xref: /freebsd/sbin/newfs/mkfs.c (revision 2f02600abfddfc4e9f20dd384a2e729b451e16bd)
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 	sblock.fs_old_flags = FS_FLAGS_UPDATED;
142 	sblock.fs_flags = 0;
143 	if (Uflag)
144 		sblock.fs_flags |= FS_DOSOFTDEP;
145 	if (Lflag)
146 		strlcpy(sblock.fs_volname, volumelabel, MAXVOLLEN);
147 	if (Jflag)
148 		sblock.fs_flags |= FS_GJOURNAL;
149 	if (lflag)
150 		sblock.fs_flags |= FS_MULTILABEL;
151 	if (tflag)
152 		sblock.fs_flags |= FS_TRIM;
153 	/*
154 	 * Validate the given file system size.
155 	 * Verify that its last block can actually be accessed.
156 	 * Convert to file system fragment sized units.
157 	 */
158 	if (fssize <= 0) {
159 		printf("preposterous size %jd\n", (intmax_t)fssize);
160 		exit(13);
161 	}
162 	wtfs(fssize - (realsectorsize / DEV_BSIZE), realsectorsize,
163 	    (char *)&sblock);
164 	/*
165 	 * collect and verify the file system density info
166 	 */
167 	sblock.fs_avgfilesize = avgfilesize;
168 	sblock.fs_avgfpdir = avgfilesperdir;
169 	if (sblock.fs_avgfilesize <= 0)
170 		printf("illegal expected average file size %d\n",
171 		    sblock.fs_avgfilesize), exit(14);
172 	if (sblock.fs_avgfpdir <= 0)
173 		printf("illegal expected number of files per directory %d\n",
174 		    sblock.fs_avgfpdir), exit(15);
175 
176 restart:
177 	/*
178 	 * collect and verify the block and fragment sizes
179 	 */
180 	sblock.fs_bsize = bsize;
181 	sblock.fs_fsize = fsize;
182 	if (!POWEROF2(sblock.fs_bsize)) {
183 		printf("block size must be a power of 2, not %d\n",
184 		    sblock.fs_bsize);
185 		exit(16);
186 	}
187 	if (!POWEROF2(sblock.fs_fsize)) {
188 		printf("fragment size must be a power of 2, not %d\n",
189 		    sblock.fs_fsize);
190 		exit(17);
191 	}
192 	if (sblock.fs_fsize < sectorsize) {
193 		printf("increasing fragment size from %d to sector size (%d)\n",
194 		    sblock.fs_fsize, sectorsize);
195 		sblock.fs_fsize = sectorsize;
196 	}
197 	if (sblock.fs_bsize > MAXBSIZE) {
198 		printf("decreasing block size from %d to maximum (%d)\n",
199 		    sblock.fs_bsize, MAXBSIZE);
200 		sblock.fs_bsize = MAXBSIZE;
201 	}
202 	if (sblock.fs_bsize < MINBSIZE) {
203 		printf("increasing block size from %d to minimum (%d)\n",
204 		    sblock.fs_bsize, MINBSIZE);
205 		sblock.fs_bsize = MINBSIZE;
206 	}
207 	if (sblock.fs_fsize > MAXBSIZE) {
208 		printf("decreasing fragment size from %d to maximum (%d)\n",
209 		    sblock.fs_fsize, MAXBSIZE);
210 		sblock.fs_fsize = MAXBSIZE;
211 	}
212 	if (sblock.fs_bsize < sblock.fs_fsize) {
213 		printf("increasing block size from %d to fragment size (%d)\n",
214 		    sblock.fs_bsize, sblock.fs_fsize);
215 		sblock.fs_bsize = sblock.fs_fsize;
216 	}
217 	if (sblock.fs_fsize * MAXFRAG < sblock.fs_bsize) {
218 		printf(
219 		"increasing fragment size from %d to block size / %d (%d)\n",
220 		    sblock.fs_fsize, MAXFRAG, sblock.fs_bsize / MAXFRAG);
221 		sblock.fs_fsize = sblock.fs_bsize / MAXFRAG;
222 	}
223 	if (maxbsize == 0)
224 		maxbsize = bsize;
225 	if (maxbsize < bsize || !POWEROF2(maxbsize)) {
226 		sblock.fs_maxbsize = sblock.fs_bsize;
227 		printf("Extent size set to %d\n", sblock.fs_maxbsize);
228 	} else if (sblock.fs_maxbsize > FS_MAXCONTIG * sblock.fs_bsize) {
229 		sblock.fs_maxbsize = FS_MAXCONTIG * sblock.fs_bsize;
230 		printf("Extent size reduced to %d\n", sblock.fs_maxbsize);
231 	} else {
232 		sblock.fs_maxbsize = maxbsize;
233 	}
234 	/*
235 	 * Maxcontig sets the default for the maximum number of blocks
236 	 * that may be allocated sequentially. With file system clustering
237 	 * it is possible to allocate contiguous blocks up to the maximum
238 	 * transfer size permitted by the controller or buffering.
239 	 */
240 	if (maxcontig == 0)
241 		maxcontig = MAX(1, MAXPHYS / bsize);
242 	sblock.fs_maxcontig = maxcontig;
243 	if (sblock.fs_maxcontig < sblock.fs_maxbsize / sblock.fs_bsize) {
244 		sblock.fs_maxcontig = sblock.fs_maxbsize / sblock.fs_bsize;
245 		printf("Maxcontig raised to %d\n", sblock.fs_maxbsize);
246 	}
247 	if (sblock.fs_maxcontig > 1)
248 		sblock.fs_contigsumsize = MIN(sblock.fs_maxcontig,FS_MAXCONTIG);
249 	sblock.fs_bmask = ~(sblock.fs_bsize - 1);
250 	sblock.fs_fmask = ~(sblock.fs_fsize - 1);
251 	sblock.fs_qbmask = ~sblock.fs_bmask;
252 	sblock.fs_qfmask = ~sblock.fs_fmask;
253 	sblock.fs_bshift = ilog2(sblock.fs_bsize);
254 	sblock.fs_fshift = ilog2(sblock.fs_fsize);
255 	sblock.fs_frag = numfrags(&sblock, sblock.fs_bsize);
256 	sblock.fs_fragshift = ilog2(sblock.fs_frag);
257 	if (sblock.fs_frag > MAXFRAG) {
258 		printf("fragment size %d is still too small (can't happen)\n",
259 		    sblock.fs_bsize / MAXFRAG);
260 		exit(21);
261 	}
262 	sblock.fs_fsbtodb = ilog2(sblock.fs_fsize / sectorsize);
263 	sblock.fs_size = fssize = dbtofsb(&sblock, fssize);
264 	sblock.fs_providersize = dbtofsb(&sblock, mediasize / sectorsize);
265 
266 	/*
267 	 * Before the filesystem is finally initialized, mark it
268 	 * as incompletely initialized.
269 	 */
270 	sblock.fs_magic = FS_BAD_MAGIC;
271 
272 	if (Oflag == 1) {
273 		sblock.fs_sblockloc = SBLOCK_UFS1;
274 		sblock.fs_nindir = sblock.fs_bsize / sizeof(ufs1_daddr_t);
275 		sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs1_dinode);
276 		sblock.fs_maxsymlinklen = ((NDADDR + NIADDR) *
277 		    sizeof(ufs1_daddr_t));
278 		sblock.fs_old_inodefmt = FS_44INODEFMT;
279 		sblock.fs_old_cgoffset = 0;
280 		sblock.fs_old_cgmask = 0xffffffff;
281 		sblock.fs_old_size = sblock.fs_size;
282 		sblock.fs_old_rotdelay = 0;
283 		sblock.fs_old_rps = 60;
284 		sblock.fs_old_nspf = sblock.fs_fsize / sectorsize;
285 		sblock.fs_old_cpg = 1;
286 		sblock.fs_old_interleave = 1;
287 		sblock.fs_old_trackskew = 0;
288 		sblock.fs_old_cpc = 0;
289 		sblock.fs_old_postblformat = 1;
290 		sblock.fs_old_nrpos = 1;
291 	} else {
292 		sblock.fs_sblockloc = SBLOCK_UFS2;
293 		sblock.fs_nindir = sblock.fs_bsize / sizeof(ufs2_daddr_t);
294 		sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs2_dinode);
295 		sblock.fs_maxsymlinklen = ((NDADDR + NIADDR) *
296 		    sizeof(ufs2_daddr_t));
297 	}
298 	sblock.fs_sblkno =
299 	    roundup(howmany(sblock.fs_sblockloc + SBLOCKSIZE, sblock.fs_fsize),
300 		sblock.fs_frag);
301 	sblock.fs_cblkno = sblock.fs_sblkno +
302 	    roundup(howmany(SBLOCKSIZE, sblock.fs_fsize), sblock.fs_frag);
303 	sblock.fs_iblkno = sblock.fs_cblkno + sblock.fs_frag;
304 	sblock.fs_maxfilesize = sblock.fs_bsize * NDADDR - 1;
305 	for (sizepb = sblock.fs_bsize, i = 0; i < NIADDR; i++) {
306 		sizepb *= NINDIR(&sblock);
307 		sblock.fs_maxfilesize += sizepb;
308 	}
309 
310 	/*
311 	 * It's impossible to create a snapshot in case that fs_maxfilesize
312 	 * is smaller than the fssize.
313 	 */
314 	if (sblock.fs_maxfilesize < (u_quad_t)fssize) {
315 		warnx("WARNING: You will be unable to create snapshots on this "
316 		      "file system.  Correct by using a larger blocksize.");
317 	}
318 
319 	/*
320 	 * Calculate the number of blocks to put into each cylinder group.
321 	 *
322 	 * This algorithm selects the number of blocks per cylinder
323 	 * group. The first goal is to have at least enough data blocks
324 	 * in each cylinder group to meet the density requirement. Once
325 	 * this goal is achieved we try to expand to have at least
326 	 * MINCYLGRPS cylinder groups. Once this goal is achieved, we
327 	 * pack as many blocks into each cylinder group map as will fit.
328 	 *
329 	 * We start by calculating the smallest number of blocks that we
330 	 * can put into each cylinder group. If this is too big, we reduce
331 	 * the density until it fits.
332 	 */
333 	maxinum = (((int64_t)(1)) << 32) - INOPB(&sblock);
334 	minfragsperinode = 1 + fssize / maxinum;
335 	if (density == 0) {
336 		density = MAX(NFPI, minfragsperinode) * fsize;
337 	} else if (density < minfragsperinode * fsize) {
338 		origdensity = density;
339 		density = minfragsperinode * fsize;
340 		fprintf(stderr, "density increased from %d to %d\n",
341 		    origdensity, density);
342 	}
343 	origdensity = density;
344 	for (;;) {
345 		fragsperinode = MAX(numfrags(&sblock, density), 1);
346 		if (fragsperinode < minfragsperinode) {
347 			bsize <<= 1;
348 			fsize <<= 1;
349 			printf("Block size too small for a file system %s %d\n",
350 			     "of this size. Increasing blocksize to", bsize);
351 			goto restart;
352 		}
353 		minfpg = fragsperinode * INOPB(&sblock);
354 		if (minfpg > sblock.fs_size)
355 			minfpg = sblock.fs_size;
356 		sblock.fs_ipg = INOPB(&sblock);
357 		sblock.fs_fpg = roundup(sblock.fs_iblkno +
358 		    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
359 		if (sblock.fs_fpg < minfpg)
360 			sblock.fs_fpg = minfpg;
361 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
362 		    INOPB(&sblock));
363 		sblock.fs_fpg = roundup(sblock.fs_iblkno +
364 		    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
365 		if (sblock.fs_fpg < minfpg)
366 			sblock.fs_fpg = minfpg;
367 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
368 		    INOPB(&sblock));
369 		if (CGSIZE(&sblock) < (unsigned long)sblock.fs_bsize)
370 			break;
371 		density -= sblock.fs_fsize;
372 	}
373 	if (density != origdensity)
374 		printf("density reduced from %d to %d\n", origdensity, density);
375 	/*
376 	 * Start packing more blocks into the cylinder group until
377 	 * it cannot grow any larger, the number of cylinder groups
378 	 * drops below MINCYLGRPS, or we reach the size requested.
379 	 * For UFS1 inodes per cylinder group are stored in an int16_t
380 	 * so fs_ipg is limited to 2^15 - 1.
381 	 */
382 	for ( ; sblock.fs_fpg < maxblkspercg; sblock.fs_fpg += sblock.fs_frag) {
383 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
384 		    INOPB(&sblock));
385 		if (Oflag > 1 || (Oflag == 1 && sblock.fs_ipg <= 0x7fff)) {
386 			if (sblock.fs_size / sblock.fs_fpg < MINCYLGRPS)
387 				break;
388 			if (CGSIZE(&sblock) < (unsigned long)sblock.fs_bsize)
389 				continue;
390 			if (CGSIZE(&sblock) == (unsigned long)sblock.fs_bsize)
391 				break;
392 		}
393 		sblock.fs_fpg -= sblock.fs_frag;
394 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
395 		    INOPB(&sblock));
396 		break;
397 	}
398 	/*
399 	 * Check to be sure that the last cylinder group has enough blocks
400 	 * to be viable. If it is too small, reduce the number of blocks
401 	 * per cylinder group which will have the effect of moving more
402 	 * blocks into the last cylinder group.
403 	 */
404 	optimalfpg = sblock.fs_fpg;
405 	for (;;) {
406 		sblock.fs_ncg = howmany(sblock.fs_size, sblock.fs_fpg);
407 		lastminfpg = roundup(sblock.fs_iblkno +
408 		    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
409 		if (sblock.fs_size < lastminfpg) {
410 			printf("Filesystem size %jd < minimum size of %d\n",
411 			    (intmax_t)sblock.fs_size, lastminfpg);
412 			exit(28);
413 		}
414 		if (sblock.fs_size % sblock.fs_fpg >= lastminfpg ||
415 		    sblock.fs_size % sblock.fs_fpg == 0)
416 			break;
417 		sblock.fs_fpg -= sblock.fs_frag;
418 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
419 		    INOPB(&sblock));
420 	}
421 	if (optimalfpg != sblock.fs_fpg)
422 		printf("Reduced frags per cylinder group from %d to %d %s\n",
423 		   optimalfpg, sblock.fs_fpg, "to enlarge last cyl group");
424 	sblock.fs_cgsize = fragroundup(&sblock, CGSIZE(&sblock));
425 	sblock.fs_dblkno = sblock.fs_iblkno + sblock.fs_ipg / INOPF(&sblock);
426 	if (Oflag == 1) {
427 		sblock.fs_old_spc = sblock.fs_fpg * sblock.fs_old_nspf;
428 		sblock.fs_old_nsect = sblock.fs_old_spc;
429 		sblock.fs_old_npsect = sblock.fs_old_spc;
430 		sblock.fs_old_ncyl = sblock.fs_ncg;
431 	}
432 	/*
433 	 * fill in remaining fields of the super block
434 	 */
435 	sblock.fs_csaddr = cgdmin(&sblock, 0);
436 	sblock.fs_cssize =
437 	    fragroundup(&sblock, sblock.fs_ncg * sizeof(struct csum));
438 	fscs = (struct csum *)calloc(1, sblock.fs_cssize);
439 	if (fscs == NULL)
440 		errx(31, "calloc failed");
441 	sblock.fs_sbsize = fragroundup(&sblock, sizeof(struct fs));
442 	if (sblock.fs_sbsize > SBLOCKSIZE)
443 		sblock.fs_sbsize = SBLOCKSIZE;
444 	sblock.fs_minfree = minfree;
445 	if (metaspace > 0 && metaspace < sblock.fs_fpg / 2)
446 		sblock.fs_metaspace = blknum(&sblock, metaspace);
447 	else if (metaspace != -1)
448 		/* reserve half of minfree for metadata blocks */
449 		sblock.fs_metaspace = blknum(&sblock,
450 		    (sblock.fs_fpg * minfree) / 200);
451 	if (maxbpg == 0)
452 		sblock.fs_maxbpg = MAXBLKPG(sblock.fs_bsize);
453 	else
454 		sblock.fs_maxbpg = maxbpg;
455 	sblock.fs_optim = opt;
456 	sblock.fs_cgrotor = 0;
457 	sblock.fs_pendingblocks = 0;
458 	sblock.fs_pendinginodes = 0;
459 	sblock.fs_fmod = 0;
460 	sblock.fs_ronly = 0;
461 	sblock.fs_state = 0;
462 	sblock.fs_clean = 1;
463 	sblock.fs_id[0] = (long)utime;
464 	sblock.fs_id[1] = newfs_random();
465 	sblock.fs_fsmnt[0] = '\0';
466 	csfrags = howmany(sblock.fs_cssize, sblock.fs_fsize);
467 	sblock.fs_dsize = sblock.fs_size - sblock.fs_sblkno -
468 	    sblock.fs_ncg * (sblock.fs_dblkno - sblock.fs_sblkno);
469 	sblock.fs_cstotal.cs_nbfree =
470 	    fragstoblks(&sblock, sblock.fs_dsize) -
471 	    howmany(csfrags, sblock.fs_frag);
472 	sblock.fs_cstotal.cs_nffree =
473 	    fragnum(&sblock, sblock.fs_size) +
474 	    (fragnum(&sblock, csfrags) > 0 ?
475 	     sblock.fs_frag - fragnum(&sblock, csfrags) : 0);
476 	sblock.fs_cstotal.cs_nifree = sblock.fs_ncg * sblock.fs_ipg - ROOTINO;
477 	sblock.fs_cstotal.cs_ndir = 0;
478 	sblock.fs_dsize -= csfrags;
479 	sblock.fs_time = utime;
480 	if (Oflag == 1) {
481 		sblock.fs_old_time = utime;
482 		sblock.fs_old_dsize = sblock.fs_dsize;
483 		sblock.fs_old_csaddr = sblock.fs_csaddr;
484 		sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
485 		sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
486 		sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
487 		sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
488 	}
489 
490 	/*
491 	 * Dump out summary information about file system.
492 	 */
493 #	define B2MBFACTOR (1 / (1024.0 * 1024.0))
494 	printf("%s: %.1fMB (%jd sectors) block size %d, fragment size %d\n",
495 	    fsys, (float)sblock.fs_size * sblock.fs_fsize * B2MBFACTOR,
496 	    (intmax_t)fsbtodb(&sblock, sblock.fs_size), sblock.fs_bsize,
497 	    sblock.fs_fsize);
498 	printf("\tusing %d cylinder groups of %.2fMB, %d blks, %d inodes.\n",
499 	    sblock.fs_ncg, (float)sblock.fs_fpg * sblock.fs_fsize * B2MBFACTOR,
500 	    sblock.fs_fpg / sblock.fs_frag, sblock.fs_ipg);
501 	if (sblock.fs_flags & FS_DOSOFTDEP)
502 		printf("\twith soft updates\n");
503 #	undef B2MBFACTOR
504 
505 	if (Eflag && !Nflag) {
506 		printf("Erasing sectors [%jd...%jd]\n",
507 		    sblock.fs_sblockloc / disk.d_bsize,
508 		    fsbtodb(&sblock, sblock.fs_size) - 1);
509 		berase(&disk, sblock.fs_sblockloc / disk.d_bsize,
510 		    sblock.fs_size * sblock.fs_fsize - sblock.fs_sblockloc);
511 	}
512 	/*
513 	 * Wipe out old UFS1 superblock(s) if necessary.
514 	 */
515 	if (!Nflag && Oflag != 1) {
516 		i = bread(&disk, part_ofs + SBLOCK_UFS1 / disk.d_bsize, chdummy, SBLOCKSIZE);
517 		if (i == -1)
518 			err(1, "can't read old UFS1 superblock: %s", disk.d_error);
519 
520 		if (fsdummy.fs_magic == FS_UFS1_MAGIC) {
521 			fsdummy.fs_magic = 0;
522 			bwrite(&disk, part_ofs + SBLOCK_UFS1 / disk.d_bsize,
523 			    chdummy, SBLOCKSIZE);
524 			for (cg = 0; cg < fsdummy.fs_ncg; cg++) {
525 				if (fsbtodb(&fsdummy, cgsblock(&fsdummy, cg)) > fssize)
526 					break;
527 				bwrite(&disk, part_ofs + fsbtodb(&fsdummy,
528 				  cgsblock(&fsdummy, cg)), chdummy, SBLOCKSIZE);
529 			}
530 		}
531 	}
532 	if (!Nflag)
533 		do_sbwrite(&disk);
534 	if (Xflag == 1) {
535 		printf("** Exiting on Xflag 1\n");
536 		exit(0);
537 	}
538 	if (Xflag == 2)
539 		printf("** Leaving BAD MAGIC on Xflag 2\n");
540 	else
541 		sblock.fs_magic = (Oflag != 1) ? FS_UFS2_MAGIC : FS_UFS1_MAGIC;
542 
543 	/*
544 	 * Now build the cylinders group blocks and
545 	 * then print out indices of cylinder groups.
546 	 */
547 	printf("super-block backups (for fsck -b #) at:\n");
548 	i = 0;
549 	width = charsperline();
550 	/*
551 	 * allocate space for superblock, cylinder group map, and
552 	 * two sets of inode blocks.
553 	 */
554 	if (sblock.fs_bsize < SBLOCKSIZE)
555 		iobufsize = SBLOCKSIZE + 3 * sblock.fs_bsize;
556 	else
557 		iobufsize = 4 * sblock.fs_bsize;
558 	if ((iobuf = calloc(1, iobufsize)) == 0) {
559 		printf("Cannot allocate I/O buffer\n");
560 		exit(38);
561 	}
562 	/*
563 	 * Make a copy of the superblock into the buffer that we will be
564 	 * writing out in each cylinder group.
565 	 */
566 	bcopy((char *)&sblock, iobuf, SBLOCKSIZE);
567 	for (cg = 0; cg < sblock.fs_ncg; cg++) {
568 		initcg(cg, utime);
569 		j = snprintf(tmpbuf, sizeof(tmpbuf), " %jd%s",
570 		    (intmax_t)fsbtodb(&sblock, cgsblock(&sblock, cg)),
571 		    cg < (sblock.fs_ncg-1) ? "," : "");
572 		if (j < 0)
573 			tmpbuf[j = 0] = '\0';
574 		if (i + j >= width) {
575 			printf("\n");
576 			i = 0;
577 		}
578 		i += j;
579 		printf("%s", tmpbuf);
580 		fflush(stdout);
581 	}
582 	printf("\n");
583 	if (Nflag)
584 		exit(0);
585 	/*
586 	 * Now construct the initial file system,
587 	 * then write out the super-block.
588 	 */
589 	fsinit(utime);
590 	if (Oflag == 1) {
591 		sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
592 		sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
593 		sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
594 		sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
595 	}
596 	if (Xflag == 3) {
597 		printf("** Exiting on Xflag 3\n");
598 		exit(0);
599 	}
600 	if (!Nflag) {
601 		do_sbwrite(&disk);
602 		/*
603 		 * For UFS1 filesystems with a blocksize of 64K, the first
604 		 * alternate superblock resides at the location used for
605 		 * the default UFS2 superblock. As there is a valid
606 		 * superblock at this location, the boot code will use
607 		 * it as its first choice. Thus we have to ensure that
608 		 * all of its statistcs on usage are correct.
609 		 */
610 		if (Oflag == 1 && sblock.fs_bsize == 65536)
611 			wtfs(fsbtodb(&sblock, cgsblock(&sblock, 0)),
612 			    sblock.fs_bsize, (char *)&sblock);
613 	}
614 	for (i = 0; i < sblock.fs_cssize; i += sblock.fs_bsize)
615 		wtfs(fsbtodb(&sblock, sblock.fs_csaddr + numfrags(&sblock, i)),
616 			sblock.fs_cssize - i < sblock.fs_bsize ?
617 			sblock.fs_cssize - i : sblock.fs_bsize,
618 			((char *)fscs) + i);
619 	/*
620 	 * Update information about this partition in pack
621 	 * label, to that it may be updated on disk.
622 	 */
623 	if (pp != NULL) {
624 		pp->p_fstype = FS_BSDFFS;
625 		pp->p_fsize = sblock.fs_fsize;
626 		pp->p_frag = sblock.fs_frag;
627 		pp->p_cpg = sblock.fs_fpg;
628 	}
629 }
630 
631 /*
632  * Initialize a cylinder group.
633  */
634 void
635 initcg(int cylno, time_t utime)
636 {
637 	long blkno, start;
638 	uint i, j, d, dlower, dupper;
639 	ufs2_daddr_t cbase, dmax;
640 	struct ufs1_dinode *dp1;
641 	struct ufs2_dinode *dp2;
642 	struct csum *cs;
643 
644 	/*
645 	 * Determine block bounds for cylinder group.
646 	 * Allow space for super block summary information in first
647 	 * cylinder group.
648 	 */
649 	cbase = cgbase(&sblock, cylno);
650 	dmax = cbase + sblock.fs_fpg;
651 	if (dmax > sblock.fs_size)
652 		dmax = sblock.fs_size;
653 	dlower = cgsblock(&sblock, cylno) - cbase;
654 	dupper = cgdmin(&sblock, cylno) - cbase;
655 	if (cylno == 0)
656 		dupper += howmany(sblock.fs_cssize, sblock.fs_fsize);
657 	cs = &fscs[cylno];
658 	memset(&acg, 0, sblock.fs_cgsize);
659 	acg.cg_time = utime;
660 	acg.cg_magic = CG_MAGIC;
661 	acg.cg_cgx = cylno;
662 	acg.cg_niblk = sblock.fs_ipg;
663 	acg.cg_initediblk = sblock.fs_ipg < 2 * INOPB(&sblock) ?
664 	    sblock.fs_ipg : 2 * INOPB(&sblock);
665 	acg.cg_ndblk = dmax - cbase;
666 	if (sblock.fs_contigsumsize > 0)
667 		acg.cg_nclusterblks = acg.cg_ndblk / sblock.fs_frag;
668 	start = &acg.cg_space[0] - (u_char *)(&acg.cg_firstfield);
669 	if (Oflag == 2) {
670 		acg.cg_iusedoff = start;
671 	} else {
672 		acg.cg_old_ncyl = sblock.fs_old_cpg;
673 		acg.cg_old_time = acg.cg_time;
674 		acg.cg_time = 0;
675 		acg.cg_old_niblk = acg.cg_niblk;
676 		acg.cg_niblk = 0;
677 		acg.cg_initediblk = 0;
678 		acg.cg_old_btotoff = start;
679 		acg.cg_old_boff = acg.cg_old_btotoff +
680 		    sblock.fs_old_cpg * sizeof(int32_t);
681 		acg.cg_iusedoff = acg.cg_old_boff +
682 		    sblock.fs_old_cpg * sizeof(u_int16_t);
683 	}
684 	acg.cg_freeoff = acg.cg_iusedoff + howmany(sblock.fs_ipg, CHAR_BIT);
685 	acg.cg_nextfreeoff = acg.cg_freeoff + howmany(sblock.fs_fpg, CHAR_BIT);
686 	if (sblock.fs_contigsumsize > 0) {
687 		acg.cg_clustersumoff =
688 		    roundup(acg.cg_nextfreeoff, sizeof(u_int32_t));
689 		acg.cg_clustersumoff -= sizeof(u_int32_t);
690 		acg.cg_clusteroff = acg.cg_clustersumoff +
691 		    (sblock.fs_contigsumsize + 1) * sizeof(u_int32_t);
692 		acg.cg_nextfreeoff = acg.cg_clusteroff +
693 		    howmany(fragstoblks(&sblock, sblock.fs_fpg), CHAR_BIT);
694 	}
695 	if (acg.cg_nextfreeoff > (unsigned)sblock.fs_cgsize) {
696 		printf("Panic: cylinder group too big\n");
697 		exit(37);
698 	}
699 	acg.cg_cs.cs_nifree += sblock.fs_ipg;
700 	if (cylno == 0)
701 		for (i = 0; i < (long)ROOTINO; i++) {
702 			setbit(cg_inosused(&acg), i);
703 			acg.cg_cs.cs_nifree--;
704 		}
705 	if (cylno > 0) {
706 		/*
707 		 * In cylno 0, beginning space is reserved
708 		 * for boot and super blocks.
709 		 */
710 		for (d = 0; d < dlower; d += sblock.fs_frag) {
711 			blkno = d / sblock.fs_frag;
712 			setblock(&sblock, cg_blksfree(&acg), blkno);
713 			if (sblock.fs_contigsumsize > 0)
714 				setbit(cg_clustersfree(&acg), blkno);
715 			acg.cg_cs.cs_nbfree++;
716 		}
717 	}
718 	if ((i = dupper % sblock.fs_frag)) {
719 		acg.cg_frsum[sblock.fs_frag - i]++;
720 		for (d = dupper + sblock.fs_frag - i; dupper < d; dupper++) {
721 			setbit(cg_blksfree(&acg), dupper);
722 			acg.cg_cs.cs_nffree++;
723 		}
724 	}
725 	for (d = dupper; d + sblock.fs_frag <= acg.cg_ndblk;
726 	     d += sblock.fs_frag) {
727 		blkno = d / sblock.fs_frag;
728 		setblock(&sblock, cg_blksfree(&acg), blkno);
729 		if (sblock.fs_contigsumsize > 0)
730 			setbit(cg_clustersfree(&acg), blkno);
731 		acg.cg_cs.cs_nbfree++;
732 	}
733 	if (d < acg.cg_ndblk) {
734 		acg.cg_frsum[acg.cg_ndblk - d]++;
735 		for (; d < acg.cg_ndblk; d++) {
736 			setbit(cg_blksfree(&acg), d);
737 			acg.cg_cs.cs_nffree++;
738 		}
739 	}
740 	if (sblock.fs_contigsumsize > 0) {
741 		int32_t *sump = cg_clustersum(&acg);
742 		u_char *mapp = cg_clustersfree(&acg);
743 		int map = *mapp++;
744 		int bit = 1;
745 		int run = 0;
746 
747 		for (i = 0; i < acg.cg_nclusterblks; i++) {
748 			if ((map & bit) != 0)
749 				run++;
750 			else if (run != 0) {
751 				if (run > sblock.fs_contigsumsize)
752 					run = sblock.fs_contigsumsize;
753 				sump[run]++;
754 				run = 0;
755 			}
756 			if ((i & (CHAR_BIT - 1)) != CHAR_BIT - 1)
757 				bit <<= 1;
758 			else {
759 				map = *mapp++;
760 				bit = 1;
761 			}
762 		}
763 		if (run != 0) {
764 			if (run > sblock.fs_contigsumsize)
765 				run = sblock.fs_contigsumsize;
766 			sump[run]++;
767 		}
768 	}
769 	*cs = acg.cg_cs;
770 	/*
771 	 * Write out the duplicate super block, the cylinder group map
772 	 * and two blocks worth of inodes in a single write.
773 	 */
774 	start = sblock.fs_bsize > SBLOCKSIZE ? sblock.fs_bsize : SBLOCKSIZE;
775 	bcopy((char *)&acg, &iobuf[start], sblock.fs_cgsize);
776 	start += sblock.fs_bsize;
777 	dp1 = (struct ufs1_dinode *)(&iobuf[start]);
778 	dp2 = (struct ufs2_dinode *)(&iobuf[start]);
779 	for (i = 0; i < acg.cg_initediblk; i++) {
780 		if (sblock.fs_magic == FS_UFS1_MAGIC) {
781 			dp1->di_gen = newfs_random();
782 			dp1++;
783 		} else {
784 			dp2->di_gen = newfs_random();
785 			dp2++;
786 		}
787 	}
788 	wtfs(fsbtodb(&sblock, cgsblock(&sblock, cylno)), iobufsize, iobuf);
789 	/*
790 	 * For the old file system, we have to initialize all the inodes.
791 	 */
792 	if (Oflag == 1) {
793 		for (i = 2 * sblock.fs_frag;
794 		     i < sblock.fs_ipg / INOPF(&sblock);
795 		     i += sblock.fs_frag) {
796 			dp1 = (struct ufs1_dinode *)(&iobuf[start]);
797 			for (j = 0; j < INOPB(&sblock); j++) {
798 				dp1->di_gen = newfs_random();
799 				dp1++;
800 			}
801 			wtfs(fsbtodb(&sblock, cgimin(&sblock, cylno) + i),
802 			    sblock.fs_bsize, &iobuf[start]);
803 		}
804 	}
805 }
806 
807 /*
808  * initialize the file system
809  */
810 #define ROOTLINKCNT 3
811 
812 static struct direct root_dir[] = {
813 	{ ROOTINO, sizeof(struct direct), DT_DIR, 1, "." },
814 	{ ROOTINO, sizeof(struct direct), DT_DIR, 2, ".." },
815 	{ ROOTINO + 1, sizeof(struct direct), DT_DIR, 5, ".snap" },
816 };
817 
818 #define SNAPLINKCNT 2
819 
820 static struct direct snap_dir[] = {
821 	{ ROOTINO + 1, sizeof(struct direct), DT_DIR, 1, "." },
822 	{ ROOTINO, sizeof(struct direct), DT_DIR, 2, ".." },
823 };
824 
825 void
826 fsinit(time_t utime)
827 {
828 	union dinode node;
829 	struct group *grp;
830 	gid_t gid;
831 	int entries;
832 
833 	memset(&node, 0, sizeof node);
834 	if ((grp = getgrnam("operator")) != NULL) {
835 		gid = grp->gr_gid;
836 	} else {
837 		warnx("Cannot retrieve operator gid, using gid 0.");
838 		gid = 0;
839 	}
840 	entries = (nflag) ? ROOTLINKCNT - 1: ROOTLINKCNT;
841 	if (sblock.fs_magic == FS_UFS1_MAGIC) {
842 		/*
843 		 * initialize the node
844 		 */
845 		node.dp1.di_atime = utime;
846 		node.dp1.di_mtime = utime;
847 		node.dp1.di_ctime = utime;
848 		/*
849 		 * create the root directory
850 		 */
851 		node.dp1.di_mode = IFDIR | UMASK;
852 		node.dp1.di_nlink = entries;
853 		node.dp1.di_size = makedir(root_dir, entries);
854 		node.dp1.di_db[0] = alloc(sblock.fs_fsize, node.dp1.di_mode);
855 		node.dp1.di_blocks =
856 		    btodb(fragroundup(&sblock, node.dp1.di_size));
857 		wtfs(fsbtodb(&sblock, node.dp1.di_db[0]), sblock.fs_fsize,
858 		    iobuf);
859 		iput(&node, ROOTINO);
860 		if (!nflag) {
861 			/*
862 			 * create the .snap directory
863 			 */
864 			node.dp1.di_mode |= 020;
865 			node.dp1.di_gid = gid;
866 			node.dp1.di_nlink = SNAPLINKCNT;
867 			node.dp1.di_size = makedir(snap_dir, SNAPLINKCNT);
868 				node.dp1.di_db[0] =
869 				    alloc(sblock.fs_fsize, node.dp1.di_mode);
870 			node.dp1.di_blocks =
871 			    btodb(fragroundup(&sblock, node.dp1.di_size));
872 				wtfs(fsbtodb(&sblock, node.dp1.di_db[0]),
873 				    sblock.fs_fsize, iobuf);
874 			iput(&node, ROOTINO + 1);
875 		}
876 	} else {
877 		/*
878 		 * initialize the node
879 		 */
880 		node.dp2.di_atime = utime;
881 		node.dp2.di_mtime = utime;
882 		node.dp2.di_ctime = utime;
883 		node.dp2.di_birthtime = utime;
884 		/*
885 		 * create the root directory
886 		 */
887 		node.dp2.di_mode = IFDIR | UMASK;
888 		node.dp2.di_nlink = entries;
889 		node.dp2.di_size = makedir(root_dir, entries);
890 		node.dp2.di_db[0] = alloc(sblock.fs_fsize, node.dp2.di_mode);
891 		node.dp2.di_blocks =
892 		    btodb(fragroundup(&sblock, node.dp2.di_size));
893 		wtfs(fsbtodb(&sblock, node.dp2.di_db[0]), sblock.fs_fsize,
894 		    iobuf);
895 		iput(&node, ROOTINO);
896 		if (!nflag) {
897 			/*
898 			 * create the .snap directory
899 			 */
900 			node.dp2.di_mode |= 020;
901 			node.dp2.di_gid = gid;
902 			node.dp2.di_nlink = SNAPLINKCNT;
903 			node.dp2.di_size = makedir(snap_dir, SNAPLINKCNT);
904 				node.dp2.di_db[0] =
905 				    alloc(sblock.fs_fsize, node.dp2.di_mode);
906 			node.dp2.di_blocks =
907 			    btodb(fragroundup(&sblock, node.dp2.di_size));
908 				wtfs(fsbtodb(&sblock, node.dp2.di_db[0]),
909 				    sblock.fs_fsize, iobuf);
910 			iput(&node, ROOTINO + 1);
911 		}
912 	}
913 }
914 
915 /*
916  * construct a set of directory entries in "iobuf".
917  * return size of directory.
918  */
919 int
920 makedir(struct direct *protodir, int entries)
921 {
922 	char *cp;
923 	int i, spcleft;
924 
925 	spcleft = DIRBLKSIZ;
926 	memset(iobuf, 0, DIRBLKSIZ);
927 	for (cp = iobuf, i = 0; i < entries - 1; i++) {
928 		protodir[i].d_reclen = DIRSIZ(0, &protodir[i]);
929 		memmove(cp, &protodir[i], protodir[i].d_reclen);
930 		cp += protodir[i].d_reclen;
931 		spcleft -= protodir[i].d_reclen;
932 	}
933 	protodir[i].d_reclen = spcleft;
934 	memmove(cp, &protodir[i], DIRSIZ(0, &protodir[i]));
935 	return (DIRBLKSIZ);
936 }
937 
938 /*
939  * allocate a block or frag
940  */
941 ufs2_daddr_t
942 alloc(int size, int mode)
943 {
944 	int i, blkno, frag;
945 	uint d;
946 
947 	bread(&disk, part_ofs + fsbtodb(&sblock, cgtod(&sblock, 0)), (char *)&acg,
948 	    sblock.fs_cgsize);
949 	if (acg.cg_magic != CG_MAGIC) {
950 		printf("cg 0: bad magic number\n");
951 		exit(38);
952 	}
953 	if (acg.cg_cs.cs_nbfree == 0) {
954 		printf("first cylinder group ran out of space\n");
955 		exit(39);
956 	}
957 	for (d = 0; d < acg.cg_ndblk; d += sblock.fs_frag)
958 		if (isblock(&sblock, cg_blksfree(&acg), d / sblock.fs_frag))
959 			goto goth;
960 	printf("internal error: can't find block in cyl 0\n");
961 	exit(40);
962 goth:
963 	blkno = fragstoblks(&sblock, d);
964 	clrblock(&sblock, cg_blksfree(&acg), blkno);
965 	if (sblock.fs_contigsumsize > 0)
966 		clrbit(cg_clustersfree(&acg), blkno);
967 	acg.cg_cs.cs_nbfree--;
968 	sblock.fs_cstotal.cs_nbfree--;
969 	fscs[0].cs_nbfree--;
970 	if (mode & IFDIR) {
971 		acg.cg_cs.cs_ndir++;
972 		sblock.fs_cstotal.cs_ndir++;
973 		fscs[0].cs_ndir++;
974 	}
975 	if (size != sblock.fs_bsize) {
976 		frag = howmany(size, sblock.fs_fsize);
977 		fscs[0].cs_nffree += sblock.fs_frag - frag;
978 		sblock.fs_cstotal.cs_nffree += sblock.fs_frag - frag;
979 		acg.cg_cs.cs_nffree += sblock.fs_frag - frag;
980 		acg.cg_frsum[sblock.fs_frag - frag]++;
981 		for (i = frag; i < sblock.fs_frag; i++)
982 			setbit(cg_blksfree(&acg), d + i);
983 	}
984 	/* XXX cgwrite(&disk, 0)??? */
985 	wtfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
986 	    (char *)&acg);
987 	return ((ufs2_daddr_t)d);
988 }
989 
990 /*
991  * Allocate an inode on the disk
992  */
993 void
994 iput(union dinode *ip, ino_t ino)
995 {
996 	ufs2_daddr_t d;
997 
998 	bread(&disk, part_ofs + fsbtodb(&sblock, cgtod(&sblock, 0)), (char *)&acg,
999 	    sblock.fs_cgsize);
1000 	if (acg.cg_magic != CG_MAGIC) {
1001 		printf("cg 0: bad magic number\n");
1002 		exit(31);
1003 	}
1004 	acg.cg_cs.cs_nifree--;
1005 	setbit(cg_inosused(&acg), ino);
1006 	wtfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
1007 	    (char *)&acg);
1008 	sblock.fs_cstotal.cs_nifree--;
1009 	fscs[0].cs_nifree--;
1010 	if (ino >= (unsigned long)sblock.fs_ipg * sblock.fs_ncg) {
1011 		printf("fsinit: inode value out of range (%ju).\n",
1012 		    (uintmax_t)ino);
1013 		exit(32);
1014 	}
1015 	d = fsbtodb(&sblock, ino_to_fsba(&sblock, ino));
1016 	bread(&disk, part_ofs + d, (char *)iobuf, sblock.fs_bsize);
1017 	if (sblock.fs_magic == FS_UFS1_MAGIC)
1018 		((struct ufs1_dinode *)iobuf)[ino_to_fsbo(&sblock, ino)] =
1019 		    ip->dp1;
1020 	else
1021 		((struct ufs2_dinode *)iobuf)[ino_to_fsbo(&sblock, ino)] =
1022 		    ip->dp2;
1023 	wtfs(d, sblock.fs_bsize, (char *)iobuf);
1024 }
1025 
1026 /*
1027  * possibly write to disk
1028  */
1029 static void
1030 wtfs(ufs2_daddr_t bno, int size, char *bf)
1031 {
1032 	if (Nflag)
1033 		return;
1034 	if (bwrite(&disk, part_ofs + bno, bf, size) < 0)
1035 		err(36, "wtfs: %d bytes at sector %jd", size, (intmax_t)bno);
1036 }
1037 
1038 /*
1039  * check if a block is available
1040  */
1041 static int
1042 isblock(struct fs *fs, unsigned char *cp, int h)
1043 {
1044 	unsigned char mask;
1045 
1046 	switch (fs->fs_frag) {
1047 	case 8:
1048 		return (cp[h] == 0xff);
1049 	case 4:
1050 		mask = 0x0f << ((h & 0x1) << 2);
1051 		return ((cp[h >> 1] & mask) == mask);
1052 	case 2:
1053 		mask = 0x03 << ((h & 0x3) << 1);
1054 		return ((cp[h >> 2] & mask) == mask);
1055 	case 1:
1056 		mask = 0x01 << (h & 0x7);
1057 		return ((cp[h >> 3] & mask) == mask);
1058 	default:
1059 		fprintf(stderr, "isblock bad fs_frag %d\n", fs->fs_frag);
1060 		return (0);
1061 	}
1062 }
1063 
1064 /*
1065  * take a block out of the map
1066  */
1067 static void
1068 clrblock(struct fs *fs, unsigned char *cp, int h)
1069 {
1070 	switch ((fs)->fs_frag) {
1071 	case 8:
1072 		cp[h] = 0;
1073 		return;
1074 	case 4:
1075 		cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
1076 		return;
1077 	case 2:
1078 		cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
1079 		return;
1080 	case 1:
1081 		cp[h >> 3] &= ~(0x01 << (h & 0x7));
1082 		return;
1083 	default:
1084 		fprintf(stderr, "clrblock bad fs_frag %d\n", fs->fs_frag);
1085 		return;
1086 	}
1087 }
1088 
1089 /*
1090  * put a block into the map
1091  */
1092 static void
1093 setblock(struct fs *fs, unsigned char *cp, int h)
1094 {
1095 	switch (fs->fs_frag) {
1096 	case 8:
1097 		cp[h] = 0xff;
1098 		return;
1099 	case 4:
1100 		cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
1101 		return;
1102 	case 2:
1103 		cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
1104 		return;
1105 	case 1:
1106 		cp[h >> 3] |= (0x01 << (h & 0x7));
1107 		return;
1108 	default:
1109 		fprintf(stderr, "setblock bad fs_frag %d\n", fs->fs_frag);
1110 		return;
1111 	}
1112 }
1113 
1114 /*
1115  * Determine the number of characters in a
1116  * single line.
1117  */
1118 
1119 static int
1120 charsperline(void)
1121 {
1122 	int columns;
1123 	char *cp;
1124 	struct winsize ws;
1125 
1126 	columns = 0;
1127 	if (ioctl(0, TIOCGWINSZ, &ws) != -1)
1128 		columns = ws.ws_col;
1129 	if (columns == 0 && (cp = getenv("COLUMNS")))
1130 		columns = atoi(cp);
1131 	if (columns == 0)
1132 		columns = 80;	/* last resort */
1133 	return (columns);
1134 }
1135 
1136 static int
1137 ilog2(int val)
1138 {
1139 	u_int n;
1140 
1141 	for (n = 0; n < sizeof(n) * CHAR_BIT; n++)
1142 		if (1 << n == val)
1143 			return (n);
1144 	errx(1, "ilog2: %d is not a power of 2\n", val);
1145 }
1146 
1147 /*
1148  * For the regression test, return predictable random values.
1149  * Otherwise use a true random number generator.
1150  */
1151 static u_int32_t
1152 newfs_random(void)
1153 {
1154 	static int nextnum = 1;
1155 
1156 	if (Rflag)
1157 		return (nextnum++);
1158 	return (arc4random());
1159 }
1160