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

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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>
This commit is contained in:
Gerd Bayer 2023-08-04 19:06:24 +02:00 committed by David S. Miller
parent 833bac7ec3
commit 30c3c4a449
1 changed files with 52 additions and 23 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

75
net/smc/af_smc.c
View file

@ -436,24 +436,9 @@ 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) | \
@ -470,9 +455,55 @@ 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);
@ -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);