3 * esd gmbh <www.esd-electronics.com>
4 * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
6 * based on code from grub2 fs/ext2.c and fs/fshelp.c by
8 * GRUB -- GRand Unified Bootloader
9 * Copyright (C) 2003, 2004 Free Software Foundation, Inc.
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
29 #include <asm/byteorder.h>
31 extern int ext2fs_devread (int sector, int byte_offset, int byte_len,
34 /* Magic value used to identify an ext2 filesystem. */
35 #define EXT2_MAGIC 0xEF53
36 /* Amount of indirect blocks in an inode. */
37 #define INDIRECT_BLOCKS 12
38 /* Maximum lenght of a pathname. */
39 #define EXT2_PATH_MAX 4096
40 /* Maximum nesting of symlinks, used to prevent a loop. */
41 #define EXT2_MAX_SYMLINKCNT 8
43 /* Filetype used in directory entry. */
44 #define FILETYPE_UNKNOWN 0
45 #define FILETYPE_REG 1
46 #define FILETYPE_DIRECTORY 2
47 #define FILETYPE_SYMLINK 7
49 /* Filetype information as used in inodes. */
50 #define FILETYPE_INO_MASK 0170000
51 #define FILETYPE_INO_REG 0100000
52 #define FILETYPE_INO_DIRECTORY 0040000
53 #define FILETYPE_INO_SYMLINK 0120000
55 /* Bits used as offset in sector */
56 #define DISK_SECTOR_BITS 9
58 /* Log2 size of ext2 block in 512 blocks. */
59 #define LOG2_EXT2_BLOCK_SIZE(data) (__le32_to_cpu (data->sblock.log2_block_size) + 1)
61 /* Log2 size of ext2 block in bytes. */
62 #define LOG2_BLOCK_SIZE(data) (__le32_to_cpu (data->sblock.log2_block_size) + 10)
64 /* The size of an ext2 block in bytes. */
65 #define EXT2_BLOCK_SIZE(data) (1 << LOG2_BLOCK_SIZE(data))
67 /* The ext2 superblock. */
69 uint32_t total_inodes;
70 uint32_t total_blocks;
71 uint32_t reserved_blocks;
74 uint32_t first_data_block;
75 uint32_t log2_block_size;
76 uint32_t log2_fragment_size;
77 uint32_t blocks_per_group;
78 uint32_t fragments_per_group;
79 uint32_t inodes_per_group;
83 uint16_t max_mnt_count;
86 uint16_t error_handling;
87 uint16_t minor_revision_level;
89 uint32_t checkinterval;
91 uint32_t revision_level;
92 uint16_t uid_reserved;
93 uint16_t gid_reserved;
96 uint16_t block_group_number;
97 uint32_t feature_compatibility;
98 uint32_t feature_incompat;
99 uint32_t feature_ro_compat;
100 uint32_t unique_id[4];
101 char volume_name[16];
102 char last_mounted_on[64];
103 uint32_t compression_info;
106 /* The ext2 blockgroup. */
107 struct ext2_block_group {
110 uint32_t inode_table_id;
111 uint16_t free_blocks;
112 uint16_t free_inodes;
114 uint32_t reserved[3];
117 /* The ext2 inode. */
128 uint32_t blockcnt; /* Blocks of 512 bytes!! */
133 uint32_t dir_blocks[INDIRECT_BLOCKS];
134 uint32_t indir_block;
135 uint32_t double_indir_block;
136 uint32_t tripple_indir_block;
143 uint32_t fragment_addr;
147 /* The header of an ext2 directory entry. */
156 struct ext2_data *data;
157 struct ext2_inode inode;
162 /* Information about a "mounted" ext2 filesystem. */
164 struct ext2_sblock sblock;
165 struct ext2_inode *inode;
166 struct ext2fs_node diropen;
170 typedef struct ext2fs_node *ext2fs_node_t;
172 struct ext2_data *ext2fs_root = NULL;
173 ext2fs_node_t ext2fs_file = NULL;
175 uint32_t *indir1_block = NULL;
177 int indir1_blkno = -1;
178 uint32_t *indir2_block = NULL;
180 int indir2_blkno = -1;
183 static int ext2fs_blockgroup
184 (struct ext2_data *data, int group, struct ext2_block_group *blkgrp) {
186 printf ("ext2fs read blockgroup\n");
188 return (ext2fs_devread
189 (((__le32_to_cpu (data->sblock.first_data_block) +
190 1) << LOG2_EXT2_BLOCK_SIZE (data)),
191 group * sizeof (struct ext2_block_group),
192 sizeof (struct ext2_block_group), (char *) blkgrp));
196 static int ext2fs_read_inode
197 (struct ext2_data *data, int ino, struct ext2_inode *inode) {
198 struct ext2_block_group blkgrp;
199 struct ext2_sblock *sblock = &data->sblock;
200 int inodes_per_block;
206 /* It is easier to calculate if the first inode is 0. */
209 printf ("ext2fs read inode %d\n", ino);
211 status = ext2fs_blockgroup (data,
213 __le32_to_cpu (sblock->inodes_per_group),
218 inodes_per_block = EXT2_BLOCK_SIZE (data) / 128;
219 blkno = (ino % __le32_to_cpu (sblock->inodes_per_group)) /
221 blkoff = (ino % __le32_to_cpu (sblock->inodes_per_group)) %
224 printf ("ext2fs read inode blkno %d blkoff %d\n", blkno, blkoff);
226 /* Read the inode. */
227 status = ext2fs_devread (((__le32_to_cpu (blkgrp.inode_table_id) +
228 blkno) << LOG2_EXT2_BLOCK_SIZE (data)),
229 sizeof (struct ext2_inode) * blkoff,
230 sizeof (struct ext2_inode), (char *) inode);
238 void ext2fs_free_node (ext2fs_node_t node, ext2fs_node_t currroot) {
239 if ((node != &ext2fs_root->diropen) && (node != currroot)) {
245 static int ext2fs_read_block (ext2fs_node_t node, int fileblock) {
246 struct ext2_data *data = node->data;
247 struct ext2_inode *inode = &node->inode;
249 int blksz = EXT2_BLOCK_SIZE (data);
250 int log2_blksz = LOG2_EXT2_BLOCK_SIZE (data);
254 if (fileblock < INDIRECT_BLOCKS) {
255 blknr = __le32_to_cpu (inode->b.blocks.dir_blocks[fileblock]);
258 else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4))) {
259 if (indir1_block == NULL) {
260 indir1_block = (uint32_t *) malloc (blksz);
261 if (indir1_block == NULL) {
262 printf ("** ext2fs read block (indir 1) malloc failed. **\n");
268 if (blksz != indir1_size) {
273 indir1_block = (uint32_t *) malloc (blksz);
274 if (indir1_block == NULL) {
275 printf ("** ext2fs read block (indir 1) malloc failed. **\n");
280 if ((__le32_to_cpu (inode->b.blocks.indir_block) <<
281 log2_blksz) != indir1_blkno) {
282 status = ext2fs_devread (__le32_to_cpu(inode->b.blocks.indir_block) << log2_blksz,
284 (char *) indir1_block);
286 printf ("** ext2fs read block (indir 1) failed. **\n");
290 __le32_to_cpu (inode->b.blocks.
291 indir_block) << log2_blksz;
293 blknr = __le32_to_cpu (indir1_block
294 [fileblock - INDIRECT_BLOCKS]);
296 /* Double indirect. */
298 (INDIRECT_BLOCKS + (blksz / 4 * (blksz / 4 + 1)))) {
299 unsigned int perblock = blksz / 4;
300 unsigned int rblock = fileblock - (INDIRECT_BLOCKS
303 if (indir1_block == NULL) {
304 indir1_block = (uint32_t *) malloc (blksz);
305 if (indir1_block == NULL) {
306 printf ("** ext2fs read block (indir 2 1) malloc failed. **\n");
312 if (blksz != indir1_size) {
317 indir1_block = (uint32_t *) malloc (blksz);
318 if (indir1_block == NULL) {
319 printf ("** ext2fs read block (indir 2 1) malloc failed. **\n");
324 if ((__le32_to_cpu (inode->b.blocks.double_indir_block) <<
325 log2_blksz) != indir1_blkno) {
326 status = ext2fs_devread (__le32_to_cpu(inode->b.blocks.double_indir_block) << log2_blksz,
328 (char *) indir1_block);
330 printf ("** ext2fs read block (indir 2 1) failed. **\n");
334 __le32_to_cpu (inode->b.blocks.double_indir_block) << log2_blksz;
337 if (indir2_block == NULL) {
338 indir2_block = (uint32_t *) malloc (blksz);
339 if (indir2_block == NULL) {
340 printf ("** ext2fs read block (indir 2 2) malloc failed. **\n");
346 if (blksz != indir2_size) {
351 indir2_block = (uint32_t *) malloc (blksz);
352 if (indir2_block == NULL) {
353 printf ("** ext2fs read block (indir 2 2) malloc failed. **\n");
358 if ((__le32_to_cpu (indir1_block[rblock / perblock]) <<
359 log2_blksz) != indir1_blkno) {
360 status = ext2fs_devread (__le32_to_cpu(indir1_block[rblock / perblock]) << log2_blksz,
362 (char *) indir2_block);
364 printf ("** ext2fs read block (indir 2 2) failed. **\n");
368 __le32_to_cpu (indir1_block[rblock / perblock]) << log2_blksz;
370 blknr = __le32_to_cpu (indir2_block[rblock % perblock]);
372 /* Tripple indirect. */
374 printf ("** ext2fs doesn't support tripple indirect blocks. **\n");
378 printf ("ext2fs_read_block %08x\n", blknr);
385 (ext2fs_node_t node, int pos, unsigned int len, char *buf) {
388 int log2blocksize = LOG2_EXT2_BLOCK_SIZE (node->data);
389 int blocksize = 1 << (log2blocksize + DISK_SECTOR_BITS);
390 unsigned int filesize = __le32_to_cpu(node->inode.size);
392 /* Adjust len so it we can't read past the end of the file. */
393 if (len > filesize) {
396 blockcnt = ((len + pos) + blocksize - 1) / blocksize;
398 for (i = pos / blocksize; i < blockcnt; i++) {
400 int blockoff = pos % blocksize;
401 int blockend = blocksize;
405 blknr = ext2fs_read_block (node, i);
409 blknr = blknr << log2blocksize;
412 if (i == blockcnt - 1) {
413 blockend = (len + pos) % blocksize;
415 /* The last portion is exactly blocksize. */
417 blockend = blocksize;
422 if (i == pos / blocksize) {
423 skipfirst = blockoff;
424 blockend -= skipfirst;
427 /* If the block number is 0 this block is not stored on disk but
428 is zero filled instead. */
432 status = ext2fs_devread (blknr, skipfirst, blockend, buf);
437 memset (buf, 0, blocksize - skipfirst);
439 buf += blocksize - skipfirst;
445 static int ext2fs_iterate_dir (ext2fs_node_t dir, char *name, ext2fs_node_t * fnode, int *ftype)
447 unsigned int fpos = 0;
449 struct ext2fs_node *diro = (struct ext2fs_node *) dir;
453 printf ("Iterate dir %s\n", name);
454 #endif /* of DEBUG */
455 if (!diro->inode_read) {
456 status = ext2fs_read_inode (diro->data, diro->ino,
462 /* Search the file. */
463 while (fpos < __le32_to_cpu (diro->inode.size)) {
464 struct ext2_dirent dirent;
466 status = ext2fs_read_file (diro, fpos,
467 sizeof (struct ext2_dirent),
472 if (dirent.namelen != 0) {
473 char filename[dirent.namelen + 1];
475 int type = FILETYPE_UNKNOWN;
477 status = ext2fs_read_file (diro,
478 fpos + sizeof (struct ext2_dirent),
479 dirent.namelen, filename);
483 fdiro = malloc (sizeof (struct ext2fs_node));
488 fdiro->data = diro->data;
489 fdiro->ino = __le32_to_cpu (dirent.inode);
491 filename[dirent.namelen] = '\0';
493 if (dirent.filetype != FILETYPE_UNKNOWN) {
494 fdiro->inode_read = 0;
496 if (dirent.filetype == FILETYPE_DIRECTORY) {
497 type = FILETYPE_DIRECTORY;
498 } else if (dirent.filetype ==
500 type = FILETYPE_SYMLINK;
501 } else if (dirent.filetype == FILETYPE_REG) {
505 /* The filetype can not be read from the dirent, get it from inode */
507 status = ext2fs_read_inode (diro->data,
508 __le32_to_cpu(dirent.inode),
514 fdiro->inode_read = 1;
516 if ((__le16_to_cpu (fdiro->inode.mode) &
517 FILETYPE_INO_MASK) ==
518 FILETYPE_INO_DIRECTORY) {
519 type = FILETYPE_DIRECTORY;
520 } else if ((__le16_to_cpu (fdiro->inode.mode)
521 & FILETYPE_INO_MASK) ==
522 FILETYPE_INO_SYMLINK) {
523 type = FILETYPE_SYMLINK;
524 } else if ((__le16_to_cpu (fdiro->inode.mode)
525 & FILETYPE_INO_MASK) ==
531 printf ("iterate >%s<\n", filename);
532 #endif /* of DEBUG */
533 if ((name != NULL) && (fnode != NULL)
534 && (ftype != NULL)) {
535 if (strcmp (filename, name) == 0) {
541 if (fdiro->inode_read == 0) {
542 status = ext2fs_read_inode (diro->data,
543 __le32_to_cpu (dirent.inode),
549 fdiro->inode_read = 1;
552 case FILETYPE_DIRECTORY:
555 case FILETYPE_SYMLINK:
566 __le32_to_cpu (fdiro->inode.size),
571 fpos += __le16_to_cpu (dirent.direntlen);
577 static char *ext2fs_read_symlink (ext2fs_node_t node) {
579 struct ext2fs_node *diro = node;
582 if (!diro->inode_read) {
583 status = ext2fs_read_inode (diro->data, diro->ino,
589 symlink = malloc (__le32_to_cpu (diro->inode.size) + 1);
593 /* If the filesize of the symlink is bigger than
594 60 the symlink is stored in a separate block,
595 otherwise it is stored in the inode. */
596 if (__le32_to_cpu (diro->inode.size) <= 60) {
597 strncpy (symlink, diro->inode.b.symlink,
598 __le32_to_cpu (diro->inode.size));
600 status = ext2fs_read_file (diro, 0,
601 __le32_to_cpu (diro->inode.size),
608 symlink[__le32_to_cpu (diro->inode.size)] = '\0';
613 int ext2fs_find_file1
614 (const char *currpath,
615 ext2fs_node_t currroot, ext2fs_node_t * currfound, int *foundtype) {
616 char fpath[strlen (currpath) + 1];
620 int type = FILETYPE_DIRECTORY;
621 ext2fs_node_t currnode = currroot;
622 ext2fs_node_t oldnode = currroot;
624 strncpy (fpath, currpath, strlen (currpath) + 1);
626 /* Remove all leading slashes. */
627 while (*name == '/') {
631 *currfound = currnode;
638 /* Extract the actual part from the pathname. */
639 next = strchr (name, '/');
641 /* Remove all leading slashes. */
642 while (*next == '/') {
647 /* At this point it is expected that the current node is a directory, check if this is true. */
648 if (type != FILETYPE_DIRECTORY) {
649 ext2fs_free_node (currnode, currroot);
655 /* Iterate over the directory. */
656 found = ext2fs_iterate_dir (currnode, name, &currnode, &type);
664 /* Read in the symlink and follow it. */
665 if (type == FILETYPE_SYMLINK) {
668 /* Test if the symlink does not loop. */
669 if (++symlinknest == 8) {
670 ext2fs_free_node (currnode, currroot);
671 ext2fs_free_node (oldnode, currroot);
675 symlink = ext2fs_read_symlink (currnode);
676 ext2fs_free_node (currnode, currroot);
679 ext2fs_free_node (oldnode, currroot);
683 printf ("Got symlink >%s<\n", symlink);
684 #endif /* of DEBUG */
685 /* The symlink is an absolute path, go back to the root inode. */
686 if (symlink[0] == '/') {
687 ext2fs_free_node (oldnode, currroot);
688 oldnode = &ext2fs_root->diropen;
691 /* Lookup the node the symlink points to. */
692 status = ext2fs_find_file1 (symlink, oldnode,
698 ext2fs_free_node (oldnode, currroot);
703 ext2fs_free_node (oldnode, currroot);
705 /* Found the node! */
706 if (!next || *next == '\0') {
707 *currfound = currnode;
719 ext2fs_node_t rootnode, ext2fs_node_t * foundnode, int expecttype) {
721 int foundtype = FILETYPE_DIRECTORY;
729 status = ext2fs_find_file1 (path, rootnode, foundnode, &foundtype);
733 /* Check if the node that was found was of the expected type. */
734 if ((expecttype == FILETYPE_REG) && (foundtype != expecttype)) {
736 } else if ((expecttype == FILETYPE_DIRECTORY)
737 && (foundtype != expecttype)) {
744 int ext2fs_ls (char *dirname) {
745 ext2fs_node_t dirnode;
748 if (ext2fs_root == NULL) {
752 status = ext2fs_find_file (dirname, &ext2fs_root->diropen, &dirnode,
755 printf ("** Can not find directory. **\n");
758 ext2fs_iterate_dir (dirnode, NULL, NULL, NULL);
759 ext2fs_free_node (dirnode, &ext2fs_root->diropen);
764 int ext2fs_open (char *filename) {
765 ext2fs_node_t fdiro = NULL;
769 if (ext2fs_root == NULL) {
773 status = ext2fs_find_file (filename, &ext2fs_root->diropen, &fdiro,
778 if (!fdiro->inode_read) {
779 status = ext2fs_read_inode (fdiro->data, fdiro->ino,
785 len = __le32_to_cpu (fdiro->inode.size);
790 ext2fs_free_node (fdiro, &ext2fs_root->diropen);
795 int ext2fs_close (void
797 if ((ext2fs_file != NULL) && (ext2fs_root != NULL)) {
798 ext2fs_free_node (ext2fs_file, &ext2fs_root->diropen);
801 if (ext2fs_root != NULL) {
805 if (indir1_block != NULL) {
811 if (indir2_block != NULL) {
821 int ext2fs_read (char *buf, unsigned len) {
824 if (ext2fs_root == NULL) {
828 if (ext2fs_file == NULL) {
832 status = ext2fs_read_file (ext2fs_file, 0, len, buf);
837 int ext2fs_mount (unsigned part_length) {
838 struct ext2_data *data;
841 data = malloc (sizeof (struct ext2_data));
845 /* Read the superblock. */
846 status = ext2fs_devread (1 * 2, 0, sizeof (struct ext2_sblock),
847 (char *) &data->sblock);
851 /* Make sure this is an ext2 filesystem. */
852 if (__le16_to_cpu (data->sblock.magic) != EXT2_MAGIC) {
855 data->diropen.data = data;
856 data->diropen.ino = 2;
857 data->diropen.inode_read = 1;
858 data->inode = &data->diropen.inode;
860 status = ext2fs_read_inode (data, 2, data->inode);
870 printf ("Failed to mount ext2 filesystem...\n");