Function Ext2ReadFile

Ext4Fsd/read.c:470–830

}

NTSTATUS
Ext2ReadFile(IN PEXT2_IRP_CONTEXT IrpContext)
{
    NTSTATUS            Status = STATUS_UNSUCCESSFUL;

    PEXT2_VCB           Vcb = NULL;
    PEXT2_FCB           Fcb = NULL;
    PEXT2_CCB           Ccb = NULL;
    PFILE_OBJECT        FileObject = NULL;

    PDEVICE_OBJECT      DeviceObject = NULL;

    PIRP                Irp = NULL;
    PIO_STACK_LOCATION  IoStackLocation = NULL;

    ULONG               Length;
    ULONG               ReturnedLength = 0;
    LARGE_INTEGER       ByteOffset;

    BOOLEAN             OpPostIrp = FALSE;
    BOOLEAN             PagingIo;
    BOOLEAN             Nocache;
    BOOLEAN             SynchronousIo;
    BOOLEAN             MainResourceAcquired = FALSE;
    BOOLEAN             PagingIoResourceAcquired = FALSE;

    PUCHAR              Buffer;

    __try {

        ASSERT(IrpContext);
        ASSERT((IrpContext->Identifier.Type == EXT2ICX) &&
               (IrpContext->Identifier.Size == sizeof(EXT2_IRP_CONTEXT)));

        DeviceObject = IrpContext->DeviceObject;
        Vcb = (PEXT2_VCB) DeviceObject->DeviceExtension;
        ASSERT(Vcb != NULL);
        ASSERT((Vcb->Identifier.Type == EXT2VCB) &&
               (Vcb->Identifier.Size == sizeof(EXT2_VCB)));

        FileObject = IrpContext->FileObject;
        Fcb = (PEXT2_FCB) FileObject->FsContext;
        ASSERT(Fcb);
        ASSERT((Fcb->Identifier.Type == EXT2FCB) &&
               (Fcb->Identifier.Size == sizeof(EXT2_FCB)));

        Ccb = (PEXT2_CCB) FileObject->FsContext2;

        Irp = IrpContext->Irp;
        IoStackLocation = IoGetCurrentIrpStackLocation(Irp);

        Length = IoStackLocation->Parameters.Read.Length;
        ByteOffset = IoStackLocation->Parameters.Read.ByteOffset;

        PagingIo = IsFlagOn(Irp->Flags, IRP_PAGING_IO);
        Nocache = IsFlagOn(Irp->Flags, IRP_NOCACHE);
        SynchronousIo = IsFlagOn(FileObject->Flags, FO_SYNCHRONOUS_IO);