From patchwork Wed May 11 09:58:49 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 9067131 Return-Path: X-Original-To: patchwork-linux-nvdimm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 4C80FBF29F for ; Wed, 11 May 2016 09:59:36 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E8FB920103 for ; Wed, 11 May 2016 09:59:30 +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 4519C20123 for ; Wed, 11 May 2016 09:59:25 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 30A471A1F7D; Wed, 11 May 2016 02:59:24 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id A8A241A1F65 for ; Wed, 11 May 2016 02:59:22 -0700 (PDT) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 981AEAC58; Wed, 11 May 2016 09:59:20 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id D6D791E09FD; Wed, 11 May 2016 11:59:18 +0200 (CEST) From: Jan Kara To: linux-nvdimm@lists.01.org Subject: [PATCH 3/7] ext2: Avoid DAX zeroing to corrupt data Date: Wed, 11 May 2016 11:58:49 +0200 Message-Id: <1462960733-29634-4-git-send-email-jack@suse.cz> X-Mailer: git-send-email 2.6.6 In-Reply-To: <1462960733-29634-1-git-send-email-jack@suse.cz> References: <1462960733-29634-1-git-send-email-jack@suse.cz> X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Ted Tso , linux-fsdevel@vger.kernel.org, Jan Kara , linux-ext4@vger.kernel.org MIME-Version: 1.0 Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Spam-Status: No, score=-3.3 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, 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 Currently ext2 zeroes any data blocks allocated for DAX inode however it still returns them as BH_New. Thus DAX code zeroes them again in dax_insert_mapping() which can possibly overwrite the data that has been already stored to those blocks by a racing dax_io(). Avoid marking pre-zeroed buffers as new. Reviewed-by: Ross Zwisler Signed-off-by: Jan Kara --- fs/ext2/inode.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index 6bd58e6ff038..1f07b758b968 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -745,11 +745,11 @@ static int ext2_get_blocks(struct inode *inode, mutex_unlock(&ei->truncate_mutex); goto cleanup; } - } + } else + set_buffer_new(bh_result); ext2_splice_branch(inode, iblock, partial, indirect_blks, count); mutex_unlock(&ei->truncate_mutex); - set_buffer_new(bh_result); got_it: map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); if (count > blocks_to_boundary)