[net-next-2.6.git] / fs / ext3 / bitmap.c

/*
 *  linux/fs/ext3/bitmap.c
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card (card@masi.ibp.fr)
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 */

#include <linux/buffer_head.h>
#include "bitmap.h"

static int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0};

unsigned long ext3_count_free (struct buffer_head * map, unsigned int numchars)
{
	unsigned int i;
	unsigned long sum = 0;

	if (!map) 
		return (0);
	for (i = 0; i < numchars; i++)
		sum += nibblemap[map->b_data[i] & 0xf] +
			nibblemap[(map->b_data[i] >> 4) & 0xf];
	return (sum);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/ext3/bitmap.c
	3	*
	4	* Copyright (C) 1992, 1993, 1994, 1995
	5	* Remy Card (card@masi.ibp.fr)
	6	* Laboratoire MASI - Institut Blaise Pascal
	7	* Universite Pierre et Marie Curie (Paris VI)
	8	*/
	9
	10	#include <linux/buffer_head.h>
381be254	11	#include "bitmap.h"
1da177e4 LT	12
	13	static int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0};
	14
	15	unsigned long ext3_count_free (struct buffer_head * map, unsigned int numchars)
	16	{
	17	unsigned int i;
	18	unsigned long sum = 0;
	19
	20	if (!map)
	21	return (0);
	22	for (i = 0; i < numchars; i++)
	23	sum += nibblemap[map->b_data[i] & 0xf] +
	24	nibblemap[(map->b_data[i] >> 4) & 0xf];
	25	return (sum);
	26	}