[LU-20082] LNet: TCP receive buffer size setting not taking effect.

• Type: Bug
• Resolution: Fixed
• Priority: Medium
• Fix Version/s: Lustre 2.18.0
• Severity: 3
• Assignee: Xinxia Qu
• Reporter: Xinxia Qu

Description

When using the lnet_sock_setbuf function to set txbufsize and rxbufsize, there is an issue: rxbufsize is incorrectly assigned to sk->sk_sndbuf. This causes both sk_sndbuf and sk_rcvbuf to behave unexpectedly.

This issue was introduced during the refactoring to support kernel 5.8 due to kernel interface changes. Refer to LU-13783.

Code:

void
lnet_sock_setbuf(struct socket *sock, int txbufsize, int rxbufsize)
{
        struct sock *sk = sock->sk;

        if (txbufsize != 0) {
                sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
                sk->sk_sndbuf = txbufsize;
                sk->sk_write_space(sk);
        }

        if (rxbufsize != 0) {
                sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
                sk->sk_sndbuf = rxbufsize;
        }
}

`sk->sk_sndbuf = rxbufsize` should be `sk->sk_rcvbuf = rxbufsize`.