mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-28 15:13:55 +08:00
5556e7e6d3
Consider eCryptfs dcache entries to be stale when the corresponding lower inode's i_nlink count is zero. This solves a problem caused by the lower inode being directly modified, without going through the eCryptfs mount, leaving stale eCryptfs dentries cached and the eCryptfs inode's i_nlink count not being cleared. Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Reported-by: Richard Weinberger <richard@nod.at> Cc: stable@vger.kernel.org
93 lines
2.6 KiB
C
93 lines
2.6 KiB
C
/**
|
|
* 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
|
|
* @flags: lookup flags
|
|
*
|
|
* 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, unsigned int flags)
|
|
{
|
|
struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
|
|
int rc = 1;
|
|
|
|
if (flags & LOOKUP_RCU)
|
|
return -ECHILD;
|
|
|
|
if (lower_dentry->d_flags & DCACHE_OP_REVALIDATE)
|
|
rc = lower_dentry->d_op->d_revalidate(lower_dentry, flags);
|
|
|
|
if (d_really_is_positive(dentry)) {
|
|
struct inode *inode = d_inode(dentry);
|
|
|
|
fsstack_copy_attr_all(inode, ecryptfs_inode_to_lower(inode));
|
|
if (!inode->i_nlink)
|
|
return 0;
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
struct kmem_cache *ecryptfs_dentry_info_cache;
|
|
|
|
static void ecryptfs_dentry_free_rcu(struct rcu_head *head)
|
|
{
|
|
kmem_cache_free(ecryptfs_dentry_info_cache,
|
|
container_of(head, struct ecryptfs_dentry_info, rcu));
|
|
}
|
|
|
|
/**
|
|
* ecryptfs_d_release
|
|
* @dentry: The ecryptfs dentry
|
|
*
|
|
* Called when a dentry is really deallocated.
|
|
*/
|
|
static void ecryptfs_d_release(struct dentry *dentry)
|
|
{
|
|
struct ecryptfs_dentry_info *p = dentry->d_fsdata;
|
|
if (p) {
|
|
path_put(&p->lower_path);
|
|
call_rcu(&p->rcu, ecryptfs_dentry_free_rcu);
|
|
}
|
|
}
|
|
|
|
const struct dentry_operations ecryptfs_dops = {
|
|
.d_revalidate = ecryptfs_d_revalidate,
|
|
.d_release = ecryptfs_d_release,
|
|
};
|