sbin/fsck_ffs/setup.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[] = "@(#)setup.c       8.10 (Berkeley) 5/9/95";
  35 #endif /* not lint */
  36 #endif
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD$");
  39
  40 #include <sys/param.h>
  41 #include <sys/disk.h>
  42 #include <sys/stat.h>
  43 #define FSTYPENAMES
  44 #include <sys/disklabel.h>
  45 #include <sys/file.h>
  46 #include <sys/sysctl.h>
  47
  48 #include <ufs/ufs/dinode.h>
  49 #include <ufs/ffs/fs.h>
  50
  51 #include <ctype.h>
  52 #include <err.h>
  53 #include <errno.h>
  54 #include <limits.h>
  55 #include <stdint.h>
  56 #include <string.h>
  57
  58 #include "fsck.h"
  59
  60 struct bufarea asblk;
  61 #define altsblock (*asblk.b_un.b_fs)
  62 #define POWEROF2(num)   (((num) & ((num) - 1)) == 0)
  63
  64 static int calcsb(char *dev, int devfd, struct fs *fs);
  65 static void saverecovery(int readfd, int writefd);
  66 static int chkrecovery(int devfd);
  67
  68 /*
  69  * Read in a superblock finding an alternate if necessary.
  70  * Return 1 if successful, 0 if unsuccessful, -1 if file system
  71  * is already clean (ckclean and preen mode only).
  72  */
  73 int
  74 setup(char *dev)
  75 {
  76         long cg, asked, i, j;
  77         long bmapsize;
  78         struct stat statb;
  79         struct fs proto;
  80         size_t size;
  81
  82         havesb = 0;
  83         fswritefd = -1;
  84         cursnapshot = 0;
  85         if (stat(dev, &statb) < 0) {
  86                 printf("Can't stat %s: %s\n", dev, strerror(errno));
  87                 if (bkgrdflag) {
  88                         unlink(snapname);
  89                         bkgrdflag = 0;
  90                 }
  91                 return (0);
  92         }
  93         if ((statb.st_mode & S_IFMT) != S_IFCHR &&
  94             (statb.st_mode & S_IFMT) != S_IFBLK) {
  95                 if (bkgrdflag != 0 && (statb.st_flags & SF_SNAPSHOT) == 0) {
  96                         unlink(snapname);
  97                         printf("background fsck lacks a snapshot\n");
  98                         exit(EEXIT);
  99                 }
 100                 if ((statb.st_flags & SF_SNAPSHOT) != 0 && cvtlevel == 0) {
 101                         cursnapshot = statb.st_ino;
 102                 } else {
 103                         if (cvtlevel == 0 ||
 104                             (statb.st_flags & SF_SNAPSHOT) == 0) {
 105                                 if (preen && bkgrdflag) {
 106                                         unlink(snapname);
 107                                         bkgrdflag = 0;
 108                                 }
 109                                 pfatal("%s is not a disk device", dev);
 110                                 if (reply("CONTINUE") == 0) {
 111                                         if (bkgrdflag) {
 112                                                 unlink(snapname);
 113                                                 bkgrdflag = 0;
 114                                         }
 115                                         return (0);
 116                                 }
 117                         } else {
 118                                 if (bkgrdflag) {
 119                                         unlink(snapname);
 120                                         bkgrdflag = 0;
 121                                 }
 122                                 pfatal("cannot convert a snapshot");
 123                                 exit(EEXIT);
 124                         }
 125                 }
 126         }
 127         if ((fsreadfd = open(dev, O_RDONLY)) < 0) {
 128                 if (bkgrdflag) {
 129                         unlink(snapname);
 130                         bkgrdflag = 0;
 131                 }
 132                 printf("Can't open %s: %s\n", dev, strerror(errno));
 133                 return (0);
 134         }
 135         if (bkgrdflag) {
 136                 unlink(snapname);
 137                 size = MIBSIZE;
 138                 if (sysctlnametomib("vfs.ffs.adjrefcnt", adjrefcnt, &size) < 0||
 139                     sysctlnametomib("vfs.ffs.adjblkcnt", adjblkcnt, &size) < 0||
 140                     sysctlnametomib("vfs.ffs.freefiles", freefiles, &size) < 0||
 141                     sysctlnametomib("vfs.ffs.freedirs", freedirs, &size) < 0 ||
 142                     sysctlnametomib("vfs.ffs.freeblks", freeblks, &size) < 0) {
 143                         pfatal("kernel lacks background fsck support\n");
 144                         exit(EEXIT);
 145                 }
 146                 /*
 147                  * When kernel is lack of runtime bgfsck superblock summary
 148                  * adjustment functionality, it does not mean we can not
 149                  * continue, as old kernels will recompute the summary at
 150                  * mount time.  However, it will be an unexpected softupdates
 151                  * inconsistency if it turns out that the summary is still
 152                  * incorrect.  Set a flag so subsequent operation can know
 153                  * this.
 154                  */
 155                 bkgrdsumadj = 1;
 156                 if (sysctlnametomib("vfs.ffs.adjndir", adjndir, &size) < 0 ||
 157                     sysctlnametomib("vfs.ffs.adjnbfree", adjnbfree, &size) < 0 ||
 158                     sysctlnametomib("vfs.ffs.adjnifree", adjnifree, &size) < 0 ||
 159                     sysctlnametomib("vfs.ffs.adjnffree", adjnffree, &size) < 0 ||
 160                     sysctlnametomib("vfs.ffs.adjnumclusters", adjnumclusters, &size) < 0) {
 161                         bkgrdsumadj = 0;
 162                         pwarn("kernel lacks runtime superblock summary adjustment support");
 163                 }
 164                 cmd.version = FFS_CMD_VERSION;
 165                 cmd.handle = fsreadfd;
 166                 fswritefd = -1;
 167         }
 168         if (preen == 0)
 169                 printf("** %s", dev);
 170         if (bkgrdflag == 0 &&
 171             (nflag || (fswritefd = open(dev, O_WRONLY)) < 0)) {
 172                 fswritefd = -1;
 173                 if (preen)
 174                         pfatal("NO WRITE ACCESS");
 175                 printf(" (NO WRITE)");
 176         }
 177         if (preen == 0)
 178                 printf("\n");
 179         /*
 180          * Read in the superblock, looking for alternates if necessary
 181          */
 182         if (readsb(1) == 0) {
 183                 skipclean = 0;
 184                 if (bflag || preen || calcsb(dev, fsreadfd, &proto) == 0)
 185                         return(0);
 186                 if (reply("LOOK FOR ALTERNATE SUPERBLOCKS") == 0)
 187                         return (0);
 188                 for (cg = 0; cg < proto.fs_ncg; cg++) {
 189                         bflag = fsbtodb(&proto, cgsblock(&proto, cg));
 190                         if (readsb(0) != 0)
 191                                 break;
 192                 }
 193                 if (cg >= proto.fs_ncg) {
 194                         printf("%s %s\n%s %s\n%s %s\n",
 195                                 "SEARCH FOR ALTERNATE SUPER-BLOCK",
 196                                 "FAILED. YOU MUST USE THE",
 197                                 "-b OPTION TO FSCK TO SPECIFY THE",
 198                                 "LOCATION OF AN ALTERNATE",
 199                                 "SUPER-BLOCK TO SUPPLY NEEDED",
 200                                 "INFORMATION; SEE fsck_ffs(8).");
 201                         bflag = 0;
 202                         return(0);
 203                 }
 204                 pwarn("USING ALTERNATE SUPERBLOCK AT %jd\n", bflag);
 205                 bflag = 0;
 206         }
 207         if (skipclean && ckclean && sblock.fs_clean) {
 208                 pwarn("FILE SYSTEM CLEAN; SKIPPING CHECKS\n");
 209                 return (-1);
 210         }
 211         maxfsblock = sblock.fs_size;
 212         maxino = sblock.fs_ncg * sblock.fs_ipg;
 213         /*
 214          * Check and potentially fix certain fields in the super block.
 215          */
 216         if (sblock.fs_optim != FS_OPTTIME && sblock.fs_optim != FS_OPTSPACE) {
 217                 pfatal("UNDEFINED OPTIMIZATION IN SUPERBLOCK");
 218                 if (reply("SET TO DEFAULT") == 1) {
 219                         sblock.fs_optim = FS_OPTTIME;
 220                         sbdirty();
 221                 }
 222         }
 223         if ((sblock.fs_minfree < 0 || sblock.fs_minfree > 99)) {
 224                 pfatal("IMPOSSIBLE MINFREE=%d IN SUPERBLOCK",
 225                         sblock.fs_minfree);
 226                 if (reply("SET TO DEFAULT") == 1) {
 227                         sblock.fs_minfree = 10;
 228                         sbdirty();
 229                 }
 230         }
 231         if (sblock.fs_magic == FS_UFS1_MAGIC &&
 232             sblock.fs_old_inodefmt < FS_44INODEFMT) {
 233                 pwarn("Format of file system is too old.\n");
 234                 pwarn("Must update to modern format using a version of fsck\n");
 235                 pfatal("from before 2002 with the command ``fsck -c 2''\n");
 236                 exit(EEXIT);
 237         }
 238         if (asblk.b_dirty && !bflag) {
 239                 memmove(&altsblock, &sblock, (size_t)sblock.fs_sbsize);
 240                 flush(fswritefd, &asblk);
 241         }
 242         if (preen == 0 && yflag == 0 && sblock.fs_magic == FS_UFS2_MAGIC &&
 243             fswritefd != -1 && chkrecovery(fsreadfd) == 0 &&
 244             reply("SAVE DATA TO FIND ALTERNATE SUPERBLOCKS") != 0)
 245                 saverecovery(fsreadfd, fswritefd);
 246         /*
 247          * read in the summary info.
 248          */
 249         asked = 0;
 250         sblock.fs_csp = Calloc(1, sblock.fs_cssize);
 251         if (sblock.fs_csp == NULL) {
 252                 printf("cannot alloc %u bytes for cg summary info\n",
 253                     (unsigned)sblock.fs_cssize);
 254                 goto badsb;
 255         }
 256         for (i = 0, j = 0; i < sblock.fs_cssize; i += sblock.fs_bsize, j++) {
 257                 size = MIN(sblock.fs_cssize - i, sblock.fs_bsize);
 258                 readcnt[sblk.b_type]++;
 259                 if (blread(fsreadfd, (char *)sblock.fs_csp + i,
 260                     fsbtodb(&sblock, sblock.fs_csaddr + j * sblock.fs_frag),
 261                     size) != 0 && !asked) {
 262                         pfatal("BAD SUMMARY INFORMATION");
 263                         if (reply("CONTINUE") == 0) {
 264                                 ckfini(0);
 265                                 exit(EEXIT);
 266                         }
 267                         asked++;
 268                 }
 269         }
 270         /*
 271          * allocate and initialize the necessary maps
 272          */
 273         bmapsize = roundup(howmany(maxfsblock, CHAR_BIT), sizeof(short));
 274         blockmap = Calloc((unsigned)bmapsize, sizeof (char));
 275         if (blockmap == NULL) {
 276                 printf("cannot alloc %u bytes for blockmap\n",
 277                     (unsigned)bmapsize);
 278                 goto badsb;
 279         }
 280         inostathead = Calloc(sblock.fs_ncg, sizeof(struct inostatlist));
 281         if (inostathead == NULL) {
 282                 printf("cannot alloc %u bytes for inostathead\n",
 283                     (unsigned)(sizeof(struct inostatlist) * (sblock.fs_ncg)));
 284                 goto badsb;
 285         }
 286         numdirs = MAX(sblock.fs_cstotal.cs_ndir, 128);
 287         dirhash = numdirs;
 288         inplast = 0;
 289         listmax = numdirs + 10;
 290         inpsort = (struct inoinfo **)Calloc(listmax, sizeof(struct inoinfo *));
 291         inphead = (struct inoinfo **)Calloc(numdirs, sizeof(struct inoinfo *));
 292         if (inpsort == NULL || inphead == NULL) {
 293                 printf("cannot alloc %ju bytes for inphead\n",
 294                     (uintmax_t)numdirs * sizeof(struct inoinfo *));
 295                 goto badsb;
 296         }
 297         bufinit();
 298         if (sblock.fs_flags & FS_DOSOFTDEP)
 299                 usedsoftdep = 1;
 300         else
 301                 usedsoftdep = 0;
 302         return (1);
 303
 304 badsb:
 305         ckfini(0);
 306         return (0);
 307 }
 308
 309 /*
 310  * Possible superblock locations ordered from most to least likely.
 311  */
 312 static int sblock_try[] = SBLOCKSEARCH;
 313
 314 #define BAD_MAGIC_MSG \
 315 "The previous newfs operation on this volume did not complete.\n" \
 316 "You must complete newfs before mounting this volume.\n"
 317
 318 /*
 319  * Read in the super block and its summary info.
 320  */
 321 int
 322 readsb(int listerr)
 323 {
 324         ufs2_daddr_t super;
 325         int i, bad;
 326
 327         if (bflag) {
 328                 super = bflag;
 329                 readcnt[sblk.b_type]++;
 330                 if ((blread(fsreadfd, (char *)&sblock, super, (long)SBLOCKSIZE)))
 331                         return (0);
 332                 if (sblock.fs_magic == FS_BAD_MAGIC) {
 333                         fprintf(stderr, BAD_MAGIC_MSG);
 334                         exit(11);
 335                 }
 336                 if (sblock.fs_magic != FS_UFS1_MAGIC &&
 337                     sblock.fs_magic != FS_UFS2_MAGIC) {
 338                         fprintf(stderr, "%jd is not a file system superblock\n",
 339                             bflag);
 340                         return (0);
 341                 }
 342         } else {
 343                 for (i = 0; sblock_try[i] != -1; i++) {
 344                         super = sblock_try[i] / dev_bsize;
 345                         readcnt[sblk.b_type]++;
 346                         if ((blread(fsreadfd, (char *)&sblock, super,
 347                             (long)SBLOCKSIZE)))
 348                                 return (0);
 349                         if (sblock.fs_magic == FS_BAD_MAGIC) {
 350                                 fprintf(stderr, BAD_MAGIC_MSG);
 351                                 exit(11);
 352                         }
 353                         if ((sblock.fs_magic == FS_UFS1_MAGIC ||
 354                              (sblock.fs_magic == FS_UFS2_MAGIC &&
 355                               sblock.fs_sblockloc == sblock_try[i])) &&
 356                             sblock.fs_ncg >= 1 &&
 357                             sblock.fs_bsize >= MINBSIZE &&
 358                             sblock.fs_sbsize >= roundup(sizeof(struct fs), dev_bsize))
 359                                 break;
 360                 }
 361                 if (sblock_try[i] == -1) {
 362                         fprintf(stderr, "Cannot find file system superblock\n");
 363                         return (0);
 364                 }
 365         }
 366         /*
 367          * Compute block size that the file system is based on,
 368          * according to fsbtodb, and adjust superblock block number
 369          * so we can tell if this is an alternate later.
 370          */
 371         super *= dev_bsize;
 372         dev_bsize = sblock.fs_fsize / fsbtodb(&sblock, 1);
 373         sblk.b_bno = super / dev_bsize;
 374         sblk.b_size = SBLOCKSIZE;
 375         /*
 376          * Compare all fields that should not differ in alternate super block.
 377          * When an alternate super-block is specified this check is skipped.
 378          */
 379         if (bflag)
 380                 goto out;
 381         getblk(&asblk, cgsblock(&sblock, sblock.fs_ncg - 1), sblock.fs_sbsize);
 382         if (asblk.b_errs)
 383                 return (0);
 384         bad = 0;
 385 #define CHK(x, y)                               \
 386         if (altsblock.x != sblock.x) {          \
 387                 bad++;                          \
 388                 if (listerr && debug)           \
 389                         printf("SUPER BLOCK VS ALTERNATE MISMATCH %s: " y " vs " y "\n", \
 390                             #x, (intmax_t)sblock.x, (intmax_t)altsblock.x); \
 391         }
 392         CHK(fs_sblkno, "%jd");
 393         CHK(fs_cblkno, "%jd");
 394         CHK(fs_iblkno, "%jd");
 395         CHK(fs_dblkno, "%jd");
 396         CHK(fs_ncg, "%jd");
 397         CHK(fs_bsize, "%jd");
 398         CHK(fs_fsize, "%jd");
 399         CHK(fs_frag, "%jd");
 400         CHK(fs_bmask, "%#jx");
 401         CHK(fs_fmask, "%#jx");
 402         CHK(fs_bshift, "%jd");
 403         CHK(fs_fshift, "%jd");
 404         CHK(fs_fragshift, "%jd");
 405         CHK(fs_fsbtodb, "%jd");
 406         CHK(fs_sbsize, "%jd");
 407         CHK(fs_nindir, "%jd");
 408         CHK(fs_inopb, "%jd");
 409         CHK(fs_cssize, "%jd");
 410         CHK(fs_ipg, "%jd");
 411         CHK(fs_fpg, "%jd");
 412         CHK(fs_magic, "%#jx");
 413 #undef CHK
 414         if (bad) {
 415                 if (listerr == 0)
 416                         return (0);
 417                 if (preen)
 418                         printf("%s: ", cdevname);
 419                 printf(
 420                     "VALUES IN SUPER BLOCK LSB=%jd DISAGREE WITH THOSE IN\n"
 421                     "LAST ALTERNATE LSB=%jd\n",
 422                     sblk.b_bno, asblk.b_bno);
 423                 if (reply("IGNORE ALTERNATE SUPER BLOCK") == 0)
 424                         return (0);
 425         }
 426 out:
 427         /*
 428          * If not yet done, update UFS1 superblock with new wider fields.
 429          */
 430         if (sblock.fs_magic == FS_UFS1_MAGIC &&
 431             sblock.fs_maxbsize != sblock.fs_bsize) {
 432                 sblock.fs_maxbsize = sblock.fs_bsize;
 433                 sblock.fs_time = sblock.fs_old_time;
 434                 sblock.fs_size = sblock.fs_old_size;
 435                 sblock.fs_dsize = sblock.fs_old_dsize;
 436                 sblock.fs_csaddr = sblock.fs_old_csaddr;
 437                 sblock.fs_cstotal.cs_ndir = sblock.fs_old_cstotal.cs_ndir;
 438                 sblock.fs_cstotal.cs_nbfree = sblock.fs_old_cstotal.cs_nbfree;
 439                 sblock.fs_cstotal.cs_nifree = sblock.fs_old_cstotal.cs_nifree;
 440                 sblock.fs_cstotal.cs_nffree = sblock.fs_old_cstotal.cs_nffree;
 441         }
 442         havesb = 1;
 443         return (1);
 444 }
 445
 446 void
 447 sblock_init(void)
 448 {
 449
 450         fswritefd = -1;
 451         fsmodified = 0;
 452         lfdir = 0;
 453         initbarea(&sblk, BT_SUPERBLK);
 454         initbarea(&asblk, BT_SUPERBLK);
 455         sblk.b_un.b_buf = Malloc(SBLOCKSIZE);
 456         asblk.b_un.b_buf = Malloc(SBLOCKSIZE);
 457         if (sblk.b_un.b_buf == NULL || asblk.b_un.b_buf == NULL)
 458                 errx(EEXIT, "cannot allocate space for superblock");
 459         dev_bsize = secsize = DEV_BSIZE;
 460 }
 461
 462 /*
 463  * Calculate a prototype superblock based on information in the boot area.
 464  * When done the cgsblock macro can be calculated and the fs_ncg field
 465  * can be used. Do NOT attempt to use other macros without verifying that
 466  * their needed information is available!
 467  */
 468 static int
 469 calcsb(char *dev, int devfd, struct fs *fs)
 470 {
 471         struct fsrecovery *fsr;
 472         char *fsrbuf;
 473         u_int secsize;
 474
 475         /*
 476          * We need fragments-per-group and the partition-size.
 477          *
 478          * Newfs stores these details at the end of the boot block area
 479          * at the start of the filesystem partition. If they have been
 480          * overwritten by a boot block, we fail. But usually they are
 481          * there and we can use them.
 482          */
 483         if (ioctl(devfd, DIOCGSECTORSIZE, &secsize) == -1)
 484                 return (0);
 485         fsrbuf = Malloc(secsize);
 486         if (fsrbuf == NULL)
 487                 errx(EEXIT, "calcsb: cannot allocate recovery buffer");
 488         if (blread(devfd, fsrbuf,
 489             (SBLOCK_UFS2 - secsize) / dev_bsize, secsize) != 0)
 490                 return (0);
 491         fsr = (struct fsrecovery *)&fsrbuf[secsize - sizeof *fsr];
 492         if (fsr->fsr_magic != FS_UFS2_MAGIC)
 493                 return (0);
 494         memset(fs, 0, sizeof(struct fs));
 495         fs->fs_fpg = fsr->fsr_fpg;
 496         fs->fs_fsbtodb = fsr->fsr_fsbtodb;
 497         fs->fs_sblkno = fsr->fsr_sblkno;
 498         fs->fs_magic = fsr->fsr_magic;
 499         fs->fs_ncg = fsr->fsr_ncg;
 500         free(fsrbuf);
 501         return (1);
 502 }
 503
 504 /*
 505  * Check to see if recovery information exists.
 506  * Return 1 if it exists or cannot be created.
 507  * Return 0 if it does not exist and can be created.
 508  */
 509 static int
 510 chkrecovery(int devfd)
 511 {
 512         struct fsrecovery *fsr;
 513         char *fsrbuf;
 514         u_int secsize;
 515
 516         /*
 517          * Could not determine if backup material exists, so do not
 518          * offer to create it.
 519          */
 520         if (ioctl(devfd, DIOCGSECTORSIZE, &secsize) == -1 ||
 521             (fsrbuf = Malloc(secsize)) == NULL ||
 522             blread(devfd, fsrbuf, (SBLOCK_UFS2 - secsize) / dev_bsize,
 523               secsize) != 0)
 524                 return (1);
 525         /*
 526          * Recovery material has already been created, so do not
 527          * need to create it again.
 528          */
 529         fsr = (struct fsrecovery *)&fsrbuf[secsize - sizeof *fsr];
 530         if (fsr->fsr_magic == FS_UFS2_MAGIC) {
 531                 free(fsrbuf);
 532                 return (1);
 533         }
 534         /*
 535          * Recovery material has not been created and can be if desired.
 536          */
 537         free(fsrbuf);
 538         return (0);
 539 }
 540
 541 /*
 542  * Read the last sector of the boot block, replace the last
 543  * 20 bytes with the recovery information, then write it back.
 544  * The recovery information only works for UFS2 filesystems.
 545  */
 546 static void
 547 saverecovery(int readfd, int writefd)
 548 {
 549         struct fsrecovery *fsr;
 550         char *fsrbuf;
 551         u_int secsize;
 552
 553         if (sblock.fs_magic != FS_UFS2_MAGIC ||
 554             ioctl(readfd, DIOCGSECTORSIZE, &secsize) == -1 ||
 555             (fsrbuf = Malloc(secsize)) == NULL ||
 556             blread(readfd, fsrbuf, (SBLOCK_UFS2 - secsize) / dev_bsize,
 557               secsize) != 0) {
 558                 printf("RECOVERY DATA COULD NOT BE CREATED\n");
 559                 return;
 560         }
 561         fsr = (struct fsrecovery *)&fsrbuf[secsize - sizeof *fsr];
 562         fsr->fsr_magic = sblock.fs_magic;
 563         fsr->fsr_fpg = sblock.fs_fpg;
 564         fsr->fsr_fsbtodb = sblock.fs_fsbtodb;
 565         fsr->fsr_sblkno = sblock.fs_sblkno;
 566         fsr->fsr_ncg = sblock.fs_ncg;
 567         blwrite(writefd, fsrbuf, (SBLOCK_UFS2 - secsize) / secsize, secsize);
 568         free(fsrbuf);
 569 }