From 237fead619984cc48818fe12ee0ceada3f55b012 Mon Sep 17 00:00:00 2001 From: Michael Halcrow Date: Wed, 4 Oct 2006 02:16:22 -0700 Subject: [PATCH] ecryptfs: fs/Makefile and fs/Kconfig eCryptfs is a stacked cryptographic filesystem for Linux. It is derived from Erez Zadok's Cryptfs, implemented through the FiST framework for generating stacked filesystems. eCryptfs extends Cryptfs to provide advanced key management and policy features. eCryptfs stores cryptographic metadata in the header of each file written, so that encrypted files can be copied between hosts; the file will be decryptable with the proper key, and there is no need to keep track of any additional information aside from what is already in the encrypted file itself. [akpm@osdl.org: updates for ongoing API changes] [bunk@stusta.de: cleanups] [akpm@osdl.org: alpha build fix] [akpm@osdl.org: cleanups] [tytso@mit.edu: inode-diet updates] [pbadari@us.ibm.com: generic_file_*_read/write() interface updates] [rdunlap@xenotime.net: printk format fixes] [akpm@osdl.org: make slab creation and teardown table-driven] Signed-off-by: Phillip Hellewell Signed-off-by: Michael Halcrow Signed-off-by: Erez Zadok Signed-off-by: Adrian Bunk Signed-off-by: Stephan Mueller Signed-off-by: "Theodore Ts'o" Signed-off-by: Badari Pulavarty Signed-off-by: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ecryptfs/dentry.c | 87 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 87 insertions(+) create mode 100644 fs/ecryptfs/dentry.c (limited to 'fs/ecryptfs/dentry.c') diff --git a/fs/ecryptfs/dentry.c b/fs/ecryptfs/dentry.c new file mode 100644 index 0000000000000..f0d2a433242b5 --- /dev/null +++ b/fs/ecryptfs/dentry.c @@ -0,0 +1,87 @@ +/** + * 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 + * + * 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 +#include +#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 = ecryptfs_dentry_to_lower(dentry); + struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry); + struct dentry *dentry_save; + struct vfsmount *vfsmount_save; + int rc = 1; + + if (!lower_dentry->d_op || !lower_dentry->d_op->d_revalidate) + goto out; + dentry_save = nd->dentry; + vfsmount_save = nd->mnt; + nd->dentry = lower_dentry; + nd->mnt = lower_mnt; + rc = lower_dentry->d_op->d_revalidate(lower_dentry, nd); + nd->dentry = dentry_save; + nd->mnt = vfsmount_save; +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) +{ + struct dentry *lower_dentry; + + lower_dentry = ecryptfs_dentry_to_lower(dentry); + if (ecryptfs_dentry_to_private(dentry)) + kmem_cache_free(ecryptfs_dentry_info_cache, + ecryptfs_dentry_to_private(dentry)); + if (lower_dentry) + dput(lower_dentry); + return; +} + +struct dentry_operations ecryptfs_dops = { + .d_revalidate = ecryptfs_d_revalidate, + .d_release = ecryptfs_d_release, +}; -- cgit 1.2.3-korg