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    SubjectRe: [RESEND] [PATCH] VFS: make file->f_pos access atomic on 32bit arch
    On Wed, Oct 08, 2008 at 01:35:44PM +1100, Nick Piggin wrote:
    > Right you are. That's the fundamental question. The actual details of
    > the fix and how likely the race is don't really matter until we
    > answer the first question (except to say that the "fix" is never going
    > to be free).
    >
    > We've lasted this long with the current semantics. So the natural
    > reaction to anything that strengthens the semantics now is "why?". If
    > we do that then we can basically never return to the weaker semantics.
    > So there had better be a really good reason.

    And it's worth saying that letter-of-the-standard arguments aren't
    necessarily enough. Linux does not honour the POSIX guarantee that
    writes are atomic (if they cross page boundaries, it's not certain).
    This seems like even more of a corner case to me.

    --
    Matthew Wilcox Intel Open Source Technology Centre
    "Bill, look, we understand that you're interested in selling us this
    operating system, but compare it to ours. We can't possibly take such
    a retrograde step."


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