fsctrl.c

winddk src目录下的文件系统驱动源码压缩!

            *Lbo = 0;
        }

        *SectorCount = ((ULONG) LiSectorCount) << MCB_SCALE_LOG2;

        if ((*SectorCount == 0) && (LiSectorCount != 0)) {
            *SectorCount = (ULONG) -1;  /* it overflowed */
        }
    }

    return Results;
}


VOID
FatRemoveMcbEntry (
    IN PVCB Vcb,
    IN PLARGE_MCB Mcb,
    IN VBO Vbo,
    IN ULONG SectorCount
    )
{

    if ((SectorCount) && (SectorCount != 0xFFFFFFFF)) {

        SectorCount--;
        SectorCount >>= MCB_SCALE_LOG2;
        SectorCount++;
    }

    Vbo >>= MCB_SCALE_LOG2;

#if DBG
    try {
#endif

        FsRtlRemoveLargeMcbEntry( Mcb,
                                  (LONGLONG) Vbo,
                                  (LONGLONG) SectorCount);

#if DBG
    } except(FatBugCheckExceptionFilter( GetExceptionInformation() )) {

          NOTHING;
    }
#endif

}


NTSTATUS
FatFsdFileSystemControl (
    IN PVOLUME_DEVICE_OBJECT VolumeDeviceObject,
    IN PIRP Irp
    )

/*++

Routine Description:

    This routine implements the FSD part of FileSystem control operations

Arguments:

    VolumeDeviceObject - Supplies the volume device object where the
        file exists

    Irp - Supplies the Irp being processed

Return Value:

    NTSTATUS - The FSD status for the IRP

--*/

{
    BOOLEAN Wait;
    NTSTATUS Status;
    PIRP_CONTEXT IrpContext = NULL;

    BOOLEAN TopLevel;

    DebugTrace(+1, Dbg,"FatFsdFileSystemControl\n", 0);

    //
    //  Call the common FileSystem Control routine, with blocking allowed if
    //  synchronous.  This opeation needs to special case the mount
    //  and verify suboperations because we know they are allowed to block.
    //  We identify these suboperations by looking at the file object field
    //  and seeing if its null.
    //

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

        Wait = TRUE;

    } else {

        Wait = CanFsdWait( Irp );
    }

    FsRtlEnterFileSystem();

    TopLevel = FatIsIrpTopLevel( Irp );

    try {

        PIO_STACK_LOCATION IrpSp;

        IrpSp = IoGetCurrentIrpStackLocation( Irp );

        //
        //  We need to made a special check here for the InvalidateVolumes
        //  FSCTL as that comes in with a FileSystem device object instead
        //  of a volume device object.
        //

        if (FatDeviceIsFatFsdo( IrpSp->DeviceObject) &&
            (IrpSp->MajorFunction == IRP_MJ_FILE_SYSTEM_CONTROL) &&
            (IrpSp->MinorFunction == IRP_MN_USER_FS_REQUEST) &&
            (IrpSp->Parameters.FileSystemControl.FsControlCode ==
             FSCTL_INVALIDATE_VOLUMES)) {

            Status = FatInvalidateVolumes( Irp );

        } else {

            IrpContext = FatCreateIrpContext( Irp, Wait );

            Status = FatCommonFileSystemControl( IrpContext, Irp );
        }

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

        //
        //  We had some trouble trying to perform the requested
        //  operation, so we'll abort the I/O request with
        //  the error status that we get back from the
        //  execption code
        //

        Status = FatProcessException( IrpContext, Irp, GetExceptionCode() );
    }

    if (TopLevel) { IoSetTopLevelIrp( NULL ); }

    FsRtlExitFileSystem();

    //
    //  And return to our caller
    //

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

    return Status;
}


NTSTATUS
FatCommonFileSystemControl (
    IN PIRP_CONTEXT IrpContext,
    IN PIRP Irp
    )

/*++

Routine Description:

    This is the common routine for doing FileSystem control operations called
    by both the fsd and fsp threads

Arguments:

    Irp - Supplies the Irp to process

Return Value:

    NTSTATUS - The return status for the operation

--*/

{
    NTSTATUS Status;
    PIO_STACK_LOCATION IrpSp;

    //
    //  Get a pointer to the current Irp stack location
    //

    IrpSp = IoGetCurrentIrpStackLocation( Irp );

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

    //
    //  We know this is a file system control so we'll case on the
    //  minor function, and call a internal worker routine to complete
    //  the irp.
    //

    switch (IrpSp->MinorFunction) {

    case IRP_MN_USER_FS_REQUEST:

        Status = FatUserFsCtrl( IrpContext, Irp );
        break;

    case IRP_MN_MOUNT_VOLUME:

        Status = FatMountVolume( IrpContext,
                                 IrpSp->Parameters.MountVolume.DeviceObject,
                                 IrpSp->Parameters.MountVolume.Vpb,
                                 IrpSp->DeviceObject );

        //
        //  Complete the request.
        //
        //  We do this here because FatMountVolume can be called recursively,
        //  but the Irp is only to be completed once.
        //
        //  NOTE: I don't think this is true anymore (danlo 3/15/1999).  Probably
        //  an artifact of the old doublespace attempt.
        //

        FatCompleteRequest( IrpContext, Irp, Status );
        break;

    case IRP_MN_VERIFY_VOLUME:

        Status = FatVerifyVolume( IrpContext, Irp );
        break;

    default:

        DebugTrace( 0, Dbg, "Invalid FS Control Minor Function %08lx\n", IrpSp->MinorFunction);

        FatCompleteRequest( IrpContext, Irp, STATUS_INVALID_DEVICE_REQUEST );
        Status = STATUS_INVALID_DEVICE_REQUEST;
        break;
    }

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

    return Status;
}


//
//  Local Support Routine
//

NTSTATUS
FatMountVolume (
    IN PIRP_CONTEXT IrpContext,
    IN PDEVICE_OBJECT TargetDeviceObject,
    IN PVPB Vpb,
    IN PDEVICE_OBJECT FsDeviceObject
    )

/*++

Routine Description:

    This routine performs the mount volume operation.  It is responsible for
    either completing of enqueuing the input Irp.

    Its job is to verify that the volume denoted in the IRP is a Fat volume,
    and create the VCB and root DCB structures.  The algorithm it uses is
    essentially as follows:

    1. Create a new Vcb Structure, and initialize it enough to do cached
       volume file I/O.

    2. Read the disk and check if it is a Fat volume.

    3. If it is not a Fat volume then free the cached volume file, delete
       the VCB, and complete the IRP with STATUS_UNRECOGNIZED_VOLUME

    4. Check if the volume was previously mounted and if it was then do a
       remount operation.  This involves reinitializing the cached volume
       file, checking the dirty bit, resetting up the allocation support,
       deleting the VCB, hooking in the old VCB, and completing the IRP.

    5. Otherwise create a root DCB, create Fsp threads as necessary, and
       complete the IRP.

Arguments:

    TargetDeviceObject - This is where we send all of our requests.

    Vpb - This gives us additional information needed to complete the mount.

Return Value:

    NTSTATUS - The return status for the operation

--*/

{
    PIO_STACK_LOCATION IrpSp = IoGetCurrentIrpStackLocation( IrpContext->OriginatingIrp );
    NTSTATUS Status;

    PBCB BootBcb;
    PPACKED_BOOT_SECTOR BootSector;

    PBCB DirentBcb;
    PDIRENT Dirent;
    ULONG ByteOffset;

    BOOLEAN MountNewVolume = FALSE;
    BOOLEAN WeClearedVerifyRequiredBit = FALSE;
    BOOLEAN DoARemount = FALSE;

    PVCB OldVcb;
    PVPB OldVpb;

    PDEVICE_OBJECT RealDevice;
    PVOLUME_DEVICE_OBJECT VolDo = NULL;
    PVCB Vcb = NULL;
    PFILE_OBJECT RootDirectoryFile = NULL;

    PLIST_ENTRY Links;

    IO_STATUS_BLOCK Iosb;
    ULONG ChangeCount = 0;

    DISK_GEOMETRY Geometry;

    PARTITION_INFORMATION_EX PartitionInformation;
    NTSTATUS StatusPartInfo;

    DebugTrace(+1, Dbg, "FatMountVolume\n", 0);
    DebugTrace( 0, Dbg, "TargetDeviceObject = %08lx\n", TargetDeviceObject);
    DebugTrace( 0, Dbg, "Vpb                = %08lx\n", Vpb);

    ASSERT( FlagOn(IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT) );
    ASSERT( FatDeviceIsFatFsdo( FsDeviceObject));

    //
    //  Verify that there is a disk here and pick up the change count.
    //

    Status = FatPerformDevIoCtrl( IrpContext,
                                  IOCTL_DISK_CHECK_VERIFY,
                                  TargetDeviceObject,
                                  &ChangeCount,
                                  sizeof(ULONG),
                                  FALSE,
                                  TRUE,
                                  &Iosb );

    if (!NT_SUCCESS( Status )) {

        //
        //  If we will allow a raw mount then avoid sending the popup.
        //
        //  Only send this on "true" disk devices to handle the accidental
        //  legacy of FAT. No other FS will throw a harderror on empty
        //  drives.
        //
        //  Cmd should really handle this per 9x.
        //

        if (!FlagOn( IrpSp->Flags, SL_ALLOW_RAW_MOUNT ) &&
            Vpb->RealDevice->DeviceType == FILE_DEVICE_DISK) {

            FatNormalizeAndRaiseStatus( IrpContext, Status );
        }

        return Status;
    }

    if (Iosb.Information != sizeof(ULONG)) {

        //
        //  Be safe about the count in case the driver didn't fill it in
        //

        ChangeCount = 0;
    }

    //
    //  If this is a CD class device,  then check to see if there is a 
    //  'data track' or not.  This is to avoid issuing paging reads which will
    //  fail later in the mount process (e.g. CD-DA or blank CD media)
    //

    if ((TargetDeviceObject->DeviceType == FILE_DEVICE_CD_ROM) &&
        !FatScanForDataTrack( IrpContext, TargetDeviceObject))  {

        return STATUS_UNRECOGNIZED_VOLUME;
    }

    //
    //  Ping the volume with a partition query and pick up the partition
    //  type.  We'll check this later to avoid some scurrilous volumes.
    //

    StatusPartInfo = FatPerformDevIoCtrl( IrpContext,
                                          IOCTL_DISK_GET_PARTITION_INFO_EX,
                                          TargetDeviceObject,
                                          &PartitionInformation,
                                          sizeof(PARTITION_INFORMATION_EX),
                                          FALSE,
                                          TRUE,
                                          &Iosb );

    //
    //  Make sure we can wait.
    //

    SetFlag(IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT);

    //
    //  Do a quick check to see if there any Vcb's which can be removed.
    //

    FatScanForDismountedVcb( IrpContext );

    //
    //  Initialize the Bcbs and our final state so that the termination
    //  handlers will know what to free or unpin
    //

    BootBcb = NULL;
    DirentBcb = NULL;

    Vcb = NULL;
    VolDo = NULL;
    MountNewVolume = FALSE;

    try {

        //
        //  Synchronize with FatCheckForDismount(), which modifies the vpb.
        //

        (VOID)FatAcquireExclusiveGlobal( IrpContext );

        //
        //  Create a new volume device object.  This will have the Vcb
        //  hanging off of its end, and set its alignment requirement
        //  from the device we talk to.
        //

        if (!NT_SUCCESS(Status = IoCreateDevice( FatData.DriverObject,
                                                 sizeof(VOLUME_DEVICE_OBJECT) - sizeof(DEVICE_OBJECT),
                                                 NULL,
                                                 FILE_DEVICE_DISK_FILE_SYSTEM,
                                                 0,
                                                 FALSE,
                                                 (PDEVICE_OBJECT *)&VolDo))) {

            try_return( Status );
        }

        //
        //  Our alignment requirement is the larger of the processor alignment requirement
        //  already in the volume device object and that in the TargetDeviceObject