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 * @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{
 47	struct dentry *lower_dentry;
 48	struct vfsmount *lower_mnt;
 49	struct dentry *dentry_save = NULL;
 50	struct vfsmount *vfsmount_save = NULL;
 51	int rc = 1;
 52
 53	if (nd && 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);
 58	if (!lower_dentry->d_op || !lower_dentry->d_op->d_revalidate)
 59		goto out;
 60	if (nd) {
 61		dentry_save = nd->path.dentry;
 62		vfsmount_save = nd->path.mnt;
 63		nd->path.dentry = lower_dentry;
 64		nd->path.mnt = lower_mnt;
 65	}
 66	rc = lower_dentry->d_op->d_revalidate(lower_dentry, nd);
 67	if (nd) {
 68		nd->path.dentry = dentry_save;
 69		nd->path.mnt = vfsmount_save;
 70	}
 71	if (dentry->d_inode) {
 72		struct inode *lower_inode =
 73			ecryptfs_inode_to_lower(dentry->d_inode);
 74
 75		fsstack_copy_attr_all(dentry->d_inode, lower_inode);
 
 
 76	}
 77out:
 78	return rc;
 79}
 80
 81struct kmem_cache *ecryptfs_dentry_info_cache;
 82
 
 
 
 
 
 
 83/**
 84 * ecryptfs_d_release
 85 * @dentry: The ecryptfs dentry
 86 *
 87 * Called when a dentry is really deallocated.
 88 */
 89static void ecryptfs_d_release(struct dentry *dentry)
 90{
 91	if (ecryptfs_dentry_to_private(dentry)) {
 92		if (ecryptfs_dentry_to_lower(dentry)) {
 93			dput(ecryptfs_dentry_to_lower(dentry));
 94			mntput(ecryptfs_dentry_to_lower_mnt(dentry));
 95		}
 96		kmem_cache_free(ecryptfs_dentry_info_cache,
 97				ecryptfs_dentry_to_private(dentry));
 98	}
 99	return;
100}
101
102const struct dentry_operations ecryptfs_dops = {
103	.d_revalidate = ecryptfs_d_revalidate,
104	.d_release = ecryptfs_d_release,
105};