mkfs.c revision 221049
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
41static char sccsid[] = "@(#)mkfs.c	8.11 (Berkeley) 5/3/95";
42#endif /* not lint */
43#endif
44#include <sys/cdefs.h>
45__FBSDID("$FreeBSD: head/sbin/newfs/mkfs.c 221049 2011-04-26 02:06:31Z cperciva $");
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
76static struct	csum *fscs;
77#define	sblock	disk.d_fs
78#define	acg	disk.d_cg
79
80union 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
88static caddr_t iobuf;
89static long iobufsize;
90static ufs2_daddr_t alloc(int size, int mode);
91static int charsperline(void);
92static void clrblock(struct fs *, unsigned char *, int);
93static void fsinit(time_t);
94static int ilog2(int);
95static void initcg(int, time_t);
96static int isblock(struct fs *, unsigned char *, int);
97static void iput(union dinode *, ino_t);
98static int makedir(struct direct *, int);
99static void setblock(struct fs *, unsigned char *, int);
100static void wtfs(ufs2_daddr_t, int, char *);
101static u_int32_t newfs_random(void);
102
103static int
104do_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
112void
113mkfs(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
178restart:
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 */
629void
630initcg(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
807struct 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
815struct direct snap_dir[] = {
816	{ ROOTINO + 1, sizeof(struct direct), DT_DIR, 1, "." },
817	{ ROOTINO, sizeof(struct direct), DT_DIR, 2, ".." },
818};
819
820void
821fsinit(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 */
914int
915makedir(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 */
936ufs2_daddr_t
937alloc(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);
957goth:
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 */
988void
989iput(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 */
1025static void
1026wtfs(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 */
1037static int
1038isblock(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 */
1063static void
1064clrblock(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 */
1088static void
1089setblock(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
1115static int
1116charsperline(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
1132static int
1133ilog2(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 */
1147static u_int32_t
1148newfs_random(void)
1149{
1150	static int nextnum = 1;
1151
1152	if (Rflag)
1153		return (nextnum++);
1154	return (arc4random());
1155}
1156