From patchwork Tue Feb 12 21:24:56 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 10808703 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8EC9A13B4 for ; Tue, 12 Feb 2019 21:37:42 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7D4552C097 for ; Tue, 12 Feb 2019 21:37:42 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 715172C09D; Tue, 12 Feb 2019 21:37:42 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 191CA2C097 for ; Tue, 12 Feb 2019 21:37:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732584AbfBLVhg (ORCPT ); Tue, 12 Feb 2019 16:37:36 -0500 Received: from mga09.intel.com ([134.134.136.24]:16717 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732531AbfBLVhf (ORCPT ); Tue, 12 Feb 2019 16:37:35 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Feb 2019 13:37:34 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,362,1544515200"; d="scan'208";a="117400830" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.16]) by orsmga008.jf.intel.com with ESMTP; 12 Feb 2019 13:37:34 -0800 Subject: [PATCH 3/7] dax: Check the end of the block-device capacity with dax_direct_access() From: Dan Williams To: linux-nvdimm@lists.01.org Cc: Jan Kara , "Darrick J. Wong" , linux-kernel@vger.kernel.org, vishal.l.verma@intel.com, linux-fsdevel@vger.kernel.org Date: Tue, 12 Feb 2019 13:24:56 -0800 Message-ID: <155000669646.348031.16690970886357498896.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <155000668075.348031.9371497273408112600.stgit@dwillia2-desk3.amr.corp.intel.com> References: <155000668075.348031.9371497273408112600.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-2-gc94f MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The checks in __bdev_dax_supported() helped mitigate a potential data corruption bug in the pmem driver's handling of section alignment padding. Strengthen the checks, including checking the end of the range, to validate the dev_pagemap, Xarray entries, and sector-to-pfn translation established for pmem namespaces. Cc: Jan Kara Cc: "Darrick J. Wong" Signed-off-by: Dan Williams --- drivers/dax/super.c | 39 +++++++++++++++++++++++++++++---------- 1 file changed, 29 insertions(+), 10 deletions(-) diff --git a/drivers/dax/super.c b/drivers/dax/super.c index 6e928f37d084..a27395cfcec6 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -86,12 +86,14 @@ bool __bdev_dax_supported(struct block_device *bdev, int blocksize) { struct dax_device *dax_dev; bool dax_enabled = false; + pgoff_t pgoff, pgoff_end; struct request_queue *q; - pgoff_t pgoff; - int err, id; - pfn_t pfn; - long len; char buf[BDEVNAME_SIZE]; + void *kaddr, *end_kaddr; + pfn_t pfn, end_pfn; + sector_t last_page; + long len, len2; + int err, id; if (blocksize != PAGE_SIZE) { pr_debug("%s: error: unsupported blocksize for dax\n", @@ -113,6 +115,15 @@ bool __bdev_dax_supported(struct block_device *bdev, int blocksize) return false; } + last_page = ALIGN_DOWN(part_nr_sects_read(bdev->bd_part) + - PAGE_SIZE / 512, PAGE_SIZE / 512); + err = bdev_dax_pgoff(bdev, last_page, PAGE_SIZE, &pgoff_end); + if (err) { + pr_debug("%s: error: unaligned partition for dax\n", + bdevname(bdev, buf)); + return false; + } + dax_dev = dax_get_by_host(bdev->bd_disk->disk_name); if (!dax_dev) { pr_debug("%s: error: device does not support dax\n", @@ -121,14 +132,15 @@ bool __bdev_dax_supported(struct block_device *bdev, int blocksize) } id = dax_read_lock(); - len = dax_direct_access(dax_dev, pgoff, 1, NULL, &pfn); + len = dax_direct_access(dax_dev, pgoff, 1, &kaddr, &pfn); + len2 = dax_direct_access(dax_dev, pgoff_end, 1, &end_kaddr, &end_pfn); dax_read_unlock(id); put_dax(dax_dev); - if (len < 1) { + if (len < 1 || len2 < 1) { pr_debug("%s: error: dax access failed (%ld)\n", - bdevname(bdev, buf), len); + bdevname(bdev, buf), len < 1 ? len : len2); return false; } @@ -143,13 +155,20 @@ bool __bdev_dax_supported(struct block_device *bdev, int blocksize) */ WARN_ON(IS_ENABLED(CONFIG_ARCH_HAS_PMEM_API)); dax_enabled = true; - } else if (pfn_t_devmap(pfn)) { - struct dev_pagemap *pgmap; + } else if (pfn_t_devmap(pfn) && pfn_t_devmap(end_pfn)) { + struct dev_pagemap *pgmap, *end_pgmap; pgmap = get_dev_pagemap(pfn_t_to_pfn(pfn), NULL); - if (pgmap && pgmap->type == MEMORY_DEVICE_FS_DAX) + end_pgmap = get_dev_pagemap(pfn_t_to_pfn(end_pfn), NULL); + if (pgmap && pgmap == end_pgmap && pgmap->type == MEMORY_DEVICE_FS_DAX + && pfn_t_to_page(pfn)->pgmap == pgmap + && pfn_t_to_page(end_pfn)->pgmap == pgmap + && pfn_t_to_pfn(pfn) == PHYS_PFN(__pa(kaddr)) + && pfn_t_to_pfn(end_pfn) == PHYS_PFN(__pa(end_kaddr))) dax_enabled = true; put_dev_pagemap(pgmap); + put_dev_pagemap(end_pgmap); + } if (!dax_enabled) {