Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/kern/subr_disk_mbr.c
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1 /* $NetBSD: subr_disk_mbr.c,v 1.57 2021/05/17 08:50:36 mrg Exp $ */ 2 3 /* 4 * Copyright (c) 1982, 1986, 1988 Regents of the University of California. 5 * 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 * @(#)ufs_disksubr.c 7.16 (Berkeley) 5/4/91 32 */ 33 34 /* 35 * Code to find a NetBSD label on a disk that contains an i386 style MBR. 36 * The first NetBSD label found in the 2nd sector of a NetBSD partition 37 * is used. 38 * If we don't find a label searching the MBR, we look at the start of the 39 * disk, if that fails then a label is faked up from the MBR. 40 * 41 * If there isn't a disklabel or anything in the MBR then the disc is searched 42 * for ecma-167/iso9660/udf style partition indicators. 43 * Useful for media or files that contain single filesystems (etc). 44 * 45 * This code will read host endian netbsd labels from little endian MBR. 46 * 47 * Based on the i386 disksubr.c 48 * 49 * Since the mbr only has 32bit fields for sector addresses, we do the same. 50 * 51 * XXX There are potential problems writing labels to disks where there 52 * is only space for 8 netbsd partitions but this code has been compiled 53 * with MAXPARTITIONS=16. 54 */ 55 56 #include <sys/cdefs.h> 57 __KERNEL_RCSID(0, "$NetBSD: subr_disk_mbr.c,v 1.57 2021/05/17 08:50:36 mrg Exp $"); 58 59 #ifdef _KERNEL_OPT 60 #include "opt_mbr.h" 61 #include "opt_disklabel.h" 62 #endif /* _KERNEL_OPT */ 63 64 #include <sys/param.h> 65 #include <sys/systm.h> 66 #include <sys/buf.h> 67 #include <sys/bootblock.h> 68 #include <sys/disklabel.h> 69 #include <sys/disk.h> 70 #include <sys/syslog.h> 71 #include <sys/vnode.h> 72 #include <sys/fcntl.h> 73 #include <sys/conf.h> 74 #include <sys/cdio.h> 75 #include <sys/dkbad.h> 76 #include <fs/udf/ecma167-udf.h> 77 78 #include <sys/kauth.h> 79 80 typedef struct mbr_partition mbr_partition_t; 81 82 /* 83 * We allocate a buffer 3 sectors large, and look in all.... 84 * That means we find labels written by other ports with different offsets. 85 * LABELSECTOR and LABELOFFSET are only used if the disk doesn't have a label. 86 */ 87 #define SCANBLOCKS 3 88 #define DISKLABEL_SIZE 404 89 #if LABELSECTOR*DEV_BSIZE + LABELOFFSET > SCANBLOCKS*DEV_BSIZE - DISKLABEL_SIZE 90 #if _MACHINE != ews4800mips /* XXX: fail silently, ews4800mips LABELSECTOR */ 91 #error Invalid LABELSECTOR or LABELOFFSET 92 #endif 93 #endif 94 95 #define MBR_LABELSECTOR 1 96 97 #define SCAN_CONTINUE 0 98 #define SCAN_FOUND 1 99 #define SCAN_ERROR 2 100 101 typedef struct mbr_args { 102 struct disklabel *lp; 103 void (*strat)(struct buf *); 104 struct buf *bp; 105 const char *msg; 106 int error; 107 int written; /* number of times we wrote label */ 108 int found_mbr; /* set if disk has a valid mbr */ 109 uint label_sector; /* where we found the label */ 110 int action; 111 uint32_t secperunit; 112 #define READ_LABEL 1 113 #define UPDATE_LABEL 2 114 #define WRITE_LABEL 3 115 } mbr_args_t; 116 117 static int validate_label(mbr_args_t *, uint); 118 static int look_netbsd_part(mbr_args_t *, mbr_partition_t *, int, uint); 119 static int write_netbsd_label(mbr_args_t *, mbr_partition_t *, int, uint); 120 121 static int 122 read_sector(mbr_args_t *a, uint sector, int count) 123 { 124 int error; 125 126 error = disk_read_sectors(a->strat, a->lp, a->bp, sector, count); 127 if (error != 0) 128 a->error = error; 129 return error; 130 } 131 132 /* 133 * Scan MBR for partitions, call 'action' routine for each. 134 */ 135 136 static int 137 scan_mbr(mbr_args_t *a, int (*actn)(mbr_args_t *, mbr_partition_t *, int, uint)) 138 { 139 mbr_partition_t ptns[MBR_PART_COUNT]; 140 mbr_partition_t *dp; 141 struct mbr_sector *mbr; 142 uint ext_base, this_ext, next_ext; 143 int rval; 144 int i; 145 int j; 146 #ifdef COMPAT_386BSD_MBRPART 147 int dp_386bsd = -1; 148 int ap_386bsd = -1; 149 #endif 150 151 ext_base = 0; 152 this_ext = 0; 153 for (;;) { 154 if (read_sector(a, this_ext, 1)) { 155 a->msg = "dos partition I/O error"; 156 return SCAN_ERROR; 157 } 158 159 /* Note: Magic number is little-endian. */ 160 mbr = (void *)a->bp->b_data; 161 if (mbr->mbr_magic != htole16(MBR_MAGIC)) 162 return SCAN_CONTINUE; 163 164 /* 165 * If this is a protective MBR, bail now. 166 */ 167 if (mbr->mbr_parts[0].mbrp_type == MBR_PTYPE_PMBR 168 && mbr->mbr_parts[1].mbrp_type == MBR_PTYPE_UNUSED 169 && mbr->mbr_parts[2].mbrp_type == MBR_PTYPE_UNUSED 170 && mbr->mbr_parts[3].mbrp_type == MBR_PTYPE_UNUSED) 171 return SCAN_CONTINUE; 172 173 /* Copy data out of buffer so action can use bp */ 174 memcpy(ptns, &mbr->mbr_parts, sizeof ptns); 175 176 /* Look for drivers and skip them */ 177 if (ext_base == 0 && ptns[0].mbrp_type == MBR_PTYPE_DM6_DDO) { 178 /* We've found a DM6 DDO partition type (used by 179 * the Ontrack Disk Manager drivers). 180 * 181 * Ensure that there are no other partitions in the 182 * MBR and jump to the real partition table (stored 183 * in the first sector of the second track). */ 184 bool ok = true; 185 186 for (i = 1; i < MBR_PART_COUNT; i++) 187 if (ptns[i].mbrp_type != MBR_PTYPE_UNUSED) 188 ok = false; 189 190 if (ok) { 191 this_ext = le32toh(a->lp->d_secpercyl / 192 a->lp->d_ntracks); 193 continue; 194 } 195 } 196 197 /* look for NetBSD partition */ 198 next_ext = 0; 199 dp = ptns; 200 j = 0; 201 for (i = 0; i < MBR_PART_COUNT; i++, dp++) { 202 if (dp->mbrp_type == MBR_PTYPE_UNUSED) 203 continue; 204 /* Check end of partition is inside disk limits */ 205 if ((uint64_t)ext_base + le32toh(dp->mbrp_start) + 206 le32toh(dp->mbrp_size) > a->lp->d_secperunit) { 207 /* This mbr doesn't look good.... */ 208 a->msg = "mbr partition exceeds disk size"; 209 /* ...but don't report this as an error (yet) */ 210 return SCAN_CONTINUE; 211 } 212 a->found_mbr = 1; 213 if (MBR_IS_EXTENDED(dp->mbrp_type)) { 214 next_ext = le32toh(dp->mbrp_start); 215 continue; 216 } 217 #ifdef COMPAT_386BSD_MBRPART 218 if (dp->mbrp_type == MBR_PTYPE_386BSD) { 219 /* 220 * If more than one matches, take last, 221 * as NetBSD install tool does. 222 */ 223 if (this_ext == 0) { 224 dp_386bsd = i; 225 ap_386bsd = j; 226 } 227 continue; 228 } 229 #endif 230 rval = (*actn)(a, dp, j, this_ext); 231 if (rval != SCAN_CONTINUE) 232 return rval; 233 j++; 234 } 235 if (next_ext == 0) 236 break; 237 if (ext_base == 0) { 238 ext_base = next_ext; 239 next_ext = 0; 240 } 241 next_ext += ext_base; 242 if (next_ext <= this_ext) 243 break; 244 this_ext = next_ext; 245 } 246 #ifdef COMPAT_386BSD_MBRPART 247 if (this_ext == 0 && dp_386bsd != -1) 248 return (*actn)(a, &ptns[dp_386bsd], ap_386bsd, 0); 249 #endif 250 return SCAN_CONTINUE; 251 } 252 253 254 static void 255 scan_iso_vrs_session(mbr_args_t *a, uint32_t first_sector, 256 int *is_iso9660, int *is_udf) 257 { 258 struct vrs_desc *vrsd; 259 uint64_t vrs; 260 int sector_size; 261 int blks, inc; 262 263 sector_size = a->lp->d_secsize; 264 blks = sector_size / DEV_BSIZE; 265 inc = MAX(1, 2048 / sector_size); 266 267 /* by definition */ 268 vrs = ((32*1024 + sector_size - 1) / sector_size) 269 + first_sector; 270 271 /* read first vrs sector */ 272 if (read_sector(a, vrs * blks, 1)) 273 return; 274 275 /* skip all CD001 records */ 276 vrsd = a->bp->b_data; 277 /* printf("vrsd->identifier = `%s`\n", vrsd->identifier); */ 278 while (memcmp(vrsd->identifier, "CD001", 5) == 0) { 279 /* for sure */ 280 *is_iso9660 = first_sector; 281 282 vrs += inc; 283 if (read_sector(a, vrs * blks, 1)) 284 return; 285 } 286 287 /* search for BEA01 */ 288 vrsd = a->bp->b_data; 289 /* printf("vrsd->identifier = `%s`\n", vrsd->identifier); */ 290 if (memcmp(vrsd->identifier, "BEA01", 5)) 291 return; 292 293 /* read successor */ 294 vrs += inc; 295 if (read_sector(a, vrs * blks, 1)) 296 return; 297 298 /* check for NSR[23] */ 299 vrsd = a->bp->b_data; 300 /* printf("vrsd->identifier = `%s`\n", vrsd->identifier); */ 301 if (memcmp(vrsd->identifier, "NSR0", 4)) 302 return; 303 304 *is_udf = first_sector; 305 } 306 307 308 /* 309 * Scan for ISO Volume Recognition Sequences 310 */ 311 312 static int 313 scan_iso_vrs(mbr_args_t *a) 314 { 315 struct mmc_discinfo di; 316 struct mmc_trackinfo ti; 317 dev_t dev; 318 uint64_t sector; 319 int is_iso9660, is_udf; 320 int tracknr, sessionnr; 321 int new_session, error; 322 323 is_iso9660 = is_udf = -1; 324 325 /* parse all sessions of disc if we're on a SCSI MMC device */ 326 if (a->lp->d_flags & D_SCSI_MMC) { 327 /* get disc info */ 328 dev = a->bp->b_dev; 329 error = bdev_ioctl(dev, MMCGETDISCINFO, &di, FKIOCTL, curlwp); 330 if (error) 331 return SCAN_CONTINUE; 332 333 /* go trough all (data) tracks */ 334 sessionnr = -1; 335 for (tracknr = di.first_track; 336 tracknr <= di.first_track_last_session; tracknr++) 337 { 338 ti.tracknr = tracknr; 339 error = bdev_ioctl(dev, MMCGETTRACKINFO, &ti, 340 FKIOCTL, curlwp); 341 if (error) 342 return SCAN_CONTINUE; 343 new_session = (ti.sessionnr != sessionnr); 344 sessionnr = ti.sessionnr; 345 if (new_session) { 346 if (ti.flags & MMC_TRACKINFO_BLANK) 347 continue; 348 if (!(ti.flags & MMC_TRACKINFO_DATA)) 349 continue; 350 sector = ti.track_start; 351 scan_iso_vrs_session(a, sector, 352 &is_iso9660, &is_udf); 353 } 354 } 355 } else { 356 /* try start of disc */ 357 sector = 0; 358 scan_iso_vrs_session(a, sector, &is_iso9660, &is_udf); 359 } 360 361 if ((is_iso9660 < 0) && (is_udf < 0)) 362 return SCAN_CONTINUE; 363 364 strncpy(a->lp->d_typename, "iso partition", 16); 365 366 /* adjust session information for iso9660 partition */ 367 if (is_iso9660 >= 0) { 368 /* set 'a' partition to iso9660 */ 369 a->lp->d_partitions[0].p_offset = 0; 370 a->lp->d_partitions[0].p_size = a->lp->d_secperunit; 371 a->lp->d_partitions[0].p_cdsession = is_iso9660; 372 a->lp->d_partitions[0].p_fstype = FS_ISO9660; 373 } 374 375 /* UDF doesn't care about the cd session specified here */ 376 377 return SCAN_FOUND; 378 } 379 380 381 /* 382 * Attempt to read a disk label from a device 383 * using the indicated strategy routine. 384 * The label must be partly set up before this: 385 * secpercyl, secsize and anything required for a block i/o read 386 * operation in the driver's strategy/start routines 387 * must be filled in before calling us. 388 * 389 * If dos partition table requested, attempt to load it and 390 * find disklabel inside a DOS partition. Also, if bad block 391 * table needed, attempt to extract it as well. Return buffer 392 * for use in signalling errors if requested. 393 * 394 * Returns null on success and an error string on failure. 395 */ 396 const char * 397 readdisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp, 398 struct cpu_disklabel *osdep) 399 { 400 int rval; 401 int i; 402 mbr_args_t a; 403 404 memset(&a, 0, sizeof a); 405 a.lp = lp; 406 a.strat = strat; 407 a.action = READ_LABEL; 408 409 /* minimal requirements for architypal disk label */ 410 if (lp->d_secsize == 0) 411 lp->d_secsize = DEV_BSIZE; 412 if (lp->d_secperunit == 0) 413 lp->d_secperunit = 0x1fffffff; 414 a.secperunit = lp->d_secperunit; 415 lp->d_npartitions = RAW_PART + 1; 416 for (i = 0; i < RAW_PART; i++) { 417 lp->d_partitions[i].p_size = 0; 418 lp->d_partitions[i].p_offset = 0; 419 } 420 if (lp->d_partitions[RAW_PART].p_size == 0) 421 lp->d_partitions[RAW_PART].p_size = lp->d_secperunit; 422 lp->d_partitions[RAW_PART].p_offset = 0; 423 424 /* 425 * Set partition 'a' to be the whole disk. 426 * Cleared if we find an mbr or a netbsd label. 427 */ 428 lp->d_partitions[0].p_size = lp->d_partitions[RAW_PART].p_size; 429 lp->d_partitions[0].p_fstype = FS_BSDFFS; 430 431 /* 432 * Get a buffer big enough to read a disklabel in and initialize it 433 * make it three sectors long for the validate_label(); see comment at 434 * start of file. 435 */ 436 a.bp = geteblk(SCANBLOCKS * (int)lp->d_secsize); 437 a.bp->b_dev = dev; 438 439 if (osdep) 440 /* 441 * Scan mbr searching for netbsd partition and saving 442 * bios partition information to use if the netbsd one 443 * is absent. 444 */ 445 rval = scan_mbr(&a, look_netbsd_part); 446 else 447 rval = SCAN_CONTINUE; 448 449 if (rval == SCAN_CONTINUE) { 450 /* Look at start of disk */ 451 rval = validate_label(&a, 0); 452 } 453 454 if (rval == SCAN_CONTINUE) { 455 rval = scan_iso_vrs(&a); 456 } 457 #if 0 458 /* 459 * Save sector where we found the label for the 'don't overwrite 460 * the label' check in bounds_check_with_label. 461 */ 462 if (rval == SCAN_FOUND) 463 xxx->label_sector = a.label_sector; 464 #endif 465 466 /* Obtain bad sector table if requested and present */ 467 #ifdef __HAVE_DISKLABEL_DKBAD 468 if (rval == SCAN_FOUND && osdep && (lp->d_flags & D_BADSECT)) { 469 struct dkbad *bdp, *db; 470 int blkno; 471 472 bdp = &osdep->bad; 473 i = 0; 474 rval = SCAN_ERROR; 475 do { 476 /* read a bad sector table */ 477 blkno = lp->d_secperunit - lp->d_nsectors + i; 478 if (lp->d_secsize > DEV_BSIZE) 479 blkno *= lp->d_secsize / DEV_BSIZE; 480 else 481 blkno /= DEV_BSIZE / lp->d_secsize; 482 /* if successful, validate, otherwise try another */ 483 if (read_sector(&a, blkno, 1)) { 484 a.msg = "bad sector table I/O error"; 485 continue; 486 } 487 db = (struct dkbad *)(a.bp->b_data); 488 #define DKBAD_MAGIC 0x4321 489 if (db->bt_mbz != 0 || db->bt_flag != DKBAD_MAGIC) { 490 a.msg = "bad sector table corrupted"; 491 continue; 492 } 493 rval = SCAN_FOUND; 494 *bdp = *db; 495 break; 496 } while (a.bp->b_error && (i += 2) < 10 && 497 i < lp->d_nsectors); 498 } 499 #endif /* __HAVE_DISKLABEL_DKBAD */ 500 501 brelse(a.bp, 0); 502 if (rval == SCAN_ERROR || rval == SCAN_CONTINUE) 503 return a.msg; 504 return NULL; 505 } 506 507 static int 508 look_netbsd_part(mbr_args_t *a, mbr_partition_t *dp, int slot, uint ext_base) 509 { 510 struct partition *pp; 511 int ptn_base = ext_base + le32toh(dp->mbrp_start); 512 int rval; 513 514 if ( 515 #ifdef COMPAT_386BSD_MBRPART 516 dp->mbrp_type == MBR_PTYPE_386BSD || 517 #endif 518 dp->mbrp_type == MBR_PTYPE_NETBSD) { 519 rval = validate_label(a, ptn_base); 520 521 #if RAW_PART == 3 522 /* Put actual location where we found the label into ptn 2 */ 523 if (rval == SCAN_FOUND || a->lp->d_partitions[2].p_size == 0) { 524 a->lp->d_partitions[2].p_size = le32toh(dp->mbrp_size); 525 a->lp->d_partitions[2].p_offset = ptn_base; 526 } 527 #endif 528 529 /* If we got a netbsd label look no further */ 530 if (rval == SCAN_FOUND) 531 return rval; 532 } 533 534 /* Install main partitions into e..h and extended into i+ */ 535 if (ext_base == 0) 536 slot += 4; 537 else { 538 slot = 4 + MBR_PART_COUNT; 539 pp = &a->lp->d_partitions[slot]; 540 for (; slot < MAXPARTITIONS; pp++, slot++) { 541 /* This gets called twice - avoid duplicates */ 542 if (pp->p_offset == ptn_base && 543 pp->p_size == le32toh(dp->mbrp_size)) 544 break; 545 if (pp->p_size == 0) 546 break; 547 } 548 } 549 550 if (slot < MAXPARTITIONS) { 551 /* Stop 'a' being the entire disk */ 552 a->lp->d_partitions[0].p_size = 0; 553 a->lp->d_partitions[0].p_fstype = 0; 554 555 /* save partition info */ 556 pp = &a->lp->d_partitions[slot]; 557 pp->p_offset = ptn_base; 558 pp->p_size = le32toh(dp->mbrp_size); 559 pp->p_fstype = xlat_mbr_fstype(dp->mbrp_type); 560 561 if (slot >= a->lp->d_npartitions) 562 a->lp->d_npartitions = slot + 1; 563 } 564 565 return SCAN_CONTINUE; 566 } 567 568 __noubsan 569 static bool 570 check_label_magic(const struct disklabel *dlp, uint32_t diskmagic) 571 { 572 return memcmp(&dlp->d_magic, &diskmagic, sizeof(diskmagic)) == 0 && 573 memcmp(&dlp->d_magic2, &diskmagic, sizeof(diskmagic)) == 0; 574 } 575 576 #ifdef DISKLABEL_EI 577 /* 578 * - For read, convert a label to the native byte order. 579 * - For update or write, if a label already exists, keep its byte order. 580 * Otherwise, write a new label in the native byte order. 581 */ 582 #endif 583 static int 584 validate_label(mbr_args_t *a, uint label_sector) 585 { 586 struct disklabel *dlp; 587 char *dlp_lim, *dlp_byte; 588 int error; 589 #ifdef DISKLABEL_EI 590 int swapped = 0; 591 uint16_t npartitions; 592 #endif 593 594 /* Next, dig out disk label */ 595 if (read_sector(a, label_sector, SCANBLOCKS)) { 596 a->msg = "disk label read failed"; 597 return SCAN_ERROR; 598 } 599 600 /* Locate disk label within block and validate */ 601 /* 602 * XXX (dsl) This search may be a waste of time, a lot of other i386 603 * code assumes the label is at offset LABELOFFSET (=0) in the sector. 604 * 605 * If we want to support disks from other netbsd ports, then the 606 * code should also allow for a shorter label nearer the end of 607 * the disk sector, and (IIRC) labels within 8k of the disk start. 608 */ 609 dlp = (void *)a->bp->b_data; 610 dlp_lim = (char *)a->bp->b_data + a->bp->b_bcount - sizeof *dlp; 611 for (;; dlp = (void *)((char *)dlp + sizeof(uint32_t))) { 612 if ((char *)dlp > dlp_lim) { 613 if (a->action != WRITE_LABEL) 614 return SCAN_CONTINUE; 615 /* Write at arch. dependent default location */ 616 dlp_byte = (char *)a->bp->b_data + LABELOFFSET; 617 if (label_sector) 618 dlp_byte += MBR_LABELSECTOR * a->lp->d_secsize; 619 else 620 dlp_byte += LABELSECTOR * a->lp->d_secsize; 621 dlp = (void *)dlp_byte; 622 break; 623 } 624 if (!check_label_magic(dlp, DISKMAGIC)) 625 #ifdef DISKLABEL_EI 626 { 627 if (!check_label_magic(dlp, bswap32(DISKMAGIC))) 628 continue; 629 630 /* 631 * The label is in the other byte order. We need to 632 * checksum before swapping the byte order. 633 */ 634 npartitions = bswap16(dlp->d_npartitions); 635 if (npartitions > MAXPARTITIONS || 636 dkcksum_sized(dlp, npartitions) != 0) 637 goto corrupted; 638 639 swapped = 1; 640 } 641 #else 642 continue; 643 #endif 644 else if (dlp->d_npartitions > MAXPARTITIONS || 645 dkcksum(dlp) != 0) { 646 #ifdef DISKLABEL_EI 647 corrupted: 648 #endif 649 a->msg = "disk label corrupted"; 650 continue; 651 } 652 break; 653 } 654 655 switch (a->action) { 656 case READ_LABEL: 657 #ifdef DISKLABEL_EI 658 if (swapped) 659 disklabel_swap(a->lp, dlp); 660 else 661 *a->lp = *dlp; 662 #else 663 *a->lp = *dlp; 664 #endif 665 if ((a->msg = convertdisklabel(a->lp, a->strat, a->bp, 666 a->secperunit)) != NULL) 667 return SCAN_ERROR; 668 a->label_sector = label_sector; 669 return SCAN_FOUND; 670 case UPDATE_LABEL: 671 case WRITE_LABEL: 672 #ifdef DISKLABEL_EI 673 /* DO NOT swap a->lp itself for later references. */ 674 if (swapped) 675 disklabel_swap(dlp, a->lp); 676 else 677 *dlp = *a->lp; 678 #else 679 *dlp = *a->lp; 680 #endif 681 a->bp->b_oflags &= ~BO_DONE; 682 a->bp->b_flags &= ~B_READ; 683 a->bp->b_flags |= B_WRITE; 684 (*a->strat)(a->bp); 685 error = biowait(a->bp); 686 if (error != 0) { 687 a->error = error; 688 a->msg = "disk label write failed"; 689 return SCAN_ERROR; 690 } 691 a->written++; 692 /* Write label to all mbr partitions */ 693 return SCAN_CONTINUE; 694 default: 695 return SCAN_ERROR; 696 } 697 } 698 699 /* 700 * Write disk label back to device after modification. 701 */ 702 int 703 writedisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp, 704 struct cpu_disklabel *osdep) 705 { 706 mbr_args_t a; 707 708 memset(&a, 0, sizeof a); 709 a.lp = lp; 710 a.strat = strat; 711 712 /* get a buffer and initialize it */ 713 a.bp = geteblk(SCANBLOCKS * (int)lp->d_secsize); 714 a.bp->b_dev = dev; 715 716 /* osdep => we expect an mbr with label in netbsd ptn */ 717 a.action = osdep != NULL ? WRITE_LABEL : UPDATE_LABEL; 718 719 /* Write/update the label to every netbsd mbr partition */ 720 scan_mbr(&a, write_netbsd_label); 721 722 /* Old write the label at the start of the volume on disks that 723 * don't have a valid mbr (always update an existing one) */ 724 a.action = a.found_mbr ? UPDATE_LABEL : WRITE_LABEL; 725 validate_label(&a, 0); 726 727 if (a.written == 0 && a.error == 0) 728 a.error = ESRCH; 729 730 brelse(a.bp, 0); 731 return a.error; 732 } 733 734 static int 735 write_netbsd_label(mbr_args_t *a, mbr_partition_t *dp, int slot, uint ext_base) 736 { 737 int ptn_base = ext_base + le32toh(dp->mbrp_start); 738 739 if (dp->mbrp_type != MBR_PTYPE_NETBSD) 740 return SCAN_CONTINUE; 741 742 return validate_label(a, ptn_base); 743 }
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