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[2620:137:e000::1:20]) by mx.google.com with ESMTP id u184-20020a6385c1000000b005303b490638si17009942pgd.466.2023.05.15.02.44.26; Mon, 15 May 2023 02:44:39 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=JCL1HuSA; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230080AbjEOJfh (ORCPT + 99 others); Mon, 15 May 2023 05:35:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39658 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238471AbjEOJfD (ORCPT ); Mon, 15 May 2023 05:35:03 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5D594E68 for ; Mon, 15 May 2023 02:34:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1684143255; 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=9s33rFBaxABfh3fue+YSREMQMkxGRapWweS5v7j7klU=; b=JCL1HuSAyvpgl/H3k+tiCxzmuyRmiw+LbZgRDLC3yUm5ydyARIvNJGAS8UrOOIc+GhXUkC lTdc2Yahk2ta637cK2j/ofwhP/Ktf9IB29gmEnFZjr5uQPIn1omuVWx4U5jnKiRD7omYkB moJJlJo7nFsrDVqiw50ptg0d8TpQxPs= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-638-ctaAd9Y3OV6hQ5fXV43Iug-1; Mon, 15 May 2023 05:34:12 -0400 X-MC-Unique: ctaAd9Y3OV6hQ5fXV43Iug-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 60F4338149AE; Mon, 15 May 2023 09:34:11 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.221]) by smtp.corp.redhat.com (Postfix) with ESMTP id E0534C15BA0; Mon, 15 May 2023 09:34:08 +0000 (UTC) From: David Howells To: netdev@vger.kernel.org Cc: David Howells , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Willem de Bruijn , David Ahern , Matthew Wilcox , Al Viro , Christoph Hellwig , Jens Axboe , Jeff Layton , Christian Brauner , Chuck Lever III , Linus Torvalds , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH net-next v7 05/16] tcp: Convert do_tcp_sendpages() to use MSG_SPLICE_PAGES Date: Mon, 15 May 2023 10:33:34 +0100 Message-Id: <20230515093345.396978-6-dhowells@redhat.com> In-Reply-To: <20230515093345.396978-1-dhowells@redhat.com> References: <20230515093345.396978-1-dhowells@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1765952852598629811?= X-GMAIL-MSGID: =?utf-8?q?1765952852598629811?= Convert do_tcp_sendpages() to use sendmsg() with MSG_SPLICE_PAGES rather than directly splicing in the pages itself. do_tcp_sendpages() can then be inlined in subsequent patches into its callers. This allows ->sendpage() to be replaced by something that can handle multiple multipage folios in a single transaction. Signed-off-by: David Howells cc: Eric Dumazet cc: "David S. Miller" cc: David Ahern cc: Jakub Kicinski cc: Paolo Abeni cc: Jens Axboe cc: Matthew Wilcox cc: netdev@vger.kernel.org --- net/ipv4/tcp.c | 158 +++---------------------------------------------- 1 file changed, 7 insertions(+), 151 deletions(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 026f483f42e3..28231e503af9 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -974,163 +974,19 @@ static int tcp_wmem_schedule(struct sock *sk, int copy) return min(copy, sk->sk_forward_alloc); } -static struct sk_buff *tcp_build_frag(struct sock *sk, int size_goal, int flags, - struct page *page, int offset, size_t *size) -{ - struct sk_buff *skb = tcp_write_queue_tail(sk); - struct tcp_sock *tp = tcp_sk(sk); - bool can_coalesce; - int copy, i; - - if (!skb || (copy = size_goal - skb->len) <= 0 || - !tcp_skb_can_collapse_to(skb)) { -new_segment: - if (!sk_stream_memory_free(sk)) - return NULL; - - skb = tcp_stream_alloc_skb(sk, 0, sk->sk_allocation, - tcp_rtx_and_write_queues_empty(sk)); - if (!skb) - return NULL; - -#ifdef CONFIG_TLS_DEVICE - skb->decrypted = !!(flags & MSG_SENDPAGE_DECRYPTED); -#endif - tcp_skb_entail(sk, skb); - copy = size_goal; - } - - if (copy > *size) - copy = *size; - - i = skb_shinfo(skb)->nr_frags; - can_coalesce = skb_can_coalesce(skb, i, page, offset); - if (!can_coalesce && i >= READ_ONCE(sysctl_max_skb_frags)) { - tcp_mark_push(tp, skb); - goto new_segment; - } - if (tcp_downgrade_zcopy_pure(sk, skb)) - return NULL; - - copy = tcp_wmem_schedule(sk, copy); - if (!copy) - return NULL; - - if (can_coalesce) { - skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); - } else { - get_page(page); - skb_fill_page_desc_noacc(skb, i, page, offset, copy); - } - - if (!(flags & MSG_NO_SHARED_FRAGS)) - skb_shinfo(skb)->flags |= SKBFL_SHARED_FRAG; - - skb->len += copy; - skb->data_len += copy; - skb->truesize += copy; - sk_wmem_queued_add(sk, copy); - sk_mem_charge(sk, copy); - WRITE_ONCE(tp->write_seq, tp->write_seq + copy); - TCP_SKB_CB(skb)->end_seq += copy; - tcp_skb_pcount_set(skb, 0); - - *size = copy; - return skb; -} - ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset, size_t size, int flags) { - struct tcp_sock *tp = tcp_sk(sk); - int mss_now, size_goal; - int err; - ssize_t copied; - long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); - - if (IS_ENABLED(CONFIG_DEBUG_VM) && - WARN_ONCE(!sendpage_ok(page), - "page must not be a Slab one and have page_count > 0")) - return -EINVAL; - - /* Wait for a connection to finish. One exception is TCP Fast Open - * (passive side) where data is allowed to be sent before a connection - * is fully established. - */ - if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) && - !tcp_passive_fastopen(sk)) { - err = sk_stream_wait_connect(sk, &timeo); - if (err != 0) - goto out_err; - } + struct bio_vec bvec; + struct msghdr msg = { .msg_flags = flags | MSG_SPLICE_PAGES, }; - sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); + bvec_set_page(&bvec, page, size, offset); + iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, size); - mss_now = tcp_send_mss(sk, &size_goal, flags); - copied = 0; + if (flags & MSG_SENDPAGE_NOTLAST) + msg.msg_flags |= MSG_MORE; - err = -EPIPE; - if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) - goto out_err; - - while (size > 0) { - struct sk_buff *skb; - size_t copy = size; - - skb = tcp_build_frag(sk, size_goal, flags, page, offset, ©); - if (!skb) - goto wait_for_space; - - if (!copied) - TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH; - - copied += copy; - offset += copy; - size -= copy; - if (!size) - goto out; - - if (skb->len < size_goal || (flags & MSG_OOB)) - continue; - - if (forced_push(tp)) { - tcp_mark_push(tp, skb); - __tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH); - } else if (skb == tcp_send_head(sk)) - tcp_push_one(sk, mss_now); - continue; - -wait_for_space: - set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); - tcp_push(sk, flags & ~MSG_MORE, mss_now, - TCP_NAGLE_PUSH, size_goal); - - err = sk_stream_wait_memory(sk, &timeo); - if (err != 0) - goto do_error; - - mss_now = tcp_send_mss(sk, &size_goal, flags); - } - -out: - if (copied) { - tcp_tx_timestamp(sk, sk->sk_tsflags); - if (!(flags & MSG_SENDPAGE_NOTLAST)) - tcp_push(sk, flags, mss_now, tp->nonagle, size_goal); - } - return copied; - -do_error: - tcp_remove_empty_skb(sk); - if (copied) - goto out; -out_err: - /* make sure we wake any epoll edge trigger waiter */ - if (unlikely(tcp_rtx_and_write_queues_empty(sk) && err == -EAGAIN)) { - sk->sk_write_space(sk); - tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED); - } - return sk_stream_error(sk, flags, err); + return tcp_sendmsg_locked(sk, &msg, size); } EXPORT_SYMBOL_GPL(do_tcp_sendpages);