xref: /kernel/linux/linux-5.10/block/partitions/ldm.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-or-later
2/**
3 * ldm - Support for Windows Logical Disk Manager (Dynamic Disks)
4 *
5 * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
6 * Copyright (c) 2001-2012 Anton Altaparmakov
7 * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
8 *
9 * Documentation is available at http://www.linux-ntfs.org/doku.php?id=downloads
10 */
11
12#include <linux/slab.h>
13#include <linux/pagemap.h>
14#include <linux/stringify.h>
15#include <linux/kernel.h>
16#include <linux/uuid.h>
17#include <linux/msdos_partition.h>
18
19#include "ldm.h"
20#include "check.h"
21
22/*
23 * ldm_debug/info/error/crit - Output an error message
24 * @f:    A printf format string containing the message
25 * @...:  Variables to substitute into @f
26 *
27 * ldm_debug() writes a DEBUG level message to the syslog but only if the
28 * driver was compiled with debug enabled. Otherwise, the call turns into a NOP.
29 */
30#ifndef CONFIG_LDM_DEBUG
31#define ldm_debug(...)	do {} while (0)
32#else
33#define ldm_debug(f, a...) _ldm_printk (KERN_DEBUG, __func__, f, ##a)
34#endif
35
36#define ldm_crit(f, a...)  _ldm_printk (KERN_CRIT,  __func__, f, ##a)
37#define ldm_error(f, a...) _ldm_printk (KERN_ERR,   __func__, f, ##a)
38#define ldm_info(f, a...)  _ldm_printk (KERN_INFO,  __func__, f, ##a)
39
40static __printf(3, 4)
41void _ldm_printk(const char *level, const char *function, const char *fmt, ...)
42{
43	struct va_format vaf;
44	va_list args;
45
46	va_start (args, fmt);
47
48	vaf.fmt = fmt;
49	vaf.va = &args;
50
51	printk("%s%s(): %pV\n", level, function, &vaf);
52
53	va_end(args);
54}
55
56/**
57 * ldm_parse_privhead - Read the LDM Database PRIVHEAD structure
58 * @data:  Raw database PRIVHEAD structure loaded from the device
59 * @ph:    In-memory privhead structure in which to return parsed information
60 *
61 * This parses the LDM database PRIVHEAD structure supplied in @data and
62 * sets up the in-memory privhead structure @ph with the obtained information.
63 *
64 * Return:  'true'   @ph contains the PRIVHEAD data
65 *          'false'  @ph contents are undefined
66 */
67static bool ldm_parse_privhead(const u8 *data, struct privhead *ph)
68{
69	bool is_vista = false;
70
71	BUG_ON(!data || !ph);
72	if (MAGIC_PRIVHEAD != get_unaligned_be64(data)) {
73		ldm_error("Cannot find PRIVHEAD structure. LDM database is"
74			" corrupt. Aborting.");
75		return false;
76	}
77	ph->ver_major = get_unaligned_be16(data + 0x000C);
78	ph->ver_minor = get_unaligned_be16(data + 0x000E);
79	ph->logical_disk_start = get_unaligned_be64(data + 0x011B);
80	ph->logical_disk_size = get_unaligned_be64(data + 0x0123);
81	ph->config_start = get_unaligned_be64(data + 0x012B);
82	ph->config_size = get_unaligned_be64(data + 0x0133);
83	/* Version 2.11 is Win2k/XP and version 2.12 is Vista. */
84	if (ph->ver_major == 2 && ph->ver_minor == 12)
85		is_vista = true;
86	if (!is_vista && (ph->ver_major != 2 || ph->ver_minor != 11)) {
87		ldm_error("Expected PRIVHEAD version 2.11 or 2.12, got %d.%d."
88			" Aborting.", ph->ver_major, ph->ver_minor);
89		return false;
90	}
91	ldm_debug("PRIVHEAD version %d.%d (Windows %s).", ph->ver_major,
92			ph->ver_minor, is_vista ? "Vista" : "2000/XP");
93	if (ph->config_size != LDM_DB_SIZE) {	/* 1 MiB in sectors. */
94		/* Warn the user and continue, carefully. */
95		ldm_info("Database is normally %u bytes, it claims to "
96			"be %llu bytes.", LDM_DB_SIZE,
97			(unsigned long long)ph->config_size);
98	}
99	if ((ph->logical_disk_size == 0) || (ph->logical_disk_start +
100			ph->logical_disk_size > ph->config_start)) {
101		ldm_error("PRIVHEAD disk size doesn't match real disk size");
102		return false;
103	}
104	if (uuid_parse(data + 0x0030, &ph->disk_id)) {
105		ldm_error("PRIVHEAD contains an invalid GUID.");
106		return false;
107	}
108	ldm_debug("Parsed PRIVHEAD successfully.");
109	return true;
110}
111
112/**
113 * ldm_parse_tocblock - Read the LDM Database TOCBLOCK structure
114 * @data:  Raw database TOCBLOCK structure loaded from the device
115 * @toc:   In-memory toc structure in which to return parsed information
116 *
117 * This parses the LDM Database TOCBLOCK (table of contents) structure supplied
118 * in @data and sets up the in-memory tocblock structure @toc with the obtained
119 * information.
120 *
121 * N.B.  The *_start and *_size values returned in @toc are not range-checked.
122 *
123 * Return:  'true'   @toc contains the TOCBLOCK data
124 *          'false'  @toc contents are undefined
125 */
126static bool ldm_parse_tocblock (const u8 *data, struct tocblock *toc)
127{
128	BUG_ON (!data || !toc);
129
130	if (MAGIC_TOCBLOCK != get_unaligned_be64(data)) {
131		ldm_crit ("Cannot find TOCBLOCK, database may be corrupt.");
132		return false;
133	}
134	strncpy (toc->bitmap1_name, data + 0x24, sizeof (toc->bitmap1_name));
135	toc->bitmap1_name[sizeof (toc->bitmap1_name) - 1] = 0;
136	toc->bitmap1_start = get_unaligned_be64(data + 0x2E);
137	toc->bitmap1_size  = get_unaligned_be64(data + 0x36);
138
139	if (strncmp (toc->bitmap1_name, TOC_BITMAP1,
140			sizeof (toc->bitmap1_name)) != 0) {
141		ldm_crit ("TOCBLOCK's first bitmap is '%s', should be '%s'.",
142				TOC_BITMAP1, toc->bitmap1_name);
143		return false;
144	}
145	strncpy (toc->bitmap2_name, data + 0x46, sizeof (toc->bitmap2_name));
146	toc->bitmap2_name[sizeof (toc->bitmap2_name) - 1] = 0;
147	toc->bitmap2_start = get_unaligned_be64(data + 0x50);
148	toc->bitmap2_size  = get_unaligned_be64(data + 0x58);
149	if (strncmp (toc->bitmap2_name, TOC_BITMAP2,
150			sizeof (toc->bitmap2_name)) != 0) {
151		ldm_crit ("TOCBLOCK's second bitmap is '%s', should be '%s'.",
152				TOC_BITMAP2, toc->bitmap2_name);
153		return false;
154	}
155	ldm_debug ("Parsed TOCBLOCK successfully.");
156	return true;
157}
158
159/**
160 * ldm_parse_vmdb - Read the LDM Database VMDB structure
161 * @data:  Raw database VMDB structure loaded from the device
162 * @vm:    In-memory vmdb structure in which to return parsed information
163 *
164 * This parses the LDM Database VMDB structure supplied in @data and sets up
165 * the in-memory vmdb structure @vm with the obtained information.
166 *
167 * N.B.  The *_start, *_size and *_seq values will be range-checked later.
168 *
169 * Return:  'true'   @vm contains VMDB info
170 *          'false'  @vm contents are undefined
171 */
172static bool ldm_parse_vmdb (const u8 *data, struct vmdb *vm)
173{
174	BUG_ON (!data || !vm);
175
176	if (MAGIC_VMDB != get_unaligned_be32(data)) {
177		ldm_crit ("Cannot find the VMDB, database may be corrupt.");
178		return false;
179	}
180
181	vm->ver_major = get_unaligned_be16(data + 0x12);
182	vm->ver_minor = get_unaligned_be16(data + 0x14);
183	if ((vm->ver_major != 4) || (vm->ver_minor != 10)) {
184		ldm_error ("Expected VMDB version %d.%d, got %d.%d. "
185			"Aborting.", 4, 10, vm->ver_major, vm->ver_minor);
186		return false;
187	}
188
189	vm->vblk_size     = get_unaligned_be32(data + 0x08);
190	if (vm->vblk_size == 0) {
191		ldm_error ("Illegal VBLK size");
192		return false;
193	}
194
195	vm->vblk_offset   = get_unaligned_be32(data + 0x0C);
196	vm->last_vblk_seq = get_unaligned_be32(data + 0x04);
197
198	ldm_debug ("Parsed VMDB successfully.");
199	return true;
200}
201
202/**
203 * ldm_compare_privheads - Compare two privhead objects
204 * @ph1:  First privhead
205 * @ph2:  Second privhead
206 *
207 * This compares the two privhead structures @ph1 and @ph2.
208 *
209 * Return:  'true'   Identical
210 *          'false'  Different
211 */
212static bool ldm_compare_privheads (const struct privhead *ph1,
213				   const struct privhead *ph2)
214{
215	BUG_ON (!ph1 || !ph2);
216
217	return ((ph1->ver_major          == ph2->ver_major)		&&
218		(ph1->ver_minor          == ph2->ver_minor)		&&
219		(ph1->logical_disk_start == ph2->logical_disk_start)	&&
220		(ph1->logical_disk_size  == ph2->logical_disk_size)	&&
221		(ph1->config_start       == ph2->config_start)		&&
222		(ph1->config_size        == ph2->config_size)		&&
223		uuid_equal(&ph1->disk_id, &ph2->disk_id));
224}
225
226/**
227 * ldm_compare_tocblocks - Compare two tocblock objects
228 * @toc1:  First toc
229 * @toc2:  Second toc
230 *
231 * This compares the two tocblock structures @toc1 and @toc2.
232 *
233 * Return:  'true'   Identical
234 *          'false'  Different
235 */
236static bool ldm_compare_tocblocks (const struct tocblock *toc1,
237				   const struct tocblock *toc2)
238{
239	BUG_ON (!toc1 || !toc2);
240
241	return ((toc1->bitmap1_start == toc2->bitmap1_start)	&&
242		(toc1->bitmap1_size  == toc2->bitmap1_size)	&&
243		(toc1->bitmap2_start == toc2->bitmap2_start)	&&
244		(toc1->bitmap2_size  == toc2->bitmap2_size)	&&
245		!strncmp (toc1->bitmap1_name, toc2->bitmap1_name,
246			sizeof (toc1->bitmap1_name))		&&
247		!strncmp (toc1->bitmap2_name, toc2->bitmap2_name,
248			sizeof (toc1->bitmap2_name)));
249}
250
251/**
252 * ldm_validate_privheads - Compare the primary privhead with its backups
253 * @state: Partition check state including device holding the LDM Database
254 * @ph1:   Memory struct to fill with ph contents
255 *
256 * Read and compare all three privheads from disk.
257 *
258 * The privheads on disk show the size and location of the main disk area and
259 * the configuration area (the database).  The values are range-checked against
260 * @hd, which contains the real size of the disk.
261 *
262 * Return:  'true'   Success
263 *          'false'  Error
264 */
265static bool ldm_validate_privheads(struct parsed_partitions *state,
266				   struct privhead *ph1)
267{
268	static const int off[3] = { OFF_PRIV1, OFF_PRIV2, OFF_PRIV3 };
269	struct privhead *ph[3] = { ph1 };
270	Sector sect;
271	u8 *data;
272	bool result = false;
273	long num_sects;
274	int i;
275
276	BUG_ON (!state || !ph1);
277
278	ph[1] = kmalloc (sizeof (*ph[1]), GFP_KERNEL);
279	ph[2] = kmalloc (sizeof (*ph[2]), GFP_KERNEL);
280	if (!ph[1] || !ph[2]) {
281		ldm_crit ("Out of memory.");
282		goto out;
283	}
284
285	/* off[1 & 2] are relative to ph[0]->config_start */
286	ph[0]->config_start = 0;
287
288	/* Read and parse privheads */
289	for (i = 0; i < 3; i++) {
290		data = read_part_sector(state, ph[0]->config_start + off[i],
291					&sect);
292		if (!data) {
293			ldm_crit ("Disk read failed.");
294			goto out;
295		}
296		result = ldm_parse_privhead (data, ph[i]);
297		put_dev_sector (sect);
298		if (!result) {
299			ldm_error ("Cannot find PRIVHEAD %d.", i+1); /* Log again */
300			if (i < 2)
301				goto out;	/* Already logged */
302			else
303				break;	/* FIXME ignore for now, 3rd PH can fail on odd-sized disks */
304		}
305	}
306
307	num_sects = state->bdev->bd_inode->i_size >> 9;
308
309	if ((ph[0]->config_start > num_sects) ||
310	   ((ph[0]->config_start + ph[0]->config_size) > num_sects)) {
311		ldm_crit ("Database extends beyond the end of the disk.");
312		goto out;
313	}
314
315	if ((ph[0]->logical_disk_start > ph[0]->config_start) ||
316	   ((ph[0]->logical_disk_start + ph[0]->logical_disk_size)
317		    > ph[0]->config_start)) {
318		ldm_crit ("Disk and database overlap.");
319		goto out;
320	}
321
322	if (!ldm_compare_privheads (ph[0], ph[1])) {
323		ldm_crit ("Primary and backup PRIVHEADs don't match.");
324		goto out;
325	}
326	/* FIXME ignore this for now
327	if (!ldm_compare_privheads (ph[0], ph[2])) {
328		ldm_crit ("Primary and backup PRIVHEADs don't match.");
329		goto out;
330	}*/
331	ldm_debug ("Validated PRIVHEADs successfully.");
332	result = true;
333out:
334	kfree (ph[1]);
335	kfree (ph[2]);
336	return result;
337}
338
339/**
340 * ldm_validate_tocblocks - Validate the table of contents and its backups
341 * @state: Partition check state including device holding the LDM Database
342 * @base:  Offset, into @state->bdev, of the database
343 * @ldb:   Cache of the database structures
344 *
345 * Find and compare the four tables of contents of the LDM Database stored on
346 * @state->bdev and return the parsed information into @toc1.
347 *
348 * The offsets and sizes of the configs are range-checked against a privhead.
349 *
350 * Return:  'true'   @toc1 contains validated TOCBLOCK info
351 *          'false'  @toc1 contents are undefined
352 */
353static bool ldm_validate_tocblocks(struct parsed_partitions *state,
354				   unsigned long base, struct ldmdb *ldb)
355{
356	static const int off[4] = { OFF_TOCB1, OFF_TOCB2, OFF_TOCB3, OFF_TOCB4};
357	struct tocblock *tb[4];
358	struct privhead *ph;
359	Sector sect;
360	u8 *data;
361	int i, nr_tbs;
362	bool result = false;
363
364	BUG_ON(!state || !ldb);
365	ph = &ldb->ph;
366	tb[0] = &ldb->toc;
367	tb[1] = kmalloc_array(3, sizeof(*tb[1]), GFP_KERNEL);
368	if (!tb[1]) {
369		ldm_crit("Out of memory.");
370		goto err;
371	}
372	tb[2] = (struct tocblock*)((u8*)tb[1] + sizeof(*tb[1]));
373	tb[3] = (struct tocblock*)((u8*)tb[2] + sizeof(*tb[2]));
374	/*
375	 * Try to read and parse all four TOCBLOCKs.
376	 *
377	 * Windows Vista LDM v2.12 does not always have all four TOCBLOCKs so
378	 * skip any that fail as long as we get at least one valid TOCBLOCK.
379	 */
380	for (nr_tbs = i = 0; i < 4; i++) {
381		data = read_part_sector(state, base + off[i], &sect);
382		if (!data) {
383			ldm_error("Disk read failed for TOCBLOCK %d.", i);
384			continue;
385		}
386		if (ldm_parse_tocblock(data, tb[nr_tbs]))
387			nr_tbs++;
388		put_dev_sector(sect);
389	}
390	if (!nr_tbs) {
391		ldm_crit("Failed to find a valid TOCBLOCK.");
392		goto err;
393	}
394	/* Range check the TOCBLOCK against a privhead. */
395	if (((tb[0]->bitmap1_start + tb[0]->bitmap1_size) > ph->config_size) ||
396			((tb[0]->bitmap2_start + tb[0]->bitmap2_size) >
397			ph->config_size)) {
398		ldm_crit("The bitmaps are out of range.  Giving up.");
399		goto err;
400	}
401	/* Compare all loaded TOCBLOCKs. */
402	for (i = 1; i < nr_tbs; i++) {
403		if (!ldm_compare_tocblocks(tb[0], tb[i])) {
404			ldm_crit("TOCBLOCKs 0 and %d do not match.", i);
405			goto err;
406		}
407	}
408	ldm_debug("Validated %d TOCBLOCKs successfully.", nr_tbs);
409	result = true;
410err:
411	kfree(tb[1]);
412	return result;
413}
414
415/**
416 * ldm_validate_vmdb - Read the VMDB and validate it
417 * @state: Partition check state including device holding the LDM Database
418 * @base:  Offset, into @bdev, of the database
419 * @ldb:   Cache of the database structures
420 *
421 * Find the vmdb of the LDM Database stored on @bdev and return the parsed
422 * information in @ldb.
423 *
424 * Return:  'true'   @ldb contains validated VBDB info
425 *          'false'  @ldb contents are undefined
426 */
427static bool ldm_validate_vmdb(struct parsed_partitions *state,
428			      unsigned long base, struct ldmdb *ldb)
429{
430	Sector sect;
431	u8 *data;
432	bool result = false;
433	struct vmdb *vm;
434	struct tocblock *toc;
435
436	BUG_ON (!state || !ldb);
437
438	vm  = &ldb->vm;
439	toc = &ldb->toc;
440
441	data = read_part_sector(state, base + OFF_VMDB, &sect);
442	if (!data) {
443		ldm_crit ("Disk read failed.");
444		return false;
445	}
446
447	if (!ldm_parse_vmdb (data, vm))
448		goto out;				/* Already logged */
449
450	/* Are there uncommitted transactions? */
451	if (get_unaligned_be16(data + 0x10) != 0x01) {
452		ldm_crit ("Database is not in a consistent state.  Aborting.");
453		goto out;
454	}
455
456	if (vm->vblk_offset != 512)
457		ldm_info ("VBLKs start at offset 0x%04x.", vm->vblk_offset);
458
459	/*
460	 * The last_vblkd_seq can be before the end of the vmdb, just make sure
461	 * it is not out of bounds.
462	 */
463	if ((vm->vblk_size * vm->last_vblk_seq) > (toc->bitmap1_size << 9)) {
464		ldm_crit ("VMDB exceeds allowed size specified by TOCBLOCK.  "
465				"Database is corrupt.  Aborting.");
466		goto out;
467	}
468
469	result = true;
470out:
471	put_dev_sector (sect);
472	return result;
473}
474
475
476/**
477 * ldm_validate_partition_table - Determine whether bdev might be a dynamic disk
478 * @state: Partition check state including device holding the LDM Database
479 *
480 * This function provides a weak test to decide whether the device is a dynamic
481 * disk or not.  It looks for an MS-DOS-style partition table containing at
482 * least one partition of type 0x42 (formerly SFS, now used by Windows for
483 * dynamic disks).
484 *
485 * N.B.  The only possible error can come from the read_part_sector and that is
486 *       only likely to happen if the underlying device is strange.  If that IS
487 *       the case we should return zero to let someone else try.
488 *
489 * Return:  'true'   @state->bdev is a dynamic disk
490 *          'false'  @state->bdev is not a dynamic disk, or an error occurred
491 */
492static bool ldm_validate_partition_table(struct parsed_partitions *state)
493{
494	Sector sect;
495	u8 *data;
496	struct msdos_partition *p;
497	int i;
498	bool result = false;
499
500	BUG_ON(!state);
501
502	data = read_part_sector(state, 0, &sect);
503	if (!data) {
504		ldm_info ("Disk read failed.");
505		return false;
506	}
507
508	if (*(__le16*) (data + 0x01FE) != cpu_to_le16 (MSDOS_LABEL_MAGIC))
509		goto out;
510
511	p = (struct msdos_partition *)(data + 0x01BE);
512	for (i = 0; i < 4; i++, p++)
513		if (p->sys_ind == LDM_PARTITION) {
514			result = true;
515			break;
516		}
517
518	if (result)
519		ldm_debug ("Found W2K dynamic disk partition type.");
520
521out:
522	put_dev_sector (sect);
523	return result;
524}
525
526/**
527 * ldm_get_disk_objid - Search a linked list of vblk's for a given Disk Id
528 * @ldb:  Cache of the database structures
529 *
530 * The LDM Database contains a list of all partitions on all dynamic disks.
531 * The primary PRIVHEAD, at the beginning of the physical disk, tells us
532 * the GUID of this disk.  This function searches for the GUID in a linked
533 * list of vblk's.
534 *
535 * Return:  Pointer, A matching vblk was found
536 *          NULL,    No match, or an error
537 */
538static struct vblk * ldm_get_disk_objid (const struct ldmdb *ldb)
539{
540	struct list_head *item;
541
542	BUG_ON (!ldb);
543
544	list_for_each (item, &ldb->v_disk) {
545		struct vblk *v = list_entry (item, struct vblk, list);
546		if (uuid_equal(&v->vblk.disk.disk_id, &ldb->ph.disk_id))
547			return v;
548	}
549
550	return NULL;
551}
552
553/**
554 * ldm_create_data_partitions - Create data partitions for this device
555 * @pp:   List of the partitions parsed so far
556 * @ldb:  Cache of the database structures
557 *
558 * The database contains ALL the partitions for ALL disk groups, so we need to
559 * filter out this specific disk. Using the disk's object id, we can find all
560 * the partitions in the database that belong to this disk.
561 *
562 * Add each partition in our database, to the parsed_partitions structure.
563 *
564 * N.B.  This function creates the partitions in the order it finds partition
565 *       objects in the linked list.
566 *
567 * Return:  'true'   Partition created
568 *          'false'  Error, probably a range checking problem
569 */
570static bool ldm_create_data_partitions (struct parsed_partitions *pp,
571					const struct ldmdb *ldb)
572{
573	struct list_head *item;
574	struct vblk *vb;
575	struct vblk *disk;
576	struct vblk_part *part;
577	int part_num = 1;
578
579	BUG_ON (!pp || !ldb);
580
581	disk = ldm_get_disk_objid (ldb);
582	if (!disk) {
583		ldm_crit ("Can't find the ID of this disk in the database.");
584		return false;
585	}
586
587	strlcat(pp->pp_buf, " [LDM]", PAGE_SIZE);
588
589	/* Create the data partitions */
590	list_for_each (item, &ldb->v_part) {
591		vb = list_entry (item, struct vblk, list);
592		part = &vb->vblk.part;
593
594		if (part->disk_id != disk->obj_id)
595			continue;
596
597		put_partition (pp, part_num, ldb->ph.logical_disk_start +
598				part->start, part->size);
599		part_num++;
600	}
601
602	strlcat(pp->pp_buf, "\n", PAGE_SIZE);
603	return true;
604}
605
606
607/**
608 * ldm_relative - Calculate the next relative offset
609 * @buffer:  Block of data being worked on
610 * @buflen:  Size of the block of data
611 * @base:    Size of the previous fixed width fields
612 * @offset:  Cumulative size of the previous variable-width fields
613 *
614 * Because many of the VBLK fields are variable-width, it's necessary
615 * to calculate each offset based on the previous one and the length
616 * of the field it pointed to.
617 *
618 * Return:  -1 Error, the calculated offset exceeded the size of the buffer
619 *           n OK, a range-checked offset into buffer
620 */
621static int ldm_relative(const u8 *buffer, int buflen, int base, int offset)
622{
623
624	base += offset;
625	if (!buffer || offset < 0 || base > buflen) {
626		if (!buffer)
627			ldm_error("!buffer");
628		if (offset < 0)
629			ldm_error("offset (%d) < 0", offset);
630		if (base > buflen)
631			ldm_error("base (%d) > buflen (%d)", base, buflen);
632		return -1;
633	}
634	if (base + buffer[base] >= buflen) {
635		ldm_error("base (%d) + buffer[base] (%d) >= buflen (%d)", base,
636				buffer[base], buflen);
637		return -1;
638	}
639	return buffer[base] + offset + 1;
640}
641
642/**
643 * ldm_get_vnum - Convert a variable-width, big endian number, into cpu order
644 * @block:  Pointer to the variable-width number to convert
645 *
646 * Large numbers in the LDM Database are often stored in a packed format.  Each
647 * number is prefixed by a one byte width marker.  All numbers in the database
648 * are stored in big-endian byte order.  This function reads one of these
649 * numbers and returns the result
650 *
651 * N.B.  This function DOES NOT perform any range checking, though the most
652 *       it will read is eight bytes.
653 *
654 * Return:  n A number
655 *          0 Zero, or an error occurred
656 */
657static u64 ldm_get_vnum (const u8 *block)
658{
659	u64 tmp = 0;
660	u8 length;
661
662	BUG_ON (!block);
663
664	length = *block++;
665
666	if (length && length <= 8)
667		while (length--)
668			tmp = (tmp << 8) | *block++;
669	else
670		ldm_error ("Illegal length %d.", length);
671
672	return tmp;
673}
674
675/**
676 * ldm_get_vstr - Read a length-prefixed string into a buffer
677 * @block:   Pointer to the length marker
678 * @buffer:  Location to copy string to
679 * @buflen:  Size of the output buffer
680 *
681 * Many of the strings in the LDM Database are not NULL terminated.  Instead
682 * they are prefixed by a one byte length marker.  This function copies one of
683 * these strings into a buffer.
684 *
685 * N.B.  This function DOES NOT perform any range checking on the input.
686 *       If the buffer is too small, the output will be truncated.
687 *
688 * Return:  0, Error and @buffer contents are undefined
689 *          n, String length in characters (excluding NULL)
690 *          buflen-1, String was truncated.
691 */
692static int ldm_get_vstr (const u8 *block, u8 *buffer, int buflen)
693{
694	int length;
695
696	BUG_ON (!block || !buffer);
697
698	length = block[0];
699	if (length >= buflen) {
700		ldm_error ("Truncating string %d -> %d.", length, buflen);
701		length = buflen - 1;
702	}
703	memcpy (buffer, block + 1, length);
704	buffer[length] = 0;
705	return length;
706}
707
708
709/**
710 * ldm_parse_cmp3 - Read a raw VBLK Component object into a vblk structure
711 * @buffer:  Block of data being worked on
712 * @buflen:  Size of the block of data
713 * @vb:      In-memory vblk in which to return information
714 *
715 * Read a raw VBLK Component object (version 3) into a vblk structure.
716 *
717 * Return:  'true'   @vb contains a Component VBLK
718 *          'false'  @vb contents are not defined
719 */
720static bool ldm_parse_cmp3 (const u8 *buffer, int buflen, struct vblk *vb)
721{
722	int r_objid, r_name, r_vstate, r_child, r_parent, r_stripe, r_cols, len;
723	struct vblk_comp *comp;
724
725	BUG_ON (!buffer || !vb);
726
727	r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
728	r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
729	r_vstate = ldm_relative (buffer, buflen, 0x18, r_name);
730	r_child  = ldm_relative (buffer, buflen, 0x1D, r_vstate);
731	r_parent = ldm_relative (buffer, buflen, 0x2D, r_child);
732
733	if (buffer[0x12] & VBLK_FLAG_COMP_STRIPE) {
734		r_stripe = ldm_relative (buffer, buflen, 0x2E, r_parent);
735		r_cols   = ldm_relative (buffer, buflen, 0x2E, r_stripe);
736		len = r_cols;
737	} else {
738		r_stripe = 0;
739		r_cols   = 0;
740		len = r_parent;
741	}
742	if (len < 0)
743		return false;
744
745	len += VBLK_SIZE_CMP3;
746	if (len != get_unaligned_be32(buffer + 0x14))
747		return false;
748
749	comp = &vb->vblk.comp;
750	ldm_get_vstr (buffer + 0x18 + r_name, comp->state,
751		sizeof (comp->state));
752	comp->type      = buffer[0x18 + r_vstate];
753	comp->children  = ldm_get_vnum (buffer + 0x1D + r_vstate);
754	comp->parent_id = ldm_get_vnum (buffer + 0x2D + r_child);
755	comp->chunksize = r_stripe ? ldm_get_vnum (buffer+r_parent+0x2E) : 0;
756
757	return true;
758}
759
760/**
761 * ldm_parse_dgr3 - Read a raw VBLK Disk Group object into a vblk structure
762 * @buffer:  Block of data being worked on
763 * @buflen:  Size of the block of data
764 * @vb:      In-memory vblk in which to return information
765 *
766 * Read a raw VBLK Disk Group object (version 3) into a vblk structure.
767 *
768 * Return:  'true'   @vb contains a Disk Group VBLK
769 *          'false'  @vb contents are not defined
770 */
771static int ldm_parse_dgr3 (const u8 *buffer, int buflen, struct vblk *vb)
772{
773	int r_objid, r_name, r_diskid, r_id1, r_id2, len;
774	struct vblk_dgrp *dgrp;
775
776	BUG_ON (!buffer || !vb);
777
778	r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
779	r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
780	r_diskid = ldm_relative (buffer, buflen, 0x18, r_name);
781
782	if (buffer[0x12] & VBLK_FLAG_DGR3_IDS) {
783		r_id1 = ldm_relative (buffer, buflen, 0x24, r_diskid);
784		r_id2 = ldm_relative (buffer, buflen, 0x24, r_id1);
785		len = r_id2;
786	} else {
787		r_id1 = 0;
788		r_id2 = 0;
789		len = r_diskid;
790	}
791	if (len < 0)
792		return false;
793
794	len += VBLK_SIZE_DGR3;
795	if (len != get_unaligned_be32(buffer + 0x14))
796		return false;
797
798	dgrp = &vb->vblk.dgrp;
799	ldm_get_vstr (buffer + 0x18 + r_name, dgrp->disk_id,
800		sizeof (dgrp->disk_id));
801	return true;
802}
803
804/**
805 * ldm_parse_dgr4 - Read a raw VBLK Disk Group object into a vblk structure
806 * @buffer:  Block of data being worked on
807 * @buflen:  Size of the block of data
808 * @vb:      In-memory vblk in which to return information
809 *
810 * Read a raw VBLK Disk Group object (version 4) into a vblk structure.
811 *
812 * Return:  'true'   @vb contains a Disk Group VBLK
813 *          'false'  @vb contents are not defined
814 */
815static bool ldm_parse_dgr4 (const u8 *buffer, int buflen, struct vblk *vb)
816{
817	char buf[64];
818	int r_objid, r_name, r_id1, r_id2, len;
819
820	BUG_ON (!buffer || !vb);
821
822	r_objid  = ldm_relative (buffer, buflen, 0x18, 0);
823	r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
824
825	if (buffer[0x12] & VBLK_FLAG_DGR4_IDS) {
826		r_id1 = ldm_relative (buffer, buflen, 0x44, r_name);
827		r_id2 = ldm_relative (buffer, buflen, 0x44, r_id1);
828		len = r_id2;
829	} else {
830		r_id1 = 0;
831		r_id2 = 0;
832		len = r_name;
833	}
834	if (len < 0)
835		return false;
836
837	len += VBLK_SIZE_DGR4;
838	if (len != get_unaligned_be32(buffer + 0x14))
839		return false;
840
841	ldm_get_vstr (buffer + 0x18 + r_objid, buf, sizeof (buf));
842	return true;
843}
844
845/**
846 * ldm_parse_dsk3 - Read a raw VBLK Disk object into a vblk structure
847 * @buffer:  Block of data being worked on
848 * @buflen:  Size of the block of data
849 * @vb:      In-memory vblk in which to return information
850 *
851 * Read a raw VBLK Disk object (version 3) into a vblk structure.
852 *
853 * Return:  'true'   @vb contains a Disk VBLK
854 *          'false'  @vb contents are not defined
855 */
856static bool ldm_parse_dsk3 (const u8 *buffer, int buflen, struct vblk *vb)
857{
858	int r_objid, r_name, r_diskid, r_altname, len;
859	struct vblk_disk *disk;
860
861	BUG_ON (!buffer || !vb);
862
863	r_objid   = ldm_relative (buffer, buflen, 0x18, 0);
864	r_name    = ldm_relative (buffer, buflen, 0x18, r_objid);
865	r_diskid  = ldm_relative (buffer, buflen, 0x18, r_name);
866	r_altname = ldm_relative (buffer, buflen, 0x18, r_diskid);
867	len = r_altname;
868	if (len < 0)
869		return false;
870
871	len += VBLK_SIZE_DSK3;
872	if (len != get_unaligned_be32(buffer + 0x14))
873		return false;
874
875	disk = &vb->vblk.disk;
876	ldm_get_vstr (buffer + 0x18 + r_diskid, disk->alt_name,
877		sizeof (disk->alt_name));
878	if (uuid_parse(buffer + 0x19 + r_name, &disk->disk_id))
879		return false;
880
881	return true;
882}
883
884/**
885 * ldm_parse_dsk4 - Read a raw VBLK Disk object into a vblk structure
886 * @buffer:  Block of data being worked on
887 * @buflen:  Size of the block of data
888 * @vb:      In-memory vblk in which to return information
889 *
890 * Read a raw VBLK Disk object (version 4) into a vblk structure.
891 *
892 * Return:  'true'   @vb contains a Disk VBLK
893 *          'false'  @vb contents are not defined
894 */
895static bool ldm_parse_dsk4 (const u8 *buffer, int buflen, struct vblk *vb)
896{
897	int r_objid, r_name, len;
898	struct vblk_disk *disk;
899
900	BUG_ON (!buffer || !vb);
901
902	r_objid = ldm_relative (buffer, buflen, 0x18, 0);
903	r_name  = ldm_relative (buffer, buflen, 0x18, r_objid);
904	len     = r_name;
905	if (len < 0)
906		return false;
907
908	len += VBLK_SIZE_DSK4;
909	if (len != get_unaligned_be32(buffer + 0x14))
910		return false;
911
912	disk = &vb->vblk.disk;
913	import_uuid(&disk->disk_id, buffer + 0x18 + r_name);
914	return true;
915}
916
917/**
918 * ldm_parse_prt3 - Read a raw VBLK Partition object into a vblk structure
919 * @buffer:  Block of data being worked on
920 * @buflen:  Size of the block of data
921 * @vb:      In-memory vblk in which to return information
922 *
923 * Read a raw VBLK Partition object (version 3) into a vblk structure.
924 *
925 * Return:  'true'   @vb contains a Partition VBLK
926 *          'false'  @vb contents are not defined
927 */
928static bool ldm_parse_prt3(const u8 *buffer, int buflen, struct vblk *vb)
929{
930	int r_objid, r_name, r_size, r_parent, r_diskid, r_index, len;
931	struct vblk_part *part;
932
933	BUG_ON(!buffer || !vb);
934	r_objid = ldm_relative(buffer, buflen, 0x18, 0);
935	if (r_objid < 0) {
936		ldm_error("r_objid %d < 0", r_objid);
937		return false;
938	}
939	r_name = ldm_relative(buffer, buflen, 0x18, r_objid);
940	if (r_name < 0) {
941		ldm_error("r_name %d < 0", r_name);
942		return false;
943	}
944	r_size = ldm_relative(buffer, buflen, 0x34, r_name);
945	if (r_size < 0) {
946		ldm_error("r_size %d < 0", r_size);
947		return false;
948	}
949	r_parent = ldm_relative(buffer, buflen, 0x34, r_size);
950	if (r_parent < 0) {
951		ldm_error("r_parent %d < 0", r_parent);
952		return false;
953	}
954	r_diskid = ldm_relative(buffer, buflen, 0x34, r_parent);
955	if (r_diskid < 0) {
956		ldm_error("r_diskid %d < 0", r_diskid);
957		return false;
958	}
959	if (buffer[0x12] & VBLK_FLAG_PART_INDEX) {
960		r_index = ldm_relative(buffer, buflen, 0x34, r_diskid);
961		if (r_index < 0) {
962			ldm_error("r_index %d < 0", r_index);
963			return false;
964		}
965		len = r_index;
966	} else {
967		r_index = 0;
968		len = r_diskid;
969	}
970	if (len < 0) {
971		ldm_error("len %d < 0", len);
972		return false;
973	}
974	len += VBLK_SIZE_PRT3;
975	if (len > get_unaligned_be32(buffer + 0x14)) {
976		ldm_error("len %d > BE32(buffer + 0x14) %d", len,
977				get_unaligned_be32(buffer + 0x14));
978		return false;
979	}
980	part = &vb->vblk.part;
981	part->start = get_unaligned_be64(buffer + 0x24 + r_name);
982	part->volume_offset = get_unaligned_be64(buffer + 0x2C + r_name);
983	part->size = ldm_get_vnum(buffer + 0x34 + r_name);
984	part->parent_id = ldm_get_vnum(buffer + 0x34 + r_size);
985	part->disk_id = ldm_get_vnum(buffer + 0x34 + r_parent);
986	if (vb->flags & VBLK_FLAG_PART_INDEX)
987		part->partnum = buffer[0x35 + r_diskid];
988	else
989		part->partnum = 0;
990	return true;
991}
992
993/**
994 * ldm_parse_vol5 - Read a raw VBLK Volume object into a vblk structure
995 * @buffer:  Block of data being worked on
996 * @buflen:  Size of the block of data
997 * @vb:      In-memory vblk in which to return information
998 *
999 * Read a raw VBLK Volume object (version 5) into a vblk structure.
1000 *
1001 * Return:  'true'   @vb contains a Volume VBLK
1002 *          'false'  @vb contents are not defined
1003 */
1004static bool ldm_parse_vol5(const u8 *buffer, int buflen, struct vblk *vb)
1005{
1006	int r_objid, r_name, r_vtype, r_disable_drive_letter, r_child, r_size;
1007	int r_id1, r_id2, r_size2, r_drive, len;
1008	struct vblk_volu *volu;
1009
1010	BUG_ON(!buffer || !vb);
1011	r_objid = ldm_relative(buffer, buflen, 0x18, 0);
1012	if (r_objid < 0) {
1013		ldm_error("r_objid %d < 0", r_objid);
1014		return false;
1015	}
1016	r_name = ldm_relative(buffer, buflen, 0x18, r_objid);
1017	if (r_name < 0) {
1018		ldm_error("r_name %d < 0", r_name);
1019		return false;
1020	}
1021	r_vtype = ldm_relative(buffer, buflen, 0x18, r_name);
1022	if (r_vtype < 0) {
1023		ldm_error("r_vtype %d < 0", r_vtype);
1024		return false;
1025	}
1026	r_disable_drive_letter = ldm_relative(buffer, buflen, 0x18, r_vtype);
1027	if (r_disable_drive_letter < 0) {
1028		ldm_error("r_disable_drive_letter %d < 0",
1029				r_disable_drive_letter);
1030		return false;
1031	}
1032	r_child = ldm_relative(buffer, buflen, 0x2D, r_disable_drive_letter);
1033	if (r_child < 0) {
1034		ldm_error("r_child %d < 0", r_child);
1035		return false;
1036	}
1037	r_size = ldm_relative(buffer, buflen, 0x3D, r_child);
1038	if (r_size < 0) {
1039		ldm_error("r_size %d < 0", r_size);
1040		return false;
1041	}
1042	if (buffer[0x12] & VBLK_FLAG_VOLU_ID1) {
1043		r_id1 = ldm_relative(buffer, buflen, 0x52, r_size);
1044		if (r_id1 < 0) {
1045			ldm_error("r_id1 %d < 0", r_id1);
1046			return false;
1047		}
1048	} else
1049		r_id1 = r_size;
1050	if (buffer[0x12] & VBLK_FLAG_VOLU_ID2) {
1051		r_id2 = ldm_relative(buffer, buflen, 0x52, r_id1);
1052		if (r_id2 < 0) {
1053			ldm_error("r_id2 %d < 0", r_id2);
1054			return false;
1055		}
1056	} else
1057		r_id2 = r_id1;
1058	if (buffer[0x12] & VBLK_FLAG_VOLU_SIZE) {
1059		r_size2 = ldm_relative(buffer, buflen, 0x52, r_id2);
1060		if (r_size2 < 0) {
1061			ldm_error("r_size2 %d < 0", r_size2);
1062			return false;
1063		}
1064	} else
1065		r_size2 = r_id2;
1066	if (buffer[0x12] & VBLK_FLAG_VOLU_DRIVE) {
1067		r_drive = ldm_relative(buffer, buflen, 0x52, r_size2);
1068		if (r_drive < 0) {
1069			ldm_error("r_drive %d < 0", r_drive);
1070			return false;
1071		}
1072	} else
1073		r_drive = r_size2;
1074	len = r_drive;
1075	if (len < 0) {
1076		ldm_error("len %d < 0", len);
1077		return false;
1078	}
1079	len += VBLK_SIZE_VOL5;
1080	if (len > get_unaligned_be32(buffer + 0x14)) {
1081		ldm_error("len %d > BE32(buffer + 0x14) %d", len,
1082				get_unaligned_be32(buffer + 0x14));
1083		return false;
1084	}
1085	volu = &vb->vblk.volu;
1086	ldm_get_vstr(buffer + 0x18 + r_name, volu->volume_type,
1087			sizeof(volu->volume_type));
1088	memcpy(volu->volume_state, buffer + 0x18 + r_disable_drive_letter,
1089			sizeof(volu->volume_state));
1090	volu->size = ldm_get_vnum(buffer + 0x3D + r_child);
1091	volu->partition_type = buffer[0x41 + r_size];
1092	memcpy(volu->guid, buffer + 0x42 + r_size, sizeof(volu->guid));
1093	if (buffer[0x12] & VBLK_FLAG_VOLU_DRIVE) {
1094		ldm_get_vstr(buffer + 0x52 + r_size, volu->drive_hint,
1095				sizeof(volu->drive_hint));
1096	}
1097	return true;
1098}
1099
1100/**
1101 * ldm_parse_vblk - Read a raw VBLK object into a vblk structure
1102 * @buf:  Block of data being worked on
1103 * @len:  Size of the block of data
1104 * @vb:   In-memory vblk in which to return information
1105 *
1106 * Read a raw VBLK object into a vblk structure.  This function just reads the
1107 * information common to all VBLK types, then delegates the rest of the work to
1108 * helper functions: ldm_parse_*.
1109 *
1110 * Return:  'true'   @vb contains a VBLK
1111 *          'false'  @vb contents are not defined
1112 */
1113static bool ldm_parse_vblk (const u8 *buf, int len, struct vblk *vb)
1114{
1115	bool result = false;
1116	int r_objid;
1117
1118	BUG_ON (!buf || !vb);
1119
1120	r_objid = ldm_relative (buf, len, 0x18, 0);
1121	if (r_objid < 0) {
1122		ldm_error ("VBLK header is corrupt.");
1123		return false;
1124	}
1125
1126	vb->flags  = buf[0x12];
1127	vb->type   = buf[0x13];
1128	vb->obj_id = ldm_get_vnum (buf + 0x18);
1129	ldm_get_vstr (buf+0x18+r_objid, vb->name, sizeof (vb->name));
1130
1131	switch (vb->type) {
1132		case VBLK_CMP3:  result = ldm_parse_cmp3 (buf, len, vb); break;
1133		case VBLK_DSK3:  result = ldm_parse_dsk3 (buf, len, vb); break;
1134		case VBLK_DSK4:  result = ldm_parse_dsk4 (buf, len, vb); break;
1135		case VBLK_DGR3:  result = ldm_parse_dgr3 (buf, len, vb); break;
1136		case VBLK_DGR4:  result = ldm_parse_dgr4 (buf, len, vb); break;
1137		case VBLK_PRT3:  result = ldm_parse_prt3 (buf, len, vb); break;
1138		case VBLK_VOL5:  result = ldm_parse_vol5 (buf, len, vb); break;
1139	}
1140
1141	if (result)
1142		ldm_debug ("Parsed VBLK 0x%llx (type: 0x%02x) ok.",
1143			 (unsigned long long) vb->obj_id, vb->type);
1144	else
1145		ldm_error ("Failed to parse VBLK 0x%llx (type: 0x%02x).",
1146			(unsigned long long) vb->obj_id, vb->type);
1147
1148	return result;
1149}
1150
1151
1152/**
1153 * ldm_ldmdb_add - Adds a raw VBLK entry to the ldmdb database
1154 * @data:  Raw VBLK to add to the database
1155 * @len:   Size of the raw VBLK
1156 * @ldb:   Cache of the database structures
1157 *
1158 * The VBLKs are sorted into categories.  Partitions are also sorted by offset.
1159 *
1160 * N.B.  This function does not check the validity of the VBLKs.
1161 *
1162 * Return:  'true'   The VBLK was added
1163 *          'false'  An error occurred
1164 */
1165static bool ldm_ldmdb_add (u8 *data, int len, struct ldmdb *ldb)
1166{
1167	struct vblk *vb;
1168	struct list_head *item;
1169
1170	BUG_ON (!data || !ldb);
1171
1172	vb = kmalloc (sizeof (*vb), GFP_KERNEL);
1173	if (!vb) {
1174		ldm_crit ("Out of memory.");
1175		return false;
1176	}
1177
1178	if (!ldm_parse_vblk (data, len, vb)) {
1179		kfree(vb);
1180		return false;			/* Already logged */
1181	}
1182
1183	/* Put vblk into the correct list. */
1184	switch (vb->type) {
1185	case VBLK_DGR3:
1186	case VBLK_DGR4:
1187		list_add (&vb->list, &ldb->v_dgrp);
1188		break;
1189	case VBLK_DSK3:
1190	case VBLK_DSK4:
1191		list_add (&vb->list, &ldb->v_disk);
1192		break;
1193	case VBLK_VOL5:
1194		list_add (&vb->list, &ldb->v_volu);
1195		break;
1196	case VBLK_CMP3:
1197		list_add (&vb->list, &ldb->v_comp);
1198		break;
1199	case VBLK_PRT3:
1200		/* Sort by the partition's start sector. */
1201		list_for_each (item, &ldb->v_part) {
1202			struct vblk *v = list_entry (item, struct vblk, list);
1203			if ((v->vblk.part.disk_id == vb->vblk.part.disk_id) &&
1204			    (v->vblk.part.start > vb->vblk.part.start)) {
1205				list_add_tail (&vb->list, &v->list);
1206				return true;
1207			}
1208		}
1209		list_add_tail (&vb->list, &ldb->v_part);
1210		break;
1211	}
1212	return true;
1213}
1214
1215/**
1216 * ldm_frag_add - Add a VBLK fragment to a list
1217 * @data:   Raw fragment to be added to the list
1218 * @size:   Size of the raw fragment
1219 * @frags:  Linked list of VBLK fragments
1220 *
1221 * Fragmented VBLKs may not be consecutive in the database, so they are placed
1222 * in a list so they can be pieced together later.
1223 *
1224 * Return:  'true'   Success, the VBLK was added to the list
1225 *          'false'  Error, a problem occurred
1226 */
1227static bool ldm_frag_add (const u8 *data, int size, struct list_head *frags)
1228{
1229	struct frag *f;
1230	struct list_head *item;
1231	int rec, num, group;
1232
1233	BUG_ON (!data || !frags);
1234
1235	if (size < 2 * VBLK_SIZE_HEAD) {
1236		ldm_error("Value of size is too small.");
1237		return false;
1238	}
1239
1240	group = get_unaligned_be32(data + 0x08);
1241	rec   = get_unaligned_be16(data + 0x0C);
1242	num   = get_unaligned_be16(data + 0x0E);
1243	if ((num < 1) || (num > 4)) {
1244		ldm_error ("A VBLK claims to have %d parts.", num);
1245		return false;
1246	}
1247	if (rec >= num) {
1248		ldm_error("REC value (%d) exceeds NUM value (%d)", rec, num);
1249		return false;
1250	}
1251
1252	list_for_each (item, frags) {
1253		f = list_entry (item, struct frag, list);
1254		if (f->group == group)
1255			goto found;
1256	}
1257
1258	f = kmalloc (sizeof (*f) + size*num, GFP_KERNEL);
1259	if (!f) {
1260		ldm_crit ("Out of memory.");
1261		return false;
1262	}
1263
1264	f->group = group;
1265	f->num   = num;
1266	f->rec   = rec;
1267	f->map   = 0xFF << num;
1268
1269	list_add_tail (&f->list, frags);
1270found:
1271	if (rec >= f->num) {
1272		ldm_error("REC value (%d) exceeds NUM value (%d)", rec, f->num);
1273		return false;
1274	}
1275	if (f->map & (1 << rec)) {
1276		ldm_error ("Duplicate VBLK, part %d.", rec);
1277		f->map &= 0x7F;			/* Mark the group as broken */
1278		return false;
1279	}
1280	f->map |= (1 << rec);
1281	if (!rec)
1282		memcpy(f->data, data, VBLK_SIZE_HEAD);
1283	data += VBLK_SIZE_HEAD;
1284	size -= VBLK_SIZE_HEAD;
1285	memcpy(f->data + VBLK_SIZE_HEAD + rec * size, data, size);
1286	return true;
1287}
1288
1289/**
1290 * ldm_frag_free - Free a linked list of VBLK fragments
1291 * @list:  Linked list of fragments
1292 *
1293 * Free a linked list of VBLK fragments
1294 *
1295 * Return:  none
1296 */
1297static void ldm_frag_free (struct list_head *list)
1298{
1299	struct list_head *item, *tmp;
1300
1301	BUG_ON (!list);
1302
1303	list_for_each_safe (item, tmp, list)
1304		kfree (list_entry (item, struct frag, list));
1305}
1306
1307/**
1308 * ldm_frag_commit - Validate fragmented VBLKs and add them to the database
1309 * @frags:  Linked list of VBLK fragments
1310 * @ldb:    Cache of the database structures
1311 *
1312 * Now that all the fragmented VBLKs have been collected, they must be added to
1313 * the database for later use.
1314 *
1315 * Return:  'true'   All the fragments we added successfully
1316 *          'false'  One or more of the fragments we invalid
1317 */
1318static bool ldm_frag_commit (struct list_head *frags, struct ldmdb *ldb)
1319{
1320	struct frag *f;
1321	struct list_head *item;
1322
1323	BUG_ON (!frags || !ldb);
1324
1325	list_for_each (item, frags) {
1326		f = list_entry (item, struct frag, list);
1327
1328		if (f->map != 0xFF) {
1329			ldm_error ("VBLK group %d is incomplete (0x%02x).",
1330				f->group, f->map);
1331			return false;
1332		}
1333
1334		if (!ldm_ldmdb_add (f->data, f->num*ldb->vm.vblk_size, ldb))
1335			return false;		/* Already logged */
1336	}
1337	return true;
1338}
1339
1340/**
1341 * ldm_get_vblks - Read the on-disk database of VBLKs into memory
1342 * @state: Partition check state including device holding the LDM Database
1343 * @base:  Offset, into @state->bdev, of the database
1344 * @ldb:   Cache of the database structures
1345 *
1346 * To use the information from the VBLKs, they need to be read from the disk,
1347 * unpacked and validated.  We cache them in @ldb according to their type.
1348 *
1349 * Return:  'true'   All the VBLKs were read successfully
1350 *          'false'  An error occurred
1351 */
1352static bool ldm_get_vblks(struct parsed_partitions *state, unsigned long base,
1353			  struct ldmdb *ldb)
1354{
1355	int size, perbuf, skip, finish, s, v, recs;
1356	u8 *data = NULL;
1357	Sector sect;
1358	bool result = false;
1359	LIST_HEAD (frags);
1360
1361	BUG_ON(!state || !ldb);
1362
1363	size   = ldb->vm.vblk_size;
1364	perbuf = 512 / size;
1365	skip   = ldb->vm.vblk_offset >> 9;		/* Bytes to sectors */
1366	finish = (size * ldb->vm.last_vblk_seq) >> 9;
1367
1368	for (s = skip; s < finish; s++) {		/* For each sector */
1369		data = read_part_sector(state, base + OFF_VMDB + s, &sect);
1370		if (!data) {
1371			ldm_crit ("Disk read failed.");
1372			goto out;
1373		}
1374
1375		for (v = 0; v < perbuf; v++, data+=size) {  /* For each vblk */
1376			if (MAGIC_VBLK != get_unaligned_be32(data)) {
1377				ldm_error ("Expected to find a VBLK.");
1378				goto out;
1379			}
1380
1381			recs = get_unaligned_be16(data + 0x0E);	/* Number of records */
1382			if (recs == 1) {
1383				if (!ldm_ldmdb_add (data, size, ldb))
1384					goto out;	/* Already logged */
1385			} else if (recs > 1) {
1386				if (!ldm_frag_add (data, size, &frags))
1387					goto out;	/* Already logged */
1388			}
1389			/* else Record is not in use, ignore it. */
1390		}
1391		put_dev_sector (sect);
1392		data = NULL;
1393	}
1394
1395	result = ldm_frag_commit (&frags, ldb);	/* Failures, already logged */
1396out:
1397	if (data)
1398		put_dev_sector (sect);
1399	ldm_frag_free (&frags);
1400
1401	return result;
1402}
1403
1404/**
1405 * ldm_free_vblks - Free a linked list of vblk's
1406 * @lh:  Head of a linked list of struct vblk
1407 *
1408 * Free a list of vblk's and free the memory used to maintain the list.
1409 *
1410 * Return:  none
1411 */
1412static void ldm_free_vblks (struct list_head *lh)
1413{
1414	struct list_head *item, *tmp;
1415
1416	BUG_ON (!lh);
1417
1418	list_for_each_safe (item, tmp, lh)
1419		kfree (list_entry (item, struct vblk, list));
1420}
1421
1422
1423/**
1424 * ldm_partition - Find out whether a device is a dynamic disk and handle it
1425 * @state: Partition check state including device holding the LDM Database
1426 *
1427 * This determines whether the device @bdev is a dynamic disk and if so creates
1428 * the partitions necessary in the gendisk structure pointed to by @hd.
1429 *
1430 * We create a dummy device 1, which contains the LDM database, and then create
1431 * each partition described by the LDM database in sequence as devices 2+. For
1432 * example, if the device is hda, we would have: hda1: LDM database, hda2, hda3,
1433 * and so on: the actual data containing partitions.
1434 *
1435 * Return:  1 Success, @state->bdev is a dynamic disk and we handled it
1436 *          0 Success, @state->bdev is not a dynamic disk
1437 *         -1 An error occurred before enough information had been read
1438 *            Or @state->bdev is a dynamic disk, but it may be corrupted
1439 */
1440int ldm_partition(struct parsed_partitions *state)
1441{
1442	struct ldmdb  *ldb;
1443	unsigned long base;
1444	int result = -1;
1445
1446	BUG_ON(!state);
1447
1448	/* Look for signs of a Dynamic Disk */
1449	if (!ldm_validate_partition_table(state))
1450		return 0;
1451
1452	ldb = kmalloc (sizeof (*ldb), GFP_KERNEL);
1453	if (!ldb) {
1454		ldm_crit ("Out of memory.");
1455		goto out;
1456	}
1457
1458	/* Parse and check privheads. */
1459	if (!ldm_validate_privheads(state, &ldb->ph))
1460		goto out;		/* Already logged */
1461
1462	/* All further references are relative to base (database start). */
1463	base = ldb->ph.config_start;
1464
1465	/* Parse and check tocs and vmdb. */
1466	if (!ldm_validate_tocblocks(state, base, ldb) ||
1467	    !ldm_validate_vmdb(state, base, ldb))
1468	    	goto out;		/* Already logged */
1469
1470	/* Initialize vblk lists in ldmdb struct */
1471	INIT_LIST_HEAD (&ldb->v_dgrp);
1472	INIT_LIST_HEAD (&ldb->v_disk);
1473	INIT_LIST_HEAD (&ldb->v_volu);
1474	INIT_LIST_HEAD (&ldb->v_comp);
1475	INIT_LIST_HEAD (&ldb->v_part);
1476
1477	if (!ldm_get_vblks(state, base, ldb)) {
1478		ldm_crit ("Failed to read the VBLKs from the database.");
1479		goto cleanup;
1480	}
1481
1482	/* Finally, create the data partition devices. */
1483	if (ldm_create_data_partitions(state, ldb)) {
1484		ldm_debug ("Parsed LDM database successfully.");
1485		result = 1;
1486	}
1487	/* else Already logged */
1488
1489cleanup:
1490	ldm_free_vblks (&ldb->v_dgrp);
1491	ldm_free_vblks (&ldb->v_disk);
1492	ldm_free_vblks (&ldb->v_volu);
1493	ldm_free_vblks (&ldb->v_comp);
1494	ldm_free_vblks (&ldb->v_part);
1495out:
1496	kfree (ldb);
1497	return result;
1498}
1499