Write-once information recording medium, information recording method, information recording apparatus, information reproducing method, information reproducing apparatus, and a method of manufacturing the information recording medium

Recording capacity per one recording layer is increased, the information recording medium size SBM is changed depending on the size of the spare area, become interdependent and the DDS and SBM, the disc management information is less likely to get. In the information recording medium of the present invention, if the assigned most increase the size of the user data area, the number of blocks needed to store the space bitmap is In such an information recording medium, and the number of blocks needed to store the space bitmap recording layer with a