diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 317a3712270f..2034d3710833 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -370,6 +370,25 @@ static inline void btrfs_set_root_last_trans(struct btrfs_root *root, u64 transi
 	WRITE_ONCE(root->last_trans, transid);
 }
 
+/*
+ * Return the generation this root started with.
+ *
+ * Every normal root that is created with root->root_key.offset set to it's
+ * originating generation.  If it is a snapshot it is the generation when the
+ * snapshot was created.
+ *
+ * However for TREE_RELOC roots root_key.offset is the objectid of the owning
+ * tree root.  Thankfully we copy the root item of the owning tree root, which
+ * has it's last_snapshot set to what we would have root_key.offset set to, so
+ * return that if this is a TREE_RELOC root.
+ */
+static inline u64 btrfs_root_origin_generation(const struct btrfs_root *root)
+{
+	if (btrfs_root_id(root) == BTRFS_TREE_RELOC_OBJECTID)
+		return btrfs_root_last_snapshot(&root->root_item);
+	return root->root_key.offset;
+}
+
 /*
  * Structure that conveys information about an extent that is going to replace
  * all the extents in a file range.
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index b43a8611aca5..f3e93ba7ec97 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5308,7 +5308,7 @@ static bool visit_node_for_delete(struct btrfs_root *root, struct walk_control *
 	 * reference to it.
 	 */
 	generation = btrfs_node_ptr_generation(eb, slot);
-	if (!wc->update_ref || generation <= root->root_key.offset)
+	if (!wc->update_ref || generation <= btrfs_root_origin_generation(root))
 		return false;
 
 	/*
@@ -5363,7 +5363,7 @@ static noinline void reada_walk_down(struct btrfs_trans_handle *trans,
 			goto reada;
 
 		if (wc->stage == UPDATE_BACKREF &&
-		    generation <= root->root_key.offset)
+		    generation <= btrfs_root_origin_generation(root))
 			continue;
 
 		/* We don't lock the tree block, it's OK to be racy here */
@@ -5706,7 +5706,7 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
 	 * for the subtree
 	 */
 	if (wc->stage == UPDATE_BACKREF &&
-	    generation <= root->root_key.offset) {
+	    generation <= btrfs_root_origin_generation(root)) {
 		wc->lookup_info = 1;
 		return 1;
 	}