From patchwork Mon Jan 23 17:30:05 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 47276 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:eb09:0:0:0:0:0 with SMTP id s9csp1736879wrn; Mon, 23 Jan 2023 09:53:19 -0800 (PST) X-Google-Smtp-Source: AMrXdXte4gdKmbvR1DUehlidey1d1c2TE2k8+5Uo2wFqFKBP2SRq3Vu4q9+vgToWgBdpHivQQYch X-Received: by 2002:a05:6402:380d:b0:49e:5ffd:5be2 with SMTP id es13-20020a056402380d00b0049e5ffd5be2mr18860247edb.40.1674496399176; Mon, 23 Jan 2023 09:53:19 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1674496399; cv=none; d=google.com; s=arc-20160816; b=TM5TxVotkxRVsgawhdAi4ZFATWBFmsAtKNU2I4eMoUBKQRph1Fc6GyeyEZlN770mKu xqAR1vyDX+X9BgV0ag6jtST5mZzUpegMGdCRih6EIsTw5te0tU9P12p9IvqTUzPlhJkT uN8+yi3OunQoxB+WaQkM3EzUJ+Bp6YRXqs77GuNK1c5fydgBIetFbEjsg3MXq/JoU5Ng aXyktyLAgNKwXWHVpWN89FneNTsx8vBbI6OyE9agUelvjCTK19M1EzQGZYXcqEV+xE2v 70+SKjT0v6U7rN6NuMI/83kF4Bb0h56yzsD9xYqbpXk83dAkWJZsfn1r1nCtvf2u12tE n4YA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=8R74HsEjH9XlBjVpyUw0TUK8fGpl//j53c7hN7ZbLp4=; b=fubOzBFle49mRn2o7ikFnyTwjkEAD43Tyhg+Qiapyx5zT0XCvTTGvN+XML5G5kqYSQ L/BRG9XE+OPNQrUNN27Jx+Raxc0UQovJXURBbICI0UgC0XYlad67jslA1o0m3pgGMihJ q5GA3fE4zjtbV4MJ5YKr901zmpADJHmb/cs4e7nFP11fU0pvrF0YuUlXH9NBy9h9yNXd j9H2BHI9/Lvafx3+V9m/UJ2MleNArVnAo5pJ4nK+KY7HAK6X0Eh66fjWIqN/9nUXGORc QRBxGpLcqTMa/1aEJLPqbE6B9CGUgdiWzwnDZ9MIAg1xi/Jfu7DAy180SSeyzpYJWjpK PxTA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=HVxQfEdc; 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: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id h10-20020a50c38a000000b00499b2eb6a0csi966876edf.348.2023.01.23.09.52.55; Mon, 23 Jan 2023 09:53:19 -0800 (PST) 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=HVxQfEdc; 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 S232498AbjAWRcy (ORCPT + 99 others); Mon, 23 Jan 2023 12:32:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38302 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232777AbjAWRck (ORCPT ); Mon, 23 Jan 2023 12:32:40 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2A4D42E0F7 for ; Mon, 23 Jan 2023 09:30:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1674495034; 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=8R74HsEjH9XlBjVpyUw0TUK8fGpl//j53c7hN7ZbLp4=; b=HVxQfEdca+HkaTNg2kgjCfV5n5o1L3BuEOnFIn5yoQcLg8te8WOjBAZnXvrQABLyVZ1876 Qxj42jgtiRkMoFlcu+T061eF88uOT60tgvjNwqmsQhfz5btQaLaKytFbmCcbA0ZqzhTdQw 00taPFLqVBJ65cLUMLIzNothkubBKrU= 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-225-4jqdVvyUNmqUbKHciUyroQ-1; Mon, 23 Jan 2023 12:30:30 -0500 X-MC-Unique: 4jqdVvyUNmqUbKHciUyroQ-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 1BF023806713; Mon, 23 Jan 2023 17:30:30 +0000 (UTC) Received: from warthog.procyon.org.uk.com (unknown [10.33.36.97]) by smtp.corp.redhat.com (Postfix) with ESMTP id AAF44492C1B; Mon, 23 Jan 2023 17:30:28 +0000 (UTC) From: David Howells To: Al Viro , Christoph Hellwig Cc: David Howells , Matthew Wilcox , Jens Axboe , Jan Kara , Jeff Layton , Logan Gunthorpe , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Christoph Hellwig Subject: [PATCH v8 08/10] block: Convert bio_iov_iter_get_pages to use iov_iter_extract_pages Date: Mon, 23 Jan 2023 17:30:05 +0000 Message-Id: <20230123173007.325544-9-dhowells@redhat.com> In-Reply-To: <20230123173007.325544-1-dhowells@redhat.com> References: <20230123173007.325544-1-dhowells@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 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 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?1755836736271046424?= X-GMAIL-MSGID: =?utf-8?q?1755836736271046424?= This will pin pages or leave them unaltered rather than getting a ref on them as appropriate to the iterator. The pages need to be pinned for DIO rather than having refs taken on them to prevent VM copy-on-write from malfunctioning during a concurrent fork() (the result of the I/O could otherwise end up being affected by/visible to the child process). Signed-off-by: David Howells cc: Al Viro cc: Jens Axboe cc: Jan Kara cc: Christoph Hellwig cc: Matthew Wilcox cc: Logan Gunthorpe cc: linux-block@vger.kernel.org Reviewed-by: Christoph Hellwig --- Notes: ver #8) - Split the patch up a bit [hch]. - We should only be using pinned/non-pinned pages and not ref'd pages, so adjust the comments appropriately. ver #7) - Don't treat BIO_PAGE_REFFED/PINNED as being the same as FOLL_GET/PIN. ver #5) - Transcribe the FOLL_* flags returned by iov_iter_extract_pages() to BIO_* flags and got rid of bi_cleanup_mode. - Replaced BIO_NO_PAGE_REF to BIO_PAGE_REFFED in the preceding patch. block/bio.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/block/bio.c b/block/bio.c index 6f98bcfc0c92..6dc54bf3ed27 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1213,7 +1213,7 @@ static int bio_iov_add_page(struct bio *bio, struct page *page, } if (same_page) - put_page(page); + bio_release_page(bio, page); return 0; } @@ -1227,7 +1227,7 @@ static int bio_iov_add_zone_append_page(struct bio *bio, struct page *page, queue_max_zone_append_sectors(q), &same_page) != len) return -EINVAL; if (same_page) - put_page(page); + bio_release_page(bio, page); return 0; } @@ -1238,10 +1238,10 @@ static int bio_iov_add_zone_append_page(struct bio *bio, struct page *page, * @bio: bio to add pages to * @iter: iov iterator describing the region to be mapped * - * Pins pages from *iter and appends them to @bio's bvec array. The - * pages will have to be released using put_page() when done. - * For multi-segment *iter, this function only adds pages from the - * next non-empty segment of the iov iterator. + * Extracts pages from *iter and appends them to @bio's bvec array. The pages + * will have to be cleaned up in the way indicated by the BIO_PAGE_PINNED flag. + * For a multi-segment *iter, this function only adds pages from the next + * non-empty segment of the iov iterator. */ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) { @@ -1273,9 +1273,9 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) * result to ensure the bio's total size is correct. The remainder of * the iov data will be picked up in the next bio iteration. */ - size = iov_iter_get_pages(iter, pages, - UINT_MAX - bio->bi_iter.bi_size, - nr_pages, &offset, extract_flags); + size = iov_iter_extract_pages(iter, &pages, + UINT_MAX - bio->bi_iter.bi_size, + nr_pages, extract_flags, &offset); if (unlikely(size <= 0)) return size ? size : -EFAULT; @@ -1308,7 +1308,7 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) iov_iter_revert(iter, left); out: while (i < nr_pages) - put_page(pages[i++]); + bio_release_page(bio, pages[i++]); return ret; } @@ -1343,7 +1343,7 @@ int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) return 0; } - bio_set_flag(bio, BIO_PAGE_REFFED); + bio_set_cleanup_mode(bio, iter); do { ret = __bio_iov_iter_get_pages(bio, iter); } while (!ret && iov_iter_count(iter) && !bio_full(bio, 0));