xref: /freebsd/sbin/newfs/mkfs.c (revision 195ebc7e9e4b129de810833791a19dfb4349d6a9)
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 <err.h>
48 #include <grp.h>
49 #include <limits.h>
50 #include <signal.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <stdint.h>
54 #include <stdio.h>
55 #include <unistd.h>
56 #include <sys/param.h>
57 #include <sys/time.h>
58 #include <sys/types.h>
59 #include <sys/wait.h>
60 #include <sys/resource.h>
61 #include <sys/stat.h>
62 #include <ufs/ufs/dinode.h>
63 #include <ufs/ufs/dir.h>
64 #include <ufs/ffs/fs.h>
65 #include <sys/disklabel.h>
66 #include <sys/file.h>
67 #include <sys/mman.h>
68 #include <sys/ioctl.h>
69 #include "newfs.h"
70 
71 /*
72  * make file system for cylinder-group style file systems
73  */
74 #define UMASK		0755
75 #define POWEROF2(num)	(((num) & ((num) - 1)) == 0)
76 
77 static struct	csum *fscs;
78 #define	sblock	disk.d_fs
79 #define	acg	disk.d_cg
80 
81 union dinode {
82 	struct ufs1_dinode dp1;
83 	struct ufs2_dinode dp2;
84 };
85 #define DIP(dp, field) \
86 	((sblock.fs_magic == FS_UFS1_MAGIC) ? \
87 	(dp)->dp1.field : (dp)->dp2.field)
88 
89 static caddr_t iobuf;
90 static long iobufsize;
91 static ufs2_daddr_t alloc(int size, int mode);
92 static int charsperline(void);
93 static void clrblock(struct fs *, unsigned char *, int);
94 static void fsinit(time_t);
95 static int ilog2(int);
96 static void initcg(int, time_t);
97 static int isblock(struct fs *, unsigned char *, int);
98 static void iput(union dinode *, ino_t);
99 static int makedir(struct direct *, int);
100 static void setblock(struct fs *, unsigned char *, int);
101 static void wtfs(ufs2_daddr_t, int, char *);
102 static u_int32_t newfs_random(void);
103 
104 static int
105 do_sbwrite(struct uufsd *disk)
106 {
107 	if (!disk->d_sblock)
108 		disk->d_sblock = disk->d_fs.fs_sblockloc / disk->d_bsize;
109 	return (pwrite(disk->d_fd, &disk->d_fs, SBLOCKSIZE, (off_t)((part_ofs +
110 	    disk->d_sblock) * disk->d_bsize)));
111 }
112 
113 void
114 mkfs(struct partition *pp, char *fsys)
115 {
116 	int fragsperinode, optimalfpg, origdensity, minfpg, lastminfpg;
117 	long i, j, cylno, csfrags;
118 	time_t utime;
119 	quad_t sizepb;
120 	int width;
121 	char tmpbuf[100];	/* XXX this will break in about 2,500 years */
122 	union {
123 		struct fs fdummy;
124 		char cdummy[SBLOCKSIZE];
125 	} dummy;
126 #define fsdummy dummy.fdummy
127 #define chdummy dummy.cdummy
128 
129 	/*
130 	 * Our blocks == sector size, and the version of UFS we are using is
131 	 * specified by Oflag.
132 	 */
133 	disk.d_bsize = sectorsize;
134 	disk.d_ufs = Oflag;
135 	if (Rflag) {
136 		utime = 1000000000;
137 	} else {
138 		time(&utime);
139 		arc4random_stir();
140 	}
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 	/*
152 	 * Validate the given file system size.
153 	 * Verify that its last block can actually be accessed.
154 	 * Convert to file system fragment sized units.
155 	 */
156 	if (fssize <= 0) {
157 		printf("preposterous size %jd\n", (intmax_t)fssize);
158 		exit(13);
159 	}
160 	wtfs(fssize - (realsectorsize / DEV_BSIZE), realsectorsize,
161 	    (char *)&sblock);
162 	/*
163 	 * collect and verify the file system density info
164 	 */
165 	sblock.fs_avgfilesize = avgfilesize;
166 	sblock.fs_avgfpdir = avgfilesperdir;
167 	if (sblock.fs_avgfilesize <= 0)
168 		printf("illegal expected average file size %d\n",
169 		    sblock.fs_avgfilesize), exit(14);
170 	if (sblock.fs_avgfpdir <= 0)
171 		printf("illegal expected number of files per directory %d\n",
172 		    sblock.fs_avgfpdir), exit(15);
173 	/*
174 	 * collect and verify the block and fragment sizes
175 	 */
176 	sblock.fs_bsize = bsize;
177 	sblock.fs_fsize = fsize;
178 	if (!POWEROF2(sblock.fs_bsize)) {
179 		printf("block size must be a power of 2, not %d\n",
180 		    sblock.fs_bsize);
181 		exit(16);
182 	}
183 	if (!POWEROF2(sblock.fs_fsize)) {
184 		printf("fragment size must be a power of 2, not %d\n",
185 		    sblock.fs_fsize);
186 		exit(17);
187 	}
188 	if (sblock.fs_fsize < sectorsize) {
189 		printf("increasing fragment size from %d to sector size (%d)\n",
190 		    sblock.fs_fsize, sectorsize);
191 		sblock.fs_fsize = sectorsize;
192 	}
193 	if (sblock.fs_bsize > MAXBSIZE) {
194 		printf("decreasing block size from %d to maximum (%d)\n",
195 		    sblock.fs_bsize, MAXBSIZE);
196 		sblock.fs_bsize = MAXBSIZE;
197 	}
198 	if (sblock.fs_bsize < MINBSIZE) {
199 		printf("increasing block size from %d to minimum (%d)\n",
200 		    sblock.fs_bsize, MINBSIZE);
201 		sblock.fs_bsize = MINBSIZE;
202 	}
203 	if (sblock.fs_fsize > MAXBSIZE) {
204 		printf("decreasing fragment size from %d to maximum (%d)\n",
205 		    sblock.fs_fsize, MAXBSIZE);
206 		sblock.fs_fsize = MAXBSIZE;
207 	}
208 	if (sblock.fs_bsize < sblock.fs_fsize) {
209 		printf("increasing block size from %d to fragment size (%d)\n",
210 		    sblock.fs_bsize, sblock.fs_fsize);
211 		sblock.fs_bsize = sblock.fs_fsize;
212 	}
213 	if (sblock.fs_fsize * MAXFRAG < sblock.fs_bsize) {
214 		printf(
215 		"increasing fragment size from %d to block size / %d (%d)\n",
216 		    sblock.fs_fsize, MAXFRAG, sblock.fs_bsize / MAXFRAG);
217 		sblock.fs_fsize = sblock.fs_bsize / MAXFRAG;
218 	}
219 	if (maxbsize < bsize || !POWEROF2(maxbsize)) {
220 		sblock.fs_maxbsize = sblock.fs_bsize;
221 		printf("Extent size set to %d\n", sblock.fs_maxbsize);
222 	} else if (sblock.fs_maxbsize > FS_MAXCONTIG * sblock.fs_bsize) {
223 		sblock.fs_maxbsize = FS_MAXCONTIG * sblock.fs_bsize;
224 		printf("Extent size reduced to %d\n", sblock.fs_maxbsize);
225 	} else {
226 		sblock.fs_maxbsize = maxbsize;
227 	}
228 	sblock.fs_maxcontig = maxcontig;
229 	if (sblock.fs_maxcontig < sblock.fs_maxbsize / sblock.fs_bsize) {
230 		sblock.fs_maxcontig = sblock.fs_maxbsize / sblock.fs_bsize;
231 		printf("Maxcontig raised to %d\n", sblock.fs_maxbsize);
232 	}
233 	if (sblock.fs_maxcontig > 1)
234 		sblock.fs_contigsumsize = MIN(sblock.fs_maxcontig,FS_MAXCONTIG);
235 	sblock.fs_bmask = ~(sblock.fs_bsize - 1);
236 	sblock.fs_fmask = ~(sblock.fs_fsize - 1);
237 	sblock.fs_qbmask = ~sblock.fs_bmask;
238 	sblock.fs_qfmask = ~sblock.fs_fmask;
239 	sblock.fs_bshift = ilog2(sblock.fs_bsize);
240 	sblock.fs_fshift = ilog2(sblock.fs_fsize);
241 	sblock.fs_frag = numfrags(&sblock, sblock.fs_bsize);
242 	sblock.fs_fragshift = ilog2(sblock.fs_frag);
243 	if (sblock.fs_frag > MAXFRAG) {
244 		printf("fragment size %d is still too small (can't happen)\n",
245 		    sblock.fs_bsize / MAXFRAG);
246 		exit(21);
247 	}
248 	sblock.fs_fsbtodb = ilog2(sblock.fs_fsize / sectorsize);
249 	sblock.fs_size = fssize = dbtofsb(&sblock, fssize);
250 
251 	/*
252 	 * Before the filesystem is finally initialized, mark it
253 	 * as incompletely initialized.
254 	 */
255 	sblock.fs_magic = FS_BAD_MAGIC;
256 
257 	if (Oflag == 1) {
258 		sblock.fs_sblockloc = SBLOCK_UFS1;
259 		sblock.fs_nindir = sblock.fs_bsize / sizeof(ufs1_daddr_t);
260 		sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs1_dinode);
261 		sblock.fs_maxsymlinklen = ((NDADDR + NIADDR) *
262 		    sizeof(ufs1_daddr_t));
263 		sblock.fs_old_inodefmt = FS_44INODEFMT;
264 		sblock.fs_old_cgoffset = 0;
265 		sblock.fs_old_cgmask = 0xffffffff;
266 		sblock.fs_old_size = sblock.fs_size;
267 		sblock.fs_old_rotdelay = 0;
268 		sblock.fs_old_rps = 60;
269 		sblock.fs_old_nspf = sblock.fs_fsize / sectorsize;
270 		sblock.fs_old_cpg = 1;
271 		sblock.fs_old_interleave = 1;
272 		sblock.fs_old_trackskew = 0;
273 		sblock.fs_old_cpc = 0;
274 		sblock.fs_old_postblformat = 1;
275 		sblock.fs_old_nrpos = 1;
276 	} else {
277 		sblock.fs_sblockloc = SBLOCK_UFS2;
278 		sblock.fs_nindir = sblock.fs_bsize / sizeof(ufs2_daddr_t);
279 		sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs2_dinode);
280 		sblock.fs_maxsymlinklen = ((NDADDR + NIADDR) *
281 		    sizeof(ufs2_daddr_t));
282 	}
283 	sblock.fs_sblkno =
284 	    roundup(howmany(sblock.fs_sblockloc + SBLOCKSIZE, sblock.fs_fsize),
285 		sblock.fs_frag);
286 	sblock.fs_cblkno = sblock.fs_sblkno +
287 	    roundup(howmany(SBLOCKSIZE, sblock.fs_fsize), sblock.fs_frag);
288 	sblock.fs_iblkno = sblock.fs_cblkno + sblock.fs_frag;
289 	sblock.fs_maxfilesize = sblock.fs_bsize * NDADDR - 1;
290 	for (sizepb = sblock.fs_bsize, i = 0; i < NIADDR; i++) {
291 		sizepb *= NINDIR(&sblock);
292 		sblock.fs_maxfilesize += sizepb;
293 	}
294 
295 	/*
296 	 * It's impossible to create a snapshot in case that fs_maxfilesize
297 	 * is smaller than the fssize.
298 	 */
299 	if (sblock.fs_maxfilesize < (u_quad_t)fssize) {
300 		warnx("WARNING: You will be unable to create snapshots on this "
301 		      "file system.  Correct by using a larger blocksize.");
302 	}
303 
304 	/*
305 	 * Calculate the number of blocks to put into each cylinder group.
306 	 *
307 	 * This algorithm selects the number of blocks per cylinder
308 	 * group. The first goal is to have at least enough data blocks
309 	 * in each cylinder group to meet the density requirement. Once
310 	 * this goal is achieved we try to expand to have at least
311 	 * MINCYLGRPS cylinder groups. Once this goal is achieved, we
312 	 * pack as many blocks into each cylinder group map as will fit.
313 	 *
314 	 * We start by calculating the smallest number of blocks that we
315 	 * can put into each cylinder group. If this is too big, we reduce
316 	 * the density until it fits.
317 	 */
318 	origdensity = density;
319 	for (;;) {
320 		fragsperinode = MAX(numfrags(&sblock, density), 1);
321 		minfpg = fragsperinode * INOPB(&sblock);
322 		if (minfpg > sblock.fs_size)
323 			minfpg = sblock.fs_size;
324 		sblock.fs_ipg = INOPB(&sblock);
325 		sblock.fs_fpg = roundup(sblock.fs_iblkno +
326 		    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
327 		if (sblock.fs_fpg < minfpg)
328 			sblock.fs_fpg = minfpg;
329 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
330 		    INOPB(&sblock));
331 		sblock.fs_fpg = roundup(sblock.fs_iblkno +
332 		    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
333 		if (sblock.fs_fpg < minfpg)
334 			sblock.fs_fpg = minfpg;
335 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
336 		    INOPB(&sblock));
337 		if (CGSIZE(&sblock) < (unsigned long)sblock.fs_bsize)
338 			break;
339 		density -= sblock.fs_fsize;
340 	}
341 	if (density != origdensity)
342 		printf("density reduced from %d to %d\n", origdensity, density);
343 	/*
344 	 * Start packing more blocks into the cylinder group until
345 	 * it cannot grow any larger, the number of cylinder groups
346 	 * drops below MINCYLGRPS, or we reach the size requested.
347 	 */
348 	for ( ; sblock.fs_fpg < maxblkspercg; sblock.fs_fpg += sblock.fs_frag) {
349 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
350 		    INOPB(&sblock));
351 		if (sblock.fs_size / sblock.fs_fpg < MINCYLGRPS)
352 			break;
353 		if (CGSIZE(&sblock) < (unsigned long)sblock.fs_bsize)
354 			continue;
355 		if (CGSIZE(&sblock) == (unsigned long)sblock.fs_bsize)
356 			break;
357 		sblock.fs_fpg -= sblock.fs_frag;
358 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
359 		    INOPB(&sblock));
360 		break;
361 	}
362 	/*
363 	 * Check to be sure that the last cylinder group has enough blocks
364 	 * to be viable. If it is too small, reduce the number of blocks
365 	 * per cylinder group which will have the effect of moving more
366 	 * blocks into the last cylinder group.
367 	 */
368 	optimalfpg = sblock.fs_fpg;
369 	for (;;) {
370 		sblock.fs_ncg = howmany(sblock.fs_size, sblock.fs_fpg);
371 		lastminfpg = roundup(sblock.fs_iblkno +
372 		    sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
373 		if (sblock.fs_size < lastminfpg) {
374 			printf("Filesystem size %jd < minimum size of %d\n",
375 			    (intmax_t)sblock.fs_size, lastminfpg);
376 			exit(28);
377 		}
378 		if (sblock.fs_size % sblock.fs_fpg >= lastminfpg ||
379 		    sblock.fs_size % sblock.fs_fpg == 0)
380 			break;
381 		sblock.fs_fpg -= sblock.fs_frag;
382 		sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
383 		    INOPB(&sblock));
384 	}
385 	if (optimalfpg != sblock.fs_fpg)
386 		printf("Reduced frags per cylinder group from %d to %d %s\n",
387 		   optimalfpg, sblock.fs_fpg, "to enlarge last cyl group");
388 	sblock.fs_cgsize = fragroundup(&sblock, CGSIZE(&sblock));
389 	sblock.fs_dblkno = sblock.fs_iblkno + sblock.fs_ipg / INOPF(&sblock);
390 	if (Oflag == 1) {
391 		sblock.fs_old_spc = sblock.fs_fpg * sblock.fs_old_nspf;
392 		sblock.fs_old_nsect = sblock.fs_old_spc;
393 		sblock.fs_old_npsect = sblock.fs_old_spc;
394 		sblock.fs_old_ncyl = sblock.fs_ncg;
395 	}
396 	/*
397 	 * fill in remaining fields of the super block
398 	 */
399 	sblock.fs_csaddr = cgdmin(&sblock, 0);
400 	sblock.fs_cssize =
401 	    fragroundup(&sblock, sblock.fs_ncg * sizeof(struct csum));
402 	fscs = (struct csum *)calloc(1, sblock.fs_cssize);
403 	if (fscs == NULL)
404 		errx(31, "calloc failed");
405 	sblock.fs_sbsize = fragroundup(&sblock, sizeof(struct fs));
406 	if (sblock.fs_sbsize > SBLOCKSIZE)
407 		sblock.fs_sbsize = SBLOCKSIZE;
408 	sblock.fs_minfree = minfree;
409 	sblock.fs_maxbpg = maxbpg;
410 	sblock.fs_optim = opt;
411 	sblock.fs_cgrotor = 0;
412 	sblock.fs_pendingblocks = 0;
413 	sblock.fs_pendinginodes = 0;
414 	sblock.fs_fmod = 0;
415 	sblock.fs_ronly = 0;
416 	sblock.fs_state = 0;
417 	sblock.fs_clean = 1;
418 	sblock.fs_id[0] = (long)utime;
419 	sblock.fs_id[1] = newfs_random();
420 	sblock.fs_fsmnt[0] = '\0';
421 	csfrags = howmany(sblock.fs_cssize, sblock.fs_fsize);
422 	sblock.fs_dsize = sblock.fs_size - sblock.fs_sblkno -
423 	    sblock.fs_ncg * (sblock.fs_dblkno - sblock.fs_sblkno);
424 	sblock.fs_cstotal.cs_nbfree =
425 	    fragstoblks(&sblock, sblock.fs_dsize) -
426 	    howmany(csfrags, sblock.fs_frag);
427 	sblock.fs_cstotal.cs_nffree =
428 	    fragnum(&sblock, sblock.fs_size) +
429 	    (fragnum(&sblock, csfrags) > 0 ?
430 	     sblock.fs_frag - fragnum(&sblock, csfrags) : 0);
431 	sblock.fs_cstotal.cs_nifree = sblock.fs_ncg * sblock.fs_ipg - ROOTINO;
432 	sblock.fs_cstotal.cs_ndir = 0;
433 	sblock.fs_dsize -= csfrags;
434 	sblock.fs_time = utime;
435 	if (Oflag == 1) {
436 		sblock.fs_old_time = utime;
437 		sblock.fs_old_dsize = sblock.fs_dsize;
438 		sblock.fs_old_csaddr = sblock.fs_csaddr;
439 		sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
440 		sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
441 		sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
442 		sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
443 	}
444 
445 	/*
446 	 * Dump out summary information about file system.
447 	 */
448 #	define B2MBFACTOR (1 / (1024.0 * 1024.0))
449 	printf("%s: %.1fMB (%jd sectors) block size %d, fragment size %d\n",
450 	    fsys, (float)sblock.fs_size * sblock.fs_fsize * B2MBFACTOR,
451 	    (intmax_t)fsbtodb(&sblock, sblock.fs_size), sblock.fs_bsize,
452 	    sblock.fs_fsize);
453 	printf("\tusing %d cylinder groups of %.2fMB, %d blks, %d inodes.\n",
454 	    sblock.fs_ncg, (float)sblock.fs_fpg * sblock.fs_fsize * B2MBFACTOR,
455 	    sblock.fs_fpg / sblock.fs_frag, sblock.fs_ipg);
456 	if (sblock.fs_flags & FS_DOSOFTDEP)
457 		printf("\twith soft updates\n");
458 #	undef B2MBFACTOR
459 
460 	if (Eflag && !Nflag) {
461 		printf("Erasing sectors [%jd...%jd]\n",
462 		    sblock.fs_sblockloc / disk.d_bsize,
463 		    fsbtodb(&sblock, sblock.fs_size) - 1);
464 		berase(&disk, sblock.fs_sblockloc / disk.d_bsize,
465 		    sblock.fs_size * sblock.fs_fsize - sblock.fs_sblockloc);
466 	}
467 	/*
468 	 * Wipe out old UFS1 superblock(s) if necessary.
469 	 */
470 	if (!Nflag && Oflag != 1) {
471 		i = bread(&disk, part_ofs + SBLOCK_UFS1 / disk.d_bsize, chdummy, SBLOCKSIZE);
472 		if (i == -1)
473 			err(1, "can't read old UFS1 superblock: %s", disk.d_error);
474 
475 		if (fsdummy.fs_magic == FS_UFS1_MAGIC) {
476 			fsdummy.fs_magic = 0;
477 			bwrite(&disk, part_ofs + SBLOCK_UFS1 / disk.d_bsize,
478 			    chdummy, SBLOCKSIZE);
479 			for (i = 0; i < fsdummy.fs_ncg; i++)
480 				bwrite(&disk, part_ofs + fsbtodb(&fsdummy,
481 				    cgsblock(&fsdummy, i)), chdummy, SBLOCKSIZE);
482 		}
483 	}
484 	if (!Nflag)
485 		do_sbwrite(&disk);
486 	if (Xflag == 1) {
487 		printf("** Exiting on Xflag 1\n");
488 		exit(0);
489 	}
490 	if (Xflag == 2)
491 		printf("** Leaving BAD MAGIC on Xflag 2\n");
492 	else
493 		sblock.fs_magic = (Oflag != 1) ? FS_UFS2_MAGIC : FS_UFS1_MAGIC;
494 
495 	/*
496 	 * Now build the cylinders group blocks and
497 	 * then print out indices of cylinder groups.
498 	 */
499 	printf("super-block backups (for fsck -b #) at:\n");
500 	i = 0;
501 	width = charsperline();
502 	/*
503 	 * allocate space for superblock, cylinder group map, and
504 	 * two sets of inode blocks.
505 	 */
506 	if (sblock.fs_bsize < SBLOCKSIZE)
507 		iobufsize = SBLOCKSIZE + 3 * sblock.fs_bsize;
508 	else
509 		iobufsize = 4 * sblock.fs_bsize;
510 	if ((iobuf = calloc(1, iobufsize)) == 0) {
511 		printf("Cannot allocate I/O buffer\n");
512 		exit(38);
513 	}
514 	/*
515 	 * Make a copy of the superblock into the buffer that we will be
516 	 * writing out in each cylinder group.
517 	 */
518 	bcopy((char *)&sblock, iobuf, SBLOCKSIZE);
519 	for (cylno = 0; cylno < sblock.fs_ncg; cylno++) {
520 		initcg(cylno, utime);
521 		j = snprintf(tmpbuf, sizeof(tmpbuf), " %jd%s",
522 		    (intmax_t)fsbtodb(&sblock, cgsblock(&sblock, cylno)),
523 		    cylno < (sblock.fs_ncg-1) ? "," : "");
524 		if (j < 0)
525 			tmpbuf[j = 0] = '\0';
526 		if (i + j >= width) {
527 			printf("\n");
528 			i = 0;
529 		}
530 		i += j;
531 		printf("%s", tmpbuf);
532 		fflush(stdout);
533 	}
534 	printf("\n");
535 	if (Nflag)
536 		exit(0);
537 	/*
538 	 * Now construct the initial file system,
539 	 * then write out the super-block.
540 	 */
541 	fsinit(utime);
542 	if (Oflag == 1) {
543 		sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
544 		sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
545 		sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
546 		sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
547 	}
548 	if (Xflag == 3) {
549 		printf("** Exiting on Xflag 3\n");
550 		exit(0);
551 	}
552 	if (!Nflag)
553 		do_sbwrite(&disk);
554 	for (i = 0; i < sblock.fs_cssize; i += sblock.fs_bsize)
555 		wtfs(fsbtodb(&sblock, sblock.fs_csaddr + numfrags(&sblock, i)),
556 			sblock.fs_cssize - i < sblock.fs_bsize ?
557 			sblock.fs_cssize - i : sblock.fs_bsize,
558 			((char *)fscs) + i);
559 	/*
560 	 * Update information about this partion in pack
561 	 * label, to that it may be updated on disk.
562 	 */
563 	if (pp != NULL) {
564 		pp->p_fstype = FS_BSDFFS;
565 		pp->p_fsize = sblock.fs_fsize;
566 		pp->p_frag = sblock.fs_frag;
567 		pp->p_cpg = sblock.fs_fpg;
568 	}
569 }
570 
571 /*
572  * Initialize a cylinder group.
573  */
574 void
575 initcg(int cylno, time_t utime)
576 {
577 	long i, j, d, dlower, dupper, blkno, start;
578 	ufs2_daddr_t cbase, dmax;
579 	struct ufs1_dinode *dp1;
580 	struct ufs2_dinode *dp2;
581 	struct csum *cs;
582 
583 	/*
584 	 * Determine block bounds for cylinder group.
585 	 * Allow space for super block summary information in first
586 	 * cylinder group.
587 	 */
588 	cbase = cgbase(&sblock, cylno);
589 	dmax = cbase + sblock.fs_fpg;
590 	if (dmax > sblock.fs_size)
591 		dmax = sblock.fs_size;
592 	dlower = cgsblock(&sblock, cylno) - cbase;
593 	dupper = cgdmin(&sblock, cylno) - cbase;
594 	if (cylno == 0)
595 		dupper += howmany(sblock.fs_cssize, sblock.fs_fsize);
596 	cs = &fscs[cylno];
597 	memset(&acg, 0, sblock.fs_cgsize);
598 	acg.cg_time = utime;
599 	acg.cg_magic = CG_MAGIC;
600 	acg.cg_cgx = cylno;
601 	acg.cg_niblk = sblock.fs_ipg;
602 	acg.cg_initediblk = sblock.fs_ipg < 2 * INOPB(&sblock) ?
603 	    sblock.fs_ipg : 2 * INOPB(&sblock);
604 	acg.cg_ndblk = dmax - cbase;
605 	if (sblock.fs_contigsumsize > 0)
606 		acg.cg_nclusterblks = acg.cg_ndblk / sblock.fs_frag;
607 	start = &acg.cg_space[0] - (u_char *)(&acg.cg_firstfield);
608 	if (Oflag == 2) {
609 		acg.cg_iusedoff = start;
610 	} else {
611 		acg.cg_old_ncyl = sblock.fs_old_cpg;
612 		acg.cg_old_time = acg.cg_time;
613 		acg.cg_time = 0;
614 		acg.cg_old_niblk = acg.cg_niblk;
615 		acg.cg_niblk = 0;
616 		acg.cg_initediblk = 0;
617 		acg.cg_old_btotoff = start;
618 		acg.cg_old_boff = acg.cg_old_btotoff +
619 		    sblock.fs_old_cpg * sizeof(int32_t);
620 		acg.cg_iusedoff = acg.cg_old_boff +
621 		    sblock.fs_old_cpg * sizeof(u_int16_t);
622 	}
623 	acg.cg_freeoff = acg.cg_iusedoff + howmany(sblock.fs_ipg, CHAR_BIT);
624 	acg.cg_nextfreeoff = acg.cg_freeoff + howmany(sblock.fs_fpg, CHAR_BIT);
625 	if (sblock.fs_contigsumsize > 0) {
626 		acg.cg_clustersumoff =
627 		    roundup(acg.cg_nextfreeoff, sizeof(u_int32_t));
628 		acg.cg_clustersumoff -= sizeof(u_int32_t);
629 		acg.cg_clusteroff = acg.cg_clustersumoff +
630 		    (sblock.fs_contigsumsize + 1) * sizeof(u_int32_t);
631 		acg.cg_nextfreeoff = acg.cg_clusteroff +
632 		    howmany(fragstoblks(&sblock, sblock.fs_fpg), CHAR_BIT);
633 	}
634 	if (acg.cg_nextfreeoff > sblock.fs_cgsize) {
635 		printf("Panic: cylinder group too big\n");
636 		exit(37);
637 	}
638 	acg.cg_cs.cs_nifree += sblock.fs_ipg;
639 	if (cylno == 0)
640 		for (i = 0; i < (long)ROOTINO; i++) {
641 			setbit(cg_inosused(&acg), i);
642 			acg.cg_cs.cs_nifree--;
643 		}
644 	if (cylno > 0) {
645 		/*
646 		 * In cylno 0, beginning space is reserved
647 		 * for boot and super blocks.
648 		 */
649 		for (d = 0; d < dlower; d += sblock.fs_frag) {
650 			blkno = d / sblock.fs_frag;
651 			setblock(&sblock, cg_blksfree(&acg), blkno);
652 			if (sblock.fs_contigsumsize > 0)
653 				setbit(cg_clustersfree(&acg), blkno);
654 			acg.cg_cs.cs_nbfree++;
655 		}
656 	}
657 	if ((i = dupper % sblock.fs_frag)) {
658 		acg.cg_frsum[sblock.fs_frag - i]++;
659 		for (d = dupper + sblock.fs_frag - i; dupper < d; dupper++) {
660 			setbit(cg_blksfree(&acg), dupper);
661 			acg.cg_cs.cs_nffree++;
662 		}
663 	}
664 	for (d = dupper; d + sblock.fs_frag <= acg.cg_ndblk;
665 	     d += sblock.fs_frag) {
666 		blkno = d / sblock.fs_frag;
667 		setblock(&sblock, cg_blksfree(&acg), blkno);
668 		if (sblock.fs_contigsumsize > 0)
669 			setbit(cg_clustersfree(&acg), blkno);
670 		acg.cg_cs.cs_nbfree++;
671 	}
672 	if (d < acg.cg_ndblk) {
673 		acg.cg_frsum[acg.cg_ndblk - d]++;
674 		for (; d < acg.cg_ndblk; d++) {
675 			setbit(cg_blksfree(&acg), d);
676 			acg.cg_cs.cs_nffree++;
677 		}
678 	}
679 	if (sblock.fs_contigsumsize > 0) {
680 		int32_t *sump = cg_clustersum(&acg);
681 		u_char *mapp = cg_clustersfree(&acg);
682 		int map = *mapp++;
683 		int bit = 1;
684 		int run = 0;
685 
686 		for (i = 0; i < acg.cg_nclusterblks; i++) {
687 			if ((map & bit) != 0)
688 				run++;
689 			else if (run != 0) {
690 				if (run > sblock.fs_contigsumsize)
691 					run = sblock.fs_contigsumsize;
692 				sump[run]++;
693 				run = 0;
694 			}
695 			if ((i & (CHAR_BIT - 1)) != CHAR_BIT - 1)
696 				bit <<= 1;
697 			else {
698 				map = *mapp++;
699 				bit = 1;
700 			}
701 		}
702 		if (run != 0) {
703 			if (run > sblock.fs_contigsumsize)
704 				run = sblock.fs_contigsumsize;
705 			sump[run]++;
706 		}
707 	}
708 	*cs = acg.cg_cs;
709 	/*
710 	 * Write out the duplicate super block, the cylinder group map
711 	 * and two blocks worth of inodes in a single write.
712 	 */
713 	start = sblock.fs_bsize > SBLOCKSIZE ? sblock.fs_bsize : SBLOCKSIZE;
714 	bcopy((char *)&acg, &iobuf[start], sblock.fs_cgsize);
715 	start += sblock.fs_bsize;
716 	dp1 = (struct ufs1_dinode *)(&iobuf[start]);
717 	dp2 = (struct ufs2_dinode *)(&iobuf[start]);
718 	for (i = 0; i < acg.cg_initediblk; i++) {
719 		if (sblock.fs_magic == FS_UFS1_MAGIC) {
720 			dp1->di_gen = newfs_random();
721 			dp1++;
722 		} else {
723 			dp2->di_gen = newfs_random();
724 			dp2++;
725 		}
726 	}
727 	wtfs(fsbtodb(&sblock, cgsblock(&sblock, cylno)), iobufsize, iobuf);
728 	/*
729 	 * For the old file system, we have to initialize all the inodes.
730 	 */
731 	if (Oflag == 1) {
732 		for (i = 2 * sblock.fs_frag;
733 		     i < sblock.fs_ipg / INOPF(&sblock);
734 		     i += sblock.fs_frag) {
735 			dp1 = (struct ufs1_dinode *)(&iobuf[start]);
736 			for (j = 0; j < INOPB(&sblock); j++) {
737 				dp1->di_gen = newfs_random();
738 				dp1++;
739 			}
740 			wtfs(fsbtodb(&sblock, cgimin(&sblock, cylno) + i),
741 			    sblock.fs_bsize, &iobuf[start]);
742 		}
743 	}
744 }
745 
746 /*
747  * initialize the file system
748  */
749 #define ROOTLINKCNT 3
750 
751 struct direct root_dir[] = {
752 	{ ROOTINO, sizeof(struct direct), DT_DIR, 1, "." },
753 	{ ROOTINO, sizeof(struct direct), DT_DIR, 2, ".." },
754 	{ ROOTINO + 1, sizeof(struct direct), DT_DIR, 5, ".snap" },
755 };
756 
757 #define SNAPLINKCNT 2
758 
759 struct direct snap_dir[] = {
760 	{ ROOTINO + 1, sizeof(struct direct), DT_DIR, 1, "." },
761 	{ ROOTINO, sizeof(struct direct), DT_DIR, 2, ".." },
762 };
763 
764 void
765 fsinit(time_t utime)
766 {
767 	union dinode node;
768 	struct group *grp;
769 	gid_t gid;
770 	int entries;
771 
772 	memset(&node, 0, sizeof node);
773 	if ((grp = getgrnam("operator")) != NULL) {
774 		gid = grp->gr_gid;
775 	} else {
776 		warnx("Cannot retrieve operator gid, using gid 0.");
777 		gid = 0;
778 	}
779 	entries = (nflag) ? ROOTLINKCNT - 1: ROOTLINKCNT;
780 	if (sblock.fs_magic == FS_UFS1_MAGIC) {
781 		/*
782 		 * initialize the node
783 		 */
784 		node.dp1.di_atime = utime;
785 		node.dp1.di_mtime = utime;
786 		node.dp1.di_ctime = utime;
787 		/*
788 		 * create the root directory
789 		 */
790 		node.dp1.di_mode = IFDIR | UMASK;
791 		node.dp1.di_nlink = entries;
792 		node.dp1.di_size = makedir(root_dir, entries);
793 		node.dp1.di_db[0] = alloc(sblock.fs_fsize, node.dp1.di_mode);
794 		node.dp1.di_blocks =
795 		    btodb(fragroundup(&sblock, node.dp1.di_size));
796 		wtfs(fsbtodb(&sblock, node.dp1.di_db[0]), sblock.fs_fsize,
797 		    iobuf);
798 		iput(&node, ROOTINO);
799 		if (!nflag) {
800 			/*
801 			 * create the .snap directory
802 			 */
803 			node.dp1.di_mode |= 020;
804 			node.dp1.di_gid = gid;
805 			node.dp1.di_nlink = SNAPLINKCNT;
806 			node.dp1.di_size = makedir(snap_dir, SNAPLINKCNT);
807 				node.dp1.di_db[0] =
808 				    alloc(sblock.fs_fsize, node.dp1.di_mode);
809 			node.dp1.di_blocks =
810 			    btodb(fragroundup(&sblock, node.dp1.di_size));
811 				wtfs(fsbtodb(&sblock, node.dp1.di_db[0]),
812 				    sblock.fs_fsize, iobuf);
813 			iput(&node, ROOTINO + 1);
814 		}
815 	} else {
816 		/*
817 		 * initialize the node
818 		 */
819 		node.dp2.di_atime = utime;
820 		node.dp2.di_mtime = utime;
821 		node.dp2.di_ctime = utime;
822 		node.dp2.di_birthtime = utime;
823 		/*
824 		 * create the root directory
825 		 */
826 		node.dp2.di_mode = IFDIR | UMASK;
827 		node.dp2.di_nlink = entries;
828 		node.dp2.di_size = makedir(root_dir, entries);
829 		node.dp2.di_db[0] = alloc(sblock.fs_fsize, node.dp2.di_mode);
830 		node.dp2.di_blocks =
831 		    btodb(fragroundup(&sblock, node.dp2.di_size));
832 		wtfs(fsbtodb(&sblock, node.dp2.di_db[0]), sblock.fs_fsize,
833 		    iobuf);
834 		iput(&node, ROOTINO);
835 		if (!nflag) {
836 			/*
837 			 * create the .snap directory
838 			 */
839 			node.dp2.di_mode |= 020;
840 			node.dp2.di_gid = gid;
841 			node.dp2.di_nlink = SNAPLINKCNT;
842 			node.dp2.di_size = makedir(snap_dir, SNAPLINKCNT);
843 				node.dp2.di_db[0] =
844 				    alloc(sblock.fs_fsize, node.dp2.di_mode);
845 			node.dp2.di_blocks =
846 			    btodb(fragroundup(&sblock, node.dp2.di_size));
847 				wtfs(fsbtodb(&sblock, node.dp2.di_db[0]),
848 				    sblock.fs_fsize, iobuf);
849 			iput(&node, ROOTINO + 1);
850 		}
851 	}
852 }
853 
854 /*
855  * construct a set of directory entries in "iobuf".
856  * return size of directory.
857  */
858 int
859 makedir(struct direct *protodir, int entries)
860 {
861 	char *cp;
862 	int i, spcleft;
863 
864 	spcleft = DIRBLKSIZ;
865 	memset(iobuf, 0, DIRBLKSIZ);
866 	for (cp = iobuf, i = 0; i < entries - 1; i++) {
867 		protodir[i].d_reclen = DIRSIZ(0, &protodir[i]);
868 		memmove(cp, &protodir[i], protodir[i].d_reclen);
869 		cp += protodir[i].d_reclen;
870 		spcleft -= protodir[i].d_reclen;
871 	}
872 	protodir[i].d_reclen = spcleft;
873 	memmove(cp, &protodir[i], DIRSIZ(0, &protodir[i]));
874 	return (DIRBLKSIZ);
875 }
876 
877 /*
878  * allocate a block or frag
879  */
880 ufs2_daddr_t
881 alloc(int size, int mode)
882 {
883 	int i, d, blkno, frag;
884 
885 	bread(&disk, part_ofs + fsbtodb(&sblock, cgtod(&sblock, 0)), (char *)&acg,
886 	    sblock.fs_cgsize);
887 	if (acg.cg_magic != CG_MAGIC) {
888 		printf("cg 0: bad magic number\n");
889 		exit(38);
890 	}
891 	if (acg.cg_cs.cs_nbfree == 0) {
892 		printf("first cylinder group ran out of space\n");
893 		exit(39);
894 	}
895 	for (d = 0; d < acg.cg_ndblk; d += sblock.fs_frag)
896 		if (isblock(&sblock, cg_blksfree(&acg), d / sblock.fs_frag))
897 			goto goth;
898 	printf("internal error: can't find block in cyl 0\n");
899 	exit(40);
900 goth:
901 	blkno = fragstoblks(&sblock, d);
902 	clrblock(&sblock, cg_blksfree(&acg), blkno);
903 	if (sblock.fs_contigsumsize > 0)
904 		clrbit(cg_clustersfree(&acg), blkno);
905 	acg.cg_cs.cs_nbfree--;
906 	sblock.fs_cstotal.cs_nbfree--;
907 	fscs[0].cs_nbfree--;
908 	if (mode & IFDIR) {
909 		acg.cg_cs.cs_ndir++;
910 		sblock.fs_cstotal.cs_ndir++;
911 		fscs[0].cs_ndir++;
912 	}
913 	if (size != sblock.fs_bsize) {
914 		frag = howmany(size, sblock.fs_fsize);
915 		fscs[0].cs_nffree += sblock.fs_frag - frag;
916 		sblock.fs_cstotal.cs_nffree += sblock.fs_frag - frag;
917 		acg.cg_cs.cs_nffree += sblock.fs_frag - frag;
918 		acg.cg_frsum[sblock.fs_frag - frag]++;
919 		for (i = frag; i < sblock.fs_frag; i++)
920 			setbit(cg_blksfree(&acg), d + i);
921 	}
922 	/* XXX cgwrite(&disk, 0)??? */
923 	wtfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
924 	    (char *)&acg);
925 	return ((ufs2_daddr_t)d);
926 }
927 
928 /*
929  * Allocate an inode on the disk
930  */
931 void
932 iput(union dinode *ip, ino_t ino)
933 {
934 	ufs2_daddr_t d;
935 	int c;
936 
937 	c = ino_to_cg(&sblock, ino);
938 	bread(&disk, part_ofs + fsbtodb(&sblock, cgtod(&sblock, 0)), (char *)&acg,
939 	    sblock.fs_cgsize);
940 	if (acg.cg_magic != CG_MAGIC) {
941 		printf("cg 0: bad magic number\n");
942 		exit(31);
943 	}
944 	acg.cg_cs.cs_nifree--;
945 	setbit(cg_inosused(&acg), ino);
946 	wtfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
947 	    (char *)&acg);
948 	sblock.fs_cstotal.cs_nifree--;
949 	fscs[0].cs_nifree--;
950 	if (ino >= (unsigned long)sblock.fs_ipg * sblock.fs_ncg) {
951 		printf("fsinit: inode value out of range (%d).\n", ino);
952 		exit(32);
953 	}
954 	d = fsbtodb(&sblock, ino_to_fsba(&sblock, ino));
955 	bread(&disk, part_ofs + d, (char *)iobuf, sblock.fs_bsize);
956 	if (sblock.fs_magic == FS_UFS1_MAGIC)
957 		((struct ufs1_dinode *)iobuf)[ino_to_fsbo(&sblock, ino)] =
958 		    ip->dp1;
959 	else
960 		((struct ufs2_dinode *)iobuf)[ino_to_fsbo(&sblock, ino)] =
961 		    ip->dp2;
962 	wtfs(d, sblock.fs_bsize, (char *)iobuf);
963 }
964 
965 /*
966  * possibly write to disk
967  */
968 static void
969 wtfs(ufs2_daddr_t bno, int size, char *bf)
970 {
971 	if (Nflag)
972 		return;
973 	if (bwrite(&disk, part_ofs + bno, bf, size) < 0)
974 		err(36, "wtfs: %d bytes at sector %jd", size, (intmax_t)bno);
975 }
976 
977 /*
978  * check if a block is available
979  */
980 static int
981 isblock(struct fs *fs, unsigned char *cp, int h)
982 {
983 	unsigned char mask;
984 
985 	switch (fs->fs_frag) {
986 	case 8:
987 		return (cp[h] == 0xff);
988 	case 4:
989 		mask = 0x0f << ((h & 0x1) << 2);
990 		return ((cp[h >> 1] & mask) == mask);
991 	case 2:
992 		mask = 0x03 << ((h & 0x3) << 1);
993 		return ((cp[h >> 2] & mask) == mask);
994 	case 1:
995 		mask = 0x01 << (h & 0x7);
996 		return ((cp[h >> 3] & mask) == mask);
997 	default:
998 		fprintf(stderr, "isblock bad fs_frag %d\n", fs->fs_frag);
999 		return (0);
1000 	}
1001 }
1002 
1003 /*
1004  * take a block out of the map
1005  */
1006 static void
1007 clrblock(struct fs *fs, unsigned char *cp, int h)
1008 {
1009 	switch ((fs)->fs_frag) {
1010 	case 8:
1011 		cp[h] = 0;
1012 		return;
1013 	case 4:
1014 		cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
1015 		return;
1016 	case 2:
1017 		cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
1018 		return;
1019 	case 1:
1020 		cp[h >> 3] &= ~(0x01 << (h & 0x7));
1021 		return;
1022 	default:
1023 		fprintf(stderr, "clrblock bad fs_frag %d\n", fs->fs_frag);
1024 		return;
1025 	}
1026 }
1027 
1028 /*
1029  * put a block into the map
1030  */
1031 static void
1032 setblock(struct fs *fs, unsigned char *cp, int h)
1033 {
1034 	switch (fs->fs_frag) {
1035 	case 8:
1036 		cp[h] = 0xff;
1037 		return;
1038 	case 4:
1039 		cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
1040 		return;
1041 	case 2:
1042 		cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
1043 		return;
1044 	case 1:
1045 		cp[h >> 3] |= (0x01 << (h & 0x7));
1046 		return;
1047 	default:
1048 		fprintf(stderr, "setblock bad fs_frag %d\n", fs->fs_frag);
1049 		return;
1050 	}
1051 }
1052 
1053 /*
1054  * Determine the number of characters in a
1055  * single line.
1056  */
1057 
1058 static int
1059 charsperline(void)
1060 {
1061 	int columns;
1062 	char *cp;
1063 	struct winsize ws;
1064 
1065 	columns = 0;
1066 	if (ioctl(0, TIOCGWINSZ, &ws) != -1)
1067 		columns = ws.ws_col;
1068 	if (columns == 0 && (cp = getenv("COLUMNS")))
1069 		columns = atoi(cp);
1070 	if (columns == 0)
1071 		columns = 80;	/* last resort */
1072 	return (columns);
1073 }
1074 
1075 static int
1076 ilog2(int val)
1077 {
1078 	u_int n;
1079 
1080 	for (n = 0; n < sizeof(n) * CHAR_BIT; n++)
1081 		if (1 << n == val)
1082 			return (n);
1083 	errx(1, "ilog2: %d is not a power of 2\n", val);
1084 }
1085 
1086 /*
1087  * For the regression test, return predictable random values.
1088  * Otherwise use a true random number generator.
1089  */
1090 static u_int32_t
1091 newfs_random(void)
1092 {
1093 	static int nextnum = 1;
1094 
1095 	if (Rflag)
1096 		return (nextnum++);
1097 	return (arc4random());
1098 }
1099