linux/fs/ext2/ioctl.c
<<
>>
Prefs
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * linux/fs/ext2/ioctl.c
   4 *
   5 * Copyright (C) 1993, 1994, 1995
   6 * Remy Card (card@masi.ibp.fr)
   7 * Laboratoire MASI - Institut Blaise Pascal
   8 * Universite Pierre et Marie Curie (Paris VI)
   9 */
  10
  11#include "ext2.h"
  12#include <linux/capability.h>
  13#include <linux/time.h>
  14#include <linux/sched.h>
  15#include <linux/compat.h>
  16#include <linux/mount.h>
  17#include <asm/current.h>
  18#include <linux/uaccess.h>
  19
  20
  21long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  22{
  23        struct inode *inode = file_inode(filp);
  24        struct ext2_inode_info *ei = EXT2_I(inode);
  25        unsigned int flags;
  26        unsigned short rsv_window_size;
  27        int ret;
  28
  29        ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
  30
  31        switch (cmd) {
  32        case EXT2_IOC_GETFLAGS:
  33                flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
  34                return put_user(flags, (int __user *) arg);
  35        case EXT2_IOC_SETFLAGS: {
  36                unsigned int oldflags;
  37
  38                ret = mnt_want_write_file(filp);
  39                if (ret)
  40                        return ret;
  41
  42                if (!inode_owner_or_capable(inode)) {
  43                        ret = -EACCES;
  44                        goto setflags_out;
  45                }
  46
  47                if (get_user(flags, (int __user *) arg)) {
  48                        ret = -EFAULT;
  49                        goto setflags_out;
  50                }
  51
  52                flags = ext2_mask_flags(inode->i_mode, flags);
  53
  54                inode_lock(inode);
  55                /* Is it quota file? Do not allow user to mess with it */
  56                if (IS_NOQUOTA(inode)) {
  57                        inode_unlock(inode);
  58                        ret = -EPERM;
  59                        goto setflags_out;
  60                }
  61                oldflags = ei->i_flags;
  62
  63                ret = vfs_ioc_setflags_prepare(inode, oldflags, flags);
  64                if (ret) {
  65                        inode_unlock(inode);
  66                        goto setflags_out;
  67                }
  68
  69                flags = flags & EXT2_FL_USER_MODIFIABLE;
  70                flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
  71                ei->i_flags = flags;
  72
  73                ext2_set_inode_flags(inode);
  74                inode->i_ctime = current_time(inode);
  75                inode_unlock(inode);
  76
  77                mark_inode_dirty(inode);
  78setflags_out:
  79                mnt_drop_write_file(filp);
  80                return ret;
  81        }
  82        case EXT2_IOC_GETVERSION:
  83                return put_user(inode->i_generation, (int __user *) arg);
  84        case EXT2_IOC_SETVERSION: {
  85                __u32 generation;
  86
  87                if (!inode_owner_or_capable(inode))
  88                        return -EPERM;
  89                ret = mnt_want_write_file(filp);
  90                if (ret)
  91                        return ret;
  92                if (get_user(generation, (int __user *) arg)) {
  93                        ret = -EFAULT;
  94                        goto setversion_out;
  95                }
  96
  97                inode_lock(inode);
  98                inode->i_ctime = current_time(inode);
  99                inode->i_generation = generation;
 100                inode_unlock(inode);
 101
 102                mark_inode_dirty(inode);
 103setversion_out:
 104                mnt_drop_write_file(filp);
 105                return ret;
 106        }
 107        case EXT2_IOC_GETRSVSZ:
 108                if (test_opt(inode->i_sb, RESERVATION)
 109                        && S_ISREG(inode->i_mode)
 110                        && ei->i_block_alloc_info) {
 111                        rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
 112                        return put_user(rsv_window_size, (int __user *)arg);
 113                }
 114                return -ENOTTY;
 115        case EXT2_IOC_SETRSVSZ: {
 116
 117                if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
 118                        return -ENOTTY;
 119
 120                if (!inode_owner_or_capable(inode))
 121                        return -EACCES;
 122
 123                if (get_user(rsv_window_size, (int __user *)arg))
 124                        return -EFAULT;
 125
 126                ret = mnt_want_write_file(filp);
 127                if (ret)
 128                        return ret;
 129
 130                if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
 131                        rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
 132
 133                /*
 134                 * need to allocate reservation structure for this inode
 135                 * before set the window size
 136                 */
 137                /*
 138                 * XXX What lock should protect the rsv_goal_size?
 139                 * Accessed in ext2_get_block only.  ext3 uses i_truncate.
 140                 */
 141                mutex_lock(&ei->truncate_mutex);
 142                if (!ei->i_block_alloc_info)
 143                        ext2_init_block_alloc_info(inode);
 144
 145                if (ei->i_block_alloc_info){
 146                        struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
 147                        rsv->rsv_goal_size = rsv_window_size;
 148                } else {
 149                        ret = -ENOMEM;
 150                }
 151
 152                mutex_unlock(&ei->truncate_mutex);
 153                mnt_drop_write_file(filp);
 154                return ret;
 155        }
 156        default:
 157                return -ENOTTY;
 158        }
 159}
 160
 161#ifdef CONFIG_COMPAT
 162long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 163{
 164        /* These are just misnamed, they actually get/put from/to user an int */
 165        switch (cmd) {
 166        case EXT2_IOC32_GETFLAGS:
 167                cmd = EXT2_IOC_GETFLAGS;
 168                break;
 169        case EXT2_IOC32_SETFLAGS:
 170                cmd = EXT2_IOC_SETFLAGS;
 171                break;
 172        case EXT2_IOC32_GETVERSION:
 173                cmd = EXT2_IOC_GETVERSION;
 174                break;
 175        case EXT2_IOC32_SETVERSION:
 176                cmd = EXT2_IOC_SETVERSION;
 177                break;
 178        default:
 179                return -ENOIOCTLCMD;
 180        }
 181        return ext2_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 182}
 183#endif
 184