Re: [PATCH 06/23] libnvdimm/labels: Add blk special cases for nlabel and position helpers

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Mon, 9 Aug 2021 15:28:19 -0700
Dan Williams <dan.j.williams@intel.com> wrote:

> In preparation for LIBNVDIMM to manage labels on CXL devices deploy
> helpers that abstract the label type from the implementation. The CXL
> label format is mostly similar to the EFI label format with concepts /
> fields added, like dynamic region creation and label type guids, and
> other concepts removed like BLK-mode and interleave-set-cookie ids.
> 
> Finish off the BLK-mode specific helper conversion with the nlabel and
> position behaviour that is specific to EFI v1.2 labels and not the
> original v1.1 definition.
> 
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
>  drivers/nvdimm/label.c |   46 +++++++++++++++++++++++++++++-----------------
>  1 file changed, 29 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/nvdimm/label.c b/drivers/nvdimm/label.c
> index d1a7f399cfe4..7188675c0955 100644
> --- a/drivers/nvdimm/label.c
> +++ b/drivers/nvdimm/label.c
> @@ -898,6 +898,10 @@ static struct resource *to_resource(struct nvdimm_drvdata *ndd,
>  	return NULL;
>  }
>  
> +/*
> + * Use the presence of the type_guid as a flag to determine isetcookie
> + * usage and nlabel + position policy for blk-aperture namespaces.
> + */
>  static void nsl_set_blk_isetcookie(struct nvdimm_drvdata *ndd,
>  				   struct nd_namespace_label *nd_label,
>  				   u64 isetcookie)
> @@ -925,6 +929,28 @@ bool nsl_validate_blk_isetcookie(struct nvdimm_drvdata *ndd,
>  	return true;
>  }
>  
> +static void nsl_set_blk_nlabel(struct nvdimm_drvdata *ndd,
> +			       struct nd_namespace_label *nd_label, int nlabel,
> +			       bool first)
> +{
> +	if (!namespace_label_has(ndd, type_guid)) {
> +		nsl_set_nlabel(ndd, nd_label, 0); /* N/A */
> +		return;
> +	}
> +	nsl_set_nlabel(ndd, nd_label, first ? nlabel : 0xffff);
> +}
> +
> +static void nsl_set_blk_position(struct nvdimm_drvdata *ndd,
> +				 struct nd_namespace_label *nd_label,
> +				 bool first)
> +{
> +	if (!namespace_label_has(ndd, type_guid)) {
> +		nsl_set_position(ndd, nd_label, 0);
> +		return;
> +	}
> +	nsl_set_position(ndd, nd_label, first ? 0 : 0xffff);
> +}
> +
>  /*
>   * 1/ Account all the labels that can be freed after this update
>   * 2/ Allocate and write the label to the staging (next) index
> @@ -1056,23 +1082,9 @@ static int __blk_label_update(struct nd_region *nd_region,
>  		nsl_set_name(ndd, nd_label, nsblk->alt_name);
>  		nsl_set_flags(ndd, nd_label, NSLABEL_FLAG_LOCAL);
>  
> -		/*
> -		 * Use the presence of the type_guid as a flag to
> -		 * determine isetcookie usage and nlabel + position
> -		 * policy for blk-aperture namespaces.
> -		 */
> -		if (namespace_label_has(ndd, type_guid)) {
> -			if (i == min_dpa_idx) {
> -				nsl_set_nlabel(ndd, nd_label, nsblk->num_resources);
> -				nsl_set_position(ndd, nd_label, 0);
> -			} else {
> -				nsl_set_nlabel(ndd, nd_label, 0xffff);
> -				nsl_set_position(ndd, nd_label, 0xffff);
> -			}
> -		} else {
> -			nsl_set_nlabel(ndd, nd_label, 0); /* N/A */
> -			nsl_set_position(ndd, nd_label, 0); /* N/A */
> -		}
> +		nsl_set_blk_nlabel(ndd, nd_label, nsblk->num_resources,
> +				   i == min_dpa_idx);
> +		nsl_set_blk_position(ndd, nd_label, i == min_dpa_idx);
>  		nsl_set_blk_isetcookie(ndd, nd_label, nd_set->cookie2);
>  
>  		nsl_set_dpa(ndd, nd_label, res->start);
>