static void null_destroy(struct vm_store *store) Frees this stores space. static off_t null_commit(struct vm_store *store, off_t size) Sets committed size to size and returns it. static int null_has_page(struct vm_store *store, off_t offset) returns 1. static ssize_t null_read(struct vm_store *store, off_t offset, iovecs *vecs) Returns -1. static ssize_t null_write(struct vm_store *store, off_t offset, iovecs *vecs) Returns -1. static int null_fault(struct vm_store *store, struct vm_address_space *aspace, off_t offset) Returns a Fatal page fault error. vm_store *vm_store_create_null(void) Creates an empty vm_store struct.