1/* 2 * fs/partitions/msdos.c 3 * 4 * Code extracted from drivers/block/genhd.c 5 * Copyright (C) 1991-1998 Linus Torvalds 6 * 7 * Thanks to Branko Lankester, lankeste@fwi.uva.nl, who found a bug 8 * in the early extended-partition checks and added DM partitions 9 * 10 * Support for DiskManager v6.0x added by Mark Lord, 11 * with information provided by OnTrack. This now works for linux fdisk 12 * and LILO, as well as loadlin and bootln. Note that disks other than 13 * /dev/hda *must* have a "DOS" type 0x51 partition in the first slot (hda1). 14 * 15 * More flexible handling of extended partitions - aeb, 950831 16 * 17 * Check partition table on IDE disks for common CHS translations 18 * 19 * Re-organised Feb 1998 Russell King 20 */ 21 22 23#include "check.h" 24#include "msdos.h" 25#include "efi.h" 26 27/* 28 * Many architectures don't like unaligned accesses, while 29 * the nr_sects and start_sect partition table entries are 30 * at a 2 (mod 4) address. 31 */ 32#include <asm/unaligned.h> 33 34#define SYS_IND(p) (get_unaligned(&p->sys_ind)) 35#define NR_SECTS(p) ({ __le32 __a = get_unaligned(&p->nr_sects); \ 36 le32_to_cpu(__a); \ 37 }) 38 39#define START_SECT(p) ({ __le32 __a = get_unaligned(&p->start_sect); \ 40 le32_to_cpu(__a); \ 41 }) 42 43static inline int is_extended_partition(struct partition *p) 44{ 45 return (SYS_IND(p) == DOS_EXTENDED_PARTITION || 46 SYS_IND(p) == WIN98_EXTENDED_PARTITION || 47 SYS_IND(p) == LINUX_EXTENDED_PARTITION); 48} 49 50#define MSDOS_LABEL_MAGIC1 0x55 51#define MSDOS_LABEL_MAGIC2 0xAA 52 53static inline int 54msdos_magic_present(unsigned char *p) 55{ 56 return (p[0] == MSDOS_LABEL_MAGIC1 && p[1] == MSDOS_LABEL_MAGIC2); 57} 58 59/* Value is EBCDIC 'IBMA' */ 60#define AIX_LABEL_MAGIC1 0xC9 61#define AIX_LABEL_MAGIC2 0xC2 62#define AIX_LABEL_MAGIC3 0xD4 63#define AIX_LABEL_MAGIC4 0xC1 64static int aix_magic_present(unsigned char *p, struct block_device *bdev) 65{ 66 struct partition *pt = (struct partition *) (p + 0x1be); 67 Sector sect; 68 unsigned char *d; 69 int slot, ret = 0; 70 71 if (!(p[0] == AIX_LABEL_MAGIC1 && 72 p[1] == AIX_LABEL_MAGIC2 && 73 p[2] == AIX_LABEL_MAGIC3 && 74 p[3] == AIX_LABEL_MAGIC4)) 75 return 0; 76 /* Assume the partition table is valid if Linux partitions exists */ 77 for (slot = 1; slot <= 4; slot++, pt++) { 78 if (pt->sys_ind == LINUX_SWAP_PARTITION || 79 pt->sys_ind == LINUX_RAID_PARTITION || 80 pt->sys_ind == LINUX_DATA_PARTITION || 81 pt->sys_ind == LINUX_LVM_PARTITION || 82 is_extended_partition(pt)) 83 return 0; 84 } 85 d = read_dev_sector(bdev, 7, §); 86 if (d) { 87 if (d[0] == '_' && d[1] == 'L' && d[2] == 'V' && d[3] == 'M') 88 ret = 1; 89 put_dev_sector(sect); 90 }; 91 return ret; 92} 93 94/* 95 * Create devices for each logical partition in an extended partition. 96 * The logical partitions form a linked list, with each entry being 97 * a partition table with two entries. The first entry 98 * is the real data partition (with a start relative to the partition 99 * table start). The second is a pointer to the next logical partition 100 * (with a start relative to the entire extended partition). 101 * We do not create a Linux partition for the partition tables, but 102 * only for the actual data partitions. 103 */ 104/* Foxconn modified start pling 04/30/2011 */ 105/* Fix 3TB partition can't be detected issue */ 106static void 107#if 0 108parse_extended(struct parsed_partitions *state, struct block_device *bdev, 109 u32 first_sector, u32 first_size) 110#endif 111parse_extended(struct parsed_partitions *state, struct block_device *bdev, 112 sector_t first_sector, sector_t first_size) 113/* Foxconn modified end pling 04/30/2011 */ 114{ 115 struct partition *p; 116 Sector sect; 117 unsigned char *data; 118 /* Foxconn modified start pling 04/30/2011 */ 119 /* Fix 3TB partition can't be detected issue */ 120 /* u32 this_sector, this_size; */ 121 sector_t this_sector, this_size; 122 /* Foxconn modified end pling 04/30/2011 */ 123 int sector_size = bdev_hardsect_size(bdev) / 512; 124 int loopct = 0; /* number of links followed 125 without finding a data partition */ 126 int i; 127 128 this_sector = first_sector; 129 this_size = first_size; 130 131 while (1) { 132 if (++loopct > 100) 133 return; 134 if (state->next == state->limit) 135 return; 136 data = read_dev_sector(bdev, this_sector, §); 137 if (!data) 138 return; 139 140 if (!msdos_magic_present(data + 510)) 141 goto done; 142 143 p = (struct partition *) (data + 0x1be); 144 145 /* 146 * Usually, the first entry is the real data partition, 147 * the 2nd entry is the next extended partition, or empty, 148 * and the 3rd and 4th entries are unused. 149 * However, DRDOS sometimes has the extended partition as 150 * the first entry (when the data partition is empty), 151 * and OS/2 seems to use all four entries. 152 */ 153 154 /* 155 * First process the data partition(s) 156 */ 157 for (i=0; i<4; i++, p++) { 158 /* Foxconn modified start pling 04/30/2011 */ 159 /* Fix 3TB partition can't be detected issue */ 160 /* u32 offs, size, next; */ 161 sector_t offs, size, next; 162 /* Foxconn modified end pling 04/30/2011 */ 163 if (!NR_SECTS(p) || is_extended_partition(p)) 164 continue; 165 166 /* Check the 3rd and 4th entries - 167 these sometimes contain random garbage */ 168 /* Foxconn modified start pling 04/30/2011 */ 169 /* Fix 3TB partition can't be detected issue */ 170#if 0 171 offs = START_SECT(p)*sector_size; 172 size = NR_SECTS(p)*sector_size; 173#endif 174 offs = (sector_t)(START_SECT(p))*sector_size; 175 size = (sector_t)(NR_SECTS(p))*sector_size; 176 /* Foxconn modified end pling 04/30/2011 */ 177 next = this_sector + offs; 178 if (i >= 2) { 179 if (offs + size > this_size) 180 continue; 181 if (next < first_sector) 182 continue; 183 if (next + size > first_sector + first_size) 184 continue; 185 } 186 187 put_partition(state, state->next, next, size); 188 if (SYS_IND(p) == LINUX_RAID_PARTITION) 189 state->parts[state->next].flags = ADDPART_FLAG_RAID; 190 loopct = 0; 191 if (++state->next == state->limit) 192 goto done; 193 } 194 /* 195 * Next, process the (first) extended partition, if present. 196 * (So far, there seems to be no reason to make 197 * parse_extended() recursive and allow a tree 198 * of extended partitions.) 199 * It should be a link to the next logical partition. 200 */ 201 p -= 4; 202 for (i=0; i<4; i++, p++) 203 if (NR_SECTS(p) && is_extended_partition(p)) 204 break; 205 if (i == 4) 206 goto done; /* nothing left to do */ 207 208 this_sector = first_sector + START_SECT(p) * sector_size; 209 this_size = NR_SECTS(p) * sector_size; 210 put_dev_sector(sect); 211 } 212done: 213 put_dev_sector(sect); 214} 215 216/* james@bpgc.com: Solaris has a nasty indicator: 0x82 which also 217 indicates linux swap. Be careful before believing this is Solaris. */ 218 219static void 220parse_solaris_x86(struct parsed_partitions *state, struct block_device *bdev, 221 u32 offset, u32 size, int origin) 222{ 223#ifdef CONFIG_SOLARIS_X86_PARTITION 224 Sector sect; 225 struct solaris_x86_vtoc *v; 226 int i; 227 228 v = (struct solaris_x86_vtoc *)read_dev_sector(bdev, offset+1, §); 229 if (!v) 230 return; 231 if (le32_to_cpu(v->v_sanity) != SOLARIS_X86_VTOC_SANE) { 232 put_dev_sector(sect); 233 return; 234 } 235 printk(" %s%d: <solaris:", state->name, origin); 236 if (le32_to_cpu(v->v_version) != 1) { 237 printk(" cannot handle version %d vtoc>\n", 238 le32_to_cpu(v->v_version)); 239 put_dev_sector(sect); 240 return; 241 } 242 for (i=0; i<SOLARIS_X86_NUMSLICE && state->next<state->limit; i++) { 243 struct solaris_x86_slice *s = &v->v_slice[i]; 244 if (s->s_size == 0) 245 continue; 246 printk(" [s%d]", i); 247 /* solaris partitions are relative to current MS-DOS 248 * one; must add the offset of the current partition */ 249 put_partition(state, state->next++, 250 le32_to_cpu(s->s_start)+offset, 251 le32_to_cpu(s->s_size)); 252 } 253 put_dev_sector(sect); 254 printk(" >\n"); 255#endif 256} 257 258#if defined(CONFIG_BSD_DISKLABEL) 259/* 260 * Create devices for BSD partitions listed in a disklabel, under a 261 * dos-like partition. See parse_extended() for more information. 262 */ 263static void 264parse_bsd(struct parsed_partitions *state, struct block_device *bdev, 265 u32 offset, u32 size, int origin, char *flavour, 266 int max_partitions) 267{ 268 Sector sect; 269 struct bsd_disklabel *l; 270 struct bsd_partition *p; 271 272 l = (struct bsd_disklabel *)read_dev_sector(bdev, offset+1, §); 273 if (!l) 274 return; 275 if (le32_to_cpu(l->d_magic) != BSD_DISKMAGIC) { 276 put_dev_sector(sect); 277 return; 278 } 279 printk(" %s%d: <%s:", state->name, origin, flavour); 280 281 if (le16_to_cpu(l->d_npartitions) < max_partitions) 282 max_partitions = le16_to_cpu(l->d_npartitions); 283 for (p = l->d_partitions; p - l->d_partitions < max_partitions; p++) { 284 u32 bsd_start, bsd_size; 285 286 if (state->next == state->limit) 287 break; 288 if (p->p_fstype == BSD_FS_UNUSED) 289 continue; 290 bsd_start = le32_to_cpu(p->p_offset); 291 bsd_size = le32_to_cpu(p->p_size); 292 if (offset == bsd_start && size == bsd_size) 293 /* full parent partition, we have it already */ 294 continue; 295 if (offset > bsd_start || offset+size < bsd_start+bsd_size) { 296 printk("bad subpartition - ignored\n"); 297 continue; 298 } 299 put_partition(state, state->next++, bsd_start, bsd_size); 300 } 301 put_dev_sector(sect); 302 if (le16_to_cpu(l->d_npartitions) > max_partitions) 303 printk(" (ignored %d more)", 304 le16_to_cpu(l->d_npartitions) - max_partitions); 305 printk(" >\n"); 306} 307#endif 308 309static void 310parse_freebsd(struct parsed_partitions *state, struct block_device *bdev, 311 u32 offset, u32 size, int origin) 312{ 313#ifdef CONFIG_BSD_DISKLABEL 314 parse_bsd(state, bdev, offset, size, origin, 315 "bsd", BSD_MAXPARTITIONS); 316#endif 317} 318 319static void 320parse_netbsd(struct parsed_partitions *state, struct block_device *bdev, 321 u32 offset, u32 size, int origin) 322{ 323#ifdef CONFIG_BSD_DISKLABEL 324 parse_bsd(state, bdev, offset, size, origin, 325 "netbsd", BSD_MAXPARTITIONS); 326#endif 327} 328 329static void 330parse_openbsd(struct parsed_partitions *state, struct block_device *bdev, 331 u32 offset, u32 size, int origin) 332{ 333#ifdef CONFIG_BSD_DISKLABEL 334 parse_bsd(state, bdev, offset, size, origin, 335 "openbsd", OPENBSD_MAXPARTITIONS); 336#endif 337} 338 339/* 340 * Create devices for Unixware partitions listed in a disklabel, under a 341 * dos-like partition. See parse_extended() for more information. 342 */ 343static void 344parse_unixware(struct parsed_partitions *state, struct block_device *bdev, 345 u32 offset, u32 size, int origin) 346{ 347#ifdef CONFIG_UNIXWARE_DISKLABEL 348 Sector sect; 349 struct unixware_disklabel *l; 350 struct unixware_slice *p; 351 352 l = (struct unixware_disklabel *)read_dev_sector(bdev, offset+29, §); 353 if (!l) 354 return; 355 if (le32_to_cpu(l->d_magic) != UNIXWARE_DISKMAGIC || 356 le32_to_cpu(l->vtoc.v_magic) != UNIXWARE_DISKMAGIC2) { 357 put_dev_sector(sect); 358 return; 359 } 360 printk(" %s%d: <unixware:", state->name, origin); 361 p = &l->vtoc.v_slice[1]; 362 /* I omit the 0th slice as it is the same as whole disk. */ 363 while (p - &l->vtoc.v_slice[0] < UNIXWARE_NUMSLICE) { 364 if (state->next == state->limit) 365 break; 366 367 if (p->s_label != UNIXWARE_FS_UNUSED) 368 put_partition(state, state->next++, 369 START_SECT(p), NR_SECTS(p)); 370 p++; 371 } 372 put_dev_sector(sect); 373 printk(" >\n"); 374#endif 375} 376 377/* 378 * Minix 2.0.0/2.0.2 subpartition support. 379 * Anand Krishnamurthy <anandk@wiproge.med.ge.com> 380 * Rajeev V. Pillai <rajeevvp@yahoo.com> 381 */ 382static void 383parse_minix(struct parsed_partitions *state, struct block_device *bdev, 384 u32 offset, u32 size, int origin) 385{ 386#ifdef CONFIG_MINIX_SUBPARTITION 387 Sector sect; 388 unsigned char *data; 389 struct partition *p; 390 int i; 391 392 data = read_dev_sector(bdev, offset, §); 393 if (!data) 394 return; 395 396 p = (struct partition *)(data + 0x1be); 397 398 /* The first sector of a Minix partition can have either 399 * a secondary MBR describing its subpartitions, or 400 * the normal boot sector. */ 401 if (msdos_magic_present (data + 510) && 402 SYS_IND(p) == MINIX_PARTITION) { /* subpartition table present */ 403 404 printk(" %s%d: <minix:", state->name, origin); 405 for (i = 0; i < MINIX_NR_SUBPARTITIONS; i++, p++) { 406 if (state->next == state->limit) 407 break; 408 /* add each partition in use */ 409 if (SYS_IND(p) == MINIX_PARTITION) 410 put_partition(state, state->next++, 411 START_SECT(p), NR_SECTS(p)); 412 } 413 printk(" >\n"); 414 } 415 put_dev_sector(sect); 416#endif /* CONFIG_MINIX_SUBPARTITION */ 417} 418 419static struct { 420 unsigned char id; 421 void (*parse)(struct parsed_partitions *, struct block_device *, 422 u32, u32, int); 423} subtypes[] = { 424 {FREEBSD_PARTITION, parse_freebsd}, 425 {NETBSD_PARTITION, parse_netbsd}, 426 {OPENBSD_PARTITION, parse_openbsd}, 427 {MINIX_PARTITION, parse_minix}, 428 {UNIXWARE_PARTITION, parse_unixware}, 429 {SOLARIS_X86_PARTITION, parse_solaris_x86}, 430 {NEW_SOLARIS_X86_PARTITION, parse_solaris_x86}, 431 {0, NULL}, 432}; 433 434int msdos_partition(struct parsed_partitions *state, struct block_device *bdev) 435{ 436 int sector_size = bdev_hardsect_size(bdev) / 512; 437 Sector sect; 438 unsigned char *data; 439 struct partition *p; 440 int slot; 441 442 data = read_dev_sector(bdev, 0, §); 443 if (!data) 444 return -1; 445 if (!msdos_magic_present(data + 510)) { 446 put_dev_sector(sect); 447 return 0; 448 } 449 450 if (aix_magic_present(data, bdev)) { 451 put_dev_sector(sect); 452 printk( " [AIX]"); 453 return 0; 454 } 455 456 /* 457 * Now that the 55aa signature is present, this is probably 458 * either the boot sector of a FAT filesystem or a DOS-type 459 * partition table. Reject this in case the boot indicator 460 * is not 0 or 0x80. 461 */ 462 p = (struct partition *) (data + 0x1be); 463 for (slot = 1; slot <= 4; slot++, p++) { 464 if (p->boot_ind != 0 && p->boot_ind != 0x80) { 465 put_dev_sector(sect); 466 return 0; 467 } 468 } 469 470#ifdef CONFIG_EFI_PARTITION 471 p = (struct partition *) (data + 0x1be); 472 for (slot = 1 ; slot <= 4 ; slot++, p++) { 473 /* If this is an EFI GPT disk, msdos should ignore it. */ 474 if (SYS_IND(p) == EFI_PMBR_OSTYPE_EFI_GPT) { 475 put_dev_sector(sect); 476 return 0; 477 } 478 } 479#endif 480 p = (struct partition *) (data + 0x1be); 481 482 /* 483 * Look for partitions in two passes: 484 * First find the primary and DOS-type extended partitions. 485 * On the second pass look inside *BSD, Unixware and Solaris partitions. 486 */ 487 488 state->next = 5; 489 for (slot = 1 ; slot <= 4 ; slot++, p++) { 490 /* Foxconn modified start pling 04/30/2011 */ 491 /* Fix 3TB partition can't be detected issue */ 492#if 0 493 u32 start = START_SECT(p)*sector_size; 494 u32 size = NR_SECTS(p)*sector_size; 495#endif 496 sector_t start = (sector_t)(START_SECT(p))*sector_size; 497 sector_t size = (sector_t)(NR_SECTS(p))*sector_size; 498 /* Foxconn modified end pling 04/30/2011 */ 499 if (!size) 500 continue; 501 if (is_extended_partition(p)) { 502 /* prevent someone doing mkfs or mkswap on an 503 extended partition, but leave room for LILO */ 504 put_partition(state, slot, start, size == 1 ? 1 : 2); 505 printk(" <"); 506 parse_extended(state, bdev, start, size); 507 printk(" >"); 508 continue; 509 } 510 put_partition(state, slot, start, size); 511 if (SYS_IND(p) == LINUX_RAID_PARTITION) 512 state->parts[slot].flags = 1; 513 if (SYS_IND(p) == DM6_PARTITION) 514 printk("[DM]"); 515 if (SYS_IND(p) == EZD_PARTITION) 516 printk("[EZD]"); 517 } 518 519 printk("\n"); 520 521 /* second pass - output for each on a separate line */ 522 p = (struct partition *) (0x1be + data); 523 for (slot = 1 ; slot <= 4 ; slot++, p++) { 524 unsigned char id = SYS_IND(p); 525 int n; 526 527 if (!NR_SECTS(p)) 528 continue; 529 530 for (n = 0; subtypes[n].parse && id != subtypes[n].id; n++) 531 ; 532 533 if (!subtypes[n].parse) 534 continue; 535 subtypes[n].parse(state, bdev, START_SECT(p)*sector_size, 536 NR_SECTS(p)*sector_size, slot); 537 } 538 put_dev_sector(sect); 539 return 1; 540} 541