Re: [RFC PATCH 06/20] nvdimm/region_label: Add region label deletion routine

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

On Tue, 17 Jun 2025 18:09:30 +0530
Neeraj Kumar <s.neeraj@samsung.com> wrote:

> Added cxl v2.1 format region label deletion routine. This function is
> used to delete region label from LSA
> 
> Signed-off-by: Neeraj Kumar <s.neeraj@samsung.com>
> ---
>  drivers/nvdimm/label.c          | 75 ++++++++++++++++++++++++++++++---
>  drivers/nvdimm/label.h          |  6 +++
>  drivers/nvdimm/namespace_devs.c | 12 ++++++
>  drivers/nvdimm/nd.h             |  9 ++++
>  include/linux/libnvdimm.h       |  1 +
>  5 files changed, 98 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/nvdimm/label.c b/drivers/nvdimm/label.c
> index 7f33d14ce0ef..9381c50086fc 100644
> --- a/drivers/nvdimm/label.c
> +++ b/drivers/nvdimm/label.c
> @@ -1034,7 +1034,8 @@ static int init_labels(struct nd_mapping *nd_mapping, int num_labels)
>  	return max(num_labels, old_num_labels);
>  }
>  
> -static int del_labels(struct nd_mapping *nd_mapping, uuid_t *uuid)
> +static int del_labels(struct nd_mapping *nd_mapping, uuid_t *uuid,
> +		enum label_type ltype)
>  {
>  	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
>  	struct nd_label_ent *label_ent, *e;
> @@ -1058,8 +1059,18 @@ static int del_labels(struct nd_mapping *nd_mapping, uuid_t *uuid)
>  		if (!nd_label)
>  			continue;
>  		active++;
> -		if (!nsl_uuid_equal(ndd, &nd_label->ns_label, uuid))
> -			continue;
> +
> +		if (ltype == NS_LABEL_TYPE) {

Perhaps a switch is more appropriate here.

> +			if (!nsl_uuid_equal(ndd, &nd_label->ns_label, uuid))
> +				continue;
> +		} else if (ltype == RG_LABEL_TYPE) {
> +			if (!nsl_uuid_equal(ndd, &nd_label->ns_label, uuid))
> +				continue;
> +		} else {
> +			dev_err(ndd->dev, "Invalid label type\n");
> +			return 0;
> +		}
> +
>  		active--;
>  		slot = to_slot(ndd, nd_label);
>  		nd_label_free_slot(ndd, slot);

> @@ -1259,6 +1271,59 @@ int nd_pmem_region_label_update(struct nd_region *nd_region)
>  	return 0;
>  }
>  
> +int nd_pmem_region_label_delete(struct nd_region *nd_region)
> +{
> +	int i, rc;
> +	struct nd_interleave_set *nd_set = nd_region->nd_set;
> +	struct nd_label_ent *label_ent;
> +	bool is_non_rgl = false;
> +	int ns_region_cnt = 0;
> +
> +	for (i = 0; i < nd_region->ndr_mappings; i++) {
> +		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
> +		struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
> +
> +		/* Find non cxl format supported ndr_mappings */
> +		if (!ndd->cxl)
> +			is_non_rgl = true;
> +
> +		/* Find if any NS label using this region */
> +		mutex_lock(&nd_mapping->lock);
> +		list_for_each_entry(label_ent, &nd_mapping->labels, list) {
> +			if (!label_ent->label)
> +				continue;
> +
> +			/* Check if any available NS labels has same

Looks like wrong style for multiline comments in this file.

			/*
			 * Check ...

> +			 * region_uuid in LSA
> +			 */
> +			if (nsl_region_uuid_equal(&label_ent->label->ns_label,
> +						  &nd_set->uuid))
> +				ns_region_cnt++;
> +		}
> +		mutex_unlock(&nd_mapping->lock);
> +	}
> +
> +	if (is_non_rgl) {
> +		dev_dbg(&nd_region->dev, "Region label deletion unsupported\n");
> +		return -EINVAL;

Why not bail out where you originally detect that above?

> +	}
> +
> +	if (ns_region_cnt) {
> +		dev_dbg(&nd_region->dev, "Region/Namespace label in use\n");
> +		return -EBUSY;
> +	}
> +
> +	for (i = 0; i < nd_region->ndr_mappings; i++) {
> +		struct nd_mapping *nd_mapping = &nd_region->mapping[i];
> +
> +		rc = del_labels(nd_mapping, &nd_set->uuid, RG_LABEL_TYPE);
> +		if (rc)
> +			return rc;
> +	}
> +
> +	return 0;
> +}