Re: [PATCH bpf v3 1/2] bpf, sockmap: Account for receive queue in FIONREAD without a verdict program

[John Fastabend <john.fastabend@gmail.com>]

On Wed, Jul 08, 2026 at 06:55:00PM +0200, Mattia Meleleo via B4 Relay wrote:
>From: Mattia Meleleo <mattia.meleleo@coralogix.com>
>
>tcp_bpf_ioctl() answers SIOCINQ from psock->msg_tot_len, which only
>counts bytes in ingress_msg. Without a stream/skb verdict program
>nothing is diverted there: data stays in sk_receive_queue, so FIONREAD
>returns 0 even though read() returns data.
>
>Add tcp_inq() to the reported value when the psock has no verdict
>program. The two queues are disjoint, so bytes redirected into
>ingress_msg from other sockets stay correctly accounted through
>msg_tot_len.
>
>Remove unused sk_psock_msg_inq().
>
>Fixes: 929e30f93125 ("bpf, sockmap: Fix FIONREAD for sockmap")
>Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev>
>Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
>Signed-off-by: Mattia Meleleo <mattia.meleleo@coralogix.com>
>---

This would be good to merge. The bots had some good callouts but mostly 
they should be follow ups IMO. There is some concern that the FIONREAD
may not be accurate on transitioning add/remove of progs, but mostly
this is done at connect and then removed only done on socket tear down.
At the moment this is causing real application problems.

The most relevant bot callout would be to make this work for UDP progs
correctly as well.

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