Commit 30c3c4a4 authored by Gerd Bayer's avatar Gerd Bayer Committed by David S. Miller
Browse files

net/smc: Use correct buffer sizes when switching between TCP and SMC 



Tuning of the effective buffer size through setsockopts was working for
SMC traffic only but not for TCP fall-back connections even before
commit 0227f058 ("net/smc: Unbind r/w buffer size from clcsock and
make them tunable"). That change made it apparent that TCP fall-back
connections would use net.smc.[rw]mem as buffer size instead of
net.ipv4_tcp_[rw]mem.

Amend the code that copies attributes between the (TCP) clcsock and the
SMC socket and adjust buffer sizes appropriately:
- Copy over sk_userlocks so that both sockets agree on whether tuning
  via setsockopt is active.
- When falling back to TCP use sk_sndbuf or sk_rcvbuf as specified with
  setsockopt. Otherwise, use the sysctl value for TCP/IPv4.
- Likewise, use either values from setsockopt or from sysctl for SMC
  (duplicated) on successful SMC connect.

In smc_tcp_listen_work() drop the explicit copy of buffer sizes as that
is taken care of by the attribute copy.

Fixes: 0227f058 ("net/smc: Unbind r/w buffer size from clcsock and make them tunable")
Reviewed-by: default avatarWenjia Zhang <wenjia@linux.ibm.com>
Reviewed-by: default avatarTony Lu <tonylu@linux.alibaba.com>
Signed-off-by: default avatarGerd Bayer <gbayer@linux.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 833bac7e

net/smc/af_smc.c

+51 −22
Original line number Diff line number Diff line
@@ -436,13 +436,60 @@ static int smc_bind(struct socket *sock, struct sockaddr *uaddr, 
	return rc;

}



/* copy only relevant settings and flags of SOL_SOCKET level from smc to

 * clc socket (since smc is not called for these options from net/core)

 */



#define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \

			     (1UL << SOCK_KEEPOPEN) | \

			     (1UL << SOCK_LINGER) | \

			     (1UL << SOCK_BROADCAST) | \

			     (1UL << SOCK_TIMESTAMP) | \

			     (1UL << SOCK_DBG) | \

			     (1UL << SOCK_RCVTSTAMP) | \

			     (1UL << SOCK_RCVTSTAMPNS) | \

			     (1UL << SOCK_LOCALROUTE) | \

			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \

			     (1UL << SOCK_RXQ_OVFL) | \

			     (1UL << SOCK_WIFI_STATUS) | \

			     (1UL << SOCK_NOFCS) | \

			     (1UL << SOCK_FILTER_LOCKED) | \

			     (1UL << SOCK_TSTAMP_NEW))



/* if set, use value set by setsockopt() - else use IPv4 or SMC sysctl value */

static void smc_adjust_sock_bufsizes(struct sock *nsk, struct sock *osk,

				     unsigned long mask)

{

	struct net *nnet = sock_net(nsk);



	nsk->sk_userlocks = osk->sk_userlocks;

	if (osk->sk_userlocks & SOCK_SNDBUF_LOCK) {

		nsk->sk_sndbuf = osk->sk_sndbuf;

	} else {

		if (mask == SK_FLAGS_SMC_TO_CLC)

			WRITE_ONCE(nsk->sk_sndbuf,

				   READ_ONCE(nnet->ipv4.sysctl_tcp_wmem[1]));

		else

			WRITE_ONCE(nsk->sk_sndbuf,

				   2 * READ_ONCE(nnet->smc.sysctl_wmem));

	}

	if (osk->sk_userlocks & SOCK_RCVBUF_LOCK) {

		nsk->sk_rcvbuf = osk->sk_rcvbuf;

	} else {

		if (mask == SK_FLAGS_SMC_TO_CLC)

			WRITE_ONCE(nsk->sk_rcvbuf,

				   READ_ONCE(nnet->ipv4.sysctl_tcp_rmem[1]));

		else

			WRITE_ONCE(nsk->sk_rcvbuf,

				   2 * READ_ONCE(nnet->smc.sysctl_rmem));

	}

}



static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,

				   unsigned long mask)

{

	/* options we don't get control via setsockopt for */

	nsk->sk_type = osk->sk_type;

	nsk->sk_sndbuf = osk->sk_sndbuf;

	nsk->sk_rcvbuf = osk->sk_rcvbuf;

	nsk->sk_sndtimeo = osk->sk_sndtimeo;

	nsk->sk_rcvtimeo = osk->sk_rcvtimeo;

	nsk->sk_mark = READ_ONCE(osk->sk_mark);
@@ -453,26 +500,10 @@ static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk, 


	nsk->sk_flags &= ~mask;

	nsk->sk_flags |= osk->sk_flags & mask;



	smc_adjust_sock_bufsizes(nsk, osk, mask);

}



#define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \

			     (1UL << SOCK_KEEPOPEN) | \

			     (1UL << SOCK_LINGER) | \

			     (1UL << SOCK_BROADCAST) | \

			     (1UL << SOCK_TIMESTAMP) | \

			     (1UL << SOCK_DBG) | \

			     (1UL << SOCK_RCVTSTAMP) | \

			     (1UL << SOCK_RCVTSTAMPNS) | \

			     (1UL << SOCK_LOCALROUTE) | \

			     (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \

			     (1UL << SOCK_RXQ_OVFL) | \

			     (1UL << SOCK_WIFI_STATUS) | \

			     (1UL << SOCK_NOFCS) | \

			     (1UL << SOCK_FILTER_LOCKED) | \

			     (1UL << SOCK_TSTAMP_NEW))

/* copy only relevant settings and flags of SOL_SOCKET level from smc to

 * clc socket (since smc is not called for these options from net/core)

 */

static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)

{

	smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
@@ -2479,8 +2510,6 @@ static void smc_tcp_listen_work(struct work_struct *work) 
		sock_hold(lsk); /* sock_put in smc_listen_work */

		INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);

		smc_copy_sock_settings_to_smc(new_smc);

		new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;

		new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;

		sock_hold(&new_smc->sk); /* sock_put in passive closing */

		if (!queue_work(smc_hs_wq, &new_smc->smc_listen_work))

			sock_put(&new_smc->sk);