29  * Each node may have a left or right sibling.  When decending the spine,
37  *     ==> rebalance(node, right sibling)
39  * [C] No right sibling
42  * [D] Both siblings, total_entries(left, node, right) <= DEL_THRESHOLD
43  *     ==> delete node adding it's contents to left and right
45  * [E] Both siblings, total_entries(left, node, right) > DEL_THRESHOLD
46  *     ==> rebalance(left, node, right)
86 static int node_copy(struct btree_node *left, struct btree_node *right, int shift)  in node_copy()  argument
91 	if (value_size != le32_to_cpu(right->header.value_size)) {  in node_copy()
105 		       key_ptr(right, 0),  in node_copy()
108 		       value_ptr(right, 0),  in node_copy()
111 		if (shift > le32_to_cpu(right->header.max_entries)) {  in node_copy()
116 		memcpy(key_ptr(right, 0),  in node_copy()
119 		memcpy(value_ptr(right, 0),  in node_copy()
192 static int shift(struct btree_node *left, struct btree_node *right, int count)  in shift()  argument
196 	uint32_t nr_right = le32_to_cpu(right->header.nr_entries);  in shift()
198 	uint32_t r_max_entries = le32_to_cpu(right->header.max_entries);  in shift()
219 		node_shift(right, count);  in shift()
220 		r = node_copy(left, right, count);  in shift()
224 		r = node_copy(left, right, count);  in shift()
227 		node_shift(right, count);  in shift()
231 	right->header.nr_entries = cpu_to_le32(nr_right + count);  in shift()
241 	struct btree_node *right = r->n;  in __rebalance2()  local
243 	uint32_t nr_right = le32_to_cpu(right->header.nr_entries);  in __rebalance2()
256 		node_copy(left, right, -nr_right);  in __rebalance2()
261 		 * We need to decrement the right block, but not it's  in __rebalance2()
271 		ret = shift(left, right, nr_left - target_left);  in __rebalance2()
274 		*key_ptr(parent, r->index) = right->keys[0];  in __rebalance2()
284 	struct child left, right;  in rebalance2()  local
292 	r = init_child(info, vt, parent, left_index + 1, &right);  in rebalance2()
298 	r = __rebalance2(info, parent, &left, &right);  in rebalance2()
301 	exit_child(info, &right);  in rebalance2()
308  * in right, then rebalance2.  This wastes some cpu, but I want something
313 			      struct btree_node *left, struct btree_node *center, struct btree_node *right,  in delete_center_node()  argument
335 		node_shift(right, shift);  in delete_center_node()
336 		node_copy(center, right, shift);  in delete_center_node()
337 		right->header.nr_entries = cpu_to_le32(nr_right + shift);  in delete_center_node()
339 	*key_ptr(parent, r->index) = right->keys[0];  in delete_center_node()
353 			 struct btree_node *left, struct btree_node *center, struct btree_node *right,  in redistribute3()  argument
376 			ret = shift(left, right, s);  in redistribute3()
387 		ret = shift(center, right, target_right - nr_right);  in redistribute3()
394 			ret = shift(center, right, nr_center);  in redistribute3()
398 			ret = shift(left, right, s);  in redistribute3()
403 			ret = shift(center, right, s);  in redistribute3()
414 	*key_ptr(parent, r->index) = right->keys[0];  in redistribute3()
423 	struct btree_node *right = r->n;  in __rebalance3()  local
427 	uint32_t nr_right = le32_to_cpu(right->header.nr_entries);  in __rebalance3()
432 	    (center->header.max_entries != right->header.max_entries)) {  in __rebalance3()
438 		return delete_center_node(info, parent, l, c, r, left, center, right,  in __rebalance3()
442 	return redistribute3(info, parent, l, c, r, left, center, right,  in __rebalance3()
451 	struct child left, center, right;  in rebalance3()  local
466 	r = init_child(info, vt, parent, left_index + 2, &right);  in rebalance3()
473 	r = __rebalance3(info, parent, &left, &center, &right);  in rebalance3()
477 	exit_child(info, &right);  in rebalance3()