[PATCH v4 6/7] net: add ref_tracker_dir_debugfs() calls for netns refcount tracking

From: Jeff Layton
Date: Fri Apr 18 2025 - 10:26:36 EST


After assigning the inode number to the namespace, use it to create a
unique name for each netns refcount tracker and register the debugfs
files for them.

init_net is registered before the ref_tracker dir is created, so add a
late_initcall() to register its files.

Reviewed-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
net/core/net_namespace.c | 34 +++++++++++++++++++++++++++++++++-
1 file changed, 33 insertions(+), 1 deletion(-)

diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 4303f2a4926243e2c0ff0c0387383cd8e0658019..f35c51f1eddacf3e84cdd51d77dee9f1d6dc4f87 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -761,12 +761,44 @@ struct net *get_net_ns_by_pid(pid_t pid)
}
EXPORT_SYMBOL_GPL(get_net_ns_by_pid);

+#ifdef CONFIG_NET_NS_REFCNT_TRACKER
+static void net_ns_net_debugfs(struct net *net)
+{
+ char name[NAME_MAX + 1];
+ size_t len;
+
+ len = snprintf(name, sizeof(name), "netns-%u-refcnt", net->ns.inum);
+ if (len < sizeof(name))
+ ref_tracker_dir_debugfs(&net->refcnt_tracker, name);
+
+ len = snprintf(name, sizeof(name), "netns-%u-notrefcnt", net->ns.inum);
+ if (len < sizeof(name))
+ ref_tracker_dir_debugfs(&net->notrefcnt_tracker, name);
+}
+
+static int __init init_net_debugfs(void)
+{
+ net_ns_net_debugfs(&init_net);
+ return 0;
+}
+late_initcall(init_net_debugfs);
+#else
+static void net_ns_net_debugfs(struct net *net)
+{
+}
+#endif
+
static __net_init int net_ns_net_init(struct net *net)
{
+ int ret;
+
#ifdef CONFIG_NET_NS
net->ns.ops = &netns_operations;
#endif
- return ns_alloc_inum(&net->ns);
+ ret = ns_alloc_inum(&net->ns);
+ if (!ret)
+ net_ns_net_debugfs(net);
+ return ret;
}

static __net_exit void net_ns_net_exit(struct net *net)

--
2.49.0