2 * inode.c --- utility routines to read and write inodes
4 * Copyright (C) 1993, 1994, 1995, 1996, 1997 Theodore Ts'o.
7 * This file may be redistributed under the terms of the GNU Public
24 #include <sys/types.h>
31 struct ext2_struct_inode_scan {
34 ext2_ino_t current_inode;
37 ext2_ino_t inodes_left;
40 blk_t inode_buffer_blocks;
46 errcode_t (*done_group)(ext2_filsys fs,
50 void * done_group_data;
57 * This routine flushes the icache, if it exists.
59 errcode_t ext2fs_flush_icache(ext2_filsys fs)
66 for (i=0; i < fs->icache->cache_size; i++)
67 fs->icache->cache[i].ino = 0;
69 fs->icache->buffer_blk = 0;
73 static errcode_t create_icache(ext2_filsys fs)
79 retval = ext2fs_get_mem(sizeof(struct ext2_inode_cache), &fs->icache);
83 memset(fs->icache, 0, sizeof(struct ext2_inode_cache));
84 retval = ext2fs_get_mem(fs->blocksize, &fs->icache->buffer);
86 ext2fs_free_mem(&fs->icache);
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_mem(sizeof(struct ext2_inode_cache_ent)
94 * fs->icache->cache_size,
97 ext2fs_free_mem(&fs->icache->buffer);
98 ext2fs_free_mem(&fs->icache);
101 ext2fs_flush_icache(fs);
105 errcode_t ext2fs_open_inode_scan(ext2_filsys fs, int buffer_blocks,
106 ext2_inode_scan *ret_scan)
108 ext2_inode_scan scan;
110 errcode_t (*save_get_blocks)(ext2_filsys f, ext2_ino_t ino, blk_t *blocks);
112 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
115 * If fs->badblocks isn't set, then set it --- since the inode
116 * scanning functions require it.
118 if (fs->badblocks == 0) {
120 * Temporarly save fs->get_blocks and set it to zero,
121 * for compatibility with old e2fsck's.
123 save_get_blocks = fs->get_blocks;
125 retval = ext2fs_read_bb_inode(fs, &fs->badblocks);
126 if (retval && fs->badblocks) {
127 ext2fs_badblocks_list_free(fs->badblocks);
130 fs->get_blocks = save_get_blocks;
133 retval = ext2fs_get_mem(sizeof(struct ext2_struct_inode_scan), &scan);
136 memset(scan, 0, sizeof(struct ext2_struct_inode_scan));
138 scan->magic = EXT2_ET_MAGIC_INODE_SCAN;
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_mem((size_t) (scan->inode_buffer_blocks *
151 &scan->inode_buffer);
152 scan->done_group = 0;
153 scan->done_group_data = 0;
154 scan->bad_block_ptr = 0;
156 ext2fs_free_mem(&scan);
159 retval = ext2fs_get_mem(scan->inode_size, &scan->temp_buffer);
161 ext2fs_free_mem(&scan->inode_buffer);
162 ext2fs_free_mem(&scan);
165 if (scan->fs->badblocks && scan->fs->badblocks->num)
166 scan->scan_flags |= EXT2_SF_CHK_BADBLOCKS;
171 void ext2fs_close_inode_scan(ext2_inode_scan scan)
173 if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
176 ext2fs_free_mem(&scan->inode_buffer);
177 scan->inode_buffer = NULL;
178 ext2fs_free_mem(&scan->temp_buffer);
179 scan->temp_buffer = NULL;
180 ext2fs_free_mem(&scan);
184 void ext2fs_set_inode_callback(ext2_inode_scan scan,
185 errcode_t (*done_group)(ext2_filsys fs,
186 ext2_inode_scan scan,
189 void *done_group_data)
191 if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
194 scan->done_group = done_group;
195 scan->done_group_data = done_group_data;
198 int ext2fs_inode_scan_flags(ext2_inode_scan scan, int set_flags,
203 if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
206 old_flags = scan->scan_flags;
207 scan->scan_flags &= ~clear_flags;
208 scan->scan_flags |= set_flags;
213 * This function is called by ext2fs_get_next_inode when it needs to
214 * get ready to read in a new blockgroup.
216 static errcode_t get_next_blockgroup(ext2_inode_scan scan)
218 scan->current_group++;
221 scan->current_block = scan->fs->
222 group_desc[scan->current_group].bg_inode_table;
224 scan->current_inode = scan->current_group *
225 EXT2_INODES_PER_GROUP(scan->fs->super);
227 scan->bytes_left = 0;
228 scan->inodes_left = EXT2_INODES_PER_GROUP(scan->fs->super);
229 scan->blocks_left = scan->fs->inode_blocks_per_group;
233 errcode_t ext2fs_inode_scan_goto_blockgroup(ext2_inode_scan scan,
236 scan->current_group = group - 1;
237 scan->groups_left = scan->fs->group_desc_count - group;
238 return get_next_blockgroup(scan);
242 * This function is called by get_next_blocks() to check for bad
243 * blocks in the inode table.
245 * This function assumes that badblocks_list->list is sorted in
248 static errcode_t check_for_inode_bad_blocks(ext2_inode_scan scan,
251 blk_t blk = scan->current_block;
252 badblocks_list bb = scan->fs->badblocks;
255 * If the inode table is missing, then obviously there are no
262 * If the current block is greater than the bad block listed
263 * in the bad block list, then advance the pointer until this
264 * is no longer the case. If we run out of bad blocks, then
265 * we don't need to do any more checking!
267 while (blk > bb->list[scan->bad_block_ptr]) {
268 if (++scan->bad_block_ptr >= bb->num) {
269 scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
275 * If the current block is equal to the bad block listed in
276 * the bad block list, then handle that one block specially.
277 * (We could try to handle runs of bad blocks, but that
278 * only increases CPU efficiency by a small amount, at the
279 * expense of a huge expense of code complexity, and for an
280 * uncommon case at that.)
282 if (blk == bb->list[scan->bad_block_ptr]) {
283 scan->scan_flags |= EXT2_SF_BAD_INODE_BLK;
285 if (++scan->bad_block_ptr >= bb->num)
286 scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
291 * If there is a bad block in the range that we're about to
292 * read in, adjust the number of blocks to read so that we we
293 * don't read in the bad block. (Then the next block to read
294 * will be the bad block, which is handled in the above case.)
296 if ((blk + *num_blocks) > bb->list[scan->bad_block_ptr])
297 *num_blocks = (int) (bb->list[scan->bad_block_ptr] - blk);
303 * This function is called by ext2fs_get_next_inode when it needs to
304 * read in more blocks from the current blockgroup's inode table.
306 static errcode_t get_next_blocks(ext2_inode_scan scan)
312 * Figure out how many blocks to read; we read at most
313 * inode_buffer_blocks, and perhaps less if there aren't that
314 * many blocks left to read.
316 num_blocks = scan->inode_buffer_blocks;
317 if (num_blocks > scan->blocks_left)
318 num_blocks = scan->blocks_left;
321 * If the past block "read" was a bad block, then mark the
322 * left-over extra bytes as also being bad.
324 if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK) {
325 if (scan->bytes_left)
326 scan->scan_flags |= EXT2_SF_BAD_EXTRA_BYTES;
327 scan->scan_flags &= ~EXT2_SF_BAD_INODE_BLK;
331 * Do inode bad block processing, if necessary.
333 if (scan->scan_flags & EXT2_SF_CHK_BADBLOCKS) {
334 retval = check_for_inode_bad_blocks(scan, &num_blocks);
339 if ((scan->scan_flags & EXT2_SF_BAD_INODE_BLK) ||
340 (scan->current_block == 0)) {
341 memset(scan->inode_buffer, 0,
342 (size_t) num_blocks * scan->fs->blocksize);
344 retval = io_channel_read_blk(scan->fs->io,
349 return EXT2_ET_NEXT_INODE_READ;
351 scan->ptr = scan->inode_buffer;
352 scan->bytes_left = num_blocks * scan->fs->blocksize;
354 scan->blocks_left -= num_blocks;
355 if (scan->current_block)
356 scan->current_block += num_blocks;
362 * Returns 1 if the entire inode_buffer has a non-zero size and
363 * contains all zeros. (Not just deleted inodes, since that means
364 * that part of the inode table was used at one point; we want all
365 * zeros, which means that the inode table is pristine.)
367 static inline int is_empty_scan(ext2_inode_scan scan)
371 if (scan->bytes_left == 0)
374 for (i=0; i < scan->bytes_left; i++)
381 errcode_t ext2fs_get_next_inode_full(ext2_inode_scan scan, ext2_ino_t *ino,
382 struct ext2_inode *inode, int bufsize)
387 EXT2_CHECK_MAGIC(scan, EXT2_ET_MAGIC_INODE_SCAN);
390 * Do we need to start reading a new block group?
392 if (scan->inodes_left <= 0) {
394 if (scan->done_group) {
395 retval = (scan->done_group)
396 (scan->fs, scan, scan->current_group,
397 scan->done_group_data);
401 if (scan->groups_left <= 0) {
405 retval = get_next_blockgroup(scan);
410 * This is done outside the above if statement so that the
411 * check can be done for block group #0.
413 if (scan->current_block == 0) {
414 if (scan->scan_flags & EXT2_SF_SKIP_MISSING_ITABLE) {
415 goto force_new_group;
417 return EXT2_ET_MISSING_INODE_TABLE;
422 * Have we run out of space in the inode buffer? If so, we
423 * need to read in more blocks.
425 if (scan->bytes_left < scan->inode_size) {
426 memcpy(scan->temp_buffer, scan->ptr, scan->bytes_left);
427 extra_bytes = scan->bytes_left;
429 retval = get_next_blocks(scan);
434 * XXX test Need check for used inode somehow.
435 * (Note: this is hard.)
437 if (is_empty_scan(scan))
438 goto force_new_group;
444 memcpy(scan->temp_buffer+extra_bytes, scan->ptr,
445 scan->inode_size - extra_bytes);
446 scan->ptr += scan->inode_size - extra_bytes;
447 scan->bytes_left -= scan->inode_size - extra_bytes;
449 #ifdef EXT2FS_ENABLE_SWAPFS
450 if ((scan->fs->flags & EXT2_FLAG_SWAP_BYTES) ||
451 (scan->fs->flags & EXT2_FLAG_SWAP_BYTES_READ))
452 ext2fs_swap_inode_full(scan->fs,
453 (struct ext2_inode_large *) inode,
454 (struct ext2_inode_large *) scan->temp_buffer,
458 *inode = *((struct ext2_inode *) scan->temp_buffer);
459 if (scan->scan_flags & EXT2_SF_BAD_EXTRA_BYTES)
460 retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE;
461 scan->scan_flags &= ~EXT2_SF_BAD_EXTRA_BYTES;
463 #ifdef EXT2FS_ENABLE_SWAPFS
464 if ((scan->fs->flags & EXT2_FLAG_SWAP_BYTES) ||
465 (scan->fs->flags & EXT2_FLAG_SWAP_BYTES_READ))
466 ext2fs_swap_inode_full(scan->fs,
467 (struct ext2_inode_large *) inode,
468 (struct ext2_inode_large *) scan->ptr,
472 memcpy(inode, scan->ptr, bufsize);
473 scan->ptr += scan->inode_size;
474 scan->bytes_left -= scan->inode_size;
475 if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK)
476 retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE;
480 scan->current_inode++;
481 *ino = scan->current_inode;
485 errcode_t ext2fs_get_next_inode(ext2_inode_scan scan, ext2_ino_t *ino,
486 struct ext2_inode *inode)
488 return ext2fs_get_next_inode_full(scan, ino, inode,
489 sizeof(struct ext2_inode));
493 * Functions to read and write a single inode.
495 errcode_t ext2fs_read_inode_full(ext2_filsys fs, ext2_ino_t ino,
496 struct ext2_inode * inode, int bufsize)
498 unsigned long group, block, block_nr, offset;
501 int clen, i, inodes_per_block, length;
504 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
506 /* Check to see if user has an override function */
507 if (fs->read_inode) {
508 retval = (fs->read_inode)(fs, ino, inode);
509 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
512 /* Create inode cache if not present */
514 retval = create_icache(fs);
518 /* Check to see if it's in the inode cache */
519 if (bufsize == sizeof(struct ext2_inode)) {
520 /* only old good inode can be retrieve from the cache */
521 for (i=0; i < fs->icache->cache_size; i++) {
522 if (fs->icache->cache[i].ino == ino) {
523 *inode = fs->icache->cache[i].inode;
528 if ((ino == 0) || (ino > fs->super->s_inodes_count))
529 return EXT2_ET_BAD_INODE_NUM;
530 if (fs->flags & EXT2_FLAG_IMAGE_FILE) {
531 inodes_per_block = fs->blocksize / EXT2_INODE_SIZE(fs->super);
532 block_nr = fs->image_header->offset_inode / fs->blocksize;
533 block_nr += (ino - 1) / inodes_per_block;
534 offset = ((ino - 1) % inodes_per_block) *
535 EXT2_INODE_SIZE(fs->super);
538 group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super);
539 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) *
540 EXT2_INODE_SIZE(fs->super);
541 block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super);
542 if (!fs->group_desc[(unsigned)group].bg_inode_table)
543 return EXT2_ET_MISSING_INODE_TABLE;
544 block_nr = fs->group_desc[(unsigned)group].bg_inode_table +
548 offset &= (EXT2_BLOCK_SIZE(fs->super) - 1);
550 length = EXT2_INODE_SIZE(fs->super);
551 if (bufsize < length)
554 ptr = (char *) inode;
557 if ((offset + length) > fs->blocksize)
558 clen = fs->blocksize - offset;
560 if (block_nr != fs->icache->buffer_blk) {
561 retval = io_channel_read_blk(io, block_nr, 1,
565 fs->icache->buffer_blk = block_nr;
568 memcpy(ptr, ((char *) fs->icache->buffer) + (unsigned) offset,
577 #ifdef EXT2FS_ENABLE_SWAPFS
578 if ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
579 (fs->flags & EXT2_FLAG_SWAP_BYTES_READ))
580 ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) inode,
581 (struct ext2_inode_large *) inode,
585 /* Update the inode cache */
586 fs->icache->cache_last = (fs->icache->cache_last + 1) %
587 fs->icache->cache_size;
588 fs->icache->cache[fs->icache->cache_last].ino = ino;
589 fs->icache->cache[fs->icache->cache_last].inode = *inode;
594 errcode_t ext2fs_read_inode(ext2_filsys fs, ext2_ino_t ino,
595 struct ext2_inode * inode)
597 return ext2fs_read_inode_full(fs, ino, inode,
598 sizeof(struct ext2_inode));
601 errcode_t ext2fs_write_inode_full(ext2_filsys fs, ext2_ino_t ino,
602 struct ext2_inode * inode, int bufsize)
604 unsigned long group, block, block_nr, offset;
605 errcode_t retval = 0;
606 struct ext2_inode_large temp_inode, *w_inode;
610 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
612 /* Check to see if user provided an override function */
613 if (fs->write_inode) {
614 retval = (fs->write_inode)(fs, ino, inode);
615 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
619 /* Check to see if the inode cache needs to be updated */
621 for (i=0; i < fs->icache->cache_size; i++) {
622 if (fs->icache->cache[i].ino == ino) {
623 fs->icache->cache[i].inode = *inode;
628 retval = create_icache(fs);
633 if (!(fs->flags & EXT2_FLAG_RW))
634 return EXT2_ET_RO_FILSYS;
636 if ((ino == 0) || (ino > fs->super->s_inodes_count))
637 return EXT2_ET_BAD_INODE_NUM;
640 if (length < EXT2_INODE_SIZE(fs->super))
641 length = EXT2_INODE_SIZE(fs->super);
643 if (length > (int) sizeof(struct ext2_inode_large)) {
644 w_inode = xmalloc(length);
646 w_inode = &temp_inode;
647 memset(w_inode, 0, length);
649 #ifdef EXT2FS_ENABLE_SWAPFS
650 if ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
651 (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE))
652 ext2fs_swap_inode_full(fs, w_inode,
653 (struct ext2_inode_large *) inode,
657 memcpy(w_inode, inode, bufsize);
659 group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super);
660 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) *
661 EXT2_INODE_SIZE(fs->super);
662 block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super);
663 if (!fs->group_desc[(unsigned) group].bg_inode_table)
664 return EXT2_ET_MISSING_INODE_TABLE;
665 block_nr = fs->group_desc[(unsigned) group].bg_inode_table + block;
667 offset &= (EXT2_BLOCK_SIZE(fs->super) - 1);
669 length = EXT2_INODE_SIZE(fs->super);
670 if (length > bufsize)
673 ptr = (char *) w_inode;
677 if ((offset + length) > fs->blocksize)
678 clen = fs->blocksize - offset;
680 if (fs->icache->buffer_blk != block_nr) {
681 retval = io_channel_read_blk(fs->io, block_nr, 1,
685 fs->icache->buffer_blk = block_nr;
689 memcpy((char *) fs->icache->buffer + (unsigned) offset,
692 retval = io_channel_write_blk(fs->io, block_nr, 1,
703 fs->flags |= EXT2_FLAG_CHANGED;
705 if (w_inode && w_inode != &temp_inode)
710 errcode_t ext2fs_write_inode(ext2_filsys fs, ext2_ino_t ino,
711 struct ext2_inode *inode)
713 return ext2fs_write_inode_full(fs, ino, inode,
714 sizeof(struct ext2_inode));
718 * This function should be called when writing a new inode. It makes
719 * sure that extra part of large inodes is initialized properly.
721 errcode_t ext2fs_write_new_inode(ext2_filsys fs, ext2_ino_t ino,
722 struct ext2_inode *inode)
724 struct ext2_inode *buf;
725 int size = EXT2_INODE_SIZE(fs->super);
726 struct ext2_inode_large *large_inode;
728 if (size == sizeof(struct ext2_inode))
729 return ext2fs_write_inode_full(fs, ino, inode,
730 sizeof(struct ext2_inode));
734 memset(buf, 0, size);
737 large_inode = (struct ext2_inode_large *) buf;
738 large_inode->i_extra_isize = sizeof(struct ext2_inode_large) -
739 EXT2_GOOD_OLD_INODE_SIZE;
741 return ext2fs_write_inode_full(fs, ino, buf, size);
745 errcode_t ext2fs_get_blocks(ext2_filsys fs, ext2_ino_t ino, blk_t *blocks)
747 struct ext2_inode inode;
751 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
753 if (ino > fs->super->s_inodes_count)
754 return EXT2_ET_BAD_INODE_NUM;
756 if (fs->get_blocks) {
757 if (!(*fs->get_blocks)(fs, ino, blocks))
760 retval = ext2fs_read_inode(fs, ino, &inode);
763 for (i=0; i < EXT2_N_BLOCKS; i++)
764 blocks[i] = inode.i_block[i];
768 errcode_t ext2fs_check_directory(ext2_filsys fs, ext2_ino_t ino)
770 struct ext2_inode inode;
773 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
775 if (ino > fs->super->s_inodes_count)
776 return EXT2_ET_BAD_INODE_NUM;
778 if (fs->check_directory) {
779 retval = (fs->check_directory)(fs, ino);
780 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
783 retval = ext2fs_read_inode(fs, ino, &inode);
786 if (!LINUX_S_ISDIR(inode.i_mode))
787 return EXT2_ET_NO_DIRECTORY;