Re: [PATCH net-next 1/2] net/smc: refatoring initialization of smc sock

D. Wythe
2024-05-11T02:26:30Z

On 5/10/24 5:50 PM, Dust Li wrote:
> On 2024-05-10 12:12:12, D. Wythe wrote:
>> From: "D. Wythe" <alibuda@linux.alibaba.com>
>>
>> This patch aims to isolate the shared components of SMC socket
>> allocation by introducing smc_sock_init() for sock initialization
>> and __smc_create_clcsk() for the initialization of clcsock.
>>
>> This is in preparation for the subsequent implementation of the
>> AF_INET version of SMC.
>>
>> Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
>> ---
>> net/smc/af_smc.c | 93 +++++++++++++++++++++++++++++++-------------------------
>> 1 file changed, 52 insertions(+), 41 deletions(-)
>>
>> diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
>> index 9389f0c..1f03724 100644
>> --- a/net/smc/af_smc.c
>> +++ b/net/smc/af_smc.c
>> @@ -361,34 +361,43 @@ static void smc_destruct(struct sock *sk)
>> return;
>> }
>>
>> -static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
>> - int protocol)
>> +static void smc_sock_init(struct net *net, struct sock *sk, int protocol)
>> {
>> - struct smc_sock *smc;
>> - struct proto *prot;
>> - struct sock *sk;
>> -
>> - prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
>> - sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
>> - if (!sk)
>> - return NULL;
>> + struct smc_sock *smc = smc_sk(sk);
>>
>> - sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
>> sk->sk_state = SMC_INIT;
>> - sk->sk_destruct = smc_destruct;
>> sk->sk_protocol = protocol;
>> + mutex_init(&smc->clcsock_release_lock);
>> WRITE_ONCE(sk->sk_sndbuf, 2 * READ_ONCE(net->smc.sysctl_wmem));
>> WRITE_ONCE(sk->sk_rcvbuf, 2 * READ_ONCE(net->smc.sysctl_rmem));
>> - smc = smc_sk(sk);
>> INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
>> INIT_WORK(&smc->connect_work, smc_connect_work);
>> INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
>> INIT_LIST_HEAD(&smc->accept_q);
>> spin_lock_init(&smc->accept_q_lock);
>> spin_lock_init(&smc->conn.send_lock);
>> - sk->sk_prot->hash(sk);
>> - mutex_init(&smc->clcsock_release_lock);
>> smc_init_saved_callbacks(smc);
>> + smc->limit_smc_hs = net->smc.limit_smc_hs;
>> + smc->use_fallback = false; /* assume rdma capability first */
>> + smc->fallback_rsn = 0;
>> +
>> + sk->sk_destruct = smc_destruct;
>> + sk->sk_prot->hash(sk);
> Why change the order here ? e.g.
>
> Before:
> sk->sk_destruct = smc_destruct;
> mutex_init(&smc->clcsock_release_lock);
> After
> mutex_init(&smc->clcsock_release_lock);
> sk->sk_destruct = smc_destruct;
>
> Same for sk->sk_prot->hash(sk)

Yes, you are right, I will fix it in the next version.
>
>
>> +}
>> +
>> +static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
>> + int protocol)
>> +{
>> + struct proto *prot;
>> + struct sock *sk;
>> +
>> + prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
>> + sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
>> + if (!sk)
>> + return NULL;
>> +
>> + sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
>> + smc_sock_init(net, sk, protocol);
>>
>> return sk;
>> }
>> @@ -3321,6 +3330,31 @@ static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
>> .splice_read = smc_splice_read,
>> };
>>
>> +static int __smc_create_clcsk(struct net *net, struct sock *sk, int family)
> Why add '__' prefix here ?

Good question, I also realize that this is not suitable, I will delete
it in the next version.

Thanks.

>
>> +{
>> + struct smc_sock *smc = smc_sk(sk);
>> + int rc;
>> +
>> + rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
>> + &smc->clcsock);
>> + if (rc) {
>> + sk_common_release(sk);
>> + return rc;
>> + }
>> +
>> + /* smc_clcsock_release() does not wait smc->clcsock->sk's
>> + * destruction; its sk_state might not be TCP_CLOSE after
>> + * smc->sk is close()d, and TCP timers can be fired later,
>> + * which need net ref.
>> + */
>> + sk = smc->clcsock->sk;
>> + __netns_tracker_free(net, &sk->ns_tracker, false);
>> + sk->sk_net_refcnt = 1;
>> + get_net_track(net, &sk->ns_tracker, GFP_KERNEL);
>> + sock_inuse_add(net, 1);
>> + return 0;
>> +}
>> +
>> static int __smc_create(struct net *net, struct socket *sock, int protocol,
>> int kern, struct socket *clcsock)
>> {
>> @@ -3346,35 +3380,12 @@ static int __smc_create(struct net *net, struct socket *sock, int protocol,
>>
>> /* create internal TCP socket for CLC handshake and fallback */
>> smc = smc_sk(sk);
>> - smc->use_fallback = false; /* assume rdma capability first */
>> - smc->fallback_rsn = 0;
>> -
>> - /* default behavior from limit_smc_hs in every net namespace */
>> - smc->limit_smc_hs = net->smc.limit_smc_hs;
>>
>> rc = 0;
>> - if (!clcsock) {
>> - rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
>> - &smc->clcsock);
>> - if (rc) {
>> - sk_common_release(sk);
>> - goto out;
>> - }
>> -
>> - /* smc_clcsock_release() does not wait smc->clcsock->sk's
>> - * destruction; its sk_state might not be TCP_CLOSE after
>> - * smc->sk is close()d, and TCP timers can be fired later,
>> - * which need net ref.
>> - */
>> - sk = smc->clcsock->sk;
>> - __netns_tracker_free(net, &sk->ns_tracker, false);
>> - sk->sk_net_refcnt = 1;
>> - get_net_track(net, &sk->ns_tracker, GFP_KERNEL);
>> - sock_inuse_add(net, 1);
>> - } else {
>> + if (!clcsock)
>> + rc = __smc_create_clcsk(net, sk, family);
>> + else
>> smc->clcsock = clcsock;
>> - }
>> -
>> out:
>> return rc;
>> }
>> --
>> 1.8.3.1
>>