1/*
   2 *  Copyright 2000 by Hans Reiser, licensing governed by reiserfs/README
   3 */
   4
   5/*
   6 *  Written by Anatoly P. Pinchuk pap@namesys.botik.ru
   7 *  Programm System Institute
   8 *  Pereslavl-Zalessky Russia
   9 */
  10
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  11#include <linux/time.h>
  12#include <linux/string.h>
  13#include <linux/pagemap.h>
  14#include "reiserfs.h"
  15#include <linux/buffer_head.h>
  16#include <linux/quotaops.h>
  17
  18/* Does the buffer contain a disk block which is in the tree. */
  19inline int B_IS_IN_TREE(const struct buffer_head *bh)
  20{
  21
  22	RFALSE(B_LEVEL(bh) > MAX_HEIGHT,
  23	       "PAP-1010: block (%b) has too big level (%z)", bh, bh);
  24
  25	return (B_LEVEL(bh) != FREE_LEVEL);
  26}
  27
  28/* to get item head in le form */
 
 
  29inline void copy_item_head(struct item_head *to,
  30			   const struct item_head *from)
  31{
  32	memcpy(to, from, IH_SIZE);
  33}
  34
  35/*
  36 * k1 is pointer to on-disk structure which is stored in little-endian
  37 * form. k2 is pointer to cpu variable. For key of items of the same
  38 * object this returns 0.
  39 * Returns: -1 if key1 < key2
  40 * 0 if key1 == key2
  41 * 1 if key1 > key2
  42 */
  43inline int comp_short_keys(const struct reiserfs_key *le_key,
  44			   const struct cpu_key *cpu_key)
  45{
  46	__u32 n;
  47	n = le32_to_cpu(le_key->k_dir_id);
  48	if (n < cpu_key->on_disk_key.k_dir_id)
  49		return -1;
  50	if (n > cpu_key->on_disk_key.k_dir_id)
  51		return 1;
  52	n = le32_to_cpu(le_key->k_objectid);
  53	if (n < cpu_key->on_disk_key.k_objectid)
  54		return -1;
  55	if (n > cpu_key->on_disk_key.k_objectid)
  56		return 1;
  57	return 0;
  58}
  59
  60/*
  61 * k1 is pointer to on-disk structure which is stored in little-endian
  62 * form. k2 is pointer to cpu variable.
  63 * Compare keys using all 4 key fields.
  64 * Returns: -1 if key1 < key2 0
  65 * if key1 = key2 1 if key1 > key2
  66 */
  67static inline int comp_keys(const struct reiserfs_key *le_key,
  68			    const struct cpu_key *cpu_key)
  69{
  70	int retval;
  71
  72	retval = comp_short_keys(le_key, cpu_key);
  73	if (retval)
  74		return retval;
  75	if (le_key_k_offset(le_key_version(le_key), le_key) <
  76	    cpu_key_k_offset(cpu_key))
  77		return -1;
  78	if (le_key_k_offset(le_key_version(le_key), le_key) >
  79	    cpu_key_k_offset(cpu_key))
  80		return 1;
  81
  82	if (cpu_key->key_length == 3)
  83		return 0;
  84
  85	/* this part is needed only when tail conversion is in progress */
  86	if (le_key_k_type(le_key_version(le_key), le_key) <
  87	    cpu_key_k_type(cpu_key))
  88		return -1;
  89
  90	if (le_key_k_type(le_key_version(le_key), le_key) >
  91	    cpu_key_k_type(cpu_key))
  92		return 1;
  93
  94	return 0;
  95}
  96
  97inline int comp_short_le_keys(const struct reiserfs_key *key1,
  98			      const struct reiserfs_key *key2)
  99{
 100	__u32 *k1_u32, *k2_u32;
 101	int key_length = REISERFS_SHORT_KEY_LEN;
 102
 103	k1_u32 = (__u32 *) key1;
 104	k2_u32 = (__u32 *) key2;
 105	for (; key_length--; ++k1_u32, ++k2_u32) {
 106		if (le32_to_cpu(*k1_u32) < le32_to_cpu(*k2_u32))
 107			return -1;
 108		if (le32_to_cpu(*k1_u32) > le32_to_cpu(*k2_u32))
 109			return 1;
 110	}
 111	return 0;
 112}
 113
 114inline void le_key2cpu_key(struct cpu_key *to, const struct reiserfs_key *from)
 115{
 116	int version;
 117	to->on_disk_key.k_dir_id = le32_to_cpu(from->k_dir_id);
 118	to->on_disk_key.k_objectid = le32_to_cpu(from->k_objectid);
 119
 120	/* find out version of the key */
 121	version = le_key_version(from);
 122	to->version = version;
 123	to->on_disk_key.k_offset = le_key_k_offset(version, from);
 124	to->on_disk_key.k_type = le_key_k_type(version, from);
 125}
 126
 127/*
 128 * this does not say which one is bigger, it only returns 1 if keys
 129 * are not equal, 0 otherwise
 130 */
 131inline int comp_le_keys(const struct reiserfs_key *k1,
 132			const struct reiserfs_key *k2)
 133{
 134	return memcmp(k1, k2, sizeof(struct reiserfs_key));
 135}
 136
 137/**************************************************************************
 138 *  Binary search toolkit function                                        *
 139 *  Search for an item in the array by the item key                       *
 140 *  Returns:    1 if found,  0 if not found;                              *
 141 *        *pos = number of the searched element if found, else the        *
 142 *        number of the first element that is larger than key.            *
 143 **************************************************************************/
 144/*
 145 * For those not familiar with binary search: lbound is the leftmost item
 146 * that it could be, rbound the rightmost item that it could be.  We examine
 147 * the item halfway between lbound and rbound, and that tells us either
 148 * that we can increase lbound, or decrease rbound, or that we have found it,
 149 * or if lbound <= rbound that there are no possible items, and we have not
 150 * found it. With each examination we cut the number of possible items it
 151 * could be by one more than half rounded down, or we find it.
 152 */
 153static inline int bin_search(const void *key,	/* Key to search for. */
 154			     const void *base,	/* First item in the array. */
 155			     int num,	/* Number of items in the array. */
 156			     /*
 157			      * Item size in the array.  searched. Lest the
 158			      * reader be confused, note that this is crafted
 159			      * as a general function, and when it is applied
 160			      * specifically to the array of item headers in a
 161			      * node, width is actually the item header size
 162			      * not the item size.
 163			      */
 164			     int width,
 165			     int *pos /* Number of the searched for element. */
 166    )
 167{
 168	int rbound, lbound, j;
 169
 170	for (j = ((rbound = num - 1) + (lbound = 0)) / 2;
 171	     lbound <= rbound; j = (rbound + lbound) / 2)
 172		switch (comp_keys
 173			((struct reiserfs_key *)((char *)base + j * width),
 174			 (struct cpu_key *)key)) {
 175		case -1:
 176			lbound = j + 1;
 177			continue;
 178		case 1:
 179			rbound = j - 1;
 180			continue;
 181		case 0:
 182			*pos = j;
 183			return ITEM_FOUND;	/* Key found in the array.  */
 184		}
 185
 186	/*
 187	 * bin_search did not find given key, it returns position of key,
 188	 * that is minimal and greater than the given one.
 189	 */
 190	*pos = lbound;
 191	return ITEM_NOT_FOUND;
 192}
 193
 194
 195/* Minimal possible key. It is never in the tree. */
 196const struct reiserfs_key MIN_KEY = { 0, 0, {{0, 0},} };
 197
 198/* Maximal possible key. It is never in the tree. */
 199static const struct reiserfs_key MAX_KEY = {
 200	cpu_to_le32(0xffffffff),
 201	cpu_to_le32(0xffffffff),
 202	{{cpu_to_le32(0xffffffff),
 203	  cpu_to_le32(0xffffffff)},}
 204};
 205
 206/*
 207 * Get delimiting key of the buffer by looking for it in the buffers in the
 208 * path, starting from the bottom of the path, and going upwards.  We must
 209 * check the path's validity at each step.  If the key is not in the path,
 210 * there is no delimiting key in the tree (buffer is first or last buffer
 211 * in tree), and in this case we return a special key, either MIN_KEY or
 212 * MAX_KEY.
 213 */
 214static inline const struct reiserfs_key *get_lkey(const struct treepath *chk_path,
 215						  const struct super_block *sb)
 216{
 217	int position, path_offset = chk_path->path_length;
 218	struct buffer_head *parent;
 219
 220	RFALSE(path_offset < FIRST_PATH_ELEMENT_OFFSET,
 221	       "PAP-5010: invalid offset in the path");
 222
 223	/* While not higher in path than first element. */
 224	while (path_offset-- > FIRST_PATH_ELEMENT_OFFSET) {
 225
 226		RFALSE(!buffer_uptodate
 227		       (PATH_OFFSET_PBUFFER(chk_path, path_offset)),
 228		       "PAP-5020: parent is not uptodate");
 229
 230		/* Parent at the path is not in the tree now. */
 231		if (!B_IS_IN_TREE
 232		    (parent =
 233		     PATH_OFFSET_PBUFFER(chk_path, path_offset)))
 234			return &MAX_KEY;
 235		/* Check whether position in the parent is correct. */
 236		if ((position =
 237		     PATH_OFFSET_POSITION(chk_path,
 238					  path_offset)) >
 239		    B_NR_ITEMS(parent))
 240			return &MAX_KEY;
 241		/* Check whether parent at the path really points to the child. */
 242		if (B_N_CHILD_NUM(parent, position) !=
 243		    PATH_OFFSET_PBUFFER(chk_path,
 244					path_offset + 1)->b_blocknr)
 245			return &MAX_KEY;
 246		/*
 247		 * Return delimiting key if position in the parent
 248		 * is not equal to zero.
 249		 */
 250		if (position)
 251			return internal_key(parent, position - 1);
 252	}
 253	/* Return MIN_KEY if we are in the root of the buffer tree. */
 254	if (PATH_OFFSET_PBUFFER(chk_path, FIRST_PATH_ELEMENT_OFFSET)->
 255	    b_blocknr == SB_ROOT_BLOCK(sb))
 256		return &MIN_KEY;
 257	return &MAX_KEY;
 258}
 259
 260/* Get delimiting key of the buffer at the path and its right neighbor. */
 261inline const struct reiserfs_key *get_rkey(const struct treepath *chk_path,
 262					   const struct super_block *sb)
 263{
 264	int position, path_offset = chk_path->path_length;
 265	struct buffer_head *parent;
 266
 267	RFALSE(path_offset < FIRST_PATH_ELEMENT_OFFSET,
 268	       "PAP-5030: invalid offset in the path");
 269
 270	while (path_offset-- > FIRST_PATH_ELEMENT_OFFSET) {
 271
 272		RFALSE(!buffer_uptodate
 273		       (PATH_OFFSET_PBUFFER(chk_path, path_offset)),
 274		       "PAP-5040: parent is not uptodate");
 275
 276		/* Parent at the path is not in the tree now. */
 277		if (!B_IS_IN_TREE
 278		    (parent =
 279		     PATH_OFFSET_PBUFFER(chk_path, path_offset)))
 280			return &MIN_KEY;
 281		/* Check whether position in the parent is correct. */
 282		if ((position =
 283		     PATH_OFFSET_POSITION(chk_path,
 284					  path_offset)) >
 285		    B_NR_ITEMS(parent))
 286			return &MIN_KEY;
 287		/*
 288		 * Check whether parent at the path really points
 289		 * to the child.
 290		 */
 291		if (B_N_CHILD_NUM(parent, position) !=
 292		    PATH_OFFSET_PBUFFER(chk_path,
 293					path_offset + 1)->b_blocknr)
 294			return &MIN_KEY;
 295
 296		/*
 297		 * Return delimiting key if position in the parent
 298		 * is not the last one.
 299		 */
 300		if (position != B_NR_ITEMS(parent))
 301			return internal_key(parent, position);
 302	}
 303
 304	/* Return MAX_KEY if we are in the root of the buffer tree. */
 305	if (PATH_OFFSET_PBUFFER(chk_path, FIRST_PATH_ELEMENT_OFFSET)->
 306	    b_blocknr == SB_ROOT_BLOCK(sb))
 307		return &MAX_KEY;
 308	return &MIN_KEY;
 309}
 310
 311/*
 312 * Check whether a key is contained in the tree rooted from a buffer at a path.
 313 * This works by looking at the left and right delimiting keys for the buffer
 314 * in the last path_element in the path.  These delimiting keys are stored
 315 * at least one level above that buffer in the tree. If the buffer is the
 316 * first or last node in the tree order then one of the delimiting keys may
 317 * be absent, and in this case get_lkey and get_rkey return a special key
 318 * which is MIN_KEY or MAX_KEY.
 319 */
 320static inline int key_in_buffer(
 321				/* Path which should be checked. */
 322				struct treepath *chk_path,
 323				/* Key which should be checked. */
 324				const struct cpu_key *key,
 325				struct super_block *sb
 326    )
 327{
 328
 329	RFALSE(!key || chk_path->path_length < FIRST_PATH_ELEMENT_OFFSET
 330	       || chk_path->path_length > MAX_HEIGHT,
 331	       "PAP-5050: pointer to the key(%p) is NULL or invalid path length(%d)",
 332	       key, chk_path->path_length);
 333	RFALSE(!PATH_PLAST_BUFFER(chk_path)->b_bdev,
 334	       "PAP-5060: device must not be NODEV");
 335
 336	if (comp_keys(get_lkey(chk_path, sb), key) == 1)
 337		/* left delimiting key is bigger, that the key we look for */
 338		return 0;
 339	/*  if ( comp_keys(key, get_rkey(chk_path, sb)) != -1 ) */
 340	if (comp_keys(get_rkey(chk_path, sb), key) != 1)
 341		/* key must be less than right delimitiing key */
 342		return 0;
 343	return 1;
 344}
 345
 346int reiserfs_check_path(struct treepath *p)
 347{
 348	RFALSE(p->path_length != ILLEGAL_PATH_ELEMENT_OFFSET,
 349	       "path not properly relsed");
 350	return 0;
 351}
 352
 353/*
 354 * Drop the reference to each buffer in a path and restore
 355 * dirty bits clean when preparing the buffer for the log.
 356 * This version should only be called from fix_nodes()
 357 */
 358void pathrelse_and_restore(struct super_block *sb,
 359			   struct treepath *search_path)
 360{
 361	int path_offset = search_path->path_length;
 362
 363	RFALSE(path_offset < ILLEGAL_PATH_ELEMENT_OFFSET,
 364	       "clm-4000: invalid path offset");
 365
 366	while (path_offset > ILLEGAL_PATH_ELEMENT_OFFSET) {
 367		struct buffer_head *bh;
 368		bh = PATH_OFFSET_PBUFFER(search_path, path_offset--);
 369		reiserfs_restore_prepared_buffer(sb, bh);
 370		brelse(bh);
 371	}
 372	search_path->path_length = ILLEGAL_PATH_ELEMENT_OFFSET;
 373}
 374
 375/* Drop the reference to each buffer in a path */
 376void pathrelse(struct treepath *search_path)
 377{
 378	int path_offset = search_path->path_length;
 379
 380	RFALSE(path_offset < ILLEGAL_PATH_ELEMENT_OFFSET,
 381	       "PAP-5090: invalid path offset");
 382
 383	while (path_offset > ILLEGAL_PATH_ELEMENT_OFFSET)
 384		brelse(PATH_OFFSET_PBUFFER(search_path, path_offset--));
 385
 386	search_path->path_length = ILLEGAL_PATH_ELEMENT_OFFSET;
 387}
 388
 389static int is_leaf(char *buf, int blocksize, struct buffer_head *bh)
 390{
 391	struct block_head *blkh;
 392	struct item_head *ih;
 393	int used_space;
 394	int prev_location;
 395	int i;
 396	int nr;
 397
 398	blkh = (struct block_head *)buf;
 399	if (blkh_level(blkh) != DISK_LEAF_NODE_LEVEL) {
 400		reiserfs_warning(NULL, "reiserfs-5080",
 401				 "this should be caught earlier");
 402		return 0;
 403	}
 404
 405	nr = blkh_nr_item(blkh);
 406	if (nr < 1 || nr > ((blocksize - BLKH_SIZE) / (IH_SIZE + MIN_ITEM_LEN))) {
 407		/* item number is too big or too small */
 408		reiserfs_warning(NULL, "reiserfs-5081",
 409				 "nr_item seems wrong: %z", bh);
 410		return 0;
 411	}
 412	ih = (struct item_head *)(buf + BLKH_SIZE) + nr - 1;
 413	used_space = BLKH_SIZE + IH_SIZE * nr + (blocksize - ih_location(ih));
 414
 415	/* free space does not match to calculated amount of use space */
 416	if (used_space != blocksize - blkh_free_space(blkh)) {
 
 417		reiserfs_warning(NULL, "reiserfs-5082",
 418				 "free space seems wrong: %z", bh);
 419		return 0;
 420	}
 421	/*
 422	 * FIXME: it is_leaf will hit performance too much - we may have
 423	 * return 1 here
 424	 */
 425
 426	/* check tables of item heads */
 427	ih = (struct item_head *)(buf + BLKH_SIZE);
 428	prev_location = blocksize;
 429	for (i = 0; i < nr; i++, ih++) {
 430		if (le_ih_k_type(ih) == TYPE_ANY) {
 431			reiserfs_warning(NULL, "reiserfs-5083",
 432					 "wrong item type for item %h",
 433					 ih);
 434			return 0;
 435		}
 436		if (ih_location(ih) >= blocksize
 437		    || ih_location(ih) < IH_SIZE * nr) {
 438			reiserfs_warning(NULL, "reiserfs-5084",
 439					 "item location seems wrong: %h",
 440					 ih);
 441			return 0;
 442		}
 443		if (ih_item_len(ih) < 1
 444		    || ih_item_len(ih) > MAX_ITEM_LEN(blocksize)) {
 445			reiserfs_warning(NULL, "reiserfs-5085",
 446					 "item length seems wrong: %h",
 447					 ih);
 448			return 0;
 449		}
 450		if (prev_location - ih_location(ih) != ih_item_len(ih)) {
 451			reiserfs_warning(NULL, "reiserfs-5086",
 452					 "item location seems wrong "
 453					 "(second one): %h", ih);
 454			return 0;
 455		}
 456		prev_location = ih_location(ih);
 457	}
 458
 459	/* one may imagine many more checks */
 460	return 1;
 461}
 462
 463/* returns 1 if buf looks like an internal node, 0 otherwise */
 464static int is_internal(char *buf, int blocksize, struct buffer_head *bh)
 465{
 466	struct block_head *blkh;
 467	int nr;
 468	int used_space;
 469
 470	blkh = (struct block_head *)buf;
 471	nr = blkh_level(blkh);
 472	if (nr <= DISK_LEAF_NODE_LEVEL || nr > MAX_HEIGHT) {
 473		/* this level is not possible for internal nodes */
 474		reiserfs_warning(NULL, "reiserfs-5087",
 475				 "this should be caught earlier");
 476		return 0;
 477	}
 478
 479	nr = blkh_nr_item(blkh);
 480	/* for internal which is not root we might check min number of keys */
 481	if (nr > (blocksize - BLKH_SIZE - DC_SIZE) / (KEY_SIZE + DC_SIZE)) {
 
 482		reiserfs_warning(NULL, "reiserfs-5088",
 483				 "number of key seems wrong: %z", bh);
 484		return 0;
 485	}
 486
 487	used_space = BLKH_SIZE + KEY_SIZE * nr + DC_SIZE * (nr + 1);
 488	if (used_space != blocksize - blkh_free_space(blkh)) {
 489		reiserfs_warning(NULL, "reiserfs-5089",
 490				 "free space seems wrong: %z", bh);
 491		return 0;
 492	}
 493
 494	/* one may imagine many more checks */
 495	return 1;
 496}
 497
 498/*
 499 * make sure that bh contains formatted node of reiserfs tree of
 500 * 'level'-th level
 501 */
 502static int is_tree_node(struct buffer_head *bh, int level)
 503{
 504	if (B_LEVEL(bh) != level) {
 505		reiserfs_warning(NULL, "reiserfs-5090", "node level %d does "
 506				 "not match to the expected one %d",
 507				 B_LEVEL(bh), level);
 508		return 0;
 509	}
 510	if (level == DISK_LEAF_NODE_LEVEL)
 511		return is_leaf(bh->b_data, bh->b_size, bh);
 512
 513	return is_internal(bh->b_data, bh->b_size, bh);
 514}
 515
 516#define SEARCH_BY_KEY_READA 16
 517
 518/*
 519 * The function is NOT SCHEDULE-SAFE!
 520 * It might unlock the write lock if we needed to wait for a block
 521 * to be read. Note that in this case it won't recover the lock to avoid
 522 * high contention resulting from too much lock requests, especially
 523 * the caller (search_by_key) will perform other schedule-unsafe
 524 * operations just after calling this function.
 525 *
 526 * @return depth of lock to be restored after read completes
 527 */
 528static int search_by_key_reada(struct super_block *s,
 529				struct buffer_head **bh,
 530				b_blocknr_t *b, int num)
 531{
 532	int i, j;
 533	int depth = -1;
 534
 535	for (i = 0; i < num; i++) {
 536		bh[i] = sb_getblk(s, b[i]);
 537	}
 538	/*
 539	 * We are going to read some blocks on which we
 540	 * have a reference. It's safe, though we might be
 541	 * reading blocks concurrently changed if we release
 542	 * the lock. But it's still fine because we check later
 543	 * if the tree changed
 544	 */
 545	for (j = 0; j < i; j++) {
 546		/*
 547		 * note, this needs attention if we are getting rid of the BKL
 548		 * you have to make sure the prepared bit isn't set on this
 549		 * buffer
 550		 */
 551		if (!buffer_uptodate(bh[j])) {
 552			if (depth == -1)
 553				depth = reiserfs_write_unlock_nested(s);
 554			ll_rw_block(READA, 1, bh + j);
 555		}
 556		brelse(bh[j]);
 557	}
 558	return depth;
 559}
 560
 561/*
 562 * This function fills up the path from the root to the leaf as it
 563 * descends the tree looking for the key.  It uses reiserfs_bread to
 564 * try to find buffers in the cache given their block number.  If it
 565 * does not find them in the cache it reads them from disk.  For each
 566 * node search_by_key finds using reiserfs_bread it then uses
 567 * bin_search to look through that node.  bin_search will find the
 568 * position of the block_number of the next node if it is looking
 569 * through an internal node.  If it is looking through a leaf node
 570 * bin_search will find the position of the item which has key either
 571 * equal to given key, or which is the maximal key less than the given
 572 * key.  search_by_key returns a path that must be checked for the
 573 * correctness of the top of the path but need not be checked for the
 574 * correctness of the bottom of the path
 575 */
 576/*
 577 * search_by_key - search for key (and item) in stree
 578 * @sb: superblock
 579 * @key: pointer to key to search for
 580 * @search_path: Allocated and initialized struct treepath; Returned filled
 581 *		 on success.
 582 * @stop_level: How far down the tree to search, Use DISK_LEAF_NODE_LEVEL to
 583 *		stop at leaf level.
 584 *
 585 * The function is NOT SCHEDULE-SAFE!
 586 */
 587int search_by_key(struct super_block *sb, const struct cpu_key *key,
 588		  struct treepath *search_path, int stop_level)
 
 
 
 
 
 589{
 590	b_blocknr_t block_number;
 591	int expected_level;
 592	struct buffer_head *bh;
 593	struct path_element *last_element;
 594	int node_level, retval;
 595	int right_neighbor_of_leaf_node;
 596	int fs_gen;
 597	struct buffer_head *reada_bh[SEARCH_BY_KEY_READA];
 598	b_blocknr_t reada_blocks[SEARCH_BY_KEY_READA];
 599	int reada_count = 0;
 600
 601#ifdef CONFIG_REISERFS_CHECK
 602	int repeat_counter = 0;
 603#endif
 604
 605	PROC_INFO_INC(sb, search_by_key);
 606
 607	/*
 608	 * As we add each node to a path we increase its count.  This means
 609	 * that we must be careful to release all nodes in a path before we
 610	 * either discard the path struct or re-use the path struct, as we
 611	 * do here.
 612	 */
 613
 614	pathrelse(search_path);
 615
 616	right_neighbor_of_leaf_node = 0;
 617
 618	/*
 619	 * With each iteration of this loop we search through the items in the
 620	 * current node, and calculate the next current node(next path element)
 621	 * for the next iteration of this loop..
 622	 */
 623	block_number = SB_ROOT_BLOCK(sb);
 624	expected_level = -1;
 625	while (1) {
 626
 627#ifdef CONFIG_REISERFS_CHECK
 628		if (!(++repeat_counter % 50000))
 629			reiserfs_warning(sb, "PAP-5100",
 630					 "%s: there were %d iterations of "
 631					 "while loop looking for key %K",
 632					 current->comm, repeat_counter,
 633					 key);
 634#endif
 635
 636		/* prep path to have another element added to it. */
 637		last_element =
 638		    PATH_OFFSET_PELEMENT(search_path,
 639					 ++search_path->path_length);
 640		fs_gen = get_generation(sb);
 641
 642		/*
 643		 * Read the next tree node, and set the last element
 644		 * in the path to have a pointer to it.
 645		 */
 646		if ((bh = last_element->pe_buffer =
 647		     sb_getblk(sb, block_number))) {
 648
 649			/*
 650			 * We'll need to drop the lock if we encounter any
 651			 * buffers that need to be read. If all of them are
 652			 * already up to date, we don't need to drop the lock.
 653			 */
 654			int depth = -1;
 655
 656			if (!buffer_uptodate(bh) && reada_count > 1)
 657				depth = search_by_key_reada(sb, reada_bh,
 658						    reada_blocks, reada_count);
 659
 660			if (!buffer_uptodate(bh) && depth == -1)
 661				depth = reiserfs_write_unlock_nested(sb);
 662
 663			ll_rw_block(READ, 1, &bh);
 664			wait_on_buffer(bh);
 665
 666			if (depth != -1)
 667				reiserfs_write_lock_nested(sb, depth);
 668			if (!buffer_uptodate(bh))
 669				goto io_error;
 670		} else {
 671io_error:
 672			search_path->path_length--;
 673			pathrelse(search_path);
 674			return IO_ERROR;
 675		}
 676		reada_count = 0;
 677		if (expected_level == -1)
 678			expected_level = SB_TREE_HEIGHT(sb);
 679		expected_level--;
 680
 681		/*
 682		 * It is possible that schedule occurred. We must check
 683		 * whether the key to search is still in the tree rooted
 684		 * from the current buffer. If not then repeat search
 685		 * from the root.
 686		 */
 687		if (fs_changed(fs_gen, sb) &&
 688		    (!B_IS_IN_TREE(bh) ||
 689		     B_LEVEL(bh) != expected_level ||
 690		     !key_in_buffer(search_path, key, sb))) {
 691			PROC_INFO_INC(sb, search_by_key_fs_changed);
 692			PROC_INFO_INC(sb, search_by_key_restarted);
 693			PROC_INFO_INC(sb,
 694				      sbk_restarted[expected_level - 1]);
 695			pathrelse(search_path);
 696
 697			/*
 698			 * Get the root block number so that we can
 699			 * repeat the search starting from the root.
 700			 */
 701			block_number = SB_ROOT_BLOCK(sb);
 702			expected_level = -1;
 703			right_neighbor_of_leaf_node = 0;
 704
 705			/* repeat search from the root */
 706			continue;
 707		}
 708
 709		/*
 710		 * only check that the key is in the buffer if key is not
 711		 * equal to the MAX_KEY. Latter case is only possible in
 712		 * "finish_unfinished()" processing during mount.
 713		 */
 714		RFALSE(comp_keys(&MAX_KEY, key) &&
 715		       !key_in_buffer(search_path, key, sb),
 716		       "PAP-5130: key is not in the buffer");
 717#ifdef CONFIG_REISERFS_CHECK
 718		if (REISERFS_SB(sb)->cur_tb) {
 719			print_cur_tb("5140");
 720			reiserfs_panic(sb, "PAP-5140",
 721				       "schedule occurred in do_balance!");
 722		}
 723#endif
 724
 725		/*
 726		 * make sure, that the node contents look like a node of
 727		 * certain level
 728		 */
 729		if (!is_tree_node(bh, expected_level)) {
 730			reiserfs_error(sb, "vs-5150",
 731				       "invalid format found in block %ld. "
 732				       "Fsck?", bh->b_blocknr);
 733			pathrelse(search_path);
 734			return IO_ERROR;
 735		}
 736
 737		/* ok, we have acquired next formatted node in the tree */
 738		node_level = B_LEVEL(bh);
 739
 740		PROC_INFO_BH_STAT(sb, bh, node_level - 1);
 741
 742		RFALSE(node_level < stop_level,
 743		       "vs-5152: tree level (%d) is less than stop level (%d)",
 744		       node_level, stop_level);
 745
 746		retval = bin_search(key, item_head(bh, 0),
 747				      B_NR_ITEMS(bh),
 748				      (node_level ==
 749				       DISK_LEAF_NODE_LEVEL) ? IH_SIZE :
 750				      KEY_SIZE,
 751				      &last_element->pe_position);
 752		if (node_level == stop_level) {
 753			return retval;
 754		}
 755
 756		/* we are not in the stop level */
 757		/*
 758		 * item has been found, so we choose the pointer which
 759		 * is to the right of the found one
 760		 */
 761		if (retval == ITEM_FOUND)
 
 762			last_element->pe_position++;
 763
 764		/*
 765		 * if item was not found we choose the position which is to
 766		 * the left of the found item. This requires no code,
 767		 * bin_search did it already.
 768		 */
 769
 770		/*
 771		 * So we have chosen a position in the current node which is
 772		 * an internal node.  Now we calculate child block number by
 773		 * position in the node.
 774		 */
 775		block_number =
 776		    B_N_CHILD_NUM(bh, last_element->pe_position);
 777
 778		/*
 779		 * if we are going to read leaf nodes, try for read
 780		 * ahead as well
 781		 */
 782		if ((search_path->reada & PATH_READA) &&
 783		    node_level == DISK_LEAF_NODE_LEVEL + 1) {
 784			int pos = last_element->pe_position;
 785			int limit = B_NR_ITEMS(bh);
 786			struct reiserfs_key *le_key;
 787
 788			if (search_path->reada & PATH_READA_BACK)
 789				limit = 0;
 790			while (reada_count < SEARCH_BY_KEY_READA) {
 791				if (pos == limit)
 792					break;
 793				reada_blocks[reada_count++] =
 794				    B_N_CHILD_NUM(bh, pos);
 795				if (search_path->reada & PATH_READA_BACK)
 796					pos--;
 797				else
 798					pos++;
 799
 800				/*
 801				 * check to make sure we're in the same object
 802				 */
 803				le_key = internal_key(bh, pos);
 804				if (le32_to_cpu(le_key->k_objectid) !=
 805				    key->on_disk_key.k_objectid) {
 806					break;
 807				}
 808			}
 809		}
 810	}
 811}
 812
 813/*
 814 * Form the path to an item and position in this item which contains
 815 * file byte defined by key. If there is no such item
 816 * corresponding to the key, we point the path to the item with
 817 * maximal key less than key, and *pos_in_item is set to one
 818 * past the last entry/byte in the item.  If searching for entry in a
 819 * directory item, and it is not found, *pos_in_item is set to one
 820 * entry more than the entry with maximal key which is less than the
 821 * sought key.
 822 *
 823 * Note that if there is no entry in this same node which is one more,
 824 * then we point to an imaginary entry.  for direct items, the
 825 * position is in units of bytes, for indirect items the position is
 826 * in units of blocknr entries, for directory items the position is in
 827 * units of directory entries.
 828 */
 829/* The function is NOT SCHEDULE-SAFE! */
 830int search_for_position_by_key(struct super_block *sb,
 831			       /* Key to search (cpu variable) */
 832			       const struct cpu_key *p_cpu_key,
 833			       /* Filled up by this function. */
 834			       struct treepath *search_path)
 835{
 836	struct item_head *p_le_ih;	/* pointer to on-disk structure */
 837	int blk_size;
 838	loff_t item_offset, offset;
 839	struct reiserfs_dir_entry de;
 840	int retval;
 841
 842	/* If searching for directory entry. */
 843	if (is_direntry_cpu_key(p_cpu_key))
 844		return search_by_entry_key(sb, p_cpu_key, search_path,
 845					   &de);
 846
 847	/* If not searching for directory entry. */
 848
 849	/* If item is found. */
 850	retval = search_item(sb, p_cpu_key, search_path);
 851	if (retval == IO_ERROR)
 852		return retval;
 853	if (retval == ITEM_FOUND) {
 854
 855		RFALSE(!ih_item_len
 856		       (item_head
 857			(PATH_PLAST_BUFFER(search_path),
 858			 PATH_LAST_POSITION(search_path))),
 859		       "PAP-5165: item length equals zero");
 860
 861		pos_in_item(search_path) = 0;
 862		return POSITION_FOUND;
 863	}
 864
 865	RFALSE(!PATH_LAST_POSITION(search_path),
 866	       "PAP-5170: position equals zero");
 867
 868	/* Item is not found. Set path to the previous item. */
 869	p_le_ih =
 870	    item_head(PATH_PLAST_BUFFER(search_path),
 871			   --PATH_LAST_POSITION(search_path));
 872	blk_size = sb->s_blocksize;
 873
 874	if (comp_short_keys(&p_le_ih->ih_key, p_cpu_key))
 875		return FILE_NOT_FOUND;
 876
 877	/* FIXME: quite ugly this far */
 878
 879	item_offset = le_ih_k_offset(p_le_ih);
 880	offset = cpu_key_k_offset(p_cpu_key);
 881
 882	/* Needed byte is contained in the item pointed to by the path. */
 883	if (item_offset <= offset &&
 884	    item_offset + op_bytes_number(p_le_ih, blk_size) > offset) {
 885		pos_in_item(search_path) = offset - item_offset;
 886		if (is_indirect_le_ih(p_le_ih)) {
 887			pos_in_item(search_path) /= blk_size;
 888		}
 889		return POSITION_FOUND;
 890	}
 891
 892	/*
 893	 * Needed byte is not contained in the item pointed to by the
 894	 * path. Set pos_in_item out of the item.
 895	 */
 896	if (is_indirect_le_ih(p_le_ih))
 897		pos_in_item(search_path) =
 898		    ih_item_len(p_le_ih) / UNFM_P_SIZE;
 899	else
 900		pos_in_item(search_path) = ih_item_len(p_le_ih);
 901
 902	return POSITION_NOT_FOUND;
 903}
 904
 905/* Compare given item and item pointed to by the path. */
 906int comp_items(const struct item_head *stored_ih, const struct treepath *path)
 907{
 908	struct buffer_head *bh = PATH_PLAST_BUFFER(path);
 909	struct item_head *ih;
 910
 911	/* Last buffer at the path is not in the tree. */
 912	if (!B_IS_IN_TREE(bh))
 913		return 1;
 914
 915	/* Last path position is invalid. */
 916	if (PATH_LAST_POSITION(path) >= B_NR_ITEMS(bh))
 917		return 1;
 918
 919	/* we need only to know, whether it is the same item */
 920	ih = tp_item_head(path);
 921	return memcmp(stored_ih, ih, IH_SIZE);
 922}
 923
 924/* unformatted nodes are not logged anymore, ever.  This is safe now */
 
 
 925#define held_by_others(bh) (atomic_read(&(bh)->b_count) > 1)
 926
 927/* block can not be forgotten as it is in I/O or held by someone */
 928#define block_in_use(bh) (buffer_locked(bh) || (held_by_others(bh)))
 929
 930/* prepare for delete or cut of direct item */
 931static inline int prepare_for_direct_item(struct treepath *path,
 932					  struct item_head *le_ih,
 933					  struct inode *inode,
 934					  loff_t new_file_length, int *cut_size)
 935{
 936	loff_t round_len;
 937
 938	if (new_file_length == max_reiserfs_offset(inode)) {
 939		/* item has to be deleted */
 940		*cut_size = -(IH_SIZE + ih_item_len(le_ih));
 941		return M_DELETE;
 942	}
 943	/* new file gets truncated */
 944	if (get_inode_item_key_version(inode) == KEY_FORMAT_3_6) {
 
 945		round_len = ROUND_UP(new_file_length);
 946		/* this was new_file_length < le_ih ... */
 947		if (round_len < le_ih_k_offset(le_ih)) {
 948			*cut_size = -(IH_SIZE + ih_item_len(le_ih));
 949			return M_DELETE;	/* Delete this item. */
 950		}
 951		/* Calculate first position and size for cutting from item. */
 952		pos_in_item(path) = round_len - (le_ih_k_offset(le_ih) - 1);
 953		*cut_size = -(ih_item_len(le_ih) - pos_in_item(path));
 954
 955		return M_CUT;	/* Cut from this item. */
 956	}
 957
 958	/* old file: items may have any length */
 959
 960	if (new_file_length < le_ih_k_offset(le_ih)) {
 961		*cut_size = -(IH_SIZE + ih_item_len(le_ih));
 962		return M_DELETE;	/* Delete this item. */
 963	}
 964
 965	/* Calculate first position and size for cutting from item. */
 966	*cut_size = -(ih_item_len(le_ih) -
 967		      (pos_in_item(path) =
 968		       new_file_length + 1 - le_ih_k_offset(le_ih)));
 969	return M_CUT;		/* Cut from this item. */
 970}
 971
 972static inline int prepare_for_direntry_item(struct treepath *path,
 973					    struct item_head *le_ih,
 974					    struct inode *inode,
 975					    loff_t new_file_length,
 976					    int *cut_size)
 977{
 978	if (le_ih_k_offset(le_ih) == DOT_OFFSET &&
 979	    new_file_length == max_reiserfs_offset(inode)) {
 980		RFALSE(ih_entry_count(le_ih) != 2,
 981		       "PAP-5220: incorrect empty directory item (%h)", le_ih);
 982		*cut_size = -(IH_SIZE + ih_item_len(le_ih));
 983		/* Delete the directory item containing "." and ".." entry. */
 984		return M_DELETE;
 985	}
 986
 987	if (ih_entry_count(le_ih) == 1) {
 988		/*
 989		 * Delete the directory item such as there is one record only
 990		 * in this item
 991		 */
 992		*cut_size = -(IH_SIZE + ih_item_len(le_ih));
 993		return M_DELETE;
 994	}
 995
 996	/* Cut one record from the directory item. */
 997	*cut_size =
 998	    -(DEH_SIZE +
 999	      entry_length(get_last_bh(path), le_ih, pos_in_item(path)));
1000	return M_CUT;
1001}
1002
1003#define JOURNAL_FOR_FREE_BLOCK_AND_UPDATE_SD (2 * JOURNAL_PER_BALANCE_CNT + 1)
1004
1005/*
1006 * If the path points to a directory or direct item, calculate mode
1007 * and the size cut, for balance.
1008 * If the path points to an indirect item, remove some number of its
1009 * unformatted nodes.
1010 * In case of file truncate calculate whether this item must be
1011 * deleted/truncated or last unformatted node of this item will be
1012 * converted to a direct item.
1013 * This function returns a determination of what balance mode the
1014 * calling function should employ.
1015 */
1016static char prepare_for_delete_or_cut(struct reiserfs_transaction_handle *th,
1017				      struct inode *inode,
1018				      struct treepath *path,
1019				      const struct cpu_key *item_key,
1020				      /*
1021				       * Number of unformatted nodes
1022				       * which were removed from end
1023				       * of the file.
1024				       */
1025				      int *removed,
1026				      int *cut_size,
1027				      /* MAX_KEY_OFFSET in case of delete. */
1028				      unsigned long long new_file_length
1029    )
1030{
1031	struct super_block *sb = inode->i_sb;
1032	struct item_head *p_le_ih = tp_item_head(path);
1033	struct buffer_head *bh = PATH_PLAST_BUFFER(path);
1034
1035	BUG_ON(!th->t_trans_id);
1036
1037	/* Stat_data item. */
1038	if (is_statdata_le_ih(p_le_ih)) {
1039
1040		RFALSE(new_file_length != max_reiserfs_offset(inode),
1041		       "PAP-5210: mode must be M_DELETE");
1042
1043		*cut_size = -(IH_SIZE + ih_item_len(p_le_ih));
1044		return M_DELETE;
1045	}
1046
1047	/* Directory item. */
1048	if (is_direntry_le_ih(p_le_ih))
1049		return prepare_for_direntry_item(path, p_le_ih, inode,
1050						 new_file_length,
1051						 cut_size);
1052
1053	/* Direct item. */
1054	if (is_direct_le_ih(p_le_ih))
1055		return prepare_for_direct_item(path, p_le_ih, inode,
1056					       new_file_length, cut_size);
1057
1058	/* Case of an indirect item. */
1059	{
1060	    int blk_size = sb->s_blocksize;
1061	    struct item_head s_ih;
1062	    int need_re_search;
1063	    int delete = 0;
1064	    int result = M_CUT;
1065	    int pos = 0;
1066
1067	    if ( new_file_length == max_reiserfs_offset (inode) ) {
1068		/*
1069		 * prepare_for_delete_or_cut() is called by
1070		 * reiserfs_delete_item()
1071		 */
1072		new_file_length = 0;
1073		delete = 1;
1074	    }
1075
1076	    do {
1077		need_re_search = 0;
1078		*cut_size = 0;
1079		bh = PATH_PLAST_BUFFER(path);
1080		copy_item_head(&s_ih, tp_item_head(path));
1081		pos = I_UNFM_NUM(&s_ih);
1082
1083		while (le_ih_k_offset (&s_ih) + (pos - 1) * blk_size > new_file_length) {
1084		    __le32 *unfm;
1085		    __u32 block;
1086
1087		    /*
1088		     * Each unformatted block deletion may involve
1089		     * one additional bitmap block into the transaction,
1090		     * thereby the initial journal space reservation
1091		     * might not be enough.
1092		     */
1093		    if (!delete && (*cut_size) != 0 &&
1094			reiserfs_transaction_free_space(th) < JOURNAL_FOR_FREE_BLOCK_AND_UPDATE_SD)
1095			break;
1096
1097		    unfm = (__le32 *)ih_item_body(bh, &s_ih) + pos - 1;
1098		    block = get_block_num(unfm, 0);
1099
1100		    if (block != 0) {
1101			reiserfs_prepare_for_journal(sb, bh, 1);
1102			put_block_num(unfm, 0, 0);
1103			journal_mark_dirty(th, bh);
1104			reiserfs_free_block(th, inode, block, 1);
1105		    }
1106
1107		    reiserfs_cond_resched(sb);
1108
1109		    if (item_moved (&s_ih, path))  {
1110			need_re_search = 1;
1111			break;
1112		    }
1113
1114		    pos --;
1115		    (*removed)++;
1116		    (*cut_size) -= UNFM_P_SIZE;
1117
1118		    if (pos == 0) {
1119			(*cut_size) -= IH_SIZE;
1120			result = M_DELETE;
1121			break;
1122		    }
1123		}
1124		/*
1125		 * a trick.  If the buffer has been logged, this will
1126		 * do nothing.  If we've broken the loop without logging
1127		 * it, it will restore the buffer
1128		 */
1129		reiserfs_restore_prepared_buffer(sb, bh);
1130	    } while (need_re_search &&
1131		     search_for_position_by_key(sb, item_key, path) == POSITION_FOUND);
1132	    pos_in_item(path) = pos * UNFM_P_SIZE;
1133
1134	    if (*cut_size == 0) {
1135		/*
1136		 * Nothing was cut. maybe convert last unformatted node to the
1137		 * direct item?
1138		 */
1139		result = M_CONVERT;
1140	    }
1141	    return result;
1142	}
1143}
1144
1145/* Calculate number of bytes which will be deleted or cut during balance */
1146static int calc_deleted_bytes_number(struct tree_balance *tb, char mode)
1147{
1148	int del_size;
1149	struct item_head *p_le_ih = tp_item_head(tb->tb_path);
1150
1151	if (is_statdata_le_ih(p_le_ih))
1152		return 0;
1153
1154	del_size =
1155	    (mode ==
1156	     M_DELETE) ? ih_item_len(p_le_ih) : -tb->insert_size[0];
1157	if (is_direntry_le_ih(p_le_ih)) {
1158		/*
1159		 * return EMPTY_DIR_SIZE; We delete emty directories only.
1160		 * we can't use EMPTY_DIR_SIZE, as old format dirs have a
1161		 * different empty size.  ick. FIXME, is this right?
1162		 */
1163		return del_size;
1164	}
1165
1166	if (is_indirect_le_ih(p_le_ih))
1167		del_size = (del_size / UNFM_P_SIZE) *
1168				(PATH_PLAST_BUFFER(tb->tb_path)->b_size);
1169	return del_size;
1170}
1171
1172static void init_tb_struct(struct reiserfs_transaction_handle *th,
1173			   struct tree_balance *tb,
1174			   struct super_block *sb,
1175			   struct treepath *path, int size)
1176{
1177
1178	BUG_ON(!th->t_trans_id);
1179
1180	memset(tb, '\0', sizeof(struct tree_balance));
1181	tb->transaction_handle = th;
1182	tb->tb_sb = sb;
1183	tb->tb_path = path;
1184	PATH_OFFSET_PBUFFER(path, ILLEGAL_PATH_ELEMENT_OFFSET) = NULL;
1185	PATH_OFFSET_POSITION(path, ILLEGAL_PATH_ELEMENT_OFFSET) = 0;
1186	tb->insert_size[0] = size;
1187}
1188
1189void padd_item(char *item, int total_length, int length)
1190{
1191	int i;
1192
1193	for (i = total_length; i > length;)
1194		item[--i] = 0;
1195}
1196
1197#ifdef REISERQUOTA_DEBUG
1198char key2type(struct reiserfs_key *ih)
1199{
1200	if (is_direntry_le_key(2, ih))
1201		return 'd';
1202	if (is_direct_le_key(2, ih))
1203		return 'D';
1204	if (is_indirect_le_key(2, ih))
1205		return 'i';
1206	if (is_statdata_le_key(2, ih))
1207		return 's';
1208	return 'u';
1209}
1210
1211char head2type(struct item_head *ih)
1212{
1213	if (is_direntry_le_ih(ih))
1214		return 'd';
1215	if (is_direct_le_ih(ih))
1216		return 'D';
1217	if (is_indirect_le_ih(ih))
1218		return 'i';
1219	if (is_statdata_le_ih(ih))
1220		return 's';
1221	return 'u';
1222}
1223#endif
1224
1225/*
1226 * Delete object item.
1227 * th       - active transaction handle
1228 * path     - path to the deleted item
1229 * item_key - key to search for the deleted item
1230 * indode   - used for updating i_blocks and quotas
1231 * un_bh    - NULL or unformatted node pointer
1232 */
1233int reiserfs_delete_item(struct reiserfs_transaction_handle *th,
1234			 struct treepath *path, const struct cpu_key *item_key,
1235			 struct inode *inode, struct buffer_head *un_bh)
1236{
1237	struct super_block *sb = inode->i_sb;
1238	struct tree_balance s_del_balance;
1239	struct item_head s_ih;
1240	struct item_head *q_ih;
1241	int quota_cut_bytes;
1242	int ret_value, del_size, removed;
1243	int depth;
1244
1245#ifdef CONFIG_REISERFS_CHECK
1246	char mode;
1247	int iter = 0;
1248#endif
1249
1250	BUG_ON(!th->t_trans_id);
1251
1252	init_tb_struct(th, &s_del_balance, sb, path,
1253		       0 /*size is unknown */ );
1254
1255	while (1) {
1256		removed = 0;
1257
1258#ifdef CONFIG_REISERFS_CHECK
1259		iter++;
1260		mode =
1261#endif
1262		    prepare_for_delete_or_cut(th, inode, path,
1263					      item_key, &removed,
1264					      &del_size,
1265					      max_reiserfs_offset(inode));
1266
1267		RFALSE(mode != M_DELETE, "PAP-5320: mode must be M_DELETE");
1268
1269		copy_item_head(&s_ih, tp_item_head(path));
1270		s_del_balance.insert_size[0] = del_size;
1271
1272		ret_value = fix_nodes(M_DELETE, &s_del_balance, NULL, NULL);
1273		if (ret_value != REPEAT_SEARCH)
1274			break;
1275
1276		PROC_INFO_INC(sb, delete_item_restarted);
1277
1278		/* file system changed, repeat search */
1279		ret_value =
1280		    search_for_position_by_key(sb, item_key, path);
1281		if (ret_value == IO_ERROR)
1282			break;
1283		if (ret_value == FILE_NOT_FOUND) {
1284			reiserfs_warning(sb, "vs-5340",
1285					 "no items of the file %K found",
1286					 item_key);
1287			break;
1288		}
1289	}			/* while (1) */
1290
1291	if (ret_value != CARRY_ON) {
1292		unfix_nodes(&s_del_balance);
1293		return 0;
1294	}
1295
1296	/* reiserfs_delete_item returns item length when success */
1297	ret_value = calc_deleted_bytes_number(&s_del_balance, M_DELETE);
1298	q_ih = tp_item_head(path);
1299	quota_cut_bytes = ih_item_len(q_ih);
1300
1301	/*
1302	 * hack so the quota code doesn't have to guess if the file has a
1303	 * tail.  On tail insert, we allocate quota for 1 unformatted node.
1304	 * We test the offset because the tail might have been
1305	 * split into multiple items, and we only want to decrement for
1306	 * the unfm node once
1307	 */
1308	if (!S_ISLNK(inode->i_mode) && is_direct_le_ih(q_ih)) {
1309		if ((le_ih_k_offset(q_ih) & (sb->s_blocksize - 1)) == 1) {
1310			quota_cut_bytes = sb->s_blocksize + UNFM_P_SIZE;
1311		} else {
1312			quota_cut_bytes = 0;
1313		}
1314	}
1315
1316	if (un_bh) {
1317		int off;
1318		char *data;
1319
1320		/*
1321		 * We are in direct2indirect conversion, so move tail contents
1322		 * to the unformatted node
1323		 */
1324		/*
1325		 * note, we do the copy before preparing the buffer because we
1326		 * don't care about the contents of the unformatted node yet.
1327		 * the only thing we really care about is the direct item's
1328		 * data is in the unformatted node.
1329		 *
1330		 * Otherwise, we would have to call
1331		 * reiserfs_prepare_for_journal on the unformatted node,
1332		 * which might schedule, meaning we'd have to loop all the
1333		 * way back up to the start of the while loop.
1334		 *
1335		 * The unformatted node must be dirtied later on.  We can't be
1336		 * sure here if the entire tail has been deleted yet.
1337		 *
1338		 * un_bh is from the page cache (all unformatted nodes are
1339		 * from the page cache) and might be a highmem page.  So, we
1340		 * can't use un_bh->b_data.
1341		 * -clm
1342		 */
1343
1344		data = kmap_atomic(un_bh->b_page);
1345		off = ((le_ih_k_offset(&s_ih) - 1) & (PAGE_SIZE - 1));
1346		memcpy(data + off,
1347		       ih_item_body(PATH_PLAST_BUFFER(path), &s_ih),
1348		       ret_value);
1349		kunmap_atomic(data);
1350	}
1351
1352	/* Perform balancing after all resources have been collected at once. */
1353	do_balance(&s_del_balance, NULL, NULL, M_DELETE);
1354
1355#ifdef REISERQUOTA_DEBUG
1356	reiserfs_debug(sb, REISERFS_DEBUG_CODE,
1357		       "reiserquota delete_item(): freeing %u, id=%u type=%c",
1358		       quota_cut_bytes, inode->i_uid, head2type(&s_ih));
1359#endif
1360	depth = reiserfs_write_unlock_nested(inode->i_sb);
1361	dquot_free_space_nodirty(inode, quota_cut_bytes);
1362	reiserfs_write_lock_nested(inode->i_sb, depth);
1363
1364	/* Return deleted body length */
1365	return ret_value;
1366}
1367
1368/*
1369 * Summary Of Mechanisms For Handling Collisions Between Processes:
1370 *
1371 *  deletion of the body of the object is performed by iput(), with the
1372 *  result that if multiple processes are operating on a file, the
1373 *  deletion of the body of the file is deferred until the last process
1374 *  that has an open inode performs its iput().
1375 *
1376 *  writes and truncates are protected from collisions by use of
1377 *  semaphores.
1378 *
1379 *  creates, linking, and mknod are protected from collisions with other
1380 *  processes by making the reiserfs_add_entry() the last step in the
1381 *  creation, and then rolling back all changes if there was a collision.
1382 *  - Hans
1383*/
1384
1385/* this deletes item which never gets split */
1386void reiserfs_delete_solid_item(struct reiserfs_transaction_handle *th,
1387				struct inode *inode, struct reiserfs_key *key)
1388{
1389	struct super_block *sb = th->t_super;
1390	struct tree_balance tb;
1391	INITIALIZE_PATH(path);
1392	int item_len = 0;
1393	int tb_init = 0;
1394	struct cpu_key cpu_key;
1395	int retval;
1396	int quota_cut_bytes = 0;
1397
1398	BUG_ON(!th->t_trans_id);
1399
1400	le_key2cpu_key(&cpu_key, key);
1401
1402	while (1) {
1403		retval = search_item(th->t_super, &cpu_key, &path);
1404		if (retval == IO_ERROR) {
1405			reiserfs_error(th->t_super, "vs-5350",
1406				       "i/o failure occurred trying "
1407				       "to delete %K", &cpu_key);
1408			break;
1409		}
1410		if (retval != ITEM_FOUND) {
1411			pathrelse(&path);
1412			/*
1413			 * No need for a warning, if there is just no free
1414			 * space to insert '..' item into the
1415			 * newly-created subdir
1416			 */
1417			if (!
1418			    ((unsigned long long)
1419			     GET_HASH_VALUE(le_key_k_offset
1420					    (le_key_version(key), key)) == 0
1421			     && (unsigned long long)
1422			     GET_GENERATION_NUMBER(le_key_k_offset
1423						   (le_key_version(key),
1424						    key)) == 1))
1425				reiserfs_warning(th->t_super, "vs-5355",
1426						 "%k not found", key);
1427			break;
1428		}
1429		if (!tb_init) {
1430			tb_init = 1;
1431			item_len = ih_item_len(tp_item_head(&path));
1432			init_tb_struct(th, &tb, th->t_super, &path,
1433				       -(IH_SIZE + item_len));
1434		}
1435		quota_cut_bytes = ih_item_len(tp_item_head(&path));
1436
1437		retval = fix_nodes(M_DELETE, &tb, NULL, NULL);
1438		if (retval == REPEAT_SEARCH) {
1439			PROC_INFO_INC(th->t_super, delete_solid_item_restarted);
1440			continue;
1441		}
1442
1443		if (retval == CARRY_ON) {
1444			do_balance(&tb, NULL, NULL, M_DELETE);
1445			/*
1446			 * Should we count quota for item? (we don't
1447			 * count quotas for save-links)
1448			 */
1449			if (inode) {
1450				int depth;
1451#ifdef REISERQUOTA_DEBUG
1452				reiserfs_debug(th->t_super, REISERFS_DEBUG_CODE,
1453					       "reiserquota delete_solid_item(): freeing %u id=%u type=%c",
1454					       quota_cut_bytes, inode->i_uid,
1455					       key2type(key));
1456#endif
1457				depth = reiserfs_write_unlock_nested(sb);
1458				dquot_free_space_nodirty(inode,
1459							 quota_cut_bytes);
1460				reiserfs_write_lock_nested(sb, depth);
1461			}
1462			break;
1463		}
1464
1465		/* IO_ERROR, NO_DISK_SPACE, etc */
1466		reiserfs_warning(th->t_super, "vs-5360",
1467				 "could not delete %K due to fix_nodes failure",
1468				 &cpu_key);
1469		unfix_nodes(&tb);
1470		break;
1471	}
1472
1473	reiserfs_check_path(&path);
1474}
1475
1476int reiserfs_delete_object(struct reiserfs_transaction_handle *th,
1477			   struct inode *inode)
1478{
1479	int err;
1480	inode->i_size = 0;
1481	BUG_ON(!th->t_trans_id);
1482
1483	/* for directory this deletes item containing "." and ".." */
1484	err =
1485	    reiserfs_do_truncate(th, inode, NULL, 0 /*no timestamp updates */ );
1486	if (err)
1487		return err;
1488
1489#if defined( USE_INODE_GENERATION_COUNTER )
1490	if (!old_format_only(th->t_super)) {
1491		__le32 *inode_generation;
1492
1493		inode_generation =
1494		    &REISERFS_SB(th->t_super)->s_rs->s_inode_generation;
1495		le32_add_cpu(inode_generation, 1);
1496	}
1497/* USE_INODE_GENERATION_COUNTER */
1498#endif
1499	reiserfs_delete_solid_item(th, inode, INODE_PKEY(inode));
1500
1501	return err;
1502}
1503
1504static void unmap_buffers(struct page *page, loff_t pos)
1505{
1506	struct buffer_head *bh;
1507	struct buffer_head *head;
1508	struct buffer_head *next;
1509	unsigned long tail_index;
1510	unsigned long cur_index;
1511
1512	if (page) {
1513		if (page_has_buffers(page)) {
1514			tail_index = pos & (PAGE_SIZE - 1);
1515			cur_index = 0;
1516			head = page_buffers(page);
1517			bh = head;
1518			do {
1519				next = bh->b_this_page;
1520
1521				/*
1522				 * we want to unmap the buffers that contain
1523				 * the tail, and all the buffers after it
1524				 * (since the tail must be at the end of the
1525				 * file).  We don't want to unmap file data
1526				 * before the tail, since it might be dirty
1527				 * and waiting to reach disk
1528				 */
1529				cur_index += bh->b_size;
1530				if (cur_index > tail_index) {
1531					reiserfs_unmap_buffer(bh);
1532				}
1533				bh = next;
1534			} while (bh != head);
1535		}
1536	}
1537}
1538
1539static int maybe_indirect_to_direct(struct reiserfs_transaction_handle *th,
1540				    struct inode *inode,
1541				    struct page *page,
1542				    struct treepath *path,
1543				    const struct cpu_key *item_key,
1544				    loff_t new_file_size, char *mode)
1545{
1546	struct super_block *sb = inode->i_sb;
1547	int block_size = sb->s_blocksize;
1548	int cut_bytes;
1549	BUG_ON(!th->t_trans_id);
1550	BUG_ON(new_file_size != inode->i_size);
1551
1552	/*
1553	 * the page being sent in could be NULL if there was an i/o error
1554	 * reading in the last block.  The user will hit problems trying to
1555	 * read the file, but for now we just skip the indirect2direct
1556	 */
1557	if (atomic_read(&inode->i_count) > 1 ||
1558	    !tail_has_to_be_packed(inode) ||
1559	    !page || (REISERFS_I(inode)->i_flags & i_nopack_mask)) {
1560		/* leave tail in an unformatted node */
1561		*mode = M_SKIP_BALANCING;
1562		cut_bytes =
1563		    block_size - (new_file_size & (block_size - 1));
1564		pathrelse(path);
1565		return cut_bytes;
1566	}
1567
1568	/* Perform the conversion to a direct_item. */
 
 
1569	return indirect2direct(th, inode, page, path, item_key,
1570			       new_file_size, mode);
1571}
1572
1573/*
1574 * we did indirect_to_direct conversion. And we have inserted direct
1575 * item successesfully, but there were no disk space to cut unfm
1576 * pointer being converted. Therefore we have to delete inserted
1577 * direct item(s)
1578 */
1579static void indirect_to_direct_roll_back(struct reiserfs_transaction_handle *th,
1580					 struct inode *inode, struct treepath *path)
1581{
1582	struct cpu_key tail_key;
1583	int tail_len;
1584	int removed;
1585	BUG_ON(!th->t_trans_id);
1586
1587	make_cpu_key(&tail_key, inode, inode->i_size + 1, TYPE_DIRECT, 4);
1588	tail_key.key_length = 4;
1589
1590	tail_len =
1591	    (cpu_key_k_offset(&tail_key) & (inode->i_sb->s_blocksize - 1)) - 1;
1592	while (tail_len) {
1593		/* look for the last byte of the tail */
1594		if (search_for_position_by_key(inode->i_sb, &tail_key, path) ==
1595		    POSITION_NOT_FOUND)
1596			reiserfs_panic(inode->i_sb, "vs-5615",
1597				       "found invalid item");
1598		RFALSE(path->pos_in_item !=
1599		       ih_item_len(tp_item_head(path)) - 1,
1600		       "vs-5616: appended bytes found");
1601		PATH_LAST_POSITION(path)--;
1602
1603		removed =
1604		    reiserfs_delete_item(th, path, &tail_key, inode,
1605					 NULL /*unbh not needed */ );
1606		RFALSE(removed <= 0
1607		       || removed > tail_len,
1608		       "vs-5617: there was tail %d bytes, removed item length %d bytes",
1609		       tail_len, removed);
1610		tail_len -= removed;
1611		set_cpu_key_k_offset(&tail_key,
1612				     cpu_key_k_offset(&tail_key) - removed);
1613	}
1614	reiserfs_warning(inode->i_sb, "reiserfs-5091", "indirect_to_direct "
1615			 "conversion has been rolled back due to "
1616			 "lack of disk space");
 
1617	mark_inode_dirty(inode);
1618}
1619
1620/* (Truncate or cut entry) or delete object item. Returns < 0 on failure */
1621int reiserfs_cut_from_item(struct reiserfs_transaction_handle *th,
1622			   struct treepath *path,
1623			   struct cpu_key *item_key,
1624			   struct inode *inode,
1625			   struct page *page, loff_t new_file_size)
1626{
1627	struct super_block *sb = inode->i_sb;
1628	/*
1629	 * Every function which is going to call do_balance must first
1630	 * create a tree_balance structure.  Then it must fill up this
1631	 * structure by using the init_tb_struct and fix_nodes functions.
1632	 * After that we can make tree balancing.
1633	 */
1634	struct tree_balance s_cut_balance;
1635	struct item_head *p_le_ih;
1636	int cut_size = 0;	/* Amount to be cut. */
1637	int ret_value = CARRY_ON;
1638	int removed = 0;	/* Number of the removed unformatted nodes. */
1639	int is_inode_locked = 0;
1640	char mode;		/* Mode of the balance. */
1641	int retval2 = -1;
1642	int quota_cut_bytes;
1643	loff_t tail_pos = 0;
1644	int depth;
1645
1646	BUG_ON(!th->t_trans_id);
1647
1648	init_tb_struct(th, &s_cut_balance, inode->i_sb, path,
1649		       cut_size);
1650
1651	/*
1652	 * Repeat this loop until we either cut the item without needing
1653	 * to balance, or we fix_nodes without schedule occurring
1654	 */
1655	while (1) {
1656		/*
1657		 * Determine the balance mode, position of the first byte to
1658		 * be cut, and size to be cut.  In case of the indirect item
1659		 * free unformatted nodes which are pointed to by the cut
1660		 * pointers.
1661		 */
1662
1663		mode =
1664		    prepare_for_delete_or_cut(th, inode, path,
1665					      item_key, &removed,
1666					      &cut_size, new_file_size);
1667		if (mode == M_CONVERT) {
1668			/*
1669			 * convert last unformatted node to direct item or
1670			 * leave tail in the unformatted node
1671			 */
1672			RFALSE(ret_value != CARRY_ON,
1673			       "PAP-5570: can not convert twice");
1674
1675			ret_value =
1676			    maybe_indirect_to_direct(th, inode, page,
1677						     path, item_key,
1678						     new_file_size, &mode);
1679			if (mode == M_SKIP_BALANCING)
1680				/* tail has been left in the unformatted node */
1681				return ret_value;
1682
1683			is_inode_locked = 1;
1684
1685			/*
1686			 * removing of last unformatted node will
1687			 * change value we have to return to truncate.
1688			 * Save it
1689			 */
1690			retval2 = ret_value;
 
1691
1692			/*
1693			 * So, we have performed the first part of the
1694			 * conversion:
1695			 * inserting the new direct item.  Now we are
1696			 * removing the last unformatted node pointer.
1697			 * Set key to search for it.
1698			 */
1699			set_cpu_key_k_type(item_key, TYPE_INDIRECT);
1700			item_key->key_length = 4;
1701			new_file_size -=
1702			    (new_file_size & (sb->s_blocksize - 1));
1703			tail_pos = new_file_size;
1704			set_cpu_key_k_offset(item_key, new_file_size + 1);
1705			if (search_for_position_by_key
1706			    (sb, item_key,
1707			     path) == POSITION_NOT_FOUND) {
1708				print_block(PATH_PLAST_BUFFER(path), 3,
1709					    PATH_LAST_POSITION(path) - 1,
1710					    PATH_LAST_POSITION(path) + 1);
1711				reiserfs_panic(sb, "PAP-5580", "item to "
1712					       "convert does not exist (%K)",
1713					       item_key);
1714			}
1715			continue;
1716		}
1717		if (cut_size == 0) {
1718			pathrelse(path);
1719			return 0;
1720		}
1721
1722		s_cut_balance.insert_size[0] = cut_size;
1723
1724		ret_value = fix_nodes(mode, &s_cut_balance, NULL, NULL);
1725		if (ret_value != REPEAT_SEARCH)
1726			break;
1727
1728		PROC_INFO_INC(sb, cut_from_item_restarted);
1729
1730		ret_value =
1731		    search_for_position_by_key(sb, item_key, path);
1732		if (ret_value == POSITION_FOUND)
1733			continue;
1734
1735		reiserfs_warning(sb, "PAP-5610", "item %K not found",
1736				 item_key);
1737		unfix_nodes(&s_cut_balance);
1738		return (ret_value == IO_ERROR) ? -EIO : -ENOENT;
1739	}			/* while */
1740
1741	/* check fix_nodes results (IO_ERROR or NO_DISK_SPACE) */
1742	if (ret_value != CARRY_ON) {
1743		if (is_inode_locked) {
1744			/*
1745			 * FIXME: this seems to be not needed: we are always
1746			 * able to cut item
1747			 */
1748			indirect_to_direct_roll_back(th, inode, path);
1749		}
1750		if (ret_value == NO_DISK_SPACE)
1751			reiserfs_warning(sb, "reiserfs-5092",
1752					 "NO_DISK_SPACE");
1753		unfix_nodes(&s_cut_balance);
1754		return -EIO;
1755	}
1756
1757	/* go ahead and perform balancing */
1758
1759	RFALSE(mode == M_PASTE || mode == M_INSERT, "invalid mode");
1760
1761	/* Calculate number of bytes that need to be cut from the item. */
1762	quota_cut_bytes =
1763	    (mode ==
1764	     M_DELETE) ? ih_item_len(tp_item_head(path)) : -s_cut_balance.
1765	    insert_size[0];
1766	if (retval2 == -1)
1767		ret_value = calc_deleted_bytes_number(&s_cut_balance, mode);
1768	else
1769		ret_value = retval2;
1770
1771	/*
1772	 * For direct items, we only change the quota when deleting the last
1773	 * item.
1774	 */
1775	p_le_ih = tp_item_head(s_cut_balance.tb_path);
1776	if (!S_ISLNK(inode->i_mode) && is_direct_le_ih(p_le_ih)) {
1777		if (mode == M_DELETE &&
1778		    (le_ih_k_offset(p_le_ih) & (sb->s_blocksize - 1)) ==
1779		    1) {
1780			/* FIXME: this is to keep 3.5 happy */
1781			REISERFS_I(inode)->i_first_direct_byte = U32_MAX;
1782			quota_cut_bytes = sb->s_blocksize + UNFM_P_SIZE;
1783		} else {
1784			quota_cut_bytes = 0;
1785		}
1786	}
1787#ifdef CONFIG_REISERFS_CHECK
1788	if (is_inode_locked) {
1789		struct item_head *le_ih =
1790		    tp_item_head(s_cut_balance.tb_path);
1791		/*
1792		 * we are going to complete indirect2direct conversion. Make
1793		 * sure, that we exactly remove last unformatted node pointer
1794		 * of the item
1795		 */
1796		if (!is_indirect_le_ih(le_ih))
1797			reiserfs_panic(sb, "vs-5652",
1798				       "item must be indirect %h", le_ih);
1799
1800		if (mode == M_DELETE && ih_item_len(le_ih) != UNFM_P_SIZE)
1801			reiserfs_panic(sb, "vs-5653", "completing "
1802				       "indirect2direct conversion indirect "
1803				       "item %h being deleted must be of "
1804				       "4 byte long", le_ih);
1805
1806		if (mode == M_CUT
1807		    && s_cut_balance.insert_size[0] != -UNFM_P_SIZE) {
1808			reiserfs_panic(sb, "vs-5654", "can not complete "
1809				       "indirect2direct conversion of %h "
1810				       "(CUT, insert_size==%d)",
1811				       le_ih, s_cut_balance.insert_size[0]);
1812		}
1813		/*
1814		 * it would be useful to make sure, that right neighboring
1815		 * item is direct item of this file
1816		 */
1817	}
1818#endif
1819
1820	do_balance(&s_cut_balance, NULL, NULL, mode);
1821	if (is_inode_locked) {
1822		/*
1823		 * we've done an indirect->direct conversion.  when the
1824		 * data block was freed, it was removed from the list of
1825		 * blocks that must be flushed before the transaction
1826		 * commits, make sure to unmap and invalidate it
1827		 */
1828		unmap_buffers(page, tail_pos);
1829		REISERFS_I(inode)->i_flags &= ~i_pack_on_close_mask;
1830	}
1831#ifdef REISERQUOTA_DEBUG
1832	reiserfs_debug(inode->i_sb, REISERFS_DEBUG_CODE,
1833		       "reiserquota cut_from_item(): freeing %u id=%u type=%c",
1834		       quota_cut_bytes, inode->i_uid, '?');
1835#endif
1836	depth = reiserfs_write_unlock_nested(sb);
1837	dquot_free_space_nodirty(inode, quota_cut_bytes);
1838	reiserfs_write_lock_nested(sb, depth);
1839	return ret_value;
1840}
1841
1842static void truncate_directory(struct reiserfs_transaction_handle *th,
1843			       struct inode *inode)
1844{
1845	BUG_ON(!th->t_trans_id);
1846	if (inode->i_nlink)
1847		reiserfs_error(inode->i_sb, "vs-5655", "link count != 0");
1848
1849	set_le_key_k_offset(KEY_FORMAT_3_5, INODE_PKEY(inode), DOT_OFFSET);
1850	set_le_key_k_type(KEY_FORMAT_3_5, INODE_PKEY(inode), TYPE_DIRENTRY);
1851	reiserfs_delete_solid_item(th, inode, INODE_PKEY(inode));
1852	reiserfs_update_sd(th, inode);
1853	set_le_key_k_offset(KEY_FORMAT_3_5, INODE_PKEY(inode), SD_OFFSET);
1854	set_le_key_k_type(KEY_FORMAT_3_5, INODE_PKEY(inode), TYPE_STAT_DATA);
1855}
1856
1857/*
1858 * Truncate file to the new size. Note, this must be called with a
1859 * transaction already started
1860 */
1861int reiserfs_do_truncate(struct reiserfs_transaction_handle *th,
1862			 struct inode *inode,	/* ->i_size contains new size */
1863			 struct page *page,	/* up to date for last block */
1864			 /*
1865			  * when it is called by file_release to convert
1866			  * the tail - no timestamps should be updated
1867			  */
1868			 int update_timestamps
1869    )
1870{
1871	INITIALIZE_PATH(s_search_path);	/* Path to the current object item. */
1872	struct item_head *p_le_ih;	/* Pointer to an item header. */
1873
1874	/* Key to search for a previous file item. */
1875	struct cpu_key s_item_key;
1876	loff_t file_size,	/* Old file size. */
1877	 new_file_size;	/* New file size. */
1878	int deleted;		/* Number of deleted or truncated bytes. */
1879	int retval;
1880	int err = 0;
1881
1882	BUG_ON(!th->t_trans_id);
1883	if (!
1884	    (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
1885	     || S_ISLNK(inode->i_mode)))
1886		return 0;
1887
1888	/* deletion of directory - no need to update timestamps */
1889	if (S_ISDIR(inode->i_mode)) {
 
1890		truncate_directory(th, inode);
1891		return 0;
1892	}
1893
1894	/* Get new file size. */
1895	new_file_size = inode->i_size;
1896
1897	/* FIXME: note, that key type is unimportant here */
1898	make_cpu_key(&s_item_key, inode, max_reiserfs_offset(inode),
1899		     TYPE_DIRECT, 3);
1900
1901	retval =
1902	    search_for_position_by_key(inode->i_sb, &s_item_key,
1903				       &s_search_path);
1904	if (retval == IO_ERROR) {
1905		reiserfs_error(inode->i_sb, "vs-5657",
1906			       "i/o failure occurred trying to truncate %K",
1907			       &s_item_key);
1908		err = -EIO;
1909		goto out;
1910	}
1911	if (retval == POSITION_FOUND || retval == FILE_NOT_FOUND) {
1912		reiserfs_error(inode->i_sb, "PAP-5660",
1913			       "wrong result %d of search for %K", retval,
1914			       &s_item_key);
1915
1916		err = -EIO;
1917		goto out;
1918	}
1919
1920	s_search_path.pos_in_item--;
1921
1922	/* Get real file size (total length of all file items) */
1923	p_le_ih = tp_item_head(&s_search_path);
1924	if (is_statdata_le_ih(p_le_ih))
1925		file_size = 0;
1926	else {
1927		loff_t offset = le_ih_k_offset(p_le_ih);
1928		int bytes =
1929		    op_bytes_number(p_le_ih, inode->i_sb->s_blocksize);
1930
1931		/*
1932		 * this may mismatch with real file size: if last direct item
1933		 * had no padding zeros and last unformatted node had no free
1934		 * space, this file would have this file size
1935		 */
1936		file_size = offset + bytes - 1;
1937	}
1938	/*
1939	 * are we doing a full truncate or delete, if so
1940	 * kick in the reada code
1941	 */
1942	if (new_file_size == 0)
1943		s_search_path.reada = PATH_READA | PATH_READA_BACK;
1944
1945	if (file_size == 0 || file_size < new_file_size) {
1946		goto update_and_out;
1947	}
1948
1949	/* Update key to search for the last file item. */
1950	set_cpu_key_k_offset(&s_item_key, file_size);
1951
1952	do {
1953		/* Cut or delete file item. */
1954		deleted =
1955		    reiserfs_cut_from_item(th, &s_search_path, &s_item_key,
1956					   inode, page, new_file_size);
1957		if (deleted < 0) {
1958			reiserfs_warning(inode->i_sb, "vs-5665",
1959					 "reiserfs_cut_from_item failed");
1960			reiserfs_check_path(&s_search_path);
1961			return 0;
1962		}
1963
1964		RFALSE(deleted > file_size,
1965		       "PAP-5670: reiserfs_cut_from_item: too many bytes deleted: deleted %d, file_size %lu, item_key %K",
1966		       deleted, file_size, &s_item_key);
1967
1968		/* Change key to search the last file item. */
1969		file_size -= deleted;
1970
1971		set_cpu_key_k_offset(&s_item_key, file_size);
1972
1973		/*
1974		 * While there are bytes to truncate and previous
1975		 * file item is presented in the tree.
1976		 */
1977
1978		/*
1979		 * This loop could take a really long time, and could log
1980		 * many more blocks than a transaction can hold.  So, we do
1981		 * a polite journal end here, and if the transaction needs
1982		 * ending, we make sure the file is consistent before ending
1983		 * the current trans and starting a new one
1984		 */
1985		if (journal_transaction_should_end(th, 0) ||
1986		    reiserfs_transaction_free_space(th) <= JOURNAL_FOR_FREE_BLOCK_AND_UPDATE_SD) {
 
1987			pathrelse(&s_search_path);
1988
1989			if (update_timestamps) {
1990				inode->i_mtime = CURRENT_TIME_SEC;
1991				inode->i_ctime = CURRENT_TIME_SEC;
1992			}
1993			reiserfs_update_sd(th, inode);
1994
1995			err = journal_end(th);
1996			if (err)
1997				goto out;
1998			err = journal_begin(th, inode->i_sb,
1999					    JOURNAL_FOR_FREE_BLOCK_AND_UPDATE_SD + JOURNAL_PER_BALANCE_CNT * 4) ;
2000			if (err)
2001				goto out;
2002			reiserfs_update_inode_transaction(inode);
2003		}
2004	} while (file_size > ROUND_UP(new_file_size) &&
2005		 search_for_position_by_key(inode->i_sb, &s_item_key,
2006					    &s_search_path) == POSITION_FOUND);
2007
2008	RFALSE(file_size > ROUND_UP(new_file_size),
2009	       "PAP-5680: truncate did not finish: new_file_size %lld, current %lld, oid %d",
2010	       new_file_size, file_size, s_item_key.on_disk_key.k_objectid);
2011
2012update_and_out:
2013	if (update_timestamps) {
2014		/* this is truncate, not file closing */
2015		inode->i_mtime = CURRENT_TIME_SEC;
2016		inode->i_ctime = CURRENT_TIME_SEC;
2017	}
2018	reiserfs_update_sd(th, inode);
2019
2020out:
2021	pathrelse(&s_search_path);
2022	return err;
2023}
2024
2025#ifdef CONFIG_REISERFS_CHECK
2026/* this makes sure, that we __append__, not overwrite or add holes */
2027static void check_research_for_paste(struct treepath *path,
2028				     const struct cpu_key *key)
2029{
2030	struct item_head *found_ih = tp_item_head(path);
2031
2032	if (is_direct_le_ih(found_ih)) {
2033		if (le_ih_k_offset(found_ih) +
2034		    op_bytes_number(found_ih,
2035				    get_last_bh(path)->b_size) !=
2036		    cpu_key_k_offset(key)
2037		    || op_bytes_number(found_ih,
2038				       get_last_bh(path)->b_size) !=
2039		    pos_in_item(path))
2040			reiserfs_panic(NULL, "PAP-5720", "found direct item "
2041				       "%h or position (%d) does not match "
2042				       "to key %K", found_ih,
2043				       pos_in_item(path), key);
2044	}
2045	if (is_indirect_le_ih(found_ih)) {
2046		if (le_ih_k_offset(found_ih) +
2047		    op_bytes_number(found_ih,
2048				    get_last_bh(path)->b_size) !=
2049		    cpu_key_k_offset(key)
2050		    || I_UNFM_NUM(found_ih) != pos_in_item(path)
2051		    || get_ih_free_space(found_ih) != 0)
2052			reiserfs_panic(NULL, "PAP-5730", "found indirect "
2053				       "item (%h) or position (%d) does not "
2054				       "match to key (%K)",
2055				       found_ih, pos_in_item(path), key);
2056	}
2057}
2058#endif				/* config reiserfs check */
2059
2060/*
2061 * Paste bytes to the existing item.
2062 * Returns bytes number pasted into the item.
2063 */
2064int reiserfs_paste_into_item(struct reiserfs_transaction_handle *th,
2065			     /* Path to the pasted item. */
2066			     struct treepath *search_path,
2067			     /* Key to search for the needed item. */
2068			     const struct cpu_key *key,
2069			     /* Inode item belongs to */
2070			     struct inode *inode,
2071			     /* Pointer to the bytes to paste. */
2072			     const char *body,
2073			     /* Size of pasted bytes. */
2074			     int pasted_size)
2075{
2076	struct super_block *sb = inode->i_sb;
2077	struct tree_balance s_paste_balance;
2078	int retval;
2079	int fs_gen;
2080	int depth;
2081
2082	BUG_ON(!th->t_trans_id);
2083
2084	fs_gen = get_generation(inode->i_sb);
2085
2086#ifdef REISERQUOTA_DEBUG
2087	reiserfs_debug(inode->i_sb, REISERFS_DEBUG_CODE,
2088		       "reiserquota paste_into_item(): allocating %u id=%u type=%c",
2089		       pasted_size, inode->i_uid,
2090		       key2type(&key->on_disk_key));
2091#endif
2092
2093	depth = reiserfs_write_unlock_nested(sb);
2094	retval = dquot_alloc_space_nodirty(inode, pasted_size);
2095	reiserfs_write_lock_nested(sb, depth);
2096	if (retval) {
2097		pathrelse(search_path);
2098		return retval;
2099	}
2100	init_tb_struct(th, &s_paste_balance, th->t_super, search_path,
2101		       pasted_size);
2102#ifdef DISPLACE_NEW_PACKING_LOCALITIES
2103	s_paste_balance.key = key->on_disk_key;
2104#endif
2105
2106	/* DQUOT_* can schedule, must check before the fix_nodes */
2107	if (fs_changed(fs_gen, inode->i_sb)) {
2108		goto search_again;
2109	}
2110
2111	while ((retval =
2112		fix_nodes(M_PASTE, &s_paste_balance, NULL,
2113			  body)) == REPEAT_SEARCH) {
2114search_again:
2115		/* file system changed while we were in the fix_nodes */
2116		PROC_INFO_INC(th->t_super, paste_into_item_restarted);
2117		retval =
2118		    search_for_position_by_key(th->t_super, key,
2119					       search_path);
2120		if (retval == IO_ERROR) {
2121			retval = -EIO;
2122			goto error_out;
2123		}
2124		if (retval == POSITION_FOUND) {
2125			reiserfs_warning(inode->i_sb, "PAP-5710",
2126					 "entry or pasted byte (%K) exists",
2127					 key);
2128			retval = -EEXIST;
2129			goto error_out;
2130		}
2131#ifdef CONFIG_REISERFS_CHECK
2132		check_research_for_paste(search_path, key);
2133#endif
2134	}
2135
2136	/*
2137	 * Perform balancing after all resources are collected by fix_nodes,
2138	 * and accessing them will not risk triggering schedule.
2139	 */
2140	if (retval == CARRY_ON) {
2141		do_balance(&s_paste_balance, NULL /*ih */ , body, M_PASTE);
2142		return 0;
2143	}
2144	retval = (retval == NO_DISK_SPACE) ? -ENOSPC : -EIO;
2145error_out:
2146	/* this also releases the path */
2147	unfix_nodes(&s_paste_balance);
2148#ifdef REISERQUOTA_DEBUG
2149	reiserfs_debug(inode->i_sb, REISERFS_DEBUG_CODE,
2150		       "reiserquota paste_into_item(): freeing %u id=%u type=%c",
2151		       pasted_size, inode->i_uid,
2152		       key2type(&key->on_disk_key));
2153#endif
2154	depth = reiserfs_write_unlock_nested(sb);
2155	dquot_free_space_nodirty(inode, pasted_size);
2156	reiserfs_write_lock_nested(sb, depth);
2157	return retval;
2158}
2159
2160/*
2161 * Insert new item into the buffer at the path.
2162 * th   - active transaction handle
2163 * path - path to the inserted item
2164 * ih   - pointer to the item header to insert
2165 * body - pointer to the bytes to insert
2166 */
2167int reiserfs_insert_item(struct reiserfs_transaction_handle *th,
2168			 struct treepath *path, const struct cpu_key *key,
2169			 struct item_head *ih, struct inode *inode,
2170			 const char *body)
2171{
2172	struct tree_balance s_ins_balance;
2173	int retval;
2174	int fs_gen = 0;
2175	int quota_bytes = 0;
2176
2177	BUG_ON(!th->t_trans_id);
2178
2179	if (inode) {		/* Do we count quotas for item? */
2180		int depth;
2181		fs_gen = get_generation(inode->i_sb);
2182		quota_bytes = ih_item_len(ih);
2183
2184		/*
2185		 * hack so the quota code doesn't have to guess
2186		 * if the file has a tail, links are always tails,
2187		 * so there's no guessing needed
2188		 */
2189		if (!S_ISLNK(inode->i_mode) && is_direct_le_ih(ih))
2190			quota_bytes = inode->i_sb->s_blocksize + UNFM_P_SIZE;
2191#ifdef REISERQUOTA_DEBUG
2192		reiserfs_debug(inode->i_sb, REISERFS_DEBUG_CODE,
2193			       "reiserquota insert_item(): allocating %u id=%u type=%c",
2194			       quota_bytes, inode->i_uid, head2type(ih));
2195#endif
2196		/*
2197		 * We can't dirty inode here. It would be immediately
2198		 * written but appropriate stat item isn't inserted yet...
2199		 */
2200		depth = reiserfs_write_unlock_nested(inode->i_sb);
2201		retval = dquot_alloc_space_nodirty(inode, quota_bytes);
2202		reiserfs_write_lock_nested(inode->i_sb, depth);
2203		if (retval) {
2204			pathrelse(path);
2205			return retval;
2206		}
2207	}
2208	init_tb_struct(th, &s_ins_balance, th->t_super, path,
2209		       IH_SIZE + ih_item_len(ih));
2210#ifdef DISPLACE_NEW_PACKING_LOCALITIES
2211	s_ins_balance.key = key->on_disk_key;
2212#endif
2213	/*
2214	 * DQUOT_* can schedule, must check to be sure calling
2215	 * fix_nodes is safe
2216	 */
2217	if (inode && fs_changed(fs_gen, inode->i_sb)) {
2218		goto search_again;
2219	}
2220
2221	while ((retval =
2222		fix_nodes(M_INSERT, &s_ins_balance, ih,
2223			  body)) == REPEAT_SEARCH) {
2224search_again:
2225		/* file system changed while we were in the fix_nodes */
2226		PROC_INFO_INC(th->t_super, insert_item_restarted);
2227		retval = search_item(th->t_super, key, path);
2228		if (retval == IO_ERROR) {
2229			retval = -EIO;
2230			goto error_out;
2231		}
2232		if (retval == ITEM_FOUND) {
2233			reiserfs_warning(th->t_super, "PAP-5760",
2234					 "key %K already exists in the tree",
2235					 key);
2236			retval = -EEXIST;
2237			goto error_out;
2238		}
2239	}
2240
2241	/* make balancing after all resources will be collected at a time */
2242	if (retval == CARRY_ON) {
2243		do_balance(&s_ins_balance, ih, body, M_INSERT);
2244		return 0;
2245	}
2246
2247	retval = (retval == NO_DISK_SPACE) ? -ENOSPC : -EIO;
2248error_out:
2249	/* also releases the path */
2250	unfix_nodes(&s_ins_balance);
2251#ifdef REISERQUOTA_DEBUG
2252	reiserfs_debug(th->t_super, REISERFS_DEBUG_CODE,
2253		       "reiserquota insert_item(): freeing %u id=%u type=%c",
2254		       quota_bytes, inode->i_uid, head2type(ih));
2255#endif
2256	if (inode) {
2257		int depth = reiserfs_write_unlock_nested(inode->i_sb);
2258		dquot_free_space_nodirty(inode, quota_bytes);
2259		reiserfs_write_lock_nested(inode->i_sb, depth);
2260	}
2261	return retval;
2262}