Re: [PATCH V4 06/17] nvdimm/label: Preserve region label during namespace creation

[Dave Jiang <dave.jiang@intel.com>]

On 11/19/25 12:52 AM, Neeraj Kumar wrote:
> During namespace creation we scan labels present in LSA using
> scan_labels(). Currently scan_labels() is only preserving
> namespace labels into label_ent list.
> 
> In this patch we also preserve region label into label_ent list
> 
> Signed-off-by: Neeraj Kumar <s.neeraj@samsung.com>

Reviewed-by: Dave Jiang <dave.jiang@intel.com>

> ---
>  drivers/nvdimm/namespace_devs.c | 47 +++++++++++++++++++++++++++++----
>  1 file changed, 42 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
> index b1abbe602a5e..9450200b4470 100644
> --- a/drivers/nvdimm/namespace_devs.c
> +++ b/drivers/nvdimm/namespace_devs.c
> @@ -1999,9 +1999,32 @@ static struct device **scan_labels(struct nd_region *nd_region)
>  
>  	if (count == 0) {
>  		struct nd_namespace_pmem *nspm;
> +		for (i = 0; i < nd_region->ndr_mappings; i++) {
> +			struct cxl_region_label *region_label;
> +			struct nd_label_ent *le, *e;
> +			LIST_HEAD(list);
>  
> -		/* Publish a zero-sized namespace for userspace to configure. */
> -		nd_mapping_free_labels(nd_mapping);
> +			nd_mapping = &nd_region->mapping[i];
> +			if (list_empty(&nd_mapping->labels))
> +				continue;
> +
> +			list_for_each_entry_safe(le, e, &nd_mapping->labels,
> +						 list) {
> +				region_label = le->region_label;
> +				if (!region_label)
> +					continue;
> +
> +				/* Preserve region labels if present */
> +				list_move_tail(&le->list, &list);
> +			}
> +
> +			/*
> +			 * Publish a zero-sized namespace for userspace
> +			 * to configure.
> +			 */
> +			nd_mapping_free_labels(nd_mapping);
> +			list_splice_init(&list, &nd_mapping->labels);
> +		}
>  		nspm = kzalloc(sizeof(*nspm), GFP_KERNEL);
>  		if (!nspm)
>  			goto err;
> @@ -2013,7 +2036,7 @@ static struct device **scan_labels(struct nd_region *nd_region)
>  	} else if (is_memory(&nd_region->dev)) {
>  		/* clean unselected labels */
>  		for (i = 0; i < nd_region->ndr_mappings; i++) {
> -			struct list_head *l, *e;
> +			struct nd_label_ent *le, *e;
>  			LIST_HEAD(list);
>  			int j;
>  
> @@ -2024,10 +2047,24 @@ static struct device **scan_labels(struct nd_region *nd_region)
>  			}
>  
>  			j = count;
> -			list_for_each_safe(l, e, &nd_mapping->labels) {
> +			list_for_each_entry_safe(le, e, &nd_mapping->labels,
> +						 list) {
> +				/* Preserve region labels */
> +				if (uuid_equal(&le->label_uuid,
> +					       &cxl_region_uuid)) {
> +					list_move_tail(&le->list, &list);
> +					continue;
> +				}
> +
> +				/*
> +				 * Once preserving selected ns label done
> +				 * break out of loop
> +				 */
>  				if (!j--)
>  					break;
> -				list_move_tail(l, &list);
> +
> +				/* Preserve selected ns label */
> +				list_move_tail(&le->list, &list);
>  			}
>  			nd_mapping_free_labels(nd_mapping);
>  			list_splice_init(&list, &nd_mapping->labels);