kldunload geom_journal hangs with jfini

[Johannes Totz]

Hi everyone,

a recent 12-stable rev 358557 amd64 build hangs on kldunload of 
geom_journal.
To reproduce:
  kldload geom_journal
  kldunload geom_journal

kldunload just hangs indefinitely. top says the state is "jfini:". It's 
using some cpu time though.
procstat -k hangs as well.

Very reproducable, on both virtualbox as well as real hardware.

Any extra info that could help?


Johannes