Comment 24 for bug 894456

* - Would be helpful to note why certain patches are dropped from ubuntu packaging. I had to investigate again myself. E.g.:
Right, thanks for adding that.

* Maybe there is some value in using btrfsck as fsck.btrfs?
The problem is that you can't run btrfsck on mounted filesystems. That includes read-only mounts. So the only way to use fsck.btrfs would be from initrd before / is mounted. In all test I did using btrfsck as fsck.btrfs it failed because / was already mounted.
On another note, some of the btrfs recovery code is in-kernel and reachable by mounting with '-o recovery'.
A different solution that came up in #btrfs on IRC would be to copy fsck.xfs for btrfs. That's a script that does nothing on boot, but tells you to use xfs_check or xfs_repair when run manually.