/** * eCryptfs: Linux filesystem encryption layer * * Copyright (C) 1997-2003 Erez Zadok * Copyright (C) 2001-2003 Stony Brook University * Copyright (C) 2004-2006 International Business Machines Corp. *   Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of the * License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA * 02111-1307, USA. */ #include <linux/dcache.h>#include <linux/namei.h>#include <linux/mount.h>#include <linux/fs_stack.h>#include <linux/slab.h>#include "ecryptfs_kernel.h" /** * ecryptfs_d_revalidate - revalidate an ecryptfs dentry * @dentry: The ecryptfs dentry * @nd: The associated nameidata * * Called when the VFS needs to revalidate a dentry. This * is called whenever a name lookup finds a dentry in the * dcache. Most filesystems leave this as NULL, because all their * dentries in the dcache are valid. * * Returns 1 if valid, 0 otherwise. * */static int ecryptfs_d_revalidate(struct dentry *dentry, struct nameidata *nd){	struct dentry *lower_dentry;	struct vfsmount *lower_mnt;	struct dentry *dentry_save = NULL;	struct vfsmount *vfsmount_save = NULL;	int rc = 1; 	if (nd && nd->flags & LOOKUP_RCU)		return -ECHILD; 	lower_dentry = ecryptfs_dentry_to_lower(dentry);	lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);	if (!lower_dentry->d_op || !lower_dentry->d_op->d_revalidate)		goto out;	if (nd) {		dentry_save = nd->path.dentry;		vfsmount_save = nd->path.mnt;		nd->path.dentry = lower_dentry;		nd->path.mnt = lower_mnt;	}	rc = lower_dentry->d_op->d_revalidate(lower_dentry, nd);	if (nd) {		nd->path.dentry = dentry_save;		nd->path.mnt = vfsmount_save;	}	if (dentry->d_inode) {		struct inode *lower_inode =			ecryptfs_inode_to_lower(dentry->d_inode); 		fsstack_copy_attr_all(dentry->d_inode, lower_inode);	}out:	return rc;} struct kmem_cache *ecryptfs_dentry_info_cache; /** * ecryptfs_d_release * @dentry: The ecryptfs dentry * * Called when a dentry is really deallocated. */static void ecryptfs_d_release(struct dentry *dentry){	if (ecryptfs_dentry_to_private(dentry)) {		if (ecryptfs_dentry_to_lower(dentry)) {			dput(ecryptfs_dentry_to_lower(dentry));			mntput(ecryptfs_dentry_to_lower_mnt(dentry));		}		kmem_cache_free(ecryptfs_dentry_info_cache,				ecryptfs_dentry_to_private(dentry));	}	return;} const struct dentry_operations ecryptfs_dops = {	.d_revalidate = ecryptfs_d_revalidate,	.d_release = ecryptfs_d_release,};