udev rule not working

Question

I have created a udev rules which is supposed to mount a USB device, backup some datas et cleanup everything. I am actually working on a Debian server.

There is the information about my usb device that I have with lsusb

Bus 001 Device 003: ID 054c:0243 Sony Corp. MicroVault Flash Drive

(Actually the lsusb returns more Bus / Device, but I have to write them by hand since I am not posting from my Debian machine :))

Then I have written my udev rule called :

10-usb_back.rules

into:

/etc/udev/rules.d/

(I used 95 because the backup script takes some seconds and I want to run it as late as I can for avoiding to delay other stuff)

And finally the rule itself:

ACTION=="add", SUBSYSTEM=="usb", ATTRS{idVendor}=="054c", ATTR{idProduct}=="0243", RUN+="/usr/local/bin/mount_usb"
ACTION=="add", SUBSYSTEM=="usb", ATTRS{idVendor}=="054c", ATTR{idProduct}=="0243", RUN+="/usr/local/bin/backup_database"

I have tried this too:

ACTION=="add", SUBSYSTEM=="usb", ATTR{idVendor}=="054c", ATTR{idProduct}=="0234", RUN+="bash /usr/local/bin/mount_usb"

Unsuccessfully :(

Then I restart udev

sudo /etc/init.d/udev restart

And when I plug my USB device I got this weird message:

[1348.295280] sd 6:0:0:0: [sdc] Assuming drive cache: write through

twice

But nothing happened. No USB device mounted, no data backed up.

I looked with tail -f /var/log/message

And the USB drive looks like detected:

usb 1-3: Product Storage Media 
usb 1-3 Manufacturer Sony`
...

Something must be wrong somewhere but I don't know what, neither where :(

Edit: Since I've been a little bit lazy because I can't rewrite everything from my server, please ask for further information if needed, such as the script or more logs messages :)

Answer 1

This is my working udev rule for executing backup on hotplug:

SUBSYSTEM=="block" ACTION=="add" \
      ENV{DEVTYPE}=="partition" \
      ENV{ID_FS_UUID}=="xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" \
      TAG+="store" \
      RUN+="/usr/bin/python3 /etc/systemd/autoback.py --udev"

Note that instead of matching the USB device, I'm matching a partition (i.e. /dev/sde1) on the mass storage endpoint of that usb device. It takes a few seconds after the USB hotplug before the disk is ready and the partition is enumerated so this is the "right" event for my use case, and probably yours too if you're trying to do backups. ID_FS_UUID is the same as reported by blkid for this partition. In my case, this is the luks UUID.

On my system udev doesn't seem to automatically reload correctly when I edit rules, but what I've found to work (which is also useful for debugging) is:

udevadm test /sys/dev/block/8:65

to force a reload/re-application of udev rules. Note that I found 8:65 by ls -l /dev/block | grep sde1. Also

udevadm info --query=property /dev/sde1

was helpful to see if my rules are applied, and

NOTE: I'm posting this answer 5 years after the OP, so things might be different now than then. My system is ubuntu 16.04.4 (xenial) on arm64.

Answer 2

You have misspelled ATTR, it should be ATTRS in this case.

Answer 3

Try having a look at the output for udevadm info --path=path/to/device --attribute-walk It will tell you every attribute and subsystem that's valid for the device. For instance, a USB device I have has a SUBSYSTEM="tty", to recognize USB for that device you need to put SUBSYSTEMS=="usb" (note: plural subsystem*s*). I suspect that something like that may be the case here. Either way udevadm info --attribute-walk is a really helpful tool for debugging udev problems.

Also ATTR{key} is not valid, instead use ATTRS{key} (It was mentioned before, but some of your examples still use the incorrect form.)

Answer 4

Aren't those typos in the idProduct portion of the rules?

You have this:

ATTR{idProduct}=="0234"

Shouldn't it be this:

ATTR{idProduct}=="0243"

Based on the output from this line:

Bus 001 Device 003: ID 054c:0243 Sony Corp. MicroVault Flash Drive