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) */
12int 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
27static 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 */
126static 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 */
205static 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 */
277static 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 */
298static 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 */
394static 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. */
429static 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 */
488static 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] */
534static 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 */
560static 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] */
609static 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 */
632static 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.*/
760static 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.*/
775static 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
803int 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	memcpy(new_insert_key_addr, &new_insert_key, KEY_SIZE);
1157	insert_ptr[0] = new_insert_ptr;
1158
1159	return order;
1160}
1161