1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * QNX4 file system, Linux implementation.
4 *
5 * Version : 0.2.1
6 *
7 * Using parts of the xiafs filesystem.
8 *
9 * History :
10 *
11 * 28-05-1998 by Richard Frowijn : first release.
12 * 20-06-1998 by Frank Denis : basic optimisations.
13 * 25-06-1998 by Frank Denis : qnx4_is_free, qnx4_set_bitmap, qnx4_bmap .
14 * 28-06-1998 by Frank Denis : qnx4_free_inode (to be fixed) .
15 */
16
17 #include <linux/buffer_head.h>
18 #include <linux/bitops.h>
19 #include "qnx4.h"
20
21 unsigned long qnx4_count_free_blocks(struct super_block *sb)
22 {
23 int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1;
24 int total = 0;
25 int total_free = 0;
26 int offset = 0;
27 int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size);
28 struct buffer_head *bh;
29
30 while (total < size) {
31 int bytes = min(size - total, QNX4_BLOCK_SIZE);
32
33 if ((bh = sb_bread(sb, start + offset)) == NULL) {
34 printk(KERN_ERR "qnx4: I/O error in counting free blocks\n");
35 break;
36 }
37 total_free += bytes * BITS_PER_BYTE -
38 memweight(bh->b_data, bytes);
39 brelse(bh);
40 total += bytes;
41 offset++;
42 }
43
44 return total_free;
45 }
46
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.