libnvdimm, namespace: fix pmem namespace leak, delete when size set to zero

Commit 98a29c39 ("libnvdimm, namespace: allow creation of multiple
pmem-namespaces per region") added support for establishing additional
pmem namespace beyond the seed device, similar to blk namespaces.
However, it neglected to delete the namespace when the size is set to
zero.

Fixes: 98a29c39 ("libnvdimm, namespace: allow creation of multiple pmem-namespaces per region")
Cc: <stable@vger.kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/nvdimm/namespace_devs.c

@@ -957,6 +957,7 @@ static ssize_t __size_store(struct device *dev, unsigned long long val)
 {
 	resource_size_t allocated = 0, available = 0;
 	struct nd_region *nd_region = to_nd_region(dev->parent);
+	struct nd_namespace_common *ndns = to_ndns(dev);
 	struct nd_mapping *nd_mapping;
 	struct nvdimm_drvdata *ndd;
 	struct nd_label_id label_id;
@@ -964,7 +965,7 @@ static ssize_t __size_store(struct device *dev, unsigned long long val)
 	u8 *uuid = NULL;
 	int rc, i;
 
-	if (dev->driver || to_ndns(dev)->claim)
+	if (dev->driver || ndns->claim)
 		return -EBUSY;
 
 	if (is_namespace_pmem(dev)) {
@@ -1034,20 +1035,16 @@ static ssize_t __size_store(struct device *dev, unsigned long long val)
 
 		nd_namespace_pmem_set_resource(nd_region, nspm,
 				val * nd_region->ndr_mappings);
-	} else if (is_namespace_blk(dev)) {
-		struct nd_namespace_blk *nsblk = to_nd_namespace_blk(dev);
-
-		/*
-		 * Try to delete the namespace if we deleted all of its
-		 * allocation, this is not the seed device for the
-		 * region, and it is not actively claimed by a btt
-		 * instance.
-		 */
-		if (val == 0 && nd_region->ns_seed != dev
-				&& !nsblk->common.claim)
-			nd_device_unregister(dev, ND_ASYNC);
 	}
 
+	/*
+	 * Try to delete the namespace if we deleted all of its
+	 * allocation, this is not the seed device for the region, and
+	 * it is not actively claimed by a btt instance.
+	 */
+	if (val == 0 && nd_region->ns_seed != dev && !ndns->claim)
+		nd_device_unregister(dev, ND_ASYNC);
+
 	return rc;
 }