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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>
Josef "Jeff" Sipek0cc72dc2006-12-08 02:36:31 -080028#include <linux/fs_stack.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090029#include <linux/slab.h>
Michael Halcrow237fead2006-10-04 02:16:22 -070030#include "ecryptfs_kernel.h"
31
32/**
33 * ecryptfs_d_revalidate - revalidate an ecryptfs dentry
34 * @dentry: The ecryptfs dentry
35 * @nd: The associated nameidata
36 *
37 * Called when the VFS needs to revalidate a dentry. This
38 * is called whenever a name lookup finds a dentry in the
39 * dcache. Most filesystems leave this as NULL, because all their
40 * dentries in the dcache are valid.
41 *
42 * Returns 1 if valid, 0 otherwise.
43 *
44 */
45static int ecryptfs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
46{
Nick Piggin34286d62011-01-07 17:49:57 +110047 struct dentry *lower_dentry;
48 struct vfsmount *lower_mnt;
Michael Halcrow237fead2006-10-04 02:16:22 -070049 struct dentry *dentry_save;
50 struct vfsmount *vfsmount_save;
51 int rc = 1;
52
Nick Piggin34286d62011-01-07 17:49:57 +110053 if (nd->flags & LOOKUP_RCU)
54 return -ECHILD;
55
56 lower_dentry = ecryptfs_dentry_to_lower(dentry);
57 lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
Michael Halcrow237fead2006-10-04 02:16:22 -070058 if (!lower_dentry->d_op || !lower_dentry->d_op->d_revalidate)
59 goto out;
Jan Blunck4ac91372008-02-14 19:34:32 -080060 dentry_save = nd->path.dentry;
61 vfsmount_save = nd->path.mnt;
62 nd->path.dentry = lower_dentry;
63 nd->path.mnt = lower_mnt;
Michael Halcrow237fead2006-10-04 02:16:22 -070064 rc = lower_dentry->d_op->d_revalidate(lower_dentry, nd);
Jan Blunck4ac91372008-02-14 19:34:32 -080065 nd->path.dentry = dentry_save;
66 nd->path.mnt = vfsmount_save;
Michael Halcrowae56fb12006-11-16 01:19:30 -080067 if (dentry->d_inode) {
68 struct inode *lower_inode =
69 ecryptfs_inode_to_lower(dentry->d_inode);
70
Erez Zadok9afa2fb2009-12-02 19:51:54 -050071 fsstack_copy_attr_all(dentry->d_inode, lower_inode);
Michael Halcrowae56fb12006-11-16 01:19:30 -080072 }
Michael Halcrow237fead2006-10-04 02:16:22 -070073out:
74 return rc;
75}
76
77struct kmem_cache *ecryptfs_dentry_info_cache;
78
79/**
80 * ecryptfs_d_release
81 * @dentry: The ecryptfs dentry
82 *
83 * Called when a dentry is really deallocated.
84 */
85static void ecryptfs_d_release(struct dentry *dentry)
86{
Michael Halcrowb228b8e2007-03-16 13:38:22 -080087 if (ecryptfs_dentry_to_private(dentry)) {
88 if (ecryptfs_dentry_to_lower(dentry)) {
Michael Halcrowb228b8e2007-03-16 13:38:22 -080089 dput(ecryptfs_dentry_to_lower(dentry));
Michael Halcrow5366dc9f2008-03-19 17:00:58 -070090 mntput(ecryptfs_dentry_to_lower_mnt(dentry));
Michael Halcrowb228b8e2007-03-16 13:38:22 -080091 }
Michael Halcrow237fead2006-10-04 02:16:22 -070092 kmem_cache_free(ecryptfs_dentry_info_cache,
93 ecryptfs_dentry_to_private(dentry));
Michael Halcrow45ec4aba2006-10-30 22:07:20 -080094 }
Michael Halcrow237fead2006-10-04 02:16:22 -070095 return;
96}
97
Al Viro5a3fd052009-02-20 05:57:52 +000098const struct dentry_operations ecryptfs_dops = {
Michael Halcrow237fead2006-10-04 02:16:22 -070099 .d_revalidate = ecryptfs_d_revalidate,
100 .d_release = ecryptfs_d_release,
101};