Comment # 9 on bug 1037118 from Jeff Mahoney

The WARNINGs are harmless qgroup underflow warnings.  I know what the cause is
and mostly how to fix them.  It's just waiting on the time to do it.

The rename failures are more likely spurious ENOSPC errors (which you won't see
via 'df' and the like).

It should've been fixed in Leap 42.3 via:

commit 8bf31dae2ad1a3c5471841801bc4f12233e3c2ec
Author: Nikolay Borisov <nborisov@suse.com>
Date:   Wed Jun 28 17:39:40 2017 +0300

    btrfs: disable possible cause of premature ENOSPC (bsc#1040182)