From patchwork Tue Jun 28 18:56:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Begunkov X-Patchwork-Id: 12898776 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7683AC43334 for ; Tue, 28 Jun 2022 19:01:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233408AbiF1TBC (ORCPT ); Tue, 28 Jun 2022 15:01:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55760 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234292AbiF1TA0 (ORCPT ); Tue, 28 Jun 2022 15:00:26 -0400 Received: from mail-ej1-x630.google.com (mail-ej1-x630.google.com [IPv6:2a00:1450:4864:20::630]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BD66A1834A; Tue, 28 Jun 2022 12:00:08 -0700 (PDT) Received: by mail-ej1-x630.google.com with SMTP id ay16so27701169ejb.6; Tue, 28 Jun 2022 12:00:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=/eliap5e56eSK1XJIKpFjzJdFDnEAAzOxoC0xRFCg9s=; b=ng4a/WkkirDrg9xLd+5D0FaZK/PEUwa33PoIhHvBn2h1I8ghHCvnimUGG1oOJZUR4l xetU9D0YQTf+cVE+EtsawtUwI4CV5EZRmNc6A4qTr7w1XshqqHtt1lpSJ6v+W1AnyuvJ wrGeb0o1+AvtKS06LvUXGS+IHTigEZMUs3di5eZm0/8mPNjAUpAoP0ljXkxvRWX5Yr3u pz7Qn5AWkkHDLBblr/lRPKobznku2l5hYyFWsd893Wuxiv9L5VAGzOzZkzziJ3PFaE9Q yhXtWwy23hNTr3i5zj9i/qQPc8U7X4Z2hc48KVmbuHF4QJ1Wh0cASOony3t3Przt5F4O QGew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=/eliap5e56eSK1XJIKpFjzJdFDnEAAzOxoC0xRFCg9s=; b=rNIY019Uo5631Ua869nPLgr8gtWD8Xomk6tUDjryYfNuUs/x+HNgGSwRw5W9wb1Gm8 fYwYL8iemygGQ0HYNfuR0xYe7FNS6D9ZN2FAEy24koaNqZWGdv+hFIYcJ7dLOL46SrDq 5OX1iUpq+tHlptwrF1owdICxNUgoDZZvDqoAB6SoRv/aVd/Q7dNrfHOg8Oq35R54DsJX 9hL6wgNfJ7CgwcAeHreNkZ4VPXJ2wGksP8R55q3zXb0beDzW9rd4+YX+esOroFQQQSfQ 83DmqxWzpcqrdrFaah23e4a2ln/auW6HiHRI57rbHOW9zoHs13dutKnm80qY5Phl+u7a dKIA== X-Gm-Message-State: AJIora8LXD2d4ZGYaogJtW/ta223PbiL6pKYKOWIebFDhTJMqYd4LSl6 Bsj0D6imHxWTDb7X3J0HRmiXFreH2pDRyQ== X-Google-Smtp-Source: AGRyM1ubd9IfdC3EMIb/uwZNW9iUepQ2Li08wZlSCpq5YyIseEz2RCZKI13ZzMvXzuq46t9Rr+V7rg== X-Received: by 2002:a17:907:6ea3:b0:726:ca39:5d98 with SMTP id sh35-20020a1709076ea300b00726ca395d98mr5385796ejc.400.1656442808005; Tue, 28 Jun 2022 12:00:08 -0700 (PDT) Received: from 127.0.0.1localhost (188.28.125.106.threembb.co.uk. [188.28.125.106]) by smtp.gmail.com with ESMTPSA id t21-20020a05640203d500b0043573c59ea0sm9758451edw.90.2022.06.28.12.00.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Jun 2022 12:00:07 -0700 (PDT) From: Pavel Begunkov To: io-uring@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: "David S . Miller" , Jakub Kicinski , Jonathan Lemon , Willem de Bruijn , Jens Axboe , kernel-team@fb.com, Pavel Begunkov Subject: [RFC net-next v3 13/29] net: let callers provide extra ubuf_info refs Date: Tue, 28 Jun 2022 19:56:35 +0100 Message-Id: X-Mailer: git-send-email 2.36.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Subsystems providing external ubufs to the net layer, i.e. ->msg_ubuf, might have a better way to refcount it. For instance, io_uring can ammortise ref allocation. Add a way to pass one extra ref to ->msg_ubuf into the network stack by setting struct msghdr::msg_ubuf_ref bit. Whoever consumes the ref should clear the flat. If not consumed, it's the responsibility of the caller to put it. Make __ip{,6}_append_data() to use it. Signed-off-by: Pavel Begunkov --- include/linux/socket.h | 1 + net/ipv4/ip_output.c | 3 +++ net/ipv6/ip6_output.c | 3 +++ 3 files changed, 7 insertions(+) diff --git a/include/linux/socket.h b/include/linux/socket.h index ba84ee614d5a..ae869dee82de 100644 --- a/include/linux/socket.h +++ b/include/linux/socket.h @@ -72,6 +72,7 @@ struct msghdr { * to be non-NULL. */ bool msg_managed_data : 1; + bool msg_ubuf_ref : 1; unsigned int msg_flags; /* flags on received message */ __kernel_size_t msg_controllen; /* ancillary data buffer length */ struct kiocb *msg_iocb; /* ptr to iocb for async requests */ diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index 3fd1bf675598..d73ec0a73bd2 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -1032,6 +1032,9 @@ static int __ip_append_data(struct sock *sk, paged = true; zc = true; uarg = msg->msg_ubuf; + /* we might've been given a free ref */ + extra_uref = msg->msg_ubuf_ref; + msg->msg_ubuf_ref = false; } } else if (sock_flag(sk, SOCK_ZEROCOPY)) { uarg = msg_zerocopy_realloc(sk, length, skb_zcopy(skb)); diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index f4138ce6eda3..90bbaab21dbc 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -1557,6 +1557,9 @@ static int __ip6_append_data(struct sock *sk, paged = true; zc = true; uarg = msg->msg_ubuf; + /* we might've been given a free ref */ + extra_uref = msg->msg_ubuf_ref; + msg->msg_ubuf_ref = false; } } else if (sock_flag(sk, SOCK_ZEROCOPY)) { uarg = msg_zerocopy_realloc(sk, length, skb_zcopy(skb));