1. A computer program product for virtual machine disk image access in a storage system, the computer program product comprising a computer readable storage device having program instructions embodied therewith, the program instructions executable by a processor to cause the processor to: in response to a disk image in a file system of the storage system receiving an I/O request, reconstructing, by the processor, the I/O request into an original file system request by: laying out the disk image; performing type-specific introspection on the disk image comprising determining a disk image type indicative of a type of file system in the disk image, and using a file system specific process for the disk image for analyzing the disk image type to access a disk image metadata structure; and converting the I/O request into the original file system request based on the disk image metadata structure.