/*
   *  linux/fs/hfsplus/dir.c
   *
   * Copyright (C) 2001
   * Brad Boyer (flar@allandria.com)
   * (C) 2003 Ardis Technologies <roman@ardistech.com>
   *
   * Handling of directories
   */
  
  #include <linux/errno.h>
  #include <linux/fs.h>

  #include <linux/slab.h>
  #include <linux/random.h>

  
  #include "hfsplus_fs.h"
  #include "hfsplus_raw.h"
  
  static inline void hfsplus_instantiate(struct dentry *dentry,
  				       struct inode *inode, u32 cnid)
  {
  	dentry->d_fsdata = (void *)(unsigned long)cnid;
  	d_instantiate(dentry, inode);
  }
  
  /* Find the entry inside dir named dentry->d_name */
  static struct dentry *hfsplus_lookup(struct inode *dir, struct dentry *dentry,
  				     struct nameidata *nd)
  {
  	struct inode *inode = NULL;
  	struct hfs_find_data fd;
  	struct super_block *sb;
  	hfsplus_cat_entry entry;
  	int err;
  	u32 cnid, linkid = 0;
  	u16 type;
  
  	sb = dir->i_sb;

  	dentry->d_fsdata = NULL;

  	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
  	if (err)
  		return ERR_PTR(err);

  	hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino, &dentry->d_name);
  again:
  	err = hfs_brec_read(&fd, &entry, sizeof(entry));
  	if (err) {
  		if (err == -ENOENT) {
  			hfs_find_exit(&fd);
  			/* No such entry */
  			inode = NULL;
  			goto out;
  		}
  		goto fail;
  	}
  	type = be16_to_cpu(entry.type);
  	if (type == HFSPLUS_FOLDER) {
  		if (fd.entrylength < sizeof(struct hfsplus_cat_folder)) {
  			err = -EIO;
  			goto fail;
  		}
  		cnid = be32_to_cpu(entry.folder.id);
  		dentry->d_fsdata = (void *)(unsigned long)cnid;
  	} else if (type == HFSPLUS_FILE) {
  		if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
  			err = -EIO;
  			goto fail;
  		}
  		cnid = be32_to_cpu(entry.file.id);

  		if (entry.file.user_info.fdType ==
  				cpu_to_be32(HFSP_HARDLINK_TYPE) &&
  				entry.file.user_info.fdCreator ==
  				cpu_to_be32(HFSP_HFSPLUS_CREATOR) &&
  				(entry.file.create_date ==
  					HFSPLUS_I(HFSPLUS_SB(sb)->hidden_dir)->
  						create_date ||
  				entry.file.create_date ==
  					HFSPLUS_I(sb->s_root->d_inode)->
  						create_date) &&
  				HFSPLUS_SB(sb)->hidden_dir) {

  			struct qstr str;
  			char name[32];
  
  			if (dentry->d_fsdata) {

  				/*
  				 * We found a link pointing to another link,
  				 * so ignore it and treat it as regular file.
  				 */
  				cnid = (unsigned long)dentry->d_fsdata;
  				linkid = 0;
  			} else {
  				dentry->d_fsdata = (void *)(unsigned long)cnid;

  				linkid =
  					be32_to_cpu(entry.file.permissions.dev);

  				str.len = sprintf(name, "iNode%d", linkid);
  				str.name = name;

  				hfsplus_cat_build_key(sb, fd.search_key,

  					HFSPLUS_SB(sb)->hidden_dir->i_ino,
  					&str);

  				goto again;

  			}

  		} else if (!dentry->d_fsdata)
  			dentry->d_fsdata = (void *)(unsigned long)cnid;
  	} else {

  		printk(KERN_ERR "hfs: invalid catalog entry type in lookup
  ");

  		err = -EIO;
  		goto fail;
  	}
  	hfs_find_exit(&fd);

  	inode = hfsplus_iget(dir->i_sb, cnid);
  	if (IS_ERR(inode))
  		return ERR_CAST(inode);

  	if (S_ISREG(inode->i_mode))

  		HFSPLUS_I(inode)->linkid = linkid;

  out:
  	d_add(dentry, inode);
  	return NULL;
  fail:
  	hfs_find_exit(&fd);
  	return ERR_PTR(err);
  }
  
  static int hfsplus_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[HFSPLUS_MAX_STRLEN + 1];
  	hfsplus_cat_entry entry;
  	struct hfs_find_data fd;
  	struct hfsplus_readdir_data *rd;
  	u16 type;
  
  	if (filp->f_pos >= inode->i_size)
  		return 0;

  	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
  	if (err)
  		return err;

  	hfsplus_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:

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

  		if (be16_to_cpu(entry.type) != HFSPLUS_FOLDER_THREAD) {

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

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

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

  			err = -EIO;
  			goto out;
  		}
  		if (filldir(dirent, "..", 2, 1,
  			    be32_to_cpu(entry.thread.parentID), 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.parent) != inode->i_ino) {

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

  			err = -EIO;
  			goto out;
  		}

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

  		type = be16_to_cpu(entry.type);
  		len = HFSPLUS_MAX_STRLEN;
  		err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
  		if (err)
  			goto out;
  		if (type == HFSPLUS_FOLDER) {

  			if (fd.entrylength <
  					sizeof(struct hfsplus_cat_folder)) {

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

  				err = -EIO;
  				goto out;
  			}

  			if (HFSPLUS_SB(sb)->hidden_dir &&
  			    HFSPLUS_SB(sb)->hidden_dir->i_ino ==
  					be32_to_cpu(entry.folder.id))

  				goto next;
  			if (filldir(dirent, strbuf, len, filp->f_pos,
  				    be32_to_cpu(entry.folder.id), DT_DIR))
  				break;
  		} else if (type == HFSPLUS_FILE) {
  			if (fd.entrylength < sizeof(struct hfsplus_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.id), DT_REG))
  				break;
  		} else {

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

  			err = -EIO;
  			goto out;
  		}

  next:

  		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 hfsplus_readdir_data), GFP_KERNEL);
  		if (!rd) {
  			err = -ENOMEM;
  			goto out;
  		}
  		filp->private_data = rd;
  		rd->file = filp;

  		list_add(&rd->list, &HFSPLUS_I(inode)->open_dir_list);

  	}
  	memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
  out:
  	hfs_find_exit(&fd);
  	return err;
  }
  
  static int hfsplus_dir_release(struct inode *inode, struct file *file)
  {
  	struct hfsplus_readdir_data *rd = file->private_data;
  	if (rd) {

  		mutex_lock(&inode->i_mutex);

  		list_del(&rd->list);

  		mutex_unlock(&inode->i_mutex);

  		kfree(rd);
  	}
  	return 0;
  }

  static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
  			struct dentry *dst_dentry)
  {

  	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dst_dir->i_sb);

  	struct inode *inode = src_dentry->d_inode;
  	struct inode *src_dir = src_dentry->d_parent->d_inode;
  	struct qstr str;
  	char name[32];
  	u32 cnid, id;
  	int res;
  
  	if (HFSPLUS_IS_RSRC(inode))
  		return -EPERM;

  	if (!S_ISREG(inode->i_mode))
  		return -EPERM;

  	mutex_lock(&sbi->vh_mutex);

  	if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
  		for (;;) {
  			get_random_bytes(&id, sizeof(cnid));
  			id &= 0x3fffffff;
  			str.name = name;
  			str.len = sprintf(name, "iNode%d", id);
  			res = hfsplus_rename_cat(inode->i_ino,
  						 src_dir, &src_dentry->d_name,

  						 sbi->hidden_dir, &str);

  			if (!res)
  				break;
  			if (res != -EEXIST)

  				goto out;

  		}

  		HFSPLUS_I(inode)->linkid = id;

  		cnid = sbi->next_cnid++;

  		src_dentry->d_fsdata = (void *)(unsigned long)cnid;

  		res = hfsplus_create_cat(cnid, src_dir,
  			&src_dentry->d_name, inode);

  		if (res)
  			/* panic? */

  			goto out;

  		sbi->file_count++;

  	}

  	cnid = sbi->next_cnid++;

  	res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
  	if (res)

  		goto out;

  	inc_nlink(inode);

  	hfsplus_instantiate(dst_dentry, inode, cnid);

  	ihold(inode);

  	inode->i_ctime = CURRENT_TIME_SEC;
  	mark_inode_dirty(inode);

  	sbi->file_count++;
  	dst_dir->i_sb->s_dirt = 1;

  out:
  	mutex_unlock(&sbi->vh_mutex);
  	return res;

  }
  
  static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
  {

  	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);

  	struct inode *inode = dentry->d_inode;
  	struct qstr str;
  	char name[32];
  	u32 cnid;
  	int res;
  
  	if (HFSPLUS_IS_RSRC(inode))
  		return -EPERM;

  	mutex_lock(&sbi->vh_mutex);

  	cnid = (u32)(unsigned long)dentry->d_fsdata;
  	if (inode->i_ino == cnid &&

  	    atomic_read(&HFSPLUS_I(inode)->opencnt)) {

  		str.name = name;
  		str.len = sprintf(name, "temp%lu", inode->i_ino);
  		res = hfsplus_rename_cat(inode->i_ino,
  					 dir, &dentry->d_name,

  					 sbi->hidden_dir, &str);

  		if (!res) {

  			inode->i_flags |= S_DEAD;

  			drop_nlink(inode);
  		}

  		goto out;

  	}
  	res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
  	if (res)

  		goto out;

  	if (inode->i_nlink > 0)

  		drop_nlink(inode);

  	if (inode->i_ino == cnid)
  		clear_nlink(inode);
  	if (!inode->i_nlink) {
  		if (inode->i_ino != cnid) {

  			sbi->file_count--;

  			if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {

  				res = hfsplus_delete_cat(inode->i_ino,

  							 sbi->hidden_dir,

  							 NULL);
  				if (!res)
  					hfsplus_delete_inode(inode);
  			} else
  				inode->i_flags |= S_DEAD;

  		} else

  			hfsplus_delete_inode(inode);

  	} else

  		sbi->file_count--;

  	inode->i_ctime = CURRENT_TIME_SEC;
  	mark_inode_dirty(inode);

  out:
  	mutex_unlock(&sbi->vh_mutex);

  	return res;
  }

  static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
  {

  	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
  	struct inode *inode = dentry->d_inode;

  	int res;

  	if (inode->i_size != 2)
  		return -ENOTEMPTY;

  
  	mutex_lock(&sbi->vh_mutex);

  	res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
  	if (res)

  		goto out;

  	clear_nlink(inode);

  	inode->i_ctime = CURRENT_TIME_SEC;
  	hfsplus_delete_inode(inode);
  	mark_inode_dirty(inode);

  out:
  	mutex_unlock(&sbi->vh_mutex);
  	return res;

  }
  
  static int hfsplus_symlink(struct inode *dir, struct dentry *dentry,
  			   const char *symname)
  {

  	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);

  	struct inode *inode;

  	int res = -ENOSPC;

  	mutex_lock(&sbi->vh_mutex);

  	inode = hfsplus_new_inode(dir->i_sb, S_IFLNK | S_IRWXUGO);

  	if (!inode)

  		goto out;

  
  	res = page_symlink(inode, symname, strlen(symname) + 1);

  	if (res)
  		goto out_err;

  	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);

  	if (res)
  		goto out_err;

  	hfsplus_instantiate(dentry, inode, inode->i_ino);
  	mark_inode_dirty(inode);

  	goto out;

  out_err:

  	clear_nlink(inode);

  	hfsplus_delete_inode(inode);
  	iput(inode);

  out:
  	mutex_unlock(&sbi->vh_mutex);

  	return res;
  }
  
  static int hfsplus_mknod(struct inode *dir, struct dentry *dentry,

  			 umode_t mode, dev_t rdev)

  {

  	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);

  	struct inode *inode;

  	int res = -ENOSPC;

  	mutex_lock(&sbi->vh_mutex);

  	inode = hfsplus_new_inode(dir->i_sb, mode);

  	if (!inode)

  		goto out;

  	if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
  		init_special_inode(inode, mode, rdev);

  	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
  	if (res) {

  		clear_nlink(inode);

  		hfsplus_delete_inode(inode);
  		iput(inode);

  		goto out;

  	}

  	hfsplus_instantiate(dentry, inode, inode->i_ino);
  	mark_inode_dirty(inode);

  out:
  	mutex_unlock(&sbi->vh_mutex);
  	return res;

  }

  static int hfsplus_create(struct inode *dir, struct dentry *dentry, umode_t mode,

  			  struct nameidata *nd)
  {
  	return hfsplus_mknod(dir, dentry, mode, 0);
  }

  static int hfsplus_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)

  {
  	return hfsplus_mknod(dir, dentry, mode | S_IFDIR, 0);
  }

  static int hfsplus_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) {

  		if (S_ISDIR(new_dentry->d_inode->i_mode))

  			res = hfsplus_rmdir(new_dir, new_dentry);

  		else

  			res = hfsplus_unlink(new_dir, new_dentry);

  		if (res)
  			return res;
  	}
  
  	res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
  				 old_dir, &old_dentry->d_name,
  				 new_dir, &new_dentry->d_name);
  	if (!res)
  		new_dentry->d_fsdata = old_dentry->d_fsdata;
  	return res;
  }

  const struct inode_operations hfsplus_dir_inode_operations = {

  	.lookup		= hfsplus_lookup,
  	.create		= hfsplus_create,
  	.link		= hfsplus_link,
  	.unlink		= hfsplus_unlink,
  	.mkdir		= hfsplus_mkdir,
  	.rmdir		= hfsplus_rmdir,
  	.symlink	= hfsplus_symlink,
  	.mknod		= hfsplus_mknod,
  	.rename		= hfsplus_rename,
  };

  const struct file_operations hfsplus_dir_operations = {

  	.fsync		= hfsplus_file_fsync,

  	.read		= generic_read_dir,
  	.readdir	= hfsplus_readdir,

  	.unlocked_ioctl = hfsplus_ioctl,

  	.llseek		= generic_file_llseek,
  	.release	= hfsplus_dir_release,
  };