devfs vs udev/hotplug

Diego Calleja García diegocg at teleline.es
Thu Apr 22 13:47:39 PDT 2004


El Thu, 22 Apr 2004 10:30:52 -0700 (PDT) Matthew Dillon <dillon at xxxxxxxxxxxxxxxxxxxx> escribió:

>     Well, I see no reason why the appropriate module could not
>     be loaded e.g. by usbd or udev when the device is detected.
>     Why wait for initial access?  In fact, it could be argued that

Altough loading all the necessary modules when something is plugged in would
solve this for usb, several people relied in other things; ej: floppies or
cdroms drivers are compiled as modules in linux these days, and things now
just don't work for them. Because altough doing cat /dev/cdromdevicenode
will load the cdrom modules when the device node is accessed, with udev
that device node won't exist (since it's compiled as a module and not loaded)
and unlike with devfs, nobody will notice that someone is trying to access a
device node which doesn't exists and load a module in consequence.

It's just a minor pitnick but since it looks like dfly will be able to 
have filesystems in userspace I was wondering how easy/feasible would be
to have a userspace fs in /dev which could be integrated with a udev-like
tool and restore that devfs behaviour...the lack of this has been (and is) the
biggest problem against udev adoption (and the inspiration of everal
"udev vs devfs" flamewars :)







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