zfs zvol's inaccessible after reboot

[Ultima]

Currently there is a bug with zvols. I have a few Bhyve containers that
startup at boot. I'v noticed in middle December of last year that after a
restart the zvols become inaccessible to the container. Nothing can be done
to the zvol, other than rename. It cannot even be destroyed in this state.
The only way to make it accessible again is to renaming the zvol, after
this occurs, functionality is restored.

The bug is still present in head r312232.