NTSTATUS FatCommonDeviceControl ( IN PIRP_CONTEXT IrpContext, IN PIRP Irp ) /*++ Routine Description: This is the common routine for doing Device control operations called by both the fsd and fsp threads Arguments: Irp - Supplies the Irp to process InFsp - Indicates if this is the fsp thread or someother thread Return Value: NTSTATUS - The return status for the operation --*/ { NTSTATUS Status; PIO_STACK_LOCATION IrpSp; KEVENT WaitEvent; PVOID CompletionContext = NULL; PVCB Vcb; PFCB Fcb; PCCB Ccb; // // Get a pointer to the current Irp stack location // IrpSp = IoGetCurrentIrpStackLocation( Irp ); DebugTrace(+1, Dbg, "FatCommonDeviceControl\n", 0); DebugTrace( 0, Dbg, "Irp = %08lx\n", Irp); DebugTrace( 0, Dbg, "MinorFunction = %08lx\n", IrpSp->MinorFunction); // // Decode the file object, the only type of opens we accept are // user volume opens. // if (FatDecodeFileObject( IrpSp->FileObject, &Vcb, &Fcb, &Ccb ) != UserVolumeOpen) { FatCompleteRequest( IrpContext, Irp, STATUS_INVALID_PARAMETER ); DebugTrace(-1, Dbg, "FatCommonDeviceControl -> %08lx\n", STATUS_INVALID_PARAMETER); return STATUS_INVALID_PARAMETER; } // // A few IOCTLs actually require some intervention on our part // switch (IrpSp->Parameters.DeviceIoControl.IoControlCode) { case IOCTL_VOLSNAP_FLUSH_AND_HOLD_WRITES: // // This is sent by the Volume Snapshot driver (Lovelace). // We flush the volume, and hold all file resources // to make sure that nothing more gets dirty. Then we wait // for the IRP to complete or cancel. // SetFlag( IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT ); FatAcquireExclusiveVolume( IrpContext, Vcb ); FatFlushAndCleanVolume( IrpContext, Irp, Vcb, FlushWithoutPurge ); KeInitializeEvent( &WaitEvent, NotificationEvent, FALSE ); CompletionContext = &WaitEvent; // // Get the next stack location, and copy over the stack location // IoCopyCurrentIrpStackLocationToNext( Irp ); // // Set up the completion routine // IoSetCompletionRoutine( Irp, FatDeviceControlCompletionRoutine, CompletionContext, TRUE, TRUE, TRUE ); break; default: // // FAT doesn't need to see this on the way back, so skip ourselves. // IoSkipCurrentIrpStackLocation( Irp ); break; } // // Send the request. // Status = IoCallDriver(Vcb->TargetDeviceObject, Irp); if (Status == STATUS_PENDING && CompletionContext) { KeWaitForSingleObject( &WaitEvent, Executive, KernelMode, FALSE, NULL ); Status = Irp->IoStatus.Status; } // // If we had a context, the IRP remains for us and we will complete it. // Handle it appropriately. // if (CompletionContext) { // // Release all the resources that we held because of a // VOLSNAP_FLUSH_AND_HOLD. // ASSERT( IrpSp->Parameters.DeviceIoControl.IoControlCode == IOCTL_VOLSNAP_FLUSH_AND_HOLD_WRITES ); FatReleaseVolume( IrpContext, Vcb ); // // If we had no context, the IRP will complete asynchronously. // } else { Irp = NULL; } FatCompleteRequest( IrpContext, Irp, Status ); DebugTrace(-1, Dbg, "FatCommonDeviceControl -> %08lx\n", Status); return Status; }
NTSTATUS FatCommonDeviceControl ( IN PIRP_CONTEXT IrpContext, IN PIRP Irp ) /*++ Routine Description: This is the common routine for doing Device control operations called by both the fsd and fsp threads Arguments: Irp - Supplies the Irp to process InFsp - Indicates if this is the fsp thread or someother thread Return Value: NTSTATUS - The return status for the operation --*/ { NTSTATUS Status; PIO_STACK_LOCATION IrpSp; KEVENT WaitEvent; PVOID CompletionContext = NULL; PVCB Vcb; PFCB Fcb; PCCB Ccb; #if __NDAS_FAT_PRIMARY__ if (IrpContext->MajorFunction == IRP_MJ_DEVICE_CONTROL && IoGetCurrentIrpStackLocation(Irp)->Parameters.DeviceIoControl.IoControlCode == IOCTL_INSERT_PRIMARY_SESSION) { PVOLUME_DEVICE_OBJECT VolDo = CONTAINING_RECORD( IoGetCurrentIrpStackLocation(Irp)->DeviceObject, VOLUME_DEVICE_OBJECT, DeviceObject ); PSESSION_INFORMATION inputBuffer = (PSESSION_INFORMATION)Irp->AssociatedIrp.SystemBuffer; ULONG inputBufferLength = IoGetCurrentIrpStackLocation(Irp)->Parameters.DeviceIoControl.InputBufferLength; ULONG outputBufferLength; PULONG outputBuffer; PPRIMARY_SESSION primarySession; if (inputBufferLength != sizeof(SESSION_INFORMATION)) { FatCompleteRequest( IrpContext, Irp, Status = STATUS_INVALID_PARAMETER ); return Status; } outputBufferLength = IoGetCurrentIrpStackLocation(Irp)->Parameters.DeviceIoControl.OutputBufferLength; outputBuffer = (PULONG)Irp->AssociatedIrp.SystemBuffer; primarySession = PrimarySession_Create( IrpContext, VolDo, inputBuffer, Irp ); ASSERT( primarySession ); FatCompleteRequest( IrpContext, NULL, 0 ); Status = STATUS_PENDING; return Status; } #endif // // Get a pointer to the current Irp stack location // IrpSp = IoGetCurrentIrpStackLocation( Irp ); DebugTrace(+1, Dbg, "FatCommonDeviceControl\n", 0); DebugTrace( 0, Dbg, "Irp = %08lx\n", Irp); DebugTrace( 0, Dbg, "MinorFunction = %08lx\n", IrpSp->MinorFunction); // // Decode the file object, the only type of opens we accept are // user volume opens. // if (FatDecodeFileObject( IrpSp->FileObject, &Vcb, &Fcb, &Ccb ) != UserVolumeOpen) { FatCompleteRequest( IrpContext, Irp, STATUS_INVALID_PARAMETER ); DebugTrace(-1, Dbg2, "FatCommonDeviceControl -> %08lx\n", STATUS_INVALID_PARAMETER); return STATUS_INVALID_PARAMETER; } #define IOCTL_VOLUME_BASE ((ULONG) 'V') #define MOUNTDEVCONTROLTYPE ((ULONG) 'M') DebugTrace2( 0, Dbg2, ("FatCommonDeviceControl: deviceType = %d, function = %d IOCTL_VOLUME_BASE = %d, MOUNTDEVCONTROLTYPE = %d\n", DEVICE_TYPE_FROM_CTL_CODE(IrpSp->Parameters.DeviceIoControl.IoControlCode), (UCHAR)((IrpSp->Parameters.DeviceIoControl.IoControlCode & 0x00003FFC) >> 2), IOCTL_VOLUME_BASE, MOUNTDEVCONTROLTYPE) ); #if __NDAS_FAT__ if (CONTAINING_RECORD(Vcb, VOLUME_DEVICE_OBJECT, Vcb)->NetdiskEnableMode == NETDISK_SECONDARY) SetFlag( IrpContext->NdFatFlags, ND_FAT_IRP_CONTEXT_FLAG_SECONDARY_CONTEXT ); #endif // // A few IOCTLs actually require some intervention on our part // switch (IrpSp->Parameters.DeviceIoControl.IoControlCode) { case IOCTL_VOLSNAP_FLUSH_AND_HOLD_WRITES: #if __NDAS_FAT_WIN2K_SUPPORT__ if (!IS_WINDOWSXP_OR_LATER()) { ASSERT( FALSE ); IoSkipCurrentIrpStackLocation( Irp ); break; } #endif // // This is sent by the Volume Snapshot driver (Lovelace). // We flush the volume, and hold all file resources // to make sure that nothing more gets dirty. Then we wait // for the IRP to complete or cancel. // SetFlag( IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT ); FatAcquireExclusiveVolume( IrpContext, Vcb ); FatFlushAndCleanVolume( IrpContext, Irp, Vcb, FlushWithoutPurge ); KeInitializeEvent( &WaitEvent, NotificationEvent, FALSE ); CompletionContext = &WaitEvent; // // Get the next stack location, and copy over the stack location // IoCopyCurrentIrpStackLocationToNext( Irp ); // // Set up the completion routine // IoSetCompletionRoutine( Irp, FatDeviceControlCompletionRoutine, CompletionContext, TRUE, TRUE, TRUE ); break; default: // // FAT doesn't need to see this on the way back, so skip ourselves. // IoSkipCurrentIrpStackLocation( Irp ); break; } // // Send the request. // Status = IoCallDriver(Vcb->TargetDeviceObject, Irp); if (Status == STATUS_PENDING && CompletionContext) { KeWaitForSingleObject( &WaitEvent, Executive, KernelMode, FALSE, NULL ); Status = Irp->IoStatus.Status; } //DebugTrace(-1, Dbg2, "FatCommonDeviceControl -> Information %08lx\n", Irp->IoStatus.Information); // // If we had a context, the IRP remains for us and we will complete it. // Handle it appropriately. // if (CompletionContext) { // // Release all the resources that we held because of a // VOLSNAP_FLUSH_AND_HOLD. // ASSERT( IrpSp->Parameters.DeviceIoControl.IoControlCode == IOCTL_VOLSNAP_FLUSH_AND_HOLD_WRITES ); FatReleaseVolume( IrpContext, Vcb ); // // If we had no context, the IRP will complete asynchronously. // } else { Irp = NULL; } FatCompleteRequest( IrpContext, Irp, Status ); DebugTrace(-1, Dbg2, "FatCommonDeviceControl -> %08lx\n", Status); return Status; }
NTSTATUS FatPnpSurpriseRemove ( PIRP_CONTEXT IrpContext, PIRP Irp, PVCB Vcb ) /*++ Routine Description: This routine handles the PnP surprise remove operation. This is another type of notification that the underlying storage device for the volume we have is gone, and is excellent indication that the volume will never reappear. The filesystem is responsible for initiation or completion the dismount. For the most part, only "real" drivers care about the distinction of a surprise remove, which is a result of our noticing that a user (usually) physically reached into the machine and pulled something out. Surprise will be followed by a Remove when all references have been shut down. Arguments: Irp - Supplies the Irp to process Vcb - Supplies the volume being removed. Return Value: NTSTATUS - The return status for the operation --*/ { NTSTATUS Status; KEVENT Event; BOOLEAN VcbDeleted; // // SURPRISE - a device was physically yanked away without // any warning. This means external forces. // FatAcquireExclusiveGlobal( IrpContext ); FatAcquireExclusiveVcb( IrpContext, Vcb ); // // We need to pass this down before starting the dismount, which // could disconnect us immediately from the stack. // // // Get the next stack location, and copy over the stack location // IoCopyCurrentIrpStackLocationToNext( Irp ); // // Set up the completion routine // KeInitializeEvent( &Event, NotificationEvent, FALSE ); IoSetCompletionRoutine( Irp, FatPnpCompletionRoutine, &Event, TRUE, TRUE, TRUE ); // // Send the request and wait. // Status = IoCallDriver(Vcb->TargetDeviceObject, Irp); if (Status == STATUS_PENDING) { KeWaitForSingleObject( &Event, Executive, KernelMode, FALSE, NULL ); Status = Irp->IoStatus.Status; } try { // // Knock as many files down for this volume as we can. // FatFlushAndCleanVolume( IrpContext, Irp, Vcb, NoFlush ); // // Now make our dismount happen. This may not vaporize the // Vcb, of course, since there could be any number of handles // outstanding since this is an out of band notification. // VcbDeleted = FatCheckForDismount( IrpContext, Vcb, TRUE ); } finally { // // Release the Vcb if it could still remain. // if (!VcbDeleted) { FatReleaseVcb( IrpContext, Vcb ); } FatReleaseGlobal( IrpContext ); } // // Cleanup our IrpContext and complete the IRP. // FatCompleteRequest( IrpContext, Irp, Status ); return Status; }
NTSTATUS FatPnpRemove ( PIRP_CONTEXT IrpContext, PIRP Irp, PVCB Vcb ) /*++ Routine Description: This routine handles the PnP remove operation. This is our notification that the underlying storage device for the volume we have is gone, and an excellent indication that the volume will never reappear. The filesystem is responsible for initiation or completion of the dismount. Arguments: Irp - Supplies the Irp to process Vcb - Supplies the volume being removed. Return Value: NTSTATUS - The return status for the operation --*/ { NTSTATUS Status; KEVENT Event; BOOLEAN VcbDeleted; // // REMOVE - a storage device is now gone. We either got // QUERY'd and said yes OR got a SURPRISE OR a storage // stack failed to spin back up from a sleep/stop state // (the only case in which this will be the first warning). // // Note that it is entirely unlikely that we will be around // for a REMOVE in the first two cases, as we try to intiate // dismount. // // // Acquire the global resource so that we can try to vaporize // the volume, and the vcb resource itself. // FatAcquireExclusiveGlobal( IrpContext ); FatAcquireExclusiveVcb( IrpContext, Vcb ); // // The device will be going away. Remove our lock (benign // if we never had it). // (VOID) FatUnlockVolumeInternal( IrpContext, Vcb, NULL ); // // We need to pass this down before starting the dismount, which // could disconnect us immediately from the stack. // // // Get the next stack location, and copy over the stack location // IoCopyCurrentIrpStackLocationToNext( Irp ); // // Set up the completion routine // KeInitializeEvent( &Event, NotificationEvent, FALSE ); IoSetCompletionRoutine( Irp, FatPnpCompletionRoutine, &Event, TRUE, TRUE, TRUE ); // // Send the request and wait. // Status = IoCallDriver(Vcb->TargetDeviceObject, Irp); if (Status == STATUS_PENDING) { KeWaitForSingleObject( &Event, Executive, KernelMode, FALSE, NULL ); Status = Irp->IoStatus.Status; } try { // // Knock as many files down for this volume as we can. // FatFlushAndCleanVolume( IrpContext, Irp, Vcb, NoFlush ); // // Now make our dismount happen. This may not vaporize the // Vcb, of course, since there could be any number of handles // outstanding if we were not preceeded by a QUERY. // // PnP will take care of disconnecting this stack if we // couldn't get off of it immediately. // VcbDeleted = FatCheckForDismount( IrpContext, Vcb, TRUE ); } finally { // // Release the Vcb if it could still remain. // if (!VcbDeleted) { FatReleaseVcb( IrpContext, Vcb ); } FatReleaseGlobal( IrpContext ); } // // Cleanup our IrpContext and complete the IRP. // FatCompleteRequest( IrpContext, Irp, Status ); return Status; }
NTSTATUS FatPnpQueryRemove ( PIRP_CONTEXT IrpContext, PIRP Irp, PVCB Vcb ) /*++ Routine Description: This routine handles the PnP query remove operation. The filesystem is responsible for answering whether there are any reasons it sees that the volume can not go away (and the device removed). Initiation of the dismount begins when we answer yes to this question. Query will be followed by a Cancel or Remove. Arguments: Irp - Supplies the Irp to process Vcb - Supplies the volume being queried. Return Value: NTSTATUS - The return status for the operation --*/ { NTSTATUS Status; KEVENT Event; BOOLEAN VcbDeleted = FALSE; BOOLEAN GlobalHeld = FALSE; // // Having said yes to a QUERY, any communication with the // underlying storage stack is undefined (and may block) // until the bounding CANCEL or REMOVE is sent. // // // Acquire the global resource so that we can try to vaporize // the volume, and the vcb resource itself. // FatAcquireExclusiveVcb( IrpContext, Vcb ); try { Status = FatLockVolumeInternal( IrpContext, Vcb, NULL ); // // Reacquire the resources in the right order. // FatReleaseVcb( IrpContext, Vcb ); FatAcquireExclusiveGlobal( IrpContext ); GlobalHeld = TRUE; FatAcquireExclusiveVcb( IrpContext, Vcb ); if (NT_SUCCESS( Status )) { // // With the volume held locked, note that we must finalize as much // as possible right now. // FatFlushAndCleanVolume( IrpContext, Irp, Vcb, Flush ); // // We need to pass this down before starting the dismount, which // could disconnect us immediately from the stack. // // // Get the next stack location, and copy over the stack location // IoCopyCurrentIrpStackLocationToNext( Irp ); // // Set up the completion routine // KeInitializeEvent( &Event, NotificationEvent, FALSE ); IoSetCompletionRoutine( Irp, FatPnpCompletionRoutine, &Event, TRUE, TRUE, TRUE ); // // Send the request and wait. // Status = IoCallDriver(Vcb->TargetDeviceObject, Irp); if (Status == STATUS_PENDING) { KeWaitForSingleObject( &Event, Executive, KernelMode, FALSE, NULL ); Status = Irp->IoStatus.Status; } // // Now if no one below us failed already, initiate the dismount // on this volume, make it go away. PnP needs to see our internal // streams close and drop their references to the target device. // // Since we were able to lock the volume, we are guaranteed to // move this volume into dismount state and disconnect it from // the underlying storage stack. The force on our part is actually // unnecesary, though complete. // // What is not strictly guaranteed, though, is that the closes // for the metadata streams take effect synchronously underneath // of this call. This would leave references on the target device // even though we are disconnected! // if (NT_SUCCESS( Status )) { VcbDeleted = FatCheckForDismount( IrpContext, Vcb, TRUE ); ASSERT( VcbDeleted || Vcb->VcbCondition == VcbBad ); } } } finally { // // Release the Vcb if it could still remain. // if (!VcbDeleted) { FatReleaseVcb( IrpContext, Vcb ); } if (GlobalHeld) { FatReleaseGlobal( IrpContext ); } } // // Cleanup our IrpContext and complete the IRP if neccesary. // FatCompleteRequest( IrpContext, Irp, Status ); return Status; }
NTSTATUS FatCommonDeviceControl ( IN PIRP_CONTEXT IrpContext, IN PIRP Irp ) /*++ Routine Description: This is the common routine for doing Device control operations called by both the fsd and fsp threads Arguments: Irp - Supplies the Irp to process InFsp - Indicates if this is the fsp thread or someother thread Return Value: NTSTATUS - The return status for the operation --*/ { NTSTATUS Status; PIO_STACK_LOCATION IrpSp; KEVENT WaitEvent; PVOID CompletionContext = NULL; PVCB Vcb; PFCB Fcb; PCCB Ccb; PAGED_CODE(); // // Get a pointer to the current Irp stack location // IrpSp = IoGetCurrentIrpStackLocation( Irp ); DebugTrace(+1, Dbg, "FatCommonDeviceControl\n", 0); DebugTrace( 0, Dbg, "Irp = %p\n", Irp); DebugTrace( 0, Dbg, "MinorFunction = %08lx\n", IrpSp->MinorFunction); // // Decode the file object, the only type of opens we accept are // user volume opens. // if (FatDecodeFileObject( IrpSp->FileObject, &Vcb, &Fcb, &Ccb ) != UserVolumeOpen) { FatCompleteRequest( IrpContext, Irp, STATUS_INVALID_PARAMETER ); DebugTrace(-1, Dbg, "FatCommonDeviceControl -> %08lx\n", STATUS_INVALID_PARAMETER); return STATUS_INVALID_PARAMETER; } // // A few IOCTLs actually require some intervention on our part // switch (IrpSp->Parameters.DeviceIoControl.IoControlCode) { case IOCTL_VOLSNAP_FLUSH_AND_HOLD_WRITES: // // This is sent by the Volume Snapshot driver (Lovelace). // We flush the volume, and hold all file resources // to make sure that nothing more gets dirty. Then we wait // for the IRP to complete or cancel. // SetFlag( IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT ); FatAcquireExclusiveVolume( IrpContext, Vcb ); FatFlushAndCleanVolume( IrpContext, Irp, Vcb, FlushWithoutPurge ); KeInitializeEvent( &WaitEvent, NotificationEvent, FALSE ); CompletionContext = &WaitEvent; // // Get the next stack location, and copy over the stack location // IoCopyCurrentIrpStackLocationToNext( Irp ); // // Set up the completion routine // IoSetCompletionRoutine( Irp, FatDeviceControlCompletionRoutine, CompletionContext, TRUE, TRUE, TRUE ); break; case IOCTL_DISK_COPY_DATA: // // We cannot allow this IOCTL to be sent unless the volume is locked, // since this IOCTL allows direct writing of data to the volume. // We do allow kernel callers to force access via a flag. A handle that // issued a dismount can send this IOCTL as well. // if (!FlagOn( Vcb->VcbState, VCB_STATE_FLAG_LOCKED ) && !FlagOn( IrpSp->Flags, SL_FORCE_DIRECT_WRITE ) && !FlagOn( Ccb->Flags, CCB_FLAG_COMPLETE_DISMOUNT )) { FatCompleteRequest( IrpContext, Irp, STATUS_ACCESS_DENIED ); DebugTrace(-1, Dbg, "FatCommonDeviceControl -> %08lx\n", STATUS_ACCESS_DENIED); return STATUS_ACCESS_DENIED; } break; case IOCTL_SCSI_PASS_THROUGH: case IOCTL_SCSI_PASS_THROUGH_DIRECT: case IOCTL_SCSI_PASS_THROUGH_EX: case IOCTL_SCSI_PASS_THROUGH_DIRECT_EX: // // If someone is issuing a format unit command underneath us, then make // sure we mark the device as needing verification when they close their // handle. // if ((!FlagOn( IrpSp->FileObject->Flags, FO_FILE_MODIFIED ) || !FlagOn( Ccb->Flags, CCB_FLAG_SENT_FORMAT_UNIT )) && (Irp->AssociatedIrp.SystemBuffer != NULL)) { PCDB Cdb = NULL; // // If this is a 32 bit application running on 64 bit then thunk the // input structures to grab the Cdb. // #if defined (_WIN64) && defined(BUILD_WOW64_ENABLED) if (IoIs32bitProcess(Irp)) { if ( (IrpSp->Parameters.DeviceIoControl.IoControlCode == IOCTL_SCSI_PASS_THROUGH) || (IrpSp->Parameters.DeviceIoControl.IoControlCode == IOCTL_SCSI_PASS_THROUGH_DIRECT )) { if (IrpSp->Parameters.DeviceIoControl.InputBufferLength >= sizeof( SCSI_PASS_THROUGH32 )) { Cdb = (PCDB)((PSCSI_PASS_THROUGH32)(Irp->AssociatedIrp.SystemBuffer))->Cdb; } } else { if (IrpSp->Parameters.DeviceIoControl.InputBufferLength >= sizeof( SCSI_PASS_THROUGH32_EX )) { Cdb = (PCDB)((PSCSI_PASS_THROUGH32_EX)(Irp->AssociatedIrp.SystemBuffer))->Cdb; } } } else { #endif if ( (IrpSp->Parameters.DeviceIoControl.IoControlCode == IOCTL_SCSI_PASS_THROUGH) || (IrpSp->Parameters.DeviceIoControl.IoControlCode == IOCTL_SCSI_PASS_THROUGH_DIRECT )) { if (IrpSp->Parameters.DeviceIoControl.InputBufferLength >= sizeof( SCSI_PASS_THROUGH )) { Cdb = (PCDB)((PSCSI_PASS_THROUGH)(Irp->AssociatedIrp.SystemBuffer))->Cdb; } } else { if (IrpSp->Parameters.DeviceIoControl.InputBufferLength >= sizeof( SCSI_PASS_THROUGH_EX )) { Cdb = (PCDB)((PSCSI_PASS_THROUGH_EX)(Irp->AssociatedIrp.SystemBuffer))->Cdb; } } #if defined (_WIN64) && defined(BUILD_WOW64_ENABLED) } #endif if ((Cdb != NULL) && (Cdb->AsByte[0] == SCSIOP_FORMAT_UNIT)) { SetFlag( Ccb->Flags, CCB_FLAG_SENT_FORMAT_UNIT ); SetFlag( IrpSp->FileObject->Flags, FO_FILE_MODIFIED ); } } // // Fall through as we do not need to know the outcome of this operation. // default: // // FAT doesn't need to see this on the way back, so skip ourselves. // IoSkipCurrentIrpStackLocation( Irp ); break; } // // Send the request. // Status = IoCallDriver(Vcb->TargetDeviceObject, Irp); if (Status == STATUS_PENDING && CompletionContext) { KeWaitForSingleObject( &WaitEvent, Executive, KernelMode, FALSE, NULL ); Status = Irp->IoStatus.Status; } // // If we had a context, the IRP remains for us and we will complete it. // Handle it appropriately. // if (CompletionContext) { // // Release all the resources that we held because of a // VOLSNAP_FLUSH_AND_HOLD. // NT_ASSERT( IrpSp->Parameters.DeviceIoControl.IoControlCode == IOCTL_VOLSNAP_FLUSH_AND_HOLD_WRITES ); FatReleaseVolume( IrpContext, Vcb ); // // If we had no context, the IRP will complete asynchronously. // } else { Irp = NULL; } FatCompleteRequest( IrpContext, Irp, Status ); DebugTrace(-1, Dbg, "FatCommonDeviceControl -> %08lx\n", Status); return Status; }