diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h
index 93fba71..f0a645a 100644
--- a/fs/btrfs/extent_map.h
+++ b/fs/btrfs/extent_map.h
@@ -33,7 +33,6 @@
 	unsigned long flags;
 	struct block_device *bdev;
 	atomic_t refs;
-	unsigned int in_tree;
 	unsigned int compress_type;
 	struct list_head list;
 };
@@ -44,6 +43,11 @@
 	rwlock_t lock;
 };
 
+static inline int extent_map_in_tree(const struct extent_map *em)
+{
+	return !RB_EMPTY_NODE(&em->rb_node);
+}
+
 static inline u64 extent_map_end(struct extent_map *em)
 {
 	if (em->start + em->len < em->start)