xref: /freebsd/usr.sbin/makefs/ffs/mkfs.c (revision 1670a1c2a47d10ecccd001970b859caf93cd3b6e)
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 
56 #include <ufs/ufs/dinode.h>
57 #include <ufs/ffs/fs.h>
58 
59 #include "ffs/ufs_bswap.h"
60 #include "ffs/ufs_inode.h"
61 #include "ffs/ffs_extern.h"
62 #include "ffs/newfs_extern.h"
63 
64 static void initcg(int, time_t, const fsinfo_t *);
65 static int ilog2(int);
66 
67 static int count_digits(int);
68 
69 /*
70  * make file system for cylinder-group style file systems
71  */
72 #define	UMASK		0755
73 #define	POWEROF2(num)	(((num) & ((num) - 1)) == 0)
74 
75 union {
76 	struct fs fs;
77 	char pad[SBLOCKSIZE];
78 } fsun;
79 #define	sblock	fsun.fs
80 struct	csum *fscs;
81 
82 union {
83 	struct cg cg;
84 	char pad[FFS_MAXBSIZE];
85 } cgun;
86 #define	acg	cgun.cg
87 
88 char *iobuf;
89 int iobufsize;
90 
91 char writebuf[FFS_MAXBSIZE];
92 
93 static int     Oflag;	   /* format as an 4.3BSD file system */
94 static int64_t fssize;	   /* file system size */
95 static int     sectorsize;	   /* bytes/sector */
96 static int     fsize;	   /* fragment size */
97 static int     bsize;	   /* block size */
98 static int     maxbsize;   /* maximum clustering */
99 static int     maxblkspercg;
100 static int     minfree;	   /* free space threshold */
101 static int     opt;		   /* optimization preference (space or time) */
102 static int     density;	   /* number of bytes per inode */
103 static int     maxcontig;	   /* max contiguous blocks to allocate */
104 static int     maxbpg;	   /* maximum blocks per file in a cyl group */
105 static int     sbsize;	   /* superblock size */
106 static int     avgfilesize;	   /* expected average file size */
107 static int     avgfpdir;	   /* expected number of files per directory */
108 
109 struct fs *
110 ffs_mkfs(const char *fsys, const fsinfo_t *fsopts)
111 {
112 	int fragsperinode, optimalfpg, origdensity, minfpg, lastminfpg;
113 	int32_t cylno, i, csfrags;
114 	long long sizepb;
115 	void *space;
116 	int size, blks;
117 	int nprintcols, printcolwidth;
118 
119 	Oflag =		fsopts->version;
120 	fssize =        fsopts->size / fsopts->sectorsize;
121 	sectorsize =    fsopts->sectorsize;
122 	fsize =         fsopts->fsize;
123 	bsize =         fsopts->bsize;
124 	maxbsize =      fsopts->maxbsize;
125 	maxblkspercg =  fsopts->maxblkspercg;
126 	minfree =       fsopts->minfree;
127 	opt =           fsopts->optimization;
128 	density =       fsopts->density;
129 	maxcontig =     fsopts->maxcontig;
130 	maxbpg =        fsopts->maxbpg;
131 	avgfilesize =   fsopts->avgfilesize;
132 	avgfpdir =      fsopts->avgfpdir;
133 	sbsize =        SBLOCKSIZE;
134 
135 	if (Oflag == 0) {
136 		sblock.fs_old_inodefmt = FS_42INODEFMT;
137 		sblock.fs_maxsymlinklen = 0;
138 		sblock.fs_old_flags = 0;
139 	} else {
140 		sblock.fs_old_inodefmt = FS_44INODEFMT;
141 		sblock.fs_maxsymlinklen = (Oflag == 1 ? MAXSYMLINKLEN_UFS1 :
142 		    MAXSYMLINKLEN_UFS2);
143 		sblock.fs_old_flags = FS_FLAGS_UPDATED;
144 		sblock.fs_flags = 0;
145 	}
146 	/*
147 	 * Validate the given file system size.
148 	 * Verify that its last block can actually be accessed.
149 	 * Convert to file system fragment sized units.
150 	 */
151 	if (fssize <= 0) {
152 		printf("preposterous size %lld\n", (long long)fssize);
153 		exit(13);
154 	}
155 	ffs_wtfs(fssize - 1, sectorsize, (char *)&sblock, fsopts);
156 
157 	/*
158 	 * collect and verify the filesystem density info
159 	 */
160 	sblock.fs_avgfilesize = avgfilesize;
161 	sblock.fs_avgfpdir = avgfpdir;
162 	if (sblock.fs_avgfilesize <= 0)
163 		printf("illegal expected average file size %d\n",
164 		    sblock.fs_avgfilesize), exit(14);
165 	if (sblock.fs_avgfpdir <= 0)
166 		printf("illegal expected number of files per directory %d\n",
167 		    sblock.fs_avgfpdir), exit(15);
168 	/*
169 	 * collect and verify the block and fragment sizes
170 	 */
171 	sblock.fs_bsize = bsize;
172 	sblock.fs_fsize = fsize;
173 	if (!POWEROF2(sblock.fs_bsize)) {
174 		printf("block size must be a power of 2, not %d\n",
175 		    sblock.fs_bsize);
176 		exit(16);
177 	}
178 	if (!POWEROF2(sblock.fs_fsize)) {
179 		printf("fragment size must be a power of 2, not %d\n",
180 		    sblock.fs_fsize);
181 		exit(17);
182 	}
183 	if (sblock.fs_fsize < sectorsize) {
184 		printf("fragment size %d is too small, minimum is %d\n",
185 		    sblock.fs_fsize, sectorsize);
186 		exit(18);
187 	}
188 	if (sblock.fs_bsize < MINBSIZE) {
189 		printf("block size %d is too small, minimum is %d\n",
190 		    sblock.fs_bsize, MINBSIZE);
191 		exit(19);
192 	}
193 	if (sblock.fs_bsize > FFS_MAXBSIZE) {
194 		printf("block size %d is too large, maximum is %d\n",
195 		    sblock.fs_bsize, FFS_MAXBSIZE);
196 		exit(19);
197 	}
198 	if (sblock.fs_bsize < sblock.fs_fsize) {
199 		printf("block size (%d) cannot be smaller than fragment size (%d)\n",
200 		    sblock.fs_bsize, sblock.fs_fsize);
201 		exit(20);
202 	}
203 
204 	if (maxbsize < bsize || !POWEROF2(maxbsize)) {
205 		sblock.fs_maxbsize = sblock.fs_bsize;
206 		printf("Extent size set to %d\n", sblock.fs_maxbsize);
207 	} else if (sblock.fs_maxbsize > FS_MAXCONTIG * sblock.fs_bsize) {
208 		sblock.fs_maxbsize = FS_MAXCONTIG * sblock.fs_bsize;
209 		printf("Extent size reduced to %d\n", sblock.fs_maxbsize);
210 	} else {
211 		sblock.fs_maxbsize = maxbsize;
212 	}
213 	sblock.fs_maxcontig = maxcontig;
214 	if (sblock.fs_maxcontig < sblock.fs_maxbsize / sblock.fs_bsize) {
215 		sblock.fs_maxcontig = sblock.fs_maxbsize / sblock.fs_bsize;
216 		printf("Maxcontig raised to %d\n", sblock.fs_maxbsize);
217 	}
218 
219 	if (sblock.fs_maxcontig > 1)
220 		sblock.fs_contigsumsize = MIN(sblock.fs_maxcontig,FS_MAXCONTIG);
221 
222 	sblock.fs_bmask = ~(sblock.fs_bsize - 1);
223 	sblock.fs_fmask = ~(sblock.fs_fsize - 1);
224 	sblock.fs_qbmask = ~sblock.fs_bmask;
225 	sblock.fs_qfmask = ~sblock.fs_fmask;
226 	for (sblock.fs_bshift = 0, i = sblock.fs_bsize; i > 1; i >>= 1)
227 		sblock.fs_bshift++;
228 	for (sblock.fs_fshift = 0, i = sblock.fs_fsize; i > 1; i >>= 1)
229 		sblock.fs_fshift++;
230 	sblock.fs_frag = numfrags(&sblock, sblock.fs_bsize);
231 	for (sblock.fs_fragshift = 0, i = sblock.fs_frag; i > 1; i >>= 1)
232 		sblock.fs_fragshift++;
233 	if (sblock.fs_frag > MAXFRAG) {
234 		printf("fragment size %d is too small, "
235 			"minimum with block size %d is %d\n",
236 		    sblock.fs_fsize, sblock.fs_bsize,
237 		    sblock.fs_bsize / MAXFRAG);
238 		exit(21);
239 	}
240 	sblock.fs_fsbtodb = ilog2(sblock.fs_fsize / sectorsize);
241 	sblock.fs_size = fssize = dbtofsb(&sblock, fssize);
242 
243 	if (Oflag <= 1) {
244 		sblock.fs_magic = FS_UFS1_MAGIC;
245 		sblock.fs_sblockloc = SBLOCK_UFS1;
246 		sblock.fs_nindir = sblock.fs_bsize / sizeof(int32_t);
247 		sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs1_dinode);
248 		sblock.fs_maxsymlinklen = ((NDADDR + NIADDR) *
249 		    sizeof (int32_t));
250 		sblock.fs_old_inodefmt = FS_44INODEFMT;
251 		sblock.fs_old_cgoffset = 0;
252 		sblock.fs_old_cgmask = 0xffffffff;
253 		sblock.fs_old_size = sblock.fs_size;
254 		sblock.fs_old_rotdelay = 0;
255 		sblock.fs_old_rps = 60;
256 		sblock.fs_old_nspf = sblock.fs_fsize / sectorsize;
257 		sblock.fs_old_cpg = 1;
258 		sblock.fs_old_interleave = 1;
259 		sblock.fs_old_trackskew = 0;
260 		sblock.fs_old_cpc = 0;
261 		sblock.fs_old_postblformat = 1;
262 		sblock.fs_old_nrpos = 1;
263 	} else {
264 		sblock.fs_magic = FS_UFS2_MAGIC;
265 #if 0 /* XXX makefs is used for small filesystems. */
266 		sblock.fs_sblockloc = SBLOCK_UFS2;
267 #else
268 		sblock.fs_sblockloc = SBLOCK_UFS1;
269 #endif
270 		sblock.fs_nindir = sblock.fs_bsize / sizeof(int64_t);
271 		sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs2_dinode);
272 		sblock.fs_maxsymlinklen = ((NDADDR + NIADDR) *
273 		    sizeof (int64_t));
274 	}
275 
276 	sblock.fs_sblkno =
277 	    roundup(howmany(sblock.fs_sblockloc + SBLOCKSIZE, sblock.fs_fsize),
278 		sblock.fs_frag);
279 	sblock.fs_cblkno = (daddr_t)(sblock.fs_sblkno +
280 	    roundup(howmany(SBLOCKSIZE, sblock.fs_fsize), sblock.fs_frag));
281 	sblock.fs_iblkno = sblock.fs_cblkno + sblock.fs_frag;
282 	sblock.fs_maxfilesize = sblock.fs_bsize * NDADDR - 1;
283 	for (sizepb = sblock.fs_bsize, i = 0; i < NIADDR; i++) {
284 		sizepb *= NINDIR(&sblock);
285 		sblock.fs_maxfilesize += sizepb;
286 	}
287 
288 	/*
289 	 * Calculate the number of blocks to put into each cylinder group.
290 	 *
291 	 * This algorithm selects the number of blocks per cylinder
292 	 * group. The first goal is to have at least enough data blocks
293 	 * in each cylinder group to meet the density requirement. Once
294 	 * this goal is achieved we try to expand to have at least
295 	 * 1 cylinder group. Once this goal is achieved, we pack as
296 	 * many blocks into each cylinder group map as will fit.
297 	 *
298 	 * We start by calculating the smallest number of blocks that we
299 	 * can put into each cylinder group. If this is too big, we reduce
300 	 * the density until it fits.
301 	 */
302 	origdensity = density;
303 	for (;;) {
304 		fragsperinode = MAX(numfrags(&sblock, density), 1);
305 		minfpg = fragsperinode * INOPB(&sblock);
306 		if (minfpg > sblock.fs_size)
307 			minfpg = sblock.fs_size;
308 		sblock.fs_ipg = INOPB(&sblock);
309 		sblock.fs_fpg = roundup(sblock.fs_iblkno +
310 		    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
311 		if (sblock.fs_fpg < minfpg)
312 			sblock.fs_fpg = minfpg;
313 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
314 		    INOPB(&sblock));
315 		sblock.fs_fpg = roundup(sblock.fs_iblkno +
316 		    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
317 		if (sblock.fs_fpg < minfpg)
318 			sblock.fs_fpg = minfpg;
319 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
320 		    INOPB(&sblock));
321 		if (CGSIZE(&sblock) < (unsigned long)sblock.fs_bsize)
322 			break;
323 		density -= sblock.fs_fsize;
324 	}
325 	if (density != origdensity)
326 		printf("density reduced from %d to %d\n", origdensity, density);
327 
328 	if (maxblkspercg <= 0 || maxblkspercg >= fssize)
329 		maxblkspercg = fssize - 1;
330 	/*
331 	 * Start packing more blocks into the cylinder group until
332 	 * it cannot grow any larger, the number of cylinder groups
333 	 * drops below 1, or we reach the size requested.
334 	 */
335 	for ( ; sblock.fs_fpg < maxblkspercg; sblock.fs_fpg += sblock.fs_frag) {
336 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
337 		    INOPB(&sblock));
338 		if (sblock.fs_size / sblock.fs_fpg < 1)
339 			break;
340 		if (CGSIZE(&sblock) < (unsigned long)sblock.fs_bsize)
341 			continue;
342 		if (CGSIZE(&sblock) == (unsigned long)sblock.fs_bsize)
343 			break;
344 		sblock.fs_fpg -= sblock.fs_frag;
345 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
346 		    INOPB(&sblock));
347 		break;
348 	}
349 	/*
350 	 * Check to be sure that the last cylinder group has enough blocks
351 	 * to be viable. If it is too small, reduce the number of blocks
352 	 * per cylinder group which will have the effect of moving more
353 	 * blocks into the last cylinder group.
354 	 */
355 	optimalfpg = sblock.fs_fpg;
356 	for (;;) {
357 		sblock.fs_ncg = howmany(sblock.fs_size, sblock.fs_fpg);
358 		lastminfpg = roundup(sblock.fs_iblkno +
359 		    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
360 		if (sblock.fs_size < lastminfpg) {
361 			printf("Filesystem size %lld < minimum size of %d\n",
362 			    (long long)sblock.fs_size, lastminfpg);
363 			exit(28);
364 		}
365 		if (sblock.fs_size % sblock.fs_fpg >= lastminfpg ||
366 		    sblock.fs_size % sblock.fs_fpg == 0)
367 			break;
368 		sblock.fs_fpg -= sblock.fs_frag;
369 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
370 		    INOPB(&sblock));
371 	}
372 	if (optimalfpg != sblock.fs_fpg)
373 		printf("Reduced frags per cylinder group from %d to %d %s\n",
374 		   optimalfpg, sblock.fs_fpg, "to enlarge last cyl group");
375 	sblock.fs_cgsize = fragroundup(&sblock, CGSIZE(&sblock));
376 	sblock.fs_dblkno = sblock.fs_iblkno + sblock.fs_ipg / INOPF(&sblock);
377 	if (Oflag <= 1) {
378 		sblock.fs_old_spc = sblock.fs_fpg * sblock.fs_old_nspf;
379 		sblock.fs_old_nsect = sblock.fs_old_spc;
380 		sblock.fs_old_npsect = sblock.fs_old_spc;
381 		sblock.fs_old_ncyl = sblock.fs_ncg;
382 	}
383 
384 	/*
385 	 * fill in remaining fields of the super block
386 	 */
387 	sblock.fs_csaddr = cgdmin(&sblock, 0);
388 	sblock.fs_cssize =
389 	    fragroundup(&sblock, sblock.fs_ncg * sizeof(struct csum));
390 
391 	/*
392 	 * Setup memory for temporary in-core cylgroup summaries.
393 	 * Cribbed from ffs_mountfs().
394 	 */
395 	size = sblock.fs_cssize;
396 	blks = howmany(size, sblock.fs_fsize);
397 	if (sblock.fs_contigsumsize > 0)
398 		size += sblock.fs_ncg * sizeof(int32_t);
399 	if ((space = (char *)calloc(1, size)) == NULL)
400 		err(1, "memory allocation error for cg summaries");
401 	sblock.fs_csp = space;
402 	space = (char *)space + sblock.fs_cssize;
403 	if (sblock.fs_contigsumsize > 0) {
404 		int32_t *lp;
405 
406 		sblock.fs_maxcluster = lp = space;
407 		for (i = 0; i < sblock.fs_ncg; i++)
408 		*lp++ = sblock.fs_contigsumsize;
409 	}
410 
411 	sblock.fs_sbsize = fragroundup(&sblock, sizeof(struct fs));
412 	if (sblock.fs_sbsize > SBLOCKSIZE)
413 		sblock.fs_sbsize = SBLOCKSIZE;
414 	sblock.fs_minfree = minfree;
415 	sblock.fs_maxcontig = maxcontig;
416 	sblock.fs_maxbpg = maxbpg;
417 	sblock.fs_optim = opt;
418 	sblock.fs_cgrotor = 0;
419 	sblock.fs_pendingblocks = 0;
420 	sblock.fs_pendinginodes = 0;
421 	sblock.fs_cstotal.cs_ndir = 0;
422 	sblock.fs_cstotal.cs_nbfree = 0;
423 	sblock.fs_cstotal.cs_nifree = 0;
424 	sblock.fs_cstotal.cs_nffree = 0;
425 	sblock.fs_fmod = 0;
426 	sblock.fs_ronly = 0;
427 	sblock.fs_state = 0;
428 	sblock.fs_clean = FS_ISCLEAN;
429 	sblock.fs_ronly = 0;
430 	sblock.fs_id[0] = start_time.tv_sec;
431 	sblock.fs_id[1] = random();
432 	sblock.fs_fsmnt[0] = '\0';
433 	csfrags = howmany(sblock.fs_cssize, sblock.fs_fsize);
434 	sblock.fs_dsize = sblock.fs_size - sblock.fs_sblkno -
435 	    sblock.fs_ncg * (sblock.fs_dblkno - sblock.fs_sblkno);
436 	sblock.fs_cstotal.cs_nbfree =
437 	    fragstoblks(&sblock, sblock.fs_dsize) -
438 	    howmany(csfrags, sblock.fs_frag);
439 	sblock.fs_cstotal.cs_nffree =
440 	    fragnum(&sblock, sblock.fs_size) +
441 	    (fragnum(&sblock, csfrags) > 0 ?
442 	    sblock.fs_frag - fragnum(&sblock, csfrags) : 0);
443 	sblock.fs_cstotal.cs_nifree = sblock.fs_ncg * sblock.fs_ipg - ROOTINO;
444 	sblock.fs_cstotal.cs_ndir = 0;
445 	sblock.fs_dsize -= csfrags;
446 	sblock.fs_time = start_time.tv_sec;
447 	if (Oflag <= 1) {
448 		sblock.fs_old_time = start_time.tv_sec;
449 		sblock.fs_old_dsize = sblock.fs_dsize;
450 		sblock.fs_old_csaddr = sblock.fs_csaddr;
451 		sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
452 		sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
453 		sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
454 		sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
455 	}
456 	/*
457 	 * Dump out summary information about file system.
458 	 */
459 #define	B2MBFACTOR (1 / (1024.0 * 1024.0))
460 	printf("%s: %.1fMB (%lld sectors) block size %d, "
461 	       "fragment size %d\n",
462 	    fsys, (float)sblock.fs_size * sblock.fs_fsize * B2MBFACTOR,
463 	    (long long)fsbtodb(&sblock, sblock.fs_size),
464 	    sblock.fs_bsize, sblock.fs_fsize);
465 	printf("\tusing %d cylinder groups of %.2fMB, %d blks, "
466 	       "%d inodes.\n",
467 	    sblock.fs_ncg,
468 	    (float)sblock.fs_fpg * sblock.fs_fsize * B2MBFACTOR,
469 	    sblock.fs_fpg / sblock.fs_frag, sblock.fs_ipg);
470 #undef B2MBFACTOR
471 	/*
472 	 * Now determine how wide each column will be, and calculate how
473 	 * many columns will fit in a 76 char line. 76 is the width of the
474 	 * subwindows in sysinst.
475 	 */
476 	printcolwidth = count_digits(
477 			fsbtodb(&sblock, cgsblock(&sblock, sblock.fs_ncg -1)));
478 	nprintcols = 76 / (printcolwidth + 2);
479 
480 	/*
481 	 * allocate space for superblock, cylinder group map, and
482 	 * two sets of inode blocks.
483 	 */
484 	if (sblock.fs_bsize < SBLOCKSIZE)
485 		iobufsize = SBLOCKSIZE + 3 * sblock.fs_bsize;
486 	else
487 		iobufsize = 4 * sblock.fs_bsize;
488 	if ((iobuf = malloc(iobufsize)) == 0) {
489 		printf("Cannot allocate I/O buffer\n");
490 		exit(38);
491 	}
492 	memset(iobuf, 0, iobufsize);
493 	/*
494 	 * Make a copy of the superblock into the buffer that we will be
495 	 * writing out in each cylinder group.
496 	 */
497 	memcpy(writebuf, &sblock, sbsize);
498 	if (fsopts->needswap)
499 		ffs_sb_swap(&sblock, (struct fs*)writebuf);
500 	memcpy(iobuf, writebuf, SBLOCKSIZE);
501 
502 	printf("super-block backups (for fsck -b #) at:");
503 	for (cylno = 0; cylno < sblock.fs_ncg; cylno++) {
504 		initcg(cylno, start_time.tv_sec, fsopts);
505 		if (cylno % nprintcols == 0)
506 			printf("\n");
507 		printf(" %*lld,", printcolwidth,
508 			(long long)fsbtodb(&sblock, cgsblock(&sblock, cylno)));
509 		fflush(stdout);
510 	}
511 	printf("\n");
512 
513 	/*
514 	 * Now construct the initial file system,
515 	 * then write out the super-block.
516 	 */
517 	sblock.fs_time = start_time.tv_sec;
518 	if (Oflag <= 1) {
519 		sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
520 		sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
521 		sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
522 		sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
523 	}
524 	if (fsopts->needswap)
525 		sblock.fs_flags |= FS_SWAPPED;
526 	ffs_write_superblock(&sblock, fsopts);
527 	return (&sblock);
528 }
529 
530 /*
531  * Write out the superblock and its duplicates,
532  * and the cylinder group summaries
533  */
534 void
535 ffs_write_superblock(struct fs *fs, const fsinfo_t *fsopts)
536 {
537 	int cylno, size, blks, i, saveflag;
538 	void *space;
539 	char *wrbuf;
540 
541 	saveflag = fs->fs_flags & FS_INTERNAL;
542 	fs->fs_flags &= ~FS_INTERNAL;
543 
544         memcpy(writebuf, &sblock, sbsize);
545 	if (fsopts->needswap)
546 		ffs_sb_swap(fs, (struct fs*)writebuf);
547 	ffs_wtfs(fs->fs_sblockloc / sectorsize, sbsize, writebuf, fsopts);
548 
549 	/* Write out the duplicate super blocks */
550 	for (cylno = 0; cylno < fs->fs_ncg; cylno++)
551 		ffs_wtfs(fsbtodb(fs, cgsblock(fs, cylno)),
552 		    sbsize, writebuf, fsopts);
553 
554 	/* Write out the cylinder group summaries */
555 	size = fs->fs_cssize;
556 	blks = howmany(size, fs->fs_fsize);
557 	space = (void *)fs->fs_csp;
558 	if ((wrbuf = malloc(size)) == NULL)
559 		err(1, "ffs_write_superblock: malloc %d", size);
560 	for (i = 0; i < blks; i+= fs->fs_frag) {
561 		size = fs->fs_bsize;
562 		if (i + fs->fs_frag > blks)
563 			size = (blks - i) * fs->fs_fsize;
564 		if (fsopts->needswap)
565 			ffs_csum_swap((struct csum *)space,
566 			    (struct csum *)wrbuf, size);
567 		else
568 			memcpy(wrbuf, space, (u_int)size);
569 		ffs_wtfs(fsbtodb(fs, fs->fs_csaddr + i), size, wrbuf, fsopts);
570 		space = (char *)space + size;
571 	}
572 	free(wrbuf);
573 	fs->fs_flags |= saveflag;
574 }
575 
576 /*
577  * Initialize a cylinder group.
578  */
579 static void
580 initcg(int cylno, time_t utime, const fsinfo_t *fsopts)
581 {
582 	daddr_t cbase, dmax;
583 	int32_t i, j, d, dlower, dupper, blkno;
584 	struct ufs1_dinode *dp1;
585 	struct ufs2_dinode *dp2;
586 	int start;
587 
588 	/*
589 	 * Determine block bounds for cylinder group.
590 	 * Allow space for super block summary information in first
591 	 * cylinder group.
592 	 */
593 	cbase = cgbase(&sblock, cylno);
594 	dmax = cbase + sblock.fs_fpg;
595 	if (dmax > sblock.fs_size)
596 		dmax = sblock.fs_size;
597 	dlower = cgsblock(&sblock, cylno) - cbase;
598 	dupper = cgdmin(&sblock, cylno) - cbase;
599 	if (cylno == 0)
600 		dupper += howmany(sblock.fs_cssize, sblock.fs_fsize);
601 	memset(&acg, 0, sblock.fs_cgsize);
602 	acg.cg_time = utime;
603 	acg.cg_magic = CG_MAGIC;
604 	acg.cg_cgx = cylno;
605 	acg.cg_niblk = sblock.fs_ipg;
606 	acg.cg_initediblk = sblock.fs_ipg < 2 * INOPB(&sblock) ?
607 	    sblock.fs_ipg : 2 * INOPB(&sblock);
608 	acg.cg_ndblk = dmax - cbase;
609 	if (sblock.fs_contigsumsize > 0)
610 		acg.cg_nclusterblks = acg.cg_ndblk >> sblock.fs_fragshift;
611 	start = &acg.cg_space[0] - (u_char *)(&acg.cg_firstfield);
612 	if (Oflag == 2) {
613 		acg.cg_iusedoff = start;
614 	} else {
615 		if (cylno == sblock.fs_ncg - 1)
616 			acg.cg_old_ncyl = howmany(acg.cg_ndblk,
617 			    sblock.fs_fpg / sblock.fs_old_cpg);
618 		else
619 			acg.cg_old_ncyl = sblock.fs_old_cpg;
620 		acg.cg_old_time = acg.cg_time;
621 		acg.cg_time = 0;
622 		acg.cg_old_niblk = acg.cg_niblk;
623 		acg.cg_niblk = 0;
624 		acg.cg_initediblk = 0;
625 		acg.cg_old_btotoff = start;
626 		acg.cg_old_boff = acg.cg_old_btotoff +
627 		    sblock.fs_old_cpg * sizeof(int32_t);
628 		acg.cg_iusedoff = acg.cg_old_boff +
629 		    sblock.fs_old_cpg * sizeof(u_int16_t);
630 	}
631 	acg.cg_freeoff = acg.cg_iusedoff + howmany(sblock.fs_ipg, CHAR_BIT);
632 	if (sblock.fs_contigsumsize <= 0) {
633 		acg.cg_nextfreeoff = acg.cg_freeoff +
634 		   howmany(sblock.fs_fpg, CHAR_BIT);
635 	} else {
636 		acg.cg_clustersumoff = acg.cg_freeoff +
637 		    howmany(sblock.fs_fpg, CHAR_BIT) - sizeof(int32_t);
638 		acg.cg_clustersumoff =
639 		    roundup(acg.cg_clustersumoff, sizeof(int32_t));
640 		acg.cg_clusteroff = acg.cg_clustersumoff +
641 		    (sblock.fs_contigsumsize + 1) * sizeof(int32_t);
642 		acg.cg_nextfreeoff = acg.cg_clusteroff +
643 		    howmany(fragstoblks(&sblock, sblock.fs_fpg), CHAR_BIT);
644 	}
645 	if (acg.cg_nextfreeoff > sblock.fs_cgsize) {
646 		printf("Panic: cylinder group too big\n");
647 		exit(37);
648 	}
649 	acg.cg_cs.cs_nifree += sblock.fs_ipg;
650 	if (cylno == 0)
651 		for (i = 0; i < ROOTINO; i++) {
652 			setbit(cg_inosused_swap(&acg, 0), i);
653 			acg.cg_cs.cs_nifree--;
654 		}
655 	if (cylno > 0) {
656 		/*
657 		 * In cylno 0, beginning space is reserved
658 		 * for boot and super blocks.
659 		 */
660 		for (d = 0, blkno = 0; d < dlower;) {
661 			ffs_setblock(&sblock, cg_blksfree_swap(&acg, 0), blkno);
662 			if (sblock.fs_contigsumsize > 0)
663 				setbit(cg_clustersfree_swap(&acg, 0), blkno);
664 			acg.cg_cs.cs_nbfree++;
665 			d += sblock.fs_frag;
666 			blkno++;
667 		}
668 	}
669 	if ((i = (dupper & (sblock.fs_frag - 1))) != 0) {
670 		acg.cg_frsum[sblock.fs_frag - i]++;
671 		for (d = dupper + sblock.fs_frag - i; dupper < d; dupper++) {
672 			setbit(cg_blksfree_swap(&acg, 0), dupper);
673 			acg.cg_cs.cs_nffree++;
674 		}
675 	}
676 	for (d = dupper, blkno = dupper >> sblock.fs_fragshift;
677 	     d + sblock.fs_frag <= acg.cg_ndblk; ) {
678 		ffs_setblock(&sblock, cg_blksfree_swap(&acg, 0), blkno);
679 		if (sblock.fs_contigsumsize > 0)
680 			setbit(cg_clustersfree_swap(&acg, 0), blkno);
681 		acg.cg_cs.cs_nbfree++;
682 		d += sblock.fs_frag;
683 		blkno++;
684 	}
685 	if (d < acg.cg_ndblk) {
686 		acg.cg_frsum[acg.cg_ndblk - d]++;
687 		for (; d < acg.cg_ndblk; d++) {
688 			setbit(cg_blksfree_swap(&acg, 0), d);
689 			acg.cg_cs.cs_nffree++;
690 		}
691 	}
692 	if (sblock.fs_contigsumsize > 0) {
693 		int32_t *sump = cg_clustersum_swap(&acg, 0);
694 		u_char *mapp = cg_clustersfree_swap(&acg, 0);
695 		int map = *mapp++;
696 		int bit = 1;
697 		int run = 0;
698 
699 		for (i = 0; i < acg.cg_nclusterblks; i++) {
700 			if ((map & bit) != 0) {
701 				run++;
702 			} else if (run != 0) {
703 				if (run > sblock.fs_contigsumsize)
704 					run = sblock.fs_contigsumsize;
705 				sump[run]++;
706 				run = 0;
707 			}
708 			if ((i & (CHAR_BIT - 1)) != (CHAR_BIT - 1)) {
709 				bit <<= 1;
710 			} else {
711 				map = *mapp++;
712 				bit = 1;
713 			}
714 		}
715 		if (run != 0) {
716 			if (run > sblock.fs_contigsumsize)
717 				run = sblock.fs_contigsumsize;
718 			sump[run]++;
719 		}
720 	}
721 	sblock.fs_cs(&sblock, cylno) = acg.cg_cs;
722 	/*
723 	 * Write out the duplicate super block, the cylinder group map
724 	 * and two blocks worth of inodes in a single write.
725 	 */
726 	start = sblock.fs_bsize > SBLOCKSIZE ? sblock.fs_bsize : SBLOCKSIZE;
727 	memcpy(&iobuf[start], &acg, sblock.fs_cgsize);
728 	if (fsopts->needswap)
729 		ffs_cg_swap(&acg, (struct cg*)&iobuf[start], &sblock);
730 	start += sblock.fs_bsize;
731 	dp1 = (struct ufs1_dinode *)(&iobuf[start]);
732 	dp2 = (struct ufs2_dinode *)(&iobuf[start]);
733 	for (i = 0; i < acg.cg_initediblk; i++) {
734 		if (sblock.fs_magic == FS_UFS1_MAGIC) {
735 			/* No need to swap, it'll stay random */
736 			dp1->di_gen = random();
737 			dp1++;
738 		} else {
739 			dp2->di_gen = random();
740 			dp2++;
741 		}
742 	}
743 	ffs_wtfs(fsbtodb(&sblock, cgsblock(&sblock, cylno)), iobufsize, iobuf,
744 	    fsopts);
745 	/*
746 	 * For the old file system, we have to initialize all the inodes.
747 	 */
748 	if (Oflag <= 1) {
749 		for (i = 2 * sblock.fs_frag;
750 		     i < sblock.fs_ipg / INOPF(&sblock);
751 		     i += sblock.fs_frag) {
752 			dp1 = (struct ufs1_dinode *)(&iobuf[start]);
753 			for (j = 0; j < INOPB(&sblock); j++) {
754 				dp1->di_gen = random();
755 				dp1++;
756 			}
757 			ffs_wtfs(fsbtodb(&sblock, cgimin(&sblock, cylno) + i),
758 			    sblock.fs_bsize, &iobuf[start], fsopts);
759 		}
760 	}
761 }
762 
763 /*
764  * read a block from the file system
765  */
766 void
767 ffs_rdfs(daddr_t bno, int size, void *bf, const fsinfo_t *fsopts)
768 {
769 	int n;
770 	off_t offset;
771 
772 	offset = bno;
773 	offset *= fsopts->sectorsize;
774 	if (lseek(fsopts->fd, offset, SEEK_SET) < 0)
775 		err(1, "ffs_rdfs: seek error for sector %lld: %s\n",
776 		    (long long)bno, strerror(errno));
777 	n = read(fsopts->fd, bf, size);
778 	if (n == -1) {
779 		abort();
780 		err(1, "ffs_rdfs: read error bno %lld size %d", (long long)bno,
781 		    size);
782 	}
783 	else if (n != size)
784 		errx(1, "ffs_rdfs: read error for sector %lld: %s\n",
785 		    (long long)bno, strerror(errno));
786 }
787 
788 /*
789  * write a block to the file system
790  */
791 void
792 ffs_wtfs(daddr_t bno, int size, void *bf, const fsinfo_t *fsopts)
793 {
794 	int n;
795 	off_t offset;
796 
797 	offset = bno;
798 	offset *= fsopts->sectorsize;
799 	if (lseek(fsopts->fd, offset, SEEK_SET) < 0)
800 		err(1, "wtfs: seek error for sector %lld: %s\n",
801 		    (long long)bno, strerror(errno));
802 	n = write(fsopts->fd, bf, size);
803 	if (n == -1)
804 		err(1, "wtfs: write error for sector %lld: %s\n",
805 		    (long long)bno, strerror(errno));
806 	else if (n != size)
807 		errx(1, "wtfs: write error for sector %lld: %s\n",
808 		    (long long)bno, strerror(errno));
809 }
810 
811 
812 /* Determine how many digits are needed to print a given integer */
813 static int
814 count_digits(int num)
815 {
816 	int ndig;
817 
818 	for(ndig = 1; num > 9; num /=10, ndig++);
819 
820 	return (ndig);
821 }
822 
823 static int
824 ilog2(int val)
825 {
826 	u_int n;
827 
828 	for (n = 0; n < sizeof(n) * CHAR_BIT; n++)
829 		if (1 << n == val)
830 			return (n);
831 	errx(1, "ilog2: %d is not a power of 2\n", val);
832 }
833