freebsd-update upgrade fails if /var is a tmpfs

[feld]

Summary

This is my lame attempt at fixing the issue documented in https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=195006

It's not going to be bulletproof as anyone could use another different non-persistent filesystem we aren't aware of, but this should help...

[cperciva]

Looks good. I don't know what sort of crazy it takes to put /var on a tmpfs, but this is definitely the right way to respond to that situation.

[feld]

@ian noticed an issue with the way mfs was being detected and suggested we use a case and df -T instead. Turns out that mfs masquerades as ufs when mounted, so we need to check for the /dev/md* string

Previous patch was committed but doesn't break anything; just won't actually detect mfs.

[• ian]

The sort of crazy I am that leads to /var on an mfs is an embedded systems person. :) I'm always having to deal with readonly root issues. Of course, I'd never use freebsd-update to update a readonly root type system.

usr.sbin/freebsd-update/freebsd-update.sh

613

Now that I see the wider context, I think it might be good to use df -T ${WORKDIR} rather than the $(...) construct I suggested. They are equivelent but it makes sense to use consistant style within the script.

[feld]

Thanks @ian for catching that mistake and suggesting a better way. :-)