Timothy Shimmin <tes@xxxxxxxxxxxxxxxxxxxxxxx> wrote:
> Thomas writes:
>> just a little question: is there anything like the immutable and
>> append only flags of ext2 (and for instance FFS in BSD) in XFS
>> too - maybe somehow realized via extended attributes or in
>> any other way?
> I didn't know what "immutable and append only flags" were :)
> Looking in the ext2 CHANGES file:
> - New file attributes:
> - Immutable files cannot be modified. Data cannot be written to
> these files. They cannot be removed, renamed and new links cannot
> be created. Even root cannot modify the files. He has to remove
> the immutable attribute first.
> - Append-only files: can only be written in append-mode when writing.
> They cannot be removed, renamed and new links cannot be created.
> Note: files may only be added to an append-only directory.
> - No-dump files: the attribute is not used by the kernel. My port
> of dump uses it to avoid backing up files which are not important.
> No, I don't believe we have any equivalents.
> Immutable sounds pretty much what one could achieve using the
> standard access modes except for ROOT being disallowed to change
> the file (without first setting the attribute).
> OOI, how useful is this attribute ?
i think it comes from 4.4BSD and the usefulness comes from the fact
that it is only possible to change those flags in the securelevel
which is normal in singleuser but not in multiuser - don't know
how it is handles by linux now but in general i think it might
be done via capabilities etc. ...
technical director innominate AG
clustering & security the linux architects
tel: +49-30-308806-13 fax: -77 http://www.innominate.com