218  * Return 0 when both refs are for the same block (and can be merged).
271  * Add @newref to the @root rbtree, merging identical refs.
300 			/* Identical refs, merge them and free @newref */  in prelim_ref_insert()
357  * delayed refs
370  * on disk refs (inline or keyed)
418 /* direct refs use root == 0, key == NULL */
428 /* indirect refs use parent == 0 */
606 	 * adding new delayed refs.  To deal with this we need to look in cache  in resolve_indirect_ref()
717  * We maintain three separate rbtrees: one for direct refs, one for
718  * indirect refs which have a key, and one for indirect refs which do not
722  * indirect refs with missing keys. An appropriate key is located and
723  * the ref is moved onto the tree for indirect refs. After all missing
750 	 * the tree, allocating new refs for each insertion, and then  in resolve_indirect_refs()
827 	 * We may have inode lists attached to refs in the parents ulist, so we  in resolve_indirect_refs()
828 	 * must free them before freeing the ulist and its refs.  in resolve_indirect_refs()
885  * add all currently queued delayed refs from this head whose seq nr is
990 		 * refs have been checked.  in add_delayed_refs()
1024 	 * enumerate all inline refs  in add_inline_refs()
1367  * refs) for the given bytenr to the refs list, merges duplicates and resolves
1368  * indirect refs to their parent bytenr.
1440 		 * lock it so we have a consistent view of the refs at the given  in find_parent_nodes()
1448 				refcount_inc(&head->refs);  in find_parent_nodes()
1577 	 * This walks the tree of merged and resolved refs. Tree blocks are  in find_parent_nodes()
1589 		 * refs with a node->action of BTRFS_DROP_DELAYED_REF.  in find_parent_nodes()
1591 		 * identical refs to keep the overall count correct.  in find_parent_nodes()
1592 		 * prelim_ref_insert() will merge only those refs  in find_parent_nodes()
1593 		 * which compare identically.  Any refs having  in find_parent_nodes()
1640 			ret = ulist_add_merge_ptr(ctx->refs, ref->parent,  in find_parent_nodes()
1666 			 * this ref to the ref we added to the 'refs' ulist.  in find_parent_nodes()
1691  * added to the ulist at @ctx->refs, and that ulist is allocated by this
1696  * Returns 0 on success and < 0 on error. On error @ctx->refs is not allocated.
1702 	ASSERT(ctx->refs == NULL);  in btrfs_find_all_leafs()
1704 	ctx->refs = ulist_alloc(GFP_NOFS);  in btrfs_find_all_leafs()
1705 	if (!ctx->refs)  in btrfs_find_all_leafs()
1711 		free_leaf_list(ctx->refs);  in btrfs_find_all_leafs()
1712 		ctx->refs = NULL;  in btrfs_find_all_leafs()
1733  * This function requires @ctx->refs to be NULL, as it uses it for allocating a
1746 	ASSERT(ctx->refs == NULL);  in btrfs_find_all_roots_safe()
1748 	ctx->refs = ulist_alloc(GFP_NOFS);  in btrfs_find_all_roots_safe()
1749 	if (!ctx->refs)  in btrfs_find_all_roots_safe()
1755 			ulist_free(ctx->refs);  in btrfs_find_all_roots_safe()
1756 			ctx->refs = NULL;  in btrfs_find_all_roots_safe()
1777 		node = ulist_next(ctx->refs, &uiter);  in btrfs_find_all_roots_safe()
1784 	ulist_free(ctx->refs);  in btrfs_find_all_roots_safe()
1785 	ctx->refs = NULL;  in btrfs_find_all_roots_safe()
1813 	ulist_init(&ctx->refs);  in btrfs_alloc_backref_share_check_ctx()
1823 	ulist_release(&ctx->refs);  in btrfs_free_backref_share_ctx()
1843  * delayed refs, but continues on even when no running transaction exists.
1878 	ulist_init(&ctx->refs);  in btrfs_is_data_extent_shared()
1913 	walk_ctx.refs = &ctx->refs;  in btrfs_is_data_extent_shared()
1919 		const unsigned long prev_ref_count = ctx->refs.nnodes;  in btrfs_is_data_extent_shared()
1938 		 * the ctx->refs ulist, in which case we have to check multiple  in btrfs_is_data_extent_shared()
1966 		if ((ctx->refs.nnodes - prev_ref_count) > 1)  in btrfs_is_data_extent_shared()
1972 		node = ulist_next(&ctx->refs, &uiter);  in btrfs_is_data_extent_shared()
2037 	ulist_release(&ctx->refs);  in btrfs_is_data_extent_shared()
2272  * helper function to iterate extent inline refs. ptr must point to a 0 value
2274  * if more refs exist, 0 is returned and the next call to
2414 	struct ulist *refs;  in iterate_extent_inodes()  local
2448 	refs = ctx->refs;  in iterate_extent_inodes()
2449 	ctx->refs = NULL;  in iterate_extent_inodes()
2452 	while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) {  in iterate_extent_inodes()
2511 	free_leaf_list(refs);  in iterate_extent_inodes()
2974 		/* We're still inside the inline refs */  in btrfs_backref_iter_next()