readonly, NTFS, and file metadata

Corinna Vinschen
Tue Aug 14 03:10:00 GMT 2001

On Tue, Aug 14, 2001 at 12:00:18PM +0200, Corinna Vinschen wrote:
> On Mon, Aug 13, 2001 at 04:54:06PM -0400, Charles Wilson wrote:
> > There is an ongoing thread on the automake list (started by yours truly,
> > agent provocateur) concerning some strangeness I've encountered on
> > NTFS(ntsec), with 'cp -p' and readonly files.  The URL for the beginning
> > [...]
> > What happens is this: first, foo is copied to bar, with perms
> > -r--r--r--.  But, the timestamp is wrong.  Since cp was called with
> > '-p', cp then tries to set the timestamp of bar to match foo.  But it
> > can't on cygwin.  On linux, it can.
> > 
> > My suggestion to the automake list, which was to make foo be -rw-r--r--,
> > was not well received.  The suggestion in return was: make cygwin act
> > like linux.  I can't really argue against that, since that's been our
> > stated goal anyway.
> > 
> > Does anybody know offhand what it would take to 'linux-ize' this
> > behavior (e.g. would we have to take a performance hit?)  Do we want to
> > be like linux in this particular? Also, please check the thread
> > referenced above.
> Check return code of SetFileTime(), check if ntsec ON and
> file is on NTFS, get current ACL, modify to have write_data
> access for current user, call SetFileTime() again, reset ACL.
> The only problem is that we need a new function set which
> _exactly_ saves and restores a given ACL and another function
> which exactly adds write access to the current user. The
> standard functions in are not appropriate.

Wait, that's not quite true. read_sd() and write_sd() are
the functions to save and restore a SD. So there's only
a function to set write access for the current user missing...

Is it true that the problem can be restricted to files
which are actually owned by the current user???


Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Developer                      
Red Hat, Inc.

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