25  * Each node may have a left or right sibling.  When decending the spine,
32  * [B] No left sibling
36  *     ==> rebalance(left sibling, node)
38  * [D] Both siblings, total_entries(left, node, right) <= DEL_THRESHOLD
39  *     ==> delete node adding it's contents to left and right
41  * [E] Both siblings, total_entries(left, node, right) > DEL_THRESHOLD
42  *     ==> rebalance(left, node, right)
82 static void node_copy(struct btree_node *left, struct btree_node *right, int shift)  in node_copy()  argument
84 	uint32_t nr_left = le32_to_cpu(left->header.nr_entries);  in node_copy()
85 	uint32_t value_size = le32_to_cpu(left->header.value_size);  in node_copy()
90 		BUG_ON(nr_left + shift > le32_to_cpu(left->header.max_entries));  in node_copy()
91 		memcpy(key_ptr(left, nr_left),  in node_copy()
94 		memcpy(value_ptr(left, nr_left),  in node_copy()
100 		       key_ptr(left, nr_left - shift),  in node_copy()
103 		       value_ptr(left, nr_left - shift),  in node_copy()
173 static void shift(struct btree_node *left, struct btree_node *right, int count)  in shift()  argument
175 	uint32_t nr_left = le32_to_cpu(left->header.nr_entries);  in shift()
177 	uint32_t max_entries = le32_to_cpu(left->header.max_entries);  in shift()
189 		node_copy(left, right, count);  in shift()
191 		node_copy(left, right, count);  in shift()
195 	left->header.nr_entries = cpu_to_le32(nr_left - count);  in shift()
202 	struct btree_node *left = l->n;  in __rebalance2()  local
204 	uint32_t nr_left = le32_to_cpu(left->header.nr_entries);  in __rebalance2()
212 	unsigned int threshold = 2 * (merge_threshold(left) + 1);  in __rebalance2()
218 		node_copy(left, right, -nr_right);  in __rebalance2()
219 		left->header.nr_entries = cpu_to_le32(nr_left + nr_right);  in __rebalance2()
224 		 * children, since they're still referenced by left.  in __rebalance2()
232 		shift(left, right, nr_left - target_left);  in __rebalance2()
242 	struct child left, right;  in rebalance2()  local
246 	r = init_child(info, vt, parent, left_index, &left);  in rebalance2()
252 		exit_child(info, &left);  in rebalance2()
256 	__rebalance2(info, parent, &left, &right);  in rebalance2()
258 	exit_child(info, &left);  in rebalance2()
265  * We dump as many entries from center as possible into left, then the rest
271 			       struct btree_node *left, struct btree_node *center, struct btree_node *right,  in delete_center_node()  argument
274 	uint32_t max_entries = le32_to_cpu(left->header.max_entries);  in delete_center_node()
278 	node_copy(left, center, -shift);  in delete_center_node()
279 	left->header.nr_entries = cpu_to_le32(nr_left + shift);  in delete_center_node()
302 			  struct btree_node *left, struct btree_node *center, struct btree_node *right,  in redistribute3()  argument
306 	uint32_t max_entries = le32_to_cpu(left->header.max_entries);  in redistribute3()
320 			shift(left, center, -nr_center);  in redistribute3()
322 			shift(left, right, s);  in redistribute3()
325 			shift(left, center, s);  in redistribute3()
335 			shift(left, right, s);  in redistribute3()
340 		shift(left, center, nr_left - target_left);  in redistribute3()
350 	struct btree_node *left = l->n;  in __rebalance3()  local
354 	uint32_t nr_left = le32_to_cpu(left->header.nr_entries);  in __rebalance3()
358 	unsigned threshold = merge_threshold(left) * 4 + 1;  in __rebalance3()
360 	BUG_ON(left->header.max_entries != center->header.max_entries);  in __rebalance3()
364 		delete_center_node(info, parent, l, c, r, left, center, right,  in __rebalance3()
367 		redistribute3(info, parent, l, c, r, left, center, right,  in __rebalance3()
376 	struct child left, center, right;  in rebalance3()  local
381 	r = init_child(info, vt, parent, left_index, &left);  in rebalance3()
387 		exit_child(info, &left);  in rebalance3()
393 		exit_child(info, &left);  in rebalance3()
398 	__rebalance3(info, parent, &left, &center, &right);  in rebalance3()
400 	exit_child(info, &left);  in rebalance3()