busybox/e2fsprogs/ext2fs/ind_block.c

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/*
* ind_block.c --- indirect block I/O routines
*
* Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
* 2001, 2002, 2003, 2004, 2005 by Theodore Ts'o.
*
* %Begin-Header%
* This file may be redistributed under the terms of the GNU Public
* License.
* %End-Header%
*/
#include <stdio.h>
#include <string.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "ext2_fs.h"
#include "ext2fs.h"
errcode_t ext2fs_read_ind_block(ext2_filsys fs, blk_t blk, void *buf)
{
errcode_t retval;
blk_t *block_nr;
int i;
int limit = fs->blocksize >> 2;
if ((fs->flags & EXT2_FLAG_IMAGE_FILE) &&
(fs->io != fs->image_io))
memset(buf, 0, fs->blocksize);
else {
retval = io_channel_read_blk(fs->io, blk, 1, buf);
if (retval)
return retval;
}
#ifdef EXT2FS_ENABLE_SWAPFS
if (fs->flags & (EXT2_FLAG_SWAP_BYTES | EXT2_FLAG_SWAP_BYTES_READ)) {
block_nr = (blk_t *) buf;
for (i = 0; i < limit; i++, block_nr++)
*block_nr = ext2fs_swab32(*block_nr);
}
#endif
return 0;
}
errcode_t ext2fs_write_ind_block(ext2_filsys fs, blk_t blk, void *buf)
{
blk_t *block_nr;
int i;
int limit = fs->blocksize >> 2;
if (fs->flags & EXT2_FLAG_IMAGE_FILE)
return 0;
#ifdef EXT2FS_ENABLE_SWAPFS
if (fs->flags & (EXT2_FLAG_SWAP_BYTES | EXT2_FLAG_SWAP_BYTES_WRITE)) {
block_nr = (blk_t *) buf;
for (i = 0; i < limit; i++, block_nr++)
*block_nr = ext2fs_swab32(*block_nr);
}
#endif
return io_channel_write_blk(fs->io, blk, 1, buf);
}