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authorUma Shankar <uma.shankar@samsung.com>2012-05-25 21:21:44 +0530
committerWolfgang Denk <wd@denx.de>2012-08-09 23:47:43 +0200
commita1596438a68921d2c9b1fdec70a720d38c85ca7d (patch)
tree41abe5c16734aae38d1ebd130103bc83d8d5180c /fs/ext4/ext4_common.c
parent4d3c95f5ea7c737a21cd6b9c59435ee693b3f127 (diff)
ext4fs ls load support
Signed-off-by: Uma Shankar <uma.shankar@samsung.com> Signed-off-by: Manjunatha C Achar <a.manjunatha@samsung.com> Signed-off-by: Iqbal Shareef <iqbal.ams@samsung.com> Signed-off-by: Hakgoo Lee <goodguy.lee@samsung.com>
Diffstat (limited to 'fs/ext4/ext4_common.c')
-rw-r--r--fs/ext4/ext4_common.c875
1 files changed, 875 insertions, 0 deletions
diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c
new file mode 100644
index 0000000000..2ddbb50e89
--- /dev/null
+++ b/fs/ext4/ext4_common.c
@@ -0,0 +1,875 @@
+/*
+ * (C) Copyright 2011 - 2012 Samsung Electronics
+ * EXT4 filesystem implementation in Uboot by
+ * Uma Shankar <uma.shankar@samsung.com>
+ * Manjunatha C Achar <a.manjunatha@samsung.com>
+ *
+ * ext4ls and ext4load : Based on ext2 ls load support in Uboot.
+ *
+ * (C) Copyright 2004
+ * esd gmbh <www.esd-electronics.com>
+ * Reinhard Arlt <reinhard.arlt@esd-electronics.com>
+ *
+ * based on code from grub2 fs/ext2.c and fs/fshelp.c by
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2003, 2004 Free Software Foundation, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <common.h>
+#include <ext_common.h>
+#include <ext4fs.h>
+#include <malloc.h>
+#include <stddef.h>
+#include <linux/stat.h>
+#include <linux/time.h>
+#include <asm/byteorder.h>
+#include "ext4_common.h"
+
+struct ext2_data *ext4fs_root;
+struct ext2fs_node *ext4fs_file;
+uint32_t *ext4fs_indir1_block;
+int ext4fs_indir1_size;
+int ext4fs_indir1_blkno = -1;
+uint32_t *ext4fs_indir2_block;
+int ext4fs_indir2_size;
+int ext4fs_indir2_blkno = -1;
+
+uint32_t *ext4fs_indir3_block;
+int ext4fs_indir3_size;
+int ext4fs_indir3_blkno = -1;
+struct ext2_inode *g_parent_inode;
+static int symlinknest;
+
+static struct ext4_extent_header *ext4fs_get_extent_block
+ (struct ext2_data *data, char *buf,
+ struct ext4_extent_header *ext_block,
+ uint32_t fileblock, int log2_blksz)
+{
+ struct ext4_extent_idx *index;
+ unsigned long long block;
+ struct ext_filesystem *fs = get_fs();
+ int i;
+
+ while (1) {
+ index = (struct ext4_extent_idx *)(ext_block + 1);
+
+ if (le32_to_cpu(ext_block->eh_magic) != EXT4_EXT_MAGIC)
+ return 0;
+
+ if (ext_block->eh_depth == 0)
+ return ext_block;
+ i = -1;
+ do {
+ i++;
+ if (i >= le32_to_cpu(ext_block->eh_entries))
+ break;
+ } while (fileblock > le32_to_cpu(index[i].ei_block));
+
+ if (--i < 0)
+ return 0;
+
+ block = le32_to_cpu(index[i].ei_leaf_hi);
+ block = (block << 32) + le32_to_cpu(index[i].ei_leaf_lo);
+
+ if (ext4fs_devread(block << log2_blksz, 0, fs->blksz, buf))
+ ext_block = (struct ext4_extent_header *)buf;
+ else
+ return 0;
+ }
+}
+
+static int ext4fs_blockgroup
+ (struct ext2_data *data, int group, struct ext2_block_group *blkgrp)
+{
+ long int blkno;
+ unsigned int blkoff, desc_per_blk;
+
+ desc_per_blk = EXT2_BLOCK_SIZE(data) / sizeof(struct ext2_block_group);
+
+ blkno = __le32_to_cpu(data->sblock.first_data_block) + 1 +
+ group / desc_per_blk;
+ blkoff = (group % desc_per_blk) * sizeof(struct ext2_block_group);
+
+ debug("ext4fs read %d group descriptor (blkno %ld blkoff %u)\n",
+ group, blkno, blkoff);
+
+ return ext4fs_devread(blkno << LOG2_EXT2_BLOCK_SIZE(data),
+ blkoff, sizeof(struct ext2_block_group),
+ (char *)blkgrp);
+}
+
+int ext4fs_read_inode(struct ext2_data *data, int ino, struct ext2_inode *inode)
+{
+ struct ext2_block_group blkgrp;
+ struct ext2_sblock *sblock = &data->sblock;
+ struct ext_filesystem *fs = get_fs();
+ int inodes_per_block, status;
+ long int blkno;
+ unsigned int blkoff;
+
+ /* It is easier to calculate if the first inode is 0. */
+ ino--;
+ status = ext4fs_blockgroup(data, ino / __le32_to_cpu
+ (sblock->inodes_per_group), &blkgrp);
+ if (status == 0)
+ return 0;
+
+ inodes_per_block = EXT2_BLOCK_SIZE(data) / fs->inodesz;
+ blkno = __le32_to_cpu(blkgrp.inode_table_id) +
+ (ino % __le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block;
+ blkoff = (ino % inodes_per_block) * fs->inodesz;
+ /* Read the inode. */
+ status = ext4fs_devread(blkno << LOG2_EXT2_BLOCK_SIZE(data), blkoff,
+ sizeof(struct ext2_inode), (char *)inode);
+ if (status == 0)
+ return 0;
+
+ return 1;
+}
+
+long int read_allocated_block(struct ext2_inode *inode, int fileblock)
+{
+ long int blknr;
+ int blksz;
+ int log2_blksz;
+ int status;
+ long int rblock;
+ long int perblock_parent;
+ long int perblock_child;
+ unsigned long long start;
+ /* get the blocksize of the filesystem */
+ blksz = EXT2_BLOCK_SIZE(ext4fs_root);
+ log2_blksz = LOG2_EXT2_BLOCK_SIZE(ext4fs_root);
+ if (le32_to_cpu(inode->flags) & EXT4_EXTENTS_FL) {
+ char *buf = zalloc(blksz);
+ if (!buf)
+ return -ENOMEM;
+ struct ext4_extent_header *ext_block;
+ struct ext4_extent *extent;
+ int i = -1;
+ ext_block = ext4fs_get_extent_block(ext4fs_root, buf,
+ (struct ext4_extent_header
+ *)inode->b.
+ blocks.dir_blocks,
+ fileblock, log2_blksz);
+ if (!ext_block) {
+ printf("invalid extent block\n");
+ free(buf);
+ return -EINVAL;
+ }
+
+ extent = (struct ext4_extent *)(ext_block + 1);
+
+ do {
+ i++;
+ if (i >= le32_to_cpu(ext_block->eh_entries))
+ break;
+ } while (fileblock >= le32_to_cpu(extent[i].ee_block));
+ if (--i >= 0) {
+ fileblock -= le32_to_cpu(extent[i].ee_block);
+ if (fileblock >= le32_to_cpu(extent[i].ee_len)) {
+ free(buf);
+ return 0;
+ }
+
+ start = le32_to_cpu(extent[i].ee_start_hi);
+ start = (start << 32) +
+ le32_to_cpu(extent[i].ee_start_lo);
+ free(buf);
+ return fileblock + start;
+ }
+
+ printf("Extent Error\n");
+ free(buf);
+ return -1;
+ }
+
+ /* Direct blocks. */
+ if (fileblock < INDIRECT_BLOCKS)
+ blknr = __le32_to_cpu(inode->b.blocks.dir_blocks[fileblock]);
+
+ /* Indirect. */
+ else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4))) {
+ if (ext4fs_indir1_block == NULL) {
+ ext4fs_indir1_block = zalloc(blksz);
+ if (ext4fs_indir1_block == NULL) {
+ printf("** SI ext2fs read block (indir 1)"
+ "malloc failed. **\n");
+ return -1;
+ }
+ ext4fs_indir1_size = blksz;
+ ext4fs_indir1_blkno = -1;
+ }
+ if (blksz != ext4fs_indir1_size) {
+ free(ext4fs_indir1_block);
+ ext4fs_indir1_block = NULL;
+ ext4fs_indir1_size = 0;
+ ext4fs_indir1_blkno = -1;
+ ext4fs_indir1_block = zalloc(blksz);
+ if (ext4fs_indir1_block == NULL) {
+ printf("** SI ext2fs read block (indir 1):"
+ "malloc failed. **\n");
+ return -1;
+ }
+ ext4fs_indir1_size = blksz;
+ }
+ if ((__le32_to_cpu(inode->b.blocks.indir_block) <<
+ log2_blksz) != ext4fs_indir1_blkno) {
+ status =
+ ext4fs_devread(__le32_to_cpu
+ (inode->b.blocks.
+ indir_block) << log2_blksz, 0,
+ blksz, (char *)ext4fs_indir1_block);
+ if (status == 0) {
+ printf("** SI ext2fs read block (indir 1)"
+ "failed. **\n");
+ return 0;
+ }
+ ext4fs_indir1_blkno =
+ __le32_to_cpu(inode->b.blocks.
+ indir_block) << log2_blksz;
+ }
+ blknr = __le32_to_cpu(ext4fs_indir1_block
+ [fileblock - INDIRECT_BLOCKS]);
+ }
+ /* Double indirect. */
+ else if (fileblock < (INDIRECT_BLOCKS + (blksz / 4 *
+ (blksz / 4 + 1)))) {
+
+ long int perblock = blksz / 4;
+ long int rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4);
+
+ if (ext4fs_indir1_block == NULL) {
+ ext4fs_indir1_block = zalloc(blksz);
+ if (ext4fs_indir1_block == NULL) {
+ printf("** DI ext2fs read block (indir 2 1)"
+ "malloc failed. **\n");
+ return -1;
+ }
+ ext4fs_indir1_size = blksz;
+ ext4fs_indir1_blkno = -1;
+ }
+ if (blksz != ext4fs_indir1_size) {
+ free(ext4fs_indir1_block);
+ ext4fs_indir1_block = NULL;
+ ext4fs_indir1_size = 0;
+ ext4fs_indir1_blkno = -1;
+ ext4fs_indir1_block = zalloc(blksz);
+ if (ext4fs_indir1_block == NULL) {
+ printf("** DI ext2fs read block (indir 2 1)"
+ "malloc failed. **\n");
+ return -1;
+ }
+ ext4fs_indir1_size = blksz;
+ }
+ if ((__le32_to_cpu(inode->b.blocks.double_indir_block) <<
+ log2_blksz) != ext4fs_indir1_blkno) {
+ status =
+ ext4fs_devread(__le32_to_cpu
+ (inode->b.blocks.
+ double_indir_block) << log2_blksz,
+ 0, blksz,
+ (char *)ext4fs_indir1_block);
+ if (status == 0) {
+ printf("** DI ext2fs read block (indir 2 1)"
+ "failed. **\n");
+ return -1;
+ }
+ ext4fs_indir1_blkno =
+ __le32_to_cpu(inode->b.blocks.double_indir_block) <<
+ log2_blksz;
+ }
+
+ if (ext4fs_indir2_block == NULL) {
+ ext4fs_indir2_block = zalloc(blksz);
+ if (ext4fs_indir2_block == NULL) {
+ printf("** DI ext2fs read block (indir 2 2)"
+ "malloc failed. **\n");
+ return -1;
+ }
+ ext4fs_indir2_size = blksz;
+ ext4fs_indir2_blkno = -1;
+ }
+ if (blksz != ext4fs_indir2_size) {
+ free(ext4fs_indir2_block);
+ ext4fs_indir2_block = NULL;
+ ext4fs_indir2_size = 0;
+ ext4fs_indir2_blkno = -1;
+ ext4fs_indir2_block = zalloc(blksz);
+ if (ext4fs_indir2_block == NULL) {
+ printf("** DI ext2fs read block (indir 2 2)"
+ "malloc failed. **\n");
+ return -1;
+ }
+ ext4fs_indir2_size = blksz;
+ }
+ if ((__le32_to_cpu(ext4fs_indir1_block[rblock / perblock]) <<
+ log2_blksz) != ext4fs_indir2_blkno) {
+ status = ext4fs_devread(__le32_to_cpu
+ (ext4fs_indir1_block
+ [rblock /
+ perblock]) << log2_blksz, 0,
+ blksz,
+ (char *)ext4fs_indir2_block);
+ if (status == 0) {
+ printf("** DI ext2fs read block (indir 2 2)"
+ "failed. **\n");
+ return -1;
+ }
+ ext4fs_indir2_blkno =
+ __le32_to_cpu(ext4fs_indir1_block[rblock
+ /
+ perblock]) <<
+ log2_blksz;
+ }
+ blknr = __le32_to_cpu(ext4fs_indir2_block[rblock % perblock]);
+ }
+ /* Tripple indirect. */
+ else {
+ rblock = fileblock - (INDIRECT_BLOCKS + blksz / 4 +
+ (blksz / 4 * blksz / 4));
+ perblock_child = blksz / 4;
+ perblock_parent = ((blksz / 4) * (blksz / 4));
+
+ if (ext4fs_indir1_block == NULL) {
+ ext4fs_indir1_block = zalloc(blksz);
+ if (ext4fs_indir1_block == NULL) {
+ printf("** TI ext2fs read block (indir 2 1)"
+ "malloc failed. **\n");
+ return -1;
+ }
+ ext4fs_indir1_size = blksz;
+ ext4fs_indir1_blkno = -1;
+ }
+ if (blksz != ext4fs_indir1_size) {
+ free(ext4fs_indir1_block);
+ ext4fs_indir1_block = NULL;
+ ext4fs_indir1_size = 0;
+ ext4fs_indir1_blkno = -1;
+ ext4fs_indir1_block = zalloc(blksz);
+ if (ext4fs_indir1_block == NULL) {
+ printf("** TI ext2fs read block (indir 2 1)"
+ "malloc failed. **\n");
+ return -1;
+ }
+ ext4fs_indir1_size = blksz;
+ }
+ if ((__le32_to_cpu(inode->b.blocks.triple_indir_block) <<
+ log2_blksz) != ext4fs_indir1_blkno) {
+ status = ext4fs_devread
+ (__le32_to_cpu(inode->b.blocks.triple_indir_block)
+ << log2_blksz, 0, blksz,
+ (char *)ext4fs_indir1_block);
+ if (status == 0) {
+ printf("** TI ext2fs read block (indir 2 1)"
+ "failed. **\n");
+ return -1;
+ }
+ ext4fs_indir1_blkno =
+ __le32_to_cpu(inode->b.blocks.triple_indir_block) <<
+ log2_blksz;
+ }
+
+ if (ext4fs_indir2_block == NULL) {
+ ext4fs_indir2_block = zalloc(blksz);
+ if (ext4fs_indir2_block == NULL) {
+ printf("** TI ext2fs read block (indir 2 2)"
+ "malloc failed. **\n");
+ return -1;
+ }
+ ext4fs_indir2_size = blksz;
+ ext4fs_indir2_blkno = -1;
+ }
+ if (blksz != ext4fs_indir2_size) {
+ free(ext4fs_indir2_block);
+ ext4fs_indir2_block = NULL;
+ ext4fs_indir2_size = 0;
+ ext4fs_indir2_blkno = -1;
+ ext4fs_indir2_block = zalloc(blksz);
+ if (ext4fs_indir2_block == NULL) {
+ printf("** TI ext2fs read block (indir 2 2)"
+ "malloc failed. **\n");
+ return -1;
+ }
+ ext4fs_indir2_size = blksz;
+ }
+ if ((__le32_to_cpu(ext4fs_indir1_block[rblock /
+ perblock_parent]) <<
+ log2_blksz)
+ != ext4fs_indir2_blkno) {
+ status = ext4fs_devread(__le32_to_cpu
+ (ext4fs_indir1_block
+ [rblock /
+ perblock_parent]) <<
+ log2_blksz, 0, blksz,
+ (char *)ext4fs_indir2_block);
+ if (status == 0) {
+ printf("** TI ext2fs read block (indir 2 2)"
+ "failed. **\n");
+ return -1;
+ }
+ ext4fs_indir2_blkno =
+ __le32_to_cpu(ext4fs_indir1_block[rblock /
+ perblock_parent])
+ << log2_blksz;
+ }
+
+ if (ext4fs_indir3_block == NULL) {
+ ext4fs_indir3_block = zalloc(blksz);
+ if (ext4fs_indir3_block == NULL) {
+ printf("** TI ext2fs read block (indir 2 2)"
+ "malloc failed. **\n");
+ return -1;
+ }
+ ext4fs_indir3_size = blksz;
+ ext4fs_indir3_blkno = -1;
+ }
+ if (blksz != ext4fs_indir3_size) {
+ free(ext4fs_indir3_block);
+ ext4fs_indir3_block = NULL;
+ ext4fs_indir3_size = 0;
+ ext4fs_indir3_blkno = -1;
+ ext4fs_indir3_block = zalloc(blksz);
+ if (ext4fs_indir3_block == NULL) {
+ printf("** TI ext2fs read block (indir 2 2)"
+ "malloc failed. **\n");
+ return -1;
+ }
+ ext4fs_indir3_size = blksz;
+ }
+ if ((__le32_to_cpu(ext4fs_indir2_block[rblock
+ /
+ perblock_child]) <<
+ log2_blksz) != ext4fs_indir3_blkno) {
+ status =
+ ext4fs_devread(__le32_to_cpu
+ (ext4fs_indir2_block
+ [(rblock / perblock_child)
+ % (blksz / 4)]) << log2_blksz, 0,
+ blksz, (char *)ext4fs_indir3_block);
+ if (status == 0) {
+ printf("** TI ext2fs read block (indir 2 2)"
+ "failed. **\n");
+ return -1;
+ }
+ ext4fs_indir3_blkno =
+ __le32_to_cpu(ext4fs_indir2_block[(rblock /
+ perblock_child) %
+ (blksz /
+ 4)]) <<
+ log2_blksz;
+ }
+
+ blknr = __le32_to_cpu(ext4fs_indir3_block
+ [rblock % perblock_child]);
+ }
+ debug("ext4fs_read_block %ld\n", blknr);
+
+ return blknr;
+}
+
+void ext4fs_close(void)
+{
+ if ((ext4fs_file != NULL) && (ext4fs_root != NULL)) {
+ ext4fs_free_node(ext4fs_file, &ext4fs_root->diropen);
+ ext4fs_file = NULL;
+ }
+ if (ext4fs_root != NULL) {
+ free(ext4fs_root);
+ ext4fs_root = NULL;
+ }
+ if (ext4fs_indir1_block != NULL) {
+ free(ext4fs_indir1_block);
+ ext4fs_indir1_block = NULL;
+ ext4fs_indir1_size = 0;
+ ext4fs_indir1_blkno = -1;
+ }
+ if (ext4fs_indir2_block != NULL) {
+ free(ext4fs_indir2_block);
+ ext4fs_indir2_block = NULL;
+ ext4fs_indir2_size = 0;
+ ext4fs_indir2_blkno = -1;
+ }
+ if (ext4fs_indir3_block != NULL) {
+ free(ext4fs_indir3_block);
+ ext4fs_indir3_block = NULL;
+ ext4fs_indir3_size = 0;
+ ext4fs_indir3_blkno = -1;
+ }
+}
+
+int ext4fs_iterate_dir(struct ext2fs_node *dir, char *name,
+ struct ext2fs_node **fnode, int *ftype)
+{
+ unsigned int fpos = 0;
+ int status;
+ struct ext2fs_node *diro = (struct ext2fs_node *) dir;
+
+#ifdef DEBUG
+ if (name != NULL)
+ printf("Iterate dir %s\n", name);
+#endif /* of DEBUG */
+ if (!diro->inode_read) {
+ status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
+ if (status == 0)
+ return 0;
+ }
+ /* Search the file. */
+ while (fpos < __le32_to_cpu(diro->inode.size)) {
+ struct ext2_dirent dirent;
+
+ status = ext4fs_read_file(diro, fpos,
+ sizeof(struct ext2_dirent),
+ (char *) &dirent);
+ if (status < 1)
+ return 0;
+
+ if (dirent.namelen != 0) {
+ char filename[dirent.namelen + 1];
+ struct ext2fs_node *fdiro;
+ int type = FILETYPE_UNKNOWN;
+
+ status = ext4fs_read_file(diro,
+ fpos +
+ sizeof(struct ext2_dirent),
+ dirent.namelen, filename);
+ if (status < 1)
+ return 0;
+
+ fdiro = zalloc(sizeof(struct ext2fs_node));
+ if (!fdiro)
+ return 0;
+
+ fdiro->data = diro->data;
+ fdiro->ino = __le32_to_cpu(dirent.inode);
+
+ filename[dirent.namelen] = '\0';
+
+ if (dirent.filetype != FILETYPE_UNKNOWN) {
+ fdiro->inode_read = 0;
+
+ if (dirent.filetype == FILETYPE_DIRECTORY)
+ type = FILETYPE_DIRECTORY;
+ else if (dirent.filetype == FILETYPE_SYMLINK)
+ type = FILETYPE_SYMLINK;
+ else if (dirent.filetype == FILETYPE_REG)
+ type = FILETYPE_REG;
+ } else {
+ status = ext4fs_read_inode(diro->data,
+ __le32_to_cpu
+ (dirent.inode),
+ &fdiro->inode);
+ if (status == 0) {
+ free(fdiro);
+ return 0;
+ }
+ fdiro->inode_read = 1;
+
+ if ((__le16_to_cpu(fdiro->inode.mode) &
+ FILETYPE_INO_MASK) ==
+ FILETYPE_INO_DIRECTORY) {
+ type = FILETYPE_DIRECTORY;
+ } else if ((__le16_to_cpu(fdiro->inode.mode)
+ & FILETYPE_INO_MASK) ==
+ FILETYPE_INO_SYMLINK) {
+ type = FILETYPE_SYMLINK;
+ } else if ((__le16_to_cpu(fdiro->inode.mode)
+ & FILETYPE_INO_MASK) ==
+ FILETYPE_INO_REG) {
+ type = FILETYPE_REG;
+ }
+ }
+#ifdef DEBUG
+ printf("iterate >%s<\n", filename);
+#endif /* of DEBUG */
+ if ((name != NULL) && (fnode != NULL)
+ && (ftype != NULL)) {
+ if (strcmp(filename, name) == 0) {
+ *ftype = type;
+ *fnode = fdiro;
+ return 1;
+ }
+ } else {
+ if (fdiro->inode_read == 0) {
+ status = ext4fs_read_inode(diro->data,
+ __le32_to_cpu(
+ dirent.inode),
+ &fdiro->inode);
+ if (status == 0) {
+ free(fdiro);
+ return 0;
+ }
+ fdiro->inode_read = 1;
+ }
+ switch (type) {
+ case FILETYPE_DIRECTORY:
+ printf("<DIR> ");
+ break;
+ case FILETYPE_SYMLINK:
+ printf("<SYM> ");
+ break;
+ case FILETYPE_REG:
+ printf(" ");
+ break;
+ default:
+ printf("< ? > ");
+ break;
+ }
+ printf("%10d %s\n",
+ __le32_to_cpu(fdiro->inode.size),
+ filename);
+ }
+ free(fdiro);
+ }
+ fpos += __le16_to_cpu(dirent.direntlen);
+ }
+ return 0;
+}
+
+static char *ext4fs_read_symlink(struct ext2fs_node *node)
+{
+ char *symlink;
+ struct ext2fs_node *diro = node;
+ int status;
+
+ if (!diro->inode_read) {
+ status = ext4fs_read_inode(diro->data, diro->ino, &diro->inode);
+ if (status == 0)
+ return 0;
+ }
+ symlink = zalloc(__le32_to_cpu(diro->inode.size) + 1);
+ if (!symlink)
+ return 0;
+
+ if (__le32_to_cpu(diro->inode.size) <= 60) {
+ strncpy(symlink, diro->inode.b.symlink,
+ __le32_to_cpu(diro->inode.size));
+ } else {
+ status = ext4fs_read_file(diro, 0,
+ __le32_to_cpu(diro->inode.size),
+ symlink);
+ if (status == 0) {
+ free(symlink);
+ return 0;
+ }
+ }
+ symlink[__le32_to_cpu(diro->inode.size)] = '\0';
+ return symlink;
+}
+
+static int ext4fs_find_file1(const char *currpath,
+ struct ext2fs_node *currroot,
+ struct ext2fs_node **currfound, int *foundtype)
+{
+ char fpath[strlen(currpath) + 1];
+ char *name = fpath;
+ char *next;
+ int status;
+ int type = FILETYPE_DIRECTORY;
+ struct ext2fs_node *currnode = currroot;
+ struct ext2fs_node *oldnode = currroot;
+
+ strncpy(fpath, currpath, strlen(currpath) + 1);
+
+ /* Remove all leading slashes. */
+ while (*name == '/')
+ name++;
+
+ if (!*name) {
+ *currfound = currnode;
+ return 1;
+ }
+
+ for (;;) {
+ int found;
+
+ /* Extract the actual part from the pathname. */
+ next = strchr(name, '/');
+ if (next) {
+ /* Remove all leading slashes. */
+ while (*next == '/')
+ *(next++) = '\0';
+ }
+
+ if (type != FILETYPE_DIRECTORY) {
+ ext4fs_free_node(currnode, currroot);
+ return 0;
+ }
+
+ oldnode = currnode;
+
+ /* Iterate over the directory. */
+ found = ext4fs_iterate_dir(currnode, name, &currnode, &type);
+ if (found == 0)
+ return 0;
+
+ if (found == -1)
+ break;
+
+ /* Read in the symlink and follow it. */
+ if (type == FILETYPE_SYMLINK) {
+ char *symlink;
+
+ /* Test if the symlink does not loop. */
+ if (++symlinknest == 8) {
+ ext4fs_free_node(currnode, currroot);
+ ext4fs_free_node(oldnode, currroot);
+ return 0;
+ }
+
+ symlink = ext4fs_read_symlink(currnode);
+ ext4fs_free_node(currnode, currroot);
+
+ if (!symlink) {
+ ext4fs_free_node(oldnode, currroot);
+ return 0;
+ }
+
+ debug("Got symlink >%s<\n", symlink);
+
+ if (symlink[0] == '/') {
+ ext4fs_free_node(oldnode, currroot);
+ oldnode = &ext4fs_root->diropen;
+ }
+
+ /* Lookup the node the symlink points to. */
+ status = ext4fs_find_file1(symlink, oldnode,
+ &currnode, &type);
+
+ free(symlink);
+
+ if (status == 0) {
+ ext4fs_free_node(oldnode, currroot);
+ return 0;
+ }
+ }
+
+ ext4fs_free_node(oldnode, currroot);
+
+ /* Found the node! */
+ if (!next || *next == '\0') {
+ *currfound = currnode;
+ *foundtype = type;
+ return 1;
+ }
+ name = next;
+ }
+ return -1;
+}
+
+int ext4fs_find_file(const char *path, struct ext2fs_node *rootnode,
+ struct ext2fs_node **foundnode, int expecttype)
+{
+ int status;
+ int foundtype = FILETYPE_DIRECTORY;
+
+ symlinknest = 0;
+ if (!path)
+ return 0;
+
+ status = ext4fs_find_file1(path, rootnode, foundnode, &foundtype);
+ if (status == 0)
+ return 0;
+
+ /* Check if the node that was found was of the expected type. */
+ if ((expecttype == FILETYPE_REG) && (foundtype != expecttype))
+ return 0;
+ else if ((expecttype == FILETYPE_DIRECTORY)
+ && (foundtype != expecttype))
+ return 0;
+
+ return 1;
+}
+
+int ext4fs_open(const char *filename)
+{
+ struct ext2fs_node *fdiro = NULL;
+ int status;
+ int len;
+
+ if (ext4fs_root == NULL)
+ return -1;
+
+ ext4fs_file = NULL;
+ status = ext4fs_find_file(filename, &ext4fs_root->diropen, &fdiro,
+ FILETYPE_REG);
+ if (status == 0)
+ goto fail;
+
+ if (!fdiro->inode_read) {
+ status = ext4fs_read_inode(fdiro->data, fdiro->ino,
+ &fdiro->inode);
+ if (status == 0)
+ goto fail;
+ }
+ len = __le32_to_cpu(fdiro->inode.size);
+ ext4fs_file = fdiro;
+
+ return len;
+fail:
+ ext4fs_free_node(fdiro, &ext4fs_root->diropen);
+
+ return -1;
+}
+
+int ext4fs_mount(unsigned part_length)
+{
+ struct ext2_data *data;
+ int status;
+ struct ext_filesystem *fs = get_fs();
+ data = zalloc(sizeof(struct ext2_data));
+ if (!data)
+ return 0;
+
+ /* Read the superblock. */
+ status = ext4fs_devread(1 * 2, 0, sizeof(struct ext2_sblock),
+ (char *)&data->sblock);
+
+ if (status == 0)
+ goto fail;
+
+ /* Make sure this is an ext2 filesystem. */
+ if (__le16_to_cpu(data->sblock.magic) != EXT2_MAGIC)
+ goto fail;
+
+ if (__le32_to_cpu(data->sblock.revision_level == 0))
+ fs->inodesz = 128;
+ else
+ fs->inodesz = __le16_to_cpu(data->sblock.inode_size);
+
+ debug("EXT2 rev %d, inode_size %d\n",
+ __le32_to_cpu(data->sblock.revision_level), fs->inodesz);
+
+ data->diropen.data = data;
+ data->diropen.ino = 2;
+ data->diropen.inode_read = 1;
+ data->inode = &data->diropen.inode;
+
+ status = ext4fs_read_inode(data, 2, data->inode);
+ if (status == 0)
+ goto fail;
+
+ ext4fs_root = data;
+
+ return 1;
+fail:
+ printf("Failed to mount ext2 filesystem...\n");
+ free(data);
+ ext4fs_root = NULL;
+
+ return 0;
+}