[GRASS-user] Re: user/group permissions for accessing data on mounted drive

[Glynn Clements]

Tim Michelsen wrote:

> > You must be the owner of the directory selected as the current mapset. 
> > A FAT/VFAT partition mounted by root must be mounted with the uid=
> > option to set the owner.
> 
> OK. I was able to get access using the right uid in fstab.
> But let's say that more than  one person uses this computer.
> What is the best way to handle this?

Use a filesystem which was designed for a multi-user OS.

> > Alternatively, you can disable the checks in the source code and
> > re-compile. The checks are in G__mapset_permissions and
> > G__mapset_permissions2 in lib/gis/mapset_msc.c. This isn't recommended
> > on a multi-user system, as it can result in a user inadvertently
> > creating directories which the mapset's owner cannot delete or rename.
> 
> Could this not be converted in a configuration parameter?

It could, but that replaces one problem (using FAT filesystems on
Unix) with another (users accidentally trashing other users' mapsets).

> See the following use case:
> A desktop/notebook used by a group of people. Of course, these collegues 
> would not work on this machine simultaniously but log in at different 
> times with different user names.
> 
> Any solutions?

The ideal solution is to skip the ownership check on filesystems which
don't have any concept of ownership. Unfortunately, I'm not sure how
to detect that.

-- 
Glynn Clements <glynn at gclements.plus.com>