From fed176bf3143362ac9935e3964949ab6a5c3286b Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Fri, 11 Apr 2025 13:52:31 -0700 Subject: [PATCH] net: Add ops_undo_single for module load/unload. If ops_init() fails while loading a module or we unload the module, free_exit_list() rolls back the changes. The rollback sequence is the same as ops_undo_list(). The ops is already removed from pernet_list before calling free_exit_list(). If we link the ops to a temporary list, we can reuse ops_undo_list(). Let's add a wrapper of ops_undo_list() and use it instead of free_exit_list(). Now, we have the central place to roll back ops_init(). Signed-off-by: Kuniyuki Iwashima Reviewed-by: Sabrina Dubroca Link: https://patch.msgid.link/20250411205258.63164-3-kuniyu@amazon.com Signed-off-by: Jakub Kicinski --- net/core/net_namespace.c | 54 ++++++++++++++++++---------------------- 1 file changed, 24 insertions(+), 30 deletions(-) diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 2612339efd71..37026776ae4e 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -235,6 +235,17 @@ static void ops_undo_list(const struct list_head *ops_list, ops_free_list(ops, net_exit_list); } +static void ops_undo_single(struct pernet_operations *ops, + struct list_head *net_exit_list) +{ + bool hold_rtnl = !!ops->exit_batch_rtnl; + LIST_HEAD(ops_list); + + list_add(&ops->list, &ops_list); + ops_undo_list(&ops_list, NULL, net_exit_list, false, hold_rtnl); + list_del(&ops->list); +} + /* should be called with nsid_lock held */ static int alloc_netid(struct net *net, struct net *peer, int reqid) { @@ -1235,31 +1246,13 @@ void __init net_ns_init(void) rtnl_register_many(net_ns_rtnl_msg_handlers); } -static void free_exit_list(struct pernet_operations *ops, struct list_head *net_exit_list) -{ - ops_pre_exit_list(ops, net_exit_list); - synchronize_rcu(); - - if (ops->exit_batch_rtnl) { - LIST_HEAD(dev_kill_list); - - rtnl_lock(); - ops->exit_batch_rtnl(net_exit_list, &dev_kill_list); - unregister_netdevice_many(&dev_kill_list); - rtnl_unlock(); - } - ops_exit_list(ops, net_exit_list); - - ops_free_list(ops, net_exit_list); -} - #ifdef CONFIG_NET_NS static int __register_pernet_operations(struct list_head *list, struct pernet_operations *ops) { + LIST_HEAD(net_exit_list); struct net *net; int error; - LIST_HEAD(net_exit_list); list_add_tail(&ops->list, list); if (ops->init || ops->id) { @@ -1278,21 +1271,21 @@ static int __register_pernet_operations(struct list_head *list, out_undo: /* If I have an error cleanup all namespaces I initialized */ list_del(&ops->list); - free_exit_list(ops, &net_exit_list); + ops_undo_single(ops, &net_exit_list); return error; } static void __unregister_pernet_operations(struct pernet_operations *ops) { - struct net *net; LIST_HEAD(net_exit_list); + struct net *net; - list_del(&ops->list); /* See comment in __register_pernet_operations() */ for_each_net(net) list_add_tail(&net->exit_list, &net_exit_list); - free_exit_list(ops, &net_exit_list); + list_del(&ops->list); + ops_undo_single(ops, &net_exit_list); } #else @@ -1300,22 +1293,23 @@ static void __unregister_pernet_operations(struct pernet_operations *ops) static int __register_pernet_operations(struct list_head *list, struct pernet_operations *ops) { - if (!init_net_initialized) { - list_add_tail(&ops->list, list); + list_add_tail(&ops->list, list); + + if (!init_net_initialized) return 0; - } return ops_init(ops, &init_net); } static void __unregister_pernet_operations(struct pernet_operations *ops) { - if (!init_net_initialized) { - list_del(&ops->list); - } else { + list_del(&ops->list); + + if (init_net_initialized) { LIST_HEAD(net_exit_list); + list_add(&init_net.exit_list, &net_exit_list); - free_exit_list(ops, &net_exit_list); + ops_undo_single(ops, &net_exit_list); } } -- 2.25.1