Movified from 686be57d0a, and re-ran
gofmt again to address for files not present in 20.10 and vice-versa.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit 686be57d0a)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
overlay2 no longer sets `archive.OverlayWhiteoutFormat` when
running in UserNS, so we can remove the complicated logic in the
archive package.
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
(cherry picked from commit 6322dfc217)
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
Ubuntu kernel supports overlayfs in user namespaces.
However, Docker had previously crafting overlay opaques directly
using mknod(2) and setxattr(2), which are not supported in userns.
Tested with LXD, Ubuntu 18.04, kernel 4.15.0-36-generic #39-Ubuntu.
Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
