blob: 0afba069d5676e03562a3b8ee2d26ef95d00b166 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * QNX4 file system, Linux implementation.
3 *
4 * Version : 0.2.1
5 *
6 * Using parts of the xiafs filesystem.
7 *
8 * History :
9 *
10 * 28-05-1998 by Richard Frowijn : first release.
11 * 20-06-1998 by Frank Denis : basic optimisations.
12 * 25-06-1998 by Frank Denis : qnx4_is_free, qnx4_set_bitmap, qnx4_bmap .
13 * 28-06-1998 by Frank Denis : qnx4_free_inode (to be fixed) .
14 */
15
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/buffer_head.h>
17#include <linux/bitops.h>
Al Viro964f5362009-06-07 09:47:13 -040018#include "qnx4.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070019
Adrian Bunk7a1119b2006-01-03 13:21:37 +010020#if 0
Linus Torvalds1da177e2005-04-16 15:20:36 -070021int qnx4_new_block(struct super_block *sb)
22{
23 return 0;
24}
Adrian Bunk7a1119b2006-01-03 13:21:37 +010025#endif /* 0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
27static void count_bits(register const char *bmPart, register int size,
28 int *const tf)
29{
30 char b;
31 int tot = *tf;
32
33 if (size > QNX4_BLOCK_SIZE) {
34 size = QNX4_BLOCK_SIZE;
35 }
36 do {
37 b = *bmPart++;
38 if ((b & 1) == 0)
39 tot++;
40 if ((b & 2) == 0)
41 tot++;
42 if ((b & 4) == 0)
43 tot++;
44 if ((b & 8) == 0)
45 tot++;
46 if ((b & 16) == 0)
47 tot++;
48 if ((b & 32) == 0)
49 tot++;
50 if ((b & 64) == 0)
51 tot++;
52 if ((b & 128) == 0)
53 tot++;
54 size--;
55 } while (size != 0);
56 *tf = tot;
57}
58
59unsigned long qnx4_count_free_blocks(struct super_block *sb)
60{
61 int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1;
62 int total = 0;
63 int total_free = 0;
64 int offset = 0;
65 int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size);
66 struct buffer_head *bh;
67
68 while (total < size) {
69 if ((bh = sb_bread(sb, start + offset)) == NULL) {
70 printk("qnx4: I/O error in counting free blocks\n");
71 break;
72 }
73 count_bits(bh->b_data, size - total, &total_free);
74 brelse(bh);
75 total += QNX4_BLOCK_SIZE;
76 offset++;
77 }
78
79 return total_free;
80}