xref: /freebsd/sbin/newfs/mkfs.c (revision 7a1c0d963366a31363d3705697a083dd8efee077)
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 
267 	/*
268 	 * Before the filesystem is finally initialized, mark it
269 	 * as incompletely initialized.
270 	 */
271 	sblock.fs_magic = FS_BAD_MAGIC;
272 
273 	if (Oflag == 1) {
274 		sblock.fs_sblockloc = SBLOCK_UFS1;
275 		sblock.fs_nindir = sblock.fs_bsize / sizeof(ufs1_daddr_t);
276 		sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs1_dinode);
277 		sblock.fs_maxsymlinklen = ((NDADDR + NIADDR) *
278 		    sizeof(ufs1_daddr_t));
279 		sblock.fs_old_inodefmt = FS_44INODEFMT;
280 		sblock.fs_old_cgoffset = 0;
281 		sblock.fs_old_cgmask = 0xffffffff;
282 		sblock.fs_old_size = sblock.fs_size;
283 		sblock.fs_old_rotdelay = 0;
284 		sblock.fs_old_rps = 60;
285 		sblock.fs_old_nspf = sblock.fs_fsize / sectorsize;
286 		sblock.fs_old_cpg = 1;
287 		sblock.fs_old_interleave = 1;
288 		sblock.fs_old_trackskew = 0;
289 		sblock.fs_old_cpc = 0;
290 		sblock.fs_old_postblformat = 1;
291 		sblock.fs_old_nrpos = 1;
292 	} else {
293 		sblock.fs_sblockloc = SBLOCK_UFS2;
294 		sblock.fs_nindir = sblock.fs_bsize / sizeof(ufs2_daddr_t);
295 		sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs2_dinode);
296 		sblock.fs_maxsymlinklen = ((NDADDR + NIADDR) *
297 		    sizeof(ufs2_daddr_t));
298 	}
299 	sblock.fs_sblkno =
300 	    roundup(howmany(sblock.fs_sblockloc + SBLOCKSIZE, sblock.fs_fsize),
301 		sblock.fs_frag);
302 	sblock.fs_cblkno = sblock.fs_sblkno +
303 	    roundup(howmany(SBLOCKSIZE, sblock.fs_fsize), sblock.fs_frag);
304 	sblock.fs_iblkno = sblock.fs_cblkno + sblock.fs_frag;
305 	sblock.fs_maxfilesize = sblock.fs_bsize * NDADDR - 1;
306 	for (sizepb = sblock.fs_bsize, i = 0; i < NIADDR; i++) {
307 		sizepb *= NINDIR(&sblock);
308 		sblock.fs_maxfilesize += sizepb;
309 	}
310 
311 	/*
312 	 * It's impossible to create a snapshot in case that fs_maxfilesize
313 	 * is smaller than the fssize.
314 	 */
315 	if (sblock.fs_maxfilesize < (u_quad_t)fssize) {
316 		warnx("WARNING: You will be unable to create snapshots on this "
317 		      "file system.  Correct by using a larger blocksize.");
318 	}
319 
320 	/*
321 	 * Calculate the number of blocks to put into each cylinder group.
322 	 *
323 	 * This algorithm selects the number of blocks per cylinder
324 	 * group. The first goal is to have at least enough data blocks
325 	 * in each cylinder group to meet the density requirement. Once
326 	 * this goal is achieved we try to expand to have at least
327 	 * MINCYLGRPS cylinder groups. Once this goal is achieved, we
328 	 * pack as many blocks into each cylinder group map as will fit.
329 	 *
330 	 * We start by calculating the smallest number of blocks that we
331 	 * can put into each cylinder group. If this is too big, we reduce
332 	 * the density until it fits.
333 	 */
334 	maxinum = (((int64_t)(1)) << 32) - INOPB(&sblock);
335 	minfragsperinode = 1 + fssize / maxinum;
336 	if (density == 0) {
337 		density = MAX(NFPI, minfragsperinode) * fsize;
338 	} else if (density < minfragsperinode * fsize) {
339 		origdensity = density;
340 		density = minfragsperinode * fsize;
341 		fprintf(stderr, "density increased from %d to %d\n",
342 		    origdensity, density);
343 	}
344 	origdensity = density;
345 	for (;;) {
346 		fragsperinode = MAX(numfrags(&sblock, density), 1);
347 		if (fragsperinode < minfragsperinode) {
348 			bsize <<= 1;
349 			fsize <<= 1;
350 			printf("Block size too small for a file system %s %d\n",
351 			     "of this size. Increasing blocksize to", bsize);
352 			goto restart;
353 		}
354 		minfpg = fragsperinode * INOPB(&sblock);
355 		if (minfpg > sblock.fs_size)
356 			minfpg = sblock.fs_size;
357 		sblock.fs_ipg = INOPB(&sblock);
358 		sblock.fs_fpg = roundup(sblock.fs_iblkno +
359 		    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
360 		if (sblock.fs_fpg < minfpg)
361 			sblock.fs_fpg = minfpg;
362 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
363 		    INOPB(&sblock));
364 		sblock.fs_fpg = roundup(sblock.fs_iblkno +
365 		    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
366 		if (sblock.fs_fpg < minfpg)
367 			sblock.fs_fpg = minfpg;
368 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
369 		    INOPB(&sblock));
370 		if (CGSIZE(&sblock) < (unsigned long)sblock.fs_bsize)
371 			break;
372 		density -= sblock.fs_fsize;
373 	}
374 	if (density != origdensity)
375 		printf("density reduced from %d to %d\n", origdensity, density);
376 	/*
377 	 * Start packing more blocks into the cylinder group until
378 	 * it cannot grow any larger, the number of cylinder groups
379 	 * drops below MINCYLGRPS, or we reach the size requested.
380 	 * For UFS1 inodes per cylinder group are stored in an int16_t
381 	 * so fs_ipg is limited to 2^15 - 1.
382 	 */
383 	for ( ; sblock.fs_fpg < maxblkspercg; sblock.fs_fpg += sblock.fs_frag) {
384 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
385 		    INOPB(&sblock));
386 		if (Oflag > 1 || (Oflag == 1 && sblock.fs_ipg <= 0x7fff)) {
387 			if (sblock.fs_size / sblock.fs_fpg < MINCYLGRPS)
388 				break;
389 			if (CGSIZE(&sblock) < (unsigned long)sblock.fs_bsize)
390 				continue;
391 			if (CGSIZE(&sblock) == (unsigned long)sblock.fs_bsize)
392 				break;
393 		}
394 		sblock.fs_fpg -= sblock.fs_frag;
395 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
396 		    INOPB(&sblock));
397 		break;
398 	}
399 	/*
400 	 * Check to be sure that the last cylinder group has enough blocks
401 	 * to be viable. If it is too small, reduce the number of blocks
402 	 * per cylinder group which will have the effect of moving more
403 	 * blocks into the last cylinder group.
404 	 */
405 	optimalfpg = sblock.fs_fpg;
406 	for (;;) {
407 		sblock.fs_ncg = howmany(sblock.fs_size, sblock.fs_fpg);
408 		lastminfpg = roundup(sblock.fs_iblkno +
409 		    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
410 		if (sblock.fs_size < lastminfpg) {
411 			printf("Filesystem size %jd < minimum size of %d\n",
412 			    (intmax_t)sblock.fs_size, lastminfpg);
413 			exit(28);
414 		}
415 		if (sblock.fs_size % sblock.fs_fpg >= lastminfpg ||
416 		    sblock.fs_size % sblock.fs_fpg == 0)
417 			break;
418 		sblock.fs_fpg -= sblock.fs_frag;
419 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
420 		    INOPB(&sblock));
421 	}
422 	if (optimalfpg != sblock.fs_fpg)
423 		printf("Reduced frags per cylinder group from %d to %d %s\n",
424 		   optimalfpg, sblock.fs_fpg, "to enlarge last cyl group");
425 	sblock.fs_cgsize = fragroundup(&sblock, CGSIZE(&sblock));
426 	sblock.fs_dblkno = sblock.fs_iblkno + sblock.fs_ipg / INOPF(&sblock);
427 	if (Oflag == 1) {
428 		sblock.fs_old_spc = sblock.fs_fpg * sblock.fs_old_nspf;
429 		sblock.fs_old_nsect = sblock.fs_old_spc;
430 		sblock.fs_old_npsect = sblock.fs_old_spc;
431 		sblock.fs_old_ncyl = sblock.fs_ncg;
432 	}
433 	/*
434 	 * fill in remaining fields of the super block
435 	 */
436 	sblock.fs_csaddr = cgdmin(&sblock, 0);
437 	sblock.fs_cssize =
438 	    fragroundup(&sblock, sblock.fs_ncg * sizeof(struct csum));
439 	fscs = (struct csum *)calloc(1, sblock.fs_cssize);
440 	if (fscs == NULL)
441 		errx(31, "calloc failed");
442 	sblock.fs_sbsize = fragroundup(&sblock, sizeof(struct fs));
443 	if (sblock.fs_sbsize > SBLOCKSIZE)
444 		sblock.fs_sbsize = SBLOCKSIZE;
445 	sblock.fs_minfree = minfree;
446 	if (maxbpg == 0)
447 		sblock.fs_maxbpg = MAXBLKPG(sblock.fs_bsize);
448 	else
449 		sblock.fs_maxbpg = maxbpg;
450 	sblock.fs_optim = opt;
451 	sblock.fs_cgrotor = 0;
452 	sblock.fs_pendingblocks = 0;
453 	sblock.fs_pendinginodes = 0;
454 	sblock.fs_fmod = 0;
455 	sblock.fs_ronly = 0;
456 	sblock.fs_state = 0;
457 	sblock.fs_clean = 1;
458 	sblock.fs_id[0] = (long)utime;
459 	sblock.fs_id[1] = newfs_random();
460 	sblock.fs_fsmnt[0] = '\0';
461 	csfrags = howmany(sblock.fs_cssize, sblock.fs_fsize);
462 	sblock.fs_dsize = sblock.fs_size - sblock.fs_sblkno -
463 	    sblock.fs_ncg * (sblock.fs_dblkno - sblock.fs_sblkno);
464 	sblock.fs_cstotal.cs_nbfree =
465 	    fragstoblks(&sblock, sblock.fs_dsize) -
466 	    howmany(csfrags, sblock.fs_frag);
467 	sblock.fs_cstotal.cs_nffree =
468 	    fragnum(&sblock, sblock.fs_size) +
469 	    (fragnum(&sblock, csfrags) > 0 ?
470 	     sblock.fs_frag - fragnum(&sblock, csfrags) : 0);
471 	sblock.fs_cstotal.cs_nifree = sblock.fs_ncg * sblock.fs_ipg - ROOTINO;
472 	sblock.fs_cstotal.cs_ndir = 0;
473 	sblock.fs_dsize -= csfrags;
474 	sblock.fs_time = utime;
475 	if (Oflag == 1) {
476 		sblock.fs_old_time = utime;
477 		sblock.fs_old_dsize = sblock.fs_dsize;
478 		sblock.fs_old_csaddr = sblock.fs_csaddr;
479 		sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
480 		sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
481 		sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
482 		sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
483 	}
484 
485 	/*
486 	 * Dump out summary information about file system.
487 	 */
488 #	define B2MBFACTOR (1 / (1024.0 * 1024.0))
489 	printf("%s: %.1fMB (%jd sectors) block size %d, fragment size %d\n",
490 	    fsys, (float)sblock.fs_size * sblock.fs_fsize * B2MBFACTOR,
491 	    (intmax_t)fsbtodb(&sblock, sblock.fs_size), sblock.fs_bsize,
492 	    sblock.fs_fsize);
493 	printf("\tusing %d cylinder groups of %.2fMB, %d blks, %d inodes.\n",
494 	    sblock.fs_ncg, (float)sblock.fs_fpg * sblock.fs_fsize * B2MBFACTOR,
495 	    sblock.fs_fpg / sblock.fs_frag, sblock.fs_ipg);
496 	if (sblock.fs_flags & FS_DOSOFTDEP)
497 		printf("\twith soft updates\n");
498 #	undef B2MBFACTOR
499 
500 	if (Eflag && !Nflag) {
501 		printf("Erasing sectors [%jd...%jd]\n",
502 		    sblock.fs_sblockloc / disk.d_bsize,
503 		    fsbtodb(&sblock, sblock.fs_size) - 1);
504 		berase(&disk, sblock.fs_sblockloc / disk.d_bsize,
505 		    sblock.fs_size * sblock.fs_fsize - sblock.fs_sblockloc);
506 	}
507 	/*
508 	 * Wipe out old UFS1 superblock(s) if necessary.
509 	 */
510 	if (!Nflag && Oflag != 1) {
511 		i = bread(&disk, part_ofs + SBLOCK_UFS1 / disk.d_bsize, chdummy, SBLOCKSIZE);
512 		if (i == -1)
513 			err(1, "can't read old UFS1 superblock: %s", disk.d_error);
514 
515 		if (fsdummy.fs_magic == FS_UFS1_MAGIC) {
516 			fsdummy.fs_magic = 0;
517 			bwrite(&disk, part_ofs + SBLOCK_UFS1 / disk.d_bsize,
518 			    chdummy, SBLOCKSIZE);
519 			for (cg = 0; cg < fsdummy.fs_ncg; cg++)
520 				bwrite(&disk, part_ofs + fsbtodb(&fsdummy,
521 				  cgsblock(&fsdummy, cg)), chdummy, SBLOCKSIZE);
522 		}
523 	}
524 	if (!Nflag)
525 		do_sbwrite(&disk);
526 	if (Xflag == 1) {
527 		printf("** Exiting on Xflag 1\n");
528 		exit(0);
529 	}
530 	if (Xflag == 2)
531 		printf("** Leaving BAD MAGIC on Xflag 2\n");
532 	else
533 		sblock.fs_magic = (Oflag != 1) ? FS_UFS2_MAGIC : FS_UFS1_MAGIC;
534 
535 	/*
536 	 * Now build the cylinders group blocks and
537 	 * then print out indices of cylinder groups.
538 	 */
539 	printf("super-block backups (for fsck -b #) at:\n");
540 	i = 0;
541 	width = charsperline();
542 	/*
543 	 * allocate space for superblock, cylinder group map, and
544 	 * two sets of inode blocks.
545 	 */
546 	if (sblock.fs_bsize < SBLOCKSIZE)
547 		iobufsize = SBLOCKSIZE + 3 * sblock.fs_bsize;
548 	else
549 		iobufsize = 4 * sblock.fs_bsize;
550 	if ((iobuf = calloc(1, iobufsize)) == 0) {
551 		printf("Cannot allocate I/O buffer\n");
552 		exit(38);
553 	}
554 	/*
555 	 * Make a copy of the superblock into the buffer that we will be
556 	 * writing out in each cylinder group.
557 	 */
558 	bcopy((char *)&sblock, iobuf, SBLOCKSIZE);
559 	for (cg = 0; cg < sblock.fs_ncg; cg++) {
560 		initcg(cg, utime);
561 		j = snprintf(tmpbuf, sizeof(tmpbuf), " %jd%s",
562 		    (intmax_t)fsbtodb(&sblock, cgsblock(&sblock, cg)),
563 		    cg < (sblock.fs_ncg-1) ? "," : "");
564 		if (j < 0)
565 			tmpbuf[j = 0] = '\0';
566 		if (i + j >= width) {
567 			printf("\n");
568 			i = 0;
569 		}
570 		i += j;
571 		printf("%s", tmpbuf);
572 		fflush(stdout);
573 	}
574 	printf("\n");
575 	if (Nflag)
576 		exit(0);
577 	/*
578 	 * Now construct the initial file system,
579 	 * then write out the super-block.
580 	 */
581 	fsinit(utime);
582 	if (Oflag == 1) {
583 		sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
584 		sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
585 		sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
586 		sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
587 	}
588 	if (Xflag == 3) {
589 		printf("** Exiting on Xflag 3\n");
590 		exit(0);
591 	}
592 	if (!Nflag) {
593 		do_sbwrite(&disk);
594 		/*
595 		 * For UFS1 filesystems with a blocksize of 64K, the first
596 		 * alternate superblock resides at the location used for
597 		 * the default UFS2 superblock. As there is a valid
598 		 * superblock at this location, the boot code will use
599 		 * it as its first choice. Thus we have to ensure that
600 		 * all of its statistcs on usage are correct.
601 		 */
602 		if (Oflag == 1 && sblock.fs_bsize == 65536)
603 			wtfs(fsbtodb(&sblock, cgsblock(&sblock, 0)),
604 			    sblock.fs_bsize, (char *)&sblock);
605 	}
606 	for (i = 0; i < sblock.fs_cssize; i += sblock.fs_bsize)
607 		wtfs(fsbtodb(&sblock, sblock.fs_csaddr + numfrags(&sblock, i)),
608 			sblock.fs_cssize - i < sblock.fs_bsize ?
609 			sblock.fs_cssize - i : sblock.fs_bsize,
610 			((char *)fscs) + i);
611 	/*
612 	 * Update information about this partition in pack
613 	 * label, to that it may be updated on disk.
614 	 */
615 	if (pp != NULL) {
616 		pp->p_fstype = FS_BSDFFS;
617 		pp->p_fsize = sblock.fs_fsize;
618 		pp->p_frag = sblock.fs_frag;
619 		pp->p_cpg = sblock.fs_fpg;
620 	}
621 }
622 
623 /*
624  * Initialize a cylinder group.
625  */
626 void
627 initcg(int cylno, time_t utime)
628 {
629 	long blkno, start;
630 	uint i, j, d, dlower, dupper;
631 	ufs2_daddr_t cbase, dmax;
632 	struct ufs1_dinode *dp1;
633 	struct ufs2_dinode *dp2;
634 	struct csum *cs;
635 
636 	/*
637 	 * Determine block bounds for cylinder group.
638 	 * Allow space for super block summary information in first
639 	 * cylinder group.
640 	 */
641 	cbase = cgbase(&sblock, cylno);
642 	dmax = cbase + sblock.fs_fpg;
643 	if (dmax > sblock.fs_size)
644 		dmax = sblock.fs_size;
645 	dlower = cgsblock(&sblock, cylno) - cbase;
646 	dupper = cgdmin(&sblock, cylno) - cbase;
647 	if (cylno == 0)
648 		dupper += howmany(sblock.fs_cssize, sblock.fs_fsize);
649 	cs = &fscs[cylno];
650 	memset(&acg, 0, sblock.fs_cgsize);
651 	acg.cg_time = utime;
652 	acg.cg_magic = CG_MAGIC;
653 	acg.cg_cgx = cylno;
654 	acg.cg_niblk = sblock.fs_ipg;
655 	acg.cg_initediblk = sblock.fs_ipg < 2 * INOPB(&sblock) ?
656 	    sblock.fs_ipg : 2 * INOPB(&sblock);
657 	acg.cg_ndblk = dmax - cbase;
658 	if (sblock.fs_contigsumsize > 0)
659 		acg.cg_nclusterblks = acg.cg_ndblk / sblock.fs_frag;
660 	start = &acg.cg_space[0] - (u_char *)(&acg.cg_firstfield);
661 	if (Oflag == 2) {
662 		acg.cg_iusedoff = start;
663 	} else {
664 		acg.cg_old_ncyl = sblock.fs_old_cpg;
665 		acg.cg_old_time = acg.cg_time;
666 		acg.cg_time = 0;
667 		acg.cg_old_niblk = acg.cg_niblk;
668 		acg.cg_niblk = 0;
669 		acg.cg_initediblk = 0;
670 		acg.cg_old_btotoff = start;
671 		acg.cg_old_boff = acg.cg_old_btotoff +
672 		    sblock.fs_old_cpg * sizeof(int32_t);
673 		acg.cg_iusedoff = acg.cg_old_boff +
674 		    sblock.fs_old_cpg * sizeof(u_int16_t);
675 	}
676 	acg.cg_freeoff = acg.cg_iusedoff + howmany(sblock.fs_ipg, CHAR_BIT);
677 	acg.cg_nextfreeoff = acg.cg_freeoff + howmany(sblock.fs_fpg, CHAR_BIT);
678 	if (sblock.fs_contigsumsize > 0) {
679 		acg.cg_clustersumoff =
680 		    roundup(acg.cg_nextfreeoff, sizeof(u_int32_t));
681 		acg.cg_clustersumoff -= sizeof(u_int32_t);
682 		acg.cg_clusteroff = acg.cg_clustersumoff +
683 		    (sblock.fs_contigsumsize + 1) * sizeof(u_int32_t);
684 		acg.cg_nextfreeoff = acg.cg_clusteroff +
685 		    howmany(fragstoblks(&sblock, sblock.fs_fpg), CHAR_BIT);
686 	}
687 	if (acg.cg_nextfreeoff > (unsigned)sblock.fs_cgsize) {
688 		printf("Panic: cylinder group too big\n");
689 		exit(37);
690 	}
691 	acg.cg_cs.cs_nifree += sblock.fs_ipg;
692 	if (cylno == 0)
693 		for (i = 0; i < (long)ROOTINO; i++) {
694 			setbit(cg_inosused(&acg), i);
695 			acg.cg_cs.cs_nifree--;
696 		}
697 	if (cylno > 0) {
698 		/*
699 		 * In cylno 0, beginning space is reserved
700 		 * for boot and super blocks.
701 		 */
702 		for (d = 0; d < dlower; d += sblock.fs_frag) {
703 			blkno = d / sblock.fs_frag;
704 			setblock(&sblock, cg_blksfree(&acg), blkno);
705 			if (sblock.fs_contigsumsize > 0)
706 				setbit(cg_clustersfree(&acg), blkno);
707 			acg.cg_cs.cs_nbfree++;
708 		}
709 	}
710 	if ((i = dupper % sblock.fs_frag)) {
711 		acg.cg_frsum[sblock.fs_frag - i]++;
712 		for (d = dupper + sblock.fs_frag - i; dupper < d; dupper++) {
713 			setbit(cg_blksfree(&acg), dupper);
714 			acg.cg_cs.cs_nffree++;
715 		}
716 	}
717 	for (d = dupper; d + sblock.fs_frag <= acg.cg_ndblk;
718 	     d += sblock.fs_frag) {
719 		blkno = d / sblock.fs_frag;
720 		setblock(&sblock, cg_blksfree(&acg), blkno);
721 		if (sblock.fs_contigsumsize > 0)
722 			setbit(cg_clustersfree(&acg), blkno);
723 		acg.cg_cs.cs_nbfree++;
724 	}
725 	if (d < acg.cg_ndblk) {
726 		acg.cg_frsum[acg.cg_ndblk - d]++;
727 		for (; d < acg.cg_ndblk; d++) {
728 			setbit(cg_blksfree(&acg), d);
729 			acg.cg_cs.cs_nffree++;
730 		}
731 	}
732 	if (sblock.fs_contigsumsize > 0) {
733 		int32_t *sump = cg_clustersum(&acg);
734 		u_char *mapp = cg_clustersfree(&acg);
735 		int map = *mapp++;
736 		int bit = 1;
737 		int run = 0;
738 
739 		for (i = 0; i < acg.cg_nclusterblks; i++) {
740 			if ((map & bit) != 0)
741 				run++;
742 			else if (run != 0) {
743 				if (run > sblock.fs_contigsumsize)
744 					run = sblock.fs_contigsumsize;
745 				sump[run]++;
746 				run = 0;
747 			}
748 			if ((i & (CHAR_BIT - 1)) != CHAR_BIT - 1)
749 				bit <<= 1;
750 			else {
751 				map = *mapp++;
752 				bit = 1;
753 			}
754 		}
755 		if (run != 0) {
756 			if (run > sblock.fs_contigsumsize)
757 				run = sblock.fs_contigsumsize;
758 			sump[run]++;
759 		}
760 	}
761 	*cs = acg.cg_cs;
762 	/*
763 	 * Write out the duplicate super block, the cylinder group map
764 	 * and two blocks worth of inodes in a single write.
765 	 */
766 	start = sblock.fs_bsize > SBLOCKSIZE ? sblock.fs_bsize : SBLOCKSIZE;
767 	bcopy((char *)&acg, &iobuf[start], sblock.fs_cgsize);
768 	start += sblock.fs_bsize;
769 	dp1 = (struct ufs1_dinode *)(&iobuf[start]);
770 	dp2 = (struct ufs2_dinode *)(&iobuf[start]);
771 	for (i = 0; i < acg.cg_initediblk; i++) {
772 		if (sblock.fs_magic == FS_UFS1_MAGIC) {
773 			dp1->di_gen = newfs_random();
774 			dp1++;
775 		} else {
776 			dp2->di_gen = newfs_random();
777 			dp2++;
778 		}
779 	}
780 	wtfs(fsbtodb(&sblock, cgsblock(&sblock, cylno)), iobufsize, iobuf);
781 	/*
782 	 * For the old file system, we have to initialize all the inodes.
783 	 */
784 	if (Oflag == 1) {
785 		for (i = 2 * sblock.fs_frag;
786 		     i < sblock.fs_ipg / INOPF(&sblock);
787 		     i += sblock.fs_frag) {
788 			dp1 = (struct ufs1_dinode *)(&iobuf[start]);
789 			for (j = 0; j < INOPB(&sblock); j++) {
790 				dp1->di_gen = newfs_random();
791 				dp1++;
792 			}
793 			wtfs(fsbtodb(&sblock, cgimin(&sblock, cylno) + i),
794 			    sblock.fs_bsize, &iobuf[start]);
795 		}
796 	}
797 }
798 
799 /*
800  * initialize the file system
801  */
802 #define ROOTLINKCNT 3
803 
804 struct direct root_dir[] = {
805 	{ ROOTINO, sizeof(struct direct), DT_DIR, 1, "." },
806 	{ ROOTINO, sizeof(struct direct), DT_DIR, 2, ".." },
807 	{ ROOTINO + 1, sizeof(struct direct), DT_DIR, 5, ".snap" },
808 };
809 
810 #define SNAPLINKCNT 2
811 
812 struct direct snap_dir[] = {
813 	{ ROOTINO + 1, sizeof(struct direct), DT_DIR, 1, "." },
814 	{ ROOTINO, sizeof(struct direct), DT_DIR, 2, ".." },
815 };
816 
817 void
818 fsinit(time_t utime)
819 {
820 	union dinode node;
821 	struct group *grp;
822 	gid_t gid;
823 	int entries;
824 
825 	memset(&node, 0, sizeof node);
826 	if ((grp = getgrnam("operator")) != NULL) {
827 		gid = grp->gr_gid;
828 	} else {
829 		warnx("Cannot retrieve operator gid, using gid 0.");
830 		gid = 0;
831 	}
832 	entries = (nflag) ? ROOTLINKCNT - 1: ROOTLINKCNT;
833 	if (sblock.fs_magic == FS_UFS1_MAGIC) {
834 		/*
835 		 * initialize the node
836 		 */
837 		node.dp1.di_atime = utime;
838 		node.dp1.di_mtime = utime;
839 		node.dp1.di_ctime = utime;
840 		/*
841 		 * create the root directory
842 		 */
843 		node.dp1.di_mode = IFDIR | UMASK;
844 		node.dp1.di_nlink = entries;
845 		node.dp1.di_size = makedir(root_dir, entries);
846 		node.dp1.di_db[0] = alloc(sblock.fs_fsize, node.dp1.di_mode);
847 		node.dp1.di_blocks =
848 		    btodb(fragroundup(&sblock, node.dp1.di_size));
849 		wtfs(fsbtodb(&sblock, node.dp1.di_db[0]), sblock.fs_fsize,
850 		    iobuf);
851 		iput(&node, ROOTINO);
852 		if (!nflag) {
853 			/*
854 			 * create the .snap directory
855 			 */
856 			node.dp1.di_mode |= 020;
857 			node.dp1.di_gid = gid;
858 			node.dp1.di_nlink = SNAPLINKCNT;
859 			node.dp1.di_size = makedir(snap_dir, SNAPLINKCNT);
860 				node.dp1.di_db[0] =
861 				    alloc(sblock.fs_fsize, node.dp1.di_mode);
862 			node.dp1.di_blocks =
863 			    btodb(fragroundup(&sblock, node.dp1.di_size));
864 				wtfs(fsbtodb(&sblock, node.dp1.di_db[0]),
865 				    sblock.fs_fsize, iobuf);
866 			iput(&node, ROOTINO + 1);
867 		}
868 	} else {
869 		/*
870 		 * initialize the node
871 		 */
872 		node.dp2.di_atime = utime;
873 		node.dp2.di_mtime = utime;
874 		node.dp2.di_ctime = utime;
875 		node.dp2.di_birthtime = utime;
876 		/*
877 		 * create the root directory
878 		 */
879 		node.dp2.di_mode = IFDIR | UMASK;
880 		node.dp2.di_nlink = entries;
881 		node.dp2.di_size = makedir(root_dir, entries);
882 		node.dp2.di_db[0] = alloc(sblock.fs_fsize, node.dp2.di_mode);
883 		node.dp2.di_blocks =
884 		    btodb(fragroundup(&sblock, node.dp2.di_size));
885 		wtfs(fsbtodb(&sblock, node.dp2.di_db[0]), sblock.fs_fsize,
886 		    iobuf);
887 		iput(&node, ROOTINO);
888 		if (!nflag) {
889 			/*
890 			 * create the .snap directory
891 			 */
892 			node.dp2.di_mode |= 020;
893 			node.dp2.di_gid = gid;
894 			node.dp2.di_nlink = SNAPLINKCNT;
895 			node.dp2.di_size = makedir(snap_dir, SNAPLINKCNT);
896 				node.dp2.di_db[0] =
897 				    alloc(sblock.fs_fsize, node.dp2.di_mode);
898 			node.dp2.di_blocks =
899 			    btodb(fragroundup(&sblock, node.dp2.di_size));
900 				wtfs(fsbtodb(&sblock, node.dp2.di_db[0]),
901 				    sblock.fs_fsize, iobuf);
902 			iput(&node, ROOTINO + 1);
903 		}
904 	}
905 }
906 
907 /*
908  * construct a set of directory entries in "iobuf".
909  * return size of directory.
910  */
911 int
912 makedir(struct direct *protodir, int entries)
913 {
914 	char *cp;
915 	int i, spcleft;
916 
917 	spcleft = DIRBLKSIZ;
918 	memset(iobuf, 0, DIRBLKSIZ);
919 	for (cp = iobuf, i = 0; i < entries - 1; i++) {
920 		protodir[i].d_reclen = DIRSIZ(0, &protodir[i]);
921 		memmove(cp, &protodir[i], protodir[i].d_reclen);
922 		cp += protodir[i].d_reclen;
923 		spcleft -= protodir[i].d_reclen;
924 	}
925 	protodir[i].d_reclen = spcleft;
926 	memmove(cp, &protodir[i], DIRSIZ(0, &protodir[i]));
927 	return (DIRBLKSIZ);
928 }
929 
930 /*
931  * allocate a block or frag
932  */
933 ufs2_daddr_t
934 alloc(int size, int mode)
935 {
936 	int i, blkno, frag;
937 	uint d;
938 
939 	bread(&disk, part_ofs + fsbtodb(&sblock, cgtod(&sblock, 0)), (char *)&acg,
940 	    sblock.fs_cgsize);
941 	if (acg.cg_magic != CG_MAGIC) {
942 		printf("cg 0: bad magic number\n");
943 		exit(38);
944 	}
945 	if (acg.cg_cs.cs_nbfree == 0) {
946 		printf("first cylinder group ran out of space\n");
947 		exit(39);
948 	}
949 	for (d = 0; d < acg.cg_ndblk; d += sblock.fs_frag)
950 		if (isblock(&sblock, cg_blksfree(&acg), d / sblock.fs_frag))
951 			goto goth;
952 	printf("internal error: can't find block in cyl 0\n");
953 	exit(40);
954 goth:
955 	blkno = fragstoblks(&sblock, d);
956 	clrblock(&sblock, cg_blksfree(&acg), blkno);
957 	if (sblock.fs_contigsumsize > 0)
958 		clrbit(cg_clustersfree(&acg), blkno);
959 	acg.cg_cs.cs_nbfree--;
960 	sblock.fs_cstotal.cs_nbfree--;
961 	fscs[0].cs_nbfree--;
962 	if (mode & IFDIR) {
963 		acg.cg_cs.cs_ndir++;
964 		sblock.fs_cstotal.cs_ndir++;
965 		fscs[0].cs_ndir++;
966 	}
967 	if (size != sblock.fs_bsize) {
968 		frag = howmany(size, sblock.fs_fsize);
969 		fscs[0].cs_nffree += sblock.fs_frag - frag;
970 		sblock.fs_cstotal.cs_nffree += sblock.fs_frag - frag;
971 		acg.cg_cs.cs_nffree += sblock.fs_frag - frag;
972 		acg.cg_frsum[sblock.fs_frag - frag]++;
973 		for (i = frag; i < sblock.fs_frag; i++)
974 			setbit(cg_blksfree(&acg), d + i);
975 	}
976 	/* XXX cgwrite(&disk, 0)??? */
977 	wtfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
978 	    (char *)&acg);
979 	return ((ufs2_daddr_t)d);
980 }
981 
982 /*
983  * Allocate an inode on the disk
984  */
985 void
986 iput(union dinode *ip, ino_t ino)
987 {
988 	ufs2_daddr_t d;
989 	int c;
990 
991 	c = ino_to_cg(&sblock, ino);
992 	bread(&disk, part_ofs + fsbtodb(&sblock, cgtod(&sblock, 0)), (char *)&acg,
993 	    sblock.fs_cgsize);
994 	if (acg.cg_magic != CG_MAGIC) {
995 		printf("cg 0: bad magic number\n");
996 		exit(31);
997 	}
998 	acg.cg_cs.cs_nifree--;
999 	setbit(cg_inosused(&acg), ino);
1000 	wtfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
1001 	    (char *)&acg);
1002 	sblock.fs_cstotal.cs_nifree--;
1003 	fscs[0].cs_nifree--;
1004 	if (ino >= (unsigned long)sblock.fs_ipg * sblock.fs_ncg) {
1005 		printf("fsinit: inode value out of range (%d).\n", ino);
1006 		exit(32);
1007 	}
1008 	d = fsbtodb(&sblock, ino_to_fsba(&sblock, ino));
1009 	bread(&disk, part_ofs + d, (char *)iobuf, sblock.fs_bsize);
1010 	if (sblock.fs_magic == FS_UFS1_MAGIC)
1011 		((struct ufs1_dinode *)iobuf)[ino_to_fsbo(&sblock, ino)] =
1012 		    ip->dp1;
1013 	else
1014 		((struct ufs2_dinode *)iobuf)[ino_to_fsbo(&sblock, ino)] =
1015 		    ip->dp2;
1016 	wtfs(d, sblock.fs_bsize, (char *)iobuf);
1017 }
1018 
1019 /*
1020  * possibly write to disk
1021  */
1022 static void
1023 wtfs(ufs2_daddr_t bno, int size, char *bf)
1024 {
1025 	if (Nflag)
1026 		return;
1027 	if (bwrite(&disk, part_ofs + bno, bf, size) < 0)
1028 		err(36, "wtfs: %d bytes at sector %jd", size, (intmax_t)bno);
1029 }
1030 
1031 /*
1032  * check if a block is available
1033  */
1034 static int
1035 isblock(struct fs *fs, unsigned char *cp, int h)
1036 {
1037 	unsigned char mask;
1038 
1039 	switch (fs->fs_frag) {
1040 	case 8:
1041 		return (cp[h] == 0xff);
1042 	case 4:
1043 		mask = 0x0f << ((h & 0x1) << 2);
1044 		return ((cp[h >> 1] & mask) == mask);
1045 	case 2:
1046 		mask = 0x03 << ((h & 0x3) << 1);
1047 		return ((cp[h >> 2] & mask) == mask);
1048 	case 1:
1049 		mask = 0x01 << (h & 0x7);
1050 		return ((cp[h >> 3] & mask) == mask);
1051 	default:
1052 		fprintf(stderr, "isblock bad fs_frag %d\n", fs->fs_frag);
1053 		return (0);
1054 	}
1055 }
1056 
1057 /*
1058  * take a block out of the map
1059  */
1060 static void
1061 clrblock(struct fs *fs, unsigned char *cp, int h)
1062 {
1063 	switch ((fs)->fs_frag) {
1064 	case 8:
1065 		cp[h] = 0;
1066 		return;
1067 	case 4:
1068 		cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
1069 		return;
1070 	case 2:
1071 		cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
1072 		return;
1073 	case 1:
1074 		cp[h >> 3] &= ~(0x01 << (h & 0x7));
1075 		return;
1076 	default:
1077 		fprintf(stderr, "clrblock bad fs_frag %d\n", fs->fs_frag);
1078 		return;
1079 	}
1080 }
1081 
1082 /*
1083  * put a block into the map
1084  */
1085 static void
1086 setblock(struct fs *fs, unsigned char *cp, int h)
1087 {
1088 	switch (fs->fs_frag) {
1089 	case 8:
1090 		cp[h] = 0xff;
1091 		return;
1092 	case 4:
1093 		cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
1094 		return;
1095 	case 2:
1096 		cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
1097 		return;
1098 	case 1:
1099 		cp[h >> 3] |= (0x01 << (h & 0x7));
1100 		return;
1101 	default:
1102 		fprintf(stderr, "setblock bad fs_frag %d\n", fs->fs_frag);
1103 		return;
1104 	}
1105 }
1106 
1107 /*
1108  * Determine the number of characters in a
1109  * single line.
1110  */
1111 
1112 static int
1113 charsperline(void)
1114 {
1115 	int columns;
1116 	char *cp;
1117 	struct winsize ws;
1118 
1119 	columns = 0;
1120 	if (ioctl(0, TIOCGWINSZ, &ws) != -1)
1121 		columns = ws.ws_col;
1122 	if (columns == 0 && (cp = getenv("COLUMNS")))
1123 		columns = atoi(cp);
1124 	if (columns == 0)
1125 		columns = 80;	/* last resort */
1126 	return (columns);
1127 }
1128 
1129 static int
1130 ilog2(int val)
1131 {
1132 	u_int n;
1133 
1134 	for (n = 0; n < sizeof(n) * CHAR_BIT; n++)
1135 		if (1 << n == val)
1136 			return (n);
1137 	errx(1, "ilog2: %d is not a power of 2\n", val);
1138 }
1139 
1140 /*
1141  * For the regression test, return predictable random values.
1142  * Otherwise use a true random number generator.
1143  */
1144 static u_int32_t
1145 newfs_random(void)
1146 {
1147 	static int nextnum = 1;
1148 
1149 	if (Rflag)
1150 		return (nextnum++);
1151 	return (arc4random());
1152 }
1153