Comment # 4 on bug 1044433 from Andreas Stieger

This is caused by a known bug/regression bug 981597 in kernel/btrfs which
causes spurious "no space left on device" errors depending on the particular
access pattern. It is happening more frequently now and is already being looked
at by the kernel team. Resolving as duplicate, also since you no longer have
the issue locally.

*** This bug has been marked as a duplicate of bug 981597 ***