Re: hotplug script before udev
On 3/8/06, Florian Kulzer <florian@molphys.leidenuniv.nl> wrote:
> David Berg wrote:
> > I'm trying to automount my digital camera (mass storage) when it is
> > connected. I have udev scripts to give me a /dev/camera symlink which
> > appears to be working, and created a map in hotplug to call a script
> > called photodl which seems to be getting called.
> >
> > The problem is that photodl is called before the device is created from udev.
> >
> > dberg@chip:/var/log$ tail daemon.log
> > Mar 8 11:01:00 localhost udev[7397]: configured rule in
> > '/etc/udev/rules.d/10-local.rules[1]' applied, 'sdd1' becomes '%k'
> > Mar 8 11:01:00 localhost udev[7397]: creating device node '/dev/sdd1'
> > dberg@chip:/var/log$ tail messages
> > Mar 8 11:00:54 localhost kernel: sdd: assuming Write Enabled
> > Mar 8 11:00:54 localhost kernel: /dev/scsi/host6/bus0/target0/lun3: p1
> > Mar 8 11:00:54 localhost kernel: Attached scsi removable disk sdd at
> > scsi6, channel 0, id 0, lun 3
> > Mar 8 11:00:55 localhost scsi.agent[7300]: sd_mod: loaded
> > sucessfully (for disk)
> > Mar 8 11:00:55 localhost scsi.agent[7332]: sd_mod: loaded
> > sucessfully (for disk)
> > Mar 8 11:00:55 localhost scsi.agent[7349]: sd_mod: loaded
> > sucessfully (for disk)
> > Mar 8 11:00:55 localhost usb.agent[7311]: usb-storage: already loaded
> > Mar 8 11:00:55 localhost usb.agent[7311]: photodl: loaded successfully
> >
> >
> > Note that photodl is "loaded successfuly" at 11:00:55 and my rule in
> > 10-local.rules is applied at 11:01:00. 5 seconds later. I've added a
> > `sleep 10` command before the mount command in photodl but that didn't
> > help.
> >
> > How can I ensure that photodl is run after the device is created?
>
> I think the most reliable way is to use the PROGRAM key in your udev
> rule for the device. The following is an example for a PCMCIA network card:
>
> KERNEL=="eth*", SYSFS{address}=="xx:xx:xx:xx:xx:xx", NAME="wlan0", PROGRAM="/path/to/your/script"
>
> (all on the same line)
>
> /path/to/your/script should point to your script. It will be called
> whenever the device is created or removed. In the script you can check
> the $ACTION environmental variable ("add" or "remove") to know which
> event occurred. The manpage of udev has more details.
>
I was under the impression that udev's sole purpose was to name /dev
entries. And that hotplug is the apropriate place for calling scripts
that will use that device.
I'm still foggy on how some of these systems fit together. Does it
matter? Looking at the hotplug scripts it would appear that scripts
could be called from hotplug, udev, or hal. Which is most
appropriate.
--Dave
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