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 = ecryptfs_dentry_to_lower(dentry); 48 struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry); 49 struct dentry *dentry_save; 50 struct vfsmount *vfsmount_save; 51 int rc = 1; 52 53 if (!lower_dentry->d_op || !lower_dentry->d_op->d_revalidate) 54 goto out; 55 dentry_save = nd->path.dentry; 56 vfsmount_save = nd->path.mnt; 57 nd->path.dentry = lower_dentry; 58 nd->path.mnt = lower_mnt; 59 rc = lower_dentry->d_op->d_revalidate(lower_dentry, nd); 60 nd->path.dentry = dentry_save; 61 nd->path.mnt = vfsmount_save; 62 if (dentry->d_inode) { 63 struct inode *lower_inode = 64 ecryptfs_inode_to_lower(dentry->d_inode); 65 66 fsstack_copy_attr_all(dentry->d_inode, lower_inode); 67 } 68out: 69 return rc; 70} 71 72struct kmem_cache *ecryptfs_dentry_info_cache; 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 if (ecryptfs_dentry_to_private(dentry)) { 83 if (ecryptfs_dentry_to_lower(dentry)) { 84 dput(ecryptfs_dentry_to_lower(dentry)); 85 mntput(ecryptfs_dentry_to_lower_mnt(dentry)); 86 } 87 kmem_cache_free(ecryptfs_dentry_info_cache, 88 ecryptfs_dentry_to_private(dentry)); 89 } 90 return; 91} 92 93const struct dentry_operations ecryptfs_dops = { 94 .d_revalidate = ecryptfs_d_revalidate, 95 .d_release = ecryptfs_d_release, 96}; 97