udev remove event not sent untill the device is closed

[Thomas Stewart <thomas@stewarts.org.uk>]

Hi,

I'm running 2.6.8.1 with udev-031. I have a usb2serial converter which has a 
udev rule to give it a persistent name in my dev tree. I want to run a script 
when the converter is attached, and another when the converter is removed.

I tried both the /etc/hotplug.d and /etc/dev.d methods to do this (I like the 
dev.d method better as I can use my persistent device name). Unfortunately I 
ran into problems.

I'm catching the tty event as it sets $DEVPATH to something useful 
(e.g. /devices/sys/class/tty/ttyUSB0). And then running a different script 
depending on $ACTION.

I made a short script to do this, and put it in /etc/dev.d/default/ttyUSB.dev:
#!/bin/sh
test "$1" != "tty" && exit
test "$ACTION" == "add"    && /usr/local/bin/on
test "$ACTION" == "remove" && /usr/local/bin/off

(I removed the various error checking that actually makes sure the tty event 
in question was actually the serial converter, and not some other device.)

This works fine, I can add and remove the converter to my hearts content and 
both scripts run accordingly.

However, if I attach the device, open it with say a "cat /dev/ttyUSB0" and 
then remove the device. No tty events get sent untill I kill the cat.

I want to be able to run the script when I remove the converter. (I actually 
want the remove script to kill the process that has the device open.)

I found it hard to use the usb events because when they run, $DEVPATH no 
longer exists. Which means I have no idea which converter was removed.

(Can replies be CC'ed to me as I'm not subscribed. Thanks)

Regards
-- 
Tom

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