Userspace heavily relies on the root inode numbers for namespaces to identify the initial namespaces. That's already a hard dependency. So we cannot change that anymore. Move the initial inode numbers to a public header and align the only two namespaces that currently don't do that with all the other namespaces. Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx> --- Christian Brauner (3): nsfs: move root inode number to uapi netns: use stable inode number for initial mount ns mntns: use stable inode number for initial mount ns fs/namespace.c | 4 +++- include/linux/proc_ns.h | 15 +++++++++------ include/uapi/linux/nsfs.h | 11 +++++++++++ net/core/net_namespace.c | 8 ++++++++ 4 files changed, 31 insertions(+), 7 deletions(-) --- base-commit: ec7714e4947909190ffb3041a03311a975350fe0 change-id: 20250606-work-nsfs-3e951f888309