[deliverable/linux.git] / fs / ecryptfs / dentry.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 "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) {
		struct vfsmount *lower_mnt =
			ecryptfs_dentry_to_lower_mnt(dentry);

		mntput(lower_mnt);
		dput(lower_dentry);
	}
	return;
}

struct dentry_operations ecryptfs_dops = {
	.d_revalidate = ecryptfs_d_revalidate,
	.d_release = ecryptfs_d_release,
};
Commit	Line	Data
237fead6 MH	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>
45ec4aba	27	#include <linux/mount.h>
237fead6 MH	28	#include "ecryptfs_kernel.h"
	29
	30	/**
	31	* ecryptfs_d_revalidate - revalidate an ecryptfs dentry
	32	* @dentry: The ecryptfs dentry
	33	* @nd: The associated nameidata
	34	*
	35	* Called when the VFS needs to revalidate a dentry. This
	36	* is called whenever a name lookup finds a dentry in the
	37	* dcache. Most filesystems leave this as NULL, because all their
	38	* dentries in the dcache are valid.
	39	*
	40	* Returns 1 if valid, 0 otherwise.
	41	*
	42	*/
	43	static int ecryptfs_d_revalidate(struct dentry dentry, struct nameidata nd)
	44	{
	45	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
	46	struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
	47	struct dentry *dentry_save;
	48	struct vfsmount *vfsmount_save;
	49	int rc = 1;
	50
	51	if (!lower_dentry->d_op \|\| !lower_dentry->d_op->d_revalidate)
	52	goto out;
	53	dentry_save = nd->dentry;
	54	vfsmount_save = nd->mnt;
	55	nd->dentry = lower_dentry;
	56	nd->mnt = lower_mnt;
	57	rc = lower_dentry->d_op->d_revalidate(lower_dentry, nd);
	58	nd->dentry = dentry_save;
	59	nd->mnt = vfsmount_save;
	60	out:
	61	return rc;
	62	}
	63
	64	struct kmem_cache *ecryptfs_dentry_info_cache;
	65
	66	/**
	67	* ecryptfs_d_release
	68	* @dentry: The ecryptfs dentry
	69	*
	70	* Called when a dentry is really deallocated.
	71	*/
	72	static void ecryptfs_d_release(struct dentry *dentry)
	73	{
	74	struct dentry *lower_dentry;
	75
	76	lower_dentry = ecryptfs_dentry_to_lower(dentry);
	77	if (ecryptfs_dentry_to_private(dentry))
	78	kmem_cache_free(ecryptfs_dentry_info_cache,
	79	ecryptfs_dentry_to_private(dentry));
45ec4aba MH	80	if (lower_dentry) {
	81	struct vfsmount *lower_mnt =
	82	ecryptfs_dentry_to_lower_mnt(dentry);
	83
	84	mntput(lower_mnt);
237fead6	85	dput(lower_dentry);
45ec4aba	86	}
237fead6 MH	87	return;
	88	}
	89
	90	struct dentry_operations ecryptfs_dops = {
	91	.d_revalidate = ecryptfs_d_revalidate,
	92	.d_release = ecryptfs_d_release,
	93	};