From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 637A570 for ; Tue, 4 May 2021 21:42:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1620164568; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=IupLeKipMId3vMj/aHRcloVYgiWrtUS+2Fnb2w3yL3g=; b=d65sNXYx2VdN05nCXeiuNxqIqIJSZ/Qd07HOJrm76aLyZr2Lbxoq3Nr2vPFuuw0FH7qZJM 1LpZKfZwo2qkJus/IyZO7rYFzOSIi0WXP3rvN0MvCcIqtrFxraVo+sJtG39fyrAWwnat7y 28bB02qO9sMbx+3gs+/rWs6BkNO7fio= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-158-3MhledR9Pe-HamkvLPUDPw-1; Tue, 04 May 2021 17:42:47 -0400 X-MC-Unique: 3MhledR9Pe-HamkvLPUDPw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4C31B107ACC7 for ; Tue, 4 May 2021 21:42:46 +0000 (UTC) Received: from gerbillo.redhat.com (ovpn-114-126.ams2.redhat.com [10.36.114.126]) by smtp.corp.redhat.com (Postfix) with ESMTP id 975945C22A for ; Tue, 4 May 2021 21:42:45 +0000 (UTC) From: Paolo Abeni To: mptcp@lists.linux.dev Subject: [PATCH v6 mptcp-next 17/22] mptcp: cleanup error path in subflow_check_data_avail() Date: Tue, 4 May 2021 23:42:05 +0200 Message-Id: In-Reply-To: References: X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=pabeni@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" Move fallback code out of the main loop and adds some brench prediction annotations. Signed-off-by: Paolo Abeni --- v3 -> v4: - moved here from previous patch - added unlikely annotations possibly not the best time ever for this kind of cleanup... --- net/mptcp/subflow.c | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-) diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 2d7579ba1536..14bdad401ff8 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -1110,21 +1110,12 @@ static bool subflow_check_data_avail(struct sock *ssk) status = get_mapping_status(ssk, msk); trace_subflow_check_data_avail(status, skb_peek(&ssk->sk_receive_queue)); - if (status == MAPPING_INVALID) { + if (unlikely(status == MAPPING_INVALID)) { ssk->sk_err = EBADMSG; goto fatal; } - if (status == MAPPING_DUMMY) { - __mptcp_do_fallback(msk); - skb = skb_peek(&ssk->sk_receive_queue); - subflow->map_valid = 1; - subflow->map_seq = READ_ONCE(msk->ack_seq); - subflow->map_data_len = skb->len; - subflow->map_subflow_seq = tcp_sk(ssk)->copied_seq - - subflow->ssn_offset; - subflow->data_avail = MPTCP_SUBFLOW_DATA_AVAIL; - return true; - } + if (unlikely(status == MAPPING_DUMMY)) + goto fallback; if (status != MAPPING_OK) goto no_data; @@ -1168,6 +1159,7 @@ static bool subflow_check_data_avail(struct sock *ssk) no_data: subflow_sched_work_if_closed(msk, ssk); return false; + fatal: /* fatal protocol error, close the socket */ /* This barrier is coupled with smp_rmb() in tcp_poll() */ @@ -1179,6 +1171,16 @@ static bool subflow_check_data_avail(struct sock *ssk) tcp_send_active_reset(ssk, GFP_ATOMIC); subflow->data_avail = 0; return false; + +fallback: + __mptcp_do_fallback(msk); + skb = skb_peek(&ssk->sk_receive_queue); + subflow->map_valid = 1; + subflow->map_seq = READ_ONCE(msk->ack_seq); + subflow->map_data_len = skb->len; + subflow->map_subflow_seq = tcp_sk(ssk)->copied_seq -subflow->ssn_offset; + subflow->data_avail = MPTCP_SUBFLOW_DATA_AVAIL; + return true; } bool mptcp_subflow_data_available(struct sock *sk) -- 2.26.2