Re: filexfer-07

[Joseph Galbraith <galb-list%vandyke.com@localhost>]

Jeffrey Hutzelman wrote:
> On Monday, April 04, 2005 06:54:18 PM -0400 Bill Sommerfeld 
> <sommerfeld%sun.com@localhost> wrote:
>
> > On Mon, 2005-04-04 at 18:39, Jeffrey Hutzelman wrote:
> >
> > > On most Unix systems, an SFTP server can guarantee to its client that I
> > > can't get a lock on a file, but it can't guarantee that I won't just
> > > write  to the file without bothering to get a lock.
> >
> >
> > unix systems which implement mandatory file locking (typically
> > SVR4-derived) typically do so on a file-by-file basis -- one particular
> > combination of file mode bits was recast to mean that  normally-advisory
> > byte-range locks become mandatory, blocking attempts to do I/O in
> > conflict with the lock.  this prevents you from mixing advisory and
> > mandatory locks on the same file.
>
>
> Correct.  It also means that changing the locking mode requires changing 
> the file mode bits, which normally can be done only by the file's owner 
> or by a superuser.

But the server can tell what locking mode is available, and
respond correctly?  Though it may have to advertise both modes
and responde with UNSUPPORTED for some files.

Thanks,

Joseph