[PATCH 4.9 036/130] libnvdimm, namespace: fix pmem namespace leak, delete when size set to zero

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Williams <dan.j.williams@xxxxxxxxx>

commit 1f19b983a8877f81763fab3e693c6befe212736d upstream.

Commit 98a29c39dc68 ("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: 98a29c39dc68 ("libnvdimm, namespace: allow creation of multiple pmem-namespaces per region")
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/nvdimm/namespace_devs.c |   23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -957,6 +957,7 @@ static ssize_t __size_store(struct devic
 {
 	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 devic
 	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 devic
 
 		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;
 }