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    SubjectRe: [PATCH] Added CONFIG_VFAT_FS_DUALNAMES option
    Hi Pavel,

    > You already know that it breaks XP and older linuxes. So... what are
    > you arguing about?! Chkdsk marks it as invalid filesystem... not a
    > vfat.

    no, wrong on all 3 counts.

    For the "breaks XP", see my previous message where I point out that I
    have never been able to crash XP with this patch, only with other
    varients on the patch that reduce the number of random bits we use.

    The "breaks older linuxes" claim is also wrong. The patch I have
    posted works fine with all older versions of the Linux kernel that I
    have tested. If you know of a old version of the Linux kernel that
    doesn't work with a filesystem written when this patch is enabled then
    please let me know. I think you may be getting confused by the
    discussion I had with Eric where I explained about the reasons for the
    change in fat/dir.c. I won't repeat that long discussion again here,
    but please re-read the reply I sent to Eric and if you still have
    questions about it then please ask.

    Finally, saying that "chkdsk marks it as an invalid filesystem" is not
    correct. It only complains if there happens (with a very low
    probability!) to be two files with the same 11 bytes in their
    respective 8.3 entries. When it complains it renames one of the two

    That rename would not in itself be a problem at all, as changing the
    8.3 entry would not affect the long filename, except that chkdsk has a
    bug where it doesn't follow the Microsoft FAT specification. When you
    rename a file on a FAT filesystem you are supposed to also update the
    8 bit checksum field in the corresponding long filename entries. If
    you don't do that update then you effectively strip off the long
    filename. Current versions of Microsoft chkdsk neglect to update the
    long filename checksum when renaming after detecting a duplicate 8.3

    So it is Microsoft's chkdsk, not the patched Linux kernel, that is in
    violation of the FAT spec. Luckily the probability of this bug
    cropping up is quite small in practice.

    Cheers, Tridge

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