1 /*
2  * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
3  */
4 
5 #include <linux/uaccess.h>
6 #include <linux/string.h>
7 #include <linux/time.h>
8 #include "reiserfs.h"
9 #include <linux/buffer_head.h>
10 
11 /* this is one and only function that is used outside (do_balance.c) */
12 int balance_internal(struct tree_balance *,
13 		     int, int, struct item_head *, struct buffer_head **);
14 
15 /*
16  * modes of internal_shift_left, internal_shift_right and
17  * internal_insert_childs
18  */
19 #define INTERNAL_SHIFT_FROM_S_TO_L 0
20 #define INTERNAL_SHIFT_FROM_R_TO_S 1
21 #define INTERNAL_SHIFT_FROM_L_TO_S 2
22 #define INTERNAL_SHIFT_FROM_S_TO_R 3
23 #define INTERNAL_INSERT_TO_S 4
24 #define INTERNAL_INSERT_TO_L 5
25 #define INTERNAL_INSERT_TO_R 6
26 
internal_define_dest_src_infos(int shift_mode,struct tree_balance * tb,int h,struct buffer_info * dest_bi,struct buffer_info * src_bi,int * d_key,struct buffer_head ** cf)27 static void internal_define_dest_src_infos(int shift_mode,
28 					   struct tree_balance *tb,
29 					   int h,
30 					   struct buffer_info *dest_bi,
31 					   struct buffer_info *src_bi,
32 					   int *d_key, struct buffer_head **cf)
33 {
34 	memset(dest_bi, 0, sizeof(struct buffer_info));
35 	memset(src_bi, 0, sizeof(struct buffer_info));
36 	/* define dest, src, dest parent, dest position */
37 	switch (shift_mode) {
38 
39 	/* used in internal_shift_left */
40 	case INTERNAL_SHIFT_FROM_S_TO_L:
41 		src_bi->tb = tb;
42 		src_bi->bi_bh = PATH_H_PBUFFER(tb->tb_path, h);
43 		src_bi->bi_parent = PATH_H_PPARENT(tb->tb_path, h);
44 		src_bi->bi_position = PATH_H_POSITION(tb->tb_path, h + 1);
45 		dest_bi->tb = tb;
46 		dest_bi->bi_bh = tb->L[h];
47 		dest_bi->bi_parent = tb->FL[h];
48 		dest_bi->bi_position = get_left_neighbor_position(tb, h);
49 		*d_key = tb->lkey[h];
50 		*cf = tb->CFL[h];
51 		break;
52 	case INTERNAL_SHIFT_FROM_L_TO_S:
53 		src_bi->tb = tb;
54 		src_bi->bi_bh = tb->L[h];
55 		src_bi->bi_parent = tb->FL[h];
56 		src_bi->bi_position = get_left_neighbor_position(tb, h);
57 		dest_bi->tb = tb;
58 		dest_bi->bi_bh = PATH_H_PBUFFER(tb->tb_path, h);
59 		dest_bi->bi_parent = PATH_H_PPARENT(tb->tb_path, h);
60 		/* dest position is analog of dest->b_item_order */
61 		dest_bi->bi_position = PATH_H_POSITION(tb->tb_path, h + 1);
62 		*d_key = tb->lkey[h];
63 		*cf = tb->CFL[h];
64 		break;
65 
66 	/* used in internal_shift_left */
67 	case INTERNAL_SHIFT_FROM_R_TO_S:
68 		src_bi->tb = tb;
69 		src_bi->bi_bh = tb->R[h];
70 		src_bi->bi_parent = tb->FR[h];
71 		src_bi->bi_position = get_right_neighbor_position(tb, h);
72 		dest_bi->tb = tb;
73 		dest_bi->bi_bh = PATH_H_PBUFFER(tb->tb_path, h);
74 		dest_bi->bi_parent = PATH_H_PPARENT(tb->tb_path, h);
75 		dest_bi->bi_position = PATH_H_POSITION(tb->tb_path, h + 1);
76 		*d_key = tb->rkey[h];
77 		*cf = tb->CFR[h];
78 		break;
79 
80 	case INTERNAL_SHIFT_FROM_S_TO_R:
81 		src_bi->tb = tb;
82 		src_bi->bi_bh = PATH_H_PBUFFER(tb->tb_path, h);
83 		src_bi->bi_parent = PATH_H_PPARENT(tb->tb_path, h);
84 		src_bi->bi_position = PATH_H_POSITION(tb->tb_path, h + 1);
85 		dest_bi->tb = tb;
86 		dest_bi->bi_bh = tb->R[h];
87 		dest_bi->bi_parent = tb->FR[h];
88 		dest_bi->bi_position = get_right_neighbor_position(tb, h);
89 		*d_key = tb->rkey[h];
90 		*cf = tb->CFR[h];
91 		break;
92 
93 	case INTERNAL_INSERT_TO_L:
94 		dest_bi->tb = tb;
95 		dest_bi->bi_bh = tb->L[h];
96 		dest_bi->bi_parent = tb->FL[h];
97 		dest_bi->bi_position = get_left_neighbor_position(tb, h);
98 		break;
99 
100 	case INTERNAL_INSERT_TO_S:
101 		dest_bi->tb = tb;
102 		dest_bi->bi_bh = PATH_H_PBUFFER(tb->tb_path, h);
103 		dest_bi->bi_parent = PATH_H_PPARENT(tb->tb_path, h);
104 		dest_bi->bi_position = PATH_H_POSITION(tb->tb_path, h + 1);
105 		break;
106 
107 	case INTERNAL_INSERT_TO_R:
108 		dest_bi->tb = tb;
109 		dest_bi->bi_bh = tb->R[h];
110 		dest_bi->bi_parent = tb->FR[h];
111 		dest_bi->bi_position = get_right_neighbor_position(tb, h);
112 		break;
113 
114 	default:
115 		reiserfs_panic(tb->tb_sb, "ibalance-1",
116 			       "shift type is unknown (%d)",
117 			       shift_mode);
118 	}
119 }
120 
121 /*
122  * Insert count node pointers into buffer cur before position to + 1.
123  * Insert count items into buffer cur before position to.
124  * Items and node pointers are specified by inserted and bh respectively.
125  */
internal_insert_childs(struct buffer_info * cur_bi,int to,int count,struct item_head * inserted,struct buffer_head ** bh)126 static void internal_insert_childs(struct buffer_info *cur_bi,
127 				   int to, int count,
128 				   struct item_head *inserted,
129 				   struct buffer_head **bh)
130 {
131 	struct buffer_head *cur = cur_bi->bi_bh;
132 	struct block_head *blkh;
133 	int nr;
134 	struct reiserfs_key *ih;
135 	struct disk_child new_dc[2];
136 	struct disk_child *dc;
137 	int i;
138 
139 	if (count <= 0)
140 		return;
141 
142 	blkh = B_BLK_HEAD(cur);
143 	nr = blkh_nr_item(blkh);
144 
145 	RFALSE(count > 2, "too many children (%d) are to be inserted", count);
146 	RFALSE(B_FREE_SPACE(cur) < count * (KEY_SIZE + DC_SIZE),
147 	       "no enough free space (%d), needed %d bytes",
148 	       B_FREE_SPACE(cur), count * (KEY_SIZE + DC_SIZE));
149 
150 	/* prepare space for count disk_child */
151 	dc = B_N_CHILD(cur, to + 1);
152 
153 	memmove(dc + count, dc, (nr + 1 - (to + 1)) * DC_SIZE);
154 
155 	/* copy to_be_insert disk children */
156 	for (i = 0; i < count; i++) {
157 		put_dc_size(&new_dc[i],
158 			    MAX_CHILD_SIZE(bh[i]) - B_FREE_SPACE(bh[i]));
159 		put_dc_block_number(&new_dc[i], bh[i]->b_blocknr);
160 	}
161 	memcpy(dc, new_dc, DC_SIZE * count);
162 
163 	/* prepare space for count items  */
164 	ih = internal_key(cur, ((to == -1) ? 0 : to));
165 
166 	memmove(ih + count, ih,
167 		(nr - to) * KEY_SIZE + (nr + 1 + count) * DC_SIZE);
168 
169 	/* copy item headers (keys) */
170 	memcpy(ih, inserted, KEY_SIZE);
171 	if (count > 1)
172 		memcpy(ih + 1, inserted + 1, KEY_SIZE);
173 
174 	/* sizes, item number */
175 	set_blkh_nr_item(blkh, blkh_nr_item(blkh) + count);
176 	set_blkh_free_space(blkh,
177 			    blkh_free_space(blkh) - count * (DC_SIZE +
178 							     KEY_SIZE));
179 
180 	do_balance_mark_internal_dirty(cur_bi->tb, cur, 0);
181 
182 	/*&&&&&&&&&&&&&&&&&&&&&&&& */
183 	check_internal(cur);
184 	/*&&&&&&&&&&&&&&&&&&&&&&&& */
185 
186 	if (cur_bi->bi_parent) {
187 		struct disk_child *t_dc =
188 		    B_N_CHILD(cur_bi->bi_parent, cur_bi->bi_position);
189 		put_dc_size(t_dc,
190 			    dc_size(t_dc) + (count * (DC_SIZE + KEY_SIZE)));
191 		do_balance_mark_internal_dirty(cur_bi->tb, cur_bi->bi_parent,
192 					       0);
193 
194 		/*&&&&&&&&&&&&&&&&&&&&&&&& */
195 		check_internal(cur_bi->bi_parent);
196 		/*&&&&&&&&&&&&&&&&&&&&&&&& */
197 	}
198 
199 }
200 
201 /*
202  * Delete del_num items and node pointers from buffer cur starting from
203  * the first_i'th item and first_p'th pointers respectively.
204  */
internal_delete_pointers_items(struct buffer_info * cur_bi,int first_p,int first_i,int del_num)205 static void internal_delete_pointers_items(struct buffer_info *cur_bi,
206 					   int first_p,
207 					   int first_i, int del_num)
208 {
209 	struct buffer_head *cur = cur_bi->bi_bh;
210 	int nr;
211 	struct block_head *blkh;
212 	struct reiserfs_key *key;
213 	struct disk_child *dc;
214 
215 	RFALSE(cur == NULL, "buffer is 0");
216 	RFALSE(del_num < 0,
217 	       "negative number of items (%d) can not be deleted", del_num);
218 	RFALSE(first_p < 0 || first_p + del_num > B_NR_ITEMS(cur) + 1
219 	       || first_i < 0,
220 	       "first pointer order (%d) < 0 or "
221 	       "no so many pointers (%d), only (%d) or "
222 	       "first key order %d < 0", first_p, first_p + del_num,
223 	       B_NR_ITEMS(cur) + 1, first_i);
224 	if (del_num == 0)
225 		return;
226 
227 	blkh = B_BLK_HEAD(cur);
228 	nr = blkh_nr_item(blkh);
229 
230 	if (first_p == 0 && del_num == nr + 1) {
231 		RFALSE(first_i != 0,
232 		       "1st deleted key must have order 0, not %d", first_i);
233 		make_empty_node(cur_bi);
234 		return;
235 	}
236 
237 	RFALSE(first_i + del_num > B_NR_ITEMS(cur),
238 	       "first_i = %d del_num = %d "
239 	       "no so many keys (%d) in the node (%b)(%z)",
240 	       first_i, del_num, first_i + del_num, cur, cur);
241 
242 	/* deleting */
243 	dc = B_N_CHILD(cur, first_p);
244 
245 	memmove(dc, dc + del_num, (nr + 1 - first_p - del_num) * DC_SIZE);
246 	key = internal_key(cur, first_i);
247 	memmove(key, key + del_num,
248 		(nr - first_i - del_num) * KEY_SIZE + (nr + 1 -
249 						       del_num) * DC_SIZE);
250 
251 	/* sizes, item number */
252 	set_blkh_nr_item(blkh, blkh_nr_item(blkh) - del_num);
253 	set_blkh_free_space(blkh,
254 			    blkh_free_space(blkh) +
255 			    (del_num * (KEY_SIZE + DC_SIZE)));
256 
257 	do_balance_mark_internal_dirty(cur_bi->tb, cur, 0);
258 	/*&&&&&&&&&&&&&&&&&&&&&&& */
259 	check_internal(cur);
260 	/*&&&&&&&&&&&&&&&&&&&&&&& */
261 
262 	if (cur_bi->bi_parent) {
263 		struct disk_child *t_dc;
264 		t_dc = B_N_CHILD(cur_bi->bi_parent, cur_bi->bi_position);
265 		put_dc_size(t_dc,
266 			    dc_size(t_dc) - (del_num * (KEY_SIZE + DC_SIZE)));
267 
268 		do_balance_mark_internal_dirty(cur_bi->tb, cur_bi->bi_parent,
269 					       0);
270 		/*&&&&&&&&&&&&&&&&&&&&&&&& */
271 		check_internal(cur_bi->bi_parent);
272 		/*&&&&&&&&&&&&&&&&&&&&&&&& */
273 	}
274 }
275 
276 /* delete n node pointers and items starting from given position */
internal_delete_childs(struct buffer_info * cur_bi,int from,int n)277 static void internal_delete_childs(struct buffer_info *cur_bi, int from, int n)
278 {
279 	int i_from;
280 
281 	i_from = (from == 0) ? from : from - 1;
282 
283 	/*
284 	 * delete n pointers starting from `from' position in CUR;
285 	 * delete n keys starting from 'i_from' position in CUR;
286 	 */
287 	internal_delete_pointers_items(cur_bi, from, i_from, n);
288 }
289 
290 /*
291  * copy cpy_num node pointers and cpy_num - 1 items from buffer src to buffer
292  * dest
293  * last_first == FIRST_TO_LAST means that we copy first items
294  *                             from src to tail of dest
295  * last_first == LAST_TO_FIRST means that we copy last items
296  *                             from src to head of dest
297  */
internal_copy_pointers_items(struct buffer_info * dest_bi,struct buffer_head * src,int last_first,int cpy_num)298 static void internal_copy_pointers_items(struct buffer_info *dest_bi,
299 					 struct buffer_head *src,
300 					 int last_first, int cpy_num)
301 {
302 	/*
303 	 * ATTENTION! Number of node pointers in DEST is equal to number
304 	 * of items in DEST  as delimiting key have already inserted to
305 	 * buffer dest.
306 	 */
307 	struct buffer_head *dest = dest_bi->bi_bh;
308 	int nr_dest, nr_src;
309 	int dest_order, src_order;
310 	struct block_head *blkh;
311 	struct reiserfs_key *key;
312 	struct disk_child *dc;
313 
314 	nr_src = B_NR_ITEMS(src);
315 
316 	RFALSE(dest == NULL || src == NULL,
317 	       "src (%p) or dest (%p) buffer is 0", src, dest);
318 	RFALSE(last_first != FIRST_TO_LAST && last_first != LAST_TO_FIRST,
319 	       "invalid last_first parameter (%d)", last_first);
320 	RFALSE(nr_src < cpy_num - 1,
321 	       "no so many items (%d) in src (%d)", cpy_num, nr_src);
322 	RFALSE(cpy_num < 0, "cpy_num less than 0 (%d)", cpy_num);
323 	RFALSE(cpy_num - 1 + B_NR_ITEMS(dest) > (int)MAX_NR_KEY(dest),
324 	       "cpy_num (%d) + item number in dest (%d) can not be > MAX_NR_KEY(%d)",
325 	       cpy_num, B_NR_ITEMS(dest), MAX_NR_KEY(dest));
326 
327 	if (cpy_num == 0)
328 		return;
329 
330 	/* coping */
331 	blkh = B_BLK_HEAD(dest);
332 	nr_dest = blkh_nr_item(blkh);
333 
334 	/*dest_order = (last_first == LAST_TO_FIRST) ? 0 : nr_dest; */
335 	/*src_order = (last_first == LAST_TO_FIRST) ? (nr_src - cpy_num + 1) : 0; */
336 	(last_first == LAST_TO_FIRST) ? (dest_order = 0, src_order =
337 					 nr_src - cpy_num + 1) : (dest_order =
338 								  nr_dest,
339 								  src_order =
340 								  0);
341 
342 	/* prepare space for cpy_num pointers */
343 	dc = B_N_CHILD(dest, dest_order);
344 
345 	memmove(dc + cpy_num, dc, (nr_dest - dest_order) * DC_SIZE);
346 
347 	/* insert pointers */
348 	memcpy(dc, B_N_CHILD(src, src_order), DC_SIZE * cpy_num);
349 
350 	/* prepare space for cpy_num - 1 item headers */
351 	key = internal_key(dest, dest_order);
352 	memmove(key + cpy_num - 1, key,
353 		KEY_SIZE * (nr_dest - dest_order) + DC_SIZE * (nr_dest +
354 							       cpy_num));
355 
356 	/* insert headers */
357 	memcpy(key, internal_key(src, src_order), KEY_SIZE * (cpy_num - 1));
358 
359 	/* sizes, item number */
360 	set_blkh_nr_item(blkh, blkh_nr_item(blkh) + (cpy_num - 1));
361 	set_blkh_free_space(blkh,
362 			    blkh_free_space(blkh) - (KEY_SIZE * (cpy_num - 1) +
363 						     DC_SIZE * cpy_num));
364 
365 	do_balance_mark_internal_dirty(dest_bi->tb, dest, 0);
366 
367 	/*&&&&&&&&&&&&&&&&&&&&&&&& */
368 	check_internal(dest);
369 	/*&&&&&&&&&&&&&&&&&&&&&&&& */
370 
371 	if (dest_bi->bi_parent) {
372 		struct disk_child *t_dc;
373 		t_dc = B_N_CHILD(dest_bi->bi_parent, dest_bi->bi_position);
374 		put_dc_size(t_dc,
375 			    dc_size(t_dc) + (KEY_SIZE * (cpy_num - 1) +
376 					     DC_SIZE * cpy_num));
377 
378 		do_balance_mark_internal_dirty(dest_bi->tb, dest_bi->bi_parent,
379 					       0);
380 		/*&&&&&&&&&&&&&&&&&&&&&&&& */
381 		check_internal(dest_bi->bi_parent);
382 		/*&&&&&&&&&&&&&&&&&&&&&&&& */
383 	}
384 
385 }
386 
387 /*
388  * Copy cpy_num node pointers and cpy_num - 1 items from buffer src to
389  * buffer dest.
390  * Delete cpy_num - del_par items and node pointers from buffer src.
391  * last_first == FIRST_TO_LAST means, that we copy/delete first items from src.
392  * last_first == LAST_TO_FIRST means, that we copy/delete last items from src.
393  */
internal_move_pointers_items(struct buffer_info * dest_bi,struct buffer_info * src_bi,int last_first,int cpy_num,int del_par)394 static void internal_move_pointers_items(struct buffer_info *dest_bi,
395 					 struct buffer_info *src_bi,
396 					 int last_first, int cpy_num,
397 					 int del_par)
398 {
399 	int first_pointer;
400 	int first_item;
401 
402 	internal_copy_pointers_items(dest_bi, src_bi->bi_bh, last_first,
403 				     cpy_num);
404 
405 	if (last_first == FIRST_TO_LAST) {	/* shift_left occurs */
406 		first_pointer = 0;
407 		first_item = 0;
408 		/*
409 		 * delete cpy_num - del_par pointers and keys starting for
410 		 * pointers with first_pointer, for key - with first_item
411 		 */
412 		internal_delete_pointers_items(src_bi, first_pointer,
413 					       first_item, cpy_num - del_par);
414 	} else {		/* shift_right occurs */
415 		int i, j;
416 
417 		i = (cpy_num - del_par ==
418 		     (j =
419 		      B_NR_ITEMS(src_bi->bi_bh)) + 1) ? 0 : j - cpy_num +
420 		    del_par;
421 
422 		internal_delete_pointers_items(src_bi,
423 					       j + 1 - cpy_num + del_par, i,
424 					       cpy_num - del_par);
425 	}
426 }
427 
428 /* Insert n_src'th key of buffer src before n_dest'th key of buffer dest. */
internal_insert_key(struct buffer_info * dest_bi,int dest_position_before,struct buffer_head * src,int src_position)429 static void internal_insert_key(struct buffer_info *dest_bi,
430 				/* insert key before key with n_dest number */
431 				int dest_position_before,
432 				struct buffer_head *src, int src_position)
433 {
434 	struct buffer_head *dest = dest_bi->bi_bh;
435 	int nr;
436 	struct block_head *blkh;
437 	struct reiserfs_key *key;
438 
439 	RFALSE(dest == NULL || src == NULL,
440 	       "source(%p) or dest(%p) buffer is 0", src, dest);
441 	RFALSE(dest_position_before < 0 || src_position < 0,
442 	       "source(%d) or dest(%d) key number less than 0",
443 	       src_position, dest_position_before);
444 	RFALSE(dest_position_before > B_NR_ITEMS(dest) ||
445 	       src_position >= B_NR_ITEMS(src),
446 	       "invalid position in dest (%d (key number %d)) or in src (%d (key number %d))",
447 	       dest_position_before, B_NR_ITEMS(dest),
448 	       src_position, B_NR_ITEMS(src));
449 	RFALSE(B_FREE_SPACE(dest) < KEY_SIZE,
450 	       "no enough free space (%d) in dest buffer", B_FREE_SPACE(dest));
451 
452 	blkh = B_BLK_HEAD(dest);
453 	nr = blkh_nr_item(blkh);
454 
455 	/* prepare space for inserting key */
456 	key = internal_key(dest, dest_position_before);
457 	memmove(key + 1, key,
458 		(nr - dest_position_before) * KEY_SIZE + (nr + 1) * DC_SIZE);
459 
460 	/* insert key */
461 	memcpy(key, internal_key(src, src_position), KEY_SIZE);
462 
463 	/* Change dirt, free space, item number fields. */
464 
465 	set_blkh_nr_item(blkh, blkh_nr_item(blkh) + 1);
466 	set_blkh_free_space(blkh, blkh_free_space(blkh) - KEY_SIZE);
467 
468 	do_balance_mark_internal_dirty(dest_bi->tb, dest, 0);
469 
470 	if (dest_bi->bi_parent) {
471 		struct disk_child *t_dc;
472 		t_dc = B_N_CHILD(dest_bi->bi_parent, dest_bi->bi_position);
473 		put_dc_size(t_dc, dc_size(t_dc) + KEY_SIZE);
474 
475 		do_balance_mark_internal_dirty(dest_bi->tb, dest_bi->bi_parent,
476 					       0);
477 	}
478 }
479 
480 /*
481  * Insert d_key'th (delimiting) key from buffer cfl to tail of dest.
482  * Copy pointer_amount node pointers and pointer_amount - 1 items from
483  * buffer src to buffer dest.
484  * Replace  d_key'th key in buffer cfl.
485  * Delete pointer_amount items and node pointers from buffer src.
486  */
487 /* this can be invoked both to shift from S to L and from R to S */
internal_shift_left(int mode,struct tree_balance * tb,int h,int pointer_amount)488 static void internal_shift_left(
489 				/*
490 				 * INTERNAL_FROM_S_TO_L | INTERNAL_FROM_R_TO_S
491 				 */
492 				int mode,
493 				struct tree_balance *tb,
494 				int h, int pointer_amount)
495 {
496 	struct buffer_info dest_bi, src_bi;
497 	struct buffer_head *cf;
498 	int d_key_position;
499 
500 	internal_define_dest_src_infos(mode, tb, h, &dest_bi, &src_bi,
501 				       &d_key_position, &cf);
502 
503 	/*printk("pointer_amount = %d\n",pointer_amount); */
504 
505 	if (pointer_amount) {
506 		/*
507 		 * insert delimiting key from common father of dest and
508 		 * src to node dest into position B_NR_ITEM(dest)
509 		 */
510 		internal_insert_key(&dest_bi, B_NR_ITEMS(dest_bi.bi_bh), cf,
511 				    d_key_position);
512 
513 		if (B_NR_ITEMS(src_bi.bi_bh) == pointer_amount - 1) {
514 			if (src_bi.bi_position /*src->b_item_order */  == 0)
515 				replace_key(tb, cf, d_key_position,
516 					    src_bi.
517 					    bi_parent /*src->b_parent */ , 0);
518 		} else
519 			replace_key(tb, cf, d_key_position, src_bi.bi_bh,
520 				    pointer_amount - 1);
521 	}
522 	/* last parameter is del_parameter */
523 	internal_move_pointers_items(&dest_bi, &src_bi, FIRST_TO_LAST,
524 				     pointer_amount, 0);
525 
526 }
527 
528 /*
529  * Insert delimiting key to L[h].
530  * Copy n node pointers and n - 1 items from buffer S[h] to L[h].
531  * Delete n - 1 items and node pointers from buffer S[h].
532  */
533 /* it always shifts from S[h] to L[h] */
internal_shift1_left(struct tree_balance * tb,int h,int pointer_amount)534 static void internal_shift1_left(struct tree_balance *tb,
535 				 int h, int pointer_amount)
536 {
537 	struct buffer_info dest_bi, src_bi;
538 	struct buffer_head *cf;
539 	int d_key_position;
540 
541 	internal_define_dest_src_infos(INTERNAL_SHIFT_FROM_S_TO_L, tb, h,
542 				       &dest_bi, &src_bi, &d_key_position, &cf);
543 
544 	/* insert lkey[h]-th key  from CFL[h] to left neighbor L[h] */
545 	if (pointer_amount > 0)
546 		internal_insert_key(&dest_bi, B_NR_ITEMS(dest_bi.bi_bh), cf,
547 				    d_key_position);
548 
549 	/* last parameter is del_parameter */
550 	internal_move_pointers_items(&dest_bi, &src_bi, FIRST_TO_LAST,
551 				     pointer_amount, 1);
552 }
553 
554 /*
555  * Insert d_key'th (delimiting) key from buffer cfr to head of dest.
556  * Copy n node pointers and n - 1 items from buffer src to buffer dest.
557  * Replace  d_key'th key in buffer cfr.
558  * Delete n items and node pointers from buffer src.
559  */
internal_shift_right(int mode,struct tree_balance * tb,int h,int pointer_amount)560 static void internal_shift_right(
561 				 /*
562 				  * INTERNAL_FROM_S_TO_R | INTERNAL_FROM_L_TO_S
563 				  */
564 				 int mode,
565 				 struct tree_balance *tb,
566 				 int h, int pointer_amount)
567 {
568 	struct buffer_info dest_bi, src_bi;
569 	struct buffer_head *cf;
570 	int d_key_position;
571 	int nr;
572 
573 	internal_define_dest_src_infos(mode, tb, h, &dest_bi, &src_bi,
574 				       &d_key_position, &cf);
575 
576 	nr = B_NR_ITEMS(src_bi.bi_bh);
577 
578 	if (pointer_amount > 0) {
579 		/*
580 		 * insert delimiting key from common father of dest
581 		 * and src to dest node into position 0
582 		 */
583 		internal_insert_key(&dest_bi, 0, cf, d_key_position);
584 		if (nr == pointer_amount - 1) {
585 			RFALSE(src_bi.bi_bh != PATH_H_PBUFFER(tb->tb_path, h) /*tb->S[h] */ ||
586 			       dest_bi.bi_bh != tb->R[h],
587 			       "src (%p) must be == tb->S[h](%p) when it disappears",
588 			       src_bi.bi_bh, PATH_H_PBUFFER(tb->tb_path, h));
589 			/* when S[h] disappers replace left delemiting key as well */
590 			if (tb->CFL[h])
591 				replace_key(tb, cf, d_key_position, tb->CFL[h],
592 					    tb->lkey[h]);
593 		} else
594 			replace_key(tb, cf, d_key_position, src_bi.bi_bh,
595 				    nr - pointer_amount);
596 	}
597 
598 	/* last parameter is del_parameter */
599 	internal_move_pointers_items(&dest_bi, &src_bi, LAST_TO_FIRST,
600 				     pointer_amount, 0);
601 }
602 
603 /*
604  * Insert delimiting key to R[h].
605  * Copy n node pointers and n - 1 items from buffer S[h] to R[h].
606  * Delete n - 1 items and node pointers from buffer S[h].
607  */
608 /* it always shift from S[h] to R[h] */
internal_shift1_right(struct tree_balance * tb,int h,int pointer_amount)609 static void internal_shift1_right(struct tree_balance *tb,
610 				  int h, int pointer_amount)
611 {
612 	struct buffer_info dest_bi, src_bi;
613 	struct buffer_head *cf;
614 	int d_key_position;
615 
616 	internal_define_dest_src_infos(INTERNAL_SHIFT_FROM_S_TO_R, tb, h,
617 				       &dest_bi, &src_bi, &d_key_position, &cf);
618 
619 	/* insert rkey from CFR[h] to right neighbor R[h] */
620 	if (pointer_amount > 0)
621 		internal_insert_key(&dest_bi, 0, cf, d_key_position);
622 
623 	/* last parameter is del_parameter */
624 	internal_move_pointers_items(&dest_bi, &src_bi, LAST_TO_FIRST,
625 				     pointer_amount, 1);
626 }
627 
628 /*
629  * Delete insert_num node pointers together with their left items
630  * and balance current node.
631  */
balance_internal_when_delete(struct tree_balance * tb,int h,int child_pos)632 static void balance_internal_when_delete(struct tree_balance *tb,
633 					 int h, int child_pos)
634 {
635 	int insert_num;
636 	int n;
637 	struct buffer_head *tbSh = PATH_H_PBUFFER(tb->tb_path, h);
638 	struct buffer_info bi;
639 
640 	insert_num = tb->insert_size[h] / ((int)(DC_SIZE + KEY_SIZE));
641 
642 	/* delete child-node-pointer(s) together with their left item(s) */
643 	bi.tb = tb;
644 	bi.bi_bh = tbSh;
645 	bi.bi_parent = PATH_H_PPARENT(tb->tb_path, h);
646 	bi.bi_position = PATH_H_POSITION(tb->tb_path, h + 1);
647 
648 	internal_delete_childs(&bi, child_pos, -insert_num);
649 
650 	RFALSE(tb->blknum[h] > 1,
651 	       "tb->blknum[%d]=%d when insert_size < 0", h, tb->blknum[h]);
652 
653 	n = B_NR_ITEMS(tbSh);
654 
655 	if (tb->lnum[h] == 0 && tb->rnum[h] == 0) {
656 		if (tb->blknum[h] == 0) {
657 			/* node S[h] (root of the tree) is empty now */
658 			struct buffer_head *new_root;
659 
660 			RFALSE(n
661 			       || B_FREE_SPACE(tbSh) !=
662 			       MAX_CHILD_SIZE(tbSh) - DC_SIZE,
663 			       "buffer must have only 0 keys (%d)", n);
664 			RFALSE(bi.bi_parent, "root has parent (%p)",
665 			       bi.bi_parent);
666 
667 			/* choose a new root */
668 			if (!tb->L[h - 1] || !B_NR_ITEMS(tb->L[h - 1]))
669 				new_root = tb->R[h - 1];
670 			else
671 				new_root = tb->L[h - 1];
672 			/*
673 			 * switch super block's tree root block
674 			 * number to the new value */
675 			PUT_SB_ROOT_BLOCK(tb->tb_sb, new_root->b_blocknr);
676 			/*REISERFS_SB(tb->tb_sb)->s_rs->s_tree_height --; */
677 			PUT_SB_TREE_HEIGHT(tb->tb_sb,
678 					   SB_TREE_HEIGHT(tb->tb_sb) - 1);
679 
680 			do_balance_mark_sb_dirty(tb,
681 						 REISERFS_SB(tb->tb_sb)->s_sbh,
682 						 1);
683 			/*&&&&&&&&&&&&&&&&&&&&&& */
684 			/* use check_internal if new root is an internal node */
685 			if (h > 1)
686 				check_internal(new_root);
687 			/*&&&&&&&&&&&&&&&&&&&&&& */
688 
689 			/* do what is needed for buffer thrown from tree */
690 			reiserfs_invalidate_buffer(tb, tbSh);
691 			return;
692 		}
693 		return;
694 	}
695 
696 	/* join S[h] with L[h] */
697 	if (tb->L[h] && tb->lnum[h] == -B_NR_ITEMS(tb->L[h]) - 1) {
698 
699 		RFALSE(tb->rnum[h] != 0,
700 		       "invalid tb->rnum[%d]==%d when joining S[h] with L[h]",
701 		       h, tb->rnum[h]);
702 
703 		internal_shift_left(INTERNAL_SHIFT_FROM_S_TO_L, tb, h, n + 1);
704 		reiserfs_invalidate_buffer(tb, tbSh);
705 
706 		return;
707 	}
708 
709 	/* join S[h] with R[h] */
710 	if (tb->R[h] && tb->rnum[h] == -B_NR_ITEMS(tb->R[h]) - 1) {
711 		RFALSE(tb->lnum[h] != 0,
712 		       "invalid tb->lnum[%d]==%d when joining S[h] with R[h]",
713 		       h, tb->lnum[h]);
714 
715 		internal_shift_right(INTERNAL_SHIFT_FROM_S_TO_R, tb, h, n + 1);
716 
717 		reiserfs_invalidate_buffer(tb, tbSh);
718 		return;
719 	}
720 
721 	/* borrow from left neighbor L[h] */
722 	if (tb->lnum[h] < 0) {
723 		RFALSE(tb->rnum[h] != 0,
724 		       "wrong tb->rnum[%d]==%d when borrow from L[h]", h,
725 		       tb->rnum[h]);
726 		internal_shift_right(INTERNAL_SHIFT_FROM_L_TO_S, tb, h,
727 				     -tb->lnum[h]);
728 		return;
729 	}
730 
731 	/* borrow from right neighbor R[h] */
732 	if (tb->rnum[h] < 0) {
733 		RFALSE(tb->lnum[h] != 0,
734 		       "invalid tb->lnum[%d]==%d when borrow from R[h]",
735 		       h, tb->lnum[h]);
736 		internal_shift_left(INTERNAL_SHIFT_FROM_R_TO_S, tb, h, -tb->rnum[h]);	/*tb->S[h], tb->CFR[h], tb->rkey[h], tb->R[h], -tb->rnum[h]); */
737 		return;
738 	}
739 
740 	/* split S[h] into two parts and put them into neighbors */
741 	if (tb->lnum[h] > 0) {
742 		RFALSE(tb->rnum[h] == 0 || tb->lnum[h] + tb->rnum[h] != n + 1,
743 		       "invalid tb->lnum[%d]==%d or tb->rnum[%d]==%d when S[h](item number == %d) is split between them",
744 		       h, tb->lnum[h], h, tb->rnum[h], n);
745 
746 		internal_shift_left(INTERNAL_SHIFT_FROM_S_TO_L, tb, h, tb->lnum[h]);	/*tb->L[h], tb->CFL[h], tb->lkey[h], tb->S[h], tb->lnum[h]); */
747 		internal_shift_right(INTERNAL_SHIFT_FROM_S_TO_R, tb, h,
748 				     tb->rnum[h]);
749 
750 		reiserfs_invalidate_buffer(tb, tbSh);
751 
752 		return;
753 	}
754 	reiserfs_panic(tb->tb_sb, "ibalance-2",
755 		       "unexpected tb->lnum[%d]==%d or tb->rnum[%d]==%d",
756 		       h, tb->lnum[h], h, tb->rnum[h]);
757 }
758 
759 /* Replace delimiting key of buffers L[h] and S[h] by the given key.*/
replace_lkey(struct tree_balance * tb,int h,struct item_head * key)760 static void replace_lkey(struct tree_balance *tb, int h, struct item_head *key)
761 {
762 	RFALSE(tb->L[h] == NULL || tb->CFL[h] == NULL,
763 	       "L[h](%p) and CFL[h](%p) must exist in replace_lkey",
764 	       tb->L[h], tb->CFL[h]);
765 
766 	if (B_NR_ITEMS(PATH_H_PBUFFER(tb->tb_path, h)) == 0)
767 		return;
768 
769 	memcpy(internal_key(tb->CFL[h], tb->lkey[h]), key, KEY_SIZE);
770 
771 	do_balance_mark_internal_dirty(tb, tb->CFL[h], 0);
772 }
773 
774 /* Replace delimiting key of buffers S[h] and R[h] by the given key.*/
replace_rkey(struct tree_balance * tb,int h,struct item_head * key)775 static void replace_rkey(struct tree_balance *tb, int h, struct item_head *key)
776 {
777 	RFALSE(tb->R[h] == NULL || tb->CFR[h] == NULL,
778 	       "R[h](%p) and CFR[h](%p) must exist in replace_rkey",
779 	       tb->R[h], tb->CFR[h]);
780 	RFALSE(B_NR_ITEMS(tb->R[h]) == 0,
781 	       "R[h] can not be empty if it exists (item number=%d)",
782 	       B_NR_ITEMS(tb->R[h]));
783 
784 	memcpy(internal_key(tb->CFR[h], tb->rkey[h]), key, KEY_SIZE);
785 
786 	do_balance_mark_internal_dirty(tb, tb->CFR[h], 0);
787 }
788 
789 
790 /*
791  * if inserting/pasting {
792  *   child_pos is the position of the node-pointer in S[h] that
793  *   pointed to S[h-1] before balancing of the h-1 level;
794  *   this means that new pointers and items must be inserted AFTER
795  *   child_pos
796  * } else {
797  *   it is the position of the leftmost pointer that must be deleted
798  *   (together with its corresponding key to the left of the pointer)
799  *   as a result of the previous level's balancing.
800  * }
801  */
802 
balance_internal(struct tree_balance * tb,int h,int child_pos,struct item_head * insert_key,struct buffer_head ** insert_ptr)803 int balance_internal(struct tree_balance *tb,
804 		     int h,	/* level of the tree */
805 		     int child_pos,
806 		     /* key for insertion on higher level    */
807 		     struct item_head *insert_key,
808 		     /* node for insertion on higher level */
809 		     struct buffer_head **insert_ptr)
810 {
811 	struct buffer_head *tbSh = PATH_H_PBUFFER(tb->tb_path, h);
812 	struct buffer_info bi;
813 
814 	/*
815 	 * we return this: it is 0 if there is no S[h],
816 	 * else it is tb->S[h]->b_item_order
817 	 */
818 	int order;
819 	int insert_num, n, k;
820 	struct buffer_head *S_new;
821 	struct item_head new_insert_key;
822 	struct buffer_head *new_insert_ptr = NULL;
823 	struct item_head *new_insert_key_addr = insert_key;
824 
825 	RFALSE(h < 1, "h (%d) can not be < 1 on internal level", h);
826 
827 	PROC_INFO_INC(tb->tb_sb, balance_at[h]);
828 
829 	order =
830 	    (tbSh) ? PATH_H_POSITION(tb->tb_path,
831 				     h + 1) /*tb->S[h]->b_item_order */ : 0;
832 
833 	/*
834 	 * Using insert_size[h] calculate the number insert_num of items
835 	 * that must be inserted to or deleted from S[h].
836 	 */
837 	insert_num = tb->insert_size[h] / ((int)(KEY_SIZE + DC_SIZE));
838 
839 	/* Check whether insert_num is proper * */
840 	RFALSE(insert_num < -2 || insert_num > 2,
841 	       "incorrect number of items inserted to the internal node (%d)",
842 	       insert_num);
843 	RFALSE(h > 1 && (insert_num > 1 || insert_num < -1),
844 	       "incorrect number of items (%d) inserted to the internal node on a level (h=%d) higher than last internal level",
845 	       insert_num, h);
846 
847 	/* Make balance in case insert_num < 0 */
848 	if (insert_num < 0) {
849 		balance_internal_when_delete(tb, h, child_pos);
850 		return order;
851 	}
852 
853 	k = 0;
854 	if (tb->lnum[h] > 0) {
855 		/*
856 		 * shift lnum[h] items from S[h] to the left neighbor L[h].
857 		 * check how many of new items fall into L[h] or CFL[h] after
858 		 * shifting
859 		 */
860 		n = B_NR_ITEMS(tb->L[h]);	/* number of items in L[h] */
861 		if (tb->lnum[h] <= child_pos) {
862 			/* new items don't fall into L[h] or CFL[h] */
863 			internal_shift_left(INTERNAL_SHIFT_FROM_S_TO_L, tb, h,
864 					    tb->lnum[h]);
865 			child_pos -= tb->lnum[h];
866 		} else if (tb->lnum[h] > child_pos + insert_num) {
867 			/* all new items fall into L[h] */
868 			internal_shift_left(INTERNAL_SHIFT_FROM_S_TO_L, tb, h,
869 					    tb->lnum[h] - insert_num);
870 			/* insert insert_num keys and node-pointers into L[h] */
871 			bi.tb = tb;
872 			bi.bi_bh = tb->L[h];
873 			bi.bi_parent = tb->FL[h];
874 			bi.bi_position = get_left_neighbor_position(tb, h);
875 			internal_insert_childs(&bi,
876 					       /*tb->L[h], tb->S[h-1]->b_next */
877 					       n + child_pos + 1,
878 					       insert_num, insert_key,
879 					       insert_ptr);
880 
881 			insert_num = 0;
882 		} else {
883 			struct disk_child *dc;
884 
885 			/*
886 			 * some items fall into L[h] or CFL[h],
887 			 * but some don't fall
888 			 */
889 			internal_shift1_left(tb, h, child_pos + 1);
890 			/* calculate number of new items that fall into L[h] */
891 			k = tb->lnum[h] - child_pos - 1;
892 			bi.tb = tb;
893 			bi.bi_bh = tb->L[h];
894 			bi.bi_parent = tb->FL[h];
895 			bi.bi_position = get_left_neighbor_position(tb, h);
896 			internal_insert_childs(&bi,
897 					       /*tb->L[h], tb->S[h-1]->b_next, */
898 					       n + child_pos + 1, k,
899 					       insert_key, insert_ptr);
900 
901 			replace_lkey(tb, h, insert_key + k);
902 
903 			/*
904 			 * replace the first node-ptr in S[h] by
905 			 * node-ptr to insert_ptr[k]
906 			 */
907 			dc = B_N_CHILD(tbSh, 0);
908 			put_dc_size(dc,
909 				    MAX_CHILD_SIZE(insert_ptr[k]) -
910 				    B_FREE_SPACE(insert_ptr[k]));
911 			put_dc_block_number(dc, insert_ptr[k]->b_blocknr);
912 
913 			do_balance_mark_internal_dirty(tb, tbSh, 0);
914 
915 			k++;
916 			insert_key += k;
917 			insert_ptr += k;
918 			insert_num -= k;
919 			child_pos = 0;
920 		}
921 	}
922 	/* tb->lnum[h] > 0 */
923 	if (tb->rnum[h] > 0) {
924 		/*shift rnum[h] items from S[h] to the right neighbor R[h] */
925 		/*
926 		 * check how many of new items fall into R or CFR
927 		 * after shifting
928 		 */
929 		n = B_NR_ITEMS(tbSh);	/* number of items in S[h] */
930 		if (n - tb->rnum[h] >= child_pos)
931 			/* new items fall into S[h] */
932 			internal_shift_right(INTERNAL_SHIFT_FROM_S_TO_R, tb, h,
933 					     tb->rnum[h]);
934 		else if (n + insert_num - tb->rnum[h] < child_pos) {
935 			/* all new items fall into R[h] */
936 			internal_shift_right(INTERNAL_SHIFT_FROM_S_TO_R, tb, h,
937 					     tb->rnum[h] - insert_num);
938 
939 			/* insert insert_num keys and node-pointers into R[h] */
940 			bi.tb = tb;
941 			bi.bi_bh = tb->R[h];
942 			bi.bi_parent = tb->FR[h];
943 			bi.bi_position = get_right_neighbor_position(tb, h);
944 			internal_insert_childs(&bi,
945 					       /*tb->R[h],tb->S[h-1]->b_next */
946 					       child_pos - n - insert_num +
947 					       tb->rnum[h] - 1,
948 					       insert_num, insert_key,
949 					       insert_ptr);
950 			insert_num = 0;
951 		} else {
952 			struct disk_child *dc;
953 
954 			/* one of the items falls into CFR[h] */
955 			internal_shift1_right(tb, h, n - child_pos + 1);
956 			/* calculate number of new items that fall into R[h] */
957 			k = tb->rnum[h] - n + child_pos - 1;
958 			bi.tb = tb;
959 			bi.bi_bh = tb->R[h];
960 			bi.bi_parent = tb->FR[h];
961 			bi.bi_position = get_right_neighbor_position(tb, h);
962 			internal_insert_childs(&bi,
963 					       /*tb->R[h], tb->R[h]->b_child, */
964 					       0, k, insert_key + 1,
965 					       insert_ptr + 1);
966 
967 			replace_rkey(tb, h, insert_key + insert_num - k - 1);
968 
969 			/*
970 			 * replace the first node-ptr in R[h] by
971 			 * node-ptr insert_ptr[insert_num-k-1]
972 			 */
973 			dc = B_N_CHILD(tb->R[h], 0);
974 			put_dc_size(dc,
975 				    MAX_CHILD_SIZE(insert_ptr
976 						   [insert_num - k - 1]) -
977 				    B_FREE_SPACE(insert_ptr
978 						 [insert_num - k - 1]));
979 			put_dc_block_number(dc,
980 					    insert_ptr[insert_num - k -
981 						       1]->b_blocknr);
982 
983 			do_balance_mark_internal_dirty(tb, tb->R[h], 0);
984 
985 			insert_num -= (k + 1);
986 		}
987 	}
988 
989 	/** Fill new node that appears instead of S[h] **/
990 	RFALSE(tb->blknum[h] > 2, "blknum can not be > 2 for internal level");
991 	RFALSE(tb->blknum[h] < 0, "blknum can not be < 0");
992 
993 	if (!tb->blknum[h]) {	/* node S[h] is empty now */
994 		RFALSE(!tbSh, "S[h] is equal NULL");
995 
996 		/* do what is needed for buffer thrown from tree */
997 		reiserfs_invalidate_buffer(tb, tbSh);
998 		return order;
999 	}
1000 
1001 	if (!tbSh) {
1002 		/* create new root */
1003 		struct disk_child *dc;
1004 		struct buffer_head *tbSh_1 = PATH_H_PBUFFER(tb->tb_path, h - 1);
1005 		struct block_head *blkh;
1006 
1007 		if (tb->blknum[h] != 1)
1008 			reiserfs_panic(NULL, "ibalance-3", "One new node "
1009 				       "required for creating the new root");
1010 		/* S[h] = empty buffer from the list FEB. */
1011 		tbSh = get_FEB(tb);
1012 		blkh = B_BLK_HEAD(tbSh);
1013 		set_blkh_level(blkh, h + 1);
1014 
1015 		/* Put the unique node-pointer to S[h] that points to S[h-1]. */
1016 
1017 		dc = B_N_CHILD(tbSh, 0);
1018 		put_dc_block_number(dc, tbSh_1->b_blocknr);
1019 		put_dc_size(dc,
1020 			    (MAX_CHILD_SIZE(tbSh_1) - B_FREE_SPACE(tbSh_1)));
1021 
1022 		tb->insert_size[h] -= DC_SIZE;
1023 		set_blkh_free_space(blkh, blkh_free_space(blkh) - DC_SIZE);
1024 
1025 		do_balance_mark_internal_dirty(tb, tbSh, 0);
1026 
1027 		/*&&&&&&&&&&&&&&&&&&&&&&&& */
1028 		check_internal(tbSh);
1029 		/*&&&&&&&&&&&&&&&&&&&&&&&& */
1030 
1031 		/* put new root into path structure */
1032 		PATH_OFFSET_PBUFFER(tb->tb_path, ILLEGAL_PATH_ELEMENT_OFFSET) =
1033 		    tbSh;
1034 
1035 		/* Change root in structure super block. */
1036 		PUT_SB_ROOT_BLOCK(tb->tb_sb, tbSh->b_blocknr);
1037 		PUT_SB_TREE_HEIGHT(tb->tb_sb, SB_TREE_HEIGHT(tb->tb_sb) + 1);
1038 		do_balance_mark_sb_dirty(tb, REISERFS_SB(tb->tb_sb)->s_sbh, 1);
1039 	}
1040 
1041 	if (tb->blknum[h] == 2) {
1042 		int snum;
1043 		struct buffer_info dest_bi, src_bi;
1044 
1045 		/* S_new = free buffer from list FEB */
1046 		S_new = get_FEB(tb);
1047 
1048 		set_blkh_level(B_BLK_HEAD(S_new), h + 1);
1049 
1050 		dest_bi.tb = tb;
1051 		dest_bi.bi_bh = S_new;
1052 		dest_bi.bi_parent = NULL;
1053 		dest_bi.bi_position = 0;
1054 		src_bi.tb = tb;
1055 		src_bi.bi_bh = tbSh;
1056 		src_bi.bi_parent = PATH_H_PPARENT(tb->tb_path, h);
1057 		src_bi.bi_position = PATH_H_POSITION(tb->tb_path, h + 1);
1058 
1059 		n = B_NR_ITEMS(tbSh);	/* number of items in S[h] */
1060 		snum = (insert_num + n + 1) / 2;
1061 		if (n - snum >= child_pos) {
1062 			/* new items don't fall into S_new */
1063 			/*  store the delimiting key for the next level */
1064 			/* new_insert_key = (n - snum)'th key in S[h] */
1065 			memcpy(&new_insert_key, internal_key(tbSh, n - snum),
1066 			       KEY_SIZE);
1067 			/* last parameter is del_par */
1068 			internal_move_pointers_items(&dest_bi, &src_bi,
1069 						     LAST_TO_FIRST, snum, 0);
1070 		} else if (n + insert_num - snum < child_pos) {
1071 			/* all new items fall into S_new */
1072 			/*  store the delimiting key for the next level */
1073 			/*
1074 			 * new_insert_key = (n + insert_item - snum)'th
1075 			 * key in S[h]
1076 			 */
1077 			memcpy(&new_insert_key,
1078 			       internal_key(tbSh, n + insert_num - snum),
1079 			       KEY_SIZE);
1080 			/* last parameter is del_par */
1081 			internal_move_pointers_items(&dest_bi, &src_bi,
1082 						     LAST_TO_FIRST,
1083 						     snum - insert_num, 0);
1084 
1085 			/*
1086 			 * insert insert_num keys and node-pointers
1087 			 * into S_new
1088 			 */
1089 			internal_insert_childs(&dest_bi,
1090 					       /*S_new,tb->S[h-1]->b_next, */
1091 					       child_pos - n - insert_num +
1092 					       snum - 1,
1093 					       insert_num, insert_key,
1094 					       insert_ptr);
1095 
1096 			insert_num = 0;
1097 		} else {
1098 			struct disk_child *dc;
1099 
1100 			/* some items fall into S_new, but some don't fall */
1101 			/* last parameter is del_par */
1102 			internal_move_pointers_items(&dest_bi, &src_bi,
1103 						     LAST_TO_FIRST,
1104 						     n - child_pos + 1, 1);
1105 			/* calculate number of new items that fall into S_new */
1106 			k = snum - n + child_pos - 1;
1107 
1108 			internal_insert_childs(&dest_bi, /*S_new, */ 0, k,
1109 					       insert_key + 1, insert_ptr + 1);
1110 
1111 			/* new_insert_key = insert_key[insert_num - k - 1] */
1112 			memcpy(&new_insert_key, insert_key + insert_num - k - 1,
1113 			       KEY_SIZE);
1114 			/*
1115 			 * replace first node-ptr in S_new by node-ptr
1116 			 * to insert_ptr[insert_num-k-1]
1117 			 */
1118 
1119 			dc = B_N_CHILD(S_new, 0);
1120 			put_dc_size(dc,
1121 				    (MAX_CHILD_SIZE
1122 				     (insert_ptr[insert_num - k - 1]) -
1123 				     B_FREE_SPACE(insert_ptr
1124 						  [insert_num - k - 1])));
1125 			put_dc_block_number(dc,
1126 					    insert_ptr[insert_num - k -
1127 						       1]->b_blocknr);
1128 
1129 			do_balance_mark_internal_dirty(tb, S_new, 0);
1130 
1131 			insert_num -= (k + 1);
1132 		}
1133 		/* new_insert_ptr = node_pointer to S_new */
1134 		new_insert_ptr = S_new;
1135 
1136 		RFALSE(!buffer_journaled(S_new) || buffer_journal_dirty(S_new)
1137 		       || buffer_dirty(S_new), "cm-00001: bad S_new (%b)",
1138 		       S_new);
1139 
1140 		/* S_new is released in unfix_nodes */
1141 	}
1142 
1143 	n = B_NR_ITEMS(tbSh);	/*number of items in S[h] */
1144 
1145 	if (0 <= child_pos && child_pos <= n && insert_num > 0) {
1146 		bi.tb = tb;
1147 		bi.bi_bh = tbSh;
1148 		bi.bi_parent = PATH_H_PPARENT(tb->tb_path, h);
1149 		bi.bi_position = PATH_H_POSITION(tb->tb_path, h + 1);
1150 		internal_insert_childs(&bi,	/*tbSh, */
1151 				       /*          ( tb->S[h-1]->b_parent == tb->S[h] ) ? tb->S[h-1]->b_next :  tb->S[h]->b_child->b_next, */
1152 				       child_pos, insert_num, insert_key,
1153 				       insert_ptr);
1154 	}
1155 
1156 	insert_ptr[0] = new_insert_ptr;
1157 	if (new_insert_ptr)
1158 		memcpy(new_insert_key_addr, &new_insert_key, KEY_SIZE);
1159 
1160 	return order;
1161 }
1162