u-boot/fs/ext4/ext4fs.c

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/*
* (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 and load support in Uboot.
* Ext4 read optimization taken from Open-Moko
* Qi bootloader
*
* (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.
*
* ext4write : Based on generic ext4 protocol.
*
* 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 "ext4_common.h"
int ext4fs_symlinknest;
struct ext_filesystem ext_fs;
struct ext_filesystem *get_fs(void)
{
return &ext_fs;
}
void ext4fs_free_node(struct ext2fs_node *node, struct ext2fs_node *currroot)
{
if ((node != &ext4fs_root->diropen) && (node != currroot))
free(node);
}
/*
* Taken from openmoko-kernel mailing list: By Andy green
* Optimized read file API : collects and defers contiguous sector
* reads into one potentially more efficient larger sequential read action
*/
int ext4fs_read_file(struct ext2fs_node *node, int pos,
unsigned int len, char *buf)
{
int i;
int blockcnt;
int log2blocksize = LOG2_EXT2_BLOCK_SIZE(node->data);
int blocksize = 1 << (log2blocksize + DISK_SECTOR_BITS);
unsigned int filesize = __le32_to_cpu(node->inode.size);
int previous_block_number = -1;
int delayed_start = 0;
int delayed_extent = 0;
int delayed_skipfirst = 0;
int delayed_next = 0;
char *delayed_buf = NULL;
short status;
/* Adjust len so it we can't read past the end of the file. */
if (len > filesize)
len = filesize;
blockcnt = ((len + pos) + blocksize - 1) / blocksize;
for (i = pos / blocksize; i < blockcnt; i++) {
int blknr;
int blockoff = pos % blocksize;
int blockend = blocksize;
int skipfirst = 0;
blknr = read_allocated_block(&(node->inode), i);
if (blknr < 0)
return -1;
blknr = blknr << log2blocksize;
/* Last block. */
if (i == blockcnt - 1) {
blockend = (len + pos) % blocksize;
/* The last portion is exactly blocksize. */
if (!blockend)
blockend = blocksize;
}
/* First block. */
if (i == pos / blocksize) {
skipfirst = blockoff;
blockend -= skipfirst;
}
if (blknr) {
int status;
if (previous_block_number != -1) {
if (delayed_next == blknr) {
delayed_extent += blockend;
delayed_next += blockend >> SECTOR_BITS;
} else { /* spill */
status = ext4fs_devread(delayed_start,
delayed_skipfirst,
delayed_extent,
delayed_buf);
if (status == 0)
return -1;
previous_block_number = blknr;
delayed_start = blknr;
delayed_extent = blockend;
delayed_skipfirst = skipfirst;
delayed_buf = buf;
delayed_next = blknr +
(blockend >> SECTOR_BITS);
}
} else {
previous_block_number = blknr;
delayed_start = blknr;
delayed_extent = blockend;
delayed_skipfirst = skipfirst;
delayed_buf = buf;
delayed_next = blknr +
(blockend >> SECTOR_BITS);
}
} else {
if (previous_block_number != -1) {
/* spill */
status = ext4fs_devread(delayed_start,
delayed_skipfirst,
delayed_extent,
delayed_buf);
if (status == 0)
return -1;
previous_block_number = -1;
}
memset(buf, 0, blocksize - skipfirst);
}
buf += blocksize - skipfirst;
}
if (previous_block_number != -1) {
/* spill */
status = ext4fs_devread(delayed_start,
delayed_skipfirst, delayed_extent,
delayed_buf);
if (status == 0)
return -1;
previous_block_number = -1;
}
return len;
}
int ext4fs_ls(const char *dirname)
{
struct ext2fs_node *dirnode;
int status;
if (dirname == NULL)
return 0;
status = ext4fs_find_file(dirname, &ext4fs_root->diropen, &dirnode,
FILETYPE_DIRECTORY);
if (status != 1) {
printf("** Can not find directory. **\n");
return 1;
}
ext4fs_iterate_dir(dirnode, NULL, NULL, NULL);
ext4fs_free_node(dirnode, &ext4fs_root->diropen);
return 0;
}
int ext4fs_read(char *buf, unsigned len)
{
if (ext4fs_root == NULL || ext4fs_file == NULL)
return 0;
return ext4fs_read_file(ext4fs_file, 0, len, buf);
}