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| author | Geliang Tang <tanggeliang@kylinos.cn> | 2026-09-22 19:06:18 +0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-09-23 02:08:02 +0000 |
| commit | 91f8613d95ad8cd99d8baf094806d1ef98bc6380 (patch) | |
| tree | 8992884a6f7c830e31161dbbb84dd4f59a42556d /net/ipv4 | |
| parent | 93f65ee79cf97f2f8a3cc832875d817755034de4 (diff) | |
| download | linux-next-91f8613d95ad8cd99d8baf094806d1ef98bc6380.tar.gz linux-next-91f8613d95ad8cd99d8baf094806d1ef98bc6380.zip | |
bpf: Drop duplicate check_app_limited in tcp_bpf_push
Commit c5c37af6ecad9 ("tcp: Convert do_tcp_sendpages() to use
MSG_SPLICE_PAGES") moved tcp_rate_check_app_limited() inside
do_tcp_sendpages(), turning it into a wrapper around tcp_sendmsg_locked().
Later, commit ebf2e8860eea ("tcp_bpf: Inline do_tcp_sendpages as it's now
a wrapper around tcp_sendmsg") inlined the wrapper in tcp_bpf_push() with
direct tcp_sendmsg_locked() calls, which perform the check on every path
that queues data, but kept the outer tcp_rate_check_app_limited() that
was previously needed to cover do_tcp_sendpages(). The outer call is now
redundant.
The site changed here, tcp_bpf_push(), holds the socket lock and invokes
tcp_sendmsg_locked() on every iteration. The early-return paths in
tcp_sendmsg_locked() that skip tcp_rate_check_app_limited() - the
MSG_ZEROCOPY allocation failure and MSG_FASTOPEN branches - return without
queueing any MSG_SPLICE_PAGES data, so there is no functional consequence
from omitting the outer check.
A potential benefit of this change is that it facilitates future reuse of
tcp_bpf_push() for sockmap support in protocols beyond TCP, such as MPTCP.
Since tcp_rate_check_app_limited() is TCP-specific while sendmsg_locked()
is a generic interface in struct proto_ops, this change allows us to switch
to different protocols via sk->sk_socket->ops->sendmsg_locked() without
carrying protocol-specific assumptions.
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Link: https://patch.msgid.link/1f7dc605b16fc0590f7cbf5a27d57271926c01ce.1790074764.git.tanggeliang@kylinos.cn
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/tcp_bpf.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c index 2e234d155b5e..d5fcf3ce4861 100644 --- a/net/ipv4/tcp_bpf.c +++ b/net/ipv4/tcp_bpf.c @@ -108,7 +108,6 @@ static int tcp_bpf_push(struct sock *sk, struct sk_msg *msg, u32 apply_bytes, off = sge->offset; page = sg_page(sge); - tcp_rate_check_app_limited(sk); retry: msghdr.msg_flags = flags | MSG_SPLICE_PAGES; has_tx_ulp = tls_sw_has_ctx_tx(sk); |