On Thu, Aug 17, 2023 at 2:05 PM Alexander Larsson <alexl@xxxxxxxxxx> wrote: > > There are cases where you want to use an overlayfs mount as a lowerdir for > another overlayfs mount. For example, if the system rootfs is on overlayfs due > to composefs, or to make it volatile (via tmps), then you cannot currently store > a lowerdir on the rootfs, becasue the inner overlayfs will eat all the whiteouts > and overlay xattrs. This means you can't e.g. store on the rootfs a prepared > container image for use using overlayfs. > > This patch series adds support for nesting of overlayfs mounts by escaping the > problematic features on and unescaping them when exposing to the overlayfs user. > > This series is also available here: > https://github.com/alexlarsson/linux/tree/ovl-nesting > > And xfstest to test it is available here: > https://github.com/alexlarsson/xfstests/tree/overlayfs-nesting > Hi Alex, Technically, the patches look pretty sane to me. I'll need Miklos to weight in on the review as well and anyway I think we should get verity merged (to 6.6) before considering this (sort of) follow up. I'd add some more tests as I commented on github including mixing user and trusted xattr use case. Thanks, Amir.
