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

[Neeraj Kumar]

On 23/06/25 10:17AM, Jonathan Cameron wrote:

On Tue, 17 Jun 2025 18:09:36 +0530
Neeraj Kumar <s.nee...@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.nee...@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.

Thanks, Will update it everywhere its inconsistent.

+                        * 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.

Sure, Will fix it up

+                                * 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);