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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
Al Viro0b728e12012-06-10 16:03:43 -040035 * @flags: lookup flags
Michael Halcrow237fead2006-10-04 02:16:22 -070036 *
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 */
Al Viro0b728e12012-06-10 16:03:43 -040045static int ecryptfs_d_revalidate(struct dentry *dentry, unsigned int flags)
Michael Halcrow237fead2006-10-04 02:16:22 -070046{
Al Viro2edbfbf2013-09-15 20:45:11 -040047 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
48 int rc;
49
50 if (!(lower_dentry->d_flags & DCACHE_OP_REVALIDATE))
51 return 1;
Michael Halcrow237fead2006-10-04 02:16:22 -070052
Al Viro0b728e12012-06-10 16:03:43 -040053 if (flags & LOOKUP_RCU)
Nick Piggin34286d62011-01-07 17:49:57 +110054 return -ECHILD;
55
Al Viro0b728e12012-06-10 16:03:43 -040056 rc = lower_dentry->d_op->d_revalidate(lower_dentry, flags);
Michael Halcrowae56fb12006-11-16 01:19:30 -080057 if (dentry->d_inode) {
58 struct inode *lower_inode =
59 ecryptfs_inode_to_lower(dentry->d_inode);
60
Erez Zadok9afa2fb2009-12-02 19:51:54 -050061 fsstack_copy_attr_all(dentry->d_inode, lower_inode);
Michael Halcrowae56fb12006-11-16 01:19:30 -080062 }
Michael Halcrow237fead2006-10-04 02:16:22 -070063 return rc;
64}
65
66struct kmem_cache *ecryptfs_dentry_info_cache;
67
Al Viro2edbfbf2013-09-15 20:45:11 -040068static void ecryptfs_dentry_free_rcu(struct rcu_head *head)
69{
70 kmem_cache_free(ecryptfs_dentry_info_cache,
71 container_of(head, struct ecryptfs_dentry_info, rcu));
72}
73
Michael Halcrow237fead2006-10-04 02:16:22 -070074/**
75 * ecryptfs_d_release
76 * @dentry: The ecryptfs dentry
77 *
78 * Called when a dentry is really deallocated.
79 */
80static void ecryptfs_d_release(struct dentry *dentry)
81{
Al Viro2edbfbf2013-09-15 20:45:11 -040082 struct ecryptfs_dentry_info *p = dentry->d_fsdata;
83 if (p) {
Al Virocbe9c082013-09-15 20:54:18 -040084 path_put(&p->lower_path);
Al Viro2edbfbf2013-09-15 20:45:11 -040085 call_rcu(&p->rcu, ecryptfs_dentry_free_rcu);
Michael Halcrow45ec4aba2006-10-30 22:07:20 -080086 }
Michael Halcrow237fead2006-10-04 02:16:22 -070087}
88
Al Viro5a3fd052009-02-20 05:57:52 +000089const struct dentry_operations ecryptfs_dops = {
Michael Halcrow237fead2006-10-04 02:16:22 -070090 .d_revalidate = ecryptfs_d_revalidate,
91 .d_release = ecryptfs_d_release,
92};