/**
   * ldm - Support for Windows Logical Disk Manager (Dynamic Disks)
   *
   * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>

   * Copyright (c) 2001-2012 Anton Altaparmakov

   * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
   *

   * Documentation is available at http://www.linux-ntfs.org/doku.php?id=downloads 

   *
   * 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 <linux/kernel.h>

  #include <linux/uuid.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, __func__, f, ##a)

  #endif

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

  static __printf(3, 4)
  void _ldm_printk(const char *level, const char *function, const char *fmt, ...)

  {

  	struct va_format vaf;

  	va_list args;
  
  	va_start (args, fmt);

  	vaf.fmt = fmt;
  	vaf.va = &args;
  
  	printk("%s%s(): %pV
  ", level, function, &vaf);
  
  	va_end(args);

  }

  /**

   * 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 != get_unaligned_be64(data)) {

  		ldm_error("Cannot find PRIVHEAD structure. LDM database is"

  			" corrupt. Aborting.");

  		return false;

  	}

  	ph->ver_major = get_unaligned_be16(data + 0x000C);
  	ph->ver_minor = get_unaligned_be16(data + 0x000E);
  	ph->logical_disk_start = get_unaligned_be64(data + 0x011B);
  	ph->logical_disk_size = get_unaligned_be64(data + 0x0123);
  	ph->config_start = get_unaligned_be64(data + 0x012B);
  	ph->config_size = get_unaligned_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,

  			(unsigned 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 (uuid_be_to_bin(data + 0x0030, (uuid_be *)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 != get_unaligned_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 = get_unaligned_be64(data + 0x2E);
  	toc->bitmap1_size  = get_unaligned_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 = get_unaligned_be64(data + 0x50);
  	toc->bitmap2_size  = get_unaligned_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 != get_unaligned_be32(data)) {

  		ldm_crit ("Cannot find the VMDB, database may be corrupt.");

  		return false;

  	}

  	vm->ver_major = get_unaligned_be16(data + 0x12);
  	vm->ver_minor = get_unaligned_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     = get_unaligned_be32(data + 0x08);

  	if (vm->vblk_size == 0) {
  		ldm_error ("Illegal VBLK size");
  		return false;
  	}

  	vm->vblk_offset   = get_unaligned_be32(data + 0x0C);
  	vm->last_vblk_seq = get_unaligned_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

   * @state: Partition check state including 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 parsed_partitions *state,
  				   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 (!state || !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_part_sector(state, 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 = state->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

   * @state: Partition check state including device holding the LDM Database
   * @base:  Offset, into @state->bdev, of the database

   * @ldb:   Cache of the database structures
   *
   * Find and compare the four tables of contents of the LDM Database stored on

   * @state->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 parsed_partitions *state,
  				   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(!state || !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_part_sector(state, 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

   * @state: Partition check state including 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 parsed_partitions *state,
  			      unsigned long base, struct ldmdb *ldb)

  {
  	Sector sect;
  	u8 *data;

  	bool result = false;

  	struct vmdb *vm;
  	struct tocblock *toc;

  	BUG_ON (!state || !ldb);

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

  	data = read_part_sector(state, 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 (get_unaligned_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

   * @state: Partition check state including 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_part_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'   @state->bdev is a dynamic disk
   *          'false'  @state->bdev is not a dynamic disk, or an error occurred

   */

  static bool ldm_validate_partition_table(struct parsed_partitions *state)

  {
  	Sector sect;
  	u8 *data;
  	struct partition *p;
  	int i;

  	bool result = false;

  	BUG_ON(!state);

  	data = read_part_sector(state, 0, &sect);

  	if (!data) {

  		ldm_info ("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;

  	}

  	strlcat(pp->pp_buf, " [LDM]", PAGE_SIZE);

  
  	/* 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++;
  	}

  	strlcat(pp->pp_buf, "
  ", PAGE_SIZE);

  	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) {
  		if (!buffer)
  			ldm_error("!buffer");
  		if (offset < 0)
  			ldm_error("offset (%d) < 0", offset);
  		if (base > buflen)
  			ldm_error("base (%d) > buflen (%d)", base, buflen);

  		return -1;

  	}
  	if (base + buffer[base] >= buflen) {
  		ldm_error("base (%d) + buffer[base] (%d) >= buflen (%d)", 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 != get_unaligned_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 != get_unaligned_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 != get_unaligned_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 != get_unaligned_be32(buffer + 0x14))

  		return false;

  
  	disk = &vb->vblk.disk;
  	ldm_get_vstr (buffer + 0x18 + r_diskid, disk->alt_name,
  		sizeof (disk->alt_name));

  	if (uuid_be_to_bin(buffer + 0x19 + r_name, (uuid_be *)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 != get_unaligned_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 > get_unaligned_be32(buffer + 0x14)) {

  		ldm_error("len %d > BE32(buffer + 0x14) %d", len,

  				get_unaligned_be32(buffer + 0x14));

  		return false;

  	}

  	part = &vb->vblk.part;

  	part->start = get_unaligned_be64(buffer + 0x24 + r_name);
  	part->volume_offset = get_unaligned_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_disable_drive_letter, r_child, r_size;
  	int r_id1, r_id2, r_size2, r_drive, len;

  	struct vblk_volu *volu;

  	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_vtype = ldm_relative(buffer, buflen, 0x18, r_name);
  	if (r_vtype < 0) {
  		ldm_error("r_vtype %d < 0", r_vtype);
  		return false;
  	}
  	r_disable_drive_letter = ldm_relative(buffer, buflen, 0x18, r_vtype);
  	if (r_disable_drive_letter < 0) {
  		ldm_error("r_disable_drive_letter %d < 0",
  				r_disable_drive_letter);
  		return false;
  	}
  	r_child = ldm_relative(buffer, buflen, 0x2D, r_disable_drive_letter);
  	if (r_child < 0) {
  		ldm_error("r_child %d < 0", r_child);
  		return false;
  	}
  	r_size = ldm_relative(buffer, buflen, 0x3D, r_child);
  	if (r_size < 0) {
  		ldm_error("r_size %d < 0", r_size);
  		return false;
  	}
  	if (buffer[0x12] & VBLK_FLAG_VOLU_ID1) {
  		r_id1 = ldm_relative(buffer, buflen, 0x52, r_size);
  		if (r_id1 < 0) {
  			ldm_error("r_id1 %d < 0", r_id1);
  			return false;
  		}
  	} else

  		r_id1 = r_size;

  	if (buffer[0x12] & VBLK_FLAG_VOLU_ID2) {
  		r_id2 = ldm_relative(buffer, buflen, 0x52, r_id1);
  		if (r_id2 < 0) {
  			ldm_error("r_id2 %d < 0", r_id2);
  			return false;
  		}
  	} else

  		r_id2 = r_id1;

  	if (buffer[0x12] & VBLK_FLAG_VOLU_SIZE) {
  		r_size2 = ldm_relative(buffer, buflen, 0x52, r_id2);
  		if (r_size2 < 0) {
  			ldm_error("r_size2 %d < 0", r_size2);
  			return false;
  		}
  	} else

  		r_size2 = r_id2;

  	if (buffer[0x12] & VBLK_FLAG_VOLU_DRIVE) {
  		r_drive = ldm_relative(buffer, buflen, 0x52, r_size2);
  		if (r_drive < 0) {
  			ldm_error("r_drive %d < 0", r_drive);
  			return false;
  		}
  	} else

  		r_drive = r_size2;

  	len = r_drive;

  	if (len < 0) {
  		ldm_error("len %d < 0", len);

  		return false;

  	}

  	len += VBLK_SIZE_VOL5;

  	if (len > get_unaligned_be32(buffer + 0x14)) {

  		ldm_error("len %d > BE32(buffer + 0x14) %d", len,

  				get_unaligned_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 + 0x18 + r_disable_drive_letter,
  			sizeof(volu->volume_state));
  	volu->size = ldm_get_vnum(buffer + 0x3D + r_child);
  	volu->partition_type = buffer[0x41 + r_size];
  	memcpy(volu->guid, buffer + 0x42 + r_size, sizeof(volu->guid));

  	if (buffer[0x12] & VBLK_FLAG_VOLU_DRIVE) {

  		ldm_get_vstr(buffer + 0x52 + 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);

  	if (size < 2 * VBLK_SIZE_HEAD) {
  		ldm_error("Value of size is to small.");
  		return false;
  	}

  	group = get_unaligned_be32(data + 0x08);
  	rec   = get_unaligned_be16(data + 0x0C);
  	num   = get_unaligned_be16(data + 0x0E);

  	if ((num < 1) || (num > 4)) {
  		ldm_error ("A VBLK claims to have %d parts.", num);

  		return false;

  	}

  	if (rec >= num) {
  		ldm_error("REC value (%d) exceeds NUM value (%d)", rec, 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 (rec >= f->num) {
  		ldm_error("REC value (%d) exceeds NUM value (%d)", rec, f->num);
  		return false;
  	}

  	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 (!rec)
  		memcpy(f->data, data, VBLK_SIZE_HEAD);

  	data += VBLK_SIZE_HEAD;
  	size -= VBLK_SIZE_HEAD;

  	memcpy(f->data + VBLK_SIZE_HEAD + rec * size, 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

   * @state: Partition check state including device holding the LDM Database
   * @base:  Offset, into @state->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 parsed_partitions *state, 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(!state || !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_part_sector(state, 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 != get_unaligned_be32(data)) {

  				ldm_error ("Expected to find a VBLK.");
  				goto out;
  			}

  			recs = get_unaligned_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

   * @state: Partition check state including 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, @state->bdev is a dynamic disk and we handled it
   *          0 Success, @state->bdev is not a dynamic disk

   *         -1 An error occurred before enough information had been read

   *            Or @state->bdev is a dynamic disk, but it may be corrupted

   */

  int ldm_partition(struct parsed_partitions *state)

  {
  	struct ldmdb  *ldb;
  	unsigned long base;
  	int result = -1;

  	BUG_ON(!state);

  
  	/* Look for signs of a Dynamic Disk */

  	if (!ldm_validate_partition_table(state))

  		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(state, &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(state, base, ldb) ||
  	    !ldm_validate_vmdb(state, 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(state, 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(state, 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;
  }