CORE-15575
Detect whether the disk is a "super-floppy", which is the name given
to partitionless disk having no MBR, with the unique partition volume
starting at sector offset zero and spanning the whole disk.
The name comes from the fact that at the partitioning level, the disk
"looks like" a large-capacity floppy disk.
This is typically how external removable (USB, ...) drives are
partitioned by default by Windows.
https://learn.microsoft.com/en-us/windows-hardware/manufacture/desktop/windows-and-gpt-faq?view=windows-11#superfloppy
The kernel-mode functions IoReadPartitionTable() / IoWritePartitionTable()
report the drive layout of a "super-floppy" disk as follows:
an MBR-style disk containing only one single partition starting at the
beginning of the disk (StartingOffset == 0) without hidden sectors, and
its type being FAT16 non-bootable.
The disk NTFT signature is set to 0x00000001.
----
Additional bug fixes to make the feature work reliably:
- Make PartMgrGetDriveLayout() also update the FDO DiskData's
PartitionStyle and Signature/GPT DiskId for consistency (code moved
from PartMgrRefreshDiskData()).
- In FdoIoctlDiskSetDriveLayout[Ex](), if the disk is "super-floppy",
but the user wants to create more than one partition, fail the call.
(In the Ex call, fail also if the partition style changes.)
warning C4267: 'function': conversion from 'size_t' to 'ULONG', possible loss of data'
The OutputBufferLength member that was temporarily stored in
outBufferLength is already a ULONG, and IssueSyncIoControlRequest()
takes the length as a ULONG. So there is no need to use 'size_t' here.
- Implement IOCTL_VOLUME_QUERY_VOLUME_NUMBER:
See usage example in:
7241cebfa2/mayfield/branches/spr/src/umapps/ndassvc/service/drivematch.cpp (L627)
- Stubplement IOCTL_VOLUME_IS_PARTITION:
The only type of volume we support right now is disk partition
so we just return success. A more robust algorithm would be
to check whether the volume has only one single extent, that
covers the whole partition on which it lies upon. If this is
not the case, return STATUS_UNSUCCESSFUL instead.
This driver works as complement to disk.sys/classpnp.sys from Windows 10
Manages partition PDOs and exposes them as volumes to mountmgr.sys.
The driver is almost complete, just some minor IOCTLs missing (will be
added on demand)
