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 <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
ext2fs_read_ind_block(ext2_filsys fs,blk_t blk,void * buf)22 errcode_t ext2fs_read_ind_block(ext2_filsys fs, blk_t blk, void *buf)
23 {
24 errcode_t retval;
25 #ifdef WORDS_BIGENDIAN
26 blk_t *block_nr;
27 int i;
28 int limit = fs->blocksize >> 2;
29 #endif
30
31 if ((fs->flags & EXT2_FLAG_IMAGE_FILE) &&
32 (fs->io != fs->image_io))
33 memset(buf, 0, fs->blocksize);
34 else {
35 retval = io_channel_read_blk(fs->io, blk, 1, buf);
36 if (retval)
37 return retval;
38 }
39 #ifdef WORDS_BIGENDIAN
40 block_nr = (blk_t *) buf;
41 for (i = 0; i < limit; i++, block_nr++)
42 *block_nr = ext2fs_swab32(*block_nr);
43 #endif
44 return 0;
45 }
46
ext2fs_write_ind_block(ext2_filsys fs,blk_t blk,void * buf)47 errcode_t ext2fs_write_ind_block(ext2_filsys fs, blk_t blk, void *buf)
48 {
49 #ifdef WORDS_BIGENDIAN
50 blk_t *block_nr;
51 int i;
52 int limit = fs->blocksize >> 2;
53 #endif
54
55 if (fs->flags & EXT2_FLAG_IMAGE_FILE)
56 return 0;
57
58 #ifdef WORDS_BIGENDIAN
59 block_nr = (blk_t *) buf;
60 for (i = 0; i < limit; i++, block_nr++)
61 *block_nr = ext2fs_swab32(*block_nr);
62 #endif
63 return io_channel_write_blk(fs->io, blk, 1, buf);
64 }
65
66
67