1 /* $NetBSD: subr_disk_mbr.c,v 1.58 2023/04/03 18:03:24 gutteridge 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 1.58 2023/04/03 18:03:24 gutteridge Exp $");
58
59 #ifdef _KERNEL_OPT
60 #include "opt_mbr.h"
61 #include "opt_disklabel.h"
62 #endif /* _KERNEL_OPT */
63
64 #include <sys/param.h>
65 #include <sys/systm.h>
66 #include <sys/buf.h>
67 #include <sys/bootblock.h>
68 #include <sys/disklabel.h>
69 #include <sys/disk.h>
70 #include <sys/syslog.h>
71 #include <sys/vnode.h>
72 #include <sys/fcntl.h>
73 #include <sys/conf.h>
74 #include <sys/cdio.h>
75 #include <sys/dkbad.h>
76 #include <fs/udf/ecma167-udf.h>
77
78 #include <sys/kauth.h>
79
80 typedef struct mbr_partition mbr_partition_t;
81
82 /*
83 * We allocate a buffer 3 sectors large, and look in all....
84 * That means we find labels written by other ports with different offsets.
85 * LABELSECTOR and LABELOFFSET are only used if the disk doesn't have a label.
86 */
87 #define SCANBLOCKS 3
88 #define DISKLABEL_SIZE 404
89 #if LABELSECTOR*DEV_BSIZE + LABELOFFSET > SCANBLOCKS*DEV_BSIZE - DISKLABEL_SIZE
90 #if _MACHINE != ews4800mips /* XXX: fail silently, ews4800mips LABELSECTOR */
91 #error Invalid LABELSECTOR or LABELOFFSET
92 #endif
93 #endif
94
95 #define MBR_LABELSECTOR 1
96
97 #define SCAN_CONTINUE 0
98 #define SCAN_FOUND 1
99 #define SCAN_ERROR 2
100
101 typedef struct mbr_args {
102 struct disklabel *lp;
103 void (*strat)(struct buf *);
104 struct buf *bp;
105 const char *msg;
106 int error;
107 int written; /* number of times we wrote label */
108 int found_mbr; /* set if disk has a valid mbr */
109 uint label_sector; /* where we found the label */
110 int action;
111 uint32_t secperunit;
112 #define READ_LABEL 1
113 #define UPDATE_LABEL 2
114 #define WRITE_LABEL 3
115 } mbr_args_t;
116
117 static int validate_label(mbr_args_t *, uint);
118 static int look_netbsd_part(mbr_args_t *, mbr_partition_t *, int, uint);
119 static int write_netbsd_label(mbr_args_t *, mbr_partition_t *, int, uint);
120
121 static int
read_sector(mbr_args_t * a,uint sector,int count)122 read_sector(mbr_args_t *a, uint sector, int count)
123 {
124 int error;
125
126 error = disk_read_sectors(a->strat, a->lp, a->bp, sector, count);
127 if (error != 0)
128 a->error = error;
129 return error;
130 }
131
132 /*
133 * Scan MBR for partitions, call 'action' routine for each.
134 */
135
136 static int
scan_mbr(mbr_args_t * a,int (* actn)(mbr_args_t *,mbr_partition_t *,int,uint))137 scan_mbr(mbr_args_t *a, int (*actn)(mbr_args_t *, mbr_partition_t *, int, uint))
138 {
139 mbr_partition_t ptns[MBR_PART_COUNT];
140 mbr_partition_t *dp;
141 struct mbr_sector *mbr;
142 uint ext_base, this_ext, next_ext;
143 int rval;
144 int i;
145 int j;
146 #ifdef COMPAT_386BSD_MBRPART
147 int dp_386bsd = -1;
148 int ap_386bsd = -1;
149 #endif
150
151 ext_base = 0;
152 this_ext = 0;
153 for (;;) {
154 if (read_sector(a, this_ext, 1)) {
155 a->msg = "dos partition I/O error";
156 return SCAN_ERROR;
157 }
158
159 /* Note: Magic number is little-endian. */
160 mbr = (void *)a->bp->b_data;
161 if (mbr->mbr_magic != htole16(MBR_MAGIC))
162 return SCAN_CONTINUE;
163
164 /*
165 * If this is a protective MBR, bail now.
166 */
167 if (mbr->mbr_parts[0].mbrp_type == MBR_PTYPE_PMBR
168 && mbr->mbr_parts[1].mbrp_type == MBR_PTYPE_UNUSED
169 && mbr->mbr_parts[2].mbrp_type == MBR_PTYPE_UNUSED
170 && mbr->mbr_parts[3].mbrp_type == MBR_PTYPE_UNUSED)
171 return SCAN_CONTINUE;
172
173 /* Copy data out of buffer so action can use bp */
174 memcpy(ptns, &mbr->mbr_parts, sizeof ptns);
175
176 /* Look for drivers and skip them */
177 if (ext_base == 0 && ptns[0].mbrp_type == MBR_PTYPE_DM6_DDO) {
178 /* We've found a DM6 DDO partition type (used by
179 * the Ontrack Disk Manager drivers).
180 *
181 * Ensure that there are no other partitions in the
182 * MBR and jump to the real partition table (stored
183 * in the first sector of the second track). */
184 bool ok = true;
185
186 for (i = 1; i < MBR_PART_COUNT; i++)
187 if (ptns[i].mbrp_type != MBR_PTYPE_UNUSED)
188 ok = false;
189
190 if (ok) {
191 this_ext = le32toh(a->lp->d_secpercyl /
192 a->lp->d_ntracks);
193 continue;
194 }
195 }
196
197 /* look for NetBSD partition */
198 next_ext = 0;
199 dp = ptns;
200 j = 0;
201 for (i = 0; i < MBR_PART_COUNT; i++, dp++) {
202 if (dp->mbrp_type == MBR_PTYPE_UNUSED)
203 continue;
204 /* Check end of partition is inside disk limits */
205 if ((uint64_t)ext_base + le32toh(dp->mbrp_start) +
206 le32toh(dp->mbrp_size) > a->lp->d_secperunit) {
207 /* This mbr doesn't look good.... */
208 a->msg = "mbr partition exceeds disk size";
209 /* ...but don't report this as an error (yet) */
210 return SCAN_CONTINUE;
211 }
212 a->found_mbr = 1;
213 if (MBR_IS_EXTENDED(dp->mbrp_type)) {
214 next_ext = le32toh(dp->mbrp_start);
215 continue;
216 }
217 #ifdef COMPAT_386BSD_MBRPART
218 if (dp->mbrp_type == MBR_PTYPE_386BSD) {
219 /*
220 * If more than one matches, take last,
221 * as NetBSD install tool does.
222 */
223 if (this_ext == 0) {
224 dp_386bsd = i;
225 ap_386bsd = j;
226 }
227 continue;
228 }
229 #endif
230 rval = (*actn)(a, dp, j, this_ext);
231 if (rval != SCAN_CONTINUE)
232 return rval;
233 j++;
234 }
235 if (next_ext == 0)
236 break;
237 if (ext_base == 0) {
238 ext_base = next_ext;
239 next_ext = 0;
240 }
241 next_ext += ext_base;
242 if (next_ext <= this_ext)
243 break;
244 this_ext = next_ext;
245 }
246 #ifdef COMPAT_386BSD_MBRPART
247 if (this_ext == 0 && dp_386bsd != -1)
248 return (*actn)(a, &ptns[dp_386bsd], ap_386bsd, 0);
249 #endif
250 return SCAN_CONTINUE;
251 }
252
253
254 static void
scan_iso_vrs_session(mbr_args_t * a,uint32_t first_sector,int * is_iso9660,int * is_udf)255 scan_iso_vrs_session(mbr_args_t *a, uint32_t first_sector,
256 int *is_iso9660, int *is_udf)
257 {
258 struct vrs_desc *vrsd;
259 uint64_t vrs;
260 int sector_size;
261 int blks, inc;
262
263 sector_size = a->lp->d_secsize;
264 blks = sector_size / DEV_BSIZE;
265 inc = MAX(1, 2048 / sector_size);
266
267 /* by definition */
268 vrs = ((32*1024 + sector_size - 1) / sector_size)
269 + first_sector;
270
271 /* read first vrs sector */
272 if (read_sector(a, vrs * blks, 1))
273 return;
274
275 /* skip all CD001 records */
276 vrsd = a->bp->b_data;
277 /* printf("vrsd->identifier = `%s`\n", vrsd->identifier); */
278 while (memcmp(vrsd->identifier, "CD001", 5) == 0) {
279 /* for sure */
280 *is_iso9660 = first_sector;
281
282 vrs += inc;
283 if (read_sector(a, vrs * blks, 1))
284 return;
285 }
286
287 /* search for BEA01 */
288 vrsd = a->bp->b_data;
289 /* printf("vrsd->identifier = `%s`\n", vrsd->identifier); */
290 if (memcmp(vrsd->identifier, "BEA01", 5))
291 return;
292
293 /* read successor */
294 vrs += inc;
295 if (read_sector(a, vrs * blks, 1))
296 return;
297
298 /* check for NSR[23] */
299 vrsd = a->bp->b_data;
300 /* printf("vrsd->identifier = `%s`\n", vrsd->identifier); */
301 if (memcmp(vrsd->identifier, "NSR0", 4))
302 return;
303
304 *is_udf = first_sector;
305 }
306
307
308 /*
309 * Scan for ISO Volume Recognition Sequences
310 */
311
312 static int
scan_iso_vrs(mbr_args_t * a)313 scan_iso_vrs(mbr_args_t *a)
314 {
315 struct mmc_discinfo di;
316 struct mmc_trackinfo ti;
317 dev_t dev;
318 uint64_t sector;
319 int is_iso9660, is_udf;
320 int tracknr, sessionnr;
321 int new_session, error;
322
323 is_iso9660 = is_udf = -1;
324
325 /* parse all sessions of disc if we're on a SCSI MMC device */
326 if (a->lp->d_flags & D_SCSI_MMC) {
327 /* get disc info */
328 dev = a->bp->b_dev;
329 error = bdev_ioctl(dev, MMCGETDISCINFO, &di, FKIOCTL, curlwp);
330 if (error)
331 return SCAN_CONTINUE;
332
333 /* go through all (data) tracks */
334 sessionnr = -1;
335 for (tracknr = di.first_track;
336 tracknr <= di.first_track_last_session; tracknr++)
337 {
338 ti.tracknr = tracknr;
339 error = bdev_ioctl(dev, MMCGETTRACKINFO, &ti,
340 FKIOCTL, curlwp);
341 if (error)
342 return SCAN_CONTINUE;
343 new_session = (ti.sessionnr != sessionnr);
344 sessionnr = ti.sessionnr;
345 if (new_session) {
346 if (ti.flags & MMC_TRACKINFO_BLANK)
347 continue;
348 if (!(ti.flags & MMC_TRACKINFO_DATA))
349 continue;
350 sector = ti.track_start;
351 scan_iso_vrs_session(a, sector,
352 &is_iso9660, &is_udf);
353 }
354 }
355 } else {
356 /* try start of disc */
357 sector = 0;
358 scan_iso_vrs_session(a, sector, &is_iso9660, &is_udf);
359 }
360
361 if ((is_iso9660 < 0) && (is_udf < 0))
362 return SCAN_CONTINUE;
363
364 strncpy(a->lp->d_typename, "iso partition", 16);
365
366 /* adjust session information for iso9660 partition */
367 if (is_iso9660 >= 0) {
368 /* set 'a' partition to iso9660 */
369 a->lp->d_partitions[0].p_offset = 0;
370 a->lp->d_partitions[0].p_size = a->lp->d_secperunit;
371 a->lp->d_partitions[0].p_cdsession = is_iso9660;
372 a->lp->d_partitions[0].p_fstype = FS_ISO9660;
373 }
374
375 /* UDF doesn't care about the cd session specified here */
376
377 return SCAN_FOUND;
378 }
379
380
381 /*
382 * Attempt to read a disk label from a device
383 * using the indicated strategy routine.
384 * The label must be partly set up before this:
385 * secpercyl, secsize and anything required for a block i/o read
386 * operation in the driver's strategy/start routines
387 * must be filled in before calling us.
388 *
389 * If dos partition table requested, attempt to load it and
390 * find disklabel inside a DOS partition. Also, if bad block
391 * table needed, attempt to extract it as well. Return buffer
392 * for use in signalling errors if requested.
393 *
394 * Returns null on success and an error string on failure.
395 */
396 const char *
readdisklabel(dev_t dev,void (* strat)(struct buf *),struct disklabel * lp,struct cpu_disklabel * osdep)397 readdisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp,
398 struct cpu_disklabel *osdep)
399 {
400 int rval;
401 int i;
402 mbr_args_t a;
403
404 memset(&a, 0, sizeof a);
405 a.lp = lp;
406 a.strat = strat;
407 a.action = READ_LABEL;
408
409 /* minimal requirements for architypal disk label */
410 if (lp->d_secsize == 0)
411 lp->d_secsize = DEV_BSIZE;
412 if (lp->d_secperunit == 0)
413 lp->d_secperunit = 0x1fffffff;
414 a.secperunit = lp->d_secperunit;
415 lp->d_npartitions = RAW_PART + 1;
416 for (i = 0; i < RAW_PART; i++) {
417 lp->d_partitions[i].p_size = 0;
418 lp->d_partitions[i].p_offset = 0;
419 }
420 if (lp->d_partitions[RAW_PART].p_size == 0)
421 lp->d_partitions[RAW_PART].p_size = lp->d_secperunit;
422 lp->d_partitions[RAW_PART].p_offset = 0;
423
424 /*
425 * Set partition 'a' to be the whole disk.
426 * Cleared if we find an mbr or a netbsd label.
427 */
428 lp->d_partitions[0].p_size = lp->d_partitions[RAW_PART].p_size;
429 lp->d_partitions[0].p_fstype = FS_BSDFFS;
430
431 /*
432 * Get a buffer big enough to read a disklabel in and initialize it
433 * make it three sectors long for the validate_label(); see comment at
434 * start of file.
435 */
436 a.bp = geteblk(SCANBLOCKS * (int)lp->d_secsize);
437 a.bp->b_dev = dev;
438
439 if (osdep)
440 /*
441 * Scan mbr searching for netbsd partition and saving
442 * bios partition information to use if the netbsd one
443 * is absent.
444 */
445 rval = scan_mbr(&a, look_netbsd_part);
446 else
447 rval = SCAN_CONTINUE;
448
449 if (rval == SCAN_CONTINUE) {
450 /* Look at start of disk */
451 rval = validate_label(&a, 0);
452 }
453
454 if (rval == SCAN_CONTINUE) {
455 rval = scan_iso_vrs(&a);
456 }
457 #if 0
458 /*
459 * Save sector where we found the label for the 'don't overwrite
460 * the label' check in bounds_check_with_label.
461 */
462 if (rval == SCAN_FOUND)
463 xxx->label_sector = a.label_sector;
464 #endif
465
466 /* Obtain bad sector table if requested and present */
467 #ifdef __HAVE_DISKLABEL_DKBAD
468 if (rval == SCAN_FOUND && osdep && (lp->d_flags & D_BADSECT)) {
469 struct dkbad *bdp, *db;
470 int blkno;
471
472 bdp = &osdep->bad;
473 i = 0;
474 rval = SCAN_ERROR;
475 do {
476 /* read a bad sector table */
477 blkno = lp->d_secperunit - lp->d_nsectors + i;
478 if (lp->d_secsize > DEV_BSIZE)
479 blkno *= lp->d_secsize / DEV_BSIZE;
480 else
481 blkno /= DEV_BSIZE / lp->d_secsize;
482 /* if successful, validate, otherwise try another */
483 if (read_sector(&a, blkno, 1)) {
484 a.msg = "bad sector table I/O error";
485 continue;
486 }
487 db = (struct dkbad *)(a.bp->b_data);
488 #define DKBAD_MAGIC 0x4321
489 if (db->bt_mbz != 0 || db->bt_flag != DKBAD_MAGIC) {
490 a.msg = "bad sector table corrupted";
491 continue;
492 }
493 rval = SCAN_FOUND;
494 *bdp = *db;
495 break;
496 } while (a.bp->b_error && (i += 2) < 10 &&
497 i < lp->d_nsectors);
498 }
499 #endif /* __HAVE_DISKLABEL_DKBAD */
500
501 brelse(a.bp, 0);
502 if (rval == SCAN_ERROR || rval == SCAN_CONTINUE)
503 return a.msg;
504 return NULL;
505 }
506
507 static int
look_netbsd_part(mbr_args_t * a,mbr_partition_t * dp,int slot,uint ext_base)508 look_netbsd_part(mbr_args_t *a, mbr_partition_t *dp, int slot, uint ext_base)
509 {
510 struct partition *pp;
511 int ptn_base = ext_base + le32toh(dp->mbrp_start);
512 int rval;
513
514 if (
515 #ifdef COMPAT_386BSD_MBRPART
516 dp->mbrp_type == MBR_PTYPE_386BSD ||
517 #endif
518 dp->mbrp_type == MBR_PTYPE_NETBSD) {
519 rval = validate_label(a, ptn_base);
520
521 #if RAW_PART == 3
522 /* Put actual location where we found the label into ptn 2 */
523 if (rval == SCAN_FOUND || a->lp->d_partitions[2].p_size == 0) {
524 a->lp->d_partitions[2].p_size = le32toh(dp->mbrp_size);
525 a->lp->d_partitions[2].p_offset = ptn_base;
526 }
527 #endif
528
529 /* If we got a netbsd label look no further */
530 if (rval == SCAN_FOUND)
531 return rval;
532 }
533
534 /* Install main partitions into e..h and extended into i+ */
535 if (ext_base == 0)
536 slot += 4;
537 else {
538 slot = 4 + MBR_PART_COUNT;
539 pp = &a->lp->d_partitions[slot];
540 for (; slot < MAXPARTITIONS; pp++, slot++) {
541 /* This gets called twice - avoid duplicates */
542 if (pp->p_offset == ptn_base &&
543 pp->p_size == le32toh(dp->mbrp_size))
544 break;
545 if (pp->p_size == 0)
546 break;
547 }
548 }
549
550 if (slot < MAXPARTITIONS) {
551 /* Stop 'a' being the entire disk */
552 a->lp->d_partitions[0].p_size = 0;
553 a->lp->d_partitions[0].p_fstype = 0;
554
555 /* save partition info */
556 pp = &a->lp->d_partitions[slot];
557 pp->p_offset = ptn_base;
558 pp->p_size = le32toh(dp->mbrp_size);
559 pp->p_fstype = xlat_mbr_fstype(dp->mbrp_type);
560
561 if (slot >= a->lp->d_npartitions)
562 a->lp->d_npartitions = slot + 1;
563 }
564
565 return SCAN_CONTINUE;
566 }
567
568 __noubsan
569 static bool
check_label_magic(const struct disklabel * dlp,uint32_t diskmagic)570 check_label_magic(const struct disklabel *dlp, uint32_t diskmagic)
571 {
572 return memcmp(&dlp->d_magic, &diskmagic, sizeof(diskmagic)) == 0 &&
573 memcmp(&dlp->d_magic2, &diskmagic, sizeof(diskmagic)) == 0;
574 }
575
576 #ifdef DISKLABEL_EI
577 /*
578 * - For read, convert a label to the native byte order.
579 * - For update or write, if a label already exists, keep its byte order.
580 * Otherwise, write a new label in the native byte order.
581 */
582 #endif
583 static int
validate_label(mbr_args_t * a,uint label_sector)584 validate_label(mbr_args_t *a, uint label_sector)
585 {
586 struct disklabel *dlp;
587 char *dlp_lim, *dlp_byte;
588 int error;
589 #ifdef DISKLABEL_EI
590 int swapped = 0;
591 uint16_t npartitions;
592 #endif
593
594 /* Next, dig out disk label */
595 if (read_sector(a, label_sector, SCANBLOCKS)) {
596 a->msg = "disk label read failed";
597 return SCAN_ERROR;
598 }
599
600 /* Locate disk label within block and validate */
601 /*
602 * XXX (dsl) This search may be a waste of time, a lot of other i386
603 * code assumes the label is at offset LABELOFFSET (=0) in the sector.
604 *
605 * If we want to support disks from other netbsd ports, then the
606 * code should also allow for a shorter label nearer the end of
607 * the disk sector, and (IIRC) labels within 8k of the disk start.
608 */
609 dlp = (void *)a->bp->b_data;
610 dlp_lim = (char *)a->bp->b_data + a->bp->b_bcount - sizeof *dlp;
611 for (;; dlp = (void *)((char *)dlp + sizeof(uint32_t))) {
612 if ((char *)dlp > dlp_lim) {
613 if (a->action != WRITE_LABEL)
614 return SCAN_CONTINUE;
615 /* Write at arch. dependent default location */
616 dlp_byte = (char *)a->bp->b_data + LABELOFFSET;
617 if (label_sector)
618 dlp_byte += MBR_LABELSECTOR * a->lp->d_secsize;
619 else
620 dlp_byte += LABELSECTOR * a->lp->d_secsize;
621 dlp = (void *)dlp_byte;
622 break;
623 }
624 if (!check_label_magic(dlp, DISKMAGIC))
625 #ifdef DISKLABEL_EI
626 {
627 if (!check_label_magic(dlp, bswap32(DISKMAGIC)))
628 continue;
629
630 /*
631 * The label is in the other byte order. We need to
632 * checksum before swapping the byte order.
633 */
634 npartitions = bswap16(dlp->d_npartitions);
635 if (npartitions > MAXPARTITIONS ||
636 dkcksum_sized(dlp, npartitions) != 0)
637 goto corrupted;
638
639 swapped = 1;
640 }
641 #else
642 continue;
643 #endif
644 else if (dlp->d_npartitions > MAXPARTITIONS ||
645 dkcksum(dlp) != 0) {
646 #ifdef DISKLABEL_EI
647 corrupted:
648 #endif
649 a->msg = "disk label corrupted";
650 continue;
651 }
652 break;
653 }
654
655 switch (a->action) {
656 case READ_LABEL:
657 #ifdef DISKLABEL_EI
658 if (swapped)
659 disklabel_swap(a->lp, dlp);
660 else
661 *a->lp = *dlp;
662 #else
663 *a->lp = *dlp;
664 #endif
665 if ((a->msg = convertdisklabel(a->lp, a->strat, a->bp,
666 a->secperunit)) != NULL)
667 return SCAN_ERROR;
668 a->label_sector = label_sector;
669 return SCAN_FOUND;
670 case UPDATE_LABEL:
671 case WRITE_LABEL:
672 #ifdef DISKLABEL_EI
673 /* DO NOT swap a->lp itself for later references. */
674 if (swapped)
675 disklabel_swap(dlp, a->lp);
676 else
677 *dlp = *a->lp;
678 #else
679 *dlp = *a->lp;
680 #endif
681 a->bp->b_oflags &= ~BO_DONE;
682 a->bp->b_flags &= ~B_READ;
683 a->bp->b_flags |= B_WRITE;
684 (*a->strat)(a->bp);
685 error = biowait(a->bp);
686 if (error != 0) {
687 a->error = error;
688 a->msg = "disk label write failed";
689 return SCAN_ERROR;
690 }
691 a->written++;
692 /* Write label to all mbr partitions */
693 return SCAN_CONTINUE;
694 default:
695 return SCAN_ERROR;
696 }
697 }
698
699 /*
700 * Write disk label back to device after modification.
701 */
702 int
writedisklabel(dev_t dev,void (* strat)(struct buf *),struct disklabel * lp,struct cpu_disklabel * osdep)703 writedisklabel(dev_t dev, void (*strat)(struct buf *), struct disklabel *lp,
704 struct cpu_disklabel *osdep)
705 {
706 mbr_args_t a;
707
708 memset(&a, 0, sizeof a);
709 a.lp = lp;
710 a.strat = strat;
711
712 /* get a buffer and initialize it */
713 a.bp = geteblk(SCANBLOCKS * (int)lp->d_secsize);
714 a.bp->b_dev = dev;
715
716 /* osdep => we expect an mbr with label in netbsd ptn */
717 a.action = osdep != NULL ? WRITE_LABEL : UPDATE_LABEL;
718
719 /* Write/update the label to every netbsd mbr partition */
720 scan_mbr(&a, write_netbsd_label);
721
722 /* Old write the label at the start of the volume on disks that
723 * don't have a valid mbr (always update an existing one) */
724 a.action = a.found_mbr ? UPDATE_LABEL : WRITE_LABEL;
725 validate_label(&a, 0);
726
727 if (a.written == 0 && a.error == 0)
728 a.error = ESRCH;
729
730 brelse(a.bp, 0);
731 return a.error;
732 }
733
734 static int
write_netbsd_label(mbr_args_t * a,mbr_partition_t * dp,int slot,uint ext_base)735 write_netbsd_label(mbr_args_t *a, mbr_partition_t *dp, int slot, uint ext_base)
736 {
737 int ptn_base = ext_base + le32toh(dp->mbrp_start);
738
739 if (dp->mbrp_type != MBR_PTYPE_NETBSD)
740 return SCAN_CONTINUE;
741
742 return validate_label(a, ptn_base);
743 }
744