From patchwork Mon Dec 16 22:25:25 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11295951 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F307117F0 for ; Mon, 16 Dec 2019 22:30:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D097821835 for ; Mon, 16 Dec 2019 22:30:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="SwZptVKs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728259AbfLPW3s (ORCPT ); Mon, 16 Dec 2019 17:29:48 -0500 Received: from hqnvemgate24.nvidia.com ([216.228.121.143]:11878 "EHLO hqnvemgate24.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727728AbfLPWZo (ORCPT ); Mon, 16 Dec 2019 17:25:44 -0500 Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 16 Dec 2019 14:25:14 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Mon, 16 Dec 2019 14:25:41 -0800 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Mon, 16 Dec 2019 14:25:41 -0800 Received: from HQMAIL109.nvidia.com (172.20.187.15) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Mon, 16 Dec 2019 22:25:41 +0000 Received: from HQMAIL109.nvidia.com (172.20.187.15) by HQMAIL109.nvidia.com (172.20.187.15) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Mon, 16 Dec 2019 22:25:40 +0000 Received: from hqnvemgw03.nvidia.com (10.124.88.68) by HQMAIL109.nvidia.com (172.20.187.15) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Mon, 16 Dec 2019 22:25:40 +0000 Received: from blueforge.nvidia.com (Not Verified[10.110.48.28]) by hqnvemgw03.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 16 Dec 2019 14:25:40 -0800 From: John Hubbard To: Andrew Morton CC: Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?utf-8?b?QmrDtnJuIFQ=?= =?utf-8?b?w7ZwZWw=?= , Christoph Hellwig , Dan Williams , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , "Mauro Carvalho Chehab" , Michael Ellerman , Michal Hocko , Mike Kravetz , "Paul Mackerras" , Shuah Khan , Vlastimil Babka , , , , , , , , , , , , , LKML , John Hubbard Subject: [PATCH v11 13/25] mm/process_vm_access: set FOLL_PIN via pin_user_pages_remote() Date: Mon, 16 Dec 2019 14:25:25 -0800 Message-ID: <20191216222537.491123-14-jhubbard@nvidia.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191216222537.491123-1-jhubbard@nvidia.com> References: <20191216222537.491123-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1576535114; bh=kDX8Nc6MeGUSG1gZLdpe1GJZUoittrssGXDLg9QnS08=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Type:Content-Transfer-Encoding; b=SwZptVKsys0/AWWifskfMyyoF2XT9B2IByk8YKc06RHDzd+SEmWSuEN9Fq04oBl8P ZlQWHuJkphTXr1iuWlFRn8wBsPzKZmg8kwdr3ecPO637v0BkfTfK/jOIC5gdkom38R B2VZHq3XQaY+gaTVXCAYWhsl4Hmp+S0XT4Adymc0bXu5ypfGmjwcpmtKJY2+UCH4lN N2R9R6EEmxzfY/k4ZxHmfBsctAZ5M+YvJgGgV+zrnw47A9G9SELIrFon9MaLit8Wmo XU5sG69sspRTN3xfuGziK82GyBToVpBQBWdl5KaVPQUx4uzzwLkmH/4FYI+SmS36df OXkgQaW6Oyn6A== Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Convert process_vm_access to use the new pin_user_pages_remote() call, which sets FOLL_PIN. Setting FOLL_PIN is now required for code that requires tracking of pinned pages. Also, release the pages via put_user_page*(). Also, rename "pages" to "pinned_pages", as this makes for easier reading of process_vm_rw_single_vec(). Reviewed-by: Jan Kara Reviewed-by: Jérôme Glisse Reviewed-by: Ira Weiny Signed-off-by: John Hubbard --- mm/process_vm_access.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c index 357aa7bef6c0..fd20ab675b85 100644 --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -42,12 +42,11 @@ static int process_vm_rw_pages(struct page **pages, if (copy > len) copy = len; - if (vm_write) { + if (vm_write) copied = copy_page_from_iter(page, offset, copy, iter); - set_page_dirty_lock(page); - } else { + else copied = copy_page_to_iter(page, offset, copy, iter); - } + len -= copied; if (copied < copy && iov_iter_count(iter)) return -EFAULT; @@ -96,7 +95,7 @@ static int process_vm_rw_single_vec(unsigned long addr, flags |= FOLL_WRITE; while (!rc && nr_pages && iov_iter_count(iter)) { - int pages = min(nr_pages, max_pages_per_loop); + int pinned_pages = min(nr_pages, max_pages_per_loop); int locked = 1; size_t bytes; @@ -106,14 +105,15 @@ static int process_vm_rw_single_vec(unsigned long addr, * current/current->mm */ down_read(&mm->mmap_sem); - pages = get_user_pages_remote(task, mm, pa, pages, flags, - process_pages, NULL, &locked); + pinned_pages = pin_user_pages_remote(task, mm, pa, pinned_pages, + flags, process_pages, + NULL, &locked); if (locked) up_read(&mm->mmap_sem); - if (pages <= 0) + if (pinned_pages <= 0) return -EFAULT; - bytes = pages * PAGE_SIZE - start_offset; + bytes = pinned_pages * PAGE_SIZE - start_offset; if (bytes > len) bytes = len; @@ -122,10 +122,12 @@ static int process_vm_rw_single_vec(unsigned long addr, vm_write); len -= bytes; start_offset = 0; - nr_pages -= pages; - pa += pages * PAGE_SIZE; - while (pages) - put_page(process_pages[--pages]); + nr_pages -= pinned_pages; + pa += pinned_pages * PAGE_SIZE; + + /* If vm_write is set, the pages need to be made dirty: */ + put_user_pages_dirty_lock(process_pages, pinned_pages, + vm_write); } return rc;