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. */