Re: [PATCH v6 1/7] common/rc: Introduce new helpers for DAX mount options and FS_XFLAG_DAX

[Ira Weiny <ira.weiny@intel.com>]

On Tue, Jul 14, 2020 at 05:40:03PM +0800, Xiao Yang wrote:
> 1) _require_scratch_dax_mountopt() checks both old and new DAX mount option
> 2) _require_dax_iflag() checks FS_XFLAG_DAX
> 
> Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>

Reviewed-by: Ira Weiny <ira.weiny@intel.com>

> ---
> 
> V5->V6:
> Simplify _require_scratch_dax_mountopt because it is enough to only check
> dax/dax=always mount option.  See the following reasons:
> 1) we cannot detect if underlying device supports dax by mounting dax=inode
>    or dax=never.
> 2) dax=always, dax=inode, dax=never are always introduced together.
> 
>  common/rc | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
> 
> diff --git a/common/rc b/common/rc
> index f17b19f2..aeec1f11 100644
> --- a/common/rc
> +++ b/common/rc
> @@ -3188,6 +3188,28 @@ _require_scratch_dax()
>  	_scratch_unmount
>  }
>  
> +# Only accept dax/dax=always mount option becasue dax=always, dax=inode
> +# and dax=never are always introduced together.
> +_require_scratch_dax_mountopt()
> +{
> +	local mountopt=$1
> +
> +	_require_scratch
> +	_scratch_mkfs > /dev/null 2>&1
> +	_try_scratch_mount "-o $mountopt" > /dev/null 2>&1 || \
> +		_notrun "mount $SCRATCH_DEV with $mountopt failed"
> +
> +	_fs_options $SCRATCH_DEV | egrep -q "dax(=always|,|$)" || \
> +		_notrun "$SCRATCH_DEV $FSTYP does not support -o $mountopt"
> +
> +	_scratch_unmount
> +}
> +
> +_require_dax_iflag()
> +{
> +	_require_xfs_io_command "chattr" "x"
> +}
> +
>  # Does norecovery support by this fs?
>  _require_norecovery()
>  {
> -- 
> 2.21.0
> 
> 
>