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    SubjectRe: CIFS: Rename bug on servers not supporting inode numbers
    From
    2011/11/4 Steve French <smfrench@gmail.com>:
    > What is the actual sequence of events from the wire perspective (the
    > actual smb requests sent)?
    >
    >
    > On Thu, Nov 3, 2011 at 6:25 PM, Anton Altaparmakov <aia21@cam.ac.uk> wrote:
    >> Hi,
    >>
    >> On 3 Nov 2011, at 17:40, Jeff Layton wrote:
    >>> On Thu, 3 Nov 2011 15:42:13 +0000 Anton Altaparmakov <aia21@cam.ac.uk> wrote:
    >>>>
    >>>> I should add that we are using iocharset=utf8 mount option which means that the dcache hash/compare functions done in the cifs module do not work because it uses nls_tolower() and nls_strnicmp() both of which for utf8 NLS in the kernel do not do anything at all and effectively behave case sensitively!
    >>>>
    >>>> Thus this bug/problem in all likelyhood only affects utf8 iocharset users on a case-insensitive but case-preserving CIFS server that does not support server inode numbers.

    Hi.
    There is no upper/lower case table on nls utf8. so If you use iocharset=utf8,
    filesystem will be case sensitive.
    so we can add upper/lower case table like other charset.
    And Currently surrogate pair is not working on nls utf8.
    because it is limited by MAX_WCHAR_T in nls utf8
    I think that upper/lower case table and surrogate pair support should
    be fixed on nls utf8.
    I should know Andrew's opinion to fix these problem.
    >>>>
    >>>> That probably explains why it has not been noticed before!
    >>>>
    >>>> We need utf8 thus we still need to fix this issue.
    >>
    >>> I'm confused...
    >>>
    >>> If the filesystem being served out by the server is using utf8, then
    >>> how is it handling the case-insensitivity?
    >>
    >>
    >> The file system being served is NSS (the Netware one but now mounted on Open Enterprise Server with Linux kernel rather than actual Netware kernel).  No idea how it works I am afraid.  It supports lots of different namespaces as well as being case-insensitive and case preserving when using the LONG name space (which is now being served through CIFS).
    >>
    >> If it was NTFS or exFAT I could tell you exactly how they work (each volume has an upcase table mapping the 65536 UCS-2 Unicode characters to their upper case equivalents and each 16-bit character is upper-cased individually, more recently Windows has switched to using UTF-16 instead of UCS-2 and the upcase table changed when that happened though it remained the same size and I think for file system purposes the fact that there are surrogates in the above UCS-2   Unicode range is simply ignored)...
    >>
    >> Best regards,
    >>
    >>        Anton
    >> --
    >> Anton Altaparmakov <aia21 at cam.ac.uk> (replace at with @)
    >> Unix Support, Computing Service, University of Cambridge, CB2 3QH, UK
    >> Linux NTFS maintainer, http://www.linux-ntfs.org/
    >>
    >>
    >
    >
    >
    > --
    > Thanks,
    >
    > Steve
    > --
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