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[2620:137:e000::1:20]) by mx.google.com with ESMTP id e17-20020aa7d7d1000000b0050223f6f6c3si2415545eds.108.2023.03.31.09.36.52; Fri, 31 Mar 2023 09:37:16 -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=fkN0rbwa; 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 S233428AbjCaQRN (ORCPT + 99 others); Fri, 31 Mar 2023 12:17:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35230 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233425AbjCaQQy (ORCPT ); Fri, 31 Mar 2023 12:16:54 -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 E2CD520D90 for ; Fri, 31 Mar 2023 09:11:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1680279059; 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=jPEZCXpX5VIblKmRhP3z5vIQLhv4QpeLvADltfz6mNU=; b=fkN0rbwa1UcRPn2C+IrJmqsAR5MBaFzay4dB7sAl+1muU4/I49MFXwVFme/OIgLy5zpDm7 k8xVTz/MPS5jLfT3ze+YN+HJTrxuO2jrslU9jWuTCou4lwnwtWjzYlvahLKL3lFffYUr1z c6kOgCqEmVA5PM0nn9QOWOLprsGZq7Q= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-650-1RKJZrZKPJSsBYeQeItUoQ-1; Fri, 31 Mar 2023 12:10:56 -0400 X-MC-Unique: 1RKJZrZKPJSsBYeQeItUoQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 504CB801206; Fri, 31 Mar 2023 16:10:55 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.18]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3D9F71121314; Fri, 31 Mar 2023 16:10:53 +0000 (UTC) From: David Howells To: Matthew Wilcox , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: David Howells , Al Viro , Christoph Hellwig , Jens Axboe , Jeff Layton , Christian Brauner , Chuck Lever III , Linus Torvalds , netdev@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Tom Herbert , Tom Herbert Subject: [PATCH v3 34/55] kcm: Convert kcm_sendpage() to use MSG_SPLICE_PAGES Date: Fri, 31 Mar 2023 17:08:53 +0100 Message-Id: <20230331160914.1608208-35-dhowells@redhat.com> In-Reply-To: <20230331160914.1608208-1-dhowells@redhat.com> References: <20230331160914.1608208-1-dhowells@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 X-Spam-Status: No, score=-0.2 required=5.0 tests=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 autolearn=unavailable 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?1761901948826691549?= X-GMAIL-MSGID: =?utf-8?q?1761901948826691549?= Convert kcm_sendpage() to use sendmsg() with MSG_SPLICE_PAGES rather than directly splicing in the pages itself. This allows ->sendpage() to be replaced by something that can handle multiple multipage folios in a single transaction. Signed-off-by: David Howells cc: Tom Herbert cc: Tom Herbert cc: Jakub Kicinski cc: Eric Dumazet cc: "David S. Miller" cc: Paolo Abeni cc: Jens Axboe cc: Matthew Wilcox cc: netdev@vger.kernel.org --- net/kcm/kcmsock.c | 161 ++++++---------------------------------------- 1 file changed, 18 insertions(+), 143 deletions(-) diff --git a/net/kcm/kcmsock.c b/net/kcm/kcmsock.c index 0a3f79d81595..d77d28fbf389 100644 --- a/net/kcm/kcmsock.c +++ b/net/kcm/kcmsock.c @@ -761,149 +761,6 @@ static void kcm_push(struct kcm_sock *kcm) kcm_write_msgs(kcm); } -static ssize_t kcm_sendpage(struct socket *sock, struct page *page, - int offset, size_t size, int flags) - -{ - struct sock *sk = sock->sk; - struct kcm_sock *kcm = kcm_sk(sk); - struct sk_buff *skb = NULL, *head = NULL; - long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); - bool eor; - int err = 0; - int i; - - if (flags & MSG_SENDPAGE_NOTLAST) - flags |= MSG_MORE; - - /* No MSG_EOR from splice, only look at MSG_MORE */ - eor = !(flags & MSG_MORE); - - lock_sock(sk); - - sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); - - err = -EPIPE; - if (sk->sk_err) - goto out_error; - - if (kcm->seq_skb) { - /* Previously opened message */ - head = kcm->seq_skb; - skb = kcm_tx_msg(head)->last_skb; - i = skb_shinfo(skb)->nr_frags; - - if (skb_can_coalesce(skb, i, page, offset)) { - skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], size); - skb_shinfo(skb)->flags |= SKBFL_SHARED_FRAG; - goto coalesced; - } - - if (i >= MAX_SKB_FRAGS) { - struct sk_buff *tskb; - - tskb = alloc_skb(0, sk->sk_allocation); - while (!tskb) { - kcm_push(kcm); - err = sk_stream_wait_memory(sk, &timeo); - if (err) - goto out_error; - } - - if (head == skb) - skb_shinfo(head)->frag_list = tskb; - else - skb->next = tskb; - - skb = tskb; - skb->ip_summed = CHECKSUM_UNNECESSARY; - i = 0; - } - } else { - /* Call the sk_stream functions to manage the sndbuf mem. */ - if (!sk_stream_memory_free(sk)) { - kcm_push(kcm); - set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); - err = sk_stream_wait_memory(sk, &timeo); - if (err) - goto out_error; - } - - head = alloc_skb(0, sk->sk_allocation); - while (!head) { - kcm_push(kcm); - err = sk_stream_wait_memory(sk, &timeo); - if (err) - goto out_error; - } - - skb = head; - i = 0; - } - - get_page(page); - skb_fill_page_desc_noacc(skb, i, page, offset, size); - skb_shinfo(skb)->flags |= SKBFL_SHARED_FRAG; - -coalesced: - skb->len += size; - skb->data_len += size; - skb->truesize += size; - sk->sk_wmem_queued += size; - sk_mem_charge(sk, size); - - if (head != skb) { - head->len += size; - head->data_len += size; - head->truesize += size; - } - - if (eor) { - bool not_busy = skb_queue_empty(&sk->sk_write_queue); - - /* Message complete, queue it on send buffer */ - __skb_queue_tail(&sk->sk_write_queue, head); - kcm->seq_skb = NULL; - KCM_STATS_INCR(kcm->stats.tx_msgs); - - if (flags & MSG_BATCH) { - kcm->tx_wait_more = true; - } else if (kcm->tx_wait_more || not_busy) { - err = kcm_write_msgs(kcm); - if (err < 0) { - /* We got a hard error in write_msgs but have - * already queued this message. Report an error - * in the socket, but don't affect return value - * from sendmsg - */ - pr_warn("KCM: Hard failure on kcm_write_msgs\n"); - report_csk_error(&kcm->sk, -err); - } - } - } else { - /* Message not complete, save state */ - kcm->seq_skb = head; - kcm_tx_msg(head)->last_skb = skb; - } - - KCM_STATS_ADD(kcm->stats.tx_bytes, size); - - release_sock(sk); - return size; - -out_error: - kcm_push(kcm); - - err = sk_stream_error(sk, flags, err); - - /* make sure we wake any epoll edge trigger waiter */ - if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN)) - sk->sk_write_space(sk); - - release_sock(sk); - return err; -} - static int kcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) { struct sock *sk = sock->sk; @@ -1143,6 +1000,24 @@ static int kcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) return err; } +static ssize_t kcm_sendpage(struct socket *sock, struct page *page, + int offset, size_t size, int flags) + +{ + struct bio_vec bvec; + struct msghdr msg = { .msg_flags = flags | MSG_SPLICE_PAGES, }; + + if (flags & MSG_SENDPAGE_NOTLAST) + msg.msg_flags |= MSG_MORE; + + if (flags & MSG_OOB) + return -EOPNOTSUPP; + + bvec_set_page(&bvec, page, offset, size); + iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, size); + return kcm_sendmsg(sock, &msg, size); +} + static int kcm_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, int flags) {