nvme: cleanup setting the disk name

Return false from nvme_set_disk_name and let the caller set the
non-multipath name instead of duplicating the naming information in two
places.  Also remove the pointless local variables for the disk name
and flags and the not needed ctrl argument.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Javier González <javier.gonz@samsung.com>

drivers/nvme/host/core.c

@@ -3998,8 +3998,7 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid,
 	struct nvme_ns *ns;
 	struct gendisk *disk;
 	struct nvme_id_ns *id;
-	char disk_name[DISK_NAME_LEN];
-	int node = ctrl->numa_node, flags = GENHD_FL_EXT_DEVT;
+	int node = ctrl->numa_node;
 
 	if (nvme_identify_ns(ctrl, nsid, ids, &id))
 		return;
@@ -4025,7 +4024,6 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid,
 
 	if (nvme_init_ns_head(ns, nsid, ids, id->nmic & NVME_NS_NMIC_SHARED))
 		goto out_free_queue;
-	nvme_set_disk_name(disk_name, ns, ctrl, &flags);
 
 	disk = alloc_disk_node(0, node);
 	if (!disk)
@@ -4034,15 +4032,22 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid,
 	disk->fops = &nvme_bdev_ops;
 	disk->private_data = ns;
 	disk->queue = ns->queue;
-	disk->flags = flags;
-	memcpy(disk->disk_name, disk_name, DISK_NAME_LEN);
+	disk->flags = GENHD_FL_EXT_DEVT;
+	/*
+	 * Without the multipath code enabled, multiple controller per
+	 * subsystems are visible as devices and thus we cannot use the
+	 * subsystem instance.
+	 */
+	if (!nvme_mpath_set_disk_name(ns, disk->disk_name, &disk->flags))
+		sprintf(disk->disk_name, "nvme%dn%d", ctrl->instance,
+			ns->head->instance);
 	ns->disk = disk;
 
 	if (nvme_update_ns_info(ns, id))
 		goto out_put_disk;
 
 	if ((ctrl->quirks & NVME_QUIRK_LIGHTNVM) && id->vs[0] == 0x1) {
-		if (nvme_nvm_register(ns, disk_name, node)) {
+		if (nvme_nvm_register(ns, disk->disk_name, node)) {
 			dev_warn(ctrl->device, "LightNVM init failure\n");
 			goto out_put_disk;
 		}

drivers/nvme/host/multipath.c

@@ -50,19 +50,19 @@ void nvme_mpath_start_freeze(struct nvme_subsystem *subsys)
  * and those that have a single controller and use the controller node
  * directly.
  */
-void nvme_set_disk_name(char *disk_name, struct nvme_ns *ns,
-			struct nvme_ctrl *ctrl, int *flags)
-{
-	if (!multipath) {
-		sprintf(disk_name, "nvme%dn%d", ctrl->instance, ns->head->instance);
-	} else if (ns->head->disk) {
-		sprintf(disk_name, "nvme%dc%dn%d", ctrl->subsys->instance,
-				ctrl->instance, ns->head->instance);
-		*flags = GENHD_FL_HIDDEN;
-	} else {
-		sprintf(disk_name, "nvme%dn%d", ctrl->subsys->instance,
+bool nvme_mpath_set_disk_name(struct nvme_ns *ns, char *disk_name, int *flags)
+{
+	if (!multipath)
+		return false;
+	if (!ns->head->disk) {
+		sprintf(disk_name, "nvme%dn%d", ns->ctrl->subsys->instance,
 			ns->head->instance);
+		return true;
 	}
+	sprintf(disk_name, "nvme%dc%dn%d", ns->ctrl->subsys->instance,
+		ns->ctrl->instance, ns->head->instance);
+	*flags = GENHD_FL_HIDDEN;
+	return true;
 }
 
 void nvme_failover_req(struct request *req)

drivers/nvme/host/nvme.h

@@ -668,8 +668,7 @@ static inline bool nvme_ctrl_use_ana(struct nvme_ctrl *ctrl)
 void nvme_mpath_unfreeze(struct nvme_subsystem *subsys);
 void nvme_mpath_wait_freeze(struct nvme_subsystem *subsys);
 void nvme_mpath_start_freeze(struct nvme_subsystem *subsys);
-void nvme_set_disk_name(char *disk_name, struct nvme_ns *ns,
-			struct nvme_ctrl *ctrl, int *flags);
+bool nvme_mpath_set_disk_name(struct nvme_ns *ns, char *disk_name, int *flags);
 void nvme_failover_req(struct request *req);
 void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl);
 int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl,struct nvme_ns_head *head);
@@ -708,16 +707,11 @@ static inline bool nvme_ctrl_use_ana(struct nvme_ctrl *ctrl)
 {
 	return false;
 }
-/*
- * Without the multipath code enabled, multiple controller per subsystems are
- * visible as devices and thus we cannot use the subsystem instance.
- */
-static inline void nvme_set_disk_name(char *disk_name, struct nvme_ns *ns,
-				      struct nvme_ctrl *ctrl, int *flags)
+static inline bool nvme_mpath_set_disk_name(struct nvme_ns *ns, char *disk_name,
+		int *flags)
 {
-	sprintf(disk_name, "nvme%dn%d", ctrl->instance, ns->head->instance);
+	return false;
 }
-
 static inline void nvme_failover_req(struct request *req)
 {
 }