From patchwork Mon May 22 20:57:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 97618 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:b0ea:0:b0:3b6:4342:cba0 with SMTP id b10csp1715703vqo; Mon, 22 May 2023 14:01:22 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ71mAJsVdxBrsAdELjvReo3SOE+ADg5v4yUFgmRBILWY3G4nrM95ZhLfdri5NAag+Qc3ShB X-Received: by 2002:a17:90a:bd83:b0:253:5de5:ece7 with SMTP id z3-20020a17090abd8300b002535de5ece7mr11159487pjr.36.1684789281740; Mon, 22 May 2023 14:01:21 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1684789281; cv=none; d=google.com; s=arc-20160816; b=UnXaOeKRedy+IjXiKA6ZLnD+8/PN1I0BHupoEl+5ZQdADnlffOt5dcXhuF4KXdsijV 2/j8ILzLUfKk/FkLJlBVDPeMUGSN+/qhgiD7CEniuXKjhnttu2dxZnmws0yIrhXFZ03h UzYaFHzhCpxwlEcNQLstkkhBpL498JmnEthoIWvnPtGQgyhHxB+z68mNUhYBh/Avp0cT S24hwTeW0iXEPllFHt+UzFb6SDrodM/rb6RA992zj+K8SC9o2I9a4KC+fvQM24nE2PhJ UVlRTl46Am4m5wS9cOvcJ34WFXqcHrHgUmCgrMEgN48aXyBWGVzrtQc3ISLx94zes513 bZ1g== 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=0UdxcT7QYPFwRvPO4h85pE794/0OGizygn6UovNdu60=; b=sugR45zddKkCTOeDRBvQXXM5+RVGLtTrxY2FwbfGIiKvBGixN6FU2d8xqtjU/Jndd8 njMTepKM3qP52YV8JVkwfkkK2IP7QSdsZqcmf9Dd7X03xkIPdgv3/zoFq4eRjRuEBnmS UX/E+sgXQ0EWyPLIbuAgWLImjrlQ5BJ+J3hA2wofhZQib+v2pWRMih6h43FcA66swLvO FVNWp333zFx6li0EgvIfgvzUF0YGXyW1roSA4MH9dpnzz6AZgBnJgxw/w1ieCrdGK1LT 66XRMm1A6ZPfRpiK4FtStMH0lThCN1FDAJl03B/qKwC17azhf9bG6RWP026X/CgYHlZ+ tXqw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=EJVPiTJz; 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 24-20020a631258000000b00530b780214bsi5302702pgs.64.2023.05.22.14.01.07; Mon, 22 May 2023 14:01:21 -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=EJVPiTJz; 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 S235286AbjEVU7e (ORCPT + 99 others); Mon, 22 May 2023 16:59:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57760 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235268AbjEVU7U (ORCPT ); Mon, 22 May 2023 16:59:20 -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 65344185 for ; Mon, 22 May 2023 13:58:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1684789095; 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=0UdxcT7QYPFwRvPO4h85pE794/0OGizygn6UovNdu60=; b=EJVPiTJz0QzlytZQB+cx4tVH/LiBSA1kU3SwyaVYQ0vyoeDzBffyZG34maMkJk9lMGirnW HpUzKYZRc1nD9OvqlGcayWfUErtdnSk7Tqn2NgEx3GhPyI5XxbsIcfVwy/7rQFgJTCH+50 PVkRvDV5SC0IE2BPeG837vTEXXhugLg= 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-36-QHGrTEFvMROVinDkIKBxuA-1; Mon, 22 May 2023 16:58:10 -0400 X-MC-Unique: QHGrTEFvMROVinDkIKBxuA-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 706D1800141; Mon, 22 May 2023 20:58:09 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.39.192.68]) by smtp.corp.redhat.com (Postfix) with ESMTP id E042D140E95D; Mon, 22 May 2023 20:58:06 +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 , Christian Brauner , Linus Torvalds , 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 v21 6/6] block: convert bio_map_user_iov to use iov_iter_extract_pages Date: Mon, 22 May 2023 21:57:44 +0100 Message-Id: <20230522205744.2825689-7-dhowells@redhat.com> In-Reply-To: <20230522205744.2825689-1-dhowells@redhat.com> References: <20230522205744.2825689-1-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,T_SCC_BODY_TEXT_LINE 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?1766629605796499991?= X-GMAIL-MSGID: =?utf-8?q?1766629605796499991?= 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 Reviewed-by: Jan Kara --- 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 33d9f6e89ba6..3551c3ff17cf 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? */