net/smc: avoid overwriting when adjusting sock bufsizes

[ Upstream commit fb0aa0781a5f457e3864da68af52c3b1f4f7fd8f ]

When copying smc settings to clcsock, avoid setting clcsock's sk_sndbuf
to sysctl_tcp_wmem[1], since this may overwrite the value set by
tcp_sndbuf_expand() in TCP connection establishment.

And the other setting sk_{snd|rcv}buf to sysctl value in
smc_adjust_sock_bufsizes() can also be omitted since the initialization
of smc sock and clcsock has set sk_{snd|rcv}buf to smc.sysctl_{w|r}mem
or ipv4_sysctl_tcp_{w|r}mem[1].

Fixes: 30c3c4a449 ("net/smc: Use correct buffer sizes when switching between TCP and SMC")
Link: https://lore.kernel.org/r/5eaf3858-e7fd-4db8-83e8-3d7a3e0e9ae2@linux.alibaba.com
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-by: Gerd Bayer <gbayer@linux.ibm.com>, too.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Wen Gu 2024-05-31 16:54:17 +08:00 committed by Greg Kroah-Hartman
parent 2d7912f3ac
commit b03255294e
1 changed files with 2 additions and 20 deletions

View File

@ -460,29 +460,11 @@ out:
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) {
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) {
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,