cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

lbalance.c (42212B)


      1/*
      2 * Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
      3 */
      4
      5#include <linux/uaccess.h>
      6#include <linux/string.h>
      7#include <linux/time.h>
      8#include "reiserfs.h"
      9#include <linux/buffer_head.h>
     10
     11/*
     12 * copy copy_count entries from source directory item to dest buffer
     13 * (creating new item if needed)
     14 */
     15static void leaf_copy_dir_entries(struct buffer_info *dest_bi,
     16				  struct buffer_head *source, int last_first,
     17				  int item_num, int from, int copy_count)
     18{
     19	struct buffer_head *dest = dest_bi->bi_bh;
     20	/*
     21	 * either the number of target item, or if we must create a
     22	 * new item, the number of the item we will create it next to
     23	 */
     24	int item_num_in_dest;
     25
     26	struct item_head *ih;
     27	struct reiserfs_de_head *deh;
     28	int copy_records_len;	/* length of all records in item to be copied */
     29	char *records;
     30
     31	ih = item_head(source, item_num);
     32
     33	RFALSE(!is_direntry_le_ih(ih), "vs-10000: item must be directory item");
     34
     35	/*
     36	 * length of all record to be copied and first byte of
     37	 * the last of them
     38	 */
     39	deh = B_I_DEH(source, ih);
     40	if (copy_count) {
     41		copy_records_len = (from ? deh_location(&deh[from - 1]) :
     42				    ih_item_len(ih)) -
     43		    deh_location(&deh[from + copy_count - 1]);
     44		records =
     45		    source->b_data + ih_location(ih) +
     46		    deh_location(&deh[from + copy_count - 1]);
     47	} else {
     48		copy_records_len = 0;
     49		records = NULL;
     50	}
     51
     52	/* when copy last to first, dest buffer can contain 0 items */
     53	item_num_in_dest =
     54	    (last_first ==
     55	     LAST_TO_FIRST) ? ((B_NR_ITEMS(dest)) ? 0 : -1) : (B_NR_ITEMS(dest)
     56							       - 1);
     57
     58	/*
     59	 * if there are no items in dest or the first/last item in
     60	 * dest is not item of the same directory
     61	 */
     62	if ((item_num_in_dest == -1) ||
     63	    (last_first == FIRST_TO_LAST && le_ih_k_offset(ih) == DOT_OFFSET) ||
     64	    (last_first == LAST_TO_FIRST
     65	     && comp_short_le_keys /*COMP_SHORT_KEYS */ (&ih->ih_key,
     66							 leaf_key(dest,
     67								  item_num_in_dest))))
     68	{
     69		/* create new item in dest */
     70		struct item_head new_ih;
     71
     72		/* form item header */
     73		memcpy(&new_ih.ih_key, &ih->ih_key, KEY_SIZE);
     74		put_ih_version(&new_ih, KEY_FORMAT_3_5);
     75		/* calculate item len */
     76		put_ih_item_len(&new_ih,
     77				DEH_SIZE * copy_count + copy_records_len);
     78		put_ih_entry_count(&new_ih, 0);
     79
     80		if (last_first == LAST_TO_FIRST) {
     81			/* form key by the following way */
     82			if (from < ih_entry_count(ih)) {
     83				set_le_ih_k_offset(&new_ih,
     84						   deh_offset(&deh[from]));
     85			} else {
     86				/*
     87				 * no entries will be copied to this
     88				 * item in this function
     89				 */
     90				set_le_ih_k_offset(&new_ih, U32_MAX);
     91				/*
     92				 * this item is not yet valid, but we
     93				 * want I_IS_DIRECTORY_ITEM to return 1
     94				 * for it, so we -1
     95				 */
     96			}
     97			set_le_key_k_type(KEY_FORMAT_3_5, &new_ih.ih_key,
     98					  TYPE_DIRENTRY);
     99		}
    100
    101		/* insert item into dest buffer */
    102		leaf_insert_into_buf(dest_bi,
    103				     (last_first ==
    104				      LAST_TO_FIRST) ? 0 : B_NR_ITEMS(dest),
    105				     &new_ih, NULL, 0);
    106	} else {
    107		/* prepare space for entries */
    108		leaf_paste_in_buffer(dest_bi,
    109				     (last_first ==
    110				      FIRST_TO_LAST) ? (B_NR_ITEMS(dest) -
    111							1) : 0, MAX_US_INT,
    112				     DEH_SIZE * copy_count + copy_records_len,
    113				     records, 0);
    114	}
    115
    116	item_num_in_dest =
    117	    (last_first == FIRST_TO_LAST) ? (B_NR_ITEMS(dest) - 1) : 0;
    118
    119	leaf_paste_entries(dest_bi, item_num_in_dest,
    120			   (last_first ==
    121			    FIRST_TO_LAST) ? ih_entry_count(item_head(dest,
    122									  item_num_in_dest))
    123			   : 0, copy_count, deh + from, records,
    124			   DEH_SIZE * copy_count + copy_records_len);
    125}
    126
    127/*
    128 * Copy the first (if last_first == FIRST_TO_LAST) or last
    129 * (last_first == LAST_TO_FIRST) item or part of it or nothing
    130 * (see the return 0 below) from SOURCE to the end (if last_first)
    131 * or beginning (!last_first) of the DEST
    132 */
    133/* returns 1 if anything was copied, else 0 */
    134static int leaf_copy_boundary_item(struct buffer_info *dest_bi,
    135				   struct buffer_head *src, int last_first,
    136				   int bytes_or_entries)
    137{
    138	struct buffer_head *dest = dest_bi->bi_bh;
    139	/* number of items in the source and destination buffers */
    140	int dest_nr_item, src_nr_item;
    141	struct item_head *ih;
    142	struct item_head *dih;
    143
    144	dest_nr_item = B_NR_ITEMS(dest);
    145
    146	/*
    147	 * if ( DEST is empty or first item of SOURCE and last item of
    148	 * DEST are the items of different objects or of different types )
    149	 * then there is no need to treat this item differently from the
    150	 * other items that we copy, so we return
    151	 */
    152	if (last_first == FIRST_TO_LAST) {
    153		ih = item_head(src, 0);
    154		dih = item_head(dest, dest_nr_item - 1);
    155
    156		/* there is nothing to merge */
    157		if (!dest_nr_item
    158		    || (!op_is_left_mergeable(&ih->ih_key, src->b_size)))
    159			return 0;
    160
    161		RFALSE(!ih_item_len(ih),
    162		       "vs-10010: item can not have empty length");
    163
    164		if (is_direntry_le_ih(ih)) {
    165			if (bytes_or_entries == -1)
    166				/* copy all entries to dest */
    167				bytes_or_entries = ih_entry_count(ih);
    168			leaf_copy_dir_entries(dest_bi, src, FIRST_TO_LAST, 0, 0,
    169					      bytes_or_entries);
    170			return 1;
    171		}
    172
    173		/*
    174		 * copy part of the body of the first item of SOURCE
    175		 * to the end of the body of the last item of the DEST
    176		 * part defined by 'bytes_or_entries'; if bytes_or_entries
    177		 * == -1 copy whole body; don't create new item header
    178		 */
    179		if (bytes_or_entries == -1)
    180			bytes_or_entries = ih_item_len(ih);
    181
    182#ifdef CONFIG_REISERFS_CHECK
    183		else {
    184			if (bytes_or_entries == ih_item_len(ih)
    185			    && is_indirect_le_ih(ih))
    186				if (get_ih_free_space(ih))
    187					reiserfs_panic(sb_from_bi(dest_bi),
    188						       "vs-10020",
    189						       "last unformatted node "
    190						       "must be filled "
    191						       "entirely (%h)", ih);
    192		}
    193#endif
    194
    195		/*
    196		 * merge first item (or its part) of src buffer with the last
    197		 * item of dest buffer. Both are of the same file
    198		 */
    199		leaf_paste_in_buffer(dest_bi,
    200				     dest_nr_item - 1, ih_item_len(dih),
    201				     bytes_or_entries, ih_item_body(src, ih), 0);
    202
    203		if (is_indirect_le_ih(dih)) {
    204			RFALSE(get_ih_free_space(dih),
    205			       "vs-10030: merge to left: last unformatted node of non-last indirect item %h must have zerto free space",
    206			       ih);
    207			if (bytes_or_entries == ih_item_len(ih))
    208				set_ih_free_space(dih, get_ih_free_space(ih));
    209		}
    210
    211		return 1;
    212	}
    213
    214	/* copy boundary item to right (last_first == LAST_TO_FIRST) */
    215
    216	/*
    217	 * (DEST is empty or last item of SOURCE and first item of DEST
    218	 * are the items of different object or of different types)
    219	 */
    220	src_nr_item = B_NR_ITEMS(src);
    221	ih = item_head(src, src_nr_item - 1);
    222	dih = item_head(dest, 0);
    223
    224	if (!dest_nr_item || !op_is_left_mergeable(&dih->ih_key, src->b_size))
    225		return 0;
    226
    227	if (is_direntry_le_ih(ih)) {
    228		/*
    229		 * bytes_or_entries = entries number in last
    230		 * item body of SOURCE
    231		 */
    232		if (bytes_or_entries == -1)
    233			bytes_or_entries = ih_entry_count(ih);
    234
    235		leaf_copy_dir_entries(dest_bi, src, LAST_TO_FIRST,
    236				      src_nr_item - 1,
    237				      ih_entry_count(ih) - bytes_or_entries,
    238				      bytes_or_entries);
    239		return 1;
    240	}
    241
    242	/*
    243	 * copy part of the body of the last item of SOURCE to the
    244	 * begin of the body of the first item of the DEST; part defined
    245	 * by 'bytes_or_entries'; if byte_or_entriess == -1 copy whole body;
    246	 * change first item key of the DEST; don't create new item header
    247	 */
    248
    249	RFALSE(is_indirect_le_ih(ih) && get_ih_free_space(ih),
    250	       "vs-10040: merge to right: last unformatted node of non-last indirect item must be filled entirely (%h)",
    251	       ih);
    252
    253	if (bytes_or_entries == -1) {
    254		/* bytes_or_entries = length of last item body of SOURCE */
    255		bytes_or_entries = ih_item_len(ih);
    256
    257		RFALSE(le_ih_k_offset(dih) !=
    258		       le_ih_k_offset(ih) + op_bytes_number(ih, src->b_size),
    259		       "vs-10050: items %h and %h do not match", ih, dih);
    260
    261		/* change first item key of the DEST */
    262		set_le_ih_k_offset(dih, le_ih_k_offset(ih));
    263
    264		/* item becomes non-mergeable */
    265		/* or mergeable if left item was */
    266		set_le_ih_k_type(dih, le_ih_k_type(ih));
    267	} else {
    268		/* merge to right only part of item */
    269		RFALSE(ih_item_len(ih) <= bytes_or_entries,
    270		       "vs-10060: no so much bytes %lu (needed %lu)",
    271		       (unsigned long)ih_item_len(ih),
    272		       (unsigned long)bytes_or_entries);
    273
    274		/* change first item key of the DEST */
    275		if (is_direct_le_ih(dih)) {
    276			RFALSE(le_ih_k_offset(dih) <=
    277			       (unsigned long)bytes_or_entries,
    278			       "vs-10070: dih %h, bytes_or_entries(%d)", dih,
    279			       bytes_or_entries);
    280			set_le_ih_k_offset(dih,
    281					   le_ih_k_offset(dih) -
    282					   bytes_or_entries);
    283		} else {
    284			RFALSE(le_ih_k_offset(dih) <=
    285			       (bytes_or_entries / UNFM_P_SIZE) * dest->b_size,
    286			       "vs-10080: dih %h, bytes_or_entries(%d)",
    287			       dih,
    288			       (bytes_or_entries / UNFM_P_SIZE) * dest->b_size);
    289			set_le_ih_k_offset(dih,
    290					   le_ih_k_offset(dih) -
    291					   ((bytes_or_entries / UNFM_P_SIZE) *
    292					    dest->b_size));
    293		}
    294	}
    295
    296	leaf_paste_in_buffer(dest_bi, 0, 0, bytes_or_entries,
    297			     ih_item_body(src,
    298				       ih) + ih_item_len(ih) - bytes_or_entries,
    299			     0);
    300	return 1;
    301}
    302
    303/*
    304 * copy cpy_mun items from buffer src to buffer dest
    305 * last_first == FIRST_TO_LAST means, that we copy cpy_num items beginning
    306 *                             from first-th item in src to tail of dest
    307 * last_first == LAST_TO_FIRST means, that we copy cpy_num items beginning
    308 *                             from first-th item in src to head of dest
    309 */
    310static void leaf_copy_items_entirely(struct buffer_info *dest_bi,
    311				     struct buffer_head *src, int last_first,
    312				     int first, int cpy_num)
    313{
    314	struct buffer_head *dest;
    315	int nr, free_space;
    316	int dest_before;
    317	int last_loc, last_inserted_loc, location;
    318	int i, j;
    319	struct block_head *blkh;
    320	struct item_head *ih;
    321
    322	RFALSE(last_first != LAST_TO_FIRST && last_first != FIRST_TO_LAST,
    323	       "vs-10090: bad last_first parameter %d", last_first);
    324	RFALSE(B_NR_ITEMS(src) - first < cpy_num,
    325	       "vs-10100: too few items in source %d, required %d from %d",
    326	       B_NR_ITEMS(src), cpy_num, first);
    327	RFALSE(cpy_num < 0, "vs-10110: can not copy negative amount of items");
    328	RFALSE(!dest_bi, "vs-10120: can not copy negative amount of items");
    329
    330	dest = dest_bi->bi_bh;
    331
    332	RFALSE(!dest, "vs-10130: can not copy negative amount of items");
    333
    334	if (cpy_num == 0)
    335		return;
    336
    337	blkh = B_BLK_HEAD(dest);
    338	nr = blkh_nr_item(blkh);
    339	free_space = blkh_free_space(blkh);
    340
    341	/*
    342	 * we will insert items before 0-th or nr-th item in dest buffer.
    343	 * It depends of last_first parameter
    344	 */
    345	dest_before = (last_first == LAST_TO_FIRST) ? 0 : nr;
    346
    347	/* location of head of first new item */
    348	ih = item_head(dest, dest_before);
    349
    350	RFALSE(blkh_free_space(blkh) < cpy_num * IH_SIZE,
    351	       "vs-10140: not enough free space for headers %d (needed %d)",
    352	       B_FREE_SPACE(dest), cpy_num * IH_SIZE);
    353
    354	/* prepare space for headers */
    355	memmove(ih + cpy_num, ih, (nr - dest_before) * IH_SIZE);
    356
    357	/* copy item headers */
    358	memcpy(ih, item_head(src, first), cpy_num * IH_SIZE);
    359
    360	free_space -= (IH_SIZE * cpy_num);
    361	set_blkh_free_space(blkh, free_space);
    362
    363	/* location of unmovable item */
    364	j = location = (dest_before == 0) ? dest->b_size : ih_location(ih - 1);
    365	for (i = dest_before; i < nr + cpy_num; i++) {
    366		location -= ih_item_len(ih + i - dest_before);
    367		put_ih_location(ih + i - dest_before, location);
    368	}
    369
    370	/* prepare space for items */
    371	last_loc = ih_location(&ih[nr + cpy_num - 1 - dest_before]);
    372	last_inserted_loc = ih_location(&ih[cpy_num - 1]);
    373
    374	/* check free space */
    375	RFALSE(free_space < j - last_inserted_loc,
    376	       "vs-10150: not enough free space for items %d (needed %d)",
    377	       free_space, j - last_inserted_loc);
    378
    379	memmove(dest->b_data + last_loc,
    380		dest->b_data + last_loc + j - last_inserted_loc,
    381		last_inserted_loc - last_loc);
    382
    383	/* copy items */
    384	memcpy(dest->b_data + last_inserted_loc,
    385	       item_body(src, (first + cpy_num - 1)),
    386	       j - last_inserted_loc);
    387
    388	/* sizes, item number */
    389	set_blkh_nr_item(blkh, nr + cpy_num);
    390	set_blkh_free_space(blkh, free_space - (j - last_inserted_loc));
    391
    392	do_balance_mark_leaf_dirty(dest_bi->tb, dest, 0);
    393
    394	if (dest_bi->bi_parent) {
    395		struct disk_child *t_dc;
    396		t_dc = B_N_CHILD(dest_bi->bi_parent, dest_bi->bi_position);
    397		RFALSE(dc_block_number(t_dc) != dest->b_blocknr,
    398		       "vs-10160: block number in bh does not match to field in disk_child structure %lu and %lu",
    399		       (long unsigned)dest->b_blocknr,
    400		       (long unsigned)dc_block_number(t_dc));
    401		put_dc_size(t_dc,
    402			    dc_size(t_dc) + (j - last_inserted_loc +
    403					     IH_SIZE * cpy_num));
    404
    405		do_balance_mark_internal_dirty(dest_bi->tb, dest_bi->bi_parent,
    406					       0);
    407	}
    408}
    409
    410/*
    411 * This function splits the (liquid) item into two items (useful when
    412 * shifting part of an item into another node.)
    413 */
    414static void leaf_item_bottle(struct buffer_info *dest_bi,
    415			     struct buffer_head *src, int last_first,
    416			     int item_num, int cpy_bytes)
    417{
    418	struct buffer_head *dest = dest_bi->bi_bh;
    419	struct item_head *ih;
    420
    421	RFALSE(cpy_bytes == -1,
    422	       "vs-10170: bytes == - 1 means: do not split item");
    423
    424	if (last_first == FIRST_TO_LAST) {
    425		/*
    426		 * if ( if item in position item_num in buffer SOURCE
    427		 * is directory item )
    428		 */
    429		ih = item_head(src, item_num);
    430		if (is_direntry_le_ih(ih))
    431			leaf_copy_dir_entries(dest_bi, src, FIRST_TO_LAST,
    432					      item_num, 0, cpy_bytes);
    433		else {
    434			struct item_head n_ih;
    435
    436			/*
    437			 * copy part of the body of the item number 'item_num'
    438			 * of SOURCE to the end of the DEST part defined by
    439			 * 'cpy_bytes'; create new item header; change old
    440			 * item_header (????); n_ih = new item_header;
    441			 */
    442			memcpy(&n_ih, ih, IH_SIZE);
    443			put_ih_item_len(&n_ih, cpy_bytes);
    444			if (is_indirect_le_ih(ih)) {
    445				RFALSE(cpy_bytes == ih_item_len(ih)
    446				       && get_ih_free_space(ih),
    447				       "vs-10180: when whole indirect item is bottle to left neighbor, it must have free_space==0 (not %lu)",
    448				       (long unsigned)get_ih_free_space(ih));
    449				set_ih_free_space(&n_ih, 0);
    450			}
    451
    452			RFALSE(op_is_left_mergeable(&ih->ih_key, src->b_size),
    453			       "vs-10190: bad mergeability of item %h", ih);
    454			n_ih.ih_version = ih->ih_version;	/* JDM Endian safe, both le */
    455			leaf_insert_into_buf(dest_bi, B_NR_ITEMS(dest), &n_ih,
    456					     item_body(src, item_num), 0);
    457		}
    458	} else {
    459		/*
    460		 * if ( if item in position item_num in buffer
    461		 * SOURCE is directory item )
    462		 */
    463		ih = item_head(src, item_num);
    464		if (is_direntry_le_ih(ih))
    465			leaf_copy_dir_entries(dest_bi, src, LAST_TO_FIRST,
    466					      item_num,
    467					      ih_entry_count(ih) - cpy_bytes,
    468					      cpy_bytes);
    469		else {
    470			struct item_head n_ih;
    471
    472			/*
    473			 * copy part of the body of the item number 'item_num'
    474			 * of SOURCE to the begin of the DEST part defined by
    475			 * 'cpy_bytes'; create new item header;
    476			 * n_ih = new item_header;
    477			 */
    478			memcpy(&n_ih.ih_key, &ih->ih_key, KEY_SIZE);
    479
    480			/* Endian safe, both le */
    481			n_ih.ih_version = ih->ih_version;
    482
    483			if (is_direct_le_ih(ih)) {
    484				set_le_ih_k_offset(&n_ih,
    485						   le_ih_k_offset(ih) +
    486						   ih_item_len(ih) - cpy_bytes);
    487				set_le_ih_k_type(&n_ih, TYPE_DIRECT);
    488				set_ih_free_space(&n_ih, MAX_US_INT);
    489			} else {
    490				/* indirect item */
    491				RFALSE(!cpy_bytes && get_ih_free_space(ih),
    492				       "vs-10200: ih->ih_free_space must be 0 when indirect item will be appended");
    493				set_le_ih_k_offset(&n_ih,
    494						   le_ih_k_offset(ih) +
    495						   (ih_item_len(ih) -
    496						    cpy_bytes) / UNFM_P_SIZE *
    497						   dest->b_size);
    498				set_le_ih_k_type(&n_ih, TYPE_INDIRECT);
    499				set_ih_free_space(&n_ih, get_ih_free_space(ih));
    500			}
    501
    502			/* set item length */
    503			put_ih_item_len(&n_ih, cpy_bytes);
    504
    505			/* Endian safe, both le */
    506			n_ih.ih_version = ih->ih_version;
    507
    508			leaf_insert_into_buf(dest_bi, 0, &n_ih,
    509					     item_body(src, item_num) +
    510						ih_item_len(ih) - cpy_bytes, 0);
    511		}
    512	}
    513}
    514
    515/*
    516 * If cpy_bytes equals minus one than copy cpy_num whole items from SOURCE
    517 * to DEST.  If cpy_bytes not equal to minus one than copy cpy_num-1 whole
    518 * items from SOURCE to DEST.  From last item copy cpy_num bytes for regular
    519 * item and cpy_num directory entries for directory item.
    520 */
    521static int leaf_copy_items(struct buffer_info *dest_bi, struct buffer_head *src,
    522			   int last_first, int cpy_num, int cpy_bytes)
    523{
    524	struct buffer_head *dest;
    525	int pos, i, src_nr_item, bytes;
    526
    527	dest = dest_bi->bi_bh;
    528	RFALSE(!dest || !src, "vs-10210: !dest || !src");
    529	RFALSE(last_first != FIRST_TO_LAST && last_first != LAST_TO_FIRST,
    530	       "vs-10220:last_first != FIRST_TO_LAST && last_first != LAST_TO_FIRST");
    531	RFALSE(B_NR_ITEMS(src) < cpy_num,
    532	       "vs-10230: No enough items: %d, req. %d", B_NR_ITEMS(src),
    533	       cpy_num);
    534	RFALSE(cpy_num < 0, "vs-10240: cpy_num < 0 (%d)", cpy_num);
    535
    536	if (cpy_num == 0)
    537		return 0;
    538
    539	if (last_first == FIRST_TO_LAST) {
    540		/* copy items to left */
    541		pos = 0;
    542		if (cpy_num == 1)
    543			bytes = cpy_bytes;
    544		else
    545			bytes = -1;
    546
    547		/*
    548		 * copy the first item or it part or nothing to the end of
    549		 * the DEST (i = leaf_copy_boundary_item(DEST,SOURCE,0,bytes))
    550		 */
    551		i = leaf_copy_boundary_item(dest_bi, src, FIRST_TO_LAST, bytes);
    552		cpy_num -= i;
    553		if (cpy_num == 0)
    554			return i;
    555		pos += i;
    556		if (cpy_bytes == -1)
    557			/*
    558			 * copy first cpy_num items starting from position
    559			 * 'pos' of SOURCE to end of DEST
    560			 */
    561			leaf_copy_items_entirely(dest_bi, src, FIRST_TO_LAST,
    562						 pos, cpy_num);
    563		else {
    564			/*
    565			 * copy first cpy_num-1 items starting from position
    566			 * 'pos-1' of the SOURCE to the end of the DEST
    567			 */
    568			leaf_copy_items_entirely(dest_bi, src, FIRST_TO_LAST,
    569						 pos, cpy_num - 1);
    570
    571			/*
    572			 * copy part of the item which number is
    573			 * cpy_num+pos-1 to the end of the DEST
    574			 */
    575			leaf_item_bottle(dest_bi, src, FIRST_TO_LAST,
    576					 cpy_num + pos - 1, cpy_bytes);
    577		}
    578	} else {
    579		/* copy items to right */
    580		src_nr_item = B_NR_ITEMS(src);
    581		if (cpy_num == 1)
    582			bytes = cpy_bytes;
    583		else
    584			bytes = -1;
    585
    586		/*
    587		 * copy the last item or it part or nothing to the
    588		 * begin of the DEST
    589		 * (i = leaf_copy_boundary_item(DEST,SOURCE,1,bytes));
    590		 */
    591		i = leaf_copy_boundary_item(dest_bi, src, LAST_TO_FIRST, bytes);
    592
    593		cpy_num -= i;
    594		if (cpy_num == 0)
    595			return i;
    596
    597		pos = src_nr_item - cpy_num - i;
    598		if (cpy_bytes == -1) {
    599			/*
    600			 * starting from position 'pos' copy last cpy_num
    601			 * items of SOURCE to begin of DEST
    602			 */
    603			leaf_copy_items_entirely(dest_bi, src, LAST_TO_FIRST,
    604						 pos, cpy_num);
    605		} else {
    606			/*
    607			 * copy last cpy_num-1 items starting from position
    608			 * 'pos+1' of the SOURCE to the begin of the DEST;
    609			 */
    610			leaf_copy_items_entirely(dest_bi, src, LAST_TO_FIRST,
    611						 pos + 1, cpy_num - 1);
    612
    613			/*
    614			 * copy part of the item which number is pos to
    615			 * the begin of the DEST
    616			 */
    617			leaf_item_bottle(dest_bi, src, LAST_TO_FIRST, pos,
    618					 cpy_bytes);
    619		}
    620	}
    621	return i;
    622}
    623
    624/*
    625 * there are types of coping: from S[0] to L[0], from S[0] to R[0],
    626 * from R[0] to L[0]. for each of these we have to define parent and
    627 * positions of destination and source buffers
    628 */
    629static void leaf_define_dest_src_infos(int shift_mode, struct tree_balance *tb,
    630				       struct buffer_info *dest_bi,
    631				       struct buffer_info *src_bi,
    632				       int *first_last,
    633				       struct buffer_head *Snew)
    634{
    635	memset(dest_bi, 0, sizeof(struct buffer_info));
    636	memset(src_bi, 0, sizeof(struct buffer_info));
    637
    638	/* define dest, src, dest parent, dest position */
    639	switch (shift_mode) {
    640	case LEAF_FROM_S_TO_L:	/* it is used in leaf_shift_left */
    641		src_bi->tb = tb;
    642		src_bi->bi_bh = PATH_PLAST_BUFFER(tb->tb_path);
    643		src_bi->bi_parent = PATH_H_PPARENT(tb->tb_path, 0);
    644
    645		/* src->b_item_order */
    646		src_bi->bi_position = PATH_H_B_ITEM_ORDER(tb->tb_path, 0);
    647		dest_bi->tb = tb;
    648		dest_bi->bi_bh = tb->L[0];
    649		dest_bi->bi_parent = tb->FL[0];
    650		dest_bi->bi_position = get_left_neighbor_position(tb, 0);
    651		*first_last = FIRST_TO_LAST;
    652		break;
    653
    654	case LEAF_FROM_S_TO_R:	/* it is used in leaf_shift_right */
    655		src_bi->tb = tb;
    656		src_bi->bi_bh = PATH_PLAST_BUFFER(tb->tb_path);
    657		src_bi->bi_parent = PATH_H_PPARENT(tb->tb_path, 0);
    658		src_bi->bi_position = PATH_H_B_ITEM_ORDER(tb->tb_path, 0);
    659		dest_bi->tb = tb;
    660		dest_bi->bi_bh = tb->R[0];
    661		dest_bi->bi_parent = tb->FR[0];
    662		dest_bi->bi_position = get_right_neighbor_position(tb, 0);
    663		*first_last = LAST_TO_FIRST;
    664		break;
    665
    666	case LEAF_FROM_R_TO_L:	/* it is used in balance_leaf_when_delete */
    667		src_bi->tb = tb;
    668		src_bi->bi_bh = tb->R[0];
    669		src_bi->bi_parent = tb->FR[0];
    670		src_bi->bi_position = get_right_neighbor_position(tb, 0);
    671		dest_bi->tb = tb;
    672		dest_bi->bi_bh = tb->L[0];
    673		dest_bi->bi_parent = tb->FL[0];
    674		dest_bi->bi_position = get_left_neighbor_position(tb, 0);
    675		*first_last = FIRST_TO_LAST;
    676		break;
    677
    678	case LEAF_FROM_L_TO_R:	/* it is used in balance_leaf_when_delete */
    679		src_bi->tb = tb;
    680		src_bi->bi_bh = tb->L[0];
    681		src_bi->bi_parent = tb->FL[0];
    682		src_bi->bi_position = get_left_neighbor_position(tb, 0);
    683		dest_bi->tb = tb;
    684		dest_bi->bi_bh = tb->R[0];
    685		dest_bi->bi_parent = tb->FR[0];
    686		dest_bi->bi_position = get_right_neighbor_position(tb, 0);
    687		*first_last = LAST_TO_FIRST;
    688		break;
    689
    690	case LEAF_FROM_S_TO_SNEW:
    691		src_bi->tb = tb;
    692		src_bi->bi_bh = PATH_PLAST_BUFFER(tb->tb_path);
    693		src_bi->bi_parent = PATH_H_PPARENT(tb->tb_path, 0);
    694		src_bi->bi_position = PATH_H_B_ITEM_ORDER(tb->tb_path, 0);
    695		dest_bi->tb = tb;
    696		dest_bi->bi_bh = Snew;
    697		dest_bi->bi_parent = NULL;
    698		dest_bi->bi_position = 0;
    699		*first_last = LAST_TO_FIRST;
    700		break;
    701
    702	default:
    703		reiserfs_panic(sb_from_bi(src_bi), "vs-10250",
    704			       "shift type is unknown (%d)", shift_mode);
    705	}
    706	RFALSE(!src_bi->bi_bh || !dest_bi->bi_bh,
    707	       "vs-10260: mode==%d, source (%p) or dest (%p) buffer is initialized incorrectly",
    708	       shift_mode, src_bi->bi_bh, dest_bi->bi_bh);
    709}
    710
    711/*
    712 * copy mov_num items and mov_bytes of the (mov_num-1)th item to
    713 * neighbor. Delete them from source
    714 */
    715int leaf_move_items(int shift_mode, struct tree_balance *tb, int mov_num,
    716		    int mov_bytes, struct buffer_head *Snew)
    717{
    718	int ret_value;
    719	struct buffer_info dest_bi, src_bi;
    720	int first_last;
    721
    722	leaf_define_dest_src_infos(shift_mode, tb, &dest_bi, &src_bi,
    723				   &first_last, Snew);
    724
    725	ret_value =
    726	    leaf_copy_items(&dest_bi, src_bi.bi_bh, first_last, mov_num,
    727			    mov_bytes);
    728
    729	leaf_delete_items(&src_bi, first_last,
    730			  (first_last ==
    731			   FIRST_TO_LAST) ? 0 : (B_NR_ITEMS(src_bi.bi_bh) -
    732						 mov_num), mov_num, mov_bytes);
    733
    734	return ret_value;
    735}
    736
    737/*
    738 * Shift shift_num items (and shift_bytes of last shifted item if
    739 * shift_bytes != -1) from S[0] to L[0] and replace the delimiting key
    740 */
    741int leaf_shift_left(struct tree_balance *tb, int shift_num, int shift_bytes)
    742{
    743	struct buffer_head *S0 = PATH_PLAST_BUFFER(tb->tb_path);
    744	int i;
    745
    746	/*
    747	 * move shift_num (and shift_bytes bytes) items from S[0]
    748	 * to left neighbor L[0]
    749	 */
    750	i = leaf_move_items(LEAF_FROM_S_TO_L, tb, shift_num, shift_bytes, NULL);
    751
    752	if (shift_num) {
    753		/* number of items in S[0] == 0 */
    754		if (B_NR_ITEMS(S0) == 0) {
    755
    756			RFALSE(shift_bytes != -1,
    757			       "vs-10270: S0 is empty now, but shift_bytes != -1 (%d)",
    758			       shift_bytes);
    759#ifdef CONFIG_REISERFS_CHECK
    760			if (tb->tb_mode == M_PASTE || tb->tb_mode == M_INSERT) {
    761				print_cur_tb("vs-10275");
    762				reiserfs_panic(tb->tb_sb, "vs-10275",
    763					       "balance condition corrupted "
    764					       "(%c)", tb->tb_mode);
    765			}
    766#endif
    767
    768			if (PATH_H_POSITION(tb->tb_path, 1) == 0)
    769				replace_key(tb, tb->CFL[0], tb->lkey[0],
    770					    PATH_H_PPARENT(tb->tb_path, 0), 0);
    771
    772		} else {
    773			/* replace lkey in CFL[0] by 0-th key from S[0]; */
    774			replace_key(tb, tb->CFL[0], tb->lkey[0], S0, 0);
    775
    776			RFALSE((shift_bytes != -1 &&
    777				!(is_direntry_le_ih(item_head(S0, 0))
    778				  && !ih_entry_count(item_head(S0, 0)))) &&
    779			       (!op_is_left_mergeable
    780				(leaf_key(S0, 0), S0->b_size)),
    781			       "vs-10280: item must be mergeable");
    782		}
    783	}
    784
    785	return i;
    786}
    787
    788/* CLEANING STOPPED HERE */
    789
    790/*
    791 * Shift shift_num (shift_bytes) items from S[0] to the right neighbor,
    792 * and replace the delimiting key
    793 */
    794int leaf_shift_right(struct tree_balance *tb, int shift_num, int shift_bytes)
    795{
    796	int ret_value;
    797
    798	/*
    799	 * move shift_num (and shift_bytes) items from S[0] to
    800	 * right neighbor R[0]
    801	 */
    802	ret_value =
    803	    leaf_move_items(LEAF_FROM_S_TO_R, tb, shift_num, shift_bytes, NULL);
    804
    805	/* replace rkey in CFR[0] by the 0-th key from R[0] */
    806	if (shift_num) {
    807		replace_key(tb, tb->CFR[0], tb->rkey[0], tb->R[0], 0);
    808
    809	}
    810
    811	return ret_value;
    812}
    813
    814static void leaf_delete_items_entirely(struct buffer_info *bi,
    815				       int first, int del_num);
    816/*
    817 * If del_bytes == -1, starting from position 'first' delete del_num
    818 * items in whole in buffer CUR.
    819 *   If not.
    820 *   If last_first == 0. Starting from position 'first' delete del_num-1
    821 *   items in whole. Delete part of body of the first item. Part defined by
    822 *   del_bytes. Don't delete first item header
    823 *   If last_first == 1. Starting from position 'first+1' delete del_num-1
    824 *   items in whole. Delete part of body of the last item . Part defined by
    825 *   del_bytes. Don't delete last item header.
    826*/
    827void leaf_delete_items(struct buffer_info *cur_bi, int last_first,
    828		       int first, int del_num, int del_bytes)
    829{
    830	struct buffer_head *bh;
    831	int item_amount = B_NR_ITEMS(bh = cur_bi->bi_bh);
    832
    833	RFALSE(!bh, "10155: bh is not defined");
    834	RFALSE(del_num < 0, "10160: del_num can not be < 0. del_num==%d",
    835	       del_num);
    836	RFALSE(first < 0
    837	       || first + del_num > item_amount,
    838	       "10165: invalid number of first item to be deleted (%d) or "
    839	       "no so much items (%d) to delete (only %d)", first,
    840	       first + del_num, item_amount);
    841
    842	if (del_num == 0)
    843		return;
    844
    845	if (first == 0 && del_num == item_amount && del_bytes == -1) {
    846		make_empty_node(cur_bi);
    847		do_balance_mark_leaf_dirty(cur_bi->tb, bh, 0);
    848		return;
    849	}
    850
    851	if (del_bytes == -1)
    852		/* delete del_num items beginning from item in position first */
    853		leaf_delete_items_entirely(cur_bi, first, del_num);
    854	else {
    855		if (last_first == FIRST_TO_LAST) {
    856			/*
    857			 * delete del_num-1 items beginning from
    858			 * item in position first
    859			 */
    860			leaf_delete_items_entirely(cur_bi, first, del_num - 1);
    861
    862			/*
    863			 * delete the part of the first item of the bh
    864			 * do not delete item header
    865			 */
    866			leaf_cut_from_buffer(cur_bi, 0, 0, del_bytes);
    867		} else {
    868			struct item_head *ih;
    869			int len;
    870
    871			/*
    872			 * delete del_num-1 items beginning from
    873			 * item in position first+1
    874			 */
    875			leaf_delete_items_entirely(cur_bi, first + 1,
    876						   del_num - 1);
    877
    878			ih = item_head(bh, B_NR_ITEMS(bh) - 1);
    879			if (is_direntry_le_ih(ih))
    880				/* the last item is directory  */
    881				/*
    882				 * len = numbers of directory entries
    883				 * in this item
    884				 */
    885				len = ih_entry_count(ih);
    886			else
    887				/* len = body len of item */
    888				len = ih_item_len(ih);
    889
    890			/*
    891			 * delete the part of the last item of the bh
    892			 * do not delete item header
    893			 */
    894			leaf_cut_from_buffer(cur_bi, B_NR_ITEMS(bh) - 1,
    895					     len - del_bytes, del_bytes);
    896		}
    897	}
    898}
    899
    900/* insert item into the leaf node in position before */
    901void leaf_insert_into_buf(struct buffer_info *bi, int before,
    902			  struct item_head * const inserted_item_ih,
    903			  const char * const inserted_item_body,
    904			  int zeros_number)
    905{
    906	struct buffer_head *bh = bi->bi_bh;
    907	int nr, free_space;
    908	struct block_head *blkh;
    909	struct item_head *ih;
    910	int i;
    911	int last_loc, unmoved_loc;
    912	char *to;
    913
    914	blkh = B_BLK_HEAD(bh);
    915	nr = blkh_nr_item(blkh);
    916	free_space = blkh_free_space(blkh);
    917
    918	/* check free space */
    919	RFALSE(free_space < ih_item_len(inserted_item_ih) + IH_SIZE,
    920	       "vs-10170: not enough free space in block %z, new item %h",
    921	       bh, inserted_item_ih);
    922	RFALSE(zeros_number > ih_item_len(inserted_item_ih),
    923	       "vs-10172: zero number == %d, item length == %d",
    924	       zeros_number, ih_item_len(inserted_item_ih));
    925
    926	/* get item new item must be inserted before */
    927	ih = item_head(bh, before);
    928
    929	/* prepare space for the body of new item */
    930	last_loc = nr ? ih_location(&ih[nr - before - 1]) : bh->b_size;
    931	unmoved_loc = before ? ih_location(ih - 1) : bh->b_size;
    932
    933	memmove(bh->b_data + last_loc - ih_item_len(inserted_item_ih),
    934		bh->b_data + last_loc, unmoved_loc - last_loc);
    935
    936	to = bh->b_data + unmoved_loc - ih_item_len(inserted_item_ih);
    937	memset(to, 0, zeros_number);
    938	to += zeros_number;
    939
    940	/* copy body to prepared space */
    941	if (inserted_item_body)
    942		memmove(to, inserted_item_body,
    943			ih_item_len(inserted_item_ih) - zeros_number);
    944	else
    945		memset(to, '\0', ih_item_len(inserted_item_ih) - zeros_number);
    946
    947	/* insert item header */
    948	memmove(ih + 1, ih, IH_SIZE * (nr - before));
    949	memmove(ih, inserted_item_ih, IH_SIZE);
    950
    951	/* change locations */
    952	for (i = before; i < nr + 1; i++) {
    953		unmoved_loc -= ih_item_len(&ih[i - before]);
    954		put_ih_location(&ih[i - before], unmoved_loc);
    955	}
    956
    957	/* sizes, free space, item number */
    958	set_blkh_nr_item(blkh, blkh_nr_item(blkh) + 1);
    959	set_blkh_free_space(blkh,
    960			    free_space - (IH_SIZE +
    961					  ih_item_len(inserted_item_ih)));
    962	do_balance_mark_leaf_dirty(bi->tb, bh, 1);
    963
    964	if (bi->bi_parent) {
    965		struct disk_child *t_dc;
    966		t_dc = B_N_CHILD(bi->bi_parent, bi->bi_position);
    967		put_dc_size(t_dc,
    968			    dc_size(t_dc) + (IH_SIZE +
    969					     ih_item_len(inserted_item_ih)));
    970		do_balance_mark_internal_dirty(bi->tb, bi->bi_parent, 0);
    971	}
    972}
    973
    974/*
    975 * paste paste_size bytes to affected_item_num-th item.
    976 * When item is a directory, this only prepare space for new entries
    977 */
    978void leaf_paste_in_buffer(struct buffer_info *bi, int affected_item_num,
    979			  int pos_in_item, int paste_size,
    980			  const char *body, int zeros_number)
    981{
    982	struct buffer_head *bh = bi->bi_bh;
    983	int nr, free_space;
    984	struct block_head *blkh;
    985	struct item_head *ih;
    986	int i;
    987	int last_loc, unmoved_loc;
    988
    989	blkh = B_BLK_HEAD(bh);
    990	nr = blkh_nr_item(blkh);
    991	free_space = blkh_free_space(blkh);
    992
    993	/* check free space */
    994	RFALSE(free_space < paste_size,
    995	       "vs-10175: not enough free space: needed %d, available %d",
    996	       paste_size, free_space);
    997
    998#ifdef CONFIG_REISERFS_CHECK
    999	if (zeros_number > paste_size) {
   1000		struct super_block *sb = NULL;
   1001		if (bi && bi->tb)
   1002			sb = bi->tb->tb_sb;
   1003		print_cur_tb("10177");
   1004		reiserfs_panic(sb, "vs-10177",
   1005			       "zeros_number == %d, paste_size == %d",
   1006			       zeros_number, paste_size);
   1007	}
   1008#endif				/* CONFIG_REISERFS_CHECK */
   1009
   1010	/* item to be appended */
   1011	ih = item_head(bh, affected_item_num);
   1012
   1013	last_loc = ih_location(&ih[nr - affected_item_num - 1]);
   1014	unmoved_loc = affected_item_num ? ih_location(ih - 1) : bh->b_size;
   1015
   1016	/* prepare space */
   1017	memmove(bh->b_data + last_loc - paste_size, bh->b_data + last_loc,
   1018		unmoved_loc - last_loc);
   1019
   1020	/* change locations */
   1021	for (i = affected_item_num; i < nr; i++)
   1022		put_ih_location(&ih[i - affected_item_num],
   1023				ih_location(&ih[i - affected_item_num]) -
   1024				paste_size);
   1025
   1026	if (body) {
   1027		if (!is_direntry_le_ih(ih)) {
   1028			if (!pos_in_item) {
   1029				/* shift data to right */
   1030				memmove(bh->b_data + ih_location(ih) +
   1031					paste_size,
   1032					bh->b_data + ih_location(ih),
   1033					ih_item_len(ih));
   1034				/* paste data in the head of item */
   1035				memset(bh->b_data + ih_location(ih), 0,
   1036				       zeros_number);
   1037				memcpy(bh->b_data + ih_location(ih) +
   1038				       zeros_number, body,
   1039				       paste_size - zeros_number);
   1040			} else {
   1041				memset(bh->b_data + unmoved_loc - paste_size, 0,
   1042				       zeros_number);
   1043				memcpy(bh->b_data + unmoved_loc - paste_size +
   1044				       zeros_number, body,
   1045				       paste_size - zeros_number);
   1046			}
   1047		}
   1048	} else
   1049		memset(bh->b_data + unmoved_loc - paste_size, '\0', paste_size);
   1050
   1051	put_ih_item_len(ih, ih_item_len(ih) + paste_size);
   1052
   1053	/* change free space */
   1054	set_blkh_free_space(blkh, free_space - paste_size);
   1055
   1056	do_balance_mark_leaf_dirty(bi->tb, bh, 0);
   1057
   1058	if (bi->bi_parent) {
   1059		struct disk_child *t_dc =
   1060		    B_N_CHILD(bi->bi_parent, bi->bi_position);
   1061		put_dc_size(t_dc, dc_size(t_dc) + paste_size);
   1062		do_balance_mark_internal_dirty(bi->tb, bi->bi_parent, 0);
   1063	}
   1064}
   1065
   1066/*
   1067 * cuts DEL_COUNT entries beginning from FROM-th entry. Directory item
   1068 * does not have free space, so it moves DEHs and remaining records as
   1069 * necessary. Return value is size of removed part of directory item
   1070 * in bytes.
   1071 */
   1072static int leaf_cut_entries(struct buffer_head *bh,
   1073			    struct item_head *ih, int from, int del_count)
   1074{
   1075	char *item;
   1076	struct reiserfs_de_head *deh;
   1077	int prev_record_offset;	/* offset of record, that is (from-1)th */
   1078	char *prev_record;	/* */
   1079	int cut_records_len;	/* length of all removed records */
   1080	int i;
   1081
   1082	/*
   1083	 * make sure that item is directory and there are enough entries to
   1084	 * remove
   1085	 */
   1086	RFALSE(!is_direntry_le_ih(ih), "10180: item is not directory item");
   1087	RFALSE(ih_entry_count(ih) < from + del_count,
   1088	       "10185: item contains not enough entries: entry_count = %d, from = %d, to delete = %d",
   1089	       ih_entry_count(ih), from, del_count);
   1090
   1091	if (del_count == 0)
   1092		return 0;
   1093
   1094	/* first byte of item */
   1095	item = bh->b_data + ih_location(ih);
   1096
   1097	/* entry head array */
   1098	deh = B_I_DEH(bh, ih);
   1099
   1100	/*
   1101	 * first byte of remaining entries, those are BEFORE cut entries
   1102	 * (prev_record) and length of all removed records (cut_records_len)
   1103	 */
   1104	prev_record_offset =
   1105	    (from ? deh_location(&deh[from - 1]) : ih_item_len(ih));
   1106	cut_records_len = prev_record_offset /*from_record */  -
   1107	    deh_location(&deh[from + del_count - 1]);
   1108	prev_record = item + prev_record_offset;
   1109
   1110	/* adjust locations of remaining entries */
   1111	for (i = ih_entry_count(ih) - 1; i > from + del_count - 1; i--)
   1112		put_deh_location(&deh[i],
   1113				 deh_location(&deh[i]) -
   1114				 (DEH_SIZE * del_count));
   1115
   1116	for (i = 0; i < from; i++)
   1117		put_deh_location(&deh[i],
   1118				 deh_location(&deh[i]) - (DEH_SIZE * del_count +
   1119							  cut_records_len));
   1120
   1121	put_ih_entry_count(ih, ih_entry_count(ih) - del_count);
   1122
   1123	/* shift entry head array and entries those are AFTER removed entries */
   1124	memmove((char *)(deh + from),
   1125		deh + from + del_count,
   1126		prev_record - cut_records_len - (char *)(deh + from +
   1127							 del_count));
   1128
   1129	/* shift records, those are BEFORE removed entries */
   1130	memmove(prev_record - cut_records_len - DEH_SIZE * del_count,
   1131		prev_record, item + ih_item_len(ih) - prev_record);
   1132
   1133	return DEH_SIZE * del_count + cut_records_len;
   1134}
   1135
   1136/*
   1137 * when cut item is part of regular file
   1138 *      pos_in_item - first byte that must be cut
   1139 *      cut_size - number of bytes to be cut beginning from pos_in_item
   1140 *
   1141 * when cut item is part of directory
   1142 *      pos_in_item - number of first deleted entry
   1143 *      cut_size - count of deleted entries
   1144 */
   1145void leaf_cut_from_buffer(struct buffer_info *bi, int cut_item_num,
   1146			  int pos_in_item, int cut_size)
   1147{
   1148	int nr;
   1149	struct buffer_head *bh = bi->bi_bh;
   1150	struct block_head *blkh;
   1151	struct item_head *ih;
   1152	int last_loc, unmoved_loc;
   1153	int i;
   1154
   1155	blkh = B_BLK_HEAD(bh);
   1156	nr = blkh_nr_item(blkh);
   1157
   1158	/* item head of truncated item */
   1159	ih = item_head(bh, cut_item_num);
   1160
   1161	if (is_direntry_le_ih(ih)) {
   1162		/* first cut entry () */
   1163		cut_size = leaf_cut_entries(bh, ih, pos_in_item, cut_size);
   1164		if (pos_in_item == 0) {
   1165			/* change key */
   1166			RFALSE(cut_item_num,
   1167			       "when 0-th enrty of item is cut, that item must be first in the node, not %d-th",
   1168			       cut_item_num);
   1169			/* change item key by key of first entry in the item */
   1170			set_le_ih_k_offset(ih, deh_offset(B_I_DEH(bh, ih)));
   1171		}
   1172	} else {
   1173		/* item is direct or indirect */
   1174		RFALSE(is_statdata_le_ih(ih), "10195: item is stat data");
   1175		RFALSE(pos_in_item && pos_in_item + cut_size != ih_item_len(ih),
   1176		       "10200: invalid offset (%lu) or trunc_size (%lu) or ih_item_len (%lu)",
   1177		       (long unsigned)pos_in_item, (long unsigned)cut_size,
   1178		       (long unsigned)ih_item_len(ih));
   1179
   1180		/* shift item body to left if cut is from the head of item */
   1181		if (pos_in_item == 0) {
   1182			memmove(bh->b_data + ih_location(ih),
   1183				bh->b_data + ih_location(ih) + cut_size,
   1184				ih_item_len(ih) - cut_size);
   1185
   1186			/* change key of item */
   1187			if (is_direct_le_ih(ih))
   1188				set_le_ih_k_offset(ih,
   1189						   le_ih_k_offset(ih) +
   1190						   cut_size);
   1191			else {
   1192				set_le_ih_k_offset(ih,
   1193						   le_ih_k_offset(ih) +
   1194						   (cut_size / UNFM_P_SIZE) *
   1195						   bh->b_size);
   1196				RFALSE(ih_item_len(ih) == cut_size
   1197				       && get_ih_free_space(ih),
   1198				       "10205: invalid ih_free_space (%h)", ih);
   1199			}
   1200		}
   1201	}
   1202
   1203	/* location of the last item */
   1204	last_loc = ih_location(&ih[nr - cut_item_num - 1]);
   1205
   1206	/* location of the item, which is remaining at the same place */
   1207	unmoved_loc = cut_item_num ? ih_location(ih - 1) : bh->b_size;
   1208
   1209	/* shift */
   1210	memmove(bh->b_data + last_loc + cut_size, bh->b_data + last_loc,
   1211		unmoved_loc - last_loc - cut_size);
   1212
   1213	/* change item length */
   1214	put_ih_item_len(ih, ih_item_len(ih) - cut_size);
   1215
   1216	if (is_indirect_le_ih(ih)) {
   1217		if (pos_in_item)
   1218			set_ih_free_space(ih, 0);
   1219	}
   1220
   1221	/* change locations */
   1222	for (i = cut_item_num; i < nr; i++)
   1223		put_ih_location(&ih[i - cut_item_num],
   1224				ih_location(&ih[i - cut_item_num]) + cut_size);
   1225
   1226	/* size, free space */
   1227	set_blkh_free_space(blkh, blkh_free_space(blkh) + cut_size);
   1228
   1229	do_balance_mark_leaf_dirty(bi->tb, bh, 0);
   1230
   1231	if (bi->bi_parent) {
   1232		struct disk_child *t_dc;
   1233		t_dc = B_N_CHILD(bi->bi_parent, bi->bi_position);
   1234		put_dc_size(t_dc, dc_size(t_dc) - cut_size);
   1235		do_balance_mark_internal_dirty(bi->tb, bi->bi_parent, 0);
   1236	}
   1237}
   1238
   1239/* delete del_num items from buffer starting from the first'th item */
   1240static void leaf_delete_items_entirely(struct buffer_info *bi,
   1241				       int first, int del_num)
   1242{
   1243	struct buffer_head *bh = bi->bi_bh;
   1244	int nr;
   1245	int i, j;
   1246	int last_loc, last_removed_loc;
   1247	struct block_head *blkh;
   1248	struct item_head *ih;
   1249
   1250	RFALSE(bh == NULL, "10210: buffer is 0");
   1251	RFALSE(del_num < 0, "10215: del_num less than 0 (%d)", del_num);
   1252
   1253	if (del_num == 0)
   1254		return;
   1255
   1256	blkh = B_BLK_HEAD(bh);
   1257	nr = blkh_nr_item(blkh);
   1258
   1259	RFALSE(first < 0 || first + del_num > nr,
   1260	       "10220: first=%d, number=%d, there is %d items", first, del_num,
   1261	       nr);
   1262
   1263	if (first == 0 && del_num == nr) {
   1264		/* this does not work */
   1265		make_empty_node(bi);
   1266
   1267		do_balance_mark_leaf_dirty(bi->tb, bh, 0);
   1268		return;
   1269	}
   1270
   1271	ih = item_head(bh, first);
   1272
   1273	/* location of unmovable item */
   1274	j = (first == 0) ? bh->b_size : ih_location(ih - 1);
   1275
   1276	/* delete items */
   1277	last_loc = ih_location(&ih[nr - 1 - first]);
   1278	last_removed_loc = ih_location(&ih[del_num - 1]);
   1279
   1280	memmove(bh->b_data + last_loc + j - last_removed_loc,
   1281		bh->b_data + last_loc, last_removed_loc - last_loc);
   1282
   1283	/* delete item headers */
   1284	memmove(ih, ih + del_num, (nr - first - del_num) * IH_SIZE);
   1285
   1286	/* change item location */
   1287	for (i = first; i < nr - del_num; i++)
   1288		put_ih_location(&ih[i - first],
   1289				ih_location(&ih[i - first]) + (j -
   1290								 last_removed_loc));
   1291
   1292	/* sizes, item number */
   1293	set_blkh_nr_item(blkh, blkh_nr_item(blkh) - del_num);
   1294	set_blkh_free_space(blkh,
   1295			    blkh_free_space(blkh) + (j - last_removed_loc +
   1296						     IH_SIZE * del_num));
   1297
   1298	do_balance_mark_leaf_dirty(bi->tb, bh, 0);
   1299
   1300	if (bi->bi_parent) {
   1301		struct disk_child *t_dc =
   1302		    B_N_CHILD(bi->bi_parent, bi->bi_position);
   1303		put_dc_size(t_dc,
   1304			    dc_size(t_dc) - (j - last_removed_loc +
   1305					     IH_SIZE * del_num));
   1306		do_balance_mark_internal_dirty(bi->tb, bi->bi_parent, 0);
   1307	}
   1308}
   1309
   1310/*
   1311 * paste new_entry_count entries (new_dehs, records) into position
   1312 * before to item_num-th item
   1313 */
   1314void leaf_paste_entries(struct buffer_info *bi,
   1315			int item_num,
   1316			int before,
   1317			int new_entry_count,
   1318			struct reiserfs_de_head *new_dehs,
   1319			const char *records, int paste_size)
   1320{
   1321	struct item_head *ih;
   1322	char *item;
   1323	struct reiserfs_de_head *deh;
   1324	char *insert_point;
   1325	int i;
   1326	struct buffer_head *bh = bi->bi_bh;
   1327
   1328	if (new_entry_count == 0)
   1329		return;
   1330
   1331	ih = item_head(bh, item_num);
   1332
   1333	/*
   1334	 * make sure, that item is directory, and there are enough
   1335	 * records in it
   1336	 */
   1337	RFALSE(!is_direntry_le_ih(ih), "10225: item is not directory item");
   1338	RFALSE(ih_entry_count(ih) < before,
   1339	       "10230: there are no entry we paste entries before. entry_count = %d, before = %d",
   1340	       ih_entry_count(ih), before);
   1341
   1342	/* first byte of dest item */
   1343	item = bh->b_data + ih_location(ih);
   1344
   1345	/* entry head array */
   1346	deh = B_I_DEH(bh, ih);
   1347
   1348	/* new records will be pasted at this point */
   1349	insert_point =
   1350	    item +
   1351	    (before ? deh_location(&deh[before - 1])
   1352	     : (ih_item_len(ih) - paste_size));
   1353
   1354	/* adjust locations of records that will be AFTER new records */
   1355	for (i = ih_entry_count(ih) - 1; i >= before; i--)
   1356		put_deh_location(&deh[i],
   1357				 deh_location(&deh[i]) +
   1358				 (DEH_SIZE * new_entry_count));
   1359
   1360	/* adjust locations of records that will be BEFORE new records */
   1361	for (i = 0; i < before; i++)
   1362		put_deh_location(&deh[i],
   1363				 deh_location(&deh[i]) + paste_size);
   1364
   1365	put_ih_entry_count(ih, ih_entry_count(ih) + new_entry_count);
   1366
   1367	/* prepare space for pasted records */
   1368	memmove(insert_point + paste_size, insert_point,
   1369		item + (ih_item_len(ih) - paste_size) - insert_point);
   1370
   1371	/* copy new records */
   1372	memcpy(insert_point + DEH_SIZE * new_entry_count, records,
   1373	       paste_size - DEH_SIZE * new_entry_count);
   1374
   1375	/* prepare space for new entry heads */
   1376	deh += before;
   1377	memmove((char *)(deh + new_entry_count), deh,
   1378		insert_point - (char *)deh);
   1379
   1380	/* copy new entry heads */
   1381	deh = (struct reiserfs_de_head *)((char *)deh);
   1382	memcpy(deh, new_dehs, DEH_SIZE * new_entry_count);
   1383
   1384	/* set locations of new records */
   1385	for (i = 0; i < new_entry_count; i++) {
   1386		put_deh_location(&deh[i],
   1387				 deh_location(&deh[i]) +
   1388				 (-deh_location
   1389				  (&new_dehs[new_entry_count - 1]) +
   1390				  insert_point + DEH_SIZE * new_entry_count -
   1391				  item));
   1392	}
   1393
   1394	/* change item key if necessary (when we paste before 0-th entry */
   1395	if (!before) {
   1396		set_le_ih_k_offset(ih, deh_offset(new_dehs));
   1397	}
   1398#ifdef CONFIG_REISERFS_CHECK
   1399	{
   1400		int prev, next;
   1401		/* check record locations */
   1402		deh = B_I_DEH(bh, ih);
   1403		for (i = 0; i < ih_entry_count(ih); i++) {
   1404			next =
   1405			    (i <
   1406			     ih_entry_count(ih) -
   1407			     1) ? deh_location(&deh[i + 1]) : 0;
   1408			prev = (i != 0) ? deh_location(&deh[i - 1]) : 0;
   1409
   1410			if (prev && prev <= deh_location(&deh[i]))
   1411				reiserfs_error(sb_from_bi(bi), "vs-10240",
   1412					       "directory item (%h) "
   1413					       "corrupted (prev %a, "
   1414					       "cur(%d) %a)",
   1415					       ih, deh + i - 1, i, deh + i);
   1416			if (next && next >= deh_location(&deh[i]))
   1417				reiserfs_error(sb_from_bi(bi), "vs-10250",
   1418					       "directory item (%h) "
   1419					       "corrupted (cur(%d) %a, "
   1420					       "next %a)",
   1421					       ih, i, deh + i, deh + i + 1);
   1422		}
   1423	}
   1424#endif
   1425
   1426}