To Reproduce Steps to reproduce the behavior:

1. https://issues.redhat.com/browse/OSPRH-13278 describes a situation where a file is potentially created and written into /dev/dm<X> because an expected device is not present

Expected behavior

• Don't do that

Bug impact

• Please provide information on the impact of this bug to the end user.

Known workaround

• Please add any known workarounds.

Additional context

• In Cinder we could check for the existence of /dev/dm<x> when calling qemu-img convert and error out if the device does not exist.  This would alleviate the impact of this bug even if it doesn't address the root cause of it.