summaryrefslogtreecommitdiff
path: root/fs/partitions/ldm.c
blob: c387812537d7450e1fb6e7bedf3ca6e407e93eab (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
/**
 * ldm - Support for Windows Logical Disk Manager (Dynamic Disks)
 *
 * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
 * Copyright (c) 2001-2007 Anton Altaparmakov
 * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
 *
 * Documentation is available at http://www.linux-ntfs.org/content/view/19/37/
 *
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program (in the main directory of the source in the file COPYING); if
 * not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA  02111-1307  USA
 */

#include <linux/slab.h>
#include <linux/pagemap.h>
#include <linux/stringify.h>
#include "ldm.h"
#include "check.h"
#include "msdos.h"

/**
 * ldm_debug/info/error/crit - Output an error message
 * @f:    A printf format string containing the message
 * @...:  Variables to substitute into @f
 *
 * ldm_debug() writes a DEBUG level message to the syslog but only if the
 * driver was compiled with debug enabled. Otherwise, the call turns into a NOP.
 */
#ifndef CONFIG_LDM_DEBUG
#define ldm_debug(...)	do {} while (0)
#else
#define ldm_debug(f, a...) _ldm_printk (KERN_DEBUG, __FUNCTION__, f, ##a)
#endif

#define ldm_crit(f, a...)  _ldm_printk (KERN_CRIT,  __FUNCTION__, f, ##a)
#define ldm_error(f, a...) _ldm_printk (KERN_ERR,   __FUNCTION__, f, ##a)
#define ldm_info(f, a...)  _ldm_printk (KERN_INFO,  __FUNCTION__, f, ##a)

__attribute__ ((format (printf, 3, 4)))
static void _ldm_printk (const char *level, const char *function,
			 const char *fmt, ...)
{
	static char buf[128];
	va_list args;

	va_start (args, fmt);
	vsnprintf (buf, sizeof (buf), fmt, args);
	va_end (args);

	printk ("%s%s(): %s\n", level, function, buf);
}

/**
 * ldm_parse_hexbyte - Convert a ASCII hex number to a byte
 * @src:  Pointer to at least 2 characters to convert.
 *
 * Convert a two character ASCII hex string to a number.
 *
 * Return:  0-255  Success, the byte was parsed correctly
 *          -1     Error, an invalid character was supplied
 */
static int ldm_parse_hexbyte (const u8 *src)
{
	unsigned int x;		/* For correct wrapping */
	int h;

	/* high part */
	if      ((x = src[0] - '0') <= '9'-'0') h = x;
	else if ((x = src[0] - 'a') <= 'f'-'a') h = x+10;
	else if ((x = src[0] - 'A') <= 'F'-'A') h = x+10;
	else return -1;
	h <<= 4;

	/* low part */
	if ((x = src[1] - '0') <= '9'-'0') return h | x;
	if ((x = src[1] - 'a') <= 'f'-'a') return h | (x+10);
	if ((x = src[1] - 'A') <= 'F'-'A') return h | (x+10);
	return -1;
}

/**
 * ldm_parse_guid - Convert GUID from ASCII to binary
 * @src:   36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba
 * @dest:  Memory block to hold binary GUID (16 bytes)
 *
 * N.B. The GUID need not be NULL terminated.
 *
 * Return:  'true'   @dest contains binary GUID
 *          'false'  @dest contents are undefined
 */
static bool ldm_parse_guid (const u8 *src, u8 *dest)
{
	static const int size[] = { 4, 2, 2, 2, 6 };
	int i, j, v;

	if (src[8]  != '-' || src[13] != '-' ||
	    src[18] != '-' || src[23] != '-')
		return false;

	for (j = 0; j < 5; j++, src++)
		for (i = 0; i < size[j]; i++, src+=2, *dest++ = v)
			if ((v = ldm_parse_hexbyte (src)) < 0)
				return false;

	return true;
}

/**
 * ldm_parse_privhead - Read the LDM Database PRIVHEAD structure
 * @data:  Raw database PRIVHEAD structure loaded from the device
 * @ph:    In-memory privhead structure in which to return parsed information
 *
 * This parses the LDM database PRIVHEAD structure supplied in @data and
 * sets up the in-memory privhead structure @ph with the obtained information.
 *
 * Return:  'true'   @ph contains the PRIVHEAD data
 *          'false'  @ph contents are undefined
 */
static bool ldm_parse_privhead(const u8 *data, struct privhead *ph)
{
	bool is_vista = false;

	BUG_ON(!data || !ph);
	if (MAGIC_PRIVHEAD != BE64(data)) {
		ldm_error("Cannot find PRIVHEAD structure. LDM database is"
			" corrupt. Aborting.");
		return false;
	}
	ph->ver_major = BE16(data + 0x000C);
	ph->ver_minor = BE16(data + 0x000E);
	ph->logical_disk_start = BE64(data + 0x011B);
	ph->logical_disk_size = BE64(data + 0x0123);
	ph->config_start = BE64(data + 0x012B);
	ph->config_size = BE64(data + 0x0133);
	/* Version 2.11 is Win2k/XP and version 2.12 is Vista. */
	if (ph->ver_major == 2 && ph->ver_minor == 12)
		is_vista = true;
	if (!is_vista && (ph->ver_major != 2 || ph->ver_minor != 11)) {
		ldm_error("Expected PRIVHEAD version 2.11 or 2.12, got %d.%d."
			" Aborting.", ph->ver_major, ph->ver_minor);
		return false;
	}
	ldm_debug("PRIVHEAD version %d.%d (Windows %s).", ph->ver_major,
			ph->ver_minor, is_vista ? "Vista" : "2000/XP");
	if (ph->config_size != LDM_DB_SIZE) {	/* 1 MiB in sectors. */
		/* Warn the user and continue, carefully. */
		ldm_info("Database is normally %u bytes, it claims to "
			"be %llu bytes.", LDM_DB_SIZE,
			udunsigned long long)ph->config_size);
	}
	if ((ph->logical_disk_size == 0) || (ph->logical_disk_start +
			ph->logical_disk_size > ph->config_start)) {
		ldm_error("PRIVHEAD disk size doesn't match real disk size");
		return false;
	}
	if (!ldm_parse_guid(data + 0x0030, ph->disk_id)) {
		ldm_error("PRIVHEAD contains an invalid GUID.");
		return false;
	}
	ldm_debug("Parsed PRIVHEAD successfully.");
	return true;
}

/**
 * ldm_parse_tocblock - Read the LDM Database TOCBLOCK structure
 * @data:  Raw database TOCBLOCK structure loaded from the device
 * @toc:   In-memory toc structure in which to return parsed information
 *
 * This parses the LDM Database TOCBLOCK (table of contents) structure supplied
 * in @data and sets up the in-memory tocblock structure @toc with the obtained
 * information.
 *
 * N.B.  The *_start and *_size values returned in @toc are not range-checked.
 *
 * Return:  'true'   @toc contains the TOCBLOCK data
 *          'false'  @toc contents are undefined
 */
static bool ldm_parse_tocblock (const u8 *data, struct tocblock *toc)
{
	BUG_ON (!data || !toc);

	if (MAGIC_TOCBLOCK != BE64 (data)) {
		ldm_crit ("Cannot find TOCBLOCK, database may be corrupt.");
		return false;
	}
	strncpy (toc->bitmap1_name, data + 0x24, sizeof (toc->bitmap1_name));
	toc->bitmap1_name[sizeof (toc->bitmap1_name) - 1] = 0;
	toc->bitmap1_start = BE64 (data + 0x2E);
	toc->bitmap1_size  = BE64 (data + 0x36);

	if (strncmp (toc->bitmap1_name, TOC_BITMAP1,
			sizeof (toc->bitmap1_name)) != 0) {
		ldm_crit ("TOCBLOCK's first bitmap is '%s', should be '%s'.",
				TOC_BITMAP1, toc->bitmap1_name);
		return false;
	}
	strncpy (toc->bitmap2_name, data + 0x46, sizeof (toc->bitmap2_name));
	toc->bitmap2_name[sizeof (toc->bitmap2_name) - 1] = 0;
	toc->bitmap2_start = BE64 (data + 0x50);
	toc->bitmap2_size  = BE64 (data + 0x58);
	if (strncmp (toc->bitmap2_name, TOC_BITMAP2,
			sizeof (toc->bitmap2_name)) != 0) {
		ldm_crit ("TOCBLOCK's second bitmap is '%s', should be '%s'.",
				TOC_BITMAP2, toc->bitmap2_name);
		return false;
	}
	ldm_debug ("Parsed TOCBLOCK successfully.");
	return true;
}

/**
 * ldm_parse_vmdb - Read the LDM Database VMDB structure
 * @data:  Raw database VMDB structure loaded from the device
 * @vm:    In-memory vmdb structure in which to return parsed information
 *
 * This parses the LDM Database VMDB structure supplied in @data and sets up
 * the in-memory vmdb structure @vm with the obtained information.
 *
 * N.B.  The *_start, *_size and *_seq values will be range-checked later.
 *
 * Return:  'true'   @vm contains VMDB info
 *          'false'  @vm contents are undefined
 */
static bool ldm_parse_vmdb (const u8 *data, struct vmdb *vm)
{
	BUG_ON (!data || !vm);

	if (MAGIC_VMDB != BE32 (data)) {
		ldm_crit ("Cannot find the VMDB, database may be corrupt.");
		return false;
	}

	vm->ver_major = BE16 (data + 0x12);
	vm->ver_minor = BE16 (data + 0x14);
	if ((vm->ver_major != 4) || (vm->ver_minor != 10)) {
		ldm_error ("Expected VMDB version %d.%d, got %d.%d. "
			"Aborting.", 4, 10, vm->ver_major, vm->ver_minor);
		return false;
	}

	vm->vblk_size     = BE32 (data + 0x08);
	vm->vblk_offset   = BE32 (data + 0x0C);
	vm->last_vblk_seq = BE32 (data + 0x04);

	ldm_debug ("Parsed VMDB successfully.");
	return true;
}

/**
 * ldm_compare_privheads - Compare two privhead objects
 * @ph1:  First privhead
 * @ph2:  Second privhead
 *
 * This compares the two privhead structures @ph1 and @ph2.
 *
 * Return:  'true'   Identical
 *          'false'  Different
 */
static bool ldm_compare_privheads (const struct privhead *ph1,
				   const struct privhead *ph2)
{
	BUG_ON (!ph1 || !ph2);

	return ((ph1->ver_major          == ph2->ver_major)		&&
		(ph1->ver_minor          == ph2->ver_minor)		&&
		(ph1->logical_disk_start == ph2->logical_disk_start)	&&
		(ph1->logical_disk_size  == ph2->logical_disk_size)	&&
		(ph1->config_start       == ph2->config_start)		&&
		(ph1->config_size        == ph2->config_size)		&&
		!memcmp (ph1->disk_id, ph2->disk_id, GUID_SIZE));
}

/**
 * ldm_compare_tocblocks - Compare two tocblock objects
 * @toc1:  First toc
 * @toc2:  Second toc
 *
 * This compares the two tocblock structures @toc1 and @toc2.
 *
 * Return:  'true'   Identical
 *          'false'  Different
 */
static bool ldm_compare_tocblocks (const struct tocblock *toc1,
				   const struct tocblock *toc2)
{
	BUG_ON (!toc1 || !toc2);

	return ((toc1->bitmap1_start == toc2->bitmap1_start)	&&
		(toc1->bitmap1_size  == toc2->bitmap1_size)	&&
		(toc1->bitmap2_start == toc2->bitmap2_start)	&&
		(toc1->bitmap2_size  == toc2->bitmap2_size)	&&
		!strncmp (toc1->bitmap1_name, toc2->bitmap1_name,
			sizeof (toc1->bitmap1_name))		&&
		!strncmp (toc1->bitmap2_name, toc2->bitmap2_name,
			sizeof (toc1->bitmap2_name)));
}

/**
 * ldm_validate_privheads - Compare the primary privhead with its backups
 * @bdev:  Device holding the LDM Database
 * @ph1:   Memory struct to fill with ph contents
 *
 * Read and compare all three privheads from disk.
 *
 * The privheads on disk show the size and location of the main disk area and
 * the configuration area (the database).  The values are range-checked against
 * @hd, which contains the real size of the disk.
 *
 * Return:  'true'   Success
 *          'false'  Error
 */
static bool ldm_validate_privheads (struct block_device *bdev,
				    struct privhead *ph1)
{
	static const int off[3] = { OFF_PRIV1, OFF_PRIV2, OFF_PRIV3 };
	struct privhead *ph[3] = { ph1 };
	Sector sect;
	u8 *data;
	bool result = false;
	long num_sects;
	int i;

	BUG_ON (!bdev || !ph1);

	ph[1] = kmalloc (sizeof (*ph[1]), GFP_KERNEL);
	ph[2] = kmalloc (sizeof (*ph[2]), GFP_KERNEL);
	if (!ph[1] || !ph[2]) {
		ldm_crit ("Out of memory.");
		goto out;
	}

	/* off[1 & 2] are relative to ph[0]->config_start */
	ph[0]->config_start = 0;

	/* Read and parse privheads */
	for (i = 0; i < 3; i++) {
		data = read_dev_sector (bdev,
			ph[0]->config_start + off[i], &sect);
		if (!data) {
			ldm_crit ("Disk read failed.");
			goto out;
		}
		result = ldm_parse_privhead (data, ph[i]);
		put_dev_sector (sect);
		if (!result) {
			ldm_error ("Cannot find PRIVHEAD %d.", i+1); /* Log again */
			if (i < 2)
				goto out;	/* Already logged */
			else
				break;	/* FIXME ignore for now, 3rd PH can fail on odd-sized disks */
		}
	}

	num_sects = bdev->bd_inode->i_size >> 9;

	if ((ph[0]->config_start > num_sects) ||
	   ((ph[0]->config_start + ph[0]->config_size) > num_sects)) {
		ldm_crit ("Database extends beyond the end of the disk.");
		goto out;
	}

	if ((ph[0]->logical_disk_start > ph[0]->config_start) ||
	   ((ph[0]->logical_disk_start + ph[0]->logical_disk_size)
		    > ph[0]->config_start)) {
		ldm_crit ("Disk and database overlap.");
		goto out;
	}

	if (!ldm_compare_privheads (ph[0], ph[1])) {
		ldm_crit ("Primary and backup PRIVHEADs don't match.");
		goto out;
	}
	/* FIXME ignore this for now
	if (!ldm_compare_privheads (ph[0], ph[2])) {
		ldm_crit ("Primary and backup PRIVHEADs don't match.");
		goto out;
	}*/
	ldm_debug ("Validated PRIVHEADs successfully.");
	result = true;
out:
	kfree (ph[1]);
	kfree (ph[2]);
	return result;
}

/**
 * ldm_validate_tocblocks - Validate the table of contents and its backups
 * @bdev:  Device holding the LDM Database
 * @base:  Offset, into @bdev, of the database
 * @ldb:   Cache of the database structures
 *
 * Find and compare the four tables of contents of the LDM Database stored on
 * @bdev and return the parsed information into @toc1.
 *
 * The offsets and sizes of the configs are range-checked against a privhead.
 *
 * Return:  'true'   @toc1 contains validated TOCBLOCK info
 *          'false'  @toc1 contents are undefined
 */
static bool ldm_validate_tocblocks(struct block_device *bdev,
	unsigned long base, struct ldmdb *ldb)
{
	static const int off[4] = { OFF_TOCB1, OFF_TOCB2, OFF_TOCB3, OFF_TOCB4};
	struct tocblock *tb[4];
	struct privhead *ph;
	Sector sect;
	u8 *data;
	int i, nr_tbs;
	bool result = false;

	BUG_ON(!bdev || !ldb);
	ph = &ldb->ph;
	tb[0] = &ldb->toc;
	tb[1] = kmalloc(sizeof(*tb[1]) * 3, GFP_KERNEL);
	if (!tb[1]) {
		ldm_crit("Out of memory.");
		goto err;
	}
	tb[2] = (struct tocblock*)((u8*)tb[1] + sizeof(*tb[1]));
	tb[3] = (struct tocblock*)((u8*)tb[2] + sizeof(*tb[2]));
	/*
	 * Try to read and parse all four TOCBLOCKs.
	 *
	 * Windows Vista LDM v2.12 does not always have all four TOCBLOCKs so
	 * skip any that fail as long as we get at least one valid TOCBLOCK.
	 */
	for (nr_tbs = i = 0; i < 4; i++) {
		data = read_dev_sector(bdev, base + off[i], &sect);
		if (!data) {
			ldm_error("Disk read failed for TOCBLOCK %d.", i);
			continue;
		}
		if (ldm_parse_tocblock(data, tb[nr_tbs]))
			nr_tbs++;
		put_dev_sector(sect);
	}
	if (!nr_tbs) {
		ldm_crit("Failed to find a valid TOCBLOCK.");
		goto err;
	}
	/* Range check the TOCBLOCK against a privhead. */
	if (((tb[0]->bitmap1_start + tb[0]->bitmap1_size) > ph->config_size) ||
			((tb[0]->bitmap2_start + tb[0]->bitmap2_size) >
			ph->config_size)) {
		ldm_crit("The bitmaps are out of range.  Giving up.");
		goto err;
	}
	/* Compare all loaded TOCBLOCKs. */
	for (i = 1; i < nr_tbs; i++) {
		if (!ldm_compare_tocblocks(tb[0], tb[i])) {
			ldm_crit("TOCBLOCKs 0 and %d do not match.", i);
			goto err;
		}
	}
	ldm_debug("Validated %d TOCBLOCKs successfully.", nr_tbs);
	result = true;
err:
	kfree(tb[1]);
	return result;
}

/**
 * ldm_validate_vmdb - Read the VMDB and validate it
 * @bdev:  Device holding the LDM Database
 * @base:  Offset, into @bdev, of the database
 * @ldb:   Cache of the database structures
 *
 * Find the vmdb of the LDM Database stored on @bdev and return the parsed
 * information in @ldb.
 *
 * Return:  'true'   @ldb contains validated VBDB info
 *          'false'  @ldb contents are undefined
 */
static bool ldm_validate_vmdb (struct block_device *bdev, unsigned long base,
			       struct ldmdb *ldb)
{
	Sector sect;
	u8 *data;
	bool result = false;
	struct vmdb *vm;
	struct tocblock *toc;

	BUG_ON (!bdev || !ldb);

	vm  = &ldb->vm;
	toc = &ldb->toc;

	data = read_dev_sector (bdev, base + OFF_VMDB, &sect);
	if (!data) {
		ldm_crit ("Disk read failed.");
		return false;
	}

	if (!ldm_parse_vmdb (data, vm))
		goto out;				/* Already logged */

	/* Are there uncommitted transactions? */
	if (BE16(data + 0x10) != 0x01) {
		ldm_crit ("Database is not in a consistent state.  Aborting.");
		goto out;
	}

	if (vm->vblk_offset != 512)
		ldm_info ("VBLKs start at offset 0x%04x.", vm->vblk_offset);

	/*
	 * The last_vblkd_seq can be before the end of the vmdb, just make sure
	 * it is not out of bounds.
	 */
	if ((vm->vblk_size * vm->last_vblk_seq) > (toc->bitmap1_size << 9)) {
		ldm_crit ("VMDB exceeds allowed size specified by TOCBLOCK.  "
				"Database is corrupt.  Aborting.");
		goto out;
	}

	result = true;
out:
	put_dev_sector (sect);
	return result;
}


/**
 * ldm_validate_partition_table - Determine whether bdev might be a dynamic disk
 * @bdev:  Device holding the LDM Database
 *
 * This function provides a weak test to decide whether the device is a dynamic
 * disk or not.  It looks for an MS-DOS-style partition table containing at
 * least one partition of type 0x42 (formerly SFS, now used by Windows for
 * dynamic disks).
 *
 * N.B.  The only possible error can come from the read_dev_sector and that is
 *       only likely to happen if the underlying device is strange.  If that IS
 *       the case we should return zero to let someone else try.
 *
 * Return:  'true'   @bdev is a dynamic disk
 *          'false'  @bdev is not a dynamic disk, or an error occurred
 */
static bool ldm_validate_partition_table (struct block_device *bdev)
{
	Sector sect;
	u8 *data;
	struct partition *p;
	int i;
	bool result = false;

	BUG_ON (!bdev);

	data = read_dev_sector (bdev, 0, &sect);
	if (!data) {
		ldm_crit ("Disk read failed.");
		return false;
	}

	if (*(__le16*) (data + 0x01FE) != cpu_to_le16 (MSDOS_LABEL_MAGIC))
		goto out;

	p = (struct partition*)(data + 0x01BE);
	for (i = 0; i < 4; i++, p++)
		if (SYS_IND (p) == LDM_PARTITION) {
			result = true;
			break;
		}

	if (result)
		ldm_debug ("Found W2K dynamic disk partition type.");

out:
	put_dev_sector (sect);
	return result;
}

/**
 * ldm_get_disk_objid - Search a linked list of vblk's for a given Disk Id
 * @ldb:  Cache of the database structures
 *
 * The LDM Database contains a list of all partitions on all dynamic disks.
 * The primary PRIVHEAD, at the beginning of the physical disk, tells us
 * the GUID of this disk.  This function searches for the GUID in a linked
 * list of vblk's.
 *
 * Return:  Pointer, A matching vblk was found
 *          NULL,    No match, or an error
 */
static struct vblk * ldm_get_disk_objid (const struct ldmdb *ldb)
{
	struct list_head *item;

	BUG_ON (!ldb);

	list_for_each (item, &ldb->v_disk) {
		struct vblk *v = list_entry (item, struct vblk, list);
		if (!memcmp (v->vblk.disk.disk_id, ldb->ph.disk_id, GUID_SIZE))
			return v;
	}

	return NULL;
}

/**
 * ldm_create_data_partitions - Create data partitions for this device
 * @pp:   List of the partitions parsed so far
 * @ldb:  Cache of the database structures
 *
 * The database contains ALL the partitions for ALL disk groups, so we need to
 * filter out this specific disk. Using the disk's object id, we can find all
 * the partitions in the database that belong to this disk.
 *
 * Add each partition in our database, to the parsed_partitions structure.
 *
 * N.B.  This function creates the partitions in the order it finds partition
 *       objects in the linked list.
 *
 * Return:  'true'   Partition created
 *          'false'  Error, probably a range checking problem
 */
static bool ldm_create_data_partitions (struct parsed_partitions *pp,
					const struct ldmdb *ldb)
{
	struct list_head *item;
	struct vblk *vb;
	struct vblk *disk;
	struct vblk_part *part;
	int part_num = 1;

	BUG_ON (!pp || !ldb);

	disk = ldm_get_disk_objid (ldb);
	if (!disk) {
		ldm_crit ("Can't find the ID of this disk in the database.");
		return false;
	}

	printk (" [LDM]");

	/* Create the data partitions */
	list_for_each (item, &ldb->v_part) {
		vb = list_entry (item, struct vblk, list);
		part = &vb->vblk.part;

		if (part->disk_id != disk->obj_id)
			continue;

		put_partition (pp, part_num, ldb->ph.logical_disk_start +
				part->start, part->size);
		part_num++;
	}

	printk ("\n");
	return true;
}


/**
 * ldm_relative - Calculate the next relative offset
 * @buffer:  Block of data being worked on
 * @buflen:  Size of the block of data
 * @base:    Size of the previous fixed width fields
 * @offset:  Cumulative size of the previous variable-width fields
 *
 * Because many of the VBLK fields are variable-width, it's necessary
 * to calculate each offset based on the previous one and the length
 * of the field it pointed to.
 *
 * Return:  -1 Error, the calculated offset exceeded the size of the buffer
 *           n OK, a range-checked offset into buffer
 */
static int ldm_relative (const u8 *buffer, int buflen, int base, int offset)
{

	base += offset;
	if ((!buffer) || (offset < 0) || (base > buflen))
		return -1;
	if ((base + buffer[base]) >= buflen)
		return -1;

	return buffer[base] + offset + 1;
}

/**
 * ldm_get_vnum - Convert a variable-width, big endian number, into cpu order
 * @block:  Pointer to the variable-width number to convert
 *
 * Large numbers in the LDM Database are often stored in a packed format.  Each
 * number is prefixed by a one byte width marker.  All numbers in the database
 * are stored in big-endian byte order.  This function reads one of these
 * numbers and returns the result
 *
 * N.B.  This function DOES NOT perform any range checking, though the most
 *       it will read is eight bytes.
 *
 * Return:  n A number
 *          0 Zero, or an error occurred
 */
static u64 ldm_get_vnum (const u8 *block)
{
	u64 tmp = 0;
	u8 length;

	BUG_ON (!block);

	length = *block++;

	if (length && length <= 8)
		while (length--)
			tmp = (tmp << 8) | *block++;
	else
		ldm_error ("Illegal length %d.", length);

	return tmp;
}

/**
 * ldm_get_vstr - Read a length-prefixed string into a buffer
 * @block:   Pointer to the length marker
 * @buffer:  Location to copy string to
 * @buflen:  Size of the output buffer
 *
 * Many of the strings in the LDM Database are not NULL terminated.  Instead
 * they are prefixed by a one byte length marker.  This function copies one of
 * these strings into a buffer.
 *
 * N.B.  This function DOES NOT perform any range checking on the input.
 *       If the buffer is too small, the output will be truncated.
 *
 * Return:  0, Error and @buffer contents are undefined
 *          n, String length in characters (excluding NULL)
 *          buflen-1, String was truncated.
 */
static int ldm_get_vstr (const u8 *block, u8 *buffer, int buflen)
{
	int length;

	BUG_ON (!block || !buffer);

	length = block[0];
	if (length >= buflen) {
		ldm_error ("Truncating string %d -> %d.", length, buflen);
		length = buflen - 1;
	}
	memcpy (buffer, block + 1, length);
	buffer[length] = 0;
	return length;
}


/**
 * ldm_parse_cmp3 - Read a raw VBLK Component object into a vblk structure
 * @buffer:  Block of data being worked on
 * @buflen:  Size of the block of data
 * @vb:      In-memory vblk in which to return information
 *
 * Read a raw VBLK Component object (version 3) into a vblk structure.
 *
 * Return:  'true'   @vb contains a Component VBLK
 *          'false'  @vb contents are not defined
 */
static bool ldm_parse_cmp3 (const u8 *buffer, int buflen, struct vblk *vb)
{
	int r_objid, r_name, r_vstate, r_child, r_parent, r_stripe, r_cols, len;
	struct vblk_comp *comp;

	BUG_ON (!buffer || !vb);

	r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
	r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
	r_vstate = ldm_relative (buffer, buflen, 0x18, r_name);
	r_child  = ldm_relative (buffer, buflen, 0x1D, r_vstate);
	r_parent = ldm_relative (buffer, buflen, 0x2D, r_child);

	if (buffer[0x12] & VBLK_FLAG_COMP_STRIPE) {
		r_stripe = ldm_relative (buffer, buflen, 0x2E, r_parent);
		r_cols   = ldm_relative (buffer, buflen, 0x2E, r_stripe);
		len = r_cols;
	} else {
		r_stripe = 0;
		r_cols   = 0;
		len = r_parent;
	}
	if (len < 0)
		return false;

	len += VBLK_SIZE_CMP3;
	if (len != BE32 (buffer + 0x14))
		return false;

	comp = &vb->vblk.comp;
	ldm_get_vstr (buffer + 0x18 + r_name, comp->state,
		sizeof (comp->state));
	comp->type      = buffer[0x18 + r_vstate];
	comp->children  = ldm_get_vnum (buffer + 0x1D + r_vstate);
	comp->parent_id = ldm_get_vnum (buffer + 0x2D + r_child);
	comp->chunksize = r_stripe ? ldm_get_vnum (buffer+r_parent+0x2E) : 0;

	return true;
}

/**
 * ldm_parse_dgr3 - Read a raw VBLK Disk Group object into a vblk structure
 * @buffer:  Block of data being worked on
 * @buflen:  Size of the block of data
 * @vb:      In-memory vblk in which to return information
 *
 * Read a raw VBLK Disk Group object (version 3) into a vblk structure.
 *
 * Return:  'true'   @vb contains a Disk Group VBLK
 *          'false'  @vb contents are not defined
 */
static int ldm_parse_dgr3 (const u8 *buffer, int buflen, struct vblk *vb)
{
	int r_objid, r_name, r_diskid, r_id1, r_id2, len;
	struct vblk_dgrp *dgrp;

	BUG_ON (!buffer || !vb);

	r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
	r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
	r_diskid = ldm_relative (buffer, buflen, 0x18, r_name);

	if (buffer[0x12] & VBLK_FLAG_DGR3_IDS) {
		r_id1 = ldm_relative (buffer, buflen, 0x24, r_diskid);
		r_id2 = ldm_relative (buffer, buflen, 0x24, r_id1);
		len = r_id2;
	} else {
		r_id1 = 0;
		r_id2 = 0;
		len = r_diskid;
	}
	if (len < 0)
		return false;

	len += VBLK_SIZE_DGR3;
	if (len != BE32 (buffer + 0x14))
		return false;

	dgrp = &vb->vblk.dgrp;
	ldm_get_vstr (buffer + 0x18 + r_name, dgrp->disk_id,
		sizeof (dgrp->disk_id));
	return true;
}

/**
 * ldm_parse_dgr4 - Read a raw VBLK Disk Group object into a vblk structure
 * @buffer:  Block of data being worked on
 * @buflen:  Size of the block of data
 * @vb:      In-memory vblk in which to return information
 *
 * Read a raw VBLK Disk Group object (version 4) into a vblk structure.
 *
 * Return:  'true'   @vb contains a Disk Group VBLK
 *          'false'  @vb contents are not defined
 */
static bool ldm_parse_dgr4 (const u8 *buffer, int buflen, struct vblk *vb)
{
	char buf[64];
	int r_objid, r_name, r_id1, r_id2, len;
	struct vblk_dgrp *dgrp;

	BUG_ON (!buffer || !vb);

	r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
	r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);

	if (buffer[0x12] & VBLK_FLAG_DGR4_IDS) {
		r_id1 = ldm_relative (buffer, buflen, 0x44, r_name);
		r_id2 = ldm_relative (buffer, buflen, 0x44, r_id1);
		len = r_id2;
	} else {
		r_id1 = 0;
		r_id2 = 0;
		len = r_name;
	}
	if (len < 0)
		return false;

	len += VBLK_SIZE_DGR4;
	if (len != BE32 (buffer + 0x14))
		return false;

	dgrp = &vb->vblk.dgrp;

	ldm_get_vstr (buffer + 0x18 + r_objid, buf, sizeof (buf));
	return true;
}

/**
 * ldm_parse_dsk3 - Read a raw VBLK Disk object into a vblk structure
 * @buffer:  Block of data being worked on
 * @buflen:  Size of the block of data
 * @vb:      In-memory vblk in which to return information
 *
 * Read a raw VBLK Disk object (version 3) into a vblk structure.
 *
 * Return:  'true'   @vb contains a Disk VBLK
 *          'false'  @vb contents are not defined
 */
static bool ldm_parse_dsk3 (const u8 *buffer, int buflen, struct vblk *vb)
{
	int r_objid, r_name, r_diskid, r_altname, len;
	struct vblk_disk *disk;

	BUG_ON (!buffer || !vb);

	r_objid   = ldm_relative (buffer, buflen, 0x18, 0);
	r_name    = ldm_relative (buffer, buflen, 0x18, r_objid);
	r_diskid  = ldm_relative (buffer, buflen, 0x18, r_name);
	r_altname = ldm_relative (buffer, buflen, 0x18, r_diskid);
	len = r_altname;
	if (len < 0)
		return false;

	len += VBLK_SIZE_DSK3;
	if (len != BE32 (buffer + 0x14))
		return false;

	disk = &vb->vblk.disk;
	ldm_get_vstr (buffer + 0x18 + r_diskid, disk->alt_name,
		sizeof (disk->alt_name));
	if (!ldm_parse_guid (buffer + 0x19 + r_name, disk->disk_id))
		return false;

	return true;
}

/**
 * ldm_parse_dsk4 - Read a raw VBLK Disk object into a vblk structure
 * @buffer:  Block of data being worked on
 * @buflen:  Size of the block of data
 * @vb:      In-memory vblk in which to return information
 *
 * Read a raw VBLK Disk object (version 4) into a vblk structure.
 *
 * Return:  'true'   @vb contains a Disk VBLK
 *          'false'  @vb contents are not defined
 */
static bool ldm_parse_dsk4 (const u8 *buffer, int buflen, struct vblk *vb)
{
	int r_objid, r_name, len;
	struct vblk_disk *disk;

	BUG_ON (!buffer || !vb);

	r_objid = ldm_relative (buffer, buflen, 0x18, 0);
	r_name  = ldm_relative (buffer, buflen, 0x18, r_objid);
	len     = r_name;
	if (len < 0)
		return false;

	len += VBLK_SIZE_DSK4;
	if (len != BE32 (buffer + 0x14))
		return false;

	disk = &vb->vblk.disk;
	memcpy (disk->disk_id, buffer + 0x18 + r_name, GUID_SIZE);
	return true;
}

/**
 * ldm_parse_prt3 - Read a raw VBLK Partition object into a vblk structure
 * @buffer:  Block of data being worked on
 * @buflen:  Size of the block of data
 * @vb:      In-memory vblk in which to return information
 *
 * Read a raw VBLK Partition object (version 3) into a vblk structure.
 *
 * Return:  'true'   @vb contains a Partition VBLK
 *          'false'  @vb contents are not defined
 */
static bool ldm_parse_prt3(const u8 *buffer, int buflen, struct vblk *vb)
{
	int r_objid, r_name, r_size, r_parent, r_diskid, r_index, len;
	struct vblk_part *part;

	BUG_ON(!buffer || !vb);
	r_objid = ldm_relative(buffer, buflen, 0x18, 0);
	if (r_objid < 0) {
		ldm_error("r_objid %d < 0", r_objid);
		return false;
	}
	r_name = ldm_relative(buffer, buflen, 0x18, r_objid);
	if (r_name < 0) {
		ldm_error("r_name %d < 0", r_name);
		return false;
	}
	r_size = ldm_relative(buffer, buflen, 0x34, r_name);
	if (r_size < 0) {
		ldm_error("r_size %d < 0", r_size);
		return false;
	}
	r_parent = ldm_relative(buffer, buflen, 0x34, r_size);
	if (r_parent < 0) {
		ldm_error("r_parent %d < 0", r_parent);
		return false;
	}
	r_diskid = ldm_relative(buffer, buflen, 0x34, r_parent);
	if (r_diskid < 0) {
		ldm_error("r_diskid %d < 0", r_diskid);
		return false;
	}
	if (buffer[0x12] & VBLK_FLAG_PART_INDEX) {
		r_index = ldm_relative(buffer, buflen, 0x34, r_diskid);
		if (r_index < 0) {
			ldm_error("r_index %d < 0", r_index);
			return false;
		}
		len = r_index;
	} else {
		r_index = 0;
		len = r_diskid;
	}
	if (len < 0) {
		ldm_error("len %d < 0", len);
		return false;
	}
	len += VBLK_SIZE_PRT3;
	if (len > BE32(buffer + 0x14)) {
		ldm_error("len %d > BE32(buffer + 0x14) %d", len,
				BE32(buffer + 0x14));
		return false;
	}
	part = &vb->vblk.part;
	part->start = BE64(buffer + 0x24 + r_name);
	part->volume_offset = BE64(buffer + 0x2C + r_name);
	part->size = ldm_get_vnum(buffer + 0x34 + r_name);
	part->parent_id = ldm_get_vnum(buffer + 0x34 + r_size);
	part->disk_id = ldm_get_vnum(buffer + 0x34 + r_parent);
	if (vb->flags & VBLK_FLAG_PART_INDEX)
		part->partnum = buffer[0x35 + r_diskid];
	else
		part->partnum = 0;
	return true;
}

/**
 * ldm_parse_vol5 - Read a raw VBLK Volume object into a vblk structure
 * @buffer:  Block of data being worked on
 * @buflen:  Size of the block of data
 * @vb:      In-memory vblk in which to return information
 *
 * Read a raw VBLK Volume object (version 5) into a vblk structure.
 *
 * Return:  'true'   @vb contains a Volume VBLK
 *          'false'  @vb contents are not defined
 */
static bool ldm_parse_vol5 (const u8 *buffer, int buflen, struct vblk *vb)
{
	int r_objid, r_name, r_vtype, r_child, r_size, r_id1, r_id2, r_size2;
	int r_drive, len;
	struct vblk_volu *volu;

	BUG_ON (!buffer || !vb);

	r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
	r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
	r_vtype  = ldm_relative (buffer, buflen, 0x18, r_name);
	r_child  = ldm_relative (buffer, buflen, 0x2E, r_vtype);
	r_size   = ldm_relative (buffer, buflen, 0x3E, r_child);

	if (buffer[0x12] & VBLK_FLAG_VOLU_ID1)
		r_id1 = ldm_relative (buffer, buflen, 0x53, r_size);
	else
		r_id1 = r_size;

	if (buffer[0x12] & VBLK_FLAG_VOLU_ID2)
		r_id2 = ldm_relative (buffer, buflen, 0x53, r_id1);
	else
		r_id2 = r_id1;

	if (buffer[0x12] & VBLK_FLAG_VOLU_SIZE)
		r_size2 = ldm_relative (buffer, buflen, 0x53, r_id2);
	else
		r_size2 = r_id2;

	if (buffer[0x12] & VBLK_FLAG_VOLU_DRIVE)
		r_drive = ldm_relative (buffer, buflen, 0x53, r_size2);
	else
		r_drive = r_size2;

	len = r_drive;
	if (len < 0)
		return false;

	len += VBLK_SIZE_VOL5;
	if (len != BE32 (buffer + 0x14))
		return false;

	volu = &vb->vblk.volu;

	ldm_get_vstr (buffer + 0x18 + r_name,  volu->volume_type,
		sizeof (volu->volume_type));
	memcpy (volu->volume_state, buffer + 0x19 + r_vtype,
			sizeof (volu->volume_state));
	volu->size = ldm_get_vnum (buffer + 0x3E + r_child);
	volu->partition_type = buffer[0x42 + r_size];
	memcpy (volu->guid, buffer + 0x43 + r_size,  sizeof (volu->guid));
	if (buffer[0x12] & VBLK_FLAG_VOLU_DRIVE) {
		ldm_get_vstr (buffer + 0x53 + r_size,  volu->drive_hint,
			sizeof (volu->drive_hint));
	}
	return true;
}

/**
 * ldm_parse_vblk - Read a raw VBLK object into a vblk structure
 * @buf:  Block of data being worked on
 * @len:  Size of the block of data
 * @vb:   In-memory vblk in which to return information
 *
 * Read a raw VBLK object into a vblk structure.  This function just reads the
 * information common to all VBLK types, then delegates the rest of the work to
 * helper functions: ldm_parse_*.
 *
 * Return:  'true'   @vb contains a VBLK
 *          'false'  @vb contents are not defined
 */
static bool ldm_parse_vblk (const u8 *buf, int len, struct vblk *vb)
{
	bool result = false;
	int r_objid;

	BUG_ON (!buf || !vb);

	r_objid = ldm_relative (buf, len, 0x18, 0);
	if (r_objid < 0) {
		ldm_error ("VBLK header is corrupt.");
		return false;
	}

	vb->flags  = buf[0x12];
	vb->type   = buf[0x13];
	vb->obj_id = ldm_get_vnum (buf + 0x18);
	ldm_get_vstr (buf+0x18+r_objid, vb->name, sizeof (vb->name));

	switch (vb->type) {
		case VBLK_CMP3:  result = ldm_parse_cmp3 (buf, len, vb); break;
		case VBLK_DSK3:  result = ldm_parse_dsk3 (buf, len, vb); break;
		case VBLK_DSK4:  result = ldm_parse_dsk4 (buf, len, vb); break;
		case VBLK_DGR3:  result = ldm_parse_dgr3 (buf, len, vb); break;
		case VBLK_DGR4:  result = ldm_parse_dgr4 (buf, len, vb); break;
		case VBLK_PRT3:  result = ldm_parse_prt3 (buf, len, vb); break;
		case VBLK_VOL5:  result = ldm_parse_vol5 (buf, len, vb); break;
	}

	if (result)
		ldm_debug ("Parsed VBLK 0x%llx (type: 0x%02x) ok.",
			 (unsigned long long) vb->obj_id, vb->type);
	else
		ldm_error ("Failed to parse VBLK 0x%llx (type: 0x%02x).",
			(unsigned long long) vb->obj_id, vb->type);

	return result;
}


/**
 * ldm_ldmdb_add - Adds a raw VBLK entry to the ldmdb database
 * @data:  Raw VBLK to add to the database
 * @len:   Size of the raw VBLK
 * @ldb:   Cache of the database structures
 *
 * The VBLKs are sorted into categories.  Partitions are also sorted by offset.
 *
 * N.B.  This function does not check the validity of the VBLKs.
 *
 * Return:  'true'   The VBLK was added
 *          'false'  An error occurred
 */
static bool ldm_ldmdb_add (u8 *data, int len, struct ldmdb *ldb)
{
	struct vblk *vb;
	struct list_head *item;

	BUG_ON (!data || !ldb);

	vb = kmalloc (sizeof (*vb), GFP_KERNEL);
	if (!vb) {
		ldm_crit ("Out of memory.");
		return false;
	}

	if (!ldm_parse_vblk (data, len, vb)) {
		kfree(vb);
		return false;			/* Already logged */
	}

	/* Put vblk into the correct list. */
	switch (vb->type) {
	case VBLK_DGR3:
	case VBLK_DGR4:
		list_add (&vb->list, &ldb->v_dgrp);
		break;
	case VBLK_DSK3:
	case VBLK_DSK4:
		list_add (&vb->list, &ldb->v_disk);
		break;
	case VBLK_VOL5:
		list_add (&vb->list, &ldb->v_volu);
		break;
	case VBLK_CMP3:
		list_add (&vb->list, &ldb->v_comp);
		break;
	case VBLK_PRT3:
		/* Sort by the partition's start sector. */
		list_for_each (item, &ldb->v_part) {
			struct vblk *v = list_entry (item, struct vblk, list);
			if ((v->vblk.part.disk_id == vb->vblk.part.disk_id) &&
			    (v->vblk.part.start > vb->vblk.part.start)) {
				list_add_tail (&vb->list, &v->list);
				return true;
			}
		}
		list_add_tail (&vb->list, &ldb->v_part);
		break;
	}
	return true;
}

/**
 * ldm_frag_add - Add a VBLK fragment to a list
 * @data:   Raw fragment to be added to the list
 * @size:   Size of the raw fragment
 * @frags:  Linked list of VBLK fragments
 *
 * Fragmented VBLKs may not be consecutive in the database, so they are placed
 * in a list so they can be pieced together later.
 *
 * Return:  'true'   Success, the VBLK was added to the list
 *          'false'  Error, a problem occurred
 */
static bool ldm_frag_add (const u8 *data, int size, struct list_head *frags)
{
	struct frag *f;
	struct list_head *item;
	int rec, num, group;

	BUG_ON (!data || !frags);

	group = BE32 (data + 0x08);
	rec   = BE16 (data + 0x0C);
	num   = BE16 (data + 0x0E);
	if ((num < 1) || (num > 4)) {
		ldm_error ("A VBLK claims to have %d parts.", num);
		return false;
	}

	list_for_each (item, frags) {
		f = list_entry (item, struct frag, list);
		if (f->group == group)
			goto found;
	}

	f = kmalloc (sizeof (*f) + size*num, GFP_KERNEL);
	if (!f) {
		ldm_crit ("Out of memory.");
		return false;
	}

	f->group = group;
	f->num   = num;
	f->rec   = rec;
	f->map   = 0xFF << num;

	list_add_tail (&f->list, frags);
found:
	if (f->map & (1 << rec)) {
		ldm_error ("Duplicate VBLK, part %d.", rec);
		f->map &= 0x7F;			/* Mark the group as broken */
		return false;
	}

	f->map |= (1 << rec);

	if (num > 0) {
		data += VBLK_SIZE_HEAD;
		size -= VBLK_SIZE_HEAD;
	}
	memcpy (f->data+rec*(size-VBLK_SIZE_HEAD)+VBLK_SIZE_HEAD, data, size);

	return true;
}

/**
 * ldm_frag_free - Free a linked list of VBLK fragments
 * @list:  Linked list of fragments
 *
 * Free a linked list of VBLK fragments
 *
 * Return:  none
 */
static void ldm_frag_free (struct list_head *list)
{
	struct list_head *item, *tmp;

	BUG_ON (!list);

	list_for_each_safe (item, tmp, list)
		kfree (list_entry (item, struct frag, list));
}

/**
 * ldm_frag_commit - Validate fragmented VBLKs and add them to the database
 * @frags:  Linked list of VBLK fragments
 * @ldb:    Cache of the database structures
 *
 * Now that all the fragmented VBLKs have been collected, they must be added to
 * the database for later use.
 *
 * Return:  'true'   All the fragments we added successfully
 *          'false'  One or more of the fragments we invalid
 */
static bool ldm_frag_commit (struct list_head *frags, struct ldmdb *ldb)
{
	struct frag *f;
	struct list_head *item;

	BUG_ON (!frags || !ldb);

	list_for_each (item, frags) {
		f = list_entry (item, struct frag, list);

		if (f->map != 0xFF) {
			ldm_error ("VBLK group %d is incomplete (0x%02x).",
				f->group, f->map);
			return false;
		}

		if (!ldm_ldmdb_add (f->data, f->num*ldb->vm.vblk_size, ldb))
			return false;		/* Already logged */
	}
	return true;
}

/**
 * ldm_get_vblks - Read the on-disk database of VBLKs into memory
 * @bdev:  Device holding the LDM Database
 * @base:  Offset, into @bdev, of the database
 * @ldb:   Cache of the database structures
 *
 * To use the information from the VBLKs, they need to be read from the disk,
 * unpacked and validated.  We cache them in @ldb according to their type.
 *
 * Return:  'true'   All the VBLKs were read successfully
 *          'false'  An error occurred
 */
static bool ldm_get_vblks (struct block_device *bdev, unsigned long base,
			   struct ldmdb *ldb)
{
	int size, perbuf, skip, finish, s, v, recs;
	u8 *data = NULL;
	Sector sect;
	bool result = false;
	LIST_HEAD (frags);

	BUG_ON (!bdev || !ldb);

	size   = ldb->vm.vblk_size;
	perbuf = 512 / size;
	skip   = ldb->vm.vblk_offset >> 9;		/* Bytes to sectors */
	finish = (size * ldb->vm.last_vblk_seq) >> 9;

	for (s = skip; s < finish; s++) {		/* For each sector */
		data = read_dev_sector (bdev, base + OFF_VMDB + s, &sect);
		if (!data) {
			ldm_crit ("Disk read failed.");
			goto out;
		}

		for (v = 0; v < perbuf; v++, data+=size) {  /* For each vblk */
			if (MAGIC_VBLK != BE32 (data)) {
				ldm_error ("Expected to find a VBLK.");
				goto out;
			}

			recs = BE16 (data + 0x0E);	/* Number of records */
			if (recs == 1) {
				if (!ldm_ldmdb_add (data, size, ldb))
					goto out;	/* Already logged */
			} else if (recs > 1) {
				if (!ldm_frag_add (data, size, &frags))
					goto out;	/* Already logged */
			}
			/* else Record is not in use, ignore it. */
		}
		put_dev_sector (sect);
		data = NULL;
	}

	result = ldm_frag_commit (&frags, ldb);	/* Failures, already logged */
out:
	if (data)
		put_dev_sector (sect);
	ldm_frag_free (&frags);

	return result;
}

/**
 * ldm_free_vblks - Free a linked list of vblk's
 * @lh:  Head of a linked list of struct vblk
 *
 * Free a list of vblk's and free the memory used to maintain the list.
 *
 * Return:  none
 */
static void ldm_free_vblks (struct list_head *lh)
{
	struct list_head *item, *tmp;

	BUG_ON (!lh);

	list_for_each_safe (item, tmp, lh)
		kfree (list_entry (item, struct vblk, list));
}


/**
 * ldm_partition - Find out whether a device is a dynamic disk and handle it
 * @pp:    List of the partitions parsed so far
 * @bdev:  Device holding the LDM Database
 *
 * This determines whether the device @bdev is a dynamic disk and if so creates
 * the partitions necessary in the gendisk structure pointed to by @hd.
 *
 * We create a dummy device 1, which contains the LDM database, and then create
 * each partition described by the LDM database in sequence as devices 2+. For
 * example, if the device is hda, we would have: hda1: LDM database, hda2, hda3,
 * and so on: the actual data containing partitions.
 *
 * Return:  1 Success, @bdev is a dynamic disk and we handled it
 *          0 Success, @bdev is not a dynamic disk
 *         -1 An error occurred before enough information had been read
 *            Or @bdev is a dynamic disk, but it may be corrupted
 */
int ldm_partition (struct parsed_partitions *pp, struct block_device *bdev)
{
	struct ldmdb  *ldb;
	unsigned long base;
	int result = -1;

	BUG_ON (!pp || !bdev);

	/* Look for signs of a Dynamic Disk */
	if (!ldm_validate_partition_table (bdev))
		return 0;

	ldb = kmalloc (sizeof (*ldb), GFP_KERNEL);
	if (!ldb) {
		ldm_crit ("Out of memory.");
		goto out;
	}

	/* Parse and check privheads. */
	if (!ldm_validate_privheads (bdev, &ldb->ph))
		goto out;		/* Already logged */

	/* All further references are relative to base (database start). */
	base = ldb->ph.config_start;

	/* Parse and check tocs and vmdb. */
	if (!ldm_validate_tocblocks (bdev, base, ldb) ||
	    !ldm_validate_vmdb      (bdev, base, ldb))
	    	goto out;		/* Already logged */

	/* Initialize vblk lists in ldmdb struct */
	INIT_LIST_HEAD (&ldb->v_dgrp);
	INIT_LIST_HEAD (&ldb->v_disk);
	INIT_LIST_HEAD (&ldb->v_volu);
	INIT_LIST_HEAD (&ldb->v_comp);
	INIT_LIST_HEAD (&ldb->v_part);

	if (!ldm_get_vblks (bdev, base, ldb)) {
		ldm_crit ("Failed to read the VBLKs from the database.");
		goto cleanup;
	}

	/* Finally, create the data partition devices. */
	if (ldm_create_data_partitions (pp, ldb)) {
		ldm_debug ("Parsed LDM database successfully.");
		result = 1;
	}
	/* else Already logged */

cleanup:
	ldm_free_vblks (&ldb->v_dgrp);
	ldm_free_vblks (&ldb->v_disk);
	ldm_free_vblks (&ldb->v_volu);
	ldm_free_vblks (&ldb->v_comp);
	ldm_free_vblks (&ldb->v_part);
out:
	kfree (ldb);
	return result;
}