swh:1:snp:173f8deb0c56c557784b4fd217e7608ac6197844
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Tip revision: 02b3e4e2d71b6058ec11cc01c72ac651eb3ded2b authored by Linus Torvalds on 28 August 2005, 23:41:01 UTC
Linux v2.6.13
Tip revision: 02b3e4e
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>


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);
}
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