[PATCH 5/6] xfs: disable noattr2/attr2 mount options for CRC enabled filesystems

[Brian Foster]

On 06/03/2013 01:28 AM, Dave Chinner wrote:
> From: Dave Chinner <dchinner at redhat.com>
> 
> attr2 format is always enabled for v5 superblock filesystems, so the
> mount options to enable or disable it need to be cause mount errors.
> 
> Signed-off-by: Dave Chinner <dchinner at redhat.com>
> ---
>  Documentation/filesystems/xfs.txt |    3 +++
>  fs/xfs/xfs_super.c                |   11 +++++++++++
>  2 files changed, 14 insertions(+)
> 
> diff --git a/Documentation/filesystems/xfs.txt b/Documentation/filesystems/xfs.txt
> index 3e4b3dd..83577f0 100644
> --- a/Documentation/filesystems/xfs.txt
> +++ b/Documentation/filesystems/xfs.txt
> @@ -33,6 +33,9 @@ When mounting an XFS filesystem, the following options are accepted.
>  	removing extended attributes) the on-disk superblock feature
>  	bit field will be updated to reflect this format being in use.
>  
> +	CRC enabled filesystems always use the attr2 format, and so
> +	will reject the noattr2 mount option if it is set.
> +
>    barrier
>  	Enables the use of block layer write barriers for writes into
>  	the journal and unwritten extent conversion.  This allows for
> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> index ea341ce..f62abb2 100644
> --- a/fs/xfs/xfs_super.c
> +++ b/fs/xfs/xfs_super.c
> @@ -1373,6 +1373,17 @@ xfs_finish_flags(
>  	}
>  
>  	/*
> +	 * CRC enabled filesystems always use attr2 format for attributes.
> +	 */
> +	if (xfs_sb_version_hascrc(&mp->m_sb) &&
> +	    (mp->m_flags & XFS_MOUNT_NOATTR2)) {
> +		xfs_warn(mp,
> +"Cannot mount a V5 filesystems as %s. %s is always enabled for v5 filesystems.",
		      filesystem

(or alternatively remove the 'a').

... and V5 and v5 is inconsistent, fwiw. :P Nits, nonetheless...

Reviewed-by: Brian Foster <bfoster at redhat.com>

> +			MNTOPT_NOATTR2, MNTOPT_ATTR2);
> +		return XFS_ERROR(EINVAL);
> +	}
> +
> +	/*
>  	 * mkfs'ed attr2 will turn on attr2 mount unless explicitly
>  	 * told by noattr2 to turn it off
>  	 */
>