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 #include "ss/ss.h"
  31
  32 /*
  33  * Definitions to be dropped in lib/ext2fs/ext2fs.h
  34  */
  35
  36 /*
  37  * Private definitions
  38  */
  39
  40 struct extent_path {
  41         char            *buf;
  42         int             entries;
  43         int             max_entries;
  44         int             left;
  45         int             visit_num;
  46         int             flags;
  47         blk64_t         end_blk;
  48         void            *curr;
  49 };
  50
  51
  52 struct ext2_extent_handle {
  53         errcode_t               magic;
  54         ext2_filsys             fs;
  55         ext2_ino_t              ino;
  56         struct ext2_inode       *inode;
  57         int                     type;
  58         int                     level;
  59         int                     max_depth;
  60         struct extent_path      *path;
  61 };
  62
  63 struct ext2_extent_path {
  64         errcode_t               magic;
  65         int                     leaf_height;
  66         blk64_t                 lblk;
  67 };
  68
  69 /*
  70  *  Useful Debugging stuff
  71  */
  72
  73 #ifdef DEBUG
  74 static void dbg_show_header(struct ext3_extent_header *eh)
  75 {
  76         printf("header: magic=%x entries=%u max=%u depth=%u generation=%u\n",
  77                eh->eh_magic, eh->eh_entries, eh->eh_max, eh->eh_depth,
  78                eh->eh_generation);
  79 }
  80
  81 static void dbg_show_index(struct ext3_extent_idx *ix)
  82 {
  83         printf("index: block=%u leaf=%u leaf_hi=%u unused=%u\n",
  84                ix->ei_block, ix->ei_leaf, ix->ei_leaf_hi, ix->ei_unused);
  85 }
  86
  87 static void dbg_show_extent(struct ext3_extent *ex)
  88 {
  89         printf("extent: block=%u-%u len=%u start=%u start_hi=%u\n",
  90                ex->ee_block, ex->ee_block + ex->ee_len - 1,
  91                ex->ee_len, ex->ee_start, ex->ee_start_hi);
  92 }
  93
  94 static void dbg_print_extent(char *desc, struct ext2fs_extent *extent)
  95 {
  96         if (desc)
  97                 printf("%s: ", desc);
  98         printf("extent: lblk %llu--%llu, len %lu, pblk %llu, flags: ",
  99                extent->e_lblk, extent->e_lblk + extent->e_len - 1,
 100                extent->e_len, extent->e_pblk);
 101         if (extent->e_flags & EXT2_EXTENT_FLAGS_LEAF)
 102                 fputs("LEAF ", stdout);
 103         if (extent->e_flags & EXT2_EXTENT_FLAGS_UNINIT)
 104                 fputs("UNINIT ", stdout);
 105         if (extent->e_flags & EXT2_EXTENT_FLAGS_SECOND_VISIT)
 106                 fputs("2ND_VISIT ", stdout);
 107         if (!extent->e_flags)
 108                 fputs("(none)", stdout);
 109         fputc('\n', stdout);
 110
 111 }
 112
 113 #define dbg_printf(fmt, args...) printf(fmt, ## args)
 114 #else
 115 #define dbg_show_header(eh) do { } while (0)
 116 #define dbg_show_index(ix) do { } while (0)
 117 #define dbg_show_extent(ex) do { } while (0)
 118 #define dbg_print_extent(desc, ex) do { } while (0)
 119 #define dbg_printf(fmt, args...) do { } while (0)
 120 #endif
 121
 122 /*
 123  * Verify the extent header as being sane
 124  */
 125 errcode_t ext2fs_extent_header_verify(void *ptr, int size)
 126 {
 127         int eh_max, entry_size;
 128         struct ext3_extent_header *eh = ptr;
 129
 130         dbg_show_header(eh);
 131         if (ext2fs_le16_to_cpu(eh->eh_magic) != EXT3_EXT_MAGIC)
 132                 return EXT2_ET_EXTENT_HEADER_BAD;
 133         if (ext2fs_le16_to_cpu(eh->eh_entries) > ext2fs_le16_to_cpu(eh->eh_max))
 134                 return EXT2_ET_EXTENT_HEADER_BAD;
 135         if (eh->eh_depth == 0)
 136                 entry_size = sizeof(struct ext3_extent);
 137         else
 138                 entry_size = sizeof(struct ext3_extent_idx);
 139
 140         eh_max = (size - sizeof(*eh)) / entry_size;
 141         /* Allow two extent-sized items at the end of the block, for
 142          * ext4_extent_tail with checksum in the future. */
 143         if ((ext2fs_le16_to_cpu(eh->eh_max) > eh_max) ||
 144             (ext2fs_le16_to_cpu(eh->eh_max) < (eh_max - 2)))
 145                 return EXT2_ET_EXTENT_HEADER_BAD;
 146
 147         return 0;
 148 }
 149
 150
 151 /*
 152  * Begin functions to handle an inode's extent information
 153  */
 154 extern void ext2fs_extent_free(ext2_extent_handle_t handle)
 155 {
 156         int                     i;
 157
 158         if (!handle)
 159                 return;
 160
 161         if (handle->inode)
 162                 ext2fs_free_mem(&handle->inode);
 163         if (handle->path) {
 164                 for (i=1; i < handle->max_depth; i++) {
 165                         if (handle->path[i].buf)
 166                                 ext2fs_free_mem(&handle->path[i].buf);
 167                 }
 168                 ext2fs_free_mem(&handle->path);
 169         }
 170         ext2fs_free_mem(&handle);
 171 }
 172
 173 extern errcode_t ext2fs_extent_open(ext2_filsys fs, ext2_ino_t ino,
 174                                     ext2_extent_handle_t *ret_handle)
 175 {
 176         struct ext2_extent_handle       *handle;
 177         errcode_t                       retval;
 178         int                             isize = EXT2_INODE_SIZE(fs->super);
 179         struct ext3_extent_header       *eh;
 180
 181         EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 182
 183         if ((ino == 0) || (ino > fs->super->s_inodes_count))
 184                 return EXT2_ET_BAD_INODE_NUM;
 185
 186         retval = ext2fs_get_mem(sizeof(struct ext2_extent_handle), &handle);
 187         if (retval)
 188                 return retval;
 189         memset(handle, 0, sizeof(struct ext2_extent_handle));
 190
 191         retval = ext2fs_get_mem(isize, &handle->inode);
 192         if (retval)
 193                 goto errout;
 194
 195         handle->ino = ino;
 196         handle->fs = fs;
 197
 198         retval = ext2fs_read_inode_full(fs, ino, handle->inode, isize);
 199         if (retval)
 200                 goto errout;
 201
 202         if (!(handle->inode->i_flags & EXT4_EXTENTS_FL))
 203                 return EXT2_ET_INODE_NOT_EXTENT;
 204
 205         eh = (struct ext3_extent_header *) &handle->inode->i_block[0];
 206
 207         retval = ext2fs_extent_header_verify(eh, sizeof(handle->inode->i_block));
 208         if (retval)
 209                 return (retval);
 210
 211         handle->max_depth = ext2fs_le16_to_cpu(eh->eh_depth);
 212         handle->type = ext2fs_le16_to_cpu(eh->eh_magic);
 213
 214         retval = ext2fs_get_mem(((handle->max_depth+1) *
 215                                  sizeof(struct extent_path)),
 216                                 &handle->path);
 217         memset(handle->path, 0,
 218                (handle->max_depth+1) * sizeof(struct extent_path));
 219         handle->path[0].buf = (char *) handle->inode->i_block;
 220
 221         handle->path[0].left = handle->path[0].entries =
 222                 ext2fs_le16_to_cpu(eh->eh_entries);
 223         handle->path[0].max_entries = ext2fs_le16_to_cpu(eh->eh_max);
 224         handle->path[0].curr = 0;
 225         handle->path[0].end_blk =
 226                 ((((__u64) handle->inode->i_size_high << 32) +
 227                   handle->inode->i_size + (fs->blocksize - 1))
 228                  >> EXT2_BLOCK_SIZE_BITS(fs->super));
 229         handle->path[0].visit_num = 1;
 230         handle->level = 0;
 231         handle->magic = EXT2_ET_MAGIC_EXTENT_HANDLE;
 232
 233         *ret_handle = handle;
 234         return 0;
 235
 236 errout:
 237         ext2fs_extent_free(handle);
 238         return retval;
 239 }
 240
 241 /*
 242  * This function is responsible for (optionally) moving through the
 243  * extent tree and then returning the current extent
 244  */
 245 errcode_t ext2fs_extent_get(ext2_extent_handle_t handle,
 246                             int flags, struct ext2fs_extent *extent)
 247 {
 248         struct extent_path      *path, *newpath;
 249         struct ext3_extent_header       *eh;
 250         struct ext3_extent_idx          *ix = 0;
 251         struct ext3_extent              *ex;
 252         errcode_t                       retval;
 253         blk_t                           blk;
 254         blk64_t                         end_blk;
 255         int                             orig_op, op;
 256
 257         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
 258
 259         if (!handle->path)
 260                 return EXT2_ET_NO_CURRENT_NODE;
 261
 262         orig_op = op = flags & EXT2_EXTENT_MOVE_MASK;
 263
 264 retry:
 265         path = handle->path + handle->level;
 266         if ((orig_op == EXT2_EXTENT_NEXT) ||
 267             (orig_op == EXT2_EXTENT_NEXT_LEAF)) {
 268                 if (handle->level < handle->max_depth) {
 269                         /* interior node */
 270                         if (path->visit_num == 0) {
 271                                 path->visit_num++;
 272                                 op = EXT2_EXTENT_DOWN;
 273                         } else if (path->left > 0)
 274                                 op = EXT2_EXTENT_NEXT_SIB;
 275                         else if (handle->level > 0)
 276                                 op = EXT2_EXTENT_UP;
 277                         else
 278                                 return EXT2_ET_EXTENT_NO_NEXT;
 279                 } else {
 280                         /* leaf node */
 281                         if (path->left > 0)
 282                                 op = EXT2_EXTENT_NEXT_SIB;
 283                         else if (handle->level > 0)
 284                                 op = EXT2_EXTENT_UP;
 285                         else
 286                                 return EXT2_ET_EXTENT_NO_NEXT;
 287                 }
 288                 if (op != EXT2_EXTENT_NEXT_SIB) {
 289                         dbg_printf("<<<< OP = %s\n",
 290                                (op == EXT2_EXTENT_DOWN) ? "down" :
 291                                ((op == EXT2_EXTENT_UP) ? "up" : "unknown"));
 292                 }
 293         }
 294
 295         if ((orig_op == EXT2_EXTENT_PREV) ||
 296             (orig_op == EXT2_EXTENT_PREV_LEAF)) {
 297                 if (handle->level < handle->max_depth) {
 298                         /* interior node */
 299                         if (path->visit_num > 0 ) {
 300                                 /* path->visit_num = 0; */
 301                                 op = EXT2_EXTENT_DOWN_AND_LAST;
 302                         } else if (path->left < path->entries-1)
 303                                 op = EXT2_EXTENT_PREV_SIB;
 304                         else if (handle->level > 0)
 305                                 op = EXT2_EXTENT_UP;
 306                         else
 307                                 return EXT2_ET_EXTENT_NO_PREV;
 308                 } else {
 309                         /* leaf node */
 310                         if (path->left < path->entries-1)
 311                                 op = EXT2_EXTENT_PREV_SIB;
 312                         else if (handle->level > 0)
 313                                 op = EXT2_EXTENT_UP;
 314                         else
 315                                 return EXT2_ET_EXTENT_NO_PREV;
 316                 }
 317                 if (op != EXT2_EXTENT_PREV_SIB) {
 318                         dbg_printf("<<<< OP = %s\n",
 319                                (op == EXT2_EXTENT_DOWN_AND_LAST) ? "down/last" :
 320                                ((op == EXT2_EXTENT_UP) ? "up" : "unknown"));
 321                 }
 322         }
 323
 324         if (orig_op == EXT2_EXTENT_LAST_LEAF) {
 325                 if ((handle->level < handle->max_depth) &&
 326                     (path->left == 0))
 327                         op = EXT2_EXTENT_DOWN;
 328                 else
 329                         op = EXT2_EXTENT_LAST_SIB;
 330                 dbg_printf("<<<< OP = %s\n",
 331                            (op == EXT2_EXTENT_DOWN) ? "down" : "last_sib");
 332         }
 333
 334         switch (op) {
 335         case EXT2_EXTENT_CURRENT:
 336                 ix = path->curr;
 337                 break;
 338         case EXT2_EXTENT_ROOT:
 339                 handle->level = 0;
 340                 path = handle->path + handle->level;
 341         case EXT2_EXTENT_FIRST_SIB:
 342                 path->left = path->entries;
 343                 path->curr = 0;
 344         case EXT2_EXTENT_NEXT_SIB:
 345                 if (path->left <= 0)
 346                         return EXT2_ET_EXTENT_NO_NEXT;
 347                 if (path->curr) {
 348                         ix = path->curr;
 349                         ix++;
 350                 } else {
 351                         eh = (struct ext3_extent_header *) path->buf;
 352                         ix = EXT_FIRST_INDEX(eh);
 353                 }
 354                 path->left--;
 355                 path->curr = ix;
 356                 path->visit_num = 0;
 357                 break;
 358         case EXT2_EXTENT_PREV_SIB:
 359                 if (!path->curr ||
 360                     path->left+1 >= path->entries)
 361                         return EXT2_ET_EXTENT_NO_PREV;
 362                 ix = path->curr;
 363                 ix--;
 364                 path->curr = ix;
 365                 path->left++;
 366                 if (handle->level < handle->max_depth)
 367                         path->visit_num = 1;
 368                 break;
 369         case EXT2_EXTENT_LAST_SIB:
 370                 eh = (struct ext3_extent_header *) path->buf;
 371                 path->curr = EXT_LAST_EXTENT(eh);
 372                 ix = path->curr;
 373                 path->left = 0;
 374                 path->visit_num = 0;
 375                 break;
 376         case EXT2_EXTENT_UP:
 377                 if (handle->level <= 0)
 378                         return EXT2_ET_EXTENT_NO_UP;
 379                 handle->level--;
 380                 path--;
 381                 ix = path->curr;
 382                 if ((orig_op == EXT2_EXTENT_PREV) ||
 383                     (orig_op == EXT2_EXTENT_PREV_LEAF))
 384                         path->visit_num = 0;
 385                 break;
 386         case EXT2_EXTENT_DOWN:
 387         case EXT2_EXTENT_DOWN_AND_LAST:
 388                 if (!path->curr ||(handle->level >= handle->max_depth))
 389                         return EXT2_ET_EXTENT_NO_DOWN;
 390
 391                 ix = path->curr;
 392                 newpath = path + 1;
 393                 if (!newpath->buf) {
 394                         retval = ext2fs_get_mem(handle->fs->blocksize,
 395                                                 &newpath->buf);
 396                         if (retval)
 397                                 return retval;
 398                 }
 399                 blk = ext2fs_le32_to_cpu(ix->ei_leaf) +
 400                         ((__u64) ext2fs_le16_to_cpu(ix->ei_leaf_hi) << 32);
 401                 if ((handle->fs->flags & EXT2_FLAG_IMAGE_FILE) &&
 402                     (handle->fs->io != handle->fs->image_io))
 403                         memset(newpath->buf, 0, handle->fs->blocksize);
 404                 else {
 405                         retval = io_channel_read_blk(handle->fs->io,
 406                                                      blk, 1, newpath->buf);
 407                         if (retval)
 408                                 return retval;
 409                 }
 410                 handle->level++;
 411
 412                 eh = (struct ext3_extent_header *) newpath->buf;
 413
 414                 retval = ext2fs_extent_header_verify(eh, handle->fs->blocksize);
 415                 if (retval)
 416                         return retval;
 417
 418                 newpath->left = newpath->entries =
 419                         ext2fs_le16_to_cpu(eh->eh_entries);
 420                 newpath->max_entries = ext2fs_le16_to_cpu(eh->eh_max);
 421
 422                 if (path->left > 0) {
 423                         ix++;
 424                         newpath->end_blk = ext2fs_le32_to_cpu(ix->ei_block);
 425                 } else
 426                         newpath->end_blk = path->end_blk;
 427
 428                 path = newpath;
 429                 if (op == EXT2_EXTENT_DOWN) {
 430                         ix = EXT_FIRST_INDEX((struct ext3_extent_header *) eh);
 431                         path->curr = ix;
 432                         path->left = path->entries - 1;
 433                         path->visit_num = 0;
 434                 } else {
 435                         ix = EXT_LAST_INDEX((struct ext3_extent_header *) eh);
 436                         path->curr = ix;
 437                         path->left = 0;
 438                         if (handle->level < handle->max_depth)
 439                                 path->visit_num = 1;
 440                 }
 441
 442                 dbg_printf("Down to level %d/%d, end_blk=%llu\n",
 443                            handle->level, handle->max_depth,
 444                            path->end_blk);
 445
 446                 break;
 447         default:
 448                 return EXT2_ET_OP_NOT_SUPPORTED;
 449         }
 450
 451         if (!ix)
 452                 return EXT2_ET_NO_CURRENT_NODE;
 453
 454         extent->e_flags = 0;
 455         dbg_printf("(Left %d)\n", path->left);
 456
 457         if (handle->level == handle->max_depth) {
 458                 ex = (struct ext3_extent *) ix;
 459
 460                 extent->e_pblk = ext2fs_le32_to_cpu(ex->ee_start) +
 461                         ((__u64) ext2fs_le16_to_cpu(ex->ee_start_hi) << 32);
 462                 extent->e_lblk = ext2fs_le32_to_cpu(ex->ee_block);
 463                 extent->e_len = ext2fs_le16_to_cpu(ex->ee_len);
 464                 extent->e_flags |= EXT2_EXTENT_FLAGS_LEAF;
 465                 if (extent->e_len > EXT_INIT_MAX_LEN) {
 466                         extent->e_len -= EXT_INIT_MAX_LEN;
 467                         extent->e_flags |= EXT2_EXTENT_FLAGS_UNINIT;
 468                 }
 469         } else {
 470                 extent->e_pblk = ext2fs_le32_to_cpu(ix->ei_leaf) +
 471                         ((__u64) ext2fs_le16_to_cpu(ix->ei_leaf_hi) << 32);
 472                 extent->e_lblk = ext2fs_le32_to_cpu(ix->ei_block);
 473                 if (path->left > 0) {
 474                         ix++;
 475                         end_blk = ext2fs_le32_to_cpu(ix->ei_block);
 476                 } else
 477                         end_blk = path->end_blk;
 478
 479                 extent->e_len = end_blk - extent->e_lblk;
 480         }
 481         if (path->visit_num)
 482                 extent->e_flags |= EXT2_EXTENT_FLAGS_SECOND_VISIT;
 483
 484         if (((orig_op == EXT2_EXTENT_NEXT_LEAF) ||
 485              (orig_op == EXT2_EXTENT_PREV_LEAF)) &&
 486             (handle->level != handle->max_depth))
 487                 goto retry;
 488
 489         if ((orig_op == EXT2_EXTENT_LAST_LEAF) &&
 490             ((handle->level != handle->max_depth) ||
 491              (path->left != 0)))
 492                 goto retry;
 493
 494         return 0;
 495 }
 496
 497 static errcode_t update_path(ext2_extent_handle_t handle)
 498 {
 499         blk64_t                         blk;
 500         errcode_t                       retval;
 501         struct ext3_extent_idx          *ix;
 502
 503         if (handle->level == 0) {
 504                 retval = ext2fs_write_inode_full(handle->fs, handle->ino,
 505                            handle->inode, EXT2_INODE_SIZE(handle->fs->super));
 506         } else {
 507                 ix = handle->path[handle->level - 1].curr;
 508                 blk = ext2fs_le32_to_cpu(ix->ei_leaf) +
 509                         ((__u64) ext2fs_le16_to_cpu(ix->ei_leaf_hi) << 32);
 510
 511                 retval = io_channel_write_blk(handle->fs->io,
 512                                       blk, 1, handle->path[handle->level].buf);
 513         }
 514         return retval;
 515 }
 516
 517 #if 0
 518 errcode_t ext2fs_extent_save_path(ext2_extent_handle_t handle,
 519                                   ext2_extent_path_t *ret_path)
 520 {
 521         ext2_extent_path_t      save_path;
 522         struct ext2fs_extent    extent;
 523         struct ext2_extent_info info;
 524         errcode_t               retval;
 525
 526         retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent);
 527         if (retval)
 528                 return retval;
 529
 530         retval = ext2fs_extent_get_info(handle, &info);
 531         if (retval)
 532                 return retval;
 533
 534         retval = ext2fs_get_mem(sizeof(struct ext2_extent_path), &save_path);
 535         if (retval)
 536                 return retval;
 537         memset(save_path, 0, sizeof(struct ext2_extent_path));
 538
 539         save_path->magic = EXT2_ET_MAGIC_EXTENT_PATH;
 540         save_path->leaf_height = info.max_depth - info.curr_level - 1;
 541         save_path->lblk = extent.e_lblk;
 542
 543         *ret_path = save_path;
 544         return 0;
 545 }
 546
 547 errcode_t ext2fs_extent_free_path(ext2_extent_path_t path)
 548 {
 549         EXT2_CHECK_MAGIC(path, EXT2_ET_MAGIC_EXTENT_PATH);
 550
 551         ext2fs_free_mem(&path);
 552         return 0;
 553 }
 554 #endif
 555
 556 /*
 557  * Go to the node at leaf_level which contains logical block blk.
 558  *
 559  * If "blk" has no mapping (hole) then handle is left at last
 560  * extent before blk.
 561  */
 562 static errcode_t extent_goto(ext2_extent_handle_t handle,
 563                              int leaf_level, blk64_t blk)
 564 {
 565         struct ext2fs_extent    extent;
 566         errcode_t               retval;
 567
 568         retval = ext2fs_extent_get(handle, EXT2_EXTENT_ROOT, &extent);
 569         if (retval)
 570                 return retval;
 571
 572         dbg_print_extent("root", &extent);
 573         while (1) {
 574                 if (handle->level - leaf_level == handle->max_depth) {
 575                         /* block is in this &extent */
 576                         if ((blk >= extent.e_lblk) &&
 577                             (blk < extent.e_lblk + extent.e_len))
 578                                 return 0;
 579                         if (blk < extent.e_lblk) {
 580                                 retval = ext2fs_extent_get(handle,
 581                                                            EXT2_EXTENT_PREV_SIB,
 582                                                            &extent);
 583                                 return EXT2_ET_EXTENT_NOT_FOUND;
 584                         }
 585                         retval = ext2fs_extent_get(handle,
 586                                                    EXT2_EXTENT_NEXT_SIB,
 587                                                    &extent);
 588                         if (retval == EXT2_ET_EXTENT_NO_NEXT)
 589                                 return EXT2_ET_EXTENT_NOT_FOUND;
 590                         if (retval)
 591                                 return retval;
 592                         continue;
 593                 }
 594
 595                 retval = ext2fs_extent_get(handle, EXT2_EXTENT_NEXT_SIB,
 596                                            &extent);
 597                 if (retval == EXT2_ET_EXTENT_NO_NEXT)
 598                         goto go_down;
 599                 if (retval)
 600                         return retval;
 601
 602                 dbg_print_extent("next", &extent);
 603                 if (blk == extent.e_lblk)
 604                         goto go_down;
 605                 if (blk > extent.e_lblk)
 606                         continue;
 607
 608                 retval = ext2fs_extent_get(handle, EXT2_EXTENT_PREV_SIB,
 609                                            &extent);
 610                 if (retval)
 611                         return retval;
 612
 613                 dbg_print_extent("prev", &extent);
 614
 615         go_down:
 616                 retval = ext2fs_extent_get(handle, EXT2_EXTENT_DOWN,
 617                                            &extent);
 618                 if (retval)
 619                         return retval;
 620
 621                 dbg_print_extent("down", &extent);
 622         }
 623 }
 624
 625 errcode_t ext2fs_extent_goto(ext2_extent_handle_t handle,
 626                              blk64_t blk)
 627 {
 628         return extent_goto(handle, 0, blk);
 629 }
 630
 631 errcode_t ext2fs_extent_replace(ext2_extent_handle_t handle,
 632                                 int flags EXT2FS_ATTR((unused)),
 633                                 struct ext2fs_extent *extent)
 634 {
 635         struct extent_path              *path;
 636         struct ext3_extent_idx          *ix;
 637         struct ext3_extent              *ex;
 638
 639         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
 640
 641         if (!(handle->fs->flags & EXT2_FLAG_RW))
 642                 return EXT2_ET_RO_FILSYS;
 643
 644         if (!handle->path)
 645                 return EXT2_ET_NO_CURRENT_NODE;
 646
 647         path = handle->path + handle->level;
 648         if (!path->curr)
 649                 return EXT2_ET_NO_CURRENT_NODE;
 650
 651         if (handle->level == handle->max_depth) {
 652                 ex = path->curr;
 653
 654                 ex->ee_block = ext2fs_cpu_to_le32(extent->e_lblk);
 655                 ex->ee_start = ext2fs_cpu_to_le32(extent->e_pblk & 0xFFFFFFFF);
 656                 ex->ee_start_hi = ext2fs_cpu_to_le16(extent->e_pblk >> 32);
 657                 ex->ee_len = ext2fs_cpu_to_le16(extent->e_len);
 658         } else {
 659                 ix = path->curr;
 660
 661                 ix->ei_leaf = ext2fs_cpu_to_le32(extent->e_pblk & 0xFFFFFFFF);
 662                 ix->ei_leaf_hi = ext2fs_cpu_to_le16(extent->e_pblk >> 32);
 663                 ix->ei_block = ext2fs_cpu_to_le32(extent->e_lblk);
 664                 ix->ei_unused = 0;
 665         }
 666         update_path(handle);
 667         return 0;
 668 }
 669
 670 errcode_t ext2fs_extent_insert(ext2_extent_handle_t handle, int flags,
 671                                       struct ext2fs_extent *extent)
 672 {
 673         struct extent_path              *path;
 674         struct ext3_extent_idx          *ix;
 675         struct ext3_extent_header       *eh;
 676         errcode_t                       retval;
 677
 678         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
 679
 680         if (!(handle->fs->flags & EXT2_FLAG_RW))
 681                 return EXT2_ET_RO_FILSYS;
 682
 683         if (!handle->path)
 684                 return EXT2_ET_NO_CURRENT_NODE;
 685
 686         path = handle->path + handle->level;
 687
 688         if (path->entries >= path->max_entries)
 689                 return EXT2_ET_CANT_INSERT_EXTENT;
 690
 691         eh = (struct ext3_extent_header *) path->buf;
 692         if (path->curr) {
 693                 ix = path->curr;
 694                 if (flags & EXT2_EXTENT_INSERT_AFTER) {
 695                         ix++;
 696                         path->left--;
 697                 }
 698         } else
 699                 ix = EXT_FIRST_INDEX(eh);
 700
 701         path->curr = ix;
 702
 703         if (path->left >= 0)
 704                 memmove(ix + 1, ix,
 705                         (path->left+1) * sizeof(struct ext3_extent_idx));
 706         path->left++;
 707         path->entries++;
 708
 709         eh = (struct ext3_extent_header *) path->buf;
 710         eh->eh_entries = ext2fs_cpu_to_le16(path->entries);
 711
 712         retval = ext2fs_extent_replace(handle, 0, extent);
 713         if (retval)
 714                 goto errout;
 715
 716         retval = update_path(handle);
 717         if (retval)
 718                 goto errout;
 719
 720         return 0;
 721
 722 errout:
 723         ext2fs_extent_delete(handle, 0);
 724         return retval;
 725 }
 726
 727 errcode_t ext2fs_extent_delete(ext2_extent_handle_t handle,
 728                                int flags EXT2FS_ATTR((unused)))
 729 {
 730         struct extent_path              *path;
 731         char                            *cp;
 732         struct ext3_extent_header       *eh;
 733         errcode_t                       retval;
 734
 735         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
 736
 737         if (!(handle->fs->flags & EXT2_FLAG_RW))
 738                 return EXT2_ET_RO_FILSYS;
 739
 740         if (!handle->path)
 741                 return EXT2_ET_NO_CURRENT_NODE;
 742
 743         path = handle->path + handle->level;
 744         if (!path->curr)
 745                 return EXT2_ET_NO_CURRENT_NODE;
 746
 747         cp = path->curr;
 748
 749         if (path->left) {
 750                 memmove(cp, cp + sizeof(struct ext3_extent_idx),
 751                         path->left * sizeof(struct ext3_extent_idx));
 752                 path->left--;
 753         } else {
 754                 struct ext3_extent_idx  *ix = path->curr;
 755                 ix--;
 756                 path->curr = ix;
 757         }
 758         path->entries--;
 759         if (path->entries == 0)
 760                 path->curr = 0;
 761
 762         eh = (struct ext3_extent_header *) path->buf;
 763         eh->eh_entries = ext2fs_cpu_to_le16(path->entries);
 764
 765         retval = update_path(handle);
 766
 767         return retval;
 768 }
 769
 770 errcode_t ext2fs_extent_get_info(ext2_extent_handle_t handle,
 771                                  struct ext2_extent_info *info)
 772 {
 773         struct extent_path              *path;
 774
 775         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
 776
 777         memset(info, 0, sizeof(struct ext2_extent_info));
 778
 779         path = handle->path + handle->level;
 780         if (path) {
 781                 if (path->curr)
 782                         info->curr_entry = ((char *) path->curr - path->buf) /
 783                                 sizeof(struct ext3_extent_idx);
 784                 else
 785                         info->curr_entry = 0;
 786                 info->num_entries = path->entries;
 787                 info->max_entries = path->max_entries;
 788                 info->bytes_avail = (path->max_entries - path->entries) *
 789                         sizeof(struct ext3_extent);
 790         }
 791
 792         info->curr_level = handle->level;
 793         info->max_depth = handle->max_depth;
 794         info->max_lblk = ((__u64) 1 << 32) - 1;
 795         info->max_pblk = ((__u64) 1 << 48) - 1;
 796         info->max_len = (1UL << 15);
 797         info->max_uninit_len = (1UL << 15) - 1;
 798
 799         return 0;
 800 }
 801
 802 #ifdef DEBUG
 803
 804 #include "debugfs.h"
 805
 806 /*
 807  * Hook in new commands into debugfs
 808  */
 809 const char *debug_prog_name = "tst_extents";
 810 extern ss_request_table extent_cmds;
 811 ss_request_table *extra_cmds = &extent_cmds;
 812
 813 ext2_ino_t      current_ino = 0;
 814 ext2_extent_handle_t current_handle;
 815
 816 void do_inode(int argc, char *argv[])
 817 {
 818         ext2_ino_t      inode;
 819         int             i;
 820         struct ext3_extent_header *eh;
 821         errcode_t retval;
 822
 823         if (check_fs_open(argv[0]))
 824                 return;
 825
 826         if (argc == 1) {
 827                 if (current_ino)
 828                         printf("Current inode is %d\n", current_ino);
 829                 else
 830                         printf("No current inode\n");
 831                 return;
 832         }
 833
 834         if (common_inode_args_process(argc, argv, &inode, 0)) {
 835                 return;
 836         }
 837
 838         current_ino = 0;
 839
 840         retval = ext2fs_extent_open(current_fs, inode, &current_handle);
 841         if (retval) {
 842                 com_err(argv[1], retval, "while opening extent handle");
 843                 return;
 844         }
 845
 846         current_ino = inode;
 847
 848         printf("Loaded inode %d\n", current_ino);
 849
 850         return;
 851 }
 852
 853 void generic_goto_node(char *cmd_name, int op)
 854 {
 855         struct ext2fs_extent    extent;
 856         errcode_t               retval;
 857
 858         if (check_fs_open(cmd_name))
 859                 return;
 860
 861         if (!current_handle) {
 862                 com_err(cmd_name, 0, "Extent handle not open");
 863                 return;
 864         }
 865
 866         retval = ext2fs_extent_get(current_handle, op, &extent);
 867         if (retval) {
 868                 com_err(cmd_name, retval, 0);
 869                 return;
 870         }
 871         dbg_print_extent(0, &extent);
 872 }
 873
 874 void do_current_node(int argc, char *argv[])
 875 {
 876         generic_goto_node(argv[0], EXT2_EXTENT_CURRENT);
 877 }
 878
 879 void do_root_node(int argc, char *argv[])
 880 {
 881         generic_goto_node(argv[0], EXT2_EXTENT_ROOT);
 882 }
 883
 884 void do_last_leaf(int argc, char *argv[])
 885 {
 886         generic_goto_node(argv[0], EXT2_EXTENT_LAST_LEAF);
 887 }
 888
 889 void do_first_sib(int argc, char *argv[])
 890 {
 891         generic_goto_node(argv[0], EXT2_EXTENT_FIRST_SIB);
 892 }
 893
 894 void do_last_sib(int argc, char *argv[])
 895 {
 896         generic_goto_node(argv[0], EXT2_EXTENT_LAST_SIB);
 897 }
 898
 899 void do_next_sib(int argc, char *argv[])
 900 {
 901         generic_goto_node(argv[0], EXT2_EXTENT_NEXT_SIB);
 902 }
 903
 904 void do_prev_sib(int argc, char *argv[])
 905 {
 906         generic_goto_node(argv[0], EXT2_EXTENT_PREV_SIB);
 907 }
 908
 909 void do_next_leaf(int argc, char *argv[])
 910 {
 911         generic_goto_node(argv[0], EXT2_EXTENT_NEXT_LEAF);
 912 }
 913
 914 void do_prev_leaf(int argc, char *argv[])
 915 {
 916         generic_goto_node(argv[0], EXT2_EXTENT_PREV_LEAF);
 917 }
 918
 919 void do_next(int argc, char *argv[])
 920 {
 921         generic_goto_node(argv[0], EXT2_EXTENT_NEXT);
 922 }
 923
 924 void do_prev(int argc, char *argv[])
 925 {
 926         generic_goto_node(argv[0], EXT2_EXTENT_PREV);
 927 }
 928
 929 void do_up(int argc, char *argv[])
 930 {
 931         generic_goto_node(argv[0], EXT2_EXTENT_UP);
 932 }
 933
 934 void do_down(int argc, char *argv[])
 935 {
 936         generic_goto_node(argv[0], EXT2_EXTENT_DOWN);
 937 }
 938
 939 void do_delete_node(int argc, char *argv[])
 940 {
 941         errcode_t       retval;
 942         int             err;
 943
 944         if (check_fs_read_write(argv[0]))
 945                 return;
 946
 947         retval = ext2fs_extent_delete(current_handle, 0);
 948         if (retval) {
 949                 com_err(argv[0], retval, 0);
 950                 return;
 951         }
 952         do_current_node(argc, argv);
 953 }
 954
 955 void do_replace_node(int argc, char *argv[])
 956 {
 957         errcode_t       retval;
 958         struct ext2fs_extent extent;
 959         int err;
 960
 961         if (check_fs_read_write(argv[0]))
 962                 return;
 963
 964         if (argc != 4) {
 965                 fprintf(stderr, "usage: %s <lblk> <len> <pblk>\n", argv[0]);
 966                 return;
 967         }
 968
 969         extent.e_lblk = parse_ulong(argv[1], argv[0],
 970                                     "logical block", &err);
 971         if (err)
 972                 return;
 973
 974         extent.e_len = parse_ulong(argv[2], argv[0],
 975                                     "logical block", &err);
 976         if (err)
 977                 return;
 978
 979         extent.e_pblk = parse_ulong(argv[3], argv[0],
 980                                     "logical block", &err);
 981         if (err)
 982                 return;
 983
 984         retval = ext2fs_extent_replace(current_handle, 0, &extent);
 985         if (retval) {
 986                 com_err(argv[0], retval, 0);
 987                 return;
 988         }
 989         do_current_node(argc, argv);
 990 }
 991
 992 void do_insert_node(int argc, char *argv[])
 993 {
 994         errcode_t       retval;
 995         struct ext2fs_extent extent;
 996         char *cmd;
 997         int err;
 998         int flags = 0;
 999
1000         if (check_fs_read_write(argv[0]))
1001                 return;
1002
1003         cmd = argv[0];
1004
1005         if (argc > 2 && !strcmp(argv[1], "--after")) {
1006                 argc--;
1007                 argv++;
1008                 flags |= EXT2_EXTENT_INSERT_AFTER;
1009         }
1010
1011         if (argc != 4) {
1012                 fprintf(stderr, "usage: %s <lblk> <len> <pblk>\n", cmd);
1013                 return;
1014         }
1015
1016         extent.e_lblk = parse_ulong(argv[1], cmd,
1017                                     "logical block", &err);
1018         if (err)
1019                 return;
1020
1021         extent.e_len = parse_ulong(argv[2], cmd,
1022                                     "length", &err);
1023         if (err)
1024                 return;
1025
1026         extent.e_pblk = parse_ulong(argv[3], cmd,
1027                                     "pysical block", &err);
1028         if (err)
1029                 return;
1030
1031         retval = ext2fs_extent_insert(current_handle, flags, &extent);
1032         if (retval) {
1033                 com_err(cmd, retval, 0);
1034                 return;
1035         }
1036         do_current_node(argc, argv);
1037 }
1038
1039 void do_print_all(int argc, char **argv)
1040 {
1041         struct ext2fs_extent    extent;
1042         errcode_t               retval;
1043         errcode_t               end_err = EXT2_ET_EXTENT_NO_NEXT;
1044         int                     op = EXT2_EXTENT_NEXT;
1045         int                     first_op = EXT2_EXTENT_ROOT;
1046
1047
1048         if (check_fs_open(argv[0]))
1049                 return;
1050
1051         if (!current_handle) {
1052                 com_err(argv[0], 0, "Extent handle not open");
1053                 return;
1054         }
1055
1056         if (argc > 2) {
1057         print_usage:
1058                 fprintf(stderr,
1059                         "Usage: %s [--leaf-only|--reverse|--reverse-leaf]\n",
1060                         argv[0]);
1061                 return;
1062         }
1063
1064         if (argc == 2) {
1065                 if (!strcmp(argv[1], "--leaf-only"))
1066                         op = EXT2_EXTENT_NEXT_LEAF;
1067                 else if (!strcmp(argv[1], "--reverse")) {
1068                         op = EXT2_EXTENT_PREV;
1069                         first_op = EXT2_EXTENT_LAST_LEAF;
1070                         end_err = EXT2_ET_EXTENT_NO_PREV;
1071                 } else if (!strcmp(argv[1], "--reverse-leaf")) {
1072                         op = EXT2_EXTENT_PREV_LEAF;
1073                         first_op = EXT2_EXTENT_LAST_LEAF;
1074                         end_err = EXT2_ET_EXTENT_NO_PREV;
1075                 } else
1076                           goto print_usage;
1077         }
1078
1079         retval = ext2fs_extent_get(current_handle, first_op, &extent);
1080         if (retval) {
1081                 com_err(argv[0], retval, 0);
1082                 return;
1083         }
1084         dbg_print_extent(0, &extent);
1085
1086         while (1) {
1087                 retval = ext2fs_extent_get(current_handle, op, &extent);
1088                 if (retval == end_err)
1089                         break;
1090
1091                 if (retval) {
1092                         com_err(argv[0], retval, 0);
1093                         return;
1094                 }
1095                 dbg_print_extent(0, &extent);
1096         }
1097 }
1098
1099 void do_info(int argc, char **argv)
1100 {
1101         struct ext2fs_extent    extent;
1102         struct ext2_extent_info info;
1103         errcode_t               retval;
1104
1105         if (check_fs_open(argv[0]))
1106                 return;
1107
1108         if (!current_handle) {
1109                 com_err(argv[0], 0, "Extent handle not open");
1110                 return;
1111         }
1112
1113         retval = ext2fs_extent_get_info(current_handle, &info);
1114         if (retval) {
1115                 com_err(argv[0], retval, 0);
1116                 return;
1117         }
1118
1119         retval = ext2fs_extent_get(current_handle,
1120                                    EXT2_EXTENT_CURRENT, &extent);
1121         if (retval) {
1122                 com_err(argv[0], retval, 0);
1123                 return;
1124         }
1125
1126         dbg_print_extent(0, &extent);
1127
1128         printf("Current handle location: %d/%d (max: %d, bytes %d), level %d/%d\n",
1129                info.curr_entry, info.num_entries, info.max_entries,
1130                info.bytes_avail, info.curr_level, info.max_depth);
1131         printf("\tmax lblk: %llu, max pblk: %llu\n", info.max_lblk,
1132                info.max_pblk);
1133         printf("\tmax_len: %u, max_uninit_len: %u\n", info.max_len,
1134                info.max_uninit_len);
1135 }
1136
1137 void do_goto_block(int argc, char **argv)
1138 {
1139         struct ext2fs_extent    extent;
1140         errcode_t               retval;
1141         int                     op = EXT2_EXTENT_NEXT_LEAF;
1142         blk_t                   blk;
1143
1144         if (check_fs_open(argv[0]))
1145                 return;
1146
1147         if (!current_handle) {
1148                 com_err(argv[0], 0, "Extent handle not open");
1149                 return;
1150         }
1151
1152         if (argc != 2) {
1153                 fprintf(stderr, "%s block\n", argv[0]);
1154                 return;
1155         }
1156
1157         if (strtoblk(argv[0], argv[1], &blk))
1158                 return;
1159
1160         retval = ext2fs_extent_goto(current_handle, (blk64_t) blk);
1161         if (retval) {
1162                 com_err(argv[0], retval, "while trying to go to block %lu",
1163                         blk);
1164                 return;
1165         }
1166
1167         generic_goto_node(argv[0], EXT2_EXTENT_CURRENT);
1168 }
1169 #endif
1170