IN  PIRP_CONTEXT IrpContext,
  IN  PERESOURCE Resource,
  IN  BOOLEAN IgnoreWait,
  IN  BOOLEAN Exclusive

Routine Description:

    This is the single routine used to acquire file system resources.  It
    looks at the IgnoreWait flag to determine whether to try to acquire the
    resource without waiting.  Returning TRUE/FALSE to indicate success or
    failure.  Otherwise it is driven by the WAIT flag in the IrpContext and
    will raise CANT_WAIT on a failure.


    Resource - This is the resource to try and acquire.

    IgnoreWait - If TRUE then this routine will not wait to acquire the
        resource and will return a boolean indicating whether the resource was
        acquired.  Otherwise we use the flag in the IrpContext and raise
        if the resource is not acquired.

    Exclusive - Indicates whether we should acquire the resource shared or

Return Value:

    BOOLEAN - TRUE if the resource is acquired.  FALSE if not acquired and
        IgnoreWait is specified.  Otherwise we raise CANT_WAIT.