[PATCH v3 08/10] nvme-multipath: add nvme_{add,delete}_ns()

Add functions to call into the mpath_add_device() and mpath_delete_device()
functions.

The per-NS gendisk pointer is used as the mpath_device disk pointer, which
is used in libmultipath for references the per-path block device.

Signed-off-by: John Garry <[email protected]>
---
 drivers/nvme/host/nvme.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 292526c9dda29..9fd958a426f1f 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -1041,6 +1041,18 @@ extern const struct block_device_operations nvme_bdev_ops;
 
 void nvme_delete_ctrl_sync(struct nvme_ctrl *ctrl);
 struct nvme_ns *nvme_find_path(struct nvme_ns_head *head);
+
+static inline void nvme_add_ns(struct nvme_ns *ns)
+{
+	mpath_add_device(&ns->mpath_device, &ns->head->mpath_head,
+		ns->disk, ns->ctrl->numa_node, &ns->ctrl->nr_active);
+}
+
+static inline bool nvme_delete_ns(struct nvme_ns *ns)
+{
+	return mpath_delete_device(&ns->mpath_device);
+}
+
 #ifdef CONFIG_NVME_MULTIPATH
 static inline bool nvme_ctrl_use_ana(struct nvme_ctrl *ctrl)
 {
-- 
2.43.7