Index: fastio.c
===================================================================
--- drivers/filesystems/fastfat/fastio.c	(revision 74432)
+++ drivers/filesystems/fastfat/fastio.c	(working copy)
@@ -31,79 +31,59 @@
     OUT PIO_STATUS_BLOCK IoStatus,
     IN PDEVICE_OBJECT DeviceObject)
 {
+    PVFATFCB Fcb;
+    LARGE_INTEGER LargeLength;
+
     /* Prevent all Fast I/O requests */
     DPRINT("VfatFastIoCheckIfPossible(): returning FALSE.\n");
 
-    UNREFERENCED_PARAMETER(FileObject);
-    UNREFERENCED_PARAMETER(FileOffset);
-    UNREFERENCED_PARAMETER(Length);
     UNREFERENCED_PARAMETER(Wait);
-    UNREFERENCED_PARAMETER(LockKey);
-    UNREFERENCED_PARAMETER(CheckForReadOperation);
     UNREFERENCED_PARAMETER(IoStatus);
     UNREFERENCED_PARAMETER(DeviceObject);
 
-    return FALSE;
-}
+    if (DeviceObject == VfatGlobalData->DeviceObject)
+    {
+        /* Not sure if this is possible */
+        ASSERT(DeviceObject != VfatGlobalData->DeviceObject);
+        return FALSE;
+    }
 
-static FAST_IO_READ VfatFastIoRead;
+    Fcb = FileObject->FsContext;
+    if (Fcb == NULL)
+    {
+        /* this happens for a volume open, right */
+        ASSERT(Fcb != NULL);
+        return FALSE;
+    }
 
-static
-BOOLEAN
-NTAPI
-VfatFastIoRead(
-    IN PFILE_OBJECT FileObject,
-    IN PLARGE_INTEGER FileOffset,
-    IN ULONG Length,
-    IN BOOLEAN Wait,
-    IN ULONG LockKey,
-    OUT PVOID Buffer,
-    OUT PIO_STATUS_BLOCK IoStatus,
-    IN PDEVICE_OBJECT DeviceObject)
-{
-    DPRINT("VfatFastIoRead()\n");
+    if (vfatFCBIsDirectory(Fcb))
+    {
+        ASSERT(!vfatFCBIsDirectory(Fcb));
+        return FALSE;
+    }
 
-    UNREFERENCED_PARAMETER(FileObject);
-    UNREFERENCED_PARAMETER(FileOffset);
-    UNREFERENCED_PARAMETER(Length);
-    UNREFERENCED_PARAMETER(Wait);
-    UNREFERENCED_PARAMETER(LockKey);
-    UNREFERENCED_PARAMETER(Buffer);
-    UNREFERENCED_PARAMETER(IoStatus);
-    UNREFERENCED_PARAMETER(DeviceObject);
-
-    return FALSE;
+    LargeLength.QuadPart = Length;
+    if (CheckForReadOperation)
+    {
+        return FsRtlFastCheckLockForRead(&Fcb->FileLock,
+                                         FileOffset,
+                                         &LargeLength,
+                                         LockKey,
+                                         FileObject,
+                                         PsGetCurrentProcess());
+    }
+    else
+    {
+        //if (write protected) return FALSE;
+        return FsRtlFastCheckLockForWrite(&Fcb->FileLock,
+                                          FileOffset,
+                                          &LargeLength,
+                                          LockKey,
+                                          FileObject,
+                                          PsGetCurrentProcess());
+    }
 }
 
-static FAST_IO_WRITE VfatFastIoWrite;
-
-static
-BOOLEAN
-NTAPI
-VfatFastIoWrite(
-    IN PFILE_OBJECT FileObject,
-    IN PLARGE_INTEGER FileOffset,
-    IN ULONG Length,
-    IN BOOLEAN Wait,
-    IN ULONG LockKey,
-    OUT PVOID Buffer,
-    OUT PIO_STATUS_BLOCK IoStatus,
-    IN PDEVICE_OBJECT DeviceObject)
-{
-    DPRINT("VfatFastIoWrite()\n");
-
-    UNREFERENCED_PARAMETER(FileObject);
-    UNREFERENCED_PARAMETER(FileOffset);
-    UNREFERENCED_PARAMETER(Length);
-    UNREFERENCED_PARAMETER(Wait);
-    UNREFERENCED_PARAMETER(LockKey);
-    UNREFERENCED_PARAMETER(Buffer);
-    UNREFERENCED_PARAMETER(IoStatus);
-    UNREFERENCED_PARAMETER(DeviceObject);
-
-    return FALSE;
-}
-
 static FAST_IO_QUERY_BASIC_INFO VfatFastIoQueryBasicInfo;
 
 static
@@ -437,100 +417,6 @@
     return STATUS_INVALID_DEVICE_REQUEST;
 }
 
-static FAST_IO_MDL_READ VfatMdlRead;
-
-static
-BOOLEAN
-NTAPI
-VfatMdlRead(
-    IN PFILE_OBJECT FileObject,
-    IN PLARGE_INTEGER FileOffset,
-    IN ULONG Length,
-    IN ULONG LockKey,
-    OUT PMDL* MdlChain,
-    OUT PIO_STATUS_BLOCK IoStatus,
-    IN PDEVICE_OBJECT DeviceObject)
-{
-    DPRINT("VfatMdlRead\n");
-
-    UNREFERENCED_PARAMETER(FileObject);
-    UNREFERENCED_PARAMETER(FileOffset);
-    UNREFERENCED_PARAMETER(Length);
-    UNREFERENCED_PARAMETER(LockKey);
-    UNREFERENCED_PARAMETER(MdlChain);
-    UNREFERENCED_PARAMETER(IoStatus);
-    UNREFERENCED_PARAMETER(DeviceObject);
-
-    return FALSE;
-}
-
-static FAST_IO_MDL_READ_COMPLETE VfatMdlReadComplete;
-
-static
-BOOLEAN
-NTAPI
-VfatMdlReadComplete(
-    IN PFILE_OBJECT FileObject,
-    IN PMDL MdlChain,
-    IN PDEVICE_OBJECT DeviceObject)
-{
-    DPRINT("VfatMdlReadComplete\n");
-
-    UNREFERENCED_PARAMETER(FileObject);
-    UNREFERENCED_PARAMETER(MdlChain);
-    UNREFERENCED_PARAMETER(DeviceObject);
-
-    return FALSE;
-}
-
-static FAST_IO_PREPARE_MDL_WRITE VfatPrepareMdlWrite;
-
-static
-BOOLEAN
-NTAPI
-VfatPrepareMdlWrite(
-    IN PFILE_OBJECT FileObject,
-    IN PLARGE_INTEGER FileOffset,
-    IN ULONG Length,
-    IN ULONG LockKey,
-    OUT PMDL* MdlChain,
-    OUT PIO_STATUS_BLOCK IoStatus,
-    IN PDEVICE_OBJECT DeviceObject)
-{
-    DPRINT("VfatPrepareMdlWrite\n");
-
-    UNREFERENCED_PARAMETER(FileObject);
-    UNREFERENCED_PARAMETER(FileOffset);
-    UNREFERENCED_PARAMETER(Length);
-    UNREFERENCED_PARAMETER(LockKey);
-    UNREFERENCED_PARAMETER(MdlChain);
-    UNREFERENCED_PARAMETER(IoStatus);
-    UNREFERENCED_PARAMETER(DeviceObject);
-
-    return FALSE;
-}
-
-static FAST_IO_MDL_WRITE_COMPLETE VfatMdlWriteComplete;
-
-static
-BOOLEAN
-NTAPI
-VfatMdlWriteComplete(
-    IN PFILE_OBJECT FileObject,
-    IN PLARGE_INTEGER FileOffset,
-    IN PMDL MdlChain,
-    IN PDEVICE_OBJECT DeviceObject)
-{
-    DPRINT("VfatMdlWriteComplete\n");
-
-    UNREFERENCED_PARAMETER(FileObject);
-    UNREFERENCED_PARAMETER(FileOffset);
-    UNREFERENCED_PARAMETER(MdlChain);
-    UNREFERENCED_PARAMETER(DeviceObject);
-
-    return FALSE;
-}
-
 static FAST_IO_READ_COMPRESSED VfatFastIoReadCompressed;
 
 static
@@ -790,8 +676,8 @@
 {
     FastIoDispatch->SizeOfFastIoDispatch = sizeof(FAST_IO_DISPATCH);
     FastIoDispatch->FastIoCheckIfPossible = VfatFastIoCheckIfPossible;
-    FastIoDispatch->FastIoRead = VfatFastIoRead;
-    FastIoDispatch->FastIoWrite = VfatFastIoWrite;
+    FastIoDispatch->FastIoRead = FsRtlCopyRead;
+    FastIoDispatch->FastIoWrite = FsRtlCopyWrite;
     FastIoDispatch->FastIoQueryBasicInfo = VfatFastIoQueryBasicInfo;
     FastIoDispatch->FastIoQueryStandardInfo = VfatFastIoQueryStandardInfo;
     FastIoDispatch->FastIoLock = VfatFastIoLock;
@@ -803,10 +689,10 @@
     FastIoDispatch->ReleaseFileForNtCreateSection = VfatReleaseFileForNtCreateSection;
     FastIoDispatch->FastIoDetachDevice = VfatFastIoDetachDevice;
     FastIoDispatch->FastIoQueryNetworkOpenInfo = VfatFastIoQueryNetworkOpenInfo;
-    FastIoDispatch->MdlRead = VfatMdlRead;
-    FastIoDispatch->MdlReadComplete = VfatMdlReadComplete;
-    FastIoDispatch->PrepareMdlWrite = VfatPrepareMdlWrite;
-    FastIoDispatch->MdlWriteComplete = VfatMdlWriteComplete;
+    FastIoDispatch->MdlRead = FsRtlMdlReadDev;
+    FastIoDispatch->MdlReadComplete = FsRtlMdlReadCompleteDev;
+    FastIoDispatch->PrepareMdlWrite = FsRtlPrepareMdlWriteDev;
+    FastIoDispatch->MdlWriteComplete = FsRtlMdlWriteCompleteDev;
     FastIoDispatch->FastIoReadCompressed = VfatFastIoReadCompressed;
     FastIoDispatch->FastIoWriteCompressed = VfatFastIoWriteCompressed;
     FastIoDispatch->MdlReadCompleteCompressed = VfatMdlReadCompleteCompressed;
Index: fcb.c
===================================================================
--- drivers/filesystems/fastfat/fcb.c	(revision 74432)
+++ drivers/filesystems/fastfat/fcb.c	(working copy)
@@ -149,7 +149,7 @@
     ExInitializeFastMutex(&rcFCB->LastMutex);
     rcFCB->RFCB.PagingIoResource = &rcFCB->PagingIoResource;
     rcFCB->RFCB.Resource = &rcFCB->MainResource;
-    rcFCB->RFCB.IsFastIoPossible = FastIoIsNotPossible;
+    rcFCB->RFCB.IsFastIoPossible = FastIoIsQuestionable;
     InitializeListHead(&rcFCB->ParentListHead);
 
     return  rcFCB;
@@ -671,7 +671,7 @@
     FCB->RFCB.FileSize.QuadPart = Size;
     FCB->RFCB.ValidDataLength.QuadPart = Size;
     FCB->RFCB.AllocationSize.QuadPart = Size;
-    FCB->RFCB.IsFastIoPossible = FastIoIsNotPossible;
+    FCB->RFCB.IsFastIoPossible = FastIoIsQuestionable;
 
     vfatFCBInitializeCacheFromVolume(pVCB, FCB);
     vfatAddFCBToTable(pVCB, FCB);