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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 Library
9  * General Public License, version 2.
10  * %End-Header%
11  */
12 
13 #include "config.h"
14 #include <stdio.h>
15 #include <string.h>
16 #if HAVE_UNISTD_H
17 #include <unistd.h>
18 #endif
19 
20 #include "ext2_fs.h"
21 #include "ext2fs.h"
22 
ext2fs_read_ind_block(ext2_filsys fs,blk_t blk,void * buf)23 errcode_t ext2fs_read_ind_block(ext2_filsys fs, blk_t blk, void *buf)
24 {
25 	errcode_t	retval;
26 #ifdef WORDS_BIGENDIAN
27 	blk_t		*block_nr;
28 	int		i;
29 	int		limit = fs->blocksize >> 2;
30 #endif
31 
32 	if ((fs->flags & EXT2_FLAG_IMAGE_FILE) &&
33 	    (fs->io != fs->image_io))
34 		memset(buf, 0, fs->blocksize);
35 	else {
36 		retval = io_channel_read_blk(fs->io, blk, 1, buf);
37 		if (retval)
38 			return retval;
39 	}
40 #ifdef WORDS_BIGENDIAN
41 	block_nr = (blk_t *) buf;
42 	for (i = 0; i < limit; i++, block_nr++)
43 		*block_nr = ext2fs_swab32(*block_nr);
44 #endif
45 	return 0;
46 }
47 
ext2fs_write_ind_block(ext2_filsys fs,blk_t blk,void * buf)48 errcode_t ext2fs_write_ind_block(ext2_filsys fs, blk_t blk, void *buf)
49 {
50 #ifdef WORDS_BIGENDIAN
51 	blk_t		*block_nr;
52 	int		i;
53 	int		limit = fs->blocksize >> 2;
54 #endif
55 
56 	if (fs->flags & EXT2_FLAG_IMAGE_FILE)
57 		return 0;
58 
59 #ifdef WORDS_BIGENDIAN
60 	block_nr = (blk_t *) buf;
61 	for (i = 0; i < limit; i++, block_nr++)
62 		*block_nr = ext2fs_swab32(*block_nr);
63 #endif
64 	return io_channel_write_blk(fs->io, blk, 1, buf);
65 }
66 
67 
68