From: Christian Brauner brauner@kernel.org Date: Fri, 12 Sep 2025 13:52:44 +0200
Support the generic ns lookup infrastructure to support file handles for namespaces.
The network namespace has a separate list with different lifetime rules which we can just leave in tact. We have a similar concept for mount namespaces as well where it is on two differenet lists for different purposes.
Signed-off-by: Christian Brauner brauner@kernel.org
include/net/net_namespace.h | 1 + net/core/net_namespace.c | 8 ++++++-- 2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index 025a7574b275..42075748dff1 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -11,6 +11,7 @@ #include <linux/list.h> #include <linux/sysctl.h> #include <linux/uidgid.h> +#include <linux/nstree.h> #include <net/flow.h> #include <net/netns/core.h> diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 5fb7bd8ac45a..169ec22c4758 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -20,6 +20,7 @@ #include <linux/sched/task.h> #include <linux/uidgid.h> #include <linux/proc_fs.h> +#include <linux/nstree.h> #include <net/aligned_data.h>
nit: This is no longer necessary.
#include <net/sock.h> @@ -445,7 +446,7 @@ static __net_init int setup_net(struct net *net) LIST_HEAD(net_exit_list); int error = 0;
- net->net_cookie = atomic64_inc_return(&net_aligned_data.net_cookie);
- net->net_cookie = ns_tree_gen_id(&net->ns);
list_for_each_entry(ops, &pernet_list, list) { error = ops_init(ops, net); @@ -455,6 +456,7 @@ static __net_init int setup_net(struct net *net) down_write(&net_rwsem); list_add_tail_rcu(&net->list, &net_namespace_list); up_write(&net_rwsem);
- ns_tree_add_raw(net);
out: return error; @@ -674,8 +676,10 @@ static void cleanup_net(struct work_struct *work) /* Don't let anyone else find us. */ down_write(&net_rwsem);
- llist_for_each_entry(net, net_kill_list, cleanup_list)
- llist_for_each_entry(net, net_kill_list, cleanup_list) {
ns_tree_remove(net);
Looking at refcount_inc_not_zero() in nsfs_fh_to_dentry(), I think ns_tree_remove() fits better in __put_net() which is called just after refcount_dec_and_test(&net->ns.count).
cleanup_net() is single threaded work and somtimes takes long with too many netns and the netns may stay longer unnecessarily until next cleanup_net().
list_del_rcu(&net->list);
- } /* Cache last net. After we unlock rtnl, no one new net
- added to net_namespace_list can assign nsid pointer
- to a net from net_kill_list (see peernet2id_alloc()).
-- 2.47.3