[linux-2.6-block.git] / fs / qnx4 / bitmap.c

/*
 * 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"

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) {
		int bytes = min(size - total, QNX4_BLOCK_SIZE);

		if ((bh = sb_bread(sb, start + offset)) == NULL) {
			printk(KERN_ERR "qnx4: I/O error in counting free blocks\n");
			break;
		}
		total_free += bytes * BITS_PER_BYTE -
				memweight(bh->b_data, bytes);
		brelse(bh);
		total += bytes;
		offset++;
	}

	return total_free;
}
Commit	Line	Data
1da177e4 LT	1	/*
	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
1da177e4 LT	16	#include <linux/buffer_head.h>
1da177e4 LT	17	#include <linux/bitops.h>
964f5369	18	#include "qnx4.h"
1da177e4	19
1da177e4 LT	20	unsigned long qnx4_count_free_blocks(struct super_block *sb)
	21	{
	22	int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1;
	23	int total = 0;
	24	int total_free = 0;
	25	int offset = 0;
	26	int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size);
	27	struct buffer_head *bh;
	28
	29	while (total < size) {
9b58f6d4 AM	30	int bytes = min(size - total, QNX4_BLOCK_SIZE);
9b58f6d4 AM	31
1da177e4	32	if ((bh = sb_bread(sb, start + offset)) == NULL) {
891ddb95	33	printk(KERN_ERR "qnx4: I/O error in counting free blocks\n");
1da177e4 LT	34	break;
1da177e4 LT	35	}
9b58f6d4 AM	36	total_free += bytes * BITS_PER_BYTE -
9b58f6d4 AM	37	memweight(bh->b_data, bytes);
1da177e4	38	brelse(bh);
9b58f6d4	39	total += bytes;
1da177e4 LT	40	offset++;
	41	}
	42
	43	return total_free;
	44	}