Comment 18 for bug 1413008

I've uploaded a test kernel containing the following upstream fix for testing:

commit 3d84be799194147e04c0e3129ed44a948773b80a
Author: Forrest Liu <email address hidden>
Date: Wed Feb 11 14:24:12 2015 +0800

    Btrfs: fix BUG_ON in btrfs_orphan_add() when delete unused block group

The packages can be downloaded from: http://kernel.ubuntu.com/~cking/lp1413008/

Please test these and let me know if it addresses the issue.