1/**
2 * eCryptfs: Linux filesystem encryption layer
3 *
4 * Copyright (C) 1997-2003 Erez Zadok
5 * Copyright (C) 2001-2003 Stony Brook University
6 * Copyright (C) 2004-2006 International Business Machines Corp.
7 *   Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation; either version 2 of the
12 * License, or (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
22 * 02111-1307, USA.
23 */
24
25#include <linux/dcache.h>
26#include <linux/namei.h>
27#include <linux/mount.h>
28#include <linux/fs_stack.h>
29#include "ecryptfs_kernel.h"
30
31/**
32 * ecryptfs_d_revalidate - revalidate an ecryptfs dentry
33 * @dentry: The ecryptfs dentry
34 * @nd: The associated nameidata
35 *
36 * Called when the VFS needs to revalidate a dentry. This
37 * is called whenever a name lookup finds a dentry in the
38 * dcache. Most filesystems leave this as NULL, because all their
39 * dentries in the dcache are valid.
40 *
41 * Returns 1 if valid, 0 otherwise.
42 *
43 */
44static int ecryptfs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
45{
46	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
47	struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
48	struct dentry *dentry_save;
49	struct vfsmount *vfsmount_save;
50	int rc = 1;
51
52	if (!lower_dentry->d_op || !lower_dentry->d_op->d_revalidate)
53		goto out;
54	dentry_save = nd->dentry;
55	vfsmount_save = nd->mnt;
56	nd->dentry = lower_dentry;
57	nd->mnt = lower_mnt;
58	rc = lower_dentry->d_op->d_revalidate(lower_dentry, nd);
59	nd->dentry = dentry_save;
60	nd->mnt = vfsmount_save;
61	if (dentry->d_inode) {
62		struct inode *lower_inode =
63			ecryptfs_inode_to_lower(dentry->d_inode);
64
65		fsstack_copy_attr_all(dentry->d_inode, lower_inode, NULL);
66	}
67out:
68	return rc;
69}
70
71struct kmem_cache *ecryptfs_dentry_info_cache;
72
73/**
74 * ecryptfs_d_release
75 * @dentry: The ecryptfs dentry
76 *
77 * Called when a dentry is really deallocated.
78 */
79static void ecryptfs_d_release(struct dentry *dentry)
80{
81	if (ecryptfs_dentry_to_private(dentry)) {
82		if (ecryptfs_dentry_to_lower(dentry)) {
83			mntput(ecryptfs_dentry_to_lower_mnt(dentry));
84			dput(ecryptfs_dentry_to_lower(dentry));
85		}
86		kmem_cache_free(ecryptfs_dentry_info_cache,
87				ecryptfs_dentry_to_private(dentry));
88	}
89	return;
90}
91
92struct dentry_operations ecryptfs_dops = {
93	.d_revalidate = ecryptfs_d_revalidate,
94	.d_release = ecryptfs_d_release,
95};
96