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The Android Open Source Project0a84e9c2008-12-17 18:04:13 -08001/*
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 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
31struct ext2_struct_inode_scan {
32 errcode_t magic;
33 ext2_filsys fs;
34 ext2_ino_t current_inode;
35 blk_t current_block;
36 dgrp_t current_group;
37 ext2_ino_t inodes_left;
38 blk_t blocks_left;
39 dgrp_t groups_left;
40 blk_t inode_buffer_blocks;
41 char * inode_buffer;
42 int inode_size;
43 char * ptr;
44 int bytes_left;
45 char *temp_buffer;
46 errcode_t (*done_group)(ext2_filsys fs,
47 ext2_inode_scan scan,
48 dgrp_t group,
49 void * priv_data);
50 void * done_group_data;
51 int bad_block_ptr;
52 int scan_flags;
53 int reserved[6];
54};
55
56/*
57 * This routine flushes the icache, if it exists.
58 */
59errcode_t ext2fs_flush_icache(ext2_filsys fs)
60{
61 int i;
62
63 if (!fs->icache)
64 return 0;
65
66 for (i=0; i < fs->icache->cache_size; i++)
67 fs->icache->cache[i].ino = 0;
68
69 fs->icache->buffer_blk = 0;
70 return 0;
71}
72
73static errcode_t create_icache(ext2_filsys fs)
74{
75 errcode_t retval;
76
77 if (fs->icache)
78 return 0;
79 retval = ext2fs_get_mem(sizeof(struct ext2_inode_cache), &fs->icache);
80 if (retval)
81 return retval;
82
83 memset(fs->icache, 0, sizeof(struct ext2_inode_cache));
84 retval = ext2fs_get_mem(fs->blocksize, &fs->icache->buffer);
85 if (retval) {
86 ext2fs_free_mem(&fs->icache);
87 return retval;
88 }
89 fs->icache->buffer_blk = 0;
90 fs->icache->cache_last = -1;
91 fs->icache->cache_size = 4;
92 fs->icache->refcount = 1;
93 retval = ext2fs_get_array(fs->icache->cache_size,
94 sizeof(struct ext2_inode_cache_ent),
95 &fs->icache->cache);
96 if (retval) {
97 ext2fs_free_mem(&fs->icache->buffer);
98 ext2fs_free_mem(&fs->icache);
99 return retval;
100 }
101 ext2fs_flush_icache(fs);
102 return 0;
103}
104
105errcode_t ext2fs_open_inode_scan(ext2_filsys fs, int buffer_blocks,
106 ext2_inode_scan *ret_scan)
107{
108 ext2_inode_scan scan;
109 errcode_t retval;
110 errcode_t (*save_get_blocks)(ext2_filsys f, ext2_ino_t ino, blk_t *blocks);
111
112 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
113
114 /*
115 * If fs->badblocks isn't set, then set it --- since the inode
116 * scanning functions require it.
117 */
118 if (fs->badblocks == 0) {
119 /*
120 * Temporarly save fs->get_blocks and set it to zero,
121 * for compatibility with old e2fsck's.
122 */
123 save_get_blocks = fs->get_blocks;
124 fs->get_blocks = 0;
125 retval = ext2fs_read_bb_inode(fs, &fs->badblocks);
126 if (retval && fs->badblocks) {
127 ext2fs_badblocks_list_free(fs->badblocks);
128 fs->badblocks = 0;
129 }
130 fs->get_blocks = save_get_blocks;
131 }
132
133 retval = ext2fs_get_mem(sizeof(struct ext2_struct_inode_scan), &scan);
134 if (retval)
135 return retval;
136 memset(scan, 0, sizeof(struct ext2_struct_inode_scan));
137
138 scan->magic = EXT2_ET_MAGIC_INODE_SCAN;
139 scan->fs = fs;
140 scan->inode_size = EXT2_INODE_SIZE(fs->super);
141 scan->bytes_left = 0;
142 scan->current_group = 0;
143 scan->groups_left = fs->group_desc_count - 1;
144 scan->inode_buffer_blocks = buffer_blocks ? buffer_blocks : 8;
145 scan->current_block = scan->fs->
146 group_desc[scan->current_group].bg_inode_table;
147 scan->inodes_left = EXT2_INODES_PER_GROUP(scan->fs->super);
148 scan->blocks_left = scan->fs->inode_blocks_per_group;
149 retval = ext2fs_get_array(scan->inode_buffer_blocks,
150 fs->blocksize,
151 &scan->inode_buffer);
152 scan->done_group = 0;
153 scan->done_group_data = 0;
154 scan->bad_block_ptr = 0;
155 if (retval) {
156 ext2fs_free_mem(&scan);
157 return retval;
158 }
159 retval = ext2fs_get_mem(scan->inode_size, &scan->temp_buffer);
160 if (retval) {
161 ext2fs_free_mem(&scan->inode_buffer);
162 ext2fs_free_mem(&scan);
163 return retval;
164 }
165 if (scan->fs->badblocks && scan->fs->badblocks->num)
166 scan->scan_flags |= EXT2_SF_CHK_BADBLOCKS;
167 if (EXT2_HAS_COMPAT_FEATURE(fs->super,
168 EXT2_FEATURE_COMPAT_LAZY_BG))
169 scan->scan_flags |= EXT2_SF_DO_LAZY;
170 *ret_scan = scan;
171 return 0;
172}
173
174void ext2fs_close_inode_scan(ext2_inode_scan scan)
175{
176 if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
177 return;
178
179 ext2fs_free_mem(&scan->inode_buffer);
180 scan->inode_buffer = NULL;
181 ext2fs_free_mem(&scan->temp_buffer);
182 scan->temp_buffer = NULL;
183 ext2fs_free_mem(&scan);
184 return;
185}
186
187void ext2fs_set_inode_callback(ext2_inode_scan scan,
188 errcode_t (*done_group)(ext2_filsys fs,
189 ext2_inode_scan scan,
190 dgrp_t group,
191 void * priv_data),
192 void *done_group_data)
193{
194 if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
195 return;
196
197 scan->done_group = done_group;
198 scan->done_group_data = done_group_data;
199}
200
201int ext2fs_inode_scan_flags(ext2_inode_scan scan, int set_flags,
202 int clear_flags)
203{
204 int old_flags;
205
206 if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
207 return 0;
208
209 old_flags = scan->scan_flags;
210 scan->scan_flags &= ~clear_flags;
211 scan->scan_flags |= set_flags;
212 return old_flags;
213}
214
215/*
216 * This function is called by ext2fs_get_next_inode when it needs to
217 * get ready to read in a new blockgroup.
218 */
219static errcode_t get_next_blockgroup(ext2_inode_scan scan)
220{
221 scan->current_group++;
222 scan->groups_left--;
223
224 scan->current_block = scan->fs->
225 group_desc[scan->current_group].bg_inode_table;
226
227 scan->current_inode = scan->current_group *
228 EXT2_INODES_PER_GROUP(scan->fs->super);
229
230 scan->bytes_left = 0;
231 scan->inodes_left = EXT2_INODES_PER_GROUP(scan->fs->super);
232 scan->blocks_left = scan->fs->inode_blocks_per_group;
233 return 0;
234}
235
236errcode_t ext2fs_inode_scan_goto_blockgroup(ext2_inode_scan scan,
237 int group)
238{
239 scan->current_group = group - 1;
240 scan->groups_left = scan->fs->group_desc_count - group;
241 return get_next_blockgroup(scan);
242}
243
244/*
245 * This function is called by get_next_blocks() to check for bad
246 * blocks in the inode table.
247 *
248 * This function assumes that badblocks_list->list is sorted in
249 * increasing order.
250 */
251static errcode_t check_for_inode_bad_blocks(ext2_inode_scan scan,
252 blk_t *num_blocks)
253{
254 blk_t blk = scan->current_block;
255 badblocks_list bb = scan->fs->badblocks;
256
257 /*
258 * If the inode table is missing, then obviously there are no
259 * bad blocks. :-)
260 */
261 if (blk == 0)
262 return 0;
263
264 /*
265 * If the current block is greater than the bad block listed
266 * in the bad block list, then advance the pointer until this
267 * is no longer the case. If we run out of bad blocks, then
268 * we don't need to do any more checking!
269 */
270 while (blk > bb->list[scan->bad_block_ptr]) {
271 if (++scan->bad_block_ptr >= bb->num) {
272 scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
273 return 0;
274 }
275 }
276
277 /*
278 * If the current block is equal to the bad block listed in
279 * the bad block list, then handle that one block specially.
280 * (We could try to handle runs of bad blocks, but that
281 * only increases CPU efficiency by a small amount, at the
282 * expense of a huge expense of code complexity, and for an
283 * uncommon case at that.)
284 */
285 if (blk == bb->list[scan->bad_block_ptr]) {
286 scan->scan_flags |= EXT2_SF_BAD_INODE_BLK;
287 *num_blocks = 1;
288 if (++scan->bad_block_ptr >= bb->num)
289 scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
290 return 0;
291 }
292
293 /*
294 * If there is a bad block in the range that we're about to
295 * read in, adjust the number of blocks to read so that we we
296 * don't read in the bad block. (Then the next block to read
297 * will be the bad block, which is handled in the above case.)
298 */
299 if ((blk + *num_blocks) > bb->list[scan->bad_block_ptr])
300 *num_blocks = (int) (bb->list[scan->bad_block_ptr] - blk);
301
302 return 0;
303}
304
305/*
306 * This function is called by ext2fs_get_next_inode when it needs to
307 * read in more blocks from the current blockgroup's inode table.
308 */
309static errcode_t get_next_blocks(ext2_inode_scan scan)
310{
311 blk_t num_blocks;
312 errcode_t retval;
313
314 /*
315 * Figure out how many blocks to read; we read at most
316 * inode_buffer_blocks, and perhaps less if there aren't that
317 * many blocks left to read.
318 */
319 num_blocks = scan->inode_buffer_blocks;
320 if (num_blocks > scan->blocks_left)
321 num_blocks = scan->blocks_left;
322
323 /*
324 * If the past block "read" was a bad block, then mark the
325 * left-over extra bytes as also being bad.
326 */
327 if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK) {
328 if (scan->bytes_left)
329 scan->scan_flags |= EXT2_SF_BAD_EXTRA_BYTES;
330 scan->scan_flags &= ~EXT2_SF_BAD_INODE_BLK;
331 }
332
333 /*
334 * Do inode bad block processing, if necessary.
335 */
336 if (scan->scan_flags & EXT2_SF_CHK_BADBLOCKS) {
337 retval = check_for_inode_bad_blocks(scan, &num_blocks);
338 if (retval)
339 return retval;
340 }
341
342 if ((scan->scan_flags & EXT2_SF_BAD_INODE_BLK) ||
343 (scan->current_block == 0)) {
344 memset(scan->inode_buffer, 0,
345 (size_t) num_blocks * scan->fs->blocksize);
346 } else {
347 retval = io_channel_read_blk(scan->fs->io,
348 scan->current_block,
349 (int) num_blocks,
350 scan->inode_buffer);
351 if (retval)
352 return EXT2_ET_NEXT_INODE_READ;
353 }
354 scan->ptr = scan->inode_buffer;
355 scan->bytes_left = num_blocks * scan->fs->blocksize;
356
357 scan->blocks_left -= num_blocks;
358 if (scan->current_block)
359 scan->current_block += num_blocks;
360 return 0;
361}
362
363#if 0
364/*
365 * Returns 1 if the entire inode_buffer has a non-zero size and
366 * contains all zeros. (Not just deleted inodes, since that means
367 * that part of the inode table was used at one point; we want all
368 * zeros, which means that the inode table is pristine.)
369 */
370static inline int is_empty_scan(ext2_inode_scan scan)
371{
372 int i;
373
374 if (scan->bytes_left == 0)
375 return 0;
376
377 for (i=0; i < scan->bytes_left; i++)
378 if (scan->ptr[i])
379 return 0;
380 return 1;
381}
382#endif
383
384errcode_t ext2fs_get_next_inode_full(ext2_inode_scan scan, ext2_ino_t *ino,
385 struct ext2_inode *inode, int bufsize)
386{
387 errcode_t retval;
388 int extra_bytes = 0;
389
390 EXT2_CHECK_MAGIC(scan, EXT2_ET_MAGIC_INODE_SCAN);
391
392 /*
393 * Do we need to start reading a new block group?
394 */
395 if (scan->inodes_left <= 0) {
396 force_new_group:
397 if (scan->done_group) {
398 retval = (scan->done_group)
399 (scan->fs, scan, scan->current_group,
400 scan->done_group_data);
401 if (retval)
402 return retval;
403 }
404 if (scan->groups_left <= 0) {
405 *ino = 0;
406 return 0;
407 }
408 retval = get_next_blockgroup(scan);
409 if (retval)
410 return retval;
411 }
412 /*
413 * These checks are done outside the above if statement so
414 * they can be done for block group #0.
415 */
416 if ((scan->scan_flags & EXT2_SF_DO_LAZY) &&
417 (scan->fs->group_desc[scan->current_group].bg_flags &
418 EXT2_BG_INODE_UNINIT))
419 goto force_new_group;
420 if (scan->current_block == 0) {
421 if (scan->scan_flags & EXT2_SF_SKIP_MISSING_ITABLE) {
422 goto force_new_group;
423 } else
424 return EXT2_ET_MISSING_INODE_TABLE;
425 }
426
427
428 /*
429 * Have we run out of space in the inode buffer? If so, we
430 * need to read in more blocks.
431 */
432 if (scan->bytes_left < scan->inode_size) {
433 memcpy(scan->temp_buffer, scan->ptr, scan->bytes_left);
434 extra_bytes = scan->bytes_left;
435
436 retval = get_next_blocks(scan);
437 if (retval)
438 return retval;
439#if 0
440 /*
441 * XXX test Need check for used inode somehow.
442 * (Note: this is hard.)
443 */
444 if (is_empty_scan(scan))
445 goto force_new_group;
446#endif
447 }
448
449 retval = 0;
450 if (extra_bytes) {
451 memcpy(scan->temp_buffer+extra_bytes, scan->ptr,
452 scan->inode_size - extra_bytes);
453 scan->ptr += scan->inode_size - extra_bytes;
454 scan->bytes_left -= scan->inode_size - extra_bytes;
455
456#ifdef EXT2FS_ENABLE_SWAPFS
457 memset(inode, 0, bufsize);
458 if ((scan->fs->flags & EXT2_FLAG_SWAP_BYTES) ||
459 (scan->fs->flags & EXT2_FLAG_SWAP_BYTES_READ))
460 ext2fs_swap_inode_full(scan->fs,
461 (struct ext2_inode_large *) inode,
462 (struct ext2_inode_large *) scan->temp_buffer,
463 0, bufsize);
464 else
465#endif
466 *inode = *((struct ext2_inode *) scan->temp_buffer);
467 if (scan->scan_flags & EXT2_SF_BAD_EXTRA_BYTES)
468 retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE;
469 scan->scan_flags &= ~EXT2_SF_BAD_EXTRA_BYTES;
470 } else {
471#ifdef EXT2FS_ENABLE_SWAPFS
472 memset(inode, 0, bufsize);
473 if ((scan->fs->flags & EXT2_FLAG_SWAP_BYTES) ||
474 (scan->fs->flags & EXT2_FLAG_SWAP_BYTES_READ))
475 ext2fs_swap_inode_full(scan->fs,
476 (struct ext2_inode_large *) inode,
477 (struct ext2_inode_large *) scan->ptr,
478 0, bufsize);
479 else
480#endif
481 memcpy(inode, scan->ptr, bufsize);
482 scan->ptr += scan->inode_size;
483 scan->bytes_left -= scan->inode_size;
484 if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK)
485 retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE;
486 }
487
488 scan->inodes_left--;
489 scan->current_inode++;
490 *ino = scan->current_inode;
491 return retval;
492}
493
494errcode_t ext2fs_get_next_inode(ext2_inode_scan scan, ext2_ino_t *ino,
495 struct ext2_inode *inode)
496{
497 return ext2fs_get_next_inode_full(scan, ino, inode,
498 sizeof(struct ext2_inode));
499}
500
501/*
502 * Functions to read and write a single inode.
503 */
504errcode_t ext2fs_read_inode_full(ext2_filsys fs, ext2_ino_t ino,
505 struct ext2_inode * inode, int bufsize)
506{
507 unsigned long group, block, block_nr, offset;
508 char *ptr;
509 errcode_t retval;
510 int clen, i, inodes_per_block, length;
511 io_channel io;
512
513 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
514
515 /* Check to see if user has an override function */
516 if (fs->read_inode) {
517 retval = (fs->read_inode)(fs, ino, inode);
518 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
519 return retval;
520 }
521 /* Create inode cache if not present */
522 if (!fs->icache) {
523 retval = create_icache(fs);
524 if (retval)
525 return retval;
526 }
527 /* Check to see if it's in the inode cache */
528 if (bufsize == sizeof(struct ext2_inode)) {
529 /* only old good inode can be retrieve from the cache */
530 for (i=0; i < fs->icache->cache_size; i++) {
531 if (fs->icache->cache[i].ino == ino) {
532 *inode = fs->icache->cache[i].inode;
533 return 0;
534 }
535 }
536 }
537 if ((ino == 0) || (ino > fs->super->s_inodes_count))
538 return EXT2_ET_BAD_INODE_NUM;
539 if (fs->flags & EXT2_FLAG_IMAGE_FILE) {
540 inodes_per_block = fs->blocksize / EXT2_INODE_SIZE(fs->super);
541 block_nr = fs->image_header->offset_inode / fs->blocksize;
542 block_nr += (ino - 1) / inodes_per_block;
543 offset = ((ino - 1) % inodes_per_block) *
544 EXT2_INODE_SIZE(fs->super);
545 io = fs->image_io;
546 } else {
547 group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super);
548 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) *
549 EXT2_INODE_SIZE(fs->super);
550 block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super);
551 if (!fs->group_desc[(unsigned)group].bg_inode_table)
552 return EXT2_ET_MISSING_INODE_TABLE;
553 block_nr = fs->group_desc[(unsigned)group].bg_inode_table +
554 block;
555 io = fs->io;
556 }
557 offset &= (EXT2_BLOCK_SIZE(fs->super) - 1);
558
559 length = EXT2_INODE_SIZE(fs->super);
560 if (bufsize < length)
561 length = bufsize;
562
563 ptr = (char *) inode;
564 while (length) {
565 clen = length;
566 if ((offset + length) > fs->blocksize)
567 clen = fs->blocksize - offset;
568
569 if (block_nr != fs->icache->buffer_blk) {
570 retval = io_channel_read_blk(io, block_nr, 1,
571 fs->icache->buffer);
572 if (retval)
573 return retval;
574 fs->icache->buffer_blk = block_nr;
575 }
576
577 memcpy(ptr, ((char *) fs->icache->buffer) + (unsigned) offset,
578 clen);
579
580 offset = 0;
581 length -= clen;
582 ptr += clen;
583 block_nr++;
584 }
585
586#ifdef EXT2FS_ENABLE_SWAPFS
587 if ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
588 (fs->flags & EXT2_FLAG_SWAP_BYTES_READ))
589 ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) inode,
590 (struct ext2_inode_large *) inode,
591 0, bufsize);
592#endif
593
594 /* Update the inode cache */
595 fs->icache->cache_last = (fs->icache->cache_last + 1) %
596 fs->icache->cache_size;
597 fs->icache->cache[fs->icache->cache_last].ino = ino;
598 fs->icache->cache[fs->icache->cache_last].inode = *inode;
599
600 return 0;
601}
602
603errcode_t ext2fs_read_inode(ext2_filsys fs, ext2_ino_t ino,
604 struct ext2_inode * inode)
605{
606 return ext2fs_read_inode_full(fs, ino, inode,
607 sizeof(struct ext2_inode));
608}
609
610errcode_t ext2fs_write_inode_full(ext2_filsys fs, ext2_ino_t ino,
611 struct ext2_inode * inode, int bufsize)
612{
613 unsigned long group, block, block_nr, offset;
614 errcode_t retval = 0;
615 struct ext2_inode_large temp_inode, *w_inode;
616 char *ptr;
617 int clen, i, length;
618
619 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
620
621 /* Check to see if user provided an override function */
622 if (fs->write_inode) {
623 retval = (fs->write_inode)(fs, ino, inode);
624 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
625 return retval;
626 }
627
628 /* Check to see if the inode cache needs to be updated */
629 if (fs->icache) {
630 for (i=0; i < fs->icache->cache_size; i++) {
631 if (fs->icache->cache[i].ino == ino) {
632 fs->icache->cache[i].inode = *inode;
633 break;
634 }
635 }
636 } else {
637 retval = create_icache(fs);
638 if (retval)
639 return retval;
640 }
641
642 if (!(fs->flags & EXT2_FLAG_RW))
643 return EXT2_ET_RO_FILSYS;
644
645 if ((ino == 0) || (ino > fs->super->s_inodes_count))
646 return EXT2_ET_BAD_INODE_NUM;
647
648 length = bufsize;
649 if (length < EXT2_INODE_SIZE(fs->super))
650 length = EXT2_INODE_SIZE(fs->super);
651
652 if (length > (int) sizeof(struct ext2_inode_large)) {
653 w_inode = malloc(length);
654 if (!w_inode)
655 return ENOMEM;
656 } else
657 w_inode = &temp_inode;
658 memset(w_inode, 0, length);
659
660#ifdef EXT2FS_ENABLE_SWAPFS
661 if ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
662 (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE))
663 ext2fs_swap_inode_full(fs, w_inode,
664 (struct ext2_inode_large *) inode,
665 1, bufsize);
666 else
667#endif
668 memcpy(w_inode, inode, bufsize);
669
670 group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super);
671 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) *
672 EXT2_INODE_SIZE(fs->super);
673 block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super);
674 if (!fs->group_desc[(unsigned) group].bg_inode_table) {
675 retval = EXT2_ET_MISSING_INODE_TABLE;
676 goto errout;
677 }
678 block_nr = fs->group_desc[(unsigned) group].bg_inode_table + block;
679
680 offset &= (EXT2_BLOCK_SIZE(fs->super) - 1);
681
682 length = EXT2_INODE_SIZE(fs->super);
683 if (length > bufsize)
684 length = bufsize;
685
686 ptr = (char *) w_inode;
687
688 while (length) {
689 clen = length;
690 if ((offset + length) > fs->blocksize)
691 clen = fs->blocksize - offset;
692
693 if (fs->icache->buffer_blk != block_nr) {
694 retval = io_channel_read_blk(fs->io, block_nr, 1,
695 fs->icache->buffer);
696 if (retval)
697 goto errout;
698 fs->icache->buffer_blk = block_nr;
699 }
700
701
702 memcpy((char *) fs->icache->buffer + (unsigned) offset,
703 ptr, clen);
704
705 retval = io_channel_write_blk(fs->io, block_nr, 1,
706 fs->icache->buffer);
707 if (retval)
708 goto errout;
709
710 offset = 0;
711 ptr += clen;
712 length -= clen;
713 block_nr++;
714 }
715
716 fs->flags |= EXT2_FLAG_CHANGED;
717errout:
718 if (w_inode && w_inode != &temp_inode)
719 free(w_inode);
720 return retval;
721}
722
723errcode_t ext2fs_write_inode(ext2_filsys fs, ext2_ino_t ino,
724 struct ext2_inode *inode)
725{
726 return ext2fs_write_inode_full(fs, ino, inode,
727 sizeof(struct ext2_inode));
728}
729
730/*
731 * This function should be called when writing a new inode. It makes
732 * sure that extra part of large inodes is initialized properly.
733 */
734errcode_t ext2fs_write_new_inode(ext2_filsys fs, ext2_ino_t ino,
735 struct ext2_inode *inode)
736{
737 struct ext2_inode *buf;
738 int size = EXT2_INODE_SIZE(fs->super);
739 struct ext2_inode_large *large_inode;
740 errcode_t retval;
741
742 if (size == sizeof(struct ext2_inode))
743 return ext2fs_write_inode_full(fs, ino, inode,
744 sizeof(struct ext2_inode));
745
746 buf = malloc(size);
747 if (!buf)
748 return ENOMEM;
749
750 memset(buf, 0, size);
751 *buf = *inode;
752
753 large_inode = (struct ext2_inode_large *) buf;
754 large_inode->i_extra_isize = sizeof(struct ext2_inode_large) -
755 EXT2_GOOD_OLD_INODE_SIZE;
756
757 retval = ext2fs_write_inode_full(fs, ino, buf, size);
758 free(buf);
759 return retval;
760}
761
762
763errcode_t ext2fs_get_blocks(ext2_filsys fs, ext2_ino_t ino, blk_t *blocks)
764{
765 struct ext2_inode inode;
766 int i;
767 errcode_t retval;
768
769 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
770
771 if (ino > fs->super->s_inodes_count)
772 return EXT2_ET_BAD_INODE_NUM;
773
774 if (fs->get_blocks) {
775 if (!(*fs->get_blocks)(fs, ino, blocks))
776 return 0;
777 }
778 retval = ext2fs_read_inode(fs, ino, &inode);
779 if (retval)
780 return retval;
781 for (i=0; i < EXT2_N_BLOCKS; i++)
782 blocks[i] = inode.i_block[i];
783 return 0;
784}
785
786errcode_t ext2fs_check_directory(ext2_filsys fs, ext2_ino_t ino)
787{
788 struct ext2_inode inode;
789 errcode_t retval;
790
791 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
792
793 if (ino > fs->super->s_inodes_count)
794 return EXT2_ET_BAD_INODE_NUM;
795
796 if (fs->check_directory) {
797 retval = (fs->check_directory)(fs, ino);
798 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
799 return retval;
800 }
801 retval = ext2fs_read_inode(fs, ino, &inode);
802 if (retval)
803 return retval;
804 if (!LINUX_S_ISDIR(inode.i_mode))
805 return EXT2_ET_NO_DIRECTORY;
806 return 0;
807}
808