LDM: Fix for Windows Vista dynamic disks

This fixes the LDM driver so that it works with Windows Vista dynamic
disks which are subtly different to Windows 2000/XP ones.

The patch was needed to get a Vista formatted dynamic disk to be
recognized and parsed successfully.

Thanks go to Chris Teachworth for the report and testing.

Cc: Richard Russon <ldm@flatcap.org>
Signed-off-by: Anton Altaparmakov <aia21@cantab.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 127 insertions, 97 deletions

diff --git a/fs/partitions/Kconfig b/fs/partitions/Kconfig
index 7638a1c42a7d..a99acd8de353 100644
--- a/fs/partitions/Kconfig
+++ b/fs/partitions/Kconfig
@@ -166,8 +166,12 @@ config LDM_PARTITION
 	depends on PARTITION_ADVANCED
 	---help---
 	  Say Y here if you would like to use hard disks under Linux which
-	  were partitioned using Windows 2000's or XP's Logical Disk Manager.
-	  They are also known as "Dynamic Disks".
+	  were partitioned using Windows 2000's/XP's or Vista's Logical Disk
+	  Manager.  They are also known as "Dynamic Disks".
+
+	  Note this driver only supports Dynamic Disks with a protective MBR
+	  label, i.e. DOS partition table.  It does not support GPT labelled
+	  Dynamic Disks yet as can be created with Vista.
 
 	  Windows 2000 introduced the concept of Dynamic Disks to get around
 	  the limitations of the PC's partitioning scheme.  The Logical Disk
@@ -175,8 +179,8 @@ config LDM_PARTITION
 	  mirrored, striped or RAID volumes, all without the need for
 	  rebooting.
 
-	  Normal partitions are now called Basic Disks under Windows 2000 and
-	  XP.
+	  Normal partitions are now called Basic Disks under Windows 2000, XP,
+	  and Vista.
 
 	  For a fuller description read <file:Documentation/ldm.txt>.
 
diff --git a/fs/partitions/ldm.c b/fs/partitions/ldm.c
index 1a60926a4ccd..c387812537d7 100644
--- a/fs/partitions/ldm.c
+++ b/fs/partitions/ldm.c
@@ -2,10 +2,10 @@
  * ldm - Support for Windows Logical Disk Manager (Dynamic Disks)
  *
  * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
- * Copyright (c) 2001-2004 Anton Altaparmakov
+ * Copyright (c) 2001-2007 Anton Altaparmakov
  * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
  *
- * Documentation is available at http://linux-ntfs.sf.net/ldm
+ * Documentation is available at http://www.linux-ntfs.org/content/view/19/37/
  *
  * This program is free software; you can redistribute it and/or modify it under
  * the terms of the GNU General Public License as published by the Free Software
@@ -62,7 +62,6 @@ static void _ldm_printk (const char *level, const char *function,
 	printk ("%s%s(): %s\n", level, function, buf);
 }
 
-
 /**
  * ldm_parse_hexbyte - Convert a ASCII hex number to a byte
  * @src:  Pointer to at least 2 characters to convert.
@@ -118,7 +117,6 @@ static bool ldm_parse_guid (const u8 *src, u8 *dest)
 	return true;
 }
 
-
 /**
  * ldm_parse_privhead - Read the LDM Database PRIVHEAD structure
  * @data:  Raw database PRIVHEAD structure loaded from the device
@@ -130,46 +128,48 @@ static bool ldm_parse_guid (const u8 *src, u8 *dest)
  * Return:  'true'   @ph contains the PRIVHEAD data
  *          'false'  @ph contents are undefined
  */
-static bool ldm_parse_privhead (const u8 *data, struct privhead *ph)
+static bool ldm_parse_privhead(const u8 *data, struct privhead *ph)
 {
-	BUG_ON (!data || !ph);
+	bool is_vista = false;
 
-	if (MAGIC_PRIVHEAD != BE64 (data)) {
-		ldm_error ("Cannot find PRIVHEAD structure. LDM database is"
+	BUG_ON(!data || !ph);
+	if (MAGIC_PRIVHEAD != BE64(data)) {
+		ldm_error("Cannot find PRIVHEAD structure. LDM database is"
 			" corrupt. Aborting.");
 		return false;
 	}
-
-	ph->ver_major          = BE16 (data + 0x000C);
-	ph->ver_minor          = BE16 (data + 0x000E);
-	ph->logical_disk_start = BE64 (data + 0x011B);
-	ph->logical_disk_size  = BE64 (data + 0x0123);
-	ph->config_start       = BE64 (data + 0x012B);
-	ph->config_size        = BE64 (data + 0x0133);
-
-	if ((ph->ver_major != 2) || (ph->ver_minor != 11)) {
-		ldm_error ("Expected PRIVHEAD version %d.%d, got %d.%d."
-			" Aborting.", 2, 11, ph->ver_major, ph->ver_minor);
+	ph->ver_major = BE16(data + 0x000C);
+	ph->ver_minor = BE16(data + 0x000E);
+	ph->logical_disk_start = BE64(data + 0x011B);
+	ph->logical_disk_size = BE64(data + 0x0123);
+	ph->config_start = BE64(data + 0x012B);
+	ph->config_size = BE64(data + 0x0133);
+	/* Version 2.11 is Win2k/XP and version 2.12 is Vista. */
+	if (ph->ver_major == 2 && ph->ver_minor == 12)
+		is_vista = true;
+	if (!is_vista && (ph->ver_major != 2 || ph->ver_minor != 11)) {
+		ldm_error("Expected PRIVHEAD version 2.11 or 2.12, got %d.%d."
+			" Aborting.", ph->ver_major, ph->ver_minor);
 		return false;
 	}
+	ldm_debug("PRIVHEAD version %d.%d (Windows %s).", ph->ver_major,
+			ph->ver_minor, is_vista ? "Vista" : "2000/XP");
 	if (ph->config_size != LDM_DB_SIZE) {	/* 1 MiB in sectors. */
-		/* Warn the user and continue, carefully */
-		ldm_info ("Database is normally %u bytes, it claims to "
+		/* 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 );
+			udunsigned long long)ph->config_size);
 	}
-	if ((ph->logical_disk_size == 0) ||
-	    (ph->logical_disk_start + ph->logical_disk_size > ph->config_start)) {
-		ldm_error ("PRIVHEAD disk size doesn't match real disk size");
+	if ((ph->logical_disk_size == 0) || (ph->logical_disk_start +
+			ph->logical_disk_size > ph->config_start)) {
+		ldm_error("PRIVHEAD disk size doesn't match real disk size");
 		return false;
 	}
-
-	if (!ldm_parse_guid (data + 0x0030, ph->disk_id)) {
-		ldm_error ("PRIVHEAD contains an invalid GUID.");
+	if (!ldm_parse_guid(data + 0x0030, ph->disk_id)) {
+		ldm_error("PRIVHEAD contains an invalid GUID.");
 		return false;
 	}
-
-	ldm_debug ("Parsed PRIVHEAD successfully.");
+	ldm_debug("Parsed PRIVHEAD successfully.");
 	return true;
 }
 
@@ -409,7 +409,7 @@ out:
  * Return:  'true'   @toc1 contains validated TOCBLOCK info
  *          'false'  @toc1 contents are undefined
  */
-static bool ldm_validate_tocblocks (struct block_device *bdev,
+static bool ldm_validate_tocblocks(struct block_device *bdev,
 	unsigned long base, struct ldmdb *ldb)
 {
 	static const int off[4] = { OFF_TOCB1, OFF_TOCB2, OFF_TOCB3, OFF_TOCB4};
@@ -417,54 +417,57 @@ static bool ldm_validate_tocblocks (struct block_device *bdev,
 	struct privhead *ph;
 	Sector sect;
 	u8 *data;
+	int i, nr_tbs;
 	bool result = false;
-	int i;
 
-	BUG_ON (!bdev || !ldb);
-
-	ph    = &ldb->ph;
+	BUG_ON(!bdev || !ldb);
+	ph = &ldb->ph;
 	tb[0] = &ldb->toc;
-	tb[1] = kmalloc (sizeof (*tb[1]), GFP_KERNEL);
-	tb[2] = kmalloc (sizeof (*tb[2]), GFP_KERNEL);
-	tb[3] = kmalloc (sizeof (*tb[3]), GFP_KERNEL);
-	if (!tb[1] || !tb[2] || !tb[3]) {
-		ldm_crit ("Out of memory.");
-		goto out;
+	tb[1] = kmalloc(sizeof(*tb[1]) * 3, GFP_KERNEL);
+	if (!tb[1]) {
+		ldm_crit("Out of memory.");
+		goto err;
 	}
-
-	for (i = 0; i < 4; i++)		/* Read and parse all four toc's. */
-	{
-		data = read_dev_sector (bdev, base + off[i], &sect);
+	tb[2] = (struct tocblock*)((u8*)tb[1] + sizeof(*tb[1]));
+	tb[3] = (struct tocblock*)((u8*)tb[2] + sizeof(*tb[2]));
+	/*
+	 * Try to read and parse all four TOCBLOCKs.
+	 *
+	 * Windows Vista LDM v2.12 does not always have all four TOCBLOCKs so
+	 * skip any that fail as long as we get at least one valid TOCBLOCK.
+	 */
+	for (nr_tbs = i = 0; i < 4; i++) {
+		data = read_dev_sector(bdev, base + off[i], &sect);
 		if (!data) {
-			ldm_crit ("Disk read failed.");
-			goto out;
+			ldm_error("Disk read failed for TOCBLOCK %d.", i);
+			continue;
 		}
-		result = ldm_parse_tocblock (data, tb[i]);
-		put_dev_sector (sect);
-		if (!result)
-			goto out;	/* Already logged */
+		if (ldm_parse_tocblock(data, tb[nr_tbs]))
+			nr_tbs++;
+		put_dev_sector(sect);
 	}
-
-	/* Range check the toc against a privhead. */
+	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 out;
+			((tb[0]->bitmap2_start + tb[0]->bitmap2_size) >
+			ph->config_size)) {
+		ldm_crit("The bitmaps are out of range.  Giving up.");
+		goto err;
 	}
-
-	if (!ldm_compare_tocblocks (tb[0], tb[1]) ||	/* Compare all tocs. */
-	    !ldm_compare_tocblocks (tb[0], tb[2]) ||
-	    !ldm_compare_tocblocks (tb[0], tb[3])) {
-		ldm_crit ("The TOCBLOCKs don't match.");
-		goto out;
+	/* 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 TOCBLOCKs successfully.");
+	ldm_debug("Validated %d TOCBLOCKs successfully.", nr_tbs);
 	result = true;
-out:
-	kfree (tb[1]);
-	kfree (tb[2]);
-	kfree (tb[3]);
+err:
+	kfree(tb[1]);
 	return result;
 }
 
@@ -566,7 +569,7 @@ static bool ldm_validate_partition_table (struct block_device *bdev)
 
 	p = (struct partition*)(data + 0x01BE);
 	for (i = 0; i < 4; i++, p++)
-		if (SYS_IND (p) == WIN2K_DYNAMIC_PARTITION) {
+		if (SYS_IND (p) == LDM_PARTITION) {
 			result = true;
 			break;
 		}
@@ -975,44 +978,68 @@ static bool ldm_parse_dsk4 (const u8 *buffer, int buflen, struct vblk *vb)
  * 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)
+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);
-	r_name   = ldm_relative (buffer, buflen, 0x18, r_objid);
-	r_size   = ldm_relative (buffer, buflen, 0x34, r_name);
-	r_parent = ldm_relative (buffer, buflen, 0x34, r_size);
-	r_diskid = ldm_relative (buffer, buflen, 0x34, r_parent);
-
+	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);
+		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)
+	if (len < 0) {
+		ldm_error("len %d < 0", len);
 		return false;
-
+	}
 	len += VBLK_SIZE_PRT3;
-	if (len != BE32 (buffer + 0x14))
+	if (len > BE32(buffer + 0x14)) {
+		ldm_error("len %d > BE32(buffer + 0x14) %d", len,
+				BE32(buffer + 0x14));
 		return false;
-
+	}
 	part = &vb->vblk.part;
-	part->start         = BE64         (buffer + 0x24 + r_name);
-	part->volume_offset = BE64         (buffer + 0x2C + r_name);
-	part->size          = ldm_get_vnum (buffer + 0x34 + r_name);
-	part->parent_id     = ldm_get_vnum (buffer + 0x34 + r_size);
-	part->disk_id       = ldm_get_vnum (buffer + 0x34 + r_parent);
+	part->start = BE64(buffer + 0x24 + r_name);
+	part->volume_offset = BE64(buffer + 0x2C + r_name);
+	part->size = ldm_get_vnum(buffer + 0x34 + r_name);
+	part->parent_id = ldm_get_vnum(buffer + 0x34 + r_size);
+	part->disk_id = ldm_get_vnum(buffer + 0x34 + r_parent);
 	if (vb->flags & VBLK_FLAG_PART_INDEX)
 		part->partnum = buffer[0x35 + r_diskid];
 	else
 		part->partnum = 0;
-
 	return true;
 }
 
@@ -1475,4 +1502,3 @@ out:
 	kfree (ldb);
 	return result;
 }
-
diff --git a/fs/partitions/ldm.h b/fs/partitions/ldm.h
index 6e8d7952b8b5..d2e6a3046939 100644
--- a/fs/partitions/ldm.h
+++ b/fs/partitions/ldm.h
@@ -2,10 +2,10 @@
  * ldm - Part of the Linux-NTFS project.
  *
  * Copyright (C) 2001,2002 Richard Russon <ldm@flatcap.org>
- * Copyright (C) 2001      Anton Altaparmakov <aia21@cantab.net>
+ * Copyright (c) 2001-2007 Anton Altaparmakov
  * Copyright (C) 2001,2002 Jakob Kemi <jakob.kemi@telia.com>
  *
- * Documentation is available at http://linux-ntfs.sf.net/ldm
+ * Documentation is available at http://www.linux-ntfs.org/content/view/19/37/
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the Free
@@ -93,7 +93,7 @@ struct parsed_partitions;
 
 #define OFF_VMDB		17		/* List of partitions. */
 
-#define WIN2K_DYNAMIC_PARTITION	0x42		/* Formerly SFS (Landis). */
+#define LDM_PARTITION		0x42		/* Formerly SFS (Landis). */
 
 #define TOC_BITMAP1		"config"	/* Names of the two defined */
 #define TOC_BITMAP2		"log"		/* bitmaps in the TOCBLOCK. */