/*
* ioctl.c - NILFS ioctl operations.
*
* Copyright (C) 2007, 2008 Nippon Telegraph and Telephone Corporation.
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Written by Koji Sato <koji@osrg.net>.
*/
#include <linux/fs.h>
#include <linux/wait.h>
#include <linux/slab.h>
#include <linux/capability.h> /* capable() */
#include <linux/uaccess.h> /* copy_from_user(), copy_to_user() */
#include <linux/vmalloc.h>
#include <linux/compat.h> /* compat_ptr() */
#include <linux/mount.h> /* mnt_want_write_file(), mnt_drop_write_file() */
#include <linux/buffer_head.h>
#include <linux/nilfs2_fs.h>
#include "nilfs.h"
#include "segment.h"
#include "bmap.h"
#include "cpfile.h"
#include "sufile.h"
#include "dat.h"
/**
* nilfs_ioctl_wrap_copy - wrapping function of get/set metadata info
* @nilfs: nilfs object
* @argv: vector of arguments from userspace
* @dir: set of direction flags
* @dofunc: concrete function of get/set metadata info
*
* Description: nilfs_ioctl_wrap_copy() gets/sets metadata info by means of
* calling dofunc() function on the basis of @argv argument.
*
* Return Value: On success, 0 is returned and requested metadata info
* is copied into userspace. On error, one of the following
* negative error codes is returned.
*
* %-EINVAL - Invalid arguments from userspace.
*
* %-ENOMEM - Insufficient amount of memory available.
*
* %-EFAULT - Failure during execution of requested operation.
*/
static int nilfs_ioctl_wrap_copy(struct the_nilfs *nilfs,
struct nilfs_argv *argv, int dir,
ssize_t (*dofunc)(struct the_nilfs *,
__u64 *, int,
void *, size_t, size_t))
{
void *buf;
void __user *base = (void __user *)(unsigned long)argv->v_base;
size_t maxmembs, total, n;
ssize_t nr;
int ret, i;
__u64 pos, ppos;
if (argv->v_nmembs == 0)
return 0;
if (argv->v_size > PAGE_SIZE)
return -EINVAL;
/*
* Reject pairs of a start item position (argv->v_index) and a
* total count (argv->v_nmembs) which leads position 'pos' to
* overflow by the increment at the end of the loop.
*/
if (argv->v_index > ~(__u64)0 - argv->v_nmembs)
return -EINVAL;
buf = (void 