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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 <linux/slab.h>
30 : : #include "ecryptfs_kernel.h"
31 : :
32 : : /**
33 : : * ecryptfs_d_revalidate - revalidate an ecryptfs dentry
34 : : * @dentry: The ecryptfs dentry
35 : : * @flags: lookup flags
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 : : */
45 : 0 : static int ecryptfs_d_revalidate(struct dentry *dentry, unsigned int flags)
46 : : {
47 : : struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
48 : : int rc;
49 : :
50 [ # # ]: 0 : if (!(lower_dentry->d_flags & DCACHE_OP_REVALIDATE))
51 : : return 1;
52 : :
53 [ # # ]: 0 : if (flags & LOOKUP_RCU)
54 : : return -ECHILD;
55 : :
56 : 0 : rc = lower_dentry->d_op->d_revalidate(lower_dentry, flags);
57 [ # # ]: 0 : if (dentry->d_inode) {
58 : : struct inode *lower_inode =
59 : : ecryptfs_inode_to_lower(dentry->d_inode);
60 : :
61 : 0 : fsstack_copy_attr_all(dentry->d_inode, lower_inode);
62 : : }
63 : 0 : return rc;
64 : : }
65 : :
66 : : struct kmem_cache *ecryptfs_dentry_info_cache;
67 : :
68 : 0 : static void ecryptfs_dentry_free_rcu(struct rcu_head *head)
69 : : {
70 : 0 : kmem_cache_free(ecryptfs_dentry_info_cache,
71 : 0 : container_of(head, struct ecryptfs_dentry_info, rcu));
72 : 0 : }
73 : :
74 : : /**
75 : : * ecryptfs_d_release
76 : : * @dentry: The ecryptfs dentry
77 : : *
78 : : * Called when a dentry is really deallocated.
79 : : */
80 : 0 : static void ecryptfs_d_release(struct dentry *dentry)
81 : : {
82 : 0 : struct ecryptfs_dentry_info *p = dentry->d_fsdata;
83 [ # # ]: 0 : if (p) {
84 : 0 : path_put(&p->lower_path);
85 : 0 : call_rcu(&p->rcu, ecryptfs_dentry_free_rcu);
86 : : }
87 : 0 : }
88 : :
89 : : const struct dentry_operations ecryptfs_dops = {
90 : : .d_revalidate = ecryptfs_d_revalidate,
91 : : .d_release = ecryptfs_d_release,
92 : : };
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