text: /*
   * 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 : Linux 2.1.99+ & dcache support.
   */
  
  #include <linux/buffer_head.h>
  #include "qnx4.h"
  
  static int qnx4_readdir(struct file *file, struct dir_context *ctx)
  {
  	struct inode *inode = file_inode(file);
  	unsigned int offset;
  	struct buffer_head *bh;
  	struct qnx4_inode_entry *de;
  	struct qnx4_link_info *le;
  	unsigned long blknum;
  	int ix, ino;
  	int size;
  
  	QNX4DEBUG((KERN_INFO "qnx4_readdir:i_size = %ld\n", (long) inode->i_size));
  	QNX4DEBUG((KERN_INFO "pos                 = %ld\n", (long) ctx->pos));
  
  	while (ctx->pos < inode->i_size) {
  		blknum = qnx4_block_map(inode, ctx->pos >> QNX4_BLOCK_SIZE_BITS);
  		bh = sb_bread(inode->i_sb, blknum);
  		if (bh == NULL) {
  			printk(KERN_ERR "qnx4_readdir: bread failed (%ld)\n", blknum);
  			return 0;
  		}
  		ix = (ctx->pos >> QNX4_DIR_ENTRY_SIZE_BITS) % QNX4_INODES_PER_BLOCK;
  		for (; ix < QNX4_INODES_PER_BLOCK; ix++, ctx->pos += QNX4_DIR_ENTRY_SIZE) {
  			offset = ix * QNX4_DIR_ENTRY_SIZE;
  			de = (struct qnx4_inode_entry *) (bh->b_data + offset);
  			if (!de->di_fname[0])
  				continue;
  			if (!(de->di_status & (QNX4_FILE_USED|QNX4_FILE_LINK)))
  				continue;
  			if (!(de->di_status & QNX4_FILE_LINK))
  				size = QNX4_SHORT_NAME_MAX;
  			else
  				size = QNX4_NAME_MAX;
  			size = strnlen(de->di_fname, size);
  			QNX4DEBUG((KERN_INFO "qnx4_readdir:%.*s\n", size, de->di_fname));
  			if (!(de->di_status & QNX4_FILE_LINK))
  				ino = blknum * QNX4_INODES_PER_BLOCK + ix - 1;
  			else {
  				le  = (struct qnx4_link_info*)de;
  				ino = ( le32_to_cpu(le->dl_inode_blk) - 1 ) *
  					QNX4_INODES_PER_BLOCK +
  					le->dl_inode_ndx;
  			}
  			if (!dir_emit(ctx, de->di_fname, size, ino, DT_UNKNOWN)) {
  				brelse(bh);
  				return 0;
  			}
  		}
  		brelse(bh);
  	}
  	return 0;
  }
  
  const struct file_operations qnx4_dir_operations =
  {
  	.llseek		= generic_file_llseek,
  	.read		= generic_read_dir,
  	.iterate_shared	= qnx4_readdir,
  	.fsync		= generic_file_fsync,
  };
  
  const struct inode_operations qnx4_dir_inode_operations =
  {
  	.lookup		= qnx4_lookup,
  };
  