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

["D. Wythe" <alibuda@xxxxxxxxxxxxxxxxx>]

On 5/28/24 11:03 AM, Tony Lu wrote:
> In subject, refatoring -> refactoring.

Oops... thanks for that.

> On Tue, May 28, 2024 at 10:29:52AM +0800, D. Wythe wrote:
> > From: "D. Wythe" <alibuda@xxxxxxxxxxxxxxxxx>
> >
> > 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@xxxxxxxxxxxxxxxxx>
> > ---
> >   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)
>              ^^^^                       ^^^^^^^^^^^^^^^^
>
> Using smc_sk_init to align the others' name style.

Make sense, I will do it in the next version.


> >   {
> > -	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;
> > -	}
> Using if (clcsock) is more intuitive.

Sounds reasonable. I'll take it.


Thanks,
D. Wythe


> > -
> >   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