DDJ, December 1995: Examining the Windows 95 Layered File System
by Mark Russinovich and Bryce Cogswell

Listing Seven

typedef struct IOP_callback_entry {
    ULONG   IOP_CB_address;     // call back address
    ULONG   IOP_CB_ref_data;    // pointer to callback ref data
} IOP_callback_entry;


Listing Eight

    mov     edi, [esi].IOP_callback_ptr
        sub     edi, size IOP_CallBack_Entry    ; point to next available
                                                ; call-back entry
        mov     [esi].IOP_callback_ptr, edi     ; update call-back Pointer

        ; IOP pointer is passed on the stack

        push    esi                             ; IOP's offset
        call    dword ptr [edi]                 ; make the call
        add     esp, 4                          ; restore stack