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/*
* QNX4 file system, Linux implementation.
*
* Version : 0.2.1
*
* Using parts of the xiafs filesystem.
*
* History :
*
* 28-05-1998 by Richard Frowijn : first release.
* 20-06-1998 by Frank Denis : basic optimisations.
* 25-06-1998 by Frank Denis : qnx4_is_free, qnx4_set_bitmap, qnx4_bmap .
* 28-06-1998 by Frank Denis : qnx4_free_inode (to be fixed) .
*/
#include <linux/buffer_head.h>
#include <linux/bitops.h>
#include "qnx4.h"
static void count_bits(register const char *bmPart, register int size,
int *const tf)
{
char b;
int tot = *tf;
if (size > QNX4_BLOCK_SIZE) {
size = QNX4_BLOCK_SIZE;
}
do {
b = *bmPart++;
tot += 8 - hweight8(b);
size--;
} while (size != 0);
*tf = tot;
}
unsigned long qnx4_count_free_blocks(struct super_block *sb)
{
int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1;
int total = 0;
int total_free = 0;
int offset = 0;
int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size);
struct buffer_head *bh;
while (total < size) {
if ((bh = sb_bread(sb, start + offset)) == NULL) {
printk(KERN_ERR "qnx4: I/O error in counting free blocks\n");
break;
}
count_bits(bh->b_data, size - total, &total_free);
brelse(bh);
total += QNX4_BLOCK_SIZE;
offset++;
}
return total_free;
}
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