"error inheriting props for ino": Btrfs "compression" property

Hello,

On two machines I have subvolumes where I backup other hosts' root filesystems via rsync. These subvolumes have the +c attribute on them.

During the backup, sometimes I get tons of messages like these in dmesg:

[Wed Jul 25 20:58:22 2018] BTRFS error (device dm-8): error inheriting props for ino 1213720 (root 1301): -28
[Wed Jul 25 20:58:22 2018] BTRFS error (device dm-8): error inheriting props for ino 1213723 (root 1301): -28
[Wed Jul 25 20:58:22 2018] BTRFS error (device dm-8): error inheriting props for ino 1213724 (root 1301): -28
[Wed Jul 25 20:58:22 2018] BTRFS error (device dm-8): error inheriting props for ino 1213725 (root 1301): -28

# btrfs inspect inode-resolve 1213720 .
./gemini/lib/modules/4.14.58-rm2+/kernel/virt

This seems to be related to the "compression" property in Btrfs:

# btrfs property get ./gemini/lib/modules/4.14.58-rm2+/
compression=zlib

# btrfs property get ./gemini/lib/modules/4.14.58-rm2+/kernel/virt

(no output)

Why would it fail like that? This does seem harmless, but the messages are annoying and it's puzzling why this happens in the first place.

With respect,
Roman