Re: [PATCH] vfs: add FS_USERNS_DELEGATABLE flag and set it for NFS

From: Jeff Layton

Date: Tue Jun 09 2026 - 07:03:08 EST


On Tue, 2026-02-03 at 16:08 +0100, Christian Brauner wrote:
> On Thu, 29 Jan 2026 16:47:43 -0500, Jeff Layton wrote:
> > Commit e1c5ae59c0f2 ("fs: don't allow non-init s_user_ns for filesystems
> > without FS_USERNS_MOUNT") prevents the mount of any filesystem inside a
> > container that doesn't have FS_USERNS_MOUNT set.
> >
> > This broke NFS mounts in our containerized environment. We have a daemon
> > somewhat like systemd-mountfsd running in the init_ns. A process does a
> > fsopen() inside the container and passes it to the daemon via unix
> > socket.
> >
> > [...]
>
> Applied to the vfs-7.0.misc branch of the vfs/vfs.git tree.
> Patches in the vfs-7.0.misc branch should appear in linux-next soon.
>
> Please report any outstanding bugs that were missed during review in a
> new review to the original patch series allowing us to drop it.
>
> It's encouraged to provide Acked-bys and Reviewed-bys even though the
> patch has now been applied. If possible patch trailers will be updated.
>
> Note that commit hashes shown below are subject to change due to rebase,
> trailer updates or similar. If in doubt, please check the listed branch.
>
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
> branch: vfs-7.0.misc
>
> [1/1] vfs: add FS_USERNS_DELEGATABLE flag and set it for NFS
> https://git.kernel.org/vfs/vfs/c/269c46e936f3

I sent something yesterday, but I'm not sure you saw it.

This patch never made it into v7.0 for some reason. Any chance we could
get it in for v7.2?

Thanks,
--
Jeff Layton <jlayton@xxxxxxxxxx>