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 "ext3.h" 11 12 #ifdef EXT3FS_DEBUG 13 14 static const int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0}; 15 ext3_count_free(struct buffer_head * map,unsigned int numchars)16 unsigned long ext3_count_free (struct buffer_head * map, unsigned int numchars) 17 { 18 unsigned int i; 19 unsigned long sum = 0; 20 21 if (!map) 22 return (0); 23 for (i = 0; i < numchars; i++) 24 sum += nibblemap[map->b_data[i] & 0xf] + 25 nibblemap[(map->b_data[i] >> 4) & 0xf]; 26 return (sum); 27 } 28 29 #endif /* EXT3FS_DEBUG */ 30 31