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 "config.h"
13 #include <stdio.h>
14 #include <string.h>
15 #if HAVE_UNISTD_H
16 #include <unistd.h>
17 #endif
18 #if HAVE_ERRNO_H
19 #include <errno.h>
20 #endif
21 #include <time.h>
22 #if HAVE_SYS_STAT_H
23 #include <sys/stat.h>
24 #endif
25 #if HAVE_SYS_TYPES_H
26 #include <sys/types.h>
27 #endif
28
29 #include "ext2_fs.h"
30 #include "ext2fsP.h"
31 #include "e2image.h"
32
33 #define IBLOCK_STATUS_CSUMS_OK 1
34 #define IBLOCK_STATUS_INSANE 2
35 #define SCAN_BLOCK_STATUS(scan) ((scan)->temp_buffer + (scan)->inode_size)
36
37 struct ext2_struct_inode_scan {
38 errcode_t magic;
39 ext2_filsys fs;
40 ext2_ino_t current_inode;
41 blk64_t current_block;
42 dgrp_t current_group;
43 ext2_ino_t inodes_left;
44 blk_t blocks_left;
45 dgrp_t groups_left;
46 blk_t inode_buffer_blocks;
47 char * inode_buffer;
48 int inode_size;
49 char * ptr;
50 int bytes_left;
51 char *temp_buffer;
52 errcode_t (*done_group)(ext2_filsys fs,
53 ext2_inode_scan scan,
54 dgrp_t group,
55 void * priv_data);
56 void * done_group_data;
57 int bad_block_ptr;
58 int scan_flags;
59 int reserved[6];
60 };
61
62 /*
63 * This routine flushes the icache, if it exists.
64 */
ext2fs_flush_icache(ext2_filsys fs)65 errcode_t ext2fs_flush_icache(ext2_filsys fs)
66 {
67 unsigned i;
68
69 if (!fs->icache)
70 return 0;
71
72 for (i=0; i < fs->icache->cache_size; i++)
73 fs->icache->cache[i].ino = 0;
74
75 fs->icache->buffer_blk = 0;
76 return 0;
77 }
78
79 /*
80 * Free the inode cache structure
81 */
ext2fs_free_inode_cache(struct ext2_inode_cache * icache)82 void ext2fs_free_inode_cache(struct ext2_inode_cache *icache)
83 {
84 unsigned i;
85
86 if (--icache->refcount)
87 return;
88 if (icache->buffer)
89 ext2fs_free_mem(&icache->buffer);
90 for (i = 0; i < icache->cache_size; i++)
91 ext2fs_free_mem(&icache->cache[i].inode);
92 if (icache->cache)
93 ext2fs_free_mem(&icache->cache);
94 icache->buffer_blk = 0;
95 ext2fs_free_mem(&icache);
96 }
97
ext2fs_create_inode_cache(ext2_filsys fs,unsigned int cache_size)98 errcode_t ext2fs_create_inode_cache(ext2_filsys fs, unsigned int cache_size)
99 {
100 unsigned i;
101 errcode_t retval;
102
103 if (fs->icache)
104 return 0;
105 retval = ext2fs_get_mem(sizeof(struct ext2_inode_cache), &fs->icache);
106 if (retval)
107 return retval;
108
109 memset(fs->icache, 0, sizeof(struct ext2_inode_cache));
110 retval = ext2fs_get_mem(fs->blocksize, &fs->icache->buffer);
111 if (retval)
112 goto errout;
113
114 fs->icache->buffer_blk = 0;
115 fs->icache->cache_last = -1;
116 fs->icache->cache_size = cache_size;
117 fs->icache->refcount = 1;
118 retval = ext2fs_get_array(fs->icache->cache_size,
119 sizeof(struct ext2_inode_cache_ent),
120 &fs->icache->cache);
121 if (retval)
122 goto errout;
123
124 for (i = 0; i < fs->icache->cache_size; i++) {
125 retval = ext2fs_get_mem(EXT2_INODE_SIZE(fs->super),
126 &fs->icache->cache[i].inode);
127 if (retval)
128 goto errout;
129 }
130
131 ext2fs_flush_icache(fs);
132 return 0;
133 errout:
134 ext2fs_free_inode_cache(fs->icache);
135 fs->icache = 0;
136 return retval;
137 }
138
ext2fs_open_inode_scan(ext2_filsys fs,int buffer_blocks,ext2_inode_scan * ret_scan)139 errcode_t ext2fs_open_inode_scan(ext2_filsys fs, int buffer_blocks,
140 ext2_inode_scan *ret_scan)
141 {
142 ext2_inode_scan scan;
143 errcode_t retval;
144 errcode_t (*save_get_blocks)(ext2_filsys f, ext2_ino_t ino, blk_t *blocks);
145
146 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
147
148 /*
149 * If fs->badblocks isn't set, then set it --- since the inode
150 * scanning functions require it.
151 */
152 if (fs->badblocks == 0) {
153 /*
154 * Temporarily save fs->get_blocks and set it to zero,
155 * for compatibility with old e2fsck's.
156 */
157 save_get_blocks = fs->get_blocks;
158 fs->get_blocks = 0;
159 retval = ext2fs_read_bb_inode(fs, &fs->badblocks);
160 if (retval && fs->badblocks) {
161 ext2fs_badblocks_list_free(fs->badblocks);
162 fs->badblocks = 0;
163 }
164 fs->get_blocks = save_get_blocks;
165 }
166
167 retval = ext2fs_get_mem(sizeof(struct ext2_struct_inode_scan), &scan);
168 if (retval)
169 return retval;
170 memset(scan, 0, sizeof(struct ext2_struct_inode_scan));
171
172 scan->magic = EXT2_ET_MAGIC_INODE_SCAN;
173 scan->fs = fs;
174 scan->inode_size = EXT2_INODE_SIZE(fs->super);
175 scan->bytes_left = 0;
176 scan->current_group = 0;
177 scan->groups_left = fs->group_desc_count - 1;
178 scan->inode_buffer_blocks = buffer_blocks ? buffer_blocks :
179 EXT2_INODE_SCAN_DEFAULT_BUFFER_BLOCKS;
180 scan->current_block = ext2fs_inode_table_loc(scan->fs,
181 scan->current_group);
182 scan->inodes_left = EXT2_INODES_PER_GROUP(scan->fs->super);
183 scan->blocks_left = scan->fs->inode_blocks_per_group;
184 if (ext2fs_has_group_desc_csum(fs)) {
185 __u32 unused = ext2fs_bg_itable_unused(fs, scan->current_group);
186 if (scan->inodes_left > unused)
187 scan->inodes_left -= unused;
188 else
189 scan->inodes_left = 0;
190 scan->blocks_left =
191 (scan->inodes_left +
192 (fs->blocksize / scan->inode_size - 1)) *
193 scan->inode_size / fs->blocksize;
194 }
195 retval = io_channel_alloc_buf(fs->io, scan->inode_buffer_blocks,
196 &scan->inode_buffer);
197 scan->done_group = 0;
198 scan->done_group_data = 0;
199 scan->bad_block_ptr = 0;
200 if (retval) {
201 ext2fs_free_mem(&scan);
202 return retval;
203 }
204 retval = ext2fs_get_mem(scan->inode_size + scan->inode_buffer_blocks,
205 &scan->temp_buffer);
206 if (retval) {
207 ext2fs_free_mem(&scan->inode_buffer);
208 ext2fs_free_mem(&scan);
209 return retval;
210 }
211 memset(SCAN_BLOCK_STATUS(scan), 0, scan->inode_buffer_blocks);
212 if (scan->fs->badblocks && scan->fs->badblocks->num)
213 scan->scan_flags |= EXT2_SF_CHK_BADBLOCKS;
214 if (ext2fs_has_group_desc_csum(fs))
215 scan->scan_flags |= EXT2_SF_DO_LAZY;
216 *ret_scan = scan;
217 return 0;
218 }
219
ext2fs_close_inode_scan(ext2_inode_scan scan)220 void ext2fs_close_inode_scan(ext2_inode_scan scan)
221 {
222 if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
223 return;
224
225 ext2fs_free_mem(&scan->inode_buffer);
226 scan->inode_buffer = NULL;
227 ext2fs_free_mem(&scan->temp_buffer);
228 scan->temp_buffer = NULL;
229 ext2fs_free_mem(&scan);
230 return;
231 }
232
ext2fs_set_inode_callback(ext2_inode_scan scan,errcode_t (* done_group)(ext2_filsys fs,ext2_inode_scan scan,dgrp_t group,void * priv_data),void * done_group_data)233 void ext2fs_set_inode_callback(ext2_inode_scan scan,
234 errcode_t (*done_group)(ext2_filsys fs,
235 ext2_inode_scan scan,
236 dgrp_t group,
237 void * priv_data),
238 void *done_group_data)
239 {
240 if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
241 return;
242
243 scan->done_group = done_group;
244 scan->done_group_data = done_group_data;
245 }
246
ext2fs_inode_scan_flags(ext2_inode_scan scan,int set_flags,int clear_flags)247 int ext2fs_inode_scan_flags(ext2_inode_scan scan, int set_flags,
248 int clear_flags)
249 {
250 int old_flags;
251
252 if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
253 return 0;
254
255 old_flags = scan->scan_flags;
256 scan->scan_flags &= ~clear_flags;
257 scan->scan_flags |= set_flags;
258 return old_flags;
259 }
260
261 /*
262 * This function is called by ext2fs_get_next_inode when it needs to
263 * get ready to read in a new blockgroup.
264 */
get_next_blockgroup(ext2_inode_scan scan)265 static errcode_t get_next_blockgroup(ext2_inode_scan scan)
266 {
267 ext2_filsys fs = scan->fs;
268
269 scan->current_group++;
270 scan->groups_left--;
271
272 scan->current_block = ext2fs_inode_table_loc(scan->fs,
273 scan->current_group);
274 scan->current_inode = scan->current_group *
275 EXT2_INODES_PER_GROUP(fs->super);
276
277 scan->bytes_left = 0;
278 scan->inodes_left = EXT2_INODES_PER_GROUP(fs->super);
279 scan->blocks_left = fs->inode_blocks_per_group;
280 if (ext2fs_has_group_desc_csum(fs)) {
281 __u32 unused = ext2fs_bg_itable_unused(fs, scan->current_group);
282 if (scan->inodes_left > unused)
283 scan->inodes_left -= unused;
284 else
285 scan->inodes_left = 0;
286 scan->blocks_left =
287 (scan->inodes_left +
288 (fs->blocksize / scan->inode_size - 1)) *
289 scan->inode_size / fs->blocksize;
290 }
291
292 return 0;
293 }
294
ext2fs_inode_scan_goto_blockgroup(ext2_inode_scan scan,int group)295 errcode_t ext2fs_inode_scan_goto_blockgroup(ext2_inode_scan scan,
296 int group)
297 {
298 scan->current_group = group - 1;
299 scan->groups_left = scan->fs->group_desc_count - group;
300 return get_next_blockgroup(scan);
301 }
302
303 /*
304 * This function is called by get_next_blocks() to check for bad
305 * blocks in the inode table.
306 *
307 * This function assumes that badblocks_list->list is sorted in
308 * increasing order.
309 */
check_for_inode_bad_blocks(ext2_inode_scan scan,blk64_t * num_blocks)310 static errcode_t check_for_inode_bad_blocks(ext2_inode_scan scan,
311 blk64_t *num_blocks)
312 {
313 blk64_t blk = scan->current_block;
314 badblocks_list bb = scan->fs->badblocks;
315
316 /*
317 * If the inode table is missing, then obviously there are no
318 * bad blocks. :-)
319 */
320 if (blk == 0)
321 return 0;
322
323 /*
324 * If the current block is greater than the bad block listed
325 * in the bad block list, then advance the pointer until this
326 * is no longer the case. If we run out of bad blocks, then
327 * we don't need to do any more checking!
328 */
329 while (blk > bb->list[scan->bad_block_ptr]) {
330 if (++scan->bad_block_ptr >= bb->num) {
331 scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
332 return 0;
333 }
334 }
335
336 /*
337 * If the current block is equal to the bad block listed in
338 * the bad block list, then handle that one block specially.
339 * (We could try to handle runs of bad blocks, but that
340 * only increases CPU efficiency by a small amount, at the
341 * expense of a huge expense of code complexity, and for an
342 * uncommon case at that.)
343 */
344 if (blk == bb->list[scan->bad_block_ptr]) {
345 scan->scan_flags |= EXT2_SF_BAD_INODE_BLK;
346 *num_blocks = 1;
347 if (++scan->bad_block_ptr >= bb->num)
348 scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
349 return 0;
350 }
351
352 /*
353 * If there is a bad block in the range that we're about to
354 * read in, adjust the number of blocks to read so that we we
355 * don't read in the bad block. (Then the next block to read
356 * will be the bad block, which is handled in the above case.)
357 */
358 if ((blk + *num_blocks) > bb->list[scan->bad_block_ptr])
359 *num_blocks = (int) (bb->list[scan->bad_block_ptr] - blk);
360
361 return 0;
362 }
363
block_map_looks_insane(ext2_filsys fs,struct ext2_inode_large * inode)364 static int block_map_looks_insane(ext2_filsys fs,
365 struct ext2_inode_large *inode)
366 {
367 unsigned int i, bad;
368
369 /* We're only interested in block mapped files, dirs, and symlinks */
370 if ((inode->i_flags & EXT4_INLINE_DATA_FL) ||
371 (inode->i_flags & EXT4_EXTENTS_FL))
372 return 0;
373 if (!LINUX_S_ISREG(inode->i_mode) &&
374 !LINUX_S_ISLNK(inode->i_mode) &&
375 !LINUX_S_ISDIR(inode->i_mode))
376 return 0;
377 if (LINUX_S_ISLNK(inode->i_mode) &&
378 EXT2_I_SIZE(inode) <= sizeof(inode->i_block))
379 return 0;
380
381 /* Unused inodes probably aren't insane */
382 if (inode->i_links_count == 0)
383 return 0;
384
385 /* See if more than half the block maps are insane */
386 for (i = 0, bad = 0; i < EXT2_N_BLOCKS; i++)
387 if (inode->i_block[i] != 0 &&
388 (inode->i_block[i] < fs->super->s_first_data_block ||
389 inode->i_block[i] >= ext2fs_blocks_count(fs->super)))
390 bad++;
391 return bad > EXT2_N_BLOCKS / 2;
392 }
393
extent_head_looks_insane(struct ext2_inode_large * inode)394 static int extent_head_looks_insane(struct ext2_inode_large *inode)
395 {
396 if (!(inode->i_flags & EXT4_EXTENTS_FL) ||
397 ext2fs_extent_header_verify(inode->i_block,
398 sizeof(inode->i_block)) == 0)
399 return 0;
400 return 1;
401 }
402
403 /*
404 * Check all the inodes that we just read into the buffer. Record what we
405 * find here -- currently, we can observe that all checksums are ok; more
406 * than half the inodes are insane; or no conclusions at all.
407 */
check_inode_block_sanity(ext2_inode_scan scan,blk64_t num_blocks)408 static void check_inode_block_sanity(ext2_inode_scan scan, blk64_t num_blocks)
409 {
410 ext2_ino_t ino, inodes_to_scan;
411 unsigned int badness, checksum_failures;
412 unsigned int inodes_in_buf, inodes_per_block;
413 char *p;
414 struct ext2_inode_large *inode;
415 char *block_status;
416 unsigned int blk, bad_csum;
417
418 if (!(scan->scan_flags & EXT2_SF_WARN_GARBAGE_INODES))
419 return;
420
421 inodes_to_scan = scan->inodes_left;
422 inodes_in_buf = num_blocks * scan->fs->blocksize / scan->inode_size;
423 if (inodes_to_scan > inodes_in_buf)
424 inodes_to_scan = inodes_in_buf;
425
426 p = (char *) scan->inode_buffer;
427 ino = scan->current_inode + 1;
428 checksum_failures = badness = 0;
429 block_status = SCAN_BLOCK_STATUS(scan);
430 memset(block_status, 0, scan->inode_buffer_blocks);
431 inodes_per_block = EXT2_INODES_PER_BLOCK(scan->fs->super);
432
433 if (inodes_per_block < 2)
434 return;
435
436 #ifdef WORDS_BIGENDIAN
437 if (ext2fs_get_mem(EXT2_INODE_SIZE(scan->fs->super), &inode))
438 return;
439 #endif
440
441 while (inodes_to_scan > 0) {
442 blk = (p - (char *)scan->inode_buffer) / scan->fs->blocksize;
443 bad_csum = ext2fs_inode_csum_verify(scan->fs, ino,
444 (struct ext2_inode_large *) p) == 0;
445
446 #ifdef WORDS_BIGENDIAN
447 ext2fs_swap_inode_full(scan->fs,
448 (struct ext2_inode_large *) inode,
449 (struct ext2_inode_large *) p,
450 0, EXT2_INODE_SIZE(scan->fs->super));
451 #else
452 inode = (struct ext2_inode_large *) p;
453 #endif
454
455 /* Is this inode insane? */
456 if (bad_csum) {
457 checksum_failures++;
458 badness++;
459 } else if (extent_head_looks_insane(inode) ||
460 block_map_looks_insane(scan->fs, inode))
461 badness++;
462
463 /* If more than half are insane, declare the whole block bad */
464 if (badness > inodes_per_block / 2) {
465 unsigned int ino_adj;
466
467 block_status[blk] |= IBLOCK_STATUS_INSANE;
468 ino_adj = inodes_per_block -
469 ((ino - 1) % inodes_per_block);
470 if (ino_adj > inodes_to_scan)
471 ino_adj = inodes_to_scan;
472 inodes_to_scan -= ino_adj;
473 p += scan->inode_size * ino_adj;
474 ino += ino_adj;
475 checksum_failures = badness = 0;
476 continue;
477 }
478
479 if ((ino % inodes_per_block) == 0) {
480 if (checksum_failures == 0)
481 block_status[blk] |= IBLOCK_STATUS_CSUMS_OK;
482 checksum_failures = badness = 0;
483 }
484 inodes_to_scan--;
485 p += scan->inode_size;
486 ino++;
487 };
488
489 #ifdef WORDS_BIGENDIAN
490 ext2fs_free_mem(&inode);
491 #endif
492 }
493
494 /*
495 * This function is called by ext2fs_get_next_inode when it needs to
496 * read in more blocks from the current blockgroup's inode table.
497 */
get_next_blocks(ext2_inode_scan scan)498 static errcode_t get_next_blocks(ext2_inode_scan scan)
499 {
500 blk64_t num_blocks;
501 errcode_t retval;
502
503 /*
504 * Figure out how many blocks to read; we read at most
505 * inode_buffer_blocks, and perhaps less if there aren't that
506 * many blocks left to read.
507 */
508 num_blocks = scan->inode_buffer_blocks;
509 if (num_blocks > scan->blocks_left)
510 num_blocks = scan->blocks_left;
511
512 /*
513 * If the past block "read" was a bad block, then mark the
514 * left-over extra bytes as also being bad.
515 */
516 if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK) {
517 if (scan->bytes_left)
518 scan->scan_flags |= EXT2_SF_BAD_EXTRA_BYTES;
519 scan->scan_flags &= ~EXT2_SF_BAD_INODE_BLK;
520 }
521
522 /*
523 * Do inode bad block processing, if necessary.
524 */
525 if (scan->scan_flags & EXT2_SF_CHK_BADBLOCKS) {
526 retval = check_for_inode_bad_blocks(scan, &num_blocks);
527 if (retval)
528 return retval;
529 }
530
531 if ((scan->scan_flags & EXT2_SF_BAD_INODE_BLK) ||
532 (scan->current_block == 0)) {
533 memset(scan->inode_buffer, 0,
534 (size_t) num_blocks * scan->fs->blocksize);
535 } else {
536 retval = io_channel_read_blk64(scan->fs->io,
537 scan->current_block,
538 (int) num_blocks,
539 scan->inode_buffer);
540 if (retval)
541 return EXT2_ET_NEXT_INODE_READ;
542 }
543 check_inode_block_sanity(scan, num_blocks);
544
545 scan->ptr = scan->inode_buffer;
546 scan->bytes_left = num_blocks * scan->fs->blocksize;
547
548 scan->blocks_left -= num_blocks;
549 if (scan->current_block)
550 scan->current_block += num_blocks;
551
552 return 0;
553 }
554
555 #if 0
556 /*
557 * Returns 1 if the entire inode_buffer has a non-zero size and
558 * contains all zeros. (Not just deleted inodes, since that means
559 * that part of the inode table was used at one point; we want all
560 * zeros, which means that the inode table is pristine.)
561 */
562 static inline int is_empty_scan(ext2_inode_scan scan)
563 {
564 int i;
565
566 if (scan->bytes_left == 0)
567 return 0;
568
569 for (i=0; i < scan->bytes_left; i++)
570 if (scan->ptr[i])
571 return 0;
572 return 1;
573 }
574 #endif
575
ext2fs_get_next_inode_full(ext2_inode_scan scan,ext2_ino_t * ino,struct ext2_inode * inode,int bufsize)576 errcode_t ext2fs_get_next_inode_full(ext2_inode_scan scan, ext2_ino_t *ino,
577 struct ext2_inode *inode, int bufsize)
578 {
579 errcode_t retval;
580 int extra_bytes = 0;
581 int length;
582 struct ext2_inode_large *iptr = (struct ext2_inode_large *)inode;
583 char *iblock_status;
584 unsigned int iblk;
585
586 EXT2_CHECK_MAGIC(scan, EXT2_ET_MAGIC_INODE_SCAN);
587 length = EXT2_INODE_SIZE(scan->fs->super);
588 iblock_status = SCAN_BLOCK_STATUS(scan);
589
590 /*
591 * Do we need to start reading a new block group?
592 */
593 if (scan->inodes_left <= 0) {
594 force_new_group:
595 if (scan->done_group) {
596 retval = (scan->done_group)
597 (scan->fs, scan, scan->current_group,
598 scan->done_group_data);
599 if (retval)
600 return retval;
601 }
602 if (scan->groups_left <= 0) {
603 *ino = 0;
604 return 0;
605 }
606 retval = get_next_blockgroup(scan);
607 if (retval)
608 return retval;
609 }
610 /*
611 * These checks are done outside the above if statement so
612 * they can be done for block group #0.
613 */
614 if ((scan->scan_flags & EXT2_SF_DO_LAZY) &&
615 (ext2fs_bg_flags_test(scan->fs, scan->current_group, EXT2_BG_INODE_UNINIT)
616 ))
617 goto force_new_group;
618 if (scan->inodes_left == 0)
619 goto force_new_group;
620 if (scan->current_block == 0) {
621 if (scan->scan_flags & EXT2_SF_SKIP_MISSING_ITABLE) {
622 goto force_new_group;
623 } else
624 return EXT2_ET_MISSING_INODE_TABLE;
625 }
626
627
628 /*
629 * Have we run out of space in the inode buffer? If so, we
630 * need to read in more blocks.
631 */
632 if (scan->bytes_left < scan->inode_size) {
633 if (scan->bytes_left)
634 memcpy(scan->temp_buffer, scan->ptr, scan->bytes_left);
635 extra_bytes = scan->bytes_left;
636
637 retval = get_next_blocks(scan);
638 if (retval)
639 return retval;
640 #if 0
641 /*
642 * XXX test Need check for used inode somehow.
643 * (Note: this is hard.)
644 */
645 if (is_empty_scan(scan))
646 goto force_new_group;
647 #endif
648 }
649
650 if (bufsize < length) {
651 retval = ext2fs_get_mem(length, &iptr);
652 if (retval)
653 return retval;
654 }
655
656 retval = 0;
657 iblk = scan->current_inode % EXT2_INODES_PER_GROUP(scan->fs->super) /
658 EXT2_INODES_PER_BLOCK(scan->fs->super) %
659 scan->inode_buffer_blocks;
660 if (extra_bytes) {
661 memcpy(scan->temp_buffer+extra_bytes, scan->ptr,
662 scan->inode_size - extra_bytes);
663 scan->ptr += scan->inode_size - extra_bytes;
664 scan->bytes_left -= scan->inode_size - extra_bytes;
665
666 /* Verify the inode checksum. */
667 if (!(iblock_status[iblk] & IBLOCK_STATUS_CSUMS_OK) &&
668 !(scan->fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
669 !ext2fs_inode_csum_verify(scan->fs, scan->current_inode + 1,
670 (struct ext2_inode_large *)scan->temp_buffer))
671 retval = EXT2_ET_INODE_CSUM_INVALID;
672
673 #ifdef WORDS_BIGENDIAN
674 memset(iptr, 0, length);
675 ext2fs_swap_inode_full(scan->fs,
676 (struct ext2_inode_large *) iptr,
677 (struct ext2_inode_large *) scan->temp_buffer,
678 0, length);
679 #else
680 memcpy(iptr, scan->temp_buffer, length);
681 #endif
682 if (scan->scan_flags & EXT2_SF_BAD_EXTRA_BYTES)
683 retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE;
684 scan->scan_flags &= ~EXT2_SF_BAD_EXTRA_BYTES;
685 } else {
686 /* Verify the inode checksum. */
687 if (!(iblock_status[iblk] & IBLOCK_STATUS_CSUMS_OK) &&
688 !(scan->fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
689 !ext2fs_inode_csum_verify(scan->fs, scan->current_inode + 1,
690 (struct ext2_inode_large *)scan->ptr))
691 retval = EXT2_ET_INODE_CSUM_INVALID;
692
693 #ifdef WORDS_BIGENDIAN
694 memset(iptr, 0, length);
695 ext2fs_swap_inode_full(scan->fs,
696 (struct ext2_inode_large *) iptr,
697 (struct ext2_inode_large *) scan->ptr,
698 0, length);
699 #else
700 memcpy(iptr, scan->ptr, length);
701 #endif
702 scan->ptr += scan->inode_size;
703 scan->bytes_left -= scan->inode_size;
704 if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK)
705 retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE;
706 }
707 if ((iblock_status[iblk] & IBLOCK_STATUS_INSANE) &&
708 (retval == 0 || retval == EXT2_ET_INODE_CSUM_INVALID))
709 retval = EXT2_ET_INODE_IS_GARBAGE;
710
711 scan->inodes_left--;
712 scan->current_inode++;
713 *ino = scan->current_inode;
714 if (iptr != (struct ext2_inode_large *)inode) {
715 memcpy(inode, iptr, bufsize);
716 ext2fs_free_mem(&iptr);
717 }
718 return retval;
719 }
720
ext2fs_get_next_inode(ext2_inode_scan scan,ext2_ino_t * ino,struct ext2_inode * inode)721 errcode_t ext2fs_get_next_inode(ext2_inode_scan scan, ext2_ino_t *ino,
722 struct ext2_inode *inode)
723 {
724 return ext2fs_get_next_inode_full(scan, ino, inode,
725 sizeof(struct ext2_inode));
726 }
727
728 /*
729 * Functions to read and write a single inode.
730 */
ext2fs_read_inode_full(ext2_filsys fs,ext2_ino_t ino,struct ext2_inode * inode,int bufsize)731 errcode_t ext2fs_read_inode_full(ext2_filsys fs, ext2_ino_t ino,
732 struct ext2_inode * inode, int bufsize)
733 {
734 blk64_t block_nr;
735 unsigned long group, block, offset;
736 char *ptr;
737 errcode_t retval;
738 unsigned i;
739 int clen, inodes_per_block;
740 io_channel io;
741 int length = EXT2_INODE_SIZE(fs->super);
742 struct ext2_inode_large *iptr;
743 int cache_slot, fail_csum;
744
745 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
746
747 /* Check to see if user has an override function */
748 if (fs->read_inode &&
749 ((bufsize == sizeof(struct ext2_inode)) ||
750 (EXT2_INODE_SIZE(fs->super) == sizeof(struct ext2_inode)))) {
751 retval = (fs->read_inode)(fs, ino, inode);
752 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
753 return retval;
754 }
755 if ((ino == 0) || (ino > fs->super->s_inodes_count))
756 return EXT2_ET_BAD_INODE_NUM;
757 /* Create inode cache if not present */
758 if (!fs->icache) {
759 retval = ext2fs_create_inode_cache(fs, 4);
760 if (retval)
761 return retval;
762 }
763 /* Check to see if it's in the inode cache */
764 for (i = 0; i < fs->icache->cache_size; i++) {
765 if (fs->icache->cache[i].ino == ino) {
766 memcpy(inode, fs->icache->cache[i].inode,
767 (bufsize > length) ? length : bufsize);
768 return 0;
769 }
770 }
771 if (fs->flags & EXT2_FLAG_IMAGE_FILE) {
772 inodes_per_block = fs->blocksize / EXT2_INODE_SIZE(fs->super);
773 block_nr = ext2fs_le32_to_cpu(fs->image_header->offset_inode) / fs->blocksize;
774 block_nr += (ino - 1) / inodes_per_block;
775 offset = ((ino - 1) % inodes_per_block) *
776 EXT2_INODE_SIZE(fs->super);
777 io = fs->image_io;
778 } else {
779 group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super);
780 if (group > fs->group_desc_count)
781 return EXT2_ET_BAD_INODE_NUM;
782 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) *
783 EXT2_INODE_SIZE(fs->super);
784 block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super);
785 if (!ext2fs_inode_table_loc(fs, (unsigned) group))
786 return EXT2_ET_MISSING_INODE_TABLE;
787 block_nr = ext2fs_inode_table_loc(fs, group) +
788 block;
789 io = fs->io;
790 }
791 offset &= (EXT2_BLOCK_SIZE(fs->super) - 1);
792
793 cache_slot = (fs->icache->cache_last + 1) % fs->icache->cache_size;
794 iptr = (struct ext2_inode_large *)fs->icache->cache[cache_slot].inode;
795
796 ptr = (char *) iptr;
797 while (length) {
798 clen = length;
799 if ((offset + length) > fs->blocksize)
800 clen = fs->blocksize - offset;
801
802 if (block_nr != fs->icache->buffer_blk) {
803 retval = io_channel_read_blk64(io, block_nr, 1,
804 fs->icache->buffer);
805 if (retval)
806 return retval;
807 fs->icache->buffer_blk = block_nr;
808 }
809
810 memcpy(ptr, ((char *) fs->icache->buffer) + (unsigned) offset,
811 clen);
812
813 offset = 0;
814 length -= clen;
815 ptr += clen;
816 block_nr++;
817 }
818 length = EXT2_INODE_SIZE(fs->super);
819
820 /* Verify the inode checksum. */
821 fail_csum = !ext2fs_inode_csum_verify(fs, ino, iptr);
822
823 #ifdef WORDS_BIGENDIAN
824 ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) iptr,
825 (struct ext2_inode_large *) iptr,
826 0, length);
827 #endif
828
829 /* Update the inode cache bookkeeping */
830 if (!fail_csum) {
831 fs->icache->cache_last = cache_slot;
832 fs->icache->cache[cache_slot].ino = ino;
833 }
834 memcpy(inode, iptr, (bufsize > length) ? length : bufsize);
835
836 if (!(fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) && fail_csum)
837 return EXT2_ET_INODE_CSUM_INVALID;
838
839 return 0;
840 }
841
ext2fs_read_inode(ext2_filsys fs,ext2_ino_t ino,struct ext2_inode * inode)842 errcode_t ext2fs_read_inode(ext2_filsys fs, ext2_ino_t ino,
843 struct ext2_inode * inode)
844 {
845 return ext2fs_read_inode_full(fs, ino, inode,
846 sizeof(struct ext2_inode));
847 }
848
ext2fs_write_inode_full(ext2_filsys fs,ext2_ino_t ino,struct ext2_inode * inode,int bufsize)849 errcode_t ext2fs_write_inode_full(ext2_filsys fs, ext2_ino_t ino,
850 struct ext2_inode * inode, int bufsize)
851 {
852 blk64_t block_nr;
853 unsigned long group, block, offset;
854 errcode_t retval = 0;
855 struct ext2_inode_large *w_inode;
856 char *ptr;
857 unsigned i;
858 int clen;
859 int length = EXT2_INODE_SIZE(fs->super);
860
861 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
862
863 /* Check to see if user provided an override function */
864 if (fs->write_inode) {
865 retval = (fs->write_inode)(fs, ino, inode);
866 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
867 return retval;
868 }
869
870 if ((ino == 0) || (ino > fs->super->s_inodes_count))
871 return EXT2_ET_BAD_INODE_NUM;
872
873 /* Prepare our shadow buffer for read/modify/byteswap/write */
874 retval = ext2fs_get_mem(length, &w_inode);
875 if (retval)
876 return retval;
877
878 if (bufsize < length) {
879 int old_flags = fs->flags;
880 fs->flags |= EXT2_FLAG_IGNORE_CSUM_ERRORS;
881 retval = ext2fs_read_inode_full(fs, ino,
882 (struct ext2_inode *)w_inode,
883 length);
884 fs->flags = (old_flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) |
885 (fs->flags & ~EXT2_FLAG_IGNORE_CSUM_ERRORS);
886 if (retval)
887 goto errout;
888 }
889
890 /* Check to see if the inode cache needs to be updated */
891 if (fs->icache) {
892 for (i=0; i < fs->icache->cache_size; i++) {
893 if (fs->icache->cache[i].ino == ino) {
894 memcpy(fs->icache->cache[i].inode, inode,
895 (bufsize > length) ? length : bufsize);
896 break;
897 }
898 }
899 } else {
900 retval = ext2fs_create_inode_cache(fs, 4);
901 if (retval)
902 goto errout;
903 }
904 memcpy(w_inode, inode, (bufsize > length) ? length : bufsize);
905
906 if (!(fs->flags & EXT2_FLAG_RW)) {
907 retval = EXT2_ET_RO_FILSYS;
908 goto errout;
909 }
910
911 #ifdef WORDS_BIGENDIAN
912 ext2fs_swap_inode_full(fs, w_inode, w_inode, 1, length);
913 #endif
914
915 retval = ext2fs_inode_csum_set(fs, ino, w_inode);
916 if (retval)
917 goto errout;
918
919 group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super);
920 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) *
921 EXT2_INODE_SIZE(fs->super);
922 block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super);
923 if (!ext2fs_inode_table_loc(fs, (unsigned) group)) {
924 retval = EXT2_ET_MISSING_INODE_TABLE;
925 goto errout;
926 }
927 block_nr = ext2fs_inode_table_loc(fs, (unsigned) group) + block;
928
929 offset &= (EXT2_BLOCK_SIZE(fs->super) - 1);
930
931 ptr = (char *) w_inode;
932
933 while (length) {
934 clen = length;
935 if ((offset + length) > fs->blocksize)
936 clen = fs->blocksize - offset;
937
938 if (fs->icache->buffer_blk != block_nr) {
939 retval = io_channel_read_blk64(fs->io, block_nr, 1,
940 fs->icache->buffer);
941 if (retval)
942 goto errout;
943 fs->icache->buffer_blk = block_nr;
944 }
945
946
947 memcpy((char *) fs->icache->buffer + (unsigned) offset,
948 ptr, clen);
949
950 retval = io_channel_write_blk64(fs->io, block_nr, 1,
951 fs->icache->buffer);
952 if (retval)
953 goto errout;
954
955 offset = 0;
956 ptr += clen;
957 length -= clen;
958 block_nr++;
959 }
960
961 fs->flags |= EXT2_FLAG_CHANGED;
962 errout:
963 ext2fs_free_mem(&w_inode);
964 return retval;
965 }
966
ext2fs_write_inode(ext2_filsys fs,ext2_ino_t ino,struct ext2_inode * inode)967 errcode_t ext2fs_write_inode(ext2_filsys fs, ext2_ino_t ino,
968 struct ext2_inode *inode)
969 {
970 return ext2fs_write_inode_full(fs, ino, inode,
971 sizeof(struct ext2_inode));
972 }
973
974 /*
975 * This function should be called when writing a new inode. It makes
976 * sure that extra part of large inodes is initialized properly.
977 */
ext2fs_write_new_inode(ext2_filsys fs,ext2_ino_t ino,struct ext2_inode * inode)978 errcode_t ext2fs_write_new_inode(ext2_filsys fs, ext2_ino_t ino,
979 struct ext2_inode *inode)
980 {
981 struct ext2_inode *buf;
982 int size = EXT2_INODE_SIZE(fs->super);
983 struct ext2_inode_large *large_inode;
984 errcode_t retval;
985 __u32 t = fs->now ? fs->now : time(NULL);
986
987 if (!inode->i_ctime)
988 inode->i_ctime = t;
989 if (!inode->i_mtime)
990 inode->i_mtime = t;
991 if (!inode->i_atime)
992 inode->i_atime = t;
993
994 if (size == sizeof(struct ext2_inode))
995 return ext2fs_write_inode_full(fs, ino, inode,
996 sizeof(struct ext2_inode));
997
998 buf = malloc(size);
999 if (!buf)
1000 return ENOMEM;
1001
1002 memset(buf, 0, size);
1003 *buf = *inode;
1004
1005 large_inode = (struct ext2_inode_large *) buf;
1006 large_inode->i_extra_isize = sizeof(struct ext2_inode_large) -
1007 EXT2_GOOD_OLD_INODE_SIZE;
1008 if (!large_inode->i_crtime)
1009 large_inode->i_crtime = t;
1010
1011 retval = ext2fs_write_inode_full(fs, ino, buf, size);
1012 free(buf);
1013 return retval;
1014 }
1015
1016
ext2fs_get_blocks(ext2_filsys fs,ext2_ino_t ino,blk_t * blocks)1017 errcode_t ext2fs_get_blocks(ext2_filsys fs, ext2_ino_t ino, blk_t *blocks)
1018 {
1019 struct ext2_inode inode;
1020 int i;
1021 errcode_t retval;
1022
1023 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
1024
1025 if (ino > fs->super->s_inodes_count)
1026 return EXT2_ET_BAD_INODE_NUM;
1027
1028 if (fs->get_blocks) {
1029 if (!(*fs->get_blocks)(fs, ino, blocks))
1030 return 0;
1031 }
1032 retval = ext2fs_read_inode(fs, ino, &inode);
1033 if (retval)
1034 return retval;
1035 for (i=0; i < EXT2_N_BLOCKS; i++)
1036 blocks[i] = inode.i_block[i];
1037 return 0;
1038 }
1039
ext2fs_check_directory(ext2_filsys fs,ext2_ino_t ino)1040 errcode_t ext2fs_check_directory(ext2_filsys fs, ext2_ino_t ino)
1041 {
1042 struct ext2_inode inode;
1043 errcode_t retval;
1044
1045 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
1046
1047 if (ino > fs->super->s_inodes_count)
1048 return EXT2_ET_BAD_INODE_NUM;
1049
1050 if (fs->check_directory) {
1051 retval = (fs->check_directory)(fs, ino);
1052 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
1053 return retval;
1054 }
1055 retval = ext2fs_read_inode(fs, ino, &inode);
1056 if (retval)
1057 return retval;
1058 if (!LINUX_S_ISDIR(inode.i_mode))
1059 return EXT2_ET_NO_DIRECTORY;
1060 return 0;
1061 }
1062
1063