[linux.git] / fs / ext4 / bitmap.c

/*
 *  linux/fs/ext4/bitmap.c
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card ([email protected])
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 */

#include <linux/buffer_head.h>
#include <linux/jbd2.h>
#include "ext4.h"

#ifdef EXT4FS_DEBUG

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

unsigned int ext4_count_free(struct buffer_head *map, unsigned int numchars)
{
	unsigned int i, 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;
}

#endif  /*  EXT4FS_DEBUG  */
Commit	Line	Data
ac27a0ec	1	/*
617ba13b	2	* linux/fs/ext4/bitmap.c
ac27a0ec DK	3	*
	4	* Copyright (C) 1992, 1993, 1994, 1995
	5	* Remy Card ([email protected])
	6	* Laboratoire MASI - Institut Blaise Pascal
	7	* Universite Pierre et Marie Curie (Paris VI)
	8	*/
	9
	10	#include <linux/buffer_head.h>
dab291af	11	#include <linux/jbd2.h>
3dcf5451	12	#include "ext4.h"
ac27a0ec	13
617ba13b	14	#ifdef EXT4FS_DEBUG
ac27a0ec	15
febfcf91	16	static const int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0};
ac27a0ec	17
498e5f24	18	unsigned int ext4_count_free(struct buffer_head *map, unsigned int numchars)
ac27a0ec	19	{
498e5f24	20	unsigned int i, sum = 0;
ac27a0ec DK	21
ac27a0ec DK	22	if (!map)
af5bc92d	23	return 0;
ac27a0ec DK	24	for (i = 0; i < numchars; i++)
	25	sum += nibblemap[map->b_data[i] & 0xf] +
	26	nibblemap[(map->b_data[i] >> 4) & 0xf];
af5bc92d	27	return sum;
ac27a0ec DK	28	}
ac27a0ec DK	29
617ba13b	30	#endif /* EXT4FS_DEBUG */
ac27a0ec	31