[PATCH net-next v3 1/3] net/smc: refatoring initialization of smc sock

D. Wythe
2024-05-28T02:30:05Z

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 | 86 +++++++++++++++++++++++++++++++-------------------------
net/smc/smc.h | 5 ++++
2 files changed, 53 insertions(+), 38 deletions(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 9389f0c..d8c116e 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -361,25 +361,15 @@ static void smc_destruct(struct sock *sk)
return;
}

-static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
- int protocol)
+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;
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);
@@ -389,6 +379,24 @@ static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
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;
+}
+
+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 +3329,31 @@ static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
.splice_read = smc_splice_read,
};

+int smc_create_clcsk(struct net *net, struct sock *sk, int family)
+{
+ 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 +3379,12 @@ 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;
}
diff --git a/net/smc/smc.h b/net/smc/smc.h
index 18c8b78..a0accb5 100644
--- a/net/smc/smc.h
+++ b/net/smc/smc.h
@@ -34,6 +34,11 @@
extern struct proto smc_proto;
extern struct proto smc_proto6;

+/* smc sock initialization */
+void smc_sock_init(struct net *net, struct sock *sk, int protocol);
+/* clcsock initialization */
+int smc_create_clcsk(struct net *net, struct sock *sk, int family);
+
#ifdef ATOMIC64_INIT
#define KERNEL_HAS_ATOMIC64
#endif
--
1.8.3.1