From 72f50e52515369ef8decda9493422d6235f5b365 Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Wed, 18 Aug 2021 11:00:12 +0100
Subject: [PATCH] v2v: windows: Do not fix NTFS heads in Windows Vista and
 later

Setting/adjusting the number of drive heads in the NTFS header is only
necessary for ancient versions of Windows.  Modern versions ignore
this.  In addition this operation broke when we added BitLocker
support.  Only do this for ancient Windows 2000/XP and skip it for
everything else.

Reported-by: Ming Xie
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1994984
(cherry picked from commit 0a394c5c2f802098c9e481b4bacee7821e5dd0ae)
---
 v2v/convert_windows.ml | 44 ++++++++++++++++++++++--------------------
 1 file changed, 23 insertions(+), 21 deletions(-)

diff --git a/v2v/convert_windows.ml b/v2v/convert_windows.ml
index 33fbd410..13de10cb 100644
--- a/v2v/convert_windows.ml
+++ b/v2v/convert_windows.ml
@@ -730,30 +730,32 @@ if errorlevel 3010 exit /b 0
        however, as this is specific to Windows 2003 it lists location
        0x1A as unused.
     *)
-    let rootpart = inspect.i_root in
+    if inspect.i_major_version < 6 (* is Windows 2000/XP *) then (
+      let rootpart = inspect.i_root in
 
-    (* Ignore if the rootpart is something like /dev/sda.  RHBZ#1276540. *)
-    if not (g#is_whole_device rootpart) then (
-      (* Check that the root device contains NTFS magic. *)
-      let magic = g#pread_device rootpart 8 3L in
-      if magic = "NTFS    " then (
-        (* Get the size of the whole disk containing the root partition. *)
-        let rootdev = g#part_to_dev rootpart in (* eg. /dev/sda *)
-        let size = g#blockdev_getsize64 rootdev in
+      (* Ignore if the rootpart is something like /dev/sda.  RHBZ#1276540. *)
+      if not (g#is_whole_device rootpart) then (
+        (* Check that the root device contains NTFS magic. *)
+        let magic = g#pread_device rootpart 8 3L in
+        if magic = "NTFS    " then (
+          (* Get the size of the whole disk containing the root partition. *)
+          let rootdev = g#part_to_dev rootpart in (* eg. /dev/sda *)
+          let size = g#blockdev_getsize64 rootdev in
 
-        let heads =             (* refer to the table above *)
-          if size < 2114445312L then 0x40
-          else if size < 4228374780L then 0x80
-          else 0xff in
+          let heads =             (* refer to the table above *)
+            if size < 2114445312L then 0x40
+            else if size < 4228374780L then 0x80
+            else 0xff in
 
-        (* Update NTFS's idea of the number of heads.  This is an
-         * unsigned 16 bit little-endian integer, offset 0x1a from the
-         * beginning of the partition.
-         *)
-        let b = Bytes.create 2 in
-        Bytes.unsafe_set b 0 (Char.chr heads);
-        Bytes.unsafe_set b 1 '\000';
-        ignore (g#pwrite_device rootpart (Bytes.to_string b) 0x1a_L)
+          (* Update NTFS's idea of the number of heads.  This is an
+           * unsigned 16 bit little-endian integer, offset 0x1a from the
+           * beginning of the partition.
+           *)
+          let b = Bytes.create 2 in
+          Bytes.unsafe_set b 0 (Char.chr heads);
+          Bytes.unsafe_set b 1 '\000';
+          ignore (g#pwrite_device rootpart (Bytes.to_string b) 0x1a_L)
+        )
       )
     )
 
-- 
2.27.0