Re: [PATCH v2 3/3] xfs: Add alignment check for DAX mount

[Toshi Kani <toshi.kani@hpe.com>]

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