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>

5 files changed, 144 insertions, 107 deletions

diff --git a/Documentation/ldm.txt b/Documentation/ldm.txt
index e266e11c19a..718085bc9f1 100644
--- a/Documentation/ldm.txt
+++ b/Documentation/ldm.txt
@@ -2,10 +2,13 @@
             LDM - Logical Disk Manager (Dynamic Disks)
             ------------------------------------------
 
+Originally Written by FlatCap - Richard Russon <ldm@flatcap.org>.
+Last Updated by Anton Altaparmakov on 30 March 2007 for Windows Vista.
+
 Overview
 --------
 
-Windows 2000 and XP use a new partitioning scheme.  It is a complete
+Windows 2000, XP, and Vista use a new partitioning scheme.  It is a complete
 replacement for the MSDOS style partitions.  It stores its information in a
 1MiB journalled database at the end of the physical disk.  The size of
 partitions is limited only by disk space.  The maximum number of partitions is
@@ -23,7 +26,11 @@ Once the LDM driver has divided up the disk, you can use the MD driver to
 assemble any multi-partition volumes, e.g.  Stripes, RAID5.
 
 To prevent legacy applications from repartitioning the disk, the LDM creates a
-dummy MSDOS partition containing one disk-sized partition.
+dummy MSDOS partition containing one disk-sized partition.  This is what is
+supported with the Linux LDM driver.
+
+A newer approach that has been implemented with Vista is to put LDM on top of a
+GPT label disk.  This is not supported by the Linux LDM driver yet.
 
 
 Example
@@ -88,13 +95,13 @@ and cannot boot from a Dynamic Disk.
 More Documentation
 ------------------
 
-There is an Overview of the LDM online together with complete Technical
-Documentation.  It can also be downloaded in html.
+There is an Overview of the LDM together with complete Technical Documentation.
+It is available for download.
 
-  http://linux-ntfs.sourceforge.net/ldm/index.html
-  http://linux-ntfs.sourceforge.net/downloads.html
+  http://www.linux-ntfs.org/content/view/19/37/
 
-If you have any LDM questions that aren't answered on the website, email me.
+If you have any LDM questions that aren't answered in the documentation, email
+me.
 
 Cheers,
     FlatCap - Richard Russon
diff --git a/MAINTAINERS b/MAINTAINERS
index 4c3277cb925..22ab4019972 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2231,11 +2231,11 @@ M:	khali@linux-fr.org
 L:      lm-sensors@lm-sensors.org
 S:      Maintained
 
-LOGICAL DISK MANAGER SUPPORT (LDM, Windows 2000/XP Dynamic Disks)
+LOGICAL DISK MANAGER SUPPORT (LDM, Windows 2000/XP/Vista Dynamic Disks)
 P:      Richard Russon (FlatCap)
 M:      ldm@flatcap.org
-L:      ldm-devel@lists.sourceforge.net
-W:      http://ldm.sourceforge.net
+L:      linux-ntfs-dev@lists.sourceforge.net
+W:      http://www.linux-ntfs.org/content/view/19/37/
 S:      Maintained
 
 LSILOGIC MPT FUSION DRIVERS (FC/SAS/SPI)
diff --git a/fs/partitions/Kconfig b/fs/partitions/Kconfig
index 7638a1c42a7..a99acd8de35 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 1a60926a4cc..c387812537d 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);
         }