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    SubjectRe: Long file names in VFAT broken with iocharset=utf8
    Hi Andrey!

    On 7 May 2007, at 19:51, Andrey Borzenkov wrote:

    > This was posted in one of Russian forums. It was not possible to
    > archive
    > (under Linux, using tar) vfat directory where files had long
    > Russian names
    > (really long - over 150 - 170 characters) - tar returned stat
    > failure. When
    > looking with plain ls, file names appeared truncated.
    > Now looking at current (2.6.21) fat driver, __fat_readdir allocates
    > large
    > enough buffer (PAGE_SIZE-522) for UTF-8 name; but for
    > iocharset=utf8 it calls
    > uni16_to_x8() which artificially limits length of UTF-8 name to
    > 256 ... which
    > is obviously not enough for long UTF-8 Russian string (2 bytes per
    > character)
    > not to mention the - theoretical - general case of 6 bytes UTF-8
    > characters.
    > Similar problem has apparently vfat_lookup()->...->fat_search_long
    > () call
    > chain. Except this appears to be broken even in case of "utf8",
    > because
    > fat_search_long allocates fixed 256 bytes buffer for UTF-8 name.
    > Am I off track here?
    PATH_MAX specifically counts _bytes_ not characters, so UTF-8 does
    not matter. ISTR that PATH_MAX was 256 at some point, but I just
    quickly grepped /usr/include and found various mention of 4096, so
    where's the central repository for this configuration item? A hard-
    coded value of 256 somewhere inside the kernel smells like a bug.


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