1 files changed, 3 insertions, 0 deletions
diff --git a/fs/btrfs/ref-cache.h b/fs/btrfs/ref-cache.h
index 6175647..16f3183 100644
--- a/fs/btrfs/ref-cache.h
+++ b/fs/btrfs/ref-cache.h
@@ -19,8 +19,11 @@
 #define __REFCACHE__
 
 struct btrfs_extent_info {
+	/* bytenr and num_bytes find the extent in the extent allocation tree */
 	u64 bytenr;
 	u64 num_bytes;
+
+	/* objectid and offset find the back reference for the file */
 	u64 objectid;
 	u64 offset;
 };