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

commit 30c3c4a449 upstream.

Tuning of the effective buffer size through setsockopts was working for
SMC traffic only but not for TCP fall-back connections even before
commit 0227f058aa ("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: 0227f058aa ("net/smc: Unbind r/w buffer size from clcsock and make them tunable")
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-by: Tony Lu <tonylu@linux.alibaba.com>
Signed-off-by: Gerd Bayer <gbayer@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Gerd Bayer 2023-08-04 19:06:24 +02:00 committed by Greg Kroah-Hartman
parent 584a783270
commit ddebdaec1a

View file

@ -438,24 +438,9 @@ static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
return rc;
}
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);
nsk->sk_priority = osk->sk_priority;
nsk->sk_rcvlowat = osk->sk_rcvlowat;
nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
nsk->sk_err = osk->sk_err;
nsk->sk_flags &= ~mask;
nsk->sk_flags |= osk->sk_flags & mask;
}
/* 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) | \
@ -472,9 +457,55 @@ static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
(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)
*/
/* 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_sndtimeo = osk->sk_sndtimeo;
nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
nsk->sk_mark = READ_ONCE(osk->sk_mark);
nsk->sk_priority = osk->sk_priority;
nsk->sk_rcvlowat = osk->sk_rcvlowat;
nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
nsk->sk_err = osk->sk_err;
nsk->sk_flags &= ~mask;
nsk->sk_flags |= osk->sk_flags & mask;
smc_adjust_sock_bufsizes(nsk, osk, mask);
}
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);
@ -2466,8 +2497,6 @@ 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);