bkltap hanging tapdisk processes

[Frederic]

Hello,

We are running xen-4.1.2-2ubuntu2 on Ubuntu 12.04 amd64.
Our setup:
- 1 san server
- 1 ubuntu xen dom0 with iscsi/multipath configured & connection to our san.
We're working with raw disk images & those are stored on the san.
The virtual disks are used in the xen.cfg with "tap2:tapdisk:aio:"

**Problem:
When we do a xm create vm.cfg, tapdisk processes are created, as expected
When we do a xm shutdown vm.cfg, the tapdisk processes are not shutdown, they are in a hanging state.

More information about the confirmed bug:
http://xen.1045712.n5.nabble.com/hanging-tapdisk2-processes-and-improper-udev-rules-td4622364.html

**Used packages/versions:
linux-image-3.2.0-24-generic 3.2.0-24.39
blktap-dkms 2.0.91-1
open-iscsi 2.0.871-0ubuntu9
multipath-tools 0.4.9-3ubuntu5