Opening /dev/ad0 for writing render the system unusable until reboot

[Eugene Grosbein]

Hi!

Would anybody be so kind to look at
http://www.FreeBSD.org/cgi/query-pr.cgi?pr=kern/112707 ?

In short: the command "true > /dev/ad0" makes all access to filesystem
fail for GENERIC and produces panic for INVARIANTS-enabled kernel.
This make it impossible to do "boot0cfg -s 2 ad0" for remote upgrade
of NanoBSD running from IDE Flash.

Thank you.

Eugene Grosbein