linux-imx

/**

 * eCryptfs: Linux filesystem encryption layer

 *

 * Copyright (C) 1997-2004 Erez Zadok

 * Copyright (C) 2001-2004 Stony Brook University

 * Copyright (C) 2004-2007 International Business Machines Corp.

 *   Author(s): Michael A. Halcrow <mhalcrow@us.ibm.com>

 *          Michael C. Thompson <mcthomps@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/file.h>

#include <linux/poll.h>

#include <linux/slab.h>

#include <linux/mount.h>

#include <linux/pagemap.h>

#include <linux/security.h>

#include <linux/compat.h>

#include <linux/fs_stack.h>

#include "ecryptfs_kernel.h"

​

/**

 * ecryptfs_read_update_atime

 *

 * generic_file_read updates the atime of upper layer inode.  But, it

 * doesn't give us a chance to update the atime of the lower layer

 * inode.  This function is a wrapper to generic_file_read.  It

 * updates the atime of the lower level inode if generic_file_read

 * returns without any errors. This is to be used only for file reads.

 * The function to be used for directory reads is ecryptfs_read.

 */

static ssize_t ecryptfs_read_update_atime(struct kiocb *iocb,

                struct iov_iter *to)

{

    ssize_t rc;

    struct path *path;

    struct file *file = iocb->ki_filp;

​

    rc = generic_file_read_iter(iocb, to);

    if (rc >= 0) {

        path = ecryptfs_dentry_to_lower_path(file->f_path.dentry);

        touch_atime(path);

    }

    return rc;

}

​

struct ecryptfs_getdents_callback {

    struct dir_context ctx;

    struct dir_context *caller;

    struct super_block *sb;

    int filldir_called;

    int entries_written;

};

​

/* Inspired by generic filldir in fs/readdir.c */

static int

ecryptfs_filldir(struct dir_context *ctx, const char *lower_name,

         int lower_namelen, loff_t offset, u64 ino, unsigned int d_type)

{

    struct ecryptfs_getdents_callback *buf =

        container_of(ctx, struct ecryptfs_getdents_callback, ctx);

    size_t name_size;

    char *name;

    int rc;

​

    buf->filldir_called++;

    rc = ecryptfs_decode_and_decrypt_filename(&name, &name_size,

                          buf->sb, lower_name,

                          lower_namelen);

    if (rc) {

        if (rc != -EINVAL) {

            ecryptfs_printk(KERN_DEBUG,

                    "%s: Error attempting to decode and decrypt filename [%s]; rc = [%d]\n",

                    __func__, lower_name, rc);

            return rc;

        }

​

        /* Mask -EINVAL errors as these are most likely due a plaintext