sys/kern/subr_diskmbr.c

   1 /*-
   2  * Copyright (c) 1994 Bruce D. Evans.
   3  * All rights reserved.
   4  *
   5  * Copyright (c) 1982, 1986, 1988 Regents of the University of California.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  *      from: @(#)ufs_disksubr.c        7.16 (Berkeley) 5/4/91
  33  *      from: ufs_disksubr.c,v 1.8 1994/06/07 01:21:39 phk Exp $
  34  * $FreeBSD: src/sys/kern/subr_diskmbr.c,v 1.45 2000/01/28 10:22:07 bde Exp $
  35  */
  36
  37 #include <sys/param.h>
  38 #include <sys/systm.h>
  39 #include <sys/buf.h>
  40 #include <sys/conf.h>
  41 #include <sys/diskslice.h>
  42 #define DOSPTYP_EXTENDED        5
  43 #define DOSPTYP_EXTENDEDX       15
  44 #define DOSPTYP_ONTRACK         84
  45 #include <sys/diskmbr.h>
  46 #include <sys/disk.h>
  47 #include <sys/malloc.h>
  48 #include <sys/syslog.h>
  49 #include <sys/device.h>
  50
  51 #define TRACE(str)      do { if (dsi_debug) kprintf str; } while (0)
  52
  53 static volatile u_char dsi_debug;
  54
  55 /*
  56  * This is what we have embedded in every boot1 for supporting the bogus
  57  * "Dangerously Dedicated" mode. However, the old table is broken because
  58  * it has an illegal geometry in it - it specifies 256 heads (heads = end
  59  * head + 1) which causes nasty stuff when that wraps to zero in bios code.
  60  * eg: divide by zero etc. This caused the dead-thinkpad problem, numerous
  61  * SCSI bios crashes, EFI to crash, etc.
  62  *
  63  * We still have to recognize the old table though, even though we stopped
  64  * inflicting it upon the world.
  65  */
  66 static struct dos_partition historical_bogus_partition_table[NDOSPART] = {
  67         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
  68         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
  69         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
  70         { 0x80, 0, 1, 0, DOSPTYP_DFLYBSD, 255, 255, 255, 0, 50000, },
  71 };
  72 static struct dos_partition historical_bogus_partition_table_fixed[NDOSPART] = {
  73         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
  74         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
  75         { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, },
  76         { 0x80, 0, 1, 0, DOSPTYP_DFLYBSD, 254, 255, 255, 0, 50000, },
  77 };
  78
  79 static int check_part (char *sname, struct dos_partition *dp,
  80                            u_int64_t offset, int nsectors, int ntracks,
  81                            u_int64_t mbr_offset);
  82 static void mbr_extended (cdev_t dev, struct disk_info *info,
  83                               struct diskslices *ssp, u_int64_t ext_offset,
  84                               u_int64_t ext_size, u_int64_t base_ext_offset,
  85                               int nsectors, int ntracks, u_int64_t mbr_offset,
  86                               int level);
  87 static int mbr_setslice (char *sname, struct disk_info *info,
  88                              struct diskslice *sp, struct dos_partition *dp,
  89                              u_int64_t br_offset);
  90
  91
  92 int
  93 mbrinit(cdev_t dev, struct disk_info *info, struct diskslices **sspp)
  94 {
  95         struct buf *bp;
  96         u_char  *cp;
  97         int     dospart;
  98         struct dos_partition *dp;
  99         struct dos_partition *dp0;
 100         struct dos_partition dpcopy[NDOSPART];
 101         int     error;
 102         int     max_ncyls;
 103         int     max_nsectors;
 104         int     max_ntracks;
 105         u_int64_t mbr_offset;
 106         char    partname[2];
 107         u_long  secpercyl;
 108         char    *sname = "tempname";
 109         struct diskslice *sp;
 110         struct diskslices *ssp;
 111         cdev_t wdev;
 112
 113         mbr_offset = DOSBBSECTOR;
 114 reread_mbr:
 115         /*
 116          * Don't bother if the block size is weird or the
 117          * media size is 0 (probably means no media present).
 118          */
 119         if (info->d_media_blksize & DEV_BMASK)
 120                 return (EIO);
 121         if (info->d_media_size == 0)
 122                 return (EIO);
 123
 124         /*
 125          * Read master boot record.
 126          */
 127         wdev = dev;
 128         bp = getpbuf_mem(NULL);
 129         KKASSERT((int)info->d_media_blksize <= bp->b_bufsize);
 130         bp->b_bio1.bio_offset = (off_t)mbr_offset * info->d_media_blksize;
 131         bp->b_bio1.bio_done = biodone_sync;
 132         bp->b_bio1.bio_flags |= BIO_SYNC;
 133         bp->b_bcount = info->d_media_blksize;
 134         bp->b_cmd = BUF_CMD_READ;
 135         bp->b_flags |= B_FAILONDIS;
 136         dev_dstrategy(wdev, &bp->b_bio1);
 137         if (biowait(&bp->b_bio1, "mbrrd") != 0) {
 138                 if ((info->d_dsflags & DSO_MBRQUIET) == 0) {
 139                         diskerr(&bp->b_bio1, wdev,
 140                                 "reading primary partition table: error",
 141                                 LOG_PRINTF, 0);
 142                         kprintf("\n");
 143                 }
 144                 error = EIO;
 145                 goto done;
 146         }
 147
 148         /* Weakly verify it. */
 149         cp = bp->b_data;
 150         sname = dsname(dev, 0, 0, 0, NULL);
 151         if (cp[0x1FE] != 0x55 || cp[0x1FF] != 0xAA) {
 152                 if (bootverbose)
 153                         kprintf("%s: invalid primary partition table: no magic\n",
 154                                sname);
 155                 error = EINVAL;
 156                 goto done;
 157         }
 158
 159         /* Make a copy of the partition table to avoid alignment problems. */
 160         memcpy(&dpcopy[0], cp + DOSPARTOFF, sizeof(dpcopy));
 161
 162         dp0 = &dpcopy[0];
 163
 164         /*
 165          * Check for "Ontrack Diskmanager" or GPT.  If a GPT is found in
 166          * the first dos partition, ignore the rest of the MBR and go
 167          * to GPT processing.
 168          */
 169         for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) {
 170                 if (dospart == 0 && dp->dp_typ == DOSPTYP_PMBR) {
 171                         if (bootverbose)
 172                                 kprintf(
 173             "%s: Found GPT in slice #%d\n", sname, dospart + 1);
 174                         error = gptinit(dev, info, sspp);
 175                         goto done;
 176                 }
 177
 178                 if (dp->dp_typ == DOSPTYP_ONTRACK) {
 179                         if (bootverbose)
 180                                 kprintf(
 181             "%s: Found \"Ontrack Disk Manager\" on this disk.\n", sname);
 182                         bp->b_flags |= B_INVAL | B_AGE;
 183                         brelse(bp);
 184                         mbr_offset = 63;
 185                         goto reread_mbr;
 186                 }
 187         }
 188
 189         if (bcmp(dp0, historical_bogus_partition_table,
 190                  sizeof historical_bogus_partition_table) == 0 ||
 191             bcmp(dp0, historical_bogus_partition_table_fixed,
 192                  sizeof historical_bogus_partition_table_fixed) == 0) {
 193 #if 0
 194                 TRACE(("%s: invalid primary partition table: historical\n",
 195                        sname));
 196 #endif /* 0 */
 197                 if (bootverbose)
 198                         kprintf(
 199      "%s: invalid primary partition table: Dangerously Dedicated (ignored)\n",
 200                                sname);
 201                 error = EINVAL;
 202                 goto done;
 203         }
 204
 205         /* Guess the geometry. */
 206         /*
 207          * TODO:
 208          * Perhaps skip entries with 0 size.
 209          * Perhaps only look at entries of type DOSPTYP_386BSD or
 210          * DOSPTYP_DFLYBSD
 211          */
 212         max_ncyls = 0;
 213         max_nsectors = 0;
 214         max_ntracks = 0;
 215         for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) {
 216                 int     ncyls;
 217                 int     nsectors;
 218                 int     ntracks;
 219
 220                 ncyls = DPCYL(dp->dp_ecyl, dp->dp_esect) + 1;
 221                 if (max_ncyls < ncyls)
 222                         max_ncyls = ncyls;
 223                 nsectors = DPSECT(dp->dp_esect);
 224                 if (max_nsectors < nsectors)
 225                         max_nsectors = nsectors;
 226                 ntracks = dp->dp_ehd + 1;
 227                 if (max_ntracks < ntracks)
 228                         max_ntracks = ntracks;
 229         }
 230
 231         /*
 232          * Check that we have guessed the geometry right by checking the
 233          * partition entries.
 234          */
 235         /*
 236          * TODO:
 237          * As above.
 238          * Check for overlaps.
 239          * Check against d_secperunit if the latter is reliable.
 240          */
 241         error = 0;
 242         for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) {
 243                 if (dp->dp_scyl == 0 && dp->dp_shd == 0 && dp->dp_ssect == 0
 244                     && dp->dp_start == 0 && dp->dp_size == 0)
 245                         continue;
 246                 //sname = dsname(dev, dkunit(dev), BASE_SLICE + dospart,
 247                 //             WHOLE_SLICE_PART, partname);
 248
 249                 /*
 250                  * Temporarily ignore errors from this check.  We could
 251                  * simplify things by accepting the table eariler if we
 252                  * always ignore errors here.  Perhaps we should always
 253                  * accept the table if the magic is right but not let
 254                  * bad entries affect the geometry.
 255                  */
 256                 check_part(sname, dp, mbr_offset, max_nsectors, max_ntracks,
 257                            mbr_offset);
 258         }
 259         if (error != 0)
 260                 goto done;
 261
 262         /*
 263          * Accept the DOS partition table.
 264          *
 265          * Adjust the disk information structure with updated CHS
 266          * conversion parameters, but only use values extracted from
 267          * the primary partition table.
 268          *
 269          * NOTE!  Regardless of our having to deal with this old cruft,
 270          * we do not screw around with the info->d_media* parameters.
 271          */
 272         secpercyl = (u_long)max_nsectors * max_ntracks;
 273         if (secpercyl != 0 && mbr_offset == DOSBBSECTOR) {
 274                 info->d_secpertrack = max_nsectors;
 275                 info->d_nheads = max_ntracks;
 276                 info->d_secpercyl = secpercyl;
 277                 info->d_ncylinders = info->d_media_blocks / secpercyl;
 278         }
 279
 280         /*
 281          * We are passed a pointer to a suitably initialized minimal
 282          * slices "struct" with no dangling pointers in it.  Replace it
 283          * by a maximal one.  This usually oversizes the "struct", but
 284          * enlarging it while searching for logical drives would be
 285          * inconvenient.
 286          */
 287         kfree(*sspp, M_DEVBUF);
 288         ssp = dsmakeslicestruct(MAX_SLICES, info);
 289         *sspp = ssp;
 290
 291         /* Initialize normal slices. */
 292         sp = &ssp->dss_slices[BASE_SLICE];
 293         for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++, sp++) {
 294                 sname = dsname(dev, dkunit(dev), BASE_SLICE + dospart,
 295                                WHOLE_SLICE_PART, partname);
 296                 (void)mbr_setslice(sname, info, sp, dp, mbr_offset);
 297         }
 298         ssp->dss_nslices = BASE_SLICE + NDOSPART;
 299
 300         /* Handle extended partitions. */
 301         sp -= NDOSPART;
 302         for (dospart = 0; dospart < NDOSPART; dospart++, sp++) {
 303                 if (sp->ds_type == DOSPTYP_EXTENDED ||
 304                     sp->ds_type == DOSPTYP_EXTENDEDX) {
 305                         mbr_extended(wdev, info, ssp,
 306                                      sp->ds_offset, sp->ds_size, sp->ds_offset,
 307                                      max_nsectors, max_ntracks, mbr_offset, 1);
 308                 }
 309         }
 310
 311         /*
 312          * mbr_extended() abuses ssp->dss_nslices for the number of slices
 313          * that would be found if there were no limit on the number of slices
 314          * in *ssp.  Cut it back now.
 315          */
 316         if (ssp->dss_nslices > MAX_SLICES)
 317                 ssp->dss_nslices = MAX_SLICES;
 318
 319 done:
 320         bp->b_flags |= B_INVAL | B_AGE;
 321         relpbuf(bp, NULL);
 322         if (error == EINVAL)
 323                 error = 0;
 324         return (error);
 325 }
 326
 327 static int
 328 check_part(char *sname, struct dos_partition *dp, u_int64_t offset,
 329             int nsectors, int ntracks, u_int64_t mbr_offset)
 330 {
 331         int     chs_ecyl;
 332         int     chs_esect;
 333         int     chs_scyl;
 334         int     chs_ssect;
 335         int     error;
 336         u_long  secpercyl;
 337         u_int64_t esector;
 338         u_int64_t esector1;
 339         u_int64_t ssector;
 340         u_int64_t ssector1;
 341
 342         secpercyl = (u_long)nsectors * ntracks;
 343         chs_scyl = DPCYL(dp->dp_scyl, dp->dp_ssect);
 344         chs_ssect = DPSECT(dp->dp_ssect);
 345         ssector = chs_ssect - 1 + dp->dp_shd * nsectors + chs_scyl * secpercyl
 346                   + mbr_offset;
 347         ssector1 = offset + dp->dp_start;
 348
 349         /*
 350          * If ssector1 is on a cylinder >= 1024, then ssector can't be right.
 351          * Allow the C/H/S for it to be 1023/ntracks-1/nsectors, or correct
 352          * apart from the cylinder being reduced modulo 1024.  Always allow
 353          * 1023/255/63, because this is the official way to represent
 354          * pure-LBA for the starting position.
 355          */
 356         if ((ssector < ssector1
 357              && ((chs_ssect == nsectors && dp->dp_shd == ntracks - 1
 358                   && chs_scyl == 1023)
 359                  || (secpercyl != 0
 360                      && (ssector1 - ssector) % (1024 * secpercyl) == 0)))
 361             || (dp->dp_scyl == 255 && dp->dp_shd == 255
 362                 && dp->dp_ssect == 255)) {
 363                 TRACE(("%s: C/H/S start %d/%d/%d, start %llu: allow\n",
 364                        sname, chs_scyl, dp->dp_shd, chs_ssect,
 365                        (long long)ssector1));
 366                 ssector = ssector1;
 367         }
 368
 369         chs_ecyl = DPCYL(dp->dp_ecyl, dp->dp_esect);
 370         chs_esect = DPSECT(dp->dp_esect);
 371         esector = chs_esect - 1 + dp->dp_ehd * nsectors + chs_ecyl * secpercyl
 372                   + mbr_offset;
 373         esector1 = ssector1 + dp->dp_size - 1;
 374
 375         /*
 376          * Allow certain bogus C/H/S values for esector, as above. However,
 377          * heads == 255 isn't really legal and causes some BIOS crashes. The
 378          * correct value to indicate a pure-LBA end is 1023/heads-1/sectors -
 379          * usually 1023/254/63. "heads" is base 0, "sectors" is base 1.
 380          */
 381         if ((esector < esector1
 382              && ((chs_esect == nsectors && dp->dp_ehd == ntracks - 1
 383                   && chs_ecyl == 1023)
 384                  || (secpercyl != 0
 385                      && (esector1 - esector) % (1024 * secpercyl) == 0)))
 386             || (dp->dp_ecyl == 255 && dp->dp_ehd == 255
 387                 && dp->dp_esect == 255)) {
 388                 TRACE(("%s: C/H/S end %d/%d/%d, end %llu: allow\n",
 389                        sname, chs_ecyl, dp->dp_ehd, chs_esect,
 390                        (long long)esector1));
 391                 esector = esector1;
 392         }
 393
 394         error = (ssector == ssector1 && esector == esector1) ? 0 : EINVAL;
 395         if (bootverbose)
 396                 kprintf("%s: type 0x%x, start %llu, end = %llu, size %u %s\n",
 397                        sname, dp->dp_typ,
 398                        (long long)ssector1, (long long)esector1,
 399                        dp->dp_size, (error ? "" : ": OK"));
 400         if (ssector != ssector1 && bootverbose)
 401                 kprintf("%s: C/H/S start %d/%d/%d (%llu) != start %llu: invalid\n",
 402                        sname, chs_scyl, dp->dp_shd, chs_ssect,
 403                        (long long)ssector, (long long)ssector1);
 404         if (esector != esector1 && bootverbose)
 405                 kprintf("%s: C/H/S end %d/%d/%d (%llu) != end %llu: invalid\n",
 406                        sname, chs_ecyl, dp->dp_ehd, chs_esect,
 407                        (long long)esector, (long long)esector1);
 408         return (error);
 409 }
 410
 411 static
 412 void
 413 mbr_extended(cdev_t dev, struct disk_info *info, struct diskslices *ssp,
 414             u_int64_t ext_offset, u_int64_t ext_size, u_int64_t base_ext_offset,
 415             int nsectors, int ntracks, u_int64_t mbr_offset, int level)
 416 {
 417         struct buf *bp;
 418         u_char  *cp;
 419         int     dospart;
 420         struct dos_partition *dp;
 421         struct dos_partition dpcopy[NDOSPART];
 422         u_int64_t ext_offsets[NDOSPART];
 423         u_int64_t ext_sizes[NDOSPART];
 424         char    partname[2];
 425         int     slice;
 426         char    *sname;
 427         struct diskslice *sp;
 428
 429         if (level >= 16) {
 430                 kprintf(
 431         "%s: excessive recursion in search for slices; aborting search\n",
 432                        devtoname(dev));
 433                 return;
 434         }
 435
 436         /* Read extended boot record. */
 437         bp = getpbuf_mem(NULL);
 438         KKASSERT((int)info->d_media_blksize <= bp->b_bufsize);
 439         bp->b_bio1.bio_offset = (off_t)ext_offset * info->d_media_blksize;
 440         bp->b_bio1.bio_done = biodone_sync;
 441         bp->b_bio1.bio_flags |= BIO_SYNC;
 442         bp->b_bcount = info->d_media_blksize;
 443         bp->b_cmd = BUF_CMD_READ;
 444         bp->b_flags |= B_FAILONDIS;
 445         dev_dstrategy(dev, &bp->b_bio1);
 446         if (biowait(&bp->b_bio1, "mbrrd") != 0) {
 447                 diskerr(&bp->b_bio1, dev,
 448                         "reading extended partition table: error",
 449                         LOG_PRINTF, 0);
 450                 kprintf("\n");
 451                 goto done;
 452         }
 453
 454         /* Weakly verify it. */
 455         cp = bp->b_data;
 456         if (cp[0x1FE] != 0x55 || cp[0x1FF] != 0xAA) {
 457                 sname = dsname(dev, dkunit(dev), WHOLE_DISK_SLICE, WHOLE_SLICE_PART,
 458                                partname);
 459                 if (bootverbose)
 460                         kprintf("%s: invalid extended partition table: no magic\n",
 461                                sname);
 462                 goto done;
 463         }
 464
 465         /* Make a copy of the partition table to avoid alignment problems. */
 466         memcpy(&dpcopy[0], cp + DOSPARTOFF, sizeof(dpcopy));
 467
 468         slice = ssp->dss_nslices;
 469         for (dospart = 0, dp = &dpcopy[0]; dospart < NDOSPART;
 470             dospart++, dp++) {
 471                 ext_sizes[dospart] = 0;
 472                 if (dp->dp_scyl == 0 && dp->dp_shd == 0 && dp->dp_ssect == 0
 473                     && dp->dp_start == 0 && dp->dp_size == 0)
 474                         continue;
 475                 if (dp->dp_typ == DOSPTYP_EXTENDED ||
 476                     dp->dp_typ == DOSPTYP_EXTENDEDX) {
 477                         static char buf[32];
 478
 479                         sname = dsname(dev, dkunit(dev), WHOLE_DISK_SLICE,
 480                                        WHOLE_SLICE_PART, partname);
 481                         ksnprintf(buf, sizeof(buf), "%s", sname);
 482                         if (strlen(buf) < sizeof buf - 11)
 483                                 strcat(buf, "<extended>");
 484                         check_part(buf, dp, base_ext_offset, nsectors,
 485                                    ntracks, mbr_offset);
 486                         ext_offsets[dospart] = base_ext_offset + dp->dp_start;
 487                         ext_sizes[dospart] = dp->dp_size;
 488                 } else {
 489                         sname = dsname(dev, dkunit(dev), slice, WHOLE_SLICE_PART,
 490                                        partname);
 491                         check_part(sname, dp, ext_offset, nsectors, ntracks,
 492                                    mbr_offset);
 493                         if (slice >= MAX_SLICES) {
 494                                 kprintf("%s: too many slices\n", sname);
 495                                 slice++;
 496                                 continue;
 497                         }
 498                         sp = &ssp->dss_slices[slice];
 499                         if (mbr_setslice(sname, info, sp, dp, ext_offset) != 0)
 500                                 continue;
 501                         slice++;
 502                 }
 503         }
 504         ssp->dss_nslices = slice;
 505
 506         /* If we found any more slices, recursively find all the subslices. */
 507         for (dospart = 0; dospart < NDOSPART; dospart++) {
 508                 if (ext_sizes[dospart] != 0) {
 509                         mbr_extended(dev, info, ssp, ext_offsets[dospart],
 510                                      ext_sizes[dospart], base_ext_offset,
 511                                      nsectors, ntracks, mbr_offset, ++level);
 512                 }
 513         }
 514
 515 done:
 516         bp->b_flags |= B_INVAL | B_AGE;
 517         relpbuf(bp, NULL);
 518 }
 519
 520 static int
 521 mbr_setslice(char *sname, struct disk_info *info, struct diskslice *sp,
 522             struct dos_partition *dp, u_int64_t br_offset)
 523 {
 524         u_int64_t       offset;
 525         u_int64_t       size;
 526
 527         offset = br_offset + dp->dp_start;
 528         if (offset > info->d_media_blocks || offset < br_offset) {
 529                 kprintf(
 530                 "%s: slice starts beyond end of the disk: rejecting it\n",
 531                        sname);
 532                 return (1);
 533         }
 534         size = info->d_media_blocks - offset;
 535         if (size >= dp->dp_size) {
 536                 if (dp->dp_size == 0xFFFFFFFFU) {
 537                         kprintf("%s: slice >2TB, using media size instead "
 538                                 "of slice table size\n", sname);
 539                 } else {
 540                         size = dp->dp_size;
 541                 }
 542         } else {
 543                 kprintf("%s: slice extends beyond end of disk: "
 544                         "truncating from %u to %llu sectors\n",
 545                         sname, dp->dp_size, (unsigned long long)size);
 546         }
 547         sp->ds_offset = offset;
 548         sp->ds_size = size;
 549         sp->ds_type = dp->dp_typ;
 550         bzero(&sp->ds_type_uuid, sizeof(sp->ds_type_uuid));
 551         bzero(&sp->ds_stor_uuid, sizeof(sp->ds_type_uuid));
 552
 553         /*
 554          * Slices do not overlap with the parent (if any).
 555          */
 556         sp->ds_reserved = 0;
 557         return (0);
 558 }