1 | /* $NetBSD: subr_disk_mbr.c,v 1.46 2013/06/26 18:47:26 matt Exp $ */ |
2 | |
3 | /* |
4 | * Copyright (c) 1982, 1986, 1988 Regents of the University of California. |
5 | * All rights reserved. |
6 | * |
7 | * Redistribution and use in source and binary forms, with or without |
8 | * modification, are permitted provided that the following conditions |
9 | * are met: |
10 | * 1. Redistributions of source code must retain the above copyright |
11 | * notice, this list of conditions and the following disclaimer. |
12 | * 2. Redistributions in binary form must reproduce the above copyright |
13 | * notice, this list of conditions and the following disclaimer in the |
14 | * documentation and/or other materials provided with the distribution. |
15 | * 3. Neither the name of the University nor the names of its contributors |
16 | * may be used to endorse or promote products derived from this software |
17 | * without specific prior written permission. |
18 | * |
19 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
20 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
21 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
22 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
23 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
24 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
25 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
26 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
27 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
28 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
29 | * SUCH DAMAGE. |
30 | * |
31 | * @(#)ufs_disksubr.c 7.16 (Berkeley) 5/4/91 |
32 | */ |
33 | |
34 | /* |
35 | * Code to find a NetBSD label on a disk that contains an i386 style MBR. |
36 | * The first NetBSD label found in the 2nd sector of a NetBSD partition |
37 | * is used. |
38 | * If we don't find a label searching the MBR, we look at the start of the |
39 | * disk, if that fails then a label is faked up from the MBR. |
40 | * |
41 | * If there isn't a disklabel or anything in the MBR then the disc is searched |
42 | * for ecma-167/iso9660/udf style partition indicators. |
43 | * Useful for media or files that contain single filesystems (etc). |
44 | * |
45 | * This code will read host endian netbsd labels from little endian MBR. |
46 | * |
47 | * Based on the i386 disksubr.c |
48 | * |
49 | * Since the mbr only has 32bit fields for sector addresses, we do the same. |
50 | * |
51 | * XXX There are potential problems writing labels to disks where there |
52 | * is only space for 8 netbsd partitions but this code has been compiled |
53 | * with MAXPARTITIONS=16. |
54 | */ |
55 | |
56 | #include <sys/cdefs.h> |
57 | __KERNEL_RCSID(0, "$NetBSD: subr_disk_mbr.c,v 1.46 2013/06/26 18:47:26 matt Exp $" ); |
58 | |
59 | #include <sys/param.h> |
60 | #include <sys/systm.h> |
61 | #include <sys/buf.h> |
62 | #include <sys/bootblock.h> |
63 | #include <sys/disklabel.h> |
64 | #include <sys/disk.h> |
65 | #include <sys/syslog.h> |
66 | #include <sys/vnode.h> |
67 | #include <sys/fcntl.h> |
68 | #include <sys/conf.h> |
69 | #include <sys/cdio.h> |
70 | #include <sys/dkbad.h> |
71 | #include <fs/udf/ecma167-udf.h> |
72 | |
73 | #include <sys/kauth.h> |
74 | |
75 | #ifdef _KERNEL_OPT |
76 | #include "opt_mbr.h" |
77 | #endif /* _KERNEL_OPT */ |
78 | |
79 | typedef struct mbr_partition mbr_partition_t; |
80 | |
81 | /* |
82 | * We allocate a buffer 3 sectors large, and look in all.... |
83 | * That means we find labels written by other ports with different offsets. |
84 | * LABELSECTOR and LABELOFFSET are only used if the disk doesn't have a label. |
85 | */ |
86 | #define SCANBLOCKS 3 |
87 | #define DISKLABEL_SIZE 404 |
88 | #if LABELSECTOR*DEV_BSIZE + LABELOFFSET > SCANBLOCKS*DEV_BSIZE - DISKLABEL_SIZE |
89 | #if _MACHINE != ews4800mips /* XXX: fail silently, ews4800mips LABELSECTOR */ |
90 | #error Invalid LABELSECTOR or LABELOFFSET |
91 | #endif |
92 | #endif |
93 | |
94 | #define MBR_LABELSECTOR 1 |
95 | |
96 | #define SCAN_CONTINUE 0 |
97 | #define SCAN_FOUND 1 |
98 | #define SCAN_ERROR 2 |
99 | |
100 | typedef struct mbr_args { |
101 | struct disklabel *lp; |
102 | void (*strat)(struct buf *); |
103 | struct buf *bp; |
104 | const char *msg; |
105 | int error; |
106 | int written; /* number of times we wrote label */ |
107 | int found_mbr; /* set if disk has a valid mbr */ |
108 | uint label_sector; /* where we found the label */ |
109 | int action; |
110 | uint32_t secperunit; |
111 | #define READ_LABEL 1 |
112 | #define UPDATE_LABEL 2 |
113 | #define WRITE_LABEL 3 |
114 | } mbr_args_t; |
115 | |
116 | static int validate_label(mbr_args_t *, uint); |
117 | static int look_netbsd_part(mbr_args_t *, mbr_partition_t *, int, uint); |
118 | static int write_netbsd_label(mbr_args_t *, mbr_partition_t *, int, uint); |
119 | |
120 | static int |
121 | read_sector(mbr_args_t *a, uint sector, int count) |
122 | { |
123 | int error; |
124 | |
125 | error = disk_read_sectors(a->strat, a->lp, a->bp, sector, count); |
126 | if (error != 0) |
127 | a->error = error; |
128 | return error; |
129 | } |
130 | |
131 | /* |
132 | * Scan MBR for partitions, call 'action' routine for each. |
133 | */ |
134 | |
135 | static int |
136 | scan_mbr(mbr_args_t *a, int (*actn)(mbr_args_t *, mbr_partition_t *, int, uint)) |
137 | { |
138 | mbr_partition_t ptns[MBR_PART_COUNT]; |
139 | mbr_partition_t *dp; |
140 | struct mbr_sector *mbr; |
141 | uint ext_base, this_ext, next_ext; |
142 | int rval; |
143 | int i; |
144 | int j; |
145 | #ifdef COMPAT_386BSD_MBRPART |
146 | int dp_386bsd = -1; |
147 | int ap_386bsd = -1; |
148 | #endif |
149 | |
150 | ext_base = 0; |
151 | this_ext = 0; |
152 | for (;;) { |
153 | if (read_sector(a, this_ext, 1)) { |
154 | a->msg = "dos partition I/O error" ; |
155 | return SCAN_ERROR; |
156 | } |
157 | |
158 | /* Note: Magic number is little-endian. */ |
159 | mbr = (void *)a->bp->b_data; |
160 | if (mbr->mbr_magic != htole16(MBR_MAGIC)) |
161 | return SCAN_CONTINUE; |
162 | |
163 | /* |
164 | * If this is a protective MBR, bail now. |
165 | */ |
166 | if (mbr->mbr_parts[0].mbrp_type == MBR_PTYPE_PMBR |
167 | && mbr->mbr_parts[1].mbrp_type == MBR_PTYPE_UNUSED |
168 | && mbr->mbr_parts[2].mbrp_type == MBR_PTYPE_UNUSED |
169 | && mbr->mbr_parts[3].mbrp_type == MBR_PTYPE_UNUSED) |
170 | return SCAN_CONTINUE; |
171 | |
172 | /* Copy data out of buffer so action can use bp */ |
173 | memcpy(ptns, &mbr->mbr_parts, sizeof ptns); |
174 | |
175 | /* Look for drivers and skip them */ |
176 | if (ext_base == 0 && ptns[0].mbrp_type == MBR_PTYPE_DM6_DDO) { |
177 | /* We've found a DM6 DDO partition type (used by |
178 | * the Ontrack Disk Manager drivers). |
179 | * |
180 | * Ensure that there are no other partitions in the |
181 | * MBR and jump to the real partition table (stored |
182 | * in the first sector of the second track). */ |
183 | bool ok = true; |
184 | |
185 | for (i = 1; i < MBR_PART_COUNT; i++) |
186 | if (ptns[i].mbrp_type != MBR_PTYPE_UNUSED) |
187 | ok = false; |
188 | |
189 | if (ok) { |
190 | this_ext = le32toh(a->lp->d_secpercyl / |
191 | a->lp->d_ntracks); |
192 | continue; |
193 | } |
194 | } |
195 | |
196 | /* look for NetBSD partition */ |
197 | next_ext = 0; |
198 | dp = ptns; |
199 | j = 0; |
200 | for (i = 0; i < MBR_PART_COUNT; i++, dp++) { |
201 | if (dp->mbrp_type == MBR_PTYPE_UNUSED) |
202 | continue; |
203 | /* Check end of partition is inside disk limits */ |
204 | if ((uint64_t)ext_base + le32toh(dp->mbrp_start) + |
205 | le32toh(dp->mbrp_size) > a->lp->d_secperunit) { |
206 | /* This mbr doesn't look good.... */ |
207 | a->msg = "mbr partition exceeds disk size" ; |
208 | /* ...but don't report this as an error (yet) */ |
209 | return SCAN_CONTINUE; |
210 | } |
211 | a->found_mbr = 1; |
212 | if (MBR_IS_EXTENDED(dp->mbrp_type)) { |
213 | next_ext = le32toh(dp->mbrp_start); |
214 | continue; |
215 | } |
216 | #ifdef COMPAT_386BSD_MBRPART |
217 | if (dp->mbrp_type == MBR_PTYPE_386BSD) { |
218 | /* |
219 | * If more than one matches, take last, |
220 | * as NetBSD install tool does. |
221 | */ |
222 | if (this_ext == 0) { |
223 | dp_386bsd = i; |
224 | ap_386bsd = j; |
225 | } |
226 | continue; |
227 | } |
228 | #endif |
229 | rval = (*actn)(a, dp, j, this_ext); |
230 | if (rval != SCAN_CONTINUE) |
231 | return rval; |
232 | j++; |
233 | } |
234 | if (next_ext == 0) |
235 | break; |
236 | if (ext_base == 0) { |
237 | ext_base = next_ext; |
238 | next_ext = 0; |
239 | } |
240 | next_ext += ext_base; |
241 | if (next_ext <= this_ext) |
242 | break; |
243 | this_ext = next_ext; |
244 | } |
245 | #ifdef COMPAT_386BSD_MBRPART |
246 | if (this_ext == 0 && dp_386bsd != -1) |
247 | return (*actn)(a, &ptns[dp_386bsd], ap_386bsd, 0); |
248 | #endif |
249 | return SCAN_CONTINUE; |
250 | } |
251 | |
252 | |
253 | static void |
254 | scan_iso_vrs_session(mbr_args_t *a, uint32_t first_sector, |
255 | int *is_iso9660, int *is_udf) |
256 | { |
257 | struct vrs_desc *vrsd; |
258 | uint64_t vrs; |
259 | int sector_size; |
260 | int blks, inc; |
261 | |
262 | sector_size = a->lp->d_secsize; |
263 | blks = sector_size / DEV_BSIZE; |
264 | inc = MAX(1, 2048 / sector_size); |
265 | |
266 | /* by definition */ |
267 | vrs = ((32*1024 + sector_size - 1) / sector_size) |
268 | + first_sector; |
269 | |
270 | /* read first vrs sector */ |
271 | if (read_sector(a, vrs * blks, 1)) |
272 | return; |
273 | |
274 | /* skip all CD001 records */ |
275 | vrsd = a->bp->b_data; |
276 | /* printf("vrsd->identifier = `%s`\n", vrsd->identifier); */ |
277 | while (memcmp(vrsd->identifier, "CD001" , 5) == 0) { |
278 | /* for sure */ |
279 | *is_iso9660 = first_sector; |
280 | |
281 | vrs += inc; |
282 | if (read_sector(a, vrs * blks, 1)) |
283 | return; |
284 | } |
285 | |
286 | /* search for BEA01 */ |
287 | vrsd = a->bp->b_data; |
288 | /* printf("vrsd->identifier = `%s`\n", vrsd->identifier); */ |
289 | if (memcmp(vrsd->identifier, "BEA01" , 5)) |
290 | return; |
291 | |
292 | /* read successor */ |
293 | vrs += inc; |
294 | if (read_sector(a, vrs * blks, 1)) |
295 | return; |
296 | |
297 | /* check for NSR[23] */ |
298 | vrsd = a->bp->b_data; |
299 | /* printf("vrsd->identifier = `%s`\n", vrsd->identifier); */ |
300 | if (memcmp(vrsd->identifier, "NSR0" , 4)) |
301 | return; |
302 | |
303 | *is_udf = first_sector; |
304 | } |
305 | |
306 | |
307 | /* |
308 | * Scan for ISO Volume Recognition Sequences |
309 | */ |
310 | |
311 | static int |
312 | scan_iso_vrs(mbr_args_t *a) |
313 | { |
314 | struct mmc_discinfo di; |
315 | struct mmc_trackinfo ti; |
316 | dev_t dev; |
317 | uint64_t sector; |
318 | int is_iso9660, is_udf; |
319 | int tracknr, sessionnr; |
320 | int new_session, error; |
321 | |
322 | is_iso9660 = is_udf = -1; |
323 | |
324 | /* parse all sessions of disc if we're on a SCSI MMC device */ |
325 | if (a->lp->d_flags & D_SCSI_MMC) { |
326 | /* get disc info */ |
327 | dev = a->bp->b_dev; |
328 | error = bdev_ioctl(dev, MMCGETDISCINFO, &di, FKIOCTL, curlwp); |
329 | if (error) |
330 | return SCAN_CONTINUE; |
331 | |
332 | /* go trough all (data) tracks */ |
333 | sessionnr = -1; |
334 | for (tracknr = di.first_track; |
335 | tracknr <= di.first_track_last_session; tracknr++) |
336 | { |
337 | ti.tracknr = tracknr; |
338 | error = bdev_ioctl(dev, MMCGETTRACKINFO, &ti, |
339 | FKIOCTL, curlwp); |
340 | if (error) |
341 | return SCAN_CONTINUE; |
342 | new_session = (ti.sessionnr != sessionnr); |
343 | sessionnr = ti.sessionnr; |
344 | if (new_session) { |
345 | if (ti.flags & MMC_TRACKINFO_BLANK) |
346 | continue; |
347 | if (!(ti.flags & MMC_TRACKINFO_DATA)) |
348 | continue; |
349 | sector = ti.track_start; |
350 | scan_iso_vrs_session(a, sector, |
351 | &is_iso9660, &is_udf); |
352 | } |
353 | } |
354 | } else { |
355 | /* try start of disc */ |
356 | sector = 0; |
357 | scan_iso_vrs_session(a, sector, &is_iso9660, &is_udf); |
358 | } |
359 | |
360 | if ((is_iso9660 < 0) && (is_udf < 0)) |
361 | return SCAN_CONTINUE; |
362 | |
363 | strncpy(a->lp->d_typename, "iso partition" , 16); |
364 | |
365 | /* adjust session information for iso9660 partition */ |
366 | if (is_iso9660 >= 0) { |
367 | /* set 'a' partition to iso9660 */ |
368 | a->lp->d_partitions[0].p_offset = 0; |
369 | a->lp->d_partitions[0].p_size = a->lp->d_secperunit; |
370 | a->lp->d_partitions[0].p_cdsession = is_iso9660; |
371 | a->lp->d_partitions[0].p_fstype = FS_ISO9660; |
372 | } |
373 | |
374 | /* UDF doesn't care about the cd session specified here */ |
375 | |
376 | return SCAN_FOUND; |
377 | } |
378 | |
379 | |
380 | /* |
381 | * Attempt to read a disk label from a device |
382 | * using the indicated strategy routine. |
383 | * The label must be partly set up before this: |
384 | * secpercyl, secsize and anything required for a block i/o read |
385 | * operation in the driver's strategy/start routines |
386 | * must be filled in before calling us. |
387 | * |
388 | * If dos partition table requested, attempt to load it and |
389 | * find disklabel inside a DOS partition. Also, if bad block |
390 | * table needed, attempt to extract it as well. Return buffer |
391 | * for use in signalling errors if requested. |
392 | * |
393 | * Returns null on success and an error string on failure. |
394 | */ |
395 | const char * |
396 | readdisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp, |
397 | struct cpu_disklabel *osdep) |
398 | { |
399 | int rval; |
400 | int i; |
401 | mbr_args_t a; |
402 | |
403 | memset(&a, 0, sizeof a); |
404 | a.lp = lp; |
405 | a.strat = strat; |
406 | a.action = READ_LABEL; |
407 | |
408 | /* minimal requirements for architypal disk label */ |
409 | if (lp->d_secsize == 0) |
410 | lp->d_secsize = DEV_BSIZE; |
411 | if (lp->d_secperunit == 0) |
412 | lp->d_secperunit = 0x1fffffff; |
413 | a.secperunit = lp->d_secperunit; |
414 | lp->d_npartitions = RAW_PART + 1; |
415 | for (i = 0; i < RAW_PART; i++) { |
416 | lp->d_partitions[i].p_size = 0; |
417 | lp->d_partitions[i].p_offset = 0; |
418 | } |
419 | if (lp->d_partitions[RAW_PART].p_size == 0) |
420 | lp->d_partitions[RAW_PART].p_size = lp->d_secperunit; |
421 | lp->d_partitions[RAW_PART].p_offset = 0; |
422 | |
423 | /* |
424 | * Set partition 'a' to be the whole disk. |
425 | * Cleared if we find an mbr or a netbsd label. |
426 | */ |
427 | lp->d_partitions[0].p_size = lp->d_partitions[RAW_PART].p_size; |
428 | lp->d_partitions[0].p_fstype = FS_BSDFFS; |
429 | |
430 | /* |
431 | * Get a buffer big enough to read a disklabel in and initialize it |
432 | * make it three sectors long for the validate_label(); see comment at |
433 | * start of file. |
434 | */ |
435 | a.bp = geteblk(SCANBLOCKS * (int)lp->d_secsize); |
436 | a.bp->b_dev = dev; |
437 | |
438 | if (osdep) |
439 | /* |
440 | * Scan mbr searching for netbsd partition and saving |
441 | * bios partition information to use if the netbsd one |
442 | * is absent. |
443 | */ |
444 | rval = scan_mbr(&a, look_netbsd_part); |
445 | else |
446 | rval = SCAN_CONTINUE; |
447 | |
448 | if (rval == SCAN_CONTINUE) { |
449 | /* Look at start of disk */ |
450 | rval = validate_label(&a, 0); |
451 | } |
452 | |
453 | if (rval == SCAN_CONTINUE) { |
454 | rval = scan_iso_vrs(&a); |
455 | } |
456 | #if 0 |
457 | /* |
458 | * Save sector where we found the label for the 'don't overwrite |
459 | * the label' check in bounds_check_with_label. |
460 | */ |
461 | if (rval == SCAN_FOUND) |
462 | xxx->label_sector = a.label_sector; |
463 | #endif |
464 | |
465 | /* Obtain bad sector table if requested and present */ |
466 | #ifdef __HAVE_DISKLABEL_DKBAD |
467 | if (rval == SCAN_FOUND && osdep && (lp->d_flags & D_BADSECT)) { |
468 | struct dkbad *bdp, *db; |
469 | int blkno; |
470 | |
471 | bdp = &osdep->bad; |
472 | i = 0; |
473 | rval = SCAN_ERROR; |
474 | do { |
475 | /* read a bad sector table */ |
476 | blkno = lp->d_secperunit - lp->d_nsectors + i; |
477 | if (lp->d_secsize > DEV_BSIZE) |
478 | blkno *= lp->d_secsize / DEV_BSIZE; |
479 | else |
480 | blkno /= DEV_BSIZE / lp->d_secsize; |
481 | /* if successful, validate, otherwise try another */ |
482 | if (read_sector(&a, blkno, 1)) { |
483 | a.msg = "bad sector table I/O error" ; |
484 | continue; |
485 | } |
486 | db = (struct dkbad *)(a.bp->b_data); |
487 | #define DKBAD_MAGIC 0x4321 |
488 | if (db->bt_mbz != 0 || db->bt_flag != DKBAD_MAGIC) { |
489 | a.msg = "bad sector table corrupted" ; |
490 | continue; |
491 | } |
492 | rval = SCAN_FOUND; |
493 | *bdp = *db; |
494 | break; |
495 | } while (a.bp->b_error && (i += 2) < 10 && |
496 | i < lp->d_nsectors); |
497 | } |
498 | #endif /* __HAVE_DISKLABEL_DKBAD */ |
499 | |
500 | brelse(a.bp, 0); |
501 | if (rval == SCAN_ERROR || rval == SCAN_CONTINUE) |
502 | return a.msg; |
503 | return NULL; |
504 | } |
505 | |
506 | static int |
507 | look_netbsd_part(mbr_args_t *a, mbr_partition_t *dp, int slot, uint ext_base) |
508 | { |
509 | struct partition *pp; |
510 | int ptn_base = ext_base + le32toh(dp->mbrp_start); |
511 | int rval; |
512 | |
513 | if ( |
514 | #ifdef COMPAT_386BSD_MBRPART |
515 | dp->mbrp_type == MBR_PTYPE_386BSD || |
516 | #endif |
517 | dp->mbrp_type == MBR_PTYPE_NETBSD) { |
518 | rval = validate_label(a, ptn_base); |
519 | |
520 | #if RAW_PART == 3 |
521 | /* Put actual location where we found the label into ptn 2 */ |
522 | if (rval == SCAN_FOUND || a->lp->d_partitions[2].p_size == 0) { |
523 | a->lp->d_partitions[2].p_size = le32toh(dp->mbrp_size); |
524 | a->lp->d_partitions[2].p_offset = ptn_base; |
525 | } |
526 | #endif |
527 | |
528 | /* If we got a netbsd label look no further */ |
529 | if (rval == SCAN_FOUND) |
530 | return rval; |
531 | } |
532 | |
533 | /* Install main partitions into e..h and extended into i+ */ |
534 | if (ext_base == 0) |
535 | slot += 4; |
536 | else { |
537 | slot = 4 + MBR_PART_COUNT; |
538 | pp = &a->lp->d_partitions[slot]; |
539 | for (; slot < MAXPARTITIONS; pp++, slot++) { |
540 | /* This gets called twice - avoid duplicates */ |
541 | if (pp->p_offset == ptn_base && |
542 | pp->p_size == le32toh(dp->mbrp_size)) |
543 | break; |
544 | if (pp->p_size == 0) |
545 | break; |
546 | } |
547 | } |
548 | |
549 | if (slot < MAXPARTITIONS) { |
550 | /* Stop 'a' being the entire disk */ |
551 | a->lp->d_partitions[0].p_size = 0; |
552 | a->lp->d_partitions[0].p_fstype = 0; |
553 | |
554 | /* save partition info */ |
555 | pp = &a->lp->d_partitions[slot]; |
556 | pp->p_offset = ptn_base; |
557 | pp->p_size = le32toh(dp->mbrp_size); |
558 | pp->p_fstype = xlat_mbr_fstype(dp->mbrp_type); |
559 | |
560 | if (slot >= a->lp->d_npartitions) |
561 | a->lp->d_npartitions = slot + 1; |
562 | } |
563 | |
564 | return SCAN_CONTINUE; |
565 | } |
566 | |
567 | |
568 | static int |
569 | validate_label(mbr_args_t *a, uint label_sector) |
570 | { |
571 | struct disklabel *dlp; |
572 | char *dlp_lim, *dlp_byte; |
573 | int error; |
574 | |
575 | /* Next, dig out disk label */ |
576 | if (read_sector(a, label_sector, SCANBLOCKS)) { |
577 | a->msg = "disk label read failed" ; |
578 | return SCAN_ERROR; |
579 | } |
580 | |
581 | /* Locate disk label within block and validate */ |
582 | /* |
583 | * XXX (dsl) This search may be a waste of time, a lot of other i386 |
584 | * code assumes the label is at offset LABELOFFSET (=0) in the sector. |
585 | * |
586 | * If we want to support disks from other netbsd ports, then the |
587 | * code should also allow for a shorter label nearer the end of |
588 | * the disk sector, and (IIRC) labels within 8k of the disk start. |
589 | */ |
590 | dlp = (void *)a->bp->b_data; |
591 | dlp_lim = (char *)a->bp->b_data + a->bp->b_bcount - sizeof *dlp; |
592 | for (;; dlp = (void *)((char *)dlp + sizeof(long))) { |
593 | if ((char *)dlp > dlp_lim) { |
594 | if (a->action != WRITE_LABEL) |
595 | return SCAN_CONTINUE; |
596 | /* Write at arch. dependent default location */ |
597 | dlp_byte = (char *)a->bp->b_data + LABELOFFSET; |
598 | if (label_sector) |
599 | dlp_byte += MBR_LABELSECTOR * a->lp->d_secsize; |
600 | else |
601 | dlp_byte += LABELSECTOR * a->lp->d_secsize; |
602 | dlp = (void *)dlp_byte; |
603 | break; |
604 | } |
605 | if (dlp->d_magic != DISKMAGIC || dlp->d_magic2 != DISKMAGIC) |
606 | continue; |
607 | if (dlp->d_npartitions > MAXPARTITIONS || dkcksum(dlp) != 0) { |
608 | a->msg = "disk label corrupted" ; |
609 | continue; |
610 | } |
611 | break; |
612 | } |
613 | |
614 | switch (a->action) { |
615 | case READ_LABEL: |
616 | *a->lp = *dlp; |
617 | if ((a->msg = convertdisklabel(a->lp, a->strat, a->bp, |
618 | a->secperunit)) != NULL) |
619 | return SCAN_ERROR; |
620 | a->label_sector = label_sector; |
621 | return SCAN_FOUND; |
622 | case UPDATE_LABEL: |
623 | case WRITE_LABEL: |
624 | *dlp = *a->lp; |
625 | a->bp->b_oflags &= ~BO_DONE; |
626 | a->bp->b_flags &= ~B_READ; |
627 | a->bp->b_flags |= B_WRITE; |
628 | (*a->strat)(a->bp); |
629 | error = biowait(a->bp); |
630 | if (error != 0) { |
631 | a->error = error; |
632 | a->msg = "disk label write failed" ; |
633 | return SCAN_ERROR; |
634 | } |
635 | a->written++; |
636 | /* Write label to all mbr partitions */ |
637 | return SCAN_CONTINUE; |
638 | default: |
639 | return SCAN_ERROR; |
640 | } |
641 | } |
642 | |
643 | /* |
644 | * Check new disk label for sensibility |
645 | * before setting it. |
646 | */ |
647 | int |
648 | setdisklabel(struct disklabel *olp, struct disklabel *nlp, u_long openmask, |
649 | struct cpu_disklabel *osdep) |
650 | { |
651 | int i; |
652 | struct partition *opp, *npp; |
653 | |
654 | /* sanity clause */ |
655 | if (nlp->d_secpercyl == 0 || nlp->d_secsize == 0 |
656 | || (nlp->d_secsize % DEV_BSIZE) != 0) |
657 | return (EINVAL); |
658 | |
659 | /* special case to allow disklabel to be invalidated */ |
660 | if (nlp->d_magic == 0xffffffff) { |
661 | *olp = *nlp; |
662 | return (0); |
663 | } |
664 | |
665 | if (nlp->d_magic != DISKMAGIC || nlp->d_magic2 != DISKMAGIC || |
666 | dkcksum(nlp) != 0) |
667 | return (EINVAL); |
668 | |
669 | /* XXX missing check if other dos partitions will be overwritten */ |
670 | |
671 | while (openmask != 0) { |
672 | i = ffs(openmask) - 1; |
673 | openmask &= ~(1 << i); |
674 | if (i > nlp->d_npartitions) |
675 | return (EBUSY); |
676 | opp = &olp->d_partitions[i]; |
677 | npp = &nlp->d_partitions[i]; |
678 | /* |
679 | * Copy internally-set partition information |
680 | * if new label doesn't include it. XXX |
681 | */ |
682 | if (npp->p_fstype == FS_UNUSED && opp->p_fstype != FS_UNUSED) { |
683 | *npp = *opp; |
684 | continue; |
685 | } |
686 | if (npp->p_offset != opp->p_offset || npp->p_size < opp->p_size) |
687 | return (EBUSY); |
688 | } |
689 | nlp->d_checksum = 0; |
690 | nlp->d_checksum = dkcksum(nlp); |
691 | *olp = *nlp; |
692 | return (0); |
693 | } |
694 | |
695 | |
696 | /* |
697 | * Write disk label back to device after modification. |
698 | */ |
699 | int |
700 | writedisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp, |
701 | struct cpu_disklabel *osdep) |
702 | { |
703 | mbr_args_t a; |
704 | |
705 | memset(&a, 0, sizeof a); |
706 | a.lp = lp; |
707 | a.strat = strat; |
708 | |
709 | /* get a buffer and initialize it */ |
710 | a.bp = geteblk(SCANBLOCKS * (int)lp->d_secsize); |
711 | a.bp->b_dev = dev; |
712 | |
713 | /* osdep => we expect an mbr with label in netbsd ptn */ |
714 | a.action = osdep != NULL ? WRITE_LABEL : UPDATE_LABEL; |
715 | |
716 | /* Write/update the label to every netbsd mbr partition */ |
717 | scan_mbr(&a, write_netbsd_label); |
718 | |
719 | /* Old write the label at the start of the volume on disks that |
720 | * don't have a valid mbr (always update an existing one) */ |
721 | a.action = a.found_mbr ? UPDATE_LABEL : WRITE_LABEL; |
722 | validate_label(&a, 0); |
723 | |
724 | if (a.written == 0 && a.error == 0) |
725 | a.error = ESRCH; |
726 | |
727 | brelse(a.bp, 0); |
728 | return a.error; |
729 | } |
730 | |
731 | static int |
732 | write_netbsd_label(mbr_args_t *a, mbr_partition_t *dp, int slot, uint ext_base) |
733 | { |
734 | int ptn_base = ext_base + le32toh(dp->mbrp_start); |
735 | |
736 | if (dp->mbrp_type != MBR_PTYPE_NETBSD) |
737 | return SCAN_CONTINUE; |
738 | |
739 | return validate_label(a, ptn_base); |
740 | } |
741 | |