Re: [PATCH 2/2] xfs: don't consider future format versions valid

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

> @@ -86,16 +87,16 @@ xfs_sb_good_version(
>  	if (xfs_sb_is_v5(sbp))
>  		return xfs_sb_validate_v5_features(sbp);
>  
> +	/* versions prior to v4 are not supported */
> +	if (XFS_SB_VERSION_NUM(sbp) != XFS_SB_VERSION_4)
> +		return false;

The comment is a bit confusing now.  But maybe the v4 checks should
move into a xfs_sb_validate_v4_features helper anyway, which
would lead to a quite nice flow here:

	if (xfs_sb_is_v5(sbp))
	 	return xfs_sb_validate_v5_features(sbp);
	if (XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_4)
	 	return xfs_sb_validate_v4_features(sbp);
	return false;