From patchwork Tue Mar 14 22:07:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 69864 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a5d:5915:0:0:0:0:0 with SMTP id v21csp2014219wrd; Tue, 14 Mar 2023 15:26:07 -0700 (PDT) X-Google-Smtp-Source: AK7set/Um5Z0nC1nCShHZcXlvn7ocH9Z5b3LgvOhf1iUlyKsP6wqct5UOcpDycxAfgDvsQp5af/p X-Received: by 2002:aa7:8893:0:b0:625:5b43:9098 with SMTP id z19-20020aa78893000000b006255b439098mr4867529pfe.3.1678832767091; Tue, 14 Mar 2023 15:26:07 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1678832767; cv=none; d=google.com; s=arc-20160816; b=j93I9YhbsVBkszKuJjAyfKHNHUNkOOC8HgmetaBKfhZ/i5SQXzHhT/O917f9fz/Cjy NLdLU2qPY7k+kiIXEZkDn0fundV/LBys9wVNMwssMGQrcrbpZ5Di6ejp0/6BXb4ban7Q bp3lIaPeuEEzj4USC0eap0Ik+pwnBtCPNqNPUNZLn+jlk5KdS7xAzuagvUPKzMFu2sNL Xxo+DOXbHkd8MOwSbWr3BLYDNT2xF78t7jQHsOrBC0R6A4b9PKrk4SsvzkUG02pId+TG jVRktv89cXz5IdxpcddSF3B3NVU8oDTlplrLbEbT+ovIM0Yoatj8+6uxMvM7plFri2M1 A79w== 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=gIKMSgtKI0+T2jjDihR3uNZ9dKHoZzHE/RnqYef6EBU=; b=gm9N0rRjKqCmFFpuaJHubXWf8nQRf+VVwkxwm/UQ06kPyMyAHNbjLiFjht+ghsZJhh l1hJ0BjFu32X0Hu98KnlBEw171RQkqB9SltAFT4oFkvdcdBrRKNeTZk/1j3atnvDS4A7 a67LDidjUU2jedQ7fhzgPqXUGe2ANA8BCedS8M5rDUXUX+Kd7rdaDFr2BwmevaOPitn9 57huQLnIrlP/OfV4DLMZdYsWzeFDb3l7XyNOLT2Im8e2BqMdKMHqZhflMKnp2jQT+ydP bDwWXhSGlODWrTiP1yRjPxDGj00ip0GXPsvfsbYCiKrJAwjHDOGKHPuf14Kqzmg/30rj 6Mtg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=e7S7MOWz; 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 k4-20020a634b44000000b004fab9a4430csi3096644pgl.177.2023.03.14.15.25.54; Tue, 14 Mar 2023 15:26:07 -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=e7S7MOWz; 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 S231451AbjCNWLT (ORCPT + 99 others); Tue, 14 Mar 2023 18:11:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40406 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231419AbjCNWKD (ORCPT ); Tue, 14 Mar 2023 18:10:03 -0400 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 29A2B35269 for ; Tue, 14 Mar 2023 15:09:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1678831745; 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=gIKMSgtKI0+T2jjDihR3uNZ9dKHoZzHE/RnqYef6EBU=; b=e7S7MOWz378uVwMDCUc0LOOvE+g49e1nwiGAvBDoFncD6zLpzsMi1wiAVv6BUX9qdleLkc nw3qBNfP8eyBhsTd63OwpV/PpJGwytRfrcHbb04/qB0BBCtw66fE/Bk0FndVy1Snd7r8jG q9enKSvCZCgeShkBtioVDLMZQ5dYRx0= 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-167-ZOrmw3hpN2OQ1vha5UlzMg-1; Tue, 14 Mar 2023 18:08:52 -0400 X-MC-Unique: ZOrmw3hpN2OQ1vha5UlzMg-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 129C91C08791; Tue, 14 Mar 2023 22:08:51 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.18]) by smtp.corp.redhat.com (Postfix) with ESMTP id EC4CA47507A; Tue, 14 Mar 2023 22:08:48 +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 v18 15/15] block: convert bio_map_user_iov to use iov_iter_extract_pages Date: Tue, 14 Mar 2023 22:07:57 +0000 Message-Id: <20230314220757.3827941-16-dhowells@redhat.com> In-Reply-To: <20230314220757.3827941-1-dhowells@redhat.com> References: <20230314220757.3827941-1-dhowells@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 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?1760383747550446343?= X-GMAIL-MSGID: =?utf-8?q?1760383747550446343?= 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 c77fdb1fbda7..7b12f4bb4d4c 100644 --- a/block/blk-map.c +++ b/block/blk-map.c @@ -280,22 +280,21 @@ 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; @@ -317,7 +316,7 @@ 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; } @@ -329,7 +328,7 @@ 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? */