[PATCH] xfs: don't allow DAX on reflink filesystems

[PATCH] xfs: don't allow DAX on reflink filesystems

[Darrick J. Wong]

From: Darrick J. Wong <darrick.wong@oracle.com>

Now that reflink is no longer experimental, reject attempts to mount
with DAX until that whole mess gets sorted out.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 fs/xfs/xfs_super.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index f436eec..fd34cf2 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1666,9 +1666,12 @@ xfs_fs_fill_super(
 			"DAX unsupported by block device. Turning off DAX.");
 			mp->m_flags &= ~XFS_MOUNT_DAX;
 		}
-		if (xfs_sb_version_hasreflink(&mp->m_sb))
+		if (xfs_sb_version_hasreflink(&mp->m_sb)) {
 			xfs_alert(mp,
 		"DAX and reflink cannot be used together!");
+			error = -EINVAL;
+			goto out_filestream_unmount;
+		}
 	}
 
 	if (mp->m_flags & XFS_MOUNT_DISCARD) {

Re: [PATCH] xfs: don't allow DAX on reflink filesystems

[Bill O'Donnell]

On Wed, Jan 31, 2018 at 02:23:24PM -0800, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> Now that reflink is no longer experimental, reject attempts to mount
> with DAX until that whole mess gets sorted out.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

nit: Check alignment of the warning message (probably ok?)...

Reviewed-by: Bill O'Donnell <billodo@redhat.com>

> ---
>  fs/xfs/xfs_super.c |    5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> index f436eec..fd34cf2 100644
> --- a/fs/xfs/xfs_super.c
> +++ b/fs/xfs/xfs_super.c
> @@ -1666,9 +1666,12 @@ xfs_fs_fill_super(
>  			"DAX unsupported by block device. Turning off DAX.");
>  			mp->m_flags &= ~XFS_MOUNT_DAX;
>  		}
> -		if (xfs_sb_version_hasreflink(&mp->m_sb))
> +		if (xfs_sb_version_hasreflink(&mp->m_sb)) {
>  			xfs_alert(mp,
>  		"DAX and reflink cannot be used together!");
> +			error = -EINVAL;
> +			goto out_filestream_unmount;
> +		}
>  	}
>  
>  	if (mp->m_flags & XFS_MOUNT_DISCARD) {
> --
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Re: [PATCH] xfs: don't allow DAX on reflink filesystems

[Bill O'Donnell]

On Wed, Jan 31, 2018 at 05:11:25PM -0600, Bill O'Donnell wrote:
> On Wed, Jan 31, 2018 at 02:23:24PM -0800, Darrick J. Wong wrote:
> > From: Darrick J. Wong <darrick.wong@oracle.com>
> > 
> > Now that reflink is no longer experimental, reject attempts to mount
> > with DAX until that whole mess gets sorted out.
> > 
> > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> 
> nit: Check alignment of the warning message (probably ok?)...

nevermind. Alignment wasn't in your change. :)

Reviewed-by: Bill O'Donnell <billodo@redhat.com>

> 
> Reviewed-by: Bill O'Donnell <billodo@redhat.com>
> 
> > ---
> >  fs/xfs/xfs_super.c |    5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> > 
> > diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> > index f436eec..fd34cf2 100644
> > --- a/fs/xfs/xfs_super.c
> > +++ b/fs/xfs/xfs_super.c
> > @@ -1666,9 +1666,12 @@ xfs_fs_fill_super(
> >  			"DAX unsupported by block device. Turning off DAX.");
> >  			mp->m_flags &= ~XFS_MOUNT_DAX;
> >  		}
> > -		if (xfs_sb_version_hasreflink(&mp->m_sb))
> > +		if (xfs_sb_version_hasreflink(&mp->m_sb)) {
> >  			xfs_alert(mp,
> >  		"DAX and reflink cannot be used together!");
> > +			error = -EINVAL;
> > +			goto out_filestream_unmount;
> > +		}
> >  	}
> >  
> >  	if (mp->m_flags & XFS_MOUNT_DISCARD) {
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> --
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Re: [PATCH] xfs: don't allow DAX on reflink filesystems

[Dave Chinner]

On Wed, Jan 31, 2018 at 02:23:24PM -0800, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> Now that reflink is no longer experimental, reject attempts to mount
> with DAX until that whole mess gets sorted out.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Make sense. Anyone trying to make this work needs to patch the
kernel, so having to patch out this check is no big deal.

Reviewed-by: Dave Chinner <dchinner@redhat.com>

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com

Re: [PATCH] xfs: don't allow DAX on reflink filesystems

[Christoph Hellwig]

On Wed, Jan 31, 2018 at 02:23:24PM -0800, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> Now that reflink is no longer experimental, reject attempts to mount
> with DAX until that whole mess gets sorted out.

Didn't I send exactly the same patch about a week ago?

Re: [PATCH] xfs: don't allow DAX on reflink filesystems

[Darrick J. Wong]

On Fri, Feb 02, 2018 at 01:51:31AM -0800, Christoph Hellwig wrote:
> On Wed, Jan 31, 2018 at 02:23:24PM -0800, Darrick J. Wong wrote:
> > From: Darrick J. Wong <darrick.wong@oracle.com>
> > 
> > Now that reflink is no longer experimental, reject attempts to mount
> > with DAX until that whole mess gets sorted out.
> 
> Didn't I send exactly the same patch about a week ago?

I haven't received any such patch (but Oracle mail has been dropping and
delaying mail recently) and marc.info doesn't bring up anything relevant
for a search of 'DAX' and 'Hellwig'. :/

--D

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Re: [PATCH] xfs: don't allow DAX on reflink filesystems

[Christoph Hellwig]

On Fri, Feb 02, 2018 at 09:47:33AM -0800, Darrick J. Wong wrote:
> I haven't received any such patch (but Oracle mail has been dropping and
> delaying mail recently) and marc.info doesn't bring up anything relevant
> for a search of 'DAX' and 'Hellwig'. :/

I've found my local commits from Jan 18, but it seems like they never
made it out, despite me remembering sending them.  So it looks the issue
was in my side.