From patchwork Tue Aug 22 22:19:12 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Verma, Vishal L" X-Patchwork-Id: 9916251 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 25618603FF for ; Tue, 22 Aug 2017 22:21:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 174A428889 for ; Tue, 22 Aug 2017 22:21:15 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0C3AB288A1; Tue, 22 Aug 2017 22:21:15 +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=-1.9 required=2.0 tests=BAYES_00, 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 CE046288D8 for ; Tue, 22 Aug 2017 22:21:14 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id C6A4921E2DA72; Tue, 22 Aug 2017 15:18:39 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) (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 1E83F21E49BAB for ; Tue, 22 Aug 2017 15:18:38 -0700 (PDT) Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga104.jf.intel.com with ESMTP; 22 Aug 2017 15:21:11 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.41,414,1498546800"; d="scan'208";a="140891268" Received: from omniknight.lm.intel.com ([10.232.112.27]) by orsmga005.jf.intel.com with ESMTP; 22 Aug 2017 15:21:10 -0700 From: Vishal Verma To: Subject: [PATCH v6 3/6] btt: ensure that flags were also unchanged during a map_read Date: Tue, 22 Aug 2017 16:19:12 -0600 Message-Id: <20170822221915.1732-4-vishal.l.verma@intel.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20170822221915.1732-1-vishal.l.verma@intel.com> References: <20170822221915.1732-1-vishal.l.verma@intel.com> X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.22 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-Virus-Scanned: ClamAV using ClamSMTP In btt_map_read, we read the map twice to make sure that the map entry didn't change after we added it to the read tracking table. In anticipation of expanding the use of the error bit, also make sure that the error and zero flags are constant across the two map reads. Signed-off-by: Vishal Verma --- drivers/nvdimm/btt.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c index 8842baa..374ae62 100644 --- a/drivers/nvdimm/btt.c +++ b/drivers/nvdimm/btt.c @@ -1032,6 +1032,7 @@ static int btt_read_pg(struct btt *btt, struct bio_integrity_payload *bip, */ while (1) { u32 new_map; + int new_t, new_e; if (t_flag) { zero_fill_data(page, off, cur_len); @@ -1050,15 +1051,18 @@ static int btt_read_pg(struct btt *btt, struct bio_integrity_payload *bip, */ barrier(); - ret = btt_map_read(arena, premap, &new_map, &t_flag, - &e_flag, NVDIMM_IO_ATOMIC); + ret = btt_map_read(arena, premap, &new_map, &new_t, + &new_e, NVDIMM_IO_ATOMIC); if (ret) goto out_rtt; - if (postmap == new_map) + if ((postmap == new_map) && (t_flag == new_t) && + (e_flag == new_e)) break; postmap = new_map; + t_flag = new_t; + e_flag = new_e; } ret = btt_data_read(arena, page, off, postmap, cur_len);