Re: [PATCH net-next 2/2] net/smc: Introduce IPPROTO_SMC

Dust Li
2024-05-11T02:46:17Z

On 2024-05-11 10:23:31, D. Wythe wrote:
>
>
>On 5/10/24 5:57 PM, Dust Li wrote:
>> On 2024-05-10 12:12:13, D. Wythe wrote:
>> > From: "D. Wythe" <alibuda@linux.alibaba.com>
>> >
>> > This patch allows to create smc socket via AF_INET,
>> > similar to the following code,
>> >
>> > /* create v4 smc sock */
>> > v4 = socket(AF_INET, SOCK_STREAM, IPPROTO_SMC);
>> >
>> > /* create v6 smc sock */
>> > v6 = socket(AF_INET6, SOCK_STREAM, IPPROTO_SMC);
>> >
>> > There are several reasons why we believe it is appropriate here:
>> >
>> > 1. For smc sockets, it actually use IPv4 (AF-INET) or IPv6 (AF-INET6)
>> > address. There is no AF_SMC address at all.
>> >
>> > 2. Create smc socket in the AF_INET(6) path, which allows us to reuse
>> > the infrastructure of AF_INET(6) path, such as common ebpf hooks.
>> > Otherwise, smc have to implement it again in AF_SMC path.
>> >
>> > Signed-off-by: D. Wythe <alibuda@linux.alibaba.com>
>> > ---
>> > include/uapi/linux/in.h | 2 +
>> > net/smc/af_smc.c | 129 +++++++++++++++++++++++++++++++++++++++++++++++-
>> > net/smc/inet_smc.h | 32 ++++++++++++
>> > 3 files changed, 162 insertions(+), 1 deletion(-)
>> > create mode 100644 net/smc/inet_smc.h
>> >
>> > diff --git a/include/uapi/linux/in.h b/include/uapi/linux/in.h
>> > index e682ab6..74c12e33 100644
>> > --- a/include/uapi/linux/in.h
>> > +++ b/include/uapi/linux/in.h
>> > @@ -83,6 +83,8 @@ enum {
>> > #define IPPROTO_RAW IPPROTO_RAW
>> > IPPROTO_MPTCP = 262, /* Multipath TCP connection */
>> > #define IPPROTO_MPTCP IPPROTO_MPTCP
>> > + IPPROTO_SMC = 263, /* Shared Memory Communications */
>> ^ use tab to align here
>
>There is a problem here, all previous definitions were aligned with 2 spaces.

I mean the tab in the annotation in the end, not the space at the beginning.

>
>> > +#define IPPROTO_SMC IPPROTO_SMC
>> > IPPROTO_MAX
>> > };
>> > #endif
>> > diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
>> > index 1f03724..b4557828 100644
>> > --- a/net/smc/af_smc.c
>> > +++ b/net/smc/af_smc.c
>> > @@ -54,6 +54,7 @@
>> > #include "smc_tracepoint.h"
>> > #include "smc_sysctl.h"
>> > #include "smc_loopback.h"
>> > +#include "inet_smc.h"
>> >
>> > static DEFINE_MUTEX(smc_server_lgr_pending); /* serialize link group
>> > * creation on server
>> > @@ -3402,6 +3403,16 @@ static int smc_create(struct net *net, struct socket *sock, int protocol,
>> > .create = smc_create,
>> > };
>> >
>> Why not put those whole bunch of inet staff into smc_inet.c ?
>> Looks like your smc_inet.h is meanless without smc_inet.c
>>
>
>This header file was originally reserved for future merging of socks. If
>nobody likes it, I can move it to the
>af_smc.c

I prefer adding a new smc_inet.c, af_smc.c is already very large.

Best regards,
Dust

>
>> > +int smc_inet_init_sock(struct sock *sk)
>> > +{
>> > + struct net *net = sock_net(sk);
>> > +
>> > + /* init common smc sock */
>> > + smc_sock_init(net, sk, IPPROTO_SMC);
>> > + /* create clcsock */
>> > + return __smc_create_clcsk(net, sk, sk->sk_family);
>> > +}
>> > +
>> > static int smc_ulp_init(struct sock *sk)
>> > {
>> > struct socket *tcp = sk->sk_socket;
>> > @@ -3460,6 +3471,90 @@ static void smc_ulp_clone(const struct request_sock *req, struct sock *newsk,
>> > .clone = smc_ulp_clone,
>> > };
>> >
>> > +struct proto smc_inet_prot = {
>> > + .name = "INET_SMC",
>> > + .owner = THIS_MODULE,
>> > + .init = smc_inet_init_sock,
>> > + .hash = smc_hash_sk,
>> > + .unhash = smc_unhash_sk,
>> > + .release_cb = smc_release_cb,
>> > + .obj_size = sizeof(struct smc_sock),
>> > + .h.smc_hash = &smc_v4_hashinfo,
>> > + .slab_flags = SLAB_TYPESAFE_BY_RCU,
>> ^
>> Align please.
>>
>Got it.
>> > +};
>> > +
>> > +const struct proto_ops smc_inet_stream_ops = {
>> > + .family = PF_INET,
>> > + .owner = THIS_MODULE,
>> > + .release = smc_release,
>> > + .bind = smc_bind,
>> > + .connect = smc_connect,
>> > + .socketpair = sock_no_socketpair,
>> > + .accept = smc_accept,
>> > + .getname = smc_getname,
>> > + .poll = smc_poll,
>> > + .ioctl = smc_ioctl,
>> > + .listen = smc_listen,
>> > + .shutdown = smc_shutdown,
>> > + .setsockopt = smc_setsockopt,
>> > + .getsockopt = smc_getsockopt,
>> > + .sendmsg = smc_sendmsg,
>> > + .recvmsg = smc_recvmsg,
>> > + .mmap = sock_no_mmap,
>> > + .splice_read = smc_splice_read,
>> Ditto
>>
>> > +};
>> > +
>> > +struct inet_protosw smc_inet_protosw = {
>> > + .type = SOCK_STREAM,
>> > + .protocol = IPPROTO_SMC,
>> > + .prot = &smc_inet_prot,
>> Ditto
>>
>> > + .ops = &smc_inet_stream_ops,
>> > + .flags = INET_PROTOSW_ICSK,
>> > +};
>> > +
>> > +#if IS_ENABLED(CONFIG_IPV6)
>> > +struct proto smc_inet6_prot = {
>> > + .name = "INET6_SMC",
>> > + .owner = THIS_MODULE,
>> > + .init = smc_inet_init_sock,
>> > + .hash = smc_hash_sk,
>> > + .unhash = smc_unhash_sk,
>> > + .release_cb = smc_release_cb,
>> > + .obj_size = sizeof(struct smc_sock),
>> > + .h.smc_hash = &smc_v6_hashinfo,
>> > + .slab_flags = SLAB_TYPESAFE_BY_RCU,
>> > +};
>> > +
>> > +const struct proto_ops smc_inet6_stream_ops = {
>> > + .family = PF_INET6,
>> > + .owner = THIS_MODULE,
>> > + .release = smc_release,
>> > + .bind = smc_bind,
>> > + .connect = smc_connect,
>> > + .socketpair = sock_no_socketpair,
>> > + .accept = smc_accept,
>> > + .getname = smc_getname,
>> > + .poll = smc_poll,
>> > + .ioctl = smc_ioctl,
>> > + .listen = smc_listen,
>> > + .shutdown = smc_shutdown,
>> > + .setsockopt = smc_setsockopt,
>> > + .getsockopt = smc_getsockopt,
>> > + .sendmsg = smc_sendmsg,
>> > + .recvmsg = smc_recvmsg,
>> > + .mmap = sock_no_mmap,
>> > + .splice_read = smc_splice_read,
>> Ditto
>>
>> > +};
>> > +
>> > +struct inet_protosw smc_inet6_protosw = {
>> > + .type = SOCK_STREAM,
>> > + .protocol = IPPROTO_SMC,
>> > + .prot = &smc_inet6_prot,
>> > + .ops = &smc_inet6_stream_ops,
>> > + .flags = INET_PROTOSW_ICSK,
>> Ditto
>>
>> > +};
>> > +#endif
>> > +
>> > unsigned int smc_net_id;
>> >
>> > static __net_init int smc_net_init(struct net *net)
>> > @@ -3595,9 +3690,28 @@ static int __init smc_init(void)
>> > goto out_lo;
>> > }
>> >
>> > + rc = proto_register(&smc_inet_prot, 1);
>> > + if (rc) {
>> > + pr_err("%s: proto_register smc_inet_prot fails with %d\n", __func__, rc);
>> > + goto out_ulp;
>> > + }
>> > + inet_register_protosw(&smc_inet_protosw);
>> > +#if IS_ENABLED(CONFIG_IPV6)
>> > + rc = proto_register(&smc_inet6_prot, 1);
>> > + if (rc) {
>> > + pr_err("%s: proto_register smc_inet6_prot fails with %d\n", __func__, rc);
>> > + goto out_inet_prot;
>> > + }
>> > + inet6_register_protosw(&smc_inet6_protosw);
>> > +#endif
>> > +
>> > static_branch_enable(&tcp_have_smc);
>> > return 0;
>> > -
>> > +out_inet_prot:
>> > + inet_unregister_protosw(&smc_inet_protosw);
>> > + proto_unregister(&smc_inet_prot);
>> > +out_ulp:
>> > + tcp_unregister_ulp(&smc_ulp_ops);
>> > out_lo:
>> > smc_loopback_exit();
>> > out_ib:
>> > @@ -3634,6 +3748,10 @@ static int __init smc_init(void)
>> > static void __exit smc_exit(void)
>> > {
>> > static_branch_disable(&tcp_have_smc);
>> > + inet_unregister_protosw(&smc_inet_protosw);
>> > +#if IS_ENABLED(CONFIG_IPV6)
>> > + inet6_unregister_protosw(&smc_inet6_protosw);
>> > +#endif
>> > tcp_unregister_ulp(&smc_ulp_ops);
>> > sock_unregister(PF_SMC);
>> > smc_core_exit();
>> > @@ -3645,6 +3763,10 @@ static void __exit smc_exit(void)
>> > destroy_workqueue(smc_hs_wq);
>> > proto_unregister(&smc_proto6);
>> > proto_unregister(&smc_proto);
>> > + proto_unregister(&smc_inet_prot);
>> > +#if IS_ENABLED(CONFIG_IPV6)
>> > + proto_unregister(&smc_inet6_prot);
>> > +#endif
>> > smc_pnet_exit();
>> > smc_nl_exit();
>> > smc_clc_exit();
>> > @@ -3661,4 +3783,9 @@ static void __exit smc_exit(void)
>> > MODULE_LICENSE("GPL");
>> > MODULE_ALIAS_NETPROTO(PF_SMC);
>> > MODULE_ALIAS_TCP_ULP("smc");
>> > +/* 263 for IPPROTO_SMC and 1 for SOCK_STREAM */
>> > +MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, 263, 1);
>> > +#if IS_ENABLED(CONFIG_IPV6)
>> > +MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET6, 263, 1);
>> > +#endif
>> > MODULE_ALIAS_GENL_FAMILY(SMC_GENL_FAMILY_NAME);
>> > diff --git a/net/smc/inet_smc.h b/net/smc/inet_smc.h
>> > new file mode 100644
>> > index 00000000..fcdcb61
>> > --- /dev/null
>> > +++ b/net/smc/inet_smc.h
>> > @@ -0,0 +1,32 @@
>> > +/* SPDX-License-Identifier: GPL-2.0 */
>> > +/*
>> > + * Shared Memory Communications over RDMA (SMC-R) and RoCE
>> > + *
>> > + * Definitions for the SMC module (socket related)
>> > +
>> > + * Copyright IBM Corp. 2016
>> You should update this.
>Got it.
>> > + *
>> > + */
>> > +#ifndef __INET_SMC
>> > +#define __INET_SMC
>> > +
>> > +#include <net/protocol.h>
>> > +#include <net/sock.h>
>> > +#include <net/tcp.h>
>> > +
>> > +extern struct proto smc_inet_prot;
>> > +extern const struct proto_ops smc_inet_stream_ops;
>> > +extern struct inet_protosw smc_inet_protosw;
>> > +
>> > +#if IS_ENABLED(CONFIG_IPV6)
>> > +#include <net/ipv6.h>
>> > +/* MUST after net/tcp.h or warning */
>> > +#include <net/transp_v6.h>
>> > +extern struct proto smc_inet6_prot;
>> > +extern const struct proto_ops smc_inet6_stream_ops;
>> > +extern struct inet_protosw smc_inet6_protosw;
>> > +#endif
>> > +
>> > +int smc_inet_init_sock(struct sock *sk);
>> > +
>> > +#endif // __INET_SMC
>> ^
>> use /* __INET_SMC */ instead
>>
>> > --
>> > 1.8.3.1
>> >
>