xref: /freebsd/sbin/newfs/mkfs.c (revision bb15ca603fa442c72dde3f3cb8b46db6970e3950)
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 				if (fsbtodb(&fsdummy, cgsblock(&fsdummy, cg)) > fssize)
521 					break;
522 				bwrite(&disk, part_ofs + fsbtodb(&fsdummy,
523 				  cgsblock(&fsdummy, cg)), chdummy, SBLOCKSIZE);
524 			}
525 		}
526 	}
527 	if (!Nflag)
528 		do_sbwrite(&disk);
529 	if (Xflag == 1) {
530 		printf("** Exiting on Xflag 1\n");
531 		exit(0);
532 	}
533 	if (Xflag == 2)
534 		printf("** Leaving BAD MAGIC on Xflag 2\n");
535 	else
536 		sblock.fs_magic = (Oflag != 1) ? FS_UFS2_MAGIC : FS_UFS1_MAGIC;
537 
538 	/*
539 	 * Now build the cylinders group blocks and
540 	 * then print out indices of cylinder groups.
541 	 */
542 	printf("super-block backups (for fsck -b #) at:\n");
543 	i = 0;
544 	width = charsperline();
545 	/*
546 	 * allocate space for superblock, cylinder group map, and
547 	 * two sets of inode blocks.
548 	 */
549 	if (sblock.fs_bsize < SBLOCKSIZE)
550 		iobufsize = SBLOCKSIZE + 3 * sblock.fs_bsize;
551 	else
552 		iobufsize = 4 * sblock.fs_bsize;
553 	if ((iobuf = calloc(1, iobufsize)) == 0) {
554 		printf("Cannot allocate I/O buffer\n");
555 		exit(38);
556 	}
557 	/*
558 	 * Make a copy of the superblock into the buffer that we will be
559 	 * writing out in each cylinder group.
560 	 */
561 	bcopy((char *)&sblock, iobuf, SBLOCKSIZE);
562 	for (cg = 0; cg < sblock.fs_ncg; cg++) {
563 		initcg(cg, utime);
564 		j = snprintf(tmpbuf, sizeof(tmpbuf), " %jd%s",
565 		    (intmax_t)fsbtodb(&sblock, cgsblock(&sblock, cg)),
566 		    cg < (sblock.fs_ncg-1) ? "," : "");
567 		if (j < 0)
568 			tmpbuf[j = 0] = '\0';
569 		if (i + j >= width) {
570 			printf("\n");
571 			i = 0;
572 		}
573 		i += j;
574 		printf("%s", tmpbuf);
575 		fflush(stdout);
576 	}
577 	printf("\n");
578 	if (Nflag)
579 		exit(0);
580 	/*
581 	 * Now construct the initial file system,
582 	 * then write out the super-block.
583 	 */
584 	fsinit(utime);
585 	if (Oflag == 1) {
586 		sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
587 		sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
588 		sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
589 		sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
590 	}
591 	if (Xflag == 3) {
592 		printf("** Exiting on Xflag 3\n");
593 		exit(0);
594 	}
595 	if (!Nflag) {
596 		do_sbwrite(&disk);
597 		/*
598 		 * For UFS1 filesystems with a blocksize of 64K, the first
599 		 * alternate superblock resides at the location used for
600 		 * the default UFS2 superblock. As there is a valid
601 		 * superblock at this location, the boot code will use
602 		 * it as its first choice. Thus we have to ensure that
603 		 * all of its statistcs on usage are correct.
604 		 */
605 		if (Oflag == 1 && sblock.fs_bsize == 65536)
606 			wtfs(fsbtodb(&sblock, cgsblock(&sblock, 0)),
607 			    sblock.fs_bsize, (char *)&sblock);
608 	}
609 	for (i = 0; i < sblock.fs_cssize; i += sblock.fs_bsize)
610 		wtfs(fsbtodb(&sblock, sblock.fs_csaddr + numfrags(&sblock, i)),
611 			sblock.fs_cssize - i < sblock.fs_bsize ?
612 			sblock.fs_cssize - i : sblock.fs_bsize,
613 			((char *)fscs) + i);
614 	/*
615 	 * Update information about this partition in pack
616 	 * label, to that it may be updated on disk.
617 	 */
618 	if (pp != NULL) {
619 		pp->p_fstype = FS_BSDFFS;
620 		pp->p_fsize = sblock.fs_fsize;
621 		pp->p_frag = sblock.fs_frag;
622 		pp->p_cpg = sblock.fs_fpg;
623 	}
624 }
625 
626 /*
627  * Initialize a cylinder group.
628  */
629 void
630 initcg(int cylno, time_t utime)
631 {
632 	long blkno, start;
633 	uint i, j, d, dlower, dupper;
634 	ufs2_daddr_t cbase, dmax;
635 	struct ufs1_dinode *dp1;
636 	struct ufs2_dinode *dp2;
637 	struct csum *cs;
638 
639 	/*
640 	 * Determine block bounds for cylinder group.
641 	 * Allow space for super block summary information in first
642 	 * cylinder group.
643 	 */
644 	cbase = cgbase(&sblock, cylno);
645 	dmax = cbase + sblock.fs_fpg;
646 	if (dmax > sblock.fs_size)
647 		dmax = sblock.fs_size;
648 	dlower = cgsblock(&sblock, cylno) - cbase;
649 	dupper = cgdmin(&sblock, cylno) - cbase;
650 	if (cylno == 0)
651 		dupper += howmany(sblock.fs_cssize, sblock.fs_fsize);
652 	cs = &fscs[cylno];
653 	memset(&acg, 0, sblock.fs_cgsize);
654 	acg.cg_time = utime;
655 	acg.cg_magic = CG_MAGIC;
656 	acg.cg_cgx = cylno;
657 	acg.cg_niblk = sblock.fs_ipg;
658 	acg.cg_initediblk = sblock.fs_ipg < 2 * INOPB(&sblock) ?
659 	    sblock.fs_ipg : 2 * INOPB(&sblock);
660 	acg.cg_ndblk = dmax - cbase;
661 	if (sblock.fs_contigsumsize > 0)
662 		acg.cg_nclusterblks = acg.cg_ndblk / sblock.fs_frag;
663 	start = &acg.cg_space[0] - (u_char *)(&acg.cg_firstfield);
664 	if (Oflag == 2) {
665 		acg.cg_iusedoff = start;
666 	} else {
667 		acg.cg_old_ncyl = sblock.fs_old_cpg;
668 		acg.cg_old_time = acg.cg_time;
669 		acg.cg_time = 0;
670 		acg.cg_old_niblk = acg.cg_niblk;
671 		acg.cg_niblk = 0;
672 		acg.cg_initediblk = 0;
673 		acg.cg_old_btotoff = start;
674 		acg.cg_old_boff = acg.cg_old_btotoff +
675 		    sblock.fs_old_cpg * sizeof(int32_t);
676 		acg.cg_iusedoff = acg.cg_old_boff +
677 		    sblock.fs_old_cpg * sizeof(u_int16_t);
678 	}
679 	acg.cg_freeoff = acg.cg_iusedoff + howmany(sblock.fs_ipg, CHAR_BIT);
680 	acg.cg_nextfreeoff = acg.cg_freeoff + howmany(sblock.fs_fpg, CHAR_BIT);
681 	if (sblock.fs_contigsumsize > 0) {
682 		acg.cg_clustersumoff =
683 		    roundup(acg.cg_nextfreeoff, sizeof(u_int32_t));
684 		acg.cg_clustersumoff -= sizeof(u_int32_t);
685 		acg.cg_clusteroff = acg.cg_clustersumoff +
686 		    (sblock.fs_contigsumsize + 1) * sizeof(u_int32_t);
687 		acg.cg_nextfreeoff = acg.cg_clusteroff +
688 		    howmany(fragstoblks(&sblock, sblock.fs_fpg), CHAR_BIT);
689 	}
690 	if (acg.cg_nextfreeoff > (unsigned)sblock.fs_cgsize) {
691 		printf("Panic: cylinder group too big\n");
692 		exit(37);
693 	}
694 	acg.cg_cs.cs_nifree += sblock.fs_ipg;
695 	if (cylno == 0)
696 		for (i = 0; i < (long)ROOTINO; i++) {
697 			setbit(cg_inosused(&acg), i);
698 			acg.cg_cs.cs_nifree--;
699 		}
700 	if (cylno > 0) {
701 		/*
702 		 * In cylno 0, beginning space is reserved
703 		 * for boot and super blocks.
704 		 */
705 		for (d = 0; d < dlower; d += sblock.fs_frag) {
706 			blkno = d / sblock.fs_frag;
707 			setblock(&sblock, cg_blksfree(&acg), blkno);
708 			if (sblock.fs_contigsumsize > 0)
709 				setbit(cg_clustersfree(&acg), blkno);
710 			acg.cg_cs.cs_nbfree++;
711 		}
712 	}
713 	if ((i = dupper % sblock.fs_frag)) {
714 		acg.cg_frsum[sblock.fs_frag - i]++;
715 		for (d = dupper + sblock.fs_frag - i; dupper < d; dupper++) {
716 			setbit(cg_blksfree(&acg), dupper);
717 			acg.cg_cs.cs_nffree++;
718 		}
719 	}
720 	for (d = dupper; d + sblock.fs_frag <= acg.cg_ndblk;
721 	     d += sblock.fs_frag) {
722 		blkno = d / sblock.fs_frag;
723 		setblock(&sblock, cg_blksfree(&acg), blkno);
724 		if (sblock.fs_contigsumsize > 0)
725 			setbit(cg_clustersfree(&acg), blkno);
726 		acg.cg_cs.cs_nbfree++;
727 	}
728 	if (d < acg.cg_ndblk) {
729 		acg.cg_frsum[acg.cg_ndblk - d]++;
730 		for (; d < acg.cg_ndblk; d++) {
731 			setbit(cg_blksfree(&acg), d);
732 			acg.cg_cs.cs_nffree++;
733 		}
734 	}
735 	if (sblock.fs_contigsumsize > 0) {
736 		int32_t *sump = cg_clustersum(&acg);
737 		u_char *mapp = cg_clustersfree(&acg);
738 		int map = *mapp++;
739 		int bit = 1;
740 		int run = 0;
741 
742 		for (i = 0; i < acg.cg_nclusterblks; i++) {
743 			if ((map & bit) != 0)
744 				run++;
745 			else if (run != 0) {
746 				if (run > sblock.fs_contigsumsize)
747 					run = sblock.fs_contigsumsize;
748 				sump[run]++;
749 				run = 0;
750 			}
751 			if ((i & (CHAR_BIT - 1)) != CHAR_BIT - 1)
752 				bit <<= 1;
753 			else {
754 				map = *mapp++;
755 				bit = 1;
756 			}
757 		}
758 		if (run != 0) {
759 			if (run > sblock.fs_contigsumsize)
760 				run = sblock.fs_contigsumsize;
761 			sump[run]++;
762 		}
763 	}
764 	*cs = acg.cg_cs;
765 	/*
766 	 * Write out the duplicate super block, the cylinder group map
767 	 * and two blocks worth of inodes in a single write.
768 	 */
769 	start = sblock.fs_bsize > SBLOCKSIZE ? sblock.fs_bsize : SBLOCKSIZE;
770 	bcopy((char *)&acg, &iobuf[start], sblock.fs_cgsize);
771 	start += sblock.fs_bsize;
772 	dp1 = (struct ufs1_dinode *)(&iobuf[start]);
773 	dp2 = (struct ufs2_dinode *)(&iobuf[start]);
774 	for (i = 0; i < acg.cg_initediblk; i++) {
775 		if (sblock.fs_magic == FS_UFS1_MAGIC) {
776 			dp1->di_gen = newfs_random();
777 			dp1++;
778 		} else {
779 			dp2->di_gen = newfs_random();
780 			dp2++;
781 		}
782 	}
783 	wtfs(fsbtodb(&sblock, cgsblock(&sblock, cylno)), iobufsize, iobuf);
784 	/*
785 	 * For the old file system, we have to initialize all the inodes.
786 	 */
787 	if (Oflag == 1) {
788 		for (i = 2 * sblock.fs_frag;
789 		     i < sblock.fs_ipg / INOPF(&sblock);
790 		     i += sblock.fs_frag) {
791 			dp1 = (struct ufs1_dinode *)(&iobuf[start]);
792 			for (j = 0; j < INOPB(&sblock); j++) {
793 				dp1->di_gen = newfs_random();
794 				dp1++;
795 			}
796 			wtfs(fsbtodb(&sblock, cgimin(&sblock, cylno) + i),
797 			    sblock.fs_bsize, &iobuf[start]);
798 		}
799 	}
800 }
801 
802 /*
803  * initialize the file system
804  */
805 #define ROOTLINKCNT 3
806 
807 static struct direct root_dir[] = {
808 	{ ROOTINO, sizeof(struct direct), DT_DIR, 1, "." },
809 	{ ROOTINO, sizeof(struct direct), DT_DIR, 2, ".." },
810 	{ ROOTINO + 1, sizeof(struct direct), DT_DIR, 5, ".snap" },
811 };
812 
813 #define SNAPLINKCNT 2
814 
815 static struct direct snap_dir[] = {
816 	{ ROOTINO + 1, sizeof(struct direct), DT_DIR, 1, "." },
817 	{ ROOTINO, sizeof(struct direct), DT_DIR, 2, ".." },
818 };
819 
820 void
821 fsinit(time_t utime)
822 {
823 	union dinode node;
824 	struct group *grp;
825 	gid_t gid;
826 	int entries;
827 
828 	memset(&node, 0, sizeof node);
829 	if ((grp = getgrnam("operator")) != NULL) {
830 		gid = grp->gr_gid;
831 	} else {
832 		warnx("Cannot retrieve operator gid, using gid 0.");
833 		gid = 0;
834 	}
835 	entries = (nflag) ? ROOTLINKCNT - 1: ROOTLINKCNT;
836 	if (sblock.fs_magic == FS_UFS1_MAGIC) {
837 		/*
838 		 * initialize the node
839 		 */
840 		node.dp1.di_atime = utime;
841 		node.dp1.di_mtime = utime;
842 		node.dp1.di_ctime = utime;
843 		/*
844 		 * create the root directory
845 		 */
846 		node.dp1.di_mode = IFDIR | UMASK;
847 		node.dp1.di_nlink = entries;
848 		node.dp1.di_size = makedir(root_dir, entries);
849 		node.dp1.di_db[0] = alloc(sblock.fs_fsize, node.dp1.di_mode);
850 		node.dp1.di_blocks =
851 		    btodb(fragroundup(&sblock, node.dp1.di_size));
852 		wtfs(fsbtodb(&sblock, node.dp1.di_db[0]), sblock.fs_fsize,
853 		    iobuf);
854 		iput(&node, ROOTINO);
855 		if (!nflag) {
856 			/*
857 			 * create the .snap directory
858 			 */
859 			node.dp1.di_mode |= 020;
860 			node.dp1.di_gid = gid;
861 			node.dp1.di_nlink = SNAPLINKCNT;
862 			node.dp1.di_size = makedir(snap_dir, SNAPLINKCNT);
863 				node.dp1.di_db[0] =
864 				    alloc(sblock.fs_fsize, node.dp1.di_mode);
865 			node.dp1.di_blocks =
866 			    btodb(fragroundup(&sblock, node.dp1.di_size));
867 				wtfs(fsbtodb(&sblock, node.dp1.di_db[0]),
868 				    sblock.fs_fsize, iobuf);
869 			iput(&node, ROOTINO + 1);
870 		}
871 	} else {
872 		/*
873 		 * initialize the node
874 		 */
875 		node.dp2.di_atime = utime;
876 		node.dp2.di_mtime = utime;
877 		node.dp2.di_ctime = utime;
878 		node.dp2.di_birthtime = utime;
879 		/*
880 		 * create the root directory
881 		 */
882 		node.dp2.di_mode = IFDIR | UMASK;
883 		node.dp2.di_nlink = entries;
884 		node.dp2.di_size = makedir(root_dir, entries);
885 		node.dp2.di_db[0] = alloc(sblock.fs_fsize, node.dp2.di_mode);
886 		node.dp2.di_blocks =
887 		    btodb(fragroundup(&sblock, node.dp2.di_size));
888 		wtfs(fsbtodb(&sblock, node.dp2.di_db[0]), sblock.fs_fsize,
889 		    iobuf);
890 		iput(&node, ROOTINO);
891 		if (!nflag) {
892 			/*
893 			 * create the .snap directory
894 			 */
895 			node.dp2.di_mode |= 020;
896 			node.dp2.di_gid = gid;
897 			node.dp2.di_nlink = SNAPLINKCNT;
898 			node.dp2.di_size = makedir(snap_dir, SNAPLINKCNT);
899 				node.dp2.di_db[0] =
900 				    alloc(sblock.fs_fsize, node.dp2.di_mode);
901 			node.dp2.di_blocks =
902 			    btodb(fragroundup(&sblock, node.dp2.di_size));
903 				wtfs(fsbtodb(&sblock, node.dp2.di_db[0]),
904 				    sblock.fs_fsize, iobuf);
905 			iput(&node, ROOTINO + 1);
906 		}
907 	}
908 }
909 
910 /*
911  * construct a set of directory entries in "iobuf".
912  * return size of directory.
913  */
914 int
915 makedir(struct direct *protodir, int entries)
916 {
917 	char *cp;
918 	int i, spcleft;
919 
920 	spcleft = DIRBLKSIZ;
921 	memset(iobuf, 0, DIRBLKSIZ);
922 	for (cp = iobuf, i = 0; i < entries - 1; i++) {
923 		protodir[i].d_reclen = DIRSIZ(0, &protodir[i]);
924 		memmove(cp, &protodir[i], protodir[i].d_reclen);
925 		cp += protodir[i].d_reclen;
926 		spcleft -= protodir[i].d_reclen;
927 	}
928 	protodir[i].d_reclen = spcleft;
929 	memmove(cp, &protodir[i], DIRSIZ(0, &protodir[i]));
930 	return (DIRBLKSIZ);
931 }
932 
933 /*
934  * allocate a block or frag
935  */
936 ufs2_daddr_t
937 alloc(int size, int mode)
938 {
939 	int i, blkno, frag;
940 	uint d;
941 
942 	bread(&disk, part_ofs + fsbtodb(&sblock, cgtod(&sblock, 0)), (char *)&acg,
943 	    sblock.fs_cgsize);
944 	if (acg.cg_magic != CG_MAGIC) {
945 		printf("cg 0: bad magic number\n");
946 		exit(38);
947 	}
948 	if (acg.cg_cs.cs_nbfree == 0) {
949 		printf("first cylinder group ran out of space\n");
950 		exit(39);
951 	}
952 	for (d = 0; d < acg.cg_ndblk; d += sblock.fs_frag)
953 		if (isblock(&sblock, cg_blksfree(&acg), d / sblock.fs_frag))
954 			goto goth;
955 	printf("internal error: can't find block in cyl 0\n");
956 	exit(40);
957 goth:
958 	blkno = fragstoblks(&sblock, d);
959 	clrblock(&sblock, cg_blksfree(&acg), blkno);
960 	if (sblock.fs_contigsumsize > 0)
961 		clrbit(cg_clustersfree(&acg), blkno);
962 	acg.cg_cs.cs_nbfree--;
963 	sblock.fs_cstotal.cs_nbfree--;
964 	fscs[0].cs_nbfree--;
965 	if (mode & IFDIR) {
966 		acg.cg_cs.cs_ndir++;
967 		sblock.fs_cstotal.cs_ndir++;
968 		fscs[0].cs_ndir++;
969 	}
970 	if (size != sblock.fs_bsize) {
971 		frag = howmany(size, sblock.fs_fsize);
972 		fscs[0].cs_nffree += sblock.fs_frag - frag;
973 		sblock.fs_cstotal.cs_nffree += sblock.fs_frag - frag;
974 		acg.cg_cs.cs_nffree += sblock.fs_frag - frag;
975 		acg.cg_frsum[sblock.fs_frag - frag]++;
976 		for (i = frag; i < sblock.fs_frag; i++)
977 			setbit(cg_blksfree(&acg), d + i);
978 	}
979 	/* XXX cgwrite(&disk, 0)??? */
980 	wtfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
981 	    (char *)&acg);
982 	return ((ufs2_daddr_t)d);
983 }
984 
985 /*
986  * Allocate an inode on the disk
987  */
988 void
989 iput(union dinode *ip, ino_t ino)
990 {
991 	ufs2_daddr_t d;
992 	int c;
993 
994 	c = ino_to_cg(&sblock, ino);
995 	bread(&disk, part_ofs + fsbtodb(&sblock, cgtod(&sblock, 0)), (char *)&acg,
996 	    sblock.fs_cgsize);
997 	if (acg.cg_magic != CG_MAGIC) {
998 		printf("cg 0: bad magic number\n");
999 		exit(31);
1000 	}
1001 	acg.cg_cs.cs_nifree--;
1002 	setbit(cg_inosused(&acg), ino);
1003 	wtfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
1004 	    (char *)&acg);
1005 	sblock.fs_cstotal.cs_nifree--;
1006 	fscs[0].cs_nifree--;
1007 	if (ino >= (unsigned long)sblock.fs_ipg * sblock.fs_ncg) {
1008 		printf("fsinit: inode value out of range (%d).\n", ino);
1009 		exit(32);
1010 	}
1011 	d = fsbtodb(&sblock, ino_to_fsba(&sblock, ino));
1012 	bread(&disk, part_ofs + d, (char *)iobuf, sblock.fs_bsize);
1013 	if (sblock.fs_magic == FS_UFS1_MAGIC)
1014 		((struct ufs1_dinode *)iobuf)[ino_to_fsbo(&sblock, ino)] =
1015 		    ip->dp1;
1016 	else
1017 		((struct ufs2_dinode *)iobuf)[ino_to_fsbo(&sblock, ino)] =
1018 		    ip->dp2;
1019 	wtfs(d, sblock.fs_bsize, (char *)iobuf);
1020 }
1021 
1022 /*
1023  * possibly write to disk
1024  */
1025 static void
1026 wtfs(ufs2_daddr_t bno, int size, char *bf)
1027 {
1028 	if (Nflag)
1029 		return;
1030 	if (bwrite(&disk, part_ofs + bno, bf, size) < 0)
1031 		err(36, "wtfs: %d bytes at sector %jd", size, (intmax_t)bno);
1032 }
1033 
1034 /*
1035  * check if a block is available
1036  */
1037 static int
1038 isblock(struct fs *fs, unsigned char *cp, int h)
1039 {
1040 	unsigned char mask;
1041 
1042 	switch (fs->fs_frag) {
1043 	case 8:
1044 		return (cp[h] == 0xff);
1045 	case 4:
1046 		mask = 0x0f << ((h & 0x1) << 2);
1047 		return ((cp[h >> 1] & mask) == mask);
1048 	case 2:
1049 		mask = 0x03 << ((h & 0x3) << 1);
1050 		return ((cp[h >> 2] & mask) == mask);
1051 	case 1:
1052 		mask = 0x01 << (h & 0x7);
1053 		return ((cp[h >> 3] & mask) == mask);
1054 	default:
1055 		fprintf(stderr, "isblock bad fs_frag %d\n", fs->fs_frag);
1056 		return (0);
1057 	}
1058 }
1059 
1060 /*
1061  * take a block out of the map
1062  */
1063 static void
1064 clrblock(struct fs *fs, unsigned char *cp, int h)
1065 {
1066 	switch ((fs)->fs_frag) {
1067 	case 8:
1068 		cp[h] = 0;
1069 		return;
1070 	case 4:
1071 		cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
1072 		return;
1073 	case 2:
1074 		cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
1075 		return;
1076 	case 1:
1077 		cp[h >> 3] &= ~(0x01 << (h & 0x7));
1078 		return;
1079 	default:
1080 		fprintf(stderr, "clrblock bad fs_frag %d\n", fs->fs_frag);
1081 		return;
1082 	}
1083 }
1084 
1085 /*
1086  * put a block into the map
1087  */
1088 static void
1089 setblock(struct fs *fs, unsigned char *cp, int h)
1090 {
1091 	switch (fs->fs_frag) {
1092 	case 8:
1093 		cp[h] = 0xff;
1094 		return;
1095 	case 4:
1096 		cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
1097 		return;
1098 	case 2:
1099 		cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
1100 		return;
1101 	case 1:
1102 		cp[h >> 3] |= (0x01 << (h & 0x7));
1103 		return;
1104 	default:
1105 		fprintf(stderr, "setblock bad fs_frag %d\n", fs->fs_frag);
1106 		return;
1107 	}
1108 }
1109 
1110 /*
1111  * Determine the number of characters in a
1112  * single line.
1113  */
1114 
1115 static int
1116 charsperline(void)
1117 {
1118 	int columns;
1119 	char *cp;
1120 	struct winsize ws;
1121 
1122 	columns = 0;
1123 	if (ioctl(0, TIOCGWINSZ, &ws) != -1)
1124 		columns = ws.ws_col;
1125 	if (columns == 0 && (cp = getenv("COLUMNS")))
1126 		columns = atoi(cp);
1127 	if (columns == 0)
1128 		columns = 80;	/* last resort */
1129 	return (columns);
1130 }
1131 
1132 static int
1133 ilog2(int val)
1134 {
1135 	u_int n;
1136 
1137 	for (n = 0; n < sizeof(n) * CHAR_BIT; n++)
1138 		if (1 << n == val)
1139 			return (n);
1140 	errx(1, "ilog2: %d is not a power of 2\n", val);
1141 }
1142 
1143 /*
1144  * For the regression test, return predictable random values.
1145  * Otherwise use a true random number generator.
1146  */
1147 static u_int32_t
1148 newfs_random(void)
1149 {
1150 	static int nextnum = 1;
1151 
1152 	if (Rflag)
1153 		return (nextnum++);
1154 	return (arc4random());
1155 }
1156