The recent landing in master of the patch "LU-684 tests: replace dev_read_only patch with dm-flakey" adds a 'modprobe dm-flakey' command to test-framework.sh. There is no corresponding rmmod of this kernel module anywhere. This leaves the kernel module always loaded, even when it stops being referenced or used by anything.

Maybe remove of the module needs to be added in relevant places like test-framework.sh and lustre_rmmod.