/* | |
* linux/fs/ext2/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 ext2_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); | |
} |