sbin/fsck_ffs/pass5.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (c) 1980, 1986, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #if 0
  33 #ifndef lint
  34 static const char sccsid[] = "@(#)pass5.c       8.9 (Berkeley) 4/28/95";
  35 #endif /* not lint */
  36 #endif
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD$");
  39
  40 #include <sys/param.h>
  41 #include <sys/sysctl.h>
  42
  43 #include <ufs/ufs/dinode.h>
  44 #include <ufs/ffs/fs.h>
  45
  46 #include <err.h>
  47 #include <inttypes.h>
  48 #include <limits.h>
  49 #include <string.h>
  50 #include <libufs.h>
  51
  52 #include "fsck.h"
  53
  54 static void check_maps(u_char *, u_char *, int, ufs2_daddr_t, const char *,
  55                         int *, int, int, int);
  56 static void clear_blocks(ufs2_daddr_t start, ufs2_daddr_t end);
  57
  58 void
  59 pass5(void)
  60 {
  61         int c, i, j, blk, frags, basesize, mapsize;
  62         int inomapsize, blkmapsize;
  63         struct fs *fs = &sblock;
  64         ufs2_daddr_t d, dbase, dmax, start;
  65         int rewritecg = 0;
  66         ino_t inum;
  67         struct csum *cs;
  68         struct csum_total cstotal;
  69         struct inodesc idesc[3];
  70         char buf[MAXBSIZE];
  71         struct cg *cg, *newcg = (struct cg *)buf;
  72         struct bufarea *cgbp;
  73
  74         inoinfo(UFS_WINO)->ino_state = USTATE;
  75         memset(newcg, 0, (size_t)fs->fs_cgsize);
  76         newcg->cg_niblk = fs->fs_ipg;
  77         /* check to see if we are to add a cylinder group check hash */
  78         if ((ckhashadd & CK_CYLGRP) != 0)
  79                 rewritecg = 1;
  80         if (cvtlevel >= 3) {
  81                 if (fs->fs_maxcontig < 2 && fs->fs_contigsumsize > 0) {
  82                         if (preen)
  83                                 pwarn("DELETING CLUSTERING MAPS\n");
  84                         if (preen || reply("DELETE CLUSTERING MAPS")) {
  85                                 fs->fs_contigsumsize = 0;
  86                                 rewritecg = 1;
  87                                 sbdirty();
  88                         }
  89                 }
  90                 if (fs->fs_maxcontig > 1) {
  91                         const char *doit = NULL;
  92
  93                         if (fs->fs_contigsumsize < 1) {
  94                                 doit = "CREAT";
  95                         } else if (fs->fs_contigsumsize < fs->fs_maxcontig &&
  96                                    fs->fs_contigsumsize < FS_MAXCONTIG) {
  97                                 doit = "EXPAND";
  98                         }
  99                         if (doit) {
 100                                 i = fs->fs_contigsumsize;
 101                                 fs->fs_contigsumsize =
 102                                     MIN(fs->fs_maxcontig, FS_MAXCONTIG);
 103                                 if (CGSIZE(fs) > (u_int)fs->fs_bsize) {
 104                                         pwarn("CANNOT %s CLUSTER MAPS\n", doit);
 105                                         fs->fs_contigsumsize = i;
 106                                 } else if (preen ||
 107                                     reply("CREATE CLUSTER MAPS")) {
 108                                         if (preen)
 109                                                 pwarn("%sING CLUSTER MAPS\n",
 110                                                     doit);
 111                                         fs->fs_cgsize =
 112                                             fragroundup(fs, CGSIZE(fs));
 113                                         rewritecg = 1;
 114                                         sbdirty();
 115                                 }
 116                         }
 117                 }
 118         }
 119         basesize = &newcg->cg_space[0] - (u_char *)(&newcg->cg_firstfield);
 120         if (sblock.fs_magic == FS_UFS2_MAGIC) {
 121                 newcg->cg_iusedoff = basesize;
 122         } else {
 123                 /*
 124                  * We reserve the space for the old rotation summary
 125                  * tables for the benefit of old kernels, but do not
 126                  * maintain them in modern kernels. In time, they can
 127                  * go away.
 128                  */
 129                 newcg->cg_old_btotoff = basesize;
 130                 newcg->cg_old_boff = newcg->cg_old_btotoff +
 131                     fs->fs_old_cpg * sizeof(int32_t);
 132                 newcg->cg_iusedoff = newcg->cg_old_boff +
 133                     fs->fs_old_cpg * fs->fs_old_nrpos * sizeof(u_int16_t);
 134                 memset(&newcg->cg_space[0], 0, newcg->cg_iusedoff - basesize);
 135         }
 136         inomapsize = howmany(fs->fs_ipg, CHAR_BIT);
 137         newcg->cg_freeoff = newcg->cg_iusedoff + inomapsize;
 138         blkmapsize = howmany(fs->fs_fpg, CHAR_BIT);
 139         newcg->cg_nextfreeoff = newcg->cg_freeoff + blkmapsize;
 140         if (fs->fs_contigsumsize > 0) {
 141                 newcg->cg_clustersumoff = newcg->cg_nextfreeoff -
 142                     sizeof(u_int32_t);
 143                 newcg->cg_clustersumoff =
 144                     roundup(newcg->cg_clustersumoff, sizeof(u_int32_t));
 145                 newcg->cg_clusteroff = newcg->cg_clustersumoff +
 146                     (fs->fs_contigsumsize + 1) * sizeof(u_int32_t);
 147                 newcg->cg_nextfreeoff = newcg->cg_clusteroff +
 148                     howmany(fragstoblks(fs, fs->fs_fpg), CHAR_BIT);
 149         }
 150         newcg->cg_magic = CG_MAGIC;
 151         mapsize = newcg->cg_nextfreeoff - newcg->cg_iusedoff;
 152         memset(&idesc[0], 0, sizeof idesc);
 153         for (i = 0; i < 3; i++)
 154                 idesc[i].id_type = ADDR;
 155         memset(&cstotal, 0, sizeof(struct csum_total));
 156         dmax = blknum(fs, fs->fs_size + fs->fs_frag - 1);
 157         for (d = fs->fs_size; d < dmax; d++)
 158                 setbmap(d);
 159         for (c = 0; c < fs->fs_ncg; c++) {
 160                 if (got_siginfo) {
 161                         printf("%s: phase 5: cyl group %d of %d (%d%%)\n",
 162                             cdevname, c, sblock.fs_ncg,
 163                             c * 100 / sblock.fs_ncg);
 164                         got_siginfo = 0;
 165                 }
 166                 if (got_sigalarm) {
 167                         setproctitle("%s p5 %d%%", cdevname,
 168                             c * 100 / sblock.fs_ncg);
 169                         got_sigalarm = 0;
 170                 }
 171                 cgbp = cglookup(c);
 172                 cg = cgbp->b_un.b_cg;
 173                 if (!cg_chkmagic(cg))
 174                         pfatal("CG %d: BAD MAGIC NUMBER\n", c);
 175                 /*
 176                  * If we have a cylinder group check hash and are not adding
 177                  * it for the first time, verify that it is good.
 178                  */
 179                 if ((fs->fs_metackhash & CK_CYLGRP) != 0 &&
 180                     (ckhashadd & CK_CYLGRP) == 0) {
 181                         uint32_t ckhash, thishash;
 182
 183                         ckhash = cg->cg_ckhash;
 184                         cg->cg_ckhash = 0;
 185                         thishash = calculate_crc32c(~0L, cg, fs->fs_cgsize);
 186                         if (ckhash == thishash) {
 187                                 cg->cg_ckhash = ckhash;
 188                         } else {
 189                                 pwarn("CG %d: BAD CHECK-HASH %#x vs %#x\n",
 190                                     c, ckhash, thishash);
 191                                 cg->cg_ckhash = thishash;
 192                                 cgdirty(cgbp);
 193                         }
 194                 }
 195                 newcg->cg_time = cg->cg_time;
 196                 newcg->cg_old_time = cg->cg_old_time;
 197                 newcg->cg_unrefs = cg->cg_unrefs;
 198                 newcg->cg_ckhash = cg->cg_ckhash;
 199                 newcg->cg_cgx = c;
 200                 dbase = cgbase(fs, c);
 201                 dmax = dbase + fs->fs_fpg;
 202                 if (dmax > fs->fs_size)
 203                         dmax = fs->fs_size;
 204                 newcg->cg_ndblk = dmax - dbase;
 205                 if (fs->fs_magic == FS_UFS1_MAGIC) {
 206                         if (c == fs->fs_ncg - 1)
 207                                 newcg->cg_old_ncyl = howmany(newcg->cg_ndblk,
 208                                     fs->fs_fpg / fs->fs_old_cpg);
 209                         else
 210                                 newcg->cg_old_ncyl = fs->fs_old_cpg;
 211                         newcg->cg_old_niblk = fs->fs_ipg;
 212                         newcg->cg_niblk = 0;
 213                 }
 214                 if (fs->fs_contigsumsize > 0)
 215                         newcg->cg_nclusterblks = newcg->cg_ndblk / fs->fs_frag;
 216                 newcg->cg_cs.cs_ndir = 0;
 217                 newcg->cg_cs.cs_nffree = 0;
 218                 newcg->cg_cs.cs_nbfree = 0;
 219                 newcg->cg_cs.cs_nifree = fs->fs_ipg;
 220                 if (cg->cg_rotor >= 0 && cg->cg_rotor < newcg->cg_ndblk)
 221                         newcg->cg_rotor = cg->cg_rotor;
 222                 else
 223                         newcg->cg_rotor = 0;
 224                 if (cg->cg_frotor >= 0 && cg->cg_frotor < newcg->cg_ndblk)
 225                         newcg->cg_frotor = cg->cg_frotor;
 226                 else
 227                         newcg->cg_frotor = 0;
 228                 if (cg->cg_irotor >= 0 && cg->cg_irotor < fs->fs_ipg)
 229                         newcg->cg_irotor = cg->cg_irotor;
 230                 else
 231                         newcg->cg_irotor = 0;
 232                 if (fs->fs_magic == FS_UFS1_MAGIC) {
 233                         newcg->cg_initediblk = 0;
 234                 } else {
 235                         if ((unsigned)cg->cg_initediblk > fs->fs_ipg)
 236                                 newcg->cg_initediblk = fs->fs_ipg;
 237                         else
 238                                 newcg->cg_initediblk = cg->cg_initediblk;
 239                 }
 240                 memset(&newcg->cg_frsum[0], 0, sizeof newcg->cg_frsum);
 241                 memset(cg_inosused(newcg), 0, (size_t)(mapsize));
 242                 inum = fs->fs_ipg * c;
 243                 for (i = 0; i < inostathead[c].il_numalloced; inum++, i++) {
 244                         switch (inoinfo(inum)->ino_state) {
 245
 246                         case USTATE:
 247                                 break;
 248
 249                         case DSTATE:
 250                         case DCLEAR:
 251                         case DFOUND:
 252                         case DZLINK:
 253                                 newcg->cg_cs.cs_ndir++;
 254                                 /* FALLTHROUGH */
 255
 256                         case FSTATE:
 257                         case FCLEAR:
 258                         case FZLINK:
 259                                 newcg->cg_cs.cs_nifree--;
 260                                 setbit(cg_inosused(newcg), i);
 261                                 break;
 262
 263                         default:
 264                                 if (inum < UFS_ROOTINO)
 265                                         break;
 266                                 errx(EEXIT, "BAD STATE %d FOR INODE I=%ju",
 267                                     inoinfo(inum)->ino_state, (uintmax_t)inum);
 268                         }
 269                 }
 270                 if (c == 0)
 271                         for (i = 0; i < (int)UFS_ROOTINO; i++) {
 272                                 setbit(cg_inosused(newcg), i);
 273                                 newcg->cg_cs.cs_nifree--;
 274                         }
 275                 start = -1;
 276                 for (i = 0, d = dbase;
 277                      d < dmax;
 278                      d += fs->fs_frag, i += fs->fs_frag) {
 279                         frags = 0;
 280                         for (j = 0; j < fs->fs_frag; j++) {
 281                                 if (testbmap(d + j)) {
 282                                         if ((Eflag || Zflag) && start != -1) {
 283                                                 clear_blocks(start, d + j - 1);
 284                                                 start = -1;
 285                                         }
 286                                         continue;
 287                                 }
 288                                 if (start == -1)
 289                                         start = d + j;
 290                                 setbit(cg_blksfree(newcg), i + j);
 291                                 frags++;
 292                         }
 293                         if (frags == fs->fs_frag) {
 294                                 newcg->cg_cs.cs_nbfree++;
 295                                 if (fs->fs_contigsumsize > 0)
 296                                         setbit(cg_clustersfree(newcg),
 297                                             i / fs->fs_frag);
 298                         } else if (frags > 0) {
 299                                 newcg->cg_cs.cs_nffree += frags;
 300                                 blk = blkmap(fs, cg_blksfree(newcg), i);
 301                                 ffs_fragacct(fs, blk, newcg->cg_frsum, 1);
 302                         }
 303                 }
 304                 if ((Eflag || Zflag) && start != -1)
 305                         clear_blocks(start, d - 1);
 306                 if (fs->fs_contigsumsize > 0) {
 307                         int32_t *sump = cg_clustersum(newcg);
 308                         u_char *mapp = cg_clustersfree(newcg);
 309                         int map = *mapp++;
 310                         int bit = 1;
 311                         int run = 0;
 312
 313                         for (i = 0; i < newcg->cg_nclusterblks; i++) {
 314                                 if ((map & bit) != 0) {
 315                                         run++;
 316                                 } else if (run != 0) {
 317                                         if (run > fs->fs_contigsumsize)
 318                                                 run = fs->fs_contigsumsize;
 319                                         sump[run]++;
 320                                         run = 0;
 321                                 }
 322                                 if ((i & (CHAR_BIT - 1)) != (CHAR_BIT - 1)) {
 323                                         bit <<= 1;
 324                                 } else {
 325                                         map = *mapp++;
 326                                         bit = 1;
 327                                 }
 328                         }
 329                         if (run != 0) {
 330                                 if (run > fs->fs_contigsumsize)
 331                                         run = fs->fs_contigsumsize;
 332                                 sump[run]++;
 333                         }
 334                 }
 335
 336                 if (bkgrdflag != 0) {
 337                         cstotal.cs_nffree += cg->cg_cs.cs_nffree;
 338                         cstotal.cs_nbfree += cg->cg_cs.cs_nbfree;
 339                         cstotal.cs_nifree += cg->cg_cs.cs_nifree;
 340                         cstotal.cs_ndir += cg->cg_cs.cs_ndir;
 341                 } else {
 342                         cstotal.cs_nffree += newcg->cg_cs.cs_nffree;
 343                         cstotal.cs_nbfree += newcg->cg_cs.cs_nbfree;
 344                         cstotal.cs_nifree += newcg->cg_cs.cs_nifree;
 345                         cstotal.cs_ndir += newcg->cg_cs.cs_ndir;
 346                 }
 347                 cs = &fs->fs_cs(fs, c);
 348                 if (cursnapshot == 0 &&
 349                     memcmp(&newcg->cg_cs, cs, sizeof *cs) != 0 &&
 350                     dofix(&idesc[0], "FREE BLK COUNT(S) WRONG IN SUPERBLK")) {
 351                         memmove(cs, &newcg->cg_cs, sizeof *cs);
 352                         sbdirty();
 353                 }
 354                 if (rewritecg) {
 355                         memmove(cg, newcg, (size_t)fs->fs_cgsize);
 356                         cgdirty(cgbp);
 357                         continue;
 358                 }
 359                 if (cursnapshot == 0 &&
 360                     memcmp(newcg, cg, basesize) != 0 &&
 361                     dofix(&idesc[2], "SUMMARY INFORMATION BAD")) {
 362                         memmove(cg, newcg, (size_t)basesize);
 363                         cgdirty(cgbp);
 364                 }
 365                 if (bkgrdflag != 0 || usedsoftdep || debug)
 366                         update_maps(cg, newcg, bkgrdflag);
 367                 if (cursnapshot == 0 &&
 368                     memcmp(cg_inosused(newcg), cg_inosused(cg), mapsize) != 0 &&
 369                     dofix(&idesc[1], "BLK(S) MISSING IN BIT MAPS")) {
 370                         memmove(cg_inosused(cg), cg_inosused(newcg),
 371                               (size_t)mapsize);
 372                         cgdirty(cgbp);
 373                 }
 374         }
 375         if (cursnapshot == 0 &&
 376             memcmp(&cstotal, &fs->fs_cstotal, sizeof cstotal) != 0
 377             && dofix(&idesc[0], "SUMMARY BLK COUNT(S) WRONG IN SUPERBLK")) {
 378                 memmove(&fs->fs_cstotal, &cstotal, sizeof cstotal);
 379                 fs->fs_ronly = 0;
 380                 fs->fs_fmod = 0;
 381                 sbdirty();
 382         }
 383
 384         /*
 385          * When doing background fsck on a snapshot, figure out whether
 386          * the superblock summary is inaccurate and correct it when
 387          * necessary.
 388          */
 389         if (cursnapshot != 0) {
 390                 cmd.size = 1;
 391
 392                 cmd.value = cstotal.cs_ndir - fs->fs_cstotal.cs_ndir;
 393                 if (cmd.value != 0) {
 394                         if (debug)
 395                                 printf("adjndir by %+" PRIi64 "\n", cmd.value);
 396                         if (bkgrdsumadj == 0 || sysctl(adjndir, MIBSIZE, 0, 0,
 397                             &cmd, sizeof cmd) == -1)
 398                                 rwerror("ADJUST NUMBER OF DIRECTORIES", cmd.value);
 399                 }
 400
 401                 cmd.value = cstotal.cs_nbfree - fs->fs_cstotal.cs_nbfree;
 402                 if (cmd.value != 0) {
 403                         if (debug)
 404                                 printf("adjnbfree by %+" PRIi64 "\n", cmd.value);
 405                         if (bkgrdsumadj == 0 || sysctl(adjnbfree, MIBSIZE, 0, 0,
 406                             &cmd, sizeof cmd) == -1)
 407                                 rwerror("ADJUST NUMBER OF FREE BLOCKS", cmd.value);
 408                 }
 409
 410                 cmd.value = cstotal.cs_nifree - fs->fs_cstotal.cs_nifree;
 411                 if (cmd.value != 0) {
 412                         if (debug)
 413                                 printf("adjnifree by %+" PRIi64 "\n", cmd.value);
 414                         if (bkgrdsumadj == 0 || sysctl(adjnifree, MIBSIZE, 0, 0,
 415                             &cmd, sizeof cmd) == -1)
 416                                 rwerror("ADJUST NUMBER OF FREE INODES", cmd.value);
 417                 }
 418
 419                 cmd.value = cstotal.cs_nffree - fs->fs_cstotal.cs_nffree;
 420                 if (cmd.value != 0) {
 421                         if (debug)
 422                                 printf("adjnffree by %+" PRIi64 "\n", cmd.value);
 423                         if (bkgrdsumadj == 0 || sysctl(adjnffree, MIBSIZE, 0, 0,
 424                             &cmd, sizeof cmd) == -1)
 425                                 rwerror("ADJUST NUMBER OF FREE FRAGS", cmd.value);
 426                 }
 427
 428                 cmd.value = cstotal.cs_numclusters - fs->fs_cstotal.cs_numclusters;
 429                 if (cmd.value != 0) {
 430                         if (debug)
 431                                 printf("adjnumclusters by %+" PRIi64 "\n", cmd.value);
 432                         if (bkgrdsumadj == 0 || sysctl(adjnumclusters, MIBSIZE, 0, 0,
 433                             &cmd, sizeof cmd) == -1)
 434                                 rwerror("ADJUST NUMBER OF FREE CLUSTERS", cmd.value);
 435                 }
 436         }
 437 }
 438
 439 /*
 440  * Compare the original cylinder group inode and block bitmaps with the
 441  * updated cylinder group inode and block bitmaps. Free inodes and blocks
 442  * that have been added. Complain if any previously freed inodes blocks
 443  * are now allocated.
 444  */
 445 void
 446 update_maps(
 447         struct cg *oldcg,       /* cylinder group of claimed allocations */
 448         struct cg *newcg,       /* cylinder group of determined allocations */
 449         int usesysctl)          /* 1 => use sysctl interface to update maps */
 450 {
 451         int inomapsize, excessdirs;
 452         struct fs *fs = &sblock;
 453
 454         inomapsize = howmany(fs->fs_ipg, CHAR_BIT);
 455         excessdirs = oldcg->cg_cs.cs_ndir - newcg->cg_cs.cs_ndir;
 456         if (excessdirs < 0) {
 457                 pfatal("LOST %d DIRECTORIES\n", -excessdirs);
 458                 excessdirs = 0;
 459         }
 460         if (excessdirs > 0)
 461                 check_maps(cg_inosused(newcg), cg_inosused(oldcg), inomapsize,
 462                     oldcg->cg_cgx * (ufs2_daddr_t)fs->fs_ipg, "DIR", freedirs,
 463                     0, excessdirs, usesysctl);
 464         check_maps(cg_inosused(newcg), cg_inosused(oldcg), inomapsize,
 465             oldcg->cg_cgx * (ufs2_daddr_t)fs->fs_ipg, "FILE", freefiles,
 466             excessdirs, fs->fs_ipg, usesysctl);
 467         check_maps(cg_blksfree(oldcg), cg_blksfree(newcg),
 468             howmany(fs->fs_fpg, CHAR_BIT),
 469             oldcg->cg_cgx * (ufs2_daddr_t)fs->fs_fpg, "FRAG",
 470             freeblks, 0, fs->fs_fpg, usesysctl);
 471 }
 472
 473 static void
 474 check_maps(
 475         u_char *map1,   /* map of claimed allocations */
 476         u_char *map2,   /* map of determined allocations */
 477         int mapsize,    /* size of above two maps */
 478         ufs2_daddr_t startvalue, /* resource value for first element in map */
 479         const char *name,       /* name of resource found in maps */
 480         int *opcode,    /* sysctl opcode to free resource */
 481         int skip,       /* number of entries to skip before starting to free */
 482         int limit,      /* limit on number of entries to free */
 483         int usesysctl)  /* 1 => use sysctl interface to update maps */
 484 {
 485 #       define BUFSIZE 16
 486         char buf[BUFSIZE];
 487         long i, j, k, l, m, size;
 488         ufs2_daddr_t n, astart, aend, ustart, uend;
 489         void (*msg)(const char *fmt, ...);
 490
 491         if (usesysctl)
 492                 msg = pfatal;
 493         else
 494                 msg = pwarn;
 495         astart = ustart = aend = uend = -1;
 496         for (i = 0; i < mapsize; i++) {
 497                 j = *map1++;
 498                 k = *map2++;
 499                 if (j == k)
 500                         continue;
 501                 for (m = 0, l = 1; m < CHAR_BIT; m++, l <<= 1) {
 502                         if ((j & l) == (k & l))
 503                                 continue;
 504                         n = startvalue + i * CHAR_BIT + m;
 505                         if ((j & l) != 0) {
 506                                 if (astart == -1) {
 507                                         astart = aend = n;
 508                                         continue;
 509                                 }
 510                                 if (aend + 1 == n) {
 511                                         aend = n;
 512                                         continue;
 513                                 }
 514                                 if (astart == aend)
 515                                         (*msg)("ALLOCATED %s %" PRId64
 516                                             " MARKED FREE\n",
 517                                             name, astart);
 518                                 else
 519                                         (*msg)("%s %sS %" PRId64 "-%" PRId64
 520                                             " MARKED FREE\n",
 521                                             "ALLOCATED", name, astart, aend);
 522                                 astart = aend = n;
 523                         } else {
 524                                 if (ustart == -1) {
 525                                         ustart = uend = n;
 526                                         continue;
 527                                 }
 528                                 if (uend + 1 == n) {
 529                                         uend = n;
 530                                         continue;
 531                                 }
 532                                 size = uend - ustart + 1;
 533                                 if (size <= skip) {
 534                                         skip -= size;
 535                                         ustart = uend = n;
 536                                         continue;
 537                                 }
 538                                 if (skip > 0) {
 539                                         ustart += skip;
 540                                         size -= skip;
 541                                         skip = 0;
 542                                 }
 543                                 if (size > limit)
 544                                         size = limit;
 545                                 if (debug && size == 1)
 546                                         pwarn("%s %s %" PRId64
 547                                             " MARKED USED\n",
 548                                             "UNALLOCATED", name, ustart);
 549                                 else if (debug)
 550                                         pwarn("%s %sS %" PRId64 "-%" PRId64
 551                                             " MARKED USED\n",
 552                                             "UNALLOCATED", name, ustart,
 553                                             ustart + size - 1);
 554                                 if (usesysctl != 0) {
 555                                         cmd.value = ustart;
 556                                         cmd.size = size;
 557                                         if (sysctl(opcode, MIBSIZE, 0, 0,
 558                                             &cmd, sizeof cmd) == -1) {
 559                                                 snprintf(buf, BUFSIZE,
 560                                                     "FREE %s", name);
 561                                                 rwerror(buf, cmd.value);
 562                                         }
 563                                 }
 564                                 limit -= size;
 565                                 if (limit <= 0)
 566                                         return;
 567                                 ustart = uend = n;
 568                         }
 569                 }
 570         }
 571         if (astart != -1) {
 572                 if (astart == aend)
 573                         (*msg)("ALLOCATED %s %" PRId64
 574                             " MARKED FREE\n", name, astart);
 575                 else
 576                         (*msg)("ALLOCATED %sS %" PRId64 "-%" PRId64
 577                             " MARKED FREE\n",
 578                             name, astart, aend);
 579         }
 580         if (ustart != -1) {
 581                 size = uend - ustart + 1;
 582                 if (size <= skip)
 583                         return;
 584                 if (skip > 0) {
 585                         ustart += skip;
 586                         size -= skip;
 587                 }
 588                 if (size > limit)
 589                         size = limit;
 590                 if (debug) {
 591                         if (size == 1)
 592                                 pwarn("UNALLOCATED %s %" PRId64
 593                                     " MARKED USED\n",
 594                                     name, ustart);
 595                         else
 596                                 pwarn("UNALLOCATED %sS %" PRId64 "-%" PRId64
 597                                     " MARKED USED\n",
 598                                     name, ustart, ustart + size - 1);
 599                 }
 600                 if (usesysctl != 0) {
 601                         cmd.value = ustart;
 602                         cmd.size = size;
 603                         if (sysctl(opcode, MIBSIZE, 0, 0, &cmd,
 604                             sizeof cmd) == -1) {
 605                                 snprintf(buf, BUFSIZE, "FREE %s", name);
 606                                 rwerror(buf, cmd.value);
 607                         }
 608                 }
 609         }
 610 }
 611
 612 static void
 613 clear_blocks(ufs2_daddr_t start, ufs2_daddr_t end)
 614 {
 615
 616         if (debug)
 617                 printf("Zero frags %jd to %jd\n", start, end);
 618         if (Zflag)
 619                 blzero(fswritefd, fsbtodb(&sblock, start),
 620                     lfragtosize(&sblock, end - start + 1));
 621         if (Eflag)
 622                 blerase(fswritefd, fsbtodb(&sblock, start),
 623                     lfragtosize(&sblock, end - start + 1));
 624 }