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/buffer_head.h> 17 #include <linux/bitops.h> 18 #include "qnx4.h" 19 20 unsigned long qnx4_count_free_blocks(struct super_block *sb) 21 { 22 int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1; 23 int total = 0; 24 int total_free = 0; 25 int offset = 0; 26 int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size); 27 struct buffer_head *bh; 28 29 while (total < size) { 30 int bytes = min(size - total, QNX4_BLOCK_SIZE); 31 32 if ((bh = sb_bread(sb, start + offset)) == NULL) { 33 printk(KERN_ERR "qnx4: I/O error in counting free blocks\n"); 34 break; 35 } 36 total_free += bytes * BITS_PER_BYTE - 37 memweight(bh->b_data, bytes); 38 brelse(bh); 39 total += bytes; 40 offset++; 41 } 42 43 return total_free; 44 } 45