]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
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 | ||
1da177e4 LT |
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)) | |
3524de1c | 35 | #define NR_SECTS(p) ({ __le32 __a = get_unaligned(&p->nr_sects); \ |
1da177e4 LT |
36 | le32_to_cpu(__a); \ |
37 | }) | |
38 | ||
3524de1c | 39 | #define START_SECT(p) ({ __le32 __a = get_unaligned(&p->start_sect); \ |
1da177e4 LT |
40 | le32_to_cpu(__a); \ |
41 | }) | |
42 | ||
43 | static 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 | ||
53 | static inline int | |
54 | msdos_magic_present(unsigned char *p) | |
55 | { | |
56 | return (p[0] == MSDOS_LABEL_MAGIC1 && p[1] == MSDOS_LABEL_MAGIC2); | |
57 | } | |
58 | ||
e1dfa92d OH |
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 | |
64 | static int aix_magic_present(unsigned char *p, struct block_device *bdev) | |
65 | { | |
66 | Sector sect; | |
67 | unsigned char *d; | |
68 | int ret = 0; | |
69 | ||
70 | if (p[0] != AIX_LABEL_MAGIC1 && | |
71 | p[1] != AIX_LABEL_MAGIC2 && | |
72 | p[2] != AIX_LABEL_MAGIC3 && | |
73 | p[3] != AIX_LABEL_MAGIC4) | |
74 | return 0; | |
75 | d = read_dev_sector(bdev, 7, §); | |
76 | if (d) { | |
77 | if (d[0] == '_' && d[1] == 'L' && d[2] == 'V' && d[3] == 'M') | |
78 | ret = 1; | |
79 | put_dev_sector(sect); | |
80 | }; | |
81 | return ret; | |
82 | } | |
83 | ||
1da177e4 LT |
84 | /* |
85 | * Create devices for each logical partition in an extended partition. | |
86 | * The logical partitions form a linked list, with each entry being | |
87 | * a partition table with two entries. The first entry | |
88 | * is the real data partition (with a start relative to the partition | |
89 | * table start). The second is a pointer to the next logical partition | |
90 | * (with a start relative to the entire extended partition). | |
91 | * We do not create a Linux partition for the partition tables, but | |
92 | * only for the actual data partitions. | |
93 | */ | |
94 | ||
95 | static void | |
96 | parse_extended(struct parsed_partitions *state, struct block_device *bdev, | |
97 | u32 first_sector, u32 first_size) | |
98 | { | |
99 | struct partition *p; | |
100 | Sector sect; | |
101 | unsigned char *data; | |
102 | u32 this_sector, this_size; | |
103 | int sector_size = bdev_hardsect_size(bdev) / 512; | |
104 | int loopct = 0; /* number of links followed | |
105 | without finding a data partition */ | |
106 | int i; | |
107 | ||
108 | this_sector = first_sector; | |
109 | this_size = first_size; | |
110 | ||
111 | while (1) { | |
112 | if (++loopct > 100) | |
113 | return; | |
114 | if (state->next == state->limit) | |
115 | return; | |
116 | data = read_dev_sector(bdev, this_sector, §); | |
117 | if (!data) | |
118 | return; | |
119 | ||
120 | if (!msdos_magic_present(data + 510)) | |
121 | goto done; | |
122 | ||
123 | p = (struct partition *) (data + 0x1be); | |
124 | ||
125 | /* | |
126 | * Usually, the first entry is the real data partition, | |
127 | * the 2nd entry is the next extended partition, or empty, | |
128 | * and the 3rd and 4th entries are unused. | |
129 | * However, DRDOS sometimes has the extended partition as | |
130 | * the first entry (when the data partition is empty), | |
131 | * and OS/2 seems to use all four entries. | |
132 | */ | |
133 | ||
134 | /* | |
135 | * First process the data partition(s) | |
136 | */ | |
137 | for (i=0; i<4; i++, p++) { | |
138 | u32 offs, size, next; | |
1da177e4 LT |
139 | if (!NR_SECTS(p) || is_extended_partition(p)) |
140 | continue; | |
141 | ||
142 | /* Check the 3rd and 4th entries - | |
143 | these sometimes contain random garbage */ | |
144 | offs = START_SECT(p)*sector_size; | |
145 | size = NR_SECTS(p)*sector_size; | |
146 | next = this_sector + offs; | |
147 | if (i >= 2) { | |
148 | if (offs + size > this_size) | |
149 | continue; | |
150 | if (next < first_sector) | |
151 | continue; | |
152 | if (next + size > first_sector + first_size) | |
153 | continue; | |
154 | } | |
155 | ||
156 | put_partition(state, state->next, next, size); | |
157 | if (SYS_IND(p) == LINUX_RAID_PARTITION) | |
158 | state->parts[state->next].flags = 1; | |
159 | loopct = 0; | |
160 | if (++state->next == state->limit) | |
161 | goto done; | |
162 | } | |
163 | /* | |
164 | * Next, process the (first) extended partition, if present. | |
165 | * (So far, there seems to be no reason to make | |
166 | * parse_extended() recursive and allow a tree | |
167 | * of extended partitions.) | |
168 | * It should be a link to the next logical partition. | |
169 | */ | |
170 | p -= 4; | |
171 | for (i=0; i<4; i++, p++) | |
172 | if (NR_SECTS(p) && is_extended_partition(p)) | |
173 | break; | |
174 | if (i == 4) | |
175 | goto done; /* nothing left to do */ | |
176 | ||
177 | this_sector = first_sector + START_SECT(p) * sector_size; | |
178 | this_size = NR_SECTS(p) * sector_size; | |
179 | put_dev_sector(sect); | |
180 | } | |
181 | done: | |
182 | put_dev_sector(sect); | |
183 | } | |
184 | ||
185 | /* james@bpgc.com: Solaris has a nasty indicator: 0x82 which also | |
186 | indicates linux swap. Be careful before believing this is Solaris. */ | |
187 | ||
188 | static void | |
189 | parse_solaris_x86(struct parsed_partitions *state, struct block_device *bdev, | |
190 | u32 offset, u32 size, int origin) | |
191 | { | |
192 | #ifdef CONFIG_SOLARIS_X86_PARTITION | |
193 | Sector sect; | |
194 | struct solaris_x86_vtoc *v; | |
195 | int i; | |
196 | ||
197 | v = (struct solaris_x86_vtoc *)read_dev_sector(bdev, offset+1, §); | |
198 | if (!v) | |
199 | return; | |
200 | if (le32_to_cpu(v->v_sanity) != SOLARIS_X86_VTOC_SANE) { | |
201 | put_dev_sector(sect); | |
202 | return; | |
203 | } | |
204 | printk(" %s%d: <solaris:", state->name, origin); | |
205 | if (le32_to_cpu(v->v_version) != 1) { | |
206 | printk(" cannot handle version %d vtoc>\n", | |
207 | le32_to_cpu(v->v_version)); | |
208 | put_dev_sector(sect); | |
209 | return; | |
210 | } | |
211 | for (i=0; i<SOLARIS_X86_NUMSLICE && state->next<state->limit; i++) { | |
212 | struct solaris_x86_slice *s = &v->v_slice[i]; | |
213 | if (s->s_size == 0) | |
214 | continue; | |
215 | printk(" [s%d]", i); | |
216 | /* solaris partitions are relative to current MS-DOS | |
217 | * one; must add the offset of the current partition */ | |
218 | put_partition(state, state->next++, | |
219 | le32_to_cpu(s->s_start)+offset, | |
220 | le32_to_cpu(s->s_size)); | |
221 | } | |
222 | put_dev_sector(sect); | |
223 | printk(" >\n"); | |
224 | #endif | |
225 | } | |
226 | ||
486fd404 | 227 | #if defined(CONFIG_BSD_DISKLABEL) |
1da177e4 LT |
228 | /* |
229 | * Create devices for BSD partitions listed in a disklabel, under a | |
230 | * dos-like partition. See parse_extended() for more information. | |
231 | */ | |
486fd404 | 232 | static void |
1da177e4 LT |
233 | parse_bsd(struct parsed_partitions *state, struct block_device *bdev, |
234 | u32 offset, u32 size, int origin, char *flavour, | |
235 | int max_partitions) | |
236 | { | |
237 | Sector sect; | |
238 | struct bsd_disklabel *l; | |
239 | struct bsd_partition *p; | |
240 | ||
241 | l = (struct bsd_disklabel *)read_dev_sector(bdev, offset+1, §); | |
242 | if (!l) | |
243 | return; | |
244 | if (le32_to_cpu(l->d_magic) != BSD_DISKMAGIC) { | |
245 | put_dev_sector(sect); | |
246 | return; | |
247 | } | |
248 | printk(" %s%d: <%s:", state->name, origin, flavour); | |
249 | ||
250 | if (le16_to_cpu(l->d_npartitions) < max_partitions) | |
251 | max_partitions = le16_to_cpu(l->d_npartitions); | |
252 | for (p = l->d_partitions; p - l->d_partitions < max_partitions; p++) { | |
253 | u32 bsd_start, bsd_size; | |
254 | ||
255 | if (state->next == state->limit) | |
256 | break; | |
257 | if (p->p_fstype == BSD_FS_UNUSED) | |
258 | continue; | |
259 | bsd_start = le32_to_cpu(p->p_offset); | |
260 | bsd_size = le32_to_cpu(p->p_size); | |
261 | if (offset == bsd_start && size == bsd_size) | |
262 | /* full parent partition, we have it already */ | |
263 | continue; | |
264 | if (offset > bsd_start || offset+size < bsd_start+bsd_size) { | |
265 | printk("bad subpartition - ignored\n"); | |
266 | continue; | |
267 | } | |
268 | put_partition(state, state->next++, bsd_start, bsd_size); | |
269 | } | |
270 | put_dev_sector(sect); | |
271 | if (le16_to_cpu(l->d_npartitions) > max_partitions) | |
272 | printk(" (ignored %d more)", | |
273 | le16_to_cpu(l->d_npartitions) - max_partitions); | |
274 | printk(" >\n"); | |
275 | } | |
276 | #endif | |
277 | ||
278 | static void | |
279 | parse_freebsd(struct parsed_partitions *state, struct block_device *bdev, | |
280 | u32 offset, u32 size, int origin) | |
281 | { | |
282 | #ifdef CONFIG_BSD_DISKLABEL | |
283 | parse_bsd(state, bdev, offset, size, origin, | |
284 | "bsd", BSD_MAXPARTITIONS); | |
285 | #endif | |
286 | } | |
287 | ||
288 | static void | |
289 | parse_netbsd(struct parsed_partitions *state, struct block_device *bdev, | |
290 | u32 offset, u32 size, int origin) | |
291 | { | |
292 | #ifdef CONFIG_BSD_DISKLABEL | |
293 | parse_bsd(state, bdev, offset, size, origin, | |
294 | "netbsd", BSD_MAXPARTITIONS); | |
295 | #endif | |
296 | } | |
297 | ||
298 | static void | |
299 | parse_openbsd(struct parsed_partitions *state, struct block_device *bdev, | |
300 | u32 offset, u32 size, int origin) | |
301 | { | |
302 | #ifdef CONFIG_BSD_DISKLABEL | |
303 | parse_bsd(state, bdev, offset, size, origin, | |
304 | "openbsd", OPENBSD_MAXPARTITIONS); | |
305 | #endif | |
306 | } | |
307 | ||
308 | /* | |
309 | * Create devices for Unixware partitions listed in a disklabel, under a | |
310 | * dos-like partition. See parse_extended() for more information. | |
311 | */ | |
312 | static void | |
313 | parse_unixware(struct parsed_partitions *state, struct block_device *bdev, | |
314 | u32 offset, u32 size, int origin) | |
315 | { | |
316 | #ifdef CONFIG_UNIXWARE_DISKLABEL | |
317 | Sector sect; | |
318 | struct unixware_disklabel *l; | |
319 | struct unixware_slice *p; | |
320 | ||
321 | l = (struct unixware_disklabel *)read_dev_sector(bdev, offset+29, §); | |
322 | if (!l) | |
323 | return; | |
324 | if (le32_to_cpu(l->d_magic) != UNIXWARE_DISKMAGIC || | |
325 | le32_to_cpu(l->vtoc.v_magic) != UNIXWARE_DISKMAGIC2) { | |
326 | put_dev_sector(sect); | |
327 | return; | |
328 | } | |
329 | printk(" %s%d: <unixware:", state->name, origin); | |
330 | p = &l->vtoc.v_slice[1]; | |
331 | /* I omit the 0th slice as it is the same as whole disk. */ | |
332 | while (p - &l->vtoc.v_slice[0] < UNIXWARE_NUMSLICE) { | |
333 | if (state->next == state->limit) | |
334 | break; | |
335 | ||
336 | if (p->s_label != UNIXWARE_FS_UNUSED) | |
337 | put_partition(state, state->next++, | |
338 | START_SECT(p), NR_SECTS(p)); | |
339 | p++; | |
340 | } | |
341 | put_dev_sector(sect); | |
342 | printk(" >\n"); | |
343 | #endif | |
344 | } | |
345 | ||
346 | /* | |
347 | * Minix 2.0.0/2.0.2 subpartition support. | |
348 | * Anand Krishnamurthy <anandk@wiproge.med.ge.com> | |
349 | * Rajeev V. Pillai <rajeevvp@yahoo.com> | |
350 | */ | |
351 | static void | |
352 | parse_minix(struct parsed_partitions *state, struct block_device *bdev, | |
353 | u32 offset, u32 size, int origin) | |
354 | { | |
355 | #ifdef CONFIG_MINIX_SUBPARTITION | |
356 | Sector sect; | |
357 | unsigned char *data; | |
358 | struct partition *p; | |
359 | int i; | |
360 | ||
361 | data = read_dev_sector(bdev, offset, §); | |
362 | if (!data) | |
363 | return; | |
364 | ||
365 | p = (struct partition *)(data + 0x1be); | |
366 | ||
367 | /* The first sector of a Minix partition can have either | |
368 | * a secondary MBR describing its subpartitions, or | |
369 | * the normal boot sector. */ | |
370 | if (msdos_magic_present (data + 510) && | |
371 | SYS_IND(p) == MINIX_PARTITION) { /* subpartition table present */ | |
372 | ||
373 | printk(" %s%d: <minix:", state->name, origin); | |
374 | for (i = 0; i < MINIX_NR_SUBPARTITIONS; i++, p++) { | |
375 | if (state->next == state->limit) | |
376 | break; | |
377 | /* add each partition in use */ | |
378 | if (SYS_IND(p) == MINIX_PARTITION) | |
379 | put_partition(state, state->next++, | |
380 | START_SECT(p), NR_SECTS(p)); | |
381 | } | |
382 | printk(" >\n"); | |
383 | } | |
384 | put_dev_sector(sect); | |
385 | #endif /* CONFIG_MINIX_SUBPARTITION */ | |
386 | } | |
387 | ||
388 | static struct { | |
389 | unsigned char id; | |
390 | void (*parse)(struct parsed_partitions *, struct block_device *, | |
391 | u32, u32, int); | |
392 | } subtypes[] = { | |
393 | {FREEBSD_PARTITION, parse_freebsd}, | |
394 | {NETBSD_PARTITION, parse_netbsd}, | |
395 | {OPENBSD_PARTITION, parse_openbsd}, | |
396 | {MINIX_PARTITION, parse_minix}, | |
397 | {UNIXWARE_PARTITION, parse_unixware}, | |
398 | {SOLARIS_X86_PARTITION, parse_solaris_x86}, | |
399 | {NEW_SOLARIS_X86_PARTITION, parse_solaris_x86}, | |
400 | {0, NULL}, | |
401 | }; | |
402 | ||
403 | int msdos_partition(struct parsed_partitions *state, struct block_device *bdev) | |
404 | { | |
405 | int sector_size = bdev_hardsect_size(bdev) / 512; | |
406 | Sector sect; | |
407 | unsigned char *data; | |
408 | struct partition *p; | |
409 | int slot; | |
410 | ||
411 | data = read_dev_sector(bdev, 0, §); | |
412 | if (!data) | |
413 | return -1; | |
414 | if (!msdos_magic_present(data + 510)) { | |
415 | put_dev_sector(sect); | |
416 | return 0; | |
417 | } | |
418 | ||
e1dfa92d OH |
419 | if (aix_magic_present(data, bdev)) { |
420 | put_dev_sector(sect); | |
421 | printk( " [AIX]"); | |
422 | return 0; | |
423 | } | |
424 | ||
1da177e4 LT |
425 | /* |
426 | * Now that the 55aa signature is present, this is probably | |
427 | * either the boot sector of a FAT filesystem or a DOS-type | |
428 | * partition table. Reject this in case the boot indicator | |
429 | * is not 0 or 0x80. | |
430 | */ | |
431 | p = (struct partition *) (data + 0x1be); | |
432 | for (slot = 1; slot <= 4; slot++, p++) { | |
433 | if (p->boot_ind != 0 && p->boot_ind != 0x80) { | |
434 | put_dev_sector(sect); | |
435 | return 0; | |
436 | } | |
437 | } | |
438 | ||
439 | #ifdef CONFIG_EFI_PARTITION | |
440 | p = (struct partition *) (data + 0x1be); | |
441 | for (slot = 1 ; slot <= 4 ; slot++, p++) { | |
442 | /* If this is an EFI GPT disk, msdos should ignore it. */ | |
443 | if (SYS_IND(p) == EFI_PMBR_OSTYPE_EFI_GPT) { | |
444 | put_dev_sector(sect); | |
445 | return 0; | |
446 | } | |
447 | } | |
448 | #endif | |
449 | p = (struct partition *) (data + 0x1be); | |
450 | ||
451 | /* | |
452 | * Look for partitions in two passes: | |
453 | * First find the primary and DOS-type extended partitions. | |
454 | * On the second pass look inside *BSD, Unixware and Solaris partitions. | |
455 | */ | |
456 | ||
457 | state->next = 5; | |
458 | for (slot = 1 ; slot <= 4 ; slot++, p++) { | |
459 | u32 start = START_SECT(p)*sector_size; | |
460 | u32 size = NR_SECTS(p)*sector_size; | |
1da177e4 LT |
461 | if (!size) |
462 | continue; | |
463 | if (is_extended_partition(p)) { | |
464 | /* prevent someone doing mkfs or mkswap on an | |
465 | extended partition, but leave room for LILO */ | |
466 | put_partition(state, slot, start, size == 1 ? 1 : 2); | |
467 | printk(" <"); | |
468 | parse_extended(state, bdev, start, size); | |
469 | printk(" >"); | |
470 | continue; | |
471 | } | |
472 | put_partition(state, slot, start, size); | |
473 | if (SYS_IND(p) == LINUX_RAID_PARTITION) | |
474 | state->parts[slot].flags = 1; | |
475 | if (SYS_IND(p) == DM6_PARTITION) | |
476 | printk("[DM]"); | |
477 | if (SYS_IND(p) == EZD_PARTITION) | |
478 | printk("[EZD]"); | |
479 | } | |
480 | ||
481 | printk("\n"); | |
482 | ||
483 | /* second pass - output for each on a separate line */ | |
484 | p = (struct partition *) (0x1be + data); | |
485 | for (slot = 1 ; slot <= 4 ; slot++, p++) { | |
486 | unsigned char id = SYS_IND(p); | |
487 | int n; | |
488 | ||
489 | if (!NR_SECTS(p)) | |
490 | continue; | |
491 | ||
492 | for (n = 0; subtypes[n].parse && id != subtypes[n].id; n++) | |
493 | ; | |
494 | ||
495 | if (!subtypes[n].parse) | |
496 | continue; | |
497 | subtypes[n].parse(state, bdev, START_SECT(p)*sector_size, | |
498 | NR_SECTS(p)*sector_size, slot); | |
499 | } | |
500 | put_dev_sector(sect); | |
501 | return 1; | |
502 | } |