lustre/kernel_patches/patches/ext3-extents-2.4.29.patch

   1 Index: linux-2.4.29/fs/ext3/extents.c
   2 ===================================================================
   3 --- linux-2.4.29.orig/fs/ext3/extents.c 2005-05-03 16:52:08.723069952 +0300
   4 +++ linux-2.4.29/fs/ext3/extents.c      2005-05-03 16:52:08.802057944 +0300
   5 @@ -0,0 +1,2308 @@
   6 +/*
   7 + * Copyright(c) 2003, 2004, 2005, Cluster File Systems, Inc, info@clusterfs.com
   8 + * Written by Alex Tomas <alex@clusterfs.com>
   9 + *
  10 + * This program is free software; you can redistribute it and/or modify
  11 + * it under the terms of the GNU General Public License version 2 as
  12 + * published by the Free Software Foundation.
  13 + *
  14 + * This program is distributed in the hope that it will be useful,
  15 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 + * GNU General Public License for more details.
  18 + *
  19 + * You should have received a copy of the GNU General Public Licens
  20 + * along with this program; if not, write to the Free Software
  21 + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
  22 + */
  23 +
  24 +/*
  25 + * Extents support for EXT3
  26 + *
  27 + * TODO:
  28 + *   - ext3_ext_walk_space() sould not use ext3_ext_find_extent()
  29 + *   - ext3_ext_calc_credits() could take 'mergable' into account
  30 + *   - ext3*_error() should be used in some situations
  31 + *   - find_goal() [to be tested and improved]
  32 + *   - smart tree reduction
  33 + *   - arch-independence
  34 + *     common on-disk format for big/little-endian arch
  35 + */
  36 +
  37 +#include <linux/module.h>
  38 +#include <linux/fs.h>
  39 +#include <linux/time.h>
  40 +#include <linux/ext3_jbd.h>
  41 +#include <linux/jbd.h>
  42 +#include <linux/locks.h>
  43 +#include <linux/smp_lock.h>
  44 +#include <linux/highuid.h>
  45 +#include <linux/pagemap.h>
  46 +#include <linux/quotaops.h>
  47 +#include <linux/string.h>
  48 +#include <linux/slab.h>
  49 +#include <linux/ext3_extents.h>
  50 +#include <asm/uaccess.h>
  51 +
  52 +
  53 +static inline int ext3_ext_check_header(struct ext3_extent_header *eh)
  54 +{
  55 +       if (eh->eh_magic != EXT3_EXT_MAGIC) {
  56 +               printk(KERN_ERR "EXT3-fs: invalid magic = 0x%x\n",
  57 +                      (unsigned)eh->eh_magic);
  58 +               return -EIO;
  59 +       }
  60 +       if (eh->eh_max == 0) {
  61 +               printk(KERN_ERR "EXT3-fs: invalid eh_max = %u\n",
  62 +                      (unsigned)eh->eh_max);
  63 +               return -EIO;
  64 +       }
  65 +       if (eh->eh_entries > eh->eh_max) {
  66 +               printk(KERN_ERR "EXT3-fs: invalid eh_entries = %u\n",
  67 +                      (unsigned)eh->eh_entries);
  68 +               return -EIO;
  69 +       }
  70 +       return 0;
  71 +}
  72 +
  73 +static handle_t *ext3_ext_journal_restart(handle_t *handle, int needed)
  74 +{
  75 +       int err;
  76 +
  77 +       if (handle->h_buffer_credits > needed)
  78 +               return handle;
  79 +       if (!ext3_journal_extend(handle, needed))
  80 +               return handle;
  81 +       err = ext3_journal_restart(handle, needed);
  82 +
  83 +       return handle;
  84 +}
  85 +
  86 +static int inline
  87 +ext3_ext_get_access_for_root(handle_t *h, struct ext3_extents_tree *tree)
  88 +{
  89 +       if (tree->ops->get_write_access)
  90 +               return tree->ops->get_write_access(h,tree->buffer);
  91 +       else
  92 +               return 0;
  93 +}
  94 +
  95 +static int inline
  96 +ext3_ext_mark_root_dirty(handle_t *h, struct ext3_extents_tree *tree)
  97 +{
  98 +       if (tree->ops->mark_buffer_dirty)
  99 +               return tree->ops->mark_buffer_dirty(h,tree->buffer);
 100 +       else
 101 +               return 0;
 102 +}
 103 +
 104 +/*
 105 + * could return:
 106 + *  - EROFS
 107 + *  - ENOMEM
 108 + */
 109 +static int ext3_ext_get_access(handle_t *handle,
 110 +                              struct ext3_extents_tree *tree,
 111 +                              struct ext3_ext_path *path)
 112 +{
 113 +       int err;
 114 +
 115 +       if (path->p_bh) {
 116 +               /* path points to block */
 117 +               err = ext3_journal_get_write_access(handle, path->p_bh);
 118 +       } else {
 119 +               /* path points to leaf/index in inode body */
 120 +               err = ext3_ext_get_access_for_root(handle, tree);
 121 +       }
 122 +       return err;
 123 +}
 124 +
 125 +/*
 126 + * could return:
 127 + *  - EROFS
 128 + *  - ENOMEM
 129 + *  - EIO
 130 + */
 131 +static int ext3_ext_dirty(handle_t *handle, struct ext3_extents_tree *tree,
 132 +                         struct ext3_ext_path *path)
 133 +{
 134 +       int err;
 135 +       if (path->p_bh) {
 136 +               /* path points to block */
 137 +               err =ext3_journal_dirty_metadata(handle, path->p_bh);
 138 +       } else {
 139 +               /* path points to leaf/index in inode body */
 140 +               err = ext3_ext_mark_root_dirty(handle, tree);
 141 +       }
 142 +       return err;
 143 +}
 144 +
 145 +static int inline
 146 +ext3_ext_new_block(handle_t *handle, struct ext3_extents_tree *tree,
 147 +                  struct ext3_ext_path *path, struct ext3_extent *ex,
 148 +                  int *err)
 149 +{
 150 +       int goal, depth, newblock;
 151 +       struct inode *inode;
 152 +
 153 +       EXT_ASSERT(tree);
 154 +       if (tree->ops->new_block)
 155 +               return tree->ops->new_block(handle, tree, path, ex, err);
 156 +
 157 +       inode = tree->inode;
 158 +       depth = EXT_DEPTH(tree);
 159 +       if (path && depth > 0) {
 160 +               goal = path[depth-1].p_block;
 161 +       } else {
 162 +               struct ext3_inode_info *ei = EXT3_I(inode);
 163 +               unsigned long bg_start;
 164 +               unsigned long colour;
 165 +
 166 +               bg_start = (ei->i_block_group *
 167 +                           EXT3_BLOCKS_PER_GROUP(inode->i_sb)) +
 168 +                       le32_to_cpu(EXT3_SB(inode->i_sb)->s_es->s_first_data_block);
 169 +               colour = (current->pid % 16) *
 170 +                       (EXT3_BLOCKS_PER_GROUP(inode->i_sb) / 16);
 171 +               goal = bg_start + colour;
 172 +       }
 173 +
 174 +       lock_kernel();
 175 +       newblock = ext3_new_block(handle, inode, goal, 0, 0, err);
 176 +       unlock_kernel();
 177 +       return newblock;
 178 +}
 179 +
 180 +static inline void ext3_ext_tree_changed(struct ext3_extents_tree *tree)
 181 +{
 182 +       struct ext3_extent_header *neh = EXT_ROOT_HDR(tree);
 183 +       neh->eh_generation = ((EXT_FLAGS(neh) & ~EXT_FLAGS_CLR_UNKNOWN) << 24) |
 184 +                            (EXT_HDR_GEN(neh) + 1);
 185 +}
 186 +
 187 +static inline int ext3_ext_space_block(struct ext3_extents_tree *tree)
 188 +{
 189 +       int size;
 190 +
 191 +       size = (tree->inode->i_sb->s_blocksize -
 192 +               sizeof(struct ext3_extent_header)) /
 193 +                               sizeof(struct ext3_extent);
 194 +#ifdef AGRESSIVE_TEST
 195 +       size = 6;
 196 +#endif
 197 +       return size;
 198 +}
 199 +
 200 +static inline int ext3_ext_space_block_idx(struct ext3_extents_tree *tree)
 201 +{
 202 +       int size;
 203 +
 204 +       size = (tree->inode->i_sb->s_blocksize -
 205 +               sizeof(struct ext3_extent_header)) /
 206 +                               sizeof(struct ext3_extent_idx);
 207 +#ifdef AGRESSIVE_TEST
 208 +       size = 5;
 209 +#endif
 210 +       return size;
 211 +}
 212 +
 213 +static inline int ext3_ext_space_root(struct ext3_extents_tree *tree)
 214 +{
 215 +       int size;
 216 +
 217 +       size = (tree->buffer_len - sizeof(struct ext3_extent_header)) /
 218 +                       sizeof(struct ext3_extent);
 219 +#ifdef AGRESSIVE_TEST
 220 +       size = 3;
 221 +#endif
 222 +       return size;
 223 +}
 224 +
 225 +static inline int ext3_ext_space_root_idx(struct ext3_extents_tree *tree)
 226 +{
 227 +       int size;
 228 +
 229 +       size = (tree->buffer_len - sizeof(struct ext3_extent_header)) /
 230 +                       sizeof(struct ext3_extent_idx);
 231 +#ifdef AGRESSIVE_TEST
 232 +       size = 4;
 233 +#endif
 234 +       return size;
 235 +}
 236 +
 237 +static void ext3_ext_show_path(struct ext3_extents_tree *tree,
 238 +                              struct ext3_ext_path *path)
 239 +{
 240 +#ifdef EXT_DEBUG
 241 +       int k, l = path->p_depth;
 242 +
 243 +       ext_debug(tree, "path:");
 244 +       for (k = 0; k <= l; k++, path++) {
 245 +               if (path->p_idx) {
 246 +                       ext_debug(tree, "  %d->%d", path->p_idx->ei_block,
 247 +                                 path->p_idx->ei_leaf);
 248 +               } else if (path->p_ext) {
 249 +                       ext_debug(tree, "  %d:%d:%d",
 250 +                                 path->p_ext->ee_block,
 251 +                                 path->p_ext->ee_len,
 252 +                                 path->p_ext->ee_start);
 253 +               } else
 254 +                       ext_debug(tree, "  []");
 255 +       }
 256 +       ext_debug(tree, "\n");
 257 +#endif
 258 +}
 259 +
 260 +static void ext3_ext_show_leaf(struct ext3_extents_tree *tree,
 261 +                              struct ext3_ext_path *path)
 262 +{
 263 +#ifdef EXT_DEBUG
 264 +       int depth = EXT_DEPTH(tree);
 265 +       struct ext3_extent_header *eh;
 266 +       struct ext3_extent *ex;
 267 +       int i;
 268 +
 269 +       if (!path)
 270 +               return;
 271 +
 272 +       eh = path[depth].p_hdr;
 273 +       ex = EXT_FIRST_EXTENT(eh);
 274 +
 275 +       for (i = 0; i < eh->eh_entries; i++, ex++) {
 276 +               ext_debug(tree, "%d:%d:%d ",
 277 +                         ex->ee_block, ex->ee_len, ex->ee_start);
 278 +       }
 279 +       ext_debug(tree, "\n");
 280 +#endif
 281 +}
 282 +
 283 +static void ext3_ext_drop_refs(struct ext3_ext_path *path)
 284 +{
 285 +       int depth = path->p_depth;
 286 +       int i;
 287 +
 288 +       for (i = 0; i <= depth; i++, path++) {
 289 +               if (path->p_bh) {
 290 +                       brelse(path->p_bh);
 291 +                       path->p_bh = NULL;
 292 +               }
 293 +       }
 294 +}
 295 +
 296 +/*
 297 + * binary search for closest index by given block
 298 + */
 299 +static inline void
 300 +ext3_ext_binsearch_idx(struct ext3_extents_tree *tree,
 301 +                      struct ext3_ext_path *path, int block)
 302 +{
 303 +       struct ext3_extent_header *eh = path->p_hdr;
 304 +       struct ext3_extent_idx *ix;
 305 +       int l = 0, k, r;
 306 +
 307 +       EXT_ASSERT(eh->eh_magic == EXT3_EXT_MAGIC);
 308 +       EXT_ASSERT(eh->eh_entries <= eh->eh_max);
 309 +       EXT_ASSERT(eh->eh_entries > 0);
 310 +
 311 +       ext_debug(tree, "binsearch for %d(idx):  ", block);
 312 +
 313 +       path->p_idx = ix = EXT_FIRST_INDEX(eh);
 314 +
 315 +       r = k = eh->eh_entries;
 316 +       while (k > 1) {
 317 +               k = (r - l) / 2;
 318 +               if (block < ix[l + k].ei_block)
 319 +                       r -= k;
 320 +               else
 321 +                       l += k;
 322 +               ext_debug(tree, "%d:%d:%d ", k, l, r);
 323 +       }
 324 +
 325 +       ix += l;
 326 +       path->p_idx = ix;
 327 +       ext_debug(tree," -> %d->%d ",path->p_idx->ei_block,path->p_idx->ei_leaf);
 328 +
 329 +       while (l++ < r) {
 330 +               if (block < ix->ei_block)
 331 +                       break;
 332 +               path->p_idx = ix++;
 333 +       }
 334 +       ext_debug(tree, "  -> %d->%d\n", path->p_idx->ei_block,
 335 +                 path->p_idx->ei_leaf);
 336 +
 337 +#ifdef CHECK_BINSEARCH
 338 +       {
 339 +               struct ext3_extent_idx *chix;
 340 +
 341 +               chix = ix = EXT_FIRST_INDEX(eh);
 342 +               for (k = 0; k < eh->eh_entries; k++, ix++) {
 343 +                       if (k != 0 && ix->ei_block <= ix[-1].ei_block) {
 344 +                               printk("k=%d, ix=0x%p, first=0x%p\n", k,
 345 +                                      ix, EXT_FIRST_INDEX(eh));
 346 +                               printk("%u <= %u\n",
 347 +                                      ix->ei_block,ix[-1].ei_block);
 348 +                       }
 349 +                       EXT_ASSERT(k == 0 || ix->ei_block > ix[-1].ei_block);
 350 +                       if (block < ix->ei_block)
 351 +                               break;
 352 +                       chix = ix;
 353 +               }
 354 +               EXT_ASSERT(chix == path->p_idx);
 355 +       }
 356 +#endif
 357 +}
 358 +
 359 +/*
 360 + * binary search for closest extent by given block
 361 + */
 362 +static inline void
 363 +ext3_ext_binsearch(struct ext3_extents_tree *tree,
 364 +                  struct ext3_ext_path *path, int block)
 365 +{
 366 +       struct ext3_extent_header *eh = path->p_hdr;
 367 +       struct ext3_extent *ex;
 368 +       int l = 0, k, r;
 369 +
 370 +       EXT_ASSERT(eh->eh_magic == EXT3_EXT_MAGIC);
 371 +       EXT_ASSERT(eh->eh_entries <= eh->eh_max);
 372 +
 373 +       if (eh->eh_entries == 0) {
 374 +               /*
 375 +                * this leaf is empty yet:
 376 +                *  we get such a leaf in split/add case
 377 +                */
 378 +               return;
 379 +       }
 380 +
 381 +       ext_debug(tree, "binsearch for %d:  ", block);
 382 +
 383 +       path->p_ext = ex = EXT_FIRST_EXTENT(eh);
 384 +
 385 +       r = k = eh->eh_entries;
 386 +       while (k > 1) {
 387 +               k = (r - l) / 2;
 388 +               if (block < ex[l + k].ee_block)
 389 +                       r -= k;
 390 +               else
 391 +                       l += k;
 392 +               ext_debug(tree, "%d:%d:%d ", k, l, r);
 393 +       }
 394 +
 395 +       ex += l;
 396 +       path->p_ext = ex;
 397 +       ext_debug(tree, "  -> %d:%d:%d ", path->p_ext->ee_block,
 398 +                 path->p_ext->ee_start, path->p_ext->ee_len);
 399 +
 400 +       while (l++ < r) {
 401 +               if (block < ex->ee_block)
 402 +                       break;
 403 +               path->p_ext = ex++;
 404 +       }
 405 +       ext_debug(tree, "  -> %d:%d:%d\n", path->p_ext->ee_block,
 406 +                 path->p_ext->ee_start, path->p_ext->ee_len);
 407 +
 408 +#ifdef CHECK_BINSEARCH
 409 +       {
 410 +               struct ext3_extent *chex;
 411 +
 412 +               chex = ex = EXT_FIRST_EXTENT(eh);
 413 +               for (k = 0; k < eh->eh_entries; k++, ex++) {
 414 +                       EXT_ASSERT(k == 0 || ex->ee_block > ex[-1].ee_block);
 415 +                       if (block < ex->ee_block)
 416 +                               break;
 417 +                       chex = ex;
 418 +               }
 419 +               EXT_ASSERT(chex == path->p_ext);
 420 +       }
 421 +#endif
 422 +}
 423 +
 424 +int ext3_extent_tree_init(handle_t *handle, struct ext3_extents_tree *tree)
 425 +{
 426 +       struct ext3_extent_header *eh;
 427 +
 428 +       BUG_ON(tree->buffer_len == 0);
 429 +       ext3_ext_get_access_for_root(handle, tree);
 430 +       eh = EXT_ROOT_HDR(tree);
 431 +       eh->eh_depth = 0;
 432 +       eh->eh_entries = 0;
 433 +       eh->eh_magic = EXT3_EXT_MAGIC;
 434 +       eh->eh_max = ext3_ext_space_root(tree);
 435 +       ext3_ext_mark_root_dirty(handle, tree);
 436 +       ext3_ext_invalidate_cache(tree);
 437 +       return 0;
 438 +}
 439 +
 440 +struct ext3_ext_path *
 441 +ext3_ext_find_extent(struct ext3_extents_tree *tree, int block,
 442 +                    struct ext3_ext_path *path)
 443 +{
 444 +       struct ext3_extent_header *eh;
 445 +       struct buffer_head *bh;
 446 +       int depth, i, ppos = 0;
 447 +
 448 +       EXT_ASSERT(tree);
 449 +       EXT_ASSERT(tree->inode);
 450 +       EXT_ASSERT(tree->root);
 451 +
 452 +       eh = EXT_ROOT_HDR(tree);
 453 +       EXT_ASSERT(eh);
 454 +       if (ext3_ext_check_header(eh))
 455 +               goto err;
 456 +
 457 +       i = depth = EXT_DEPTH(tree);
 458 +       EXT_ASSERT(eh->eh_max);
 459 +       EXT_ASSERT(eh->eh_magic == EXT3_EXT_MAGIC);
 460 +
 461 +       /* account possible depth increase */
 462 +       if (!path) {
 463 +               path = kmalloc(sizeof(struct ext3_ext_path) * (depth + 2),
 464 +                              GFP_NOFS);
 465 +               if (!path)
 466 +                       return ERR_PTR(-ENOMEM);
 467 +       }
 468 +       memset(path, 0, sizeof(struct ext3_ext_path) * (depth + 1));
 469 +       path[0].p_hdr = eh;
 470 +
 471 +       /* walk through the tree */
 472 +       while (i) {
 473 +               ext_debug(tree, "depth %d: num %d, max %d\n",
 474 +                         ppos, eh->eh_entries, eh->eh_max);
 475 +               ext3_ext_binsearch_idx(tree, path + ppos, block);
 476 +               path[ppos].p_block = path[ppos].p_idx->ei_leaf;
 477 +               path[ppos].p_depth = i;
 478 +               path[ppos].p_ext = NULL;
 479 +
 480 +               bh = sb_bread(tree->inode->i_sb, path[ppos].p_block);
 481 +               if (!bh)
 482 +                       goto err;
 483 +               eh = EXT_BLOCK_HDR(bh);
 484 +               ppos++;
 485 +               EXT_ASSERT(ppos <= depth);
 486 +               path[ppos].p_bh = bh;
 487 +               path[ppos].p_hdr = eh;
 488 +               i--;
 489 +
 490 +               if (ext3_ext_check_header(eh))
 491 +                       goto err;
 492 +       }
 493 +
 494 +       path[ppos].p_depth = i;
 495 +       path[ppos].p_hdr = eh;
 496 +       path[ppos].p_ext = NULL;
 497 +       path[ppos].p_idx = NULL;
 498 +
 499 +       if (ext3_ext_check_header(eh))
 500 +               goto err;
 501 +
 502 +       /* find extent */
 503 +       ext3_ext_binsearch(tree, path + ppos, block);
 504 +
 505 +       ext3_ext_show_path(tree, path);
 506 +
 507 +       return path;
 508 +
 509 +err:
 510 +       printk(KERN_ERR "EXT3-fs: header is corrupted!\n");
 511 +       ext3_ext_drop_refs(path);
 512 +       kfree(path);
 513 +       return ERR_PTR(-EIO);
 514 +}
 515 +
 516 +/*
 517 + * insert new index [logical;ptr] into the block at cupr
 518 + * it check where to insert: before curp or after curp
 519 + */
 520 +static int ext3_ext_insert_index(handle_t *handle,
 521 +                                struct ext3_extents_tree *tree,
 522 +                                struct ext3_ext_path *curp,
 523 +                                int logical, int ptr)
 524 +{
 525 +       struct ext3_extent_idx *ix;
 526 +       int len, err;
 527 +
 528 +       if ((err = ext3_ext_get_access(handle, tree, curp)))
 529 +               return err;
 530 +
 531 +       EXT_ASSERT(logical != curp->p_idx->ei_block);
 532 +       len = EXT_MAX_INDEX(curp->p_hdr) - curp->p_idx;
 533 +       if (logical > curp->p_idx->ei_block) {
 534 +               /* insert after */
 535 +               if (curp->p_idx != EXT_LAST_INDEX(curp->p_hdr)) {
 536 +                       len = (len - 1) * sizeof(struct ext3_extent_idx);
 537 +                       len = len < 0 ? 0 : len;
 538 +                       ext_debug(tree, "insert new index %d after: %d. "
 539 +                                 "move %d from 0x%p to 0x%p\n",
 540 +                                 logical, ptr, len,
 541 +                                 (curp->p_idx + 1), (curp->p_idx + 2));
 542 +                       memmove(curp->p_idx + 2, curp->p_idx + 1, len);
 543 +               }
 544 +               ix = curp->p_idx + 1;
 545 +       } else {
 546 +               /* insert before */
 547 +               len = len * sizeof(struct ext3_extent_idx);
 548 +               len = len < 0 ? 0 : len;
 549 +               ext_debug(tree, "insert new index %d before: %d. "
 550 +                         "move %d from 0x%p to 0x%p\n",
 551 +                         logical, ptr, len,
 552 +                         curp->p_idx, (curp->p_idx + 1));
 553 +               memmove(curp->p_idx + 1, curp->p_idx, len);
 554 +               ix = curp->p_idx;
 555 +       }
 556 +
 557 +       ix->ei_block = logical;
 558 +       ix->ei_leaf = ptr;
 559 +       curp->p_hdr->eh_entries++;
 560 +
 561 +       EXT_ASSERT(curp->p_hdr->eh_entries <= curp->p_hdr->eh_max);
 562 +       EXT_ASSERT(ix <= EXT_LAST_INDEX(curp->p_hdr));
 563 +
 564 +       err = ext3_ext_dirty(handle, tree, curp);
 565 +       ext3_std_error(tree->inode->i_sb, err);
 566 +
 567 +       return err;
 568 +}
 569 +
 570 +/*
 571 + * routine inserts new subtree into the path, using free index entry
 572 + * at depth 'at:
 573 + *  - allocates all needed blocks (new leaf and all intermediate index blocks)
 574 + *  - makes decision where to split
 575 + *  - moves remaining extens and index entries (right to the split point)
 576 + *    into the newly allocated blocks
 577 + *  - initialize subtree
 578 + */
 579 +static int ext3_ext_split(handle_t *handle, struct ext3_extents_tree *tree,
 580 +                         struct ext3_ext_path *path,
 581 +                         struct ext3_extent *newext, int at)
 582 +{
 583 +       struct buffer_head *bh = NULL;
 584 +       int depth = EXT_DEPTH(tree);
 585 +       struct ext3_extent_header *neh;
 586 +       struct ext3_extent_idx *fidx;
 587 +       struct ext3_extent *ex;
 588 +       int i = at, k, m, a;
 589 +       unsigned long newblock, oldblock, border;
 590 +       int *ablocks = NULL; /* array of allocated blocks */
 591 +       int err = 0;
 592 +
 593 +       /* make decision: where to split? */
 594 +       /* FIXME: now desicion is simplest: at current extent */
 595 +
 596 +       /* if current leaf will be splitted, then we should use
 597 +        * border from split point */
 598 +       EXT_ASSERT(path[depth].p_ext <= EXT_MAX_EXTENT(path[depth].p_hdr));
 599 +       if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
 600 +               border = path[depth].p_ext[1].ee_block;
 601 +               ext_debug(tree, "leaf will be splitted."
 602 +                         " next leaf starts at %d\n",
 603 +                         (int)border);
 604 +       } else {
 605 +               border = newext->ee_block;
 606 +               ext_debug(tree, "leaf will be added."
 607 +                         " next leaf starts at %d\n",
 608 +                         (int)border);
 609 +       }
 610 +
 611 +       /*
 612 +        * if error occurs, then we break processing
 613 +        * and turn filesystem read-only. so, index won't
 614 +        * be inserted and tree will be in consistent
 615 +        * state. next mount will repair buffers too
 616 +        */
 617 +
 618 +       /*
 619 +        * get array to track all allocated blocks
 620 +        * we need this to handle errors and free blocks
 621 +        * upon them
 622 +        */
 623 +       ablocks = kmalloc(sizeof(unsigned long) * depth, GFP_NOFS);
 624 +       if (!ablocks)
 625 +               return -ENOMEM;
 626 +       memset(ablocks, 0, sizeof(unsigned long) * depth);
 627 +
 628 +       /* allocate all needed blocks */
 629 +       ext_debug(tree, "allocate %d blocks for indexes/leaf\n", depth - at);
 630 +       for (a = 0; a < depth - at; a++) {
 631 +               newblock = ext3_ext_new_block(handle, tree, path, newext, &err);
 632 +               if (newblock == 0)
 633 +                       goto cleanup;
 634 +               ablocks[a] = newblock;
 635 +       }
 636 +
 637 +       /* initialize new leaf */
 638 +       newblock = ablocks[--a];
 639 +       EXT_ASSERT(newblock);
 640 +       bh = sb_getblk(tree->inode->i_sb, newblock);
 641 +       if (!bh) {
 642 +               err = -EIO;
 643 +               goto cleanup;
 644 +       }
 645 +       lock_buffer(bh);
 646 +
 647 +       if ((err = ext3_journal_get_create_access(handle, bh)))
 648 +               goto cleanup;
 649 +
 650 +       neh = EXT_BLOCK_HDR(bh);
 651 +       neh->eh_entries = 0;
 652 +       neh->eh_max = ext3_ext_space_block(tree);
 653 +       neh->eh_magic = EXT3_EXT_MAGIC;
 654 +       neh->eh_depth = 0;
 655 +       ex = EXT_FIRST_EXTENT(neh);
 656 +
 657 +       /* move remain of path[depth] to the new leaf */
 658 +       EXT_ASSERT(path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max);
 659 +       /* start copy from next extent */
 660 +       /* TODO: we could do it by single memmove */
 661 +       m = 0;
 662 +       path[depth].p_ext++;
 663 +       while (path[depth].p_ext <=
 664 +                       EXT_MAX_EXTENT(path[depth].p_hdr)) {
 665 +               ext_debug(tree, "move %d:%d:%d in new leaf %lu\n",
 666 +                         path[depth].p_ext->ee_block,
 667 +                         path[depth].p_ext->ee_start,
 668 +                         path[depth].p_ext->ee_len,
 669 +                         newblock);
 670 +               memmove(ex++, path[depth].p_ext++, sizeof(struct ext3_extent));
 671 +               neh->eh_entries++;
 672 +               m++;
 673 +       }
 674 +       mark_buffer_uptodate(bh, 1);
 675 +       unlock_buffer(bh);
 676 +
 677 +       if ((err = ext3_journal_dirty_metadata(handle, bh)))
 678 +               goto cleanup;
 679 +       brelse(bh);
 680 +       bh = NULL;
 681 +
 682 +       /* correct old leaf */
 683 +       if (m) {
 684 +               if ((err = ext3_ext_get_access(handle, tree, path + depth)))
 685 +                       goto cleanup;
 686 +               path[depth].p_hdr->eh_entries -= m;
 687 +               if ((err = ext3_ext_dirty(handle, tree, path + depth)))
 688 +                       goto cleanup;
 689 +
 690 +       }
 691 +
 692 +       /* create intermediate indexes */
 693 +       k = depth - at - 1;
 694 +       EXT_ASSERT(k >= 0);
 695 +       if (k)
 696 +               ext_debug(tree, "create %d intermediate indices\n", k);
 697 +       /* insert new index into current index block */
 698 +       /* current depth stored in i var */
 699 +       i = depth - 1;
 700 +       while (k--) {
 701 +               oldblock = newblock;
 702 +               newblock = ablocks[--a];
 703 +               bh = sb_getblk(tree->inode->i_sb, newblock);
 704 +               if (!bh) {
 705 +                       err = -EIO;
 706 +                       goto cleanup;
 707 +               }
 708 +               lock_buffer(bh);
 709 +
 710 +               if ((err = ext3_journal_get_create_access(handle, bh)))
 711 +                       goto cleanup;
 712 +
 713 +               neh = EXT_BLOCK_HDR(bh);
 714 +               neh->eh_entries = 1;
 715 +               neh->eh_magic = EXT3_EXT_MAGIC;
 716 +               neh->eh_max = ext3_ext_space_block_idx(tree);
 717 +               neh->eh_depth = depth - i;
 718 +               fidx = EXT_FIRST_INDEX(neh);
 719 +               fidx->ei_block = border;
 720 +               fidx->ei_leaf = oldblock;
 721 +
 722 +               ext_debug(tree, "int.index at %d (block %lu): %lu -> %lu\n",
 723 +                         i, newblock, border, oldblock);
 724 +               /* copy indexes */
 725 +               m = 0;
 726 +               path[i].p_idx++;
 727 +
 728 +               ext_debug(tree, "cur 0x%p, last 0x%p\n", path[i].p_idx,
 729 +                         EXT_MAX_INDEX(path[i].p_hdr));
 730 +               EXT_ASSERT(EXT_MAX_INDEX(path[i].p_hdr) ==
 731 +                          EXT_LAST_INDEX(path[i].p_hdr));
 732 +               while (path[i].p_idx <= EXT_MAX_INDEX(path[i].p_hdr)) {
 733 +                       ext_debug(tree, "%d: move %d:%d in new index %lu\n",
 734 +                                 i, path[i].p_idx->ei_block,
 735 +                                 path[i].p_idx->ei_leaf, newblock);
 736 +                       memmove(++fidx, path[i].p_idx++,
 737 +                               sizeof(struct ext3_extent_idx));
 738 +                       neh->eh_entries++;
 739 +                       EXT_ASSERT(neh->eh_entries <= neh->eh_max);
 740 +                       m++;
 741 +               }
 742 +               mark_buffer_uptodate(bh, 1);
 743 +               unlock_buffer(bh);
 744 +
 745 +               if ((err = ext3_journal_dirty_metadata(handle, bh)))
 746 +                       goto cleanup;
 747 +               brelse(bh);
 748 +               bh = NULL;
 749 +
 750 +               /* correct old index */
 751 +               if (m) {
 752 +                       err = ext3_ext_get_access(handle, tree, path + i);
 753 +                       if (err)
 754 +                               goto cleanup;
 755 +                       path[i].p_hdr->eh_entries -= m;
 756 +                       err = ext3_ext_dirty(handle, tree, path + i);
 757 +                       if (err)
 758 +                               goto cleanup;
 759 +               }
 760 +
 761 +               i--;
 762 +       }
 763 +
 764 +       /* insert new index */
 765 +       if (!err)
 766 +               err = ext3_ext_insert_index(handle, tree, path + at,
 767 +                                           border, newblock);
 768 +
 769 +cleanup:
 770 +       if (bh) {
 771 +               if (buffer_locked(bh))
 772 +                       unlock_buffer(bh);
 773 +               brelse(bh);
 774 +       }
 775 +
 776 +       if (err) {
 777 +               /* free all allocated blocks in error case */
 778 +               for (i = 0; i < depth; i++) {
 779 +                       if (!ablocks[i])
 780 +                               continue;
 781 +                       ext3_free_blocks(handle, tree->inode, ablocks[i], 1);
 782 +               }
 783 +       }
 784 +       kfree(ablocks);
 785 +
 786 +       return err;
 787 +}
 788 +
 789 +/*
 790 + * routine implements tree growing procedure:
 791 + *  - allocates new block
 792 + *  - moves top-level data (index block or leaf) into the new block
 793 + *  - initialize new top-level, creating index that points to the
 794 + *    just created block
 795 + */
 796 +static int ext3_ext_grow_indepth(handle_t *handle,
 797 +                                struct ext3_extents_tree *tree,
 798 +                                struct ext3_ext_path *path,
 799 +                                struct ext3_extent *newext)
 800 +{
 801 +       struct ext3_ext_path *curp = path;
 802 +       struct ext3_extent_header *neh;
 803 +       struct ext3_extent_idx *fidx;
 804 +       struct buffer_head *bh;
 805 +       unsigned long newblock;
 806 +       int err = 0;
 807 +
 808 +       newblock = ext3_ext_new_block(handle, tree, path, newext, &err);
 809 +       if (newblock == 0)
 810 +               return err;
 811 +
 812 +       bh = sb_getblk(tree->inode->i_sb, newblock);
 813 +       if (!bh) {
 814 +               err = -EIO;
 815 +               ext3_std_error(tree->inode->i_sb, err);
 816 +               return err;
 817 +       }
 818 +       lock_buffer(bh);
 819 +
 820 +       if ((err = ext3_journal_get_create_access(handle, bh))) {
 821 +               unlock_buffer(bh);
 822 +               goto out;
 823 +       }
 824 +
 825 +       /* move top-level index/leaf into new block */
 826 +       memmove(bh->b_data, curp->p_hdr, tree->buffer_len);
 827 +
 828 +       /* set size of new block */
 829 +       neh = EXT_BLOCK_HDR(bh);
 830 +       /* old root could have indexes or leaves
 831 +        * so calculate eh_max right way */
 832 +       if (EXT_DEPTH(tree))
 833 +               neh->eh_max = ext3_ext_space_block_idx(tree);
 834 +       else
 835 +               neh->eh_max = ext3_ext_space_block(tree);
 836 +       neh->eh_magic = EXT3_EXT_MAGIC;
 837 +       mark_buffer_uptodate(bh, 1);
 838 +       unlock_buffer(bh);
 839 +
 840 +       if ((err = ext3_journal_dirty_metadata(handle, bh)))
 841 +               goto out;
 842 +
 843 +       /* create index in new top-level index: num,max,pointer */
 844 +       if ((err = ext3_ext_get_access(handle, tree, curp)))
 845 +               goto out;
 846 +
 847 +       curp->p_hdr->eh_magic = EXT3_EXT_MAGIC;
 848 +       curp->p_hdr->eh_max = ext3_ext_space_root_idx(tree);
 849 +       curp->p_hdr->eh_entries = 1;
 850 +       curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr);
 851 +       /* FIXME: it works, but actually path[0] can be index */
 852 +       curp->p_idx->ei_block = EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block;
 853 +       curp->p_idx->ei_leaf = newblock;
 854 +
 855 +       neh = EXT_ROOT_HDR(tree);
 856 +       fidx = EXT_FIRST_INDEX(neh);
 857 +       ext_debug(tree, "new root: num %d(%d), lblock %d, ptr %d\n",
 858 +                 neh->eh_entries, neh->eh_max, fidx->ei_block, fidx->ei_leaf);
 859 +
 860 +       neh->eh_depth = path->p_depth + 1;
 861 +       err = ext3_ext_dirty(handle, tree, curp);
 862 +out:
 863 +       brelse(bh);
 864 +
 865 +       return err;
 866 +}
 867 +
 868 +/*
 869 + * routine finds empty index and adds new leaf. if no free index found
 870 + * then it requests in-depth growing
 871 + */
 872 +static int ext3_ext_create_new_leaf(handle_t *handle,
 873 +                                   struct ext3_extents_tree *tree,
 874 +                                   struct ext3_ext_path *path,
 875 +                                   struct ext3_extent *newext)
 876 +{
 877 +       struct ext3_ext_path *curp;
 878 +       int depth, i, err = 0;
 879 +
 880 +repeat:
 881 +       i = depth = EXT_DEPTH(tree);
 882 +
 883 +       /* walk up to the tree and look for free index entry */
 884 +       curp = path + depth;
 885 +       while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
 886 +               i--;
 887 +               curp--;
 888 +       }
 889 +
 890 +       /* we use already allocated block for index block
 891 +        * so, subsequent data blocks should be contigoues */
 892 +       if (EXT_HAS_FREE_INDEX(curp)) {
 893 +               /* if we found index with free entry, then use that
 894 +                * entry: create all needed subtree and add new leaf */
 895 +               err = ext3_ext_split(handle, tree, path, newext, i);
 896 +
 897 +               /* refill path */
 898 +               ext3_ext_drop_refs(path);
 899 +               path = ext3_ext_find_extent(tree, newext->ee_block, path);
 900 +               if (IS_ERR(path))
 901 +                       err = PTR_ERR(path);
 902 +       } else {
 903 +               /* tree is full, time to grow in depth */
 904 +               err = ext3_ext_grow_indepth(handle, tree, path, newext);
 905 +
 906 +               /* refill path */
 907 +               ext3_ext_drop_refs(path);
 908 +               path = ext3_ext_find_extent(tree, newext->ee_block, path);
 909 +               if (IS_ERR(path))
 910 +                       err = PTR_ERR(path);
 911 +
 912 +               /*
 913 +                * only first (depth 0 -> 1) produces free space
 914 +                * in all other cases we have to split growed tree
 915 +                */
 916 +               depth = EXT_DEPTH(tree);
 917 +               if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
 918 +                       /* now we need split */
 919 +                       goto repeat;
 920 +               }
 921 +       }
 922 +
 923 +       if (err)
 924 +               return err;
 925 +
 926 +       return 0;
 927 +}
 928 +
 929 +/*
 930 + * returns allocated block in subsequent extent or EXT_MAX_BLOCK
 931 + * NOTE: it consider block number from index entry as
 932 + * allocated block. thus, index entries have to be consistent
 933 + * with leafs
 934 + */
 935 +static unsigned long
 936 +ext3_ext_next_allocated_block(struct ext3_ext_path *path)
 937 +{
 938 +       int depth;
 939 +
 940 +       EXT_ASSERT(path != NULL);
 941 +       depth = path->p_depth;
 942 +
 943 +       if (depth == 0 && path->p_ext == NULL)
 944 +               return EXT_MAX_BLOCK;
 945 +
 946 +       /* FIXME: what if index isn't full ?! */
 947 +       while (depth >= 0) {
 948 +               if (depth == path->p_depth) {
 949 +                       /* leaf */
 950 +                       if (path[depth].p_ext !=
 951 +                           EXT_LAST_EXTENT(path[depth].p_hdr))
 952 +                               return path[depth].p_ext[1].ee_block;
 953 +               } else {
 954 +                       /* index */
 955 +                       if (path[depth].p_idx !=
 956 +                           EXT_LAST_INDEX(path[depth].p_hdr))
 957 +                               return path[depth].p_idx[1].ei_block;
 958 +               }
 959 +               depth--;
 960 +       }
 961 +
 962 +       return EXT_MAX_BLOCK;
 963 +}
 964 +
 965 +/*
 966 + * returns first allocated block from next leaf or EXT_MAX_BLOCK
 967 + */
 968 +static unsigned ext3_ext_next_leaf_block(struct ext3_extents_tree *tree,
 969 +                                        struct ext3_ext_path *path)
 970 +{
 971 +       int depth;
 972 +
 973 +       EXT_ASSERT(path != NULL);
 974 +       depth = path->p_depth;
 975 +
 976 +       /* zero-tree has no leaf blocks at all */
 977 +       if (depth == 0)
 978 +               return EXT_MAX_BLOCK;
 979 +
 980 +       /* go to index block */
 981 +       depth--;
 982 +
 983 +       while (depth >= 0) {
 984 +               if (path[depth].p_idx !=
 985 +                   EXT_LAST_INDEX(path[depth].p_hdr))
 986 +                       return path[depth].p_idx[1].ei_block;
 987 +               depth--;
 988 +       }
 989 +
 990 +       return EXT_MAX_BLOCK;
 991 +}
 992 +
 993 +/*
 994 + * if leaf gets modified and modified extent is first in the leaf
 995 + * then we have to correct all indexes above
 996 + * TODO: do we need to correct tree in all cases?
 997 + */
 998 +int ext3_ext_correct_indexes(handle_t *handle, struct ext3_extents_tree *tree,
 999 +                            struct ext3_ext_path *path)
1000 +{
1001 +       struct ext3_extent_header *eh;
1002 +       int depth = EXT_DEPTH(tree);
1003 +       struct ext3_extent *ex;
1004 +       unsigned long border;
1005 +       int k, err = 0;
1006 +
1007 +       eh = path[depth].p_hdr;
1008 +       ex = path[depth].p_ext;
1009 +       EXT_ASSERT(ex);
1010 +       EXT_ASSERT(eh);
1011 +
1012 +       if (depth == 0) {
1013 +               /* there is no tree at all */
1014 +               return 0;
1015 +       }
1016 +
1017 +       if (ex != EXT_FIRST_EXTENT(eh)) {
1018 +               /* we correct tree if first leaf got modified only */
1019 +               return 0;
1020 +       }
1021 +
1022 +       /*
1023 +        * TODO: we need correction if border is smaller then current one
1024 +        */
1025 +       k = depth - 1;
1026 +       border = path[depth].p_ext->ee_block;
1027 +       if ((err = ext3_ext_get_access(handle, tree, path + k)))
1028 +               return err;
1029 +       path[k].p_idx->ei_block = border;
1030 +       if ((err = ext3_ext_dirty(handle, tree, path + k)))
1031 +               return err;
1032 +
1033 +       while (k--) {
1034 +               /* change all left-side indexes */
1035 +               if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1036 +                       break;
1037 +               if ((err = ext3_ext_get_access(handle, tree, path + k)))
1038 +                       break;
1039 +               path[k].p_idx->ei_block = border;
1040 +               if ((err = ext3_ext_dirty(handle, tree, path + k)))
1041 +                       break;
1042 +       }
1043 +
1044 +       return err;
1045 +}
1046 +
1047 +static int inline
1048 +ext3_can_extents_be_merged(struct ext3_extents_tree *tree,
1049 +                          struct ext3_extent *ex1,
1050 +                          struct ext3_extent *ex2)
1051 +{
1052 +       if (ex1->ee_block + ex1->ee_len != ex2->ee_block)
1053 +               return 0;
1054 +
1055 +#ifdef AGRESSIVE_TEST
1056 +       if (ex1->ee_len >= 4)
1057 +               return 0;
1058 +#endif
1059 +
1060 +       if (!tree->ops->mergable)
1061 +               return 1;
1062 +
1063 +       return tree->ops->mergable(ex1, ex2);
1064 +}
1065 +
1066 +/*
1067 + * this routine tries to merge requsted extent into the existing
1068 + * extent or inserts requested extent as new one into the tree,
1069 + * creating new leaf in no-space case
1070 + */
1071 +int ext3_ext_insert_extent(handle_t *handle, struct ext3_extents_tree *tree,
1072 +                          struct ext3_ext_path *path,
1073 +                          struct ext3_extent *newext)
1074 +{
1075 +       struct ext3_extent_header * eh;
1076 +       struct ext3_extent *ex, *fex;
1077 +       struct ext3_extent *nearex; /* nearest extent */
1078 +       struct ext3_ext_path *npath = NULL;
1079 +       int depth, len, err, next;
1080 +
1081 +       EXT_ASSERT(newext->ee_len > 0);
1082 +       depth = EXT_DEPTH(tree);
1083 +       ex = path[depth].p_ext;
1084 +       EXT_ASSERT(path[depth].p_hdr);
1085 +
1086 +       /* try to insert block into found extent and return */
1087 +       if (ex && ext3_can_extents_be_merged(tree, ex, newext)) {
1088 +               ext_debug(tree, "append %d block to %d:%d (from %d)\n",
1089 +                         newext->ee_len, ex->ee_block, ex->ee_len,
1090 +                         ex->ee_start);
1091 +               if ((err = ext3_ext_get_access(handle, tree, path + depth)))
1092 +                       return err;
1093 +               ex->ee_len += newext->ee_len;
1094 +               eh = path[depth].p_hdr;
1095 +               nearex = ex;
1096 +               goto merge;
1097 +       }
1098 +
1099 +repeat:
1100 +       depth = EXT_DEPTH(tree);
1101 +       eh = path[depth].p_hdr;
1102 +       if (eh->eh_entries < eh->eh_max)
1103 +               goto has_space;
1104 +
1105 +       /* probably next leaf has space for us? */
1106 +       fex = EXT_LAST_EXTENT(eh);
1107 +       next = ext3_ext_next_leaf_block(tree, path);
1108 +       if (newext->ee_block > fex->ee_block && next != EXT_MAX_BLOCK) {
1109 +               ext_debug(tree, "next leaf block - %d\n", next);
1110 +               EXT_ASSERT(!npath);
1111 +               npath = ext3_ext_find_extent(tree, next, NULL);
1112 +               if (IS_ERR(npath))
1113 +                       return PTR_ERR(npath);
1114 +               EXT_ASSERT(npath->p_depth == path->p_depth);
1115 +               eh = npath[depth].p_hdr;
1116 +               if (eh->eh_entries < eh->eh_max) {
1117 +                       ext_debug(tree, "next leaf isnt full(%d)\n",
1118 +                                 eh->eh_entries);
1119 +                       path = npath;
1120 +                       goto repeat;
1121 +               }
1122 +               ext_debug(tree, "next leaf hasno free space(%d,%d)\n",
1123 +                         eh->eh_entries, eh->eh_max);
1124 +       }
1125 +
1126 +       /*
1127 +        * there is no free space in found leaf
1128 +        * we're gonna add new leaf in the tree
1129 +        */
1130 +       err = ext3_ext_create_new_leaf(handle, tree, path, newext);
1131 +       if (err)
1132 +               goto cleanup;
1133 +       depth = EXT_DEPTH(tree);
1134 +       eh = path[depth].p_hdr;
1135 +
1136 +has_space:
1137 +       nearex = path[depth].p_ext;
1138 +
1139 +       if ((err = ext3_ext_get_access(handle, tree, path + depth)))
1140 +               goto cleanup;
1141 +
1142 +       if (!nearex) {
1143 +               /* there is no extent in this leaf, create first one */
1144 +               ext_debug(tree, "first extent in the leaf: %d:%d:%d\n",
1145 +                         newext->ee_block, newext->ee_start,
1146 +                         newext->ee_len);
1147 +               path[depth].p_ext = EXT_FIRST_EXTENT(eh);
1148 +       } else if (newext->ee_block > nearex->ee_block) {
1149 +               EXT_ASSERT(newext->ee_block != nearex->ee_block);
1150 +               if (nearex != EXT_LAST_EXTENT(eh)) {
1151 +                       len = EXT_MAX_EXTENT(eh) - nearex;
1152 +                       len = (len - 1) * sizeof(struct ext3_extent);
1153 +                       len = len < 0 ? 0 : len;
1154 +                       ext_debug(tree, "insert %d:%d:%d after: nearest 0x%p, "
1155 +                                 "move %d from 0x%p to 0x%p\n",
1156 +                                 newext->ee_block, newext->ee_start,
1157 +                                 newext->ee_len,
1158 +                                 nearex, len, nearex + 1, nearex + 2);
1159 +                       memmove(nearex + 2, nearex + 1, len);
1160 +               }
1161 +               path[depth].p_ext = nearex + 1;
1162 +       } else {
1163 +               EXT_ASSERT(newext->ee_block != nearex->ee_block);
1164 +               len = (EXT_MAX_EXTENT(eh) - nearex) * sizeof(struct ext3_extent);
1165 +               len = len < 0 ? 0 : len;
1166 +               ext_debug(tree, "insert %d:%d:%d before: nearest 0x%p, "
1167 +                         "move %d from 0x%p to 0x%p\n",
1168 +                         newext->ee_block, newext->ee_start, newext->ee_len,
1169 +                         nearex, len, nearex + 1, nearex + 2);
1170 +               memmove(nearex + 1, nearex, len);
1171 +               path[depth].p_ext = nearex;
1172 +       }
1173 +
1174 +       eh->eh_entries++;
1175 +       nearex = path[depth].p_ext;
1176 +       nearex->ee_block = newext->ee_block;
1177 +       nearex->ee_start = newext->ee_start;
1178 +       nearex->ee_len = newext->ee_len;
1179 +       /* FIXME: support for large fs */
1180 +       nearex->ee_start_hi = 0;
1181 +
1182 +merge:
1183 +       /* try to merge extents to the right */
1184 +       while (nearex < EXT_LAST_EXTENT(eh)) {
1185 +               if (!ext3_can_extents_be_merged(tree, nearex, nearex + 1))
1186 +                       break;
1187 +               /* merge with next extent! */
1188 +               nearex->ee_len += nearex[1].ee_len;
1189 +               if (nearex + 1 < EXT_LAST_EXTENT(eh)) {
1190 +                       len = (EXT_LAST_EXTENT(eh) - nearex - 1) *
1191 +                               sizeof(struct ext3_extent);
1192 +                       memmove(nearex + 1, nearex + 2, len);
1193 +               }
1194 +               eh->eh_entries--;
1195 +               EXT_ASSERT(eh->eh_entries > 0);
1196 +       }
1197 +
1198 +       /* try to merge extents to the left */
1199 +
1200 +       /* time to correct all indexes above */
1201 +       err = ext3_ext_correct_indexes(handle, tree, path);
1202 +       if (err)
1203 +               goto cleanup;
1204 +
1205 +       err = ext3_ext_dirty(handle, tree, path + depth);
1206 +
1207 +cleanup:
1208 +       if (npath) {
1209 +               ext3_ext_drop_refs(npath);
1210 +               kfree(npath);
1211 +       }
1212 +       ext3_ext_tree_changed(tree);
1213 +       ext3_ext_invalidate_cache(tree);
1214 +       return err;
1215 +}
1216 +
1217 +int ext3_ext_walk_space(struct ext3_extents_tree *tree, unsigned long block,
1218 +                       unsigned long num, ext_prepare_callback func)
1219 +{
1220 +       struct ext3_ext_path *path = NULL;
1221 +       struct ext3_ext_cache cbex;
1222 +       struct ext3_extent *ex;
1223 +       unsigned long next, start = 0, end = 0;
1224 +       unsigned long last = block + num;
1225 +       int depth, exists, err = 0;
1226 +
1227 +       EXT_ASSERT(tree);
1228 +       EXT_ASSERT(func);
1229 +       EXT_ASSERT(tree->inode);
1230 +       EXT_ASSERT(tree->root);
1231 +
1232 +       while (block < last && block != EXT_MAX_BLOCK) {
1233 +               num = last - block;
1234 +               /* find extent for this block */
1235 +               path = ext3_ext_find_extent(tree, block, path);
1236 +               if (IS_ERR(path)) {
1237 +                       err = PTR_ERR(path);
1238 +                       path = NULL;
1239 +                       break;
1240 +               }
1241 +
1242 +               depth = EXT_DEPTH(tree);
1243 +               EXT_ASSERT(path[depth].p_hdr);
1244 +               ex = path[depth].p_ext;
1245 +               next = ext3_ext_next_allocated_block(path);
1246 +
1247 +               exists = 0;
1248 +               if (!ex) {
1249 +                       /* there is no extent yet, so try to allocate
1250 +                        * all requested space */
1251 +                       start = block;
1252 +                       end = block + num;
1253 +               } else if (ex->ee_block > block) {
1254 +                       /* need to allocate space before found extent */
1255 +                       start = block;
1256 +                       end = ex->ee_block;
1257 +                       if (block + num < end)
1258 +                               end = block + num;
1259 +               } else if (block >= ex->ee_block + ex->ee_len) {
1260 +                       /* need to allocate space after found extent */
1261 +                       start = block;
1262 +                       end = block + num;
1263 +                       if (end >= next)
1264 +                               end = next;
1265 +               } else if (block >= ex->ee_block) {
1266 +                       /*
1267 +                        * some part of requested space is covered
1268 +                        * by found extent
1269 +                        */
1270 +                       start = block;
1271 +                       end = ex->ee_block + ex->ee_len;
1272 +                       if (block + num < end)
1273 +                               end = block + num;
1274 +                       exists = 1;
1275 +               } else {
1276 +                       BUG();
1277 +               }
1278 +               EXT_ASSERT(end > start);
1279 +
1280 +               if (!exists) {
1281 +                       cbex.ec_block = start;
1282 +                       cbex.ec_len = end - start;
1283 +                       cbex.ec_start = 0;
1284 +                       cbex.ec_type = EXT3_EXT_CACHE_GAP;
1285 +               } else {
1286 +                       cbex.ec_block = ex->ee_block;
1287 +                       cbex.ec_len = ex->ee_len;
1288 +                       cbex.ec_start = ex->ee_start;
1289 +                       cbex.ec_type = EXT3_EXT_CACHE_EXTENT;
1290 +               }
1291 +
1292 +               EXT_ASSERT(cbex.ec_len > 0);
1293 +               EXT_ASSERT(path[depth].p_hdr);
1294 +               err = func(tree, path, &cbex);
1295 +               ext3_ext_drop_refs(path);
1296 +
1297 +               if (err < 0)
1298 +                       break;
1299 +               if (err == EXT_REPEAT)
1300 +                       continue;
1301 +               else if (err == EXT_BREAK) {
1302 +                       err = 0;
1303 +                       break;
1304 +               }
1305 +
1306 +               if (EXT_DEPTH(tree) != depth) {
1307 +                       /* depth was changed. we have to realloc path */
1308 +                       kfree(path);
1309 +                       path = NULL;
1310 +               }
1311 +
1312 +               block = cbex.ec_block + cbex.ec_len;
1313 +       }
1314 +
1315 +       if (path) {
1316 +               ext3_ext_drop_refs(path);
1317 +               kfree(path);
1318 +       }
1319 +
1320 +       return err;
1321 +}
1322 +
1323 +static inline void
1324 +ext3_ext_put_in_cache(struct ext3_extents_tree *tree, __u32 block,
1325 +                     __u32 len, __u32 start, int type)
1326 +{
1327 +       EXT_ASSERT(len > 0);
1328 +       if (tree->cex) {
1329 +               tree->cex->ec_type = type;
1330 +               tree->cex->ec_block = block;
1331 +               tree->cex->ec_len = len;
1332 +               tree->cex->ec_start = start;
1333 +       }
1334 +}
1335 +
1336 +/*
1337 + * this routine calculate boundaries of the gap requested block fits into
1338 + * and cache this gap
1339 + */
1340 +static inline void
1341 +ext3_ext_put_gap_in_cache(struct ext3_extents_tree *tree,
1342 +                         struct ext3_ext_path *path,
1343 +                         unsigned long block)
1344 +{
1345 +       int depth = EXT_DEPTH(tree);
1346 +       unsigned long lblock, len;
1347 +       struct ext3_extent *ex;
1348 +
1349 +       if (!tree->cex)
1350 +               return;
1351 +
1352 +       ex = path[depth].p_ext;
1353 +       if (ex == NULL) {
1354 +               /* there is no extent yet, so gap is [0;-] */
1355 +               lblock = 0;
1356 +               len = EXT_MAX_BLOCK;
1357 +               ext_debug(tree, "cache gap(whole file):");
1358 +       } else if (block < ex->ee_block) {
1359 +               lblock = block;
1360 +               len = ex->ee_block - block;
1361 +               ext_debug(tree, "cache gap(before): %lu [%lu:%lu]",
1362 +                         (unsigned long) block,
1363 +                         (unsigned long) ex->ee_block,
1364 +                         (unsigned long) ex->ee_len);
1365 +       } else if (block >= ex->ee_block + ex->ee_len) {
1366 +               lblock = ex->ee_block + ex->ee_len;
1367 +               len = ext3_ext_next_allocated_block(path);
1368 +               ext_debug(tree, "cache gap(after): [%lu:%lu] %lu",
1369 +                         (unsigned long) ex->ee_block,
1370 +                         (unsigned long) ex->ee_len,
1371 +                         (unsigned long) block);
1372 +               EXT_ASSERT(len > lblock);
1373 +               len = len - lblock;
1374 +       } else {
1375 +               lblock = len = 0;
1376 +               BUG();
1377 +       }
1378 +
1379 +       ext_debug(tree, " -> %lu:%lu\n", (unsigned long) lblock, len);
1380 +       ext3_ext_put_in_cache(tree, lblock, len, 0, EXT3_EXT_CACHE_GAP);
1381 +}
1382 +
1383 +static inline int
1384 +ext3_ext_in_cache(struct ext3_extents_tree *tree, unsigned long block,
1385 +                 struct ext3_extent *ex)
1386 +{
1387 +       struct ext3_ext_cache *cex = tree->cex;
1388 +
1389 +       /* is there cache storage at all? */
1390 +       if (!cex)
1391 +               return EXT3_EXT_CACHE_NO;
1392 +
1393 +       /* has cache valid data? */
1394 +       if (cex->ec_type == EXT3_EXT_CACHE_NO)
1395 +               return EXT3_EXT_CACHE_NO;
1396 +
1397 +       EXT_ASSERT(cex->ec_type == EXT3_EXT_CACHE_GAP ||
1398 +                  cex->ec_type == EXT3_EXT_CACHE_EXTENT);
1399 +       if (block >= cex->ec_block && block < cex->ec_block + cex->ec_len) {
1400 +               ex->ee_block = cex->ec_block;
1401 +               ex->ee_start = cex->ec_start;
1402 +               ex->ee_len = cex->ec_len;
1403 +               ext_debug(tree, "%lu cached by %lu:%lu:%lu\n",
1404 +                         (unsigned long) block,
1405 +                         (unsigned long) ex->ee_block,
1406 +                         (unsigned long) ex->ee_len,
1407 +                         (unsigned long) ex->ee_start);
1408 +               return cex->ec_type;
1409 +       }
1410 +
1411 +       /* not in cache */
1412 +       return EXT3_EXT_CACHE_NO;
1413 +}
1414 +
1415 +/*
1416 + * routine removes index from the index block
1417 + * it's used in truncate case only. thus all requests are for
1418 + * last index in the block only
1419 + */
1420 +int ext3_ext_rm_idx(handle_t *handle, struct ext3_extents_tree *tree,
1421 +                   struct ext3_ext_path *path)
1422 +{
1423 +       struct buffer_head *bh;
1424 +       int err;
1425 +
1426 +       /* free index block */
1427 +       path--;
1428 +       EXT_ASSERT(path->p_hdr->eh_entries);
1429 +       if ((err = ext3_ext_get_access(handle, tree, path)))
1430 +               return err;
1431 +       path->p_hdr->eh_entries--;
1432 +       if ((err = ext3_ext_dirty(handle, tree, path)))
1433 +               return err;
1434 +       ext_debug(tree, "index is empty, remove it, free block %d\n",
1435 +                 path->p_idx->ei_leaf);
1436 +       bh = sb_get_hash_table(tree->inode->i_sb, path->p_idx->ei_leaf);
1437 +       ext3_forget(handle, 1, tree->inode, bh, path->p_idx->ei_leaf);
1438 +       ext3_free_blocks(handle, tree->inode, path->p_idx->ei_leaf, 1);
1439 +       return err;
1440 +}
1441 +
1442 +int ext3_ext_calc_credits_for_insert(struct ext3_extents_tree *tree,
1443 +                                    struct ext3_ext_path *path)
1444 +{
1445 +       int depth = EXT_DEPTH(tree);
1446 +       int needed;
1447 +
1448 +       if (path) {
1449 +               /* probably there is space in leaf? */
1450 +               if (path[depth].p_hdr->eh_entries < path[depth].p_hdr->eh_max)
1451 +                       return 1;
1452 +       }
1453 +
1454 +       /*
1455 +        * the worste case we're expecting is creation of the
1456 +        * new root (growing in depth) with index splitting
1457 +        * for splitting we have to consider depth + 1 because
1458 +        * previous growing could increase it
1459 +        */
1460 +       depth = depth + 1;
1461 +
1462 +       /*
1463 +        * growing in depth:
1464 +        * block allocation + new root + old root
1465 +        */
1466 +       needed = EXT3_ALLOC_NEEDED + 2;
1467 +
1468 +       /* index split. we may need:
1469 +        *   allocate intermediate indexes and new leaf
1470 +        *   change two blocks at each level, but root
1471 +        *   modify root block (inode)
1472 +        */
1473 +       needed += (depth * EXT3_ALLOC_NEEDED) + (2 * depth) + 1;
1474 +
1475 +       return needed;
1476 +}
1477 +
1478 +static int
1479 +ext3_ext_split_for_rm(handle_t *handle, struct ext3_extents_tree *tree,
1480 +                     struct ext3_ext_path *path, unsigned long start,
1481 +                     unsigned long end)
1482 +{
1483 +       struct ext3_extent *ex, tex;
1484 +       struct ext3_ext_path *npath;
1485 +       int depth, creds, err;
1486 +
1487 +       depth = EXT_DEPTH(tree);
1488 +       ex = path[depth].p_ext;
1489 +       EXT_ASSERT(ex);
1490 +       EXT_ASSERT(end < ex->ee_block + ex->ee_len - 1);
1491 +       EXT_ASSERT(ex->ee_block < start);
1492 +
1493 +       /* calculate tail extent */
1494 +       tex.ee_block = end + 1;
1495 +       EXT_ASSERT(tex.ee_block < ex->ee_block + ex->ee_len);
1496 +       tex.ee_len = ex->ee_block + ex->ee_len - tex.ee_block;
1497 +
1498 +       creds = ext3_ext_calc_credits_for_insert(tree, path);
1499 +       handle = ext3_ext_journal_restart(handle, creds);
1500 +       if (IS_ERR(handle))
1501 +               return PTR_ERR(handle);
1502 +
1503 +       /* calculate head extent. use primary extent */
1504 +       err = ext3_ext_get_access(handle, tree, path + depth);
1505 +       if (err)
1506 +               return err;
1507 +       ex->ee_len = start - ex->ee_block;
1508 +       err = ext3_ext_dirty(handle, tree, path + depth);
1509 +       if (err)
1510 +               return err;
1511 +
1512 +       /* FIXME: some callback to free underlying resource
1513 +        * and correct ee_start? */
1514 +       ext_debug(tree, "split extent: head %u:%u, tail %u:%u\n",
1515 +                 ex->ee_block, ex->ee_len, tex.ee_block, tex.ee_len);
1516 +
1517 +       npath = ext3_ext_find_extent(tree, ex->ee_block, NULL);
1518 +       if (IS_ERR(npath))
1519 +               return PTR_ERR(npath);
1520 +       depth = EXT_DEPTH(tree);
1521 +       EXT_ASSERT(npath[depth].p_ext->ee_block == ex->ee_block);
1522 +       EXT_ASSERT(npath[depth].p_ext->ee_len == ex->ee_len);
1523 +
1524 +       err = ext3_ext_insert_extent(handle, tree, npath, &tex);
1525 +       ext3_ext_drop_refs(npath);
1526 +       kfree(npath);
1527 +
1528 +       return err;
1529 +}
1530 +
1531 +static int
1532 +ext3_ext_rm_leaf(handle_t *handle, struct ext3_extents_tree *tree,
1533 +                struct ext3_ext_path *path, unsigned long start,
1534 +                unsigned long end)
1535 +{
1536 +       struct ext3_extent *ex, *fu = NULL, *lu, *le;
1537 +       int err = 0, correct_index = 0;
1538 +       int depth = EXT_DEPTH(tree), credits;
1539 +       struct ext3_extent_header *eh;
1540 +       unsigned a, b, block, num;
1541 +
1542 +       ext_debug(tree, "remove [%lu:%lu] in leaf\n", start, end);
1543 +       if (!path[depth].p_hdr)
1544 +               path[depth].p_hdr = EXT_BLOCK_HDR(path[depth].p_bh);
1545 +       eh = path[depth].p_hdr;
1546 +       EXT_ASSERT(eh);
1547 +       EXT_ASSERT(eh->eh_entries <= eh->eh_max);
1548 +       EXT_ASSERT(eh->eh_magic == EXT3_EXT_MAGIC);
1549 +
1550 +       /* find where to start removing */
1551 +       le = ex = EXT_LAST_EXTENT(eh);
1552 +       while (ex != EXT_FIRST_EXTENT(eh)) {
1553 +               if (ex->ee_block <= end)
1554 +                       break;
1555 +               ex--;
1556 +       }
1557 +
1558 +       if (start > ex->ee_block && end < ex->ee_block + ex->ee_len - 1) {
1559 +               /* removal of internal part of the extent requested
1560 +                * tail and head must be placed in different extent
1561 +                * so, we have to insert one more extent */
1562 +               path[depth].p_ext = ex;
1563 +               return ext3_ext_split_for_rm(handle, tree, path, start, end);
1564 +       }
1565 +
1566 +       lu = ex;
1567 +       while (ex >= EXT_FIRST_EXTENT(eh) && ex->ee_block + ex->ee_len > start) {
1568 +               ext_debug(tree, "remove ext %u:%u\n", ex->ee_block, ex->ee_len);
1569 +               path[depth].p_ext = ex;
1570 +
1571 +               a = ex->ee_block > start ? ex->ee_block : start;
1572 +               b = ex->ee_block + ex->ee_len - 1 < end ?
1573 +                       ex->ee_block + ex->ee_len - 1 : end;
1574 +
1575 +               ext_debug(tree, "  border %u:%u\n", a, b);
1576 +
1577 +               if (a != ex->ee_block && b != ex->ee_block + ex->ee_len - 1) {
1578 +                       block = 0;
1579 +                       num = 0;
1580 +                       BUG();
1581 +               } else if (a != ex->ee_block) {
1582 +                       /* remove tail of the extent */
1583 +                       block = ex->ee_block;
1584 +                       num = a - block;
1585 +               } else if (b != ex->ee_block + ex->ee_len - 1) {
1586 +                       /* remove head of the extent */
1587 +                       block = a;
1588 +                       num = b - a;
1589 +               } else {
1590 +                       /* remove whole extent: excelent! */
1591 +                       block = ex->ee_block;
1592 +                       num = 0;
1593 +                       EXT_ASSERT(a == ex->ee_block &&
1594 +                                  b == ex->ee_block + ex->ee_len - 1);
1595 +               }
1596 +
1597 +               if (ex == EXT_FIRST_EXTENT(eh))
1598 +                       correct_index = 1;
1599 +
1600 +               credits = 1;
1601 +               if (correct_index)
1602 +                       credits += (EXT_DEPTH(tree) * EXT3_ALLOC_NEEDED) + 1;
1603 +               if (tree->ops->remove_extent_credits)
1604 +                       credits+=tree->ops->remove_extent_credits(tree,ex,a,b);
1605 +
1606 +               handle = ext3_ext_journal_restart(handle, credits);
1607 +               if (IS_ERR(handle)) {
1608 +                       err = PTR_ERR(handle);
1609 +                       goto out;
1610 +               }
1611 +
1612 +               err = ext3_ext_get_access(handle, tree, path + depth);
1613 +               if (err)
1614 +                       goto out;
1615 +
1616 +               if (tree->ops->remove_extent)
1617 +                       err = tree->ops->remove_extent(tree, ex, a, b);
1618 +               if (err)
1619 +                       goto out;
1620 +
1621 +               if (num == 0) {
1622 +                       /* this extent is removed entirely mark slot unused */
1623 +                       ex->ee_start = 0;
1624 +                       eh->eh_entries--;
1625 +                       fu = ex;
1626 +               }
1627 +
1628 +               ex->ee_block = block;
1629 +               ex->ee_len = num;
1630 +
1631 +               err = ext3_ext_dirty(handle, tree, path + depth);
1632 +               if (err)
1633 +                       goto out;
1634 +
1635 +               ext_debug(tree, "new extent: %u:%u:%u\n",
1636 +                         ex->ee_block, ex->ee_len, ex->ee_start);
1637 +               ex--;
1638 +       }
1639 +
1640 +       if (fu) {
1641 +               /* reuse unused slots */
1642 +               while (lu < le) {
1643 +                       if (lu->ee_start) {
1644 +                               *fu = *lu;
1645 +                               lu->ee_start = 0;
1646 +                               fu++;
1647 +                       }
1648 +                       lu++;
1649 +               }
1650 +       }
1651 +
1652 +       if (correct_index && eh->eh_entries)
1653 +               err = ext3_ext_correct_indexes(handle, tree, path);
1654 +
1655 +       /* if this leaf is free, then we should
1656 +        * remove it from index block above */
1657 +       if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
1658 +               err = ext3_ext_rm_idx(handle, tree, path + depth);
1659 +
1660 +out:
1661 +       return err;
1662 +}
1663 +
1664 +
1665 +static struct ext3_extent_idx *
1666 +ext3_ext_last_covered(struct ext3_extent_header *hdr, unsigned long block)
1667 +{
1668 +       struct ext3_extent_idx *ix;
1669 +
1670 +       ix = EXT_LAST_INDEX(hdr);
1671 +       while (ix != EXT_FIRST_INDEX(hdr)) {
1672 +               if (ix->ei_block <= block)
1673 +                       break;
1674 +               ix--;
1675 +       }
1676 +       return ix;
1677 +}
1678 +
1679 +/*
1680 + * returns 1 if current index have to be freed (even partial)
1681 + */
1682 +static int inline
1683 +ext3_ext_more_to_rm(struct ext3_ext_path *path)
1684 +{
1685 +       EXT_ASSERT(path->p_idx);
1686 +
1687 +       if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
1688 +               return 0;
1689 +
1690 +       /*
1691 +        * if truncate on deeper level happened it it wasn't partial
1692 +        * so we have to consider current index for truncation
1693 +        */
1694 +       if (path->p_hdr->eh_entries == path->p_block)
1695 +               return 0;
1696 +       return 1;
1697 +}
1698 +
1699 +int ext3_ext_remove_space(struct ext3_extents_tree *tree,
1700 +                         unsigned long start, unsigned long end)
1701 +{
1702 +       struct inode *inode = tree->inode;
1703 +       struct super_block *sb = inode->i_sb;
1704 +       int depth = EXT_DEPTH(tree);
1705 +       struct ext3_ext_path *path;
1706 +       handle_t *handle;
1707 +       int i = 0, err = 0;
1708 +
1709 +       ext_debug(tree, "space to be removed: %lu:%lu\n", start, end);
1710 +
1711 +       /* probably first extent we're gonna free will be last in block */
1712 +       handle = ext3_journal_start(inode, depth + 1);
1713 +       if (IS_ERR(handle))
1714 +               return PTR_ERR(handle);
1715 +
1716 +       ext3_ext_invalidate_cache(tree);
1717 +
1718 +       /*
1719 +        * we start scanning from right side freeing all the blocks
1720 +        * after i_size and walking into the deep
1721 +        */
1722 +       path = kmalloc(sizeof(struct ext3_ext_path) * (depth + 1), GFP_KERNEL);
1723 +       if (IS_ERR(path)) {
1724 +               ext3_error(sb, __FUNCTION__, "Can't allocate path array");
1725 +               ext3_journal_stop(handle, inode);
1726 +               return -ENOMEM;
1727 +       }
1728 +       memset(path, 0, sizeof(struct ext3_ext_path) * (depth + 1));
1729 +       path[i].p_hdr = EXT_ROOT_HDR(tree);
1730 +
1731 +       while (i >= 0 && err == 0) {
1732 +               if (i == depth) {
1733 +                       /* this is leaf block */
1734 +                       err = ext3_ext_rm_leaf(handle, tree, path, start, end);
1735 +                       /* root level have p_bh == NULL, brelse() eats this */
1736 +                       brelse(path[i].p_bh);
1737 +                       i--;
1738 +                       continue;
1739 +               }
1740 +
1741 +               /* this is index block */
1742 +               if (!path[i].p_hdr) {
1743 +                       ext_debug(tree, "initialize header\n");
1744 +                       path[i].p_hdr = EXT_BLOCK_HDR(path[i].p_bh);
1745 +               }
1746 +
1747 +               EXT_ASSERT(path[i].p_hdr->eh_entries <= path[i].p_hdr->eh_max);
1748 +               EXT_ASSERT(path[i].p_hdr->eh_magic == EXT3_EXT_MAGIC);
1749 +
1750 +               if (!path[i].p_idx) {
1751 +                       /* this level hasn't touched yet */
1752 +                       path[i].p_idx =
1753 +                               ext3_ext_last_covered(path[i].p_hdr, end);
1754 +                       path[i].p_block = path[i].p_hdr->eh_entries + 1;
1755 +                       ext_debug(tree, "init index ptr: hdr 0x%p, num %d\n",
1756 +                                 path[i].p_hdr, path[i].p_hdr->eh_entries);
1757 +               } else {
1758 +                       /* we've already was here, see at next index */
1759 +                       path[i].p_idx--;
1760 +               }
1761 +
1762 +               ext_debug(tree, "level %d - index, first 0x%p, cur 0x%p\n",
1763 +                         i, EXT_FIRST_INDEX(path[i].p_hdr),
1764 +                         path[i].p_idx);
1765 +               if (ext3_ext_more_to_rm(path + i)) {
1766 +                       /* go to the next level */
1767 +                       ext_debug(tree, "move to level %d (block %d)\n",
1768 +                                 i + 1, path[i].p_idx->ei_leaf);
1769 +                       memset(path + i + 1, 0, sizeof(*path));
1770 +                       path[i+1].p_bh = sb_bread(sb, path[i].p_idx->ei_leaf);
1771 +                       if (!path[i+1].p_bh) {
1772 +                               /* should we reset i_size? */
1773 +                               err = -EIO;
1774 +                               break;
1775 +                       }
1776 +                       /* put actual number of indexes to know is this
1777 +                        * number got changed at the next iteration */
1778 +                       path[i].p_block = path[i].p_hdr->eh_entries;
1779 +                       i++;
1780 +               } else {
1781 +                       /* we finish processing this index, go up */
1782 +                       if (path[i].p_hdr->eh_entries == 0 && i > 0) {
1783 +                               /* index is empty, remove it
1784 +                                * handle must be already prepared by the
1785 +                                * truncatei_leaf() */
1786 +                               err = ext3_ext_rm_idx(handle, tree, path + i);
1787 +                       }
1788 +                       /* root level have p_bh == NULL, brelse() eats this */
1789 +                       brelse(path[i].p_bh);
1790 +                       i--;
1791 +                       ext_debug(tree, "return to level %d\n", i);
1792 +               }
1793 +       }
1794 +
1795 +       /* TODO: flexible tree reduction should be here */
1796 +       if (path->p_hdr->eh_entries == 0) {
1797 +               /*
1798 +                * truncate to zero freed all the tree
1799 +                * so, we need to correct eh_depth
1800 +                */
1801 +               err = ext3_ext_get_access(handle, tree, path);
1802 +               if (err == 0) {
1803 +                       EXT_ROOT_HDR(tree)->eh_depth = 0;
1804 +                       EXT_ROOT_HDR(tree)->eh_max = ext3_ext_space_root(tree);
1805 +                       err = ext3_ext_dirty(handle, tree, path);
1806 +               }
1807 +       }
1808 +       ext3_ext_tree_changed(tree);
1809 +
1810 +       kfree(path);
1811 +       ext3_journal_stop(handle, inode);
1812 +
1813 +       return err;
1814 +}
1815 +
1816 +/*
1817 + * called at mount time
1818 + */
1819 +void ext3_ext_init(struct super_block *sb)
1820 +{
1821 +       /*
1822 +        * possible initialization would be here
1823 +        */
1824 +
1825 +       if (test_opt(sb, EXTENTS)) {
1826 +               printk("EXT3-fs: file extents enabled");
1827 +#ifdef AGRESSIVE_TEST
1828 +               printk(", agressive tests");
1829 +#endif
1830 +#ifdef CHECK_BINSEARCH
1831 +               printk(", check binsearch");
1832 +#endif
1833 +               printk("\n");
1834 +       }
1835 +}
1836 +
1837 +/*
1838 + * called at umount time
1839 + */
1840 +void ext3_ext_release(struct super_block *sb)
1841 +{
1842 +}
1843 +
1844 +/************************************************************************
1845 + * VFS related routines
1846 + ************************************************************************/
1847 +
1848 +static int ext3_get_inode_write_access(handle_t *handle, void *buffer)
1849 +{
1850 +       /* we use in-core data, not bh */
1851 +       return 0;
1852 +}
1853 +
1854 +static int ext3_mark_buffer_dirty(handle_t *handle, void *buffer)
1855 +{
1856 +       struct inode *inode = buffer;
1857 +       return ext3_mark_inode_dirty(handle, inode);
1858 +}
1859 +
1860 +static int ext3_ext_mergable(struct ext3_extent *ex1,
1861 +                            struct ext3_extent *ex2)
1862 +{
1863 +       /* FIXME: support for large fs */
1864 +       if (ex1->ee_start + ex1->ee_len == ex2->ee_start)
1865 +               return 1;
1866 +       return 0;
1867 +}
1868 +
1869 +static int
1870 +ext3_remove_blocks_credits(struct ext3_extents_tree *tree,
1871 +                          struct ext3_extent *ex,
1872 +                          unsigned long from, unsigned long to)
1873 +{
1874 +       int needed;
1875 +
1876 +       /* at present, extent can't cross block group */;
1877 +       needed = 4; /* bitmap + group desc + sb + inode */
1878 +
1879 +#ifdef CONFIG_QUOTA
1880 +       needed += 2 * EXT3_SINGLEDATA_TRANS_BLOCKS;
1881 +#endif
1882 +       return needed;
1883 +}
1884 +
1885 +static int
1886 +ext3_remove_blocks(struct ext3_extents_tree *tree,
1887 +                  struct ext3_extent *ex,
1888 +                  unsigned long from, unsigned long to)
1889 +{
1890 +       int needed = ext3_remove_blocks_credits(tree, ex, from, to);
1891 +       handle_t *handle = ext3_journal_start(tree->inode, needed);
1892 +       struct buffer_head *bh;
1893 +       int i;
1894 +
1895 +       if (IS_ERR(handle))
1896 +               return PTR_ERR(handle);
1897 +       if (from >= ex->ee_block && to == ex->ee_block + ex->ee_len - 1) {
1898 +               /* tail removal */
1899 +               unsigned long num, start;
1900 +               num = ex->ee_block + ex->ee_len - from;
1901 +               start = ex->ee_start + ex->ee_len - num;
1902 +               ext_debug(tree, "free last %lu blocks starting %lu\n",
1903 +                         num, start);
1904 +               for (i = 0; i < num; i++) {
1905 +                       bh = sb_get_hash_table(tree->inode->i_sb, start + i);
1906 +                       ext3_forget(handle, 0, tree->inode, bh, start + i);
1907 +               }
1908 +               ext3_free_blocks(handle, tree->inode, start, num);
1909 +       } else if (from == ex->ee_block && to <= ex->ee_block + ex->ee_len - 1) {
1910 +               printk("strange request: removal %lu-%lu from %u:%u\n",
1911 +                      from, to, ex->ee_block, ex->ee_len);
1912 +       } else {
1913 +               printk("strange request: removal(2) %lu-%lu from %u:%u\n",
1914 +                      from, to, ex->ee_block, ex->ee_len);
1915 +       }
1916 +       ext3_journal_stop(handle, tree->inode);
1917 +       return 0;
1918 +}
1919 +
1920 +int ext3_ext_find_goal(struct inode *inode, struct ext3_ext_path *path,
1921 +                      unsigned long block)
1922 +{
1923 +       struct ext3_inode_info *ei = EXT3_I(inode);
1924 +       unsigned long bg_start;
1925 +       unsigned long colour;
1926 +       int depth;
1927 +
1928 +       if (path) {
1929 +               struct ext3_extent *ex;
1930 +               depth = path->p_depth;
1931 +
1932 +               /* try to predict block placement */
1933 +               if ((ex = path[depth].p_ext))
1934 +                       return ex->ee_start + (block - ex->ee_block);
1935 +
1936 +               /* it looks index is empty
1937 +                * try to find starting from index itself */
1938 +               if (path[depth].p_bh)
1939 +                       return path[depth].p_bh->b_blocknr;
1940 +       }
1941 +
1942 +       /* OK. use inode's group */
1943 +       bg_start = (ei->i_block_group * EXT3_BLOCKS_PER_GROUP(inode->i_sb)) +
1944 +               le32_to_cpu(EXT3_SB(inode->i_sb)->s_es->s_first_data_block);
1945 +       colour = (current->pid % 16) *
1946 +                       (EXT3_BLOCKS_PER_GROUP(inode->i_sb) / 16);
1947 +       return bg_start + colour + block;
1948 +}
1949 +
1950 +static int ext3_new_block_cb(handle_t *handle, struct ext3_extents_tree *tree,
1951 +                            struct ext3_ext_path *path,
1952 +                            struct ext3_extent *ex, int *err)
1953 +{
1954 +       struct inode *inode = tree->inode;
1955 +       int newblock, goal;
1956 +
1957 +       EXT_ASSERT(path);
1958 +       EXT_ASSERT(ex);
1959 +       EXT_ASSERT(ex->ee_start);
1960 +       EXT_ASSERT(ex->ee_len);
1961 +
1962 +       /* reuse block from the extent to order data/metadata */
1963 +       newblock = ex->ee_start++;
1964 +       ex->ee_len--;
1965 +       if (ex->ee_len == 0) {
1966 +               ex->ee_len = 1;
1967 +               /* allocate new block for the extent */
1968 +               goal = ext3_ext_find_goal(inode, path, ex->ee_block);
1969 +               lock_kernel();
1970 +               ex->ee_start = ext3_new_block(handle, inode, goal, 0, 0, err);
1971 +               unlock_kernel();
1972 +               if (ex->ee_start == 0) {
1973 +                       /* error occured: restore old extent */
1974 +                       ex->ee_start = newblock;
1975 +                       return 0;
1976 +               }
1977 +       }
1978 +       return newblock;
1979 +}
1980 +
1981 +static struct ext3_extents_helpers ext3_blockmap_helpers = {
1982 +       .get_write_access       = ext3_get_inode_write_access,
1983 +       .mark_buffer_dirty      = ext3_mark_buffer_dirty,
1984 +       .mergable               = ext3_ext_mergable,
1985 +       .new_block              = ext3_new_block_cb,
1986 +       .remove_extent          = ext3_remove_blocks,
1987 +       .remove_extent_credits  = ext3_remove_blocks_credits,
1988 +};
1989 +
1990 +void ext3_init_tree_desc(struct ext3_extents_tree *tree,
1991 +                        struct inode *inode)
1992 +{
1993 +       tree->inode = inode;
1994 +       tree->root = (void *) EXT3_I(inode)->i_data;
1995 +       tree->buffer = (void *) inode;
1996 +       tree->buffer_len = sizeof(EXT3_I(inode)->i_data);
1997 +       tree->cex = (struct ext3_ext_cache *) &EXT3_I(inode)->i_cached_extent;
1998 +       tree->ops = &ext3_blockmap_helpers;
1999 +}
2000 +
2001 +int ext3_ext_get_block(handle_t *handle, struct inode *inode,
2002 +                      long iblock, struct buffer_head *bh_result, int create)
2003 +{
2004 +       struct ext3_ext_path *path = NULL;
2005 +       struct ext3_extent newex;
2006 +       struct ext3_extent *ex;
2007 +       int goal, newblock, err = 0, depth;
2008 +       struct ext3_extents_tree tree;
2009 +
2010 +       clear_bit(BH_New, &bh_result->b_state);
2011 +       ext3_init_tree_desc(&tree, inode);
2012 +       ext_debug(&tree, "block %d requested for inode %u\n",
2013 +                 (int) iblock, (unsigned) inode->i_ino);
2014 +       down_write(&EXT3_I(inode)->truncate_sem);
2015 +
2016 +       /* check in cache */
2017 +       if ((goal = ext3_ext_in_cache(&tree, iblock, &newex))) {
2018 +               if (goal == EXT3_EXT_CACHE_GAP) {
2019 +                       if (!create) {
2020 +                               /* block isn't allocated yet and
2021 +                                * user don't want to allocate it */
2022 +                               goto out2;
2023 +                       }
2024 +                       /* we should allocate requested block */
2025 +               } else if (goal == EXT3_EXT_CACHE_EXTENT) {
2026 +                       /* block is already allocated */
2027 +                       newblock = iblock - newex.ee_block + newex.ee_start;
2028 +                       goto out;
2029 +               } else {
2030 +                       EXT_ASSERT(0);
2031 +               }
2032 +       }
2033 +
2034 +       /* find extent for this block */
2035 +       path = ext3_ext_find_extent(&tree, iblock, NULL);
2036 +       if (IS_ERR(path)) {
2037 +               err = PTR_ERR(path);
2038 +               path = NULL;
2039 +               goto out2;
2040 +       }
2041 +
2042 +       depth = EXT_DEPTH(&tree);
2043 +
2044 +       /*
2045 +        * consistent leaf must not be empty
2046 +        * this situations is possible, though, _during_ tree modification
2047 +        * this is why assert can't be put in ext3_ext_find_extent()
2048 +        */
2049 +       EXT_ASSERT(path[depth].p_ext != NULL || depth == 0);
2050 +
2051 +       if ((ex = path[depth].p_ext)) {
2052 +               /* if found exent covers block, simple return it */
2053 +               if (iblock >= ex->ee_block && iblock < ex->ee_block + ex->ee_len) {
2054 +                       newblock = iblock - ex->ee_block + ex->ee_start;
2055 +                       ext_debug(&tree, "%d fit into %d:%d -> %d\n",
2056 +                                 (int) iblock, ex->ee_block, ex->ee_len,
2057 +                                 newblock);
2058 +                       ext3_ext_put_in_cache(&tree, ex->ee_block,
2059 +                                             ex->ee_len, ex->ee_start,
2060 +                                             EXT3_EXT_CACHE_EXTENT);
2061 +                       goto out;
2062 +               }
2063 +       }
2064 +
2065 +       /*
2066 +        * requested block isn't allocated yet
2067 +        * we couldn't try to create block if create flag is zero
2068 +        */
2069 +       if (!create) {
2070 +               /* put just found gap into cache to speedup subsequest reqs */
2071 +               ext3_ext_put_gap_in_cache(&tree, path, iblock);
2072 +               goto out2;
2073 +       }
2074 +
2075 +       /* allocate new block */
2076 +       goal = ext3_ext_find_goal(inode, path, iblock);
2077 +       lock_kernel();
2078 +       newblock = ext3_new_block(handle, inode, goal, 0, 0, &err);
2079 +       unlock_kernel();
2080 +       if (!newblock)
2081 +               goto out2;
2082 +       ext_debug(&tree, "allocate new block: goal %d, found %d\n",
2083 +                 goal, newblock);
2084 +
2085 +       /* try to insert new extent into found leaf and return */
2086 +       newex.ee_block = iblock;
2087 +       newex.ee_start = newblock;
2088 +       newex.ee_len = 1;
2089 +       err = ext3_ext_insert_extent(handle, &tree, path, &newex);
2090 +       if (err)
2091 +               goto out2;
2092 +
2093 +       if (inode->i_size > EXT3_I(inode)->i_disksize)
2094 +               EXT3_I(inode)->i_disksize = inode->i_size;
2095 +
2096 +       /* previous routine could use block we allocated */
2097 +       newblock = newex.ee_start;
2098 +       set_bit(BH_New, &bh_result->b_state);
2099 +
2100 +       ext3_ext_put_in_cache(&tree, newex.ee_block, newex.ee_len,
2101 +                             newex.ee_start, EXT3_EXT_CACHE_EXTENT);
2102 +out:
2103 +       ext3_ext_show_leaf(&tree, path);
2104 +       set_bit(BH_Mapped, &bh_result->b_state);
2105 +       bh_result->b_dev = inode->i_sb->s_dev;
2106 +       bh_result->b_blocknr = newblock;
2107 +out2:
2108 +       if (path) {
2109 +               ext3_ext_drop_refs(path);
2110 +               kfree(path);
2111 +       }
2112 +       up_write(&EXT3_I(inode)->truncate_sem);
2113 +
2114 +       return err;
2115 +}
2116 +
2117 +void ext3_ext_truncate(struct inode * inode)
2118 +{
2119 +       struct address_space *mapping = inode->i_mapping;
2120 +       struct super_block *sb = inode->i_sb;
2121 +       struct ext3_extents_tree tree;
2122 +       unsigned long last_block;
2123 +       handle_t *handle;
2124 +       int err = 0;
2125 +
2126 +       ext3_init_tree_desc(&tree, inode);
2127 +
2128 +       /*
2129 +        * probably first extent we're gonna free will be last in block
2130 +        */
2131 +       err = ext3_writepage_trans_blocks(inode) + 3;
2132 +       handle = ext3_journal_start(inode, err);
2133 +       if (IS_ERR(handle))
2134 +               return;
2135 +
2136 +       ext3_block_truncate_page(handle, mapping, inode->i_size);
2137 +
2138 +       down_write(&EXT3_I(inode)->truncate_sem);
2139 +       ext3_ext_invalidate_cache(&tree);
2140 +
2141 +       /*
2142 +        * TODO: optimization is possible here
2143 +        * probably we need not scaning at all,
2144 +        * because page truncation is enough
2145 +        */
2146 +       if (ext3_orphan_add(handle, inode))
2147 +               goto out_stop;
2148 +
2149 +       /* we have to know where to truncate from in crash case */
2150 +       EXT3_I(inode)->i_disksize = inode->i_size;
2151 +       ext3_mark_inode_dirty(handle, inode);
2152 +
2153 +       last_block = (inode->i_size + sb->s_blocksize - 1) >>
2154 +                       EXT3_BLOCK_SIZE_BITS(sb);
2155 +       err = ext3_ext_remove_space(&tree, last_block, EXT_MAX_BLOCK);
2156 +
2157 +       /* In a multi-transaction truncate, we only make the final
2158 +        * transaction synchronous */
2159 +       if (IS_SYNC(inode))
2160 +               handle->h_sync = 1;
2161 +
2162 +out_stop:
2163 +       /*
2164 +        * If this was a simple ftruncate(), and the file will remain alive
2165 +        * then we need to clear up the orphan record which we created above.
2166 +        * However, if this was a real unlink then we were called by
2167 +        * ext3_delete_inode(), and we allow that function to clean up the
2168 +        * orphan info for us.
2169 +        */
2170 +       if (inode->i_nlink)
2171 +               ext3_orphan_del(handle, inode);
2172 +
2173 +       up_write(&EXT3_I(inode)->truncate_sem);
2174 +       ext3_journal_stop(handle, inode);
2175 +}
2176 +
2177 +/*
2178 + * this routine calculate max number of blocks we could modify
2179 + * in order to allocate new block for an inode
2180 + */
2181 +int ext3_ext_writepage_trans_blocks(struct inode *inode, int num)
2182 +{
2183 +       struct ext3_extents_tree tree;
2184 +       int needed;
2185 +
2186 +       ext3_init_tree_desc(&tree, inode);
2187 +
2188 +       needed = ext3_ext_calc_credits_for_insert(&tree, NULL);
2189 +
2190 +       /* caller want to allocate num blocks */
2191 +       needed *= num;
2192 +
2193 +#ifdef CONFIG_QUOTA
2194 +       /*
2195 +        * FIXME: real calculation should be here
2196 +        * it depends on blockmap format of qouta file
2197 +        */
2198 +       needed += 2 * EXT3_SINGLEDATA_TRANS_BLOCKS;
2199 +#endif
2200 +
2201 +       return needed;
2202 +}
2203 +
2204 +void ext3_extents_initialize_blockmap(handle_t *handle, struct inode *inode)
2205 +{
2206 +       struct ext3_extents_tree tree;
2207 +
2208 +       ext3_init_tree_desc(&tree, inode);
2209 +       ext3_extent_tree_init(handle, &tree);
2210 +}
2211 +
2212 +static int
2213 +ext3_ext_store_extent_cb(struct ext3_extents_tree *tree,
2214 +                        struct ext3_ext_path *path,
2215 +                        struct ext3_ext_cache *newex)
2216 +{
2217 +       struct ext3_extent_buf *buf = (struct ext3_extent_buf *) tree->private;
2218 +
2219 +       if (newex->ec_type != EXT3_EXT_CACHE_EXTENT)
2220 +               return EXT_CONTINUE;
2221 +
2222 +       if (buf->err < 0)
2223 +               return EXT_BREAK;
2224 +       if (buf->cur - buf->buffer + sizeof(*newex) > buf->buflen)
2225 +               return EXT_BREAK;
2226 +
2227 +       if (!copy_to_user(buf->cur, newex, sizeof(*newex))) {
2228 +               buf->err++;
2229 +               buf->cur += sizeof(*newex);
2230 +       } else {
2231 +               buf->err = -EFAULT;
2232 +               return EXT_BREAK;
2233 +       }
2234 +       return EXT_CONTINUE;
2235 +}
2236 +
2237 +static int
2238 +ext3_ext_collect_stats_cb(struct ext3_extents_tree *tree,
2239 +                         struct ext3_ext_path *path,
2240 +                         struct ext3_ext_cache *ex)
2241 +{
2242 +       struct ext3_extent_tree_stats *buf =
2243 +               (struct ext3_extent_tree_stats *) tree->private;
2244 +       int depth;
2245 +
2246 +       if (ex->ec_type != EXT3_EXT_CACHE_EXTENT)
2247 +               return EXT_CONTINUE;
2248 +
2249 +       depth = EXT_DEPTH(tree);
2250 +       buf->extents_num++;
2251 +       if (path[depth].p_ext == EXT_FIRST_EXTENT(path[depth].p_hdr))
2252 +               buf->leaf_num++;
2253 +       return EXT_CONTINUE;
2254 +}
2255 +
2256 +int ext3_ext_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
2257 +                  unsigned long arg)
2258 +{
2259 +       int err = 0;
2260 +
2261 +       if (!(EXT3_I(inode)->i_flags & EXT3_EXTENTS_FL))
2262 +               return -EINVAL;
2263 +
2264 +       if (cmd == EXT3_IOC_GET_EXTENTS) {
2265 +               struct ext3_extent_buf buf;
2266 +               struct ext3_extents_tree tree;
2267 +
2268 +               if (copy_from_user(&buf, (void *) arg, sizeof(buf)))
2269 +                       return -EFAULT;
2270 +
2271 +               ext3_init_tree_desc(&tree, inode);
2272 +               buf.cur = buf.buffer;
2273 +               buf.err = 0;
2274 +               tree.private = &buf;
2275 +               down_write(&EXT3_I(inode)->truncate_sem);
2276 +               err = ext3_ext_walk_space(&tree, buf.start, EXT_MAX_BLOCK,
2277 +                                         ext3_ext_store_extent_cb);
2278 +               up_write(&EXT3_I(inode)->truncate_sem);
2279 +               if (err == 0)
2280 +                       err = buf.err;
2281 +       } else if (cmd == EXT3_IOC_GET_TREE_STATS) {
2282 +               struct ext3_extent_tree_stats buf;
2283 +               struct ext3_extents_tree tree;
2284 +
2285 +               ext3_init_tree_desc(&tree, inode);
2286 +               down_write(&EXT3_I(inode)->truncate_sem);
2287 +               buf.depth = EXT_DEPTH(&tree);
2288 +               buf.extents_num = 0;
2289 +               buf.leaf_num = 0;
2290 +               tree.private = &buf;
2291 +               err = ext3_ext_walk_space(&tree, 0, EXT_MAX_BLOCK,
2292 +                                         ext3_ext_collect_stats_cb);
2293 +               up_write(&EXT3_I(inode)->truncate_sem);
2294 +               if (!err)
2295 +                       err = copy_to_user((void *) arg, &buf, sizeof(buf));
2296 +       } else if (cmd == EXT3_IOC_GET_TREE_DEPTH) {
2297 +               struct ext3_extents_tree tree;
2298 +               ext3_init_tree_desc(&tree, inode);
2299 +               down_write(&EXT3_I(inode)->truncate_sem);
2300 +               err = EXT_DEPTH(&tree);
2301 +               up_write(&EXT3_I(inode)->truncate_sem);
2302 +       }
2303 +
2304 +       return err;
2305 +}
2306 +
2307 +EXPORT_SYMBOL(ext3_init_tree_desc);
2308 +EXPORT_SYMBOL(ext3_mark_inode_dirty);
2309 +EXPORT_SYMBOL(ext3_ext_invalidate_cache);
2310 +EXPORT_SYMBOL(ext3_ext_insert_extent);
2311 +EXPORT_SYMBOL(ext3_ext_walk_space);
2312 +EXPORT_SYMBOL(ext3_ext_find_goal);
2313 +EXPORT_SYMBOL(ext3_ext_calc_credits_for_insert);
2314 Index: linux-2.4.29/fs/ext3/ialloc.c
2315 ===================================================================
2316 --- linux-2.4.29.orig/fs/ext3/ialloc.c  2005-05-03 16:50:30.216045296 +0300
2317 +++ linux-2.4.29/fs/ext3/ialloc.c       2005-05-03 16:52:08.804057640 +0300
2318 @@ -553,7 +553,8 @@
2319         inode->i_blksize = PAGE_SIZE;
2320         inode->i_blocks = 0;
2321         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
2322 -       inode->u.ext3_i.i_flags = dir->u.ext3_i.i_flags & ~EXT3_INDEX_FL;
2323 +       inode->u.ext3_i.i_flags = dir->u.ext3_i.i_flags &
2324 +               ~(EXT3_INDEX_FL | EXT3_EXTENTS_FL);
2325         if (S_ISLNK(mode))
2326                 inode->u.ext3_i.i_flags &= ~(EXT3_IMMUTABLE_FL|EXT3_APPEND_FL);
2327  #ifdef EXT3_FRAGMENTS
2328 @@ -592,6 +593,19 @@
2329                 iloc.bh = NULL;
2330                 goto fail;
2331         }
2332 +       if (test_opt(sb, EXTENTS) && S_ISREG(inode->i_mode)) {
2333 +               EXT3_I(inode)->i_flags |= EXT3_EXTENTS_FL;
2334 +               memset(&EXT3_I(inode)->i_cached_extent, 0, sizeof(__u32) * 4);
2335 +               ext3_extents_initialize_blockmap(handle, inode);
2336 +               if (!EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_EXTENTS)) {
2337 +                       err = ext3_journal_get_write_access(handle, EXT3_SB(sb)->s_sbh);
2338 +                       if (err) goto fail;
2339 +                       EXT3_SET_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_EXTENTS);
2340 +                       BUFFER_TRACE(EXT3_SB(sb)->s_sbh, "call ext3_journal_dirty_metadata");
2341 +                       err = ext3_journal_dirty_metadata(handle, EXT3_SB(sb)->s_sbh);
2342 +               }
2343 +       }
2344 +
2345         err = ext3_mark_iloc_dirty(handle, inode, &iloc);
2346         if (err) goto fail;
2347
2348 Index: linux-2.4.29/fs/ext3/inode.c
2349 ===================================================================
2350 --- linux-2.4.29.orig/fs/ext3/inode.c   2005-05-03 16:51:50.331865840 +0300
2351 +++ linux-2.4.29/fs/ext3/inode.c        2005-05-03 16:52:08.808057032 +0300
2352 @@ -861,6 +861,15 @@
2353         goto reread;
2354  }
2355
2356 +static inline int
2357 +ext3_get_block_wrap(handle_t *handle, struct inode *inode, long block,
2358 +                   struct buffer_head *bh, int create)
2359 +{
2360 +       if (EXT3_I(inode)->i_flags & EXT3_EXTENTS_FL)
2361 +               return ext3_ext_get_block(handle, inode, block, bh, create);
2362 +       return ext3_get_block_handle(handle, inode, block, bh, create);
2363 +}
2364 +
2365  /*
2366   * The BKL is not held on entry here.
2367   */
2368 @@ -874,7 +883,7 @@
2369                 handle = ext3_journal_current_handle();
2370                 J_ASSERT(handle != 0);
2371         }
2372 -       ret = ext3_get_block_handle(handle, inode, iblock, bh_result, create);
2373 +       ret = ext3_get_block_wrap(handle, inode, iblock, bh_result, create);
2374         return ret;
2375  }
2376
2377 @@ -892,7 +901,7 @@
2378         dummy.b_state = 0;
2379         dummy.b_blocknr = -1000;
2380         buffer_trace_init(&dummy.b_history);
2381 -       *errp = ext3_get_block_handle(handle, inode, block, &dummy, create);
2382 +       *errp = ext3_get_block_wrap(handle, inode, block, &dummy, create);
2383         if (!*errp && buffer_mapped(&dummy)) {
2384                 struct buffer_head *bh;
2385                 bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
2386 @@ -1416,7 +1425,7 @@
2387   * This required during truncate. We need to physically zero the tail end
2388   * of that block so it doesn't yield old data if the file is later grown.
2389   */
2390 -static int ext3_block_truncate_page(handle_t *handle,
2391 +int ext3_block_truncate_page(handle_t *handle,
2392                 struct address_space *mapping, loff_t from)
2393  {
2394         unsigned long index = from >> PAGE_CACHE_SHIFT;
2395 @@ -1904,6 +1913,9 @@
2396
2397         ext3_discard_prealloc(inode);
2398
2399 +       if (EXT3_I(inode)->i_flags & EXT3_EXTENTS_FL)
2400 +               return ext3_ext_truncate(inode);
2401 +
2402         handle = start_transaction(inode);
2403         if (IS_ERR(handle))
2404                 return;         /* AKPM: return what? */
2405 @@ -2240,6 +2252,7 @@
2406         for (block = 0; block < EXT3_N_BLOCKS; block++)
2407                 inode->u.ext3_i.i_data[block] = iloc.raw_inode->i_block[block];
2408         INIT_LIST_HEAD(&inode->u.ext3_i.i_orphan);
2409 +       memset(&EXT3_I(inode)->i_cached_extent, 0, sizeof(__u32) * 4);
2410
2411         if (EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE)
2412                 inode->u.ext3_i.i_extra_isize =
2413 @@ -2546,6 +2559,9 @@
2414         int indirects = (EXT3_NDIR_BLOCKS % bpp) ? 5 : 3;
2415         int ret;
2416
2417 +       if (EXT3_I(inode)->i_flags & EXT3_EXTENTS_FL)
2418 +               return ext3_ext_writepage_trans_blocks(inode, bpp);
2419 +
2420         if (ext3_should_journal_data(inode))
2421                 ret = 3 * (bpp + indirects) + 2;
2422         else
2423 @@ -2982,7 +2998,7 @@
2424
2425         /* alloc blocks one by one */
2426         for (i = 0; i < nblocks; i++) {
2427 -               ret = ext3_get_block_handle(handle, inode, blocks[i],
2428 +               ret = ext3_get_block_wrap(handle, inode, blocks[i],
2429                                                 &bh_tmp, 1);
2430                 if (ret)
2431                         break;
2432 @@ -3058,7 +3074,7 @@
2433                  if (blocks[i] != 0)
2434                          continue;
2435
2436 -                rc = ext3_get_block_handle(handle, inode, iblock, &bh, 1);
2437 +                rc = ext3_get_block_wrap(handle, inode, iblock, &bh, 1);
2438                  if (rc) {
2439                          printk(KERN_INFO "ext3_map_inode_page: error %d "
2440                                 "allocating block %ld\n", rc, iblock);
2441 Index: linux-2.4.29/fs/ext3/Makefile
2442 ===================================================================
2443 --- linux-2.4.29.orig/fs/ext3/Makefile  2005-05-03 16:51:32.127633304 +0300
2444 +++ linux-2.4.29/fs/ext3/Makefile       2005-05-03 16:53:38.634401352 +0300
2445 @@ -13,7 +13,9 @@
2446
2447  obj-y    := balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o iopen.o \
2448                 ioctl.o namei.o super.o symlink.o hash.o ext3-exports.o \
2449 -               xattr_trusted.o
2450 +               xattr_trusted.o extents.o
2451 +export-objs += extents.o
2452 +
2453  obj-m    := $(O_TARGET)
2454
2455  export-objs += xattr.o
2456 Index: linux-2.4.29/fs/ext3/super.c
2457 ===================================================================
2458 --- linux-2.4.29.orig/fs/ext3/super.c   2005-05-03 16:50:14.750396432 +0300
2459 +++ linux-2.4.29/fs/ext3/super.c        2005-05-03 16:52:08.813056272 +0300
2460 @@ -531,6 +531,7 @@
2461  #ifdef EXT3_DELETE_THREAD
2462         J_ASSERT(sbi->s_delete_inodes == 0);
2463  #endif
2464 +       ext3_ext_release(sb);
2465         ext3_xattr_put_super(sb);
2466         journal_destroy(sbi->s_journal);
2467         if (!(sb->s_flags & MS_RDONLY)) {
2468 @@ -702,6 +703,12 @@
2469                                 return 0;
2470                         }
2471                 }
2472 +               else if (!strcmp (this_char, "extents"))
2473 +                       set_opt (*mount_options, EXTENTS);
2474 +               else if (!strcmp (this_char, "noextents"))
2475 +                       clear_opt (*mount_options, EXTENTS);
2476 +               else if (!strcmp (this_char, "extdebug"))
2477 +                       set_opt (*mount_options, EXTDEBUG);
2478                 else if (!strcmp (this_char, "grpid") ||
2479                          !strcmp (this_char, "bsdgroups"))
2480                         set_opt (*mount_options, GRPID);
2481 @@ -1405,6 +1410,8 @@
2482                 test_opt(sb,DATA_FLAGS) == EXT3_MOUNT_ORDERED_DATA ? "ordered":
2483                 "writeback");
2484
2485 +       ext3_ext_init(sb);
2486 +
2487         return sb;
2488
2489  failed_mount3:
2490 Index: linux-2.4.29/fs/ext3/ioctl.c
2491 ===================================================================
2492 --- linux-2.4.29.orig/fs/ext3/ioctl.c   2005-05-03 16:49:36.825161944 +0300
2493 +++ linux-2.4.29/fs/ext3/ioctl.c        2005-05-03 16:52:08.814056120 +0300
2494 @@ -174,6 +174,10 @@
2495                         return ret;
2496                 }
2497  #endif
2498 +       case EXT3_IOC_GET_EXTENTS:
2499 +       case EXT3_IOC_GET_TREE_STATS:
2500 +       case EXT3_IOC_GET_TREE_DEPTH:
2501 +               return ext3_ext_ioctl(inode, filp, cmd, arg);
2502         default:
2503                 return -ENOTTY;
2504         }
2505 Index: linux-2.4.29/include/linux/ext3_fs.h
2506 ===================================================================
2507 --- linux-2.4.29.orig/include/linux/ext3_fs.h   2005-05-03 16:50:30.228043472 +0300
2508 +++ linux-2.4.29/include/linux/ext3_fs.h        2005-05-03 16:52:08.817055664 +0300
2509 @@ -184,8 +184,9 @@
2510  #define EXT3_IMAGIC_FL                 0x00002000 /* AFS directory */
2511  #define EXT3_JOURNAL_DATA_FL           0x00004000 /* file data should be journaled */
2512  #define EXT3_RESERVED_FL               0x80000000 /* reserved for ext3 lib */
2513 +#define EXT3_EXTENTS_FL                        0x00080000 /* Inode uses extents */
2514
2515 -#define EXT3_FL_USER_VISIBLE           0x00005FFF /* User visible flags */
2516 +#define EXT3_FL_USER_VISIBLE           0x00085FFF /* User visible flags */
2517  #define EXT3_FL_USER_MODIFIABLE                0x000000FF /* User modifiable flags */
2518
2519  /*
2520 @@ -208,6 +209,9 @@
2521  #ifdef CONFIG_JBD_DEBUG
2522  #define EXT3_IOC_WAIT_FOR_READONLY     _IOR('f', 99, long)
2523  #endif
2524 +#define EXT3_IOC_GET_EXTENTS           _IOR('f', 7, long)
2525 +#define EXT3_IOC_GET_TREE_DEPTH                _IOR('f', 8, long)
2526 +#define EXT3_IOC_GET_TREE_STATS                _IOR('f', 9, long)
2527
2528  /*
2529   * Structure of an inode on the disk
2530 @@ -327,6 +331,8 @@
2531  #define EXT3_MOUNT_ASYNCDEL            0x20000 /* Delayed deletion */
2532  #define EXT3_MOUNT_IOPEN               0x80000 /* Allow access via iopen */
2533  #define EXT3_MOUNT_IOPEN_NOPRIV                0x100000/* Make iopen world-readable */
2534 +#define EXT3_MOUNT_EXTENTS             0x200000/* Extents support */
2535 +#define EXT3_MOUNT_EXTDEBUG            0x400000/* Extents debug */
2536
2537  /* Compatibility, for having both ext2_fs.h and ext3_fs.h included at once */
2538  #ifndef _LINUX_EXT2_FS_H
2539 @@ -506,11 +512,13 @@
2540  #define EXT3_FEATURE_INCOMPAT_RECOVER          0x0004 /* Needs recovery */
2541  #define EXT3_FEATURE_INCOMPAT_JOURNAL_DEV      0x0008 /* Journal device */
2542  #define EXT3_FEATURE_INCOMPAT_META_BG          0x0010
2543 +#define EXT3_FEATURE_INCOMPAT_EXTENTS          0x0040 /* extents support */
2544
2545  #define EXT3_FEATURE_COMPAT_SUPP       EXT2_FEATURE_COMPAT_EXT_ATTR
2546  #define EXT3_FEATURE_INCOMPAT_SUPP     (EXT3_FEATURE_INCOMPAT_FILETYPE| \
2547                                          EXT3_FEATURE_INCOMPAT_RECOVER| \
2548 -                                        EXT3_FEATURE_INCOMPAT_META_BG)
2549 +                                        EXT3_FEATURE_INCOMPAT_META_BG| \
2550 +                                        EXT3_FEATURE_INCOMPAT_EXTENTS)
2551  #define EXT3_FEATURE_RO_COMPAT_SUPP    (EXT3_FEATURE_RO_COMPAT_SPARSE_SUPER| \
2552                                          EXT3_FEATURE_RO_COMPAT_LARGE_FILE| \
2553                                          EXT3_FEATURE_RO_COMPAT_BTREE_DIR)
2554 @@ -702,6 +711,8 @@
2555  extern unsigned long ext3_count_free (struct buffer_head *, unsigned);
2556
2557  /* inode.c */
2558 +extern int ext3_block_truncate_page(handle_t *, struct address_space *, loff_t);
2559 +extern int ext3_writepage_trans_blocks(struct inode *inode);
2560  extern int ext3_forget(handle_t *, int, struct inode *, struct buffer_head *, int);
2561  extern struct buffer_head * ext3_getblk (handle_t *, struct inode *, long, int, int *);
2562  extern struct buffer_head * ext3_bread (handle_t *, struct inode *, int, int, int *);
2563 @@ -783,6 +793,16 @@
2564  extern struct inode_operations ext3_symlink_inode_operations;
2565  extern struct inode_operations ext3_fast_symlink_inode_operations;
2566
2567 +/* extents.c */
2568 +extern int ext3_ext_writepage_trans_blocks(struct inode *, int);
2569 +extern int ext3_ext_get_block(handle_t *, struct inode *, long,
2570 +                             struct buffer_head *, int);
2571 +extern void ext3_ext_truncate(struct inode *);
2572 +extern void ext3_ext_init(struct super_block *);
2573 +extern void ext3_ext_release(struct super_block *);
2574 +extern void ext3_extents_initialize_blockmap(handle_t *, struct inode *);
2575 +extern int ext3_ext_ioctl(struct inode *inode, struct file *filp,
2576 +                         unsigned int cmd, unsigned long arg);
2577
2578  #endif /* __KERNEL__ */
2579
2580 Index: linux-2.4.29/include/linux/ext3_extents.h
2581 ===================================================================
2582 --- linux-2.4.29.orig/include/linux/ext3_extents.h      2005-05-03 16:52:08.724069800 +0300
2583 +++ linux-2.4.29/include/linux/ext3_extents.h   2005-05-03 16:52:08.819055360 +0300
2584 @@ -0,0 +1,261 @@
2585 +/*
2586 + * Copyright (c) 2003, Cluster File Systems, Inc, info@clusterfs.com
2587 + * Written by Alex Tomas <alex@clusterfs.com>
2588 + *
2589 + * This program is free software; you can redistribute it and/or modify
2590 + * it under the terms of the GNU General Public License version 2 as
2591 + * published by the Free Software Foundation.
2592 + *
2593 + * This program is distributed in the hope that it will be useful,
2594 + * but WITHOUT ANY WARRANTY; without even the implied warranty of
2595 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
2596 + * GNU General Public License for more details.
2597 + *
2598 + * You should have received a copy of the GNU General Public Licens
2599 + * along with this program; if not, write to the Free Software
2600 + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
2601 + */
2602 +
2603 +#ifndef _LINUX_EXT3_EXTENTS
2604 +#define _LINUX_EXT3_EXTENTS
2605 +
2606 +/*
2607 + * with AGRESSIVE_TEST defined capacity of index/leaf blocks
2608 + * become very little, so index split, in-depth growing and
2609 + * other hard changes happens much more often
2610 + * this is for debug purposes only
2611 + */
2612 +#define AGRESSIVE_TEST_
2613 +
2614 +/*
2615 + * if CHECK_BINSEARCH defined, then results of binary search
2616 + * will be checked by linear search
2617 + */
2618 +#define CHECK_BINSEARCH_
2619 +
2620 +/*
2621 + * if EXT_DEBUG is defined you can use 'extdebug' mount option
2622 + * to get lots of info what's going on
2623 + */
2624 +#define EXT_DEBUG_
2625 +#ifdef EXT_DEBUG
2626 +#define ext_debug(tree,fmt,a...)                       \
2627 +do {                                                   \
2628 +       if (test_opt((tree)->inode->i_sb, EXTDEBUG))    \
2629 +               printk(fmt, ##a);                       \
2630 +} while (0);
2631 +#else
2632 +#define ext_debug(tree,fmt,a...)
2633 +#endif
2634 +
2635 +/*
2636 + * if EXT_STATS is defined then stats numbers are collected
2637 + * these number will be displayed at umount time
2638 + */
2639 +#define EXT_STATS_
2640 +
2641 +
2642 +#define EXT3_ALLOC_NEEDED      3       /* block bitmap + group desc. + sb */
2643 +
2644 +/*
2645 + * ext3_inode has i_block array (total 60 bytes)
2646 + * first 4 bytes are used to store:
2647 + *  - tree depth (0 mean there is no tree yet. all extents in the inode)
2648 + *  - number of alive extents in the inode
2649 + */
2650 +
2651 +/*
2652 + * this is extent on-disk structure
2653 + * it's used at the bottom of the tree
2654 + */
2655 +struct ext3_extent {
2656 +       __u32   ee_block;       /* first logical block extent covers */
2657 +       __u16   ee_len;         /* number of blocks covered by extent */
2658 +       __u16   ee_start_hi;    /* high 16 bits of physical block */
2659 +       __u32   ee_start;       /* low 32 bigs of physical block */
2660 +};
2661 +
2662 +/*
2663 + * this is index on-disk structure
2664 + * it's used at all the levels, but the bottom
2665 + */
2666 +struct ext3_extent_idx {
2667 +       __u32   ei_block;       /* index covers logical blocks from 'block' */
2668 +       __u32   ei_leaf;        /* pointer to the physical block of the next *
2669 +                                * level. leaf or next index could bet here */
2670 +       __u16   ei_leaf_hi;     /* high 16 bits of physical block */
2671 +       __u16   ei_unused;
2672 +};
2673 +
2674 +/*
2675 + * each block (leaves and indexes), even inode-stored has header
2676 + */
2677 +struct ext3_extent_header {
2678 +       __u16   eh_magic;       /* probably will support different formats */
2679 +       __u16   eh_entries;     /* number of valid entries */
2680 +       __u16   eh_max;         /* capacity of store in entries */
2681 +       __u16   eh_depth;       /* has tree real underlaying blocks? */
2682 +       __u32   eh_generation;  /* flags(8 bits) | generation of the tree */
2683 +};
2684 +
2685 +#define EXT3_EXT_MAGIC         0xf30a
2686 +
2687 +/*
2688 + * array of ext3_ext_path contains path to some extent
2689 + * creation/lookup routines use it for traversal/splitting/etc
2690 + * truncate uses it to simulate recursive walking
2691 + */
2692 +struct ext3_ext_path {
2693 +       __u32                           p_block;
2694 +       __u16                           p_depth;
2695 +       struct ext3_extent              *p_ext;
2696 +       struct ext3_extent_idx          *p_idx;
2697 +       struct ext3_extent_header       *p_hdr;
2698 +       struct buffer_head              *p_bh;
2699 +};
2700 +
2701 +/*
2702 + * structure for external API
2703 + */
2704 +
2705 +/*
2706 + * storage for cached extent
2707 + */
2708 +struct ext3_ext_cache {
2709 +       __u32   ec_start;
2710 +       __u32   ec_block;
2711 +       __u32   ec_len;
2712 +       __u32   ec_type;
2713 +};
2714 +
2715 +#define EXT3_EXT_CACHE_NO      0
2716 +#define EXT3_EXT_CACHE_GAP     1
2717 +#define EXT3_EXT_CACHE_EXTENT  2
2718 +
2719 +/*
2720 + * ext3_extents_tree is used to pass initial information
2721 + * to top-level extents API
2722 + */
2723 +struct ext3_extents_helpers;
2724 +struct ext3_extents_tree {
2725 +       struct inode *inode;    /* inode which tree belongs to */
2726 +       void *root;             /* ptr to data top of tree resides at */
2727 +       void *buffer;           /* will be passed as arg to ^^ routines */
2728 +       int buffer_len;
2729 +       void *private;
2730 +       struct ext3_ext_cache *cex;/* last found extent */
2731 +       struct ext3_extents_helpers *ops;
2732 +};
2733 +
2734 +struct ext3_extents_helpers {
2735 +       int (*get_write_access)(handle_t *h, void *buffer);
2736 +       int (*mark_buffer_dirty)(handle_t *h, void *buffer);
2737 +       int (*mergable)(struct ext3_extent *ex1, struct ext3_extent *ex2);
2738 +       int (*remove_extent_credits)(struct ext3_extents_tree *,
2739 +                                    struct ext3_extent *, unsigned long,
2740 +                                    unsigned long);
2741 +       int (*remove_extent)(struct ext3_extents_tree *,
2742 +                            struct ext3_extent *, unsigned long,
2743 +                            unsigned long);
2744 +       int (*new_block)(handle_t *, struct ext3_extents_tree *,
2745 +                        struct ext3_ext_path *, struct ext3_extent *,
2746 +                        int *);
2747 +};
2748 +
2749 +/*
2750 + * to be called by ext3_ext_walk_space()
2751 + * negative retcode - error
2752 + * positive retcode - signal for ext3_ext_walk_space(), see below
2753 + * callback must return valid extent (passed or newly created)
2754 + */
2755 +typedef int (*ext_prepare_callback)(struct ext3_extents_tree *,
2756 +                                   struct ext3_ext_path *,
2757 +                                   struct ext3_ext_cache *);
2758 +
2759 +#define EXT_CONTINUE   0
2760 +#define EXT_BREAK      1
2761 +#define EXT_REPEAT     2
2762 +
2763 +
2764 +#define EXT_MAX_BLOCK  0xffffffff
2765 +
2766 +
2767 +#define EXT_FIRST_EXTENT(__hdr__) \
2768 +       ((struct ext3_extent *) (((char *) (__hdr__)) +         \
2769 +                                sizeof(struct ext3_extent_header)))
2770 +#define EXT_FIRST_INDEX(__hdr__) \
2771 +       ((struct ext3_extent_idx *) (((char *) (__hdr__)) +     \
2772 +                                    sizeof(struct ext3_extent_header)))
2773 +#define EXT_HAS_FREE_INDEX(__path__) \
2774 +       ((__path__)->p_hdr->eh_entries < (__path__)->p_hdr->eh_max)
2775 +#define EXT_LAST_EXTENT(__hdr__) \
2776 +       (EXT_FIRST_EXTENT((__hdr__)) + (__hdr__)->eh_entries - 1)
2777 +#define EXT_LAST_INDEX(__hdr__) \
2778 +       (EXT_FIRST_INDEX((__hdr__)) + (__hdr__)->eh_entries - 1)
2779 +#define EXT_MAX_EXTENT(__hdr__) \
2780 +       (EXT_FIRST_EXTENT((__hdr__)) + (__hdr__)->eh_max - 1)
2781 +#define EXT_MAX_INDEX(__hdr__) \
2782 +       (EXT_FIRST_INDEX((__hdr__)) + (__hdr__)->eh_max - 1)
2783 +#define EXT_HDR_GEN(__hdr__)   ((__hdr__)->eh_generation & 0x00ffffff)
2784 +#define EXT_FLAGS(__hdr__)     ((__hdr__)->eh_generation >> 24)
2785 +#define EXT_FLAGS_CLR_UNKNOWN  0x7     /* Flags cleared on modification */
2786 +
2787 +#define EXT_BLOCK_HDR(__bh__)  ((struct ext3_extent_header *)(__bh__)->b_data)
2788 +#define EXT_ROOT_HDR(__tree__) ((struct ext3_extent_header *)(__tree__)->root)
2789 +#define EXT_DEPTH(__tree__)    (EXT_ROOT_HDR(__tree__)->eh_depth)
2790 +#define EXT_GENERATION(__tree__) EXT_HDR_GEN(EXT_ROOT_HDR(__tree__))
2791 +
2792 +#define EXT_ASSERT(__x__) if (!(__x__)) BUG();
2793 +
2794 +#define EXT_CHECK_PATH(tree,path)                                      \
2795 +{                                                                      \
2796 +       int depth = EXT_DEPTH(tree);                                    \
2797 +       BUG_ON((unsigned long) (path) < __PAGE_OFFSET);                 \
2798 +       BUG_ON((unsigned long) (path)[depth].p_idx <                    \
2799 +                       __PAGE_OFFSET && (path)[depth].p_idx != NULL);  \
2800 +       BUG_ON((unsigned long) (path)[depth].p_ext <                    \
2801 +                       __PAGE_OFFSET && (path)[depth].p_ext != NULL);  \
2802 +       BUG_ON((unsigned long) (path)[depth].p_hdr < __PAGE_OFFSET);    \
2803 +       BUG_ON((unsigned long) (path)[depth].p_bh < __PAGE_OFFSET       \
2804 +                       && depth != 0);                                 \
2805 +       BUG_ON((path)[0].p_depth != depth);                             \
2806 +}
2807 +
2808 +
2809 +/*
2810 + * this structure is used to gather extents from the tree via ioctl
2811 + */
2812 +struct ext3_extent_buf {
2813 +       unsigned long start;
2814 +       int buflen;
2815 +       void *buffer;
2816 +       void *cur;
2817 +       int err;
2818 +};
2819 +
2820 +/*
2821 + * this structure is used to collect stats info about the tree
2822 + */
2823 +struct ext3_extent_tree_stats {
2824 +       int depth;
2825 +       int extents_num;
2826 +       int leaf_num;
2827 +};
2828 +
2829 +extern void ext3_init_tree_desc(struct ext3_extents_tree *, struct inode *);
2830 +extern int ext3_extent_tree_init(handle_t *, struct ext3_extents_tree *);
2831 +extern int ext3_ext_calc_credits_for_insert(struct ext3_extents_tree *, struct ext3_ext_path *);
2832 +extern int ext3_ext_insert_extent(handle_t *, struct ext3_extents_tree *, struct ext3_ext_path *, struct ext3_extent *);
2833 +extern int ext3_ext_walk_space(struct ext3_extents_tree *, unsigned long, unsigned long, ext_prepare_callback);
2834 +extern int ext3_ext_remove_space(struct ext3_extents_tree *, unsigned long, unsigned long);
2835 +extern struct ext3_ext_path * ext3_ext_find_extent(struct ext3_extents_tree *, int, struct ext3_ext_path *);
2836 +
2837 +static inline void
2838 +ext3_ext_invalidate_cache(struct ext3_extents_tree *tree)
2839 +{
2840 +       if (tree->cex)
2841 +               tree->cex->ec_type = EXT3_EXT_CACHE_NO;
2842 +}
2843 +
2844 +
2845 +#endif /* _LINUX_EXT3_EXTENTS */
2846 Index: linux-2.4.29/include/linux/ext3_fs_i.h
2847 ===================================================================
2848 --- linux-2.4.29.orig/include/linux/ext3_fs_i.h 2005-05-03 16:50:30.229043320 +0300
2849 +++ linux-2.4.29/include/linux/ext3_fs_i.h      2005-05-03 16:52:08.823054752 +0300
2850 @@ -76,6 +76,8 @@
2851          * by other means, so we have truncate_sem.
2852          */
2853         struct rw_semaphore truncate_sem;
2854 +
2855 +       __u32 i_cached_extent[4];
2856  };
2857
2858  #endif /* _LINUX_EXT3_FS_I */