Windows device driver: FSCTL_LOCK_VOLUME on raw partition - Access is Denied - windows

Question

I am currently writing a Windows utility that does a similar job as Linux dd. But this utility only copy USED block instead of cloning the whole disk block by block.
The way I write it is to
*
(1) Copy MBR from disk A which contains three partitions to disk B.
(2) after step A. I am able see three raw partitions from disk management GUI. (no drive letter, no file system).
(3) Copy each partitions from A to B in a loop.*
The problem I have is:
in step (3) after I get the file handle from OpenDevice and I try to use that handle to lock a raw partition, I get Access Denied (error 5) and I am 100% sure that my program did not accidentally hold the lock somewhere else. My dev and testing environment is Windows 2003 server and my utility is executed as Admin privilege.
Here is the code snippet:
...
shareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;
fHandle= OpenDevice(shareMode);
res = DeviceIoControl(fHandle, FSCTL_LOCK_VOLUME, NULL, 0, NULL, 0, &dummy, NULL);
if (res == 0)
{
DismountAndLockVolume();
}
...
in my OpenDevice function in use:
DWORD access = (fOpenMode==forWriting) ? (GENERIC_READ | GENERIC_WRITE | SYNCHRONIZE) : GENERIC_READ| SYNCHRONIZE;
NTOpen(&fHandle, fName.c_str(), access, FILE_ATTRIBUTE_NORMAL, shareMode, FILE_OPEN,FILE_SYNCHRONOUS_IO_NONALERT|FILE_RANDOM_ACCESS|FILE_NON_DIRECTORY_FILE);
to get the file handle(fHandle).
In DismountAndLockVolume function, I try to dismount this volume and grab the lock on it again.
DeviceIoControl(fHandle, FSCTL_DISMOUNT_VOLUME, NULL, 0, NULL, 0, &dummy, NULL);
DWORD shareMode = FILE_SHARE_DELETE | FILE_SHARE_WRITE | FILE_SHARE_READ;
ntStatus = OpenDevice(shareMode);
res = DeviceIoControl(fHandle, FSCTL_LOCK_VOLUME, NULL, 0, NULL, 0, &dummy, NULL);
The problem is, when I my code try to dismount this volume, an exception is thrown due to access denied.
Then I browsed the Internet and get the following discussion thread: QUOTE
A write on a volume handle will succeed if the volume is not mounted by a
file system, or if one of the following conditions is true:
1. The sectors to be written to are boot sectors.
2. The sectors to be written to reside outside of file system space.
3. You have explicitly locked or dismounted the volume by using
FSCTL_LOCK_VOLUME or FSCTL_DISMOUNT_VOLUME.
4 . The volume has no file system. (In other words, it has been mounted
as a RAW volume.)
A write on a disk handle will succeed if one of the following conditions
is true:
1. The sectors to be written to do not fall within a volume's extents.
2. The sectors to be written to fall within a mounted volume, but you
have explicitly locked or dismounted the volume by using FSCTL_LOCK_VOLUME
or FSCTL_DISMOUNT_VOLUME.
3. The sectors to be written to fall within a volume that is not mounted
or has no file system.
The modification of some disk parts, like the boot sector ( upto 16 ), is
still allowed . But my utility relies on raw write access to the disk. I am
not able to lock volume by FSCTL_LOCK_VOLUME. Result is ACCESS DENIED. While
searching through net i come to know that kernel mode driver is only
solution. But in this group i come to know driver is not require. I work on
services and pass through SCSI, but i am not able to find the solution. If
kernel mode driver is require then what kind of driver it should be ?
Is anybody know the solution of the problem then please help me out
This thread terminates with no conclusion. Can somebody give me a hand on what was going on? Any hint for possible solution?
Millions of Thanks. I have been scratching my hair for days :-(((.