diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 74c8e18f3720da..64599625c7d7e4 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -462,8 +462,8 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
 		BUG_ON(ret < 0);
 		rcu_assign_pointer(root->node, cow);
 
-		btrfs_free_tree_block(trans, root, buf, parent_start,
-				      last_ref);
+		btrfs_free_tree_block(trans, btrfs_root_id(root), buf,
+				      parent_start, last_ref);
 		free_extent_buffer(buf);
 		add_root_to_dirty_list(root);
 	} else {
@@ -484,8 +484,8 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
 				return ret;
 			}
 		}
-		btrfs_free_tree_block(trans, root, buf, parent_start,
-				      last_ref);
+		btrfs_free_tree_block(trans, btrfs_root_id(root), buf,
+				      parent_start, last_ref);
 	}
 	if (unlock_orig)
 		btrfs_tree_unlock(buf);
@@ -926,7 +926,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 		free_extent_buffer(mid);
 
 		root_sub_used(root, mid->len);
-		btrfs_free_tree_block(trans, root, mid, 0, 1);
+		btrfs_free_tree_block(trans, btrfs_root_id(root), mid, 0, 1);
 		/* once for the root ptr */
 		free_extent_buffer_stale(mid);
 		return 0;
@@ -985,7 +985,8 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 			btrfs_tree_unlock(right);
 			del_ptr(root, path, level + 1, pslot + 1);
 			root_sub_used(root, right->len);
-			btrfs_free_tree_block(trans, root, right, 0, 1);
+			btrfs_free_tree_block(trans, btrfs_root_id(root), right,
+					      0, 1);
 			free_extent_buffer_stale(right);
 			right = NULL;
 		} else {
@@ -1030,7 +1031,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 		btrfs_tree_unlock(mid);
 		del_ptr(root, path, level + 1, pslot);
 		root_sub_used(root, mid->len);
-		btrfs_free_tree_block(trans, root, mid, 0, 1);
+		btrfs_free_tree_block(trans, btrfs_root_id(root), mid, 0, 1);
 		free_extent_buffer_stale(mid);
 		mid = NULL;
 	} else {
@@ -4031,7 +4032,7 @@ static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans,
 	root_sub_used(root, leaf->len);
 
 	atomic_inc(&leaf->refs);
-	btrfs_free_tree_block(trans, root, leaf, 0, 1);
+	btrfs_free_tree_block(trans, btrfs_root_id(root), leaf, 0, 1);
 	free_extent_buffer_stale(leaf);
 }
 /*
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 7553e9dc5f9383..5fe5eccb3c874b 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2257,6 +2257,11 @@ static inline bool btrfs_root_dead(const struct btrfs_root *root)
 	return (root->root_item.flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_DEAD)) != 0;
 }
 
+static inline u64 btrfs_root_id(const struct btrfs_root *root)
+{
+	return root->root_key.objectid;
+}
+
 /* struct btrfs_root_backup */
 BTRFS_SETGET_STACK_FUNCS(backup_tree_root, struct btrfs_root_backup,
 		   tree_root, 64);
@@ -2719,7 +2724,7 @@ struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
 					     u64 empty_size,
 					     enum btrfs_lock_nesting nest);
 void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
-			   struct btrfs_root *root,
+			   u64 root_id,
 			   struct extent_buffer *buf,
 			   u64 parent, int last_ref);
 int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans,
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index fc4895e6a62cd1..25ef6e3fd3069f 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3275,20 +3275,20 @@ static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans,
 }
 
 void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
-			   struct btrfs_root *root,
+			   u64 root_id,
 			   struct extent_buffer *buf,
 			   u64 parent, int last_ref)
 {
-	struct btrfs_fs_info *fs_info = root->fs_info;
+	struct btrfs_fs_info *fs_info = trans->fs_info;
 	struct btrfs_ref generic_ref = { 0 };
 	int ret;
 
 	btrfs_init_generic_ref(&generic_ref, BTRFS_DROP_DELAYED_REF,
 			       buf->start, buf->len, parent);
 	btrfs_init_tree_ref(&generic_ref, btrfs_header_level(buf),
-			    root->root_key.objectid, 0, false);
+			    root_id, 0, false);
 
-	if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
+	if (root_id != BTRFS_TREE_LOG_OBJECTID) {
 		btrfs_ref_tree_mod(fs_info, &generic_ref);
 		ret = btrfs_add_delayed_tree_ref(trans, &generic_ref, NULL);
 		BUG_ON(ret); /* -ENOMEM */
@@ -3298,7 +3298,7 @@ void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
 		struct btrfs_block_group *cache;
 		bool must_pin = false;
 
-		if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
+		if (root_id != BTRFS_TREE_LOG_OBJECTID) {
 			ret = check_ref_cleanup(trans, buf->start);
 			if (!ret) {
 				btrfs_redirty_list_add(trans->transaction, buf);
@@ -5472,7 +5472,8 @@ static noinline int walk_up_proc(struct btrfs_trans_handle *trans,
 			goto owner_mismatch;
 	}
 
-	btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1);
+	btrfs_free_tree_block(trans, btrfs_root_id(root), eb, parent,
+			      wc->refs[level] == 1);
 out:
 	wc->refs[level] = 0;
 	wc->flags[level] = 0;
diff --git a/fs/btrfs/free-space-tree.c b/fs/btrfs/free-space-tree.c
index a33bca94d133ec..3abec44c62559d 100644
--- a/fs/btrfs/free-space-tree.c
+++ b/fs/btrfs/free-space-tree.c
@@ -1256,8 +1256,8 @@ int btrfs_clear_free_space_tree(struct btrfs_fs_info *fs_info)
 	btrfs_tree_lock(free_space_root->node);
 	btrfs_clean_tree_block(free_space_root->node);
 	btrfs_tree_unlock(free_space_root->node);
-	btrfs_free_tree_block(trans, free_space_root, free_space_root->node,
-			      0, 1);
+	btrfs_free_tree_block(trans, btrfs_root_id(free_space_root),
+			      free_space_root->node, 0, 1);
 
 	btrfs_put_root(free_space_root);
 
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 1b85d98df66be1..a7533416370abd 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -617,11 +617,12 @@ static noinline int create_subvol(struct user_namespace *mnt_userns,
 		 * Since we don't abort the transaction in this case, free the
 		 * tree block so that we don't leak space and leave the
 		 * filesystem in an inconsistent state (an extent item in the
-		 * extent tree without backreferences). Also no need to have
-		 * the tree block locked since it is not in any tree at this
-		 * point, so no other task can find it and use it.
+		 * extent tree with a backreference for a root that does not
+		 * exists). Also no need to have the tree block locked since it
+		 * is not in any tree at this point, so no other task can find
+		 * it and use it.
 		 */
-		btrfs_free_tree_block(trans, root, leaf, 0, 1);
+		btrfs_free_tree_block(trans, objectid, leaf, 0, 1);
 		free_extent_buffer(leaf);
 		goto fail;
 	}
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index db680f5be745a0..6c037f1252b776 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -1219,7 +1219,8 @@ int btrfs_quota_disable(struct btrfs_fs_info *fs_info)
 	btrfs_tree_lock(quota_root->node);
 	btrfs_clean_tree_block(quota_root->node);
 	btrfs_tree_unlock(quota_root->node);
-	btrfs_free_tree_block(trans, quota_root, quota_root->node, 0, 1);
+	btrfs_free_tree_block(trans, btrfs_root_id(quota_root),
+			      quota_root->node, 0, 1);
 
 	btrfs_put_root(quota_root);