forked from mirrors/linux
70b8902199
Allow for NULL nameidata pointers in eCryptfs create, lookup, and d_revalidate functions. Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
105 lines
3 KiB
C
105 lines
3 KiB
C
/**
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* eCryptfs: Linux filesystem encryption layer
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*
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* Copyright (C) 1997-2003 Erez Zadok
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* Copyright (C) 2001-2003 Stony Brook University
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* Copyright (C) 2004-2006 International Business Machines Corp.
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* Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
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* 02111-1307, USA.
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*/
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#include <linux/dcache.h>
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#include <linux/namei.h>
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#include <linux/mount.h>
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#include <linux/fs_stack.h>
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#include <linux/slab.h>
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#include "ecryptfs_kernel.h"
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/**
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* ecryptfs_d_revalidate - revalidate an ecryptfs dentry
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* @dentry: The ecryptfs dentry
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* @nd: The associated nameidata
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*
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* Called when the VFS needs to revalidate a dentry. This
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* is called whenever a name lookup finds a dentry in the
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* dcache. Most filesystems leave this as NULL, because all their
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* dentries in the dcache are valid.
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*
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* Returns 1 if valid, 0 otherwise.
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*
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*/
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static int ecryptfs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
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{
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struct dentry *lower_dentry;
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struct vfsmount *lower_mnt;
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struct dentry *dentry_save = NULL;
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struct vfsmount *vfsmount_save = NULL;
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int rc = 1;
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if (nd && nd->flags & LOOKUP_RCU)
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return -ECHILD;
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lower_dentry = ecryptfs_dentry_to_lower(dentry);
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lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
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if (!lower_dentry->d_op || !lower_dentry->d_op->d_revalidate)
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goto out;
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if (nd) {
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dentry_save = nd->path.dentry;
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vfsmount_save = nd->path.mnt;
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nd->path.dentry = lower_dentry;
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nd->path.mnt = lower_mnt;
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}
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rc = lower_dentry->d_op->d_revalidate(lower_dentry, nd);
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if (nd) {
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nd->path.dentry = dentry_save;
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nd->path.mnt = vfsmount_save;
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}
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if (dentry->d_inode) {
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struct inode *lower_inode =
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ecryptfs_inode_to_lower(dentry->d_inode);
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fsstack_copy_attr_all(dentry->d_inode, lower_inode);
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}
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out:
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return rc;
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}
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struct kmem_cache *ecryptfs_dentry_info_cache;
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/**
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* ecryptfs_d_release
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* @dentry: The ecryptfs dentry
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*
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* Called when a dentry is really deallocated.
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*/
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static void ecryptfs_d_release(struct dentry *dentry)
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{
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if (ecryptfs_dentry_to_private(dentry)) {
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if (ecryptfs_dentry_to_lower(dentry)) {
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dput(ecryptfs_dentry_to_lower(dentry));
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mntput(ecryptfs_dentry_to_lower_mnt(dentry));
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}
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kmem_cache_free(ecryptfs_dentry_info_cache,
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ecryptfs_dentry_to_private(dentry));
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}
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return;
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}
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const struct dentry_operations ecryptfs_dops = {
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.d_revalidate = ecryptfs_d_revalidate,
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.d_release = ecryptfs_d_release,
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};
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