1// SPDX-License-Identifier: GPL-2.0-or-later
 2/*
 3 * eCryptfs: Linux filesystem encryption layer
 4 *
 5 * Copyright (C) 1997-2003 Erez Zadok
 6 * Copyright (C) 2001-2003 Stony Brook University
 7 * Copyright (C) 2004-2006 International Business Machines Corp.
 8 *   Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 9 */
10
11#include <linux/dcache.h>
12#include <linux/namei.h>
13#include <linux/mount.h>
14#include <linux/fs_stack.h>
15#include <linux/slab.h>
16#include "ecryptfs_kernel.h"
17
18/**
19 * ecryptfs_d_revalidate - revalidate an ecryptfs dentry
20 * @dentry: The ecryptfs dentry
21 * @flags: lookup flags
22 *
23 * Called when the VFS needs to revalidate a dentry. This
24 * is called whenever a name lookup finds a dentry in the
25 * dcache. Most filesystems leave this as NULL, because all their
26 * dentries in the dcache are valid.
27 *
28 * Returns 1 if valid, 0 otherwise.
29 *
30 */
31static int ecryptfs_d_revalidate(struct dentry *dentry, unsigned int flags)
32{
33	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
34	int rc = 1;
 
 
 
35
36	if (flags & LOOKUP_RCU)
37		return -ECHILD;
38
39	if (lower_dentry->d_flags & DCACHE_OP_REVALIDATE)
40		rc = lower_dentry->d_op->d_revalidate(lower_dentry, flags);
41
42	if (d_really_is_positive(dentry)) {
43		struct inode *inode = d_inode(dentry);
44
45		fsstack_copy_attr_all(inode, ecryptfs_inode_to_lower(inode));
46		if (!inode->i_nlink)
47			return 0;
48	}
49	return rc;
50}
51
52struct kmem_cache *ecryptfs_dentry_info_cache;
53
54static void ecryptfs_dentry_free_rcu(struct rcu_head *head)
55{
56	kmem_cache_free(ecryptfs_dentry_info_cache,
57		container_of(head, struct ecryptfs_dentry_info, rcu));
58}
59
60/**
61 * ecryptfs_d_release
62 * @dentry: The ecryptfs dentry
63 *
64 * Called when a dentry is really deallocated.
65 */
66static void ecryptfs_d_release(struct dentry *dentry)
67{
68	struct ecryptfs_dentry_info *p = dentry->d_fsdata;
69	if (p) {
70		path_put(&p->lower_path);
71		call_rcu(&p->rcu, ecryptfs_dentry_free_rcu);
72	}
73}
74
75const struct dentry_operations ecryptfs_dops = {
76	.d_revalidate = ecryptfs_d_revalidate,
77	.d_release = ecryptfs_d_release,
78};

 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 */
45static 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	if (!(lower_dentry->d_flags & DCACHE_OP_REVALIDATE))
51		return 1;
52
53	if (flags & LOOKUP_RCU)
54		return -ECHILD;
55
56	rc = lower_dentry->d_op->d_revalidate(lower_dentry, flags);
57	if (dentry->d_inode) {
58		struct inode *lower_inode =
59			ecryptfs_inode_to_lower(dentry->d_inode);
 
60
61		fsstack_copy_attr_all(dentry->d_inode, lower_inode);
 
 
62	}
63	return rc;
64}
65
66struct kmem_cache *ecryptfs_dentry_info_cache;
67
68static 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
74/**
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{
82	struct ecryptfs_dentry_info *p = dentry->d_fsdata;
83	if (p) {
84		path_put(&p->lower_path);
85		call_rcu(&p->rcu, ecryptfs_dentry_free_rcu);
86	}
87}
88
89const struct dentry_operations ecryptfs_dops = {
90	.d_revalidate = ecryptfs_d_revalidate,
91	.d_release = ecryptfs_d_release,
92};