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
read_sector(mbr_args_t * a,uint sector,int count)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
scan_mbr(mbr_args_t * a,int (* actn)(mbr_args_t *,mbr_partition_t *,int,uint))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
scan_iso_vrs_session(mbr_args_t * a,uint32_t first_sector,int * is_iso9660,int * is_udf)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
scan_iso_vrs(mbr_args_t * a)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 *
readdisklabel(dev_t dev,void (* strat)(struct buf *),struct disklabel * lp,struct cpu_disklabel * osdep)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
look_netbsd_part(mbr_args_t * a,mbr_partition_t * dp,int slot,uint ext_base)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
validate_label(mbr_args_t * a,uint label_sector)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
setdisklabel(struct disklabel * olp,struct disklabel * nlp,u_long openmask,struct cpu_disklabel * osdep)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
writedisklabel(dev_t dev,void (* strat)(struct buf *),struct disklabel * lp,struct cpu_disklabel * osdep)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
write_netbsd_label(mbr_args_t * a,mbr_partition_t * dp,int slot,uint ext_base)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