blob: b9176eed98d1258518bd9cebfbbdb071baa458fc [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 <linux/buffer_head.h>
Kirk Truec1f5a192006-03-25 03:07:47 -080011#include <linux/jbd.h>
12#include <linux/ext3_fs.h>
Adrian Bunk3af13762006-01-09 20:54:06 -080013
Kirk Truec1f5a192006-03-25 03:07:47 -080014#ifdef EXT3FS_DEBUG
Linus Torvalds1da177e2005-04-16 15:20:36 -070015
16static int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0};
17
18unsigned long ext3_count_free (struct buffer_head * map, unsigned int numchars)
19{
20 unsigned int i;
21 unsigned long sum = 0;
22
Mingming Caoae6ddcc2006-09-27 01:49:27 -070023 if (!map)
Linus Torvalds1da177e2005-04-16 15:20:36 -070024 return (0);
25 for (i = 0; i < numchars; i++)
26 sum += nibblemap[map->b_data[i] & 0xf] +
27 nibblemap[(map->b_data[i] >> 4) & 0xf];
28 return (sum);
29}
Adrian Bunk3af13762006-01-09 20:54:06 -080030
31#endif /* EXT3FS_DEBUG */
32