45aebeaf4f67 "ovl: Ensure upper filesystem supports d_type" breaking Docker

[Daniel Axtens]

Hi,

I installed a fresh 4.6.0 kernel on my ppc64le system, and tried to run
a docker container. It failed.

Docker gave me errors like this:

docker: Error response from daemon: error creating overlay mount to /var/lib/docker/overlay/2bc07cedad2770da2f384d5c1e81a6f45fa3c44a7658f10d02e5973ef76620fc-init/merged: invalid argument.

In dmesg, I'm seeing:

overlayfs: upper fs needs to support d_type.

Reverting 45aebeaf4f67 ("ovl: Ensure upper filesystem supports d_type")
fixes the issue for me. I haven't investigated the root cause yet - at a
guess I'd say either Docker's layering system, or some weird interaction
with namespacing, maybe? I'll have a look when I get a spare moment.

For reference, I'm using docker 1.11.0-dev.

Regards,
Daniel Axtens