diff options
Diffstat (limited to 'fs/ext4/ext4fs.c')
-rw-r--r-- | fs/ext4/ext4fs.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/fs/ext4/ext4fs.c b/fs/ext4/ext4fs.c new file mode 100644 index 0000000000..1b9af80f80 --- /dev/null +++ b/fs/ext4/ext4fs.c @@ -0,0 +1,153 @@ +/* + * (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. + * + * + * 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. + * + */ + +#include <common.h> +#include <malloc.h> +#include <linux/stat.h> +#include <linux/time.h> +#include <asm/byteorder.h> +#include "ext4_common.h" + +void ext4fs_free_node(struct ext2fs_node *node, struct ext2fs_node *currroot) +{ + if ((node != &node->data->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 ret; + struct ext_filesystem *fs = node->data->fs; + + /* 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, i); + if (blknr < 0) + return blknr; + + 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) { + if (previous_block_number != -1) { + if (delayed_next == blknr) { + delayed_extent += blockend; + delayed_next += blockend >> SECTOR_BITS; + } else { /* spill */ + ret = ext4fs_devread(fs, delayed_start, + delayed_skipfirst, + delayed_extent, + delayed_buf); + if (ret) + return ret; + 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 */ + ret = ext4fs_devread(fs, delayed_start, + delayed_skipfirst, + delayed_extent, + delayed_buf); + if (ret) + return ret; + previous_block_number = -1; + } + memset(buf, 0, blocksize - skipfirst); + } + buf += blocksize - skipfirst; + } + if (previous_block_number != -1) { + /* spill */ + ret = ext4fs_devread(fs, delayed_start, + delayed_skipfirst, delayed_extent, + delayed_buf); + if (ret) + return ret; + previous_block_number = -1; + } + + return len; +} |