize)
725 				run = sblock.fs_contigsumsize;
726 			sump[run]++;
727 		}
728 	}
729 	sblock.fs_cs(&sblock, cylno) = acg.cg_cs;
730 	/*
731 	 * Write out the duplicate super block, the cylinder group map
732 	 * and two blocks worth of inodes in a single write.
733 	 */
734 	start = sblock.fs_bsize > SBLOCKSIZE ? sblock.fs_bsize : SBLOCKSIZE;
735 	memcpy(&iobuf[start], &acg, sblock.fs_cgsize);
736 	if (fsopts->needswap)
737 		ffs_cg_swap(&acg, (struct cg*)&iobuf[start], &sblock);
738 	start += sblock.fs_bsize;
739 	dp1 = (struct ufs1_dinode *)(&iobuf[start]);
740 	dp2 = (struct ufs2_dinode *)(&iobuf[start]);
741 	for (i = 0; i < acg.cg_initediblk; i++) {
742 		if (sblock.fs_magic == FS_UFS1_MAGIC) {
743 			/* No need to swap, it'll stay random */
744 			dp1->di_gen = random();
745 			dp1++;
746 		} else {
747 			dp2->di_gen = random();
748 			dp2++;
749 		}
750 	}
751 	ffs_wtfs(fsbtodb(&sblock, cgsblock(&sblock, cylno)), iobufsize, iobuf,
752 	    fsopts);
753 	/*
754 	 * For the old file system, we have to initialize all the inodes.
755 	 */
756 	if (Oflag <= 1) {
757 		for (i = 2 * sblock.fs_frag;
758 		     i < sblock.fs_ipg / INOPF(&sblock);
759 		     i += sblock.fs_frag) {
760 			dp1 = (struct ufs1_dinode *)(&iobuf[start]);
761 			for (j = 0; j < INOPB(&sblock); j++) {
762 				dp1->di_gen = random();
763 				dp1++;
764 			}
765 			ffs_wtfs(fsbtodb(&sblock, cgimin(&sblock, cylno) + i),
766 			    sblock.fs_bsize, &iobuf[start], fsopts);
767 		}
768 	}
769 }
770 
771 /*
772  * read a block from the file system
773  */
774 void
775 ffs_rdfs(daddr_t bno, int size, void *bf, const fsinfo_t *fsopts)
776 {
777 	int n;
778 	off_t offset;
779 
780 	offset = bno;
781 	offset *= fsopts->sectorsize;
782 	if (lseek(fsopts->fd, offset, SEEK_SET) < 0)
783 		err(1, "ffs_rdfs: seek error for sector %lld: %s\n",
784 		    (long long)bno, strerror(errno));
785 	n = read(fsopts->fd, bf, size);
786 	if (n == -1) {
787 		abort();
788 		err(1, "ffs_rdfs: read error bno %lld size %d", (long long)bno,
789 		    size);
790 	}
791 	else if (n != size)
792 		errx(1, "ffs_rdfs: read error for sector %lld: %s\n",
793 		    (long long)bno, strerror(errno));
794 }
795 
796 /*
797  * write a block to the file system
798  */
799 void
800 ffs_wtfs(daddr_t bno, int size, void *bf, const fsinfo_t *fsopts)
801 {
802 	int n;
803 	off_t offset;
804 
805 	offset = bno;
806 	offset *= fsopts->sectorsize;
807 	if (lseek(fsopts->fd, offset, SEEK_SET) < 0)
808 		err(1, "wtfs: seek error for sector %lld: %s\n",
809 		    (long long)bno, strerror(errno));
810 	n = write(fsopts->fd, bf, size);
811 	if (n == -1)
812 		err(1, "wtfs: write error for sector %lld: %s\n",
813 		    (long long)bno, strerror(errno));
814 	else if (n != size)
815 		errx(1, "wtfs: write error for sector %lld: %s\n",
816 		    (long long)bno, strerror(errno));
817 }
818 
819 
820 /* Determine how many digits are needed to print a given integer */
821 static int
822 count_digits(int num)
823 {
824 	int ndig;
825 
826 	for(ndig = 1; num > 9; num /=10, ndig++);
827 
828 	return (ndig);
829 }
830 
831 static int
832 ilog2(int val)
833 {
834 	u_int n;
835 
836 	for (n = 0; n < sizeof(n) * CHAR_BIT; n++)
837 		if (1 << n == val)
838 			return (n);
839 	errx(1, "ilog2: %d is not a power of 2\n", val);
840 }
841