lkml.org 
[lkml]   [2004]   [May]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [ANNOUNCEMENT PATCH COW] proof of concept impementation of cowlinks
    On Sun, 9 May 2004 23:15:33 -0600, Eric W. Biederman wrote:
    > Jörn Engel <joern@wohnheim.fh-wedel.de> writes:
    > > 3 copyfile - new copyfile() system call
    > > http://wohnheim.fh-wedel.de/~joern/cowlink/
    >
    > Question about sys_copyfile.
    >
    > Is the intention that a new file with completely new permissions
    > be created?
    >
    > Some people have wanted a copyfile that copies all of the extra
    > metadata user/group/acls.
    >
    > I currently see technical merit in both approaches.
    >
    > Looking at the CIFS information it appears that the CopyFILE RPC
    > copies the permissions. It is not at all clear about that, and
    > the fact it appears to copy permissions may simply be a specification
    > bug. Given that FAT does not really have permissions, let alone
    > extended attributes it would be an easy mistake to make.
    >
    > In the general case you cannot copy permissions from one file to
    > another, either you don't have those permissions yourself or the
    > target file system may not support them all. Not copying
    > permissions leads to a simpler implementation with the burden
    > of the work left to user space. What is not done is a loop through
    > the extended attributes.

    Unless someone finds a good reason to change this, I prefer to create
    new permissions and not copy the acl's. That way, I can also
    copyfile() a file belonging to someone else, as long as I have read
    access to it.

    Jörn

    --
    Don't worry about people stealing your ideas. If your ideas are any good,
    you'll have to ram them down people's throats.
    -- Howard Aiken quoted by Ken Iverson quoted by Jim Horning quoted by
    Raph Levien, 1979
    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-03-22 14:03    [W:0.027 / U:156.880 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site