28  * Each node may have a left or right sibling.  When decending the spine,
35  * [B] No left sibling
39  *     ==> rebalance(left sibling, node)
41  * [D] Both siblings, total_entries(left, node, right) <= DEL_THRESHOLD
42  *     ==> delete node adding it's contents to left and right
44  * [E] Both siblings, total_entries(left, node, right) > DEL_THRESHOLD
45  *     ==> rebalance(left, node, right)
85 static int node_copy(struct btree_node *left, struct btree_node *right, int shift)  in node_copy()  argument
87 	uint32_t nr_left = le32_to_cpu(left->header.nr_entries);  in node_copy()
88 	uint32_t value_size = le32_to_cpu(left->header.value_size);  in node_copy()
97 		if (nr_left + shift > le32_to_cpu(left->header.max_entries)) {  in node_copy()
102 		memcpy(key_ptr(left, nr_left),  in node_copy()
105 		memcpy(value_ptr(left, nr_left),  in node_copy()
115 		       key_ptr(left, nr_left - shift),  in node_copy()
118 		       value_ptr(left, nr_left - shift),  in node_copy()
189 static int shift(struct btree_node *left, struct btree_node *right, int count)  in shift()  argument
192 	uint32_t nr_left = le32_to_cpu(left->header.nr_entries);  in shift()
194 	uint32_t max_entries = le32_to_cpu(left->header.max_entries);  in shift()
217 		r = node_copy(left, right, count);  in shift()
221 		r = node_copy(left, right, count);  in shift()
227 	left->header.nr_entries = cpu_to_le32(nr_left - count);  in shift()
237 	struct btree_node *left = l->n;  in __rebalance2()  local
239 	uint32_t nr_left = le32_to_cpu(left->header.nr_entries);  in __rebalance2()
247 	unsigned int threshold = 2 * (merge_threshold(left) + 1);  in __rebalance2()
253 		node_copy(left, right, -nr_right);  in __rebalance2()
254 		left->header.nr_entries = cpu_to_le32(nr_left + nr_right);  in __rebalance2()
259 		 * children, since they're still referenced by left.  in __rebalance2()
267 		ret = shift(left, right, nr_left - target_left);  in __rebalance2()
280 	struct child left, right;  in rebalance2()  local
284 	r = init_child(info, vt, parent, left_index, &left);  in rebalance2()
290 		exit_child(info, &left);  in rebalance2()
294 	r = __rebalance2(info, parent, &left, &right);  in rebalance2()
296 	exit_child(info, &left);  in rebalance2()
303  * We dump as many entries from center as possible into left, then the rest
309 			      struct btree_node *left, struct btree_node *center, struct btree_node *right,  in delete_center_node()  argument
312 	uint32_t max_entries = le32_to_cpu(left->header.max_entries);  in delete_center_node()
320 	node_copy(left, center, -shift);  in delete_center_node()
321 	left->header.nr_entries = cpu_to_le32(nr_left + shift);  in delete_center_node()
349 			 struct btree_node *left, struct btree_node *center, struct btree_node *right,  in redistribute3()  argument
353 	uint32_t max_entries = le32_to_cpu(left->header.max_entries);  in redistribute3()
367 			ret = shift(left, center, -nr_center);  in redistribute3()
372 			ret = shift(left, right, s);  in redistribute3()
378 			ret = shift(left, center, s);  in redistribute3()
394 			ret = shift(left, right, s);  in redistribute3()
404 		ret = shift(left, center, nr_left - target_left);  in redistribute3()
417 	struct btree_node *left = l->n;  in __rebalance3()  local
421 	uint32_t nr_left = le32_to_cpu(left->header.nr_entries);  in __rebalance3()
425 	unsigned threshold = merge_threshold(left) * 4 + 1;  in __rebalance3()
427 	if ((left->header.max_entries != center->header.max_entries) ||  in __rebalance3()
434 		return delete_center_node(info, parent, l, c, r, left, center, right,  in __rebalance3()
438 	return redistribute3(info, parent, l, c, r, left, center, right,  in __rebalance3()
447 	struct child left, center, right;  in rebalance3()  local
452 	r = init_child(info, vt, parent, left_index, &left);  in rebalance3()
458 		exit_child(info, &left);  in rebalance3()
464 		exit_child(info, &left);  in rebalance3()
469 	r = __rebalance3(info, parent, &left, &center, &right);  in rebalance3()
471 	exit_child(info, &left);  in rebalance3()