From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752819AbcF1Tie (ORCPT ); Tue, 28 Jun 2016 15:38:34 -0400 Received: from g2t1383g.austin.hpe.com ([15.233.16.89]:37767 "EHLO g2t1383g.austin.hpe.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752805AbcF1Ti3 (ORCPT ); Tue, 28 Jun 2016 15:38:29 -0400 From: Toshi Kani To: snitzer@redhat.com Cc: agk@redhat.com, dan.j.williams@intel.com, linux-nvdimm@ml01.01.org, dm-devel@redhat.com, linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 0/2] Support DAX for device-mapper dm-linear devices Date: Tue, 28 Jun 2016 13:37:14 -0600 Message-Id: <1467142636-21094-1-git-send-email-toshi.kani@hpe.com> X-Mailer: git-send-email 2.5.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I noticed that dm-snap reloads DM table of target mapped-device, which fails for dax-capable device after dax support is added. Ideally, adding dax support to dm-snap solves the issue, but it cannot be done easily. This patch-set allows dm-snap to work with dax-capable target devices when bio-based operation is used. dax operation is unsupported with dm-snap, such that: a) After snapshot is taken, mount with dax option to a target device or a snapshot device fails. They can be mounted without dax. b) After snapshot is taken to a dax-mounted target device, any writes to the target device fails (EIO). b) can be protected by changing lvcreate to fail when snapshot is requested to a dax-mounted target device. - Patch 1 solves an error when lvremove is made to a snapshot device. - Patch 2 solves an error when lvcreate --snapshot is made to a dax- capable device. --- Toshi Kani (2): 1/2 dm: update table type check for dax 2/2 dm snap: add fake origin_direct_access --- drivers/md/dm-ioctl.c | 11 ++++++++++- drivers/md/dm-snap.c | 8 ++++++++ 2 files changed, 18 insertions(+), 1 deletion(-)