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 16 #include <linux/time.h> 17 #include <linux/fs.h> 18 #include <linux/qnx4_fs.h> 19 #include <linux/stat.h> 20 #include <linux/kernel.h> 21 #include <linux/string.h> 22 #include <linux/buffer_head.h> 23 #include <linux/bitops.h> 24 25 #if 0 26 int qnx4_new_block(struct super_block *sb) 27 { 28 return 0; 29 } 30 #endif /* 0 */ 31 32 static void count_bits(register const char *bmPart, register int size, 33 int *const tf) 34 { 35 char b; 36 int tot = *tf; 37 38 if (size > QNX4_BLOCK_SIZE) { 39 size = QNX4_BLOCK_SIZE; 40 } 41 do { 42 b = *bmPart++; 43 if ((b & 1) == 0) 44 tot++; 45 if ((b & 2) == 0) 46 tot++; 47 if ((b & 4) == 0) 48 tot++; 49 if ((b & 8) == 0) 50 tot++; 51 if ((b & 16) == 0) 52 tot++; 53 if ((b & 32) == 0) 54 tot++; 55 if ((b & 64) == 0) 56 tot++; 57 if ((b & 128) == 0) 58 tot++; 59 size--; 60 } while (size != 0); 61 *tf = tot; 62 } 63 64 unsigned long qnx4_count_free_blocks(struct super_block *sb) 65 { 66 int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1; 67 int total = 0; 68 int total_free = 0; 69 int offset = 0; 70 int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size); 71 struct buffer_head *bh; 72 73 while (total < size) { 74 if ((bh = sb_bread(sb, start + offset)) == NULL) { 75 printk("qnx4: I/O error in counting free blocks\n"); 76 break; 77 } 78 count_bits(bh->b_data, size - total, &total_free); 79 brelse(bh); 80 total += QNX4_BLOCK_SIZE; 81 offset++; 82 } 83 84 return total_free; 85 } 86 87 #ifdef CONFIG_QNX4FS_RW 88 89 int qnx4_is_free(struct super_block *sb, long block) 90 { 91 int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1; 92 int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size); 93 struct buffer_head *bh; 94 const char *g; 95 int ret = -EIO; 96 97 start += block / (QNX4_BLOCK_SIZE * 8); 98 QNX4DEBUG(("qnx4: is_free requesting block [%lu], bitmap in block [%lu]\n", 99 (unsigned long) block, (unsigned long) start)); 100 (void) size; /* CHECKME */ 101 bh = sb_bread(sb, start); 102 if (bh == NULL) { 103 return -EIO; 104 } 105 g = bh->b_data + (block % QNX4_BLOCK_SIZE); 106 if (((*g) & (1 << (block % 8))) == 0) { 107 QNX4DEBUG(("qnx4: is_free -> block is free\n")); 108 ret = 1; 109 } else { 110 QNX4DEBUG(("qnx4: is_free -> block is busy\n")); 111 ret = 0; 112 } 113 brelse(bh); 114 115 return ret; 116 } 117 118 int qnx4_set_bitmap(struct super_block *sb, long block, int busy) 119 { 120 int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1; 121 int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size); 122 struct buffer_head *bh; 123 char *g; 124 125 start += block / (QNX4_BLOCK_SIZE * 8); 126 QNX4DEBUG(("qnx4: set_bitmap requesting block [%lu], bitmap in block [%lu]\n", 127 (unsigned long) block, (unsigned long) start)); 128 (void) size; /* CHECKME */ 129 bh = sb_bread(sb, start); 130 if (bh == NULL) { 131 return -EIO; 132 } 133 g = bh->b_data + (block % QNX4_BLOCK_SIZE); 134 if (busy == 0) { 135 (*g) &= ~(1 << (block % 8)); 136 } else { 137 (*g) |= (1 << (block % 8)); 138 } 139 mark_buffer_dirty(bh); 140 brelse(bh); 141 142 return 0; 143 } 144 145 static void qnx4_clear_inode(struct inode *inode) 146 { 147 struct qnx4_inode_entry *qnx4_ino = qnx4_raw_inode(inode); 148 /* What for? */ 149 memset(qnx4_ino->di_fname, 0, sizeof qnx4_ino->di_fname); 150 qnx4_ino->di_size = 0; 151 qnx4_ino->di_num_xtnts = 0; 152 qnx4_ino->di_mode = 0; 153 qnx4_ino->di_status = 0; 154 } 155 156 void qnx4_free_inode(struct inode *inode) 157 { 158 if (inode->i_ino < 1) { 159 printk("free_inode: inode 0 or nonexistent inode\n"); 160 return; 161 } 162 qnx4_clear_inode(inode); 163 clear_inode(inode); 164 } 165 166 #endif 167