projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
1 | /* |
| 2 | * QNX4 file system, Linux implementation. | |
| 3 | * | |
| 4 | * Version : 0.2.1 | |
| 5 | * | |
| 6 | * Using parts of the xiafs filesystem. | |
| 7 | * | |
| 8 | * History : | |
| 9 | * | |
| 10 | * 28-05-1998 by Richard Frowijn : first release. | |
| 11 | * 20-06-1998 by Frank Denis : basic optimisations. | |
| 12 | * 25-06-1998 by Frank Denis : qnx4_is_free, qnx4_set_bitmap, qnx4_bmap . | |
| 13 | * 28-06-1998 by Frank Denis : qnx4_free_inode (to be fixed) . | |
| 14 | */ | |
| 15 | ||
| 1da177e4 LT |
16 | #include <linux/buffer_head.h> |
| 17 | #include <linux/bitops.h> | |
| 964f5369 | 18 | #include "qnx4.h" |
| 1da177e4 | 19 | |
| 1da177e4 LT |
20 | static void count_bits(register const char *bmPart, register int size, |
| 21 | int *const tf) | |
| 22 | { | |
| 23 | char b; | |
| 24 | int tot = *tf; | |
| 25 | ||
| 26 | if (size > QNX4_BLOCK_SIZE) { | |
| 27 | size = QNX4_BLOCK_SIZE; | |
| 28 | } | |
| 29 | do { | |
| 30 | b = *bmPart++; | |
| 31 | if ((b & 1) == 0) | |
| 32 | tot++; | |
| 33 | if ((b & 2) == 0) | |
| 34 | tot++; | |
| 35 | if ((b & 4) == 0) | |
| 36 | tot++; | |
| 37 | if ((b & 8) == 0) | |
| 38 | tot++; | |
| 39 | if ((b & 16) == 0) | |
| 40 | tot++; | |
| 41 | if ((b & 32) == 0) | |
| 42 | tot++; | |
| 43 | if ((b & 64) == 0) | |
| 44 | tot++; | |
| 45 | if ((b & 128) == 0) | |
| 46 | tot++; | |
| 47 | size--; | |
| 48 | } while (size != 0); | |
| 49 | *tf = tot; | |
| 50 | } | |
| 51 | ||
| 52 | unsigned long qnx4_count_free_blocks(struct super_block *sb) | |
| 53 | { | |
| 54 | int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1; | |
| 55 | int total = 0; | |
| 56 | int total_free = 0; | |
| 57 | int offset = 0; | |
| 58 | int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size); | |
| 59 | struct buffer_head *bh; | |
| 60 | ||
| 61 | while (total < size) { | |
| 62 | if ((bh = sb_bread(sb, start + offset)) == NULL) { | |
| 891ddb95 | 63 | printk(KERN_ERR "qnx4: I/O error in counting free blocks\n"); |
| 1da177e4 LT |
64 | break; |
| 65 | } | |
| 66 | count_bits(bh->b_data, size - total, &total_free); | |
| 67 | brelse(bh); | |
| 68 | total += QNX4_BLOCK_SIZE; | |
| 69 | offset++; | |
| 70 | } | |
| 71 | ||
| 72 | return total_free; | |
| 73 | } |