OverlayFS Can Be Paired With VirtIO-FS On Linux 5.7
Notable to OverlayFS in the Linux 5.7 kernel is support for allowing a remote upper file-system, which in step with other changes allow for VirtIO-FS to be used as an upper layer. VirtIO-FS is the shared file-system for allowing VMs to access a directory on the host and is supported by most of the open-source Linux virtualization components. Up to now though VirtIO-FS hasn't worked as an upper (writable) layer in an OverlayFS configuration while now that is possible.
OverlayFS also now uses more consistent inode numbering, fixing a failure to copy-up files from some NFSv4 mounts, and other changes as outlined via this pull request.