disklabel disappeared after power loss

[Mikhail Teterin]

Hello!

This is a 4.11-STABLE from Dec 24.

After a sudden power loss, one of the disks (ad2) can not recover.

It was "dangerously dedicated" and had two partitions -- swap (ad2b) and
data (ad2e). Any attempts to use either (swapon, fsck, mount) now result
in EINVAL.

`disklabel ad2' creates an imaginary label with only the ad2c covering
the entire drive. If I try to add the ad2b and ad2e in disklabel (I
remember the sizes), I get:

	disklabel: Operation not supported by device

I can read from /dev/ad2 directly. How can I restore access to the
filesystem?

Thanks!

	-mi