extern int lib_ring_buffer_read_cstr(struct lib_ring_buffer_backend *bufb,
size_t offset, void *dest, size_t len);
-extern struct page **
-lib_ring_buffer_read_get_page(struct lib_ring_buffer_backend *bufb, size_t offset,
+extern unsigned long *
+lib_ring_buffer_read_get_pfn(struct lib_ring_buffer_backend *bufb, size_t offset,
void ***virt);
/*