2021-08-17 10:23:07

by Yajun Deng

Subject: [PATCH net-next] net: net_namespace: Optimize the code

Inline ops_free(), becase there is only one caller.
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.

Signed-off-by: Yajun Deng <[email protected]>
---
net/core/net_namespace.c | 49 ++++++++++++++++++----------------------
1 file changed, 22 insertions(+), 27 deletions(-)

diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 9b5a767eddd5..27acbf2df78f 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -148,13 +148,6 @@ static int ops_init(const struct pernet_operations *ops, struct net *net)
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 +426,17 @@ static struct net *net_alloc(void)

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 +474,7 @@ 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 +606,7 @@ 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 +1115,14 @@ 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 +1148,7 @@ 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 +1161,8 @@ 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 +1185,7 @@ 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);
}
}

--
2.32.0

2021-08-17 13:47:12

by Jakub Kicinski

Subject: Re: [PATCH net-next] net: net_namespace: Optimize the code

On Tue, 17 Aug 2021 18:20:01 +0800 Yajun Deng wrote:
> Inline ops_free(), becase there is only one caller.
> 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.
>
> Signed-off-by: Yajun Deng <[email protected]>

This patch does not apply, please rebase.