xref: /freebsd/sbin/newfs/mkfs.c (revision b85e1f7d05ac7889868f2364474e02b6a024af25)
1 /*
2  * Copyright (c) 2002 Networks Associates Technology, Inc.
3  * All rights reserved.
4  *
5  * This software was developed for the FreeBSD Project by Marshall
6  * Kirk McKusick and Network Associates Laboratories, the Security
7  * Research Division of Network Associates, Inc. under DARPA/SPAWAR
8  * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS
9  * research program.
10  *
11  * Copyright (c) 1980, 1989, 1993
12  *	The Regents of the University of California.  All rights reserved.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 #if 0
40 #ifndef lint
41 static char sccsid[] = "@(#)mkfs.c	8.11 (Berkeley) 5/3/95";
42 #endif /* not lint */
43 #endif
44 #include <sys/cdefs.h>
45 __FBSDID("$FreeBSD$");
46 
47 #include <sys/param.h>
48 #include <sys/disklabel.h>
49 #include <sys/file.h>
50 #include <sys/ioctl.h>
51 #include <sys/mman.h>
52 #include <sys/resource.h>
53 #include <sys/stat.h>
54 #include <sys/wait.h>
55 #include <err.h>
56 #include <grp.h>
57 #include <limits.h>
58 #include <signal.h>
59 #include <stdlib.h>
60 #include <string.h>
61 #include <stdint.h>
62 #include <stdio.h>
63 #include <time.h>
64 #include <unistd.h>
65 #include <ufs/ufs/dinode.h>
66 #include <ufs/ufs/dir.h>
67 #include <ufs/ffs/fs.h>
68 #include "newfs.h"
69 
70 /*
71  * make file system for cylinder-group style file systems
72  */
73 #define UMASK		0755
74 #define POWEROF2(num)	(((num) & ((num) - 1)) == 0)
75 
76 static struct	csum *fscs;
77 #define	sblock	disk.d_fs
78 #define	acg	disk.d_cg
79 
80 union dinode {
81 	struct ufs1_dinode dp1;
82 	struct ufs2_dinode dp2;
83 };
84 #define DIP(dp, field) \
85 	((sblock.fs_magic == FS_UFS1_MAGIC) ? \
86 	(dp)->dp1.field : (dp)->dp2.field)
87 
88 static caddr_t iobuf;
89 static long iobufsize;
90 static ufs2_daddr_t alloc(int size, int mode);
91 static int charsperline(void);
92 static void clrblock(struct fs *, unsigned char *, int);
93 static void fsinit(time_t);
94 static int ilog2(int);
95 static void initcg(int, time_t);
96 static int isblock(struct fs *, unsigned char *, int);
97 static void iput(union dinode *, ino_t);
98 static int makedir(struct direct *, int);
99 static void setblock(struct fs *, unsigned char *, int);
100 static void wtfs(ufs2_daddr_t, int, char *);
101 static u_int32_t newfs_random(void);
102 
103 static int
104 do_sbwrite(struct uufsd *disk)
105 {
106 	if (!disk->d_sblock)
107 		disk->d_sblock = disk->d_fs.fs_sblockloc / disk->d_bsize;
108 	return (pwrite(disk->d_fd, &disk->d_fs, SBLOCKSIZE, (off_t)((part_ofs +
109 	    disk->d_sblock) * disk->d_bsize)));
110 }
111 
112 void
113 mkfs(struct partition *pp, char *fsys)
114 {
115 	int fragsperinode, optimalfpg, origdensity, minfpg, lastminfpg;
116 	long i, j, csfrags;
117 	uint cg;
118 	time_t utime;
119 	quad_t sizepb;
120 	int width;
121 	ino_t maxinum;
122 	int minfragsperinode;	/* minimum ratio of frags to inodes */
123 	char tmpbuf[100];	/* XXX this will break in about 2,500 years */
124 	union {
125 		struct fs fdummy;
126 		char cdummy[SBLOCKSIZE];
127 	} dummy;
128 #define fsdummy dummy.fdummy
129 #define chdummy dummy.cdummy
130 
131 	/*
132 	 * Our blocks == sector size, and the version of UFS we are using is
133 	 * specified by Oflag.
134 	 */
135 	disk.d_bsize = sectorsize;
136 	disk.d_ufs = Oflag;
137 	if (Rflag) {
138 		utime = 1000000000;
139 	} else {
140 		time(&utime);
141 		arc4random_stir();
142 	}
143 	sblock.fs_old_flags = FS_FLAGS_UPDATED;
144 	sblock.fs_flags = 0;
145 	if (Uflag)
146 		sblock.fs_flags |= FS_DOSOFTDEP;
147 	if (Lflag)
148 		strlcpy(sblock.fs_volname, volumelabel, MAXVOLLEN);
149 	if (Jflag)
150 		sblock.fs_flags |= FS_GJOURNAL;
151 	if (lflag)
152 		sblock.fs_flags |= FS_MULTILABEL;
153 	if (tflag)
154 		sblock.fs_flags |= FS_TRIM;
155 	/*
156 	 * Validate the given file system size.
157 	 * Verify that its last block can actually be accessed.
158 	 * Convert to file system fragment sized units.
159 	 */
160 	if (fssize <= 0) {
161 		printf("preposterous size %jd\n", (intmax_t)fssize);
162 		exit(13);
163 	}
164 	wtfs(fssize - (realsectorsize / DEV_BSIZE), realsectorsize,
165 	    (char *)&sblock);
166 	/*
167 	 * collect and verify the file system density info
168 	 */
169 	sblock.fs_avgfilesize = avgfilesize;
170 	sblock.fs_avgfpdir = avgfilesperdir;
171 	if (sblock.fs_avgfilesize <= 0)
172 		printf("illegal expected average file size %d\n",
173 		    sblock.fs_avgfilesize), exit(14);
174 	if (sblock.fs_avgfpdir <= 0)
175 		printf("illegal expected number of files per directory %d\n",
176 		    sblock.fs_avgfpdir), exit(15);
177 
178 restart:
179 	/*
180 	 * collect and verify the block and fragment sizes
181 	 */
182 	sblock.fs_bsize = bsize;
183 	sblock.fs_fsize = fsize;
184 	if (!POWEROF2(sblock.fs_bsize)) {
185 		printf("block size must be a power of 2, not %d\n",
186 		    sblock.fs_bsize);
187 		exit(16);
188 	}
189 	if (!POWEROF2(sblock.fs_fsize)) {
190 		printf("fragment size must be a power of 2, not %d\n",
191 		    sblock.fs_fsize);
192 		exit(17);
193 	}
194 	if (sblock.fs_fsize < sectorsize) {
195 		printf("increasing fragment size from %d to sector size (%d)\n",
196 		    sblock.fs_fsize, sectorsize);
197 		sblock.fs_fsize = sectorsize;
198 	}
199 	if (sblock.fs_bsize > MAXBSIZE) {
200 		printf("decreasing block size from %d to maximum (%d)\n",
201 		    sblock.fs_bsize, MAXBSIZE);
202 		sblock.fs_bsize = MAXBSIZE;
203 	}
204 	if (sblock.fs_bsize < MINBSIZE) {
205 		printf("increasing block size from %d to minimum (%d)\n",
206 		    sblock.fs_bsize, MINBSIZE);
207 		sblock.fs_bsize = MINBSIZE;
208 	}
209 	if (sblock.fs_fsize > MAXBSIZE) {
210 		printf("decreasing fragment size from %d to maximum (%d)\n",
211 		    sblock.fs_fsize, MAXBSIZE);
212 		sblock.fs_fsize = MAXBSIZE;
213 	}
214 	if (sblock.fs_bsize < sblock.fs_fsize) {
215 		printf("increasing block size from %d to fragment size (%d)\n",
216 		    sblock.fs_bsize, sblock.fs_fsize);
217 		sblock.fs_bsize = sblock.fs_fsize;
218 	}
219 	if (sblock.fs_fsize * MAXFRAG < sblock.fs_bsize) {
220 		printf(
221 		"increasing fragment size from %d to block size / %d (%d)\n",
222 		    sblock.fs_fsize, MAXFRAG, sblock.fs_bsize / MAXFRAG);
223 		sblock.fs_fsize = sblock.fs_bsize / MAXFRAG;
224 	}
225 	if (maxbsize == 0)
226 		maxbsize = bsize;
227 	if (maxbsize < bsize || !POWEROF2(maxbsize)) {
228 		sblock.fs_maxbsize = sblock.fs_bsize;
229 		printf("Extent size set to %d\n", sblock.fs_maxbsize);
230 	} else if (sblock.fs_maxbsize > FS_MAXCONTIG * sblock.fs_bsize) {
231 		sblock.fs_maxbsize = FS_MAXCONTIG * sblock.fs_bsize;
232 		printf("Extent size reduced to %d\n", sblock.fs_maxbsize);
233 	} else {
234 		sblock.fs_maxbsize = maxbsize;
235 	}
236 	/*
237 	 * Maxcontig sets the default for the maximum number of blocks
238 	 * that may be allocated sequentially. With file system clustering
239 	 * it is possible to allocate contiguous blocks up to the maximum
240 	 * transfer size permitted by the controller or buffering.
241 	 */
242 	if (maxcontig == 0)
243 		maxcontig = MAX(1, MAXPHYS / bsize);
244 	sblock.fs_maxcontig = maxcontig;
245 	if (sblock.fs_maxcontig < sblock.fs_maxbsize / sblock.fs_bsize) {
246 		sblock.fs_maxcontig = sblock.fs_maxbsize / sblock.fs_bsize;
247 		printf("Maxcontig raised to %d\n", sblock.fs_maxbsize);
248 	}
249 	if (sblock.fs_maxcontig > 1)
250 		sblock.fs_contigsumsize = MIN(sblock.fs_maxcontig,FS_MAXCONTIG);
251 	sblock.fs_bmask = ~(sblock.fs_bsize - 1);
252 	sblock.fs_fmask = ~(sblock.fs_fsize - 1);
253 	sblock.fs_qbmask = ~sblock.fs_bmask;
254 	sblock.fs_qfmask = ~sblock.fs_fmask;
255 	sblock.fs_bshift = ilog2(sblock.fs_bsize);
256 	sblock.fs_fshift = ilog2(sblock.fs_fsize);
257 	sblock.fs_frag = numfrags(&sblock, sblock.fs_bsize);
258 	sblock.fs_fragshift = ilog2(sblock.fs_frag);
259 	if (sblock.fs_frag > MAXFRAG) {
260 		printf("fragment size %d is still too small (can't happen)\n",
261 		    sblock.fs_bsize / MAXFRAG);
262 		exit(21);
263 	}
264 	sblock.fs_fsbtodb = ilog2(sblock.fs_fsize / sectorsize);
265 	sblock.fs_size = fssize = dbtofsb(&sblock, fssize);
266 	sblock.fs_providersize = dbtofsb(&sblock, mediasize / sectorsize);
267 
268 	/*
269 	 * Before the filesystem is finally initialized, mark it
270 	 * as incompletely initialized.
271 	 */
272 	sblock.fs_magic = FS_BAD_MAGIC;
273 
274 	if (Oflag == 1) {
275 		sblock.fs_sblockloc = SBLOCK_UFS1;
276 		sblock.fs_nindir = sblock.fs_bsize / sizeof(ufs1_daddr_t);
277 		sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs1_dinode);
278 		sblock.fs_maxsymlinklen = ((NDADDR + NIADDR) *
279 		    sizeof(ufs1_daddr_t));
280 		sblock.fs_old_inodefmt = FS_44INODEFMT;
281 		sblock.fs_old_cgoffset = 0;
282 		sblock.fs_old_cgmask = 0xffffffff;
283 		sblock.fs_old_size = sblock.fs_size;
284 		sblock.fs_old_rotdelay = 0;
285 		sblock.fs_old_rps = 60;
286 		sblock.fs_old_nspf = sblock.fs_fsize / sectorsize;
287 		sblock.fs_old_cpg = 1;
288 		sblock.fs_old_interleave = 1;
289 		sblock.fs_old_trackskew = 0;
290 		sblock.fs_old_cpc = 0;
291 		sblock.fs_old_postblformat = 1;
292 		sblock.fs_old_nrpos = 1;
293 	} else {
294 		sblock.fs_sblockloc = SBLOCK_UFS2;
295 		sblock.fs_nindir = sblock.fs_bsize / sizeof(ufs2_daddr_t);
296 		sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs2_dinode);
297 		sblock.fs_maxsymlinklen = ((NDADDR + NIADDR) *
298 		    sizeof(ufs2_daddr_t));
299 	}
300 	sblock.fs_sblkno =
301 	    roundup(howmany(sblock.fs_sblockloc + SBLOCKSIZE, sblock.fs_fsize),
302 		sblock.fs_frag);
303 	sblock.fs_cblkno = sblock.fs_sblkno +
304 	    roundup(howmany(SBLOCKSIZE, sblock.fs_fsize), sblock.fs_frag);
305 	sblock.fs_iblkno = sblock.fs_cblkno + sblock.fs_frag;
306 	sblock.fs_maxfilesize = sblock.fs_bsize * NDADDR - 1;
307 	for (sizepb = sblock.fs_bsize, i = 0; i < NIADDR; i++) {
308 		sizepb *= NINDIR(&sblock);
309 		sblock.fs_maxfilesize += sizepb;
310 	}
311 
312 	/*
313 	 * It's impossible to create a snapshot in case that fs_maxfilesize
314 	 * is smaller than the fssize.
315 	 */
316 	if (sblock.fs_maxfilesize < (u_quad_t)fssize) {
317 		warnx("WARNING: You will be unable to create snapshots on this "
318 		      "file system.  Correct by using a larger blocksize.");
319 	}
320 
321 	/*
322 	 * Calculate the number of blocks to put into each cylinder group.
323 	 *
324 	 * This algorithm selects the number of blocks per cylinder
325 	 * group. The first goal is to have at least enough data blocks
326 	 * in each cylinder group to meet the density requirement. Once
327 	 * this goal is achieved we try to expand to have at least
328 	 * MINCYLGRPS cylinder groups. Once this goal is achieved, we
329 	 * pack as many blocks into each cylinder group map as will fit.
330 	 *
331 	 * We start by calculating the smallest number of blocks that we
332 	 * can put into each cylinder group. If this is too big, we reduce
333 	 * the density until it fits.
334 	 */
335 	maxinum = (((int64_t)(1)) << 32) - INOPB(&sblock);
336 	minfragsperinode = 1 + fssize / maxinum;
337 	if (density == 0) {
338 		density = MAX(NFPI, minfragsperinode) * fsize;
339 	} else if (density < minfragsperinode * fsize) {
340 		origdensity = density;
341 		density = minfragsperinode * fsize;
342 		fprintf(stderr, "density increased from %d to %d\n",
343 		    origdensity, density);
344 	}
345 	origdensity = density;
346 	for (;;) {
347 		fragsperinode = MAX(numfrags(&sblock, density), 1);
348 		if (fragsperinode < minfragsperinode) {
349 			bsize <<= 1;
350 			fsize <<= 1;
351 			printf("Block size too small for a file system %s %d\n",
352 			     "of this size. Increasing blocksize to", bsize);
353 			goto restart;
354 		}
355 		minfpg = fragsperinode * INOPB(&sblock);
356 		if (minfpg > sblock.fs_size)
357 			minfpg = sblock.fs_size;
358 		sblock.fs_ipg = INOPB(&sblock);
359 		sblock.fs_fpg = roundup(sblock.fs_iblkno +
360 		    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
361 		if (sblock.fs_fpg < minfpg)
362 			sblock.fs_fpg = minfpg;
363 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
364 		    INOPB(&sblock));
365 		sblock.fs_fpg = roundup(sblock.fs_iblkno +
366 		    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
367 		if (sblock.fs_fpg < minfpg)
368 			sblock.fs_fpg = minfpg;
369 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
370 		    INOPB(&sblock));
371 		if (CGSIZE(&sblock) < (unsigned long)sblock.fs_bsize)
372 			break;
373 		density -= sblock.fs_fsize;
374 	}
375 	if (density != origdensity)
376 		printf("density reduced from %d to %d\n", origdensity, density);
377 	/*
378 	 * Start packing more blocks into the cylinder group until
379 	 * it cannot grow any larger, the number of cylinder groups
380 	 * drops below MINCYLGRPS, or we reach the size requested.
381 	 * For UFS1 inodes per cylinder group are stored in an int16_t
382 	 * so fs_ipg is limited to 2^15 - 1.
383 	 */
384 	for ( ; sblock.fs_fpg < maxblkspercg; sblock.fs_fpg += sblock.fs_frag) {
385 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
386 		    INOPB(&sblock));
387 		if (Oflag > 1 || (Oflag == 1 && sblock.fs_ipg <= 0x7fff)) {
388 			if (sblock.fs_size / sblock.fs_fpg < MINCYLGRPS)
389 				break;
390 			if (CGSIZE(&sblock) < (unsigned long)sblock.fs_bsize)
391 				continue;
392 			if (CGSIZE(&sblock) == (unsigned long)sblock.fs_bsize)
393 				break;
394 		}
395 		sblock.fs_fpg -= sblock.fs_frag;
396 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
397 		    INOPB(&sblock));
398 		break;
399 	}
400 	/*
401 	 * Check to be sure that the last cylinder group has enough blocks
402 	 * to be viable. If it is too small, reduce the number of blocks
403 	 * per cylinder group which will have the effect of moving more
404 	 * blocks into the last cylinder group.
405 	 */
406 	optimalfpg = sblock.fs_fpg;
407 	for (;;) {
408 		sblock.fs_ncg = howmany(sblock.fs_size, sblock.fs_fpg);
409 		lastminfpg = roundup(sblock.fs_iblkno +
410 		    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
411 		if (sblock.fs_size < lastminfpg) {
412 			printf("Filesystem size %jd < minimum size of %d\n",
413 			    (intmax_t)sblock.fs_size, lastminfpg);
414 			exit(28);
415 		}
416 		if (sblock.fs_size % sblock.fs_fpg >= lastminfpg ||
417 		    sblock.fs_size % sblock.fs_fpg == 0)
418 			break;
419 		sblock.fs_fpg -= sblock.fs_frag;
420 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
421 		    INOPB(&sblock));
422 	}
423 	if (optimalfpg != sblock.fs_fpg)
424 		printf("Reduced frags per cylinder group from %d to %d %s\n",
425 		   optimalfpg, sblock.fs_fpg, "to enlarge last cyl group");
426 	sblock.fs_cgsize = fragroundup(&sblock, CGSIZE(&sblock));
427 	sblock.fs_dblkno = sblock.fs_iblkno + sblock.fs_ipg / INOPF(&sblock);
428 	if (Oflag == 1) {
429 		sblock.fs_old_spc = sblock.fs_fpg * sblock.fs_old_nspf;
430 		sblock.fs_old_nsect = sblock.fs_old_spc;
431 		sblock.fs_old_npsect = sblock.fs_old_spc;
432 		sblock.fs_old_ncyl = sblock.fs_ncg;
433 	}
434 	/*
435 	 * fill in remaining fields of the super block
436 	 */
437 	sblock.fs_csaddr = cgdmin(&sblock, 0);
438 	sblock.fs_cssize =
439 	    fragroundup(&sblock, sblock.fs_ncg * sizeof(struct csum));
440 	fscs = (struct csum *)calloc(1, sblock.fs_cssize);
441 	if (fscs == NULL)
442 		errx(31, "calloc failed");
443 	sblock.fs_sbsize = fragroundup(&sblock, sizeof(struct fs));
444 	if (sblock.fs_sbsize > SBLOCKSIZE)
445 		sblock.fs_sbsize = SBLOCKSIZE;
446 	sblock.fs_minfree = minfree;
447 	if (metaspace > 0 && metaspace < sblock.fs_fpg / 2)
448 		sblock.fs_metaspace = blknum(&sblock, metaspace);
449 	else if (metaspace != -1)
450 		/* reserve half of minfree for metadata blocks */
451 		sblock.fs_metaspace = blknum(&sblock,
452 		    (sblock.fs_fpg * minfree) / 200);
453 	if (maxbpg == 0)
454 		sblock.fs_maxbpg = MAXBLKPG(sblock.fs_bsize);
455 	else
456 		sblock.fs_maxbpg = maxbpg;
457 	sblock.fs_optim = opt;
458 	sblock.fs_cgrotor = 0;
459 	sblock.fs_pendingblocks = 0;
460 	sblock.fs_pendinginodes = 0;
461 	sblock.fs_fmod = 0;
462 	sblock.fs_ronly = 0;
463 	sblock.fs_state = 0;
464 	sblock.fs_clean = 1;
465 	sblock.fs_id[0] = (long)utime;
466 	sblock.fs_id[1] = newfs_random();
467 	sblock.fs_fsmnt[0] = '\0';
468 	csfrags = howmany(sblock.fs_cssize, sblock.fs_fsize);
469 	sblock.fs_dsize = sblock.fs_size - sblock.fs_sblkno -
470 	    sblock.fs_ncg * (sblock.fs_dblkno - sblock.fs_sblkno);
471 	sblock.fs_cstotal.cs_nbfree =
472 	    fragstoblks(&sblock, sblock.fs_dsize) -
473 	    howmany(csfrags, sblock.fs_frag);
474 	sblock.fs_cstotal.cs_nffree =
475 	    fragnum(&sblock, sblock.fs_size) +
476 	    (fragnum(&sblock, csfrags) > 0 ?
477 	     sblock.fs_frag - fragnum(&sblock, csfrags) : 0);
478 	sblock.fs_cstotal.cs_nifree = sblock.fs_ncg * sblock.fs_ipg - ROOTINO;
479 	sblock.fs_cstotal.cs_ndir = 0;
480 	sblock.fs_dsize -= csfrags;
481 	sblock.fs_time = utime;
482 	if (Oflag == 1) {
483 		sblock.fs_old_time = utime;
484 		sblock.fs_old_dsize = sblock.fs_dsize;
485 		sblock.fs_old_csaddr = sblock.fs_csaddr;
486 		sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
487 		sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
488 		sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
489 		sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
490 	}
491 
492 	/*
493 	 * Dump out summary information about file system.
494 	 */
495 #	define B2MBFACTOR (1 / (1024.0 * 1024.0))
496 	printf("%s: %.1fMB (%jd sectors) block size %d, fragment size %d\n",
497 	    fsys, (float)sblock.fs_size * sblock.fs_fsize * B2MBFACTOR,
498 	    (intmax_t)fsbtodb(&sblock, sblock.fs_size), sblock.fs_bsize,
499 	    sblock.fs_fsize);
500 	printf("\tusing %d cylinder groups of %.2fMB, %d blks, %d inodes.\n",
501 	    sblock.fs_ncg, (float)sblock.fs_fpg * sblock.fs_fsize * B2MBFACTOR,
502 	    sblock.fs_fpg / sblock.fs_frag, sblock.fs_ipg);
503 	if (sblock.fs_flags & FS_DOSOFTDEP)
504 		printf("\twith soft updates\n");
505 #	undef B2MBFACTOR
506 
507 	if (Eflag && !Nflag) {
508 		printf("Erasing sectors [%jd...%jd]\n",
509 		    sblock.fs_sblockloc / disk.d_bsize,
510 		    fsbtodb(&sblock, sblock.fs_size) - 1);
511 		berase(&disk, sblock.fs_sblockloc / disk.d_bsize,
512 		    sblock.fs_size * sblock.fs_fsize - sblock.fs_sblockloc);
513 	}
514 	/*
515 	 * Wipe out old UFS1 superblock(s) if necessary.
516 	 */
517 	if (!Nflag && Oflag != 1) {
518 		i = bread(&disk, part_ofs + SBLOCK_UFS1 / disk.d_bsize, chdummy, SBLOCKSIZE);
519 		if (i == -1)
520 			err(1, "can't read old UFS1 superblock: %s", disk.d_error);
521 
522 		if (fsdummy.fs_magic == FS_UFS1_MAGIC) {
523 			fsdummy.fs_magic = 0;
524 			bwrite(&disk, part_ofs + SBLOCK_UFS1 / disk.d_bsize,
525 			    chdummy, SBLOCKSIZE);
526 			for (cg = 0; cg < fsdummy.fs_ncg; cg++) {
527 				if (fsbtodb(&fsdummy, cgsblock(&fsdummy, cg)) > fssize)
528 					break;
529 				bwrite(&disk, part_ofs + fsbtodb(&fsdummy,
530 				  cgsblock(&fsdummy, cg)), chdummy, SBLOCKSIZE);
531 			}
532 		}
533 	}
534 	if (!Nflag)
535 		do_sbwrite(&disk);
536 	if (Xflag == 1) {
537 		printf("** Exiting on Xflag 1\n");
538 		exit(0);
539 	}
540 	if (Xflag == 2)
541 		printf("** Leaving BAD MAGIC on Xflag 2\n");
542 	else
543 		sblock.fs_magic = (Oflag != 1) ? FS_UFS2_MAGIC : FS_UFS1_MAGIC;
544 
545 	/*
546 	 * Now build the cylinders group blocks and
547 	 * then print out indices of cylinder groups.
548 	 */
549 	printf("super-block backups (for fsck -b #) at:\n");
550 	i = 0;
551 	width = charsperline();
552 	/*
553 	 * allocate space for superblock, cylinder group map, and
554 	 * two sets of inode blocks.
555 	 */
556 	if (sblock.fs_bsize < SBLOCKSIZE)
557 		iobufsize = SBLOCKSIZE + 3 * sblock.fs_bsize;
558 	else
559 		iobufsize = 4 * sblock.fs_bsize;
560 	if ((iobuf = calloc(1, iobufsize)) == 0) {
561 		printf("Cannot allocate I/O buffer\n");
562 		exit(38);
563 	}
564 	/*
565 	 * Make a copy of the superblock into the buffer that we will be
566 	 * writing out in each cylinder group.
567 	 */
568 	bcopy((char *)&sblock, iobuf, SBLOCKSIZE);
569 	for (cg = 0; cg < sblock.fs_ncg; cg++) {
570 		initcg(cg, utime);
571 		j = snprintf(tmpbuf, sizeof(tmpbuf), " %jd%s",
572 		    (intmax_t)fsbtodb(&sblock, cgsblock(&sblock, cg)),
573 		    cg < (sblock.fs_ncg-1) ? "," : "");
574 		if (j < 0)
575 			tmpbuf[j = 0] = '\0';
576 		if (i + j >= width) {
577 			printf("\n");
578 			i = 0;
579 		}
580 		i += j;
581 		printf("%s", tmpbuf);
582 		fflush(stdout);
583 	}
584 	printf("\n");
585 	if (Nflag)
586 		exit(0);
587 	/*
588 	 * Now construct the initial file system,
589 	 * then write out the super-block.
590 	 */
591 	fsinit(utime);
592 	if (Oflag == 1) {
593 		sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
594 		sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
595 		sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
596 		sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
597 	}
598 	if (Xflag == 3) {
599 		printf("** Exiting on Xflag 3\n");
600 		exit(0);
601 	}
602 	if (!Nflag) {
603 		do_sbwrite(&disk);
604 		/*
605 		 * For UFS1 filesystems with a blocksize of 64K, the first
606 		 * alternate superblock resides at the location used for
607 		 * the default UFS2 superblock. As there is a valid
608 		 * superblock at this location, the boot code will use
609 		 * it as its first choice. Thus we have to ensure that
610 		 * all of its statistcs on usage are correct.
611 		 */
612 		if (Oflag == 1 && sblock.fs_bsize == 65536)
613 			wtfs(fsbtodb(&sblock, cgsblock(&sblock, 0)),
614 			    sblock.fs_bsize, (char *)&sblock);
615 	}
616 	for (i = 0; i < sblock.fs_cssize; i += sblock.fs_bsize)
617 		wtfs(fsbtodb(&sblock, sblock.fs_csaddr + numfrags(&sblock, i)),
618 			sblock.fs_cssize - i < sblock.fs_bsize ?
619 			sblock.fs_cssize - i : sblock.fs_bsize,
620 			((char *)fscs) + i);
621 	/*
622 	 * Update information about this partition in pack
623 	 * label, to that it may be updated on disk.
624 	 */
625 	if (pp != NULL) {
626 		pp->p_fstype = FS_BSDFFS;
627 		pp->p_fsize = sblock.fs_fsize;
628 		pp->p_frag = sblock.fs_frag;
629 		pp->p_cpg = sblock.fs_fpg;
630 	}
631 }
632 
633 /*
634  * Initialize a cylinder group.
635  */
636 void
637 initcg(int cylno, time_t utime)
638 {
639 	long blkno, start;
640 	uint i, j, d, dlower, dupper;
641 	ufs2_daddr_t cbase, dmax;
642 	struct ufs1_dinode *dp1;
643 	struct ufs2_dinode *dp2;
644 	struct csum *cs;
645 
646 	/*
647 	 * Determine block bounds for cylinder group.
648 	 * Allow space for super block summary information in first
649 	 * cylinder group.
650 	 */
651 	cbase = cgbase(&sblock, cylno);
652 	dmax = cbase + sblock.fs_fpg;
653 	if (dmax > sblock.fs_size)
654 		dmax = sblock.fs_size;
655 	dlower = cgsblock(&sblock, cylno) - cbase;
656 	dupper = cgdmin(&sblock, cylno) - cbase;
657 	if (cylno == 0)
658 		dupper += howmany(sblock.fs_cssize, sblock.fs_fsize);
659 	cs = &fscs[cylno];
660 	memset(&acg, 0, sblock.fs_cgsize);
661 	acg.cg_time = utime;
662 	acg.cg_magic = CG_MAGIC;
663 	acg.cg_cgx = cylno;
664 	acg.cg_niblk = sblock.fs_ipg;
665 	acg.cg_initediblk = sblock.fs_ipg < 2 * INOPB(&sblock) ?
666 	    sblock.fs_ipg : 2 * INOPB(&sblock);
667 	acg.cg_ndblk = dmax - cbase;
668 	if (sblock.fs_contigsumsize > 0)
669 		acg.cg_nclusterblks = acg.cg_ndblk / sblock.fs_frag;
670 	start = &acg.cg_space[0] - (u_char *)(&acg.cg_firstfield);
671 	if (Oflag == 2) {
672 		acg.cg_iusedoff = start;
673 	} else {
674 		acg.cg_old_ncyl = sblock.fs_old_cpg;
675 		acg.cg_old_time = acg.cg_time;
676 		acg.cg_time = 0;
677 		acg.cg_old_niblk = acg.cg_niblk;
678 		acg.cg_niblk = 0;
679 		acg.cg_initediblk = 0;
680 		acg.cg_old_btotoff = start;
681 		acg.cg_old_boff = acg.cg_old_btotoff +
682 		    sblock.fs_old_cpg * sizeof(int32_t);
683 		acg.cg_iusedoff = acg.cg_old_boff +
684 		    sblock.fs_old_cpg * sizeof(u_int16_t);
685 	}
686 	acg.cg_freeoff = acg.cg_iusedoff + howmany(sblock.fs_ipg, CHAR_BIT);
687 	acg.cg_nextfreeoff = acg.cg_freeoff + howmany(sblock.fs_fpg, CHAR_BIT);
688 	if (sblock.fs_contigsumsize > 0) {
689 		acg.cg_clustersumoff =
690 		    roundup(acg.cg_nextfreeoff, sizeof(u_int32_t));
691 		acg.cg_clustersumoff -= sizeof(u_int32_t);
692 		acg.cg_clusteroff = acg.cg_clustersumoff +
693 		    (sblock.fs_contigsumsize + 1) * sizeof(u_int32_t);
694 		acg.cg_nextfreeoff = acg.cg_clusteroff +
695 		    howmany(fragstoblks(&sblock, sblock.fs_fpg), CHAR_BIT);
696 	}
697 	if (acg.cg_nextfreeoff > (unsigned)sblock.fs_cgsize) {
698 		printf("Panic: cylinder group too big\n");
699 		exit(37);
700 	}
701 	acg.cg_cs.cs_nifree += sblock.fs_ipg;
702 	if (cylno == 0)
703 		for (i = 0; i < (long)ROOTINO; i++) {
704 			setbit(cg_inosused(&acg), i);
705 			acg.cg_cs.cs_nifree--;
706 		}
707 	if (cylno > 0) {
708 		/*
709 		 * In cylno 0, beginning space is reserved
710 		 * for boot and super blocks.
711 		 */
712 		for (d = 0; d < dlower; d += sblock.fs_frag) {
713 			blkno = d / sblock.fs_frag;
714 			setblock(&sblock, cg_blksfree(&acg), blkno);
715 			if (sblock.fs_contigsumsize > 0)
716 				setbit(cg_clustersfree(&acg), blkno);
717 			acg.cg_cs.cs_nbfree++;
718 		}
719 	}
720 	if ((i = dupper % sblock.fs_frag)) {
721 		acg.cg_frsum[sblock.fs_frag - i]++;
722 		for (d = dupper + sblock.fs_frag - i; dupper < d; dupper++) {
723 			setbit(cg_blksfree(&acg), dupper);
724 			acg.cg_cs.cs_nffree++;
725 		}
726 	}
727 	for (d = dupper; d + sblock.fs_frag <= acg.cg_ndblk;
728 	     d += sblock.fs_frag) {
729 		blkno = d / sblock.fs_frag;
730 		setblock(&sblock, cg_blksfree(&acg), blkno);
731 		if (sblock.fs_contigsumsize > 0)
732 			setbit(cg_clustersfree(&acg), blkno);
733 		acg.cg_cs.cs_nbfree++;
734 	}
735 	if (d < acg.cg_ndblk) {
736 		acg.cg_frsum[acg.cg_ndblk - d]++;
737 		for (; d < acg.cg_ndblk; d++) {
738 			setbit(cg_blksfree(&acg), d);
739 			acg.cg_cs.cs_nffree++;
740 		}
741 	}
742 	if (sblock.fs_contigsumsize > 0) {
743 		int32_t *sump = cg_clustersum(&acg);
744 		u_char *mapp = cg_clustersfree(&acg);
745 		int map = *mapp++;
746 		int bit = 1;
747 		int run = 0;
748 
749 		for (i = 0; i < acg.cg_nclusterblks; i++) {
750 			if ((map & bit) != 0)
751 				run++;
752 			else if (run != 0) {
753 				if (run > sblock.fs_contigsumsize)
754 					run = sblock.fs_contigsumsize;
755 				sump[run]++;
756 				run = 0;
757 			}
758 			if ((i & (CHAR_BIT - 1)) != CHAR_BIT - 1)
759 				bit <<= 1;
760 			else {
761 				map = *mapp++;
762 				bit = 1;
763 			}
764 		}
765 		if (run != 0) {
766 			if (run > sblock.fs_contigsumsize)
767 				run = sblock.fs_contigsumsize;
768 			sump[run]++;
769 		}
770 	}
771 	*cs = acg.cg_cs;
772 	/*
773 	 * Write out the duplicate super block, the cylinder group map
774 	 * and two blocks worth of inodes in a single write.
775 	 */
776 	start = sblock.fs_bsize > SBLOCKSIZE ? sblock.fs_bsize : SBLOCKSIZE;
777 	bcopy((char *)&acg, &iobuf[start], sblock.fs_cgsize);
778 	start += sblock.fs_bsize;
779 	dp1 = (struct ufs1_dinode *)(&iobuf[start]);
780 	dp2 = (struct ufs2_dinode *)(&iobuf[start]);
781 	for (i = 0; i < acg.cg_initediblk; i++) {
782 		if (sblock.fs_magic == FS_UFS1_MAGIC) {
783 			dp1->di_gen = newfs_random();
784 			dp1++;
785 		} else {
786 			dp2->di_gen = newfs_random();
787 			dp2++;
788 		}
789 	}
790 	wtfs(fsbtodb(&sblock, cgsblock(&sblock, cylno)), iobufsize, iobuf);
791 	/*
792 	 * For the old file system, we have to initialize all the inodes.
793 	 */
794 	if (Oflag == 1) {
795 		for (i = 2 * sblock.fs_frag;
796 		     i < sblock.fs_ipg / INOPF(&sblock);
797 		     i += sblock.fs_frag) {
798 			dp1 = (struct ufs1_dinode *)(&iobuf[start]);
799 			for (j = 0; j < INOPB(&sblock); j++) {
800 				dp1->di_gen = newfs_random();
801 				dp1++;
802 			}
803 			wtfs(fsbtodb(&sblock, cgimin(&sblock, cylno) + i),
804 			    sblock.fs_bsize, &iobuf[start]);
805 		}
806 	}
807 }
808 
809 /*
810  * initialize the file system
811  */
812 #define ROOTLINKCNT 3
813 
814 static struct direct root_dir[] = {
815 	{ ROOTINO, sizeof(struct direct), DT_DIR, 1, "." },
816 	{ ROOTINO, sizeof(struct direct), DT_DIR, 2, ".." },
817 	{ ROOTINO + 1, sizeof(struct direct), DT_DIR, 5, ".snap" },
818 };
819 
820 #define SNAPLINKCNT 2
821 
822 static struct direct snap_dir[] = {
823 	{ ROOTINO + 1, sizeof(struct direct), DT_DIR, 1, "." },
824 	{ ROOTINO, sizeof(struct direct), DT_DIR, 2, ".." },
825 };
826 
827 void
828 fsinit(time_t utime)
829 {
830 	union dinode node;
831 	struct group *grp;
832 	gid_t gid;
833 	int entries;
834 
835 	memset(&node, 0, sizeof node);
836 	if ((grp = getgrnam("operator")) != NULL) {
837 		gid = grp->gr_gid;
838 	} else {
839 		warnx("Cannot retrieve operator gid, using gid 0.");
840 		gid = 0;
841 	}
842 	entries = (nflag) ? ROOTLINKCNT - 1: ROOTLINKCNT;
843 	if (sblock.fs_magic == FS_UFS1_MAGIC) {
844 		/*
845 		 * initialize the node
846 		 */
847 		node.dp1.di_atime = utime;
848 		node.dp1.di_mtime = utime;
849 		node.dp1.di_ctime = utime;
850 		/*
851 		 * create the root directory
852 		 */
853 		node.dp1.di_mode = IFDIR | UMASK;
854 		node.dp1.di_nlink = entries;
855 		node.dp1.di_size = makedir(root_dir, entries);
856 		node.dp1.di_db[0] = alloc(sblock.fs_fsize, node.dp1.di_mode);
857 		node.dp1.di_blocks =
858 		    btodb(fragroundup(&sblock, node.dp1.di_size));
859 		wtfs(fsbtodb(&sblock, node.dp1.di_db[0]), sblock.fs_fsize,
860 		    iobuf);
861 		iput(&node, ROOTINO);
862 		if (!nflag) {
863 			/*
864 			 * create the .snap directory
865 			 */
866 			node.dp1.di_mode |= 020;
867 			node.dp1.di_gid = gid;
868 			node.dp1.di_nlink = SNAPLINKCNT;
869 			node.dp1.di_size = makedir(snap_dir, SNAPLINKCNT);
870 				node.dp1.di_db[0] =
871 				    alloc(sblock.fs_fsize, node.dp1.di_mode);
872 			node.dp1.di_blocks =
873 			    btodb(fragroundup(&sblock, node.dp1.di_size));
874 				wtfs(fsbtodb(&sblock, node.dp1.di_db[0]),
875 				    sblock.fs_fsize, iobuf);
876 			iput(&node, ROOTINO + 1);
877 		}
878 	} else {
879 		/*
880 		 * initialize the node
881 		 */
882 		node.dp2.di_atime = utime;
883 		node.dp2.di_mtime = utime;
884 		node.dp2.di_ctime = utime;
885 		node.dp2.di_birthtime = utime;
886 		/*
887 		 * create the root directory
888 		 */
889 		node.dp2.di_mode = IFDIR | UMASK;
890 		node.dp2.di_nlink = entries;
891 		node.dp2.di_size = makedir(root_dir, entries);
892 		node.dp2.di_db[0] = alloc(sblock.fs_fsize, node.dp2.di_mode);
893 		node.dp2.di_blocks =
894 		    btodb(fragroundup(&sblock, node.dp2.di_size));
895 		wtfs(fsbtodb(&sblock, node.dp2.di_db[0]), sblock.fs_fsize,
896 		    iobuf);
897 		iput(&node, ROOTINO);
898 		if (!nflag) {
899 			/*
900 			 * create the .snap directory
901 			 */
902 			node.dp2.di_mode |= 020;
903 			node.dp2.di_gid = gid;
904 			node.dp2.di_nlink = SNAPLINKCNT;
905 			node.dp2.di_size = makedir(snap_dir, SNAPLINKCNT);
906 				node.dp2.di_db[0] =
907 				    alloc(sblock.fs_fsize, node.dp2.di_mode);
908 			node.dp2.di_blocks =
909 			    btodb(fragroundup(&sblock, node.dp2.di_size));
910 				wtfs(fsbtodb(&sblock, node.dp2.di_db[0]),
911 				    sblock.fs_fsize, iobuf);
912 			iput(&node, ROOTINO + 1);
913 		}
914 	}
915 }
916 
917 /*
918  * construct a set of directory entries in "iobuf".
919  * return size of directory.
920  */
921 int
922 makedir(struct direct *protodir, int entries)
923 {
924 	char *cp;
925 	int i, spcleft;
926 
927 	spcleft = DIRBLKSIZ;
928 	memset(iobuf, 0, DIRBLKSIZ);
929 	for (cp = iobuf, i = 0; i < entries - 1; i++) {
930 		protodir[i].d_reclen = DIRSIZ(0, &protodir[i]);
931 		memmove(cp, &protodir[i], protodir[i].d_reclen);
932 		cp += protodir[i].d_reclen;
933 		spcleft -= protodir[i].d_reclen;
934 	}
935 	protodir[i].d_reclen = spcleft;
936 	memmove(cp, &protodir[i], DIRSIZ(0, &protodir[i]));
937 	return (DIRBLKSIZ);
938 }
939 
940 /*
941  * allocate a block or frag
942  */
943 ufs2_daddr_t
944 alloc(int size, int mode)
945 {
946 	int i, blkno, frag;
947 	uint d;
948 
949 	bread(&disk, part_ofs + fsbtodb(&sblock, cgtod(&sblock, 0)), (char *)&acg,
950 	    sblock.fs_cgsize);
951 	if (acg.cg_magic != CG_MAGIC) {
952 		printf("cg 0: bad magic number\n");
953 		exit(38);
954 	}
955 	if (acg.cg_cs.cs_nbfree == 0) {
956 		printf("first cylinder group ran out of space\n");
957 		exit(39);
958 	}
959 	for (d = 0; d < acg.cg_ndblk; d += sblock.fs_frag)
960 		if (isblock(&sblock, cg_blksfree(&acg), d / sblock.fs_frag))
961 			goto goth;
962 	printf("internal error: can't find block in cyl 0\n");
963 	exit(40);
964 goth:
965 	blkno = fragstoblks(&sblock, d);
966 	clrblock(&sblock, cg_blksfree(&acg), blkno);
967 	if (sblock.fs_contigsumsize > 0)
968 		clrbit(cg_clustersfree(&acg), blkno);
969 	acg.cg_cs.cs_nbfree--;
970 	sblock.fs_cstotal.cs_nbfree--;
971 	fscs[0].cs_nbfree--;
972 	if (mode & IFDIR) {
973 		acg.cg_cs.cs_ndir++;
974 		sblock.fs_cstotal.cs_ndir++;
975 		fscs[0].cs_ndir++;
976 	}
977 	if (size != sblock.fs_bsize) {
978 		frag = howmany(size, sblock.fs_fsize);
979 		fscs[0].cs_nffree += sblock.fs_frag - frag;
980 		sblock.fs_cstotal.cs_nffree += sblock.fs_frag - frag;
981 		acg.cg_cs.cs_nffree += sblock.fs_frag - frag;
982 		acg.cg_frsum[sblock.fs_frag - frag]++;
983 		for (i = frag; i < sblock.fs_frag; i++)
984 			setbit(cg_blksfree(&acg), d + i);
985 	}
986 	/* XXX cgwrite(&disk, 0)??? */
987 	wtfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
988 	    (char *)&acg);
989 	return ((ufs2_daddr_t)d);
990 }
991 
992 /*
993  * Allocate an inode on the disk
994  */
995 void
996 iput(union dinode *ip, ino_t ino)
997 {
998 	ufs2_daddr_t d;
999 
1000 	bread(&disk, part_ofs + fsbtodb(&sblock, cgtod(&sblock, 0)), (char *)&acg,
1001 	    sblock.fs_cgsize);
1002 	if (acg.cg_magic != CG_MAGIC) {
1003 		printf("cg 0: bad magic number\n");
1004 		exit(31);
1005 	}
1006 	acg.cg_cs.cs_nifree--;
1007 	setbit(cg_inosused(&acg), ino);
1008 	wtfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
1009 	    (char *)&acg);
1010 	sblock.fs_cstotal.cs_nifree--;
1011 	fscs[0].cs_nifree--;
1012 	if (ino >= (unsigned long)sblock.fs_ipg * sblock.fs_ncg) {
1013 		printf("fsinit: inode value out of range (%ju).\n",
1014 		    (uintmax_t)ino);
1015 		exit(32);
1016 	}
1017 	d = fsbtodb(&sblock, ino_to_fsba(&sblock, ino));
1018 	bread(&disk, part_ofs + d, (char *)iobuf, sblock.fs_bsize);
1019 	if (sblock.fs_magic == FS_UFS1_MAGIC)
1020 		((struct ufs1_dinode *)iobuf)[ino_to_fsbo(&sblock, ino)] =
1021 		    ip->dp1;
1022 	else
1023 		((struct ufs2_dinode *)iobuf)[ino_to_fsbo(&sblock, ino)] =
1024 		    ip->dp2;
1025 	wtfs(d, sblock.fs_bsize, (char *)iobuf);
1026 }
1027 
1028 /*
1029  * possibly write to disk
1030  */
1031 static void
1032 wtfs(ufs2_daddr_t bno, int size, char *bf)
1033 {
1034 	if (Nflag)
1035 		return;
1036 	if (bwrite(&disk, part_ofs + bno, bf, size) < 0)
1037 		err(36, "wtfs: %d bytes at sector %jd", size, (intmax_t)bno);
1038 }
1039 
1040 /*
1041  * check if a block is available
1042  */
1043 static int
1044 isblock(struct fs *fs, unsigned char *cp, int h)
1045 {
1046 	unsigned char mask;
1047 
1048 	switch (fs->fs_frag) {
1049 	case 8:
1050 		return (cp[h] == 0xff);
1051 	case 4:
1052 		mask = 0x0f << ((h & 0x1) << 2);
1053 		return ((cp[h >> 1] & mask) == mask);
1054 	case 2:
1055 		mask = 0x03 << ((h & 0x3) << 1);
1056 		return ((cp[h >> 2] & mask) == mask);
1057 	case 1:
1058 		mask = 0x01 << (h & 0x7);
1059 		return ((cp[h >> 3] & mask) == mask);
1060 	default:
1061 		fprintf(stderr, "isblock bad fs_frag %d\n", fs->fs_frag);
1062 		return (0);
1063 	}
1064 }
1065 
1066 /*
1067  * take a block out of the map
1068  */
1069 static void
1070 clrblock(struct fs *fs, unsigned char *cp, int h)
1071 {
1072 	switch ((fs)->fs_frag) {
1073 	case 8:
1074 		cp[h] = 0;
1075 		return;
1076 	case 4:
1077 		cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
1078 		return;
1079 	case 2:
1080 		cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
1081 		return;
1082 	case 1:
1083 		cp[h >> 3] &= ~(0x01 << (h & 0x7));
1084 		return;
1085 	default:
1086 		fprintf(stderr, "clrblock bad fs_frag %d\n", fs->fs_frag);
1087 		return;
1088 	}
1089 }
1090 
1091 /*
1092  * put a block into the map
1093  */
1094 static void
1095 setblock(struct fs *fs, unsigned char *cp, int h)
1096 {
1097 	switch (fs->fs_frag) {
1098 	case 8:
1099 		cp[h] = 0xff;
1100 		return;
1101 	case 4:
1102 		cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
1103 		return;
1104 	case 2:
1105 		cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
1106 		return;
1107 	case 1:
1108 		cp[h >> 3] |= (0x01 << (h & 0x7));
1109 		return;
1110 	default:
1111 		fprintf(stderr, "setblock bad fs_frag %d\n", fs->fs_frag);
1112 		return;
1113 	}
1114 }
1115 
1116 /*
1117  * Determine the number of characters in a
1118  * single line.
1119  */
1120 
1121 static int
1122 charsperline(void)
1123 {
1124 	int columns;
1125 	char *cp;
1126 	struct winsize ws;
1127 
1128 	columns = 0;
1129 	if (ioctl(0, TIOCGWINSZ, &ws) != -1)
1130 		columns = ws.ws_col;
1131 	if (columns == 0 && (cp = getenv("COLUMNS")))
1132 		columns = atoi(cp);
1133 	if (columns == 0)
1134 		columns = 80;	/* last resort */
1135 	return (columns);
1136 }
1137 
1138 static int
1139 ilog2(int val)
1140 {
1141 	u_int n;
1142 
1143 	for (n = 0; n < sizeof(n) * CHAR_BIT; n++)
1144 		if (1 << n == val)
1145 			return (n);
1146 	errx(1, "ilog2: %d is not a power of 2\n", val);
1147 }
1148 
1149 /*
1150  * For the regression test, return predictable random values.
1151  * Otherwise use a true random number generator.
1152  */
1153 static u_int32_t
1154 newfs_random(void)
1155 {
1156 	static int nextnum = 1;
1157 
1158 	if (Rflag)
1159 		return (nextnum++);
1160 	return (arc4random());
1161 }
1162