nvme: merge nvme_ns_ioctl into nvme_ioctl

Merge the two functions to make future changes a little easier.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>

drivers/nvme/host/core.c

@@ -1382,32 +1382,11 @@ static void nvme_put_ns_from_disk(struct nvme_ns_head *head, int idx)
 		srcu_read_unlock(&head->srcu, idx);
 }
 
-static int nvme_ns_ioctl(struct nvme_ns *ns, unsigned cmd, unsigned long arg)
-{
-	switch (cmd) {
-	case NVME_IOCTL_ID:
-		force_successful_syscall_return();
-		return ns->head->ns_id;
-	case NVME_IOCTL_ADMIN_CMD:
-		return nvme_user_cmd(ns->ctrl, NULL, (void __user *)arg);
-	case NVME_IOCTL_IO_CMD:
-		return nvme_user_cmd(ns->ctrl, ns, (void __user *)arg);
-	case NVME_IOCTL_SUBMIT_IO:
-		return nvme_submit_io(ns, (void __user *)arg);
-	default:
-		if (ns->ndev)
-			return nvme_nvm_ioctl(ns, cmd, arg);
-		if (is_sed_ioctl(cmd))
-			return sed_ioctl(ns->ctrl->opal_dev, cmd,
-					 (void __user *) arg);
-		return -ENOTTY;
-	}
-}
-
 static int nvme_ioctl(struct block_device *bdev, fmode_t mode,
 		unsigned int cmd, unsigned long arg)
 {
 	struct nvme_ns_head *head = NULL;
+	void __user *argp = (void __user *)arg;
 	struct nvme_ns *ns;
 	int srcu_idx, ret;
 
@@ -1415,7 +1394,29 @@ static int nvme_ioctl(struct block_device *bdev, fmode_t mode,
 	if (unlikely(!ns))
 		return -EWOULDBLOCK;
 
-	ret = nvme_ns_ioctl(ns, cmd, arg);
+	switch (cmd) {
+	case NVME_IOCTL_ID:
+		force_successful_syscall_return();
+		ret = ns->head->ns_id;
+		break;
+	case NVME_IOCTL_ADMIN_CMD:
+		ret = nvme_user_cmd(ns->ctrl, NULL, argp);
+		break;
+	case NVME_IOCTL_IO_CMD:
+		ret = nvme_user_cmd(ns->ctrl, ns, argp);
+		break;
+	case NVME_IOCTL_SUBMIT_IO:
+		ret = nvme_submit_io(ns, argp);
+		break;
+	default:
+		if (ns->ndev)
+			ret = nvme_nvm_ioctl(ns, cmd, arg);
+		else if (is_sed_ioctl(cmd))
+			ret = sed_ioctl(ns->ctrl->opal_dev, cmd, argp);
+		else
+			ret = -ENOTTY;
+	}
+
 	nvme_put_ns_from_disk(head, srcu_idx);
 	return ret;
 }