From: Saeed Mahameed <saeed@kernel.org>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: netdev@vger.kernel.org, g.nault@alphalink.fr,
Cong Wang <cong.wang@bytedance.com>,
Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
Jakub Sitnicki <jakub@cloudflare.com>,
Eric Dumazet <edumazet@google.com>
Subject: Re: [Patch net 1/2] l2tp: convert l2tp_tunnel_list to idr
Date: Sat, 7 Jan 2023 10:25:04 -0800 [thread overview]
Message-ID: <Y7m5AKECbfk0Mq0K@x130> (raw)
In-Reply-To: <20230105191339.506839-2-xiyou.wangcong@gmail.com>
On 05 Jan 11:13, Cong Wang wrote:
>From: Cong Wang <cong.wang@bytedance.com>
>
>l2tp uses l2tp_tunnel_list to track all registered tunnels and
>to allocate tunnel ID's. IDR can do the same job.
>
>More importantly, with IDR we can hold the ID before a successful
>registration so that we don't need to worry about late error
>hanlding, it is not easy to rollback socket changes.
>
>This is a preparation for the following fix.
>
>Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
>Cc: Guillaume Nault <g.nault@alphalink.fr>
>Cc: Jakub Sitnicki <jakub@cloudflare.com>
>Cc: Eric Dumazet <edumazet@google.com>
>Signed-off-by: Cong Wang <cong.wang@bytedance.com>
>---
> net/l2tp/l2tp_core.c | 93 ++++++++++++++++++++++-------------------
> net/l2tp/l2tp_core.h | 3 +-
> net/l2tp/l2tp_netlink.c | 3 +-
> net/l2tp/l2tp_ppp.c | 3 +-
> 4 files changed, 57 insertions(+), 45 deletions(-)
>
>diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
>index 9a1415fe3fa7..570249a91c6c 100644
>--- a/net/l2tp/l2tp_core.c
>+++ b/net/l2tp/l2tp_core.c
>@@ -104,9 +104,9 @@ static struct workqueue_struct *l2tp_wq;
> /* per-net private data for this module */
> static unsigned int l2tp_net_id;
> struct l2tp_net {
>- struct list_head l2tp_tunnel_list;
>- /* Lock for write access to l2tp_tunnel_list */
>- spinlock_t l2tp_tunnel_list_lock;
>+ /* Lock for write access to l2tp_tunnel_idr */
>+ spinlock_t l2tp_tunnel_idr_lock;
>+ struct idr l2tp_tunnel_idr;
> struct hlist_head l2tp_session_hlist[L2TP_HASH_SIZE_2];
> /* Lock for write access to l2tp_session_hlist */
> spinlock_t l2tp_session_hlist_lock;
>@@ -208,13 +208,10 @@ struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id)
> struct l2tp_tunnel *tunnel;
>
> rcu_read_lock_bh();
>- list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) {
>- if (tunnel->tunnel_id == tunnel_id &&
>- refcount_inc_not_zero(&tunnel->ref_count)) {
>- rcu_read_unlock_bh();
>-
>- return tunnel;
>- }
>+ tunnel = idr_find(&pn->l2tp_tunnel_idr, tunnel_id);
>+ if (tunnel && refcount_inc_not_zero(&tunnel->ref_count)) {
>+ rcu_read_unlock_bh();
>+ return tunnel;
> }
> rcu_read_unlock_bh();
>
>@@ -224,13 +221,14 @@ EXPORT_SYMBOL_GPL(l2tp_tunnel_get);
>
> struct l2tp_tunnel *l2tp_tunnel_get_nth(const struct net *net, int nth)
> {
>- const struct l2tp_net *pn = l2tp_pernet(net);
>+ struct l2tp_net *pn = l2tp_pernet(net);
Any reason to remove the const keyword ?
Other than that LGTM:
Reviewed-by: Saeed Mahameed <saeed@kernel.org>
next prev parent reply other threads:[~2023-01-07 18:25 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-05 19:13 [Patch net 0/2] l2tp: fix race conditions in l2tp_tunnel_register() Cong Wang
2023-01-05 19:13 ` [Patch net 1/2] l2tp: convert l2tp_tunnel_list to idr Cong Wang
2023-01-07 18:25 ` Saeed Mahameed [this message]
2023-01-07 19:48 ` Cong Wang
2023-01-07 19:48 ` Guillaume Nault
2023-01-09 9:55 ` Tom Parkin
2023-01-10 6:49 ` Cong Wang
2023-01-05 19:13 ` [Patch net 2/2] l2tp: close all race conditions in l2tp_tunnel_register() Cong Wang
2023-01-07 18:41 ` Saeed Mahameed
2023-01-07 19:52 ` Cong Wang
2023-01-10 1:36 ` Jakub Kicinski
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