From patchwork Thu Feb 9 10:29:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 54852 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:adf:eb09:0:0:0:0:0 with SMTP id s9csp256114wrn; Thu, 9 Feb 2023 02:35:01 -0800 (PST) X-Google-Smtp-Source: AK7set/1MqaON9wkHMxA5KpJ5q9nfw2HyDOhGP+5BT/0p59JUtraMVb6XB9t7slafnu7+TG7JmWE X-Received: by 2002:a05:6a21:3397:b0:c2:e30c:9be5 with SMTP id yy23-20020a056a21339700b000c2e30c9be5mr9262091pzb.12.1675938901000; Thu, 09 Feb 2023 02:35:01 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1675938900; cv=none; d=google.com; s=arc-20160816; b=MCynh0q0Qp1EbXDYL8Qs27Niz279phpWXOJKNqxjqHQ4yDCCCMDqN/GFFR4MOKk5Pz 7LSR/VegiS3ciUq6LCeiz2cj5R0EtqxEuk2dnGb/s4e2a7ob3mbtY64sglp7HEdKe79W gTIllb0y5PDMSlR7p+U6ImOuHtuHwq6rwvnn52qMmSayJeHQ8m59Ked/HYjneWWhhXGN rQzY0e7DORrq+UidGk6rcjNVILKgi7YG8clT1fd7EbEtqrYKLLUMT5A1EfSezLj21n4M BIQhA4MxEubHjHkb5T8SLgvPHhKhn/GGxuls0mAnY25hplPgX2kES6ycgC+/UvIgAWsw Y1kA== 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=7RYncx3d2QCFno76YxQ26A3gARIW2WsBk/g5n5z32ew=; b=CP2Kum0GWrn6cye1yV1npm7Qtt68lli375nTIu6Od8+eWqKNjXgYSSc5ptC/Qr9Q7R d5Wl5Z9M/z8nYeiUHDvqezKkvnGDUZSIOD6pp2zV9eFWOAxDfl+LiDdiHPOZa6Nn5T6F X61EHiUzMMQT+k1Y/zK0ODAHz/e+/xWHYbiELi1VPI7NKOBBSu2O+yXRkFV97ZmLnwyi Qlksuf5CMiYMfqXrYNk0b3pnRfEQ1ZzwGMjYcnw+EpqJbliYyAd5gsaQ5PyQvoNTOcTr e1aQCraD0cp75ITjqPJu8xJPQppTzlT17D6eOoTz2LzVq5PFqnO/7AtQSCXtnLLipmk3 GwZw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=KOKZsLzY; 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 m23-20020a637117000000b004f1bfbf42d0si1812659pgc.135.2023.02.09.02.34.48; Thu, 09 Feb 2023 02:35:00 -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=KOKZsLzY; 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 S229911AbjBIKdn (ORCPT + 99 others); Thu, 9 Feb 2023 05:33:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52000 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229881AbjBIKc2 (ORCPT ); Thu, 9 Feb 2023 05:32:28 -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 A203B34C23 for ; Thu, 9 Feb 2023 02:30:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1675938634; 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=7RYncx3d2QCFno76YxQ26A3gARIW2WsBk/g5n5z32ew=; b=KOKZsLzYA9YeQE+dygKUxbWFT3v3jX/jRXQXg9MNgGNuQrBAjjCwJLawHvwI7OhV+7kVNH efFAJ+DVfU8ilEPk1fz+6Xeo/JG1B4MiiiYaTtjUdb69yOxRaz7497Ws8HrdPzFpaG7xya 0J0WG38V/bZt2v7U8KrVFtfqGXkvYgA= 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-657-CE4ph_C5NsGWDH9cPINp8A-1; Thu, 09 Feb 2023 05:30:31 -0500 X-MC-Unique: CE4ph_C5NsGWDH9cPINp8A-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B5B3385D062; Thu, 9 Feb 2023 10:30:30 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.24]) by smtp.corp.redhat.com (Postfix) with ESMTP id C4D75140EBF6; Thu, 9 Feb 2023 10:30:28 +0000 (UTC) From: David Howells To: Jens Axboe , Al Viro , Christoph Hellwig Cc: David Howells , Matthew Wilcox , Jan Kara , Jeff Layton , David Hildenbrand , Jason Gunthorpe , Logan Gunthorpe , Hillf Danton , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Christoph Hellwig , John Hubbard Subject: [PATCH v13 12/12] block: convert bio_map_user_iov to use iov_iter_extract_pages Date: Thu, 9 Feb 2023 10:29:54 +0000 Message-Id: <20230209102954.528942-13-dhowells@redhat.com> In-Reply-To: <20230209102954.528942-1-dhowells@redhat.com> References: <20230209102954.528942-1-dhowells@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.7 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?1757349308694331123?= X-GMAIL-MSGID: =?utf-8?q?1757349308694331123?= 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 visible to/affected by the child process). Signed-off-by: David Howells Reviewed-by: Christoph Hellwig Reviewed-by: John Hubbard cc: Al Viro cc: Jens Axboe cc: Jan Kara cc: Matthew Wilcox cc: Logan Gunthorpe cc: linux-block@vger.kernel.org --- Notes: ver #10) - Drop bio_set_cleanup_mode(), open coding it instead. 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/blk-map.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) diff --git a/block/blk-map.c b/block/blk-map.c index f1f70b50388d..0f1593e144da 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -281,22 +281,21 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter, if (blk_queue_pci_p2pdma(rq->q)) extraction_flags |= ITER_ALLOW_P2PDMA; + if (iov_iter_extract_will_pin(iter)) + bio_set_flag(bio, BIO_PAGE_PINNED); - bio_set_flag(bio, BIO_PAGE_REFFED); while (iov_iter_count(iter)) { - struct page **pages, *stack_pages[UIO_FASTIOV]; + struct page *stack_pages[UIO_FASTIOV]; + struct page **pages = stack_pages; ssize_t bytes; size_t offs; int npages; - if (nr_vecs <= ARRAY_SIZE(stack_pages)) { - pages = stack_pages; - bytes = iov_iter_get_pages(iter, pages, LONG_MAX, - nr_vecs, &offs, extraction_flags); - } else { - bytes = iov_iter_get_pages_alloc(iter, &pages, - LONG_MAX, &offs, extraction_flags); - } + if (nr_vecs > ARRAY_SIZE(stack_pages)) + pages = NULL; + + bytes = iov_iter_extract_pages(iter, &pages, LONG_MAX, + nr_vecs, extraction_flags, &offs); if (unlikely(bytes <= 0)) { ret = bytes ? bytes : -EFAULT; goto out_unmap; @@ -318,7 +317,7 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter, if (!bio_add_hw_page(rq->q, bio, page, n, offs, max_sectors, &same_page)) { if (same_page) - put_page(page); + bio_release_page(bio, page); break; } @@ -330,7 +329,7 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter, * release the pages we didn't map into the bio, if any */ while (j < npages) - put_page(pages[j++]); + bio_release_page(bio, pages[j++]); if (pages != stack_pages) kvfree(pages); /* couldn't stuff something into bio? */