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    SubjectRe: [PATCH] Added CONFIG_VFAT_FS_DUALNAMES option
    Hi Alan,

    > > What happens on collision? With 60000 entries in directory, there will
    > > be 50% chance of collision. BAD.
    > Far more surely - its a birthday paradox.

    If you want to do it accurately, the maximum number of long filenames
    in a VFAT directory is actually 32767. (it isn't 65536, as each long
    filename consumes at least two 8.3 entries, plus you lose the . and
    .. entries).

    With the patch I've posted there are 30 bits of randomness in each
    entry. You could do an accurate binomial expansion to get the exact
    probability, but a very good approximation using exponentiation comes
    out as a 39.3% chance of a single duplicate appearing in a directory
    that is fully populated.

    As I mentioned to Pavel, this isn't the whole story though. To cause
    the bluescreen the duplicate entries need to be accessed by WindowsXP
    in quick succession in a particular pattern. This lowers the
    probability a lot. Exactly how much is hard to estimate, but
    experiments I've done with deliberately higher probabilities (ie. less
    bits of randomness) show that the probability of the bluescreen is
    _very_ low.

    > Agreed 100%. I'm also not sure it should be called "vfat" when operating
    > in this mode as it's not vfat any more - it needs a new name.

    If the code differed significantly between the two implementations I'd
    probably agree, but as the two are extremely close I think maintaining
    a separate filesystem isn't worth it.

    Cheers, Tridge

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