From patchwork Tue Apr 11 17:34:15 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hanna Czenczek X-Patchwork-Id: 13207972 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 76F64C76196 for ; Tue, 11 Apr 2023 17:35:34 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pmHt8-0004si-IY; Tue, 11 Apr 2023 13:34:38 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pmHsx-0004pk-Ae for qemu-devel@nongnu.org; Tue, 11 Apr 2023 13:34:27 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pmHsv-00037F-MJ for qemu-devel@nongnu.org; Tue, 11 Apr 2023 13:34:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1681234465; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rywU8qKijEbleewWpvG8Ak/csx8RfR2RxvlSfew+ppM=; b=NrXOj0oDb2M0X8/lt3kic1Q7UA+l8d953Sg6VUpzoHI16kb/hiGZJXp9ECjnL6rF+lxZ08 kaZvIWKzkRxEDWWZVGJ1EuODZHg5KYjSwCP9Ohas3O/Hwuxhz8d7Ie1srBpCBcaYaPS7bR h9AP1W/hQt9Y7EPcfnl+WoeRHIdG0W4= 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-670-xiW81hDEMRKGuRnH1uks2w-1; Tue, 11 Apr 2023 13:34:21 -0400 X-MC-Unique: xiW81hDEMRKGuRnH1uks2w-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 778BF3C0F666; Tue, 11 Apr 2023 17:34:21 +0000 (UTC) Received: from localhost (unknown [10.39.194.86]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1276C492C13; Tue, 11 Apr 2023 17:34:20 +0000 (UTC) From: Hanna Czenczek To: qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, Hanna Czenczek , Vladimir Sementsov-Ogievskiy , Eric Blake , Kevin Wolf , Stefan Hajnoczi , Fam Zheng Subject: [PATCH v2 1/4] util/iov: Make qiov_slice() public Date: Tue, 11 Apr 2023 19:34:15 +0200 Message-Id: <20230411173418.19549-2-hreitz@redhat.com> In-Reply-To: <20230411173418.19549-1-hreitz@redhat.com> References: <20230411173418.19549-1-hreitz@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 Received-SPF: pass client-ip=170.10.133.124; envelope-from=hreitz@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org We want to inline qemu_iovec_init_extended() in block/io.c for padding requests, and having access to qiov_slice() is useful for this. As a public function, it is renamed to qemu_iovec_slice(). (We will need to count the number of I/O vector elements of a slice there, and then later process this slice. Without qiov_slice(), we would need to call qemu_iovec_subvec_niov(), and all further IOV-processing functions may need to skip prefixing elements to accomodate for a qiov_offset. Because qemu_iovec_subvec_niov() internally calls qiov_slice(), we can just have the block/io.c code call qiov_slice() itself, thus get the number of elements, and also create an iovec array with the superfluous prefixing elements stripped, so the following processing functions no longer need to skip them.) Reviewed-by: Eric Blake Reviewed-by: Vladimir Sementsov-Ogievskiy Signed-off-by: Hanna Czenczek --- include/qemu/iov.h | 3 +++ util/iov.c | 14 +++++++------- 2 files changed, 10 insertions(+), 7 deletions(-) diff --git a/include/qemu/iov.h b/include/qemu/iov.h index 9330746680..46fadfb27a 100644 --- a/include/qemu/iov.h +++ b/include/qemu/iov.h @@ -229,6 +229,9 @@ int qemu_iovec_init_extended( void *tail_buf, size_t tail_len); void qemu_iovec_init_slice(QEMUIOVector *qiov, QEMUIOVector *source, size_t offset, size_t len); +struct iovec *qemu_iovec_slice(QEMUIOVector *qiov, + size_t offset, size_t len, + size_t *head, size_t *tail, int *niov); int qemu_iovec_subvec_niov(QEMUIOVector *qiov, size_t offset, size_t len); void qemu_iovec_add(QEMUIOVector *qiov, void *base, size_t len); void qemu_iovec_concat(QEMUIOVector *dst, diff --git a/util/iov.c b/util/iov.c index b4be580022..65a70449da 100644 --- a/util/iov.c +++ b/util/iov.c @@ -378,15 +378,15 @@ static struct iovec *iov_skip_offset(struct iovec *iov, size_t offset, } /* - * qiov_slice + * qemu_iovec_slice * * Find subarray of iovec's, containing requested range. @head would * be offset in first iov (returned by the function), @tail would be * count of extra bytes in last iovec (returned iov + @niov - 1). */ -static struct iovec *qiov_slice(QEMUIOVector *qiov, - size_t offset, size_t len, - size_t *head, size_t *tail, int *niov) +struct iovec *qemu_iovec_slice(QEMUIOVector *qiov, + size_t offset, size_t len, + size_t *head, size_t *tail, int *niov) { struct iovec *iov, *end_iov; @@ -411,7 +411,7 @@ int qemu_iovec_subvec_niov(QEMUIOVector *qiov, size_t offset, size_t len) size_t head, tail; int niov; - qiov_slice(qiov, offset, len, &head, &tail, &niov); + qemu_iovec_slice(qiov, offset, len, &head, &tail, &niov); return niov; } @@ -439,8 +439,8 @@ int qemu_iovec_init_extended( } if (mid_len) { - mid_iov = qiov_slice(mid_qiov, mid_offset, mid_len, - &mid_head, &mid_tail, &mid_niov); + mid_iov = qemu_iovec_slice(mid_qiov, mid_offset, mid_len, + &mid_head, &mid_tail, &mid_niov); } total_niov = !!head_len + mid_niov + !!tail_len;