On Tue, May 15, 2012 at 4:23 AM, Greg KH <gregkh@g.o> wrote:
> We learned that this is not a good idea at all, and should be left to userspace helper applications
> that listen for dbus messages.

Could you perhaps expand a bit on those reasons? E.g., I had good
experience with the following short script for coupling udev events
with autofs: https://github.com/mkdesu/liberte/blob/master/src/usr/local/sbin/ps-mount.
Gentoo wiki has a similar tutorial as well. Granted, it is a
single-user setup, but I can imagine it being extended to work with
ConsoleKit. One obvious problem is mounting encrypted volumes. I
thought about moving to e.g., udisks-glue (as a more standard
solution), but from what I hear there are too many bugs with udisks at
the moment.

> Actually with all the hype about mdev these days, why not just use a 3
> year old version of udev (or maybe 4), that is probably what mdev is at
> as far as functionality goes.

I don't know at what state udev was 3 or 4 years ago, but mdev can:

1. Populate /dev (now unnecessary due to devtmpfs).
2. Handle ownership, permissions and symlinks to /dev nodes once they
appear, according to simple rules (can be probably done with inotify).
3. Act as /sbin/hotplug, typically doing something equivalent to this one-liner:
   [ "${ACTION}" = add  -a  -n "${MODALIAS}" ] && modprobe -qb "${MODALIAS}"

I don't think mdev can do anything else. Building any serious
framework on top of mdev seems pointless to me, since it will probably
end up as a small subset of udev core reimplemented with scripts.

-- 
Maxim Kammerer
Liberté Linux (discussion / support: http://dee.su/liberte-contribute)