1 /* 2 * inode.c --- utility routines to read and write inodes 3 * 4 * Copyright (C) 1993, 1994, 1995, 1996, 1997 Theodore Ts'o. 5 * 6 * %Begin-Header% 7 * This file may be redistributed under the terms of the GNU Library 8 * General Public License, version 2. 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 #include <time.h> 21 #if HAVE_SYS_STAT_H 22 #include <sys/stat.h> 23 #endif 24 #if HAVE_SYS_TYPES_H 25 #include <sys/types.h> 26 #endif 27 28 #include "ext2_fs.h" 29 #include "ext2fsP.h" 30 #include "e2image.h" 31 32 struct ext2_struct_inode_scan { 33 errcode_t magic; 34 ext2_filsys fs; 35 ext2_ino_t current_inode; 36 blk_t current_block; 37 dgrp_t current_group; 38 ext2_ino_t inodes_left; 39 blk_t blocks_left; 40 dgrp_t groups_left; 41 blk_t inode_buffer_blocks; 42 char * inode_buffer; 43 int inode_size; 44 char * ptr; 45 int bytes_left; 46 char *temp_buffer; 47 errcode_t (*done_group)(ext2_filsys fs, 48 ext2_inode_scan scan, 49 dgrp_t group, 50 void * priv_data); 51 void * done_group_data; 52 int bad_block_ptr; 53 int scan_flags; 54 int reserved[6]; 55 }; 56 57 /* 58 * This routine flushes the icache, if it exists. 59 */ 60 errcode_t ext2fs_flush_icache(ext2_filsys fs) 61 { 62 int i; 63 64 if (!fs->icache) 65 return 0; 66 67 for (i=0; i < fs->icache->cache_size; i++) 68 fs->icache->cache[i].ino = 0; 69 70 fs->icache->buffer_blk = 0; 71 return 0; 72 } 73 74 static errcode_t create_icache(ext2_filsys fs) 75 { 76 errcode_t retval; 77 78 if (fs->icache) 79 return 0; 80 retval = ext2fs_get_mem(sizeof(struct ext2_inode_cache), &fs->icache); 81 if (retval) 82 return retval; 83 84 memset(fs->icache, 0, sizeof(struct ext2_inode_cache)); 85 retval = ext2fs_get_mem(fs->blocksize, &fs->icache->buffer); 86 if (retval) { 87 ext2fs_free_mem(&fs->icache); 88 return retval; 89 } 90 fs->icache->buffer_blk = 0; 91 fs->icache->cache_last = -1; 92 fs->icache->cache_size = 4; 93 fs->icache->refcount = 1; 94 retval = ext2fs_get_array(fs->icache->cache_size, 95 sizeof(struct ext2_inode_cache_ent), 96 &fs->icache->cache); 97 if (retval) { 98 ext2fs_free_mem(&fs->icache->buffer); 99 ext2fs_free_mem(&fs->icache); 100 return retval; 101 } 102 ext2fs_flush_icache(fs); 103 return 0; 104 } 105 106 errcode_t ext2fs_open_inode_scan(ext2_filsys fs, int buffer_blocks, 107 ext2_inode_scan *ret_scan) 108 { 109 ext2_inode_scan scan; 110 errcode_t retval; 111 errcode_t (*save_get_blocks)(ext2_filsys f, ext2_ino_t ino, blk_t *blocks); 112 113 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); 114 115 /* 116 * If fs->badblocks isn't set, then set it --- since the inode 117 * scanning functions require it. 118 */ 119 if (fs->badblocks == 0) { 120 /* 121 * Temporarly save fs->get_blocks and set it to zero, 122 * for compatibility with old e2fsck's. 123 */ 124 save_get_blocks = fs->get_blocks; 125 fs->get_blocks = 0; 126 retval = ext2fs_read_bb_inode(fs, &fs->badblocks); 127 if (retval && fs->badblocks) { 128 ext2fs_badblocks_list_free(fs->badblocks); 129 fs->badblocks = 0; 130 } 131 fs->get_blocks = save_get_blocks; 132 } 133 134 retval = ext2fs_get_mem(sizeof(struct ext2_struct_inode_scan), &scan); 135 if (retval) 136 return retval; 137 memset(scan, 0, sizeof(struct ext2_struct_inode_scan)); 138 139 scan->magic = EXT2_ET_MAGIC_INODE_SCAN; 140 scan->fs = fs; 141 scan->inode_size = EXT2_INODE_SIZE(fs->super); 142 scan->bytes_left = 0; 143 scan->current_group = 0; 144 scan->groups_left = fs->group_desc_count - 1; 145 scan->inode_buffer_blocks = buffer_blocks ? buffer_blocks : 8; 146 scan->current_block = scan->fs-> 147 group_desc[scan->current_group].bg_inode_table; 148 scan->inodes_left = EXT2_INODES_PER_GROUP(scan->fs->super); 149 scan->blocks_left = scan->fs->inode_blocks_per_group; 150 if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super, 151 EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) { 152 scan->inodes_left -= 153 fs->group_desc[scan->current_group].bg_itable_unused; 154 scan->blocks_left = 155 (scan->inodes_left + 156 (fs->blocksize / scan->inode_size - 1)) * 157 scan->inode_size / fs->blocksize; 158 } 159 retval = ext2fs_get_memalign(scan->inode_buffer_blocks * fs->blocksize, 160 fs->blocksize, &scan->inode_buffer); 161 scan->done_group = 0; 162 scan->done_group_data = 0; 163 scan->bad_block_ptr = 0; 164 if (retval) { 165 ext2fs_free_mem(&scan); 166 return retval; 167 } 168 retval = ext2fs_get_mem(scan->inode_size, &scan->temp_buffer); 169 if (retval) { 170 ext2fs_free_mem(&scan->inode_buffer); 171 ext2fs_free_mem(&scan); 172 return retval; 173 } 174 if (scan->fs->badblocks && scan->fs->badblocks->num) 175 scan->scan_flags |= EXT2_SF_CHK_BADBLOCKS; 176 if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super, 177 EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) 178 scan->scan_flags |= EXT2_SF_DO_LAZY; 179 *ret_scan = scan; 180 return 0; 181 } 182 183 void ext2fs_close_inode_scan(ext2_inode_scan scan) 184 { 185 if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN)) 186 return; 187 188 ext2fs_free_mem(&scan->inode_buffer); 189 scan->inode_buffer = NULL; 190 ext2fs_free_mem(&scan->temp_buffer); 191 scan->temp_buffer = NULL; 192 ext2fs_free_mem(&scan); 193 return; 194 } 195 196 void ext2fs_set_inode_callback(ext2_inode_scan scan, 197 errcode_t (*done_group)(ext2_filsys fs, 198 ext2_inode_scan scan, 199 dgrp_t group, 200 void * priv_data), 201 void *done_group_data) 202 { 203 if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN)) 204 return; 205 206 scan->done_group = done_group; 207 scan->done_group_data = done_group_data; 208 } 209 210 int ext2fs_inode_scan_flags(ext2_inode_scan scan, int set_flags, 211 int clear_flags) 212 { 213 int old_flags; 214 215 if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN)) 216 return 0; 217 218 old_flags = scan->scan_flags; 219 scan->scan_flags &= ~clear_flags; 220 scan->scan_flags |= set_flags; 221 return old_flags; 222 } 223 224 /* 225 * This function is called by ext2fs_get_next_inode when it needs to 226 * get ready to read in a new blockgroup. 227 */ 228 static errcode_t get_next_blockgroup(ext2_inode_scan scan) 229 { 230 ext2_filsys fs = scan->fs; 231 232 scan->current_group++; 233 scan->groups_left--; 234 235 scan->current_block =fs->group_desc[scan->current_group].bg_inode_table; 236 237 scan->current_inode = scan->current_group * 238 EXT2_INODES_PER_GROUP(fs->super); 239 240 scan->bytes_left = 0; 241 scan->inodes_left = EXT2_INODES_PER_GROUP(fs->super); 242 scan->blocks_left = fs->inode_blocks_per_group; 243 if (EXT2_HAS_RO_COMPAT_FEATURE(fs->super, 244 EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) { 245 scan->inodes_left -= 246 fs->group_desc[scan->current_group].bg_itable_unused; 247 scan->blocks_left = 248 (scan->inodes_left + 249 (fs->blocksize / scan->inode_size - 1)) * 250 scan->inode_size / fs->blocksize; 251 } 252 253 return 0; 254 } 255 256 errcode_t ext2fs_inode_scan_goto_blockgroup(ext2_inode_scan scan, 257 int group) 258 { 259 scan->current_group = group - 1; 260 scan->groups_left = scan->fs->group_desc_count - group; 261 return get_next_blockgroup(scan); 262 } 263 264 /* 265 * This function is called by get_next_blocks() to check for bad 266 * blocks in the inode table. 267 * 268 * This function assumes that badblocks_list->list is sorted in 269 * increasing order. 270 */ 271 static errcode_t check_for_inode_bad_blocks(ext2_inode_scan scan, 272 blk_t *num_blocks) 273 { 274 blk_t blk = scan->current_block; 275 badblocks_list bb = scan->fs->badblocks; 276 277 /* 278 * If the inode table is missing, then obviously there are no 279 * bad blocks. :-) 280 */ 281 if (blk == 0) 282 return 0; 283 284 /* 285 * If the current block is greater than the bad block listed 286 * in the bad block list, then advance the pointer until this 287 * is no longer the case. If we run out of bad blocks, then 288 * we don't need to do any more checking! 289 */ 290 while (blk > bb->list[scan->bad_block_ptr]) { 291 if (++scan->bad_block_ptr >= bb->num) { 292 scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS; 293 return 0; 294 } 295 } 296 297 /* 298 * If the current block is equal to the bad block listed in 299 * the bad block list, then handle that one block specially. 300 * (We could try to handle runs of bad blocks, but that 301 * only increases CPU efficiency by a small amount, at the 302 * expense of a huge expense of code complexity, and for an 303 * uncommon case at that.) 304 */ 305 if (blk == bb->list[scan->bad_block_ptr]) { 306 scan->scan_flags |= EXT2_SF_BAD_INODE_BLK; 307 *num_blocks = 1; 308 if (++scan->bad_block_ptr >= bb->num) 309 scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS; 310 return 0; 311 } 312 313 /* 314 * If there is a bad block in the range that we're about to 315 * read in, adjust the number of blocks to read so that we we 316 * don't read in the bad block. (Then the next block to read 317 * will be the bad block, which is handled in the above case.) 318 */ 319 if ((blk + *num_blocks) > bb->list[scan->bad_block_ptr]) 320 *num_blocks = (int) (bb->list[scan->bad_block_ptr] - blk); 321 322 return 0; 323 } 324 325 /* 326 * This function is called by ext2fs_get_next_inode when it needs to 327 * read in more blocks from the current blockgroup's inode table. 328 */ 329 static errcode_t get_next_blocks(ext2_inode_scan scan) 330 { 331 blk_t num_blocks; 332 errcode_t retval; 333 334 /* 335 * Figure out how many blocks to read; we read at most 336 * inode_buffer_blocks, and perhaps less if there aren't that 337 * many blocks left to read. 338 */ 339 num_blocks = scan->inode_buffer_blocks; 340 if (num_blocks > scan->blocks_left) 341 num_blocks = scan->blocks_left; 342 343 /* 344 * If the past block "read" was a bad block, then mark the 345 * left-over extra bytes as also being bad. 346 */ 347 if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK) { 348 if (scan->bytes_left) 349 scan->scan_flags |= EXT2_SF_BAD_EXTRA_BYTES; 350 scan->scan_flags &= ~EXT2_SF_BAD_INODE_BLK; 351 } 352 353 /* 354 * Do inode bad block processing, if necessary. 355 */ 356 if (scan->scan_flags & EXT2_SF_CHK_BADBLOCKS) { 357 retval = check_for_inode_bad_blocks(scan, &num_blocks); 358 if (retval) 359 return retval; 360 } 361 362 if ((scan->scan_flags & EXT2_SF_BAD_INODE_BLK) || 363 (scan->current_block == 0)) { 364 memset(scan->inode_buffer, 0, 365 (size_t) num_blocks * scan->fs->blocksize); 366 } else { 367 retval = io_channel_read_blk(scan->fs->io, 368 scan->current_block, 369 (int) num_blocks, 370 scan->inode_buffer); 371 if (retval) 372 return EXT2_ET_NEXT_INODE_READ; 373 } 374 scan->ptr = scan->inode_buffer; 375 scan->bytes_left = num_blocks * scan->fs->blocksize; 376 377 scan->blocks_left -= num_blocks; 378 if (scan->current_block) 379 scan->current_block += num_blocks; 380 return 0; 381 } 382 383 #if 0 384 /* 385 * Returns 1 if the entire inode_buffer has a non-zero size and 386 * contains all zeros. (Not just deleted inodes, since that means 387 * that part of the inode table was used at one point; we want all 388 * zeros, which means that the inode table is pristine.) 389 */ 390 static inline int is_empty_scan(ext2_inode_scan scan) 391 { 392 int i; 393 394 if (scan->bytes_left == 0) 395 return 0; 396 397 for (i=0; i < scan->bytes_left; i++) 398 if (scan->ptr[i]) 399 return 0; 400 return 1; 401 } 402 #endif 403 404 errcode_t ext2fs_get_next_inode_full(ext2_inode_scan scan, ext2_ino_t *ino, 405 struct ext2_inode *inode, int bufsize) 406 { 407 errcode_t retval; 408 int extra_bytes = 0; 409 410 EXT2_CHECK_MAGIC(scan, EXT2_ET_MAGIC_INODE_SCAN); 411 412 /* 413 * Do we need to start reading a new block group? 414 */ 415 if (scan->inodes_left <= 0) { 416 force_new_group: 417 if (scan->done_group) { 418 retval = (scan->done_group) 419 (scan->fs, scan, scan->current_group, 420 scan->done_group_data); 421 if (retval) 422 return retval; 423 } 424 if (scan->groups_left <= 0) { 425 *ino = 0; 426 return 0; 427 } 428 retval = get_next_blockgroup(scan); 429 if (retval) 430 return retval; 431 } 432 /* 433 * These checks are done outside the above if statement so 434 * they can be done for block group #0. 435 */ 436 if ((scan->scan_flags & EXT2_SF_DO_LAZY) && 437 (scan->fs->group_desc[scan->current_group].bg_flags & 438 EXT2_BG_INODE_UNINIT)) 439 goto force_new_group; 440 if (scan->inodes_left == 0) 441 goto force_new_group; 442 if (scan->current_block == 0) { 443 if (scan->scan_flags & EXT2_SF_SKIP_MISSING_ITABLE) { 444 goto force_new_group; 445 } else 446 return EXT2_ET_MISSING_INODE_TABLE; 447 } 448 449 450 /* 451 * Have we run out of space in the inode buffer? If so, we 452 * need to read in more blocks. 453 */ 454 if (scan->bytes_left < scan->inode_size) { 455 memcpy(scan->temp_buffer, scan->ptr, scan->bytes_left); 456 extra_bytes = scan->bytes_left; 457 458 retval = get_next_blocks(scan); 459 if (retval) 460 return retval; 461 #if 0 462 /* 463 * XXX test Need check for used inode somehow. 464 * (Note: this is hard.) 465 */ 466 if (is_empty_scan(scan)) 467 goto force_new_group; 468 #endif 469 } 470 471 retval = 0; 472 if (extra_bytes) { 473 memcpy(scan->temp_buffer+extra_bytes, scan->ptr, 474 scan->inode_size - extra_bytes); 475 scan->ptr += scan->inode_size - extra_bytes; 476 scan->bytes_left -= scan->inode_size - extra_bytes; 477 478 #ifdef WORDS_BIGENDIAN 479 memset(inode, 0, bufsize); 480 ext2fs_swap_inode_full(scan->fs, 481 (struct ext2_inode_large *) inode, 482 (struct ext2_inode_large *) scan->temp_buffer, 483 0, bufsize); 484 #else 485 *inode = *((struct ext2_inode *) scan->temp_buffer); 486 #endif 487 if (scan->scan_flags & EXT2_SF_BAD_EXTRA_BYTES) 488 retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE; 489 scan->scan_flags &= ~EXT2_SF_BAD_EXTRA_BYTES; 490 } else { 491 #ifdef WORDS_BIGENDIAN 492 memset(inode, 0, bufsize); 493 ext2fs_swap_inode_full(scan->fs, 494 (struct ext2_inode_large *) inode, 495 (struct ext2_inode_large *) scan->ptr, 496 0, bufsize); 497 #else 498 memcpy(inode, scan->ptr, bufsize); 499 #endif 500 scan->ptr += scan->inode_size; 501 scan->bytes_left -= scan->inode_size; 502 if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK) 503 retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE; 504 } 505 506 scan->inodes_left--; 507 scan->current_inode++; 508 *ino = scan->current_inode; 509 return retval; 510 } 511 512 errcode_t ext2fs_get_next_inode(ext2_inode_scan scan, ext2_ino_t *ino, 513 struct ext2_inode *inode) 514 { 515 return ext2fs_get_next_inode_full(scan, ino, inode, 516 sizeof(struct ext2_inode)); 517 } 518 519 /* 520 * Functions to read and write a single inode. 521 */ 522 errcode_t ext2fs_read_inode_full(ext2_filsys fs, ext2_ino_t ino, 523 struct ext2_inode * inode, int bufsize) 524 { 525 unsigned long group, block, block_nr, offset; 526 char *ptr; 527 errcode_t retval; 528 int clen, i, inodes_per_block, length; 529 io_channel io; 530 531 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); 532 533 /* Check to see if user has an override function */ 534 if (fs->read_inode) { 535 retval = (fs->read_inode)(fs, ino, inode); 536 if (retval != EXT2_ET_CALLBACK_NOTHANDLED) 537 return retval; 538 } 539 if ((ino == 0) || (ino > fs->super->s_inodes_count)) 540 return EXT2_ET_BAD_INODE_NUM; 541 /* Create inode cache if not present */ 542 if (!fs->icache) { 543 retval = create_icache(fs); 544 if (retval) 545 return retval; 546 } 547 /* Check to see if it's in the inode cache */ 548 if (bufsize == sizeof(struct ext2_inode)) { 549 /* only old good inode can be retrieved from the cache */ 550 for (i=0; i < fs->icache->cache_size; i++) { 551 if (fs->icache->cache[i].ino == ino) { 552 *inode = fs->icache->cache[i].inode; 553 return 0; 554 } 555 } 556 } 557 if (fs->flags & EXT2_FLAG_IMAGE_FILE) { 558 inodes_per_block = fs->blocksize / EXT2_INODE_SIZE(fs->super); 559 block_nr = fs->image_header->offset_inode / fs->blocksize; 560 block_nr += (ino - 1) / inodes_per_block; 561 offset = ((ino - 1) % inodes_per_block) * 562 EXT2_INODE_SIZE(fs->super); 563 io = fs->image_io; 564 } else { 565 group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super); 566 if (group > fs->group_desc_count) 567 return EXT2_ET_BAD_INODE_NUM; 568 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) * 569 EXT2_INODE_SIZE(fs->super); 570 block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super); 571 if (!fs->group_desc[(unsigned)group].bg_inode_table) 572 return EXT2_ET_MISSING_INODE_TABLE; 573 block_nr = fs->group_desc[(unsigned)group].bg_inode_table + 574 block; 575 io = fs->io; 576 } 577 offset &= (EXT2_BLOCK_SIZE(fs->super) - 1); 578 579 length = EXT2_INODE_SIZE(fs->super); 580 if (bufsize < length) 581 length = bufsize; 582 583 ptr = (char *) inode; 584 while (length) { 585 clen = length; 586 if ((offset + length) > fs->blocksize) 587 clen = fs->blocksize - offset; 588 589 if (block_nr != fs->icache->buffer_blk) { 590 retval = io_channel_read_blk(io, block_nr, 1, 591 fs->icache->buffer); 592 if (retval) 593 return retval; 594 fs->icache->buffer_blk = block_nr; 595 } 596 597 memcpy(ptr, ((char *) fs->icache->buffer) + (unsigned) offset, 598 clen); 599 600 offset = 0; 601 length -= clen; 602 ptr += clen; 603 block_nr++; 604 } 605 606 #ifdef WORDS_BIGENDIAN 607 ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) inode, 608 (struct ext2_inode_large *) inode, 609 0, bufsize); 610 #endif 611 612 /* Update the inode cache */ 613 fs->icache->cache_last = (fs->icache->cache_last + 1) % 614 fs->icache->cache_size; 615 fs->icache->cache[fs->icache->cache_last].ino = ino; 616 fs->icache->cache[fs->icache->cache_last].inode = *inode; 617 618 return 0; 619 } 620 621 errcode_t ext2fs_read_inode(ext2_filsys fs, ext2_ino_t ino, 622 struct ext2_inode * inode) 623 { 624 return ext2fs_read_inode_full(fs, ino, inode, 625 sizeof(struct ext2_inode)); 626 } 627 628 errcode_t ext2fs_write_inode_full(ext2_filsys fs, ext2_ino_t ino, 629 struct ext2_inode * inode, int bufsize) 630 { 631 unsigned long group, block, block_nr, offset; 632 errcode_t retval = 0; 633 struct ext2_inode_large temp_inode, *w_inode; 634 char *ptr; 635 int clen, i, length; 636 637 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); 638 639 /* Check to see if user provided an override function */ 640 if (fs->write_inode) { 641 retval = (fs->write_inode)(fs, ino, inode); 642 if (retval != EXT2_ET_CALLBACK_NOTHANDLED) 643 return retval; 644 } 645 646 /* Check to see if the inode cache needs to be updated */ 647 if (fs->icache) { 648 for (i=0; i < fs->icache->cache_size; i++) { 649 if (fs->icache->cache[i].ino == ino) { 650 fs->icache->cache[i].inode = *inode; 651 break; 652 } 653 } 654 } else { 655 retval = create_icache(fs); 656 if (retval) 657 return retval; 658 } 659 660 if (!(fs->flags & EXT2_FLAG_RW)) 661 return EXT2_ET_RO_FILSYS; 662 663 if ((ino == 0) || (ino > fs->super->s_inodes_count)) 664 return EXT2_ET_BAD_INODE_NUM; 665 666 length = bufsize; 667 if (length < EXT2_INODE_SIZE(fs->super)) 668 length = EXT2_INODE_SIZE(fs->super); 669 670 if (length > (int) sizeof(struct ext2_inode_large)) { 671 w_inode = malloc(length); 672 if (!w_inode) 673 return ENOMEM; 674 } else 675 w_inode = &temp_inode; 676 memset(w_inode, 0, length); 677 678 #ifdef WORDS_BIGENDIAN 679 ext2fs_swap_inode_full(fs, w_inode, 680 (struct ext2_inode_large *) inode, 681 1, bufsize); 682 #else 683 memcpy(w_inode, inode, bufsize); 684 #endif 685 686 group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super); 687 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) * 688 EXT2_INODE_SIZE(fs->super); 689 block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super); 690 if (!fs->group_desc[(unsigned) group].bg_inode_table) { 691 retval = EXT2_ET_MISSING_INODE_TABLE; 692 goto errout; 693 } 694 block_nr = fs->group_desc[(unsigned) group].bg_inode_table + block; 695 696 offset &= (EXT2_BLOCK_SIZE(fs->super) - 1); 697 698 length = EXT2_INODE_SIZE(fs->super); 699 if (length > bufsize) 700 length = bufsize; 701 702 ptr = (char *) w_inode; 703 704 while (length) { 705 clen = length; 706 if ((offset + length) > fs->blocksize) 707 clen = fs->blocksize - offset; 708 709 if (fs->icache->buffer_blk != block_nr) { 710 retval = io_channel_read_blk(fs->io, block_nr, 1, 711 fs->icache->buffer); 712 if (retval) 713 goto errout; 714 fs->icache->buffer_blk = block_nr; 715 } 716 717 718 memcpy((char *) fs->icache->buffer + (unsigned) offset, 719 ptr, clen); 720 721 retval = io_channel_write_blk(fs->io, block_nr, 1, 722 fs->icache->buffer); 723 if (retval) 724 goto errout; 725 726 offset = 0; 727 ptr += clen; 728 length -= clen; 729 block_nr++; 730 } 731 732 fs->flags |= EXT2_FLAG_CHANGED; 733 errout: 734 if (w_inode && w_inode != &temp_inode) 735 free(w_inode); 736 return retval; 737 } 738 739 errcode_t ext2fs_write_inode(ext2_filsys fs, ext2_ino_t ino, 740 struct ext2_inode *inode) 741 { 742 return ext2fs_write_inode_full(fs, ino, inode, 743 sizeof(struct ext2_inode)); 744 } 745 746 /* 747 * This function should be called when writing a new inode. It makes 748 * sure that extra part of large inodes is initialized properly. 749 */ 750 errcode_t ext2fs_write_new_inode(ext2_filsys fs, ext2_ino_t ino, 751 struct ext2_inode *inode) 752 { 753 struct ext2_inode *buf; 754 int size = EXT2_INODE_SIZE(fs->super); 755 struct ext2_inode_large *large_inode; 756 errcode_t retval; 757 __u32 t = fs->now ? fs->now : time(NULL); 758 759 if (!inode->i_ctime) 760 inode->i_ctime = t; 761 if (!inode->i_mtime) 762 inode->i_mtime = t; 763 if (!inode->i_atime) 764 inode->i_atime = t; 765 766 if (size == sizeof(struct ext2_inode)) 767 return ext2fs_write_inode_full(fs, ino, inode, 768 sizeof(struct ext2_inode)); 769 770 buf = malloc(size); 771 if (!buf) 772 return ENOMEM; 773 774 memset(buf, 0, size); 775 *buf = *inode; 776 777 large_inode = (struct ext2_inode_large *) buf; 778 large_inode->i_extra_isize = sizeof(struct ext2_inode_large) - 779 EXT2_GOOD_OLD_INODE_SIZE; 780 if (!large_inode->i_crtime) 781 large_inode->i_crtime = t; 782 783 retval = ext2fs_write_inode_full(fs, ino, buf, size); 784 free(buf); 785 return retval; 786 } 787 788 789 errcode_t ext2fs_get_blocks(ext2_filsys fs, ext2_ino_t ino, blk_t *blocks) 790 { 791 struct ext2_inode inode; 792 int i; 793 errcode_t retval; 794 795 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); 796 797 if (ino > fs->super->s_inodes_count) 798 return EXT2_ET_BAD_INODE_NUM; 799 800 if (fs->get_blocks) { 801 if (!(*fs->get_blocks)(fs, ino, blocks)) 802 return 0; 803 } 804 retval = ext2fs_read_inode(fs, ino, &inode); 805 if (retval) 806 return retval; 807 for (i=0; i < EXT2_N_BLOCKS; i++) 808 blocks[i] = inode.i_block[i]; 809 return 0; 810 } 811 812 errcode_t ext2fs_check_directory(ext2_filsys fs, ext2_ino_t ino) 813 { 814 struct ext2_inode inode; 815 errcode_t retval; 816 817 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); 818 819 if (ino > fs->super->s_inodes_count) 820 return EXT2_ET_BAD_INODE_NUM; 821 822 if (fs->check_directory) { 823 retval = (fs->check_directory)(fs, ino); 824 if (retval != EXT2_ET_CALLBACK_NOTHANDLED) 825 return retval; 826 } 827 retval = ext2fs_read_inode(fs, ino, &inode); 828 if (retval) 829 return retval; 830 if (!LINUX_S_ISDIR(inode.i_mode)) 831 return EXT2_ET_NO_DIRECTORY; 832 return 0; 833 } 834 835
