On Wed, Mar 13, 2024 at 1:50 PM Amir Goldstein <amir73il@xxxxxxxxx> wrote: > > On Tue, Mar 12, 2024 at 8:13 PM Raul Rangel <rrangel@xxxxxxxxxxxx> wrote: > > > > Hello, > > I was wondering if it was possible for the bind mounts created under a > > lower layer to be exposed via overlayfs? > > > > I have attached a test script that reproduces what I'm trying to achieve: > > $ unshare --user --map-root-user --mount bash -xe mount-test > > + mkdir -p real/usr/lib > > + touch real/usr/lib/foo > > > > + mkdir -p stage/input > > + mount --bind real stage/input <-- I want to mount `real` under `input`. > > + ls -l stage/input > > drwxr-xr-x 3 root root 4096 Mar 12 11:53 usr <-- `usr` is visible. > > > > + mkdir work upper merged > > + mount -t overlay overlay > > -olowerdir=./stage,upperdir=./upper,workdir=./work ./merged > > + ls -Rl merged/input > > merged/input: > > total 0 <-- The `usr` directory is not passed through. > > > > I wasn't able to find anything that explicitly states it's not > > supported. Is something like this possible? I tried setting the mount > > propagation to shared, but that didn't have any effect. > > Overlayfs does not follow children (bind) mounts. Ok thanks for confirming. I wasn't sure if I was just doing something wrong. > > It looks like you are trying to overlay the tree at real over > the tree in stage/input. > Why not use an overlayfs layer of real on top of the stage > layer? I can do that. I was trying to get away with having a single overlayfs mount, but it's not really required. > > Please explain what you want to achieve rather than how > you tried to achieve it, so maybe I can help more. > Sorry, I simplified the problem a bit too much. Your comments were exactly what I was looking for though. > Thanks, > Amir. Thanks!
