Yeah and that is IMO the wrong abstraction. Blocks on disk should be organized into records, where multiple blocks can belong to a single or multiple (if using dedup or Copy-on-Write) records. Implementing a performant stream over that can be done in libc with minimal overhead.
No? ZFS already organizes blocks on disks this way to some extend and Btrfs uses extends which include multiple blocks together and can be referenced multiple times.
