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/*
  12 *  This file contains functions dealing with S+tree
  13 *
  14 * B_IS_IN_TREE
  15 * copy_item_head
  16 * comp_short_keys
  17 * comp_keys
  18 * comp_short_le_keys
  19 * le_key2cpu_key
  20 * comp_le_keys
  21 * bin_search
  22 * get_lkey
  23 * get_rkey
  24 * key_in_buffer
  25 * decrement_bcount
  26 * reiserfs_check_path
  27 * pathrelse_and_restore
  28 * pathrelse
  29 * search_by_key_reada
  30 * search_by_key
  31 * search_for_position_by_key
  32 * comp_items
  33 * prepare_for_direct_item
  34 * prepare_for_direntry_item
  35 * prepare_for_delete_or_cut
  36 * calc_deleted_bytes_number
  37 * init_tb_struct
  38 * padd_item
  39 * reiserfs_delete_item
  40 * reiserfs_delete_solid_item
  41 * reiserfs_delete_object
  42 * maybe_indirect_to_direct
  43 * indirect_to_direct_roll_back
  44 * reiserfs_cut_from_item
  45 * truncate_directory
  46 * reiserfs_do_truncate
  47 * reiserfs_paste_into_item
  48 * reiserfs_insert_item
  49 */
  50
  51#include <linux/time.h>
  52#include <linux/string.h>
  53#include <linux/pagemap.h>
  54#include <linux/reiserfs_fs.h>
 
  55#include <linux/buffer_head.h>
  56#include <linux/quotaops.h>
  57
  58/* Does the buffer contain a disk block which is in the tree. */
  59inline int B_IS_IN_TREE(const struct buffer_head *bh)
  60{
  61
  62	RFALSE(B_LEVEL(bh) > MAX_HEIGHT,
  63	       "PAP-1010: block (%b) has too big level (%z)", bh, bh);
  64
  65	return (B_LEVEL(bh) != FREE_LEVEL);
  66}
  67
  68//
  69// to gets item head in le form
  70//
  71inline void copy_item_head(struct item_head *to,
  72			   const struct item_head *from)
  73{
  74	memcpy(to, from, IH_SIZE);
  75}
  76
  77/* k1 is pointer to on-disk structure which is stored in little-endian
  78   form. k2 is pointer to cpu variable. For key of items of the same
  79   object this returns 0.
  80   Returns: -1 if key1 < key2
  81   0 if key1 == key2
  82   1 if key1 > key2 */
 
 
  83inline int comp_short_keys(const struct reiserfs_key *le_key,
  84			   const struct cpu_key *cpu_key)
  85{
  86	__u32 n;
  87	n = le32_to_cpu(le_key->k_dir_id);
  88	if (n < cpu_key->on_disk_key.k_dir_id)
  89		return -1;
  90	if (n > cpu_key->on_disk_key.k_dir_id)
  91		return 1;
  92	n = le32_to_cpu(le_key->k_objectid);
  93	if (n < cpu_key->on_disk_key.k_objectid)
  94		return -1;
  95	if (n > cpu_key->on_disk_key.k_objectid)
  96		return 1;
  97	return 0;
  98}
  99
 100/* k1 is pointer to on-disk structure which is stored in little-endian
 101   form. k2 is pointer to cpu variable.
 102   Compare keys using all 4 key fields.
 103   Returns: -1 if key1 < key2 0
 104   if key1 = key2 1 if key1 > key2 */
 
 
 105static inline int comp_keys(const struct reiserfs_key *le_key,
 106			    const struct cpu_key *cpu_key)
 107{
 108	int retval;
 109
 110	retval = comp_short_keys(le_key, cpu_key);
 111	if (retval)
 112		return retval;
 113	if (le_key_k_offset(le_key_version(le_key), le_key) <
 114	    cpu_key_k_offset(cpu_key))
 115		return -1;
 116	if (le_key_k_offset(le_key_version(le_key), le_key) >
 117	    cpu_key_k_offset(cpu_key))
 118		return 1;
 119
 120	if (cpu_key->key_length == 3)
 121		return 0;
 122
 123	/* this part is needed only when tail conversion is in progress */
 124	if (le_key_k_type(le_key_version(le_key), le_key) <
 125	    cpu_key_k_type(cpu_key))
 126		return -1;
 127
 128	if (le_key_k_type(le_key_version(le_key), le_key) >
 129	    cpu_key_k_type(cpu_key))
 130		return 1;
 131
 132	return 0;
 133}
 134
 135inline int comp_short_le_keys(const struct reiserfs_key *key1,
 136			      const struct reiserfs_key *key2)
 137{
 138	__u32 *k1_u32, *k2_u32;
 139	int key_length = REISERFS_SHORT_KEY_LEN;
 140
 141	k1_u32 = (__u32 *) key1;
 142	k2_u32 = (__u32 *) key2;
 143	for (; key_length--; ++k1_u32, ++k2_u32) {
 144		if (le32_to_cpu(*k1_u32) < le32_to_cpu(*k2_u32))
 145			return -1;
 146		if (le32_to_cpu(*k1_u32) > le32_to_cpu(*k2_u32))
 147			return 1;
 148	}
 149	return 0;
 150}
 151
 152inline void le_key2cpu_key(struct cpu_key *to, const struct reiserfs_key *from)
 153{
 154	int version;
 155	to->on_disk_key.k_dir_id = le32_to_cpu(from->k_dir_id);
 156	to->on_disk_key.k_objectid = le32_to_cpu(from->k_objectid);
 157
 158	// find out version of the key
 159	version = le_key_version(from);
 160	to->version = version;
 161	to->on_disk_key.k_offset = le_key_k_offset(version, from);
 162	to->on_disk_key.k_type = le_key_k_type(version, from);
 163}
 164
 165// this does not say which one is bigger, it only returns 1 if keys
 166// are not equal, 0 otherwise
 
 
 167inline int comp_le_keys(const struct reiserfs_key *k1,
 168			const struct reiserfs_key *k2)
 169{
 170	return memcmp(k1, k2, sizeof(struct reiserfs_key));
 171}
 172
 173/**************************************************************************
 174 *  Binary search toolkit function                                        *
 175 *  Search for an item in the array by the item key                       *
 176 *  Returns:    1 if found,  0 if not found;                              *
 177 *        *pos = number of the searched element if found, else the        *
 178 *        number of the first element that is larger than key.            *
 179 **************************************************************************/
 180/* For those not familiar with binary search: lbound is the leftmost item that it
 181 could be, rbound the rightmost item that it could be.  We examine the item
 182 halfway between lbound and rbound, and that tells us either that we can increase
 183 lbound, or decrease rbound, or that we have found it, or if lbound <= rbound that
 184 there are no possible items, and we have not found it. With each examination we
 185 cut the number of possible items it could be by one more than half rounded down,
 186 or we find it. */
 
 
 187static inline int bin_search(const void *key,	/* Key to search for. */
 188			     const void *base,	/* First item in the array. */
 189			     int num,	/* Number of items in the array. */
 190			     int width,	/* Item size in the array.
 191					   searched. Lest the reader be
 192					   confused, note that this is crafted
 193					   as a general function, and when it
 194					   is applied specifically to the array
 195					   of item headers in a node, width
 196					   is actually the item header size not
 197					   the item size. */
 
 198			     int *pos /* Number of the searched for element. */
 199    )
 200{
 201	int rbound, lbound, j;
 202
 203	for (j = ((rbound = num - 1) + (lbound = 0)) / 2;
 204	     lbound <= rbound; j = (rbound + lbound) / 2)
 205		switch (comp_keys
 206			((struct reiserfs_key *)((char *)base + j * width),
 207			 (struct cpu_key *)key)) {
 208		case -1:
 209			lbound = j + 1;
 210			continue;
 211		case 1:
 212			rbound = j - 1;
 213			continue;
 214		case 0:
 215			*pos = j;
 216			return ITEM_FOUND;	/* Key found in the array.  */
 217		}
 218
 219	/* bin_search did not find given key, it returns position of key,
 220	   that is minimal and greater than the given one. */
 
 
 221	*pos = lbound;
 222	return ITEM_NOT_FOUND;
 223}
 224
 225
 226/* Minimal possible key. It is never in the tree. */
 227const struct reiserfs_key MIN_KEY = { 0, 0, {{0, 0},} };
 228
 229/* Maximal possible key. It is never in the tree. */
 230static const struct reiserfs_key MAX_KEY = {
 231	__constant_cpu_to_le32(0xffffffff),
 232	__constant_cpu_to_le32(0xffffffff),
 233	{{__constant_cpu_to_le32(0xffffffff),
 234	  __constant_cpu_to_le32(0xffffffff)},}
 235};
 236
 237/* Get delimiting key of the buffer by looking for it in the buffers in the path, starting from the bottom
 238   of the path, and going upwards.  We must check the path's validity at each step.  If the key is not in
 239   the path, there is no delimiting key in the tree (buffer is first or last buffer in tree), and in this
 240   case we return a special key, either MIN_KEY or MAX_KEY. */
 
 
 
 
 241static inline const struct reiserfs_key *get_lkey(const struct treepath *chk_path,
 242						  const struct super_block *sb)
 243{
 244	int position, path_offset = chk_path->path_length;
 245	struct buffer_head *parent;
 246
 247	RFALSE(path_offset < FIRST_PATH_ELEMENT_OFFSET,
 248	       "PAP-5010: invalid offset in the path");
 249
 250	/* While not higher in path than first element. */
 251	while (path_offset-- > FIRST_PATH_ELEMENT_OFFSET) {
 252
 253		RFALSE(!buffer_uptodate
 254		       (PATH_OFFSET_PBUFFER(chk_path, path_offset)),
 255		       "PAP-5020: parent is not uptodate");
 256
 257		/* Parent at the path is not in the tree now. */
 258		if (!B_IS_IN_TREE
 259		    (parent =
 260		     PATH_OFFSET_PBUFFER(chk_path, path_offset)))
 261			return &MAX_KEY;
 262		/* Check whether position in the parent is correct. */
 263		if ((position =
 264		     PATH_OFFSET_POSITION(chk_path,
 265					  path_offset)) >
 266		    B_NR_ITEMS(parent))
 267			return &MAX_KEY;
 268		/* Check whether parent at the path really points to the child. */
 269		if (B_N_CHILD_NUM(parent, position) !=
 270		    PATH_OFFSET_PBUFFER(chk_path,
 271					path_offset + 1)->b_blocknr)
 272			return &MAX_KEY;
 273		/* Return delimiting key if position in the parent is not equal to zero. */
 
 
 
 274		if (position)
 275			return B_N_PDELIM_KEY(parent, position - 1);
 276	}
 277	/* Return MIN_KEY if we are in the root of the buffer tree. */
 278	if (PATH_OFFSET_PBUFFER(chk_path, FIRST_PATH_ELEMENT_OFFSET)->
 279	    b_blocknr == SB_ROOT_BLOCK(sb))
 280		return &MIN_KEY;
 281	return &MAX_KEY;
 282}
 283
 284/* Get delimiting key of the buffer at the path and its right neighbor. */
 285inline const struct reiserfs_key *get_rkey(const struct treepath *chk_path,
 286					   const struct super_block *sb)
 287{
 288	int position, path_offset = chk_path->path_length;
 289	struct buffer_head *parent;
 290
 291	RFALSE(path_offset < FIRST_PATH_ELEMENT_OFFSET,
 292	       "PAP-5030: invalid offset in the path");
 293
 294	while (path_offset-- > FIRST_PATH_ELEMENT_OFFSET) {
 295
 296		RFALSE(!buffer_uptodate
 297		       (PATH_OFFSET_PBUFFER(chk_path, path_offset)),
 298		       "PAP-5040: parent is not uptodate");
 299
 300		/* Parent at the path is not in the tree now. */
 301		if (!B_IS_IN_TREE
 302		    (parent =
 303		     PATH_OFFSET_PBUFFER(chk_path, path_offset)))
 304			return &MIN_KEY;
 305		/* Check whether position in the parent is correct. */
 306		if ((position =
 307		     PATH_OFFSET_POSITION(chk_path,
 308					  path_offset)) >
 309		    B_NR_ITEMS(parent))
 310			return &MIN_KEY;
 311		/* Check whether parent at the path really points to the child. */
 
 
 
 312		if (B_N_CHILD_NUM(parent, position) !=
 313		    PATH_OFFSET_PBUFFER(chk_path,
 314					path_offset + 1)->b_blocknr)
 315			return &MIN_KEY;
 316		/* Return delimiting key if position in the parent is not the last one. */
 
 
 
 
 317		if (position != B_NR_ITEMS(parent))
 318			return B_N_PDELIM_KEY(parent, position);
 319	}
 
 320	/* Return MAX_KEY if we are in the root of the buffer tree. */
 321	if (PATH_OFFSET_PBUFFER(chk_path, FIRST_PATH_ELEMENT_OFFSET)->
 322	    b_blocknr == SB_ROOT_BLOCK(sb))
 323		return &MAX_KEY;
 324	return &MIN_KEY;
 325}
 326
 327/* Check whether a key is contained in the tree rooted from a buffer at a path. */
 328/* This works by looking at the left and right delimiting keys for the buffer in the last path_element in
 329   the path.  These delimiting keys are stored at least one level above that buffer in the tree. If the
 330   buffer is the first or last node in the tree order then one of the delimiting keys may be absent, and in
 331   this case get_lkey and get_rkey return a special key which is MIN_KEY or MAX_KEY. */
 332static inline int key_in_buffer(struct treepath *chk_path,	/* Path which should be checked.  */
 333				const struct cpu_key *key,	/* Key which should be checked.   */
 
 
 
 
 
 
 
 334				struct super_block *sb
 335    )
 336{
 337
 338	RFALSE(!key || chk_path->path_length < FIRST_PATH_ELEMENT_OFFSET
 339	       || chk_path->path_length > MAX_HEIGHT,
 340	       "PAP-5050: pointer to the key(%p) is NULL or invalid path length(%d)",
 341	       key, chk_path->path_length);
 342	RFALSE(!PATH_PLAST_BUFFER(chk_path)->b_bdev,
 343	       "PAP-5060: device must not be NODEV");
 344
 345	if (comp_keys(get_lkey(chk_path, sb), key) == 1)
 346		/* left delimiting key is bigger, that the key we look for */
 347		return 0;
 348	/*  if ( comp_keys(key, get_rkey(chk_path, sb)) != -1 ) */
 349	if (comp_keys(get_rkey(chk_path, sb), key) != 1)
 350		/* key must be less than right delimitiing key */
 351		return 0;
 352	return 1;
 353}
 354
 355int reiserfs_check_path(struct treepath *p)
 356{
 357	RFALSE(p->path_length != ILLEGAL_PATH_ELEMENT_OFFSET,
 358	       "path not properly relsed");
 359	return 0;
 360}
 361
 362/* Drop the reference to each buffer in a path and restore
 
 363 * dirty bits clean when preparing the buffer for the log.
 364 * This version should only be called from fix_nodes() */
 
 365void pathrelse_and_restore(struct super_block *sb,
 366			   struct treepath *search_path)
 367{
 368	int path_offset = search_path->path_length;
 369
 370	RFALSE(path_offset < ILLEGAL_PATH_ELEMENT_OFFSET,
 371	       "clm-4000: invalid path offset");
 372
 373	while (path_offset > ILLEGAL_PATH_ELEMENT_OFFSET) {
 374		struct buffer_head *bh;
 375		bh = PATH_OFFSET_PBUFFER(search_path, path_offset--);
 376		reiserfs_restore_prepared_buffer(sb, bh);
 377		brelse(bh);
 378	}
 379	search_path->path_length = ILLEGAL_PATH_ELEMENT_OFFSET;
 380}
 381
 382/* Drop the reference to each buffer in a path */
 383void pathrelse(struct treepath *search_path)
 384{
 385	int path_offset = search_path->path_length;
 386
 387	RFALSE(path_offset < ILLEGAL_PATH_ELEMENT_OFFSET,
 388	       "PAP-5090: invalid path offset");
 389
 390	while (path_offset > ILLEGAL_PATH_ELEMENT_OFFSET)
 391		brelse(PATH_OFFSET_PBUFFER(search_path, path_offset--));
 392
 393	search_path->path_length = ILLEGAL_PATH_ELEMENT_OFFSET;
 394}
 395
 396static int is_leaf(char *buf, int blocksize, struct buffer_head *bh)
 397{
 398	struct block_head *blkh;
 399	struct item_head *ih;
 400	int used_space;
 401	int prev_location;
 402	int i;
 403	int nr;
 404
 405	blkh = (struct block_head *)buf;
 406	if (blkh_level(blkh) != DISK_LEAF_NODE_LEVEL) {
 407		reiserfs_warning(NULL, "reiserfs-5080",
 408				 "this should be caught earlier");
 409		return 0;
 410	}
 411
 412	nr = blkh_nr_item(blkh);
 413	if (nr < 1 || nr > ((blocksize - BLKH_SIZE) / (IH_SIZE + MIN_ITEM_LEN))) {
 414		/* item number is too big or too small */
 415		reiserfs_warning(NULL, "reiserfs-5081",
 416				 "nr_item seems wrong: %z", bh);
 417		return 0;
 418	}
 419	ih = (struct item_head *)(buf + BLKH_SIZE) + nr - 1;
 420	used_space = BLKH_SIZE + IH_SIZE * nr + (blocksize - ih_location(ih));
 
 
 421	if (used_space != blocksize - blkh_free_space(blkh)) {
 422		/* free space does not match to calculated amount of use space */
 423		reiserfs_warning(NULL, "reiserfs-5082",
 424				 "free space seems wrong: %z", bh);
 425		return 0;
 426	}
 427	// FIXME: it is_leaf will hit performance too much - we may have
 428	// return 1 here
 
 
 429
 430	/* check tables of item heads */
 431	ih = (struct item_head *)(buf + BLKH_SIZE);
 432	prev_location = blocksize;
 433	for (i = 0; i < nr; i++, ih++) {
 434		if (le_ih_k_type(ih) == TYPE_ANY) {
 435			reiserfs_warning(NULL, "reiserfs-5083",
 436					 "wrong item type for item %h",
 437					 ih);
 438			return 0;
 439		}
 440		if (ih_location(ih) >= blocksize
 441		    || ih_location(ih) < IH_SIZE * nr) {
 442			reiserfs_warning(NULL, "reiserfs-5084",
 443					 "item location seems wrong: %h",
 444					 ih);
 445			return 0;
 446		}
 447		if (ih_item_len(ih) < 1
 448		    || ih_item_len(ih) > MAX_ITEM_LEN(blocksize)) {
 449			reiserfs_warning(NULL, "reiserfs-5085",
 450					 "item length seems wrong: %h",
 451					 ih);
 452			return 0;
 453		}
 454		if (prev_location - ih_location(ih) != ih_item_len(ih)) {
 455			reiserfs_warning(NULL, "reiserfs-5086",
 456					 "item location seems wrong "
 457					 "(second one): %h", ih);
 458			return 0;
 459		}
 460		prev_location = ih_location(ih);
 461	}
 462
 463	// one may imagine much more checks
 464	return 1;
 465}
 466
 467/* returns 1 if buf looks like an internal node, 0 otherwise */
 468static int is_internal(char *buf, int blocksize, struct buffer_head *bh)
 469{
 470	struct block_head *blkh;
 471	int nr;
 472	int used_space;
 473
 474	blkh = (struct block_head *)buf;
 475	nr = blkh_level(blkh);
 476	if (nr <= DISK_LEAF_NODE_LEVEL || nr > MAX_HEIGHT) {
 477		/* this level is not possible for internal nodes */
 478		reiserfs_warning(NULL, "reiserfs-5087",
 479				 "this should be caught earlier");
 480		return 0;
 481	}
 482
 483	nr = blkh_nr_item(blkh);
 
 484	if (nr > (blocksize - BLKH_SIZE - DC_SIZE) / (KEY_SIZE + DC_SIZE)) {
 485		/* for internal which is not root we might check min number of keys */
 486		reiserfs_warning(NULL, "reiserfs-5088",
 487				 "number of key seems wrong: %z", bh);
 488		return 0;
 489	}
 490
 491	used_space = BLKH_SIZE + KEY_SIZE * nr + DC_SIZE * (nr + 1);
 492	if (used_space != blocksize - blkh_free_space(blkh)) {
 493		reiserfs_warning(NULL, "reiserfs-5089",
 494				 "free space seems wrong: %z", bh);
 495		return 0;
 496	}
 497	// one may imagine much more checks
 
 498	return 1;
 499}
 500
 501// make sure that bh contains formatted node of reiserfs tree of
 502// 'level'-th level
 
 
 503static int is_tree_node(struct buffer_head *bh, int level)
 504{
 505	if (B_LEVEL(bh) != level) {
 506		reiserfs_warning(NULL, "reiserfs-5090", "node level %d does "
 507				 "not match to the expected one %d",
 508				 B_LEVEL(bh), level);
 509		return 0;
 510	}
 511	if (level == DISK_LEAF_NODE_LEVEL)
 512		return is_leaf(bh->b_data, bh->b_size, bh);
 513
 514	return is_internal(bh->b_data, bh->b_size, bh);
 515}
 516
 517#define SEARCH_BY_KEY_READA 16
 518
 519/*
 520 * The function is NOT SCHEDULE-SAFE!
 521 * It might unlock the write lock if we needed to wait for a block
 522 * to be read. Note that in this case it won't recover the lock to avoid
 523 * high contention resulting from too much lock requests, especially
 524 * the caller (search_by_key) will perform other schedule-unsafe
 525 * operations just after calling this function.
 526 *
 527 * @return true if we have unlocked
 528 */
 529static bool search_by_key_reada(struct super_block *s,
 530				struct buffer_head **bh,
 531				b_blocknr_t *b, int num)
 532{
 533	int i, j;
 534	bool unlocked = false;
 535
 536	for (i = 0; i < num; i++) {
 537		bh[i] = sb_getblk(s, b[i]);
 538	}
 539	/*
 540	 * We are going to read some blocks on which we
 541	 * have a reference. It's safe, though we might be
 542	 * reading blocks concurrently changed if we release
 543	 * the lock. But it's still fine because we check later
 544	 * if the tree changed
 545	 */
 546	for (j = 0; j < i; j++) {
 547		/*
 548		 * note, this needs attention if we are getting rid of the BKL
 549		 * you have to make sure the prepared bit isn't set on this buffer
 
 550		 */
 551		if (!buffer_uptodate(bh[j])) {
 552			if (!unlocked) {
 553				reiserfs_write_unlock(s);
 554				unlocked = true;
 555			}
 556			ll_rw_block(READA, 1, bh + j);
 557		}
 558		brelse(bh[j]);
 559	}
 560	return unlocked;
 561}
 562
 563/**************************************************************************
 564 * Algorithm   SearchByKey                                                *
 565 *             look for item in the Disk S+Tree by its key                *
 566 * Input:  sb   -  super block                                            *
 567 *         key  - pointer to the key to search                            *
 568 * Output: ITEM_FOUND, ITEM_NOT_FOUND or IO_ERROR                         *
 569 *         search_path - path from the root to the needed leaf            *
 570 **************************************************************************/
 571
 572/* This function fills up the path from the root to the leaf as it
 573   descends the tree looking for the key.  It uses reiserfs_bread to
 574   try to find buffers in the cache given their block number.  If it
 575   does not find them in the cache it reads them from disk.  For each
 576   node search_by_key finds using reiserfs_bread it then uses
 577   bin_search to look through that node.  bin_search will find the
 578   position of the block_number of the next node if it is looking
 579   through an internal node.  If it is looking through a leaf node
 580   bin_search will find the position of the item which has key either
 581   equal to given key, or which is the maximal key less than the given
 582   key.  search_by_key returns a path that must be checked for the
 583   correctness of the top of the path but need not be checked for the
 584   correctness of the bottom of the path */
 585/* The function is NOT SCHEDULE-SAFE! */
 586int search_by_key(struct super_block *sb, const struct cpu_key *key,	/* Key to search. */
 587		  struct treepath *search_path,/* This structure was
 588						   allocated and initialized
 589						   by the calling
 590						   function. It is filled up
 591						   by this function.  */
 592		  int stop_level	/* How far down the tree to search. To
 593					   stop at leaf level - set to
 594					   DISK_LEAF_NODE_LEVEL */
 595    )
 596{
 597	b_blocknr_t block_number;
 598	int expected_level;
 599	struct buffer_head *bh;
 600	struct path_element *last_element;
 601	int node_level, retval;
 602	int right_neighbor_of_leaf_node;
 603	int fs_gen;
 604	struct buffer_head *reada_bh[SEARCH_BY_KEY_READA];
 605	b_blocknr_t reada_blocks[SEARCH_BY_KEY_READA];
 606	int reada_count = 0;
 607
 608#ifdef CONFIG_REISERFS_CHECK
 609	int repeat_counter = 0;
 610#endif
 611
 612	PROC_INFO_INC(sb, search_by_key);
 613
 614	/* As we add each node to a path we increase its count.  This means that
 615	   we must be careful to release all nodes in a path before we either
 616	   discard the path struct or re-use the path struct, as we do here. */
 
 
 
 617
 618	pathrelse(search_path);
 619
 620	right_neighbor_of_leaf_node = 0;
 621
 622	/* With each iteration of this loop we search through the items in the
 623	   current node, and calculate the next current node(next path element)
 624	   for the next iteration of this loop.. */
 625	block_number = SB_ROOT_BLOCK(sb);
 626	expected_level = -1;
 627	while (1) {
 628
 629#ifdef CONFIG_REISERFS_CHECK
 630		if (!(++repeat_counter % 50000))
 631			reiserfs_warning(sb, "PAP-5100",
 632					 "%s: there were %d iterations of "
 633					 "while loop looking for key %K",
 634					 current->comm, repeat_counter,
 635					 key);
 636#endif
 637
 638		/* prep path to have another element added to it. */
 639		last_element =
 640		    PATH_OFFSET_PELEMENT(search_path,
 641					 ++search_path->path_length);
 642		fs_gen = get_generation(sb);
 643
 644		/* Read the next tree node, and set the last element in the path to
 645		   have a pointer to it. */
 
 
 646		if ((bh = last_element->pe_buffer =
 647		     sb_getblk(sb, block_number))) {
 648			bool unlocked = false;
 649
 650			if (!buffer_uptodate(bh) && reada_count > 1)
 651				/* may unlock the write lock */
 652				unlocked = search_by_key_reada(sb, reada_bh,
 653						    reada_blocks, reada_count);
 654			/*
 655			 * If we haven't already unlocked the write lock,
 656			 * then we need to do that here before reading
 657			 * the current block
 658			 */
 659			if (!buffer_uptodate(bh) && !unlocked) {
 660				reiserfs_write_unlock(sb);
 661				unlocked = true;
 662			}
 663			ll_rw_block(READ, 1, &bh);
 
 
 
 
 
 664			wait_on_buffer(bh);
 665
 666			if (unlocked)
 667				reiserfs_write_lock(sb);
 668			if (!buffer_uptodate(bh))
 669				goto io_error;
 670		} else {
 671		      io_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		/* It is possible that schedule occurred. We must check whether the key
 682		   to search is still in the tree rooted from the current buffer. If
 683		   not then repeat search from the root. */
 
 
 
 684		if (fs_changed(fs_gen, sb) &&
 685		    (!B_IS_IN_TREE(bh) ||
 686		     B_LEVEL(bh) != expected_level ||
 687		     !key_in_buffer(search_path, key, sb))) {
 688			PROC_INFO_INC(sb, search_by_key_fs_changed);
 689			PROC_INFO_INC(sb, search_by_key_restarted);
 690			PROC_INFO_INC(sb,
 691				      sbk_restarted[expected_level - 1]);
 692			pathrelse(search_path);
 693
 694			/* Get the root block number so that we can repeat the search
 695			   starting from the root. */
 
 
 696			block_number = SB_ROOT_BLOCK(sb);
 697			expected_level = -1;
 698			right_neighbor_of_leaf_node = 0;
 699
 700			/* repeat search from the root */
 701			continue;
 702		}
 703
 704		/* only check that the key is in the buffer if key is not
 705		   equal to the MAX_KEY. Latter case is only possible in
 706		   "finish_unfinished()" processing during mount. */
 
 
 707		RFALSE(comp_keys(&MAX_KEY, key) &&
 708		       !key_in_buffer(search_path, key, sb),
 709		       "PAP-5130: key is not in the buffer");
 710#ifdef CONFIG_REISERFS_CHECK
 711		if (REISERFS_SB(sb)->cur_tb) {
 712			print_cur_tb("5140");
 713			reiserfs_panic(sb, "PAP-5140",
 714				       "schedule occurred in do_balance!");
 715		}
 716#endif
 717
 718		// make sure, that the node contents look like a node of
 719		// certain level
 
 
 720		if (!is_tree_node(bh, expected_level)) {
 721			reiserfs_error(sb, "vs-5150",
 722				       "invalid format found in block %ld. "
 723				       "Fsck?", bh->b_blocknr);
 724			pathrelse(search_path);
 725			return IO_ERROR;
 726		}
 727
 728		/* ok, we have acquired next formatted node in the tree */
 729		node_level = B_LEVEL(bh);
 730
 731		PROC_INFO_BH_STAT(sb, bh, node_level - 1);
 732
 733		RFALSE(node_level < stop_level,
 734		       "vs-5152: tree level (%d) is less than stop level (%d)",
 735		       node_level, stop_level);
 736
 737		retval = bin_search(key, B_N_PITEM_HEAD(bh, 0),
 738				      B_NR_ITEMS(bh),
 739				      (node_level ==
 740				       DISK_LEAF_NODE_LEVEL) ? IH_SIZE :
 741				      KEY_SIZE,
 742				      &(last_element->pe_position));
 743		if (node_level == stop_level) {
 744			return retval;
 745		}
 746
 747		/* we are not in the stop level */
 
 
 
 
 748		if (retval == ITEM_FOUND)
 749			/* item has been found, so we choose the pointer which is to the right of the found one */
 750			last_element->pe_position++;
 751
 752		/* if item was not found we choose the position which is to
 753		   the left of the found item. This requires no code,
 754		   bin_search did it already. */
 755
 756		/* So we have chosen a position in the current node which is
 757		   an internal node.  Now we calculate child block number by
 758		   position in the node. */
 
 
 
 
 759		block_number =
 760		    B_N_CHILD_NUM(bh, last_element->pe_position);
 761
 762		/* if we are going to read leaf nodes, try for read ahead as well */
 
 
 
 763		if ((search_path->reada & PATH_READA) &&
 764		    node_level == DISK_LEAF_NODE_LEVEL + 1) {
 765			int pos = last_element->pe_position;
 766			int limit = B_NR_ITEMS(bh);
 767			struct reiserfs_key *le_key;
 768
 769			if (search_path->reada & PATH_READA_BACK)
 770				limit = 0;
 771			while (reada_count < SEARCH_BY_KEY_READA) {
 772				if (pos == limit)
 773					break;
 774				reada_blocks[reada_count++] =
 775				    B_N_CHILD_NUM(bh, pos);
 776				if (search_path->reada & PATH_READA_BACK)
 777					pos--;
 778				else
 779					pos++;
 780
 781				/*
 782				 * check to make sure we're in the same object
 783				 */
 784				le_key = B_N_PDELIM_KEY(bh, pos);
 785				if (le32_to_cpu(le_key->k_objectid) !=
 786				    key->on_disk_key.k_objectid) {
 787					break;
 788				}
 789			}
 790		}
 791	}
 792}
 793
 794/* Form the path to an item and position in this item which contains
 795   file byte defined by key. If there is no such item
 796   corresponding to the key, we point the path to the item with
 797   maximal key less than key, and *pos_in_item is set to one
 798   past the last entry/byte in the item.  If searching for entry in a
 799   directory item, and it is not found, *pos_in_item is set to one
 800   entry more than the entry with maximal key which is less than the
 801   sought key.
 802
 803   Note that if there is no entry in this same node which is one more,
 804   then we point to an imaginary entry.  for direct items, the
 805   position is in units of bytes, for indirect items the position is
 806   in units of blocknr entries, for directory items the position is in
 807   units of directory entries.  */
 808
 
 809/* The function is NOT SCHEDULE-SAFE! */
 810int search_for_position_by_key(struct super_block *sb,	/* Pointer to the super block.          */
 811			       const struct cpu_key *p_cpu_key,	/* Key to search (cpu variable)         */
 812			       struct treepath *search_path	/* Filled up by this function.          */
 813    )
 
 814{
 815	struct item_head *p_le_ih;	/* pointer to on-disk structure */
 816	int blk_size;
 817	loff_t item_offset, offset;
 818	struct reiserfs_dir_entry de;
 819	int retval;
 820
 821	/* If searching for directory entry. */
 822	if (is_direntry_cpu_key(p_cpu_key))
 823		return search_by_entry_key(sb, p_cpu_key, search_path,
 824					   &de);
 825
 826	/* If not searching for directory entry. */
 827
 828	/* If item is found. */
 829	retval = search_item(sb, p_cpu_key, search_path);
 830	if (retval == IO_ERROR)
 831		return retval;
 832	if (retval == ITEM_FOUND) {
 833
 834		RFALSE(!ih_item_len
 835		       (B_N_PITEM_HEAD
 836			(PATH_PLAST_BUFFER(search_path),
 837			 PATH_LAST_POSITION(search_path))),
 838		       "PAP-5165: item length equals zero");
 839
 840		pos_in_item(search_path) = 0;
 841		return POSITION_FOUND;
 842	}
 843
 844	RFALSE(!PATH_LAST_POSITION(search_path),
 845	       "PAP-5170: position equals zero");
 846
 847	/* Item is not found. Set path to the previous item. */
 848	p_le_ih =
 849	    B_N_PITEM_HEAD(PATH_PLAST_BUFFER(search_path),
 850			   --PATH_LAST_POSITION(search_path));
 851	blk_size = sb->s_blocksize;
 852
 853	if (comp_short_keys(&(p_le_ih->ih_key), p_cpu_key)) {
 854		return FILE_NOT_FOUND;
 855	}
 856	// FIXME: quite ugly this far
 857
 858	item_offset = le_ih_k_offset(p_le_ih);
 859	offset = cpu_key_k_offset(p_cpu_key);
 860
 861	/* Needed byte is contained in the item pointed to by the path. */
 862	if (item_offset <= offset &&
 863	    item_offset + op_bytes_number(p_le_ih, blk_size) > offset) {
 864		pos_in_item(search_path) = offset - item_offset;
 865		if (is_indirect_le_ih(p_le_ih)) {
 866			pos_in_item(search_path) /= blk_size;
 867		}
 868		return POSITION_FOUND;
 869	}
 870
 871	/* Needed byte is not contained in the item pointed to by the
 872	   path. Set pos_in_item out of the item. */
 
 
 873	if (is_indirect_le_ih(p_le_ih))
 874		pos_in_item(search_path) =
 875		    ih_item_len(p_le_ih) / UNFM_P_SIZE;
 876	else
 877		pos_in_item(search_path) = ih_item_len(p_le_ih);
 878
 879	return POSITION_NOT_FOUND;
 880}
 881
 882/* Compare given item and item pointed to by the path. */
 883int comp_items(const struct item_head *stored_ih, const struct treepath *path)
 884{
 885	struct buffer_head *bh = PATH_PLAST_BUFFER(path);
 886	struct item_head *ih;
 887
 888	/* Last buffer at the path is not in the tree. */
 889	if (!B_IS_IN_TREE(bh))
 890		return 1;
 891
 892	/* Last path position is invalid. */
 893	if (PATH_LAST_POSITION(path) >= B_NR_ITEMS(bh))
 894		return 1;
 895
 896	/* we need only to know, whether it is the same item */
 897	ih = get_ih(path);
 898	return memcmp(stored_ih, ih, IH_SIZE);
 899}
 900
 901/* unformatted nodes are not logged anymore, ever.  This is safe
 902** now
 903*/
 904#define held_by_others(bh) (atomic_read(&(bh)->b_count) > 1)
 905
 906// block can not be forgotten as it is in I/O or held by someone
 907#define block_in_use(bh) (buffer_locked(bh) || (held_by_others(bh)))
 908
 909// prepare for delete or cut of direct item
 910static inline int prepare_for_direct_item(struct treepath *path,
 911					  struct item_head *le_ih,
 912					  struct inode *inode,
 913					  loff_t new_file_length, int *cut_size)
 914{
 915	loff_t round_len;
 916
 917	if (new_file_length == max_reiserfs_offset(inode)) {
 918		/* item has to be deleted */
 919		*cut_size = -(IH_SIZE + ih_item_len(le_ih));
 920		return M_DELETE;
 921	}
 922	// new file gets truncated
 923	if (get_inode_item_key_version(inode) == KEY_FORMAT_3_6) {
 924		//
 925		round_len = ROUND_UP(new_file_length);
 926		/* this was new_file_length < le_ih ... */
 927		if (round_len < le_ih_k_offset(le_ih)) {
 928			*cut_size = -(IH_SIZE + ih_item_len(le_ih));
 929			return M_DELETE;	/* Delete this item. */
 930		}
 931		/* Calculate first position and size for cutting from item. */
 932		pos_in_item(path) = round_len - (le_ih_k_offset(le_ih) - 1);
 933		*cut_size = -(ih_item_len(le_ih) - pos_in_item(path));
 934
 935		return M_CUT;	/* Cut from this item. */
 936	}
 937
 938	// old file: items may have any length
 939
 940	if (new_file_length < le_ih_k_offset(le_ih)) {
 941		*cut_size = -(IH_SIZE + ih_item_len(le_ih));
 942		return M_DELETE;	/* Delete this item. */
 943	}
 
 944	/* Calculate first position and size for cutting from item. */
 945	*cut_size = -(ih_item_len(le_ih) -
 946		      (pos_in_item(path) =
 947		       new_file_length + 1 - le_ih_k_offset(le_ih)));
 948	return M_CUT;		/* Cut from this item. */
 949}
 950
 951static inline int prepare_for_direntry_item(struct treepath *path,
 952					    struct item_head *le_ih,
 953					    struct inode *inode,
 954					    loff_t new_file_length,
 955					    int *cut_size)
 956{
 957	if (le_ih_k_offset(le_ih) == DOT_OFFSET &&
 958	    new_file_length == max_reiserfs_offset(inode)) {
 959		RFALSE(ih_entry_count(le_ih) != 2,
 960		       "PAP-5220: incorrect empty directory item (%h)", le_ih);
 961		*cut_size = -(IH_SIZE + ih_item_len(le_ih));
 962		return M_DELETE;	/* Delete the directory item containing "." and ".." entry. */
 
 963	}
 964
 965	if (ih_entry_count(le_ih) == 1) {
 966		/* Delete the directory item such as there is one record only
 967		   in this item */
 
 
 968		*cut_size = -(IH_SIZE + ih_item_len(le_ih));
 969		return M_DELETE;
 970	}
 971
 972	/* Cut one record from the directory item. */
 973	*cut_size =
 974	    -(DEH_SIZE +
 975	      entry_length(get_last_bh(path), le_ih, pos_in_item(path)));
 976	return M_CUT;
 977}
 978
 979#define JOURNAL_FOR_FREE_BLOCK_AND_UPDATE_SD (2 * JOURNAL_PER_BALANCE_CNT + 1)
 980
 981/*  If the path points to a directory or direct item, calculate mode and the size cut, for balance.
 982    If the path points to an indirect item, remove some number of its unformatted nodes.
 983    In case of file truncate calculate whether this item must be deleted/truncated or last
 984    unformatted node of this item will be converted to a direct item.
 985    This function returns a determination of what balance mode the calling function should employ. */
 986static char prepare_for_delete_or_cut(struct reiserfs_transaction_handle *th, struct inode *inode, struct treepath *path, const struct cpu_key *item_key, int *removed,	/* Number of unformatted nodes which were removed
 987																						   from end of the file. */
 988				      int *cut_size, unsigned long long new_file_length	/* MAX_KEY_OFFSET in case of delete. */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 989    )
 990{
 991	struct super_block *sb = inode->i_sb;
 992	struct item_head *p_le_ih = PATH_PITEM_HEAD(path);
 993	struct buffer_head *bh = PATH_PLAST_BUFFER(path);
 994
 995	BUG_ON(!th->t_trans_id);
 996
 997	/* Stat_data item. */
 998	if (is_statdata_le_ih(p_le_ih)) {
 999
1000		RFALSE(new_file_length != max_reiserfs_offset(inode),
1001		       "PAP-5210: mode must be M_DELETE");
1002
1003		*cut_size = -(IH_SIZE + ih_item_len(p_le_ih));
1004		return M_DELETE;
1005	}
1006
1007	/* Directory item. */
1008	if (is_direntry_le_ih(p_le_ih))
1009		return prepare_for_direntry_item(path, p_le_ih, inode,
1010						 new_file_length,
1011						 cut_size);
1012
1013	/* Direct item. */
1014	if (is_direct_le_ih(p_le_ih))
1015		return prepare_for_direct_item(path, p_le_ih, inode,
1016					       new_file_length, cut_size);
1017
1018	/* Case of an indirect item. */
1019	{
1020	    int blk_size = sb->s_blocksize;
1021	    struct item_head s_ih;
1022	    int need_re_search;
1023	    int delete = 0;
1024	    int result = M_CUT;
1025	    int pos = 0;
1026
1027	    if ( new_file_length == max_reiserfs_offset (inode) ) {
1028		/* prepare_for_delete_or_cut() is called by
1029		 * reiserfs_delete_item() */
 
 
1030		new_file_length = 0;
1031		delete = 1;
1032	    }
1033
1034	    do {
1035		need_re_search = 0;
1036		*cut_size = 0;
1037		bh = PATH_PLAST_BUFFER(path);
1038		copy_item_head(&s_ih, PATH_PITEM_HEAD(path));
1039		pos = I_UNFM_NUM(&s_ih);
1040
1041		while (le_ih_k_offset (&s_ih) + (pos - 1) * blk_size > new_file_length) {
1042		    __le32 *unfm;
1043		    __u32 block;
1044
1045		    /* Each unformatted block deletion may involve one additional
1046		     * bitmap block into the transaction, thereby the initial
1047		     * journal space reservation might not be enough. */
 
 
 
1048		    if (!delete && (*cut_size) != 0 &&
1049			reiserfs_transaction_free_space(th) < JOURNAL_FOR_FREE_BLOCK_AND_UPDATE_SD)
1050			break;
1051
1052		    unfm = (__le32 *)B_I_PITEM(bh, &s_ih) + pos - 1;
1053		    block = get_block_num(unfm, 0);
1054
1055		    if (block != 0) {
1056			reiserfs_prepare_for_journal(sb, bh, 1);
1057			put_block_num(unfm, 0, 0);
1058			journal_mark_dirty(th, sb, bh);
1059			reiserfs_free_block(th, inode, block, 1);
1060		    }
1061
1062		    reiserfs_write_unlock(sb);
1063		    cond_resched();
1064		    reiserfs_write_lock(sb);
1065
1066		    if (item_moved (&s_ih, path))  {
1067			need_re_search = 1;
1068			break;
1069		    }
1070
1071		    pos --;
1072		    (*removed)++;
1073		    (*cut_size) -= UNFM_P_SIZE;
1074
1075		    if (pos == 0) {
1076			(*cut_size) -= IH_SIZE;
1077			result = M_DELETE;
1078			break;
1079		    }
1080		}
1081		/* a trick.  If the buffer has been logged, this will do nothing.  If
1082		** we've broken the loop without logging it, it will restore the
1083		** buffer */
 
 
1084		reiserfs_restore_prepared_buffer(sb, bh);
1085	    } while (need_re_search &&
1086		     search_for_position_by_key(sb, item_key, path) == POSITION_FOUND);
1087	    pos_in_item(path) = pos * UNFM_P_SIZE;
1088
1089	    if (*cut_size == 0) {
1090		/* Nothing were cut. maybe convert last unformatted node to the
1091		 * direct item? */
 
 
1092		result = M_CONVERT;
1093	    }
1094	    return result;
1095	}
1096}
1097
1098/* Calculate number of bytes which will be deleted or cut during balance */
1099static int calc_deleted_bytes_number(struct tree_balance *tb, char mode)
1100{
1101	int del_size;
1102	struct item_head *p_le_ih = PATH_PITEM_HEAD(tb->tb_path);
1103
1104	if (is_statdata_le_ih(p_le_ih))
1105		return 0;
1106
1107	del_size =
1108	    (mode ==
1109	     M_DELETE) ? ih_item_len(p_le_ih) : -tb->insert_size[0];
1110	if (is_direntry_le_ih(p_le_ih)) {
1111		/* return EMPTY_DIR_SIZE; We delete emty directoris only.
1112		 * we can't use EMPTY_DIR_SIZE, as old format dirs have a different
1113		 * empty size.  ick. FIXME, is this right? */
 
 
1114		return del_size;
1115	}
1116
1117	if (is_indirect_le_ih(p_le_ih))
1118		del_size = (del_size / UNFM_P_SIZE) *
1119				(PATH_PLAST_BUFFER(tb->tb_path)->b_size);
1120	return del_size;
1121}
1122
1123static void init_tb_struct(struct reiserfs_transaction_handle *th,
1124			   struct tree_balance *tb,
1125			   struct super_block *sb,
1126			   struct treepath *path, int size)
1127{
1128
1129	BUG_ON(!th->t_trans_id);
1130
1131	memset(tb, '\0', sizeof(struct tree_balance));
1132	tb->transaction_handle = th;
1133	tb->tb_sb = sb;
1134	tb->tb_path = path;
1135	PATH_OFFSET_PBUFFER(path, ILLEGAL_PATH_ELEMENT_OFFSET) = NULL;
1136	PATH_OFFSET_POSITION(path, ILLEGAL_PATH_ELEMENT_OFFSET) = 0;
1137	tb->insert_size[0] = size;
1138}
1139
1140void padd_item(char *item, int total_length, int length)
1141{
1142	int i;
1143
1144	for (i = total_length; i > length;)
1145		item[--i] = 0;
1146}
1147
1148#ifdef REISERQUOTA_DEBUG
1149char key2type(struct reiserfs_key *ih)
1150{
1151	if (is_direntry_le_key(2, ih))
1152		return 'd';
1153	if (is_direct_le_key(2, ih))
1154		return 'D';
1155	if (is_indirect_le_key(2, ih))
1156		return 'i';
1157	if (is_statdata_le_key(2, ih))
1158		return 's';
1159	return 'u';
1160}
1161
1162char head2type(struct item_head *ih)
1163{
1164	if (is_direntry_le_ih(ih))
1165		return 'd';
1166	if (is_direct_le_ih(ih))
1167		return 'D';
1168	if (is_indirect_le_ih(ih))
1169		return 'i';
1170	if (is_statdata_le_ih(ih))
1171		return 's';
1172	return 'u';
1173}
1174#endif
1175
1176/* Delete object item.
 
1177 * th       - active transaction handle
1178 * path     - path to the deleted item
1179 * item_key - key to search for the deleted item
1180 * indode   - used for updating i_blocks and quotas
1181 * un_bh    - NULL or unformatted node pointer
1182 */
1183int reiserfs_delete_item(struct reiserfs_transaction_handle *th,
1184			 struct treepath *path, const struct cpu_key *item_key,
1185			 struct inode *inode, struct buffer_head *un_bh)
1186{
1187	struct super_block *sb = inode->i_sb;
1188	struct tree_balance s_del_balance;
1189	struct item_head s_ih;
1190	struct item_head *q_ih;
1191	int quota_cut_bytes;
1192	int ret_value, del_size, removed;
 
1193
1194#ifdef CONFIG_REISERFS_CHECK
1195	char mode;
1196	int iter = 0;
1197#endif
1198
1199	BUG_ON(!th->t_trans_id);
1200
1201	init_tb_struct(th, &s_del_balance, sb, path,
1202		       0 /*size is unknown */ );
1203
1204	while (1) {
1205		removed = 0;
1206
1207#ifdef CONFIG_REISERFS_CHECK
1208		iter++;
1209		mode =
1210#endif
1211		    prepare_for_delete_or_cut(th, inode, path,
1212					      item_key, &removed,
1213					      &del_size,
1214					      max_reiserfs_offset(inode));
1215
1216		RFALSE(mode != M_DELETE, "PAP-5320: mode must be M_DELETE");
1217
1218		copy_item_head(&s_ih, PATH_PITEM_HEAD(path));
1219		s_del_balance.insert_size[0] = del_size;
1220
1221		ret_value = fix_nodes(M_DELETE, &s_del_balance, NULL, NULL);
1222		if (ret_value != REPEAT_SEARCH)
1223			break;
1224
1225		PROC_INFO_INC(sb, delete_item_restarted);
1226
1227		// file system changed, repeat search
1228		ret_value =
1229		    search_for_position_by_key(sb, item_key, path);
1230		if (ret_value == IO_ERROR)
1231			break;
1232		if (ret_value == FILE_NOT_FOUND) {
1233			reiserfs_warning(sb, "vs-5340",
1234					 "no items of the file %K found",
1235					 item_key);
1236			break;
1237		}
1238	}			/* while (1) */
1239
1240	if (ret_value != CARRY_ON) {
1241		unfix_nodes(&s_del_balance);
1242		return 0;
1243	}
1244	// reiserfs_delete_item returns item length when success
 
1245	ret_value = calc_deleted_bytes_number(&s_del_balance, M_DELETE);
1246	q_ih = get_ih(path);
1247	quota_cut_bytes = ih_item_len(q_ih);
1248
1249	/* hack so the quota code doesn't have to guess if the file
1250	 ** has a tail.  On tail insert, we allocate quota for 1 unformatted node.
1251	 ** We test the offset because the tail might have been
1252	 ** split into multiple items, and we only want to decrement for
1253	 ** the unfm node once
 
1254	 */
1255	if (!S_ISLNK(inode->i_mode) && is_direct_le_ih(q_ih)) {
1256		if ((le_ih_k_offset(q_ih) & (sb->s_blocksize - 1)) == 1) {
1257			quota_cut_bytes = sb->s_blocksize + UNFM_P_SIZE;
1258		} else {
1259			quota_cut_bytes = 0;
1260		}
1261	}
1262
1263	if (un_bh) {
1264		int off;
1265		char *data;
1266
1267		/* We are in direct2indirect conversion, so move tail contents
1268		   to the unformatted node */
1269		/* note, we do the copy before preparing the buffer because we
1270		 ** don't care about the contents of the unformatted node yet.
1271		 ** the only thing we really care about is the direct item's data
1272		 ** is in the unformatted node.
1273		 **
1274		 ** Otherwise, we would have to call reiserfs_prepare_for_journal on
1275		 ** the unformatted node, which might schedule, meaning we'd have to
1276		 ** loop all the way back up to the start of the while loop.
1277		 **
1278		 ** The unformatted node must be dirtied later on.  We can't be
1279		 ** sure here if the entire tail has been deleted yet.
1280		 **
1281		 ** un_bh is from the page cache (all unformatted nodes are
1282		 ** from the page cache) and might be a highmem page.  So, we
1283		 ** can't use un_bh->b_data.
1284		 ** -clm
 
 
 
 
1285		 */
1286
1287		data = kmap_atomic(un_bh->b_page, KM_USER0);
1288		off = ((le_ih_k_offset(&s_ih) - 1) & (PAGE_CACHE_SIZE - 1));
1289		memcpy(data + off,
1290		       B_I_PITEM(PATH_PLAST_BUFFER(path), &s_ih),
1291		       ret_value);
1292		kunmap_atomic(data, KM_USER0);
1293	}
 
1294	/* Perform balancing after all resources have been collected at once. */
1295	do_balance(&s_del_balance, NULL, NULL, M_DELETE);
1296
1297#ifdef REISERQUOTA_DEBUG
1298	reiserfs_debug(sb, REISERFS_DEBUG_CODE,
1299		       "reiserquota delete_item(): freeing %u, id=%u type=%c",
1300		       quota_cut_bytes, inode->i_uid, head2type(&s_ih));
1301#endif
 
1302	dquot_free_space_nodirty(inode, quota_cut_bytes);
 
1303
1304	/* Return deleted body length */
1305	return ret_value;
1306}
1307
1308/* Summary Of Mechanisms For Handling Collisions Between Processes:
1309
1310 deletion of the body of the object is performed by iput(), with the
1311 result that if multiple processes are operating on a file, the
1312 deletion of the body of the file is deferred until the last process
1313 that has an open inode performs its iput().
1314
1315 writes and truncates are protected from collisions by use of
1316 semaphores.
1317
1318 creates, linking, and mknod are protected from collisions with other
1319 processes by making the reiserfs_add_entry() the last step in the
1320 creation, and then rolling back all changes if there was a collision.
1321 - Hans
 
1322*/
1323
1324/* this deletes item which never gets split */
1325void reiserfs_delete_solid_item(struct reiserfs_transaction_handle *th,
1326				struct inode *inode, struct reiserfs_key *key)
1327{
 
1328	struct tree_balance tb;
1329	INITIALIZE_PATH(path);
1330	int item_len = 0;
1331	int tb_init = 0;
1332	struct cpu_key cpu_key;
1333	int retval;
1334	int quota_cut_bytes = 0;
1335
1336	BUG_ON(!th->t_trans_id);
1337
1338	le_key2cpu_key(&cpu_key, key);
1339
1340	while (1) {
1341		retval = search_item(th->t_super, &cpu_key, &path);
1342		if (retval == IO_ERROR) {
1343			reiserfs_error(th->t_super, "vs-5350",
1344				       "i/o failure occurred trying "
1345				       "to delete %K", &cpu_key);
1346			break;
1347		}
1348		if (retval != ITEM_FOUND) {
1349			pathrelse(&path);
1350			// No need for a warning, if there is just no free space to insert '..' item into the newly-created subdir
 
 
 
 
1351			if (!
1352			    ((unsigned long long)
1353			     GET_HASH_VALUE(le_key_k_offset
1354					    (le_key_version(key), key)) == 0
1355			     && (unsigned long long)
1356			     GET_GENERATION_NUMBER(le_key_k_offset
1357						   (le_key_version(key),
1358						    key)) == 1))
1359				reiserfs_warning(th->t_super, "vs-5355",
1360						 "%k not found", key);
1361			break;
1362		}
1363		if (!tb_init) {
1364			tb_init = 1;
1365			item_len = ih_item_len(PATH_PITEM_HEAD(&path));
1366			init_tb_struct(th, &tb, th->t_super, &path,
1367				       -(IH_SIZE + item_len));
1368		}
1369		quota_cut_bytes = ih_item_len(PATH_PITEM_HEAD(&path));
1370
1371		retval = fix_nodes(M_DELETE, &tb, NULL, NULL);
1372		if (retval == REPEAT_SEARCH) {
1373			PROC_INFO_INC(th->t_super, delete_solid_item_restarted);
1374			continue;
1375		}
1376
1377		if (retval == CARRY_ON) {
1378			do_balance(&tb, NULL, NULL, M_DELETE);
1379			if (inode) {	/* Should we count quota for item? (we don't count quotas for save-links) */
 
 
 
 
 
1380#ifdef REISERQUOTA_DEBUG
1381				reiserfs_debug(th->t_super, REISERFS_DEBUG_CODE,
1382					       "reiserquota delete_solid_item(): freeing %u id=%u type=%c",
1383					       quota_cut_bytes, inode->i_uid,
1384					       key2type(key));
1385#endif
 
1386				dquot_free_space_nodirty(inode,
1387							 quota_cut_bytes);
 
1388			}
1389			break;
1390		}
1391		// IO_ERROR, NO_DISK_SPACE, etc
 
1392		reiserfs_warning(th->t_super, "vs-5360",
1393				 "could not delete %K due to fix_nodes failure",
1394				 &cpu_key);
1395		unfix_nodes(&tb);
1396		break;
1397	}
1398
1399	reiserfs_check_path(&path);
1400}
1401
1402int reiserfs_delete_object(struct reiserfs_transaction_handle *th,
1403			   struct inode *inode)
1404{
1405	int err;
1406	inode->i_size = 0;
1407	BUG_ON(!th->t_trans_id);
1408
1409	/* for directory this deletes item containing "." and ".." */
1410	err =
1411	    reiserfs_do_truncate(th, inode, NULL, 0 /*no timestamp updates */ );
1412	if (err)
1413		return err;
1414
1415#if defined( USE_INODE_GENERATION_COUNTER )
1416	if (!old_format_only(th->t_super)) {
1417		__le32 *inode_generation;
1418
1419		inode_generation =
1420		    &REISERFS_SB(th->t_super)->s_rs->s_inode_generation;
1421		le32_add_cpu(inode_generation, 1);
1422	}
1423/* USE_INODE_GENERATION_COUNTER */
1424#endif
1425	reiserfs_delete_solid_item(th, inode, INODE_PKEY(inode));
1426
1427	return err;
1428}
1429
1430static void unmap_buffers(struct page *page, loff_t pos)
1431{
1432	struct buffer_head *bh;
1433	struct buffer_head *head;
1434	struct buffer_head *next;
1435	unsigned long tail_index;
1436	unsigned long cur_index;
1437
1438	if (page) {
1439		if (page_has_buffers(page)) {
1440			tail_index = pos & (PAGE_CACHE_SIZE - 1);
1441			cur_index = 0;
1442			head = page_buffers(page);
1443			bh = head;
1444			do {
1445				next = bh->b_this_page;
1446
1447				/* we want to unmap the buffers that contain the tail, and
1448				 ** all the buffers after it (since the tail must be at the
1449				 ** end of the file).  We don't want to unmap file data
1450				 ** before the tail, since it might be dirty and waiting to
1451				 ** reach disk
 
 
1452				 */
1453				cur_index += bh->b_size;
1454				if (cur_index > tail_index) {
1455					reiserfs_unmap_buffer(bh);
1456				}
1457				bh = next;
1458			} while (bh != head);
1459		}
1460	}
1461}
1462
1463static int maybe_indirect_to_direct(struct reiserfs_transaction_handle *th,
1464				    struct inode *inode,
1465				    struct page *page,
1466				    struct treepath *path,
1467				    const struct cpu_key *item_key,
1468				    loff_t new_file_size, char *mode)
1469{
1470	struct super_block *sb = inode->i_sb;
1471	int block_size = sb->s_blocksize;
1472	int cut_bytes;
1473	BUG_ON(!th->t_trans_id);
1474	BUG_ON(new_file_size != inode->i_size);
1475
1476	/* the page being sent in could be NULL if there was an i/o error
1477	 ** reading in the last block.  The user will hit problems trying to
1478	 ** read the file, but for now we just skip the indirect2direct
 
1479	 */
1480	if (atomic_read(&inode->i_count) > 1 ||
1481	    !tail_has_to_be_packed(inode) ||
1482	    !page || (REISERFS_I(inode)->i_flags & i_nopack_mask)) {
1483		/* leave tail in an unformatted node */
1484		*mode = M_SKIP_BALANCING;
1485		cut_bytes =
1486		    block_size - (new_file_size & (block_size - 1));
1487		pathrelse(path);
1488		return cut_bytes;
1489	}
 
1490	/* Perform the conversion to a direct_item. */
1491	/* return indirect_to_direct(inode, path, item_key,
1492				  new_file_size, mode); */
1493	return indirect2direct(th, inode, page, path, item_key,
1494			       new_file_size, mode);
1495}
1496
1497/* we did indirect_to_direct conversion. And we have inserted direct
1498   item successesfully, but there were no disk space to cut unfm
1499   pointer being converted. Therefore we have to delete inserted
1500   direct item(s) */
 
 
1501static void indirect_to_direct_roll_back(struct reiserfs_transaction_handle *th,
1502					 struct inode *inode, struct treepath *path)
1503{
1504	struct cpu_key tail_key;
1505	int tail_len;
1506	int removed;
1507	BUG_ON(!th->t_trans_id);
1508
1509	make_cpu_key(&tail_key, inode, inode->i_size + 1, TYPE_DIRECT, 4);	// !!!!
1510	tail_key.key_length = 4;
1511
1512	tail_len =
1513	    (cpu_key_k_offset(&tail_key) & (inode->i_sb->s_blocksize - 1)) - 1;
1514	while (tail_len) {
1515		/* look for the last byte of the tail */
1516		if (search_for_position_by_key(inode->i_sb, &tail_key, path) ==
1517		    POSITION_NOT_FOUND)
1518			reiserfs_panic(inode->i_sb, "vs-5615",
1519				       "found invalid item");
1520		RFALSE(path->pos_in_item !=
1521		       ih_item_len(PATH_PITEM_HEAD(path)) - 1,
1522		       "vs-5616: appended bytes found");
1523		PATH_LAST_POSITION(path)--;
1524
1525		removed =
1526		    reiserfs_delete_item(th, path, &tail_key, inode,
1527					 NULL /*unbh not needed */ );
1528		RFALSE(removed <= 0
1529		       || removed > tail_len,
1530		       "vs-5617: there was tail %d bytes, removed item length %d bytes",
1531		       tail_len, removed);
1532		tail_len -= removed;
1533		set_cpu_key_k_offset(&tail_key,
1534				     cpu_key_k_offset(&tail_key) - removed);
1535	}
1536	reiserfs_warning(inode->i_sb, "reiserfs-5091", "indirect_to_direct "
1537			 "conversion has been rolled back due to "
1538			 "lack of disk space");
1539	//mark_file_without_tail (inode);
1540	mark_inode_dirty(inode);
1541}
1542
1543/* (Truncate or cut entry) or delete object item. Returns < 0 on failure */
1544int reiserfs_cut_from_item(struct reiserfs_transaction_handle *th,
1545			   struct treepath *path,
1546			   struct cpu_key *item_key,
1547			   struct inode *inode,
1548			   struct page *page, loff_t new_file_size)
1549{
1550	struct super_block *sb = inode->i_sb;
1551	/* Every function which is going to call do_balance must first
1552	   create a tree_balance structure.  Then it must fill up this
1553	   structure by using the init_tb_struct and fix_nodes functions.
1554	   After that we can make tree balancing. */
 
 
1555	struct tree_balance s_cut_balance;
1556	struct item_head *p_le_ih;
1557	int cut_size = 0,	/* Amount to be cut. */
1558	    ret_value = CARRY_ON, removed = 0,	/* Number of the removed unformatted nodes. */
1559	    is_inode_locked = 0;
 
1560	char mode;		/* Mode of the balance. */
1561	int retval2 = -1;
1562	int quota_cut_bytes;
1563	loff_t tail_pos = 0;
 
1564
1565	BUG_ON(!th->t_trans_id);
1566
1567	init_tb_struct(th, &s_cut_balance, inode->i_sb, path,
1568		       cut_size);
1569
1570	/* Repeat this loop until we either cut the item without needing
1571	   to balance, or we fix_nodes without schedule occurring */
 
 
1572	while (1) {
1573		/* Determine the balance mode, position of the first byte to
1574		   be cut, and size to be cut.  In case of the indirect item
1575		   free unformatted nodes which are pointed to by the cut
1576		   pointers. */
 
 
1577
1578		mode =
1579		    prepare_for_delete_or_cut(th, inode, path,
1580					      item_key, &removed,
1581					      &cut_size, new_file_size);
1582		if (mode == M_CONVERT) {
1583			/* convert last unformatted node to direct item or leave
1584			   tail in the unformatted node */
 
 
1585			RFALSE(ret_value != CARRY_ON,
1586			       "PAP-5570: can not convert twice");
1587
1588			ret_value =
1589			    maybe_indirect_to_direct(th, inode, page,
1590						     path, item_key,
1591						     new_file_size, &mode);
1592			if (mode == M_SKIP_BALANCING)
1593				/* tail has been left in the unformatted node */
1594				return ret_value;
1595
1596			is_inode_locked = 1;
1597
1598			/* removing of last unformatted node will change value we
1599			   have to return to truncate. Save it */
 
 
 
1600			retval2 = ret_value;
1601			/*retval2 = sb->s_blocksize - (new_file_size & (sb->s_blocksize - 1)); */
1602
1603			/* So, we have performed the first part of the conversion:
1604			   inserting the new direct item.  Now we are removing the
1605			   last unformatted node pointer. Set key to search for
1606			   it. */
 
 
 
1607			set_cpu_key_k_type(item_key, TYPE_INDIRECT);
1608			item_key->key_length = 4;
1609			new_file_size -=
1610			    (new_file_size & (sb->s_blocksize - 1));
1611			tail_pos = new_file_size;
1612			set_cpu_key_k_offset(item_key, new_file_size + 1);
1613			if (search_for_position_by_key
1614			    (sb, item_key,
1615			     path) == POSITION_NOT_FOUND) {
1616				print_block(PATH_PLAST_BUFFER(path), 3,
1617					    PATH_LAST_POSITION(path) - 1,
1618					    PATH_LAST_POSITION(path) + 1);
1619				reiserfs_panic(sb, "PAP-5580", "item to "
1620					       "convert does not exist (%K)",
1621					       item_key);
1622			}
1623			continue;
1624		}
1625		if (cut_size == 0) {
1626			pathrelse(path);
1627			return 0;
1628		}
1629
1630		s_cut_balance.insert_size[0] = cut_size;
1631
1632		ret_value = fix_nodes(mode, &s_cut_balance, NULL, NULL);
1633		if (ret_value != REPEAT_SEARCH)
1634			break;
1635
1636		PROC_INFO_INC(sb, cut_from_item_restarted);
1637
1638		ret_value =
1639		    search_for_position_by_key(sb, item_key, path);
1640		if (ret_value == POSITION_FOUND)
1641			continue;
1642
1643		reiserfs_warning(sb, "PAP-5610", "item %K not found",
1644				 item_key);
1645		unfix_nodes(&s_cut_balance);
1646		return (ret_value == IO_ERROR) ? -EIO : -ENOENT;
1647	}			/* while */
1648
1649	// check fix_nodes results (IO_ERROR or NO_DISK_SPACE)
1650	if (ret_value != CARRY_ON) {
1651		if (is_inode_locked) {
1652			// FIXME: this seems to be not needed: we are always able
1653			// to cut item
 
 
1654			indirect_to_direct_roll_back(th, inode, path);
1655		}
1656		if (ret_value == NO_DISK_SPACE)
1657			reiserfs_warning(sb, "reiserfs-5092",
1658					 "NO_DISK_SPACE");
1659		unfix_nodes(&s_cut_balance);
1660		return -EIO;
1661	}
1662
1663	/* go ahead and perform balancing */
1664
1665	RFALSE(mode == M_PASTE || mode == M_INSERT, "invalid mode");
1666
1667	/* Calculate number of bytes that need to be cut from the item. */
1668	quota_cut_bytes =
1669	    (mode ==
1670	     M_DELETE) ? ih_item_len(get_ih(path)) : -s_cut_balance.
1671	    insert_size[0];
1672	if (retval2 == -1)
1673		ret_value = calc_deleted_bytes_number(&s_cut_balance, mode);
1674	else
1675		ret_value = retval2;
1676
1677	/* For direct items, we only change the quota when deleting the last
1678	 ** item.
 
1679	 */
1680	p_le_ih = PATH_PITEM_HEAD(s_cut_balance.tb_path);
1681	if (!S_ISLNK(inode->i_mode) && is_direct_le_ih(p_le_ih)) {
1682		if (mode == M_DELETE &&
1683		    (le_ih_k_offset(p_le_ih) & (sb->s_blocksize - 1)) ==
1684		    1) {
1685			// FIXME: this is to keep 3.5 happy
1686			REISERFS_I(inode)->i_first_direct_byte = U32_MAX;
1687			quota_cut_bytes = sb->s_blocksize + UNFM_P_SIZE;
1688		} else {
1689			quota_cut_bytes = 0;
1690		}
1691	}
1692#ifdef CONFIG_REISERFS_CHECK
1693	if (is_inode_locked) {
1694		struct item_head *le_ih =
1695		    PATH_PITEM_HEAD(s_cut_balance.tb_path);
1696		/* we are going to complete indirect2direct conversion. Make
1697		   sure, that we exactly remove last unformatted node pointer
1698		   of the item */
 
 
1699		if (!is_indirect_le_ih(le_ih))
1700			reiserfs_panic(sb, "vs-5652",
1701				       "item must be indirect %h", le_ih);
1702
1703		if (mode == M_DELETE && ih_item_len(le_ih) != UNFM_P_SIZE)
1704			reiserfs_panic(sb, "vs-5653", "completing "
1705				       "indirect2direct conversion indirect "
1706				       "item %h being deleted must be of "
1707				       "4 byte long", le_ih);
1708
1709		if (mode == M_CUT
1710		    && s_cut_balance.insert_size[0] != -UNFM_P_SIZE) {
1711			reiserfs_panic(sb, "vs-5654", "can not complete "
1712				       "indirect2direct conversion of %h "
1713				       "(CUT, insert_size==%d)",
1714				       le_ih, s_cut_balance.insert_size[0]);
1715		}
1716		/* it would be useful to make sure, that right neighboring
1717		   item is direct item of this file */
 
 
1718	}
1719#endif
1720
1721	do_balance(&s_cut_balance, NULL, NULL, mode);
1722	if (is_inode_locked) {
1723		/* we've done an indirect->direct conversion.  when the data block
1724		 ** was freed, it was removed from the list of blocks that must
1725		 ** be flushed before the transaction commits, make sure to
1726		 ** unmap and invalidate it
 
1727		 */
1728		unmap_buffers(page, tail_pos);
1729		REISERFS_I(inode)->i_flags &= ~i_pack_on_close_mask;
1730	}
1731#ifdef REISERQUOTA_DEBUG
1732	reiserfs_debug(inode->i_sb, REISERFS_DEBUG_CODE,
1733		       "reiserquota cut_from_item(): freeing %u id=%u type=%c",
1734		       quota_cut_bytes, inode->i_uid, '?');
1735#endif
 
1736	dquot_free_space_nodirty(inode, quota_cut_bytes);
 
1737	return ret_value;
1738}
1739
1740static void truncate_directory(struct reiserfs_transaction_handle *th,
1741			       struct inode *inode)
1742{
1743	BUG_ON(!th->t_trans_id);
1744	if (inode->i_nlink)
1745		reiserfs_error(inode->i_sb, "vs-5655", "link count != 0");
1746
1747	set_le_key_k_offset(KEY_FORMAT_3_5, INODE_PKEY(inode), DOT_OFFSET);
1748	set_le_key_k_type(KEY_FORMAT_3_5, INODE_PKEY(inode), TYPE_DIRENTRY);
1749	reiserfs_delete_solid_item(th, inode, INODE_PKEY(inode));
1750	reiserfs_update_sd(th, inode);
1751	set_le_key_k_offset(KEY_FORMAT_3_5, INODE_PKEY(inode), SD_OFFSET);
1752	set_le_key_k_type(KEY_FORMAT_3_5, INODE_PKEY(inode), TYPE_STAT_DATA);
1753}
1754
1755/* Truncate file to the new size. Note, this must be called with a transaction
1756   already started */
 
 
1757int reiserfs_do_truncate(struct reiserfs_transaction_handle *th,
1758			  struct inode *inode,	/* ->i_size contains new size */
1759			 struct page *page,	/* up to date for last block */
1760			 int update_timestamps	/* when it is called by
1761						   file_release to convert
1762						   the tail - no timestamps
1763						   should be updated */
 
1764    )
1765{
1766	INITIALIZE_PATH(s_search_path);	/* Path to the current object item. */
1767	struct item_head *p_le_ih;	/* Pointer to an item header. */
1768	struct cpu_key s_item_key;	/* Key to search for a previous file item. */
 
 
1769	loff_t file_size,	/* Old file size. */
1770	 new_file_size;	/* New file size. */
1771	int deleted;		/* Number of deleted or truncated bytes. */
1772	int retval;
1773	int err = 0;
1774
1775	BUG_ON(!th->t_trans_id);
1776	if (!
1777	    (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
1778	     || S_ISLNK(inode->i_mode)))
1779		return 0;
1780
 
1781	if (S_ISDIR(inode->i_mode)) {
1782		// deletion of directory - no need to update timestamps
1783		truncate_directory(th, inode);
1784		return 0;
1785	}
1786
1787	/* Get new file size. */
1788	new_file_size = inode->i_size;
1789
1790	// FIXME: note, that key type is unimportant here
1791	make_cpu_key(&s_item_key, inode, max_reiserfs_offset(inode),
1792		     TYPE_DIRECT, 3);
1793
1794	retval =
1795	    search_for_position_by_key(inode->i_sb, &s_item_key,
1796				       &s_search_path);
1797	if (retval == IO_ERROR) {
1798		reiserfs_error(inode->i_sb, "vs-5657",
1799			       "i/o failure occurred trying to truncate %K",
1800			       &s_item_key);
1801		err = -EIO;
1802		goto out;
1803	}
1804	if (retval == POSITION_FOUND || retval == FILE_NOT_FOUND) {
1805		reiserfs_error(inode->i_sb, "PAP-5660",
1806			       "wrong result %d of search for %K", retval,
1807			       &s_item_key);
1808
1809		err = -EIO;
1810		goto out;
1811	}
1812
1813	s_search_path.pos_in_item--;
1814
1815	/* Get real file size (total length of all file items) */
1816	p_le_ih = PATH_PITEM_HEAD(&s_search_path);
1817	if (is_statdata_le_ih(p_le_ih))
1818		file_size = 0;
1819	else {
1820		loff_t offset = le_ih_k_offset(p_le_ih);
1821		int bytes =
1822		    op_bytes_number(p_le_ih, inode->i_sb->s_blocksize);
1823
1824		/* this may mismatch with real file size: if last direct item
1825		   had no padding zeros and last unformatted node had no free
1826		   space, this file would have this file size */
 
 
1827		file_size = offset + bytes - 1;
1828	}
1829	/*
1830	 * are we doing a full truncate or delete, if so
1831	 * kick in the reada code
1832	 */
1833	if (new_file_size == 0)
1834		s_search_path.reada = PATH_READA | PATH_READA_BACK;
1835
1836	if (file_size == 0 || file_size < new_file_size) {
1837		goto update_and_out;
1838	}
1839
1840	/* Update key to search for the last file item. */
1841	set_cpu_key_k_offset(&s_item_key, file_size);
1842
1843	do {
1844		/* Cut or delete file item. */
1845		deleted =
1846		    reiserfs_cut_from_item(th, &s_search_path, &s_item_key,
1847					   inode, page, new_file_size);
1848		if (deleted < 0) {
1849			reiserfs_warning(inode->i_sb, "vs-5665",
1850					 "reiserfs_cut_from_item failed");
1851			reiserfs_check_path(&s_search_path);
1852			return 0;
1853		}
1854
1855		RFALSE(deleted > file_size,
1856		       "PAP-5670: reiserfs_cut_from_item: too many bytes deleted: deleted %d, file_size %lu, item_key %K",
1857		       deleted, file_size, &s_item_key);
1858
1859		/* Change key to search the last file item. */
1860		file_size -= deleted;
1861
1862		set_cpu_key_k_offset(&s_item_key, file_size);
1863
1864		/* While there are bytes to truncate and previous file item is presented in the tree. */
 
 
 
1865
1866		/*
1867		 ** This loop could take a really long time, and could log
1868		 ** many more blocks than a transaction can hold.  So, we do a polite
1869		 ** journal end here, and if the transaction needs ending, we make
1870		 ** sure the file is consistent before ending the current trans
1871		 ** and starting a new one
1872		 */
1873		if (journal_transaction_should_end(th, 0) ||
1874		    reiserfs_transaction_free_space(th) <= JOURNAL_FOR_FREE_BLOCK_AND_UPDATE_SD) {
1875			int orig_len_alloc = th->t_blocks_allocated;
1876			pathrelse(&s_search_path);
1877
1878			if (update_timestamps) {
1879				inode->i_mtime = CURRENT_TIME_SEC;
1880				inode->i_ctime = CURRENT_TIME_SEC;
1881			}
1882			reiserfs_update_sd(th, inode);
1883
1884			err = journal_end(th, inode->i_sb, orig_len_alloc);
1885			if (err)
1886				goto out;
1887			err = journal_begin(th, inode->i_sb,
1888					    JOURNAL_FOR_FREE_BLOCK_AND_UPDATE_SD + JOURNAL_PER_BALANCE_CNT * 4) ;
1889			if (err)
1890				goto out;
1891			reiserfs_update_inode_transaction(inode);
1892		}
1893	} while (file_size > ROUND_UP(new_file_size) &&
1894		 search_for_position_by_key(inode->i_sb, &s_item_key,
1895					    &s_search_path) == POSITION_FOUND);
1896
1897	RFALSE(file_size > ROUND_UP(new_file_size),
1898	       "PAP-5680: truncate did not finish: new_file_size %Ld, current %Ld, oid %d",
1899	       new_file_size, file_size, s_item_key.on_disk_key.k_objectid);
1900
1901      update_and_out:
1902	if (update_timestamps) {
1903		// this is truncate, not file closing
1904		inode->i_mtime = CURRENT_TIME_SEC;
1905		inode->i_ctime = CURRENT_TIME_SEC;
1906	}
1907	reiserfs_update_sd(th, inode);
1908
1909      out:
1910	pathrelse(&s_search_path);
1911	return err;
1912}
1913
1914#ifdef CONFIG_REISERFS_CHECK
1915// this makes sure, that we __append__, not overwrite or add holes
1916static void check_research_for_paste(struct treepath *path,
1917				     const struct cpu_key *key)
1918{
1919	struct item_head *found_ih = get_ih(path);
1920
1921	if (is_direct_le_ih(found_ih)) {
1922		if (le_ih_k_offset(found_ih) +
1923		    op_bytes_number(found_ih,
1924				    get_last_bh(path)->b_size) !=
1925		    cpu_key_k_offset(key)
1926		    || op_bytes_number(found_ih,
1927				       get_last_bh(path)->b_size) !=
1928		    pos_in_item(path))
1929			reiserfs_panic(NULL, "PAP-5720", "found direct item "
1930				       "%h or position (%d) does not match "
1931				       "to key %K", found_ih,
1932				       pos_in_item(path), key);
1933	}
1934	if (is_indirect_le_ih(found_ih)) {
1935		if (le_ih_k_offset(found_ih) +
1936		    op_bytes_number(found_ih,
1937				    get_last_bh(path)->b_size) !=
1938		    cpu_key_k_offset(key)
1939		    || I_UNFM_NUM(found_ih) != pos_in_item(path)
1940		    || get_ih_free_space(found_ih) != 0)
1941			reiserfs_panic(NULL, "PAP-5730", "found indirect "
1942				       "item (%h) or position (%d) does not "
1943				       "match to key (%K)",
1944				       found_ih, pos_in_item(path), key);
1945	}
1946}
1947#endif				/* config reiserfs check */
1948
1949/* Paste bytes to the existing item. Returns bytes number pasted into the item. */
1950int reiserfs_paste_into_item(struct reiserfs_transaction_handle *th, struct treepath *search_path,	/* Path to the pasted item.	  */
1951			     const struct cpu_key *key,	/* Key to search for the needed item. */
1952			     struct inode *inode,	/* Inode item belongs to */
1953			     const char *body,	/* Pointer to the bytes to paste.    */
 
 
 
 
 
 
 
 
 
1954			     int pasted_size)
1955{				/* Size of pasted bytes.             */
 
1956	struct tree_balance s_paste_balance;
1957	int retval;
1958	int fs_gen;
 
1959
1960	BUG_ON(!th->t_trans_id);
1961
1962	fs_gen = get_generation(inode->i_sb);
1963
1964#ifdef REISERQUOTA_DEBUG
1965	reiserfs_debug(inode->i_sb, REISERFS_DEBUG_CODE,
1966		       "reiserquota paste_into_item(): allocating %u id=%u type=%c",
1967		       pasted_size, inode->i_uid,
1968		       key2type(&(key->on_disk_key)));
1969#endif
1970
 
1971	retval = dquot_alloc_space_nodirty(inode, pasted_size);
 
1972	if (retval) {
1973		pathrelse(search_path);
1974		return retval;
1975	}
1976	init_tb_struct(th, &s_paste_balance, th->t_super, search_path,
1977		       pasted_size);
1978#ifdef DISPLACE_NEW_PACKING_LOCALITIES
1979	s_paste_balance.key = key->on_disk_key;
1980#endif
1981
1982	/* DQUOT_* can schedule, must check before the fix_nodes */
1983	if (fs_changed(fs_gen, inode->i_sb)) {
1984		goto search_again;
1985	}
1986
1987	while ((retval =
1988		fix_nodes(M_PASTE, &s_paste_balance, NULL,
1989			  body)) == REPEAT_SEARCH) {
1990	      search_again:
1991		/* file system changed while we were in the fix_nodes */
1992		PROC_INFO_INC(th->t_super, paste_into_item_restarted);
1993		retval =
1994		    search_for_position_by_key(th->t_super, key,
1995					       search_path);
1996		if (retval == IO_ERROR) {
1997			retval = -EIO;
1998			goto error_out;
1999		}
2000		if (retval == POSITION_FOUND) {
2001			reiserfs_warning(inode->i_sb, "PAP-5710",
2002					 "entry or pasted byte (%K) exists",
2003					 key);
2004			retval = -EEXIST;
2005			goto error_out;
2006		}
2007#ifdef CONFIG_REISERFS_CHECK
2008		check_research_for_paste(search_path, key);
2009#endif
2010	}
2011
2012	/* Perform balancing after all resources are collected by fix_nodes, and
2013	   accessing them will not risk triggering schedule. */
 
 
2014	if (retval == CARRY_ON) {
2015		do_balance(&s_paste_balance, NULL /*ih */ , body, M_PASTE);
2016		return 0;
2017	}
2018	retval = (retval == NO_DISK_SPACE) ? -ENOSPC : -EIO;
2019      error_out:
2020	/* this also releases the path */
2021	unfix_nodes(&s_paste_balance);
2022#ifdef REISERQUOTA_DEBUG
2023	reiserfs_debug(inode->i_sb, REISERFS_DEBUG_CODE,
2024		       "reiserquota paste_into_item(): freeing %u id=%u type=%c",
2025		       pasted_size, inode->i_uid,
2026		       key2type(&(key->on_disk_key)));
2027#endif
 
2028	dquot_free_space_nodirty(inode, pasted_size);
 
2029	return retval;
2030}
2031
2032/* Insert new item into the buffer at the path.
 
2033 * th   - active transaction handle
2034 * path - path to the inserted item
2035 * ih   - pointer to the item header to insert
2036 * body - pointer to the bytes to insert
2037 */
2038int reiserfs_insert_item(struct reiserfs_transaction_handle *th,
2039			 struct treepath *path, const struct cpu_key *key,
2040			 struct item_head *ih, struct inode *inode,
2041			 const char *body)
2042{
2043	struct tree_balance s_ins_balance;
2044	int retval;
2045	int fs_gen = 0;
2046	int quota_bytes = 0;
2047
2048	BUG_ON(!th->t_trans_id);
2049
2050	if (inode) {		/* Do we count quotas for item? */
 
2051		fs_gen = get_generation(inode->i_sb);
2052		quota_bytes = ih_item_len(ih);
2053
2054		/* hack so the quota code doesn't have to guess if the file has
2055		 ** a tail, links are always tails, so there's no guessing needed
 
 
2056		 */
2057		if (!S_ISLNK(inode->i_mode) && is_direct_le_ih(ih))
2058			quota_bytes = inode->i_sb->s_blocksize + UNFM_P_SIZE;
2059#ifdef REISERQUOTA_DEBUG
2060		reiserfs_debug(inode->i_sb, REISERFS_DEBUG_CODE,
2061			       "reiserquota insert_item(): allocating %u id=%u type=%c",
2062			       quota_bytes, inode->i_uid, head2type(ih));
2063#endif
2064		/* We can't dirty inode here. It would be immediately written but
2065		 * appropriate stat item isn't inserted yet... */
 
 
 
2066		retval = dquot_alloc_space_nodirty(inode, quota_bytes);
 
2067		if (retval) {
2068			pathrelse(path);
2069			return retval;
2070		}
2071	}
2072	init_tb_struct(th, &s_ins_balance, th->t_super, path,
2073		       IH_SIZE + ih_item_len(ih));
2074#ifdef DISPLACE_NEW_PACKING_LOCALITIES
2075	s_ins_balance.key = key->on_disk_key;
2076#endif
2077	/* DQUOT_* can schedule, must check to be sure calling fix_nodes is safe */
 
 
 
2078	if (inode && fs_changed(fs_gen, inode->i_sb)) {
2079		goto search_again;
2080	}
2081
2082	while ((retval =
2083		fix_nodes(M_INSERT, &s_ins_balance, ih,
2084			  body)) == REPEAT_SEARCH) {
2085	      search_again:
2086		/* file system changed while we were in the fix_nodes */
2087		PROC_INFO_INC(th->t_super, insert_item_restarted);
2088		retval = search_item(th->t_super, key, path);
2089		if (retval == IO_ERROR) {
2090			retval = -EIO;
2091			goto error_out;
2092		}
2093		if (retval == ITEM_FOUND) {
2094			reiserfs_warning(th->t_super, "PAP-5760",
2095					 "key %K already exists in the tree",
2096					 key);
2097			retval = -EEXIST;
2098			goto error_out;
2099		}
2100	}
2101
2102	/* make balancing after all resources will be collected at a time */
2103	if (retval == CARRY_ON) {
2104		do_balance(&s_ins_balance, ih, body, M_INSERT);
2105		return 0;
2106	}
2107
2108	retval = (retval == NO_DISK_SPACE) ? -ENOSPC : -EIO;
2109      error_out:
2110	/* also releases the path */
2111	unfix_nodes(&s_ins_balance);
2112#ifdef REISERQUOTA_DEBUG
2113	reiserfs_debug(th->t_super, REISERFS_DEBUG_CODE,
2114		       "reiserquota insert_item(): freeing %u id=%u type=%c",
2115		       quota_bytes, inode->i_uid, head2type(ih));
2116#endif
2117	if (inode)
 
2118		dquot_free_space_nodirty(inode, quota_bytes);
 
 
2119	return retval;
2120}