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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#include <linux/msdos_fs.h>
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
36static inline sector_t nr_sects(struct partition *p)
37{
38 return (sector_t)get_unaligned_le32(&p->nr_sects);
39}
40
41static inline sector_t start_sect(struct partition *p)
42{
43 return (sector_t)get_unaligned_le32(&p->start_sect);
44}
45
46static inline int is_extended_partition(struct partition *p)
47{
48 return (SYS_IND(p) == DOS_EXTENDED_PARTITION ||
49 SYS_IND(p) == WIN98_EXTENDED_PARTITION ||
50 SYS_IND(p) == LINUX_EXTENDED_PARTITION);
51}
52
53#define MSDOS_LABEL_MAGIC1 0x55
54#define MSDOS_LABEL_MAGIC2 0xAA
55
56static inline int
57msdos_magic_present(unsigned char *p)
58{
59 return (p[0] == MSDOS_LABEL_MAGIC1 && p[1] == MSDOS_LABEL_MAGIC2);
60}
61
62/* Value is EBCDIC 'IBMA' */
63#define AIX_LABEL_MAGIC1 0xC9
64#define AIX_LABEL_MAGIC2 0xC2
65#define AIX_LABEL_MAGIC3 0xD4
66#define AIX_LABEL_MAGIC4 0xC1
67static int aix_magic_present(struct parsed_partitions *state, unsigned char *p)
68{
69 struct partition *pt = (struct partition *) (p + 0x1be);
70 Sector sect;
71 unsigned char *d;
72 int slot, ret = 0;
73
74 if (!(p[0] == AIX_LABEL_MAGIC1 &&
75 p[1] == AIX_LABEL_MAGIC2 &&
76 p[2] == AIX_LABEL_MAGIC3 &&
77 p[3] == AIX_LABEL_MAGIC4))
78 return 0;
79 /* Assume the partition table is valid if Linux partitions exists */
80 for (slot = 1; slot <= 4; slot++, pt++) {
81 if (pt->sys_ind == LINUX_SWAP_PARTITION ||
82 pt->sys_ind == LINUX_RAID_PARTITION ||
83 pt->sys_ind == LINUX_DATA_PARTITION ||
84 pt->sys_ind == LINUX_LVM_PARTITION ||
85 is_extended_partition(pt))
86 return 0;
87 }
88 d = read_part_sector(state, 7, §);
89 if (d) {
90 if (d[0] == '_' && d[1] == 'L' && d[2] == 'V' && d[3] == 'M')
91 ret = 1;
92 put_dev_sector(sect);
93 };
94 return ret;
95}
96
97/*
98 * Create devices for each logical partition in an extended partition.
99 * The logical partitions form a linked list, with each entry being
100 * a partition table with two entries. The first entry
101 * is the real data partition (with a start relative to the partition
102 * table start). The second is a pointer to the next logical partition
103 * (with a start relative to the entire extended partition).
104 * We do not create a Linux partition for the partition tables, but
105 * only for the actual data partitions.
106 */
107
108static void parse_extended(struct parsed_partitions *state,
109 sector_t first_sector, sector_t first_size)
110{
111 struct partition *p;
112 Sector sect;
113 unsigned char *data;
114 sector_t this_sector, this_size;
115 sector_t sector_size = bdev_logical_block_size(state->bdev) / 512;
116 int loopct = 0; /* number of links followed
117 without finding a data partition */
118 int i;
119
120 this_sector = first_sector;
121 this_size = first_size;
122
123 while (1) {
124 if (++loopct > 100)
125 return;
126 if (state->next == state->limit)
127 return;
128 data = read_part_sector(state, this_sector, §);
129 if (!data)
130 return;
131
132 if (!msdos_magic_present(data + 510))
133 goto done;
134
135 p = (struct partition *) (data + 0x1be);
136
137 /*
138 * Usually, the first entry is the real data partition,
139 * the 2nd entry is the next extended partition, or empty,
140 * and the 3rd and 4th entries are unused.
141 * However, DRDOS sometimes has the extended partition as
142 * the first entry (when the data partition is empty),
143 * and OS/2 seems to use all four entries.
144 */
145
146 /*
147 * First process the data partition(s)
148 */
149 for (i=0; i<4; i++, p++) {
150 sector_t offs, size, next;
151 if (!nr_sects(p) || is_extended_partition(p))
152 continue;
153
154 /* Check the 3rd and 4th entries -
155 these sometimes contain random garbage */
156 offs = start_sect(p)*sector_size;
157 size = nr_sects(p)*sector_size;
158 next = this_sector + offs;
159 if (i >= 2) {
160 if (offs + size > this_size)
161 continue;
162 if (next < first_sector)
163 continue;
164 if (next + size > first_sector + first_size)
165 continue;
166 }
167
168 put_partition(state, state->next, next, size);
169 if (SYS_IND(p) == LINUX_RAID_PARTITION)
170 state->parts[state->next].flags = ADDPART_FLAG_RAID;
171 loopct = 0;
172 if (++state->next == state->limit)
173 goto done;
174 }
175 /*
176 * Next, process the (first) extended partition, if present.
177 * (So far, there seems to be no reason to make
178 * parse_extended() recursive and allow a tree
179 * of extended partitions.)
180 * It should be a link to the next logical partition.
181 */
182 p -= 4;
183 for (i=0; i<4; i++, p++)
184 if (nr_sects(p) && is_extended_partition(p))
185 break;
186 if (i == 4)
187 goto done; /* nothing left to do */
188
189 this_sector = first_sector + start_sect(p) * sector_size;
190 this_size = nr_sects(p) * sector_size;
191 put_dev_sector(sect);
192 }
193done:
194 put_dev_sector(sect);
195}
196
197/* james@bpgc.com: Solaris has a nasty indicator: 0x82 which also
198 indicates linux swap. Be careful before believing this is Solaris. */
199
200static void parse_solaris_x86(struct parsed_partitions *state,
201 sector_t offset, sector_t size, int origin)
202{
203#ifdef CONFIG_SOLARIS_X86_PARTITION
204 Sector sect;
205 struct solaris_x86_vtoc *v;
206 int i;
207 short max_nparts;
208
209 v = read_part_sector(state, offset + 1, §);
210 if (!v)
211 return;
212 if (le32_to_cpu(v->v_sanity) != SOLARIS_X86_VTOC_SANE) {
213 put_dev_sector(sect);
214 return;
215 }
216 {
217 char tmp[1 + BDEVNAME_SIZE + 10 + 11 + 1];
218
219 snprintf(tmp, sizeof(tmp), " %s%d: <solaris:", state->name, origin);
220 strlcat(state->pp_buf, tmp, PAGE_SIZE);
221 }
222 if (le32_to_cpu(v->v_version) != 1) {
223 char tmp[64];
224
225 snprintf(tmp, sizeof(tmp), " cannot handle version %d vtoc>\n",
226 le32_to_cpu(v->v_version));
227 strlcat(state->pp_buf, tmp, PAGE_SIZE);
228 put_dev_sector(sect);
229 return;
230 }
231 /* Ensure we can handle previous case of VTOC with 8 entries gracefully */
232 max_nparts = le16_to_cpu (v->v_nparts) > 8 ? SOLARIS_X86_NUMSLICE : 8;
233 for (i=0; i<max_nparts && state->next<state->limit; i++) {
234 struct solaris_x86_slice *s = &v->v_slice[i];
235 char tmp[3 + 10 + 1 + 1];
236
237 if (s->s_size == 0)
238 continue;
239 snprintf(tmp, sizeof(tmp), " [s%d]", i);
240 strlcat(state->pp_buf, tmp, PAGE_SIZE);
241 /* solaris partitions are relative to current MS-DOS
242 * one; must add the offset of the current partition */
243 put_partition(state, state->next++,
244 le32_to_cpu(s->s_start)+offset,
245 le32_to_cpu(s->s_size));
246 }
247 put_dev_sector(sect);
248 strlcat(state->pp_buf, " >\n", PAGE_SIZE);
249#endif
250}
251
252#if defined(CONFIG_BSD_DISKLABEL)
253/*
254 * Create devices for BSD partitions listed in a disklabel, under a
255 * dos-like partition. See parse_extended() for more information.
256 */
257static void parse_bsd(struct parsed_partitions *state,
258 sector_t offset, sector_t size, int origin, char *flavour,
259 int max_partitions)
260{
261 Sector sect;
262 struct bsd_disklabel *l;
263 struct bsd_partition *p;
264 char tmp[64];
265
266 l = read_part_sector(state, offset + 1, §);
267 if (!l)
268 return;
269 if (le32_to_cpu(l->d_magic) != BSD_DISKMAGIC) {
270 put_dev_sector(sect);
271 return;
272 }
273
274 snprintf(tmp, sizeof(tmp), " %s%d: <%s:", state->name, origin, flavour);
275 strlcat(state->pp_buf, tmp, PAGE_SIZE);
276
277 if (le16_to_cpu(l->d_npartitions) < max_partitions)
278 max_partitions = le16_to_cpu(l->d_npartitions);
279 for (p = l->d_partitions; p - l->d_partitions < max_partitions; p++) {
280 sector_t bsd_start, bsd_size;
281
282 if (state->next == state->limit)
283 break;
284 if (p->p_fstype == BSD_FS_UNUSED)
285 continue;
286 bsd_start = le32_to_cpu(p->p_offset);
287 bsd_size = le32_to_cpu(p->p_size);
288 if (offset == bsd_start && size == bsd_size)
289 /* full parent partition, we have it already */
290 continue;
291 if (offset > bsd_start || offset+size < bsd_start+bsd_size) {
292 strlcat(state->pp_buf, "bad subpartition - ignored\n", PAGE_SIZE);
293 continue;
294 }
295 put_partition(state, state->next++, bsd_start, bsd_size);
296 }
297 put_dev_sector(sect);
298 if (le16_to_cpu(l->d_npartitions) > max_partitions) {
299 snprintf(tmp, sizeof(tmp), " (ignored %d more)",
300 le16_to_cpu(l->d_npartitions) - max_partitions);
301 strlcat(state->pp_buf, tmp, PAGE_SIZE);
302 }
303 strlcat(state->pp_buf, " >\n", PAGE_SIZE);
304}
305#endif
306
307static void parse_freebsd(struct parsed_partitions *state,
308 sector_t offset, sector_t size, int origin)
309{
310#ifdef CONFIG_BSD_DISKLABEL
311 parse_bsd(state, offset, size, origin, "bsd", BSD_MAXPARTITIONS);
312#endif
313}
314
315static void parse_netbsd(struct parsed_partitions *state,
316 sector_t offset, sector_t size, int origin)
317{
318#ifdef CONFIG_BSD_DISKLABEL
319 parse_bsd(state, offset, size, origin, "netbsd", BSD_MAXPARTITIONS);
320#endif
321}
322
323static void parse_openbsd(struct parsed_partitions *state,
324 sector_t offset, sector_t size, int origin)
325{
326#ifdef CONFIG_BSD_DISKLABEL
327 parse_bsd(state, offset, size, origin, "openbsd",
328 OPENBSD_MAXPARTITIONS);
329#endif
330}
331
332/*
333 * Create devices for Unixware partitions listed in a disklabel, under a
334 * dos-like partition. See parse_extended() for more information.
335 */
336static void parse_unixware(struct parsed_partitions *state,
337 sector_t offset, sector_t size, int origin)
338{
339#ifdef CONFIG_UNIXWARE_DISKLABEL
340 Sector sect;
341 struct unixware_disklabel *l;
342 struct unixware_slice *p;
343
344 l = read_part_sector(state, offset + 29, §);
345 if (!l)
346 return;
347 if (le32_to_cpu(l->d_magic) != UNIXWARE_DISKMAGIC ||
348 le32_to_cpu(l->vtoc.v_magic) != UNIXWARE_DISKMAGIC2) {
349 put_dev_sector(sect);
350 return;
351 }
352 {
353 char tmp[1 + BDEVNAME_SIZE + 10 + 12 + 1];
354
355 snprintf(tmp, sizeof(tmp), " %s%d: <unixware:", state->name, origin);
356 strlcat(state->pp_buf, tmp, PAGE_SIZE);
357 }
358 p = &l->vtoc.v_slice[1];
359 /* I omit the 0th slice as it is the same as whole disk. */
360 while (p - &l->vtoc.v_slice[0] < UNIXWARE_NUMSLICE) {
361 if (state->next == state->limit)
362 break;
363
364 if (p->s_label != UNIXWARE_FS_UNUSED)
365 put_partition(state, state->next++,
366 le32_to_cpu(p->start_sect),
367 le32_to_cpu(p->nr_sects));
368 p++;
369 }
370 put_dev_sector(sect);
371 strlcat(state->pp_buf, " >\n", PAGE_SIZE);
372#endif
373}
374
375/*
376 * Minix 2.0.0/2.0.2 subpartition support.
377 * Anand Krishnamurthy <anandk@wiproge.med.ge.com>
378 * Rajeev V. Pillai <rajeevvp@yahoo.com>
379 */
380static void parse_minix(struct parsed_partitions *state,
381 sector_t offset, sector_t size, int origin)
382{
383#ifdef CONFIG_MINIX_SUBPARTITION
384 Sector sect;
385 unsigned char *data;
386 struct partition *p;
387 int i;
388
389 data = read_part_sector(state, offset, §);
390 if (!data)
391 return;
392
393 p = (struct partition *)(data + 0x1be);
394
395 /* The first sector of a Minix partition can have either
396 * a secondary MBR describing its subpartitions, or
397 * the normal boot sector. */
398 if (msdos_magic_present (data + 510) &&
399 SYS_IND(p) == MINIX_PARTITION) { /* subpartition table present */
400 char tmp[1 + BDEVNAME_SIZE + 10 + 9 + 1];
401
402 snprintf(tmp, sizeof(tmp), " %s%d: <minix:", state->name, origin);
403 strlcat(state->pp_buf, tmp, PAGE_SIZE);
404 for (i = 0; i < MINIX_NR_SUBPARTITIONS; i++, p++) {
405 if (state->next == state->limit)
406 break;
407 /* add each partition in use */
408 if (SYS_IND(p) == MINIX_PARTITION)
409 put_partition(state, state->next++,
410 start_sect(p), nr_sects(p));
411 }
412 strlcat(state->pp_buf, " >\n", PAGE_SIZE);
413 }
414 put_dev_sector(sect);
415#endif /* CONFIG_MINIX_SUBPARTITION */
416}
417
418static struct {
419 unsigned char id;
420 void (*parse)(struct parsed_partitions *, sector_t, sector_t, int);
421} subtypes[] = {
422 {FREEBSD_PARTITION, parse_freebsd},
423 {NETBSD_PARTITION, parse_netbsd},
424 {OPENBSD_PARTITION, parse_openbsd},
425 {MINIX_PARTITION, parse_minix},
426 {UNIXWARE_PARTITION, parse_unixware},
427 {SOLARIS_X86_PARTITION, parse_solaris_x86},
428 {NEW_SOLARIS_X86_PARTITION, parse_solaris_x86},
429 {0, NULL},
430};
431
432int msdos_partition(struct parsed_partitions *state)
433{
434 sector_t sector_size = bdev_logical_block_size(state->bdev) / 512;
435 Sector sect;
436 unsigned char *data;
437 struct partition *p;
438 struct fat_boot_sector *fb;
439 int slot;
440
441 data = read_part_sector(state, 0, §);
442 if (!data)
443 return -1;
444 if (!msdos_magic_present(data + 510)) {
445 put_dev_sector(sect);
446 return 0;
447 }
448
449 if (aix_magic_present(state, data)) {
450 put_dev_sector(sect);
451 strlcat(state->pp_buf, " [AIX]", PAGE_SIZE);
452 return 0;
453 }
454
455 /*
456 * Now that the 55aa signature is present, this is probably
457 * either the boot sector of a FAT filesystem or a DOS-type
458 * partition table. Reject this in case the boot indicator
459 * is not 0 or 0x80.
460 */
461 p = (struct partition *) (data + 0x1be);
462 for (slot = 1; slot <= 4; slot++, p++) {
463 if (p->boot_ind != 0 && p->boot_ind != 0x80) {
464 /*
465 * Even without a valid boot inidicator value
466 * its still possible this is valid FAT filesystem
467 * without a partition table.
468 */
469 fb = (struct fat_boot_sector *) data;
470 if (slot == 1 && fb->reserved && fb->fats
471 && fat_valid_media(fb->media)) {
472 strlcat(state->pp_buf, "\n", PAGE_SIZE);
473 put_dev_sector(sect);
474 return 1;
475 } else {
476 put_dev_sector(sect);
477 return 0;
478 }
479 }
480 }
481
482#ifdef CONFIG_EFI_PARTITION
483 p = (struct partition *) (data + 0x1be);
484 for (slot = 1 ; slot <= 4 ; slot++, p++) {
485 /* If this is an EFI GPT disk, msdos should ignore it. */
486 if (SYS_IND(p) == EFI_PMBR_OSTYPE_EFI_GPT) {
487 put_dev_sector(sect);
488 return 0;
489 }
490 }
491#endif
492 p = (struct partition *) (data + 0x1be);
493
494 /*
495 * Look for partitions in two passes:
496 * First find the primary and DOS-type extended partitions.
497 * On the second pass look inside *BSD, Unixware and Solaris partitions.
498 */
499
500 state->next = 5;
501 for (slot = 1 ; slot <= 4 ; slot++, p++) {
502 sector_t start = start_sect(p)*sector_size;
503 sector_t size = nr_sects(p)*sector_size;
504 if (!size)
505 continue;
506 if (is_extended_partition(p)) {
507 /*
508 * prevent someone doing mkfs or mkswap on an
509 * extended partition, but leave room for LILO
510 * FIXME: this uses one logical sector for > 512b
511 * sector, although it may not be enough/proper.
512 */
513 sector_t n = 2;
514 n = min(size, max(sector_size, n));
515 put_partition(state, slot, start, n);
516
517 strlcat(state->pp_buf, " <", PAGE_SIZE);
518 parse_extended(state, start, size);
519 strlcat(state->pp_buf, " >", PAGE_SIZE);
520 continue;
521 }
522 put_partition(state, slot, start, size);
523 if (SYS_IND(p) == LINUX_RAID_PARTITION)
524 state->parts[slot].flags = ADDPART_FLAG_RAID;
525 if (SYS_IND(p) == DM6_PARTITION)
526 strlcat(state->pp_buf, "[DM]", PAGE_SIZE);
527 if (SYS_IND(p) == EZD_PARTITION)
528 strlcat(state->pp_buf, "[EZD]", PAGE_SIZE);
529 }
530
531 strlcat(state->pp_buf, "\n", PAGE_SIZE);
532
533 /* second pass - output for each on a separate line */
534 p = (struct partition *) (0x1be + data);
535 for (slot = 1 ; slot <= 4 ; slot++, p++) {
536 unsigned char id = SYS_IND(p);
537 int n;
538
539 if (!nr_sects(p))
540 continue;
541
542 for (n = 0; subtypes[n].parse && id != subtypes[n].id; n++)
543 ;
544
545 if (!subtypes[n].parse)
546 continue;
547 subtypes[n].parse(state, start_sect(p) * sector_size,
548 nr_sects(p) * sector_size, slot);
549 }
550 put_dev_sector(sect);
551 return 1;
552}
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#include <linux/msdos_fs.h>
23
24#include "check.h"
25#include "msdos.h"
26#include "efi.h"
27#include "aix.h"
28
29/*
30 * Many architectures don't like unaligned accesses, while
31 * the nr_sects and start_sect partition table entries are
32 * at a 2 (mod 4) address.
33 */
34#include <asm/unaligned.h>
35
36#define SYS_IND(p) get_unaligned(&p->sys_ind)
37
38static inline sector_t nr_sects(struct partition *p)
39{
40 return (sector_t)get_unaligned_le32(&p->nr_sects);
41}
42
43static inline sector_t start_sect(struct partition *p)
44{
45 return (sector_t)get_unaligned_le32(&p->start_sect);
46}
47
48static inline int is_extended_partition(struct partition *p)
49{
50 return (SYS_IND(p) == DOS_EXTENDED_PARTITION ||
51 SYS_IND(p) == WIN98_EXTENDED_PARTITION ||
52 SYS_IND(p) == LINUX_EXTENDED_PARTITION);
53}
54
55#define MSDOS_LABEL_MAGIC1 0x55
56#define MSDOS_LABEL_MAGIC2 0xAA
57
58static inline int
59msdos_magic_present(unsigned char *p)
60{
61 return (p[0] == MSDOS_LABEL_MAGIC1 && p[1] == MSDOS_LABEL_MAGIC2);
62}
63
64/* Value is EBCDIC 'IBMA' */
65#define AIX_LABEL_MAGIC1 0xC9
66#define AIX_LABEL_MAGIC2 0xC2
67#define AIX_LABEL_MAGIC3 0xD4
68#define AIX_LABEL_MAGIC4 0xC1
69static int aix_magic_present(struct parsed_partitions *state, unsigned char *p)
70{
71 struct partition *pt = (struct partition *) (p + 0x1be);
72 Sector sect;
73 unsigned char *d;
74 int slot, ret = 0;
75
76 if (!(p[0] == AIX_LABEL_MAGIC1 &&
77 p[1] == AIX_LABEL_MAGIC2 &&
78 p[2] == AIX_LABEL_MAGIC3 &&
79 p[3] == AIX_LABEL_MAGIC4))
80 return 0;
81 /* Assume the partition table is valid if Linux partitions exists */
82 for (slot = 1; slot <= 4; slot++, pt++) {
83 if (pt->sys_ind == LINUX_SWAP_PARTITION ||
84 pt->sys_ind == LINUX_RAID_PARTITION ||
85 pt->sys_ind == LINUX_DATA_PARTITION ||
86 pt->sys_ind == LINUX_LVM_PARTITION ||
87 is_extended_partition(pt))
88 return 0;
89 }
90 d = read_part_sector(state, 7, §);
91 if (d) {
92 if (d[0] == '_' && d[1] == 'L' && d[2] == 'V' && d[3] == 'M')
93 ret = 1;
94 put_dev_sector(sect);
95 }
96 return ret;
97}
98
99static void set_info(struct parsed_partitions *state, int slot,
100 u32 disksig)
101{
102 struct partition_meta_info *info = &state->parts[slot].info;
103
104 snprintf(info->uuid, sizeof(info->uuid), "%08x-%02x", disksig,
105 slot);
106 info->volname[0] = 0;
107 state->parts[slot].has_info = true;
108}
109
110/*
111 * Create devices for each logical partition in an extended partition.
112 * The logical partitions form a linked list, with each entry being
113 * a partition table with two entries. The first entry
114 * is the real data partition (with a start relative to the partition
115 * table start). The second is a pointer to the next logical partition
116 * (with a start relative to the entire extended partition).
117 * We do not create a Linux partition for the partition tables, but
118 * only for the actual data partitions.
119 */
120
121static void parse_extended(struct parsed_partitions *state,
122 sector_t first_sector, sector_t first_size,
123 u32 disksig)
124{
125 struct partition *p;
126 Sector sect;
127 unsigned char *data;
128 sector_t this_sector, this_size;
129 sector_t sector_size = bdev_logical_block_size(state->bdev) / 512;
130 int loopct = 0; /* number of links followed
131 without finding a data partition */
132 int i;
133
134 this_sector = first_sector;
135 this_size = first_size;
136
137 while (1) {
138 if (++loopct > 100)
139 return;
140 if (state->next == state->limit)
141 return;
142 data = read_part_sector(state, this_sector, §);
143 if (!data)
144 return;
145
146 if (!msdos_magic_present(data + 510))
147 goto done;
148
149 p = (struct partition *) (data + 0x1be);
150
151 /*
152 * Usually, the first entry is the real data partition,
153 * the 2nd entry is the next extended partition, or empty,
154 * and the 3rd and 4th entries are unused.
155 * However, DRDOS sometimes has the extended partition as
156 * the first entry (when the data partition is empty),
157 * and OS/2 seems to use all four entries.
158 */
159
160 /*
161 * First process the data partition(s)
162 */
163 for (i = 0; i < 4; i++, p++) {
164 sector_t offs, size, next;
165
166 if (!nr_sects(p) || is_extended_partition(p))
167 continue;
168
169 /* Check the 3rd and 4th entries -
170 these sometimes contain random garbage */
171 offs = start_sect(p)*sector_size;
172 size = nr_sects(p)*sector_size;
173 next = this_sector + offs;
174 if (i >= 2) {
175 if (offs + size > this_size)
176 continue;
177 if (next < first_sector)
178 continue;
179 if (next + size > first_sector + first_size)
180 continue;
181 }
182
183 put_partition(state, state->next, next, size);
184 set_info(state, state->next, disksig);
185 if (SYS_IND(p) == LINUX_RAID_PARTITION)
186 state->parts[state->next].flags = ADDPART_FLAG_RAID;
187 loopct = 0;
188 if (++state->next == state->limit)
189 goto done;
190 }
191 /*
192 * Next, process the (first) extended partition, if present.
193 * (So far, there seems to be no reason to make
194 * parse_extended() recursive and allow a tree
195 * of extended partitions.)
196 * It should be a link to the next logical partition.
197 */
198 p -= 4;
199 for (i = 0; i < 4; i++, p++)
200 if (nr_sects(p) && is_extended_partition(p))
201 break;
202 if (i == 4)
203 goto done; /* nothing left to do */
204
205 this_sector = first_sector + start_sect(p) * sector_size;
206 this_size = nr_sects(p) * sector_size;
207 put_dev_sector(sect);
208 }
209done:
210 put_dev_sector(sect);
211}
212
213/* james@bpgc.com: Solaris has a nasty indicator: 0x82 which also
214 indicates linux swap. Be careful before believing this is Solaris. */
215
216static void parse_solaris_x86(struct parsed_partitions *state,
217 sector_t offset, sector_t size, int origin)
218{
219#ifdef CONFIG_SOLARIS_X86_PARTITION
220 Sector sect;
221 struct solaris_x86_vtoc *v;
222 int i;
223 short max_nparts;
224
225 v = read_part_sector(state, offset + 1, §);
226 if (!v)
227 return;
228 if (le32_to_cpu(v->v_sanity) != SOLARIS_X86_VTOC_SANE) {
229 put_dev_sector(sect);
230 return;
231 }
232 {
233 char tmp[1 + BDEVNAME_SIZE + 10 + 11 + 1];
234
235 snprintf(tmp, sizeof(tmp), " %s%d: <solaris:", state->name, origin);
236 strlcat(state->pp_buf, tmp, PAGE_SIZE);
237 }
238 if (le32_to_cpu(v->v_version) != 1) {
239 char tmp[64];
240
241 snprintf(tmp, sizeof(tmp), " cannot handle version %d vtoc>\n",
242 le32_to_cpu(v->v_version));
243 strlcat(state->pp_buf, tmp, PAGE_SIZE);
244 put_dev_sector(sect);
245 return;
246 }
247 /* Ensure we can handle previous case of VTOC with 8 entries gracefully */
248 max_nparts = le16_to_cpu(v->v_nparts) > 8 ? SOLARIS_X86_NUMSLICE : 8;
249 for (i = 0; i < max_nparts && state->next < state->limit; i++) {
250 struct solaris_x86_slice *s = &v->v_slice[i];
251 char tmp[3 + 10 + 1 + 1];
252
253 if (s->s_size == 0)
254 continue;
255 snprintf(tmp, sizeof(tmp), " [s%d]", i);
256 strlcat(state->pp_buf, tmp, PAGE_SIZE);
257 /* solaris partitions are relative to current MS-DOS
258 * one; must add the offset of the current partition */
259 put_partition(state, state->next++,
260 le32_to_cpu(s->s_start)+offset,
261 le32_to_cpu(s->s_size));
262 }
263 put_dev_sector(sect);
264 strlcat(state->pp_buf, " >\n", PAGE_SIZE);
265#endif
266}
267
268#if defined(CONFIG_BSD_DISKLABEL)
269/*
270 * Create devices for BSD partitions listed in a disklabel, under a
271 * dos-like partition. See parse_extended() for more information.
272 */
273static void parse_bsd(struct parsed_partitions *state,
274 sector_t offset, sector_t size, int origin, char *flavour,
275 int max_partitions)
276{
277 Sector sect;
278 struct bsd_disklabel *l;
279 struct bsd_partition *p;
280 char tmp[64];
281
282 l = read_part_sector(state, offset + 1, §);
283 if (!l)
284 return;
285 if (le32_to_cpu(l->d_magic) != BSD_DISKMAGIC) {
286 put_dev_sector(sect);
287 return;
288 }
289
290 snprintf(tmp, sizeof(tmp), " %s%d: <%s:", state->name, origin, flavour);
291 strlcat(state->pp_buf, tmp, PAGE_SIZE);
292
293 if (le16_to_cpu(l->d_npartitions) < max_partitions)
294 max_partitions = le16_to_cpu(l->d_npartitions);
295 for (p = l->d_partitions; p - l->d_partitions < max_partitions; p++) {
296 sector_t bsd_start, bsd_size;
297
298 if (state->next == state->limit)
299 break;
300 if (p->p_fstype == BSD_FS_UNUSED)
301 continue;
302 bsd_start = le32_to_cpu(p->p_offset);
303 bsd_size = le32_to_cpu(p->p_size);
304 /* FreeBSD has relative offset if C partition offset is zero */
305 if (memcmp(flavour, "bsd\0", 4) == 0 &&
306 le32_to_cpu(l->d_partitions[2].p_offset) == 0)
307 bsd_start += offset;
308 if (offset == bsd_start && size == bsd_size)
309 /* full parent partition, we have it already */
310 continue;
311 if (offset > bsd_start || offset+size < bsd_start+bsd_size) {
312 strlcat(state->pp_buf, "bad subpartition - ignored\n", PAGE_SIZE);
313 continue;
314 }
315 put_partition(state, state->next++, bsd_start, bsd_size);
316 }
317 put_dev_sector(sect);
318 if (le16_to_cpu(l->d_npartitions) > max_partitions) {
319 snprintf(tmp, sizeof(tmp), " (ignored %d more)",
320 le16_to_cpu(l->d_npartitions) - max_partitions);
321 strlcat(state->pp_buf, tmp, PAGE_SIZE);
322 }
323 strlcat(state->pp_buf, " >\n", PAGE_SIZE);
324}
325#endif
326
327static void parse_freebsd(struct parsed_partitions *state,
328 sector_t offset, sector_t size, int origin)
329{
330#ifdef CONFIG_BSD_DISKLABEL
331 parse_bsd(state, offset, size, origin, "bsd", BSD_MAXPARTITIONS);
332#endif
333}
334
335static void parse_netbsd(struct parsed_partitions *state,
336 sector_t offset, sector_t size, int origin)
337{
338#ifdef CONFIG_BSD_DISKLABEL
339 parse_bsd(state, offset, size, origin, "netbsd", BSD_MAXPARTITIONS);
340#endif
341}
342
343static void parse_openbsd(struct parsed_partitions *state,
344 sector_t offset, sector_t size, int origin)
345{
346#ifdef CONFIG_BSD_DISKLABEL
347 parse_bsd(state, offset, size, origin, "openbsd",
348 OPENBSD_MAXPARTITIONS);
349#endif
350}
351
352/*
353 * Create devices for Unixware partitions listed in a disklabel, under a
354 * dos-like partition. See parse_extended() for more information.
355 */
356static void parse_unixware(struct parsed_partitions *state,
357 sector_t offset, sector_t size, int origin)
358{
359#ifdef CONFIG_UNIXWARE_DISKLABEL
360 Sector sect;
361 struct unixware_disklabel *l;
362 struct unixware_slice *p;
363
364 l = read_part_sector(state, offset + 29, §);
365 if (!l)
366 return;
367 if (le32_to_cpu(l->d_magic) != UNIXWARE_DISKMAGIC ||
368 le32_to_cpu(l->vtoc.v_magic) != UNIXWARE_DISKMAGIC2) {
369 put_dev_sector(sect);
370 return;
371 }
372 {
373 char tmp[1 + BDEVNAME_SIZE + 10 + 12 + 1];
374
375 snprintf(tmp, sizeof(tmp), " %s%d: <unixware:", state->name, origin);
376 strlcat(state->pp_buf, tmp, PAGE_SIZE);
377 }
378 p = &l->vtoc.v_slice[1];
379 /* I omit the 0th slice as it is the same as whole disk. */
380 while (p - &l->vtoc.v_slice[0] < UNIXWARE_NUMSLICE) {
381 if (state->next == state->limit)
382 break;
383
384 if (p->s_label != UNIXWARE_FS_UNUSED)
385 put_partition(state, state->next++,
386 le32_to_cpu(p->start_sect),
387 le32_to_cpu(p->nr_sects));
388 p++;
389 }
390 put_dev_sector(sect);
391 strlcat(state->pp_buf, " >\n", PAGE_SIZE);
392#endif
393}
394
395/*
396 * Minix 2.0.0/2.0.2 subpartition support.
397 * Anand Krishnamurthy <anandk@wiproge.med.ge.com>
398 * Rajeev V. Pillai <rajeevvp@yahoo.com>
399 */
400static void parse_minix(struct parsed_partitions *state,
401 sector_t offset, sector_t size, int origin)
402{
403#ifdef CONFIG_MINIX_SUBPARTITION
404 Sector sect;
405 unsigned char *data;
406 struct partition *p;
407 int i;
408
409 data = read_part_sector(state, offset, §);
410 if (!data)
411 return;
412
413 p = (struct partition *)(data + 0x1be);
414
415 /* The first sector of a Minix partition can have either
416 * a secondary MBR describing its subpartitions, or
417 * the normal boot sector. */
418 if (msdos_magic_present(data + 510) &&
419 SYS_IND(p) == MINIX_PARTITION) { /* subpartition table present */
420 char tmp[1 + BDEVNAME_SIZE + 10 + 9 + 1];
421
422 snprintf(tmp, sizeof(tmp), " %s%d: <minix:", state->name, origin);
423 strlcat(state->pp_buf, tmp, PAGE_SIZE);
424 for (i = 0; i < MINIX_NR_SUBPARTITIONS; i++, p++) {
425 if (state->next == state->limit)
426 break;
427 /* add each partition in use */
428 if (SYS_IND(p) == MINIX_PARTITION)
429 put_partition(state, state->next++,
430 start_sect(p), nr_sects(p));
431 }
432 strlcat(state->pp_buf, " >\n", PAGE_SIZE);
433 }
434 put_dev_sector(sect);
435#endif /* CONFIG_MINIX_SUBPARTITION */
436}
437
438static struct {
439 unsigned char id;
440 void (*parse)(struct parsed_partitions *, sector_t, sector_t, int);
441} subtypes[] = {
442 {FREEBSD_PARTITION, parse_freebsd},
443 {NETBSD_PARTITION, parse_netbsd},
444 {OPENBSD_PARTITION, parse_openbsd},
445 {MINIX_PARTITION, parse_minix},
446 {UNIXWARE_PARTITION, parse_unixware},
447 {SOLARIS_X86_PARTITION, parse_solaris_x86},
448 {NEW_SOLARIS_X86_PARTITION, parse_solaris_x86},
449 {0, NULL},
450};
451
452int msdos_partition(struct parsed_partitions *state)
453{
454 sector_t sector_size = bdev_logical_block_size(state->bdev) / 512;
455 Sector sect;
456 unsigned char *data;
457 struct partition *p;
458 struct fat_boot_sector *fb;
459 int slot;
460 u32 disksig;
461
462 data = read_part_sector(state, 0, §);
463 if (!data)
464 return -1;
465
466 /*
467 * Note order! (some AIX disks, e.g. unbootable kind,
468 * have no MSDOS 55aa)
469 */
470 if (aix_magic_present(state, data)) {
471 put_dev_sector(sect);
472#ifdef CONFIG_AIX_PARTITION
473 return aix_partition(state);
474#else
475 strlcat(state->pp_buf, " [AIX]", PAGE_SIZE);
476 return 0;
477#endif
478 }
479
480 if (!msdos_magic_present(data + 510)) {
481 put_dev_sector(sect);
482 return 0;
483 }
484
485 /*
486 * Now that the 55aa signature is present, this is probably
487 * either the boot sector of a FAT filesystem or a DOS-type
488 * partition table. Reject this in case the boot indicator
489 * is not 0 or 0x80.
490 */
491 p = (struct partition *) (data + 0x1be);
492 for (slot = 1; slot <= 4; slot++, p++) {
493 if (p->boot_ind != 0 && p->boot_ind != 0x80) {
494 /*
495 * Even without a valid boot inidicator value
496 * its still possible this is valid FAT filesystem
497 * without a partition table.
498 */
499 fb = (struct fat_boot_sector *) data;
500 if (slot == 1 && fb->reserved && fb->fats
501 && fat_valid_media(fb->media)) {
502 strlcat(state->pp_buf, "\n", PAGE_SIZE);
503 put_dev_sector(sect);
504 return 1;
505 } else {
506 put_dev_sector(sect);
507 return 0;
508 }
509 }
510 }
511
512#ifdef CONFIG_EFI_PARTITION
513 p = (struct partition *) (data + 0x1be);
514 for (slot = 1 ; slot <= 4 ; slot++, p++) {
515 /* If this is an EFI GPT disk, msdos should ignore it. */
516 if (SYS_IND(p) == EFI_PMBR_OSTYPE_EFI_GPT) {
517 put_dev_sector(sect);
518 return 0;
519 }
520 }
521#endif
522 p = (struct partition *) (data + 0x1be);
523
524 disksig = le32_to_cpup((__le32 *)(data + 0x1b8));
525
526 /*
527 * Look for partitions in two passes:
528 * First find the primary and DOS-type extended partitions.
529 * On the second pass look inside *BSD, Unixware and Solaris partitions.
530 */
531
532 state->next = 5;
533 for (slot = 1 ; slot <= 4 ; slot++, p++) {
534 sector_t start = start_sect(p)*sector_size;
535 sector_t size = nr_sects(p)*sector_size;
536
537 if (!size)
538 continue;
539 if (is_extended_partition(p)) {
540 /*
541 * prevent someone doing mkfs or mkswap on an
542 * extended partition, but leave room for LILO
543 * FIXME: this uses one logical sector for > 512b
544 * sector, although it may not be enough/proper.
545 */
546 sector_t n = 2;
547
548 n = min(size, max(sector_size, n));
549 put_partition(state, slot, start, n);
550
551 strlcat(state->pp_buf, " <", PAGE_SIZE);
552 parse_extended(state, start, size, disksig);
553 strlcat(state->pp_buf, " >", PAGE_SIZE);
554 continue;
555 }
556 put_partition(state, slot, start, size);
557 set_info(state, slot, disksig);
558 if (SYS_IND(p) == LINUX_RAID_PARTITION)
559 state->parts[slot].flags = ADDPART_FLAG_RAID;
560 if (SYS_IND(p) == DM6_PARTITION)
561 strlcat(state->pp_buf, "[DM]", PAGE_SIZE);
562 if (SYS_IND(p) == EZD_PARTITION)
563 strlcat(state->pp_buf, "[EZD]", PAGE_SIZE);
564 }
565
566 strlcat(state->pp_buf, "\n", PAGE_SIZE);
567
568 /* second pass - output for each on a separate line */
569 p = (struct partition *) (0x1be + data);
570 for (slot = 1 ; slot <= 4 ; slot++, p++) {
571 unsigned char id = SYS_IND(p);
572 int n;
573
574 if (!nr_sects(p))
575 continue;
576
577 for (n = 0; subtypes[n].parse && id != subtypes[n].id; n++)
578 ;
579
580 if (!subtypes[n].parse)
581 continue;
582 subtypes[n].parse(state, start_sect(p) * sector_size,
583 nr_sects(p) * sector_size, slot);
584 }
585 put_dev_sector(sect);
586 return 1;
587}