From patchwork Sat Aug 27 08:36:04 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 12956872 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 E7A0AC6FA69 for ; Sat, 27 Aug 2022 08:36:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238286AbiH0IgV (ORCPT ); Sat, 27 Aug 2022 04:36:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33588 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230176AbiH0IgT (ORCPT ); Sat, 27 Aug 2022 04:36:19 -0400 Received: from NAM12-DM6-obe.outbound.protection.outlook.com (mail-dm6nam12on2083.outbound.protection.outlook.com [40.107.243.83]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 70C14B14EC; Sat, 27 Aug 2022 01:36:15 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=TRn4JAVnSRE7dSLyjcLJ5Eb3xcKqQMMqMNmHhtMp7YOdAncnU0SubYx8gaJf0JYtE+gpnIYWa0UQ8nABIFfW49Sr2og6tmG7eLSgAyeRZ7J0aY1HKT2kny1T5N/cb69SjbKQep3ePUfF7Qr3mnI3a0v0AUsgoPF6yE8KGtJnIOR19zmkyzSC83dgdS/eJgb+6fyXo/7NkttFMm0zToUy1sfn5mVOjkEqm1OdUc8sopk8UlQbW1JCxNMO6E9lbFM7OJSpJl34W66s6s7Q8Lp6kbSWZLvXBL04LXQ7kHkf03Y9ODNKrPiPfYqpQsDsC9gAL92ms1SYzTJpPdXAZky+bg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=1se43bUMAuKkiRhgWx+GCO+PuzkFi6R5U8K9kr66PVU=; b=QXQeaoETZ/yLGtZwuHySGH7LFNFYNCXGVIJf7GnO1NgNwhZ5z8nRix/yOjKqAliIv6GuHJgJ7GRVgovPCx6OM91WI2if59gihCDULYYj9Rct6PzVREqpu5UJQw/+iGYwsej84kRzAK2lnXA280jrBBMq9cT+qTRQ+1JEQJ5wRoOhoeV/hvaMgVfG8TMHz0i3EOaYiH4nyFYcMGulXYmQ4MIulxj8tAELuqiQWtAxqIF3l9ZDuR67wVBFQrrwYm6Sfk+BV61nbQqERbSuau4a/l3TyFIbY8skmG1DAFa9mnXlG0di3kt5FcmTy9Jcu8wi7PgU1Gorio0dRyAjL81wJA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass (sender ip is 12.22.5.234) smtp.rcpttodomain=kernel.org smtp.mailfrom=nvidia.com; dmarc=pass (p=reject sp=reject pct=100) action=none header.from=nvidia.com; dkim=none (message not signed); arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=1se43bUMAuKkiRhgWx+GCO+PuzkFi6R5U8K9kr66PVU=; b=MYgtZjwqzG6Ih6wekWj7eIwOKOc2sW+4TK13gy6L+Rbp8hJxnvgbLbaAlP3vSSnyfJBczdTNL1JLuKIwRrlY/4UyZFCbZXgdSyRGZxt620GFX2owQP119R6onJw0nQcS/p0HKpcWtlvSccyXfuS1E/BlruwzE/Y8V3CN44HF2g89/nqIRGwTC/YwlPBoKHuS5qOJPm96GyJp0k/NCiVKqOBGzFwivQSmSkALIgDjomJDH61SoC3jJCm43npqGwCr5Bdd6+iNMM9sn46kGRAY5uoIFN2BA82mfM3DK3rQHl/gRIJTXq6lnipcdynXiK1nBXuMozOuFzfRpKMzz9e00A== Received: from DM6PR03CA0045.namprd03.prod.outlook.com (2603:10b6:5:100::22) by CY4PR12MB1333.namprd12.prod.outlook.com (2603:10b6:903:41::15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5566.15; Sat, 27 Aug 2022 08:36:13 +0000 Received: from DM6NAM11FT085.eop-nam11.prod.protection.outlook.com (2603:10b6:5:100:cafe::bc) by DM6PR03CA0045.outlook.office365.com (2603:10b6:5:100::22) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.5566.15 via Frontend Transport; Sat, 27 Aug 2022 08:36:13 +0000 X-MS-Exchange-Authentication-Results: spf=pass (sender IP is 12.22.5.234) smtp.mailfrom=nvidia.com; dkim=none (message not signed) header.d=none;dmarc=pass action=none header.from=nvidia.com; Received-SPF: Pass (protection.outlook.com: domain of nvidia.com designates 12.22.5.234 as permitted sender) receiver=protection.outlook.com; client-ip=12.22.5.234; helo=mail.nvidia.com; pr=C Received: from mail.nvidia.com (12.22.5.234) by DM6NAM11FT085.mail.protection.outlook.com (10.13.172.236) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.20.5566.15 via Frontend Transport; Sat, 27 Aug 2022 08:36:13 +0000 Received: from drhqmail202.nvidia.com (10.126.190.181) by DRHQMAIL101.nvidia.com (10.27.9.10) with Microsoft SMTP Server (TLS) id 15.0.1497.38; Sat, 27 Aug 2022 08:36:12 +0000 Received: from drhqmail203.nvidia.com (10.126.190.182) by drhqmail202.nvidia.com (10.126.190.181) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.29; Sat, 27 Aug 2022 01:36:12 -0700 Received: from sandstorm.attlocal.net (10.127.8.9) by mail.nvidia.com (10.126.190.182) with Microsoft SMTP Server id 15.2.986.29 via Frontend Transport; Sat, 27 Aug 2022 01:36:11 -0700 From: John Hubbard To: Andrew Morton CC: Jens Axboe , Alexander Viro , Miklos Szeredi , Christoph Hellwig , "Darrick J . Wong" , Trond Myklebust , Anna Schumaker , Jan Kara , Logan Gunthorpe , , , , , , LKML , John Hubbard Subject: [PATCH 3/6] iov_iter: new iov_iter_pin_pages*() routines Date: Sat, 27 Aug 2022 01:36:04 -0700 Message-ID: <20220827083607.2345453-4-jhubbard@nvidia.com> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220827083607.2345453-1-jhubbard@nvidia.com> References: <20220827083607.2345453-1-jhubbard@nvidia.com> MIME-Version: 1.0 X-NVConfidentiality: public X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 37c9f01e-66aa-4fcb-ef44-08da88073340 X-MS-TrafficTypeDiagnostic: CY4PR12MB1333:EE_ X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:12.22.5.234;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:mail.nvidia.com;PTR:InfoNoRecords;CAT:NONE;SFS:(13230016)(4636009)(39860400002)(396003)(346002)(136003)(376002)(40470700004)(46966006)(36840700001)(82740400003)(83380400001)(36860700001)(426003)(47076005)(2616005)(186003)(2906002)(1076003)(336012)(356005)(81166007)(40460700003)(26005)(107886003)(86362001)(6666004)(40480700001)(82310400005)(70586007)(316002)(41300700001)(478600001)(36756003)(7416002)(54906003)(5660300002)(6916009)(8936002)(8676002)(4326008)(70206006)(36900700001);DIR:OUT;SFP:1101; X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 27 Aug 2022 08:36:13.1138 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 37c9f01e-66aa-4fcb-ef44-08da88073340 X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=43083d15-7273-40c1-b7db-39efd9ccc17a;Ip=[12.22.5.234];Helo=[mail.nvidia.com] X-MS-Exchange-CrossTenant-AuthSource: DM6NAM11FT085.eop-nam11.prod.protection.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY4PR12MB1333 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org Provide two new wrapper routines that are intended for user space pages only: iov_iter_pin_pages() iov_iter_pin_pages_alloc() Internally, these routines call pin_user_pages_fast(), instead of get_user_pages_fast(). As always, callers must use unpin_user_pages() or a suitable FOLL_PIN variant, to release the pages, if they actually were acquired via pin_user_pages_fast(). This is a prerequisite to converting bio/block layers over to use pin_user_pages_fast(). Signed-off-by: John Hubbard --- include/linux/uio.h | 4 +++ lib/iov_iter.c | 74 ++++++++++++++++++++++++++++++++++++++++++--- 2 files changed, 74 insertions(+), 4 deletions(-) diff --git a/include/linux/uio.h b/include/linux/uio.h index 5896af36199c..e26908e443d1 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -251,6 +251,10 @@ ssize_t iov_iter_get_pages2(struct iov_iter *i, struct page **pages, size_t maxsize, unsigned maxpages, size_t *start); ssize_t iov_iter_get_pages_alloc2(struct iov_iter *i, struct page ***pages, size_t maxsize, size_t *start); +ssize_t iov_iter_pin_pages(struct iov_iter *i, struct page **pages, + size_t maxsize, unsigned int maxpages, size_t *start); +ssize_t iov_iter_pin_pages_alloc(struct iov_iter *i, struct page ***pages, + size_t maxsize, size_t *start); int iov_iter_npages(const struct iov_iter *i, int maxpages); void iov_iter_restore(struct iov_iter *i, struct iov_iter_state *state); diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 4b7fce72e3e5..1c08014c8498 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1425,9 +1425,23 @@ static struct page *first_bvec_segment(const struct iov_iter *i, return page; } +enum pages_alloc_internal_flags { + USE_FOLL_GET, + USE_FOLL_PIN +}; + +/* + * TODO: get rid of the how_to_pin arg, and just call pin_user_pages_fast() + * unconditionally for the user_back_iter(i) case in this function. That can be + * done once all callers are ready to deal with FOLL_PIN pages for their + * user-space pages. (FOLL_PIN pages must be released via unpin_user_page(), + * rather than put_page().) + */ static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages, size_t maxsize, - unsigned int maxpages, size_t *start) + unsigned int maxpages, size_t *start, + enum pages_alloc_internal_flags how_to_pin) + { unsigned int n; @@ -1454,7 +1468,12 @@ static ssize_t __iov_iter_get_pages_alloc(struct iov_iter *i, n = want_pages_array(pages, maxsize, *start, maxpages); if (!n) return -ENOMEM; - res = get_user_pages_fast(addr, n, gup_flags, *pages); + + if (how_to_pin == USE_FOLL_PIN) + res = pin_user_pages_fast(addr, n, gup_flags, *pages); + else + res = get_user_pages_fast(addr, n, gup_flags, *pages); + if (unlikely(res <= 0)) return res; maxsize = min_t(size_t, maxsize, res * PAGE_SIZE - *start); @@ -1497,10 +1516,31 @@ ssize_t iov_iter_get_pages2(struct iov_iter *i, return 0; BUG_ON(!pages); - return __iov_iter_get_pages_alloc(i, &pages, maxsize, maxpages, start); + return __iov_iter_get_pages_alloc(i, &pages, maxsize, maxpages, start, + USE_FOLL_GET); } EXPORT_SYMBOL(iov_iter_get_pages2); +/* + * A FOLL_PIN variant that calls pin_user_pages_fast() instead of + * get_user_pages_fast(). + */ +ssize_t iov_iter_pin_pages(struct iov_iter *i, + struct page **pages, size_t maxsize, unsigned int maxpages, + size_t *start) +{ + if (!maxpages) + return 0; + if (WARN_ON_ONCE(!pages)) + return -EINVAL; + if (WARN_ON_ONCE(!user_backed_iter(i))) + return -EINVAL; + + return __iov_iter_get_pages_alloc(i, &pages, maxsize, maxpages, start, + USE_FOLL_PIN); +} +EXPORT_SYMBOL(iov_iter_pin_pages); + ssize_t iov_iter_get_pages_alloc2(struct iov_iter *i, struct page ***pages, size_t maxsize, size_t *start) @@ -1509,7 +1549,8 @@ ssize_t iov_iter_get_pages_alloc2(struct iov_iter *i, *pages = NULL; - len = __iov_iter_get_pages_alloc(i, pages, maxsize, ~0U, start); + len = __iov_iter_get_pages_alloc(i, pages, maxsize, ~0U, start, + USE_FOLL_GET); if (len <= 0) { kvfree(*pages); *pages = NULL; @@ -1518,6 +1559,31 @@ ssize_t iov_iter_get_pages_alloc2(struct iov_iter *i, } EXPORT_SYMBOL(iov_iter_get_pages_alloc2); +/* + * A FOLL_PIN variant that calls pin_user_pages_fast() instead of + * get_user_pages_fast(). + */ +ssize_t iov_iter_pin_pages_alloc(struct iov_iter *i, + struct page ***pages, size_t maxsize, + size_t *start) +{ + ssize_t len; + + *pages = NULL; + + if (WARN_ON_ONCE(!user_backed_iter(i))) + return -EINVAL; + + len = __iov_iter_get_pages_alloc(i, pages, maxsize, ~0U, start, + USE_FOLL_PIN); + if (len <= 0) { + kvfree(*pages); + *pages = NULL; + } + return len; +} +EXPORT_SYMBOL(iov_iter_pin_pages_alloc); + size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i) {