path: root/fs/ecryptfs/inode.c

/**
 * eCryptfs: Linux filesystem encryption layer
 *
 * Copyright (C) 1997-2004 Erez Zadok
 * Copyright (C) 2001-2004 Stony Brook University
 * Copyright (C) 2004-2007 International Business Machines Corp.
 *   Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
 *              Michael C. Thompsion <mcthomps@us.ibm.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 */

#include <linux/file.h>
#include <linux/vmalloc.h>
#include <linux/pagemap.h>
#include <linux/dcache.h>
#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/crypto.h>
#include <linux/fs_stack.h>
#include <linux/slab.h>
#include <linux/xattr.h>
#include <asm/unaligned.h>
#include "ecryptfs_kernel.h"

static struct dentry *lock_parent(struct dentry *dentry)
{
	struct dentry *dir;

	dir = dget_parent(dentry);
	mutex_lock_nested(&(dir->d_inode->i_mutex), I_MUTEX_PARENT);
	return dir;
}

static void unlock_dir(struct dentry *dir)
{
	mutex_unlock(&dir->d_inode->i_mutex);
	dput(dir);
}

static int ecryptfs_inode_test(struct inode *inode, void *lower_inode)
{
	if (ecryptfs_inode_to_lower(inode) == (struct inode *)lower_inode)
		return 1;
	return 0;
}

static int ecryptfs_inode_set(struct inode *inode, void *opaque)
{
	struct inode *lower_inode = opaque;

	ecryptfs_set_inode_lower(inode, lower_inode);
	fsstack_copy_attr_all(inode, lower_inode);
	/* i_size will be overwritten for encrypted regular files */
	fsstack_copy_inode_size(inode, lower_inode);
	inode->i_ino = lower_inode->i_ino;
	inode->i_version++;
	inode->i_mapping->a_ops = &ecryptfs_aops;
	inode->i_mapping->backing_dev_info = inode->i_sb->s_bdi;

	if (S_ISLNK(inode->i_mode))
		inode->i_op = &ecryptfs_symlink_iops;
	else if (S_ISDIR(inode->i_mode))
		inode->i_op = &ecryptfs_dir_iops;
	else
		inode->i_op = &ecryptfs_main_iops;

	if (S_ISDIR(inode->i_mode))
		inode->i_fop = &ecryptfs_dir_fops;
	else if (special_file(inode->i_mode))
		init_special_inode(inode, inode->i_mode, inode->i_rdev);
	else
		inode->i_fop = &ecryptfs_main_fops;

	return 0;
}

static struct inode *__ecryptfs_get_inode(struct inode *lower_inode,
					  struct super_block *sb)
{
	struct inode *inode;

	if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb))
		return ERR_PTR(-EXDEV);
	if (!igrab(lower_inode))
		return ERR_PTR(-ESTALE);
	inode = iget5_locked(sb, (unsigned long)lower_inode,
			     <