Bug#773868: union=overlay broken for me (3.18 + 5.0a1-1)

["Trent W. Buck" <trentbuck@gmail.com>]

I tried to get live-boot to work with

    <jessie>
    linux-image-3.18.0-trunk-amd64
    live-boot{,-initramfs-tools}/experimental (5.0~a1-1)

The first problem I hit was in 9990-overlay.sh:

    if ! cut -f2 /proc/filesystems | grep -q "^${UNIONTYPE}\$"
    then
            panic "${UNIONTYPE} not available."
    fi

    modprobe -q -b ${UNIONTYPE}

The file overlay.ko was in the ramdisk,
but the module wasn't mention in /proc/filesystems.
I kludged that with

    echo overlay >>/etc/initramfs-tools/modules

The second problem I hit was in 9990-misc-helpers.sh:

    unionmountopts="-o noatime,lowerdir=${unionro},upperdir=${unionrw}"
    mount -t ${UNIONTYPE} ${unionmountopts} ${UNIONTYPE} "${unionmountpoint}"

I got dumped into a panic shell.
When I run the above mount by hand, I get
    overlayfs: missing upperdir or lowerdir or workdir

Per https://www.kernel.org/doc/Documentation/filesystems/overlayfs.txt

| At mount time, the two directories given as mount options "lowerdir" and
| "upperdir" are combined into a merged directory:
|
|   mount -t overlay overlay -olowerdir=/lower,upperdir=/upper,\
| workdir=/work /merged
|
| The "workdir" needs to be an empty directory on the same filesystem
| as upperdir.

I haven't fixed this, and I'm out of time today.

I hope this helps.