Comment 1 for bug 1017715

Indeed there is a serialization issue regarding the DM_COOKIE events. I was able to reproduce with the test case attached, that must be run as root.

Simply let the test case running, it stress test the creation/removal of a dm device. On the buggy udev, it'll fail at some point, usually leaving a /dev/disk/by-id/dm-name- link, lacking the device name. On a good udev, the test case will run indefinitely without errors.

The problem only happens when stress testing device creation/removal so far, unlikely this to be an issue in practice, where usually no devices are removed.