From patchwork Tue Jul 21 22:37:45 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Verma, Vishal L" X-Patchwork-Id: 6838611 X-Patchwork-Delegate: vishal.l.verma@intel.com Return-Path: X-Original-To: patchwork-linux-nvdimm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 77C9E9F358 for ; Tue, 21 Jul 2015 22:38:02 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 8903F2049D for ; Tue, 21 Jul 2015 22:38:01 +0000 (UTC) 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.kernel.org (Postfix) with ESMTPS id 8795C20456 for ; Tue, 21 Jul 2015 22:38:00 +0000 (UTC) Received: from ml01.vlan14.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 7AC89182A25; Tue, 21 Jul 2015 15:38:00 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by ml01.01.org (Postfix) with ESMTP id F2577182A20 for ; Tue, 21 Jul 2015 15:37:58 -0700 (PDT) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga101.jf.intel.com with ESMTP; 21 Jul 2015 15:37:59 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.15,519,1432623600"; d="scan'208";a="766994395" Received: from vverma7-desk2.amr.corp.intel.com (HELO omniknight.lm.intel.com) ([10.232.112.76]) by fmsmga002.fm.intel.com with ESMTP; 21 Jul 2015 15:37:58 -0700 From: Vishal Verma To: linux-nvdimm@lists.01.org Subject: [PATCH 3/3] libnvdimm, btt: consolidate arena validation Date: Tue, 21 Jul 2015 16:37:45 -0600 Message-Id: <1437518265-14294-4-git-send-email-vishal.l.verma@intel.com> X-Mailer: git-send-email 2.4.3 In-Reply-To: <1437518265-14294-1-git-send-email-vishal.l.verma@intel.com> References: <1437518265-14294-1-git-send-email-vishal.l.verma@intel.com> X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Spam-Status: No, score=-3.8 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_LOW, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Use arena_is_valid as a common routine for checking the validity of an info block from both discover_arenas, and nd_btt_probe. As a result, don't check for validity of the BTT's UUID, and lbasize. The checksum in the BTT info block and parent_uuid are the necessary and sufficient conditions to make sure a BTT is both, consistent with itself, and not associated with a stale namespace. Signed-off-by: Vishal Verma --- drivers/nvdimm/btt.c | 43 +----------------------------------- drivers/nvdimm/btt.h | 3 +++ drivers/nvdimm/btt_devs.c | 55 +++++++++++++++++++++++++++++++++++++++-------- 3 files changed, 50 insertions(+), 51 deletions(-) diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c index 81781db..1958829 100644 --- a/drivers/nvdimm/btt.c +++ b/drivers/nvdimm/btt.c @@ -582,47 +582,6 @@ static void free_arenas(struct btt *btt) } } -static int uuid_is_null(u8 *uuid) -{ - static const u8 null_uuid[16]; - - return !memcmp(uuid, null_uuid, 16); -} - -/* - * This function checks if the metadata layout is valid and error free - */ -static int arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super) -{ - const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev); - u64 checksum; - - if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0) - return 0; - - if (memcmp(super->uuid, nd_btt->uuid, 16)) - return 0; - - if (!uuid_is_null(super->parent_uuid)) - if (memcmp(super->parent_uuid, parent_uuid, 16)) - return 0; - - checksum = le64_to_cpu(super->checksum); - super->checksum = 0; - if (checksum != nd_btt_sb_checksum(super)) - return 0; - super->checksum = cpu_to_le64(checksum); - - if (nd_btt->lbasize != le32_to_cpu(super->external_lbasize)) - return 0; - - /* TODO: figure out action for this */ - if ((le32_to_cpu(super->flags) & IB_FLAG_ERROR_MASK) != 0) - dev_info(&nd_btt->dev, "Found arena with an error flag\n"); - - return 1; -} - /* * This function reads an existing valid btt superblock and * populates the corresponding arena_info struct @@ -680,7 +639,7 @@ static int discover_arenas(struct btt *btt) if (ret) goto out; - if (!arena_is_valid(btt->nd_btt, super)) { + if (!nd_btt_arena_is_valid(btt->nd_btt, super)) { if (remaining == btt->rawsize) { btt->init_state = INIT_NOTFOUND; dev_info(to_dev(arena), "No existing arenas\n"); diff --git a/drivers/nvdimm/btt.h b/drivers/nvdimm/btt.h index 75b0d80..f2ac1bd 100644 --- a/drivers/nvdimm/btt.h +++ b/drivers/nvdimm/btt.h @@ -182,4 +182,7 @@ struct btt { int init_state; int num_arenas; }; + +int nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super); + #endif diff --git a/drivers/nvdimm/btt_devs.c b/drivers/nvdimm/btt_devs.c index 6ac8c0f..4ad4de6 100644 --- a/drivers/nvdimm/btt_devs.c +++ b/drivers/nvdimm/btt_devs.c @@ -342,6 +342,51 @@ struct device *nd_btt_create(struct nd_region *nd_region) return dev; } +static int uuid_is_null(u8 *uuid) +{ + static const u8 null_uuid[16]; + + return !memcmp(uuid, null_uuid, 16); +} + +/** + * nd_btt_arena_is_valid - check if the metadata layout is valid + * @nd_btt: device with BTT geometry and backing device info + * @super: pointer to the arena's info block being tested + * + * Check consistency of the btt info block with itself by validating + * the checksum, and with the parent namespace by verifying the + * parent_uuid contained in the info block with the one supplied in. + * + * Returns: + * 0 for an invalid info block, 1 for a valid one + */ +int nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super) +{ + const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev); + u64 checksum; + + if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0) + return 0; + + if (!uuid_is_null(super->parent_uuid)) + if (memcmp(super->parent_uuid, parent_uuid, 16)) + return 0; + + checksum = le64_to_cpu(super->checksum); + super->checksum = 0; + if (checksum != nd_btt_sb_checksum(super)) + return 0; + super->checksum = cpu_to_le64(checksum); + + /* TODO: figure out action for this */ + if ((le32_to_cpu(super->flags) & IB_FLAG_ERROR_MASK) != 0) + dev_info(&nd_btt->dev, "Found arena with an error flag\n"); + + return 1; +} +EXPORT_SYMBOL(nd_btt_arena_is_valid); + /* * nd_btt_sb_checksum: compute checksum for btt info block * @@ -364,8 +409,6 @@ EXPORT_SYMBOL(nd_btt_sb_checksum); static int __nd_btt_probe(struct nd_btt *nd_btt, struct nd_namespace_common *ndns, struct btt_sb *btt_sb) { - u64 checksum; - if (!btt_sb || !ndns || !nd_btt) return -ENODEV; @@ -375,14 +418,8 @@ static int __nd_btt_probe(struct nd_btt *nd_btt, if (nvdimm_namespace_capacity(ndns) < SZ_16M) return -ENXIO; - if (memcmp(btt_sb->signature, BTT_SIG, BTT_SIG_LEN) != 0) - return -ENODEV; - - checksum = le64_to_cpu(btt_sb->checksum); - btt_sb->checksum = 0; - if (checksum != nd_btt_sb_checksum(btt_sb)) + if (!nd_btt_arena_is_valid(nd_btt, btt_sb)) return -ENODEV; - btt_sb->checksum = cpu_to_le64(checksum); nd_btt->lbasize = le32_to_cpu(btt_sb->external_lbasize); nd_btt->uuid = kmemdup(btt_sb->uuid, 16, GFP_KERNEL);