| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
| Al Viro | 4613ad1 | 2012-03-29 22:30:07 -0400 | [diff] [blame] | 10 | #include "ext3.h" |
| Adrian Bunk | 3af1376 | 2006-01-09 20:54:06 -0800 | [diff] [blame] | 11 | |
| Kirk True | c1f5a19 | 2006-03-25 03:07:47 -0800 | [diff] [blame] | 12 | #ifdef EXT3FS_DEBUG |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | |
| Philippe De Muyter | febfcf9 | 2007-10-16 23:26:15 -0700 | [diff] [blame] | 14 | static const int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0}; |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | |
| 16 | unsigned long ext3_count_free (struct buffer_head * map, unsigned int numchars) |
| 17 | { |
| 18 | unsigned int i; |
| 19 | unsigned long sum = 0; |
| 20 | |
| Mingming Cao | ae6ddcc | 2006-09-27 01:49:27 -0700 | [diff] [blame] | 21 | if (!map) |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | } |
| Adrian Bunk | 3af1376 | 2006-01-09 20:54:06 -0800 | [diff] [blame] | 28 | |
| 29 | #endif /* EXT3FS_DEBUG */ |
| 30 | |