On Sat, Nov 01, 2025 at 08:20:50PM +0100, Thomas Gleixner wrote:
> Christian!
>
> On Wed, Oct 29 2025 at 13:20, Christian Brauner wrote:
> > --- a/kernel/time/namespace.c
> > +++ b/kernel/time/namespace.c
> > @@ -488,6 +488,7 @@ struct time_namespace init_time_ns = {
> > .ns.ns_owner = LIST_HEAD_INIT(init_time_ns.ns.ns_owner),
> > .frozen_offsets = true,
> > .ns.ns_list_node = LIST_HEAD_INIT(init_time_ns.ns.ns_list_node),
> > + .ns.ns_unified_list_node = LIST_HEAD_INIT(init_time_ns.ns.ns_unified_list_node),
>
> Sorry that I did not catch that earlier, but
>
> 1) this screws up the proper tabular struct initializer
>
> 2) the churn of touching every compile time struct each time you add a
> new field and add the same stupid initialization to each of them
> can be avoided, when you do something like the uncompiled below.
> You get the idea.
>
> Thanks,
Nice! I'm stealing that and I'll slap a Suggested-by for you on it.
Thanks!
>
> tglx
> ---
> fs/namespace.c | 9 +--------
> include/linux/ns_common.h | 12 ++++++++++++
> init/version-timestamp.c | 9 +--------
> ipc/msgutil.c | 9 +--------
> kernel/pid.c | 8 +-------
> kernel/time/namespace.c | 9 +--------
> kernel/user.c | 9 +--------
> 7 files changed, 18 insertions(+), 47 deletions(-)
>
> --- a/fs/namespace.c
> +++ b/fs/namespace.c
> @@ -5985,19 +5985,12 @@ SYSCALL_DEFINE4(listmount, const struct
> }
>
> struct mnt_namespace init_mnt_ns = {
> - .ns.inum = ns_init_inum(&init_mnt_ns),
> + .ns = NS_COMMON_INIT(init_mnt_ns, 1, 1),
> .ns.ops = &mntns_operations,
> .user_ns = &init_user_ns,
> - .ns.__ns_ref = REFCOUNT_INIT(1),
> - .ns.__ns_ref_active = ATOMIC_INIT(1),
> - .ns.ns_type = ns_common_type(&init_mnt_ns),
> .passive = REFCOUNT_INIT(1),
> .mounts = RB_ROOT,
> .poll = __WAIT_QUEUE_HEAD_INITIALIZER(init_mnt_ns.poll),
> - .ns.ns_list_node = LIST_HEAD_INIT(init_mnt_ns.ns.ns_list_node),
> - .ns.ns_unified_list_node = LIST_HEAD_INIT(init_mnt_ns.ns.ns_unified_list_node),
> - .ns.ns_owner_entry = LIST_HEAD_INIT(init_mnt_ns.ns.ns_owner_entry),
> - .ns.ns_owner = LIST_HEAD_INIT(init_mnt_ns.ns.ns_owner),
> };
>
> static void __init init_mount_tree(void)
> --- a/include/linux/ns_common.h
> +++ b/include/linux/ns_common.h
> @@ -129,6 +129,18 @@ struct ns_common {
> };
> };
>
> +#define NS_COMMON_INIT(nsname, refs, active) \
> +{ \
> + .ns_type = ns_common_type(&nsname), \
> + .inum = ns_init_inum(&nsname), \
> + .__ns_ref = REFCOUNT_INIT(refs), \
> + .__ns_ref_active = ATOMIC_INIT(active), \
> + .ns_list_node = LIST_HEAD_INIT(nsname.ns.ns_list_node), \
> + .ns_unified_list_node = LIST_HEAD_INIT(nsname.ns.ns_unified_list_node), \
> + .ns_owner_entry = LIST_HEAD_INIT(nsname.ns.ns_owner_entry), \
> + .ns_owner = LIST_HEAD_INIT(nsname.ns.ns_owner), \
> +}
> +
> int __ns_common_init(struct ns_common *ns, u32 ns_type, const struct proc_ns_operations *ops, int inum);
> void __ns_common_free(struct ns_common *ns);
>
> --- a/init/version-timestamp.c
> +++ b/init/version-timestamp.c
> @@ -8,9 +8,7 @@
> #include <linux/utsname.h>
>
> struct uts_namespace init_uts_ns = {
> - .ns.ns_type = ns_common_type(&init_uts_ns),
> - .ns.__ns_ref = REFCOUNT_INIT(2),
> - .ns.__ns_ref_active = ATOMIC_INIT(1),
> + .ns = NS_COMMON_INIT(init_uts_ns, 2, 1),
> .name = {
> .sysname = UTS_SYSNAME,
> .nodename = UTS_NODENAME,
> @@ -20,11 +18,6 @@ struct uts_namespace init_uts_ns = {
> .domainname = UTS_DOMAINNAME,
> },
> .user_ns = &init_user_ns,
> - .ns.inum = ns_init_inum(&init_uts_ns),
> - .ns.ns_list_node = LIST_HEAD_INIT(init_uts_ns.ns.ns_list_node),
> - .ns.ns_unified_list_node = LIST_HEAD_INIT(init_uts_ns.ns.ns_unified_list_node),
> - .ns.ns_owner_entry = LIST_HEAD_INIT(init_uts_ns.ns.ns_owner_entry),
> - .ns.ns_owner = LIST_HEAD_INIT(init_uts_ns.ns.ns_owner),
> #ifdef CONFIG_UTS_NS
> .ns.ops = &utsns_operations,
> #endif
> --- a/ipc/msgutil.c
> +++ b/ipc/msgutil.c
> @@ -27,18 +27,11 @@ DEFINE_SPINLOCK(mq_lock);
> * and not CONFIG_IPC_NS.
> */
> struct ipc_namespace init_ipc_ns = {
> - .ns.__ns_ref = REFCOUNT_INIT(1),
> - .ns.__ns_ref_active = ATOMIC_INIT(1),
> + .ns = NS_COMMON_INIT(init_ipc_ns, 1, 1),
> .user_ns = &init_user_ns,
> - .ns.inum = ns_init_inum(&init_ipc_ns),
> - .ns.ns_list_node = LIST_HEAD_INIT(init_ipc_ns.ns.ns_list_node),
> - .ns.ns_unified_list_node = LIST_HEAD_INIT(init_ipc_ns.ns.ns_unified_list_node),
> - .ns.ns_owner_entry = LIST_HEAD_INIT(init_ipc_ns.ns.ns_owner_entry),
> - .ns.ns_owner = LIST_HEAD_INIT(init_ipc_ns.ns.ns_owner),
> #ifdef CONFIG_IPC_NS
> .ns.ops = &ipcns_operations,
> #endif
> - .ns.ns_type = ns_common_type(&init_ipc_ns),
> };
>
> struct msg_msgseg {
> --- a/kernel/pid.c
> +++ b/kernel/pid.c
> @@ -71,18 +71,12 @@ static int pid_max_max = PID_MAX_LIMIT;
> * the scheme scales to up to 4 million PIDs, runtime.
> */
> struct pid_namespace init_pid_ns = {
> - .ns.__ns_ref = REFCOUNT_INIT(2),
> - .ns.__ns_ref_active = ATOMIC_INIT(1),
> + .ns = NS_COMMON_INIT(init_pid_ns, 2, 1),
> .idr = IDR_INIT(init_pid_ns.idr),
> .pid_allocated = PIDNS_ADDING,
> .level = 0,
> .child_reaper = &init_task,
> .user_ns = &init_user_ns,
> - .ns.inum = ns_init_inum(&init_pid_ns),
> - .ns.ns_list_node = LIST_HEAD_INIT(init_pid_ns.ns.ns_list_node),
> - .ns.ns_unified_list_node = LIST_HEAD_INIT(init_pid_ns.ns.ns_unified_list_node),
> - .ns.ns_owner_entry = LIST_HEAD_INIT(init_pid_ns.ns.ns_owner_entry),
> - .ns.ns_owner = LIST_HEAD_INIT(init_pid_ns.ns.ns_owner),
> #ifdef CONFIG_PID_NS
> .ns.ops = &pidns_operations,
> #endif
> --- a/kernel/time/namespace.c
> +++ b/kernel/time/namespace.c
> @@ -478,17 +478,10 @@ const struct proc_ns_operations timens_f
> };
>
> struct time_namespace init_time_ns = {
> - .ns.ns_type = ns_common_type(&init_time_ns),
> - .ns.__ns_ref = REFCOUNT_INIT(3),
> - .ns.__ns_ref_active = ATOMIC_INIT(1),
> + .ns = NS_COMMON_INIT(init_time_ns, 3, 1),
> .user_ns = &init_user_ns,
> - .ns.inum = ns_init_inum(&init_time_ns),
> .ns.ops = &timens_operations,
> - .ns.ns_owner_entry = LIST_HEAD_INIT(init_time_ns.ns.ns_owner_entry),
> - .ns.ns_owner = LIST_HEAD_INIT(init_time_ns.ns.ns_owner),
> .frozen_offsets = true,
> - .ns.ns_list_node = LIST_HEAD_INIT(init_time_ns.ns.ns_list_node),
> - .ns.ns_unified_list_node = LIST_HEAD_INIT(init_time_ns.ns.ns_unified_list_node),
> };
>
> void __init time_ns_init(void)
> --- a/kernel/user.c
> +++ b/kernel/user.c
> @@ -65,16 +65,9 @@ struct user_namespace init_user_ns = {
> .nr_extents = 1,
> },
> },
> - .ns.ns_type = ns_common_type(&init_user_ns),
> - .ns.__ns_ref = REFCOUNT_INIT(3),
> - .ns.__ns_ref_active = ATOMIC_INIT(1),
> + .ns = NS_COMMON_INIT(init_user_ns, 3, 1),
> .owner = GLOBAL_ROOT_UID,
> .group = GLOBAL_ROOT_GID,
> - .ns.inum = ns_init_inum(&init_user_ns),
> - .ns.ns_list_node = LIST_HEAD_INIT(init_user_ns.ns.ns_list_node),
> - .ns.ns_unified_list_node = LIST_HEAD_INIT(init_user_ns.ns.ns_unified_list_node),
> - .ns.ns_owner_entry = LIST_HEAD_INIT(init_user_ns.ns.ns_owner_entry),
> - .ns.ns_owner = LIST_HEAD_INIT(init_user_ns.ns.ns_owner),
> #ifdef CONFIG_USER_NS
> .ns.ops = &userns_operations,
> #endif