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 (Jflag)
 139                 sblock.fs_flags |= FS_GJOURNAL;
 140         if (lflag)
 141                 sblock.fs_flags |= FS_MULTILABEL;
 142         /*
 143          * Validate the given file system size.
 144          * Verify that its last block can actually be accessed.
 145          * Convert to file system fragment sized units.
 146          */
 147         if (fssize <= 0) {
 148                 printf("preposterous size %jd\n", (intmax_t)fssize);
 149                 exit(13);
 150         }
 151         wtfs(fssize - (realsectorsize / DEV_BSIZE), realsectorsize,
 152             (char *)&sblock);
 153         /*
 154          * collect and verify the file system density info
 155          */
 156         sblock.fs_avgfilesize = avgfilesize;
 157         sblock.fs_avgfpdir = avgfilesperdir;
 158         if (sblock.fs_avgfilesize <= 0)
 159                 printf("illegal expected average file size %d\n",
 160                     sblock.fs_avgfilesize), exit(14);
 161         if (sblock.fs_avgfpdir <= 0)
 162                 printf("illegal expected number of files per directory %d\n",
 163                     sblock.fs_avgfpdir), exit(15);
 164         /*
 165          * collect and verify the block and fragment sizes
 166          */
 167         sblock.fs_bsize = bsize;
 168         sblock.fs_fsize = fsize;
 169         if (!POWEROF2(sblock.fs_bsize)) {
 170                 printf("block size must be a power of 2, not %d\n",
 171                     sblock.fs_bsize);
 172                 exit(16);
 173         }
 174         if (!POWEROF2(sblock.fs_fsize)) {
 175                 printf("fragment size must be a power of 2, not %d\n",
 176                     sblock.fs_fsize);
 177                 exit(17);
 178         }
 179         if (sblock.fs_fsize < sectorsize) {
 180                 printf("increasing fragment size from %d to sector size (%d)\n",
 181                     sblock.fs_fsize, sectorsize);
 182                 sblock.fs_fsize = sectorsize;
 183         }
 184         if (sblock.fs_bsize > MAXBSIZE) {
 185                 printf("decreasing block size from %d to maximum (%d)\n",
 186                     sblock.fs_bsize, MAXBSIZE);
 187                 sblock.fs_bsize = MAXBSIZE;
 188         }
 189         if (sblock.fs_bsize < MINBSIZE) {
 190                 printf("increasing block size from %d to minimum (%d)\n",
 191                     sblock.fs_bsize, MINBSIZE);
 192                 sblock.fs_bsize = MINBSIZE;
 193         }
 194         if (sblock.fs_fsize > MAXBSIZE) {
 195                 printf("decreasing fragment size from %d to maximum (%d)\n",
 196                     sblock.fs_fsize, MAXBSIZE);
 197                 sblock.fs_fsize = MAXBSIZE;
 198         }
 199         if (sblock.fs_bsize < sblock.fs_fsize) {
 200                 printf("increasing block size from %d to fragment size (%d)\n",
 201                     sblock.fs_bsize, sblock.fs_fsize);
 202                 sblock.fs_bsize = sblock.fs_fsize;
 203         }
 204         if (sblock.fs_fsize * MAXFRAG < sblock.fs_bsize) {
 205                 printf(
 206                 "increasing fragment size from %d to block size / %d (%d)\n",
 207                     sblock.fs_fsize, MAXFRAG, sblock.fs_bsize / MAXFRAG);
 208                 sblock.fs_fsize = sblock.fs_bsize / MAXFRAG;
 209         }
 210         if (maxbsize < bsize || !POWEROF2(maxbsize)) {
 211                 sblock.fs_maxbsize = sblock.fs_bsize;
 212                 printf("Extent size set to %d\n", sblock.fs_maxbsize);
 213         } else if (sblock.fs_maxbsize > FS_MAXCONTIG * sblock.fs_bsize) {
 214                 sblock.fs_maxbsize = FS_MAXCONTIG * sblock.fs_bsize;
 215                 printf("Extent size reduced to %d\n", sblock.fs_maxbsize);
 216         } else {
 217                 sblock.fs_maxbsize = maxbsize;
 218         }
 219         sblock.fs_maxcontig = maxcontig;
 220         if (sblock.fs_maxcontig < sblock.fs_maxbsize / sblock.fs_bsize) {
 221                 sblock.fs_maxcontig = sblock.fs_maxbsize / sblock.fs_bsize;
 222                 printf("Maxcontig raised to %d\n", sblock.fs_maxbsize);
 223         }
 224         if (sblock.fs_maxcontig > 1)
 225                 sblock.fs_contigsumsize = MIN(sblock.fs_maxcontig,FS_MAXCONTIG);
 226         sblock.fs_bmask = ~(sblock.fs_bsize - 1);
 227         sblock.fs_fmask = ~(sblock.fs_fsize - 1);
 228         sblock.fs_qbmask = ~sblock.fs_bmask;
 229         sblock.fs_qfmask = ~sblock.fs_fmask;
 230         sblock.fs_bshift = ilog2(sblock.fs_bsize);
 231         sblock.fs_fshift = ilog2(sblock.fs_fsize);
 232         sblock.fs_frag = numfrags(&sblock, sblock.fs_bsize);
 233         sblock.fs_fragshift = ilog2(sblock.fs_frag);
 234         if (sblock.fs_frag > MAXFRAG) {
 235                 printf("fragment size %d is still too small (can't happen)\n",
 236                     sblock.fs_bsize / MAXFRAG);
 237                 exit(21);
 238         }
 239         sblock.fs_fsbtodb = ilog2(sblock.fs_fsize / sectorsize);
 240         sblock.fs_size = fssize = dbtofsb(&sblock, fssize);
 241
 242         /*
 243          * Before the filesystem is finally initialized, mark it
 244          * as incompletely initialized.
 245          */
 246         sblock.fs_magic = FS_BAD_MAGIC;
 247
 248         if (Oflag == 1) {
 249                 sblock.fs_sblockloc = SBLOCK_UFS1;
 250                 sblock.fs_nindir = sblock.fs_bsize / sizeof(ufs1_daddr_t);
 251                 sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs1_dinode);
 252                 sblock.fs_maxsymlinklen = ((NDADDR + NIADDR) *
 253                     sizeof(ufs1_daddr_t));
 254                 sblock.fs_old_inodefmt = FS_44INODEFMT;
 255                 sblock.fs_old_cgoffset = 0;
 256                 sblock.fs_old_cgmask = 0xffffffff;
 257                 sblock.fs_old_size = sblock.fs_size;
 258                 sblock.fs_old_rotdelay = 0;
 259                 sblock.fs_old_rps = 60;
 260                 sblock.fs_old_nspf = sblock.fs_fsize / sectorsize;
 261                 sblock.fs_old_cpg = 1;
 262                 sblock.fs_old_interleave = 1;
 263                 sblock.fs_old_trackskew = 0;
 264                 sblock.fs_old_cpc = 0;
 265                 sblock.fs_old_postblformat = 1;
 266                 sblock.fs_old_nrpos = 1;
 267         } else {
 268                 sblock.fs_sblockloc = SBLOCK_UFS2;
 269                 sblock.fs_nindir = sblock.fs_bsize / sizeof(ufs2_daddr_t);
 270                 sblock.fs_inopb = sblock.fs_bsize / sizeof(struct ufs2_dinode);
 271                 sblock.fs_maxsymlinklen = ((NDADDR + NIADDR) *
 272                     sizeof(ufs2_daddr_t));
 273         }
 274         sblock.fs_sblkno =
 275             roundup(howmany(sblock.fs_sblockloc + SBLOCKSIZE, sblock.fs_fsize),
 276                 sblock.fs_frag);
 277         sblock.fs_cblkno = sblock.fs_sblkno +
 278             roundup(howmany(SBLOCKSIZE, sblock.fs_fsize), sblock.fs_frag);
 279         sblock.fs_iblkno = sblock.fs_cblkno + sblock.fs_frag;
 280         sblock.fs_maxfilesize = sblock.fs_bsize * NDADDR - 1;
 281         for (sizepb = sblock.fs_bsize, i = 0; i < NIADDR; i++) {
 282                 sizepb *= NINDIR(&sblock);
 283                 sblock.fs_maxfilesize += sizepb;
 284         }
 285
 286         /*
 287          * It's impossible to create a snapshot in case that fs_maxfilesize
 288          * is smaller than the fssize.
 289          */
 290         if (sblock.fs_maxfilesize < (u_quad_t)fssize) {
 291                 warnx("WARNING: You will be unable to create snapshots on this "
 292                       "file system.  Correct by using a larger blocksize.");
 293         }
 294
 295         /*
 296          * Calculate the number of blocks to put into each cylinder group.
 297          *
 298          * This algorithm selects the number of blocks per cylinder
 299          * group. The first goal is to have at least enough data blocks
 300          * in each cylinder group to meet the density requirement. Once
 301          * this goal is achieved we try to expand to have at least
 302          * MINCYLGRPS cylinder groups. Once this goal is achieved, we
 303          * pack as many blocks into each cylinder group map as will fit.
 304          *
 305          * We start by calculating the smallest number of blocks that we
 306          * can put into each cylinder group. If this is too big, we reduce
 307          * the density until it fits.
 308          */
 309         origdensity = density;
 310         for (;;) {
 311                 fragsperinode = MAX(numfrags(&sblock, density), 1);
 312                 minfpg = fragsperinode * INOPB(&sblock);
 313                 if (minfpg > sblock.fs_size)
 314                         minfpg = sblock.fs_size;
 315                 sblock.fs_ipg = INOPB(&sblock);
 316                 sblock.fs_fpg = roundup(sblock.fs_iblkno +
 317                     sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
 318                 if (sblock.fs_fpg < minfpg)
 319                         sblock.fs_fpg = minfpg;
 320                 sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
 321                     INOPB(&sblock));
 322                 sblock.fs_fpg = roundup(sblock.fs_iblkno +
 323                     sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
 324                 if (sblock.fs_fpg < minfpg)
 325                         sblock.fs_fpg = minfpg;
 326                 sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
 327                     INOPB(&sblock));
 328                 if (CGSIZE(&sblock) < (unsigned long)sblock.fs_bsize)
 329                         break;
 330                 density -= sblock.fs_fsize;
 331         }
 332         if (density != origdensity)
 333                 printf("density reduced from %d to %d\n", origdensity, density);
 334         /*
 335          * Start packing more blocks into the cylinder group until
 336          * it cannot grow any larger, the number of cylinder groups
 337          * drops below MINCYLGRPS, or we reach the size requested.
 338          */
 339         for ( ; sblock.fs_fpg < maxblkspercg; sblock.fs_fpg += sblock.fs_frag) {
 340                 sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
 341                     INOPB(&sblock));
 342                 if (sblock.fs_size / sblock.fs_fpg < MINCYLGRPS)
 343                         break;
 344                 if (CGSIZE(&sblock) < (unsigned long)sblock.fs_bsize)
 345                         continue;
 346                 if (CGSIZE(&sblock) == (unsigned long)sblock.fs_bsize)
 347                         break;
 348                 sblock.fs_fpg -= sblock.fs_frag;
 349                 sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
 350                     INOPB(&sblock));
 351                 break;
 352         }
 353         /*
 354          * Check to be sure that the last cylinder group has enough blocks
 355          * to be viable. If it is too small, reduce the number of blocks
 356          * per cylinder group which will have the effect of moving more
 357          * blocks into the last cylinder group.
 358          */
 359         optimalfpg = sblock.fs_fpg;
 360         for (;;) {
 361                 sblock.fs_ncg = howmany(sblock.fs_size, sblock.fs_fpg);
 362                 lastminfpg = roundup(sblock.fs_iblkno +
 363                     sblock.fs_ipg / INOPF(&sblock), sblock.fs_frag);
 364                 if (sblock.fs_size < lastminfpg) {
 365                         printf("Filesystem size %jd < minimum size of %d\n",
 366                             (intmax_t)sblock.fs_size, lastminfpg);
 367                         exit(28);
 368                 }
 369                 if (sblock.fs_size % sblock.fs_fpg >= lastminfpg ||
 370                     sblock.fs_size % sblock.fs_fpg == 0)
 371                         break;
 372                 sblock.fs_fpg -= sblock.fs_frag;
 373                 sblock.fs_ipg = roundup(howmany(sblock.fs_fpg, fragsperinode),
 374                     INOPB(&sblock));
 375         }
 376         if (optimalfpg != sblock.fs_fpg)
 377                 printf("Reduced frags per cylinder group from %d to %d %s\n",
 378                    optimalfpg, sblock.fs_fpg, "to enlarge last cyl group");
 379         sblock.fs_cgsize = fragroundup(&sblock, CGSIZE(&sblock));
 380         sblock.fs_dblkno = sblock.fs_iblkno + sblock.fs_ipg / INOPF(&sblock);
 381         if (Oflag == 1) {
 382                 sblock.fs_old_spc = sblock.fs_fpg * sblock.fs_old_nspf;
 383                 sblock.fs_old_nsect = sblock.fs_old_spc;
 384                 sblock.fs_old_npsect = sblock.fs_old_spc;
 385                 sblock.fs_old_ncyl = sblock.fs_ncg;
 386         }
 387         /*
 388          * fill in remaining fields of the super block
 389          */
 390         sblock.fs_csaddr = cgdmin(&sblock, 0);
 391         sblock.fs_cssize =
 392             fragroundup(&sblock, sblock.fs_ncg * sizeof(struct csum));
 393         fscs = (struct csum *)calloc(1, sblock.fs_cssize);
 394         if (fscs == NULL)
 395                 errx(31, "calloc failed");
 396         sblock.fs_sbsize = fragroundup(&sblock, sizeof(struct fs));
 397         if (sblock.fs_sbsize > SBLOCKSIZE)
 398                 sblock.fs_sbsize = SBLOCKSIZE;
 399         sblock.fs_minfree = minfree;
 400         sblock.fs_maxbpg = maxbpg;
 401         sblock.fs_optim = opt;
 402         sblock.fs_cgrotor = 0;
 403         sblock.fs_pendingblocks = 0;
 404         sblock.fs_pendinginodes = 0;
 405         sblock.fs_fmod = 0;
 406         sblock.fs_ronly = 0;
 407         sblock.fs_state = 0;
 408         sblock.fs_clean = 1;
 409         sblock.fs_id[0] = (long)utime;
 410         sblock.fs_id[1] = newfs_random();
 411         sblock.fs_fsmnt[0] = '\0';
 412         csfrags = howmany(sblock.fs_cssize, sblock.fs_fsize);
 413         sblock.fs_dsize = sblock.fs_size - sblock.fs_sblkno -
 414             sblock.fs_ncg * (sblock.fs_dblkno - sblock.fs_sblkno);
 415         sblock.fs_cstotal.cs_nbfree =
 416             fragstoblks(&sblock, sblock.fs_dsize) -
 417             howmany(csfrags, sblock.fs_frag);
 418         sblock.fs_cstotal.cs_nffree =
 419             fragnum(&sblock, sblock.fs_size) +
 420             (fragnum(&sblock, csfrags) > 0 ?
 421              sblock.fs_frag - fragnum(&sblock, csfrags) : 0);
 422         sblock.fs_cstotal.cs_nifree = sblock.fs_ncg * sblock.fs_ipg - ROOTINO;
 423         sblock.fs_cstotal.cs_ndir = 0;
 424         sblock.fs_dsize -= csfrags;
 425         sblock.fs_time = utime;
 426         if (Oflag == 1) {
 427                 sblock.fs_old_time = utime;
 428                 sblock.fs_old_dsize = sblock.fs_dsize;
 429                 sblock.fs_old_csaddr = sblock.fs_csaddr;
 430                 sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
 431                 sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
 432                 sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
 433                 sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
 434         }
 435
 436         /*
 437          * Dump out summary information about file system.
 438          */
 439 #       define B2MBFACTOR (1 / (1024.0 * 1024.0))
 440         printf("%s: %.1fMB (%jd sectors) block size %d, fragment size %d\n",
 441             fsys, (float)sblock.fs_size * sblock.fs_fsize * B2MBFACTOR,
 442             (intmax_t)fsbtodb(&sblock, sblock.fs_size), sblock.fs_bsize,
 443             sblock.fs_fsize);
 444         printf("\tusing %d cylinder groups of %.2fMB, %d blks, %d inodes.\n",
 445             sblock.fs_ncg, (float)sblock.fs_fpg * sblock.fs_fsize * B2MBFACTOR,
 446             sblock.fs_fpg / sblock.fs_frag, sblock.fs_ipg);
 447         if (sblock.fs_flags & FS_DOSOFTDEP)
 448                 printf("\twith soft updates\n");
 449 #       undef B2MBFACTOR
 450
 451         /*
 452          * Wipe out old UFS1 superblock(s) if necessary.
 453          */
 454         if (!Nflag && Oflag != 1) {
 455                 i = bread(&disk, SBLOCK_UFS1 / disk.d_bsize, chdummy, SBLOCKSIZE);
 456                 if (i == -1)
 457                         err(1, "can't read old UFS1 superblock: %s", disk.d_error);
 458
 459                 if (fsdummy.fs_magic == FS_UFS1_MAGIC) {
 460                         fsdummy.fs_magic = 0;
 461                         bwrite(&disk, SBLOCK_UFS1 / disk.d_bsize, chdummy, SBLOCKSIZE);
 462                         for (i = 0; i < fsdummy.fs_ncg; i++)
 463                                 bwrite(&disk, fsbtodb(&fsdummy, cgsblock(&fsdummy, i)),
 464                             chdummy, SBLOCKSIZE);
 465                 }
 466         }
 467         if (!Nflag)
 468                 sbwrite(&disk, 0);
 469         if (Eflag == 1) {
 470                 printf("** Exiting on Eflag 1\n");
 471                 exit(0);
 472         }
 473         if (Eflag == 2)
 474                 printf("** Leaving BAD MAGIC on Eflag 2\n");
 475         else
 476                 sblock.fs_magic = (Oflag != 1) ? FS_UFS2_MAGIC : FS_UFS1_MAGIC;
 477
 478         /*
 479          * Now build the cylinders group blocks and
 480          * then print out indices of cylinder groups.
 481          */
 482         printf("super-block backups (for fsck -b #) at:\n");
 483         i = 0;
 484         width = charsperline();
 485         /*
 486          * allocate space for superblock, cylinder group map, and
 487          * two sets of inode blocks.
 488          */
 489         if (sblock.fs_bsize < SBLOCKSIZE)
 490                 iobufsize = SBLOCKSIZE + 3 * sblock.fs_bsize;
 491         else
 492                 iobufsize = 4 * sblock.fs_bsize;
 493         if ((iobuf = malloc(iobufsize)) == 0) {
 494                 printf("Cannot allocate I/O buffer\n");
 495                 exit(38);
 496         }
 497         bzero(iobuf, iobufsize);
 498         /*
 499          * Make a copy of the superblock into the buffer that we will be
 500          * writing out in each cylinder group.
 501          */
 502         bcopy((char *)&sblock, iobuf, SBLOCKSIZE);
 503         for (cylno = 0; cylno < sblock.fs_ncg; cylno++) {
 504                 initcg(cylno, utime);
 505                 j = snprintf(tmpbuf, sizeof(tmpbuf), " %jd%s",
 506                     (intmax_t)fsbtodb(&sblock, cgsblock(&sblock, cylno)),
 507                     cylno < (sblock.fs_ncg-1) ? "," : "");
 508                 if (j < 0)
 509                         tmpbuf[j = 0] = '\0';
 510                 if (i + j >= width) {
 511                         printf("\n");
 512                         i = 0;
 513                 }
 514                 i += j;
 515                 printf("%s", tmpbuf);
 516                 fflush(stdout);
 517         }
 518         printf("\n");
 519         if (Nflag)
 520                 exit(0);
 521         /*
 522          * Now construct the initial file system,
 523          * then write out the super-block.
 524          */
 525         fsinit(utime);
 526         if (Oflag == 1) {
 527                 sblock.fs_old_cstotal.cs_ndir = sblock.fs_cstotal.cs_ndir;
 528                 sblock.fs_old_cstotal.cs_nbfree = sblock.fs_cstotal.cs_nbfree;
 529                 sblock.fs_old_cstotal.cs_nifree = sblock.fs_cstotal.cs_nifree;
 530                 sblock.fs_old_cstotal.cs_nffree = sblock.fs_cstotal.cs_nffree;
 531         }
 532         if (Eflag == 3) {
 533                 printf("** Exiting on Eflag 3\n");
 534                 exit(0);
 535         }
 536         if (!Nflag)
 537                 sbwrite(&disk, 0);
 538         for (i = 0; i < sblock.fs_cssize; i += sblock.fs_bsize)
 539                 wtfs(fsbtodb(&sblock, sblock.fs_csaddr + numfrags(&sblock, i)),
 540                         sblock.fs_cssize - i < sblock.fs_bsize ?
 541                         sblock.fs_cssize - i : sblock.fs_bsize,
 542                         ((char *)fscs) + i);
 543         /*
 544          * Update information about this partion in pack
 545          * label, to that it may be updated on disk.
 546          */
 547         if (pp != NULL) {
 548                 pp->p_fstype = FS_BSDFFS;
 549                 pp->p_fsize = sblock.fs_fsize;
 550                 pp->p_frag = sblock.fs_frag;
 551                 pp->p_cpg = sblock.fs_fpg;
 552         }
 553 }
 554
 555 /*
 556  * Initialize a cylinder group.
 557  */
 558 void
 559 initcg(int cylno, time_t utime)
 560 {
 561         long i, j, d, dlower, dupper, blkno, start;
 562         ufs2_daddr_t cbase, dmax;
 563         struct ufs1_dinode *dp1;
 564         struct ufs2_dinode *dp2;
 565         struct csum *cs;
 566
 567         /*
 568          * Determine block bounds for cylinder group.
 569          * Allow space for super block summary information in first
 570          * cylinder group.
 571          */
 572         cbase = cgbase(&sblock, cylno);
 573         dmax = cbase + sblock.fs_fpg;
 574         if (dmax > sblock.fs_size)
 575                 dmax = sblock.fs_size;
 576         dlower = cgsblock(&sblock, cylno) - cbase;
 577         dupper = cgdmin(&sblock, cylno) - cbase;
 578         if (cylno == 0)
 579                 dupper += howmany(sblock.fs_cssize, sblock.fs_fsize);
 580         cs = &fscs[cylno];
 581         memset(&acg, 0, sblock.fs_cgsize);
 582         acg.cg_time = utime;
 583         acg.cg_magic = CG_MAGIC;
 584         acg.cg_cgx = cylno;
 585         acg.cg_niblk = sblock.fs_ipg;
 586         acg.cg_initediblk = sblock.fs_ipg < 2 * INOPB(&sblock) ?
 587             sblock.fs_ipg : 2 * INOPB(&sblock);
 588         acg.cg_ndblk = dmax - cbase;
 589         if (sblock.fs_contigsumsize > 0)
 590                 acg.cg_nclusterblks = acg.cg_ndblk / sblock.fs_frag;
 591         start = &acg.cg_space[0] - (u_char *)(&acg.cg_firstfield);
 592         if (Oflag == 2) {
 593                 acg.cg_iusedoff = start;
 594         } else {
 595                 acg.cg_old_ncyl = sblock.fs_old_cpg;
 596                 acg.cg_old_time = acg.cg_time;
 597                 acg.cg_time = 0;
 598                 acg.cg_old_niblk = acg.cg_niblk;
 599                 acg.cg_niblk = 0;
 600                 acg.cg_initediblk = 0;
 601                 acg.cg_old_btotoff = start;
 602                 acg.cg_old_boff = acg.cg_old_btotoff +
 603                     sblock.fs_old_cpg * sizeof(int32_t);
 604                 acg.cg_iusedoff = acg.cg_old_boff +
 605                     sblock.fs_old_cpg * sizeof(u_int16_t);
 606         }
 607         acg.cg_freeoff = acg.cg_iusedoff + howmany(sblock.fs_ipg, CHAR_BIT);
 608         acg.cg_nextfreeoff = acg.cg_freeoff + howmany(sblock.fs_fpg, CHAR_BIT);
 609         if (sblock.fs_contigsumsize > 0) {
 610                 acg.cg_clustersumoff =
 611                     roundup(acg.cg_nextfreeoff, sizeof(u_int32_t));
 612                 acg.cg_clustersumoff -= sizeof(u_int32_t);
 613                 acg.cg_clusteroff = acg.cg_clustersumoff +
 614                     (sblock.fs_contigsumsize + 1) * sizeof(u_int32_t);
 615                 acg.cg_nextfreeoff = acg.cg_clusteroff +
 616                     howmany(fragstoblks(&sblock, sblock.fs_fpg), CHAR_BIT);
 617         }
 618         if (acg.cg_nextfreeoff > sblock.fs_cgsize) {
 619                 printf("Panic: cylinder group too big\n");
 620                 exit(37);
 621         }
 622         acg.cg_cs.cs_nifree += sblock.fs_ipg;
 623         if (cylno == 0)
 624                 for (i = 0; i < (long)ROOTINO; i++) {
 625                         setbit(cg_inosused(&acg), i);
 626                         acg.cg_cs.cs_nifree--;
 627                 }
 628         if (cylno > 0) {
 629                 /*
 630                  * In cylno 0, beginning space is reserved
 631                  * for boot and super blocks.
 632                  */
 633                 for (d = 0; d < dlower; d += sblock.fs_frag) {
 634                         blkno = d / sblock.fs_frag;
 635                         setblock(&sblock, cg_blksfree(&acg), blkno);
 636                         if (sblock.fs_contigsumsize > 0)
 637                                 setbit(cg_clustersfree(&acg), blkno);
 638                         acg.cg_cs.cs_nbfree++;
 639                 }
 640         }
 641         if ((i = dupper % sblock.fs_frag)) {
 642                 acg.cg_frsum[sblock.fs_frag - i]++;
 643                 for (d = dupper + sblock.fs_frag - i; dupper < d; dupper++) {
 644                         setbit(cg_blksfree(&acg), dupper);
 645                         acg.cg_cs.cs_nffree++;
 646                 }
 647         }
 648         for (d = dupper; d + sblock.fs_frag <= acg.cg_ndblk;
 649              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         if (d < acg.cg_ndblk) {
 657                 acg.cg_frsum[acg.cg_ndblk - d]++;
 658                 for (; d < acg.cg_ndblk; d++) {
 659                         setbit(cg_blksfree(&acg), d);
 660                         acg.cg_cs.cs_nffree++;
 661                 }
 662         }
 663         if (sblock.fs_contigsumsize > 0) {
 664                 int32_t *sump = cg_clustersum(&acg);
 665                 u_char *mapp = cg_clustersfree(&acg);
 666                 int map = *mapp++;
 667                 int bit = 1;
 668                 int run = 0;
 669
 670                 for (i = 0; i < acg.cg_nclusterblks; i++) {
 671                         if ((map & bit) != 0)
 672                                 run++;
 673                         else if (run != 0) {
 674                                 if (run > sblock.fs_contigsumsize)
 675                                         run = sblock.fs_contigsumsize;
 676                                 sump[run]++;
 677                                 run = 0;
 678                         }
 679                         if ((i & (CHAR_BIT - 1)) != CHAR_BIT - 1)
 680                                 bit <<= 1;
 681                         else {
 682                                 map = *mapp++;
 683                                 bit = 1;
 684                         }
 685                 }
 686                 if (run != 0) {
 687                         if (run > sblock.fs_contigsumsize)
 688                                 run = sblock.fs_contigsumsize;
 689                         sump[run]++;
 690                 }
 691         }
 692         *cs = acg.cg_cs;
 693         /*
 694          * Write out the duplicate super block, the cylinder group map
 695          * and two blocks worth of inodes in a single write.
 696          */
 697         start = sblock.fs_bsize > SBLOCKSIZE ? sblock.fs_bsize : SBLOCKSIZE;
 698         bcopy((char *)&acg, &iobuf[start], sblock.fs_cgsize);
 699         start += sblock.fs_bsize;
 700         dp1 = (struct ufs1_dinode *)(&iobuf[start]);
 701         dp2 = (struct ufs2_dinode *)(&iobuf[start]);
 702         for (i = 0; i < acg.cg_initediblk; i++) {
 703                 if (sblock.fs_magic == FS_UFS1_MAGIC) {
 704                         dp1->di_gen = newfs_random();
 705                         dp1++;
 706                 } else {
 707                         dp2->di_gen = newfs_random();
 708                         dp2++;
 709                 }
 710         }
 711         wtfs(fsbtodb(&sblock, cgsblock(&sblock, cylno)), iobufsize, iobuf);
 712         /*
 713          * For the old file system, we have to initialize all the inodes.
 714          */
 715         if (Oflag == 1) {
 716                 for (i = 2 * sblock.fs_frag;
 717                      i < sblock.fs_ipg / INOPF(&sblock);
 718                      i += sblock.fs_frag) {
 719                         dp1 = (struct ufs1_dinode *)(&iobuf[start]);
 720                         for (j = 0; j < INOPB(&sblock); j++) {
 721                                 dp1->di_gen = newfs_random();
 722                                 dp1++;
 723                         }
 724                         wtfs(fsbtodb(&sblock, cgimin(&sblock, cylno) + i),
 725                             sblock.fs_bsize, &iobuf[start]);
 726                 }
 727         }
 728 }
 729
 730 /*
 731  * initialize the file system
 732  */
 733 #define ROOTLINKCNT 3
 734
 735 struct direct root_dir[] = {
 736         { ROOTINO, sizeof(struct direct), DT_DIR, 1, "." },
 737         { ROOTINO, sizeof(struct direct), DT_DIR, 2, ".." },
 738         { ROOTINO + 1, sizeof(struct direct), DT_DIR, 5, ".snap" },
 739 };
 740
 741 #define SNAPLINKCNT 2
 742
 743 struct direct snap_dir[] = {
 744         { ROOTINO + 1, sizeof(struct direct), DT_DIR, 1, "." },
 745         { ROOTINO, sizeof(struct direct), DT_DIR, 2, ".." },
 746 };
 747
 748 void
 749 fsinit(time_t utime)
 750 {
 751         union dinode node;
 752         struct group *grp;
 753         gid_t gid;
 754         int entries;
 755
 756         memset(&node, 0, sizeof node);
 757         if ((grp = getgrnam("operator")) != NULL) {
 758                 gid = grp->gr_gid;
 759         } else {
 760                 warnx("Cannot retrieve operator gid, using gid 0.");
 761                 gid = 0;
 762         }
 763         entries = (nflag) ? ROOTLINKCNT - 1: ROOTLINKCNT;
 764         if (sblock.fs_magic == FS_UFS1_MAGIC) {
 765                 /*
 766                  * initialize the node
 767                  */
 768                 node.dp1.di_atime = utime;
 769                 node.dp1.di_mtime = utime;
 770                 node.dp1.di_ctime = utime;
 771                 /*
 772                  * create the root directory
 773                  */
 774                 node.dp1.di_mode = IFDIR | UMASK;
 775                 node.dp1.di_nlink = entries;
 776                 node.dp1.di_size = makedir(root_dir, entries);
 777                 node.dp1.di_db[0] = alloc(sblock.fs_fsize, node.dp1.di_mode);
 778                 node.dp1.di_blocks =
 779                     btodb(fragroundup(&sblock, node.dp1.di_size));
 780                 wtfs(fsbtodb(&sblock, node.dp1.di_db[0]), sblock.fs_fsize,
 781                     iobuf);
 782                 iput(&node, ROOTINO);
 783                 if (!nflag) {
 784                         /*
 785                          * create the .snap directory
 786                          */
 787                         node.dp1.di_mode |= 020;
 788                         node.dp1.di_gid = gid;
 789                         node.dp1.di_nlink = SNAPLINKCNT;
 790                         node.dp1.di_size = makedir(snap_dir, SNAPLINKCNT);
 791                                 node.dp1.di_db[0] =
 792                                     alloc(sblock.fs_fsize, node.dp1.di_mode);
 793                         node.dp1.di_blocks =
 794                             btodb(fragroundup(&sblock, node.dp1.di_size));
 795                                 wtfs(fsbtodb(&sblock, node.dp1.di_db[0]),
 796                                     sblock.fs_fsize, iobuf);
 797                         iput(&node, ROOTINO + 1);
 798                 }
 799         } else {
 800                 /*
 801                  * initialize the node
 802                  */
 803                 node.dp2.di_atime = utime;
 804                 node.dp2.di_mtime = utime;
 805                 node.dp2.di_ctime = utime;
 806                 node.dp2.di_birthtime = utime;
 807                 /*
 808                  * create the root directory
 809                  */
 810                 node.dp2.di_mode = IFDIR | UMASK;
 811                 node.dp2.di_nlink = entries;
 812                 node.dp2.di_size = makedir(root_dir, entries);
 813                 node.dp2.di_db[0] = alloc(sblock.fs_fsize, node.dp2.di_mode);
 814                 node.dp2.di_blocks =
 815                     btodb(fragroundup(&sblock, node.dp2.di_size));
 816                 wtfs(fsbtodb(&sblock, node.dp2.di_db[0]), sblock.fs_fsize,
 817                     iobuf);
 818                 iput(&node, ROOTINO);
 819                 if (!nflag) {
 820                         /*
 821                          * create the .snap directory
 822                          */
 823                         node.dp2.di_mode |= 020;
 824                         node.dp2.di_gid = gid;
 825                         node.dp2.di_nlink = SNAPLINKCNT;
 826                         node.dp2.di_size = makedir(snap_dir, SNAPLINKCNT);
 827                                 node.dp2.di_db[0] =
 828                                     alloc(sblock.fs_fsize, node.dp2.di_mode);
 829                         node.dp2.di_blocks =
 830                             btodb(fragroundup(&sblock, node.dp2.di_size));
 831                                 wtfs(fsbtodb(&sblock, node.dp2.di_db[0]),
 832                                     sblock.fs_fsize, iobuf);
 833                         iput(&node, ROOTINO + 1);
 834                 }
 835         }
 836 }
 837
 838 /*
 839  * construct a set of directory entries in "iobuf".
 840  * return size of directory.
 841  */
 842 int
 843 makedir(struct direct *protodir, int entries)
 844 {
 845         char *cp;
 846         int i, spcleft;
 847
 848         spcleft = DIRBLKSIZ;
 849         memset(iobuf, 0, DIRBLKSIZ);
 850         for (cp = iobuf, i = 0; i < entries - 1; i++) {
 851                 protodir[i].d_reclen = DIRSIZ(0, &protodir[i]);
 852                 memmove(cp, &protodir[i], protodir[i].d_reclen);
 853                 cp += protodir[i].d_reclen;
 854                 spcleft -= protodir[i].d_reclen;
 855         }
 856         protodir[i].d_reclen = spcleft;
 857         memmove(cp, &protodir[i], DIRSIZ(0, &protodir[i]));
 858         return (DIRBLKSIZ);
 859 }
 860
 861 /*
 862  * allocate a block or frag
 863  */
 864 ufs2_daddr_t
 865 alloc(int size, int mode)
 866 {
 867         int i, d, blkno, frag;
 868
 869         bread(&disk, fsbtodb(&sblock, cgtod(&sblock, 0)), (char *)&acg,
 870             sblock.fs_cgsize);
 871         if (acg.cg_magic != CG_MAGIC) {
 872                 printf("cg 0: bad magic number\n");
 873                 exit(38);
 874         }
 875         if (acg.cg_cs.cs_nbfree == 0) {
 876                 printf("first cylinder group ran out of space\n");
 877                 exit(39);
 878         }
 879         for (d = 0; d < acg.cg_ndblk; d += sblock.fs_frag)
 880                 if (isblock(&sblock, cg_blksfree(&acg), d / sblock.fs_frag))
 881                         goto goth;
 882         printf("internal error: can't find block in cyl 0\n");
 883         exit(40);
 884 goth:
 885         blkno = fragstoblks(&sblock, d);
 886         clrblock(&sblock, cg_blksfree(&acg), blkno);
 887         if (sblock.fs_contigsumsize > 0)
 888                 clrbit(cg_clustersfree(&acg), blkno);
 889         acg.cg_cs.cs_nbfree--;
 890         sblock.fs_cstotal.cs_nbfree--;
 891         fscs[0].cs_nbfree--;
 892         if (mode & IFDIR) {
 893                 acg.cg_cs.cs_ndir++;
 894                 sblock.fs_cstotal.cs_ndir++;
 895                 fscs[0].cs_ndir++;
 896         }
 897         if (size != sblock.fs_bsize) {
 898                 frag = howmany(size, sblock.fs_fsize);
 899                 fscs[0].cs_nffree += sblock.fs_frag - frag;
 900                 sblock.fs_cstotal.cs_nffree += sblock.fs_frag - frag;
 901                 acg.cg_cs.cs_nffree += sblock.fs_frag - frag;
 902                 acg.cg_frsum[sblock.fs_frag - frag]++;
 903                 for (i = frag; i < sblock.fs_frag; i++)
 904                         setbit(cg_blksfree(&acg), d + i);
 905         }
 906         /* XXX cgwrite(&disk, 0)??? */
 907         wtfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
 908             (char *)&acg);
 909         return ((ufs2_daddr_t)d);
 910 }
 911
 912 /*
 913  * Allocate an inode on the disk
 914  */
 915 void
 916 iput(union dinode *ip, ino_t ino)
 917 {
 918         ufs2_daddr_t d;
 919         int c;
 920
 921         c = ino_to_cg(&sblock, ino);
 922         bread(&disk, fsbtodb(&sblock, cgtod(&sblock, 0)), (char *)&acg,
 923             sblock.fs_cgsize);
 924         if (acg.cg_magic != CG_MAGIC) {
 925                 printf("cg 0: bad magic number\n");
 926                 exit(31);
 927         }
 928         acg.cg_cs.cs_nifree--;
 929         setbit(cg_inosused(&acg), ino);
 930         wtfs(fsbtodb(&sblock, cgtod(&sblock, 0)), sblock.fs_cgsize,
 931             (char *)&acg);
 932         sblock.fs_cstotal.cs_nifree--;
 933         fscs[0].cs_nifree--;
 934         if (ino >= (unsigned long)sblock.fs_ipg * sblock.fs_ncg) {
 935                 printf("fsinit: inode value out of range (%d).\n", ino);
 936                 exit(32);
 937         }
 938         d = fsbtodb(&sblock, ino_to_fsba(&sblock, ino));
 939         bread(&disk, d, (char *)iobuf, sblock.fs_bsize);
 940         if (sblock.fs_magic == FS_UFS1_MAGIC)
 941                 ((struct ufs1_dinode *)iobuf)[ino_to_fsbo(&sblock, ino)] =
 942                     ip->dp1;
 943         else
 944                 ((struct ufs2_dinode *)iobuf)[ino_to_fsbo(&sblock, ino)] =
 945                     ip->dp2;
 946         wtfs(d, sblock.fs_bsize, (char *)iobuf);
 947 }
 948
 949 /*
 950  * possibly write to disk
 951  */
 952 static void
 953 wtfs(ufs2_daddr_t bno, int size, char *bf)
 954 {
 955         if (Nflag)
 956                 return;
 957         if (bwrite(&disk, bno, bf, size) < 0)
 958                 err(36, "wtfs: %d bytes at sector %jd", size, (intmax_t)bno);
 959 }
 960
 961 /*
 962  * check if a block is available
 963  */
 964 static int
 965 isblock(struct fs *fs, unsigned char *cp, int h)
 966 {
 967         unsigned char mask;
 968
 969         switch (fs->fs_frag) {
 970         case 8:
 971                 return (cp[h] == 0xff);
 972         case 4:
 973                 mask = 0x0f << ((h & 0x1) << 2);
 974                 return ((cp[h >> 1] & mask) == mask);
 975         case 2:
 976                 mask = 0x03 << ((h & 0x3) << 1);
 977                 return ((cp[h >> 2] & mask) == mask);
 978         case 1:
 979                 mask = 0x01 << (h & 0x7);
 980                 return ((cp[h >> 3] & mask) == mask);
 981         default:
 982                 fprintf(stderr, "isblock bad fs_frag %d\n", fs->fs_frag);
 983                 return (0);
 984         }
 985 }
 986
 987 /*
 988  * take a block out of the map
 989  */
 990 static void
 991 clrblock(struct fs *fs, unsigned char *cp, int h)
 992 {
 993         switch ((fs)->fs_frag) {
 994         case 8:
 995                 cp[h] = 0;
 996                 return;
 997         case 4:
 998                 cp[h >> 1] &= ~(0x0f << ((h & 0x1) << 2));
 999                 return;
1000         case 2:
1001                 cp[h >> 2] &= ~(0x03 << ((h & 0x3) << 1));
1002                 return;
1003         case 1:
1004                 cp[h >> 3] &= ~(0x01 << (h & 0x7));
1005                 return;
1006         default:
1007                 fprintf(stderr, "clrblock bad fs_frag %d\n", fs->fs_frag);
1008                 return;
1009         }
1010 }
1011
1012 /*
1013  * put a block into the map
1014  */
1015 static void
1016 setblock(struct fs *fs, unsigned char *cp, int h)
1017 {
1018         switch (fs->fs_frag) {
1019         case 8:
1020                 cp[h] = 0xff;
1021                 return;
1022         case 4:
1023                 cp[h >> 1] |= (0x0f << ((h & 0x1) << 2));
1024                 return;
1025         case 2:
1026                 cp[h >> 2] |= (0x03 << ((h & 0x3) << 1));
1027                 return;
1028         case 1:
1029                 cp[h >> 3] |= (0x01 << (h & 0x7));
1030                 return;
1031         default:
1032                 fprintf(stderr, "setblock bad fs_frag %d\n", fs->fs_frag);
1033                 return;
1034         }
1035 }
1036
1037 /*
1038  * Determine the number of characters in a
1039  * single line.
1040  */
1041
1042 static int
1043 charsperline(void)
1044 {
1045         int columns;
1046         char *cp;
1047         struct winsize ws;
1048
1049         columns = 0;
1050         if (ioctl(0, TIOCGWINSZ, &ws) != -1)
1051                 columns = ws.ws_col;
1052         if (columns == 0 && (cp = getenv("COLUMNS")))
1053                 columns = atoi(cp);
1054         if (columns == 0)
1055                 columns = 80;   /* last resort */
1056         return (columns);
1057 }
1058
1059 static int
1060 ilog2(int val)
1061 {
1062         u_int n;
1063
1064         for (n = 0; n < sizeof(n) * CHAR_BIT; n++)
1065                 if (1 << n == val)
1066                         return (n);
1067         errx(1, "ilog2: %d is not a power of 2\n", val);
1068 }
1069
1070 /*
1071  * For the regression test, return predictable random values.
1072  * Otherwise use a true random number generator.
1073  */
1074 static u_int32_t
1075 newfs_random(void)
1076 {
1077         static int nextnum = 1;
1078
1079         if (Rflag)
1080                 return (nextnum++);
1081         return (arc4random());
1082 }