Container volumes with ID Maps mounted in a merged directory

[connelhooley]

Hi, I've tried to use a podman volume with an idmap, mounted in a mergerfs directory like this:

[user@hostname ~]$ sudo podman run --userns auto --volume '/var/mnt/merged:/test:Z,idmap=uids=@1000-0-1;gids=@1000-0-1' --rm fedora ls -lan /test
Error: OCI runtime error: crun: mount_setattr `/test` (maybe the file system used doesn't support idmap mounts on this kernel?): Invalid argument
[user@hostname ~]$ mergerfs --version
mergerfs v2.41.1

Is this error going to be fixed by #1595? Or do I need to update my mount unit:

[Unit]
Description=Merge disks
RequiresMountsFor=/var/mnt/disk1 /var/mnt/disk2 /var/mnt/disk3

[Mount]
What=/var/mnt/disk*
Where=/var/mnt/merged
Type=fuse.mergerfs
Options=cache.files=off,category.create=pfrd,func.getattr=newest,dropcacheonclose=false

[Install]
WantedBy=multi-user.target

Is there an option I need to set? I can use idmaps successfully in "none mergerfs" directories.

I've seen this discussion #1517 (comment) but I believe this is referring to creating the merged mount itself with an ID map, whereas I want to place a podman volume inside the mount with an ID map.

[trapexit]

idmapping requires explicit support from the filesystem and the current release does not support it. It should in the next release but due to the magnitude of the change I'm being cautious about the release and need to do more testing.

[connelhooley]

Ok thanks for letting me know. I really appreciate all the hard work that goes into this project, I'm more than happy to wait until it's ready. I just wanted to understand if I was doing something wrong or not with the current version, which you've answered.

Thanks again