From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E9DE2C33CA4 for ; Fri, 10 Jan 2020 19:30:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BFEEF2082E for ; Fri, 10 Jan 2020 19:30:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728946AbgAJTaH (ORCPT ); Fri, 10 Jan 2020 14:30:07 -0500 Received: from mga18.intel.com ([134.134.136.126]:33892 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728924AbgAJTaG (ORCPT ); Fri, 10 Jan 2020 14:30:06 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Jan 2020 11:30:05 -0800 X-IronPort-AV: E=Sophos;i="5.69,418,1571727600"; d="scan'208";a="396531775" Received: from iweiny-desk2.sc.intel.com (HELO localhost) ([10.3.52.157]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Jan 2020 11:30:04 -0800 From: ira.weiny@intel.com To: linux-kernel@vger.kernel.org Cc: Ira Weiny , Alexander Viro , "Darrick J. Wong" , Dan Williams , Dave Chinner , Christoph Hellwig , "Theodore Y. Ts'o" , Jan Kara , linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: [RFC PATCH V2 06/12] fs/xfs: Check if the inode supports DAX under lock Date: Fri, 10 Jan 2020 11:29:36 -0800 Message-Id: <20200110192942.25021-7-ira.weiny@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20200110192942.25021-1-ira.weiny@intel.com> References: <20200110192942.25021-1-ira.weiny@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Ira Weiny One of the checks for an inode supporting DAX is if the inode is reflinked. During a non-DAX to DAX mode change we could race with the file being reflinked and end up with a reflinked file being in DAX mode. Prevent this race by checking for DAX support under the MMAP_LOCK. Signed-off-by: Ira Weiny --- fs/xfs/xfs_ioctl.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c index b5e00b67c297..bc3654fe3b5d 100644 --- a/fs/xfs/xfs_ioctl.c +++ b/fs/xfs/xfs_ioctl.c @@ -1180,10 +1180,6 @@ xfs_ioctl_setattr_dax_invalidate( *join_flags = 0; - if ((fa->fsx_xflags & FS_XFLAG_DAX) == FS_XFLAG_DAX && - !xfs_inode_supports_dax(ip)) - return -EINVAL; - /* If the DAX state is not changing, we have nothing to do here. */ if ((fa->fsx_xflags & FS_XFLAG_DAX) && (ip->i_d.di_flags2 & XFS_DIFLAG2_DAX)) @@ -1197,6 +1193,13 @@ xfs_ioctl_setattr_dax_invalidate( /* lock, flush and invalidate mapping in preparation for flag change */ xfs_ilock(ip, XFS_MMAPLOCK_EXCL | XFS_IOLOCK_EXCL); + + if ((fa->fsx_xflags & FS_XFLAG_DAX) == FS_XFLAG_DAX && + !xfs_inode_supports_dax(ip)) { + error = -EINVAL; + goto out_unlock; + } + error = filemap_write_and_wait(inode->i_mapping); if (error) goto out_unlock; -- 2.21.0