Comment # 3 on bug 1200259 from Gr���ner

I was able to strip it further down. I started the system im rescue mode.
Then:
#systemctl isolate rescue.target
#fstrim -av
=> went through
#fstrim -av
=> Kernel panic

Again restart in normal mode
#systemctl isolate rescue.target
#fstrim -av
=> Kernel panic

Identical stack trace.

Now the core dump is a bit more handy. Only 800 MB instead of the previous 8GB.

I can also attach the full dmesg if needed, to see details of the system.

Later I can try to isolate the call I suspect, to see if this helps. But this
might only be the removal of the sympthom not the root cause, why the structure
is not valid to be hand over to bfq_bic_update_cgroup().