Well that's the end of btrfs for me; barely a month in it's shat itself and taken my /home with it.
I've lived this long without metadata checksum and snapshot...
I was able to extract a list of trees, even though it wouldn't mount, even with the various recovery options, using
This will split out a bunch 'well' things. I got lucky and when I passed the number of one of those to
btrfs restore -v -m --symlinks -o -t 206293467136 /dev/mapper/vgkubuntu-home /mnt
This extracted all the files, at what looks like their most recent versions, from the broken mess of btrfs and on to a working filesystem.