1// SPDX-License-Identifier: GPL-2.0 2/* 3 * fs/partitions/msdos.c 4 * 5 * Code extracted from drivers/block/genhd.c 6 * Copyright (C) 1991-1998 Linus Torvalds 7 * 8 * Thanks to Branko Lankester, lankeste@fwi.uva.nl, who found a bug 9 * in the early extended-partition checks and added DM partitions 10 * 11 * Support for DiskManager v6.0x added by Mark Lord, 12 * with information provided by OnTrack. This now works for linux fdisk 13 * and LILO, as well as loadlin and bootln. Note that disks other than 14 * /dev/hda *must* have a "DOS" type 0x51 partition in the first slot (hda1). 15 * 16 * More flexible handling of extended partitions - aeb, 950831 17 * 18 * Check partition table on IDE disks for common CHS translations 19 * 20 * Re-organised Feb 1998 Russell King 21 * 22 * BSD disklabel support by Yossi Gottlieb <yogo@math.tau.ac.il> 23 * updated by Marc Espie <Marc.Espie@openbsd.org> 24 * 25 * Unixware slices support by Andrzej Krzysztofowicz <ankry@mif.pg.gda.pl> 26 * and Krzysztof G. Baranowski <kgb@knm.org.pl> 27 */ 28#include <linux/msdos_fs.h> 29#include <linux/msdos_partition.h> 30 31#include "check.h" 32#include "efi.h" 33 34/* 35 * Many architectures don't like unaligned accesses, while 36 * the nr_sects and start_sect partition table entries are 37 * at a 2 (mod 4) address. 38 */ 39#include <asm/unaligned.h> 40 41static inline sector_t nr_sects(struct msdos_partition *p) 42{ 43 return (sector_t)get_unaligned_le32(&p->nr_sects); 44} 45 46static inline sector_t start_sect(struct msdos_partition *p) 47{ 48 return (sector_t)get_unaligned_le32(&p->start_sect); 49} 50 51static inline int is_extended_partition(struct msdos_partition *p) 52{ 53 return (p->sys_ind == DOS_EXTENDED_PARTITION || 54 p->sys_ind == WIN98_EXTENDED_PARTITION || 55 p->sys_ind == LINUX_EXTENDED_PARTITION); 56} 57 58#define MSDOS_LABEL_MAGIC1 0x55 59#define MSDOS_LABEL_MAGIC2 0xAA 60 61static inline int 62msdos_magic_present(unsigned char *p) 63{ 64 return (p[0] == MSDOS_LABEL_MAGIC1 && p[1] == MSDOS_LABEL_MAGIC2); 65} 66 67/* Value is EBCDIC 'IBMA' */ 68#define AIX_LABEL_MAGIC1 0xC9 69#define AIX_LABEL_MAGIC2 0xC2 70#define AIX_LABEL_MAGIC3 0xD4 71#define AIX_LABEL_MAGIC4 0xC1 72static int aix_magic_present(struct parsed_partitions *state, unsigned char *p) 73{ 74 struct msdos_partition *pt = (struct msdos_partition *) (p + 0x1be); 75 Sector sect; 76 unsigned char *d; 77 int slot, ret = 0; 78 79 if (!(p[0] == AIX_LABEL_MAGIC1 && 80 p[1] == AIX_LABEL_MAGIC2 && 81 p[2] == AIX_LABEL_MAGIC3 && 82 p[3] == AIX_LABEL_MAGIC4)) 83 return 0; 84 85 /* 86 * Assume the partition table is valid if Linux partitions exists. 87 * Note that old Solaris/x86 partitions use the same indicator as 88 * Linux swap partitions, so we consider that a Linux partition as 89 * well. 90 */ 91 for (slot = 1; slot <= 4; slot++, pt++) { 92 if (pt->sys_ind == SOLARIS_X86_PARTITION || 93 pt->sys_ind == LINUX_RAID_PARTITION || 94 pt->sys_ind == LINUX_DATA_PARTITION || 95 pt->sys_ind == LINUX_LVM_PARTITION || 96 is_extended_partition(pt)) 97 return 0; 98 } 99 d = read_part_sector(state, 7, §); 100 if (d) { 101 if (d[0] == '_' && d[1] == 'L' && d[2] == 'V' && d[3] == 'M') 102 ret = 1; 103 put_dev_sector(sect); 104 } 105 return ret; 106} 107 108static void set_info(struct parsed_partitions *state, int slot, 109 u32 disksig) 110{ 111 struct partition_meta_info *info = &state->parts[slot].info; 112 113 snprintf(info->uuid, sizeof(info->uuid), "%08x-%02x", disksig, 114 slot); 115 info->volname[0] = 0; 116 state->parts[slot].has_info = true; 117} 118 119/* 120 * Create devices for each logical partition in an extended partition. 121 * The logical partitions form a linked list, with each entry being 122 * a partition table with two entries. The first entry 123 * is the real data partition (with a start relative to the partition 124 * table start). The second is a pointer to the next logical partition 125 * (with a start relative to the entire extended partition). 126 * We do not create a Linux partition for the partition tables, but 127 * only for the actual data partitions. 128 */ 129 130static void parse_extended(struct parsed_partitions *state, 131 sector_t first_sector, sector_t first_size, 132 u32 disksig) 133{ 134 struct msdos_partition *p; 135 Sector sect; 136 unsigned char *data; 137 sector_t this_sector, this_size; 138 sector_t sector_size = bdev_logical_block_size(state->bdev) / 512; 139 int loopct = 0; /* number of links followed 140 without finding a data partition */ 141 int i; 142 143 this_sector = first_sector; 144 this_size = first_size; 145 146 while (1) { 147 if (++loopct > 100) 148 return; 149 if (state->next == state->limit) 150 return; 151 data = read_part_sector(state, this_sector, §); 152 if (!data) 153 return; 154 155 if (!msdos_magic_present(data + 510)) 156 goto done; 157 158 p = (struct msdos_partition *) (data + 0x1be); 159 160 /* 161 * Usually, the first entry is the real data partition, 162 * the 2nd entry is the next extended partition, or empty, 163 * and the 3rd and 4th entries are unused. 164 * However, DRDOS sometimes has the extended partition as 165 * the first entry (when the data partition is empty), 166 * and OS/2 seems to use all four entries. 167 */ 168 169 /* 170 * First process the data partition(s) 171 */ 172 for (i = 0; i < 4; i++, p++) { 173 sector_t offs, size, next; 174 175 if (!nr_sects(p) || is_extended_partition(p)) 176 continue; 177 178 /* Check the 3rd and 4th entries - 179 these sometimes contain random garbage */ 180 offs = start_sect(p)*sector_size; 181 size = nr_sects(p)*sector_size; 182 next = this_sector + offs; 183 if (i >= 2) { 184 if (offs + size > this_size) 185 continue; 186 if (next < first_sector) 187 continue; 188 if (next + size > first_sector + first_size) 189 continue; 190 } 191 192 put_partition(state, state->next, next, size); 193 set_info(state, state->next, disksig); 194 if (p->sys_ind == LINUX_RAID_PARTITION) 195 state->parts[state->next].flags = ADDPART_FLAG_RAID; 196 loopct = 0; 197 if (++state->next == state->limit) 198 goto done; 199 } 200 /* 201 * Next, process the (first) extended partition, if present. 202 * (So far, there seems to be no reason to make 203 * parse_extended() recursive and allow a tree 204 * of extended partitions.) 205 * It should be a link to the next logical partition. 206 */ 207 p -= 4; 208 for (i = 0; i < 4; i++, p++) 209 if (nr_sects(p) && is_extended_partition(p)) 210 break; 211 if (i == 4) 212 goto done; /* nothing left to do */ 213 214 this_sector = first_sector + start_sect(p) * sector_size; 215 this_size = nr_sects(p) * sector_size; 216 put_dev_sector(sect); 217 } 218done: 219 put_dev_sector(sect); 220} 221 222#define SOLARIS_X86_NUMSLICE 16 223#define SOLARIS_X86_VTOC_SANE (0x600DDEEEUL) 224 225struct solaris_x86_slice { 226 __le16 s_tag; /* ID tag of partition */ 227 __le16 s_flag; /* permission flags */ 228 __le32 s_start; /* start sector no of partition */ 229 __le32 s_size; /* # of blocks in partition */ 230}; 231 232struct solaris_x86_vtoc { 233 unsigned int v_bootinfo[3]; /* info needed by mboot */ 234 __le32 v_sanity; /* to verify vtoc sanity */ 235 __le32 v_version; /* layout version */ 236 char v_volume[8]; /* volume name */ 237 __le16 v_sectorsz; /* sector size in bytes */ 238 __le16 v_nparts; /* number of partitions */ 239 unsigned int v_reserved[10]; /* free space */ 240 struct solaris_x86_slice 241 v_slice[SOLARIS_X86_NUMSLICE]; /* slice headers */ 242 unsigned int timestamp[SOLARIS_X86_NUMSLICE]; /* timestamp */ 243 char v_asciilabel[128]; /* for compatibility */ 244}; 245 246/* james@bpgc.com: Solaris has a nasty indicator: 0x82 which also 247 indicates linux swap. Be careful before believing this is Solaris. */ 248 249static void parse_solaris_x86(struct parsed_partitions *state, 250 sector_t offset, sector_t size, int origin) 251{ 252#ifdef CONFIG_SOLARIS_X86_PARTITION 253 Sector sect; 254 struct solaris_x86_vtoc *v; 255 int i; 256 short max_nparts; 257 258 v = read_part_sector(state, offset + 1, §); 259 if (!v) 260 return; 261 if (le32_to_cpu(v->v_sanity) != SOLARIS_X86_VTOC_SANE) { 262 put_dev_sector(sect); 263 return; 264 } 265 { 266 char tmp[1 + BDEVNAME_SIZE + 10 + 11 + 1]; 267 268 snprintf(tmp, sizeof(tmp), " %s%d: <solaris:", state->name, origin); 269 strlcat(state->pp_buf, tmp, PAGE_SIZE); 270 } 271 if (le32_to_cpu(v->v_version) != 1) { 272 char tmp[64]; 273 274 snprintf(tmp, sizeof(tmp), " cannot handle version %d vtoc>\n", 275 le32_to_cpu(v->v_version)); 276 strlcat(state->pp_buf, tmp, PAGE_SIZE); 277 put_dev_sector(sect); 278 return; 279 } 280 /* Ensure we can handle previous case of VTOC with 8 entries gracefully */ 281 max_nparts = le16_to_cpu(v->v_nparts) > 8 ? SOLARIS_X86_NUMSLICE : 8; 282 for (i = 0; i < max_nparts && state->next < state->limit; i++) { 283 struct solaris_x86_slice *s = &v->v_slice[i]; 284 char tmp[3 + 10 + 1 + 1]; 285 286 if (s->s_size == 0) 287 continue; 288 snprintf(tmp, sizeof(tmp), " [s%d]", i); 289 strlcat(state->pp_buf, tmp, PAGE_SIZE); 290 /* solaris partitions are relative to current MS-DOS 291 * one; must add the offset of the current partition */ 292 put_partition(state, state->next++, 293 le32_to_cpu(s->s_start)+offset, 294 le32_to_cpu(s->s_size)); 295 } 296 put_dev_sector(sect); 297 strlcat(state->pp_buf, " >\n", PAGE_SIZE); 298#endif 299} 300 301/* check against BSD src/sys/sys/disklabel.h for consistency */ 302#define BSD_DISKMAGIC (0x82564557UL) /* The disk magic number */ 303#define BSD_MAXPARTITIONS 16 304#define OPENBSD_MAXPARTITIONS 16 305#define BSD_FS_UNUSED 0 /* disklabel unused partition entry ID */ 306struct bsd_disklabel { 307 __le32 d_magic; /* the magic number */ 308 __s16 d_type; /* drive type */ 309 __s16 d_subtype; /* controller/d_type specific */ 310 char d_typename[16]; /* type name, e.g. "eagle" */ 311 char d_packname[16]; /* pack identifier */ 312 __u32 d_secsize; /* # of bytes per sector */ 313 __u32 d_nsectors; /* # of data sectors per track */ 314 __u32 d_ntracks; /* # of tracks per cylinder */ 315 __u32 d_ncylinders; /* # of data cylinders per unit */ 316 __u32 d_secpercyl; /* # of data sectors per cylinder */ 317 __u32 d_secperunit; /* # of data sectors per unit */ 318 __u16 d_sparespertrack; /* # of spare sectors per track */ 319 __u16 d_sparespercyl; /* # of spare sectors per cylinder */ 320 __u32 d_acylinders; /* # of alt. cylinders per unit */ 321 __u16 d_rpm; /* rotational speed */ 322 __u16 d_interleave; /* hardware sector interleave */ 323 __u16 d_trackskew; /* sector 0 skew, per track */ 324 __u16 d_cylskew; /* sector 0 skew, per cylinder */ 325 __u32 d_headswitch; /* head switch time, usec */ 326 __u32 d_trkseek; /* track-to-track seek, usec */ 327 __u32 d_flags; /* generic flags */ 328#define NDDATA 5 329 __u32 d_drivedata[NDDATA]; /* drive-type specific information */ 330#define NSPARE 5 331 __u32 d_spare[NSPARE]; /* reserved for future use */ 332 __le32 d_magic2; /* the magic number (again) */ 333 __le16 d_checksum; /* xor of data incl. partitions */ 334 335 /* filesystem and partition information: */ 336 __le16 d_npartitions; /* number of partitions in following */ 337 __le32 d_bbsize; /* size of boot area at sn0, bytes */ 338 __le32 d_sbsize; /* max size of fs superblock, bytes */ 339 struct bsd_partition { /* the partition table */ 340 __le32 p_size; /* number of sectors in partition */ 341 __le32 p_offset; /* starting sector */ 342 __le32 p_fsize; /* filesystem basic fragment size */ 343 __u8 p_fstype; /* filesystem type, see below */ 344 __u8 p_frag; /* filesystem fragments per block */ 345 __le16 p_cpg; /* filesystem cylinders per group */ 346 } d_partitions[BSD_MAXPARTITIONS]; /* actually may be more */ 347}; 348 349#if defined(CONFIG_BSD_DISKLABEL) 350/* 351 * Create devices for BSD partitions listed in a disklabel, under a 352 * dos-like partition. See parse_extended() for more information. 353 */ 354static void parse_bsd(struct parsed_partitions *state, 355 sector_t offset, sector_t size, int origin, char *flavour, 356 int max_partitions) 357{ 358 Sector sect; 359 struct bsd_disklabel *l; 360 struct bsd_partition *p; 361 char tmp[64]; 362 363 l = read_part_sector(state, offset + 1, §); 364 if (!l) 365 return; 366 if (le32_to_cpu(l->d_magic) != BSD_DISKMAGIC) { 367 put_dev_sector(sect); 368 return; 369 } 370 371 snprintf(tmp, sizeof(tmp), " %s%d: <%s:", state->name, origin, flavour); 372 strlcat(state->pp_buf, tmp, PAGE_SIZE); 373 374 if (le16_to_cpu(l->d_npartitions) < max_partitions) 375 max_partitions = le16_to_cpu(l->d_npartitions); 376 for (p = l->d_partitions; p - l->d_partitions < max_partitions; p++) { 377 sector_t bsd_start, bsd_size; 378 379 if (state->next == state->limit) 380 break; 381 if (p->p_fstype == BSD_FS_UNUSED) 382 continue; 383 bsd_start = le32_to_cpu(p->p_offset); 384 bsd_size = le32_to_cpu(p->p_size); 385 /* FreeBSD has relative offset if C partition offset is zero */ 386 if (memcmp(flavour, "bsd\0", 4) == 0 && 387 le32_to_cpu(l->d_partitions[2].p_offset) == 0) 388 bsd_start += offset; 389 if (offset == bsd_start && size == bsd_size) 390 /* full parent partition, we have it already */ 391 continue; 392 if (offset > bsd_start || offset+size < bsd_start+bsd_size) { 393 strlcat(state->pp_buf, "bad subpartition - ignored\n", PAGE_SIZE); 394 continue; 395 } 396 put_partition(state, state->next++, bsd_start, bsd_size); 397 } 398 put_dev_sector(sect); 399 if (le16_to_cpu(l->d_npartitions) > max_partitions) { 400 snprintf(tmp, sizeof(tmp), " (ignored %d more)", 401 le16_to_cpu(l->d_npartitions) - max_partitions); 402 strlcat(state->pp_buf, tmp, PAGE_SIZE); 403 } 404 strlcat(state->pp_buf, " >\n", PAGE_SIZE); 405} 406#endif 407 408static void parse_freebsd(struct parsed_partitions *state, 409 sector_t offset, sector_t size, int origin) 410{ 411#ifdef CONFIG_BSD_DISKLABEL 412 parse_bsd(state, offset, size, origin, "bsd", BSD_MAXPARTITIONS); 413#endif 414} 415 416static void parse_netbsd(struct parsed_partitions *state, 417 sector_t offset, sector_t size, int origin) 418{ 419#ifdef CONFIG_BSD_DISKLABEL 420 parse_bsd(state, offset, size, origin, "netbsd", BSD_MAXPARTITIONS); 421#endif 422} 423 424static void parse_openbsd(struct parsed_partitions *state, 425 sector_t offset, sector_t size, int origin) 426{ 427#ifdef CONFIG_BSD_DISKLABEL 428 parse_bsd(state, offset, size, origin, "openbsd", 429 OPENBSD_MAXPARTITIONS); 430#endif 431} 432 433#define UNIXWARE_DISKMAGIC (0xCA5E600DUL) /* The disk magic number */ 434#define UNIXWARE_DISKMAGIC2 (0x600DDEEEUL) /* The slice table magic nr */ 435#define UNIXWARE_NUMSLICE 16 436#define UNIXWARE_FS_UNUSED 0 /* Unused slice entry ID */ 437 438struct unixware_slice { 439 __le16 s_label; /* label */ 440 __le16 s_flags; /* permission flags */ 441 __le32 start_sect; /* starting sector */ 442 __le32 nr_sects; /* number of sectors in slice */ 443}; 444 445struct unixware_disklabel { 446 __le32 d_type; /* drive type */ 447 __le32 d_magic; /* the magic number */ 448 __le32 d_version; /* version number */ 449 char d_serial[12]; /* serial number of the device */ 450 __le32 d_ncylinders; /* # of data cylinders per device */ 451 __le32 d_ntracks; /* # of tracks per cylinder */ 452 __le32 d_nsectors; /* # of data sectors per track */ 453 __le32 d_secsize; /* # of bytes per sector */ 454 __le32 d_part_start; /* # of first sector of this partition*/ 455 __le32 d_unknown1[12]; /* ? */ 456 __le32 d_alt_tbl; /* byte offset of alternate table */ 457 __le32 d_alt_len; /* byte length of alternate table */ 458 __le32 d_phys_cyl; /* # of physical cylinders per device */ 459 __le32 d_phys_trk; /* # of physical tracks per cylinder */ 460 __le32 d_phys_sec; /* # of physical sectors per track */ 461 __le32 d_phys_bytes; /* # of physical bytes per sector */ 462 __le32 d_unknown2; /* ? */ 463 __le32 d_unknown3; /* ? */ 464 __le32 d_pad[8]; /* pad */ 465 466 struct unixware_vtoc { 467 __le32 v_magic; /* the magic number */ 468 __le32 v_version; /* version number */ 469 char v_name[8]; /* volume name */ 470 __le16 v_nslices; /* # of slices */ 471 __le16 v_unknown1; /* ? */ 472 __le32 v_reserved[10]; /* reserved */ 473 struct unixware_slice 474 v_slice[UNIXWARE_NUMSLICE]; /* slice headers */ 475 } vtoc; 476}; /* 408 */ 477 478/* 479 * Create devices for Unixware partitions listed in a disklabel, under a 480 * dos-like partition. See parse_extended() for more information. 481 */ 482static void parse_unixware(struct parsed_partitions *state, 483 sector_t offset, sector_t size, int origin) 484{ 485#ifdef CONFIG_UNIXWARE_DISKLABEL 486 Sector sect; 487 struct unixware_disklabel *l; 488 struct unixware_slice *p; 489 490 l = read_part_sector(state, offset + 29, §); 491 if (!l) 492 return; 493 if (le32_to_cpu(l->d_magic) != UNIXWARE_DISKMAGIC || 494 le32_to_cpu(l->vtoc.v_magic) != UNIXWARE_DISKMAGIC2) { 495 put_dev_sector(sect); 496 return; 497 } 498 { 499 char tmp[1 + BDEVNAME_SIZE + 10 + 12 + 1]; 500 501 snprintf(tmp, sizeof(tmp), " %s%d: <unixware:", state->name, origin); 502 strlcat(state->pp_buf, tmp, PAGE_SIZE); 503 } 504 p = &l->vtoc.v_slice[1]; 505 /* I omit the 0th slice as it is the same as whole disk. */ 506 while (p - &l->vtoc.v_slice[0] < UNIXWARE_NUMSLICE) { 507 if (state->next == state->limit) 508 break; 509 510 if (p->s_label != UNIXWARE_FS_UNUSED) 511 put_partition(state, state->next++, 512 le32_to_cpu(p->start_sect), 513 le32_to_cpu(p->nr_sects)); 514 p++; 515 } 516 put_dev_sector(sect); 517 strlcat(state->pp_buf, " >\n", PAGE_SIZE); 518#endif 519} 520 521#define MINIX_NR_SUBPARTITIONS 4 522 523/* 524 * Minix 2.0.0/2.0.2 subpartition support. 525 * Anand Krishnamurthy <anandk@wiproge.med.ge.com> 526 * Rajeev V. Pillai <rajeevvp@yahoo.com> 527 */ 528static void parse_minix(struct parsed_partitions *state, 529 sector_t offset, sector_t size, int origin) 530{ 531#ifdef CONFIG_MINIX_SUBPARTITION 532 Sector sect; 533 unsigned char *data; 534 struct msdos_partition *p; 535 int i; 536 537 data = read_part_sector(state, offset, §); 538 if (!data) 539 return; 540 541 p = (struct msdos_partition *)(data + 0x1be); 542 543 /* The first sector of a Minix partition can have either 544 * a secondary MBR describing its subpartitions, or 545 * the normal boot sector. */ 546 if (msdos_magic_present(data + 510) && 547 p->sys_ind == MINIX_PARTITION) { /* subpartition table present */ 548 char tmp[1 + BDEVNAME_SIZE + 10 + 9 + 1]; 549 550 snprintf(tmp, sizeof(tmp), " %s%d: <minix:", state->name, origin); 551 strlcat(state->pp_buf, tmp, PAGE_SIZE); 552 for (i = 0; i < MINIX_NR_SUBPARTITIONS; i++, p++) { 553 if (state->next == state->limit) 554 break; 555 /* add each partition in use */ 556 if (p->sys_ind == MINIX_PARTITION) 557 put_partition(state, state->next++, 558 start_sect(p), nr_sects(p)); 559 } 560 strlcat(state->pp_buf, " >\n", PAGE_SIZE); 561 } 562 put_dev_sector(sect); 563#endif /* CONFIG_MINIX_SUBPARTITION */ 564} 565 566static struct { 567 unsigned char id; 568 void (*parse)(struct parsed_partitions *, sector_t, sector_t, int); 569} subtypes[] = { 570 {FREEBSD_PARTITION, parse_freebsd}, 571 {NETBSD_PARTITION, parse_netbsd}, 572 {OPENBSD_PARTITION, parse_openbsd}, 573 {MINIX_PARTITION, parse_minix}, 574 {UNIXWARE_PARTITION, parse_unixware}, 575 {SOLARIS_X86_PARTITION, parse_solaris_x86}, 576 {NEW_SOLARIS_X86_PARTITION, parse_solaris_x86}, 577 {0, NULL}, 578}; 579 580int msdos_partition(struct parsed_partitions *state) 581{ 582 sector_t sector_size = bdev_logical_block_size(state->bdev) / 512; 583 Sector sect; 584 unsigned char *data; 585 struct msdos_partition *p; 586 struct fat_boot_sector *fb; 587 int slot; 588 u32 disksig; 589 590 data = read_part_sector(state, 0, §); 591 if (!data) 592 return -1; 593 594 /* 595 * Note order! (some AIX disks, e.g. unbootable kind, 596 * have no MSDOS 55aa) 597 */ 598 if (aix_magic_present(state, data)) { 599 put_dev_sector(sect); 600#ifdef CONFIG_AIX_PARTITION 601 return aix_partition(state); 602#else 603 strlcat(state->pp_buf, " [AIX]", PAGE_SIZE); 604 return 0; 605#endif 606 } 607 608 if (!msdos_magic_present(data + 510)) { 609 put_dev_sector(sect); 610 return 0; 611 } 612 613 /* 614 * Now that the 55aa signature is present, this is probably 615 * either the boot sector of a FAT filesystem or a DOS-type 616 * partition table. Reject this in case the boot indicator 617 * is not 0 or 0x80. 618 */ 619 p = (struct msdos_partition *) (data + 0x1be); 620 for (slot = 1; slot <= 4; slot++, p++) { 621 if (p->boot_ind != 0 && p->boot_ind != 0x80) { 622 /* 623 * Even without a valid boot inidicator value 624 * its still possible this is valid FAT filesystem 625 * without a partition table. 626 */ 627 fb = (struct fat_boot_sector *) data; 628 if (slot == 1 && fb->reserved && fb->fats 629 && fat_valid_media(fb->media)) { 630 strlcat(state->pp_buf, "\n", PAGE_SIZE); 631 put_dev_sector(sect); 632 return 1; 633 } else { 634 put_dev_sector(sect); 635 return 0; 636 } 637 } 638 } 639 640#ifdef CONFIG_EFI_PARTITION 641 p = (struct msdos_partition *) (data + 0x1be); 642 for (slot = 1 ; slot <= 4 ; slot++, p++) { 643 /* If this is an EFI GPT disk, msdos should ignore it. */ 644 if (p->sys_ind == EFI_PMBR_OSTYPE_EFI_GPT) { 645 put_dev_sector(sect); 646 return 0; 647 } 648 } 649#endif 650 p = (struct msdos_partition *) (data + 0x1be); 651 652 disksig = le32_to_cpup((__le32 *)(data + 0x1b8)); 653 654 /* 655 * Look for partitions in two passes: 656 * First find the primary and DOS-type extended partitions. 657 * On the second pass look inside *BSD, Unixware and Solaris partitions. 658 */ 659 660 state->next = 5; 661 for (slot = 1 ; slot <= 4 ; slot++, p++) { 662 sector_t start = start_sect(p)*sector_size; 663 sector_t size = nr_sects(p)*sector_size; 664 665 if (!size) 666 continue; 667 if (is_extended_partition(p)) { 668 /* 669 * prevent someone doing mkfs or mkswap on an 670 * extended partition, but leave room for LILO 671 * FIXME: this uses one logical sector for > 512b 672 * sector, although it may not be enough/proper. 673 */ 674 sector_t n = 2; 675 676 n = min(size, max(sector_size, n)); 677 put_partition(state, slot, start, n); 678 679 strlcat(state->pp_buf, " <", PAGE_SIZE); 680 parse_extended(state, start, size, disksig); 681 strlcat(state->pp_buf, " >", PAGE_SIZE); 682 continue; 683 } 684 put_partition(state, slot, start, size); 685 set_info(state, slot, disksig); 686 if (p->sys_ind == LINUX_RAID_PARTITION) 687 state->parts[slot].flags = ADDPART_FLAG_RAID; 688 if (p->sys_ind == DM6_PARTITION) 689 strlcat(state->pp_buf, "[DM]", PAGE_SIZE); 690 if (p->sys_ind == EZD_PARTITION) 691 strlcat(state->pp_buf, "[EZD]", PAGE_SIZE); 692 } 693 694 strlcat(state->pp_buf, "\n", PAGE_SIZE); 695 696 /* second pass - output for each on a separate line */ 697 p = (struct msdos_partition *) (0x1be + data); 698 for (slot = 1 ; slot <= 4 ; slot++, p++) { 699 unsigned char id = p->sys_ind; 700 int n; 701 702 if (!nr_sects(p)) 703 continue; 704 705 for (n = 0; subtypes[n].parse && id != subtypes[n].id; n++) 706 ; 707 708 if (!subtypes[n].parse) 709 continue; 710 subtypes[n].parse(state, start_sect(p) * sector_size, 711 nr_sects(p) * sector_size, slot); 712 } 713 put_dev_sector(sect); 714 return 1; 715} 716