After adding some debug I see that multipath is opening the device, hence bd_openers > 0 and we get the EBUSY return. Killing multipath fixes this. It also explains why we can't remove the module at the end of the test.
After adding some debug I see that multipath is opening the device, hence bd_openers > 0 and we get the EBUSY return. Killing multipath fixes this. It also explains why we can't remove the module at the end of the test.