ind_block.c revision dc8ce3463791366ac844d3f0436709511fa09c49 
1/*
2 * ind_block.c --- indirect block I/O routines
3 *
4 * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
5 * 	2001, 2002, 2003, 2004, 2005 by  Theodore Ts'o.
6 *
7 * %Begin-Header%
8 * This file may be redistributed under the terms of the GNU Public
9 * License.
10 * %End-Header%
11 */
12
13#include <stdio.h>
14#include <string.h>
15#if HAVE_UNISTD_H
16#include <unistd.h>
17#endif
18
19#include "ext2_fs.h"
20#include "ext2fs.h"
21
22errcode_t ext2fs_read_ind_block(ext2_filsys fs, blk_t blk, void *buf)
23{
24	errcode_t	retval;
25	blk_t		*block_nr;
26	int		i;
27	int		limit = fs->blocksize >> 2;
28
29	if ((fs->flags & EXT2_FLAG_IMAGE_FILE) &&
30	    (fs->io != fs->image_io))
31		memset(buf, 0, fs->blocksize);
32	else {
33		retval = io_channel_read_blk(fs->io, blk, 1, buf);
34		if (retval)
35			retval;
36	}
37#ifdef EXT2FS_ENABLE_SWAPFS
38	if (fs->flags & (EXT2_FLAG_SWAP_BYTES | EXT2_FLAG_SWAP_BYTES_READ)) {
39		block_nr = (blk_t *) buf;
40		for (i = 0; i < limit; i++, block_nr++)
41			*block_nr = ext2fs_swab32(*block_nr);
42	}
43#endif
44	return 0;
45}
46
47errcode_t ext2fs_write_ind_block(ext2_filsys fs, blk_t blk, void *buf)
48{
49	blk_t		*block_nr;
50	int		i;
51	int		limit = fs->blocksize >> 2;
52
53	if (fs->flags & EXT2_FLAG_IMAGE_FILE)
54		return 0;
55
56#ifdef EXT2FS_ENABLE_SWAPFS
57	if (fs->flags & (EXT2_FLAG_SWAP_BYTES | EXT2_FLAG_SWAP_BYTES_WRITE)) {
58		block_nr = (blk_t *) buf;
59		for (i = 0; i < limit; i++, block_nr++)
60			*block_nr = ext2fs_swab32(*block_nr);
61	}
62#endif
63	return io_channel_write_blk(fs->io, blk, 1, buf);
64}
65
66
67