udev not called on USB disconnect

udev not called on USB disconnect

[Ondrej Zary]

Hello,
I'm trying to do automount/umount for my Canon camera using udev. The 
camera does not support mass storage so I'm using gphotofs+fuse to 
access it.
I created canon.rules file in /etc/udev/rules.d which contains:

BUS=="usb", SYSFS{idVendor}=="04a9", SYSFS{idProduct}=="306e", 
ACTION=="add", RUN+="/usr/bin/gphotofs /mnt/camera -o allow_other"
BUS=="usb", SYSFS{idVendor}=="04a9", SYSFS{idProduct}=="306e", 
ACTION=="remove", RUN+="/sbin/umount -f /mnt/camera"

(the file contains only two lines).
When I plug in the camera, the first rule is executed and camera mounted 
properly. However, disconnecting it does not do anything, the second 
rule is never executed. I also tried rule as simple as:

BUS=="usb", RUN+="/bin/touch /123"

If I understand udev correctly, that should create /123 file on each USB 
event. It works when connecting the camera but does not do anything on 
disconnect.

USB connect/disconnect is properly detected by kernel (2.6.16):
usb 1-2: new full speed USB device using uhci_hcd and address 22
usb 1-2: configuration #1 chosen from 1 choice
usb 1-2: USB disconnect, address 22

Is this a bug or a feature?

-- 
Ondrej Zary

Re: udev not called on USB disconnect

[Greg KH]

On Mon, Jun 05, 2006 at 10:34:20AM +0200, Ondrej Zary wrote:
> Hello,
> I'm trying to do automount/umount for my Canon camera using udev. The 
> camera does not support mass storage so I'm using gphotofs+fuse to 
> access it.
> I created canon.rules file in /etc/udev/rules.d which contains:
> 
> BUS=="usb", SYSFS{idVendor}=="04a9", SYSFS{idProduct}=="306e", 
> ACTION=="add", RUN+="/usr/bin/gphotofs /mnt/camera -o allow_other"
> BUS=="usb", SYSFS{idVendor}=="04a9", SYSFS{idProduct}=="306e", 
> ACTION=="remove", RUN+="/sbin/umount -f /mnt/camera"

You can't read sysfs values when a device is removed, because those
sysfs files are not present anymore.  Try testing the environment
variables instead.

> (the file contains only two lines).
> When I plug in the camera, the first rule is executed and camera mounted 
> properly. However, disconnecting it does not do anything, the second 
> rule is never executed. I also tried rule as simple as:
> 
> BUS=="usb", RUN+="/bin/touch /123"
> 
> If I understand udev correctly, that should create /123 file on each USB 
> event. It works when connecting the camera but does not do anything on 
> disconnect.

Are you sure that no other rule ahead of this one stopped this rule from
ever being read?

Also, udev questions belong on the linux-hotplug-devel mailing list...

thanks,

greg k-h