[PATCH v3 03/10] nvme-multipath: add nvme_mpath_{add, remove}_cdev()

These are for mpath_head_template.add_cdev+del_cdev callbacks.

Currently the same functionality is in nvme_add_ns_head_cdev() and
nvme_cdev_del().

Signed-off-by: John Garry <[email protected]>
---
 drivers/nvme/host/multipath.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 14c4370f7303f..e0573ca71ec60 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -630,6 +630,24 @@ const struct block_device_operations nvme_ns_head_ops = {
 	.pr_ops		= &nvme_pr_ops,
 };
 
+static int nvme_mpath_add_cdev(struct mpath_head *mpath_head)
+{
+	struct nvme_ns_head *head = nvme_mpath_to_ns_head(mpath_head);
+	char name[32];
+
+	head->cdev_device.parent = &head->subsys->dev;
+	snprintf(name, sizeof(name), "ng%dn%d", head->subsys->instance,
+		 head->instance);
+
+	return nvme_cdev_add(name, &mpath_head->cdev, &mpath_head->cdev_device,
+			&mpath_chr_fops, THIS_MODULE);
+}
+
+static void nvme_mpath_del_cdev(struct mpath_head *mpath_head)
+{
+	nvme_cdev_del(&mpath_head->cdev, &mpath_head->cdev_device);
+}
+
 static inline struct nvme_ns_head *cdev_to_ns_head(struct cdev *cdev)
 {
 	return container_of(cdev, struct nvme_ns_head, cdev);
@@ -1519,4 +1537,6 @@ void nvme_mpath_uninit(struct nvme_ctrl *ctrl)
 __maybe_unused
 static const struct mpath_head_template mpdt = {
 	.available_path = nvme_mpath_available_path,
+	.add_cdev = nvme_mpath_add_cdev,
+	.del_cdev = nvme_mpath_del_cdev,
 };
-- 
2.43.7