# RE: \[Patch bpf-next v7 04/13\] skmsg: avoid lock\_sock() in sk\_psock\_backlog()

- From: John Fastabend \<john.fastabend@gmail.com\>
- Date: 2021-03-29 19:42:26 
- List: netdev
- Page: https://ratatoskr.run/netdev/2021/03/7764146
- Thread: https://ratatoskr.run/netdev/2021/03/7764102/t.md

```text
Cong Wang wrote:
> From: Cong Wang <redacted>
> 
> We do not have to lock the sock to avoid losing sk_socket,
> instead we can purge all the ingress queues when we close
> the socket. Sending or receiving packets after orphaning
> socket makes no sense.
> 
> We do purge these queues when psock refcnt reaches zero but
> here we want to purge them explicitly in sock_map_close().
> There are also some nasty race conditions on testing bit
> SK_PSOCK_TX_ENABLED and queuing/canceling the psock work,
> we can expand psock->ingress_lock a bit to protect them too.
> 
> As noticed by John, we still have to lock the psock->work,
> because the same work item could be running concurrently on
> different CPU's.
> 
> Cc: John Fastabend <john.fastabend@gmail.com>
> Cc: Daniel Borkmann <daniel@iogearbox.net>
> Cc: Jakub Sitnicki <jakub@cloudflare.com>
> Cc: Lorenz Bauer <redacted>
> Signed-off-by: Cong Wang <redacted>
> ---

Acked-by: John Fastabend <john.fastabend@gmail.com>
```