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

Dust Li
2024-05-10T09:50:37Z

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)

>+}
>+
>+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 ?

>+{
>+ 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
>