Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | #include <linux/buffer_head.h> |
| 17 | #include <linux/bitops.h> |
Al Viro | 964f536 | 2009-06-07 09:47:13 -0400 | [diff] [blame^] | 18 | #include "qnx4.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | |
Adrian Bunk | 7a1119b | 2006-01-03 13:21:37 +0100 | [diff] [blame] | 20 | #if 0 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | int qnx4_new_block(struct super_block *sb) |
| 22 | { |
| 23 | return 0; |
| 24 | } |
Adrian Bunk | 7a1119b | 2006-01-03 13:21:37 +0100 | [diff] [blame] | 25 | #endif /* 0 */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | |
| 27 | static void count_bits(register const char *bmPart, register int size, |
| 28 | int *const tf) |
| 29 | { |
| 30 | char b; |
| 31 | int tot = *tf; |
| 32 | |
| 33 | if (size > QNX4_BLOCK_SIZE) { |
| 34 | size = QNX4_BLOCK_SIZE; |
| 35 | } |
| 36 | do { |
| 37 | b = *bmPart++; |
| 38 | if ((b & 1) == 0) |
| 39 | tot++; |
| 40 | if ((b & 2) == 0) |
| 41 | tot++; |
| 42 | if ((b & 4) == 0) |
| 43 | tot++; |
| 44 | if ((b & 8) == 0) |
| 45 | tot++; |
| 46 | if ((b & 16) == 0) |
| 47 | tot++; |
| 48 | if ((b & 32) == 0) |
| 49 | tot++; |
| 50 | if ((b & 64) == 0) |
| 51 | tot++; |
| 52 | if ((b & 128) == 0) |
| 53 | tot++; |
| 54 | size--; |
| 55 | } while (size != 0); |
| 56 | *tf = tot; |
| 57 | } |
| 58 | |
| 59 | unsigned long qnx4_count_free_blocks(struct super_block *sb) |
| 60 | { |
| 61 | int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1; |
| 62 | int total = 0; |
| 63 | int total_free = 0; |
| 64 | int offset = 0; |
| 65 | int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size); |
| 66 | struct buffer_head *bh; |
| 67 | |
| 68 | while (total < size) { |
| 69 | if ((bh = sb_bread(sb, start + offset)) == NULL) { |
| 70 | printk("qnx4: I/O error in counting free blocks\n"); |
| 71 | break; |
| 72 | } |
| 73 | count_bits(bh->b_data, size - total, &total_free); |
| 74 | brelse(bh); |
| 75 | total += QNX4_BLOCK_SIZE; |
| 76 | offset++; |
| 77 | } |
| 78 | |
| 79 | return total_free; |
| 80 | } |
| 81 | |
| 82 | #ifdef CONFIG_QNX4FS_RW |
| 83 | |
| 84 | int qnx4_is_free(struct super_block *sb, long block) |
| 85 | { |
| 86 | int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1; |
| 87 | int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size); |
| 88 | struct buffer_head *bh; |
| 89 | const char *g; |
| 90 | int ret = -EIO; |
| 91 | |
| 92 | start += block / (QNX4_BLOCK_SIZE * 8); |
| 93 | QNX4DEBUG(("qnx4: is_free requesting block [%lu], bitmap in block [%lu]\n", |
| 94 | (unsigned long) block, (unsigned long) start)); |
| 95 | (void) size; /* CHECKME */ |
| 96 | bh = sb_bread(sb, start); |
| 97 | if (bh == NULL) { |
| 98 | return -EIO; |
| 99 | } |
| 100 | g = bh->b_data + (block % QNX4_BLOCK_SIZE); |
| 101 | if (((*g) & (1 << (block % 8))) == 0) { |
| 102 | QNX4DEBUG(("qnx4: is_free -> block is free\n")); |
| 103 | ret = 1; |
| 104 | } else { |
| 105 | QNX4DEBUG(("qnx4: is_free -> block is busy\n")); |
| 106 | ret = 0; |
| 107 | } |
| 108 | brelse(bh); |
| 109 | |
| 110 | return ret; |
| 111 | } |
| 112 | |
| 113 | int qnx4_set_bitmap(struct super_block *sb, long block, int busy) |
| 114 | { |
| 115 | int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1; |
| 116 | int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size); |
| 117 | struct buffer_head *bh; |
| 118 | char *g; |
| 119 | |
| 120 | start += block / (QNX4_BLOCK_SIZE * 8); |
| 121 | QNX4DEBUG(("qnx4: set_bitmap requesting block [%lu], bitmap in block [%lu]\n", |
| 122 | (unsigned long) block, (unsigned long) start)); |
| 123 | (void) size; /* CHECKME */ |
| 124 | bh = sb_bread(sb, start); |
| 125 | if (bh == NULL) { |
| 126 | return -EIO; |
| 127 | } |
| 128 | g = bh->b_data + (block % QNX4_BLOCK_SIZE); |
| 129 | if (busy == 0) { |
| 130 | (*g) &= ~(1 << (block % 8)); |
| 131 | } else { |
| 132 | (*g) |= (1 << (block % 8)); |
| 133 | } |
| 134 | mark_buffer_dirty(bh); |
| 135 | brelse(bh); |
| 136 | |
| 137 | return 0; |
| 138 | } |
| 139 | |
| 140 | static void qnx4_clear_inode(struct inode *inode) |
| 141 | { |
| 142 | struct qnx4_inode_entry *qnx4_ino = qnx4_raw_inode(inode); |
| 143 | /* What for? */ |
| 144 | memset(qnx4_ino->di_fname, 0, sizeof qnx4_ino->di_fname); |
| 145 | qnx4_ino->di_size = 0; |
| 146 | qnx4_ino->di_num_xtnts = 0; |
| 147 | qnx4_ino->di_mode = 0; |
| 148 | qnx4_ino->di_status = 0; |
| 149 | } |
| 150 | |
| 151 | void qnx4_free_inode(struct inode *inode) |
| 152 | { |
| 153 | if (inode->i_ino < 1) { |
| 154 | printk("free_inode: inode 0 or nonexistent inode\n"); |
| 155 | return; |
| 156 | } |
| 157 | qnx4_clear_inode(inode); |
| 158 | clear_inode(inode); |
| 159 | } |
| 160 | |
| 161 | #endif |