lib/ext2fs/extent.c

   1 /*
   2  * extent.c --- routines to implement extents support
   3  *
   4  * Copyright (C) 2007 Theodore Ts'o.
   5  *
   6  * %Begin-Header%
   7  * This file may be redistributed under the terms of the GNU Public
   8  * License.
   9  * %End-Header%
  10  */
  11
  12 #include <stdio.h>
  13 #include <string.h>
  14 #if HAVE_UNISTD_H
  15 #include <unistd.h>
  16 #endif
  17 #if HAVE_ERRNO_H
  18 #include <errno.h>
  19 #endif
  20 #if HAVE_SYS_STAT_H
  21 #include <sys/stat.h>
  22 #endif
  23 #if HAVE_SYS_TYPES_H
  24 #include <sys/types.h>
  25 #endif
  26
  27 #include "ext2_fs.h"
  28 #include "ext2fsP.h"
  29 #include "e2image.h"
  30
  31 /*
  32  * Definitions to be dropped in lib/ext2fs/ext2fs.h
  33  */
  34
  35 /*
  36  * Private definitions
  37  */
  38
  39 struct extent_path {
  40         char            *buf;
  41         int             entries;
  42         int             max_entries;
  43         int             left;
  44         int             visit_num;
  45         int             flags;
  46         blk64_t         end_blk;
  47         void            *curr;
  48 };
  49
  50
  51 struct ext2_extent_handle {
  52         errcode_t               magic;
  53         ext2_filsys             fs;
  54         ext2_ino_t              ino;
  55         struct ext2_inode       *inode;
  56         int                     type;
  57         int                     level;
  58         int                     max_depth;
  59         struct extent_path      *path;
  60 };
  61
  62 struct ext2_extent_path {
  63         errcode_t               magic;
  64         int                     leaf_height;
  65         blk64_t                 lblk;
  66 };
  67
  68 /*
  69  *  Useful Debugging stuff
  70  */
  71
  72 #ifdef DEBUG
  73 static void dbg_show_header(struct ext3_extent_header *eh)
  74 {
  75         printf("header: magic=%x entries=%u max=%u depth=%u generation=%u\n",
  76                         ext2fs_le16_to_cpu(eh->eh_magic),
  77                         ext2fs_le16_to_cpu(eh->eh_entries),
  78                         ext2fs_le16_to_cpu(eh->eh_max),
  79                         ext2fs_le16_to_cpu(eh->eh_depth),
  80                         ext2fs_le32_to_cpu(eh->eh_generation));
  81 }
  82
  83 static void dbg_show_index(struct ext3_extent_idx *ix)
  84 {
  85         printf("index: block=%u leaf=%u leaf_hi=%u unused=%u\n",
  86                         ext2fs_le32_to_cpu(ix->ei_block),
  87                         ext2fs_le32_to_cpu(ix->ei_leaf),
  88                         ext2fs_le16_to_cpu(ix->ei_leaf_hi),
  89                         ext2fs_le16_to_cpu(ix->ei_unused));
  90 }
  91
  92 static void dbg_show_extent(struct ext3_extent *ex)
  93 {
  94         printf("extent: block=%u-%u len=%u start=%u start_hi=%u\n",
  95                         ext2fs_le32_to_cpu(ex->ee_block),
  96                         ext2fs_le32_to_cpu(ex->ee_block) +
  97                         ext2fs_le16_to_cpu(ex->ee_len) - 1,
  98                         ext2fs_le16_to_cpu(ex->ee_len),
  99                         ext2fs_le32_to_cpu(ex->ee_start),
 100                         ext2fs_le16_to_cpu(ex->ee_start_hi));
 101 }
 102
 103 static void dbg_print_extent(char *desc, struct ext2fs_extent *extent)
 104 {
 105         if (desc)
 106                 printf("%s: ", desc);
 107         printf("extent: lblk %llu--%llu, len %lu, pblk %llu, flags: ",
 108                extent->e_lblk, extent->e_lblk + extent->e_len - 1,
 109                extent->e_len, extent->e_pblk);
 110         if (extent->e_flags & EXT2_EXTENT_FLAGS_LEAF)
 111                 fputs("LEAF ", stdout);
 112         if (extent->e_flags & EXT2_EXTENT_FLAGS_UNINIT)
 113                 fputs("UNINIT ", stdout);
 114         if (extent->e_flags & EXT2_EXTENT_FLAGS_SECOND_VISIT)
 115                 fputs("2ND_VISIT ", stdout);
 116         if (!extent->e_flags)
 117                 fputs("(none)", stdout);
 118         fputc('\n', stdout);
 119
 120 }
 121
 122 #else
 123 #define dbg_show_header(eh) do { } while (0)
 124 #define dbg_show_index(ix) do { } while (0)
 125 #define dbg_show_extent(ex) do { } while (0)
 126 #define dbg_print_extent(desc, ex) do { } while (0)
 127 #endif
 128
 129 /*
 130  * Verify the extent header as being sane
 131  */
 132 errcode_t ext2fs_extent_header_verify(void *ptr, int size)
 133 {
 134         int eh_max, entry_size;
 135         struct ext3_extent_header *eh = ptr;
 136
 137         dbg_show_header(eh);
 138         if (ext2fs_le16_to_cpu(eh->eh_magic) != EXT3_EXT_MAGIC)
 139                 return EXT2_ET_EXTENT_HEADER_BAD;
 140         if (ext2fs_le16_to_cpu(eh->eh_entries) > ext2fs_le16_to_cpu(eh->eh_max))
 141                 return EXT2_ET_EXTENT_HEADER_BAD;
 142         if (eh->eh_depth == 0)
 143                 entry_size = sizeof(struct ext3_extent);
 144         else
 145                 entry_size = sizeof(struct ext3_extent_idx);
 146
 147         eh_max = (size - sizeof(*eh)) / entry_size;
 148         /* Allow two extent-sized items at the end of the block, for
 149          * ext4_extent_tail with checksum in the future. */
 150         if ((ext2fs_le16_to_cpu(eh->eh_max) > eh_max) ||
 151             (ext2fs_le16_to_cpu(eh->eh_max) < (eh_max - 2)))
 152                 return EXT2_ET_EXTENT_HEADER_BAD;
 153
 154         return 0;
 155 }
 156
 157
 158 /*
 159  * Begin functions to handle an inode's extent information
 160  */
 161 extern void ext2fs_extent_free(ext2_extent_handle_t handle)
 162 {
 163         int                     i;
 164
 165         if (!handle)
 166                 return;
 167
 168         if (handle->inode)
 169                 ext2fs_free_mem(&handle->inode);
 170         if (handle->path) {
 171                 for (i=1; i <= handle->max_depth; i++) {
 172                         if (handle->path[i].buf)
 173                                 ext2fs_free_mem(&handle->path[i].buf);
 174                 }
 175                 ext2fs_free_mem(&handle->path);
 176         }
 177         ext2fs_free_mem(&handle);
 178 }
 179
 180 extern errcode_t ext2fs_extent_open(ext2_filsys fs, ext2_ino_t ino,
 181                                     ext2_extent_handle_t *ret_handle)
 182 {
 183         return ext2fs_extent_open2(fs, ino, NULL, ret_handle);
 184 }
 185
 186 extern errcode_t ext2fs_extent_open2(ext2_filsys fs, ext2_ino_t ino,
 187                                     struct ext2_inode *inode,
 188                                     ext2_extent_handle_t *ret_handle)
 189 {
 190         struct ext2_extent_handle       *handle;
 191         errcode_t                       retval;
 192         int                             i;
 193         struct ext3_extent_header       *eh;
 194
 195         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 196
 197         if (!inode)
 198                 if ((ino == 0) || (ino > fs->super->s_inodes_count))
 199                         return EXT2_ET_BAD_INODE_NUM;
 200
 201         retval = ext2fs_get_mem(sizeof(struct ext2_extent_handle), &handle);
 202         if (retval)
 203                 return retval;
 204         memset(handle, 0, sizeof(struct ext2_extent_handle));
 205
 206         retval = ext2fs_get_mem(sizeof(struct ext2_inode), &handle->inode);
 207         if (retval)
 208                 goto errout;
 209
 210         handle->ino = ino;
 211         handle->fs = fs;
 212
 213         if (inode) {
 214                 memcpy(handle->inode, inode, sizeof(struct ext2_inode));
 215         }
 216         else {
 217                 retval = ext2fs_read_inode(fs, ino, handle->inode);
 218                 if (retval)
 219                         goto errout;
 220         }
 221
 222         eh = (struct ext3_extent_header *) &handle->inode->i_block[0];
 223
 224         for (i=0; i < EXT2_N_BLOCKS; i++)
 225                 if (handle->inode->i_block[i])
 226                         break;
 227         if (i >= EXT2_N_BLOCKS) {
 228                 eh->eh_magic = ext2fs_cpu_to_le16(EXT3_EXT_MAGIC);
 229                 eh->eh_depth = 0;
 230                 eh->eh_entries = 0;
 231                 i = (sizeof(handle->inode->i_block) - sizeof(*eh)) /
 232                         sizeof(struct ext3_extent);
 233                 eh->eh_max = ext2fs_cpu_to_le16(i);
 234                 handle->inode->i_flags |= EXT4_EXTENTS_FL;
 235         }
 236
 237         if (!(handle->inode->i_flags & EXT4_EXTENTS_FL)) {
 238                 retval = EXT2_ET_INODE_NOT_EXTENT;
 239                 goto errout;
 240         }
 241
 242         retval = ext2fs_extent_header_verify(eh, sizeof(handle->inode->i_block));
 243         if (retval)
 244                 goto errout;
 245
 246         handle->max_depth = ext2fs_le16_to_cpu(eh->eh_depth);
 247         handle->type = ext2fs_le16_to_cpu(eh->eh_magic);
 248
 249         retval = ext2fs_get_mem(((handle->max_depth+1) *
 250                                  sizeof(struct extent_path)),
 251                                 &handle->path);
 252         memset(handle->path, 0,
 253                (handle->max_depth+1) * sizeof(struct extent_path));
 254         handle->path[0].buf = (char *) handle->inode->i_block;
 255
 256         handle->path[0].left = handle->path[0].entries =
 257                 ext2fs_le16_to_cpu(eh->eh_entries);
 258         handle->path[0].max_entries = ext2fs_le16_to_cpu(eh->eh_max);
 259         handle->path[0].curr = 0;
 260         handle->path[0].end_blk =
 261                 ((((__u64) handle->inode->i_size_high << 32) +
 262                   handle->inode->i_size + (fs->blocksize - 1))
 263                  >> EXT2_BLOCK_SIZE_BITS(fs->super));
 264         handle->path[0].visit_num = 1;
 265         handle->level = 0;
 266         handle->magic = EXT2_ET_MAGIC_EXTENT_HANDLE;
 267
 268         *ret_handle = handle;
 269         return 0;
 270
 271 errout:
 272         ext2fs_extent_free(handle);
 273         return retval;
 274 }
 275
 276 /*
 277  * This function is responsible for (optionally) moving through the
 278  * extent tree and then returning the current extent
 279  */
 280 errcode_t ext2fs_extent_get(ext2_extent_handle_t handle,
 281                             int flags, struct ext2fs_extent *extent)
 282 {
 283         struct extent_path      *path, *newpath;
 284         struct ext3_extent_header       *eh;
 285         struct ext3_extent_idx          *ix = 0;
 286         struct ext3_extent              *ex;
 287         errcode_t                       retval;
 288         blk_t                           blk;
 289         blk64_t                         end_blk;
 290         int                             orig_op, op;
 291
 292         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
 293
 294         if (!handle->path)
 295                 return EXT2_ET_NO_CURRENT_NODE;
 296
 297         orig_op = op = flags & EXT2_EXTENT_MOVE_MASK;
 298
 299 retry:
 300         path = handle->path + handle->level;
 301         if ((orig_op == EXT2_EXTENT_NEXT) ||
 302             (orig_op == EXT2_EXTENT_NEXT_LEAF)) {
 303                 if (handle->level < handle->max_depth) {
 304                         /* interior node */
 305                         if (path->visit_num == 0) {
 306                                 path->visit_num++;
 307                                 op = EXT2_EXTENT_DOWN;
 308                         } else if (path->left > 0)
 309                                 op = EXT2_EXTENT_NEXT_SIB;
 310                         else if (handle->level > 0)
 311                                 op = EXT2_EXTENT_UP;
 312                         else
 313                                 return EXT2_ET_EXTENT_NO_NEXT;
 314                 } else {
 315                         /* leaf node */
 316                         if (path->left > 0)
 317                                 op = EXT2_EXTENT_NEXT_SIB;
 318                         else if (handle->level > 0)
 319                                 op = EXT2_EXTENT_UP;
 320                         else
 321                                 return EXT2_ET_EXTENT_NO_NEXT;
 322                 }
 323                 if (op != EXT2_EXTENT_NEXT_SIB) {
 324 #ifdef DEBUG
 325                         printf("<<<< OP = %s\n",
 326                                (op == EXT2_EXTENT_DOWN) ? "down" :
 327                                ((op == EXT2_EXTENT_UP) ? "up" : "unknown"));
 328 #endif
 329                 }
 330         }
 331
 332         if ((orig_op == EXT2_EXTENT_PREV) ||
 333             (orig_op == EXT2_EXTENT_PREV_LEAF)) {
 334                 if (handle->level < handle->max_depth) {
 335                         /* interior node */
 336                         if (path->visit_num > 0 ) {
 337                                 /* path->visit_num = 0; */
 338                                 op = EXT2_EXTENT_DOWN_AND_LAST;
 339                         } else if (path->left < path->entries-1)
 340                                 op = EXT2_EXTENT_PREV_SIB;
 341                         else if (handle->level > 0)
 342                                 op = EXT2_EXTENT_UP;
 343                         else
 344                                 return EXT2_ET_EXTENT_NO_PREV;
 345                 } else {
 346                         /* leaf node */
 347                         if (path->left < path->entries-1)
 348                                 op = EXT2_EXTENT_PREV_SIB;
 349                         else if (handle->level > 0)
 350                                 op = EXT2_EXTENT_UP;
 351                         else
 352                                 return EXT2_ET_EXTENT_NO_PREV;
 353                 }
 354                 if (op != EXT2_EXTENT_PREV_SIB) {
 355 #ifdef DEBUG
 356                         printf("<<<< OP = %s\n",
 357                                (op == EXT2_EXTENT_DOWN_AND_LAST) ? "down/last" :
 358                                ((op == EXT2_EXTENT_UP) ? "up" : "unknown"));
 359 #endif
 360                 }
 361         }
 362
 363         if (orig_op == EXT2_EXTENT_LAST_LEAF) {
 364                 if ((handle->level < handle->max_depth) &&
 365                     (path->left == 0))
 366                         op = EXT2_EXTENT_DOWN;
 367                 else
 368                         op = EXT2_EXTENT_LAST_SIB;
 369 #ifdef DEBUG
 370                 printf("<<<< OP = %s\n",
 371                            (op == EXT2_EXTENT_DOWN) ? "down" : "last_sib");
 372 #endif
 373         }
 374
 375         switch (op) {
 376         case EXT2_EXTENT_CURRENT:
 377                 ix = path->curr;
 378                 break;
 379         case EXT2_EXTENT_ROOT:
 380                 handle->level = 0;
 381                 path = handle->path + handle->level;
 382         case EXT2_EXTENT_FIRST_SIB:
 383                 path->left = path->entries;
 384                 path->curr = 0;
 385         case EXT2_EXTENT_NEXT_SIB:
 386                 if (path->left <= 0)
 387                         return EXT2_ET_EXTENT_NO_NEXT;
 388                 if (path->curr) {
 389                         ix = path->curr;
 390                         ix++;
 391                 } else {
 392                         eh = (struct ext3_extent_header *) path->buf;
 393                         ix = EXT_FIRST_INDEX(eh);
 394                 }
 395                 path->left--;
 396                 path->curr = ix;
 397                 path->visit_num = 0;
 398                 break;
 399         case EXT2_EXTENT_PREV_SIB:
 400                 if (!path->curr ||
 401                     path->left+1 >= path->entries)
 402                         return EXT2_ET_EXTENT_NO_PREV;
 403                 ix = path->curr;
 404                 ix--;
 405                 path->curr = ix;
 406                 path->left++;
 407                 if (handle->level < handle->max_depth)
 408                         path->visit_num = 1;
 409                 break;
 410         case EXT2_EXTENT_LAST_SIB:
 411                 eh = (struct ext3_extent_header *) path->buf;
 412                 path->curr = EXT_LAST_EXTENT(eh);
 413                 ix = path->curr;
 414                 path->left = 0;
 415                 path->visit_num = 0;
 416                 break;
 417         case EXT2_EXTENT_UP:
 418                 if (handle->level <= 0)
 419                         return EXT2_ET_EXTENT_NO_UP;
 420                 handle->level--;
 421                 path--;
 422                 ix = path->curr;
 423                 if ((orig_op == EXT2_EXTENT_PREV) ||
 424                     (orig_op == EXT2_EXTENT_PREV_LEAF))
 425                         path->visit_num = 0;
 426                 break;
 427         case EXT2_EXTENT_DOWN:
 428         case EXT2_EXTENT_DOWN_AND_LAST:
 429                 if (!path->curr ||(handle->level >= handle->max_depth))
 430                         return EXT2_ET_EXTENT_NO_DOWN;
 431
 432                 ix = path->curr;
 433                 newpath = path + 1;
 434                 if (!newpath->buf) {
 435                         retval = ext2fs_get_mem(handle->fs->blocksize,
 436                                                 &newpath->buf);
 437                         if (retval)
 438                                 return retval;
 439                 }
 440                 blk = ext2fs_le32_to_cpu(ix->ei_leaf) +
 441                         ((__u64) ext2fs_le16_to_cpu(ix->ei_leaf_hi) << 32);
 442                 if ((handle->fs->flags & EXT2_FLAG_IMAGE_FILE) &&
 443                     (handle->fs->io != handle->fs->image_io))
 444                         memset(newpath->buf, 0, handle->fs->blocksize);
 445                 else {
 446                         retval = io_channel_read_blk(handle->fs->io,
 447                                                      blk, 1, newpath->buf);
 448                         if (retval)
 449                                 return retval;
 450                 }
 451                 handle->level++;
 452
 453                 eh = (struct ext3_extent_header *) newpath->buf;
 454
 455                 retval = ext2fs_extent_header_verify(eh, handle->fs->blocksize);
 456                 if (retval) {
 457                         handle->level--;
 458                         return retval;
 459                 }
 460
 461                 newpath->left = newpath->entries =
 462                         ext2fs_le16_to_cpu(eh->eh_entries);
 463                 newpath->max_entries = ext2fs_le16_to_cpu(eh->eh_max);
 464
 465                 if (path->left > 0) {
 466                         ix++;
 467                         newpath->end_blk = ext2fs_le32_to_cpu(ix->ei_block);
 468                 } else
 469                         newpath->end_blk = path->end_blk;
 470
 471                 path = newpath;
 472                 if (op == EXT2_EXTENT_DOWN) {
 473                         ix = EXT_FIRST_INDEX((struct ext3_extent_header *) eh);
 474                         path->curr = ix;
 475                         path->left = path->entries - 1;
 476                         path->visit_num = 0;
 477                 } else {
 478                         ix = EXT_LAST_INDEX((struct ext3_extent_header *) eh);
 479                         path->curr = ix;
 480                         path->left = 0;
 481                         if (handle->level < handle->max_depth)
 482                                 path->visit_num = 1;
 483                 }
 484 #ifdef DEBUG
 485                 printf("Down to level %d/%d, end_blk=%llu\n",
 486                            handle->level, handle->max_depth,
 487                            path->end_blk);
 488 #endif
 489                 break;
 490         default:
 491                 return EXT2_ET_OP_NOT_SUPPORTED;
 492         }
 493
 494         if (!ix)
 495                 return EXT2_ET_NO_CURRENT_NODE;
 496
 497         extent->e_flags = 0;
 498 #ifdef DEBUG
 499         printf("(Left %d)\n", path->left);
 500 #endif
 501
 502         if (handle->level == handle->max_depth) {
 503                 ex = (struct ext3_extent *) ix;
 504
 505                 extent->e_pblk = ext2fs_le32_to_cpu(ex->ee_start) +
 506                         ((__u64) ext2fs_le16_to_cpu(ex->ee_start_hi) << 32);
 507                 extent->e_lblk = ext2fs_le32_to_cpu(ex->ee_block);
 508                 extent->e_len = ext2fs_le16_to_cpu(ex->ee_len);
 509                 extent->e_flags |= EXT2_EXTENT_FLAGS_LEAF;
 510                 if (extent->e_len > EXT_INIT_MAX_LEN) {
 511                         extent->e_len -= EXT_INIT_MAX_LEN;
 512                         extent->e_flags |= EXT2_EXTENT_FLAGS_UNINIT;
 513                 }
 514         } else {
 515                 extent->e_pblk = ext2fs_le32_to_cpu(ix->ei_leaf) +
 516                         ((__u64) ext2fs_le16_to_cpu(ix->ei_leaf_hi) << 32);
 517                 extent->e_lblk = ext2fs_le32_to_cpu(ix->ei_block);
 518                 if (path->left > 0) {
 519                         ix++;
 520                         end_blk = ext2fs_le32_to_cpu(ix->ei_block);
 521                 } else
 522                         end_blk = path->end_blk;
 523
 524                 extent->e_len = end_blk - extent->e_lblk;
 525         }
 526         if (path->visit_num)
 527                 extent->e_flags |= EXT2_EXTENT_FLAGS_SECOND_VISIT;
 528
 529         if (((orig_op == EXT2_EXTENT_NEXT_LEAF) ||
 530              (orig_op == EXT2_EXTENT_PREV_LEAF)) &&
 531             (handle->level != handle->max_depth))
 532                 goto retry;
 533
 534         if ((orig_op == EXT2_EXTENT_LAST_LEAF) &&
 535             ((handle->level != handle->max_depth) ||
 536              (path->left != 0)))
 537                 goto retry;
 538
 539         return 0;
 540 }
 541
 542 static errcode_t update_path(ext2_extent_handle_t handle)
 543 {
 544         blk64_t                         blk;
 545         errcode_t                       retval;
 546         struct ext3_extent_idx          *ix;
 547
 548         if (handle->level == 0) {
 549                 retval = ext2fs_write_inode(handle->fs, handle->ino,
 550                                             handle->inode);
 551         } else {
 552                 ix = handle->path[handle->level - 1].curr;
 553                 blk = ext2fs_le32_to_cpu(ix->ei_leaf) +
 554                         ((__u64) ext2fs_le16_to_cpu(ix->ei_leaf_hi) << 32);
 555
 556                 retval = io_channel_write_blk(handle->fs->io,
 557                                       blk, 1, handle->path[handle->level].buf);
 558         }
 559         return retval;
 560 }
 561
 562 #if 0
 563 errcode_t ext2fs_extent_save_path(ext2_extent_handle_t handle,
 564                                   ext2_extent_path_t *ret_path)
 565 {
 566         ext2_extent_path_t      save_path;
 567         struct ext2fs_extent    extent;
 568         struct ext2_extent_info info;
 569         errcode_t               retval;
 570
 571         retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
 572         if (retval)
 573                 return retval;
 574
 575         retval = ext2fs_extent_get_info(handle, &info);
 576         if (retval)
 577                 return retval;
 578
 579         retval = ext2fs_get_mem(sizeof(struct ext2_extent_path), &save_path);
 580         if (retval)
 581                 return retval;
 582         memset(save_path, 0, sizeof(struct ext2_extent_path));
 583
 584         save_path->magic = EXT2_ET_MAGIC_EXTENT_PATH;
 585         save_path->leaf_height = info.max_depth - info.curr_level - 1;
 586         save_path->lblk = extent.e_lblk;
 587
 588         *ret_path = save_path;
 589         return 0;
 590 }
 591
 592 errcode_t ext2fs_extent_free_path(ext2_extent_path_t path)
 593 {
 594         EXT2_CHECK_MAGIC(path, EXT2_ET_MAGIC_EXTENT_PATH);
 595
 596         ext2fs_free_mem(&path);
 597         return 0;
 598 }
 599 #endif
 600
 601 /*
 602  * Go to the node at leaf_level which contains logical block blk.
 603  *
 604  * leaf_level is height from the leaf node level, i.e.
 605  * leaf_level 0 is at leaf node, leaf_level 1 is 1 above etc.
 606  *
 607  * If "blk" has no mapping (hole) then handle is left at last
 608  * extent before blk.
 609  */
 610 static errcode_t extent_goto(ext2_extent_handle_t handle,
 611                              int leaf_level, blk64_t blk)
 612 {
 613         struct ext2fs_extent    extent;
 614         errcode_t               retval;
 615
 616         retval = ext2fs_extent_get(handle, EXT2_EXTENT_ROOT, &extent);
 617         if (retval) {
 618                 if (retval == EXT2_ET_EXTENT_NO_NEXT)
 619                         retval = EXT2_ET_EXTENT_NOT_FOUND;
 620                 return retval;
 621         }
 622
 623         if (leaf_level > handle->max_depth) {
 624 #ifdef DEBUG
 625                 printf("leaf level %d greater than tree depth %d\n",
 626                         leaf_level, handle->max_depth);
 627 #endif
 628                 return EXT2_ET_OP_NOT_SUPPORTED;
 629         }
 630
 631         dbg_print_extent("root", &extent);
 632         while (1) {
 633                 if (handle->max_depth - handle->level == leaf_level) {
 634                         /* block is in this &extent */
 635                         if ((blk >= extent.e_lblk) &&
 636                             (blk < extent.e_lblk + extent.e_len))
 637                                 return 0;
 638                         if (blk < extent.e_lblk) {
 639                                 retval = ext2fs_extent_get(handle,
 640                                                            EXT2_EXTENT_PREV_SIB,
 641                                                            &extent);
 642                                 return EXT2_ET_EXTENT_NOT_FOUND;
 643                         }
 644                         retval = ext2fs_extent_get(handle,
 645                                                    EXT2_EXTENT_NEXT_SIB,
 646                                                    &extent);
 647                         if (retval == EXT2_ET_EXTENT_NO_NEXT)
 648                                 return EXT2_ET_EXTENT_NOT_FOUND;
 649                         if (retval)
 650                                 return retval;
 651                         continue;
 652                 }
 653
 654                 retval = ext2fs_extent_get(handle, EXT2_EXTENT_NEXT_SIB,
 655                                            &extent);
 656                 if (retval == EXT2_ET_EXTENT_NO_NEXT)
 657                         goto go_down;
 658                 if (retval)
 659                         return retval;
 660
 661                 dbg_print_extent("next", &extent);
 662                 if (blk == extent.e_lblk)
 663                         goto go_down;
 664                 if (blk > extent.e_lblk)
 665                         continue;
 666
 667                 retval = ext2fs_extent_get(handle, EXT2_EXTENT_PREV_SIB,
 668                                            &extent);
 669                 if (retval)
 670                         return retval;
 671
 672                 dbg_print_extent("prev", &extent);
 673
 674         go_down:
 675                 retval = ext2fs_extent_get(handle, EXT2_EXTENT_DOWN,
 676                                            &extent);
 677                 if (retval)
 678                         return retval;
 679
 680                 dbg_print_extent("down", &extent);
 681         }
 682 }
 683
 684 errcode_t ext2fs_extent_goto(ext2_extent_handle_t handle,
 685                              blk64_t blk)
 686 {
 687         return extent_goto(handle, 0, blk);
 688 }
 689
 690 /*
 691  * Traverse back up to root fixing parents of current node as needed.
 692  *
 693  * If we changed start of first entry in a node, fix parent index start
 694  * and so on.
 695  *
 696  * Safe to call for any position in node; if not at the first entry,
 697  * will  simply return.
 698  */
 699 static errcode_t ext2fs_extent_fix_parents(ext2_extent_handle_t handle)
 700 {
 701         int                             retval = 0;
 702         blk64_t                         start;
 703         struct extent_path              *path;
 704         struct ext2fs_extent            extent;
 705
 706         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
 707
 708         if (!(handle->fs->flags & EXT2_FLAG_RW))
 709                 return EXT2_ET_RO_FILSYS;
 710
 711         if (!handle->path)
 712                 return EXT2_ET_NO_CURRENT_NODE;
 713
 714         path = handle->path + handle->level;
 715         if (!path->curr)
 716                 return EXT2_ET_NO_CURRENT_NODE;
 717
 718         retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
 719         if (retval)
 720                 goto done;
 721
 722         /* modified node's start block */
 723         start = extent.e_lblk;
 724
 725         /* traverse up until index not first, or startblk matches, or top */
 726         while (handle->level > 0 &&
 727                (path->left == path->entries - 1)) {
 728                 retval = ext2fs_extent_get(handle, EXT2_EXTENT_UP, &extent);
 729                 if (retval)
 730                         goto done;
 731                 if (extent.e_lblk == start)
 732                         break;
 733                 path = handle->path + handle->level;
 734                 extent.e_len += (extent.e_lblk - start);
 735                 extent.e_lblk = start;
 736                 retval = ext2fs_extent_replace(handle, 0, &extent);
 737                 if (retval)
 738                         goto done;
 739                 update_path(handle);
 740         }
 741
 742         /* put handle back to where we started */
 743         retval = ext2fs_extent_goto(handle, start);
 744 done:
 745         return retval;
 746 }
 747
 748 errcode_t ext2fs_extent_replace(ext2_extent_handle_t handle,
 749                                 int flags EXT2FS_ATTR((unused)),
 750                                 struct ext2fs_extent *extent)
 751 {
 752         struct extent_path              *path;
 753         struct ext3_extent_idx          *ix;
 754         struct ext3_extent              *ex;
 755
 756         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
 757
 758         if (!(handle->fs->flags & EXT2_FLAG_RW))
 759                 return EXT2_ET_RO_FILSYS;
 760
 761         if (!handle->path)
 762                 return EXT2_ET_NO_CURRENT_NODE;
 763
 764         path = handle->path + handle->level;
 765         if (!path->curr)
 766                 return EXT2_ET_NO_CURRENT_NODE;
 767
 768         if (handle->level == handle->max_depth) {
 769                 ex = path->curr;
 770
 771                 ex->ee_block = ext2fs_cpu_to_le32(extent->e_lblk);
 772                 ex->ee_start = ext2fs_cpu_to_le32(extent->e_pblk & 0xFFFFFFFF);
 773                 ex->ee_start_hi = ext2fs_cpu_to_le16(extent->e_pblk >> 32);
 774                 if (extent->e_flags & EXT2_EXTENT_FLAGS_UNINIT) {
 775                         if (extent->e_len > EXT_UNINIT_MAX_LEN)
 776                                 return EXT2_ET_EXTENT_INVALID_LENGTH;
 777                         ex->ee_len = ext2fs_cpu_to_le16(extent->e_len +
 778                                                         EXT_INIT_MAX_LEN);
 779                 } else {
 780                         if (extent->e_len > EXT_INIT_MAX_LEN)
 781                                 return EXT2_ET_EXTENT_INVALID_LENGTH;
 782                         ex->ee_len = ext2fs_cpu_to_le16(extent->e_len);
 783                 }
 784         } else {
 785                 ix = path->curr;
 786
 787                 ix->ei_leaf = ext2fs_cpu_to_le32(extent->e_pblk & 0xFFFFFFFF);
 788                 ix->ei_leaf_hi = ext2fs_cpu_to_le16(extent->e_pblk >> 32);
 789                 ix->ei_block = ext2fs_cpu_to_le32(extent->e_lblk);
 790                 ix->ei_unused = 0;
 791         }
 792         update_path(handle);
 793         return 0;
 794 }
 795
 796 /*
 797  * allocate a new block, move half the current node to it, and update parent
 798  *
 799  * handle will be left pointing at original record.
 800  */
 801 static errcode_t extent_node_split(ext2_extent_handle_t handle)
 802 {
 803         errcode_t                       retval = 0;
 804         blk_t                           new_node_pblk;
 805         blk64_t                         new_node_start;
 806         blk64_t                         orig_lblk;
 807         blk64_t                         goal_blk = 0;
 808         int                             orig_height;
 809         char                            *block_buf = NULL;
 810         struct ext2fs_extent            extent;
 811         struct extent_path              *path, *newpath = 0;
 812         struct ext3_extent_header       *eh, *neweh;
 813         int                             tocopy;
 814         int                             new_root = 0;
 815         struct ext2_extent_info         info;
 816
 817         /* basic sanity */
 818         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
 819
 820         if (!(handle->fs->flags & EXT2_FLAG_RW))
 821                 return EXT2_ET_RO_FILSYS;
 822
 823         if (!handle->path)
 824                 return EXT2_ET_NO_CURRENT_NODE;
 825
 826 #ifdef DEBUG
 827         printf("splitting node at level %d\n", handle->level);
 828 #endif
 829         retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
 830         if (retval)
 831                 goto done;
 832
 833         retval = ext2fs_extent_get_info(handle, &info);
 834         if (retval)
 835                 goto done;
 836
 837         /* save the position we were originally splitting... */
 838         orig_height = info.max_depth - info.curr_level;
 839         orig_lblk = extent.e_lblk;
 840
 841         /* Is there room in the parent for a new entry? */
 842         if (handle->level &&
 843                         (handle->path[handle->level - 1].entries >=
 844                          handle->path[handle->level - 1].max_entries)) {
 845
 846 #ifdef DEBUG
 847                 printf("parent level %d full; splitting it too\n",
 848                                                         handle->level - 1);
 849 #endif
 850                 /* split the parent */
 851                 retval = ext2fs_extent_get(handle, EXT2_EXTENT_UP, &extent);
 852                 if (retval)
 853                         goto done;
 854                 goal_blk = extent.e_pblk;
 855
 856                 retval = extent_node_split(handle);
 857                 if (retval)
 858                         goto done;
 859
 860                 /* get handle back to our original split position */
 861                 retval = extent_goto(handle, orig_height, orig_lblk);
 862                 if (retval)
 863                         goto done;
 864         }
 865
 866         /* At this point, parent should have room for this split */
 867         path = handle->path + handle->level;
 868         if (!path->curr)
 869                 return EXT2_ET_NO_CURRENT_NODE;
 870
 871         /* extent header of the current node we'll split */
 872         eh = (struct ext3_extent_header *)path->buf;
 873
 874         /* splitting root level means moving them all out */
 875         if (handle->level == 0) {
 876                 new_root = 1;
 877                 tocopy = ext2fs_le16_to_cpu(eh->eh_entries);
 878                 retval = ext2fs_get_mem(((handle->max_depth+2) *
 879                                          sizeof(struct extent_path)),
 880                                         &newpath);
 881                 if (retval)
 882                         goto done;
 883                 memset(newpath, 0,
 884                        ((handle->max_depth+2) * sizeof(struct extent_path)));
 885         } else {
 886                 tocopy = ext2fs_le16_to_cpu(eh->eh_entries) / 2;
 887         }
 888
 889 #ifdef DEBUG
 890         printf("will copy out %d of %d entries at level %d\n",
 891                                 tocopy, ext2fs_le16_to_cpu(eh->eh_entries),
 892                                 handle->level);
 893 #endif
 894
 895         if (!tocopy) {
 896 #ifdef DEBUG
 897                 printf("Nothing to copy to new block!\n");
 898 #endif
 899                 retval = EXT2_ET_CANT_SPLIT_EXTENT;
 900                 goto done;
 901         }
 902
 903         /* first we need a new block, or can do nothing. */
 904         block_buf = malloc(handle->fs->blocksize);
 905         if (!block_buf) {
 906                 retval = ENOMEM;
 907                 goto done;
 908         }
 909
 910         if (!goal_blk) {
 911                 dgrp_t  group = ext2fs_group_of_ino(handle->fs, handle->ino);
 912                 __u8    log_flex = handle->fs->super->s_log_groups_per_flex;
 913
 914                 if (log_flex)
 915                         group = group & ~((1 << (log_flex)) - 1);
 916                 goal_blk = (group * handle->fs->super->s_blocks_per_group) +
 917                         handle->fs->super->s_first_data_block;
 918         }
 919         retval = ext2fs_alloc_block(handle->fs, (blk_t) goal_blk, block_buf,
 920                                     &new_node_pblk);
 921         if (retval)
 922                 goto done;
 923
 924 #ifdef DEBUG
 925         printf("will copy to new node at block %lu\n", new_node_pblk);
 926 #endif
 927
 928         /* Copy data into new block buffer */
 929         /* First the header for the new block... */
 930         neweh = (struct ext3_extent_header *) block_buf;
 931         memcpy(neweh, eh, sizeof(struct ext3_extent_header));
 932         neweh->eh_entries = ext2fs_cpu_to_le16(tocopy);
 933         neweh->eh_max = ext2fs_cpu_to_le16((handle->fs->blocksize -
 934                          sizeof(struct ext3_extent_header)) /
 935                                 sizeof(struct ext3_extent));
 936
 937         /* then the entries for the new block... */
 938         memcpy(EXT_FIRST_INDEX(neweh),
 939                 EXT_FIRST_INDEX(eh) +
 940                         (ext2fs_le16_to_cpu(eh->eh_entries) - tocopy),
 941                 sizeof(struct ext3_extent_idx) * tocopy);
 942
 943         new_node_start = ext2fs_le32_to_cpu(EXT_FIRST_INDEX(neweh)->ei_block);
 944
 945         /* ...and write the new node block out to disk. */
 946         retval = io_channel_write_blk(handle->fs->io, new_node_pblk, 1, block_buf);
 947
 948         if (retval)
 949                 goto done;
 950
 951         /* OK! we've created the new node; now adjust the tree */
 952
 953         /* current path now has fewer active entries, we copied some out */
 954         if (handle->level == 0) {
 955                 memcpy(newpath, path,
 956                        sizeof(struct extent_path) * (handle->max_depth+1));
 957                 handle->path = newpath;
 958                 newpath = path;
 959                 path = handle->path;
 960                 path->entries = 1;
 961                 path->left = path->max_entries - 1;
 962                 handle->max_depth++;
 963                 eh->eh_depth = ext2fs_cpu_to_le16(handle->max_depth);
 964         } else {
 965                 path->entries -= tocopy;
 966                 path->left -= tocopy;
 967         }
 968
 969         eh->eh_entries = ext2fs_cpu_to_le16(path->entries);
 970         /* this writes out the node, incl. the modified header */
 971         retval = update_path(handle);
 972         if (retval)
 973                 goto done;
 974
 975         /* now go up and insert/replace index for new node we created */
 976         if (new_root) {
 977                 retval = ext2fs_extent_get(handle, EXT2_EXTENT_FIRST_SIB, &extent);
 978                 if (retval)
 979                         goto done;
 980
 981                 extent.e_lblk = new_node_start;
 982                 extent.e_pblk = new_node_pblk;
 983                 extent.e_len = handle->path[0].end_blk - extent.e_lblk;
 984                 retval = ext2fs_extent_replace(handle, 0, &extent);
 985                 if (retval)
 986                         goto done;
 987         } else {
 988                 __u32 new_node_length;
 989
 990                 retval = ext2fs_extent_get(handle, EXT2_EXTENT_UP, &extent);
 991                 /* will insert after this one; it's length is shorter now */
 992                 new_node_length = new_node_start - extent.e_lblk;
 993                 extent.e_len -= new_node_length;
 994                 retval = ext2fs_extent_replace(handle, 0, &extent);
 995                 if (retval)
 996                         goto done;
 997
 998                 /* now set up the new extent and insert it */
 999                 extent.e_lblk = new_node_start;
1000                 extent.e_pblk = new_node_pblk;
1001                 extent.e_len = new_node_length;
1002                 retval = ext2fs_extent_insert(handle, EXT2_EXTENT_INSERT_AFTER, &extent);
1003                 if (retval)
1004                         goto done;
1005         }
1006
1007         /* get handle back to our original position */
1008         retval = extent_goto(handle, orig_height, orig_lblk);
1009         if (retval)
1010                 goto done;
1011
1012         /* new node hooked in, so update inode block count (do this here?) */
1013         handle->inode->i_blocks += handle->fs->blocksize / 512;
1014         retval = ext2fs_write_inode(handle->fs, handle->ino,
1015                                     handle->inode);
1016         if (retval)
1017                 goto done;
1018
1019 done:
1020         if (newpath)
1021                 ext2fs_free_mem(&newpath);
1022         free(block_buf);
1023
1024         return retval;
1025 }
1026
1027 errcode_t ext2fs_extent_insert(ext2_extent_handle_t handle, int flags,
1028                                       struct ext2fs_extent *extent)
1029 {
1030         struct extent_path              *path;
1031         struct ext3_extent_idx          *ix;
1032         struct ext3_extent_header       *eh;
1033         errcode_t                       retval;
1034
1035         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
1036
1037         if (!(handle->fs->flags & EXT2_FLAG_RW))
1038                 return EXT2_ET_RO_FILSYS;
1039
1040         if (!handle->path)
1041                 return EXT2_ET_NO_CURRENT_NODE;
1042
1043         path = handle->path + handle->level;
1044
1045         if (path->entries >= path->max_entries) {
1046                 if (flags & EXT2_EXTENT_INSERT_NOSPLIT) {
1047                         return EXT2_ET_CANT_INSERT_EXTENT;
1048                 } else {
1049 #ifdef DEBUG
1050                         printf("node full (level %d) - splitting\n",
1051                                    handle->level);
1052 #endif
1053                         retval = extent_node_split(handle);
1054                         if (retval)
1055                                 return retval;
1056                         path = handle->path + handle->level;
1057                 }
1058         }
1059
1060         eh = (struct ext3_extent_header *) path->buf;
1061         if (path->curr) {
1062                 ix = path->curr;
1063                 if (flags & EXT2_EXTENT_INSERT_AFTER) {
1064                         ix++;
1065                         path->left--;
1066                 }
1067         } else
1068                 ix = EXT_FIRST_INDEX(eh);
1069
1070         path->curr = ix;
1071
1072         if (path->left >= 0)
1073                 memmove(ix + 1, ix,
1074                         (path->left+1) * sizeof(struct ext3_extent_idx));
1075         path->left++;
1076         path->entries++;
1077
1078         eh = (struct ext3_extent_header *) path->buf;
1079         eh->eh_entries = ext2fs_cpu_to_le16(path->entries);
1080
1081         retval = ext2fs_extent_replace(handle, 0, extent);
1082         if (retval)
1083                 goto errout;
1084
1085         retval = update_path(handle);
1086         if (retval)
1087                 goto errout;
1088
1089         return 0;
1090
1091 errout:
1092         ext2fs_extent_delete(handle, 0);
1093         return retval;
1094 }
1095
1096 /*
1097  * Sets the physical block for a logical file block in the extent tree.
1098  *
1099  * May: map unmapped, unmap mapped, or remap mapped blocks.
1100  *
1101  * Mapping an unmapped block adds a single-block extent.
1102  *
1103  * Unmapping first or last block modifies extent in-place
1104  *  - But may need to fix parent's starts too in first-block case
1105  *
1106  * Mapping any unmapped block requires adding a (single-block) extent
1107  * and inserting into proper point in tree.
1108  *
1109  * Modifying (unmapping or remapping) a block in the middle
1110  * of an extent requires splitting the extent.
1111  *  - Remapping case requires new single-block extent.
1112  *
1113  * Remapping first or last block adds an extent.
1114  *
1115  * We really need extent adding to be smart about merging.
1116  */
1117
1118 errcode_t ext2fs_extent_set_bmap(ext2_extent_handle_t handle,
1119                                  blk64_t logical, blk64_t physical, int flags)
1120 {
1121         errcode_t               ec, retval = 0;
1122         int                     mapped = 1; /* logical is mapped? */
1123         int                     orig_height;
1124         int                     extent_uninit = 0;
1125         int                     new_uninit = 0;
1126         int                     max_len = EXT_INIT_MAX_LEN;
1127         blk64_t                 orig_lblk;
1128         struct extent_path      *path;
1129         struct ext2fs_extent    extent;
1130         struct ext2fs_extent    newextent;
1131         struct ext2_extent_info info;
1132
1133         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
1134
1135         if (!(handle->fs->flags & EXT2_FLAG_RW))
1136                 return EXT2_ET_RO_FILSYS;
1137
1138         if (!handle->path)
1139                 return EXT2_ET_NO_CURRENT_NODE;
1140
1141         path = handle->path + handle->level;
1142
1143         if (flags & EXT2_EXTENT_SET_BMAP_UNINIT) {
1144                 new_uninit = 1;
1145                 max_len = EXT_UNINIT_MAX_LEN;
1146         }
1147
1148         /* if (re)mapping, set up new extent to insert */
1149         if (physical) {
1150                 newextent.e_len = 1;
1151                 newextent.e_pblk = physical;
1152                 newextent.e_lblk = logical;
1153                 newextent.e_flags = EXT2_EXTENT_FLAGS_LEAF;
1154                 if (new_uninit)
1155                         newextent.e_flags |= EXT2_EXTENT_FLAGS_UNINIT;
1156         }
1157
1158         /* special case if the extent tree is completely empty */
1159         if ((handle->max_depth == 0) && (path->entries == 0)) {
1160                 retval = ext2fs_extent_insert(handle, 0, &newextent);
1161                 return retval;
1162         }
1163
1164         /* save our original location in the extent tree */
1165         if ((retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT,
1166                                         &extent))) {
1167                 if (retval != EXT2_ET_NO_CURRENT_NODE)
1168                         return retval;
1169                 memset(&extent, 0, sizeof(extent));
1170         }
1171         if ((retval = ext2fs_extent_get_info(handle, &info)))
1172                 return retval;
1173         orig_height = info.max_depth - info.curr_level;
1174         orig_lblk = extent.e_lblk;
1175
1176 again:
1177         /* go to the logical spot we want to (re/un)map */
1178         retval = ext2fs_extent_goto(handle, logical);
1179         if (retval) {
1180                 if (retval == EXT2_ET_EXTENT_NOT_FOUND) {
1181                         retval = 0;
1182                         mapped = 0;
1183                         if (!physical) {
1184 #ifdef DEBUG
1185                                 printf("block %llu already unmapped\n",
1186                                         logical);
1187 #endif
1188                                 goto done;
1189                         }
1190                 } else
1191                         goto done;
1192         }
1193
1194         /*
1195          * This may be the extent *before* the requested logical,
1196          * if it's currently unmapped.
1197          */
1198         retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
1199         if (retval)
1200                 goto done;
1201         if (extent.e_flags & EXT2_EXTENT_FLAGS_UNINIT)
1202                 extent_uninit = 1;
1203
1204         /* check if already pointing to the requested physical */
1205         if (mapped && (new_uninit == extent_uninit) &&
1206             (extent.e_pblk + (logical - extent.e_lblk) == physical)) {
1207 #ifdef DEBUG
1208                 printf("physical block (at %llu) unchanged\n", logical);
1209 #endif
1210                 goto done;
1211         }
1212
1213         if (!mapped) {
1214 #ifdef DEBUG
1215                 printf("mapping unmapped logical block %llu\n", logical);
1216 #endif
1217                 if ((logical == extent.e_lblk + extent.e_len) &&
1218                     (physical == extent.e_pblk + extent.e_len) &&
1219                     (new_uninit == extent_uninit) &&
1220                     ((int) extent.e_len < max_len-1)) {
1221                         extent.e_len++;
1222                         retval = ext2fs_extent_replace(handle, 0, &extent);
1223                 } else if (logical < extent.e_lblk)
1224                         retval = ext2fs_extent_insert(handle, 0, &newextent);
1225                 else
1226                         retval = ext2fs_extent_insert(handle,
1227                                       EXT2_EXTENT_INSERT_AFTER, &newextent);
1228                 if (retval)
1229                         goto done;
1230                 retval = ext2fs_extent_fix_parents(handle);
1231                 if (retval)
1232                         goto done;
1233         } else if ((logical == extent.e_lblk) && (extent.e_len == 1))  {
1234 #ifdef DEBUG
1235                 printf("(re/un)mapping only block in extent\n");
1236 #endif
1237                 if (physical) {
1238                         retval = ext2fs_extent_replace(handle, 0, &newextent);
1239                 } else {
1240                         retval = ext2fs_extent_delete(handle, 0);
1241                         if (retval)
1242                                 goto done;
1243                         ec = ext2fs_extent_fix_parents(handle);
1244                         if (ec != EXT2_ET_NO_CURRENT_NODE)
1245                                 retval = ec;
1246                 }
1247
1248                 if (retval)
1249                         goto done;
1250         } else if (logical == extent.e_lblk + extent.e_len - 1)  {
1251 #ifdef DEBUG
1252                 printf("(re/un)mapping last block in extent\n");
1253 #endif
1254                 /* Make sure insert works before replacing old extent */
1255                 if (physical) {
1256                         retval = ext2fs_extent_insert(handle,
1257                                         EXT2_EXTENT_INSERT_AFTER, &newextent);
1258                         if (retval)
1259                                 goto done;
1260                         /* Now pointing at inserted extent; move back to prev */
1261                         retval = ext2fs_extent_goto(handle, logical - 1);
1262                         if (retval)
1263                                 goto done;
1264                 }
1265                 extent.e_len--;
1266                 retval = ext2fs_extent_replace(handle, 0, &extent);
1267                 if (retval)
1268                         goto done;
1269         } else if (logical == extent.e_lblk) {
1270 #ifdef DEBUG
1271                 printf("(re/un)mapping first block in extent\n");
1272 #endif
1273                 extent.e_pblk++;
1274                 extent.e_lblk++;
1275                 extent.e_len--;
1276                 retval = ext2fs_extent_replace(handle, 0, &extent);
1277                 if (retval)
1278                         goto done;
1279                 if (physical) {
1280                         /*
1281                          * We've removed the old block, now rely on
1282                          * the optimized hueristics for adding a new
1283                          * mapping with appropriate merging if necessary.
1284                          */
1285                         goto again;
1286                 } else {
1287                         retval = ext2fs_extent_fix_parents(handle);
1288                         if (retval)
1289                                 goto done;
1290                 }
1291         } else {
1292                 __u32   orig_length;
1293
1294 #ifdef DEBUG
1295                 printf("(re/un)mapping in middle of extent\n");
1296 #endif
1297                 /* need to split this extent; later */
1298
1299                 orig_length = extent.e_len;
1300
1301                 /* shorten pre-split extent */
1302                 extent.e_len = (logical - extent.e_lblk);
1303                 retval = ext2fs_extent_replace(handle, 0, &extent);
1304                 if (retval)
1305                         goto done;
1306                 /* insert our new extent, if any */
1307                 if (physical) {
1308                         /* insert new extent after current */
1309                         retval = ext2fs_extent_insert(handle,
1310                                         EXT2_EXTENT_INSERT_AFTER, &newextent);
1311                         if (retval)
1312                                 goto done;
1313                 }
1314                 /* add post-split extent */
1315                 extent.e_pblk += extent.e_len + 1;
1316                 extent.e_lblk += extent.e_len + 1;
1317                 extent.e_len = orig_length - extent.e_len - 1;
1318                 retval = ext2fs_extent_insert(handle,
1319                                 EXT2_EXTENT_INSERT_AFTER, &extent);
1320                 if (retval)
1321                         goto done;
1322         }
1323
1324 done:
1325         /* get handle back to its position */
1326         if (orig_height > handle->max_depth)
1327                 orig_height = handle->max_depth; /* In case we shortened the tree */
1328         extent_goto(handle, orig_height, orig_lblk);
1329         return retval;
1330 }
1331
1332 errcode_t ext2fs_extent_delete(ext2_extent_handle_t handle, int flags)
1333 {
1334         struct extent_path              *path;
1335         char                            *cp;
1336         struct ext3_extent_header       *eh;
1337         errcode_t                       retval = 0;
1338
1339         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
1340
1341         if (!(handle->fs->flags & EXT2_FLAG_RW))
1342                 return EXT2_ET_RO_FILSYS;
1343
1344         if (!handle->path)
1345                 return EXT2_ET_NO_CURRENT_NODE;
1346
1347         path = handle->path + handle->level;
1348         if (!path->curr)
1349                 return EXT2_ET_NO_CURRENT_NODE;
1350
1351         cp = path->curr;
1352
1353         if (path->left) {
1354                 memmove(cp, cp + sizeof(struct ext3_extent_idx),
1355                         path->left * sizeof(struct ext3_extent_idx));
1356                 path->left--;
1357         } else {
1358                 struct ext3_extent_idx  *ix = path->curr;
1359                 ix--;
1360                 path->curr = ix;
1361         }
1362         if (--path->entries == 0)
1363                 path->curr = 0;
1364
1365         /* if non-root node has no entries left, remove it & parent ptr to it */
1366         if (path->entries == 0 && handle->level) {
1367                 if (!(flags & EXT2_EXTENT_DELETE_KEEP_EMPTY)) {
1368                         struct ext2fs_extent    extent;
1369
1370                         retval = ext2fs_extent_get(handle, EXT2_EXTENT_UP,
1371                                                                 &extent);
1372                         if (retval)
1373                                 return retval;
1374
1375                         retval = ext2fs_extent_delete(handle, flags);
1376                         handle->inode->i_blocks -= handle->fs->blocksize / 512;
1377                         retval = ext2fs_write_inode(handle->fs, handle->ino,
1378                                                     handle->inode);
1379                         ext2fs_block_alloc_stats(handle->fs, extent.e_pblk, -1);
1380                 }
1381         } else {
1382                 eh = (struct ext3_extent_header *) path->buf;
1383                 eh->eh_entries = ext2fs_cpu_to_le16(path->entries);
1384                 if ((path->entries == 0) && (handle->level == 0))
1385                         eh->eh_depth = handle->max_depth = 0;
1386                 retval = update_path(handle);
1387         }
1388         return retval;
1389 }
1390
1391 errcode_t ext2fs_extent_get_info(ext2_extent_handle_t handle,
1392                                  struct ext2_extent_info *info)
1393 {
1394         struct extent_path              *path;
1395
1396         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
1397
1398         memset(info, 0, sizeof(struct ext2_extent_info));
1399
1400         path = handle->path + handle->level;
1401         if (path) {
1402                 if (path->curr)
1403                         info->curr_entry = ((char *) path->curr - path->buf) /
1404                                 sizeof(struct ext3_extent_idx);
1405                 else
1406                         info->curr_entry = 0;
1407                 info->num_entries = path->entries;
1408                 info->max_entries = path->max_entries;
1409                 info->bytes_avail = (path->max_entries - path->entries) *
1410                         sizeof(struct ext3_extent);
1411         }
1412
1413         info->curr_level = handle->level;
1414         info->max_depth = handle->max_depth;
1415         info->max_lblk = ((__u64) 1 << 32) - 1;
1416         info->max_pblk = ((__u64) 1 << 48) - 1;
1417         info->max_len = (1UL << 15);
1418         info->max_uninit_len = (1UL << 15) - 1;
1419
1420         return 0;
1421 }
1422
1423 #ifdef DEBUG
1424
1425 #include "ss/ss.h"
1426
1427 #include "debugfs.h"
1428
1429 /*
1430  * Hook in new commands into debugfs
1431  */
1432 const char *debug_prog_name = "tst_extents";
1433 extern ss_request_table extent_cmds;
1434 ss_request_table *extra_cmds = &extent_cmds;
1435
1436 ext2_ino_t      current_ino = 0;
1437 ext2_extent_handle_t current_handle;
1438
1439 int common_extent_args_process(int argc, char *argv[], int min_argc,
1440                                int max_argc, const char *cmd,
1441                                const char *usage, int flags)
1442 {
1443         if (common_args_process(argc, argv, min_argc, max_argc, cmd,
1444                                 usage, flags))
1445                 return 1;
1446
1447         if (!current_handle) {
1448                 com_err(cmd, 0, "Extent handle not open");
1449                 return 1;
1450         }
1451         return 0;
1452 }
1453
1454 void do_inode(int argc, char *argv[])
1455 {
1456         ext2_ino_t      inode;
1457         int             i;
1458         struct ext3_extent_header *eh;
1459         errcode_t retval;
1460
1461         if (check_fs_open(argv[0]))
1462                 return;
1463
1464         if (argc == 1) {
1465                 if (current_ino)
1466                         printf("Current inode is %d\n", current_ino);
1467                 else
1468                         printf("No current inode\n");
1469                 return;
1470         }
1471
1472         if (common_inode_args_process(argc, argv, &inode, 0)) {
1473                 return;
1474         }
1475
1476         current_ino = 0;
1477
1478         retval = ext2fs_extent_open(current_fs, inode, &current_handle);
1479         if (retval) {
1480                 com_err(argv[1], retval, "while opening extent handle");
1481                 return;
1482         }
1483
1484         current_ino = inode;
1485
1486         printf("Loaded inode %d\n", current_ino);
1487
1488         return;
1489 }
1490
1491 void generic_goto_node(char *cmd_name, int op)
1492 {
1493         struct ext2fs_extent    extent;
1494         errcode_t               retval;
1495
1496         if (check_fs_open(cmd_name))
1497                 return;
1498
1499         if (!current_handle) {
1500                 com_err(cmd_name, 0, "Extent handle not open");
1501                 return;
1502         }
1503
1504         retval = ext2fs_extent_get(current_handle, op, &extent);
1505         if (retval) {
1506                 com_err(cmd_name, retval, 0);
1507                 return;
1508         }
1509         dbg_print_extent(0, &extent);
1510 }
1511
1512 void do_current_node(int argc, char *argv[])
1513 {
1514         generic_goto_node(argv[0], EXT2_EXTENT_CURRENT);
1515 }
1516
1517 void do_root_node(int argc, char *argv[])
1518 {
1519         generic_goto_node(argv[0], EXT2_EXTENT_ROOT);
1520 }
1521
1522 void do_last_leaf(int argc, char *argv[])
1523 {
1524         generic_goto_node(argv[0], EXT2_EXTENT_LAST_LEAF);
1525 }
1526
1527 void do_first_sib(int argc, char *argv[])
1528 {
1529         generic_goto_node(argv[0], EXT2_EXTENT_FIRST_SIB);
1530 }
1531
1532 void do_last_sib(int argc, char *argv[])
1533 {
1534         generic_goto_node(argv[0], EXT2_EXTENT_LAST_SIB);
1535 }
1536
1537 void do_next_sib(int argc, char *argv[])
1538 {
1539         generic_goto_node(argv[0], EXT2_EXTENT_NEXT_SIB);
1540 }
1541
1542 void do_prev_sib(int argc, char *argv[])
1543 {
1544         generic_goto_node(argv[0], EXT2_EXTENT_PREV_SIB);
1545 }
1546
1547 void do_next_leaf(int argc, char *argv[])
1548 {
1549         generic_goto_node(argv[0], EXT2_EXTENT_NEXT_LEAF);
1550 }
1551
1552 void do_prev_leaf(int argc, char *argv[])
1553 {
1554         generic_goto_node(argv[0], EXT2_EXTENT_PREV_LEAF);
1555 }
1556
1557 void do_next(int argc, char *argv[])
1558 {
1559         generic_goto_node(argv[0], EXT2_EXTENT_NEXT);
1560 }
1561
1562 void do_prev(int argc, char *argv[])
1563 {
1564         generic_goto_node(argv[0], EXT2_EXTENT_PREV);
1565 }
1566
1567 void do_up(int argc, char *argv[])
1568 {
1569         generic_goto_node(argv[0], EXT2_EXTENT_UP);
1570 }
1571
1572 void do_down(int argc, char *argv[])
1573 {
1574         generic_goto_node(argv[0], EXT2_EXTENT_DOWN);
1575 }
1576
1577 void do_delete_node(int argc, char *argv[])
1578 {
1579         errcode_t       retval;
1580         int             err;
1581
1582         if (common_extent_args_process(argc, argv, 1, 1, "delete_node",
1583                                        "", CHECK_FS_RW | CHECK_FS_BITMAPS))
1584                 return;
1585
1586         retval = ext2fs_extent_delete(current_handle, 0);
1587         if (retval) {
1588                 com_err(argv[0], retval, 0);
1589                 return;
1590         }
1591         if (current_handle->path && current_handle->path[0].curr)
1592                 do_current_node(argc, argv);
1593 }
1594
1595 void do_replace_node(int argc, char *argv[])
1596 {
1597         const char      *usage = "[--uninit] <lblk> <len> <pblk>";
1598         errcode_t       retval;
1599         struct ext2fs_extent extent;
1600         int err;
1601
1602         if (common_extent_args_process(argc, argv, 3, 5, "replace_node",
1603                                        usage, CHECK_FS_RW | CHECK_FS_BITMAPS))
1604                 return;
1605
1606         extent.e_flags = 0;
1607
1608         if (!strcmp(argv[1], "--uninit")) {
1609                 argc--;
1610                 argv++;
1611                 extent.e_flags |= EXT2_EXTENT_FLAGS_UNINIT;
1612         }
1613
1614         if (argc != 4) {
1615                 fprintf(stderr, "Usage: %s %s\n", argv[0], usage);
1616                 return;
1617         }
1618
1619         extent.e_lblk = parse_ulong(argv[1], argv[0], "logical block", &err);
1620         if (err)
1621                 return;
1622
1623         extent.e_len = parse_ulong(argv[2], argv[0], "logical block", &err);
1624         if (err)
1625                 return;
1626
1627         extent.e_pblk = parse_ulong(argv[3], argv[0], "logical block", &err);
1628         if (err)
1629                 return;
1630
1631         retval = ext2fs_extent_replace(current_handle, 0, &extent);
1632         if (retval) {
1633                 com_err(argv[0], retval, 0);
1634                 return;
1635         }
1636         do_current_node(argc, argv);
1637 }
1638
1639 void do_split_node(int argc, char *argv[])
1640 {
1641         errcode_t       retval;
1642         struct ext2fs_extent extent;
1643         int err;
1644
1645         if (common_extent_args_process(argc, argv, 1, 1, "split_node",
1646                                        "", CHECK_FS_RW | CHECK_FS_BITMAPS))
1647                 return;
1648
1649         retval = extent_node_split(current_handle);
1650         if (retval) {
1651                 com_err(argv[0], retval, 0);
1652                 return;
1653         }
1654         do_current_node(argc, argv);
1655 }
1656
1657 void do_insert_node(int argc, char *argv[])
1658 {
1659         const char      *usage = "[--after] [--uninit] <lblk> <len> <pblk>";
1660         errcode_t       retval;
1661         struct ext2fs_extent extent;
1662         char *cmd;
1663         int err;
1664         int flags = 0;
1665
1666         if (common_extent_args_process(argc, argv, 3, 6, "insert_node",
1667                                        usage, CHECK_FS_RW | CHECK_FS_BITMAPS))
1668                 return;
1669
1670         cmd = argv[0];
1671
1672         extent.e_flags = 0;
1673
1674         while (argc > 2) {
1675                 if (!strcmp(argv[1], "--after")) {
1676                         argc--;
1677                         argv++;
1678                         flags |= EXT2_EXTENT_INSERT_AFTER;
1679                         continue;
1680                 }
1681                 if (!strcmp(argv[1], "--uninit")) {
1682                         argc--;
1683                         argv++;
1684                         extent.e_flags |= EXT2_EXTENT_FLAGS_UNINIT;
1685                         continue;
1686                 }
1687                 break;
1688         }
1689
1690         if (argc != 4) {
1691                 fprintf(stderr, "usage: %s %s\n", cmd, usage);
1692                 return;
1693         }
1694
1695         extent.e_lblk = parse_ulong(argv[1], cmd,
1696                                     "logical block", &err);
1697         if (err)
1698                 return;
1699
1700         extent.e_len = parse_ulong(argv[2], cmd,
1701                                     "length", &err);
1702         if (err)
1703                 return;
1704
1705         extent.e_pblk = parse_ulong(argv[3], cmd,
1706                                     "pysical block", &err);
1707         if (err)
1708                 return;
1709
1710         retval = ext2fs_extent_insert(current_handle, flags, &extent);
1711         if (retval) {
1712                 com_err(cmd, retval, 0);
1713                 return;
1714         }
1715         do_current_node(argc, argv);
1716 }
1717
1718 void do_set_bmap(int argc, char **argv)
1719 {
1720         const char      *usage = "[--uninit] <lblk> <pblk>";
1721         errcode_t       retval;
1722         blk_t           logical;
1723         blk_t           physical;
1724         char            *cmd = argv[0];
1725         int             flags = 0;
1726         int             err;
1727
1728         if (common_extent_args_process(argc, argv, 3, 5, "set_bmap",
1729                                        usage, CHECK_FS_RW | CHECK_FS_BITMAPS))
1730                 return;
1731
1732         if (argc > 2 && !strcmp(argv[1], "--uninit")) {
1733                 argc--;
1734                 argv++;
1735                 flags |= EXT2_EXTENT_SET_BMAP_UNINIT;
1736         }
1737
1738         if (argc != 3) {
1739                 fprintf(stderr, "Usage: %s %s\n", cmd, usage);
1740                 return;
1741         }
1742
1743         logical = parse_ulong(argv[1], cmd,
1744                                     "logical block", &err);
1745         if (err)
1746                 return;
1747
1748         physical = parse_ulong(argv[2], cmd,
1749                                     "physical block", &err);
1750         if (err)
1751                 return;
1752
1753         retval = ext2fs_extent_set_bmap(current_handle, logical,
1754                                         (blk64_t) physical, flags);
1755         if (retval) {
1756                 com_err(cmd, retval, 0);
1757                 return;
1758         }
1759         if (current_handle->path && current_handle->path[0].curr)
1760                 do_current_node(argc, argv);
1761 }
1762
1763 void do_print_all(int argc, char **argv)
1764 {
1765         const char      *usage = "[--leaf-only|--reverse|--reverse-leaf]";
1766         struct ext2fs_extent    extent;
1767         errcode_t               retval;
1768         errcode_t               end_err = EXT2_ET_EXTENT_NO_NEXT;
1769         int                     op = EXT2_EXTENT_NEXT;
1770         int                     first_op = EXT2_EXTENT_ROOT;
1771
1772
1773         if (common_extent_args_process(argc, argv, 1, 2, "print_all",
1774                                        usage, 0))
1775                 return;
1776
1777         if (argc == 2) {
1778                 if (!strcmp(argv[1], "--leaf-only"))
1779                         op = EXT2_EXTENT_NEXT_LEAF;
1780                 else if (!strcmp(argv[1], "--reverse")) {
1781                         op = EXT2_EXTENT_PREV;
1782                         first_op = EXT2_EXTENT_LAST_LEAF;
1783                         end_err = EXT2_ET_EXTENT_NO_PREV;
1784                 } else if (!strcmp(argv[1], "--reverse-leaf")) {
1785                         op = EXT2_EXTENT_PREV_LEAF;
1786                         first_op = EXT2_EXTENT_LAST_LEAF;
1787                         end_err = EXT2_ET_EXTENT_NO_PREV;
1788                 } else {
1789                         fprintf(stderr, "Usage: %s %s\n", argv[0], usage);
1790                         return;
1791                 }
1792         }
1793
1794         retval = ext2fs_extent_get(current_handle, first_op, &extent);
1795         if (retval) {
1796                 com_err(argv[0], retval, 0);
1797                 return;
1798         }
1799         dbg_print_extent(0, &extent);
1800
1801         while (1) {
1802                 retval = ext2fs_extent_get(current_handle, op, &extent);
1803                 if (retval == end_err)
1804                         break;
1805
1806                 if (retval) {
1807                         com_err(argv[0], retval, 0);
1808                         return;
1809                 }
1810                 dbg_print_extent(0, &extent);
1811         }
1812 }
1813
1814 void do_info(int argc, char **argv)
1815 {
1816         struct ext2fs_extent    extent;
1817         struct ext2_extent_info info;
1818         errcode_t               retval;
1819
1820         if (common_extent_args_process(argc, argv, 1, 1, "info", "", 0))
1821                 return;
1822
1823         retval = ext2fs_extent_get_info(current_handle, &info);
1824         if (retval) {
1825                 com_err(argv[0], retval, 0);
1826                 return;
1827         }
1828
1829         retval = ext2fs_extent_get(current_handle,
1830                                    EXT2_EXTENT_CURRENT, &extent);
1831         if (retval) {
1832                 com_err(argv[0], retval, 0);
1833                 return;
1834         }
1835
1836         dbg_print_extent(0, &extent);
1837
1838         printf("Current handle location: %d/%d (max: %d, bytes %d), level %d/%d\n",
1839                info.curr_entry, info.num_entries, info.max_entries,
1840                info.bytes_avail, info.curr_level, info.max_depth);
1841         printf("\tmax lblk: %llu, max pblk: %llu\n", info.max_lblk,
1842                info.max_pblk);
1843         printf("\tmax_len: %u, max_uninit_len: %u\n", info.max_len,
1844                info.max_uninit_len);
1845 }
1846
1847 void do_goto_block(int argc, char **argv)
1848 {
1849         struct ext2fs_extent    extent;
1850         errcode_t               retval;
1851         int                     op = EXT2_EXTENT_NEXT_LEAF;
1852         blk_t                   blk;
1853         int                     level = 0;
1854
1855         if (common_extent_args_process(argc, argv, 2, 3, "goto_block",
1856                                        "block [level]", 0))
1857                 return;
1858
1859         if (strtoblk(argv[0], argv[1], &blk))
1860                 return;
1861
1862         if (argc == 3)
1863                 if (strtoblk(argv[0], argv[2], &level))
1864                         return;
1865
1866         retval = extent_goto(current_handle, level, (blk64_t) blk);
1867
1868         if (retval) {
1869                 com_err(argv[0], retval, "while trying to go to block %lu, level %d",
1870                         blk, level);
1871                 return;
1872         }
1873
1874         generic_goto_node(argv[0], EXT2_EXTENT_CURRENT);
1875 }
1876 #endif
1877