From 41467d2ff4dfe1837cbb0f45e2088e6e787580c6 Mon Sep 17 00:00:00 2001 From: Yajun Deng Date: Tue, 17 Aug 2021 23:23:00 +0800 Subject: [PATCH] net: net_namespace: Optimize the code There is only one caller for ops_free(), so inline it. Separate net_drop_ns() and net_free(), so the net_free() can be called directly. Add free_exit_list() helper function for free net_exit_list. ==================== v2: - v1 does not apply, rebase it. ==================== Signed-off-by: Yajun Deng Signed-off-by: David S. Miller --- net/core/net_namespace.c | 52 ++++++++++++++++++++++-------------------------- 1 file changed, 24 insertions(+), 28 deletions(-) diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 9b5a767..a448a9b 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -98,7 +98,7 @@ static int net_assign_generic(struct net *net, unsigned int id, void *data) } ng = net_alloc_generic(); - if (ng == NULL) + if (!ng) return -ENOMEM; /* @@ -148,13 +148,6 @@ out: return err; } -static void ops_free(const struct pernet_operations *ops, struct net *net) -{ - if (ops->id && ops->size) { - kfree(net_generic(net, *ops->id)); - } -} - static void ops_pre_exit_list(const struct pernet_operations *ops, struct list_head *net_exit_list) { @@ -184,7 +177,7 @@ static void ops_free_list(const struct pernet_operations *ops, struct net *net; if (ops->size && ops->id) { list_for_each_entry(net, net_exit_list, exit_list) - ops_free(ops, net); + kfree(net_generic(net, *ops->id)); } } @@ -433,15 +426,18 @@ out_free: static void net_free(struct net *net) { - kfree(rcu_access_pointer(net->gen)); - kmem_cache_free(net_cachep, net); + if (refcount_dec_and_test(&net->passive)) { + kfree(rcu_access_pointer(net->gen)); + kmem_cache_free(net_cachep, net); + } } void net_drop_ns(void *p) { - struct net *ns = p; - if (ns && refcount_dec_and_test(&ns->passive)) - net_free(ns); + struct net *net = (struct net *)p; + + if (net) + net_free(net); } struct net *copy_net_ns(unsigned long flags, @@ -479,7 +475,7 @@ struct net *copy_net_ns(unsigned long flags, put_userns: key_remove_domain(net->key_domain); put_user_ns(user_ns); - net_drop_ns(net); + net_free(net); dec_ucounts: dec_net_namespaces(ucounts); return ERR_PTR(rv); @@ -611,7 +607,7 @@ static void cleanup_net(struct work_struct *work) dec_net_namespaces(net->ucounts); key_remove_domain(net->key_domain); put_user_ns(net->user_ns); - net_drop_ns(net); + net_free(net); } } @@ -1120,6 +1116,14 @@ static int __init net_ns_init(void) pure_initcall(net_ns_init); +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(); + 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) @@ -1145,10 +1149,7 @@ 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); - ops_pre_exit_list(ops, &net_exit_list); - synchronize_rcu(); - ops_exit_list(ops, &net_exit_list); - ops_free_list(ops, &net_exit_list); + free_exit_list(ops, &net_exit_list); return error; } @@ -1161,10 +1162,8 @@ static void __unregister_pernet_operations(struct pernet_operations *ops) /* See comment in __register_pernet_operations() */ for_each_net(net) list_add_tail(&net->exit_list, &net_exit_list); - ops_pre_exit_list(ops, &net_exit_list); - synchronize_rcu(); - ops_exit_list(ops, &net_exit_list); - ops_free_list(ops, &net_exit_list); + + free_exit_list(ops, &net_exit_list); } #else @@ -1187,10 +1186,7 @@ static void __unregister_pernet_operations(struct pernet_operations *ops) } else { LIST_HEAD(net_exit_list); list_add(&init_net.exit_list, &net_exit_list); - ops_pre_exit_list(ops, &net_exit_list); - synchronize_rcu(); - ops_exit_list(ops, &net_exit_list); - ops_free_list(ops, &net_exit_list); + free_exit_list(ops, &net_exit_list); } } -- 2.7.4