Re: [PATCH bpf-next v3] bpf: drop duplicate check_app_limited in tcp_bpf_push

bpf: drop duplicate check_app_limited in tcp_bpf_push

Before commit c5c37af6ecad9 ("tcp: Convert do_tcp_sendpages() to use
MSG_SPLICE_PAGES"), do_tcp_sendpages() did not call
tcp_rate_check_app_limited() internally, so callers needed an explicit
tcp_rate_check_app_limited() to cover it. That commit replaced
do_tcp_sendpages() with direct tcp_sendmsg_locked() calls, which perform
the check on every path that queues data. The outer call became redundant
but was left in place.

This isn't a bug, but would it be clearer to cite ebf2e8860eea ("tcp_bpf:
Inline do_tcp_sendpages as it's now a wrapper around tcp_sendmsg") as the
commit that left the outer tcp_rate_check_app_limited() in tcp_bpf_push(),
with c5c37af6ecad9 mentioned as the commit that moved the check inside
do_tcp_sendpages()?

Looking at the git history, c5c37af6ecad9 only touched net/ipv4/tcp.c and
turned do_tcp_sendpages() into a wrapper that calls tcp_sendmsg_locked().
The direct tcp_sendmsg_locked() call in tcp_bpf_push() was introduced by
ebf2e8860eea, which kept the outer tcp_rate_check_app_limited(sk) while
inlining the wrapper.


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CI run summary: https://github.com/kernel-patches/bpf/actions/runs/35203307255