Re: [RFC PATCH 12/20] nvdimm/namespace_label: Skip region label during namespace creation

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

On Tue, 17 Jun 2025 18:09:36 +0530
Neeraj Kumar <s.neeraj@samsung.com> wrote:

> During namespace creation skip presence of region label if present.
> Also preserve region label into labels list if present.
> 
> Signed-off-by: Neeraj Kumar <s.neeraj@samsung.com>
> ---
>  drivers/nvdimm/namespace_devs.c | 48 +++++++++++++++++++++++++++++----
>  1 file changed, 43 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
> index b081661b7aaa..ca8f8546170c 100644
> --- a/drivers/nvdimm/namespace_devs.c
> +++ b/drivers/nvdimm/namespace_devs.c
> @@ -1976,6 +1976,10 @@ static struct device **scan_labels(struct nd_region *nd_region)
>  		if (!nd_label)
>  			continue;
>  
> +		/* skip region labels if present */
> +		if (is_region_label(ndd, nd_label))
> +			continue;
> +
>  		/* skip labels that describe extents outside of the region */
>  		if (nsl_get_dpa(ndd, &nd_label->ns_label) < nd_mapping->start ||
>  		    nsl_get_dpa(ndd, &nd_label->ns_label) > map_end)
> @@ -2014,9 +2018,29 @@ 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 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) {
> +				struct nd_lsa_label *nd_label = le->label;
> +
> +				/* preserve region labels if present */
> +				if (is_region_label(ndd, nd_label))
> +					list_move_tail(&le->list, &list);
> +			}
> +
> +			/* Publish a zero-sized namespace for userspace

Comment syntax as before looks to be inconsistent with file.

> +			 * 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;
> @@ -2028,7 +2052,7 @@ 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;
>  
> @@ -2039,10 +2063,24 @@ 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) {
> +				struct nd_lsa_label *nd_label = le->label;
> +
> +				/* preserve region labels */
> +				if (is_region_label(ndd, nd_label)) {
> +					list_move_tail(&le->list, &list);
> +					continue;
> +				}
> +
> +				/* Once preserving selected ns label done
Comment syntax.
> +				 * 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);