From patchwork Thu May 25 15:50:59 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13255407 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E3F15C77B7E for ; Thu, 25 May 2023 15:52:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235116AbjEYPwM (ORCPT ); Thu, 25 May 2023 11:52:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41370 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241476AbjEYPvz (ORCPT ); Thu, 25 May 2023 11:51:55 -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 CD25B195 for ; Thu, 25 May 2023 08:51:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1685029874; 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; bh=Dnh9Ymd0aXLnszSbYXuRCQIZeE9p62JOLrx7AW+9I7M=; b=KSgwlo2RN8f9vTH7giF8JQ/77SxQyWMhMowIxy7F2umFExQzSsOsS1tvTOttuk+Lt6Ohju DgB/A3BjMBUm4zyS6mmJNTp2XyxY8nnXtXJWc+/eVmMJJBCtfeVgOyUXxX2m0npc/yruUT 2CHBagotBnIdFAOuW+TyYhzv8Gw6K2o= 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-138-tBX-uUEGPaSF-e1H0150-Q-1; Thu, 25 May 2023 11:51:08 -0400 X-MC-Unique: tBX-uUEGPaSF-e1H0150-Q-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7E1DD8030D2; Thu, 25 May 2023 15:51:07 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.39.192.68]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7180D200BA65; Thu, 25 May 2023 15:51:04 +0000 (UTC) From: David Howells To: Christoph Hellwig , David Hildenbrand Cc: David Howells , Jens Axboe , Al Viro , Matthew Wilcox , Jan Kara , Jeff Layton , 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 Subject: [RFC PATCH 0/3] block: Make old dio use iov_iter_extract_pages() and page pinning Date: Thu, 25 May 2023 16:50:59 +0100 Message-Id: <20230525155102.87353-1-dhowells@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Hi Christoph, David, Since Christoph asked nicely[1] ;-), here are three patches that go on top of the similar patches for bio structs now in the block tree that make the old block direct-IO code use iov_iter_extract_pages() and page pinning. There are three patches: (1) Make page pinning not add or remove a pin to/from the ZERO_PAGE, thereby allowing the dio code to insert zero pages in the middle of dealing with pinned pages. (2) Provide a function to allow an additional pin to be taken on a page we already have pinned (and do nothing for the zero page). (3) Switch direct-io.c over to using page pinning and to use iov_iter_extract_pages() so that pages from non-user-backed iterators aren't pinned. Note that I haven't managed to test this yet as SELinux is refusing to let me mount things like ext2 filesystems on account of it not having xattrs:-/ I've pushed the patches here also: https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs.git/log/?h=iov-old-dio David Link: https://lore.kernel.org/r/ZGxfrOLZ4aN9/MvE@infradead.org/ [1] David Howells (3): mm: Don't pin ZERO_PAGE in pin_user_pages() mm: Provide a function to get an additional pin on a page block: Use iov_iter_extract_pages() and page pinning in direct-io.c fs/direct-io.c | 68 ++++++++++++++++++++++++++++------------------ include/linux/mm.h | 1 + mm/gup.c | 54 +++++++++++++++++++++++++++++++++++- 3 files changed, 95 insertions(+), 28 deletions(-)