diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/partitions/msdos.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/partitions/msdos.c')
-rw-r--r-- | fs/partitions/msdos.c | 479 |
1 files changed, 479 insertions, 0 deletions
diff --git a/fs/partitions/msdos.c b/fs/partitions/msdos.c new file mode 100644 index 000000000000..17ee1b4ff087 --- /dev/null +++ b/fs/partitions/msdos.c | |||
@@ -0,0 +1,479 @@ | |||
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 | #include <linux/config.h> | ||
23 | |||
24 | #include "check.h" | ||
25 | #include "msdos.h" | ||
26 | #include "efi.h" | ||
27 | |||
28 | /* | ||
29 | * Many architectures don't like unaligned accesses, while | ||
30 | * the nr_sects and start_sect partition table entries are | ||
31 | * at a 2 (mod 4) address. | ||
32 | */ | ||
33 | #include <asm/unaligned.h> | ||
34 | |||
35 | #define SYS_IND(p) (get_unaligned(&p->sys_ind)) | ||
36 | #define NR_SECTS(p) ({ __typeof__(p->nr_sects) __a = \ | ||
37 | get_unaligned(&p->nr_sects); \ | ||
38 | le32_to_cpu(__a); \ | ||
39 | }) | ||
40 | |||
41 | #define START_SECT(p) ({ __typeof__(p->start_sect) __a = \ | ||
42 | get_unaligned(&p->start_sect); \ | ||
43 | le32_to_cpu(__a); \ | ||
44 | }) | ||
45 | |||
46 | static 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 | |||
56 | static inline int | ||
57 | msdos_magic_present(unsigned char *p) | ||
58 | { | ||
59 | return (p[0] == MSDOS_LABEL_MAGIC1 && p[1] == MSDOS_LABEL_MAGIC2); | ||
60 | } | ||
61 | |||
62 | /* | ||
63 | * Create devices for each logical partition in an extended partition. | ||
64 | * The logical partitions form a linked list, with each entry being | ||
65 | * a partition table with two entries. The first entry | ||
66 | * is the real data partition (with a start relative to the partition | ||
67 | * table start). The second is a pointer to the next logical partition | ||
68 | * (with a start relative to the entire extended partition). | ||
69 | * We do not create a Linux partition for the partition tables, but | ||
70 | * only for the actual data partitions. | ||
71 | */ | ||
72 | |||
73 | static void | ||
74 | parse_extended(struct parsed_partitions *state, struct block_device *bdev, | ||
75 | u32 first_sector, u32 first_size) | ||
76 | { | ||
77 | struct partition *p; | ||
78 | Sector sect; | ||
79 | unsigned char *data; | ||
80 | u32 this_sector, this_size; | ||
81 | int sector_size = bdev_hardsect_size(bdev) / 512; | ||
82 | int loopct = 0; /* number of links followed | ||
83 | without finding a data partition */ | ||
84 | int i; | ||
85 | |||
86 | this_sector = first_sector; | ||
87 | this_size = first_size; | ||
88 | |||
89 | while (1) { | ||
90 | if (++loopct > 100) | ||
91 | return; | ||
92 | if (state->next == state->limit) | ||
93 | return; | ||
94 | data = read_dev_sector(bdev, this_sector, §); | ||
95 | if (!data) | ||
96 | return; | ||
97 | |||
98 | if (!msdos_magic_present(data + 510)) | ||
99 | goto done; | ||
100 | |||
101 | p = (struct partition *) (data + 0x1be); | ||
102 | |||
103 | /* | ||
104 | * Usually, the first entry is the real data partition, | ||
105 | * the 2nd entry is the next extended partition, or empty, | ||
106 | * and the 3rd and 4th entries are unused. | ||
107 | * However, DRDOS sometimes has the extended partition as | ||
108 | * the first entry (when the data partition is empty), | ||
109 | * and OS/2 seems to use all four entries. | ||
110 | */ | ||
111 | |||
112 | /* | ||
113 | * First process the data partition(s) | ||
114 | */ | ||
115 | for (i=0; i<4; i++, p++) { | ||
116 | u32 offs, size, next; | ||
117 | |||
118 | if (SYS_IND(p) == 0) | ||
119 | continue; | ||
120 | if (!NR_SECTS(p) || is_extended_partition(p)) | ||
121 | continue; | ||
122 | |||
123 | /* Check the 3rd and 4th entries - | ||
124 | these sometimes contain random garbage */ | ||
125 | offs = START_SECT(p)*sector_size; | ||
126 | size = NR_SECTS(p)*sector_size; | ||
127 | next = this_sector + offs; | ||
128 | if (i >= 2) { | ||
129 | if (offs + size > this_size) | ||
130 | continue; | ||
131 | if (next < first_sector) | ||
132 | continue; | ||
133 | if (next + size > first_sector + first_size) | ||
134 | continue; | ||
135 | } | ||
136 | |||
137 | put_partition(state, state->next, next, size); | ||
138 | if (SYS_IND(p) == LINUX_RAID_PARTITION) | ||
139 | state->parts[state->next].flags = 1; | ||
140 | loopct = 0; | ||
141 | if (++state->next == state->limit) | ||
142 | goto done; | ||
143 | } | ||
144 | /* | ||
145 | * Next, process the (first) extended partition, if present. | ||
146 | * (So far, there seems to be no reason to make | ||
147 | * parse_extended() recursive and allow a tree | ||
148 | * of extended partitions.) | ||
149 | * It should be a link to the next logical partition. | ||
150 | */ | ||
151 | p -= 4; | ||
152 | for (i=0; i<4; i++, p++) | ||
153 | if (NR_SECTS(p) && is_extended_partition(p)) | ||
154 | break; | ||
155 | if (i == 4) | ||
156 | goto done; /* nothing left to do */ | ||
157 | |||
158 | this_sector = first_sector + START_SECT(p) * sector_size; | ||
159 | this_size = NR_SECTS(p) * sector_size; | ||
160 | put_dev_sector(sect); | ||
161 | } | ||
162 | done: | ||
163 | put_dev_sector(sect); | ||
164 | } | ||
165 | |||
166 | /* james@bpgc.com: Solaris has a nasty indicator: 0x82 which also | ||
167 | indicates linux swap. Be careful before believing this is Solaris. */ | ||
168 | |||
169 | static void | ||
170 | parse_solaris_x86(struct parsed_partitions *state, struct block_device *bdev, | ||
171 | u32 offset, u32 size, int origin) | ||
172 | { | ||
173 | #ifdef CONFIG_SOLARIS_X86_PARTITION | ||
174 | Sector sect; | ||
175 | struct solaris_x86_vtoc *v; | ||
176 | int i; | ||
177 | |||
178 | v = (struct solaris_x86_vtoc *)read_dev_sector(bdev, offset+1, §); | ||
179 | if (!v) | ||
180 | return; | ||
181 | if (le32_to_cpu(v->v_sanity) != SOLARIS_X86_VTOC_SANE) { | ||
182 | put_dev_sector(sect); | ||
183 | return; | ||
184 | } | ||
185 | printk(" %s%d: <solaris:", state->name, origin); | ||
186 | if (le32_to_cpu(v->v_version) != 1) { | ||
187 | printk(" cannot handle version %d vtoc>\n", | ||
188 | le32_to_cpu(v->v_version)); | ||
189 | put_dev_sector(sect); | ||
190 | return; | ||
191 | } | ||
192 | for (i=0; i<SOLARIS_X86_NUMSLICE && state->next<state->limit; i++) { | ||
193 | struct solaris_x86_slice *s = &v->v_slice[i]; | ||
194 | if (s->s_size == 0) | ||
195 | continue; | ||
196 | printk(" [s%d]", i); | ||
197 | /* solaris partitions are relative to current MS-DOS | ||
198 | * one; must add the offset of the current partition */ | ||
199 | put_partition(state, state->next++, | ||
200 | le32_to_cpu(s->s_start)+offset, | ||
201 | le32_to_cpu(s->s_size)); | ||
202 | } | ||
203 | put_dev_sector(sect); | ||
204 | printk(" >\n"); | ||
205 | #endif | ||
206 | } | ||
207 | |||
208 | #if defined(CONFIG_BSD_DISKLABEL) || defined(CONFIG_NEC98_PARTITION) | ||
209 | /* | ||
210 | * Create devices for BSD partitions listed in a disklabel, under a | ||
211 | * dos-like partition. See parse_extended() for more information. | ||
212 | */ | ||
213 | void | ||
214 | parse_bsd(struct parsed_partitions *state, struct block_device *bdev, | ||
215 | u32 offset, u32 size, int origin, char *flavour, | ||
216 | int max_partitions) | ||
217 | { | ||
218 | Sector sect; | ||
219 | struct bsd_disklabel *l; | ||
220 | struct bsd_partition *p; | ||
221 | |||
222 | l = (struct bsd_disklabel *)read_dev_sector(bdev, offset+1, §); | ||
223 | if (!l) | ||
224 | return; | ||
225 | if (le32_to_cpu(l->d_magic) != BSD_DISKMAGIC) { | ||
226 | put_dev_sector(sect); | ||
227 | return; | ||
228 | } | ||
229 | printk(" %s%d: <%s:", state->name, origin, flavour); | ||
230 | |||
231 | if (le16_to_cpu(l->d_npartitions) < max_partitions) | ||
232 | max_partitions = le16_to_cpu(l->d_npartitions); | ||
233 | for (p = l->d_partitions; p - l->d_partitions < max_partitions; p++) { | ||
234 | u32 bsd_start, bsd_size; | ||
235 | |||
236 | if (state->next == state->limit) | ||
237 | break; | ||
238 | if (p->p_fstype == BSD_FS_UNUSED) | ||
239 | continue; | ||
240 | bsd_start = le32_to_cpu(p->p_offset); | ||
241 | bsd_size = le32_to_cpu(p->p_size); | ||
242 | if (offset == bsd_start && size == bsd_size) | ||
243 | /* full parent partition, we have it already */ | ||
244 | continue; | ||
245 | if (offset > bsd_start || offset+size < bsd_start+bsd_size) { | ||
246 | printk("bad subpartition - ignored\n"); | ||
247 | continue; | ||
248 | } | ||
249 | put_partition(state, state->next++, bsd_start, bsd_size); | ||
250 | } | ||
251 | put_dev_sector(sect); | ||
252 | if (le16_to_cpu(l->d_npartitions) > max_partitions) | ||
253 | printk(" (ignored %d more)", | ||
254 | le16_to_cpu(l->d_npartitions) - max_partitions); | ||
255 | printk(" >\n"); | ||
256 | } | ||
257 | #endif | ||
258 | |||
259 | static void | ||
260 | parse_freebsd(struct parsed_partitions *state, struct block_device *bdev, | ||
261 | u32 offset, u32 size, int origin) | ||
262 | { | ||
263 | #ifdef CONFIG_BSD_DISKLABEL | ||
264 | parse_bsd(state, bdev, offset, size, origin, | ||
265 | "bsd", BSD_MAXPARTITIONS); | ||
266 | #endif | ||
267 | } | ||
268 | |||
269 | static void | ||
270 | parse_netbsd(struct parsed_partitions *state, struct block_device *bdev, | ||
271 | u32 offset, u32 size, int origin) | ||
272 | { | ||
273 | #ifdef CONFIG_BSD_DISKLABEL | ||
274 | parse_bsd(state, bdev, offset, size, origin, | ||
275 | "netbsd", BSD_MAXPARTITIONS); | ||
276 | #endif | ||
277 | } | ||
278 | |||
279 | static void | ||
280 | parse_openbsd(struct parsed_partitions *state, struct block_device *bdev, | ||
281 | u32 offset, u32 size, int origin) | ||
282 | { | ||
283 | #ifdef CONFIG_BSD_DISKLABEL | ||
284 | parse_bsd(state, bdev, offset, size, origin, | ||
285 | "openbsd", OPENBSD_MAXPARTITIONS); | ||
286 | #endif | ||
287 | } | ||
288 | |||
289 | /* | ||
290 | * Create devices for Unixware partitions listed in a disklabel, under a | ||
291 | * dos-like partition. See parse_extended() for more information. | ||
292 | */ | ||
293 | static void | ||
294 | parse_unixware(struct parsed_partitions *state, struct block_device *bdev, | ||
295 | u32 offset, u32 size, int origin) | ||
296 | { | ||
297 | #ifdef CONFIG_UNIXWARE_DISKLABEL | ||
298 | Sector sect; | ||
299 | struct unixware_disklabel *l; | ||
300 | struct unixware_slice *p; | ||
301 | |||
302 | l = (struct unixware_disklabel *)read_dev_sector(bdev, offset+29, §); | ||
303 | if (!l) | ||
304 | return; | ||
305 | if (le32_to_cpu(l->d_magic) != UNIXWARE_DISKMAGIC || | ||
306 | le32_to_cpu(l->vtoc.v_magic) != UNIXWARE_DISKMAGIC2) { | ||
307 | put_dev_sector(sect); | ||
308 | return; | ||
309 | } | ||
310 | printk(" %s%d: <unixware:", state->name, origin); | ||
311 | p = &l->vtoc.v_slice[1]; | ||
312 | /* I omit the 0th slice as it is the same as whole disk. */ | ||
313 | while (p - &l->vtoc.v_slice[0] < UNIXWARE_NUMSLICE) { | ||
314 | if (state->next == state->limit) | ||
315 | break; | ||
316 | |||
317 | if (p->s_label != UNIXWARE_FS_UNUSED) | ||
318 | put_partition(state, state->next++, | ||
319 | START_SECT(p), NR_SECTS(p)); | ||
320 | p++; | ||
321 | } | ||
322 | put_dev_sector(sect); | ||
323 | printk(" >\n"); | ||
324 | #endif | ||
325 | } | ||
326 | |||
327 | /* | ||
328 | * Minix 2.0.0/2.0.2 subpartition support. | ||
329 | * Anand Krishnamurthy <anandk@wiproge.med.ge.com> | ||
330 | * Rajeev V. Pillai <rajeevvp@yahoo.com> | ||
331 | */ | ||
332 | static void | ||
333 | parse_minix(struct parsed_partitions *state, struct block_device *bdev, | ||
334 | u32 offset, u32 size, int origin) | ||
335 | { | ||
336 | #ifdef CONFIG_MINIX_SUBPARTITION | ||
337 | Sector sect; | ||
338 | unsigned char *data; | ||
339 | struct partition *p; | ||
340 | int i; | ||
341 | |||
342 | data = read_dev_sector(bdev, offset, §); | ||
343 | if (!data) | ||
344 | return; | ||
345 | |||
346 | p = (struct partition *)(data + 0x1be); | ||
347 | |||
348 | /* The first sector of a Minix partition can have either | ||
349 | * a secondary MBR describing its subpartitions, or | ||
350 | * the normal boot sector. */ | ||
351 | if (msdos_magic_present (data + 510) && | ||
352 | SYS_IND(p) == MINIX_PARTITION) { /* subpartition table present */ | ||
353 | |||
354 | printk(" %s%d: <minix:", state->name, origin); | ||
355 | for (i = 0; i < MINIX_NR_SUBPARTITIONS; i++, p++) { | ||
356 | if (state->next == state->limit) | ||
357 | break; | ||
358 | /* add each partition in use */ | ||
359 | if (SYS_IND(p) == MINIX_PARTITION) | ||
360 | put_partition(state, state->next++, | ||
361 | START_SECT(p), NR_SECTS(p)); | ||
362 | } | ||
363 | printk(" >\n"); | ||
364 | } | ||
365 | put_dev_sector(sect); | ||
366 | #endif /* CONFIG_MINIX_SUBPARTITION */ | ||
367 | } | ||
368 | |||
369 | static struct { | ||
370 | unsigned char id; | ||
371 | void (*parse)(struct parsed_partitions *, struct block_device *, | ||
372 | u32, u32, int); | ||
373 | } subtypes[] = { | ||
374 | {FREEBSD_PARTITION, parse_freebsd}, | ||
375 | {NETBSD_PARTITION, parse_netbsd}, | ||
376 | {OPENBSD_PARTITION, parse_openbsd}, | ||
377 | {MINIX_PARTITION, parse_minix}, | ||
378 | {UNIXWARE_PARTITION, parse_unixware}, | ||
379 | {SOLARIS_X86_PARTITION, parse_solaris_x86}, | ||
380 | {NEW_SOLARIS_X86_PARTITION, parse_solaris_x86}, | ||
381 | {0, NULL}, | ||
382 | }; | ||
383 | |||
384 | int msdos_partition(struct parsed_partitions *state, struct block_device *bdev) | ||
385 | { | ||
386 | int sector_size = bdev_hardsect_size(bdev) / 512; | ||
387 | Sector sect; | ||
388 | unsigned char *data; | ||
389 | struct partition *p; | ||
390 | int slot; | ||
391 | |||
392 | data = read_dev_sector(bdev, 0, §); | ||
393 | if (!data) | ||
394 | return -1; | ||
395 | if (!msdos_magic_present(data + 510)) { | ||
396 | put_dev_sector(sect); | ||
397 | return 0; | ||
398 | } | ||
399 | |||
400 | /* | ||
401 | * Now that the 55aa signature is present, this is probably | ||
402 | * either the boot sector of a FAT filesystem or a DOS-type | ||
403 | * partition table. Reject this in case the boot indicator | ||
404 | * is not 0 or 0x80. | ||
405 | */ | ||
406 | p = (struct partition *) (data + 0x1be); | ||
407 | for (slot = 1; slot <= 4; slot++, p++) { | ||
408 | if (p->boot_ind != 0 && p->boot_ind != 0x80) { | ||
409 | put_dev_sector(sect); | ||
410 | return 0; | ||
411 | } | ||
412 | } | ||
413 | |||
414 | #ifdef CONFIG_EFI_PARTITION | ||
415 | p = (struct partition *) (data + 0x1be); | ||
416 | for (slot = 1 ; slot <= 4 ; slot++, p++) { | ||
417 | /* If this is an EFI GPT disk, msdos should ignore it. */ | ||
418 | if (SYS_IND(p) == EFI_PMBR_OSTYPE_EFI_GPT) { | ||
419 | put_dev_sector(sect); | ||
420 | return 0; | ||
421 | } | ||
422 | } | ||
423 | #endif | ||
424 | p = (struct partition *) (data + 0x1be); | ||
425 | |||
426 | /* | ||
427 | * Look for partitions in two passes: | ||
428 | * First find the primary and DOS-type extended partitions. | ||
429 | * On the second pass look inside *BSD, Unixware and Solaris partitions. | ||
430 | */ | ||
431 | |||
432 | state->next = 5; | ||
433 | for (slot = 1 ; slot <= 4 ; slot++, p++) { | ||
434 | u32 start = START_SECT(p)*sector_size; | ||
435 | u32 size = NR_SECTS(p)*sector_size; | ||
436 | if (SYS_IND(p) == 0) | ||
437 | continue; | ||
438 | if (!size) | ||
439 | continue; | ||
440 | if (is_extended_partition(p)) { | ||
441 | /* prevent someone doing mkfs or mkswap on an | ||
442 | extended partition, but leave room for LILO */ | ||
443 | put_partition(state, slot, start, size == 1 ? 1 : 2); | ||
444 | printk(" <"); | ||
445 | parse_extended(state, bdev, start, size); | ||
446 | printk(" >"); | ||
447 | continue; | ||
448 | } | ||
449 | put_partition(state, slot, start, size); | ||
450 | if (SYS_IND(p) == LINUX_RAID_PARTITION) | ||
451 | state->parts[slot].flags = 1; | ||
452 | if (SYS_IND(p) == DM6_PARTITION) | ||
453 | printk("[DM]"); | ||
454 | if (SYS_IND(p) == EZD_PARTITION) | ||
455 | printk("[EZD]"); | ||
456 | } | ||
457 | |||
458 | printk("\n"); | ||
459 | |||
460 | /* second pass - output for each on a separate line */ | ||
461 | p = (struct partition *) (0x1be + data); | ||
462 | for (slot = 1 ; slot <= 4 ; slot++, p++) { | ||
463 | unsigned char id = SYS_IND(p); | ||
464 | int n; | ||
465 | |||
466 | if (!NR_SECTS(p)) | ||
467 | continue; | ||
468 | |||
469 | for (n = 0; subtypes[n].parse && id != subtypes[n].id; n++) | ||
470 | ; | ||
471 | |||
472 | if (!subtypes[n].parse) | ||
473 | continue; | ||
474 | subtypes[n].parse(state, bdev, START_SECT(p)*sector_size, | ||
475 | NR_SECTS(p)*sector_size, slot); | ||
476 | } | ||
477 | put_dev_sector(sect); | ||
478 | return 1; | ||
479 | } | ||