[lvc-project] Reaching official SMC maintainers

[Jan Karcher]

On 05/03/2024 17:39, Dmitry Antipov wrote:
> On 3/4/24 13:51, Wen Gu wrote:
> 
>> IMHO, if we want to address the problem of fasync_struct entries being
>> incorrectly inserted to old socket, we may have to change the general 
>> code.
> 
> BTW what about using shared wait queue? Just to illustrate an idea:

I'm sorry but could we please clean up the e-mail threads?
This one here is a question if we are still alive: Yes, we are.

The other one i currently treat as an RFC and gracefully ignore the 
PATCH tag. If you want to post it as an patch please come up with a 
solution, clean it up and re-post it.
See patchwork errors for example: 
https://patchwork.kernel.org/project/netdevbpf/patch/20240221051608.43241-1-dmantipov@yandex.ru/

For the general RFC discussion we are going to comment on it as soon as 
we have something to say about it.
Feel free to re-post your idea regarding a shared wait queue there.

Thank you for your interest in smc and the ideas!
- Jan

> 
> diff --git a/include/linux/net.h b/include/linux/net.h
> index c9b4a63791a4..02df64747db7 100644
> --- a/include/linux/net.h
> +++ b/include/linux/net.h
> @@ -126,6 +126,7 @@ struct socket {
>       const struct proto_ops    *ops; /* Might change with IPV6_ADDRFORM 
> or MPTCP. */
> 
>       struct socket_wq    wq;
> +    struct socket_wq    *shared_wq;
>   };
> 
>   /*
> diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
> index 0f53a5c6fd9d..f04d61e316b2 100644
> --- a/net/smc/af_smc.c
> +++ b/net/smc/af_smc.c
> @@ -3360,6 +3360,9 @@ static int __smc_create(struct net *net, struct 
> socket *sock, int protocol,
>           smc->clcsock = clcsock;
>       }
> 
> +    sock->shared_wq = &smc->shared_wq;
> +    smc->clcsock->shared_wq = &smc->shared_wq;
> +
>   out:
>       return rc;
>   }
> diff --git a/net/smc/smc.h b/net/smc/smc.h
> index df64efd2dee8..26e66c289d4f 100644
> --- a/net/smc/smc.h
> +++ b/net/smc/smc.h
> @@ -287,6 +287,7 @@ struct smc_sock {                /* smc sock 
> container */
>                           /* protects clcsock of a listen
>                            * socket
>                            * */
> +    struct socket_wq    shared_wq;
>   };
> 
>   #define smc_sk(ptr) container_of_const(ptr, struct smc_sock, sk)
> diff --git a/net/socket.c b/net/socket.c
> index ed3df2f749bf..9b9e6932906f 100644
> --- a/net/socket.c
> +++ b/net/socket.c
> @@ -1437,7 +1437,8 @@ static int sock_fasync(int fd, struct file *filp, 
> int on)
>   {
>       struct socket *sock = filp->private_data;
>       struct sock *sk = sock->sk;
> -    struct socket_wq *wq = &sock->wq;
> +    struct socket_wq *wq = (unlikely(sock->shared_wq) ?
> +                sock->shared_wq : &sock->wq);
> 
>       if (sk == NULL)
>           return -EINVAL;
> 
> Dmitry
>