| Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 1 | /* |
| Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 2 | * linux/fs/ext4/bitmap.c |
| Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 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> |
| Mingming Cao | dab291a | 2006-10-11 01:21:01 -0700 | [diff] [blame] | 11 | #include <linux/jbd2.h> |
| Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 12 | #include <linux/ext4_fs.h> |
| Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 13 | |
| Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 14 | #ifdef EXT4FS_DEBUG |
| Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 15 | |
| Philippe De Muyter | febfcf9 | 2007-10-16 23:26:15 -0700 | [diff] [blame] | 16 | static const int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0}; |
| Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 17 | |
| Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 18 | unsigned long ext4_count_free (struct buffer_head * map, unsigned int numchars) |
| Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 19 | { |
| 20 | unsigned int i; |
| 21 | unsigned long sum = 0; |
| 22 | |
| 23 | if (!map) |
| 24 | 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 | } |
| 30 | |
| Mingming Cao | 617ba13 | 2006-10-11 01:20:53 -0700 | [diff] [blame] | 31 | #endif /* EXT4FS_DEBUG */ |
| Dave Kleikamp | ac27a0e | 2006-10-11 01:20:50 -0700 | [diff] [blame] | 32 | |