From patchwork Thu Feb 21 05:15:51 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 10823149 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 4345B13A4 for ; Thu, 21 Feb 2019 05:28:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2CF892E519 for ; Thu, 21 Feb 2019 05:28:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1E58C2F26B; Thu, 21 Feb 2019 05:28:33 +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=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 88F802E519 for ; Thu, 21 Feb 2019 05:28:32 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 2D302211CBCFE; Wed, 20 Feb 2019 21:28:32 -0800 (PST) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=134.134.136.65; helo=mga03.intel.com; envelope-from=dan.j.williams@intel.com; receiver=linux-nvdimm@lists.01.org Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 428B9208D6133 for ; Wed, 20 Feb 2019 21:28:30 -0800 (PST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Feb 2019 21:28:30 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,393,1544515200"; d="scan'208";a="126056461" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.16]) by fmsmga008.fm.intel.com with ESMTP; 20 Feb 2019 21:28:29 -0800 Subject: [PATCH v2] dax: Check the end of the block-device capacity with dax_direct_access() From: Dan Williams To: linux-nvdimm@lists.01.org Date: Wed, 20 Feb 2019 21:15:51 -0800 Message-ID: <155072611007.2172474.11471824752162528833.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: References: User-Agent: StGit/0.18-2-gc94f MIME-Version: 1.0 X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-fsdevel@vger.kernel.org, Jan Kara , linux-kernel@vger.kernel.org, "Darrick J. Wong" Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" 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. Acked-by: Jan Kara Cc: "Darrick J. Wong" Signed-off-by: Dan Williams --- Changes in v2, simplify the calculation of the sector representing the last page / pfn of the device. drivers/dax/super.c | 38 ++++++++++++++++++++++++++++---------- 1 file changed, 28 insertions(+), 10 deletions(-) diff --git a/drivers/dax/super.c b/drivers/dax/super.c index 6e928f37d084..0cb8c30ea278 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 +115,14 @@ bool __bdev_dax_supported(struct block_device *bdev, int blocksize) return false; } + last_page = PFN_DOWN(i_size_read(bdev->bd_inode) - 1) * 8; + 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 +131,15 @@ 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 +154,20 @@ 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) {