xref: /linux/fs/reiserfs/lbalance.c (revision c4c11dd160a8cc98f402c4e12f94b1572e822ffd)
1 /*
2  * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
3  */
4 
5 #include <asm/uaccess.h>
6 #include <linux/string.h>
7 #include <linux/time.h>
8 #include "reiserfs.h"
9 #include <linux/buffer_head.h>
10 
11 /* these are used in do_balance.c */
12 
13 /* leaf_move_items
14    leaf_shift_left
15    leaf_shift_right
16    leaf_delete_items
17    leaf_insert_into_buf
18    leaf_paste_in_buffer
19    leaf_cut_from_buffer
20    leaf_paste_entries
21    */
22 
23 /* copy copy_count entries from source directory item to dest buffer (creating new item if needed) */
24 static void leaf_copy_dir_entries(struct buffer_info *dest_bi,
25 				  struct buffer_head *source, int last_first,
26 				  int item_num, int from, int copy_count)
27 {
28 	struct buffer_head *dest = dest_bi->bi_bh;
29 	int item_num_in_dest;	/* either the number of target item,
30 				   or if we must create a new item,
31 				   the number of the item we will
32 				   create it next to */
33 	struct item_head *ih;
34 	struct reiserfs_de_head *deh;
35 	int copy_records_len;	/* length of all records in item to be copied */
36 	char *records;
37 
38 	ih = B_N_PITEM_HEAD(source, item_num);
39 
40 	RFALSE(!is_direntry_le_ih(ih), "vs-10000: item must be directory item");
41 
42 	/* length of all record to be copied and first byte of the last of them */
43 	deh = B_I_DEH(source, ih);
44 	if (copy_count) {
45 		copy_records_len = (from ? deh_location(&(deh[from - 1])) :
46 				    ih_item_len(ih)) -
47 		    deh_location(&(deh[from + copy_count - 1]));
48 		records =
49 		    source->b_data + ih_location(ih) +
50 		    deh_location(&(deh[from + copy_count - 1]));
51 	} else {
52 		copy_records_len = 0;
53 		records = NULL;
54 	}
55 
56 	/* when copy last to first, dest buffer can contain 0 items */
57 	item_num_in_dest =
58 	    (last_first ==
59 	     LAST_TO_FIRST) ? ((B_NR_ITEMS(dest)) ? 0 : -1) : (B_NR_ITEMS(dest)
60 							       - 1);
61 
62 	/* if there are no items in dest or the first/last item in dest is not item of the same directory */
63 	if ((item_num_in_dest == -1) ||
64 	    (last_first == FIRST_TO_LAST && le_ih_k_offset(ih) == DOT_OFFSET) ||
65 	    (last_first == LAST_TO_FIRST
66 	     && comp_short_le_keys /*COMP_SHORT_KEYS */ (&ih->ih_key,
67 							 B_N_PKEY(dest,
68 								  item_num_in_dest))))
69 	{
70 		/* create new item in dest */
71 		struct item_head new_ih;
72 
73 		/* form item header */
74 		memcpy(&new_ih.ih_key, &ih->ih_key, KEY_SIZE);
75 		put_ih_version(&new_ih, KEY_FORMAT_3_5);
76 		/* calculate item len */
77 		put_ih_item_len(&new_ih,
78 				DEH_SIZE * copy_count + copy_records_len);
79 		put_ih_entry_count(&new_ih, 0);
80 
81 		if (last_first == LAST_TO_FIRST) {
82 			/* form key by the following way */
83 			if (from < I_ENTRY_COUNT(ih)) {
84 				set_le_ih_k_offset(&new_ih,
85 						   deh_offset(&(deh[from])));
86 				/*memcpy (&new_ih.ih_key.k_offset, &deh[from].deh_offset, SHORT_KEY_SIZE); */
87 			} else {
88 				/* no entries will be copied to this item in this function */
89 				set_le_ih_k_offset(&new_ih, U32_MAX);
90 				/* this item is not yet valid, but we want I_IS_DIRECTORY_ITEM to return 1 for it, so we -1 */
91 			}
92 			set_le_key_k_type(KEY_FORMAT_3_5, &(new_ih.ih_key),
93 					  TYPE_DIRENTRY);
94 		}
95 
96 		/* insert item into dest buffer */
97 		leaf_insert_into_buf(dest_bi,
98 				     (last_first ==
99 				      LAST_TO_FIRST) ? 0 : B_NR_ITEMS(dest),
100 				     &new_ih, NULL, 0);
101 	} else {
102 		/* prepare space for entries */
103 		leaf_paste_in_buffer(dest_bi,
104 				     (last_first ==
105 				      FIRST_TO_LAST) ? (B_NR_ITEMS(dest) -
106 							1) : 0, MAX_US_INT,
107 				     DEH_SIZE * copy_count + copy_records_len,
108 				     records, 0);
109 	}
110 
111 	item_num_in_dest =
112 	    (last_first == FIRST_TO_LAST) ? (B_NR_ITEMS(dest) - 1) : 0;
113 
114 	leaf_paste_entries(dest_bi, item_num_in_dest,
115 			   (last_first ==
116 			    FIRST_TO_LAST) ? I_ENTRY_COUNT(B_N_PITEM_HEAD(dest,
117 									  item_num_in_dest))
118 			   : 0, copy_count, deh + from, records,
119 			   DEH_SIZE * copy_count + copy_records_len);
120 }
121 
122 /* Copy the first (if last_first == FIRST_TO_LAST) or last (last_first == LAST_TO_FIRST) item or
123    part of it or nothing (see the return 0 below) from SOURCE to the end
124    (if last_first) or beginning (!last_first) of the DEST */
125 /* returns 1 if anything was copied, else 0 */
126 static int leaf_copy_boundary_item(struct buffer_info *dest_bi,
127 				   struct buffer_head *src, int last_first,
128 				   int bytes_or_entries)
129 {
130 	struct buffer_head *dest = dest_bi->bi_bh;
131 	int dest_nr_item, src_nr_item;	/* number of items in the source and destination buffers */
132 	struct item_head *ih;
133 	struct item_head *dih;
134 
135 	dest_nr_item = B_NR_ITEMS(dest);
136 
137 	if (last_first == FIRST_TO_LAST) {
138 		/* if ( DEST is empty or first item of SOURCE and last item of DEST are the items of different objects
139 		   or of different types ) then there is no need to treat this item differently from the other items
140 		   that we copy, so we return */
141 		ih = B_N_PITEM_HEAD(src, 0);
142 		dih = B_N_PITEM_HEAD(dest, dest_nr_item - 1);
143 		if (!dest_nr_item
144 		    || (!op_is_left_mergeable(&(ih->ih_key), src->b_size)))
145 			/* there is nothing to merge */
146 			return 0;
147 
148 		RFALSE(!ih_item_len(ih),
149 		       "vs-10010: item can not have empty length");
150 
151 		if (is_direntry_le_ih(ih)) {
152 			if (bytes_or_entries == -1)
153 				/* copy all entries to dest */
154 				bytes_or_entries = ih_entry_count(ih);
155 			leaf_copy_dir_entries(dest_bi, src, FIRST_TO_LAST, 0, 0,
156 					      bytes_or_entries);
157 			return 1;
158 		}
159 
160 		/* copy part of the body of the first item of SOURCE to the end of the body of the last item of the DEST
161 		   part defined by 'bytes_or_entries'; if bytes_or_entries == -1 copy whole body; don't create new item header
162 		 */
163 		if (bytes_or_entries == -1)
164 			bytes_or_entries = ih_item_len(ih);
165 
166 #ifdef CONFIG_REISERFS_CHECK
167 		else {
168 			if (bytes_or_entries == ih_item_len(ih)
169 			    && is_indirect_le_ih(ih))
170 				if (get_ih_free_space(ih))
171 					reiserfs_panic(sb_from_bi(dest_bi),
172 						       "vs-10020",
173 						       "last unformatted node "
174 						       "must be filled "
175 						       "entirely (%h)", ih);
176 		}
177 #endif
178 
179 		/* merge first item (or its part) of src buffer with the last
180 		   item of dest buffer. Both are of the same file */
181 		leaf_paste_in_buffer(dest_bi,
182 				     dest_nr_item - 1, ih_item_len(dih),
183 				     bytes_or_entries, B_I_PITEM(src, ih), 0);
184 
185 		if (is_indirect_le_ih(dih)) {
186 			RFALSE(get_ih_free_space(dih),
187 			       "vs-10030: merge to left: last unformatted node of non-last indirect item %h must have zerto free space",
188 			       ih);
189 			if (bytes_or_entries == ih_item_len(ih))
190 				set_ih_free_space(dih, get_ih_free_space(ih));
191 		}
192 
193 		return 1;
194 	}
195 
196 	/* copy boundary item to right (last_first == LAST_TO_FIRST) */
197 
198 	/* ( DEST is empty or last item of SOURCE and first item of DEST
199 	   are the items of different object or of different types )
200 	 */
201 	src_nr_item = B_NR_ITEMS(src);
202 	ih = B_N_PITEM_HEAD(src, src_nr_item - 1);
203 	dih = B_N_PITEM_HEAD(dest, 0);
204 
205 	if (!dest_nr_item || !op_is_left_mergeable(&(dih->ih_key), src->b_size))
206 		return 0;
207 
208 	if (is_direntry_le_ih(ih)) {
209 		if (bytes_or_entries == -1)
210 			/* bytes_or_entries = entries number in last item body of SOURCE */
211 			bytes_or_entries = ih_entry_count(ih);
212 
213 		leaf_copy_dir_entries(dest_bi, src, LAST_TO_FIRST,
214 				      src_nr_item - 1,
215 				      ih_entry_count(ih) - bytes_or_entries,
216 				      bytes_or_entries);
217 		return 1;
218 	}
219 
220 	/* copy part of the body of the last item of SOURCE to the begin of the body of the first item of the DEST;
221 	   part defined by 'bytes_or_entries'; if byte_or_entriess == -1 copy whole body; change first item key of the DEST;
222 	   don't create new item header
223 	 */
224 
225 	RFALSE(is_indirect_le_ih(ih) && get_ih_free_space(ih),
226 	       "vs-10040: merge to right: last unformatted node of non-last indirect item must be filled entirely (%h)",
227 	       ih);
228 
229 	if (bytes_or_entries == -1) {
230 		/* bytes_or_entries = length of last item body of SOURCE */
231 		bytes_or_entries = ih_item_len(ih);
232 
233 		RFALSE(le_ih_k_offset(dih) !=
234 		       le_ih_k_offset(ih) + op_bytes_number(ih, src->b_size),
235 		       "vs-10050: items %h and %h do not match", ih, dih);
236 
237 		/* change first item key of the DEST */
238 		set_le_ih_k_offset(dih, le_ih_k_offset(ih));
239 
240 		/* item becomes non-mergeable */
241 		/* or mergeable if left item was */
242 		set_le_ih_k_type(dih, le_ih_k_type(ih));
243 	} else {
244 		/* merge to right only part of item */
245 		RFALSE(ih_item_len(ih) <= bytes_or_entries,
246 		       "vs-10060: no so much bytes %lu (needed %lu)",
247 		       (unsigned long)ih_item_len(ih),
248 		       (unsigned long)bytes_or_entries);
249 
250 		/* change first item key of the DEST */
251 		if (is_direct_le_ih(dih)) {
252 			RFALSE(le_ih_k_offset(dih) <=
253 			       (unsigned long)bytes_or_entries,
254 			       "vs-10070: dih %h, bytes_or_entries(%d)", dih,
255 			       bytes_or_entries);
256 			set_le_ih_k_offset(dih,
257 					   le_ih_k_offset(dih) -
258 					   bytes_or_entries);
259 		} else {
260 			RFALSE(le_ih_k_offset(dih) <=
261 			       (bytes_or_entries / UNFM_P_SIZE) * dest->b_size,
262 			       "vs-10080: dih %h, bytes_or_entries(%d)",
263 			       dih,
264 			       (bytes_or_entries / UNFM_P_SIZE) * dest->b_size);
265 			set_le_ih_k_offset(dih,
266 					   le_ih_k_offset(dih) -
267 					   ((bytes_or_entries / UNFM_P_SIZE) *
268 					    dest->b_size));
269 		}
270 	}
271 
272 	leaf_paste_in_buffer(dest_bi, 0, 0, bytes_or_entries,
273 			     B_I_PITEM(src,
274 				       ih) + ih_item_len(ih) - bytes_or_entries,
275 			     0);
276 	return 1;
277 }
278 
279 /* copy cpy_mun items from buffer src to buffer dest
280  * last_first == FIRST_TO_LAST means, that we copy cpy_num  items beginning from first-th item in src to tail of dest
281  * last_first == LAST_TO_FIRST means, that we copy cpy_num  items beginning from first-th item in src to head of dest
282  */
283 static void leaf_copy_items_entirely(struct buffer_info *dest_bi,
284 				     struct buffer_head *src, int last_first,
285 				     int first, int cpy_num)
286 {
287 	struct buffer_head *dest;
288 	int nr, free_space;
289 	int dest_before;
290 	int last_loc, last_inserted_loc, location;
291 	int i, j;
292 	struct block_head *blkh;
293 	struct item_head *ih;
294 
295 	RFALSE(last_first != LAST_TO_FIRST && last_first != FIRST_TO_LAST,
296 	       "vs-10090: bad last_first parameter %d", last_first);
297 	RFALSE(B_NR_ITEMS(src) - first < cpy_num,
298 	       "vs-10100: too few items in source %d, required %d from %d",
299 	       B_NR_ITEMS(src), cpy_num, first);
300 	RFALSE(cpy_num < 0, "vs-10110: can not copy negative amount of items");
301 	RFALSE(!dest_bi, "vs-10120: can not copy negative amount of items");
302 
303 	dest = dest_bi->bi_bh;
304 
305 	RFALSE(!dest, "vs-10130: can not copy negative amount of items");
306 
307 	if (cpy_num == 0)
308 		return;
309 
310 	blkh = B_BLK_HEAD(dest);
311 	nr = blkh_nr_item(blkh);
312 	free_space = blkh_free_space(blkh);
313 
314 	/* we will insert items before 0-th or nr-th item in dest buffer. It depends of last_first parameter */
315 	dest_before = (last_first == LAST_TO_FIRST) ? 0 : nr;
316 
317 	/* location of head of first new item */
318 	ih = B_N_PITEM_HEAD(dest, dest_before);
319 
320 	RFALSE(blkh_free_space(blkh) < cpy_num * IH_SIZE,
321 	       "vs-10140: not enough free space for headers %d (needed %d)",
322 	       B_FREE_SPACE(dest), cpy_num * IH_SIZE);
323 
324 	/* prepare space for headers */
325 	memmove(ih + cpy_num, ih, (nr - dest_before) * IH_SIZE);
326 
327 	/* copy item headers */
328 	memcpy(ih, B_N_PITEM_HEAD(src, first), cpy_num * IH_SIZE);
329 
330 	free_space -= (IH_SIZE * cpy_num);
331 	set_blkh_free_space(blkh, free_space);
332 
333 	/* location of unmovable item */
334 	j = location = (dest_before == 0) ? dest->b_size : ih_location(ih - 1);
335 	for (i = dest_before; i < nr + cpy_num; i++) {
336 		location -= ih_item_len(ih + i - dest_before);
337 		put_ih_location(ih + i - dest_before, location);
338 	}
339 
340 	/* prepare space for items */
341 	last_loc = ih_location(&(ih[nr + cpy_num - 1 - dest_before]));
342 	last_inserted_loc = ih_location(&(ih[cpy_num - 1]));
343 
344 	/* check free space */
345 	RFALSE(free_space < j - last_inserted_loc,
346 	       "vs-10150: not enough free space for items %d (needed %d)",
347 	       free_space, j - last_inserted_loc);
348 
349 	memmove(dest->b_data + last_loc,
350 		dest->b_data + last_loc + j - last_inserted_loc,
351 		last_inserted_loc - last_loc);
352 
353 	/* copy items */
354 	memcpy(dest->b_data + last_inserted_loc,
355 	       B_N_PITEM(src, (first + cpy_num - 1)), j - last_inserted_loc);
356 
357 	/* sizes, item number */
358 	set_blkh_nr_item(blkh, nr + cpy_num);
359 	set_blkh_free_space(blkh, free_space - (j - last_inserted_loc));
360 
361 	do_balance_mark_leaf_dirty(dest_bi->tb, dest, 0);
362 
363 	if (dest_bi->bi_parent) {
364 		struct disk_child *t_dc;
365 		t_dc = B_N_CHILD(dest_bi->bi_parent, dest_bi->bi_position);
366 		RFALSE(dc_block_number(t_dc) != dest->b_blocknr,
367 		       "vs-10160: block number in bh does not match to field in disk_child structure %lu and %lu",
368 		       (long unsigned)dest->b_blocknr,
369 		       (long unsigned)dc_block_number(t_dc));
370 		put_dc_size(t_dc,
371 			    dc_size(t_dc) + (j - last_inserted_loc +
372 					     IH_SIZE * cpy_num));
373 
374 		do_balance_mark_internal_dirty(dest_bi->tb, dest_bi->bi_parent,
375 					       0);
376 	}
377 }
378 
379 /* This function splits the (liquid) item into two items (useful when
380    shifting part of an item into another node.) */
381 static void leaf_item_bottle(struct buffer_info *dest_bi,
382 			     struct buffer_head *src, int last_first,
383 			     int item_num, int cpy_bytes)
384 {
385 	struct buffer_head *dest = dest_bi->bi_bh;
386 	struct item_head *ih;
387 
388 	RFALSE(cpy_bytes == -1,
389 	       "vs-10170: bytes == - 1 means: do not split item");
390 
391 	if (last_first == FIRST_TO_LAST) {
392 		/* if ( if item in position item_num in buffer SOURCE is directory item ) */
393 		ih = B_N_PITEM_HEAD(src, item_num);
394 		if (is_direntry_le_ih(ih))
395 			leaf_copy_dir_entries(dest_bi, src, FIRST_TO_LAST,
396 					      item_num, 0, cpy_bytes);
397 		else {
398 			struct item_head n_ih;
399 
400 			/* copy part of the body of the item number 'item_num' of SOURCE to the end of the DEST
401 			   part defined by 'cpy_bytes'; create new item header; change old item_header (????);
402 			   n_ih = new item_header;
403 			 */
404 			memcpy(&n_ih, ih, IH_SIZE);
405 			put_ih_item_len(&n_ih, cpy_bytes);
406 			if (is_indirect_le_ih(ih)) {
407 				RFALSE(cpy_bytes == ih_item_len(ih)
408 				       && get_ih_free_space(ih),
409 				       "vs-10180: when whole indirect item is bottle to left neighbor, it must have free_space==0 (not %lu)",
410 				       (long unsigned)get_ih_free_space(ih));
411 				set_ih_free_space(&n_ih, 0);
412 			}
413 
414 			RFALSE(op_is_left_mergeable(&(ih->ih_key), src->b_size),
415 			       "vs-10190: bad mergeability of item %h", ih);
416 			n_ih.ih_version = ih->ih_version;	/* JDM Endian safe, both le */
417 			leaf_insert_into_buf(dest_bi, B_NR_ITEMS(dest), &n_ih,
418 					     B_N_PITEM(src, item_num), 0);
419 		}
420 	} else {
421 		/*  if ( if item in position item_num in buffer SOURCE is directory item ) */
422 		ih = B_N_PITEM_HEAD(src, item_num);
423 		if (is_direntry_le_ih(ih))
424 			leaf_copy_dir_entries(dest_bi, src, LAST_TO_FIRST,
425 					      item_num,
426 					      I_ENTRY_COUNT(ih) - cpy_bytes,
427 					      cpy_bytes);
428 		else {
429 			struct item_head n_ih;
430 
431 			/* copy part of the body of the item number 'item_num' of SOURCE to the begin of the DEST
432 			   part defined by 'cpy_bytes'; create new item header;
433 			   n_ih = new item_header;
434 			 */
435 			memcpy(&n_ih, ih, SHORT_KEY_SIZE);
436 
437 			n_ih.ih_version = ih->ih_version;	/* JDM Endian safe, both le */
438 
439 			if (is_direct_le_ih(ih)) {
440 				set_le_ih_k_offset(&n_ih,
441 						   le_ih_k_offset(ih) +
442 						   ih_item_len(ih) - cpy_bytes);
443 				set_le_ih_k_type(&n_ih, TYPE_DIRECT);
444 				set_ih_free_space(&n_ih, MAX_US_INT);
445 			} else {
446 				/* indirect item */
447 				RFALSE(!cpy_bytes && get_ih_free_space(ih),
448 				       "vs-10200: ih->ih_free_space must be 0 when indirect item will be appended");
449 				set_le_ih_k_offset(&n_ih,
450 						   le_ih_k_offset(ih) +
451 						   (ih_item_len(ih) -
452 						    cpy_bytes) / UNFM_P_SIZE *
453 						   dest->b_size);
454 				set_le_ih_k_type(&n_ih, TYPE_INDIRECT);
455 				set_ih_free_space(&n_ih, get_ih_free_space(ih));
456 			}
457 
458 			/* set item length */
459 			put_ih_item_len(&n_ih, cpy_bytes);
460 
461 			n_ih.ih_version = ih->ih_version;	/* JDM Endian safe, both le */
462 
463 			leaf_insert_into_buf(dest_bi, 0, &n_ih,
464 					     B_N_PITEM(src,
465 						       item_num) +
466 					     ih_item_len(ih) - cpy_bytes, 0);
467 		}
468 	}
469 }
470 
471 /* If cpy_bytes equals minus one than copy cpy_num whole items from SOURCE to DEST.
472    If cpy_bytes not equal to minus one than copy cpy_num-1 whole items from SOURCE to DEST.
473    From last item copy cpy_num bytes for regular item and cpy_num directory entries for
474    directory item. */
475 static int leaf_copy_items(struct buffer_info *dest_bi, struct buffer_head *src,
476 			   int last_first, int cpy_num, int cpy_bytes)
477 {
478 	struct buffer_head *dest;
479 	int pos, i, src_nr_item, bytes;
480 
481 	dest = dest_bi->bi_bh;
482 	RFALSE(!dest || !src, "vs-10210: !dest || !src");
483 	RFALSE(last_first != FIRST_TO_LAST && last_first != LAST_TO_FIRST,
484 	       "vs-10220:last_first != FIRST_TO_LAST && last_first != LAST_TO_FIRST");
485 	RFALSE(B_NR_ITEMS(src) < cpy_num,
486 	       "vs-10230: No enough items: %d, req. %d", B_NR_ITEMS(src),
487 	       cpy_num);
488 	RFALSE(cpy_num < 0, "vs-10240: cpy_num < 0 (%d)", cpy_num);
489 
490 	if (cpy_num == 0)
491 		return 0;
492 
493 	if (last_first == FIRST_TO_LAST) {
494 		/* copy items to left */
495 		pos = 0;
496 		if (cpy_num == 1)
497 			bytes = cpy_bytes;
498 		else
499 			bytes = -1;
500 
501 		/* copy the first item or it part or nothing to the end of the DEST (i = leaf_copy_boundary_item(DEST,SOURCE,0,bytes)) */
502 		i = leaf_copy_boundary_item(dest_bi, src, FIRST_TO_LAST, bytes);
503 		cpy_num -= i;
504 		if (cpy_num == 0)
505 			return i;
506 		pos += i;
507 		if (cpy_bytes == -1)
508 			/* copy first cpy_num items starting from position 'pos' of SOURCE to end of DEST */
509 			leaf_copy_items_entirely(dest_bi, src, FIRST_TO_LAST,
510 						 pos, cpy_num);
511 		else {
512 			/* copy first cpy_num-1 items starting from position 'pos-1' of the SOURCE to the end of the DEST */
513 			leaf_copy_items_entirely(dest_bi, src, FIRST_TO_LAST,
514 						 pos, cpy_num - 1);
515 
516 			/* copy part of the item which number is cpy_num+pos-1 to the end of the DEST */
517 			leaf_item_bottle(dest_bi, src, FIRST_TO_LAST,
518 					 cpy_num + pos - 1, cpy_bytes);
519 		}
520 	} else {
521 		/* copy items to right */
522 		src_nr_item = B_NR_ITEMS(src);
523 		if (cpy_num == 1)
524 			bytes = cpy_bytes;
525 		else
526 			bytes = -1;
527 
528 		/* copy the last item or it part or nothing to the begin of the DEST (i = leaf_copy_boundary_item(DEST,SOURCE,1,bytes)); */
529 		i = leaf_copy_boundary_item(dest_bi, src, LAST_TO_FIRST, bytes);
530 
531 		cpy_num -= i;
532 		if (cpy_num == 0)
533 			return i;
534 
535 		pos = src_nr_item - cpy_num - i;
536 		if (cpy_bytes == -1) {
537 			/* starting from position 'pos' copy last cpy_num items of SOURCE to begin of DEST */
538 			leaf_copy_items_entirely(dest_bi, src, LAST_TO_FIRST,
539 						 pos, cpy_num);
540 		} else {
541 			/* copy last cpy_num-1 items starting from position 'pos+1' of the SOURCE to the begin of the DEST; */
542 			leaf_copy_items_entirely(dest_bi, src, LAST_TO_FIRST,
543 						 pos + 1, cpy_num - 1);
544 
545 			/* copy part of the item which number is pos to the begin of the DEST */
546 			leaf_item_bottle(dest_bi, src, LAST_TO_FIRST, pos,
547 					 cpy_bytes);
548 		}
549 	}
550 	return i;
551 }
552 
553 /* there are types of coping: from S[0] to L[0], from S[0] to R[0],
554    from R[0] to L[0]. for each of these we have to define parent and
555    positions of destination and source buffers */
556 static void leaf_define_dest_src_infos(int shift_mode, struct tree_balance *tb,
557 				       struct buffer_info *dest_bi,
558 				       struct buffer_info *src_bi,
559 				       int *first_last,
560 				       struct buffer_head *Snew)
561 {
562 	memset(dest_bi, 0, sizeof(struct buffer_info));
563 	memset(src_bi, 0, sizeof(struct buffer_info));
564 
565 	/* define dest, src, dest parent, dest position */
566 	switch (shift_mode) {
567 	case LEAF_FROM_S_TO_L:	/* it is used in leaf_shift_left */
568 		src_bi->tb = tb;
569 		src_bi->bi_bh = PATH_PLAST_BUFFER(tb->tb_path);
570 		src_bi->bi_parent = PATH_H_PPARENT(tb->tb_path, 0);
571 		src_bi->bi_position = PATH_H_B_ITEM_ORDER(tb->tb_path, 0);	/* src->b_item_order */
572 		dest_bi->tb = tb;
573 		dest_bi->bi_bh = tb->L[0];
574 		dest_bi->bi_parent = tb->FL[0];
575 		dest_bi->bi_position = get_left_neighbor_position(tb, 0);
576 		*first_last = FIRST_TO_LAST;
577 		break;
578 
579 	case LEAF_FROM_S_TO_R:	/* it is used in leaf_shift_right */
580 		src_bi->tb = tb;
581 		src_bi->bi_bh = PATH_PLAST_BUFFER(tb->tb_path);
582 		src_bi->bi_parent = PATH_H_PPARENT(tb->tb_path, 0);
583 		src_bi->bi_position = PATH_H_B_ITEM_ORDER(tb->tb_path, 0);
584 		dest_bi->tb = tb;
585 		dest_bi->bi_bh = tb->R[0];
586 		dest_bi->bi_parent = tb->FR[0];
587 		dest_bi->bi_position = get_right_neighbor_position(tb, 0);
588 		*first_last = LAST_TO_FIRST;
589 		break;
590 
591 	case LEAF_FROM_R_TO_L:	/* it is used in balance_leaf_when_delete */
592 		src_bi->tb = tb;
593 		src_bi->bi_bh = tb->R[0];
594 		src_bi->bi_parent = tb->FR[0];
595 		src_bi->bi_position = get_right_neighbor_position(tb, 0);
596 		dest_bi->tb = tb;
597 		dest_bi->bi_bh = tb->L[0];
598 		dest_bi->bi_parent = tb->FL[0];
599 		dest_bi->bi_position = get_left_neighbor_position(tb, 0);
600 		*first_last = FIRST_TO_LAST;
601 		break;
602 
603 	case LEAF_FROM_L_TO_R:	/* it is used in balance_leaf_when_delete */
604 		src_bi->tb = tb;
605 		src_bi->bi_bh = tb->L[0];
606 		src_bi->bi_parent = tb->FL[0];
607 		src_bi->bi_position = get_left_neighbor_position(tb, 0);
608 		dest_bi->tb = tb;
609 		dest_bi->bi_bh = tb->R[0];
610 		dest_bi->bi_parent = tb->FR[0];
611 		dest_bi->bi_position = get_right_neighbor_position(tb, 0);
612 		*first_last = LAST_TO_FIRST;
613 		break;
614 
615 	case LEAF_FROM_S_TO_SNEW:
616 		src_bi->tb = tb;
617 		src_bi->bi_bh = PATH_PLAST_BUFFER(tb->tb_path);
618 		src_bi->bi_parent = PATH_H_PPARENT(tb->tb_path, 0);
619 		src_bi->bi_position = PATH_H_B_ITEM_ORDER(tb->tb_path, 0);
620 		dest_bi->tb = tb;
621 		dest_bi->bi_bh = Snew;
622 		dest_bi->bi_parent = NULL;
623 		dest_bi->bi_position = 0;
624 		*first_last = LAST_TO_FIRST;
625 		break;
626 
627 	default:
628 		reiserfs_panic(sb_from_bi(src_bi), "vs-10250",
629 			       "shift type is unknown (%d)", shift_mode);
630 	}
631 	RFALSE(!src_bi->bi_bh || !dest_bi->bi_bh,
632 	       "vs-10260: mode==%d, source (%p) or dest (%p) buffer is initialized incorrectly",
633 	       shift_mode, src_bi->bi_bh, dest_bi->bi_bh);
634 }
635 
636 /* copy mov_num items and mov_bytes of the (mov_num-1)th item to
637    neighbor. Delete them from source */
638 int leaf_move_items(int shift_mode, struct tree_balance *tb, int mov_num,
639 		    int mov_bytes, struct buffer_head *Snew)
640 {
641 	int ret_value;
642 	struct buffer_info dest_bi, src_bi;
643 	int first_last;
644 
645 	leaf_define_dest_src_infos(shift_mode, tb, &dest_bi, &src_bi,
646 				   &first_last, Snew);
647 
648 	ret_value =
649 	    leaf_copy_items(&dest_bi, src_bi.bi_bh, first_last, mov_num,
650 			    mov_bytes);
651 
652 	leaf_delete_items(&src_bi, first_last,
653 			  (first_last ==
654 			   FIRST_TO_LAST) ? 0 : (B_NR_ITEMS(src_bi.bi_bh) -
655 						 mov_num), mov_num, mov_bytes);
656 
657 	return ret_value;
658 }
659 
660 /* Shift shift_num items (and shift_bytes of last shifted item if shift_bytes != -1)
661    from S[0] to L[0] and replace the delimiting key */
662 int leaf_shift_left(struct tree_balance *tb, int shift_num, int shift_bytes)
663 {
664 	struct buffer_head *S0 = PATH_PLAST_BUFFER(tb->tb_path);
665 	int i;
666 
667 	/* move shift_num (and shift_bytes bytes) items from S[0] to left neighbor L[0] */
668 	i = leaf_move_items(LEAF_FROM_S_TO_L, tb, shift_num, shift_bytes, NULL);
669 
670 	if (shift_num) {
671 		if (B_NR_ITEMS(S0) == 0) {	/* number of items in S[0] == 0 */
672 
673 			RFALSE(shift_bytes != -1,
674 			       "vs-10270: S0 is empty now, but shift_bytes != -1 (%d)",
675 			       shift_bytes);
676 #ifdef CONFIG_REISERFS_CHECK
677 			if (tb->tb_mode == M_PASTE || tb->tb_mode == M_INSERT) {
678 				print_cur_tb("vs-10275");
679 				reiserfs_panic(tb->tb_sb, "vs-10275",
680 					       "balance condition corrupted "
681 					       "(%c)", tb->tb_mode);
682 			}
683 #endif
684 
685 			if (PATH_H_POSITION(tb->tb_path, 1) == 0)
686 				replace_key(tb, tb->CFL[0], tb->lkey[0],
687 					    PATH_H_PPARENT(tb->tb_path, 0), 0);
688 
689 		} else {
690 			/* replace lkey in CFL[0] by 0-th key from S[0]; */
691 			replace_key(tb, tb->CFL[0], tb->lkey[0], S0, 0);
692 
693 			RFALSE((shift_bytes != -1 &&
694 				!(is_direntry_le_ih(B_N_PITEM_HEAD(S0, 0))
695 				  && !I_ENTRY_COUNT(B_N_PITEM_HEAD(S0, 0)))) &&
696 			       (!op_is_left_mergeable
697 				(B_N_PKEY(S0, 0), S0->b_size)),
698 			       "vs-10280: item must be mergeable");
699 		}
700 	}
701 
702 	return i;
703 }
704 
705 /* CLEANING STOPPED HERE */
706 
707 /* Shift shift_num (shift_bytes) items from S[0] to the right neighbor, and replace the delimiting key */
708 int leaf_shift_right(struct tree_balance *tb, int shift_num, int shift_bytes)
709 {
710 	//  struct buffer_head * S0 = PATH_PLAST_BUFFER (tb->tb_path);
711 	int ret_value;
712 
713 	/* move shift_num (and shift_bytes) items from S[0] to right neighbor R[0] */
714 	ret_value =
715 	    leaf_move_items(LEAF_FROM_S_TO_R, tb, shift_num, shift_bytes, NULL);
716 
717 	/* replace rkey in CFR[0] by the 0-th key from R[0] */
718 	if (shift_num) {
719 		replace_key(tb, tb->CFR[0], tb->rkey[0], tb->R[0], 0);
720 
721 	}
722 
723 	return ret_value;
724 }
725 
726 static void leaf_delete_items_entirely(struct buffer_info *bi,
727 				       int first, int del_num);
728 /*  If del_bytes == -1, starting from position 'first' delete del_num items in whole in buffer CUR.
729     If not.
730     If last_first == 0. Starting from position 'first' delete del_num-1 items in whole. Delete part of body of
731     the first item. Part defined by del_bytes. Don't delete first item header
732     If last_first == 1. Starting from position 'first+1' delete del_num-1 items in whole. Delete part of body of
733     the last item . Part defined by del_bytes. Don't delete last item header.
734 */
735 void leaf_delete_items(struct buffer_info *cur_bi, int last_first,
736 		       int first, int del_num, int del_bytes)
737 {
738 	struct buffer_head *bh;
739 	int item_amount = B_NR_ITEMS(bh = cur_bi->bi_bh);
740 
741 	RFALSE(!bh, "10155: bh is not defined");
742 	RFALSE(del_num < 0, "10160: del_num can not be < 0. del_num==%d",
743 	       del_num);
744 	RFALSE(first < 0
745 	       || first + del_num > item_amount,
746 	       "10165: invalid number of first item to be deleted (%d) or "
747 	       "no so much items (%d) to delete (only %d)", first,
748 	       first + del_num, item_amount);
749 
750 	if (del_num == 0)
751 		return;
752 
753 	if (first == 0 && del_num == item_amount && del_bytes == -1) {
754 		make_empty_node(cur_bi);
755 		do_balance_mark_leaf_dirty(cur_bi->tb, bh, 0);
756 		return;
757 	}
758 
759 	if (del_bytes == -1)
760 		/* delete del_num items beginning from item in position first */
761 		leaf_delete_items_entirely(cur_bi, first, del_num);
762 	else {
763 		if (last_first == FIRST_TO_LAST) {
764 			/* delete del_num-1 items beginning from item in position first  */
765 			leaf_delete_items_entirely(cur_bi, first, del_num - 1);
766 
767 			/* delete the part of the first item of the bh
768 			   do not delete item header
769 			 */
770 			leaf_cut_from_buffer(cur_bi, 0, 0, del_bytes);
771 		} else {
772 			struct item_head *ih;
773 			int len;
774 
775 			/* delete del_num-1 items beginning from item in position first+1  */
776 			leaf_delete_items_entirely(cur_bi, first + 1,
777 						   del_num - 1);
778 
779 			ih = B_N_PITEM_HEAD(bh, B_NR_ITEMS(bh) - 1);
780 			if (is_direntry_le_ih(ih))
781 				/* the last item is directory  */
782 				/* len = numbers of directory entries in this item */
783 				len = ih_entry_count(ih);
784 			else
785 				/* len = body len of item */
786 				len = ih_item_len(ih);
787 
788 			/* delete the part of the last item of the bh
789 			   do not delete item header
790 			 */
791 			leaf_cut_from_buffer(cur_bi, B_NR_ITEMS(bh) - 1,
792 					     len - del_bytes, del_bytes);
793 		}
794 	}
795 }
796 
797 /* insert item into the leaf node in position before */
798 void leaf_insert_into_buf(struct buffer_info *bi, int before,
799 			  struct item_head *inserted_item_ih,
800 			  const char *inserted_item_body, int zeros_number)
801 {
802 	struct buffer_head *bh = bi->bi_bh;
803 	int nr, free_space;
804 	struct block_head *blkh;
805 	struct item_head *ih;
806 	int i;
807 	int last_loc, unmoved_loc;
808 	char *to;
809 
810 	blkh = B_BLK_HEAD(bh);
811 	nr = blkh_nr_item(blkh);
812 	free_space = blkh_free_space(blkh);
813 
814 	/* check free space */
815 	RFALSE(free_space < ih_item_len(inserted_item_ih) + IH_SIZE,
816 	       "vs-10170: not enough free space in block %z, new item %h",
817 	       bh, inserted_item_ih);
818 	RFALSE(zeros_number > ih_item_len(inserted_item_ih),
819 	       "vs-10172: zero number == %d, item length == %d",
820 	       zeros_number, ih_item_len(inserted_item_ih));
821 
822 	/* get item new item must be inserted before */
823 	ih = B_N_PITEM_HEAD(bh, before);
824 
825 	/* prepare space for the body of new item */
826 	last_loc = nr ? ih_location(&(ih[nr - before - 1])) : bh->b_size;
827 	unmoved_loc = before ? ih_location(ih - 1) : bh->b_size;
828 
829 	memmove(bh->b_data + last_loc - ih_item_len(inserted_item_ih),
830 		bh->b_data + last_loc, unmoved_loc - last_loc);
831 
832 	to = bh->b_data + unmoved_loc - ih_item_len(inserted_item_ih);
833 	memset(to, 0, zeros_number);
834 	to += zeros_number;
835 
836 	/* copy body to prepared space */
837 	if (inserted_item_body)
838 		memmove(to, inserted_item_body,
839 			ih_item_len(inserted_item_ih) - zeros_number);
840 	else
841 		memset(to, '\0', ih_item_len(inserted_item_ih) - zeros_number);
842 
843 	/* insert item header */
844 	memmove(ih + 1, ih, IH_SIZE * (nr - before));
845 	memmove(ih, inserted_item_ih, IH_SIZE);
846 
847 	/* change locations */
848 	for (i = before; i < nr + 1; i++) {
849 		unmoved_loc -= ih_item_len(&(ih[i - before]));
850 		put_ih_location(&(ih[i - before]), unmoved_loc);
851 	}
852 
853 	/* sizes, free space, item number */
854 	set_blkh_nr_item(blkh, blkh_nr_item(blkh) + 1);
855 	set_blkh_free_space(blkh,
856 			    free_space - (IH_SIZE +
857 					  ih_item_len(inserted_item_ih)));
858 	do_balance_mark_leaf_dirty(bi->tb, bh, 1);
859 
860 	if (bi->bi_parent) {
861 		struct disk_child *t_dc;
862 		t_dc = B_N_CHILD(bi->bi_parent, bi->bi_position);
863 		put_dc_size(t_dc,
864 			    dc_size(t_dc) + (IH_SIZE +
865 					     ih_item_len(inserted_item_ih)));
866 		do_balance_mark_internal_dirty(bi->tb, bi->bi_parent, 0);
867 	}
868 }
869 
870 /* paste paste_size bytes to affected_item_num-th item.
871    When item is a directory, this only prepare space for new entries */
872 void leaf_paste_in_buffer(struct buffer_info *bi, int affected_item_num,
873 			  int pos_in_item, int paste_size,
874 			  const char *body, int zeros_number)
875 {
876 	struct buffer_head *bh = bi->bi_bh;
877 	int nr, free_space;
878 	struct block_head *blkh;
879 	struct item_head *ih;
880 	int i;
881 	int last_loc, unmoved_loc;
882 
883 	blkh = B_BLK_HEAD(bh);
884 	nr = blkh_nr_item(blkh);
885 	free_space = blkh_free_space(blkh);
886 
887 	/* check free space */
888 	RFALSE(free_space < paste_size,
889 	       "vs-10175: not enough free space: needed %d, available %d",
890 	       paste_size, free_space);
891 
892 #ifdef CONFIG_REISERFS_CHECK
893 	if (zeros_number > paste_size) {
894 		struct super_block *sb = NULL;
895 		if (bi && bi->tb)
896 			sb = bi->tb->tb_sb;
897 		print_cur_tb("10177");
898 		reiserfs_panic(sb, "vs-10177",
899 			       "zeros_number == %d, paste_size == %d",
900 			       zeros_number, paste_size);
901 	}
902 #endif				/* CONFIG_REISERFS_CHECK */
903 
904 	/* item to be appended */
905 	ih = B_N_PITEM_HEAD(bh, affected_item_num);
906 
907 	last_loc = ih_location(&(ih[nr - affected_item_num - 1]));
908 	unmoved_loc = affected_item_num ? ih_location(ih - 1) : bh->b_size;
909 
910 	/* prepare space */
911 	memmove(bh->b_data + last_loc - paste_size, bh->b_data + last_loc,
912 		unmoved_loc - last_loc);
913 
914 	/* change locations */
915 	for (i = affected_item_num; i < nr; i++)
916 		put_ih_location(&(ih[i - affected_item_num]),
917 				ih_location(&(ih[i - affected_item_num])) -
918 				paste_size);
919 
920 	if (body) {
921 		if (!is_direntry_le_ih(ih)) {
922 			if (!pos_in_item) {
923 				/* shift data to right */
924 				memmove(bh->b_data + ih_location(ih) +
925 					paste_size,
926 					bh->b_data + ih_location(ih),
927 					ih_item_len(ih));
928 				/* paste data in the head of item */
929 				memset(bh->b_data + ih_location(ih), 0,
930 				       zeros_number);
931 				memcpy(bh->b_data + ih_location(ih) +
932 				       zeros_number, body,
933 				       paste_size - zeros_number);
934 			} else {
935 				memset(bh->b_data + unmoved_loc - paste_size, 0,
936 				       zeros_number);
937 				memcpy(bh->b_data + unmoved_loc - paste_size +
938 				       zeros_number, body,
939 				       paste_size - zeros_number);
940 			}
941 		}
942 	} else
943 		memset(bh->b_data + unmoved_loc - paste_size, '\0', paste_size);
944 
945 	put_ih_item_len(ih, ih_item_len(ih) + paste_size);
946 
947 	/* change free space */
948 	set_blkh_free_space(blkh, free_space - paste_size);
949 
950 	do_balance_mark_leaf_dirty(bi->tb, bh, 0);
951 
952 	if (bi->bi_parent) {
953 		struct disk_child *t_dc =
954 		    B_N_CHILD(bi->bi_parent, bi->bi_position);
955 		put_dc_size(t_dc, dc_size(t_dc) + paste_size);
956 		do_balance_mark_internal_dirty(bi->tb, bi->bi_parent, 0);
957 	}
958 }
959 
960 /* cuts DEL_COUNT entries beginning from FROM-th entry. Directory item
961    does not have free space, so it moves DEHs and remaining records as
962    necessary. Return value is size of removed part of directory item
963    in bytes. */
964 static int leaf_cut_entries(struct buffer_head *bh,
965 			    struct item_head *ih, int from, int del_count)
966 {
967 	char *item;
968 	struct reiserfs_de_head *deh;
969 	int prev_record_offset;	/* offset of record, that is (from-1)th */
970 	char *prev_record;	/* */
971 	int cut_records_len;	/* length of all removed records */
972 	int i;
973 
974 	/* make sure, that item is directory and there are enough entries to
975 	   remove */
976 	RFALSE(!is_direntry_le_ih(ih), "10180: item is not directory item");
977 	RFALSE(I_ENTRY_COUNT(ih) < from + del_count,
978 	       "10185: item contains not enough entries: entry_count = %d, from = %d, to delete = %d",
979 	       I_ENTRY_COUNT(ih), from, del_count);
980 
981 	if (del_count == 0)
982 		return 0;
983 
984 	/* first byte of item */
985 	item = bh->b_data + ih_location(ih);
986 
987 	/* entry head array */
988 	deh = B_I_DEH(bh, ih);
989 
990 	/* first byte of remaining entries, those are BEFORE cut entries
991 	   (prev_record) and length of all removed records (cut_records_len) */
992 	prev_record_offset =
993 	    (from ? deh_location(&(deh[from - 1])) : ih_item_len(ih));
994 	cut_records_len = prev_record_offset /*from_record */  -
995 	    deh_location(&(deh[from + del_count - 1]));
996 	prev_record = item + prev_record_offset;
997 
998 	/* adjust locations of remaining entries */
999 	for (i = I_ENTRY_COUNT(ih) - 1; i > from + del_count - 1; i--)
1000 		put_deh_location(&(deh[i]),
1001 				 deh_location(&deh[i]) -
1002 				 (DEH_SIZE * del_count));
1003 
1004 	for (i = 0; i < from; i++)
1005 		put_deh_location(&(deh[i]),
1006 				 deh_location(&deh[i]) - (DEH_SIZE * del_count +
1007 							  cut_records_len));
1008 
1009 	put_ih_entry_count(ih, ih_entry_count(ih) - del_count);
1010 
1011 	/* shift entry head array and entries those are AFTER removed entries */
1012 	memmove((char *)(deh + from),
1013 		deh + from + del_count,
1014 		prev_record - cut_records_len - (char *)(deh + from +
1015 							 del_count));
1016 
1017 	/* shift records, those are BEFORE removed entries */
1018 	memmove(prev_record - cut_records_len - DEH_SIZE * del_count,
1019 		prev_record, item + ih_item_len(ih) - prev_record);
1020 
1021 	return DEH_SIZE * del_count + cut_records_len;
1022 }
1023 
1024 /*  when cut item is part of regular file
1025         pos_in_item - first byte that must be cut
1026         cut_size - number of bytes to be cut beginning from pos_in_item
1027 
1028    when cut item is part of directory
1029         pos_in_item - number of first deleted entry
1030         cut_size - count of deleted entries
1031     */
1032 void leaf_cut_from_buffer(struct buffer_info *bi, int cut_item_num,
1033 			  int pos_in_item, int cut_size)
1034 {
1035 	int nr;
1036 	struct buffer_head *bh = bi->bi_bh;
1037 	struct block_head *blkh;
1038 	struct item_head *ih;
1039 	int last_loc, unmoved_loc;
1040 	int i;
1041 
1042 	blkh = B_BLK_HEAD(bh);
1043 	nr = blkh_nr_item(blkh);
1044 
1045 	/* item head of truncated item */
1046 	ih = B_N_PITEM_HEAD(bh, cut_item_num);
1047 
1048 	if (is_direntry_le_ih(ih)) {
1049 		/* first cut entry () */
1050 		cut_size = leaf_cut_entries(bh, ih, pos_in_item, cut_size);
1051 		if (pos_in_item == 0) {
1052 			/* change key */
1053 			RFALSE(cut_item_num,
1054 			       "when 0-th enrty of item is cut, that item must be first in the node, not %d-th",
1055 			       cut_item_num);
1056 			/* change item key by key of first entry in the item */
1057 			set_le_ih_k_offset(ih, deh_offset(B_I_DEH(bh, ih)));
1058 			/*memcpy (&ih->ih_key.k_offset, &(B_I_DEH (bh, ih)->deh_offset), SHORT_KEY_SIZE); */
1059 		}
1060 	} else {
1061 		/* item is direct or indirect */
1062 		RFALSE(is_statdata_le_ih(ih), "10195: item is stat data");
1063 		RFALSE(pos_in_item && pos_in_item + cut_size != ih_item_len(ih),
1064 		       "10200: invalid offset (%lu) or trunc_size (%lu) or ih_item_len (%lu)",
1065 		       (long unsigned)pos_in_item, (long unsigned)cut_size,
1066 		       (long unsigned)ih_item_len(ih));
1067 
1068 		/* shift item body to left if cut is from the head of item */
1069 		if (pos_in_item == 0) {
1070 			memmove(bh->b_data + ih_location(ih),
1071 				bh->b_data + ih_location(ih) + cut_size,
1072 				ih_item_len(ih) - cut_size);
1073 
1074 			/* change key of item */
1075 			if (is_direct_le_ih(ih))
1076 				set_le_ih_k_offset(ih,
1077 						   le_ih_k_offset(ih) +
1078 						   cut_size);
1079 			else {
1080 				set_le_ih_k_offset(ih,
1081 						   le_ih_k_offset(ih) +
1082 						   (cut_size / UNFM_P_SIZE) *
1083 						   bh->b_size);
1084 				RFALSE(ih_item_len(ih) == cut_size
1085 				       && get_ih_free_space(ih),
1086 				       "10205: invalid ih_free_space (%h)", ih);
1087 			}
1088 		}
1089 	}
1090 
1091 	/* location of the last item */
1092 	last_loc = ih_location(&(ih[nr - cut_item_num - 1]));
1093 
1094 	/* location of the item, which is remaining at the same place */
1095 	unmoved_loc = cut_item_num ? ih_location(ih - 1) : bh->b_size;
1096 
1097 	/* shift */
1098 	memmove(bh->b_data + last_loc + cut_size, bh->b_data + last_loc,
1099 		unmoved_loc - last_loc - cut_size);
1100 
1101 	/* change item length */
1102 	put_ih_item_len(ih, ih_item_len(ih) - cut_size);
1103 
1104 	if (is_indirect_le_ih(ih)) {
1105 		if (pos_in_item)
1106 			set_ih_free_space(ih, 0);
1107 	}
1108 
1109 	/* change locations */
1110 	for (i = cut_item_num; i < nr; i++)
1111 		put_ih_location(&(ih[i - cut_item_num]),
1112 				ih_location(&ih[i - cut_item_num]) + cut_size);
1113 
1114 	/* size, free space */
1115 	set_blkh_free_space(blkh, blkh_free_space(blkh) + cut_size);
1116 
1117 	do_balance_mark_leaf_dirty(bi->tb, bh, 0);
1118 
1119 	if (bi->bi_parent) {
1120 		struct disk_child *t_dc;
1121 		t_dc = B_N_CHILD(bi->bi_parent, bi->bi_position);
1122 		put_dc_size(t_dc, dc_size(t_dc) - cut_size);
1123 		do_balance_mark_internal_dirty(bi->tb, bi->bi_parent, 0);
1124 	}
1125 }
1126 
1127 /* delete del_num items from buffer starting from the first'th item */
1128 static void leaf_delete_items_entirely(struct buffer_info *bi,
1129 				       int first, int del_num)
1130 {
1131 	struct buffer_head *bh = bi->bi_bh;
1132 	int nr;
1133 	int i, j;
1134 	int last_loc, last_removed_loc;
1135 	struct block_head *blkh;
1136 	struct item_head *ih;
1137 
1138 	RFALSE(bh == NULL, "10210: buffer is 0");
1139 	RFALSE(del_num < 0, "10215: del_num less than 0 (%d)", del_num);
1140 
1141 	if (del_num == 0)
1142 		return;
1143 
1144 	blkh = B_BLK_HEAD(bh);
1145 	nr = blkh_nr_item(blkh);
1146 
1147 	RFALSE(first < 0 || first + del_num > nr,
1148 	       "10220: first=%d, number=%d, there is %d items", first, del_num,
1149 	       nr);
1150 
1151 	if (first == 0 && del_num == nr) {
1152 		/* this does not work */
1153 		make_empty_node(bi);
1154 
1155 		do_balance_mark_leaf_dirty(bi->tb, bh, 0);
1156 		return;
1157 	}
1158 
1159 	ih = B_N_PITEM_HEAD(bh, first);
1160 
1161 	/* location of unmovable item */
1162 	j = (first == 0) ? bh->b_size : ih_location(ih - 1);
1163 
1164 	/* delete items */
1165 	last_loc = ih_location(&(ih[nr - 1 - first]));
1166 	last_removed_loc = ih_location(&(ih[del_num - 1]));
1167 
1168 	memmove(bh->b_data + last_loc + j - last_removed_loc,
1169 		bh->b_data + last_loc, last_removed_loc - last_loc);
1170 
1171 	/* delete item headers */
1172 	memmove(ih, ih + del_num, (nr - first - del_num) * IH_SIZE);
1173 
1174 	/* change item location */
1175 	for (i = first; i < nr - del_num; i++)
1176 		put_ih_location(&(ih[i - first]),
1177 				ih_location(&(ih[i - first])) + (j -
1178 								 last_removed_loc));
1179 
1180 	/* sizes, item number */
1181 	set_blkh_nr_item(blkh, blkh_nr_item(blkh) - del_num);
1182 	set_blkh_free_space(blkh,
1183 			    blkh_free_space(blkh) + (j - last_removed_loc +
1184 						     IH_SIZE * del_num));
1185 
1186 	do_balance_mark_leaf_dirty(bi->tb, bh, 0);
1187 
1188 	if (bi->bi_parent) {
1189 		struct disk_child *t_dc =
1190 		    B_N_CHILD(bi->bi_parent, bi->bi_position);
1191 		put_dc_size(t_dc,
1192 			    dc_size(t_dc) - (j - last_removed_loc +
1193 					     IH_SIZE * del_num));
1194 		do_balance_mark_internal_dirty(bi->tb, bi->bi_parent, 0);
1195 	}
1196 }
1197 
1198 /* paste new_entry_count entries (new_dehs, records) into position before to item_num-th item */
1199 void leaf_paste_entries(struct buffer_info *bi,
1200 			int item_num,
1201 			int before,
1202 			int new_entry_count,
1203 			struct reiserfs_de_head *new_dehs,
1204 			const char *records, int paste_size)
1205 {
1206 	struct item_head *ih;
1207 	char *item;
1208 	struct reiserfs_de_head *deh;
1209 	char *insert_point;
1210 	int i, old_entry_num;
1211 	struct buffer_head *bh = bi->bi_bh;
1212 
1213 	if (new_entry_count == 0)
1214 		return;
1215 
1216 	ih = B_N_PITEM_HEAD(bh, item_num);
1217 
1218 	/* make sure, that item is directory, and there are enough records in it */
1219 	RFALSE(!is_direntry_le_ih(ih), "10225: item is not directory item");
1220 	RFALSE(I_ENTRY_COUNT(ih) < before,
1221 	       "10230: there are no entry we paste entries before. entry_count = %d, before = %d",
1222 	       I_ENTRY_COUNT(ih), before);
1223 
1224 	/* first byte of dest item */
1225 	item = bh->b_data + ih_location(ih);
1226 
1227 	/* entry head array */
1228 	deh = B_I_DEH(bh, ih);
1229 
1230 	/* new records will be pasted at this point */
1231 	insert_point =
1232 	    item +
1233 	    (before ? deh_location(&(deh[before - 1]))
1234 	     : (ih_item_len(ih) - paste_size));
1235 
1236 	/* adjust locations of records that will be AFTER new records */
1237 	for (i = I_ENTRY_COUNT(ih) - 1; i >= before; i--)
1238 		put_deh_location(&(deh[i]),
1239 				 deh_location(&(deh[i])) +
1240 				 (DEH_SIZE * new_entry_count));
1241 
1242 	/* adjust locations of records that will be BEFORE new records */
1243 	for (i = 0; i < before; i++)
1244 		put_deh_location(&(deh[i]),
1245 				 deh_location(&(deh[i])) + paste_size);
1246 
1247 	old_entry_num = I_ENTRY_COUNT(ih);
1248 	put_ih_entry_count(ih, ih_entry_count(ih) + new_entry_count);
1249 
1250 	/* prepare space for pasted records */
1251 	memmove(insert_point + paste_size, insert_point,
1252 		item + (ih_item_len(ih) - paste_size) - insert_point);
1253 
1254 	/* copy new records */
1255 	memcpy(insert_point + DEH_SIZE * new_entry_count, records,
1256 	       paste_size - DEH_SIZE * new_entry_count);
1257 
1258 	/* prepare space for new entry heads */
1259 	deh += before;
1260 	memmove((char *)(deh + new_entry_count), deh,
1261 		insert_point - (char *)deh);
1262 
1263 	/* copy new entry heads */
1264 	deh = (struct reiserfs_de_head *)((char *)deh);
1265 	memcpy(deh, new_dehs, DEH_SIZE * new_entry_count);
1266 
1267 	/* set locations of new records */
1268 	for (i = 0; i < new_entry_count; i++) {
1269 		put_deh_location(&(deh[i]),
1270 				 deh_location(&(deh[i])) +
1271 				 (-deh_location
1272 				  (&(new_dehs[new_entry_count - 1])) +
1273 				  insert_point + DEH_SIZE * new_entry_count -
1274 				  item));
1275 	}
1276 
1277 	/* change item key if necessary (when we paste before 0-th entry */
1278 	if (!before) {
1279 		set_le_ih_k_offset(ih, deh_offset(new_dehs));
1280 /*      memcpy (&ih->ih_key.k_offset,
1281 		       &new_dehs->deh_offset, SHORT_KEY_SIZE);*/
1282 	}
1283 #ifdef CONFIG_REISERFS_CHECK
1284 	{
1285 		int prev, next;
1286 		/* check record locations */
1287 		deh = B_I_DEH(bh, ih);
1288 		for (i = 0; i < I_ENTRY_COUNT(ih); i++) {
1289 			next =
1290 			    (i <
1291 			     I_ENTRY_COUNT(ih) -
1292 			     1) ? deh_location(&(deh[i + 1])) : 0;
1293 			prev = (i != 0) ? deh_location(&(deh[i - 1])) : 0;
1294 
1295 			if (prev && prev <= deh_location(&(deh[i])))
1296 				reiserfs_error(sb_from_bi(bi), "vs-10240",
1297 					       "directory item (%h) "
1298 					       "corrupted (prev %a, "
1299 					       "cur(%d) %a)",
1300 					       ih, deh + i - 1, i, deh + i);
1301 			if (next && next >= deh_location(&(deh[i])))
1302 				reiserfs_error(sb_from_bi(bi), "vs-10250",
1303 					       "directory item (%h) "
1304 					       "corrupted (cur(%d) %a, "
1305 					       "next %a)",
1306 					       ih, i, deh + i, deh + i + 1);
1307 		}
1308 	}
1309 #endif
1310 
1311 }
1312