libnvdimm, label: populate 'isetcookie' for blk-aperture namespaces

Starting with the v1.2 definition of namespace labels, the isetcookie
field is populated and validated for blk-aperture namespaces. This adds
some safety against inadvertent copying of namespace labels from one
DIMM-device to another.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

2 files changed, 25 insertions, 7 deletions

diff --git a/drivers/nvdimm/label.c b/drivers/nvdimm/label.c
index d8b87d3a0ebe..ba0582fb0e21 100644
--- a/drivers/nvdimm/label.c
+++ b/drivers/nvdimm/label.c
@@ -787,7 +787,17 @@ static int __blk_label_update(struct nd_region *nd_region,
 		nd_label->flags = __cpu_to_le32(NSLABEL_FLAG_LOCAL);
 		nd_label->nlabel = __cpu_to_le16(0); /* N/A */
 		nd_label->position = __cpu_to_le16(0); /* N/A */
-		nd_label->isetcookie = __cpu_to_le64(0); /* N/A */
+
+		/*
+		 * Use the presence of the type_guid as a flag to
+		 * determine isetcookie usage for blk-aperture
+		 * namespaces.
+		 */
+		if (namespace_label_has(ndd, type_guid))
+			nd_label->isetcookie = __cpu_to_le64(nd_set->cookie2);
+		else
+			nd_label->isetcookie = __cpu_to_le64(0); /* N/A */
+
 		nd_label->dpa = __cpu_to_le64(res->start);
 		nd_label->rawsize = __cpu_to_le64(resource_size(res));
 		nd_label->lbasize = __cpu_to_le64(nsblk->lbasize);
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index e101aec186c7..7aba9a569c8e 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -2065,12 +2065,20 @@ struct device *create_namespace_blk(struct nd_region *nd_region,
 	struct device *dev = NULL;
 	struct resource *res;
 
-	if (namespace_label_has(ndd, type_guid)
-			&& !guid_equal(&nd_set->type_guid,
-				&nd_label->type_guid)) {
-		dev_dbg(ndd->dev, "expect type_guid %pUb got %pUb\n",
-				nd_set->type_guid.b, nd_label->type_guid.b);
-		return ERR_PTR(-EAGAIN);
+	if (namespace_label_has(ndd, type_guid)) {
+		if (!guid_equal(&nd_set->type_guid, &nd_label->type_guid)) {
+			dev_dbg(ndd->dev, "expect type_guid %pUb got %pUb\n",
+					nd_set->type_guid.b,
+					nd_label->type_guid.b);
+			return ERR_PTR(-EAGAIN);
+		}
+
+		if (nd_label->isetcookie != __cpu_to_le64(nd_set->cookie2)) {
+			dev_dbg(ndd->dev, "expect cookie %#llx got %#llx\n",
+					nd_set->cookie2,
+					__le64_to_cpu(nd_label->isetcookie));
+			return ERR_PTR(-EAGAIN);
+		}
 	}
 
 	nsblk = kzalloc(sizeof(*nsblk), GFP_KERNEL);