sbin/newfs/mkfs.c

   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 void
 105 mkfs(struct partition *pp, char *fsys)
 106 {
 107         int fragsperinode, optimalfpg, origdensity, minfpg, lastminfpg;
 108         long i, j, cylno, csfrags;
 109         time_t utime;
 110         quad_t sizepb;
 111         int width;
 112         char tmpbuf[100];       /* XXX this will break in about 2,500 years */
 113         union {
 114                 struct fs fdummy;
 115                 char cdummy[SBLOCKSIZE];
 116         } dummy;
 117 #define fsdummy dummy.fdummy
 118 #define chdummy dummy.cdummy
 119
 120         /*
 121          * Our blocks == sector size, and the version of UFS we are using is
 122          * specified by Oflag.
 123          */
 124         disk.d_bsize = sectorsize;
 125         disk.d_ufs = Oflag;
 126         if (Rflag) {
 127                 utime = 1000000000;
 128         } else {
 129                 time(&utime);
 130                 arc4random_stir();
 131         }
 132         sblock.fs_old_flags = FS_FLAGS_UPDATED;
 133         sblock.fs_flags = 0;
 134         if (Uflag)
 135                 sblock.fs_flags |= FS_DOSOFTDEP;
 136         if (Lflag)
 137                 strlcpy(sblock.fs_volname, volumelabel, MAXVOLLEN);
 138         if (lflag)
 139                 sblock.fs_flags |= FS_MULTILABEL;
 140         /*
 141          * Validate the given file system size.
 142          * Verify that its last block can actually be accessed.
 143          * Convert to file system fragment sized units.
 144          */
 145         if (fssize <= 0) {
 146                 printf("preposterous size %jd\n", (intmax_t)fssize);
 147                 exit(13);
 148         }
 149         wtfs(fssize - (realsectorsize / DEV_BSIZE), realsectorsize,
 150             (char *)&sblock);
 151         /*
 152          * collect and verify the file system density info
 153          */
 154         sblock.fs_avgfilesize = avgfilesize;
 155         sblock.fs_avgfpdir = avgfilesperdir;
 156         if (sblock.fs_avgfilesize <= 0)
 157                 printf("illegal expected average file size %d\n",
 158                     sblock.fs_avgfilesize), exit(14);
 159         if (sblock.fs_avgfpdir <= 0)
 160                 printf("illegal expected number of files per directory %d\n",
 161                     sblock.fs_avgfpdir), exit(15);
 162         /*
 163          * collect and verify the block and fragment sizes
 164          */
 165         sblock.fs_bsize = bsize;
 166         sblock.fs_fsize = fsize;
 167         if (!POWEROF2(sblock.fs_bsize)) {
 168                 printf("block size must be a power of 2, not %d\n",
 169                     sblock.fs_bsize);
 170                 exit(16);
 171         }
 172         if (!POWEROF2(sblock.fs_fsize)) {
 173                 printf("fragment size must be a power of 2, not %d\n",
 174                     sblock.fs_fsize);
 175                 exit(17);
 176         }
 177         if (sblock.fs_fsize < sectorsize) {
 178                 printf("increasing fragment size from %d to sector size (%d)\n",
 179                     sblock.fs_fsize, sectorsize);
 180                 sblock.fs_fsize = sectorsize;
 181         }
 182         if (sblock.fs_bsize > MAXBSIZE) {
 183                 printf("decreasing block size from %d to maximum (%d)\n",
 184                     sblock.fs_bsize, MAXBSIZE);
 185                 sblock.fs_bsize = MAXBSIZE;
 186         }
 187         if (sblock.fs_bsize < MINBSIZE) {
 188                 printf("increasing block size from %d to minimum (%d)\n",
 189                     sblock.fs_bsize, MINBSIZE);
 190                 sblock.fs_bsize = MINBSIZE;
 191         }
 192         if (sblock.fs_fsize > MAXBSIZE) {
 193                 printf("decreasing fragment size from %d to maximum (%d)\n",
 194                     sblock.fs_fsize, MAXBSIZE);
 195                 sblock.fs_fsize = MAXBSIZE;
 196         }
 197         if (sblock.fs_bsize < sblock.fs_fsize) {
 198                 printf("increasing block size from %d to fragment size (%d)\n",
 199                     sblock.fs_bsize, sblock.fs_fsize);
 200                 sblock.fs_bsize = sblock.fs_fsize;
 201         }
 202         if (sblock.fs_fsize * MAXFRAG < sblock.fs_bsize) {
 203                 printf(
 204                 "increasing fragment size from %d to block size / %d (%d)\n",
 205                     sblock.fs_fsize, MAXFRAG, sblock.fs_bsize / MAXFRAG);
 206                 sblock.fs_fsize = sblock.fs_bsize / MAXFRAG;
 207         }
 208         if (maxbsize < bsize || !POWEROF2(maxbsize)) {
 209                 sblock.fs_maxbsize = sblock.fs_bsize;
 210                 printf("Extent size set to %d\n", sblock.fs_maxbsize);
 211         } else if (sblock.fs_maxbsize > FS_MAXCONTIG * sblock.fs_bsize) {
 212                 sblock.fs_maxbsize = FS_MAXCONTIG * sblock.fs_bsize;
 213                 printf("Extent size reduced to %d\n", sblock.fs_maxbsize);
 214         } else {
 215                 sblock.fs_maxbsize = maxbsize;
 216         }
 217         sblock.fs_maxcontig = maxcontig;
 218         if (sblock.fs_maxcontig < sblock.fs_maxbsize / sblock.fs_bsize) {
 219                 sblock.fs_maxcontig = sblock.fs_maxbsize / sblock.fs_bsize;
 220                 printf("Maxcontig raised to %d\n", sblock.fs_maxbsize);
 221         }
 222         if (sblock.fs_maxcontig > 1)
 223                 sblock.fs_contigsumsize = MIN(sblock.fs_maxcontig,FS_MAXCONTIG);
 224         sblock.fs_bmask = ~(sblock.fs_bsize - 1);
 225         sblock.fs_fmask = ~(sblock.fs_fsize - 1);
 226         sblock.fs_qbmask = ~sblock.fs_bmask;
 227         sblock.fs_qfmask = ~sblock.fs_fmask;
 228         sblock.fs_bshift = ilog2(sblock.fs_bsize);
 229         sblock.fs_fshift = ilog2(sblock.fs_fsize);
 230         sblock.fs_frag = numfrags(&sblock, sblock.fs_bsize);
 231         sblock.fs_fragshift = ilog2(sblock.fs_frag);
 232         if (sblock.fs_frag > MAXFRAG) {
 233                 printf("fragment size %d is still too small (can't happen)\n",
 234                     sblock.fs_bsize / MAXFRAG);
 235                 exit(21);
 236         }
 237         sblock.fs_fsbtodb = ilog2(sblock.fs_fsize / sectorsize);
 238         sblock.fs_size = fssize = dbtofsb(&sblock, fssize);
 239
 240         /*
 241          * Before the filesystem is finally initialized, mark it
 242          * as incompletely initialized.
 243          */
 244         sblock.fs_magic = FS_BAD_MAGIC;
 245
 246         if (Oflag == 1) {
 247                 sblock.fs_sblockloc = SBLOCK_UFS1;
 248                 sblock.fs_nindir = sblock.fs_bsize / sizeof(ufs1_daddr_t);
 249                 sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs1_dinode);
 250                 sblock.fs_maxsymlinklen = ((NDADDR + NIADDR) *
 251                     sizeof(ufs1_daddr_t));
 252                 sblock.fs_old_inodefmt = FS_44INODEFMT;
 253                 sblock.fs_old_cgoffset = 0;
 254                 sblock.fs_old_cgmask = 0xffffffff;
 255                 sblock.fs_old_size = sblock.fs_size;
 256                 sblock.fs_old_rotdelay = 0;
 257                 sblock.fs_old_rps = 60;
 258                 sblock.fs_old_nspf = sblock.fs_fsize / sectorsize;
 259                 sblock.fs_old_cpg = 1;
 260                 sblock.fs_old_interleave = 1;
 261                 sblock.fs_old_trackskew = 0;
 262                 sblock.fs_old_cpc = 0;
 263                 sblock.fs_old_postblformat = 1;
 264                 sblock.fs_old_nrpos = 1;
 265         } else {
 266                 sblock.fs_sblockloc = SBLOCK_UFS2;
 267                 sblock.fs_nindir = sblock.fs_bsize / sizeof(ufs2_daddr_t);
 268                 sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs2_dinode);
 269                 sblock.fs_maxsymlinklen = ((NDADDR + NIADDR) *
 270                     sizeof(ufs2_daddr_t));
 271         }
 272         sblock.fs_sblkno =
 273             roundup(howmany(sblock.fs_sblockloc + SBLOCKSIZE, sblock.fs_fsize),
 274                 sblock.fs_frag);
 275         sblock.fs_cblkno = sblock.fs_sblkno +
 276             roundup(howmany(SBLOCKSIZE, sblock.fs_fsize), sblock.fs_frag);
 277         sblock.fs_iblkno = sblock.fs_cblkno + sblock.fs_frag;
 278         sblock.fs_maxfilesize = sblock.fs_bsize * NDADDR - 1;
 279         for (sizepb = sblock.fs_bsize, i = 0; i < NIADDR; i++) {
 280                 sizepb *= NINDIR(&sblock);
 281                 sblock.fs_maxfilesize += sizepb;
 282         }
 283
 284         /*
 285          * It's impossible to create a snapshot in case that fs_maxfilesize
 286          * is smaller than the fssize.
 287          */
 288         if (sblock.fs_maxfilesize < (u_quad_t)fssize) {
 289                 warnx("WARNING: You will be unable to create snapshots on this "
 290                       "file system.  Correct by using a larger blocksize.");
 291         }
 292
 293         /*
 294          * Calculate the number of blocks to put into each cylinder group.
 295          *
 296          * This algorithm selects the number of blocks per cylinder
 297          * group. The first goal is to have at least enough data blocks
 298          * in each cylinder group to meet the density requirement. Once
 299          * this goal is achieved we try to expand to have at least
 300          * MINCYLGRPS cylinder groups. Once this goal is achieved, we
 301          * pack as many blocks into each cylinder group map as will fit.
 302          *
 303          * We start by calculating the smallest number of blocks that we
 304          * can put into each cylinder group. If this is too big, we reduce
 305          * the density until it fits.
 306          */
 307         origdensity = density;
 308         for (;;) {
 309                 fragsperinode = MAX(numfrags(&sblock, density), 1);
 310                 minfpg = fragsperinode * INOPB(&sblock);
 311                 if (minfpg > sblock.fs_size)
 312                         minfpg = sblock.fs_size;
 313                 sblock.fs_ipg = INOPB(&sblock);
 314                 sblock.fs_fpg = roundup(sblock.fs_iblkno +
 315                     sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
 316                 if (sblock.fs_fpg < minfpg)
 317                         sblock.fs_fpg = minfpg;
 318                 sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
 319                     INOPB(&sblock));
 320                 sblock.fs_fpg = roundup(sblock.fs_iblkno +
 321                     sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
 322                 if (sblock.fs_fpg < minfpg)
 323                         sblock.fs_fpg = minfpg;
 324                 sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
 325                     INOPB(&sblock));
 326                 if (CGSIZE(&sblock) < (unsigned long)sblock.fs_bsize)
 327                         break;
 328                 density -= sblock.fs_fsize;
 329         }
 330         if (density != origdensity)
 331                 printf("density reduced from %d to %d\n", origdensity, density);
 332         /*
 333          * Start packing more blocks into the cylinder group until
 334          * it cannot grow any larger, the number of cylinder groups
 335          * drops below MINCYLGRPS, or we reach the size requested.
 336          */
 337         for ( ; sblock.fs_fpg < maxblkspercg; sblock.fs_fpg += sblock.fs_frag) {
 338                 sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
 339                     INOPB(&sblock));
 340                 if (sblock.fs_size / sblock.fs_fpg < MINCYLGRPS)
 341                         break;
 342                 if (CGSIZE(&sblock) < (unsigned long)sblock.fs_bsize)
 343                         continue;
 344                 if (CGSIZE(&sblock) == (unsigned long)sblock.fs_bsize)
 345                         break;
 346                 sblock.fs_fpg -= sblock.fs_frag;
 347                 sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
 348                     INOPB(&sblock));
 349                 break;
 350         }
 351         /*
 352          * Check to be sure that the last cylinder group has enough blocks
 353          * to be viable. If it is too small, reduce the number of blocks
 354          * per cylinder group which will have the effect of moving more
 355          * blocks into the last cylinder group.
 356          */
 357         optimalfpg = sblock.fs_fpg;
 358         for (;;) {
 359                 sblock.fs_ncg = howmany(sblock.fs_size, sblock.fs_fpg);
 360                 lastminfpg = roundup(sblock.fs_iblkno +
 361                     sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
 362                 if (sblock.fs_size < lastminfpg) {
 363                         printf("Filesystem size %jd < minimum size of %d\n",
 364                             (intmax_t)sblock.fs_size, lastminfpg);
 365                         exit(28);
 366                 }
 367                 if (sblock.fs_size % sblock.fs_fpg >= lastminfpg ||
 368                     sblock.fs_size % sblock.fs_fpg == 0)
 369                         break;
 370                 sblock.fs_fpg -= sblock.fs_frag;
 371                 sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
 372                     INOPB(&sblock));
 373         }
 374         if (optimalfpg != sblock.fs_fpg)
 375                 printf("Reduced frags per cylinder group from %d to %d %s\n",
 376                    optimalfpg, sblock.fs_fpg, "to enlarge last cyl group");
 377         sblock.fs_cgsize = fragroundup(&sblock, CGSIZE(&sblock));
 378         sblock.fs_dblkno = sblock.fs_iblkno + sblock.fs_ipg / INOPF(&sblock);
 379         if (Oflag == 1) {
 380                 sblock.fs_old_spc = sblock.fs_fpg * sblock.fs_old_nspf;
 381                 sblock.fs_old_nsect = sblock.fs_old_spc;
 382                 sblock.fs_old_npsect = sblock.fs_old_spc;
 383                 sblock.fs_old_ncyl = sblock.fs_ncg;
 384         }
 385         /*
 386          * fill in remaining fields of the super block
 387          */
 388         sblock.fs_csaddr = cgdmin(&sblock, 0);
 389         sblock.fs_cssize =
 390             fragroundup(&sblock, sblock.fs_ncg * sizeof(struct csum));
 391         fscs = (struct csum *)calloc(1, sblock.fs_cssize);
 392         if (fscs == NULL)
 393                 errx(31, "calloc failed");
 394         sblock.fs_sbsize = fragroundup(&sblock, sizeof(struct fs));
 395         if (sblock.fs_sbsize > SBLOCKSIZE)
 396                 sblock.fs_sbsize = SBLOCKSIZE;
 397         sblock.fs_minfree = minfree;
 398         sblock.fs_maxbpg = maxbpg;
 399         sblock.fs_optim = opt;
 400         sblock.fs_cgrotor = 0;
 401         sblock.fs_pendingblocks = 0;
 402         sblock.fs_pendinginodes = 0;
 403         sblock.fs_fmod = 0;
 404         sblock.fs_ronly = 0;
 405         sblock.fs_state = 0;
 406         sblock.fs_clean = 1;
 407         sblock.fs_id[0] = (long)utime;
 408         sblock.fs_id[1] = newfs_random();
 409         sblock.fs_fsmnt[0] = '\0';
 410         csfrags = howmany(sblock.fs_cssize, sblock.fs_fsize);
 411         sblock.fs_dsize = sblock.fs_size - sblock.fs_sblkno -
 412             sblock.fs_ncg * (sblock.fs_dblkno - sblock.fs_sblkno);
 413         sblock.fs_cstotal.cs_nbfree =
 414             fragstoblks(&sblock, sblock.fs_dsize) -
 415             howmany(csfrags, sblock.fs_frag);
 416         sblock.fs_cstotal.cs_nffree =
 417             fragnum(&sblock, sblock.fs_size) +
 418             (fragnum(&sblock, csfrags) > 0 ?
 419              sblock.fs_frag - fragnum(&sblock, csfrags) : 0);
 420         sblock.fs_cstotal.cs_nifree = sblock.fs_ncg * sblock.fs_ipg - ROOTINO;
 421         sblock.fs_cstotal.cs_ndir = 0;
 422         sblock.fs_dsize -= csfrags;
 423         sblock.fs_time = utime;
 424         if (Oflag == 1) {
 425                 sblock.fs_old_time = utime;
 426                 sblock.fs_old_dsize = sblock.fs_dsize;
 427                 sblock.fs_old_csaddr = sblock.fs_csaddr;
 428                 sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
 429                 sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
 430                 sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
 431                 sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
 432         }
 433
 434         /*
 435          * Dump out summary information about file system.
 436          */
 437 #       define B2MBFACTOR (1 / (1024.0 * 1024.0))
 438         printf("%s: %.1fMB (%jd sectors) block size %d, fragment size %d\n",
 439             fsys, (float)sblock.fs_size * sblock.fs_fsize * B2MBFACTOR,
 440             (intmax_t)fsbtodb(&sblock, sblock.fs_size), sblock.fs_bsize,
 441             sblock.fs_fsize);
 442         printf("\tusing %d cylinder groups of %.2fMB, %d blks, %d inodes.\n",
 443             sblock.fs_ncg, (float)sblock.fs_fpg * sblock.fs_fsize * B2MBFACTOR,
 444             sblock.fs_fpg / sblock.fs_frag, sblock.fs_ipg);
 445         if (sblock.fs_flags & FS_DOSOFTDEP)
 446                 printf("\twith soft updates\n");
 447 #       undef B2MBFACTOR
 448
 449         /*
 450          * Wipe out old UFS1 superblock(s) if necessary.
 451          */
 452         if (!Nflag && Oflag != 1) {
 453                 i = bread(&disk, SBLOCK_UFS1 / disk.d_bsize, chdummy, SBLOCKSIZE);
 454                 if (i == -1)
 455                         err(1, "can't read old UFS1 superblock: %s", disk.d_error);
 456
 457                 if (fsdummy.fs_magic == FS_UFS1_MAGIC) {
 458                         fsdummy.fs_magic = 0;
 459                         bwrite(&disk, SBLOCK_UFS1 / disk.d_bsize, chdummy, SBLOCKSIZE);
 460                         for (i = 0; i < fsdummy.fs_ncg; i++)
 461                                 bwrite(&disk, fsbtodb(&fsdummy, cgsblock(&fsdummy, i)),
 462                             chdummy, SBLOCKSIZE);
 463                 }
 464         }
 465         if (!Nflag)
 466                 sbwrite(&disk, 0);
 467         if (Eflag == 1) {
 468                 printf("** Exiting on Eflag 1\n");
 469                 exit(0);
 470         }
 471         if (Eflag == 2)
 472                 printf("** Leaving BAD MAGIC on Eflag 2\n");
 473         else
 474                 sblock.fs_magic = (Oflag != 1) ? FS_UFS2_MAGIC : FS_UFS1_MAGIC;
 475
 476         /*
 477          * Now build the cylinders group blocks and
 478          * then print out indices of cylinder groups.
 479          */
 480         printf("super-block backups (for fsck -b #) at:\n");
 481         i = 0;
 482         width = charsperline();
 483         /*
 484          * allocate space for superblock, cylinder group map, and
 485          * two sets of inode blocks.
 486          */
 487         if (sblock.fs_bsize < SBLOCKSIZE)
 488                 iobufsize = SBLOCKSIZE + 3 * sblock.fs_bsize;
 489         else
 490                 iobufsize = 4 * sblock.fs_bsize;
 491         if ((iobuf = malloc(iobufsize)) == 0) {
 492                 printf("Cannot allocate I/O buffer\n");
 493                 exit(38);
 494         }
 495         bzero(iobuf, iobufsize);
 496         /*
 497          * Make a copy of the superblock into the buffer that we will be
 498          * writing out in each cylinder group.
 499          */
 500         bcopy((char *)&sblock, iobuf, SBLOCKSIZE);
 501         for (cylno = 0; cylno < sblock.fs_ncg; cylno++) {
 502                 initcg(cylno, utime);
 503                 j = snprintf(tmpbuf, sizeof(tmpbuf), " %jd%s",
 504                     (intmax_t)fsbtodb(&sblock, cgsblock(&sblock, cylno)),
 505                     cylno < (sblock.fs_ncg-1) ? "," : "");
 506                 if (j < 0)
 507                         tmpbuf[j = 0] = '\0';
 508                 if (i + j >= width) {
 509                         printf("\n");
 510                         i = 0;
 511                 }
 512                 i += j;
 513                 printf("%s", tmpbuf);
 514                 fflush(stdout);
 515         }
 516         printf("\n");
 517         if (Nflag)
 518                 exit(0);
 519         /*
 520          * Now construct the initial file system,
 521          * then write out the super-block.
 522          */
 523         fsinit(utime);
 524         if (Oflag == 1) {
 525                 sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
 526                 sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
 527                 sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
 528                 sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
 529         }
 530         if (Eflag == 3) {
 531                 printf("** Exiting on Eflag 3\n");
 532                 exit(0);
 533         }
 534         if (!Nflag)
 535                 sbwrite(&disk, 0);
 536         for (i = 0; i < sblock.fs_cssize; i += sblock.fs_bsize)
 537                 wtfs(fsbtodb(&sblock, sblock.fs_csaddr + numfrags(&sblock, i)),
 538                         sblock.fs_cssize - i < sblock.fs_bsize ?
 539                         sblock.fs_cssize - i : sblock.fs_bsize,
 540                         ((char *)fscs) + i);
 541         /*
 542          * Update information about this partion in pack
 543          * label, to that it may be updated on disk.
 544          */
 545         if (pp != NULL) {
 546                 pp->p_fstype = FS_BSDFFS;
 547                 pp->p_fsize = sblock.fs_fsize;
 548                 pp->p_frag = sblock.fs_frag;
 549                 pp->p_cpg = sblock.fs_fpg;
 550         }
 551 }
 552
 553 /*
 554  * Initialize a cylinder group.
 555  */
 556 void
 557 initcg(int cylno, time_t utime)
 558 {
 559         long i, j, d, dlower, dupper, blkno, start;
 560         ufs2_daddr_t cbase, dmax;
 561         struct ufs1_dinode *dp1;
 562         struct ufs2_dinode *dp2;
 563         struct csum *cs;
 564
 565         /*
 566          * Determine block bounds for cylinder group.
 567          * Allow space for super block summary information in first
 568          * cylinder group.
 569          */
 570         cbase = cgbase(&sblock, cylno);
 571         dmax = cbase + sblock.fs_fpg;
 572         if (dmax > sblock.fs_size)
 573                 dmax = sblock.fs_size;
 574         dlower = cgsblock(&sblock, cylno) - cbase;
 575         dupper = cgdmin(&sblock, cylno) - cbase;
 576         if (cylno == 0)
 577                 dupper += howmany(sblock.fs_cssize, sblock.fs_fsize);
 578         cs = &fscs[cylno];
 579         memset(&acg, 0, sblock.fs_cgsize);
 580         acg.cg_time = utime;
 581         acg.cg_magic = CG_MAGIC;
 582         acg.cg_cgx = cylno;
 583         acg.cg_niblk = sblock.fs_ipg;
 584         acg.cg_initediblk = sblock.fs_ipg < 2 * INOPB(&sblock) ?
 585             sblock.fs_ipg : 2 * INOPB(&sblock);
 586         acg.cg_ndblk = dmax - cbase;
 587         if (sblock.fs_contigsumsize > 0)
 588                 acg.cg_nclusterblks = acg.cg_ndblk / sblock.fs_frag;
 589         start = &acg.cg_space[0] - (u_char *)(&acg.cg_firstfield);
 590         if (Oflag == 2) {
 591                 acg.cg_iusedoff = start;
 592         } else {
 593                 acg.cg_old_ncyl = sblock.fs_old_cpg;
 594                 acg.cg_old_time = acg.cg_time;
 595                 acg.cg_time = 0;
 596                 acg.cg_old_niblk = acg.cg_niblk;
 597                 acg.cg_niblk = 0;
 598                 acg.cg_initediblk = 0;
 599                 acg.cg_old_btotoff = start;
 600                 acg.cg_old_boff = acg.cg_old_btotoff +
 601                     sblock.fs_old_cpg * sizeof(int32_t);
 602                 acg.cg_iusedoff = acg.cg_old_boff +
 603                     sblock.fs_old_cpg * sizeof(u_int16_t);
 604         }
 605         acg.cg_freeoff = acg.cg_iusedoff + howmany(sblock.fs_ipg, CHAR_BIT);
 606         acg.cg_nextfreeoff = acg.cg_freeoff + howmany(sblock.fs_fpg, CHAR_BIT);
 607         if (sblock.fs_contigsumsize > 0) {
 608                 acg.cg_clustersumoff =
 609                     roundup(acg.cg_nextfreeoff, sizeof(u_int32_t));
 610                 acg.cg_clustersumoff -= sizeof(u_int32_t);
 611                 acg.cg_clusteroff = acg.cg_clustersumoff +
 612                     (sblock.fs_contigsumsize + 1) * sizeof(u_int32_t);
 613                 acg.cg_nextfreeoff = acg.cg_clusteroff +
 614                     howmany(fragstoblks(&sblock, sblock.fs_fpg), CHAR_BIT);
 615         }
 616         if (acg.cg_nextfreeoff > sblock.fs_cgsize) {
 617                 printf("Panic: cylinder group too big\n");
 618                 exit(37);
 619         }
 620         acg.cg_cs.cs_nifree += sblock.fs_ipg;
 621         if (cylno == 0)
 622                 for (i = 0; i < (long)ROOTINO; i++) {
 623                         setbit(cg_inosused(&acg), i);
 624                         acg.cg_cs.cs_nifree--;
 625                 }
 626         if (cylno > 0) {
 627                 /*
 628                  * In cylno 0, beginning space is reserved
 629                  * for boot and super blocks.
 630                  */
 631                 for (d = 0; d < dlower; d += sblock.fs_frag) {
 632                         blkno = d / sblock.fs_frag;
 633                         setblock(&sblock, cg_blksfree(&acg), blkno);
 634                         if (sblock.fs_contigsumsize > 0)
 635                                 setbit(cg_clustersfree(&acg), blkno);
 636                         acg.cg_cs.cs_nbfree++;
 637                 }
 638         }
 639         if ((i = dupper % sblock.fs_frag)) {
 640                 acg.cg_frsum[sblock.fs_frag - i]++;
 641                 for (d = dupper + sblock.fs_frag - i; dupper < d; dupper++) {
 642                         setbit(cg_blksfree(&acg), dupper);
 643                         acg.cg_cs.cs_nffree++;
 644                 }
 645         }
 646         for (d = dupper; d + sblock.fs_frag <= acg.cg_ndblk;
 647              d += sblock.fs_frag) {
 648                 blkno = d / sblock.fs_frag;
 649                 setblock(&sblock, cg_blksfree(&acg), blkno);
 650                 if (sblock.fs_contigsumsize > 0)
 651                         setbit(cg_clustersfree(&acg), blkno);
 652                 acg.cg_cs.cs_nbfree++;
 653         }
 654         if (d < acg.cg_ndblk) {
 655                 acg.cg_frsum[acg.cg_ndblk - d]++;
 656                 for (; d < acg.cg_ndblk; d++) {
 657                         setbit(cg_blksfree(&acg), d);
 658                         acg.cg_cs.cs_nffree++;
 659                 }
 660         }
 661         if (sblock.fs_contigsumsize > 0) {
 662                 int32_t *sump = cg_clustersum(&acg);
 663                 u_char *mapp = cg_clustersfree(&acg);
 664                 int map = *mapp++;
 665                 int bit = 1;
 666                 int run = 0;
 667
 668                 for (i = 0; i < acg.cg_nclusterblks; i++) {
 669                         if ((map & bit) != 0)
 670                                 run++;
 671                         else if (run != 0) {
 672                                 if (run > sblock.fs_contigsumsize)
 673                                         run = sblock.fs_contigsumsize;
 674                                 sump[run]++;
 675                                 run = 0;
 676                         }
 677                         if ((i & (CHAR_BIT - 1)) != CHAR_BIT - 1)
 678                                 bit <<= 1;
 679                         else {
 680                                 map = *mapp++;
 681                                 bit = 1;
 682                         }
 683                 }
 684                 if (run != 0) {
 685                         if (run > sblock.fs_contigsumsize)
 686                                 run = sblock.fs_contigsumsize;
 687                         sump[run]++;
 688                 }
 689         }
 690         *cs = acg.cg_cs;
 691         /*
 692          * Write out the duplicate super block, the cylinder group map
 693          * and two blocks worth of inodes in a single write.
 694          */
 695         start = sblock.fs_bsize > SBLOCKSIZE ? sblock.fs_bsize : SBLOCKSIZE;
 696         bcopy((char *)&acg, &iobuf[start], sblock.fs_cgsize);
 697         start += sblock.fs_bsize;
 698         dp1 = (struct ufs1_dinode *)(&iobuf[start]);
 699         dp2 = (struct ufs2_dinode *)(&iobuf[start]);
 700         for (i = 0; i < acg.cg_initediblk; i++) {
 701                 if (sblock.fs_magic == FS_UFS1_MAGIC) {
 702                         dp1->di_gen = newfs_random();
 703                         dp1++;
 704                 } else {
 705                         dp2->di_gen = newfs_random();
 706                         dp2++;
 707                 }
 708         }
 709         wtfs(fsbtodb(&sblock, cgsblock(&sblock, cylno)), iobufsize, iobuf);
 710         /*
 711          * For the old file system, we have to initialize all the inodes.
 712          */
 713         if (Oflag == 1) {
 714                 for (i = 2 * sblock.fs_frag;
 715                      i < sblock.fs_ipg / INOPF(&sblock);
 716                      i += sblock.fs_frag) {
 717                         dp1 = (struct ufs1_dinode *)(&iobuf[start]);
 718                         for (j = 0; j < INOPB(&sblock); j++) {
 719                                 dp1->di_gen = newfs_random();
 720                                 dp1++;
 721                         }
 722                         wtfs(fsbtodb(&sblock, cgimin(&sblock, cylno) + i),
 723                             sblock.fs_bsize, &iobuf[start]);
 724                 }
 725         }
 726 }
 727
 728 /*
 729  * initialize the file system
 730  */
 731 #define ROOTLINKCNT 3
 732
 733 struct direct root_dir[] = {
 734         { ROOTINO, sizeof(struct direct), DT_DIR, 1, "." },
 735         { ROOTINO, sizeof(struct direct), DT_DIR, 2, ".." },
 736         { ROOTINO + 1, sizeof(struct direct), DT_DIR, 5, ".snap" },
 737 };
 738
 739 #define SNAPLINKCNT 2
 740
 741 struct direct snap_dir[] = {
 742         { ROOTINO + 1, sizeof(struct direct), DT_DIR, 1, "." },
 743         { ROOTINO, sizeof(struct direct), DT_DIR, 2, ".." },
 744 };
 745
 746 void
 747 fsinit(time_t utime)
 748 {
 749         union dinode node;
 750         struct group *grp;
 751         gid_t gid;
 752         int entries;
 753
 754         memset(&node, 0, sizeof node);
 755         if ((grp = getgrnam("operator")) != NULL) {
 756                 gid = grp->gr_gid;
 757         } else {
 758                 warnx("Cannot retrieve operator gid.");
 759                 gid = 0;
 760         }
 761         entries = (nflag) ? ROOTLINKCNT - 1: ROOTLINKCNT;
 762         if (sblock.fs_magic == FS_UFS1_MAGIC) {
 763                 /*
 764                  * initialize the node
 765                  */
 766                 node.dp1.di_atime = utime;
 767                 node.dp1.di_mtime = utime;
 768                 node.dp1.di_ctime = utime;
 769                 /*
 770                  * create the root directory
 771                  */
 772                 node.dp1.di_mode = IFDIR | UMASK;
 773                 node.dp1.di_nlink = entries;
 774                 node.dp1.di_size = makedir(root_dir, entries);
 775                 node.dp1.di_db[0] = alloc(sblock.fs_fsize, node.dp1.di_mode);
 776                 node.dp1.di_blocks =
 777                     btodb(fragroundup(&sblock, node.dp1.di_size));
 778                 wtfs(fsbtodb(&sblock, node.dp1.di_db[0]), sblock.fs_fsize,
 779                     iobuf);
 780                 iput(&node, ROOTINO);
 781                 if (!nflag) {
 782                         /*
 783                          * create the .snap directory
 784                          */
 785                         node.dp1.di_mode |= 020;
 786                         node.dp1.di_gid = gid;
 787                         node.dp1.di_nlink = SNAPLINKCNT;
 788                         node.dp1.di_size = makedir(snap_dir, SNAPLINKCNT);
 789                                 node.dp1.di_db[0] =
 790                                     alloc(sblock.fs_fsize, node.dp1.di_mode);
 791                         node.dp1.di_blocks =
 792                             btodb(fragroundup(&sblock, node.dp1.di_size));
 793                                 wtfs(fsbtodb(&sblock, node.dp1.di_db[0]),
 794                                     sblock.fs_fsize, iobuf);
 795                         iput(&node, ROOTINO + 1);
 796                 }
 797         } else {
 798                 /*
 799                  * initialize the node
 800                  */
 801                 node.dp2.di_atime = utime;
 802                 node.dp2.di_mtime = utime;
 803                 node.dp2.di_ctime = utime;
 804                 node.dp2.di_birthtime = utime;
 805                 /*
 806                  * create the root directory
 807                  */
 808                 node.dp2.di_mode = IFDIR | UMASK;
 809                 node.dp2.di_nlink = entries;
 810                 node.dp2.di_size = makedir(root_dir, entries);
 811                 node.dp2.di_db[0] = alloc(sblock.fs_fsize, node.dp2.di_mode);
 812                 node.dp2.di_blocks =
 813                     btodb(fragroundup(&sblock, node.dp2.di_size));
 814                 wtfs(fsbtodb(&sblock, node.dp2.di_db[0]), sblock.fs_fsize,
 815                     iobuf);
 816                 iput(&node, ROOTINO);
 817                 if (!nflag) {
 818                         /*
 819                          * create the .snap directory
 820                          */
 821                         node.dp2.di_mode |= 020;
 822                         node.dp2.di_gid = gid;
 823                         node.dp2.di_nlink = SNAPLINKCNT;
 824                         node.dp2.di_size = makedir(snap_dir, SNAPLINKCNT);
 825                                 node.dp2.di_db[0] =
 826                                     alloc(sblock.fs_fsize, node.dp2.di_mode);
 827                         node.dp2.di_blocks =
 828                             btodb(fragroundup(&sblock, node.dp2.di_size));
 829                                 wtfs(fsbtodb(&sblock, node.dp2.di_db[0]),
 830                                     sblock.fs_fsize, iobuf);
 831                         iput(&node, ROOTINO + 1);
 832                 }
 833         }
 834 }
 835
 836 /*
 837  * construct a set of directory entries in "iobuf".
 838  * return size of directory.
 839  */
 840 int
 841 makedir(struct direct *protodir, int entries)
 842 {
 843         char *cp;
 844         int i, spcleft;
 845
 846         spcleft = DIRBLKSIZ;
 847         memset(iobuf, 0, DIRBLKSIZ);
 848         for (cp = iobuf, i = 0; i < entries - 1; i++) {
 849                 protodir[i].d_reclen = DIRSIZ(0, &protodir[i]);
 850                 memmove(cp, &protodir[i], protodir[i].d_reclen);
 851                 cp += protodir[i].d_reclen;
 852                 spcleft -= protodir[i].d_reclen;
 853         }
 854         protodir[i].d_reclen = spcleft;
 855         memmove(cp, &protodir[i], DIRSIZ(0, &protodir[i]));
 856         return (DIRBLKSIZ);
 857 }
 858
 859 /*
 860  * allocate a block or frag
 861  */
 862 ufs2_daddr_t
 863 alloc(int size, int mode)
 864 {
 865         int i, d, blkno, frag;
 866
 867         bread(&disk, fsbtodb(&sblock, cgtod(&sblock, 0)), (char *)&acg,
 868             sblock.fs_cgsize);
 869         if (acg.cg_magic != CG_MAGIC) {
 870                 printf("cg 0: bad magic number\n");
 871                 exit(38);
 872         }
 873         if (acg.cg_cs.cs_nbfree == 0) {
 874                 printf("first cylinder group ran out of space\n");
 875                 exit(39);
 876         }
 877         for (d = 0; d < acg.cg_ndblk; d += sblock.fs_frag)
 878                 if (isblock(&sblock, cg_blksfree(&acg), d / sblock.fs_frag))
 879                         goto goth;
 880         printf("internal error: can't find block in cyl 0\n");
 881         exit(40);
 882 goth:
 883         blkno = fragstoblks(&sblock, d);
 884         clrblock(&sblock, cg_blksfree(&acg), blkno);
 885         if (sblock.fs_contigsumsize > 0)
 886                 clrbit(cg_clustersfree(&acg), blkno);
 887         acg.cg_cs.cs_nbfree--;
 888         sblock.fs_cstotal.cs_nbfree--;
 889         fscs[0].cs_nbfree--;
 890         if (mode & IFDIR) {
 891                 acg.cg_cs.cs_ndir++;
 892                 sblock.fs_cstotal.cs_ndir++;
 893                 fscs[0].cs_ndir++;
 894         }
 895         if (size != sblock.fs_bsize) {
 896                 frag = howmany(size, sblock.fs_fsize);
 897                 fscs[0].cs_nffree += sblock.fs_frag - frag;
 898                 sblock.fs_cstotal.cs_nffree += sblock.fs_frag - frag;
 899                 acg.cg_cs.cs_nffree += sblock.fs_frag - frag;
 900                 acg.cg_frsum[sblock.fs_frag - frag]++;
 901                 for (i = frag; i < sblock.fs_frag; i++)
 902                         setbit(cg_blksfree(&acg), d + i);
 903         }
 904         /* XXX cgwrite(&disk, 0)??? */
 905         wtfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
 906             (char *)&acg);
 907         return ((ufs2_daddr_t)d);
 908 }
 909
 910 /*
 911  * Allocate an inode on the disk
 912  */
 913 void
 914 iput(union dinode *ip, ino_t ino)
 915 {
 916         ufs2_daddr_t d;
 917         int c;
 918
 919         c = ino_to_cg(&sblock, ino);
 920         bread(&disk, fsbtodb(&sblock, cgtod(&sblock, 0)), (char *)&acg,
 921             sblock.fs_cgsize);
 922         if (acg.cg_magic != CG_MAGIC) {
 923                 printf("cg 0: bad magic number\n");
 924                 exit(31);
 925         }
 926         acg.cg_cs.cs_nifree--;
 927         setbit(cg_inosused(&acg), ino);
 928         wtfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
 929             (char *)&acg);
 930         sblock.fs_cstotal.cs_nifree--;
 931         fscs[0].cs_nifree--;
 932         if (ino >= (unsigned long)sblock.fs_ipg * sblock.fs_ncg) {
 933                 printf("fsinit: inode value out of range (%d).\n", ino);
 934                 exit(32);
 935         }
 936         d = fsbtodb(&sblock, ino_to_fsba(&sblock, ino));
 937         bread(&disk, d, (char *)iobuf, sblock.fs_bsize);
 938         if (sblock.fs_magic == FS_UFS1_MAGIC)
 939                 ((struct ufs1_dinode *)iobuf)[ino_to_fsbo(&sblock, ino)] =
 940                     ip->dp1;
 941         else
 942                 ((struct ufs2_dinode *)iobuf)[ino_to_fsbo(&sblock, ino)] =
 943                     ip->dp2;
 944         wtfs(d, sblock.fs_bsize, (char *)iobuf);
 945 }
 946
 947 /*
 948  * possibly write to disk
 949  */
 950 static void
 951 wtfs(ufs2_daddr_t bno, int size, char *bf)
 952 {
 953         if (Nflag)
 954                 return;
 955         if (bwrite(&disk, bno, bf, size) < 0)
 956                 err(36, "wtfs: %d bytes at sector %jd", size, (intmax_t)bno);
 957 }
 958
 959 /*
 960  * check if a block is available
 961  */
 962 static int
 963 isblock(struct fs *fs, unsigned char *cp, int h)
 964 {
 965         unsigned char mask;
 966
 967         switch (fs->fs_frag) {
 968         case 8:
 969                 return (cp[h] == 0xff);
 970         case 4:
 971                 mask = 0x0f << ((h & 0x1) << 2);
 972                 return ((cp[h >> 1] & mask) == mask);
 973         case 2:
 974                 mask = 0x03 << ((h & 0x3) << 1);
 975                 return ((cp[h >> 2] & mask) == mask);
 976         case 1:
 977                 mask = 0x01 << (h & 0x7);
 978                 return ((cp[h >> 3] & mask) == mask);
 979         default:
 980                 fprintf(stderr, "isblock bad fs_frag %d\n", fs->fs_frag);
 981                 return (0);
 982         }
 983 }
 984
 985 /*
 986  * take a block out of the map
 987  */
 988 static void
 989 clrblock(struct fs *fs, unsigned char *cp, int h)
 990 {
 991         switch ((fs)->fs_frag) {
 992         case 8:
 993                 cp[h] = 0;
 994                 return;
 995         case 4:
 996                 cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
 997                 return;
 998         case 2:
 999                 cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
1000                 return;
1001         case 1:
1002                 cp[h >> 3] &= ~(0x01 << (h & 0x7));
1003                 return;
1004         default:
1005                 fprintf(stderr, "clrblock bad fs_frag %d\n", fs->fs_frag);
1006                 return;
1007         }
1008 }
1009
1010 /*
1011  * put a block into the map
1012  */
1013 static void
1014 setblock(struct fs *fs, unsigned char *cp, int h)
1015 {
1016         switch (fs->fs_frag) {
1017         case 8:
1018                 cp[h] = 0xff;
1019                 return;
1020         case 4:
1021                 cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
1022                 return;
1023         case 2:
1024                 cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
1025                 return;
1026         case 1:
1027                 cp[h >> 3] |= (0x01 << (h & 0x7));
1028                 return;
1029         default:
1030                 fprintf(stderr, "setblock bad fs_frag %d\n", fs->fs_frag);
1031                 return;
1032         }
1033 }
1034
1035 /*
1036  * Determine the number of characters in a
1037  * single line.
1038  */
1039
1040 static int
1041 charsperline(void)
1042 {
1043         int columns;
1044         char *cp;
1045         struct winsize ws;
1046
1047         columns = 0;
1048         if (ioctl(0, TIOCGWINSZ, &ws) != -1)
1049                 columns = ws.ws_col;
1050         if (columns == 0 && (cp = getenv("COLUMNS")))
1051                 columns = atoi(cp);
1052         if (columns == 0)
1053                 columns = 80;   /* last resort */
1054         return (columns);
1055 }
1056
1057 static int
1058 ilog2(int val)
1059 {
1060         u_int n;
1061
1062         for (n = 0; n < sizeof(n) * CHAR_BIT; n++)
1063                 if (1 << n == val)
1064                         return (n);
1065         errx(1, "ilog2: %d is not a power of 2\n", val);
1066 }
1067
1068 /*
1069  * For the regression test, return predictable random values.
1070  * Otherwise use a true random number generator.
1071  */
1072 static u_int32_t
1073 newfs_random(void)
1074 {
1075         static int nextnum = 1;
1076
1077         if (Rflag)
1078                 return (nextnum++);
1079         return (arc4random());
1080 }