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, block: 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(ptr: bh->b_data, bytes); |
39 | brelse(bh); |
40 | total += bytes; |
41 | offset++; |
42 | } |
43 | |
44 | return total_free; |
45 | } |
46 |