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[sven/exfat-utils.git] / mkfs / cbm.c
1 /*
2         cbm.c (09.11.10)
3         Clusters Bitmap creation code.
4
5         Free exFAT implementation.
6         Copyright (C) 2011-2015  Andrew Nayenko
7
8         This program is free software; you can redistribute it and/or modify
9         it under the terms of the GNU General Public License as published by
10         the Free Software Foundation, either version 2 of the License, or
11         (at your option) any later version.
12
13         This program is distributed in the hope that it will be useful,
14         but WITHOUT ANY WARRANTY; without even the implied warranty of
15         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16         GNU General Public License for more details.
17
18         You should have received a copy of the GNU General Public License along
19         with this program; if not, write to the Free Software Foundation, Inc.,
20         51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
21 */
22
23 #include "cbm.h"
24 #include "fat.h"
25 #include "uct.h"
26 #include "rootdir.h"
27 #include <limits.h>
28 #include <string.h>
29
30 static off_t cbm_alignment(void)
31 {
32         return get_cluster_size();
33 }
34
35 static off_t cbm_size(void)
36 {
37         return DIV_ROUND_UP(
38                         (get_volume_size() - get_position(&cbm)) / get_cluster_size(),
39                         CHAR_BIT);
40 }
41
42 static int cbm_write(struct exfat_dev* dev)
43 {
44         uint32_t allocated_clusters =
45                         DIV_ROUND_UP(cbm.get_size(), get_cluster_size()) +
46                         DIV_ROUND_UP(uct.get_size(), get_cluster_size()) +
47                         DIV_ROUND_UP(rootdir.get_size(), get_cluster_size());
48         size_t bitmap_size = ROUND_UP(allocated_clusters, CHAR_BIT);
49         bitmap_t* bitmap = malloc(BMAP_SIZE(bitmap_size));
50         size_t i;
51
52         if (bitmap == NULL)
53         {
54                 exfat_error("failed to allocate bitmap of %zu bytes",
55                                 BMAP_SIZE(bitmap_size));
56                 return 1;
57         }
58         memset(bitmap, 0, BMAP_SIZE(bitmap_size));
59
60         for (i = 0; i < bitmap_size; i++)
61                 if (i < allocated_clusters)
62                         BMAP_SET(bitmap, i);
63         if (exfat_write(dev, bitmap, bitmap_size / CHAR_BIT) < 0)
64         {
65                 free(bitmap);
66                 exfat_error("failed to write bitmap of %zu bytes",
67                                 bitmap_size / CHAR_BIT);
68                 return 1;
69         }
70         free(bitmap);
71         return 0;
72 }
73
74 const struct fs_object cbm =
75 {
76         .get_alignment = cbm_alignment,
77         .get_size = cbm_size,
78         .write = cbm_write,
79 };