/* * QNX4 file system, Linux implementation. * * Version : 0.2.1 * * Using parts of the xiafs filesystem. * * History : * * 28-05-1998 by Richard Frowijn : first release. * 20-06-1998 by Frank Denis : basic optimisations. * 25-06-1998 by Frank Denis : qnx4_is_free, qnx4_set_bitmap, qnx4_bmap . * 28-06-1998 by Frank Denis : qnx4_free_inode (to be fixed) . */ #include <linux/buffer_head.h> #include <linux/bitops.h> #include "qnx4.h" #if 0 int qnx4_new_block(struct super_block *sb) { return 0; } #endif /* 0 */ static void count_bits(register const char *bmPart, register int size, int *const tf) { char b; int tot = *tf; if (size > QNX4_BLOCK_SIZE) { size = QNX4_BLOCK_SIZE; } do { b = *bmPart++; if ((b & 1) == 0) tot++; if ((b & 2) == 0) tot++; if ((b & 4) == 0) tot++; if ((b & 8) == 0) tot++; if ((b & 16) == 0) tot++; if ((b & 32) == 0) tot++; if ((b & 64) == 0) tot++; if ((b & 128) == 0) tot++; size--; } while (size != 0); *tf = tot; } unsigned long qnx4_count_free_blocks(struct super_block *sb) { int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1; int total = 0; int total_free = 0; int offset = 0; int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size); struct buffer_head *bh; while (total < size) { if ((bh = sb_bread(sb, start + offset)) == NULL) { printk("qnx4: I/O error in counting free blocks\n"); break; } count_bits(bh->b_data, size - total, &total_free); brelse(bh); total += QNX4_BLOCK_SIZE; offset++; } return total_free; }