From 30c3c4a4497c3765bf6b298f5072c8165aeaf7cc Mon Sep 17 00:00:00 2001 From: Gerd Bayer Date: Fri, 4 Aug 2023 19:06:24 +0200 Subject: [PATCH] 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 0227f058aa29 ("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: 0227f058aa29 ("net/smc: Unbind r/w buffer size from clcsock and make them tunable") Reviewed-by: Wenjia Zhang Reviewed-by: Tony Lu Signed-off-by: Gerd Bayer Signed-off-by: David S. Miller --- net/smc/af_smc.c | 73 +++++++++++++++++++++++++++++++++++++++----------------- 1 file changed, 51 insertions(+), 22 deletions(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index 5b878e5..f5834af 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -436,13 +436,60 @@ out: 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); -- 2.7.4