From 7a60d91c690bf73c2c78e763efa29f294e217c3a Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Fri, 11 Apr 2025 13:52:32 -0700 Subject: net: Add ->exit_rtnl() hook to struct pernet_operations. struct pernet_operations provides two batching hooks; ->exit_batch() and ->exit_batch_rtnl(). The batching variant is beneficial if ->exit() meets any of the following conditions: 1) ->exit() repeatedly acquires a global lock for each netns 2) ->exit() has a time-consuming operation that can be factored out (e.g. synchronize_rcu(), smp_mb(), etc) 3) ->exit() does not need to repeat the same iterations for each netns (e.g. inet_twsk_purge()) Currently, none of the ->exit_batch_rtnl() functions satisfy any of the above conditions because RTNL is factored out and held by the caller and all of these functions iterate over the dying netns list. Also, we want to hold per-netns RTNL there but avoid spreading __rtnl_net_lock() across multiple locations. Let's add ->exit_rtnl() hook and run it under __rtnl_net_lock(). The following patches will convert all ->exit_batch_rtnl() users to ->exit_rtnl(). Signed-off-by: Kuniyuki Iwashima Reviewed-by: Sabrina Dubroca Link: https://patch.msgid.link/20250411205258.63164-4-kuniyu@amazon.com Signed-off-by: Jakub Kicinski --- include/net/net_namespace.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/net/net_namespace.h') diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index bd57d8fb54f1..b071e6eed9d5 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -475,6 +475,8 @@ struct pernet_operations { void (*exit)(struct net *net); void (*exit_batch)(struct list_head *net_exit_list); /* Following method is called with RTNL held. */ + void (*exit_rtnl)(struct net *net, + struct list_head *dev_kill_list); void (*exit_batch_rtnl)(struct list_head *net_exit_list, struct list_head *dev_kill_list); unsigned int * const id; -- cgit v1.2.3 From c57a9c503543cd8829eeaaf88362199e0491c0d7 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Fri, 11 Apr 2025 13:52:43 -0700 Subject: net: Remove ->exit_batch_rtnl(). There are no ->exit_batch_rtnl() users remaining. Let's remove the hook. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Sabrina Dubroca Link: https://patch.msgid.link/20250411205258.63164-15-kuniyu@amazon.com Signed-off-by: Jakub Kicinski --- include/net/net_namespace.h | 2 -- net/core/net_namespace.c | 8 +------- 2 files changed, 1 insertion(+), 9 deletions(-) (limited to 'include/net/net_namespace.h') diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index b071e6eed9d5..025a7574b275 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -477,8 +477,6 @@ struct pernet_operations { /* Following method is called with RTNL held. */ void (*exit_rtnl)(struct net *net, struct list_head *dev_kill_list); - void (*exit_batch_rtnl)(struct list_head *net_exit_list, - struct list_head *dev_kill_list); unsigned int * const id; const size_t size; }; diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index afaa3d1bda8d..0a2b24af4028 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -185,12 +185,6 @@ static void ops_exit_rtnl_list(const struct list_head *ops_list, __rtnl_net_unlock(net); } - ops = saved_ops; - list_for_each_entry_continue_reverse(ops, ops_list, list) { - if (ops->exit_batch_rtnl) - ops->exit_batch_rtnl(net_exit_list, &dev_kill_list); - } - unregister_netdevice_many(&dev_kill_list); rtnl_unlock(); @@ -263,7 +257,7 @@ static void ops_undo_list(const struct list_head *ops_list, static void ops_undo_single(struct pernet_operations *ops, struct list_head *net_exit_list) { - bool hold_rtnl = ops->exit_rtnl || ops->exit_batch_rtnl; + bool hold_rtnl = !!ops->exit_rtnl; LIST_HEAD(ops_list); list_add(&ops->list, &ops_list); -- cgit v1.2.3