ioctl.c
/*
* This file is part of UBIFS.
*
* Copyright (C) 2006-2008 Nokia Corporation.
* Copyright (C) 2006, 2007 University of Szeged, Hungary
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* 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
*
* Authors: Zoltan Sogor
* Artem Bityutskiy (Битюцкий Артём)
* Adrian Hunter
*/
/* This file implements EXT2-compatible extended attribute ioctl() calls */
#include <linux/compat.h>
#include <linux/mount.h>
#include "ubifs.h"
/**
* ubifs_set_inode_flags - set VFS inode flags.
* @inode: VFS inode to set flags for
*
* This function propagates flags from UBIFS inode object to VFS inode object.
*/
void ubifs_set_inode_flags(struct inode *inode)
{
unsigned int flags = ubifs_inode(inode)->flags;
inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_DIRSYNC);
if (flags & UBIFS_SYNC_FL)
inode->i_flags |= S_SYNC;
if (flags & UBIFS_APPEND_FL)
inode->i_flags |= S_APPEND;
if (flags & UBIFS_IMMUTABLE_FL)
inode->i_flags |= S_IMMUTABLE;
if (flags & UBIFS_DIRSYNC_FL)
inode->i_flags |= S_DIRSYNC;
}
/*
* ioctl2ubifs - convert ioctl inode flags to UBIFS inode flags.
* @ioctl_flags: flags to convert
*
* This function convert ioctl flags (@FS_COMPR_FL, etc) to UBIFS inode flags
* (@UBIFS_COMPR_FL, etc).
*/
static int ioctl2ubifs(int ioctl_flags)
{
int ubifs_flags = 0;
if (ioctl_flags & FS_COMPR_FL)
ubifs_flags |= UBIFS_COMPR_FL;
if (ioctl_flags & FS_SYNC_FL)
ubifs_flags |= UBIFS_SYNC_FL;
if (ioctl_flags & FS_APPEND_FL)
ubifs_flags |= UBIFS_APPEND_FL;
if (ioctl_flags & FS_IMMUTABLE_FL)
ubifs_flags |= UBIFS_IMMUTABLE_FL;
if (ioctl_flags & FS_DIRSYNC_FL)
ubifs_flags |= UBIFS_DIRSYNC_FL;
return ubifs_flags;
}
/*
* ubifs2ioctl - convert UBIFS inode flags to ioctl inode flags.
* @ubifs_flags: flags to convert
*
* This function convert UBIFS (@UBIFS_COMPR_FL, etc) to ioctl flags
* (@FS_COMPR_FL, etc).
*/
static int ubifs2ioctl(int ubifs_flags)
{
int ioctl_flags = 0;
if (ubifs_flags & UBIFS_COMPR_FL)
ioctl_flags |= FS_COMPR_FL;
if (ubifs_flags & UBIFS_SYNC_FL)
ioctl_flags |= FS_SYNC_FL;
if (ubifs_flags & UBIFS_APPEND_FL)
ioctl_flags |= FS_APPEND_FL;
if (ubifs_flags & UBIFS_IMMUTABLE_FL)
ioctl_flags |= FS_IMMUTABLE_FL;
if (ubifs_flags & UBIFS_DIRSYNC_FL)
ioctl_flags |= FS_DIRSYNC_FL;
return ioctl_flags;
}
static int setflags(struct inode *inode, int flags)
{
int oldflags, err, release;
struct ubifs_inode *ui = ubifs_inode(inode);
struct ubifs_info *c = inode->i_sb->s_fs_info;
struct ubifs_budget_req req = { .dirtied_ino = 1,
.dirtied_ino_d = ui->data_len };
err = ubifs_budget_space(c, &req);
if (err)
return err;
/*
* The IMMUTABLE and APPEND_ONLY flags can only be changed by
* the relevant capability.
*/
mutex_lock(&ui->ui_mutex);
oldflags = ubifs2ioctl(ui->flags);
if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
if (!capable(CAP_LINUX_IMMUTABLE)) {
err = -EPERM;
goto out_unlock;
}
}
ui->flags = ioctl2ubifs(flags);
ubifs_set_inode_flags(inode);
inode->i_ctime = ubifs_current_time(inode);
release = ui->dirty;
mark_inode_dirty_sync(inode);
mutex_unlock(&ui->ui_mutex);
if (release)
ubifs_release_budget(c, &req);
if (IS_SYNC(inode))
err = write_inode_now(inode, 1);
return err;
out_unlock:
ubifs_err("can't modify inode %lu attributes", inode->i_ino);
mutex_unlock(&ui->ui_mutex);
ubifs_release_budget(c, &req);
return err;
}
long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
int flags, err;
struct inode *inode = file->f_path.dentry->d_inode;
switch (cmd) {
case FS_IOC_GETFLAGS:
flags = ubifs2ioctl(ubifs_inode(inode)->flags);
dbg_gen("get flags: %#x, i_flags %#x", flags, inode->i_flags);
return put_user(flags, (int __user *) arg);
case FS_IOC_SETFLAGS: {
if (IS_RDONLY(inode))
return -EROFS;
if (!is_owner_or_cap(inode))
return -EACCES;
if (get_user(flags, (int __user *) arg))
return -EFAULT;
if (!S_ISDIR(inode->i_mode))
flags &= ~FS_DIRSYNC_FL;
/*
* Make sure the file-system is read-write and make sure it
* will not become read-only while we are changing the flags.
*/
err = mnt_want_write(file->f_path.mnt);
if (err)
return err;
dbg_gen("set flags: %#x, i_flags %#x", flags, inode->i_flags);
err = setflags(inode, flags);
mnt_drop_write(file->f_path.mnt);
return err;
}
default:
return -ENOTTY;
}
}
#ifdef CONFIG_COMPAT
long ubifs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
switch (cmd) {
case FS_IOC32_GETFLAGS:
cmd = FS_IOC_GETFLAGS;
break;
case FS_IOC32_SETFLAGS:
cmd = FS_IOC_SETFLAGS;
break;
default:
return -ENOIOCTLCMD;
}
return ubifs_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
}
#endif