From patchwork Wed Jul 26 23:35:43 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: 9866019 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 0C8C8603F9 for ; Wed, 26 Jul 2017 23:37:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F05E1287CF for ; Wed, 26 Jul 2017 23:37:48 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E5462287D2; Wed, 26 Jul 2017 23:37:48 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham 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 60F4A287D8 for ; Wed, 26 Jul 2017 23:37:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751461AbdGZXhp (ORCPT ); Wed, 26 Jul 2017 19:37:45 -0400 Received: from mga07.intel.com ([134.134.136.100]:21047 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751448AbdGZXho (ORCPT ); Wed, 26 Jul 2017 19:37:44 -0400 Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga105.jf.intel.com with ESMTP; 26 Jul 2017 16:37:43 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.40,417,1496127600"; d="scan'208";a="883202693" Received: from omniknight.lm.intel.com ([10.232.112.27]) by FMSMGA003.fm.intel.com with ESMTP; 26 Jul 2017 16:37:42 -0700 From: Vishal Verma To: Cc: , Dan Williams , Jeff Moyer , "Rafael J. Wysocki" , Toshi Kani , Vishal Verma Subject: [PATCH v4 3/6] btt: ensure that flags were also unchanged during a map_read Date: Wed, 26 Jul 2017 17:35:43 -0600 Message-Id: <20170726233546.29052-4-vishal.l.verma@intel.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20170726233546.29052-1-vishal.l.verma@intel.com> References: <20170726233546.29052-1-vishal.l.verma@intel.com> Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org 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);