linux/fs/reiserfs/stree.c
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   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 "reiserfs.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);
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);
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        reiserfs_write_unlock(inode->i_sb);
1972        retval = dquot_alloc_space_nodirty(inode, pasted_size);
1973        reiserfs_write_lock(inode->i_sb);
1974        if (retval) {
1975                pathrelse(search_path);
1976                return retval;
1977        }
1978        init_tb_struct(th, &s_paste_balance, th->t_super, search_path,
1979                       pasted_size);
1980#ifdef DISPLACE_NEW_PACKING_LOCALITIES
1981        s_paste_balance.key = key->on_disk_key;
1982#endif
1983
1984        /* DQUOT_* can schedule, must check before the fix_nodes */
1985        if (fs_changed(fs_gen, inode->i_sb)) {
1986                goto search_again;
1987        }
1988
1989        while ((retval =
1990                fix_nodes(M_PASTE, &s_paste_balance, NULL,
1991                          body)) == REPEAT_SEARCH) {
1992              search_again:
1993                /* file system changed while we were in the fix_nodes */
1994                PROC_INFO_INC(th->t_super, paste_into_item_restarted);
1995                retval =
1996                    search_for_position_by_key(th->t_super, key,
1997                                               search_path);
1998                if (retval == IO_ERROR) {
1999                        retval = -EIO;
2000                        goto error_out;
2001                }
2002                if (retval == POSITION_FOUND) {
2003                        reiserfs_warning(inode->i_sb, "PAP-5710",
2004                                         "entry or pasted byte (%K) exists",
2005                                         key);
2006                        retval = -EEXIST;
2007                        goto error_out;
2008                }
2009#ifdef CONFIG_REISERFS_CHECK
2010                check_research_for_paste(search_path, key);
2011#endif
2012        }
2013
2014        /* Perform balancing after all resources are collected by fix_nodes, and
2015           accessing them will not risk triggering schedule. */
2016        if (retval == CARRY_ON) {
2017                do_balance(&s_paste_balance, NULL /*ih */ , body, M_PASTE);
2018                return 0;
2019        }
2020        retval = (retval == NO_DISK_SPACE) ? -ENOSPC : -EIO;
2021      error_out:
2022        /* this also releases the path */
2023        unfix_nodes(&s_paste_balance);
2024#ifdef REISERQUOTA_DEBUG
2025        reiserfs_debug(inode->i_sb, REISERFS_DEBUG_CODE,
2026                       "reiserquota paste_into_item(): freeing %u id=%u type=%c",
2027                       pasted_size, inode->i_uid,
2028                       key2type(&(key->on_disk_key)));
2029#endif
2030        dquot_free_space_nodirty(inode, pasted_size);
2031        return retval;
2032}
2033
2034/* Insert new item into the buffer at the path.
2035 * th   - active transaction handle
2036 * path - path to the inserted item
2037 * ih   - pointer to the item header to insert
2038 * body - pointer to the bytes to insert
2039 */
2040int reiserfs_insert_item(struct reiserfs_transaction_handle *th,
2041                         struct treepath *path, const struct cpu_key *key,
2042                         struct item_head *ih, struct inode *inode,
2043                         const char *body)
2044{
2045        struct tree_balance s_ins_balance;
2046        int retval;
2047        int fs_gen = 0;
2048        int quota_bytes = 0;
2049
2050        BUG_ON(!th->t_trans_id);
2051
2052        if (inode) {            /* Do we count quotas for item? */
2053                fs_gen = get_generation(inode->i_sb);
2054                quota_bytes = ih_item_len(ih);
2055
2056                /* hack so the quota code doesn't have to guess if the file has
2057                 ** a tail, links are always tails, so there's no guessing needed
2058                 */
2059                if (!S_ISLNK(inode->i_mode) && is_direct_le_ih(ih))
2060                        quota_bytes = inode->i_sb->s_blocksize + UNFM_P_SIZE;
2061#ifdef REISERQUOTA_DEBUG
2062                reiserfs_debug(inode->i_sb, REISERFS_DEBUG_CODE,
2063                               "reiserquota insert_item(): allocating %u id=%u type=%c",
2064                               quota_bytes, inode->i_uid, head2type(ih));
2065#endif
2066                reiserfs_write_unlock(inode->i_sb);
2067                /* We can't dirty inode here. It would be immediately written but
2068                 * appropriate stat item isn't inserted yet... */
2069                retval = dquot_alloc_space_nodirty(inode, quota_bytes);
2070                reiserfs_write_lock(inode->i_sb);
2071                if (retval) {
2072                        pathrelse(path);
2073                        return retval;
2074                }
2075        }
2076        init_tb_struct(th, &s_ins_balance, th->t_super, path,
2077                       IH_SIZE + ih_item_len(ih));
2078#ifdef DISPLACE_NEW_PACKING_LOCALITIES
2079        s_ins_balance.key = key->on_disk_key;
2080#endif
2081        /* DQUOT_* can schedule, must check to be sure calling fix_nodes is safe */
2082        if (inode && fs_changed(fs_gen, inode->i_sb)) {
2083                goto search_again;
2084        }
2085
2086        while ((retval =
2087                fix_nodes(M_INSERT, &s_ins_balance, ih,
2088                          body)) == REPEAT_SEARCH) {
2089              search_again:
2090                /* file system changed while we were in the fix_nodes */
2091                PROC_INFO_INC(th->t_super, insert_item_restarted);
2092                retval = search_item(th->t_super, key, path);
2093                if (retval == IO_ERROR) {
2094                        retval = -EIO;
2095                        goto error_out;
2096                }
2097                if (retval == ITEM_FOUND) {
2098                        reiserfs_warning(th->t_super, "PAP-5760",
2099                                         "key %K already exists in the tree",
2100                                         key);
2101                        retval = -EEXIST;
2102                        goto error_out;
2103                }
2104        }
2105
2106        /* make balancing after all resources will be collected at a time */
2107        if (retval == CARRY_ON) {
2108                do_balance(&s_ins_balance, ih, body, M_INSERT);
2109                return 0;
2110        }
2111
2112        retval = (retval == NO_DISK_SPACE) ? -ENOSPC : -EIO;
2113      error_out:
2114        /* also releases the path */
2115        unfix_nodes(&s_ins_balance);
2116#ifdef REISERQUOTA_DEBUG
2117        reiserfs_debug(th->t_super, REISERFS_DEBUG_CODE,
2118                       "reiserquota insert_item(): freeing %u id=%u type=%c",
2119                       quota_bytes, inode->i_uid, head2type(ih));
2120#endif
2121        if (inode)
2122                dquot_free_space_nodirty(inode, quota_bytes);
2123        return retval;
2124}
2125
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