swh:1:snp:173f8deb0c56c557784b4fd217e7608ac6197844
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Tip revision: 28d0325ce6e0a52f53d8af687e6427fee59004d3 authored by Linus Torvalds on 24 June 2009, 23:25:37 UTC
Linux 2.6.31-rc1
Tip revision: 28d0325
bitmap.c
/*
 *  linux/fs/ext4/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 <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  */

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