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 if (fs->blocksize < 1024)
148 return EXT2_FILSYS_CORRUPTED; /* Should never happen */
149
150 /*
151 * If fs->badblocks isn't set, then set it --- since the inode
152 * scanning functions require it.
153 */
154 if (fs->badblocks == 0) {
155 /*
156 * Temporarily save fs->get_blocks and set it to zero,
157 * for compatibility with old e2fsck's.
158 */
159 save_get_blocks = fs->get_blocks;
160 fs->get_blocks = 0;
161 retval = ext2fs_read_bb_inode(fs, &fs->badblocks);
162 if (retval && fs->badblocks) {
163 ext2fs_badblocks_list_free(fs->badblocks);
164 fs->badblocks = 0;
165 }
166 fs->get_blocks = save_get_blocks;
167 }
168
169 retval = ext2fs_get_mem(sizeof(struct ext2_struct_inode_scan), &scan);
170 if (retval)
171 return retval;
172 memset(scan, 0, sizeof(struct ext2_struct_inode_scan));
173
174 scan->magic = EXT2_ET_MAGIC_INODE_SCAN;
175 scan->fs = fs;
176 scan->inode_size = EXT2_INODE_SIZE(fs->super);
177 scan->bytes_left = 0;
178 scan->current_group = 0;
179 scan->groups_left = fs->group_desc_count - 1;
180 scan->inode_buffer_blocks = buffer_blocks ? buffer_blocks :
181 EXT2_INODE_SCAN_DEFAULT_BUFFER_BLOCKS;
182 scan->current_block = ext2fs_inode_table_loc(scan->fs,
183 scan->current_group);
184 if (scan->current_block &&
185 ((scan->current_block < fs->super->s_first_data_block) ||
186 (scan->current_block + fs->inode_blocks_per_group - 1 >=
187 ext2fs_blocks_count(fs->super)))) {
188 ext2fs_free_mem(&scan);
189 return EXT2_ET_GDESC_BAD_INODE_TABLE;
190 }
191
192 scan->inodes_left = EXT2_INODES_PER_GROUP(scan->fs->super);
193 scan->blocks_left = scan->fs->inode_blocks_per_group;
194 if (ext2fs_has_group_desc_csum(fs)) {
195 __u32 unused = ext2fs_bg_itable_unused(fs, scan->current_group);
196 if (scan->inodes_left > unused)
197 scan->inodes_left -= unused;
198 else
199 scan->inodes_left = 0;
200 scan->blocks_left =
201 (scan->inodes_left +
202 (fs->blocksize / scan->inode_size - 1)) *
203 scan->inode_size / fs->blocksize;
204 }
205 retval = io_channel_alloc_buf(fs->io, scan->inode_buffer_blocks,
206 &scan->inode_buffer);
207 scan->done_group = 0;
208 scan->done_group_data = 0;
209 scan->bad_block_ptr = 0;
210 if (retval) {
211 ext2fs_free_mem(&scan);
212 return retval;
213 }
214 retval = ext2fs_get_mem(scan->inode_size + scan->inode_buffer_blocks,
215 &scan->temp_buffer);
216 if (retval) {
217 ext2fs_free_mem(&scan->inode_buffer);
218 ext2fs_free_mem(&scan);
219 return retval;
220 }
221 memset(SCAN_BLOCK_STATUS(scan), 0, scan->inode_buffer_blocks);
222 if (scan->fs->badblocks && scan->fs->badblocks->num)
223 scan->scan_flags |= EXT2_SF_CHK_BADBLOCKS;
224 if (ext2fs_has_group_desc_csum(fs))
225 scan->scan_flags |= EXT2_SF_DO_LAZY;
226 *ret_scan = scan;
227 return 0;
228 }
229
ext2fs_close_inode_scan(ext2_inode_scan scan)230 void ext2fs_close_inode_scan(ext2_inode_scan scan)
231 {
232 if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
233 return;
234
235 ext2fs_free_mem(&scan->inode_buffer);
236 scan->inode_buffer = NULL;
237 ext2fs_free_mem(&scan->temp_buffer);
238 scan->temp_buffer = NULL;
239 ext2fs_free_mem(&scan);
240 return;
241 }
242
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)243 void ext2fs_set_inode_callback(ext2_inode_scan scan,
244 errcode_t (*done_group)(ext2_filsys fs,
245 ext2_inode_scan scan,
246 dgrp_t group,
247 void * priv_data),
248 void *done_group_data)
249 {
250 if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
251 return;
252
253 scan->done_group = done_group;
254 scan->done_group_data = done_group_data;
255 }
256
ext2fs_inode_scan_flags(ext2_inode_scan scan,int set_flags,int clear_flags)257 int ext2fs_inode_scan_flags(ext2_inode_scan scan, int set_flags,
258 int clear_flags)
259 {
260 int old_flags;
261
262 if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
263 return 0;
264
265 old_flags = scan->scan_flags;
266 scan->scan_flags &= ~clear_flags;
267 scan->scan_flags |= set_flags;
268 return old_flags;
269 }
270
271 /*
272 * This function is called by ext2fs_get_next_inode when it needs to
273 * get ready to read in a new blockgroup.
274 */
get_next_blockgroup(ext2_inode_scan scan)275 static errcode_t get_next_blockgroup(ext2_inode_scan scan)
276 {
277 ext2_filsys fs = scan->fs;
278
279 scan->current_group++;
280 scan->groups_left--;
281
282 scan->current_block = ext2fs_inode_table_loc(scan->fs,
283 scan->current_group);
284 scan->current_inode = scan->current_group *
285 EXT2_INODES_PER_GROUP(fs->super);
286
287 scan->bytes_left = 0;
288 scan->inodes_left = EXT2_INODES_PER_GROUP(fs->super);
289 scan->blocks_left = fs->inode_blocks_per_group;
290 if (ext2fs_has_group_desc_csum(fs)) {
291 __u32 unused = ext2fs_bg_itable_unused(fs, scan->current_group);
292 if (scan->inodes_left > unused)
293 scan->inodes_left -= unused;
294 else
295 scan->inodes_left = 0;
296 scan->blocks_left =
297 (scan->inodes_left +
298 (fs->blocksize / scan->inode_size - 1)) *
299 scan->inode_size / fs->blocksize;
300 }
301 if (scan->current_block &&
302 ((scan->current_block < fs->super->s_first_data_block) ||
303 (scan->current_block + fs->inode_blocks_per_group - 1 >=
304 ext2fs_blocks_count(fs->super))))
305 return EXT2_ET_GDESC_BAD_INODE_TABLE;
306 return 0;
307 }
308
ext2fs_inode_scan_goto_blockgroup(ext2_inode_scan scan,int group)309 errcode_t ext2fs_inode_scan_goto_blockgroup(ext2_inode_scan scan,
310 int group)
311 {
312 scan->current_group = group - 1;
313 scan->groups_left = scan->fs->group_desc_count - group;
314 scan->bad_block_ptr = 0;
315 return get_next_blockgroup(scan);
316 }
317
318 /*
319 * This function is called by get_next_blocks() to check for bad
320 * blocks in the inode table.
321 *
322 * This function assumes that badblocks_list->list is sorted in
323 * increasing order.
324 */
check_for_inode_bad_blocks(ext2_inode_scan scan,blk64_t * num_blocks)325 static errcode_t check_for_inode_bad_blocks(ext2_inode_scan scan,
326 blk64_t *num_blocks)
327 {
328 blk64_t blk = scan->current_block;
329 badblocks_list bb = scan->fs->badblocks;
330
331 /*
332 * If the inode table is missing, then obviously there are no
333 * bad blocks. :-)
334 */
335 if (blk == 0)
336 return 0;
337
338 /* Make sure bad_block_ptr is still valid */
339 if (scan->bad_block_ptr >= bb->num) {
340 scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
341 return 0;
342 }
343
344 /*
345 * If the current block is greater than the bad block listed
346 * in the bad block list, then advance the pointer until this
347 * is no longer the case. If we run out of bad blocks, then
348 * we don't need to do any more checking!
349 */
350 while (blk > bb->list[scan->bad_block_ptr]) {
351 if (++scan->bad_block_ptr >= bb->num) {
352 scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
353 return 0;
354 }
355 }
356
357 /*
358 * If the current block is equal to the bad block listed in
359 * the bad block list, then handle that one block specially.
360 * (We could try to handle runs of bad blocks, but that
361 * only increases CPU efficiency by a small amount, at the
362 * expense of a huge expense of code complexity, and for an
363 * uncommon case at that.)
364 */
365 if (blk == bb->list[scan->bad_block_ptr]) {
366 scan->scan_flags |= EXT2_SF_BAD_INODE_BLK;
367 *num_blocks = 1;
368 if (++scan->bad_block_ptr >= bb->num)
369 scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
370 return 0;
371 }
372
373 /*
374 * If there is a bad block in the range that we're about to
375 * read in, adjust the number of blocks to read so that we we
376 * don't read in the bad block. (Then the next block to read
377 * will be the bad block, which is handled in the above case.)
378 */
379 if ((blk + *num_blocks) > bb->list[scan->bad_block_ptr])
380 *num_blocks = (int) (bb->list[scan->bad_block_ptr] - blk);
381
382 return 0;
383 }
384
block_map_looks_insane(ext2_filsys fs,struct ext2_inode_large * inode)385 static int block_map_looks_insane(ext2_filsys fs,
386 struct ext2_inode_large *inode)
387 {
388 unsigned int i, bad;
389
390 /* We're only interested in block mapped files, dirs, and symlinks */
391 if ((inode->i_flags & EXT4_INLINE_DATA_FL) ||
392 (inode->i_flags & EXT4_EXTENTS_FL))
393 return 0;
394 if (!LINUX_S_ISREG(inode->i_mode) &&
395 !LINUX_S_ISLNK(inode->i_mode) &&
396 !LINUX_S_ISDIR(inode->i_mode))
397 return 0;
398 if (LINUX_S_ISLNK(inode->i_mode) &&
399 EXT2_I_SIZE(inode) <= sizeof(inode->i_block))
400 return 0;
401
402 /* Unused inodes probably aren't insane */
403 if (inode->i_links_count == 0)
404 return 0;
405
406 /* See if more than half the block maps are insane */
407 for (i = 0, bad = 0; i < EXT2_N_BLOCKS; i++)
408 if (inode->i_block[i] != 0 &&
409 (inode->i_block[i] < fs->super->s_first_data_block ||
410 inode->i_block[i] >= ext2fs_blocks_count(fs->super)))
411 bad++;
412 return bad > EXT2_N_BLOCKS / 2;
413 }
414
extent_head_looks_insane(struct ext2_inode_large * inode)415 static int extent_head_looks_insane(struct ext2_inode_large *inode)
416 {
417 if (!(inode->i_flags & EXT4_EXTENTS_FL) ||
418 ext2fs_extent_header_verify(inode->i_block,
419 sizeof(inode->i_block)) == 0)
420 return 0;
421 return 1;
422 }
423
424 /*
425 * Check all the inodes that we just read into the buffer. Record what we
426 * find here -- currently, we can observe that all checksums are ok; more
427 * than half the inodes are insane; or no conclusions at all.
428 */
check_inode_block_sanity(ext2_inode_scan scan,blk64_t num_blocks)429 static void check_inode_block_sanity(ext2_inode_scan scan, blk64_t num_blocks)
430 {
431 ext2_ino_t ino, inodes_to_scan;
432 unsigned int badness, checksum_failures;
433 unsigned int inodes_in_buf, inodes_per_block;
434 char *p;
435 struct ext2_inode_large *inode;
436 char *block_status;
437 unsigned int blk, bad_csum;
438
439 if (!(scan->scan_flags & EXT2_SF_WARN_GARBAGE_INODES))
440 return;
441
442 inodes_to_scan = scan->inodes_left;
443 inodes_in_buf = num_blocks * scan->fs->blocksize / scan->inode_size;
444 if (inodes_to_scan > inodes_in_buf)
445 inodes_to_scan = inodes_in_buf;
446
447 p = (char *) scan->inode_buffer;
448 ino = scan->current_inode + 1;
449 checksum_failures = badness = 0;
450 block_status = SCAN_BLOCK_STATUS(scan);
451 memset(block_status, 0, scan->inode_buffer_blocks);
452 inodes_per_block = EXT2_INODES_PER_BLOCK(scan->fs->super);
453
454 if (inodes_per_block < 2)
455 return;
456
457 #ifdef WORDS_BIGENDIAN
458 if (ext2fs_get_mem(EXT2_INODE_SIZE(scan->fs->super), &inode))
459 return;
460 #endif
461
462 while (inodes_to_scan > 0) {
463 blk = (p - (char *)scan->inode_buffer) / scan->fs->blocksize;
464 bad_csum = ext2fs_inode_csum_verify(scan->fs, ino,
465 (struct ext2_inode_large *) p) == 0;
466
467 #ifdef WORDS_BIGENDIAN
468 ext2fs_swap_inode_full(scan->fs,
469 (struct ext2_inode_large *) inode,
470 (struct ext2_inode_large *) p,
471 0, EXT2_INODE_SIZE(scan->fs->super));
472 #else
473 inode = (struct ext2_inode_large *) p;
474 #endif
475
476 /* Is this inode insane? */
477 if (bad_csum) {
478 checksum_failures++;
479 badness++;
480 } else if (extent_head_looks_insane(inode) ||
481 block_map_looks_insane(scan->fs, inode))
482 badness++;
483
484 /* If more than half are insane, declare the whole block bad */
485 if (badness > inodes_per_block / 2) {
486 unsigned int ino_adj;
487
488 block_status[blk] |= IBLOCK_STATUS_INSANE;
489 ino_adj = inodes_per_block -
490 ((ino - 1) % inodes_per_block);
491 if (ino_adj > inodes_to_scan)
492 ino_adj = inodes_to_scan;
493 inodes_to_scan -= ino_adj;
494 p += scan->inode_size * ino_adj;
495 ino += ino_adj;
496 checksum_failures = badness = 0;
497 continue;
498 }
499
500 if ((ino % inodes_per_block) == 0) {
501 if (checksum_failures == 0)
502 block_status[blk] |= IBLOCK_STATUS_CSUMS_OK;
503 checksum_failures = badness = 0;
504 }
505 inodes_to_scan--;
506 p += scan->inode_size;
507 ino++;
508 };
509
510 #ifdef WORDS_BIGENDIAN
511 ext2fs_free_mem(&inode);
512 #endif
513 }
514
515 /*
516 * This function is called by ext2fs_get_next_inode when it needs to
517 * read in more blocks from the current blockgroup's inode table.
518 */
get_next_blocks(ext2_inode_scan scan)519 static errcode_t get_next_blocks(ext2_inode_scan scan)
520 {
521 blk64_t num_blocks;
522 errcode_t retval;
523
524 /*
525 * Figure out how many blocks to read; we read at most
526 * inode_buffer_blocks, and perhaps less if there aren't that
527 * many blocks left to read.
528 */
529 num_blocks = scan->inode_buffer_blocks;
530 if (num_blocks > scan->blocks_left)
531 num_blocks = scan->blocks_left;
532
533 /*
534 * If the past block "read" was a bad block, then mark the
535 * left-over extra bytes as also being bad.
536 */
537 if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK) {
538 if (scan->bytes_left)
539 scan->scan_flags |= EXT2_SF_BAD_EXTRA_BYTES;
540 scan->scan_flags &= ~EXT2_SF_BAD_INODE_BLK;
541 }
542
543 /*
544 * Do inode bad block processing, if necessary.
545 */
546 if (scan->scan_flags & EXT2_SF_CHK_BADBLOCKS) {
547 retval = check_for_inode_bad_blocks(scan, &num_blocks);
548 if (retval)
549 return retval;
550 }
551
552 if ((scan->scan_flags & EXT2_SF_BAD_INODE_BLK) ||
553 (scan->current_block == 0)) {
554 memset(scan->inode_buffer, 0,
555 (size_t) num_blocks * scan->fs->blocksize);
556 } else {
557 retval = io_channel_read_blk64(scan->fs->io,
558 scan->current_block,
559 (int) num_blocks,
560 scan->inode_buffer);
561 if (retval)
562 return EXT2_ET_NEXT_INODE_READ;
563 }
564 check_inode_block_sanity(scan, num_blocks);
565
566 scan->ptr = scan->inode_buffer;
567 scan->bytes_left = num_blocks * scan->fs->blocksize;
568
569 scan->blocks_left -= num_blocks;
570 if (scan->current_block)
571 scan->current_block += num_blocks;
572
573 return 0;
574 }
575
576 #if 0
577 /*
578 * Returns 1 if the entire inode_buffer has a non-zero size and
579 * contains all zeros. (Not just deleted inodes, since that means
580 * that part of the inode table was used at one point; we want all
581 * zeros, which means that the inode table is pristine.)
582 */
583 static inline int is_empty_scan(ext2_inode_scan scan)
584 {
585 int i;
586
587 if (scan->bytes_left == 0)
588 return 0;
589
590 for (i=0; i < scan->bytes_left; i++)
591 if (scan->ptr[i])
592 return 0;
593 return 1;
594 }
595 #endif
596
ext2fs_get_next_inode_full(ext2_inode_scan scan,ext2_ino_t * ino,struct ext2_inode * inode,int bufsize)597 errcode_t ext2fs_get_next_inode_full(ext2_inode_scan scan, ext2_ino_t *ino,
598 struct ext2_inode *inode, int bufsize)
599 {
600 errcode_t retval;
601 int extra_bytes = 0;
602 int length;
603 struct ext2_inode_large *iptr = (struct ext2_inode_large *)inode;
604 char *iblock_status;
605 unsigned int iblk;
606
607 EXT2_CHECK_MAGIC(scan, EXT2_ET_MAGIC_INODE_SCAN);
608 length = EXT2_INODE_SIZE(scan->fs->super);
609 iblock_status = SCAN_BLOCK_STATUS(scan);
610
611 /*
612 * Do we need to start reading a new block group?
613 */
614 if (scan->inodes_left <= 0) {
615 force_new_group:
616 if (scan->done_group) {
617 retval = (scan->done_group)
618 (scan->fs, scan, scan->current_group,
619 scan->done_group_data);
620 if (retval)
621 return retval;
622 }
623 if (scan->groups_left <= 0) {
624 *ino = 0;
625 return 0;
626 }
627 retval = get_next_blockgroup(scan);
628 if (retval)
629 return retval;
630 }
631 /*
632 * These checks are done outside the above if statement so
633 * they can be done for block group #0.
634 */
635 if ((scan->scan_flags & EXT2_SF_DO_LAZY) &&
636 (ext2fs_bg_flags_test(scan->fs, scan->current_group, EXT2_BG_INODE_UNINIT)
637 ))
638 goto force_new_group;
639 if (scan->inodes_left == 0)
640 goto force_new_group;
641 if (scan->current_block == 0) {
642 if (scan->scan_flags & EXT2_SF_SKIP_MISSING_ITABLE) {
643 goto force_new_group;
644 } else
645 return EXT2_ET_MISSING_INODE_TABLE;
646 }
647
648
649 /*
650 * Have we run out of space in the inode buffer? If so, we
651 * need to read in more blocks.
652 */
653 if (scan->bytes_left < scan->inode_size) {
654 if (scan->bytes_left)
655 memcpy(scan->temp_buffer, scan->ptr, scan->bytes_left);
656 extra_bytes = scan->bytes_left;
657
658 retval = get_next_blocks(scan);
659 if (retval)
660 return retval;
661 #if 0
662 /*
663 * XXX test Need check for used inode somehow.
664 * (Note: this is hard.)
665 */
666 if (is_empty_scan(scan))
667 goto force_new_group;
668 #endif
669 }
670
671 if (bufsize < length) {
672 retval = ext2fs_get_mem(length, &iptr);
673 if (retval)
674 return retval;
675 }
676
677 retval = 0;
678 iblk = scan->current_inode % EXT2_INODES_PER_GROUP(scan->fs->super) /
679 EXT2_INODES_PER_BLOCK(scan->fs->super) %
680 scan->inode_buffer_blocks;
681 if (extra_bytes) {
682 memcpy(scan->temp_buffer+extra_bytes, scan->ptr,
683 scan->inode_size - extra_bytes);
684 scan->ptr += scan->inode_size - extra_bytes;
685 scan->bytes_left -= scan->inode_size - extra_bytes;
686
687 /* Verify the inode checksum. */
688 if (!(iblock_status[iblk] & IBLOCK_STATUS_CSUMS_OK) &&
689 !(scan->fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
690 !ext2fs_inode_csum_verify(scan->fs, scan->current_inode + 1,
691 (struct ext2_inode_large *)scan->temp_buffer))
692 retval = EXT2_ET_INODE_CSUM_INVALID;
693
694 #ifdef WORDS_BIGENDIAN
695 memset(iptr, 0, length);
696 ext2fs_swap_inode_full(scan->fs,
697 (struct ext2_inode_large *) iptr,
698 (struct ext2_inode_large *) scan->temp_buffer,
699 0, length);
700 #else
701 memcpy(iptr, scan->temp_buffer, length);
702 #endif
703 if (scan->scan_flags & EXT2_SF_BAD_EXTRA_BYTES)
704 retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE;
705 scan->scan_flags &= ~EXT2_SF_BAD_EXTRA_BYTES;
706 } else {
707 /* Verify the inode checksum. */
708 if (!(iblock_status[iblk] & IBLOCK_STATUS_CSUMS_OK) &&
709 !(scan->fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
710 !ext2fs_inode_csum_verify(scan->fs, scan->current_inode + 1,
711 (struct ext2_inode_large *)scan->ptr))
712 retval = EXT2_ET_INODE_CSUM_INVALID;
713
714 #ifdef WORDS_BIGENDIAN
715 memset(iptr, 0, length);
716 ext2fs_swap_inode_full(scan->fs,
717 (struct ext2_inode_large *) iptr,
718 (struct ext2_inode_large *) scan->ptr,
719 0, length);
720 #else
721 memcpy(iptr, scan->ptr, length);
722 #endif
723 scan->ptr += scan->inode_size;
724 scan->bytes_left -= scan->inode_size;
725 if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK)
726 retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE;
727 }
728 if ((iblock_status[iblk] & IBLOCK_STATUS_INSANE) &&
729 (retval == 0 || retval == EXT2_ET_INODE_CSUM_INVALID))
730 retval = EXT2_ET_INODE_IS_GARBAGE;
731
732 scan->inodes_left--;
733 scan->current_inode++;
734 *ino = scan->current_inode;
735 if (iptr != (struct ext2_inode_large *)inode) {
736 memcpy(inode, iptr, bufsize);
737 ext2fs_free_mem(&iptr);
738 }
739 return retval;
740 }
741
ext2fs_get_next_inode(ext2_inode_scan scan,ext2_ino_t * ino,struct ext2_inode * inode)742 errcode_t ext2fs_get_next_inode(ext2_inode_scan scan, ext2_ino_t *ino,
743 struct ext2_inode *inode)
744 {
745 return ext2fs_get_next_inode_full(scan, ino, inode,
746 sizeof(struct ext2_inode));
747 }
748
749 /*
750 * Functions to read and write a single inode.
751 */
ext2fs_read_inode2(ext2_filsys fs,ext2_ino_t ino,struct ext2_inode * inode,int bufsize,int flags)752 errcode_t ext2fs_read_inode2(ext2_filsys fs, ext2_ino_t ino,
753 struct ext2_inode * inode, int bufsize,
754 int flags)
755 {
756 blk64_t block_nr;
757 dgrp_t group;
758 unsigned long block, offset;
759 char *ptr;
760 errcode_t retval;
761 unsigned i;
762 int clen, inodes_per_block;
763 io_channel io;
764 int length = EXT2_INODE_SIZE(fs->super);
765 struct ext2_inode_large *iptr;
766 int cache_slot, fail_csum;
767
768 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
769 if (fs->blocksize < 1024)
770 return EXT2_FILSYS_CORRUPTED; /* Should never happen */
771
772 /* Check to see if user has an override function */
773 if (fs->read_inode &&
774 ((bufsize == sizeof(struct ext2_inode)) ||
775 (EXT2_INODE_SIZE(fs->super) == sizeof(struct ext2_inode)))) {
776 retval = (fs->read_inode)(fs, ino, inode);
777 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
778 return retval;
779 }
780 if ((ino == 0) || (ino > fs->super->s_inodes_count))
781 return EXT2_ET_BAD_INODE_NUM;
782 /* Create inode cache if not present */
783 if (!fs->icache) {
784 retval = ext2fs_create_inode_cache(fs, 4);
785 if (retval)
786 return retval;
787 }
788 /* Check to see if it's in the inode cache */
789 for (i = 0; i < fs->icache->cache_size; i++) {
790 if (fs->icache->cache[i].ino == ino) {
791 memcpy(inode, fs->icache->cache[i].inode,
792 (bufsize > length) ? length : bufsize);
793 return 0;
794 }
795 }
796 if (fs->flags & EXT2_FLAG_IMAGE_FILE) {
797 inodes_per_block = fs->blocksize / EXT2_INODE_SIZE(fs->super);
798 block_nr = ext2fs_le32_to_cpu(fs->image_header->offset_inode) / fs->blocksize;
799 block_nr += (ino - 1) / inodes_per_block;
800 offset = ((ino - 1) % inodes_per_block) *
801 EXT2_INODE_SIZE(fs->super);
802 io = fs->image_io;
803 } else {
804 group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super);
805 if (group > fs->group_desc_count)
806 return EXT2_ET_BAD_INODE_NUM;
807 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) *
808 EXT2_INODE_SIZE(fs->super);
809 block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super);
810 block_nr = ext2fs_inode_table_loc(fs, group);
811 if (!block_nr)
812 return EXT2_ET_MISSING_INODE_TABLE;
813 if ((block_nr < fs->super->s_first_data_block) ||
814 (block_nr + fs->inode_blocks_per_group - 1 >=
815 ext2fs_blocks_count(fs->super)))
816 return EXT2_ET_GDESC_BAD_INODE_TABLE;
817 block_nr += block;
818 io = fs->io;
819 }
820 offset &= (EXT2_BLOCK_SIZE(fs->super) - 1);
821
822 cache_slot = (fs->icache->cache_last + 1) % fs->icache->cache_size;
823 iptr = (struct ext2_inode_large *)fs->icache->cache[cache_slot].inode;
824
825 ptr = (char *) iptr;
826 while (length) {
827 clen = length;
828 if ((offset + length) > fs->blocksize)
829 clen = fs->blocksize - offset;
830
831 if (block_nr != fs->icache->buffer_blk) {
832 retval = io_channel_read_blk64(io, block_nr, 1,
833 fs->icache->buffer);
834 if (retval)
835 return retval;
836 fs->icache->buffer_blk = block_nr;
837 }
838
839 memcpy(ptr, ((char *) fs->icache->buffer) + (unsigned) offset,
840 clen);
841
842 offset = 0;
843 length -= clen;
844 ptr += clen;
845 block_nr++;
846 }
847 length = EXT2_INODE_SIZE(fs->super);
848
849 /* Verify the inode checksum. */
850 fail_csum = !ext2fs_inode_csum_verify(fs, ino, iptr);
851
852 #ifdef WORDS_BIGENDIAN
853 ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) iptr,
854 (struct ext2_inode_large *) iptr,
855 0, length);
856 #endif
857
858 /* Update the inode cache bookkeeping */
859 if (!fail_csum) {
860 fs->icache->cache_last = cache_slot;
861 fs->icache->cache[cache_slot].ino = ino;
862 }
863 memcpy(inode, iptr, (bufsize > length) ? length : bufsize);
864
865 if (!(fs->flags & EXT2_FLAG_IGNORE_CSUM_ERRORS) &&
866 !(flags & READ_INODE_NOCSUM) && fail_csum)
867 return EXT2_ET_INODE_CSUM_INVALID;
868
869 return 0;
870 }
871
ext2fs_read_inode_full(ext2_filsys fs,ext2_ino_t ino,struct ext2_inode * inode,int bufsize)872 errcode_t ext2fs_read_inode_full(ext2_filsys fs, ext2_ino_t ino,
873 struct ext2_inode * inode, int bufsize)
874 {
875 return ext2fs_read_inode2(fs, ino, inode, bufsize, 0);
876 }
877
ext2fs_read_inode(ext2_filsys fs,ext2_ino_t ino,struct ext2_inode * inode)878 errcode_t ext2fs_read_inode(ext2_filsys fs, ext2_ino_t ino,
879 struct ext2_inode * inode)
880 {
881 return ext2fs_read_inode2(fs, ino, inode,
882 sizeof(struct ext2_inode), 0);
883 }
884
ext2fs_write_inode2(ext2_filsys fs,ext2_ino_t ino,struct ext2_inode * inode,int bufsize,int flags)885 errcode_t ext2fs_write_inode2(ext2_filsys fs, ext2_ino_t ino,
886 struct ext2_inode * inode, int bufsize,
887 int flags)
888 {
889 blk64_t block_nr;
890 dgrp_t group;
891 unsigned long block, offset;
892 errcode_t retval = 0;
893 struct ext2_inode_large *w_inode;
894 char *ptr;
895 unsigned i;
896 int clen;
897 int length = EXT2_INODE_SIZE(fs->super);
898
899 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
900
901 /* Check to see if user provided an override function */
902 if (fs->write_inode) {
903 retval = (fs->write_inode)(fs, ino, inode);
904 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
905 return retval;
906 }
907
908 if ((ino == 0) || (ino > fs->super->s_inodes_count))
909 return EXT2_ET_BAD_INODE_NUM;
910
911 /* Prepare our shadow buffer for read/modify/byteswap/write */
912 retval = ext2fs_get_mem(length, &w_inode);
913 if (retval)
914 return retval;
915
916 if (bufsize < length) {
917 retval = ext2fs_read_inode2(fs, ino,
918 (struct ext2_inode *)w_inode,
919 length, READ_INODE_NOCSUM);
920 if (retval)
921 goto errout;
922 }
923
924 /* Check to see if the inode cache needs to be updated */
925 if (fs->icache) {
926 for (i=0; i < fs->icache->cache_size; i++) {
927 if (fs->icache->cache[i].ino == ino) {
928 memcpy(fs->icache->cache[i].inode, inode,
929 (bufsize > length) ? length : bufsize);
930 break;
931 }
932 }
933 } else {
934 retval = ext2fs_create_inode_cache(fs, 4);
935 if (retval)
936 goto errout;
937 }
938 memcpy(w_inode, inode, (bufsize > length) ? length : bufsize);
939
940 if (!(fs->flags & EXT2_FLAG_RW)) {
941 retval = EXT2_ET_RO_FILSYS;
942 goto errout;
943 }
944
945 #ifdef WORDS_BIGENDIAN
946 ext2fs_swap_inode_full(fs, w_inode, w_inode, 1, length);
947 #endif
948
949 if ((flags & WRITE_INODE_NOCSUM) == 0) {
950 retval = ext2fs_inode_csum_set(fs, ino, w_inode);
951 if (retval)
952 goto errout;
953 }
954
955 group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super);
956 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) *
957 EXT2_INODE_SIZE(fs->super);
958 block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super);
959 block_nr = ext2fs_inode_table_loc(fs, (unsigned) group);
960 if (!block_nr) {
961 retval = EXT2_ET_MISSING_INODE_TABLE;
962 goto errout;
963 }
964 if ((block_nr < fs->super->s_first_data_block) ||
965 (block_nr + fs->inode_blocks_per_group - 1 >=
966 ext2fs_blocks_count(fs->super))) {
967 retval = EXT2_ET_GDESC_BAD_INODE_TABLE;
968 goto errout;
969 }
970 block_nr += block;
971
972 offset &= (EXT2_BLOCK_SIZE(fs->super) - 1);
973
974 ptr = (char *) w_inode;
975
976 while (length) {
977 clen = length;
978 if ((offset + length) > fs->blocksize)
979 clen = fs->blocksize - offset;
980
981 if (fs->icache->buffer_blk != block_nr) {
982 retval = io_channel_read_blk64(fs->io, block_nr, 1,
983 fs->icache->buffer);
984 if (retval)
985 goto errout;
986 fs->icache->buffer_blk = block_nr;
987 }
988
989
990 memcpy((char *) fs->icache->buffer + (unsigned) offset,
991 ptr, clen);
992
993 retval = io_channel_write_blk64(fs->io, block_nr, 1,
994 fs->icache->buffer);
995 if (retval)
996 goto errout;
997
998 offset = 0;
999 ptr += clen;
1000 length -= clen;
1001 block_nr++;
1002 }
1003
1004 fs->flags |= EXT2_FLAG_CHANGED;
1005 errout:
1006 ext2fs_free_mem(&w_inode);
1007 return retval;
1008 }
1009
ext2fs_write_inode_full(ext2_filsys fs,ext2_ino_t ino,struct ext2_inode * inode,int bufsize)1010 errcode_t ext2fs_write_inode_full(ext2_filsys fs, ext2_ino_t ino,
1011 struct ext2_inode * inode, int bufsize)
1012 {
1013 return ext2fs_write_inode2(fs, ino, inode, bufsize, 0);
1014 }
1015
ext2fs_write_inode(ext2_filsys fs,ext2_ino_t ino,struct ext2_inode * inode)1016 errcode_t ext2fs_write_inode(ext2_filsys fs, ext2_ino_t ino,
1017 struct ext2_inode *inode)
1018 {
1019 return ext2fs_write_inode2(fs, ino, inode,
1020 sizeof(struct ext2_inode), 0);
1021 }
1022
1023 /*
1024 * This function should be called when writing a new inode. It makes
1025 * sure that extra part of large inodes is initialized properly.
1026 */
ext2fs_write_new_inode(ext2_filsys fs,ext2_ino_t ino,struct ext2_inode * inode)1027 errcode_t ext2fs_write_new_inode(ext2_filsys fs, ext2_ino_t ino,
1028 struct ext2_inode *inode)
1029 {
1030 struct ext2_inode *buf;
1031 int size = EXT2_INODE_SIZE(fs->super);
1032 struct ext2_inode_large *large_inode;
1033 errcode_t retval;
1034 __u32 t = fs->now ? fs->now : time(NULL);
1035
1036 if (!inode->i_ctime)
1037 inode->i_ctime = t;
1038 if (!inode->i_mtime)
1039 inode->i_mtime = t;
1040 if (!inode->i_atime)
1041 inode->i_atime = t;
1042
1043 if (size == sizeof(struct ext2_inode))
1044 return ext2fs_write_inode_full(fs, ino, inode,
1045 sizeof(struct ext2_inode));
1046
1047 buf = malloc(size);
1048 if (!buf)
1049 return ENOMEM;
1050
1051 memset(buf, 0, size);
1052 *buf = *inode;
1053
1054 large_inode = (struct ext2_inode_large *) buf;
1055 large_inode->i_extra_isize = sizeof(struct ext2_inode_large) -
1056 EXT2_GOOD_OLD_INODE_SIZE;
1057 if (!large_inode->i_crtime)
1058 large_inode->i_crtime = t;
1059
1060 retval = ext2fs_write_inode_full(fs, ino, buf, size);
1061 free(buf);
1062 return retval;
1063 }
1064
1065
ext2fs_get_blocks(ext2_filsys fs,ext2_ino_t ino,blk_t * blocks)1066 errcode_t ext2fs_get_blocks(ext2_filsys fs, ext2_ino_t ino, blk_t *blocks)
1067 {
1068 struct ext2_inode inode;
1069 int i;
1070 errcode_t retval;
1071
1072 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
1073
1074 if (ino > fs->super->s_inodes_count)
1075 return EXT2_ET_BAD_INODE_NUM;
1076
1077 if (fs->get_blocks) {
1078 if (!(*fs->get_blocks)(fs, ino, blocks))
1079 return 0;
1080 }
1081 retval = ext2fs_read_inode(fs, ino, &inode);
1082 if (retval)
1083 return retval;
1084 for (i=0; i < EXT2_N_BLOCKS; i++)
1085 blocks[i] = inode.i_block[i];
1086 return 0;
1087 }
1088
ext2fs_check_directory(ext2_filsys fs,ext2_ino_t ino)1089 errcode_t ext2fs_check_directory(ext2_filsys fs, ext2_ino_t ino)
1090 {
1091 struct ext2_inode inode;
1092 errcode_t retval;
1093
1094 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
1095
1096 if (ino > fs->super->s_inodes_count)
1097 return EXT2_ET_BAD_INODE_NUM;
1098
1099 if (fs->check_directory) {
1100 retval = (fs->check_directory)(fs, ino);
1101 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
1102 return retval;
1103 }
1104 retval = ext2fs_read_inode(fs, ino, &inode);
1105 if (retval)
1106 return retval;
1107 if (!LINUX_S_ISDIR(inode.i_mode))
1108 return EXT2_ET_NO_DIRECTORY;
1109 return 0;
1110 }
1111
1112