// SPDX-License-Identifier: GPL-2.0

  /*
   * 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
  ", (long) inode->i_size));

  	QNX4DEBUG((KERN_INFO "pos                 = %ld
  ", (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)
  ", 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
  ", 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,

  };