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