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Michael Halcrow237fead2006-10-04 02:16:22 -07001/**
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>
Michael Halcrow45ec4aba2006-10-30 22:07:20 -080027#include <linux/mount.h>
Michael Halcrow237fead2006-10-04 02:16:22 -070028#include "ecryptfs_kernel.h"
29
30/**
31 * ecryptfs_d_revalidate - revalidate an ecryptfs dentry
32 * @dentry: The ecryptfs dentry
33 * @nd: The associated nameidata
34 *
35 * Called when the VFS needs to revalidate a dentry. This
36 * is called whenever a name lookup finds a dentry in the
37 * dcache. Most filesystems leave this as NULL, because all their
38 * dentries in the dcache are valid.
39 *
40 * Returns 1 if valid, 0 otherwise.
41 *
42 */
43static int ecryptfs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
44{
45 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
46 struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
47 struct dentry *dentry_save;
48 struct vfsmount *vfsmount_save;
49 int rc = 1;
50
51 if (!lower_dentry->d_op || !lower_dentry->d_op->d_revalidate)
52 goto out;
53 dentry_save = nd->dentry;
54 vfsmount_save = nd->mnt;
55 nd->dentry = lower_dentry;
56 nd->mnt = lower_mnt;
57 rc = lower_dentry->d_op->d_revalidate(lower_dentry, nd);
58 nd->dentry = dentry_save;
59 nd->mnt = vfsmount_save;
60out:
61 return rc;
62}
63
64struct kmem_cache *ecryptfs_dentry_info_cache;
65
66/**
67 * ecryptfs_d_release
68 * @dentry: The ecryptfs dentry
69 *
70 * Called when a dentry is really deallocated.
71 */
72static void ecryptfs_d_release(struct dentry *dentry)
73{
74 struct dentry *lower_dentry;
75
76 lower_dentry = ecryptfs_dentry_to_lower(dentry);
77 if (ecryptfs_dentry_to_private(dentry))
78 kmem_cache_free(ecryptfs_dentry_info_cache,
79 ecryptfs_dentry_to_private(dentry));
Michael Halcrow45ec4aba2006-10-30 22:07:20 -080080 if (lower_dentry) {
81 struct vfsmount *lower_mnt =
82 ecryptfs_dentry_to_lower_mnt(dentry);
83
84 mntput(lower_mnt);
Michael Halcrow237fead2006-10-04 02:16:22 -070085 dput(lower_dentry);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -080086 }
Michael Halcrow237fead2006-10-04 02:16:22 -070087 return;
88}
89
90struct dentry_operations ecryptfs_dops = {
91 .d_revalidate = ecryptfs_d_revalidate,
92 .d_release = ecryptfs_d_release,
93};