From patchwork Thu Nov 12 10:48:00 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Abeni X-Patchwork-Id: 11899659 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DEB7AC2D0A3 for ; Thu, 12 Nov 2020 10:49:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 89EE422228 for ; Thu, 12 Nov 2020 10:49:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="eWeM3ONS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727986AbgKLKtJ (ORCPT ); Thu, 12 Nov 2020 05:49:09 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:48329 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727822AbgKLKtD (ORCPT ); Thu, 12 Nov 2020 05:49:03 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1605178142; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=VUYvbbfy6T6Sm7+J87lHgVC3YiqT/xVkivx28njVxWI=; b=eWeM3ONSL+FX7o/Rmvxag9JR328K0sVVgIgFSD5UvuDCNsNqHBTDi4bG8NUXEZdiaGPxRU fNU4bY0G1R7zuqkmVjNQh4VwPHXxoVQjs2xFqO7Dnfx50vJFAk8TOlBgt5DCYJyYv0k9gr hz0R793R6dFcFvq4Fu761Ucx23oW9J8= 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-467-qZAjORKzNdms4mSaa2AKaA-1; Thu, 12 Nov 2020 05:49:00 -0500 X-MC-Unique: qZAjORKzNdms4mSaa2AKaA-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 17DB6108594F; Thu, 12 Nov 2020 10:48:59 +0000 (UTC) Received: from gerbillo.redhat.com (ovpn-112-208.ams2.redhat.com [10.36.112.208]) by smtp.corp.redhat.com (Postfix) with ESMTP id DDDDD5C3E1; Thu, 12 Nov 2020 10:48:57 +0000 (UTC) From: Paolo Abeni To: netdev@vger.kernel.org Cc: Eric Dumazet , mptcp@lists.01.org, Jakub Kicinski Subject: [PATCH net-next 02/13] mptcp: use tcp_build_frag() Date: Thu, 12 Nov 2020 11:48:00 +0100 Message-Id: In-Reply-To: References: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org mptcp_push_pending() is called even on orphaned msk (and orphaned subflows), if there is outstanding data at close() time. To cope with the above MPTCP needs to handle explicitly the allocation failure on xmit. The newly introduced do_tcp_sendfrag() allows that, just plug it. We can additionally drop a couple of sanity checks, duplicate in the TCP code. Signed-off-by: Paolo Abeni --- net/mptcp/protocol.c | 25 ++++++++----------------- 1 file changed, 8 insertions(+), 17 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index b84b84adc9ad..0d712755d7fc 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -992,17 +992,13 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk, psize = min_t(size_t, dfrag->data_len, avail_size); } - /* tell the TCP stack to delay the push so that we can safely - * access the skb after the sendpages call - */ - ret = do_tcp_sendpages(ssk, page, offset, psize, - msg->msg_flags | MSG_SENDPAGE_NOTLAST | MSG_DONTWAIT); - if (ret <= 0) { - if (!retransmission) - iov_iter_revert(&msg->msg_iter, psize); - return ret; + tail = tcp_build_frag(ssk, psize, msg->msg_flags, page, offset, &psize); + if (!tail) { + tcp_remove_empty_skb(sk, tcp_write_queue_tail(ssk)); + return -ENOMEM; } + ret = psize; frag_truesize += ret; if (!retransmission) { if (unlikely(ret < psize)) @@ -1026,20 +1022,15 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk, sk->sk_forward_alloc -= frag_truesize; } - /* if the tail skb extension is still the cached one, collapsing - * really happened. Note: we can't check for 'same skb' as the sk_buff - * hdr on tail can be transmitted, freed and re-allocated by the - * do_tcp_sendpages() call + /* if the tail skb is still the cached one, collapsing really happened. */ - tail = tcp_write_queue_tail(ssk); - if (mpext && tail && mpext == skb_ext_find(tail, SKB_EXT_MPTCP)) { + if (skb == tail) { WARN_ON_ONCE(!can_collapse); mpext->data_len += ret; goto out; } - skb = tcp_write_queue_tail(ssk); - mpext = __skb_ext_set(skb, SKB_EXT_MPTCP, msk->cached_ext); + mpext = __skb_ext_set(tail, SKB_EXT_MPTCP, msk->cached_ext); msk->cached_ext = NULL; memset(mpext, 0, sizeof(*mpext));