Пример #1
0
__drv_mustHoldCriticalRegion    
NTSTATUS
FatCommonShutdown (
    IN PIRP_CONTEXT IrpContext,
    IN PIRP Irp
    )

/*++

Routine Description:

    This is the common routine for shutdown called by both the fsd and
    fsp threads.

Arguments:

    Irp - Supplies the Irp being processed

Return Value:

    NTSTATUS - The return status for the operation

--*/

{
    KEVENT Event;
    PLIST_ENTRY Links;
    PVCB Vcb;
    PIRP NewIrp;
    IO_STATUS_BLOCK Iosb;
    BOOLEAN VcbDeleted;

    PAGED_CODE();

    //
    //  Make sure we don't get any pop-ups, and write everything through.
    //

    SetFlag(IrpContext->Flags, IRP_CONTEXT_FLAG_DISABLE_POPUPS |
                               IRP_CONTEXT_FLAG_WRITE_THROUGH);

    //
    //  Initialize an event for doing calls down to
    //  our target device objects.
    //

    KeInitializeEvent( &Event, NotificationEvent, FALSE );

    //
    //  Indicate that shutdown has started.  This is used in FatFspClose.
    //

    FatData.ShutdownStarted = TRUE;    

    //
    //  Get everyone else out of the way
    //
    
    ASSERT( FlagOn(IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT) );

#pragma prefast( push )
#pragma prefast( disable: 28137, "prefast wants the wait to be a constant, but that isn't possible for the way fastfat is designed" )
#pragma prefast( disable: 28193, "this will always wait" )

    (VOID) FatAcquireExclusiveGlobal( IrpContext );

#pragma prefast( pop )

    try {

        //
        //  For every volume that is mounted we will flush the
        //  volume and then shutdown the target device objects.
        //

        Links = FatData.VcbQueue.Flink;
        while (Links != &FatData.VcbQueue) {

            Vcb = CONTAINING_RECORD(Links, VCB, VcbLinks);

            Links = Links->Flink;

            //
            //  If we have already been called before for this volume
            //  (and yes this does happen), skip this volume as no writes
            //  have been allowed since the first shutdown.
            //

            if ( FlagOn( Vcb->VcbState, VCB_STATE_FLAG_SHUTDOWN) ||
                 (Vcb->VcbCondition != VcbGood) ) {

                continue;
            }

            FatAcquireExclusiveVolume( IrpContext, Vcb );

            try {

                (VOID)FatFlushVolume( IrpContext, Vcb, Flush );

                //
                //  The volume is now clean, note it.  We purge the
                //  volume file cache map before marking the volume
                //  clean incase there is a stale Bpb in the cache.
                //

                if (!FlagOn(Vcb->VcbState, VCB_STATE_FLAG_MOUNTED_DIRTY)) {

                    CcPurgeCacheSection( &Vcb->SectionObjectPointers,
                                         NULL,
                                         0,
                                         FALSE );

                    FatMarkVolume( IrpContext, Vcb, VolumeClean );
                }

            } except( EXCEPTION_EXECUTE_HANDLER ) {

                  FatResetExceptionState( IrpContext );
            }

            //
            //  Sometimes we take an excepion while flushing the volume, such
            //  as when autoconv has converted the volume and is rebooting.
            //  Even in that case we want to send the shutdown irp to the
            //  target device so it can know to flush its cache, if it has one.
            //

            try {

                NewIrp = IoBuildSynchronousFsdRequest( IRP_MJ_SHUTDOWN,
                                                       Vcb->TargetDeviceObject,
                                                       NULL,
                                                       0,
                                                       NULL,
                                                       &Event,
                                                       &Iosb );

                if (NewIrp != NULL) {

                    if (NT_SUCCESS(IoCallDriver( Vcb->TargetDeviceObject, NewIrp ))) {

                        (VOID) KeWaitForSingleObject( &Event,
                                                      Executive,
                                                      KernelMode,
                                                      FALSE,
                                                      NULL );

                        KeClearEvent( &Event );
                    }
                }

            } except( EXCEPTION_EXECUTE_HANDLER ) {

                  FatResetExceptionState( IrpContext );
            }

            SetFlag( Vcb->VcbState, VCB_STATE_FLAG_SHUTDOWN );

            //
            //  Attempt to punch the volume down.
            //

            VcbDeleted = FatCheckForDismount( IrpContext,
                                              Vcb,
                                              FALSE );

            if (!VcbDeleted) {
                
#pragma prefast( suppress:28107, "prefast is having trouble figuring out that Vcb is acquired" )
                FatReleaseVolume( IrpContext, Vcb );
            }
        }

    } finally {

        FatReleaseGlobal( IrpContext );

        //
        //  Unregister the file system.
        //
        
        IoUnregisterFileSystem( FatDiskFileSystemDeviceObject);
        IoUnregisterFileSystem( FatCdromFileSystemDeviceObject);
        IoDeleteDevice( FatDiskFileSystemDeviceObject);
        IoDeleteDevice( FatCdromFileSystemDeviceObject);

        FatCompleteRequest( IrpContext, Irp, STATUS_SUCCESS );
    }

    //
    //  And return to our caller
    //

    DebugTrace(-1, Dbg, "FatFsdShutdown -> STATUS_SUCCESS\n", 0);

    return STATUS_SUCCESS;
}
Пример #2
0
NTSTATUS
NdFatCommonFlushBuffers (
    IN PIRP_CONTEXT IrpContext,
    IN PIRP Irp
    )

/*++

Routine Description:

    This is the common routine for flushing a buffer.

Arguments:

    Irp - Supplies the Irp to process

Return Value:

    NTSTATUS - The return status for the operation

--*/

{
    NTSTATUS Status;

    PIO_STACK_LOCATION IrpSp;

    PFILE_OBJECT FileObject;

    TYPE_OF_OPEN TypeOfOpen;
    PVCB Vcb;
    PFCB Fcb;
    PCCB Ccb;

    BOOLEAN VcbAcquired = FALSE;
    BOOLEAN FcbAcquired = FALSE;

    PDIRENT Dirent;
    PBCB DirentBcb = NULL;

	PVOLUME_DEVICE_OBJECT		volDo = CONTAINING_RECORD( IrpContext->Vcb, VOLUME_DEVICE_OBJECT, Vcb );
	BOOLEAN						secondarySessionResourceAcquired = FALSE;

	PSECONDARY_REQUEST			secondaryRequest = NULL;

	PNDFS_REQUEST_HEADER		ndfsRequestHeader;
	PNDFS_WINXP_REQUEST_HEADER	ndfsWinxpRequestHeader;
	PNDFS_WINXP_REPLY_HEADER	ndfsWinxpReplytHeader;

	LARGE_INTEGER				timeOut;



    PAGED_CODE();

    IrpSp = IoGetCurrentIrpStackLocation( Irp );

    DebugTrace(+1, Dbg, "FatCommonFlushBuffers\n", 0);
    DebugTrace( 0, Dbg, "Irp           = %08lx\n", Irp);
    DebugTrace( 0, Dbg, "->FileObject  = %08lx\n", IrpSp->FileObject);

	
	//
    //  Extract and decode the file object
    //

    FileObject = IrpSp->FileObject;
    TypeOfOpen = FatDecodeFileObject( FileObject, &Vcb, &Fcb, &Ccb );

    //
    //  CcFlushCache is always synchronous, so if we can't wait enqueue
    //  the irp to the Fsp.
    //

    if ( !FlagOn(IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT) ) {

        Status = FatFsdPostRequest( IrpContext, Irp );

        DebugTrace(-1, Dbg, "FatCommonFlushBuffers -> %08lx\n", Status );
        return Status;
    }

    Status = STATUS_SUCCESS;

    try {

		if (!FlagOn(Ccb->NdFatFlags, ND_FAT_CCB_FLAG_UNOPENED)) {

			do {
			
				secondarySessionResourceAcquired 
					= SecondaryAcquireResourceExclusiveLite( IrpContext, 
															 &volDo->Secondary->SessionResource, 
															 BooleanFlagOn(IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT) );

				if (FlagOn(volDo->Secondary->Thread.Flags, SECONDARY_THREAD_FLAG_REMOTE_DISCONNECTED) ) {

					PrintIrp( Dbg2, "SECONDARY_THREAD_FLAG_REMOTE_DISCONNECTED", NULL, IrpContext->OriginatingIrp );
					FatRaiseStatus( IrpContext, STATUS_CANT_WAIT );	
				}

				secondaryRequest = ALLOC_WINXP_SECONDARY_REQUEST( volDo->Secondary, IRP_MJ_FLUSH_BUFFERS, 0 );

				if (secondaryRequest == NULL) {
	
					Status = STATUS_INSUFFICIENT_RESOURCES;
					break;
				}

				ndfsRequestHeader = &secondaryRequest->NdfsRequestHeader;

				INITIALIZE_NDFS_REQUEST_HEADER( ndfsRequestHeader, NDFS_COMMAND_EXECUTE, volDo->Secondary, IRP_MJ_FLUSH_BUFFERS, 0 );

				ndfsWinxpRequestHeader = (PNDFS_WINXP_REQUEST_HEADER)(ndfsRequestHeader+1);
				ASSERT( ndfsWinxpRequestHeader == (PNDFS_WINXP_REQUEST_HEADER)secondaryRequest->NdfsRequestData );

				INITIALIZE_NDFS_WINXP_REQUEST_HEADER( ndfsWinxpRequestHeader, 
													  IrpContext->OriginatingIrp, 
													  IoGetCurrentIrpStackLocation(IrpContext->OriginatingIrp), 
													  Ccb->PrimaryFileHandle );
				
				ASSERT( !ExIsResourceAcquiredSharedLite(&IrpContext->Vcb->Resource) );	

				secondaryRequest->RequestType = SECONDARY_REQ_SEND_MESSAGE;
				QueueingSecondaryRequest( volDo->Secondary, secondaryRequest );

				timeOut.QuadPart = -NDFAT_TIME_OUT;		
				Status = KeWaitForSingleObject( &secondaryRequest->CompleteEvent, Executive, KernelMode, FALSE, &timeOut );
			
				if (Status != STATUS_SUCCESS) {

					ASSERT( NDFAT_BUG );
					break;
				}

				KeClearEvent (&secondaryRequest->CompleteEvent);

				if (BooleanFlagOn(volDo->Secondary->Thread.Flags, SECONDARY_THREAD_FLAG_REMOTE_DISCONNECTED)) {

					FatRaiseStatus( IrpContext, STATUS_CANT_WAIT );
				}

				if (secondaryRequest->ExecuteStatus == STATUS_SUCCESS) {

					ndfsWinxpReplytHeader = (PNDFS_WINXP_REPLY_HEADER)secondaryRequest->NdfsReplyData;
					ASSERT(ndfsWinxpReplytHeader->Status == STATUS_SUCCESS);
				}

				if (secondaryRequest) {

					DereferenceSecondaryRequest( secondaryRequest );
					secondaryRequest = NULL;
				}

				if ( secondarySessionResourceAcquired == TRUE ) {
					
					SecondaryReleaseResourceLite( IrpContext, &volDo->Secondary->SessionResource );		
					secondarySessionResourceAcquired = FALSE;
				}

				break;

			} while(0);
		} 

		Status = STATUS_SUCCESS;

        //
        //  Case on the type of open that we are trying to flush
        //

        switch (TypeOfOpen) {

        case VirtualVolumeFile:
        case EaFile:
        case DirectoryFile:

            DebugTrace(0, Dbg, "Flush that does nothing\n", 0);
            break;

        case UserFileOpen:

            DebugTrace(0, Dbg, "Flush User File Open\n", 0);

            (VOID)FatAcquireExclusiveFcb( IrpContext, Fcb );

            FcbAcquired = TRUE;

            FatVerifyFcb( IrpContext, Fcb );

            //
            //  If the file is cached then flush its cache
            //

            Status = FatFlushFile( IrpContext, Fcb, Flush );

            //
            //  Also update and flush the file's dirent in the parent directory if the
            //  file flush worked.
            //

            if (NT_SUCCESS( Status )) {

                //
                //  Insure that we get the filesize to disk correctly.  This is
                //  benign if it was already good.
                //
                //  (why do we need to do this?)
                //

                SetFlag(FileObject->Flags, FO_FILE_SIZE_CHANGED);
#if 0
                FatUpdateDirentFromFcb( IrpContext, FileObject, Fcb, Ccb );
#endif                
                //
                //  Flush the volume file to get any allocation information
                //  updates to disk.
                //

                if (FlagOn(Fcb->FcbState, FCB_STATE_FLUSH_FAT)) {

                    Status = FatFlushFat( IrpContext, Vcb );

                    ClearFlag(Fcb->FcbState, FCB_STATE_FLUSH_FAT);
                }

                //
                //  Set the write through bit so that these modifications
                //  will be completed with the request.
                //

                SetFlag(IrpContext->Flags, IRP_CONTEXT_FLAG_WRITE_THROUGH);
            }

            break;

        case UserDirectoryOpen:

            //
            //  If the user had opened the root directory then we'll
            //  oblige by flushing the volume.
            //

            if (NodeType(Fcb) != FAT_NTC_ROOT_DCB) {

                DebugTrace(0, Dbg, "Flush a directory does nothing\n", 0);
                break;
            }

        case UserVolumeOpen:

            DebugTrace(0, Dbg, "Flush User Volume Open, or root dcb\n", 0);

            //
            //  Acquire exclusive access to the Vcb.
            //

            {
                BOOLEAN Finished;
                Finished = FatAcquireExclusiveSecondaryVcb( IrpContext, Vcb );
                ASSERT( Finished );
            }

            VcbAcquired = TRUE;

            //
            //  Mark the volume clean and then flush the volume file,
            //  and then all directories
            //

            Status = FatFlushVolume( IrpContext, Vcb, Flush );

            //
            //  If the volume was dirty, do the processing that the delayed
            //  callback would have done.
            //

            if (FlagOn(Vcb->VcbState, VCB_STATE_FLAG_VOLUME_DIRTY)) {

                //
                //  Cancel any pending clean volumes.
                //

                (VOID)KeCancelTimer( &Vcb->CleanVolumeTimer );
                (VOID)KeRemoveQueueDpc( &Vcb->CleanVolumeDpc );

                //
                //  The volume is now clean, note it.
                //

                if (!FlagOn(Vcb->VcbState, VCB_STATE_FLAG_MOUNTED_DIRTY)) {

                    FatMarkVolume( IrpContext, Vcb, VolumeClean );
                    ClearFlag( Vcb->VcbState, VCB_STATE_FLAG_VOLUME_DIRTY );
                }

                //
                //  Unlock the volume if it is removable.
                //

                if (FlagOn(Vcb->VcbState, VCB_STATE_FLAG_REMOVABLE_MEDIA) &&
                    !FlagOn(Vcb->VcbState, VCB_STATE_FLAG_BOOT_OR_PAGING_FILE)) {

                    FatToggleMediaEjectDisable( IrpContext, Vcb, FALSE );
                }
            }

            break;

        default:

            FatBugCheck( TypeOfOpen, 0, 0 );
        }

        FatUnpinBcb( IrpContext, DirentBcb );

        FatUnpinRepinnedBcbs( IrpContext );

    } finally {

        DebugUnwind( FatCommonFlushBuffers );

		if (secondaryRequest)
			DereferenceSecondaryRequest( secondaryRequest );

		if (secondarySessionResourceAcquired) {

			SecondaryReleaseResourceLite( IrpContext, &volDo->Secondary->SessionResource );		
		}

        FatUnpinBcb( IrpContext, DirentBcb );

        if (VcbAcquired) { FatReleaseSecondaryVcb( IrpContext, Vcb ); }

        if (FcbAcquired) { FatReleaseFcb( IrpContext, Fcb ); }

        //
        //  If this is a normal termination then pass the request on
        //  to the target device object.
        //

        if (!AbnormalTermination()) {

            NTSTATUS DriverStatus;
            PIO_STACK_LOCATION NextIrpSp;

            //
            //  Get the next stack location, and copy over the stack location
            //

            NextIrpSp = IoGetNextIrpStackLocation( Irp );

            *NextIrpSp = *IrpSp;

            //
            //  Set up the completion routine
            //

            IoSetCompletionRoutine( Irp,
                                    FatFlushCompletionRoutine,
                                    ULongToPtr( Status ),
                                    TRUE,
                                    TRUE,
                                    TRUE );

            //
            //  Send the request.
            //

            DriverStatus = IoCallDriver(Vcb->TargetDeviceObject, Irp);

            Status = (DriverStatus == STATUS_INVALID_DEVICE_REQUEST) ?
                     Status : DriverStatus;

            //
            //  Free the IrpContext and return to the caller.
            //

            FatCompleteRequest( IrpContext, FatNull, STATUS_SUCCESS );
        }

        DebugTrace(-1, Dbg, "FatCommonFlushBuffers -> %08lx\n", Status);
    }

    return Status;
}
Пример #3
0
NTSTATUS
FatProcessException (
    IN PIRP_CONTEXT IrpContext,
    IN PIRP Irp,
    IN NTSTATUS ExceptionCode
    )

/*++

Routine Description:

    This routine process an exception.  It either completes the request
    with the saved exception status or it sends it off to IoRaiseHardError()

Arguments:

    Irp - Supplies the Irp being processed

    ExceptionCode - Supplies the normalized exception status being handled

Return Value:

    NTSTATUS - Returns the results of either posting the Irp or the
        saved completion status.

--*/

{
    PVCB Vcb;
    PIO_STACK_LOCATION IrpSp;
    FAT_VOLUME_STATE TransitionState = VolumeDirty;
    ULONG SavedFlags;

    DebugTrace(0, Dbg, "FatProcessException\n", 0);

    //
    //  If there is not an irp context, we must have had insufficient resources.
    //

    if ( !ARGUMENT_PRESENT( IrpContext ) ) {

        FatCompleteRequest( FatNull, Irp, ExceptionCode );

        return ExceptionCode;
    }

    //
    //  Get the real exception status from IrpContext->ExceptionStatus, and
    //  reset it.
    //

    ExceptionCode = IrpContext->ExceptionStatus;
    FatResetExceptionState( IrpContext );

    //
    //  If this is an Mdl write request, then take care of the Mdl
    //  here so that things get cleaned up properly.  Cc now leaves
    //  the MDL in place so a filesystem can retry after clearing an
    //  internal condition (FAT does not).
    //

#if __NDAS_FAT_WIN2K_SUPPORT__

    if (NdFatCcMdlWriteAbort &&
		(IrpContext->MajorFunction == IRP_MJ_WRITE) &&
        (FlagOn( IrpContext->MinorFunction, IRP_MN_COMPLETE_MDL ) == IRP_MN_COMPLETE_MDL) &&
        (Irp->MdlAddress != NULL)) {

        PIO_STACK_LOCATION LocalIrpSp = IoGetCurrentIrpStackLocation(Irp);

        NdFatCcMdlWriteAbort( LocalIrpSp->FileObject, Irp->MdlAddress );
        Irp->MdlAddress = NULL;
    }

#else

    if ((IrpContext->MajorFunction == IRP_MJ_WRITE) &&
        (FlagOn( IrpContext->MinorFunction, IRP_MN_COMPLETE_MDL ) == IRP_MN_COMPLETE_MDL) &&
        (Irp->MdlAddress != NULL)) {

        PIO_STACK_LOCATION LocalIrpSp = IoGetCurrentIrpStackLocation(Irp);

        CcMdlWriteAbort( LocalIrpSp->FileObject, Irp->MdlAddress );
        Irp->MdlAddress = NULL;
    }

#endif

    //
    //  If we are going to post the request, we may have to lock down the
    //  user's buffer, so do it here in a try except so that we failed the
    //  request if the LockPages fails.
    //
    //  Also unpin any repinned Bcbs, protected by the try {} except {} filter.
    //

    try {

        SavedFlags = IrpContext->Flags;

        //
        //  Make sure we don't try to write through Bcbs
        //

        SetFlag(IrpContext->Flags, IRP_CONTEXT_FLAG_DISABLE_WRITE_THROUGH);

        FatUnpinRepinnedBcbs( IrpContext );

        IrpContext->Flags = SavedFlags;

        //
        //  If we will have to post the request, do it here.  Note
        //  that the last thing FatPrePostIrp() does is mark the Irp pending,
        //  so it is critical that we actually return PENDING.  Nothing
        //  from this point to return can fail, so we are OK.
        //
        //  We cannot do a verify operations at APC level because we
        //  have to wait for Io operations to complete.
        //

#if __NDAS_FAT__

        if (!FlagOn(IrpContext->Flags, IRP_CONTEXT_FLAG_RECURSIVE_CALL) &&
            (((ExceptionCode == STATUS_VERIFY_REQUIRED) && (KeGetCurrentIrql() >= APC_LEVEL)) ||
			(!FlagOn(IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT) && ExceptionCode == STATUS_CANT_WAIT))) {

            ExceptionCode = FatFsdPostRequest( IrpContext, Irp );
        }

#else
        
		if (!FlagOn(IrpContext->Flags, IRP_CONTEXT_FLAG_RECURSIVE_CALL) &&
            (((ExceptionCode == STATUS_VERIFY_REQUIRED) && (KeGetCurrentIrql() >= APC_LEVEL)) ||
             (ExceptionCode == STATUS_CANT_WAIT))) {

            ExceptionCode = FatFsdPostRequest( IrpContext, Irp );
        }

#endif

	} except( FatExceptionFilter( IrpContext, GetExceptionInformation() ) ) {

        ExceptionCode = IrpContext->ExceptionStatus;
        IrpContext->ExceptionStatus = 0;

        IrpContext->Flags = SavedFlags;
    }

    //
    //  If we posted the request, just return here.
    //

    if (ExceptionCode == STATUS_PENDING) {

        return ExceptionCode;
    }

    Irp->IoStatus.Status = ExceptionCode;

    //
    //  If this request is not a "top-level" irp, just complete it.
    //

    if (FlagOn(IrpContext->Flags, IRP_CONTEXT_FLAG_RECURSIVE_CALL)) {

        //
        //  If there is a cache operation above us, commute verify
        //  to a lock conflict.  This will cause retries so that
        //  we have a chance of getting through without needing
        //  to return an unaesthetic error for the operation.
        //

        if (IoGetTopLevelIrp() == (PIRP)FSRTL_CACHE_TOP_LEVEL_IRP &&
            ExceptionCode == STATUS_VERIFY_REQUIRED) {

            ExceptionCode = STATUS_FILE_LOCK_CONFLICT;
        }
        
        FatCompleteRequest( IrpContext, Irp, ExceptionCode );

        return ExceptionCode;
    }

    if (IoIsErrorUserInduced(ExceptionCode)) {

        //
        //  Check for the various error conditions that can be caused by,
        //  and possibly resolved by the user.
        //

        if (ExceptionCode == STATUS_VERIFY_REQUIRED) {

            PDEVICE_OBJECT Device;

            DebugTrace(0, Dbg, "Perform Verify Operation\n", 0);

            //
            //  Now we are at the top level file system entry point.
            //
            //  Grab the device to verify from the thread local storage
            //  and stick it in the information field for transportation
            //  to the fsp.  We also clear the field at this time.
            //

            Device = IoGetDeviceToVerify( Irp->Tail.Overlay.Thread );
            IoSetDeviceToVerify( Irp->Tail.Overlay.Thread, NULL );

            if ( Device == NULL ) {

                Device = IoGetDeviceToVerify( PsGetCurrentThread() );
                IoSetDeviceToVerify( PsGetCurrentThread(), NULL );

                ASSERT( Device != NULL );
            }

            //
            //  Let's not BugCheck just because the driver messed up.
            //

            if (Device == NULL) {

                ExceptionCode = STATUS_DRIVER_INTERNAL_ERROR;

                FatCompleteRequest( IrpContext, Irp, ExceptionCode );

                return ExceptionCode;
            }

            //
            //  FatPerformVerify() will do the right thing with the Irp.

            return FatPerformVerify( IrpContext, Irp, Device );
        }

        //
        //  The other user induced conditions generate an error unless
        //  they have been disabled for this request.
        //

        if (FlagOn(IrpContext->Flags, IRP_CONTEXT_FLAG_DISABLE_POPUPS)) {

            FatCompleteRequest( IrpContext, Irp, ExceptionCode );

            return ExceptionCode;

        } else {

            //
            //  Generate a pop-up
            //

            PDEVICE_OBJECT RealDevice;
            PVPB Vpb;
            PETHREAD Thread;

            if (IoGetCurrentIrpStackLocation(Irp)->FileObject != NULL) {

                Vpb = IoGetCurrentIrpStackLocation(Irp)->FileObject->Vpb;

            } else {

                Vpb = NULL;
            }

            //
            //  The device to verify is either in my thread local storage
            //  or that of the thread that owns the Irp.
            //

            Thread = Irp->Tail.Overlay.Thread;
            RealDevice = IoGetDeviceToVerify( Thread );

            if ( RealDevice == NULL ) {

                Thread = PsGetCurrentThread();
                RealDevice = IoGetDeviceToVerify( Thread );

                ASSERT( RealDevice != NULL );
            }

            //
            //  Let's not BugCheck just because the driver messed up.
            //

            if (RealDevice == NULL) {

                FatCompleteRequest( IrpContext, Irp, ExceptionCode );

                return ExceptionCode;
            }

            //
            //  This routine actually causes the pop-up.  It usually
            //  does this by queuing an APC to the callers thread,
            //  but in some cases it will complete the request immediately,
            //  so it is very important to IoMarkIrpPending() first.
            //

            IoMarkIrpPending( Irp );
            IoRaiseHardError( Irp, Vpb, RealDevice );

            //
            //  We will be handing control back to the caller here, so
            //  reset the saved device object.
            //

            IoSetDeviceToVerify( Thread, NULL );

            //
            //  The Irp will be completed by Io or resubmitted.  In either
            //  case we must clean up the IrpContext here.
            //

            FatDeleteIrpContext( IrpContext );
            return STATUS_PENDING;
        }
    }

    //
    //  This is just a run of the mill error.  If is a STATUS that we
    //  raised ourselves, and the information would be use for the
    //  user, raise an informational pop-up.
    //

    IrpSp = IoGetCurrentIrpStackLocation( Irp );
    Vcb = IrpContext->Vcb;

    //
    //  Now, if the Vcb is unknown to us this means that the error was raised
    //  in the process of a mount and before we even had a chance to build
    //  a full Vcb - and was really handled there.
    //

    if (Vcb != NULL) {

        if ( !FatDeviceIsFatFsdo( IrpSp->DeviceObject) &&
             !NT_SUCCESS(ExceptionCode) &&
             !FsRtlIsTotalDeviceFailure(ExceptionCode) ) {

            TransitionState = VolumeDirtyWithSurfaceTest;
        }

        //
        //  If this was a STATUS_FILE_CORRUPT or similar error indicating some
        //  nastiness out on the media, then mark the volume permanently dirty.
        //

        if (!FlagOn(IrpContext->Flags, IRP_CONTEXT_FLAG_DISABLE_POPUPS) &&
            ( TransitionState == VolumeDirtyWithSurfaceTest ||
              (ExceptionCode == STATUS_FILE_CORRUPT_ERROR) ||
              (ExceptionCode == STATUS_DISK_CORRUPT_ERROR) ||
              (ExceptionCode == STATUS_EA_CORRUPT_ERROR) ||
              (ExceptionCode == STATUS_INVALID_EA_NAME) ||
              (ExceptionCode == STATUS_EA_LIST_INCONSISTENT) ||
              (ExceptionCode == STATUS_NO_EAS_ON_FILE) )) {

            ASSERT( NodeType(Vcb) == FAT_NTC_VCB );

            SetFlag( Vcb->VcbState, VCB_STATE_FLAG_MOUNTED_DIRTY );

            //
            //  Do the "dirty" work, ignoring any error.
            //

            try {

                FatMarkVolume( IrpContext, Vcb, TransitionState );

            } except( FatExceptionFilter( IrpContext, GetExceptionInformation() ) ) {

                NOTHING;
            }
        }
    }