From 20889d4553a132cd8749a73853715fd3a0f237e5 Mon Sep 17 00:00:00 2001
From: Mounir IDRASSI <mounir.idrassi@idrix.fr>
Date: Sat, 18 Aug 2018 11:13:20 +0200
Subject: [PATCH] Windows: Implement workaround on Windows 10 to make VeraCrypt
 encrypted disks visible to Windows defragmenter

---
 src/Driver/Ntdriver.c | 26 +++++++++++++++++++++-----
 src/Driver/Ntdriver.h |  1 +
 src/Driver/Ntvol.c    | 10 ++++++++++
 3 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/src/Driver/Ntdriver.c b/src/Driver/Ntdriver.c
index e7451a8f..6e774724 100644
--- a/src/Driver/Ntdriver.c
+++ b/src/Driver/Ntdriver.c
@@ -1263,8 +1263,10 @@ NTSTATUS ProcessVolumeDeviceControlIrp (PDEVICE_OBJECT DeviceObject, PEXTENSION
 
 	case IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS:
 		Dump ("ProcessVolumeDeviceControlIrp (IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS)\n");
-		// Vista's filesystem defragmenter fails if IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS does not succeed.
-		if (!(OsMajorVersion == 6 && OsMinorVersion == 0))
+		// Vista's and Windows 10 filesystem defragmenter fails if IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS does not succeed.
+		if (!(OsMajorVersion == 6 && OsMinorVersion == 0) 
+			&& !(OsMajorVersion == 10 && EnableExtendedIoctlSupport && Extension->bRawDevice)
+			)
 		{
 			Irp->IoStatus.Status = STATUS_INVALID_DEVICE_REQUEST;
 			Irp->IoStatus.Information = 0;
@@ -1272,10 +1274,24 @@ NTSTATUS ProcessVolumeDeviceControlIrp (PDEVICE_OBJECT DeviceObject, PEXTENSION
 		else if (ValidateIOBufferSize (Irp, sizeof (VOLUME_DISK_EXTENTS), ValidateOutput))
 		{
 			VOLUME_DISK_EXTENTS *extents = (VOLUME_DISK_EXTENTS *) Irp->AssociatedIrp.SystemBuffer;
+			
 
-			// No extent data can be returned as this is not a physical drive.
-			memset (extents, 0, sizeof (*extents));
-			extents->NumberOfDiskExtents = 0;
+			if (OsMajorVersion == 10)
+			{
+				// Windows 10 filesystem defragmenter works only if we report an extent with a real disk number
+				// So in the case of a VeraCrypt disk based volume, we use the disk number
+				// of the underlaying physical disk and we report a single extent 
+				extents->NumberOfDiskExtents = 1;
+				extents->Extents[0].DiskNumber = Extension->DeviceNumber;
+				extents->Extents[0].StartingOffset.QuadPart = Extension->BytesPerSector;
+				extents->Extents[0].ExtentLength.QuadPart = Extension->DiskLength;
+			}
+			else
+			{
+				// Vista: No extent data can be returned as this is not a physical drive.				
+				memset (extents, 0, sizeof (*extents));
+				extents->NumberOfDiskExtents = 0;
+			}
 
 			Irp->IoStatus.Status = STATUS_SUCCESS;
 			Irp->IoStatus.Information = sizeof (*extents);
diff --git a/src/Driver/Ntdriver.h b/src/Driver/Ntdriver.h
index 8403f212..b679952a 100644
--- a/src/Driver/Ntdriver.h
+++ b/src/Driver/Ntdriver.h
@@ -66,6 +66,7 @@ typedef struct EXTENSION
 	ULONG HostMaximumTransferLength;
 	ULONG HostMaximumPhysicalPages;
 	ULONG HostAlignmentMask;
+	ULONG DeviceNumber;
 
 	BOOL IncursSeekPenalty;
 	BOOL TrimEnabled;
diff --git a/src/Driver/Ntvol.c b/src/Driver/Ntvol.c
index c8552ab3..852aafd0 100644
--- a/src/Driver/Ntvol.c
+++ b/src/Driver/Ntvol.c
@@ -72,6 +72,8 @@ NTSTATUS TCOpenVolume (PDEVICE_OBJECT DeviceObject,
 	Extension->IncursSeekPenalty = TRUE;
 	Extension->TrimEnabled = FALSE;
 
+	Extension->DeviceNumber = (ULONG) -1;
+
 	RtlInitUnicodeString (&FullFileName, pwszMountVolume);
 	InitializeObjectAttributes (&oaFileAttributes, &FullFileName, OBJ_CASE_INSENSITIVE | (forceAccessCheck ? OBJ_FORCE_ACCESS_CHECK : 0) | OBJ_KERNEL_HANDLE, NULL, NULL);
 	KeInitializeEvent (&Extension->keVolumeEvent, NotificationEvent, FALSE);
@@ -94,6 +96,7 @@ NTSTATUS TCOpenVolume (PDEVICE_OBJECT DeviceObject,
 		DISK_GEOMETRY_EX dg;
 		STORAGE_PROPERTY_QUERY storagePropertyQuery = {0};
 		byte* dgBuffer;
+		STORAGE_DEVICE_NUMBER storageDeviceNumber;
 
 		ntStatus = IoGetDeviceObjectPointer (&FullFileName,
 			FILE_READ_DATA | FILE_READ_ATTRIBUTES,
@@ -147,6 +150,13 @@ NTSTATUS TCOpenVolume (PDEVICE_OBJECT DeviceObject,
 
 		TCfree (dgBuffer);
 
+		if (NT_SUCCESS (TCSendHostDeviceIoControlRequest (DeviceObject, Extension,
+					IOCTL_STORAGE_GET_DEVICE_NUMBER,
+					(char*) &storageDeviceNumber, sizeof (storageDeviceNumber))))
+		{
+			Extension->DeviceNumber = storageDeviceNumber.DeviceNumber;
+		}
+
 		lDiskLength.QuadPart = dg.DiskSize.QuadPart;
 		Extension->HostBytesPerSector = dg.Geometry.BytesPerSector;
 		Extension->HostBytesPerPhysicalSector = dg.Geometry.BytesPerSector;