From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-fsdevel-owner@vger.kernel.org>
Received: from g4t3425.houston.hp.com ([15.201.208.53]:23226 "EHLO
	g4t3425.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1753952AbcEDXuV (ORCPT
	<rfc822;linux-fsdevel@vger.kernel.org>);
	Wed, 4 May 2016 19:50:21 -0400
Message-ID: <1462405286.27137.88.camel@hpe.com>
Subject: Re: [PATCH v2 3/3] xfs: Add alignment check for DAX mount
From: Toshi Kani <toshi.kani@hpe.com>
To: Dave Chinner <david@fromorbit.com>
Cc: dan.j.williams@intel.com, jack@suse.cz, hch@infradead.org,
	boaz@plexistor.com, tytso@mit.edu, adilger.kernel@dilger.ca,
	ross.zwisler@linux.intel.com, micah.parrish@hpe.com,
	linux-nvdimm@lists.01.org, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org
Date: Wed, 04 May 2016 17:41:26 -0600
In-Reply-To: <20160504231855.GA26977@dastard>
References: <1462214578-27122-1-git-send-email-toshi.kani@hpe.com>
	 <1462214578-27122-4-git-send-email-toshi.kani@hpe.com>
	 <20160504231855.GA26977@dastard>
Content-Type: text/plain; charset="UTF-8"
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
Sender: linux-fsdevel-owner@vger.kernel.org
List-ID: <linux-fsdevel.vger.kernel.org>

On Thu, 2016-05-05 at 09:18 +1000, Dave Chinner wrote:
> On Mon, May 02, 2016 at 12:42:58PM -0600, Toshi Kani wrote:
> > 
:
> Please write a helper along the lines of:
> 
> 	error = blkdev_supports_dax(sb->s_bdev, sb->s_blocksize);
> 
> and encapsulate all this, including the specific error messages in the
> helper (i.e. "Block device %s does not support DAX."). Then the rest
> of the filesystem code looks something like this:
> 
> 	if (mp->m_flags & XFS_MOUNT_DAX) {
> 		error = blkdev_supports_dax(sb->s_bdev, sb->s_blocksize);
> 		if (error) {
> 			xfs_alert(mp,
> 		"DAX unsupported by block device. Turning off DAX.");
> 			mp->m_flags &= ~XFS_MOUNT_DAX;
> 		}
> 	}
> 
> And each filesystem can choose to do what it wants with the error
> without having to care exactly why DAX is not supported.

Yes, I had this change in mind and was wondering if you are OK with it
since I am incline to keep the ext2/4 message style as majority rule. :)
https://lkml.org/lkml/2016/5/3/543

Assuming that's OK, I will make this change.

Thanks!
-Toshi