1 files changed, 2 insertions, 0 deletions
diff --git a/ctree.h b/ctree.h
index 2818441f..81c193f1 100644
--- a/ctree.h
+++ b/ctree.h
@@ -138,6 +138,8 @@ struct btrfs_free_space_ctl;
  */
 #define BTRFS_DEV_ITEMS_OBJECTID 1ULL
 
+#define BTRFS_EMPTY_SUBVOL_DIR_OBJECTID 2ULL
+
 /*
  * the max metadata block size.  This limit is somewhat artificial,
  * but the memmove costs go through the roof for larger blocks.