/* * 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/time.h> #include <linux/fs.h> #include <linux/qnx4_fs.h> #include <linux/stat.h> #include <linux/kernel.h> #include <linux/string.h> #include <linux/buffer_head.h> #include <linux/bitops.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; } #ifdef CONFIG_QNX4FS_RW int qnx4_is_free(struct super_block *sb, long block) { int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1; int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size); struct buffer_head *bh; const char *g; int ret = -EIO; start += block / (QNX4_BLOCK_SIZE * 8); QNX4DEBUG(("qnx4: is_free requesting block [%lu], bitmap in block [%lu]\n", (unsigned long) block, (unsigned long) start)); (void) size; /* CHECKME */ bh = sb_bread(sb, start); if (bh == NULL) { return -EIO; } g = bh->b_data + (block % QNX4_BLOCK_SIZE); if (((*g) & (1 << (block % 8))) == 0) { QNX4DEBUG(("qnx4: is_free -> block is free\n")); ret = 1; } else { QNX4DEBUG(("qnx4: is_free -> block is busy\n")); ret = 0; } brelse(bh); return ret; } int qnx4_set_bitmap(struct super_block *sb, long block, int busy) { int start = le32_to_cpu(qnx4_sb(sb)->BitMap->di_first_xtnt.xtnt_blk) - 1; int size = le32_to_cpu(qnx4_sb(sb)->BitMap->di_size); struct buffer_head *bh; char *g; start += block / (QNX4_BLOCK_SIZE * 8); QNX4DEBUG(("qnx4: set_bitmap requesting block [%lu], bitmap in block [%lu]\n", (unsigned long) block, (unsigned long) start)); (void) size; /* CHECKME */ bh = sb_bread(sb, start); if (bh == NULL) { return -EIO; } g = bh->b_data + (block % QNX4_BLOCK_SIZE); if (busy == 0) { (*g) &= ~(1 << (block % 8)); } else { (*g) |= (1 << (block % 8)); } mark_buffer_dirty(bh); brelse(bh); return 0; } static void qnx4_clear_inode(struct inode *inode) { struct qnx4_inode_entry *qnx4_ino = qnx4_raw_inode(inode); /* What for? */ memset(qnx4_ino->di_fname, 0, sizeof qnx4_ino->di_fname); qnx4_ino->di_size = 0; qnx4_ino->di_num_xtnts = 0; qnx4_ino->di_mode = 0; qnx4_ino->di_status = 0; } void qnx4_free_inode(struct inode *inode) { if (inode->i_ino < 1) { printk("free_inode: inode 0 or nonexistent inode\n"); return; } qnx4_clear_inode(inode); clear_inode(inode); } #endif