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 static errcode_t extent_goto(ext2_extent_handle_t handle,
 557                              int leaf_level, blk64_t blk)
 558 {
 559         struct ext2fs_extent    extent;
 560         errcode_t               retval;
 561
 562         retval = ext2fs_extent_get(handle, EXT2_EXTENT_ROOT, &extent);
 563         if (retval)
 564                 return retval;
 565
 566         dbg_print_extent("root", &extent);
 567         while (1) {
 568                 if (handle->level - leaf_level == handle->max_depth) {
 569                         if ((blk >= extent.e_lblk) &&
 570                             (blk < extent.e_lblk + extent.e_len))
 571                                 return 0;
 572                         if (blk < extent.e_lblk)
 573                                 return EXT2_ET_EXTENT_NOT_FOUND;
 574                         retval = ext2fs_extent_get(handle,
 575                                                    EXT2_EXTENT_NEXT_SIB,
 576                                                    &extent);
 577                         if (retval == EXT2_ET_EXTENT_NO_NEXT)
 578                                 return EXT2_ET_EXTENT_NOT_FOUND;
 579                         if (retval)
 580                                 return retval;
 581                         continue;
 582                 }
 583
 584                 retval = ext2fs_extent_get(handle, EXT2_EXTENT_NEXT_SIB,
 585                                            &extent);
 586                 if (retval == EXT2_ET_EXTENT_NO_NEXT)
 587                         goto go_down;
 588                 if (retval)
 589                         return retval;
 590
 591                 dbg_print_extent("next", &extent);
 592                 if (blk == extent.e_lblk)
 593                         goto go_down;
 594                 if (blk > extent.e_lblk)
 595                         continue;
 596
 597                 retval = ext2fs_extent_get(handle, EXT2_EXTENT_PREV_SIB,
 598                                            &extent);
 599                 if (retval)
 600                         return retval;
 601
 602                 dbg_print_extent("prev", &extent);
 603
 604         go_down:
 605                 retval = ext2fs_extent_get(handle, EXT2_EXTENT_DOWN,
 606                                            &extent);
 607                 if (retval)
 608                         return retval;
 609
 610                 dbg_print_extent("down", &extent);
 611         }
 612 }
 613
 614 errcode_t ext2fs_extent_goto(ext2_extent_handle_t handle,
 615                              blk64_t blk)
 616 {
 617         return extent_goto(handle, 0, blk);
 618 }
 619
 620 errcode_t ext2fs_extent_replace(ext2_extent_handle_t handle,
 621                                 int flags EXT2FS_ATTR((unused)),
 622                                 struct ext2fs_extent *extent)
 623 {
 624         struct extent_path              *path;
 625         struct ext3_extent_idx          *ix;
 626         struct ext3_extent              *ex;
 627
 628         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
 629
 630         if (!(handle->fs->flags & EXT2_FLAG_RW))
 631                 return EXT2_ET_RO_FILSYS;
 632
 633         if (!handle->path)
 634                 return EXT2_ET_NO_CURRENT_NODE;
 635
 636         path = handle->path + handle->level;
 637         if (!path->curr)
 638                 return EXT2_ET_NO_CURRENT_NODE;
 639
 640         if (handle->level == handle->max_depth) {
 641                 ex = path->curr;
 642
 643                 ex->ee_block = ext2fs_cpu_to_le32(extent->e_lblk);
 644                 ex->ee_start = ext2fs_cpu_to_le32(extent->e_pblk & 0xFFFFFFFF);
 645                 ex->ee_start_hi = ext2fs_cpu_to_le16(extent->e_pblk >> 32);
 646                 ex->ee_len = ext2fs_cpu_to_le16(extent->e_len);
 647         } else {
 648                 ix = path->curr;
 649
 650                 ix->ei_leaf = ext2fs_cpu_to_le32(extent->e_pblk & 0xFFFFFFFF);
 651                 ix->ei_leaf_hi = ext2fs_cpu_to_le16(extent->e_pblk >> 32);
 652                 ix->ei_block = ext2fs_cpu_to_le32(extent->e_lblk);
 653                 ix->ei_unused = 0;
 654         }
 655         update_path(handle);
 656         return 0;
 657 }
 658
 659 errcode_t ext2fs_extent_insert(ext2_extent_handle_t handle, int flags,
 660                                       struct ext2fs_extent *extent)
 661 {
 662         struct extent_path              *path;
 663         struct ext3_extent_idx          *ix;
 664         struct ext3_extent_header       *eh;
 665         errcode_t                       retval;
 666
 667         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
 668
 669         if (!(handle->fs->flags & EXT2_FLAG_RW))
 670                 return EXT2_ET_RO_FILSYS;
 671
 672         if (!handle->path)
 673                 return EXT2_ET_NO_CURRENT_NODE;
 674
 675         path = handle->path + handle->level;
 676
 677         if (path->entries >= path->max_entries)
 678                 return EXT2_ET_CANT_INSERT_EXTENT;
 679
 680         eh = (struct ext3_extent_header *) path->buf;
 681         if (path->curr) {
 682                 ix = path->curr;
 683                 if (flags & EXT2_EXTENT_INSERT_AFTER) {
 684                         ix++;
 685                         path->left--;
 686                 }
 687         } else
 688                 ix = EXT_FIRST_INDEX(eh);
 689
 690         path->curr = ix;
 691
 692         if (path->left > 0)
 693                 memmove(ix + 1, ix,
 694                         (path->left+1) * sizeof(struct ext3_extent_idx));
 695         path->left++;
 696         path->entries++;
 697
 698         eh = (struct ext3_extent_header *) path->buf;
 699         eh->eh_entries = ext2fs_cpu_to_le16(path->entries);
 700
 701         retval = ext2fs_extent_replace(handle, 0, extent);
 702         if (retval)
 703                 goto errout;
 704
 705         retval = update_path(handle);
 706         if (retval)
 707                 goto errout;
 708
 709         return 0;
 710
 711 errout:
 712         ext2fs_extent_delete(handle, 0);
 713         return retval;
 714 }
 715
 716 errcode_t ext2fs_extent_delete(ext2_extent_handle_t handle,
 717                                int flags EXT2FS_ATTR((unused)))
 718 {
 719         struct extent_path              *path;
 720         char                            *cp;
 721         struct ext3_extent_header       *eh;
 722         errcode_t                       retval;
 723
 724         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
 725
 726         if (!(handle->fs->flags & EXT2_FLAG_RW))
 727                 return EXT2_ET_RO_FILSYS;
 728
 729         if (!handle->path)
 730                 return EXT2_ET_NO_CURRENT_NODE;
 731
 732         path = handle->path + handle->level;
 733         if (!path->curr)
 734                 return EXT2_ET_NO_CURRENT_NODE;
 735
 736         cp = path->curr;
 737
 738         if (path->left) {
 739                 memmove(cp, cp + sizeof(struct ext3_extent_idx),
 740                         path->left * sizeof(struct ext3_extent_idx));
 741                 path->left--;
 742         } else {
 743                 struct ext3_extent_idx  *ix = path->curr;
 744                 ix--;
 745                 path->curr = ix;
 746         }
 747         path->entries--;
 748         if (path->entries == 0)
 749                 path->curr = 0;
 750
 751         eh = (struct ext3_extent_header *) path->buf;
 752         eh->eh_entries = ext2fs_cpu_to_le16(path->entries);
 753
 754         retval = update_path(handle);
 755
 756         return retval;
 757 }
 758
 759 errcode_t ext2fs_extent_get_info(ext2_extent_handle_t handle,
 760                                  struct ext2_extent_info *info)
 761 {
 762         struct extent_path              *path;
 763
 764         EXT2_CHECK_MAGIC(handle, EXT2_ET_MAGIC_EXTENT_HANDLE);
 765
 766         memset(info, 0, sizeof(struct ext2_extent_info));
 767
 768         path = handle->path + handle->level;
 769         if (path) {
 770                 if (path->curr)
 771                         info->curr_entry = ((char *) path->curr - path->buf) /
 772                                 sizeof(struct ext3_extent_idx);
 773                 else
 774                         info->curr_entry = 0;
 775                 info->num_entries = path->entries;
 776                 info->max_entries = path->max_entries;
 777                 info->bytes_avail = (path->max_entries - path->entries) *
 778                         sizeof(struct ext3_extent);
 779         }
 780
 781         info->curr_level = handle->level;
 782         info->max_depth = handle->max_depth;
 783         info->max_lblk = ((__u64) 1 << 32) - 1;
 784         info->max_pblk = ((__u64) 1 << 48) - 1;
 785         info->max_len = (1UL << 15);
 786         info->max_uninit_len = (1UL << 15) - 1;
 787
 788         return 0;
 789 }
 790
 791 #ifdef DEBUG
 792
 793 #include "debugfs.h"
 794
 795 /*
 796  * Hook in new commands into debugfs
 797  */
 798 const char *debug_prog_name = "tst_extents";
 799 extern ss_request_table extent_cmds;
 800 ss_request_table *extra_cmds = &extent_cmds;
 801
 802 ext2_ino_t      current_ino = 0;
 803 ext2_extent_handle_t current_handle;
 804
 805 void do_inode(int argc, char *argv[])
 806 {
 807         ext2_ino_t      inode;
 808         int             i;
 809         struct ext3_extent_header *eh;
 810         errcode_t retval;
 811
 812         if (check_fs_open(argv[0]))
 813                 return;
 814
 815         if (argc == 1) {
 816                 if (current_ino)
 817                         printf("Current inode is %d\n", current_ino);
 818                 else
 819                         printf("No current inode\n");
 820                 return;
 821         }
 822
 823         if (common_inode_args_process(argc, argv, &inode, 0)) {
 824                 return;
 825         }
 826
 827         current_ino = 0;
 828
 829         retval = ext2fs_extent_open(current_fs, inode, &current_handle);
 830         if (retval) {
 831                 com_err(argv[1], retval, "while opening extent handle");
 832                 return;
 833         }
 834
 835         current_ino = inode;
 836
 837         printf("Loaded inode %d\n", current_ino);
 838
 839         return;
 840 }
 841
 842 void generic_goto_node(char *cmd_name, int op)
 843 {
 844         struct ext2fs_extent    extent;
 845         errcode_t               retval;
 846
 847         if (check_fs_open(cmd_name))
 848                 return;
 849
 850         if (!current_handle) {
 851                 com_err(cmd_name, 0, "Extent handle not open");
 852                 return;
 853         }
 854
 855         retval = ext2fs_extent_get(current_handle, op, &extent);
 856         if (retval) {
 857                 com_err(cmd_name, retval, 0);
 858                 return;
 859         }
 860         dbg_print_extent(0, &extent);
 861 }
 862
 863 void do_current_node(int argc, char *argv[])
 864 {
 865         generic_goto_node(argv[0], EXT2_EXTENT_CURRENT);
 866 }
 867
 868 void do_root_node(int argc, char *argv[])
 869 {
 870         generic_goto_node(argv[0], EXT2_EXTENT_ROOT);
 871 }
 872
 873 void do_last_leaf(int argc, char *argv[])
 874 {
 875         generic_goto_node(argv[0], EXT2_EXTENT_LAST_LEAF);
 876 }
 877
 878 void do_first_sib(int argc, char *argv[])
 879 {
 880         generic_goto_node(argv[0], EXT2_EXTENT_FIRST_SIB);
 881 }
 882
 883 void do_last_sib(int argc, char *argv[])
 884 {
 885         generic_goto_node(argv[0], EXT2_EXTENT_LAST_SIB);
 886 }
 887
 888 void do_next_sib(int argc, char *argv[])
 889 {
 890         generic_goto_node(argv[0], EXT2_EXTENT_NEXT_SIB);
 891 }
 892
 893 void do_prev_sib(int argc, char *argv[])
 894 {
 895         generic_goto_node(argv[0], EXT2_EXTENT_PREV_SIB);
 896 }
 897
 898 void do_next_leaf(int argc, char *argv[])
 899 {
 900         generic_goto_node(argv[0], EXT2_EXTENT_NEXT_LEAF);
 901 }
 902
 903 void do_prev_leaf(int argc, char *argv[])
 904 {
 905         generic_goto_node(argv[0], EXT2_EXTENT_PREV_LEAF);
 906 }
 907
 908 void do_next(int argc, char *argv[])
 909 {
 910         generic_goto_node(argv[0], EXT2_EXTENT_NEXT);
 911 }
 912
 913 void do_prev(int argc, char *argv[])
 914 {
 915         generic_goto_node(argv[0], EXT2_EXTENT_PREV);
 916 }
 917
 918 void do_up(int argc, char *argv[])
 919 {
 920         generic_goto_node(argv[0], EXT2_EXTENT_UP);
 921 }
 922
 923 void do_down(int argc, char *argv[])
 924 {
 925         generic_goto_node(argv[0], EXT2_EXTENT_DOWN);
 926 }
 927
 928 void do_delete_node(int argc, char *argv[])
 929 {
 930         errcode_t       retval;
 931         int             err;
 932
 933         if (check_fs_read_write(argv[0]))
 934                 return;
 935
 936         retval = ext2fs_extent_delete(current_handle, 0);
 937         if (retval) {
 938                 com_err(argv[0], retval, 0);
 939                 return;
 940         }
 941         do_current_node(argc, argv);
 942 }
 943
 944 void do_replace_node(int argc, char *argv[])
 945 {
 946         errcode_t       retval;
 947         struct ext2fs_extent extent;
 948         int err;
 949
 950         if (check_fs_read_write(argv[0]))
 951                 return;
 952
 953         if (argc != 4) {
 954                 fprintf(stderr, "usage: %s <lblk> <len> <pblk>\n", argv[0]);
 955                 return;
 956         }
 957
 958         extent.e_lblk = parse_ulong(argv[1], argv[0],
 959                                     "logical block", &err);
 960         if (err)
 961                 return;
 962
 963         extent.e_len = parse_ulong(argv[2], argv[0],
 964                                     "logical block", &err);
 965         if (err)
 966                 return;
 967
 968         extent.e_pblk = parse_ulong(argv[3], argv[0],
 969                                     "logical block", &err);
 970         if (err)
 971                 return;
 972
 973         retval = ext2fs_extent_replace(current_handle, 0, &extent);
 974         if (retval) {
 975                 com_err(argv[0], retval, 0);
 976                 return;
 977         }
 978         do_current_node(argc, argv);
 979 }
 980
 981 void do_insert_node(int argc, char *argv[])
 982 {
 983         errcode_t       retval;
 984         struct ext2fs_extent extent;
 985         char *cmd;
 986         int err;
 987         int flags = 0;
 988
 989         if (check_fs_read_write(argv[0]))
 990                 return;
 991
 992         cmd = argv[0];
 993
 994         if (argc > 2 && !strcmp(argv[1], "--after")) {
 995                 argc--;
 996                 argv++;
 997                 flags |= EXT2_EXTENT_INSERT_AFTER;
 998         }
 999
1000         if (argc != 4) {
1001                 fprintf(stderr, "usage: %s <lblk> <len> <pblk>\n", cmd);
1002                 return;
1003         }
1004
1005         extent.e_lblk = parse_ulong(argv[1], cmd,
1006                                     "logical block", &err);
1007         if (err)
1008                 return;
1009
1010         extent.e_len = parse_ulong(argv[2], cmd,
1011                                     "length", &err);
1012         if (err)
1013                 return;
1014
1015         extent.e_pblk = parse_ulong(argv[3], cmd,
1016                                     "pysical block", &err);
1017         if (err)
1018                 return;
1019
1020         retval = ext2fs_extent_insert(current_handle, flags, &extent);
1021         if (retval) {
1022                 com_err(cmd, retval, 0);
1023                 return;
1024         }
1025         do_current_node(argc, argv);
1026 }
1027
1028 void do_print_all(int argc, char **argv)
1029 {
1030         struct ext2fs_extent    extent;
1031         errcode_t               retval;
1032         errcode_t               end_err = EXT2_ET_EXTENT_NO_NEXT;
1033         int                     op = EXT2_EXTENT_NEXT;
1034         int                     first_op = EXT2_EXTENT_ROOT;
1035
1036
1037         if (check_fs_open(argv[0]))
1038                 return;
1039
1040         if (!current_handle) {
1041                 com_err(argv[0], 0, "Extent handle not open");
1042                 return;
1043         }
1044
1045         if (argc > 2) {
1046         print_usage:
1047                 fprintf(stderr,
1048                         "Usage: %s [--leaf-only|--reverse|--reverse-leaf]\n",
1049                         argv[0]);
1050                 return;
1051         }
1052
1053         if (argc == 2) {
1054                 if (!strcmp(argv[1], "--leaf-only"))
1055                         op = EXT2_EXTENT_NEXT_LEAF;
1056                 else if (!strcmp(argv[1], "--reverse")) {
1057                         op = EXT2_EXTENT_PREV;
1058                         first_op = EXT2_EXTENT_LAST_LEAF;
1059                         end_err = EXT2_ET_EXTENT_NO_PREV;
1060                 } else if (!strcmp(argv[1], "--reverse-leaf")) {
1061                         op = EXT2_EXTENT_PREV_LEAF;
1062                         first_op = EXT2_EXTENT_LAST_LEAF;
1063                         end_err = EXT2_ET_EXTENT_NO_PREV;
1064                 } else
1065                           goto print_usage;
1066         }
1067
1068         retval = ext2fs_extent_get(current_handle, first_op, &extent);
1069         if (retval) {
1070                 com_err(argv[0], retval, 0);
1071                 return;
1072         }
1073         dbg_print_extent(0, &extent);
1074
1075         while (1) {
1076                 retval = ext2fs_extent_get(current_handle, op, &extent);
1077                 if (retval == end_err)
1078                         break;
1079
1080                 if (retval) {
1081                         com_err(argv[0], retval, 0);
1082                         return;
1083                 }
1084                 dbg_print_extent(0, &extent);
1085         }
1086 }
1087
1088 void do_info(int argc, char **argv)
1089 {
1090         struct ext2_extent_info info;
1091         errcode_t               retval;
1092
1093         if (check_fs_open(argv[0]))
1094                 return;
1095
1096         if (!current_handle) {
1097                 com_err(argv[0], 0, "Extent handle not open");
1098                 return;
1099         }
1100
1101         retval = ext2fs_extent_get_info(current_handle, &info);
1102         if (retval) {
1103                 com_err(argv[0], retval, 0);
1104                 return;
1105         }
1106
1107         printf("Current handle location: %d/%d (max: %d, bytes %d), level %d/%d\n",
1108                info.curr_entry, info.num_entries, info.max_entries,
1109                info.bytes_avail, info.curr_level, info.max_depth);
1110         printf("\tmax lblk: %llu, max pblk: %llu\n", info.max_lblk,
1111                info.max_pblk);
1112         printf("\tmax_len: %u, max_uninit_len: %u\n", info.max_len,
1113                info.max_uninit_len);
1114 }
1115
1116 void do_goto_block(int argc, char **argv)
1117 {
1118         struct ext2fs_extent    extent;
1119         errcode_t               retval;
1120         int                     op = EXT2_EXTENT_NEXT_LEAF;
1121         blk_t                   blk;
1122
1123         if (check_fs_open(argv[0]))
1124                 return;
1125
1126         if (!current_handle) {
1127                 com_err(argv[0], 0, "Extent handle not open");
1128                 return;
1129         }
1130
1131         if (argc != 2) {
1132                 fprintf(stderr, "%s block\n", argv[0]);
1133                 return;
1134         }
1135
1136         if (strtoblk(argv[0], argv[1], &blk))
1137                 return;
1138
1139         retval = ext2fs_extent_goto(current_handle, (blk64_t) blk);
1140         if (retval) {
1141                 com_err(argv[0], retval, "while trying to go to block %lu",
1142                         blk);
1143                 return;
1144         }
1145
1146         generic_goto_node(argv[0], EXT2_EXTENT_CURRENT);
1147 }
1148 #endif
1149