/*
   *  linux/fs/hfs/dir.c
   *
   * Copyright (C) 1995-1997  Paul H. Hargrove
   * (C) 2003 Ardis Technologies <roman@ardistech.com>
   * This file may be distributed under the terms of the GNU General Public License.
   *
   * This file contains directory-related functions independent of which
   * scheme is being used to represent forks.
   *
   * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
   */
  
  #include "hfs_fs.h"
  #include "btree.h"
  
  /*
   * hfs_lookup()
   */
  static struct dentry *hfs_lookup(struct inode *dir, struct dentry *dentry,
  				 struct nameidata *nd)
  {
  	hfs_cat_rec rec;
  	struct hfs_find_data fd;
  	struct inode *inode = NULL;
  	int res;

  	hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);

  	hfs_cat_build_key(dir->i_sb, fd.search_key, dir->i_ino, &dentry->d_name);

  	res = hfs_brec_read(&fd, &rec, sizeof(rec));
  	if (res) {
  		hfs_find_exit(&fd);
  		if (res == -ENOENT) {
  			/* No such entry */
  			inode = NULL;
  			goto done;
  		}
  		return ERR_PTR(res);
  	}
  	inode = hfs_iget(dir->i_sb, &fd.search_key->cat, &rec);
  	hfs_find_exit(&fd);
  	if (!inode)
  		return ERR_PTR(-EACCES);
  done:
  	d_add(dentry, inode);
  	return NULL;
  }
  
  /*
   * hfs_readdir
   */
  static int hfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
  {

  	struct inode *inode = filp->f_path.dentry->d_inode;

  	struct super_block *sb = inode->i_sb;
  	int len, err;

  	char strbuf[HFS_MAX_NAMELEN];

  	union hfs_cat_rec entry;
  	struct hfs_find_data fd;
  	struct hfs_readdir_data *rd;
  	u16 type;
  
  	if (filp->f_pos >= inode->i_size)
  		return 0;
  
  	hfs_find_init(HFS_SB(sb)->cat_tree, &fd);

  	hfs_cat_build_key(sb, fd.search_key, inode->i_ino, NULL);

  	err = hfs_brec_find(&fd);
  	if (err)
  		goto out;
  
  	switch ((u32)filp->f_pos) {
  	case 0:
  		/* This is completely artificial... */
  		if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR))
  			goto out;
  		filp->f_pos++;
  		/* fall through */
  	case 1:

  		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
  			err = -EIO;
  			goto out;
  		}

  		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength);
  		if (entry.type != HFS_CDR_THD) {

  			printk(KERN_ERR "hfs: bad catalog folder thread
  ");

  			err = -EIO;
  			goto out;
  		}
  		//if (fd.entrylength < HFS_MIN_THREAD_SZ) {

  		//	printk(KERN_ERR "hfs: truncated catalog thread
  ");

  		//	err = -EIO;
  		//	goto out;
  		//}
  		if (filldir(dirent, "..", 2, 1,
  			    be32_to_cpu(entry.thread.ParID), DT_DIR))
  			goto out;
  		filp->f_pos++;
  		/* fall through */
  	default:
  		if (filp->f_pos >= inode->i_size)
  			goto out;
  		err = hfs_brec_goto(&fd, filp->f_pos - 1);
  		if (err)
  			goto out;
  	}
  
  	for (;;) {
  		if (be32_to_cpu(fd.key->cat.ParID) != inode->i_ino) {

  			printk(KERN_ERR "hfs: walked past end of dir
  ");

  			err = -EIO;
  			goto out;
  		}

  
  		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
  			err = -EIO;
  			goto out;
  		}

  		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength);
  		type = entry.type;

  		len = hfs_mac2asc(sb, strbuf, &fd.key->cat.CName);

  		if (type == HFS_CDR_DIR) {
  			if (fd.entrylength < sizeof(struct hfs_cat_dir)) {

  				printk(KERN_ERR "hfs: small dir entry
  ");

  				err = -EIO;
  				goto out;
  			}
  			if (filldir(dirent, strbuf, len, filp->f_pos,
  				    be32_to_cpu(entry.dir.DirID), DT_DIR))
  				break;
  		} else if (type == HFS_CDR_FIL) {
  			if (fd.entrylength < sizeof(struct hfs_cat_file)) {

  				printk(KERN_ERR "hfs: small file entry
  ");

  				err = -EIO;
  				goto out;
  			}
  			if (filldir(dirent, strbuf, len, filp->f_pos,
  				    be32_to_cpu(entry.file.FlNum), DT_REG))
  				break;
  		} else {

  			printk(KERN_ERR "hfs: bad catalog entry type %d
  ", type);

  			err = -EIO;
  			goto out;
  		}
  		filp->f_pos++;
  		if (filp->f_pos >= inode->i_size)
  			goto out;
  		err = hfs_brec_goto(&fd, 1);
  		if (err)
  			goto out;
  	}
  	rd = filp->private_data;
  	if (!rd) {
  		rd = kmalloc(sizeof(struct hfs_readdir_data), GFP_KERNEL);
  		if (!rd) {
  			err = -ENOMEM;
  			goto out;
  		}
  		filp->private_data = rd;
  		rd->file = filp;
  		list_add(&rd->list, &HFS_I(inode)->open_dir_list);
  	}
  	memcpy(&rd->key, &fd.key, sizeof(struct hfs_cat_key));
  out:
  	hfs_find_exit(&fd);
  	return err;
  }
  
  static int hfs_dir_release(struct inode *inode, struct file *file)
  {
  	struct hfs_readdir_data *rd = file->private_data;
  	if (rd) {
  		list_del(&rd->list);
  		kfree(rd);
  	}
  	return 0;
  }
  
  /*
   * hfs_create()
   *
   * This is the create() entry in the inode_operations structure for
   * regular HFS directories.  The purpose is to create a new file in
   * a directory and return a corresponding inode, given the inode for
   * the directory and the name (and its length) of the new file.
   */
  static int hfs_create(struct inode *dir, struct dentry *dentry, int mode,
  		      struct nameidata *nd)
  {
  	struct inode *inode;
  	int res;
  
  	inode = hfs_new_inode(dir, &dentry->d_name, mode);
  	if (!inode)
  		return -ENOSPC;
  
  	res = hfs_cat_create(inode->i_ino, dir, &dentry->d_name, inode);
  	if (res) {

  		clear_nlink(inode);

  		hfs_delete_inode(inode);
  		iput(inode);
  		return res;
  	}
  	d_instantiate(dentry, inode);
  	mark_inode_dirty(inode);
  	return 0;
  }
  
  /*
   * hfs_mkdir()
   *
   * This is the mkdir() entry in the inode_operations structure for
   * regular HFS directories.  The purpose is to create a new directory
   * in a directory, given the inode for the parent directory and the
   * name (and its length) of the new directory.
   */
  static int hfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
  {
  	struct inode *inode;
  	int res;
  
  	inode = hfs_new_inode(dir, &dentry->d_name, S_IFDIR | mode);
  	if (!inode)
  		return -ENOSPC;
  
  	res = hfs_cat_create(inode->i_ino, dir, &dentry->d_name, inode);
  	if (res) {

  		clear_nlink(inode);

  		hfs_delete_inode(inode);
  		iput(inode);
  		return res;
  	}
  	d_instantiate(dentry, inode);
  	mark_inode_dirty(inode);
  	return 0;
  }
  
  /*

   * hfs_remove()

   *

   * This serves as both unlink() and rmdir() in the inode_operations
   * structure for regular HFS directories.  The purpose is to delete
   * an existing child, given the inode for the parent directory and
   * the name (and its length) of the existing directory.

   *

   * HFS does not have hardlinks, so both rmdir and unlink set the
   * link count to 0.  The only difference is the emptiness check.

   */

  static int hfs_remove(struct inode *dir, struct dentry *dentry)

  {

  	struct inode *inode = dentry->d_inode;

  	int res;

  	if (S_ISDIR(inode->i_mode) && inode->i_size != 2)

  		return -ENOTEMPTY;
  	res = hfs_cat_delete(inode->i_ino, dir, &dentry->d_name);
  	if (res)
  		return res;

  	clear_nlink(inode);

  	inode->i_ctime = CURRENT_TIME_SEC;
  	hfs_delete_inode(inode);
  	mark_inode_dirty(inode);
  	return 0;
  }
  
  /*
   * hfs_rename()
   *
   * This is the rename() entry in the inode_operations structure for
   * regular HFS directories.  The purpose is to rename an existing
   * file or directory, given the inode for the current directory and
   * the name (and its length) of the existing file/directory and the
   * inode for the new directory and the name (and its length) of the
   * new file/directory.
   * XXX: how do you handle must_be dir?
   */
  static int hfs_rename(struct inode *old_dir, struct dentry *old_dentry,
  		      struct inode *new_dir, struct dentry *new_dentry)
  {
  	int res;
  
  	/* Unlink destination if it already exists */
  	if (new_dentry->d_inode) {

  		res = hfs_remove(new_dir, new_dentry);

  		if (res)
  			return res;
  	}
  
  	res = hfs_cat_move(old_dentry->d_inode->i_ino,
  			   old_dir, &old_dentry->d_name,
  			   new_dir, &new_dentry->d_name);
  	if (!res)

  		hfs_cat_build_key(old_dir->i_sb,
  				  (btree_key *)&HFS_I(old_dentry->d_inode)->cat_key,

  				  new_dir->i_ino, &new_dentry->d_name);
  	return res;
  }

  const struct file_operations hfs_dir_operations = {

  	.read		= generic_read_dir,
  	.readdir	= hfs_readdir,
  	.llseek		= generic_file_llseek,
  	.release	= hfs_dir_release,
  };

  const struct inode_operations hfs_dir_inode_operations = {

  	.create		= hfs_create,
  	.lookup		= hfs_lookup,

  	.unlink		= hfs_remove,

  	.mkdir		= hfs_mkdir,

  	.rmdir		= hfs_remove,

  	.rename		= hfs_rename,
  	.setattr	= hfs_inode_setattr,
  };