1 /* vi: set sw=4 ts=4: */
3 * inode.c --- utility routines to read and write inodes
5 * Copyright (C) 1993, 1994, 1995, 1996, 1997 Theodore Ts'o.
8 * This file may be redistributed under the terms of the GNU Public
25 #include <sys/types.h>
32 struct ext2_struct_inode_scan {
35 ext2_ino_t current_inode;
38 ext2_ino_t inodes_left;
41 blk_t inode_buffer_blocks;
47 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);
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,
188 void *done_group_data)
190 if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
193 scan->done_group = done_group;
194 scan->done_group_data = done_group_data;
197 int ext2fs_inode_scan_flags(ext2_inode_scan scan, int set_flags,
202 if (!scan || (scan->magic != EXT2_ET_MAGIC_INODE_SCAN))
205 old_flags = scan->scan_flags;
206 scan->scan_flags &= ~clear_flags;
207 scan->scan_flags |= set_flags;
212 * This function is called by ext2fs_get_next_inode when it needs to
213 * get ready to read in a new blockgroup.
215 static errcode_t get_next_blockgroup(ext2_inode_scan scan)
217 scan->current_group++;
220 scan->current_block = scan->fs->
221 group_desc[scan->current_group].bg_inode_table;
223 scan->current_inode = scan->current_group *
224 EXT2_INODES_PER_GROUP(scan->fs->super);
226 scan->bytes_left = 0;
227 scan->inodes_left = EXT2_INODES_PER_GROUP(scan->fs->super);
228 scan->blocks_left = scan->fs->inode_blocks_per_group;
232 errcode_t ext2fs_inode_scan_goto_blockgroup(ext2_inode_scan scan,
235 scan->current_group = group - 1;
236 scan->groups_left = scan->fs->group_desc_count - group;
237 return get_next_blockgroup(scan);
241 * This function is called by get_next_blocks() to check for bad
242 * blocks in the inode table.
244 * This function assumes that badblocks_list->list is sorted in
247 static errcode_t check_for_inode_bad_blocks(ext2_inode_scan scan,
250 blk_t blk = scan->current_block;
251 badblocks_list bb = scan->fs->badblocks;
254 * If the inode table is missing, then obviously there are no
261 * If the current block is greater than the bad block listed
262 * in the bad block list, then advance the pointer until this
263 * is no longer the case. If we run out of bad blocks, then
264 * we don't need to do any more checking!
266 while (blk > bb->list[scan->bad_block_ptr]) {
267 if (++scan->bad_block_ptr >= bb->num) {
268 scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
274 * If the current block is equal to the bad block listed in
275 * the bad block list, then handle that one block specially.
276 * (We could try to handle runs of bad blocks, but that
277 * only increases CPU efficiency by a small amount, at the
278 * expense of a huge expense of code complexity, and for an
279 * uncommon case at that.)
281 if (blk == bb->list[scan->bad_block_ptr]) {
282 scan->scan_flags |= EXT2_SF_BAD_INODE_BLK;
284 if (++scan->bad_block_ptr >= bb->num)
285 scan->scan_flags &= ~EXT2_SF_CHK_BADBLOCKS;
290 * If there is a bad block in the range that we're about to
291 * read in, adjust the number of blocks to read so that we we
292 * don't read in the bad block. (Then the next block to read
293 * will be the bad block, which is handled in the above case.)
295 if ((blk + *num_blocks) > bb->list[scan->bad_block_ptr])
296 *num_blocks = (int) (bb->list[scan->bad_block_ptr] - blk);
302 * This function is called by ext2fs_get_next_inode when it needs to
303 * read in more blocks from the current blockgroup's inode table.
305 static errcode_t get_next_blocks(ext2_inode_scan scan)
311 * Figure out how many blocks to read; we read at most
312 * inode_buffer_blocks, and perhaps less if there aren't that
313 * many blocks left to read.
315 num_blocks = scan->inode_buffer_blocks;
316 if (num_blocks > scan->blocks_left)
317 num_blocks = scan->blocks_left;
320 * If the past block "read" was a bad block, then mark the
321 * left-over extra bytes as also being bad.
323 if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK) {
324 if (scan->bytes_left)
325 scan->scan_flags |= EXT2_SF_BAD_EXTRA_BYTES;
326 scan->scan_flags &= ~EXT2_SF_BAD_INODE_BLK;
330 * Do inode bad block processing, if necessary.
332 if (scan->scan_flags & EXT2_SF_CHK_BADBLOCKS) {
333 retval = check_for_inode_bad_blocks(scan, &num_blocks);
338 if ((scan->scan_flags & EXT2_SF_BAD_INODE_BLK) ||
339 (scan->current_block == 0)) {
340 memset(scan->inode_buffer, 0,
341 (size_t) num_blocks * scan->fs->blocksize);
343 retval = io_channel_read_blk(scan->fs->io,
348 return EXT2_ET_NEXT_INODE_READ;
350 scan->ptr = scan->inode_buffer;
351 scan->bytes_left = num_blocks * scan->fs->blocksize;
353 scan->blocks_left -= num_blocks;
354 if (scan->current_block)
355 scan->current_block += num_blocks;
359 errcode_t ext2fs_get_next_inode_full(ext2_inode_scan scan, ext2_ino_t *ino,
360 struct ext2_inode *inode, int bufsize)
365 EXT2_CHECK_MAGIC(scan, EXT2_ET_MAGIC_INODE_SCAN);
368 * Do we need to start reading a new block group?
370 if (scan->inodes_left <= 0) {
372 if (scan->done_group) {
373 retval = (scan->done_group)
374 (scan->fs, scan->current_group,
375 scan->done_group_data);
379 if (scan->groups_left <= 0) {
383 retval = get_next_blockgroup(scan);
388 * This is done outside the above if statement so that the
389 * check can be done for block group #0.
391 if (scan->current_block == 0) {
392 if (scan->scan_flags & EXT2_SF_SKIP_MISSING_ITABLE) {
393 goto force_new_group;
395 return EXT2_ET_MISSING_INODE_TABLE;
400 * Have we run out of space in the inode buffer? If so, we
401 * need to read in more blocks.
403 if (scan->bytes_left < scan->inode_size) {
404 memcpy(scan->temp_buffer, scan->ptr, scan->bytes_left);
405 extra_bytes = scan->bytes_left;
407 retval = get_next_blocks(scan);
412 * XXX test Need check for used inode somehow.
413 * (Note: this is hard.)
415 if (is_empty_scan(scan))
416 goto force_new_group;
422 memcpy(scan->temp_buffer+extra_bytes, scan->ptr,
423 scan->inode_size - extra_bytes);
424 scan->ptr += scan->inode_size - extra_bytes;
425 scan->bytes_left -= scan->inode_size - extra_bytes;
428 if ((scan->fs->flags & EXT2_FLAG_SWAP_BYTES) ||
429 (scan->fs->flags & EXT2_FLAG_SWAP_BYTES_READ))
430 ext2fs_swap_inode_full(scan->fs,
431 (struct ext2_inode_large *) inode,
432 (struct ext2_inode_large *) scan->temp_buffer,
436 *inode = *((struct ext2_inode *) scan->temp_buffer);
437 if (scan->scan_flags & EXT2_SF_BAD_EXTRA_BYTES)
438 retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE;
439 scan->scan_flags &= ~EXT2_SF_BAD_EXTRA_BYTES;
442 if ((scan->fs->flags & EXT2_FLAG_SWAP_BYTES) ||
443 (scan->fs->flags & EXT2_FLAG_SWAP_BYTES_READ))
444 ext2fs_swap_inode_full(scan->fs,
445 (struct ext2_inode_large *) inode,
446 (struct ext2_inode_large *) scan->ptr,
450 memcpy(inode, scan->ptr, bufsize);
451 scan->ptr += scan->inode_size;
452 scan->bytes_left -= scan->inode_size;
453 if (scan->scan_flags & EXT2_SF_BAD_INODE_BLK)
454 retval = EXT2_ET_BAD_BLOCK_IN_INODE_TABLE;
458 scan->current_inode++;
459 *ino = scan->current_inode;
463 errcode_t ext2fs_get_next_inode(ext2_inode_scan scan, ext2_ino_t *ino,
464 struct ext2_inode *inode)
466 return ext2fs_get_next_inode_full(scan, ino, inode,
467 sizeof(struct ext2_inode));
471 * Functions to read and write a single inode.
473 errcode_t ext2fs_read_inode_full(ext2_filsys fs, ext2_ino_t ino,
474 struct ext2_inode * inode, int bufsize)
476 unsigned long group, block, block_nr, offset;
479 int clen, i, inodes_per_block, length;
482 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
484 /* Check to see if user has an override function */
485 if (fs->read_inode) {
486 retval = (fs->read_inode)(fs, ino, inode);
487 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
490 /* Create inode cache if not present */
492 retval = create_icache(fs);
496 /* Check to see if it's in the inode cache */
497 if (bufsize == sizeof(struct ext2_inode)) {
498 /* only old good inode can be retrieve from the cache */
499 for (i=0; i < fs->icache->cache_size; i++) {
500 if (fs->icache->cache[i].ino == ino) {
501 *inode = fs->icache->cache[i].inode;
506 if ((ino == 0) || (ino > fs->super->s_inodes_count))
507 return EXT2_ET_BAD_INODE_NUM;
508 if (fs->flags & EXT2_FLAG_IMAGE_FILE) {
509 inodes_per_block = fs->blocksize / EXT2_INODE_SIZE(fs->super);
510 block_nr = fs->image_header->offset_inode / fs->blocksize;
511 block_nr += (ino - 1) / inodes_per_block;
512 offset = ((ino - 1) % inodes_per_block) *
513 EXT2_INODE_SIZE(fs->super);
516 group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super);
517 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) *
518 EXT2_INODE_SIZE(fs->super);
519 block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super);
520 if (!fs->group_desc[(unsigned)group].bg_inode_table)
521 return EXT2_ET_MISSING_INODE_TABLE;
522 block_nr = fs->group_desc[(unsigned)group].bg_inode_table +
526 offset &= (EXT2_BLOCK_SIZE(fs->super) - 1);
528 length = EXT2_INODE_SIZE(fs->super);
529 if (bufsize < length)
532 ptr = (char *) inode;
535 if ((offset + length) > fs->blocksize)
536 clen = fs->blocksize - offset;
538 if (block_nr != fs->icache->buffer_blk) {
539 retval = io_channel_read_blk(io, block_nr, 1,
543 fs->icache->buffer_blk = block_nr;
546 memcpy(ptr, ((char *) fs->icache->buffer) + (unsigned) offset,
556 if ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
557 (fs->flags & EXT2_FLAG_SWAP_BYTES_READ))
558 ext2fs_swap_inode_full(fs, (struct ext2_inode_large *) inode,
559 (struct ext2_inode_large *) inode,
563 /* Update the inode cache */
564 fs->icache->cache_last = (fs->icache->cache_last + 1) %
565 fs->icache->cache_size;
566 fs->icache->cache[fs->icache->cache_last].ino = ino;
567 fs->icache->cache[fs->icache->cache_last].inode = *inode;
572 errcode_t ext2fs_read_inode(ext2_filsys fs, ext2_ino_t ino,
573 struct ext2_inode * inode)
575 return ext2fs_read_inode_full(fs, ino, inode,
576 sizeof(struct ext2_inode));
579 errcode_t ext2fs_write_inode_full(ext2_filsys fs, ext2_ino_t ino,
580 struct ext2_inode * inode, int bufsize)
582 unsigned long group, block, block_nr, offset;
583 errcode_t retval = 0;
584 struct ext2_inode_large temp_inode, *w_inode;
588 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
590 /* Check to see if user provided an override function */
591 if (fs->write_inode) {
592 retval = (fs->write_inode)(fs, ino, inode);
593 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
597 /* Check to see if the inode cache needs to be updated */
599 for (i=0; i < fs->icache->cache_size; i++) {
600 if (fs->icache->cache[i].ino == ino) {
601 fs->icache->cache[i].inode = *inode;
606 retval = create_icache(fs);
611 if (!(fs->flags & EXT2_FLAG_RW))
612 return EXT2_ET_RO_FILSYS;
614 if ((ino == 0) || (ino > fs->super->s_inodes_count))
615 return EXT2_ET_BAD_INODE_NUM;
618 if (length < EXT2_INODE_SIZE(fs->super))
619 length = EXT2_INODE_SIZE(fs->super);
621 if (length > (int) sizeof(struct ext2_inode_large)) {
622 w_inode = xmalloc(length);
624 w_inode = &temp_inode;
625 memset(w_inode, 0, length);
628 if ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
629 (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE))
630 ext2fs_swap_inode_full(fs, w_inode,
631 (struct ext2_inode_large *) inode,
635 memcpy(w_inode, inode, bufsize);
637 group = (ino - 1) / EXT2_INODES_PER_GROUP(fs->super);
638 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(fs->super)) *
639 EXT2_INODE_SIZE(fs->super);
640 block = offset >> EXT2_BLOCK_SIZE_BITS(fs->super);
641 if (!fs->group_desc[(unsigned) group].bg_inode_table)
642 return EXT2_ET_MISSING_INODE_TABLE;
643 block_nr = fs->group_desc[(unsigned) group].bg_inode_table + block;
645 offset &= (EXT2_BLOCK_SIZE(fs->super) - 1);
647 length = EXT2_INODE_SIZE(fs->super);
648 if (length > bufsize)
651 ptr = (char *) w_inode;
655 if ((offset + length) > fs->blocksize)
656 clen = fs->blocksize - offset;
658 if (fs->icache->buffer_blk != block_nr) {
659 retval = io_channel_read_blk(fs->io, block_nr, 1,
663 fs->icache->buffer_blk = block_nr;
667 memcpy((char *) fs->icache->buffer + (unsigned) offset,
670 retval = io_channel_write_blk(fs->io, block_nr, 1,
681 fs->flags |= EXT2_FLAG_CHANGED;
683 if (w_inode && w_inode != &temp_inode)
688 errcode_t ext2fs_write_inode(ext2_filsys fs, ext2_ino_t ino,
689 struct ext2_inode *inode)
691 return ext2fs_write_inode_full(fs, ino, inode,
692 sizeof(struct ext2_inode));
696 * This function should be called when writing a new inode. It makes
697 * sure that extra part of large inodes is initialized properly.
699 errcode_t ext2fs_write_new_inode(ext2_filsys fs, ext2_ino_t ino,
700 struct ext2_inode *inode)
702 struct ext2_inode *buf;
703 int size = EXT2_INODE_SIZE(fs->super);
704 struct ext2_inode_large *large_inode;
706 if (size == sizeof(struct ext2_inode))
707 return ext2fs_write_inode_full(fs, ino, inode,
708 sizeof(struct ext2_inode));
712 memset(buf, 0, size);
715 large_inode = (struct ext2_inode_large *) buf;
716 large_inode->i_extra_isize = sizeof(struct ext2_inode_large) -
717 EXT2_GOOD_OLD_INODE_SIZE;
719 return ext2fs_write_inode_full(fs, ino, buf, size);
723 errcode_t ext2fs_get_blocks(ext2_filsys fs, ext2_ino_t ino, blk_t *blocks)
725 struct ext2_inode inode;
729 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
731 if (ino > fs->super->s_inodes_count)
732 return EXT2_ET_BAD_INODE_NUM;
734 if (fs->get_blocks) {
735 if (!(*fs->get_blocks)(fs, ino, blocks))
738 retval = ext2fs_read_inode(fs, ino, &inode);
741 for (i=0; i < EXT2_N_BLOCKS; i++)
742 blocks[i] = inode.i_block[i];
746 errcode_t ext2fs_check_directory(ext2_filsys fs, ext2_ino_t ino)
748 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->check_directory) {
757 retval = (fs->check_directory)(fs, ino);
758 if (retval != EXT2_ET_CALLBACK_NOTHANDLED)
761 retval = ext2fs_read_inode(fs, ino, &inode);
764 if (!LINUX_S_ISDIR(inode.i_mode))
765 return EXT2_ET_NO_DIRECTORY;