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    SubjectRe: silent semantic changes with reiser4
    Rik van Riel wrote:
    > And if an unaware application reads the compound file
    > and then writes it out again, does the filesystem
    > interpret the contents and create the other streams ?

    Yes, exactly that. The streams are created on demand of course, and
    by userspace helpers when that's appropriate which I suspect it almost
    always is.

    > Unless I overlook something (please tell me what), the
    > scheme just proposed requires filesystems to look at
    > the content of files that is being written out, in
    > order to make the streams work.

    Yes. Hence the idea of coherent views between two files: writing to
    one affects the content of the other, although the calcalation is only
    done on demand (or when the fs wants to migrate the representation --
    for example, creating the flat container prior to deleting the
    regeneratable pieces in order to save space).

    I haven't seen anything from Namesys that says they'll do that. I
    have the impression the streams are just generated in memory on the
    fly, not stored on disk with a cacheing policy, but that's just an
    impression. (We've all seen the Namesys white papers, they're not
    _that_ revealing). :)

    I'm just pointing out how to do it _right_. I think it will turn out
    like this eventually, either next year or some time over the next
    decade after some iterations. Inevitable. Mark my words, etc. :)

    -- Jamie
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