xref: /openbmc/linux/fs/reiserfs/do_balan.c (revision 70342287)
1 /*
2  * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
3  */
4 
5 /* Now we have all buffers that must be used in balancing of the tree 	*/
6 /* Further calculations can not cause schedule(), and thus the buffer 	*/
7 /* tree will be stable until the balancing will be finished 		*/
8 /* balance the tree according to the analysis made before,		*/
9 /* and using buffers obtained after all above.				*/
10 
11 /**
12  ** balance_leaf_when_delete
13  ** balance_leaf
14  ** do_balance
15  **
16  **/
17 
18 #include <asm/uaccess.h>
19 #include <linux/time.h>
20 #include "reiserfs.h"
21 #include <linux/buffer_head.h>
22 #include <linux/kernel.h>
23 
24 static inline void buffer_info_init_left(struct tree_balance *tb,
25                                          struct buffer_info *bi)
26 {
27 	bi->tb          = tb;
28 	bi->bi_bh       = tb->L[0];
29 	bi->bi_parent   = tb->FL[0];
30 	bi->bi_position = get_left_neighbor_position(tb, 0);
31 }
32 
33 static inline void buffer_info_init_right(struct tree_balance *tb,
34                                           struct buffer_info *bi)
35 {
36 	bi->tb          = tb;
37 	bi->bi_bh       = tb->R[0];
38 	bi->bi_parent   = tb->FR[0];
39 	bi->bi_position = get_right_neighbor_position(tb, 0);
40 }
41 
42 static inline void buffer_info_init_tbS0(struct tree_balance *tb,
43                                          struct buffer_info *bi)
44 {
45 	bi->tb          = tb;
46 	bi->bi_bh        = PATH_PLAST_BUFFER(tb->tb_path);
47 	bi->bi_parent   = PATH_H_PPARENT(tb->tb_path, 0);
48 	bi->bi_position = PATH_H_POSITION(tb->tb_path, 1);
49 }
50 
51 static inline void buffer_info_init_bh(struct tree_balance *tb,
52                                        struct buffer_info *bi,
53                                        struct buffer_head *bh)
54 {
55 	bi->tb          = tb;
56 	bi->bi_bh       = bh;
57 	bi->bi_parent   = NULL;
58 	bi->bi_position = 0;
59 }
60 
61 inline void do_balance_mark_leaf_dirty(struct tree_balance *tb,
62 				       struct buffer_head *bh, int flag)
63 {
64 	journal_mark_dirty(tb->transaction_handle,
65 			   tb->transaction_handle->t_super, bh);
66 }
67 
68 #define do_balance_mark_internal_dirty do_balance_mark_leaf_dirty
69 #define do_balance_mark_sb_dirty do_balance_mark_leaf_dirty
70 
71 /* summary:
72  if deleting something ( tb->insert_size[0] < 0 )
73    return(balance_leaf_when_delete()); (flag d handled here)
74  else
75    if lnum is larger than 0 we put items into the left node
76    if rnum is larger than 0 we put items into the right node
77    if snum1 is larger than 0 we put items into the new node s1
78    if snum2 is larger than 0 we put items into the new node s2
79 Note that all *num* count new items being created.
80 
81 It would be easier to read balance_leaf() if each of these summary
82 lines was a separate procedure rather than being inlined.  I think
83 that there are many passages here and in balance_leaf_when_delete() in
84 which two calls to one procedure can replace two passages, and it
85 might save cache space and improve software maintenance costs to do so.
86 
87 Vladimir made the perceptive comment that we should offload most of
88 the decision making in this function into fix_nodes/check_balance, and
89 then create some sort of structure in tb that says what actions should
90 be performed by do_balance.
91 
92 -Hans */
93 
94 /* Balance leaf node in case of delete or cut: insert_size[0] < 0
95  *
96  * lnum, rnum can have values >= -1
97  *	-1 means that the neighbor must be joined with S
98  *	 0 means that nothing should be done with the neighbor
99  *	>0 means to shift entirely or partly the specified number of items to the neighbor
100  */
101 static int balance_leaf_when_delete(struct tree_balance *tb, int flag)
102 {
103 	struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
104 	int item_pos = PATH_LAST_POSITION(tb->tb_path);
105 	int pos_in_item = tb->tb_path->pos_in_item;
106 	struct buffer_info bi;
107 	int n;
108 	struct item_head *ih;
109 
110 	RFALSE(tb->FR[0] && B_LEVEL(tb->FR[0]) != DISK_LEAF_NODE_LEVEL + 1,
111 	       "vs- 12000: level: wrong FR %z", tb->FR[0]);
112 	RFALSE(tb->blknum[0] > 1,
113 	       "PAP-12005: tb->blknum == %d, can not be > 1", tb->blknum[0]);
114 	RFALSE(!tb->blknum[0] && !PATH_H_PPARENT(tb->tb_path, 0),
115 	       "PAP-12010: tree can not be empty");
116 
117 	ih = B_N_PITEM_HEAD(tbS0, item_pos);
118 	buffer_info_init_tbS0(tb, &bi);
119 
120 	/* Delete or truncate the item */
121 
122 	switch (flag) {
123 	case M_DELETE:		/* delete item in S[0] */
124 
125 		RFALSE(ih_item_len(ih) + IH_SIZE != -tb->insert_size[0],
126 		       "vs-12013: mode Delete, insert size %d, ih to be deleted %h",
127 		       -tb->insert_size[0], ih);
128 
129 		leaf_delete_items(&bi, 0, item_pos, 1, -1);
130 
131 		if (!item_pos && tb->CFL[0]) {
132 			if (B_NR_ITEMS(tbS0)) {
133 				replace_key(tb, tb->CFL[0], tb->lkey[0], tbS0,
134 					    0);
135 			} else {
136 				if (!PATH_H_POSITION(tb->tb_path, 1))
137 					replace_key(tb, tb->CFL[0], tb->lkey[0],
138 						    PATH_H_PPARENT(tb->tb_path,
139 								   0), 0);
140 			}
141 		}
142 
143 		RFALSE(!item_pos && !tb->CFL[0],
144 		       "PAP-12020: tb->CFL[0]==%p, tb->L[0]==%p", tb->CFL[0],
145 		       tb->L[0]);
146 
147 		break;
148 
149 	case M_CUT:{		/* cut item in S[0] */
150 			if (is_direntry_le_ih(ih)) {
151 
152 				/* UFS unlink semantics are such that you can only delete one directory entry at a time. */
153 				/* when we cut a directory tb->insert_size[0] means number of entries to be cut (always 1) */
154 				tb->insert_size[0] = -1;
155 				leaf_cut_from_buffer(&bi, item_pos, pos_in_item,
156 						     -tb->insert_size[0]);
157 
158 				RFALSE(!item_pos && !pos_in_item && !tb->CFL[0],
159 				       "PAP-12030: can not change delimiting key. CFL[0]=%p",
160 				       tb->CFL[0]);
161 
162 				if (!item_pos && !pos_in_item && tb->CFL[0]) {
163 					replace_key(tb, tb->CFL[0], tb->lkey[0],
164 						    tbS0, 0);
165 				}
166 			} else {
167 				leaf_cut_from_buffer(&bi, item_pos, pos_in_item,
168 						     -tb->insert_size[0]);
169 
170 				RFALSE(!ih_item_len(ih),
171 				       "PAP-12035: cut must leave non-zero dynamic length of item");
172 			}
173 			break;
174 		}
175 
176 	default:
177 		print_cur_tb("12040");
178 		reiserfs_panic(tb->tb_sb, "PAP-12040",
179 			       "unexpected mode: %s(%d)",
180 			       (flag ==
181 				M_PASTE) ? "PASTE" : ((flag ==
182 						       M_INSERT) ? "INSERT" :
183 						      "UNKNOWN"), flag);
184 	}
185 
186 	/* the rule is that no shifting occurs unless by shifting a node can be freed */
187 	n = B_NR_ITEMS(tbS0);
188 	if (tb->lnum[0]) {	/* L[0] takes part in balancing */
189 		if (tb->lnum[0] == -1) {	/* L[0] must be joined with S[0] */
190 			if (tb->rnum[0] == -1) {	/* R[0] must be also joined with S[0] */
191 				if (tb->FR[0] == PATH_H_PPARENT(tb->tb_path, 0)) {
192 					/* all contents of all the 3 buffers will be in L[0] */
193 					if (PATH_H_POSITION(tb->tb_path, 1) == 0
194 					    && 1 < B_NR_ITEMS(tb->FR[0]))
195 						replace_key(tb, tb->CFL[0],
196 							    tb->lkey[0],
197 							    tb->FR[0], 1);
198 
199 					leaf_move_items(LEAF_FROM_S_TO_L, tb, n,
200 							-1, NULL);
201 					leaf_move_items(LEAF_FROM_R_TO_L, tb,
202 							B_NR_ITEMS(tb->R[0]),
203 							-1, NULL);
204 
205 					reiserfs_invalidate_buffer(tb, tbS0);
206 					reiserfs_invalidate_buffer(tb,
207 								   tb->R[0]);
208 
209 					return 0;
210 				}
211 				/* all contents of all the 3 buffers will be in R[0] */
212 				leaf_move_items(LEAF_FROM_S_TO_R, tb, n, -1,
213 						NULL);
214 				leaf_move_items(LEAF_FROM_L_TO_R, tb,
215 						B_NR_ITEMS(tb->L[0]), -1, NULL);
216 
217 				/* right_delimiting_key is correct in R[0] */
218 				replace_key(tb, tb->CFR[0], tb->rkey[0],
219 					    tb->R[0], 0);
220 
221 				reiserfs_invalidate_buffer(tb, tbS0);
222 				reiserfs_invalidate_buffer(tb, tb->L[0]);
223 
224 				return -1;
225 			}
226 
227 			RFALSE(tb->rnum[0] != 0,
228 			       "PAP-12045: rnum must be 0 (%d)", tb->rnum[0]);
229 			/* all contents of L[0] and S[0] will be in L[0] */
230 			leaf_shift_left(tb, n, -1);
231 
232 			reiserfs_invalidate_buffer(tb, tbS0);
233 
234 			return 0;
235 		}
236 		/* a part of contents of S[0] will be in L[0] and the rest part of S[0] will be in R[0] */
237 
238 		RFALSE((tb->lnum[0] + tb->rnum[0] < n) ||
239 		       (tb->lnum[0] + tb->rnum[0] > n + 1),
240 		       "PAP-12050: rnum(%d) and lnum(%d) and item number(%d) in S[0] are not consistent",
241 		       tb->rnum[0], tb->lnum[0], n);
242 		RFALSE((tb->lnum[0] + tb->rnum[0] == n) &&
243 		       (tb->lbytes != -1 || tb->rbytes != -1),
244 		       "PAP-12055: bad rbytes (%d)/lbytes (%d) parameters when items are not split",
245 		       tb->rbytes, tb->lbytes);
246 		RFALSE((tb->lnum[0] + tb->rnum[0] == n + 1) &&
247 		       (tb->lbytes < 1 || tb->rbytes != -1),
248 		       "PAP-12060: bad rbytes (%d)/lbytes (%d) parameters when items are split",
249 		       tb->rbytes, tb->lbytes);
250 
251 		leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
252 		leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
253 
254 		reiserfs_invalidate_buffer(tb, tbS0);
255 
256 		return 0;
257 	}
258 
259 	if (tb->rnum[0] == -1) {
260 		/* all contents of R[0] and S[0] will be in R[0] */
261 		leaf_shift_right(tb, n, -1);
262 		reiserfs_invalidate_buffer(tb, tbS0);
263 		return 0;
264 	}
265 
266 	RFALSE(tb->rnum[0],
267 	       "PAP-12065: bad rnum parameter must be 0 (%d)", tb->rnum[0]);
268 	return 0;
269 }
270 
271 static int balance_leaf(struct tree_balance *tb, struct item_head *ih,	/* item header of inserted item (this is on little endian) */
272 			const char *body,	/* body  of inserted item or bytes to paste */
273 			int flag,	/* i - insert, d - delete, c - cut, p - paste
274 					   (see comment to do_balance) */
275 			struct item_head *insert_key,	/* in our processing of one level we sometimes determine what
276 							   must be inserted into the next higher level.  This insertion
277 							   consists of a key or two keys and their corresponding
278 							   pointers */
279 			struct buffer_head **insert_ptr	/* inserted node-ptrs for the next level */
280     )
281 {
282 	struct buffer_head *tbS0 = PATH_PLAST_BUFFER(tb->tb_path);
283 	int item_pos = PATH_LAST_POSITION(tb->tb_path);	/*  index into the array of item headers in S[0]
284 							   of the affected item */
285 	struct buffer_info bi;
286 	struct buffer_head *S_new[2];	/* new nodes allocated to hold what could not fit into S */
287 	int snum[2];		/* number of items that will be placed
288 				   into S_new (includes partially shifted
289 				   items) */
290 	int sbytes[2];		/* if an item is partially shifted into S_new then
291 				   if it is a directory item
292 				   it is the number of entries from the item that are shifted into S_new
293 				   else
294 				   it is the number of bytes from the item that are shifted into S_new
295 				 */
296 	int n, i;
297 	int ret_val;
298 	int pos_in_item;
299 	int zeros_num;
300 
301 	PROC_INFO_INC(tb->tb_sb, balance_at[0]);
302 
303 	/* Make balance in case insert_size[0] < 0 */
304 	if (tb->insert_size[0] < 0)
305 		return balance_leaf_when_delete(tb, flag);
306 
307 	zeros_num = 0;
308 	if (flag == M_INSERT && !body)
309 		zeros_num = ih_item_len(ih);
310 
311 	pos_in_item = tb->tb_path->pos_in_item;
312 	/* for indirect item pos_in_item is measured in unformatted node
313 	   pointers. Recalculate to bytes */
314 	if (flag != M_INSERT
315 	    && is_indirect_le_ih(B_N_PITEM_HEAD(tbS0, item_pos)))
316 		pos_in_item *= UNFM_P_SIZE;
317 
318 	if (tb->lnum[0] > 0) {
319 		/* Shift lnum[0] items from S[0] to the left neighbor L[0] */
320 		if (item_pos < tb->lnum[0]) {
321 			/* new item or it part falls to L[0], shift it too */
322 			n = B_NR_ITEMS(tb->L[0]);
323 
324 			switch (flag) {
325 			case M_INSERT:	/* insert item into L[0] */
326 
327 				if (item_pos == tb->lnum[0] - 1
328 				    && tb->lbytes != -1) {
329 					/* part of new item falls into L[0] */
330 					int new_item_len;
331 					int version;
332 
333 					ret_val =
334 					    leaf_shift_left(tb, tb->lnum[0] - 1,
335 							    -1);
336 
337 					/* Calculate item length to insert to S[0] */
338 					new_item_len =
339 					    ih_item_len(ih) - tb->lbytes;
340 					/* Calculate and check item length to insert to L[0] */
341 					put_ih_item_len(ih,
342 							ih_item_len(ih) -
343 							new_item_len);
344 
345 					RFALSE(ih_item_len(ih) <= 0,
346 					       "PAP-12080: there is nothing to insert into L[0]: ih_item_len=%d",
347 					       ih_item_len(ih));
348 
349 					/* Insert new item into L[0] */
350 					buffer_info_init_left(tb, &bi);
351 					leaf_insert_into_buf(&bi,
352 							     n + item_pos -
353 							     ret_val, ih, body,
354 							     zeros_num >
355 							     ih_item_len(ih) ?
356 							     ih_item_len(ih) :
357 							     zeros_num);
358 
359 					version = ih_version(ih);
360 
361 					/* Calculate key component, item length and body to insert into S[0] */
362 					set_le_ih_k_offset(ih,
363 							   le_ih_k_offset(ih) +
364 							   (tb->
365 							    lbytes <<
366 							    (is_indirect_le_ih
367 							     (ih) ? tb->tb_sb->
368 							     s_blocksize_bits -
369 							     UNFM_P_SHIFT :
370 							     0)));
371 
372 					put_ih_item_len(ih, new_item_len);
373 					if (tb->lbytes > zeros_num) {
374 						body +=
375 						    (tb->lbytes - zeros_num);
376 						zeros_num = 0;
377 					} else
378 						zeros_num -= tb->lbytes;
379 
380 					RFALSE(ih_item_len(ih) <= 0,
381 					       "PAP-12085: there is nothing to insert into S[0]: ih_item_len=%d",
382 					       ih_item_len(ih));
383 				} else {
384 					/* new item in whole falls into L[0] */
385 					/* Shift lnum[0]-1 items to L[0] */
386 					ret_val =
387 					    leaf_shift_left(tb, tb->lnum[0] - 1,
388 							    tb->lbytes);
389 					/* Insert new item into L[0] */
390 					buffer_info_init_left(tb, &bi);
391 					leaf_insert_into_buf(&bi,
392 							     n + item_pos -
393 							     ret_val, ih, body,
394 							     zeros_num);
395 					tb->insert_size[0] = 0;
396 					zeros_num = 0;
397 				}
398 				break;
399 
400 			case M_PASTE:	/* append item in L[0] */
401 
402 				if (item_pos == tb->lnum[0] - 1
403 				    && tb->lbytes != -1) {
404 					/* we must shift the part of the appended item */
405 					if (is_direntry_le_ih
406 					    (B_N_PITEM_HEAD(tbS0, item_pos))) {
407 
408 						RFALSE(zeros_num,
409 						       "PAP-12090: invalid parameter in case of a directory");
410 						/* directory item */
411 						if (tb->lbytes > pos_in_item) {
412 							/* new directory entry falls into L[0] */
413 							struct item_head
414 							    *pasted;
415 							int l_pos_in_item =
416 							    pos_in_item;
417 
418 							/* Shift lnum[0] - 1 items in whole. Shift lbytes - 1 entries from given directory item */
419 							ret_val =
420 							    leaf_shift_left(tb,
421 									    tb->
422 									    lnum
423 									    [0],
424 									    tb->
425 									    lbytes
426 									    -
427 									    1);
428 							if (ret_val
429 							    && !item_pos) {
430 								pasted =
431 								    B_N_PITEM_HEAD
432 								    (tb->L[0],
433 								     B_NR_ITEMS
434 								     (tb->
435 								      L[0]) -
436 								     1);
437 								l_pos_in_item +=
438 								    I_ENTRY_COUNT
439 								    (pasted) -
440 								    (tb->
441 								     lbytes -
442 								     1);
443 							}
444 
445 							/* Append given directory entry to directory item */
446 							buffer_info_init_left(tb, &bi);
447 							leaf_paste_in_buffer
448 							    (&bi,
449 							     n + item_pos -
450 							     ret_val,
451 							     l_pos_in_item,
452 							     tb->insert_size[0],
453 							     body, zeros_num);
454 
455 							/* previous string prepared space for pasting new entry, following string pastes this entry */
456 
457 							/* when we have merge directory item, pos_in_item has been changed too */
458 
459 							/* paste new directory entry. 1 is entry number */
460 							leaf_paste_entries(&bi,
461 									   n +
462 									   item_pos
463 									   -
464 									   ret_val,
465 									   l_pos_in_item,
466 									   1,
467 									   (struct
468 									    reiserfs_de_head
469 									    *)
470 									   body,
471 									   body
472 									   +
473 									   DEH_SIZE,
474 									   tb->
475 									   insert_size
476 									   [0]
477 							    );
478 							tb->insert_size[0] = 0;
479 						} else {
480 							/* new directory item doesn't fall into L[0] */
481 							/* Shift lnum[0]-1 items in whole. Shift lbytes directory entries from directory item number lnum[0] */
482 							leaf_shift_left(tb,
483 									tb->
484 									lnum[0],
485 									tb->
486 									lbytes);
487 						}
488 						/* Calculate new position to append in item body */
489 						pos_in_item -= tb->lbytes;
490 					} else {
491 						/* regular object */
492 						RFALSE(tb->lbytes <= 0,
493 						       "PAP-12095: there is nothing to shift to L[0]. lbytes=%d",
494 						       tb->lbytes);
495 						RFALSE(pos_in_item !=
496 						       ih_item_len
497 						       (B_N_PITEM_HEAD
498 							(tbS0, item_pos)),
499 						       "PAP-12100: incorrect position to paste: item_len=%d, pos_in_item=%d",
500 						       ih_item_len
501 						       (B_N_PITEM_HEAD
502 							(tbS0, item_pos)),
503 						       pos_in_item);
504 
505 						if (tb->lbytes >= pos_in_item) {
506 							/* appended item will be in L[0] in whole */
507 							int l_n;
508 
509 							/* this bytes number must be appended to the last item of L[h] */
510 							l_n =
511 							    tb->lbytes -
512 							    pos_in_item;
513 
514 							/* Calculate new insert_size[0] */
515 							tb->insert_size[0] -=
516 							    l_n;
517 
518 							RFALSE(tb->
519 							       insert_size[0] <=
520 							       0,
521 							       "PAP-12105: there is nothing to paste into L[0]. insert_size=%d",
522 							       tb->
523 							       insert_size[0]);
524 							ret_val =
525 							    leaf_shift_left(tb,
526 									    tb->
527 									    lnum
528 									    [0],
529 									    ih_item_len
530 									    (B_N_PITEM_HEAD
531 									     (tbS0,
532 									      item_pos)));
533 							/* Append to body of item in L[0] */
534 							buffer_info_init_left(tb, &bi);
535 							leaf_paste_in_buffer
536 							    (&bi,
537 							     n + item_pos -
538 							     ret_val,
539 							     ih_item_len
540 							     (B_N_PITEM_HEAD
541 							      (tb->L[0],
542 							       n + item_pos -
543 							       ret_val)), l_n,
544 							     body,
545 							     zeros_num >
546 							     l_n ? l_n :
547 							     zeros_num);
548 							/* 0-th item in S0 can be only of DIRECT type when l_n != 0 */
549 							{
550 								int version;
551 								int temp_l =
552 								    l_n;
553 
554 								RFALSE
555 								    (ih_item_len
556 								     (B_N_PITEM_HEAD
557 								      (tbS0,
558 								       0)),
559 								     "PAP-12106: item length must be 0");
560 								RFALSE
561 								    (comp_short_le_keys
562 								     (B_N_PKEY
563 								      (tbS0, 0),
564 								      B_N_PKEY
565 								      (tb->L[0],
566 								       n +
567 								       item_pos
568 								       -
569 								       ret_val)),
570 								     "PAP-12107: items must be of the same file");
571 								if (is_indirect_le_ih(B_N_PITEM_HEAD(tb->L[0], n + item_pos - ret_val))) {
572 									temp_l =
573 									    l_n
574 									    <<
575 									    (tb->
576 									     tb_sb->
577 									     s_blocksize_bits
578 									     -
579 									     UNFM_P_SHIFT);
580 								}
581 								/* update key of first item in S0 */
582 								version =
583 								    ih_version
584 								    (B_N_PITEM_HEAD
585 								     (tbS0, 0));
586 								set_le_key_k_offset
587 								    (version,
588 								     B_N_PKEY
589 								     (tbS0, 0),
590 								     le_key_k_offset
591 								     (version,
592 								      B_N_PKEY
593 								      (tbS0,
594 								       0)) +
595 								     temp_l);
596 								/* update left delimiting key */
597 								set_le_key_k_offset
598 								    (version,
599 								     B_N_PDELIM_KEY
600 								     (tb->
601 								      CFL[0],
602 								      tb->
603 								      lkey[0]),
604 								     le_key_k_offset
605 								     (version,
606 								      B_N_PDELIM_KEY
607 								      (tb->
608 								       CFL[0],
609 								       tb->
610 								       lkey[0]))
611 								     + temp_l);
612 							}
613 
614 							/* Calculate new body, position in item and insert_size[0] */
615 							if (l_n > zeros_num) {
616 								body +=
617 								    (l_n -
618 								     zeros_num);
619 								zeros_num = 0;
620 							} else
621 								zeros_num -=
622 								    l_n;
623 							pos_in_item = 0;
624 
625 							RFALSE
626 							    (comp_short_le_keys
627 							     (B_N_PKEY(tbS0, 0),
628 							      B_N_PKEY(tb->L[0],
629 								       B_NR_ITEMS
630 								       (tb->
631 									L[0]) -
632 								       1))
633 							     ||
634 							     !op_is_left_mergeable
635 							     (B_N_PKEY(tbS0, 0),
636 							      tbS0->b_size)
637 							     ||
638 							     !op_is_left_mergeable
639 							     (B_N_PDELIM_KEY
640 							      (tb->CFL[0],
641 							       tb->lkey[0]),
642 							      tbS0->b_size),
643 							     "PAP-12120: item must be merge-able with left neighboring item");
644 						} else {	/* only part of the appended item will be in L[0] */
645 
646 							/* Calculate position in item for append in S[0] */
647 							pos_in_item -=
648 							    tb->lbytes;
649 
650 							RFALSE(pos_in_item <= 0,
651 							       "PAP-12125: no place for paste. pos_in_item=%d",
652 							       pos_in_item);
653 
654 							/* Shift lnum[0] - 1 items in whole. Shift lbytes - 1 byte from item number lnum[0] */
655 							leaf_shift_left(tb,
656 									tb->
657 									lnum[0],
658 									tb->
659 									lbytes);
660 						}
661 					}
662 				} else {	/* appended item will be in L[0] in whole */
663 
664 					struct item_head *pasted;
665 
666 					if (!item_pos && op_is_left_mergeable(B_N_PKEY(tbS0, 0), tbS0->b_size)) {	/* if we paste into first item of S[0] and it is left mergable */
667 						/* then increment pos_in_item by the size of the last item in L[0] */
668 						pasted =
669 						    B_N_PITEM_HEAD(tb->L[0],
670 								   n - 1);
671 						if (is_direntry_le_ih(pasted))
672 							pos_in_item +=
673 							    ih_entry_count
674 							    (pasted);
675 						else
676 							pos_in_item +=
677 							    ih_item_len(pasted);
678 					}
679 
680 					/* Shift lnum[0] - 1 items in whole. Shift lbytes - 1 byte from item number lnum[0] */
681 					ret_val =
682 					    leaf_shift_left(tb, tb->lnum[0],
683 							    tb->lbytes);
684 					/* Append to body of item in L[0] */
685 					buffer_info_init_left(tb, &bi);
686 					leaf_paste_in_buffer(&bi,
687 							     n + item_pos -
688 							     ret_val,
689 							     pos_in_item,
690 							     tb->insert_size[0],
691 							     body, zeros_num);
692 
693 					/* if appended item is directory, paste entry */
694 					pasted =
695 					    B_N_PITEM_HEAD(tb->L[0],
696 							   n + item_pos -
697 							   ret_val);
698 					if (is_direntry_le_ih(pasted))
699 						leaf_paste_entries(&bi,
700 								   n +
701 								   item_pos -
702 								   ret_val,
703 								   pos_in_item,
704 								   1,
705 								   (struct
706 								    reiserfs_de_head
707 								    *)body,
708 								   body +
709 								   DEH_SIZE,
710 								   tb->
711 								   insert_size
712 								   [0]
713 						    );
714 					/* if appended item is indirect item, put unformatted node into un list */
715 					if (is_indirect_le_ih(pasted))
716 						set_ih_free_space(pasted, 0);
717 					tb->insert_size[0] = 0;
718 					zeros_num = 0;
719 				}
720 				break;
721 			default:	/* cases d and t */
722 				reiserfs_panic(tb->tb_sb, "PAP-12130",
723 					       "lnum > 0: unexpected mode: "
724 					       " %s(%d)",
725 					       (flag ==
726 						M_DELETE) ? "DELETE" : ((flag ==
727 									 M_CUT)
728 									? "CUT"
729 									:
730 									"UNKNOWN"),
731 					       flag);
732 			}
733 		} else {
734 			/* new item doesn't fall into L[0] */
735 			leaf_shift_left(tb, tb->lnum[0], tb->lbytes);
736 		}
737 	}
738 
739 	/* tb->lnum[0] > 0 */
740 	/* Calculate new item position */
741 	item_pos -= (tb->lnum[0] - ((tb->lbytes != -1) ? 1 : 0));
742 
743 	if (tb->rnum[0] > 0) {
744 		/* shift rnum[0] items from S[0] to the right neighbor R[0] */
745 		n = B_NR_ITEMS(tbS0);
746 		switch (flag) {
747 
748 		case M_INSERT:	/* insert item */
749 			if (n - tb->rnum[0] < item_pos) {	/* new item or its part falls to R[0] */
750 				if (item_pos == n - tb->rnum[0] + 1 && tb->rbytes != -1) {	/* part of new item falls into R[0] */
751 					loff_t old_key_comp, old_len,
752 					    r_zeros_number;
753 					const char *r_body;
754 					int version;
755 					loff_t offset;
756 
757 					leaf_shift_right(tb, tb->rnum[0] - 1,
758 							 -1);
759 
760 					version = ih_version(ih);
761 					/* Remember key component and item length */
762 					old_key_comp = le_ih_k_offset(ih);
763 					old_len = ih_item_len(ih);
764 
765 					/* Calculate key component and item length to insert into R[0] */
766 					offset =
767 					    le_ih_k_offset(ih) +
768 					    ((old_len -
769 					      tb->
770 					      rbytes) << (is_indirect_le_ih(ih)
771 							  ? tb->tb_sb->
772 							  s_blocksize_bits -
773 							  UNFM_P_SHIFT : 0));
774 					set_le_ih_k_offset(ih, offset);
775 					put_ih_item_len(ih, tb->rbytes);
776 					/* Insert part of the item into R[0] */
777 					buffer_info_init_right(tb, &bi);
778 					if ((old_len - tb->rbytes) > zeros_num) {
779 						r_zeros_number = 0;
780 						r_body =
781 						    body + (old_len -
782 							    tb->rbytes) -
783 						    zeros_num;
784 					} else {
785 						r_body = body;
786 						r_zeros_number =
787 						    zeros_num - (old_len -
788 								 tb->rbytes);
789 						zeros_num -= r_zeros_number;
790 					}
791 
792 					leaf_insert_into_buf(&bi, 0, ih, r_body,
793 							     r_zeros_number);
794 
795 					/* Replace right delimiting key by first key in R[0] */
796 					replace_key(tb, tb->CFR[0], tb->rkey[0],
797 						    tb->R[0], 0);
798 
799 					/* Calculate key component and item length to insert into S[0] */
800 					set_le_ih_k_offset(ih, old_key_comp);
801 					put_ih_item_len(ih,
802 							old_len - tb->rbytes);
803 
804 					tb->insert_size[0] -= tb->rbytes;
805 
806 				} else {	/* whole new item falls into R[0] */
807 
808 					/* Shift rnum[0]-1 items to R[0] */
809 					ret_val =
810 					    leaf_shift_right(tb,
811 							     tb->rnum[0] - 1,
812 							     tb->rbytes);
813 					/* Insert new item into R[0] */
814 					buffer_info_init_right(tb, &bi);
815 					leaf_insert_into_buf(&bi,
816 							     item_pos - n +
817 							     tb->rnum[0] - 1,
818 							     ih, body,
819 							     zeros_num);
820 
821 					if (item_pos - n + tb->rnum[0] - 1 == 0) {
822 						replace_key(tb, tb->CFR[0],
823 							    tb->rkey[0],
824 							    tb->R[0], 0);
825 
826 					}
827 					zeros_num = tb->insert_size[0] = 0;
828 				}
829 			} else {	/* new item or part of it doesn't fall into R[0] */
830 
831 				leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
832 			}
833 			break;
834 
835 		case M_PASTE:	/* append item */
836 
837 			if (n - tb->rnum[0] <= item_pos) {	/* pasted item or part of it falls to R[0] */
838 				if (item_pos == n - tb->rnum[0] && tb->rbytes != -1) {	/* we must shift the part of the appended item */
839 					if (is_direntry_le_ih(B_N_PITEM_HEAD(tbS0, item_pos))) {	/* we append to directory item */
840 						int entry_count;
841 
842 						RFALSE(zeros_num,
843 						       "PAP-12145: invalid parameter in case of a directory");
844 						entry_count =
845 						    I_ENTRY_COUNT(B_N_PITEM_HEAD
846 								  (tbS0,
847 								   item_pos));
848 						if (entry_count - tb->rbytes <
849 						    pos_in_item)
850 							/* new directory entry falls into R[0] */
851 						{
852 							int paste_entry_position;
853 
854 							RFALSE(tb->rbytes - 1 >=
855 							       entry_count
856 							       || !tb->
857 							       insert_size[0],
858 							       "PAP-12150: no enough of entries to shift to R[0]: rbytes=%d, entry_count=%d",
859 							       tb->rbytes,
860 							       entry_count);
861 							/* Shift rnum[0]-1 items in whole. Shift rbytes-1 directory entries from directory item number rnum[0] */
862 							leaf_shift_right(tb,
863 									 tb->
864 									 rnum
865 									 [0],
866 									 tb->
867 									 rbytes
868 									 - 1);
869 							/* Paste given directory entry to directory item */
870 							paste_entry_position =
871 							    pos_in_item -
872 							    entry_count +
873 							    tb->rbytes - 1;
874 							buffer_info_init_right(tb, &bi);
875 							leaf_paste_in_buffer
876 							    (&bi, 0,
877 							     paste_entry_position,
878 							     tb->insert_size[0],
879 							     body, zeros_num);
880 							/* paste entry */
881 							leaf_paste_entries(&bi,
882 									   0,
883 									   paste_entry_position,
884 									   1,
885 									   (struct
886 									    reiserfs_de_head
887 									    *)
888 									   body,
889 									   body
890 									   +
891 									   DEH_SIZE,
892 									   tb->
893 									   insert_size
894 									   [0]
895 							    );
896 
897 							if (paste_entry_position
898 							    == 0) {
899 								/* change delimiting keys */
900 								replace_key(tb,
901 									    tb->
902 									    CFR
903 									    [0],
904 									    tb->
905 									    rkey
906 									    [0],
907 									    tb->
908 									    R
909 									    [0],
910 									    0);
911 							}
912 
913 							tb->insert_size[0] = 0;
914 							pos_in_item++;
915 						} else {	/* new directory entry doesn't fall into R[0] */
916 
917 							leaf_shift_right(tb,
918 									 tb->
919 									 rnum
920 									 [0],
921 									 tb->
922 									 rbytes);
923 						}
924 					} else {	/* regular object */
925 
926 						int n_shift, n_rem,
927 						    r_zeros_number;
928 						const char *r_body;
929 
930 						/* Calculate number of bytes which must be shifted from appended item */
931 						if ((n_shift =
932 						     tb->rbytes -
933 						     tb->insert_size[0]) < 0)
934 							n_shift = 0;
935 
936 						RFALSE(pos_in_item !=
937 						       ih_item_len
938 						       (B_N_PITEM_HEAD
939 							(tbS0, item_pos)),
940 						       "PAP-12155: invalid position to paste. ih_item_len=%d, pos_in_item=%d",
941 						       pos_in_item,
942 						       ih_item_len
943 						       (B_N_PITEM_HEAD
944 							(tbS0, item_pos)));
945 
946 						leaf_shift_right(tb,
947 								 tb->rnum[0],
948 								 n_shift);
949 						/* Calculate number of bytes which must remain in body after appending to R[0] */
950 						if ((n_rem =
951 						     tb->insert_size[0] -
952 						     tb->rbytes) < 0)
953 							n_rem = 0;
954 
955 						{
956 							int version;
957 							unsigned long temp_rem =
958 							    n_rem;
959 
960 							version =
961 							    ih_version
962 							    (B_N_PITEM_HEAD
963 							     (tb->R[0], 0));
964 							if (is_indirect_le_key
965 							    (version,
966 							     B_N_PKEY(tb->R[0],
967 								      0))) {
968 								temp_rem =
969 								    n_rem <<
970 								    (tb->tb_sb->
971 								     s_blocksize_bits
972 								     -
973 								     UNFM_P_SHIFT);
974 							}
975 							set_le_key_k_offset
976 							    (version,
977 							     B_N_PKEY(tb->R[0],
978 								      0),
979 							     le_key_k_offset
980 							     (version,
981 							      B_N_PKEY(tb->R[0],
982 								       0)) +
983 							     temp_rem);
984 							set_le_key_k_offset
985 							    (version,
986 							     B_N_PDELIM_KEY(tb->
987 									    CFR
988 									    [0],
989 									    tb->
990 									    rkey
991 									    [0]),
992 							     le_key_k_offset
993 							     (version,
994 							      B_N_PDELIM_KEY
995 							      (tb->CFR[0],
996 							       tb->rkey[0])) +
997 							     temp_rem);
998 						}
999 /*		  k_offset (B_N_PKEY(tb->R[0],0)) += n_rem;
1000 		  k_offset (B_N_PDELIM_KEY(tb->CFR[0],tb->rkey[0])) += n_rem;*/
1001 						do_balance_mark_internal_dirty
1002 						    (tb, tb->CFR[0], 0);
1003 
1004 						/* Append part of body into R[0] */
1005 						buffer_info_init_right(tb, &bi);
1006 						if (n_rem > zeros_num) {
1007 							r_zeros_number = 0;
1008 							r_body =
1009 							    body + n_rem -
1010 							    zeros_num;
1011 						} else {
1012 							r_body = body;
1013 							r_zeros_number =
1014 							    zeros_num - n_rem;
1015 							zeros_num -=
1016 							    r_zeros_number;
1017 						}
1018 
1019 						leaf_paste_in_buffer(&bi, 0,
1020 								     n_shift,
1021 								     tb->
1022 								     insert_size
1023 								     [0] -
1024 								     n_rem,
1025 								     r_body,
1026 								     r_zeros_number);
1027 
1028 						if (is_indirect_le_ih
1029 						    (B_N_PITEM_HEAD
1030 						     (tb->R[0], 0))) {
1031 #if 0
1032 							RFALSE(n_rem,
1033 							       "PAP-12160: paste more than one unformatted node pointer");
1034 #endif
1035 							set_ih_free_space
1036 							    (B_N_PITEM_HEAD
1037 							     (tb->R[0], 0), 0);
1038 						}
1039 						tb->insert_size[0] = n_rem;
1040 						if (!n_rem)
1041 							pos_in_item++;
1042 					}
1043 				} else {	/* pasted item in whole falls into R[0] */
1044 
1045 					struct item_head *pasted;
1046 
1047 					ret_val =
1048 					    leaf_shift_right(tb, tb->rnum[0],
1049 							     tb->rbytes);
1050 					/* append item in R[0] */
1051 					if (pos_in_item >= 0) {
1052 						buffer_info_init_right(tb, &bi);
1053 						leaf_paste_in_buffer(&bi,
1054 								     item_pos -
1055 								     n +
1056 								     tb->
1057 								     rnum[0],
1058 								     pos_in_item,
1059 								     tb->
1060 								     insert_size
1061 								     [0], body,
1062 								     zeros_num);
1063 					}
1064 
1065 					/* paste new entry, if item is directory item */
1066 					pasted =
1067 					    B_N_PITEM_HEAD(tb->R[0],
1068 							   item_pos - n +
1069 							   tb->rnum[0]);
1070 					if (is_direntry_le_ih(pasted)
1071 					    && pos_in_item >= 0) {
1072 						leaf_paste_entries(&bi,
1073 								   item_pos -
1074 								   n +
1075 								   tb->rnum[0],
1076 								   pos_in_item,
1077 								   1,
1078 								   (struct
1079 								    reiserfs_de_head
1080 								    *)body,
1081 								   body +
1082 								   DEH_SIZE,
1083 								   tb->
1084 								   insert_size
1085 								   [0]
1086 						    );
1087 						if (!pos_in_item) {
1088 
1089 							RFALSE(item_pos - n +
1090 							       tb->rnum[0],
1091 							       "PAP-12165: directory item must be first item of node when pasting is in 0th position");
1092 
1093 							/* update delimiting keys */
1094 							replace_key(tb,
1095 								    tb->CFR[0],
1096 								    tb->rkey[0],
1097 								    tb->R[0],
1098 								    0);
1099 						}
1100 					}
1101 
1102 					if (is_indirect_le_ih(pasted))
1103 						set_ih_free_space(pasted, 0);
1104 					zeros_num = tb->insert_size[0] = 0;
1105 				}
1106 			} else {	/* new item doesn't fall into R[0] */
1107 
1108 				leaf_shift_right(tb, tb->rnum[0], tb->rbytes);
1109 			}
1110 			break;
1111 		default:	/* cases d and t */
1112 			reiserfs_panic(tb->tb_sb, "PAP-12175",
1113 				       "rnum > 0: unexpected mode: %s(%d)",
1114 				       (flag ==
1115 					M_DELETE) ? "DELETE" : ((flag ==
1116 								 M_CUT) ? "CUT"
1117 								: "UNKNOWN"),
1118 				       flag);
1119 		}
1120 
1121 	}
1122 
1123 	/* tb->rnum[0] > 0 */
1124 	RFALSE(tb->blknum[0] > 3,
1125 	       "PAP-12180: blknum can not be %d. It must be <= 3",
1126 	       tb->blknum[0]);
1127 	RFALSE(tb->blknum[0] < 0,
1128 	       "PAP-12185: blknum can not be %d. It must be >= 0",
1129 	       tb->blknum[0]);
1130 
1131 	/* if while adding to a node we discover that it is possible to split
1132 	   it in two, and merge the left part into the left neighbor and the
1133 	   right part into the right neighbor, eliminating the node */
1134 	if (tb->blknum[0] == 0) {	/* node S[0] is empty now */
1135 
1136 		RFALSE(!tb->lnum[0] || !tb->rnum[0],
1137 		       "PAP-12190: lnum and rnum must not be zero");
1138 		/* if insertion was done before 0-th position in R[0], right
1139 		   delimiting key of the tb->L[0]'s and left delimiting key are
1140 		   not set correctly */
1141 		if (tb->CFL[0]) {
1142 			if (!tb->CFR[0])
1143 				reiserfs_panic(tb->tb_sb, "vs-12195",
1144 					       "CFR not initialized");
1145 			copy_key(B_N_PDELIM_KEY(tb->CFL[0], tb->lkey[0]),
1146 				 B_N_PDELIM_KEY(tb->CFR[0], tb->rkey[0]));
1147 			do_balance_mark_internal_dirty(tb, tb->CFL[0], 0);
1148 		}
1149 
1150 		reiserfs_invalidate_buffer(tb, tbS0);
1151 		return 0;
1152 	}
1153 
1154 	/* Fill new nodes that appear in place of S[0] */
1155 
1156 	/* I am told that this copying is because we need an array to enable
1157 	   the looping code. -Hans */
1158 	snum[0] = tb->s1num, snum[1] = tb->s2num;
1159 	sbytes[0] = tb->s1bytes;
1160 	sbytes[1] = tb->s2bytes;
1161 	for (i = tb->blknum[0] - 2; i >= 0; i--) {
1162 
1163 		RFALSE(!snum[i], "PAP-12200: snum[%d] == %d. Must be > 0", i,
1164 		       snum[i]);
1165 
1166 		/* here we shift from S to S_new nodes */
1167 
1168 		S_new[i] = get_FEB(tb);
1169 
1170 		/* initialized block type and tree level */
1171 		set_blkh_level(B_BLK_HEAD(S_new[i]), DISK_LEAF_NODE_LEVEL);
1172 
1173 		n = B_NR_ITEMS(tbS0);
1174 
1175 		switch (flag) {
1176 		case M_INSERT:	/* insert item */
1177 
1178 			if (n - snum[i] < item_pos) {	/* new item or it's part falls to first new node S_new[i] */
1179 				if (item_pos == n - snum[i] + 1 && sbytes[i] != -1) {	/* part of new item falls into S_new[i] */
1180 					int old_key_comp, old_len,
1181 					    r_zeros_number;
1182 					const char *r_body;
1183 					int version;
1184 
1185 					/* Move snum[i]-1 items from S[0] to S_new[i] */
1186 					leaf_move_items(LEAF_FROM_S_TO_SNEW, tb,
1187 							snum[i] - 1, -1,
1188 							S_new[i]);
1189 					/* Remember key component and item length */
1190 					version = ih_version(ih);
1191 					old_key_comp = le_ih_k_offset(ih);
1192 					old_len = ih_item_len(ih);
1193 
1194 					/* Calculate key component and item length to insert into S_new[i] */
1195 					set_le_ih_k_offset(ih,
1196 							   le_ih_k_offset(ih) +
1197 							   ((old_len -
1198 							     sbytes[i]) <<
1199 							    (is_indirect_le_ih
1200 							     (ih) ? tb->tb_sb->
1201 							     s_blocksize_bits -
1202 							     UNFM_P_SHIFT :
1203 							     0)));
1204 
1205 					put_ih_item_len(ih, sbytes[i]);
1206 
1207 					/* Insert part of the item into S_new[i] before 0-th item */
1208 					buffer_info_init_bh(tb, &bi, S_new[i]);
1209 
1210 					if ((old_len - sbytes[i]) > zeros_num) {
1211 						r_zeros_number = 0;
1212 						r_body =
1213 						    body + (old_len -
1214 							    sbytes[i]) -
1215 						    zeros_num;
1216 					} else {
1217 						r_body = body;
1218 						r_zeros_number =
1219 						    zeros_num - (old_len -
1220 								 sbytes[i]);
1221 						zeros_num -= r_zeros_number;
1222 					}
1223 
1224 					leaf_insert_into_buf(&bi, 0, ih, r_body,
1225 							     r_zeros_number);
1226 
1227 					/* Calculate key component and item length to insert into S[i] */
1228 					set_le_ih_k_offset(ih, old_key_comp);
1229 					put_ih_item_len(ih,
1230 							old_len - sbytes[i]);
1231 					tb->insert_size[0] -= sbytes[i];
1232 				} else {	/* whole new item falls into S_new[i] */
1233 
1234 					/* Shift snum[0] - 1 items to S_new[i] (sbytes[i] of split item) */
1235 					leaf_move_items(LEAF_FROM_S_TO_SNEW, tb,
1236 							snum[i] - 1, sbytes[i],
1237 							S_new[i]);
1238 
1239 					/* Insert new item into S_new[i] */
1240 					buffer_info_init_bh(tb, &bi, S_new[i]);
1241 					leaf_insert_into_buf(&bi,
1242 							     item_pos - n +
1243 							     snum[i] - 1, ih,
1244 							     body, zeros_num);
1245 
1246 					zeros_num = tb->insert_size[0] = 0;
1247 				}
1248 			}
1249 
1250 			else {	/* new item or it part don't falls into S_new[i] */
1251 
1252 				leaf_move_items(LEAF_FROM_S_TO_SNEW, tb,
1253 						snum[i], sbytes[i], S_new[i]);
1254 			}
1255 			break;
1256 
1257 		case M_PASTE:	/* append item */
1258 
1259 			if (n - snum[i] <= item_pos) {	/* pasted item or part if it falls to S_new[i] */
1260 				if (item_pos == n - snum[i] && sbytes[i] != -1) {	/* we must shift part of the appended item */
1261 					struct item_head *aux_ih;
1262 
1263 					RFALSE(ih, "PAP-12210: ih must be 0");
1264 
1265 					aux_ih = B_N_PITEM_HEAD(tbS0, item_pos);
1266 					if (is_direntry_le_ih(aux_ih)) {
1267 						/* we append to directory item */
1268 
1269 						int entry_count;
1270 
1271 						entry_count =
1272 						    ih_entry_count(aux_ih);
1273 
1274 						if (entry_count - sbytes[i] <
1275 						    pos_in_item
1276 						    && pos_in_item <=
1277 						    entry_count) {
1278 							/* new directory entry falls into S_new[i] */
1279 
1280 							RFALSE(!tb->
1281 							       insert_size[0],
1282 							       "PAP-12215: insert_size is already 0");
1283 							RFALSE(sbytes[i] - 1 >=
1284 							       entry_count,
1285 							       "PAP-12220: there are no so much entries (%d), only %d",
1286 							       sbytes[i] - 1,
1287 							       entry_count);
1288 
1289 							/* Shift snum[i]-1 items in whole. Shift sbytes[i] directory entries from directory item number snum[i] */
1290 							leaf_move_items
1291 							    (LEAF_FROM_S_TO_SNEW,
1292 							     tb, snum[i],
1293 							     sbytes[i] - 1,
1294 							     S_new[i]);
1295 							/* Paste given directory entry to directory item */
1296 							buffer_info_init_bh(tb, &bi, S_new[i]);
1297 							leaf_paste_in_buffer
1298 							    (&bi, 0,
1299 							     pos_in_item -
1300 							     entry_count +
1301 							     sbytes[i] - 1,
1302 							     tb->insert_size[0],
1303 							     body, zeros_num);
1304 							/* paste new directory entry */
1305 							leaf_paste_entries(&bi,
1306 									   0,
1307 									   pos_in_item
1308 									   -
1309 									   entry_count
1310 									   +
1311 									   sbytes
1312 									   [i] -
1313 									   1, 1,
1314 									   (struct
1315 									    reiserfs_de_head
1316 									    *)
1317 									   body,
1318 									   body
1319 									   +
1320 									   DEH_SIZE,
1321 									   tb->
1322 									   insert_size
1323 									   [0]
1324 							    );
1325 							tb->insert_size[0] = 0;
1326 							pos_in_item++;
1327 						} else {	/* new directory entry doesn't fall into S_new[i] */
1328 							leaf_move_items
1329 							    (LEAF_FROM_S_TO_SNEW,
1330 							     tb, snum[i],
1331 							     sbytes[i],
1332 							     S_new[i]);
1333 						}
1334 					} else {	/* regular object */
1335 
1336 						int n_shift, n_rem,
1337 						    r_zeros_number;
1338 						const char *r_body;
1339 
1340 						RFALSE(pos_in_item !=
1341 						       ih_item_len
1342 						       (B_N_PITEM_HEAD
1343 							(tbS0, item_pos))
1344 						       || tb->insert_size[0] <=
1345 						       0,
1346 						       "PAP-12225: item too short or insert_size <= 0");
1347 
1348 						/* Calculate number of bytes which must be shifted from appended item */
1349 						n_shift =
1350 						    sbytes[i] -
1351 						    tb->insert_size[0];
1352 						if (n_shift < 0)
1353 							n_shift = 0;
1354 						leaf_move_items
1355 						    (LEAF_FROM_S_TO_SNEW, tb,
1356 						     snum[i], n_shift,
1357 						     S_new[i]);
1358 
1359 						/* Calculate number of bytes which must remain in body after append to S_new[i] */
1360 						n_rem =
1361 						    tb->insert_size[0] -
1362 						    sbytes[i];
1363 						if (n_rem < 0)
1364 							n_rem = 0;
1365 						/* Append part of body into S_new[0] */
1366 						buffer_info_init_bh(tb, &bi, S_new[i]);
1367 						if (n_rem > zeros_num) {
1368 							r_zeros_number = 0;
1369 							r_body =
1370 							    body + n_rem -
1371 							    zeros_num;
1372 						} else {
1373 							r_body = body;
1374 							r_zeros_number =
1375 							    zeros_num - n_rem;
1376 							zeros_num -=
1377 							    r_zeros_number;
1378 						}
1379 
1380 						leaf_paste_in_buffer(&bi, 0,
1381 								     n_shift,
1382 								     tb->
1383 								     insert_size
1384 								     [0] -
1385 								     n_rem,
1386 								     r_body,
1387 								     r_zeros_number);
1388 						{
1389 							struct item_head *tmp;
1390 
1391 							tmp =
1392 							    B_N_PITEM_HEAD(S_new
1393 									   [i],
1394 									   0);
1395 							if (is_indirect_le_ih
1396 							    (tmp)) {
1397 								set_ih_free_space
1398 								    (tmp, 0);
1399 								set_le_ih_k_offset
1400 								    (tmp,
1401 								     le_ih_k_offset
1402 								     (tmp) +
1403 								     (n_rem <<
1404 								      (tb->
1405 								       tb_sb->
1406 								       s_blocksize_bits
1407 								       -
1408 								       UNFM_P_SHIFT)));
1409 							} else {
1410 								set_le_ih_k_offset
1411 								    (tmp,
1412 								     le_ih_k_offset
1413 								     (tmp) +
1414 								     n_rem);
1415 							}
1416 						}
1417 
1418 						tb->insert_size[0] = n_rem;
1419 						if (!n_rem)
1420 							pos_in_item++;
1421 					}
1422 				} else
1423 					/* item falls wholly into S_new[i] */
1424 				{
1425 					int leaf_mi;
1426 					struct item_head *pasted;
1427 
1428 #ifdef CONFIG_REISERFS_CHECK
1429 					struct item_head *ih_check =
1430 					    B_N_PITEM_HEAD(tbS0, item_pos);
1431 
1432 					if (!is_direntry_le_ih(ih_check)
1433 					    && (pos_in_item != ih_item_len(ih_check)
1434 						|| tb->insert_size[0] <= 0))
1435 						reiserfs_panic(tb->tb_sb,
1436 							     "PAP-12235",
1437 							     "pos_in_item "
1438 							     "must be equal "
1439 							     "to ih_item_len");
1440 #endif				/* CONFIG_REISERFS_CHECK */
1441 
1442 					leaf_mi =
1443 					    leaf_move_items(LEAF_FROM_S_TO_SNEW,
1444 							    tb, snum[i],
1445 							    sbytes[i],
1446 							    S_new[i]);
1447 
1448 					RFALSE(leaf_mi,
1449 					       "PAP-12240: unexpected value returned by leaf_move_items (%d)",
1450 					       leaf_mi);
1451 
1452 					/* paste into item */
1453 					buffer_info_init_bh(tb, &bi, S_new[i]);
1454 					leaf_paste_in_buffer(&bi,
1455 							     item_pos - n +
1456 							     snum[i],
1457 							     pos_in_item,
1458 							     tb->insert_size[0],
1459 							     body, zeros_num);
1460 
1461 					pasted =
1462 					    B_N_PITEM_HEAD(S_new[i],
1463 							   item_pos - n +
1464 							   snum[i]);
1465 					if (is_direntry_le_ih(pasted)) {
1466 						leaf_paste_entries(&bi,
1467 								   item_pos -
1468 								   n + snum[i],
1469 								   pos_in_item,
1470 								   1,
1471 								   (struct
1472 								    reiserfs_de_head
1473 								    *)body,
1474 								   body +
1475 								   DEH_SIZE,
1476 								   tb->
1477 								   insert_size
1478 								   [0]
1479 						    );
1480 					}
1481 
1482 					/* if we paste to indirect item update ih_free_space */
1483 					if (is_indirect_le_ih(pasted))
1484 						set_ih_free_space(pasted, 0);
1485 					zeros_num = tb->insert_size[0] = 0;
1486 				}
1487 			}
1488 
1489 			else {	/* pasted item doesn't fall into S_new[i] */
1490 
1491 				leaf_move_items(LEAF_FROM_S_TO_SNEW, tb,
1492 						snum[i], sbytes[i], S_new[i]);
1493 			}
1494 			break;
1495 		default:	/* cases d and t */
1496 			reiserfs_panic(tb->tb_sb, "PAP-12245",
1497 				       "blknum > 2: unexpected mode: %s(%d)",
1498 				       (flag ==
1499 					M_DELETE) ? "DELETE" : ((flag ==
1500 								 M_CUT) ? "CUT"
1501 								: "UNKNOWN"),
1502 				       flag);
1503 		}
1504 
1505 		memcpy(insert_key + i, B_N_PKEY(S_new[i], 0), KEY_SIZE);
1506 		insert_ptr[i] = S_new[i];
1507 
1508 		RFALSE(!buffer_journaled(S_new[i])
1509 		       || buffer_journal_dirty(S_new[i])
1510 		       || buffer_dirty(S_new[i]), "PAP-12247: S_new[%d] : (%b)",
1511 		       i, S_new[i]);
1512 	}
1513 
1514 	/* if the affected item was not wholly shifted then we perform all necessary operations on that part or whole of the
1515 	   affected item which remains in S */
1516 	if (0 <= item_pos && item_pos < tb->s0num) {	/* if we must insert or append into buffer S[0] */
1517 
1518 		switch (flag) {
1519 		case M_INSERT:	/* insert item into S[0] */
1520 			buffer_info_init_tbS0(tb, &bi);
1521 			leaf_insert_into_buf(&bi, item_pos, ih, body,
1522 					     zeros_num);
1523 
1524 			/* If we insert the first key change the delimiting key */
1525 			if (item_pos == 0) {
1526 				if (tb->CFL[0])	/* can be 0 in reiserfsck */
1527 					replace_key(tb, tb->CFL[0], tb->lkey[0],
1528 						    tbS0, 0);
1529 
1530 			}
1531 			break;
1532 
1533 		case M_PASTE:{	/* append item in S[0] */
1534 				struct item_head *pasted;
1535 
1536 				pasted = B_N_PITEM_HEAD(tbS0, item_pos);
1537 				/* when directory, may be new entry already pasted */
1538 				if (is_direntry_le_ih(pasted)) {
1539 					if (pos_in_item >= 0 &&
1540 					    pos_in_item <=
1541 					    ih_entry_count(pasted)) {
1542 
1543 						RFALSE(!tb->insert_size[0],
1544 						       "PAP-12260: insert_size is 0 already");
1545 
1546 						/* prepare space */
1547 						buffer_info_init_tbS0(tb, &bi);
1548 						leaf_paste_in_buffer(&bi,
1549 								     item_pos,
1550 								     pos_in_item,
1551 								     tb->
1552 								     insert_size
1553 								     [0], body,
1554 								     zeros_num);
1555 
1556 						/* paste entry */
1557 						leaf_paste_entries(&bi,
1558 								   item_pos,
1559 								   pos_in_item,
1560 								   1,
1561 								   (struct
1562 								    reiserfs_de_head
1563 								    *)body,
1564 								   body +
1565 								   DEH_SIZE,
1566 								   tb->
1567 								   insert_size
1568 								   [0]
1569 						    );
1570 						if (!item_pos && !pos_in_item) {
1571 							RFALSE(!tb->CFL[0]
1572 							       || !tb->L[0],
1573 							       "PAP-12270: CFL[0]/L[0] must be specified");
1574 							if (tb->CFL[0]) {
1575 								replace_key(tb,
1576 									    tb->
1577 									    CFL
1578 									    [0],
1579 									    tb->
1580 									    lkey
1581 									    [0],
1582 									    tbS0,
1583 									    0);
1584 
1585 							}
1586 						}
1587 						tb->insert_size[0] = 0;
1588 					}
1589 				} else {	/* regular object */
1590 					if (pos_in_item == ih_item_len(pasted)) {
1591 
1592 						RFALSE(tb->insert_size[0] <= 0,
1593 						       "PAP-12275: insert size must not be %d",
1594 						       tb->insert_size[0]);
1595 						buffer_info_init_tbS0(tb, &bi);
1596 						leaf_paste_in_buffer(&bi,
1597 								     item_pos,
1598 								     pos_in_item,
1599 								     tb->
1600 								     insert_size
1601 								     [0], body,
1602 								     zeros_num);
1603 
1604 						if (is_indirect_le_ih(pasted)) {
1605 #if 0
1606 							RFALSE(tb->
1607 							       insert_size[0] !=
1608 							       UNFM_P_SIZE,
1609 							       "PAP-12280: insert_size for indirect item must be %d, not %d",
1610 							       UNFM_P_SIZE,
1611 							       tb->
1612 							       insert_size[0]);
1613 #endif
1614 							set_ih_free_space
1615 							    (pasted, 0);
1616 						}
1617 						tb->insert_size[0] = 0;
1618 					}
1619 #ifdef CONFIG_REISERFS_CHECK
1620 					else {
1621 						if (tb->insert_size[0]) {
1622 							print_cur_tb("12285");
1623 							reiserfs_panic(tb->
1624 								       tb_sb,
1625 							    "PAP-12285",
1626 							    "insert_size "
1627 							    "must be 0 "
1628 							    "(%d)",
1629 							    tb->insert_size[0]);
1630 						}
1631 					}
1632 #endif				/* CONFIG_REISERFS_CHECK */
1633 
1634 				}
1635 			}	/* case M_PASTE: */
1636 		}
1637 	}
1638 #ifdef CONFIG_REISERFS_CHECK
1639 	if (flag == M_PASTE && tb->insert_size[0]) {
1640 		print_cur_tb("12290");
1641 		reiserfs_panic(tb->tb_sb,
1642 			       "PAP-12290", "insert_size is still not 0 (%d)",
1643 			       tb->insert_size[0]);
1644 	}
1645 #endif				/* CONFIG_REISERFS_CHECK */
1646 	return 0;
1647 }				/* Leaf level of the tree is balanced (end of balance_leaf) */
1648 
1649 /* Make empty node */
1650 void make_empty_node(struct buffer_info *bi)
1651 {
1652 	struct block_head *blkh;
1653 
1654 	RFALSE(bi->bi_bh == NULL, "PAP-12295: pointer to the buffer is NULL");
1655 
1656 	blkh = B_BLK_HEAD(bi->bi_bh);
1657 	set_blkh_nr_item(blkh, 0);
1658 	set_blkh_free_space(blkh, MAX_CHILD_SIZE(bi->bi_bh));
1659 
1660 	if (bi->bi_parent)
1661 		B_N_CHILD(bi->bi_parent, bi->bi_position)->dc_size = 0;	/* Endian safe if 0 */
1662 }
1663 
1664 /* Get first empty buffer */
1665 struct buffer_head *get_FEB(struct tree_balance *tb)
1666 {
1667 	int i;
1668 	struct buffer_info bi;
1669 
1670 	for (i = 0; i < MAX_FEB_SIZE; i++)
1671 		if (tb->FEB[i] != NULL)
1672 			break;
1673 
1674 	if (i == MAX_FEB_SIZE)
1675 		reiserfs_panic(tb->tb_sb, "vs-12300", "FEB list is empty");
1676 
1677 	buffer_info_init_bh(tb, &bi, tb->FEB[i]);
1678 	make_empty_node(&bi);
1679 	set_buffer_uptodate(tb->FEB[i]);
1680 	tb->used[i] = tb->FEB[i];
1681 	tb->FEB[i] = NULL;
1682 
1683 	return tb->used[i];
1684 }
1685 
1686 /* This is now used because reiserfs_free_block has to be able to
1687 ** schedule.
1688 */
1689 static void store_thrown(struct tree_balance *tb, struct buffer_head *bh)
1690 {
1691 	int i;
1692 
1693 	if (buffer_dirty(bh))
1694 		reiserfs_warning(tb->tb_sb, "reiserfs-12320",
1695 				 "called with dirty buffer");
1696 	for (i = 0; i < ARRAY_SIZE(tb->thrown); i++)
1697 		if (!tb->thrown[i]) {
1698 			tb->thrown[i] = bh;
1699 			get_bh(bh);	/* free_thrown puts this */
1700 			return;
1701 		}
1702 	reiserfs_warning(tb->tb_sb, "reiserfs-12321",
1703 			 "too many thrown buffers");
1704 }
1705 
1706 static void free_thrown(struct tree_balance *tb)
1707 {
1708 	int i;
1709 	b_blocknr_t blocknr;
1710 	for (i = 0; i < ARRAY_SIZE(tb->thrown); i++) {
1711 		if (tb->thrown[i]) {
1712 			blocknr = tb->thrown[i]->b_blocknr;
1713 			if (buffer_dirty(tb->thrown[i]))
1714 				reiserfs_warning(tb->tb_sb, "reiserfs-12322",
1715 						 "called with dirty buffer %d",
1716 						 blocknr);
1717 			brelse(tb->thrown[i]);	/* incremented in store_thrown */
1718 			reiserfs_free_block(tb->transaction_handle, NULL,
1719 					    blocknr, 0);
1720 		}
1721 	}
1722 }
1723 
1724 void reiserfs_invalidate_buffer(struct tree_balance *tb, struct buffer_head *bh)
1725 {
1726 	struct block_head *blkh;
1727 	blkh = B_BLK_HEAD(bh);
1728 	set_blkh_level(blkh, FREE_LEVEL);
1729 	set_blkh_nr_item(blkh, 0);
1730 
1731 	clear_buffer_dirty(bh);
1732 	store_thrown(tb, bh);
1733 }
1734 
1735 /* Replace n_dest'th key in buffer dest by n_src'th key of buffer src.*/
1736 void replace_key(struct tree_balance *tb, struct buffer_head *dest, int n_dest,
1737 		 struct buffer_head *src, int n_src)
1738 {
1739 
1740 	RFALSE(dest == NULL || src == NULL,
1741 	       "vs-12305: source or destination buffer is 0 (src=%p, dest=%p)",
1742 	       src, dest);
1743 	RFALSE(!B_IS_KEYS_LEVEL(dest),
1744 	       "vs-12310: invalid level (%z) for destination buffer. dest must be leaf",
1745 	       dest);
1746 	RFALSE(n_dest < 0 || n_src < 0,
1747 	       "vs-12315: src(%d) or dest(%d) key number < 0", n_src, n_dest);
1748 	RFALSE(n_dest >= B_NR_ITEMS(dest) || n_src >= B_NR_ITEMS(src),
1749 	       "vs-12320: src(%d(%d)) or dest(%d(%d)) key number is too big",
1750 	       n_src, B_NR_ITEMS(src), n_dest, B_NR_ITEMS(dest));
1751 
1752 	if (B_IS_ITEMS_LEVEL(src))
1753 		/* source buffer contains leaf node */
1754 		memcpy(B_N_PDELIM_KEY(dest, n_dest), B_N_PITEM_HEAD(src, n_src),
1755 		       KEY_SIZE);
1756 	else
1757 		memcpy(B_N_PDELIM_KEY(dest, n_dest), B_N_PDELIM_KEY(src, n_src),
1758 		       KEY_SIZE);
1759 
1760 	do_balance_mark_internal_dirty(tb, dest, 0);
1761 }
1762 
1763 int get_left_neighbor_position(struct tree_balance *tb, int h)
1764 {
1765 	int Sh_position = PATH_H_POSITION(tb->tb_path, h + 1);
1766 
1767 	RFALSE(PATH_H_PPARENT(tb->tb_path, h) == NULL || tb->FL[h] == NULL,
1768 	       "vs-12325: FL[%d](%p) or F[%d](%p) does not exist",
1769 	       h, tb->FL[h], h, PATH_H_PPARENT(tb->tb_path, h));
1770 
1771 	if (Sh_position == 0)
1772 		return B_NR_ITEMS(tb->FL[h]);
1773 	else
1774 		return Sh_position - 1;
1775 }
1776 
1777 int get_right_neighbor_position(struct tree_balance *tb, int h)
1778 {
1779 	int Sh_position = PATH_H_POSITION(tb->tb_path, h + 1);
1780 
1781 	RFALSE(PATH_H_PPARENT(tb->tb_path, h) == NULL || tb->FR[h] == NULL,
1782 	       "vs-12330: F[%d](%p) or FR[%d](%p) does not exist",
1783 	       h, PATH_H_PPARENT(tb->tb_path, h), h, tb->FR[h]);
1784 
1785 	if (Sh_position == B_NR_ITEMS(PATH_H_PPARENT(tb->tb_path, h)))
1786 		return 0;
1787 	else
1788 		return Sh_position + 1;
1789 }
1790 
1791 #ifdef CONFIG_REISERFS_CHECK
1792 
1793 int is_reusable(struct super_block *s, b_blocknr_t block, int bit_value);
1794 static void check_internal_node(struct super_block *s, struct buffer_head *bh,
1795 				char *mes)
1796 {
1797 	struct disk_child *dc;
1798 	int i;
1799 
1800 	RFALSE(!bh, "PAP-12336: bh == 0");
1801 
1802 	if (!bh || !B_IS_IN_TREE(bh))
1803 		return;
1804 
1805 	RFALSE(!buffer_dirty(bh) &&
1806 	       !(buffer_journaled(bh) || buffer_journal_dirty(bh)),
1807 	       "PAP-12337: buffer (%b) must be dirty", bh);
1808 	dc = B_N_CHILD(bh, 0);
1809 
1810 	for (i = 0; i <= B_NR_ITEMS(bh); i++, dc++) {
1811 		if (!is_reusable(s, dc_block_number(dc), 1)) {
1812 			print_cur_tb(mes);
1813 			reiserfs_panic(s, "PAP-12338",
1814 				       "invalid child pointer %y in %b",
1815 				       dc, bh);
1816 		}
1817 	}
1818 }
1819 
1820 static int locked_or_not_in_tree(struct tree_balance *tb,
1821 				  struct buffer_head *bh, char *which)
1822 {
1823 	if ((!buffer_journal_prepared(bh) && buffer_locked(bh)) ||
1824 	    !B_IS_IN_TREE(bh)) {
1825 		reiserfs_warning(tb->tb_sb, "vs-12339", "%s (%b)", which, bh);
1826 		return 1;
1827 	}
1828 	return 0;
1829 }
1830 
1831 static int check_before_balancing(struct tree_balance *tb)
1832 {
1833 	int retval = 0;
1834 
1835 	if (REISERFS_SB(tb->tb_sb)->cur_tb) {
1836 		reiserfs_panic(tb->tb_sb, "vs-12335", "suspect that schedule "
1837 			       "occurred based on cur_tb not being null at "
1838 			       "this point in code. do_balance cannot properly "
1839 			       "handle concurrent tree accesses on a same "
1840 			       "mount point.");
1841 	}
1842 
1843 	/* double check that buffers that we will modify are unlocked. (fix_nodes should already have
1844 	   prepped all of these for us). */
1845 	if (tb->lnum[0]) {
1846 		retval |= locked_or_not_in_tree(tb, tb->L[0], "L[0]");
1847 		retval |= locked_or_not_in_tree(tb, tb->FL[0], "FL[0]");
1848 		retval |= locked_or_not_in_tree(tb, tb->CFL[0], "CFL[0]");
1849 		check_leaf(tb->L[0]);
1850 	}
1851 	if (tb->rnum[0]) {
1852 		retval |= locked_or_not_in_tree(tb, tb->R[0], "R[0]");
1853 		retval |= locked_or_not_in_tree(tb, tb->FR[0], "FR[0]");
1854 		retval |= locked_or_not_in_tree(tb, tb->CFR[0], "CFR[0]");
1855 		check_leaf(tb->R[0]);
1856 	}
1857 	retval |= locked_or_not_in_tree(tb, PATH_PLAST_BUFFER(tb->tb_path),
1858 					"S[0]");
1859 	check_leaf(PATH_PLAST_BUFFER(tb->tb_path));
1860 
1861 	return retval;
1862 }
1863 
1864 static void check_after_balance_leaf(struct tree_balance *tb)
1865 {
1866 	if (tb->lnum[0]) {
1867 		if (B_FREE_SPACE(tb->L[0]) !=
1868 		    MAX_CHILD_SIZE(tb->L[0]) -
1869 		    dc_size(B_N_CHILD
1870 			    (tb->FL[0], get_left_neighbor_position(tb, 0)))) {
1871 			print_cur_tb("12221");
1872 			reiserfs_panic(tb->tb_sb, "PAP-12355",
1873 				       "shift to left was incorrect");
1874 		}
1875 	}
1876 	if (tb->rnum[0]) {
1877 		if (B_FREE_SPACE(tb->R[0]) !=
1878 		    MAX_CHILD_SIZE(tb->R[0]) -
1879 		    dc_size(B_N_CHILD
1880 			    (tb->FR[0], get_right_neighbor_position(tb, 0)))) {
1881 			print_cur_tb("12222");
1882 			reiserfs_panic(tb->tb_sb, "PAP-12360",
1883 				       "shift to right was incorrect");
1884 		}
1885 	}
1886 	if (PATH_H_PBUFFER(tb->tb_path, 1) &&
1887 	    (B_FREE_SPACE(PATH_H_PBUFFER(tb->tb_path, 0)) !=
1888 	     (MAX_CHILD_SIZE(PATH_H_PBUFFER(tb->tb_path, 0)) -
1889 	      dc_size(B_N_CHILD(PATH_H_PBUFFER(tb->tb_path, 1),
1890 				PATH_H_POSITION(tb->tb_path, 1)))))) {
1891 		int left = B_FREE_SPACE(PATH_H_PBUFFER(tb->tb_path, 0));
1892 		int right = (MAX_CHILD_SIZE(PATH_H_PBUFFER(tb->tb_path, 0)) -
1893 			     dc_size(B_N_CHILD(PATH_H_PBUFFER(tb->tb_path, 1),
1894 					       PATH_H_POSITION(tb->tb_path,
1895 							       1))));
1896 		print_cur_tb("12223");
1897 		reiserfs_warning(tb->tb_sb, "reiserfs-12363",
1898 				 "B_FREE_SPACE (PATH_H_PBUFFER(tb->tb_path,0)) = %d; "
1899 				 "MAX_CHILD_SIZE (%d) - dc_size( %y, %d ) [%d] = %d",
1900 				 left,
1901 				 MAX_CHILD_SIZE(PATH_H_PBUFFER(tb->tb_path, 0)),
1902 				 PATH_H_PBUFFER(tb->tb_path, 1),
1903 				 PATH_H_POSITION(tb->tb_path, 1),
1904 				 dc_size(B_N_CHILD
1905 					 (PATH_H_PBUFFER(tb->tb_path, 1),
1906 					  PATH_H_POSITION(tb->tb_path, 1))),
1907 				 right);
1908 		reiserfs_panic(tb->tb_sb, "PAP-12365", "S is incorrect");
1909 	}
1910 }
1911 
1912 static void check_leaf_level(struct tree_balance *tb)
1913 {
1914 	check_leaf(tb->L[0]);
1915 	check_leaf(tb->R[0]);
1916 	check_leaf(PATH_PLAST_BUFFER(tb->tb_path));
1917 }
1918 
1919 static void check_internal_levels(struct tree_balance *tb)
1920 {
1921 	int h;
1922 
1923 	/* check all internal nodes */
1924 	for (h = 1; tb->insert_size[h]; h++) {
1925 		check_internal_node(tb->tb_sb, PATH_H_PBUFFER(tb->tb_path, h),
1926 				    "BAD BUFFER ON PATH");
1927 		if (tb->lnum[h])
1928 			check_internal_node(tb->tb_sb, tb->L[h], "BAD L");
1929 		if (tb->rnum[h])
1930 			check_internal_node(tb->tb_sb, tb->R[h], "BAD R");
1931 	}
1932 
1933 }
1934 
1935 #endif
1936 
1937 /* Now we have all of the buffers that must be used in balancing of
1938    the tree.  We rely on the assumption that schedule() will not occur
1939    while do_balance works. ( Only interrupt handlers are acceptable.)
1940    We balance the tree according to the analysis made before this,
1941    using buffers already obtained.  For SMP support it will someday be
1942    necessary to add ordered locking of tb. */
1943 
1944 /* Some interesting rules of balancing:
1945 
1946    we delete a maximum of two nodes per level per balancing: we never
1947    delete R, when we delete two of three nodes L, S, R then we move
1948    them into R.
1949 
1950    we only delete L if we are deleting two nodes, if we delete only
1951    one node we delete S
1952 
1953    if we shift leaves then we shift as much as we can: this is a
1954    deliberate policy of extremism in node packing which results in
1955    higher average utilization after repeated random balance operations
1956    at the cost of more memory copies and more balancing as a result of
1957    small insertions to full nodes.
1958 
1959    if we shift internal nodes we try to evenly balance the node
1960    utilization, with consequent less balancing at the cost of lower
1961    utilization.
1962 
1963    one could argue that the policy for directories in leaves should be
1964    that of internal nodes, but we will wait until another day to
1965    evaluate this....  It would be nice to someday measure and prove
1966    these assumptions as to what is optimal....
1967 
1968 */
1969 
1970 static inline void do_balance_starts(struct tree_balance *tb)
1971 {
1972 	/* use print_cur_tb() to see initial state of struct
1973 	   tree_balance */
1974 
1975 	/* store_print_tb (tb); */
1976 
1977 	/* do not delete, just comment it out */
1978 /*    print_tb(flag, PATH_LAST_POSITION(tb->tb_path), tb->tb_path->pos_in_item, tb,
1979 	     "check");*/
1980 	RFALSE(check_before_balancing(tb), "PAP-12340: locked buffers in TB");
1981 #ifdef CONFIG_REISERFS_CHECK
1982 	REISERFS_SB(tb->tb_sb)->cur_tb = tb;
1983 #endif
1984 }
1985 
1986 static inline void do_balance_completed(struct tree_balance *tb)
1987 {
1988 
1989 #ifdef CONFIG_REISERFS_CHECK
1990 	check_leaf_level(tb);
1991 	check_internal_levels(tb);
1992 	REISERFS_SB(tb->tb_sb)->cur_tb = NULL;
1993 #endif
1994 
1995 	/* reiserfs_free_block is no longer schedule safe.  So, we need to
1996 	 ** put the buffers we want freed on the thrown list during do_balance,
1997 	 ** and then free them now
1998 	 */
1999 
2000 	REISERFS_SB(tb->tb_sb)->s_do_balance++;
2001 
2002 	/* release all nodes hold to perform the balancing */
2003 	unfix_nodes(tb);
2004 
2005 	free_thrown(tb);
2006 }
2007 
2008 void do_balance(struct tree_balance *tb,	/* tree_balance structure */
2009 		struct item_head *ih,	/* item header of inserted item */
2010 		const char *body,	/* body  of inserted item or bytes to paste */
2011 		int flag)
2012 {				/* i - insert, d - delete
2013 				   c - cut, p - paste
2014 
2015 				   Cut means delete part of an item
2016 				   (includes removing an entry from a
2017 				   directory).
2018 
2019 				   Delete means delete whole item.
2020 
2021 				   Insert means add a new item into the
2022 				   tree.
2023 
2024 				   Paste means to append to the end of an
2025 				   existing file or to insert a directory
2026 				   entry.  */
2027 	int child_pos,		/* position of a child node in its parent */
2028 	 h;			/* level of the tree being processed */
2029 	struct item_head insert_key[2];	/* in our processing of one level
2030 					   we sometimes determine what
2031 					   must be inserted into the next
2032 					   higher level.  This insertion
2033 					   consists of a key or two keys
2034 					   and their corresponding
2035 					   pointers */
2036 	struct buffer_head *insert_ptr[2];	/* inserted node-ptrs for the next
2037 						   level */
2038 
2039 	tb->tb_mode = flag;
2040 	tb->need_balance_dirty = 0;
2041 
2042 	if (FILESYSTEM_CHANGED_TB(tb)) {
2043 		reiserfs_panic(tb->tb_sb, "clm-6000", "fs generation has "
2044 			       "changed");
2045 	}
2046 	/* if we have no real work to do  */
2047 	if (!tb->insert_size[0]) {
2048 		reiserfs_warning(tb->tb_sb, "PAP-12350",
2049 				 "insert_size == 0, mode == %c", flag);
2050 		unfix_nodes(tb);
2051 		return;
2052 	}
2053 
2054 	atomic_inc(&(fs_generation(tb->tb_sb)));
2055 	do_balance_starts(tb);
2056 
2057 	/* balance leaf returns 0 except if combining L R and S into
2058 	   one node.  see balance_internal() for explanation of this
2059 	   line of code. */
2060 	child_pos = PATH_H_B_ITEM_ORDER(tb->tb_path, 0) +
2061 	    balance_leaf(tb, ih, body, flag, insert_key, insert_ptr);
2062 
2063 #ifdef CONFIG_REISERFS_CHECK
2064 	check_after_balance_leaf(tb);
2065 #endif
2066 
2067 	/* Balance internal level of the tree. */
2068 	for (h = 1; h < MAX_HEIGHT && tb->insert_size[h]; h++)
2069 		child_pos =
2070 		    balance_internal(tb, h, child_pos, insert_key, insert_ptr);
2071 
2072 	do_balance_completed(tb);
2073 
2074 }
2075