ioctl.c
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/*
* linux/fs/ext2/ioctl.c
*
* Copyright (C) 1993, 1994, 1995
* Remy Card (card@masi.ibp.fr)
* Laboratoire MASI - Institut Blaise Pascal
* Universite Pierre et Marie Curie (Paris VI)
*/
#include "ext2.h"
#include <linux/capability.h>
#include <linux/time.h>
#include <linux/sched.h>
#include <linux/compat.h>
#include <linux/mount.h>
#include <asm/current.h>
#include <asm/uaccess.h>
long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(filp);
struct ext2_inode_info *ei = EXT2_I(inode);
unsigned int flags;
unsigned short rsv_window_size;
int ret;
ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
switch (cmd) {
case EXT2_IOC_GETFLAGS:
ext2_get_inode_flags(ei);
flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
return put_user(flags, (int __user *) arg);
case EXT2_IOC_SETFLAGS: {
unsigned int oldflags;
ret = mnt_want_write_file(filp);
if (ret)
return ret;
if (!inode_owner_or_capable(inode)) {
ret = -EACCES;
goto setflags_out;
}
if (get_user(flags, (int __user *) arg)) {
ret = -EFAULT;
goto setflags_out;
}
flags = ext2_mask_flags(inode->i_mode, flags);
mutex_lock(&inode->i_mutex);
/* Is it quota file? Do not allow user to mess with it */
if (IS_NOQUOTA(inode)) {
mutex_unlock(&inode->i_mutex);
ret = -EPERM;
goto setflags_out;
}
oldflags = ei->i_flags;
/*
* The IMMUTABLE and APPEND_ONLY flags can only be changed by
* the relevant capability.
*
* This test looks nicer. Thanks to Pauline Middelink
*/
if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
if (!capable(CAP_LINUX_IMMUTABLE)) {
mutex_unlock(&inode->i_mutex);
ret = -EPERM;
goto setflags_out;
}
}
flags = flags & EXT2_FL_USER_MODIFIABLE;
flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
ei->i_flags = flags;
ext2_set_inode_flags(inode);
inode->i_ctime = CURRENT_TIME_SEC;
mutex_unlock(&inode->i_mutex);
mark_inode_dirty(inode);
setflags_out:
mnt_drop_write_file(filp);
return ret;
}
case EXT2_IOC_GETVERSION:
return put_user(inode->i_generation, (int __user *) arg);
case EXT2_IOC_SETVERSION: {
__u32 generation;
if (!inode_owner_or_capable(inode))
return -EPERM;
ret = mnt_want_write_file(filp);
if (ret)
return ret;
if (get_user(generation, (int __user *) arg)) {
ret = -EFAULT;
goto setversion_out;
}
mutex_lock(&inode->i_mutex);
inode->i_ctime = CURRENT_TIME_SEC;
inode->i_generation = generation;
mutex_unlock(&inode->i_mutex);
mark_inode_dirty(inode);
setversion_out:
mnt_drop_write_file(filp);
return ret;
}
case EXT2_IOC_GETRSVSZ:
if (test_opt(inode->i_sb, RESERVATION)
&& S_ISREG(inode->i_mode)
&& ei->i_block_alloc_info) {
rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
return put_user(rsv_window_size, (int __user *)arg);
}
return -ENOTTY;
case EXT2_IOC_SETRSVSZ: {
if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
return -ENOTTY;
if (!inode_owner_or_capable(inode))
return -EACCES;
if (get_user(rsv_window_size, (int __user *)arg))
return -EFAULT;
ret = mnt_want_write_file(filp);
if (ret)
return ret;
if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
/*
* need to allocate reservation structure for this inode
* before set the window size
*/
/*
* XXX What lock should protect the rsv_goal_size?
* Accessed in ext2_get_block only. ext3 uses i_truncate.
*/
mutex_lock(&ei->truncate_mutex);
if (!ei->i_block_alloc_info)
ext2_init_block_alloc_info(inode);
if (ei->i_block_alloc_info){
struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
rsv->rsv_goal_size = rsv_window_size;
}
mutex_unlock(&ei->truncate_mutex);
mnt_drop_write_file(filp);
return 0;
}
default:
return -ENOTTY;
}
}
#ifdef CONFIG_COMPAT
long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
/* These are just misnamed, they actually get/put from/to user an int */
switch (cmd) {
case EXT2_IOC32_GETFLAGS:
cmd = EXT2_IOC_GETFLAGS;
break;
case EXT2_IOC32_SETFLAGS:
cmd = EXT2_IOC_SETFLAGS;
break;
case EXT2_IOC32_GETVERSION:
cmd = EXT2_IOC_GETVERSION;
break;
case EXT2_IOC32_SETVERSION:
cmd = EXT2_IOC_SETVERSION;
break;
default:
return -ENOIOCTLCMD;
}
return ext2_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
}
#endif