ubifs: wire up FS_IOC_GET_ENCRYPTION_NONCE

This new ioctl retrieves a file's encryption nonce, which is useful for
testing.  See the corresponding fs/crypto/ patch for more details.

Link: https://lore.kernel.org/r/20200314205052.93294-5-ebiggers@kernel.orgSigned-off-by: Eric Biggers <ebiggers@google.com>

fs/ubifs/ioctl.c

@@ -208,6 +208,9 @@ long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	case FS_IOC_GET_ENCRYPTION_KEY_STATUS:
 		return fscrypt_ioctl_get_key_status(file, (void __user *)arg);
 
+	case FS_IOC_GET_ENCRYPTION_NONCE:
+		return fscrypt_ioctl_get_nonce(file, (void __user *)arg);
+
 	default:
 		return -ENOTTY;
 	}
@@ -230,6 +233,7 @@ long ubifs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	case FS_IOC_REMOVE_ENCRYPTION_KEY:
 	case FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS:
 	case FS_IOC_GET_ENCRYPTION_KEY_STATUS:
+	case FS_IOC_GET_ENCRYPTION_NONCE:
 		break;
 	default:
 		return -ENOIOCTLCMD;