LXR linux/fs/ext2/ioctl.c

   1/*
   2 * linux/fs/ext2/ioctl.c
   3 *
   4 * Copyright (C) 1993, 1994, 1995
   5 * Remy Card (card@masi.ibp.fr)
   6 * Laboratoire MASI - Institut Blaise Pascal
   7 * Universite Pierre et Marie Curie (Paris VI)
   8 */
   9
  10#include "ext2.h"
  11#include <linux/capability.h>
  12#include <linux/time.h>
  13#include <linux/sched.h>
  14#include <linux/compat.h>
  15#include <linux/mount.h>
  16#include <asm/current.h>
  17#include <asm/uaccess.h>
  18
  19
  20long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  21{
  22        struct inode *inode = file_inode(filp);
  23        struct ext2_inode_info *ei = EXT2_I(inode);
  24        unsigned int flags;
  25        unsigned short rsv_window_size;
  26        int ret;
  27
  28        ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
  29
  30        switch (cmd) {
  31        case EXT2_IOC_GETFLAGS:
  32                ext2_get_inode_flags(ei);
  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                mutex_lock(&inode->i_mutex);
  55                /* Is it quota file? Do not allow user to mess with it */
  56                if (IS_NOQUOTA(inode)) {
  57                        mutex_unlock(&inode->i_mutex);
  58                        ret = -EPERM;
  59                        goto setflags_out;
  60                }
  61                oldflags = ei->i_flags;
  62
  63                /*
  64                 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  65                 * the relevant capability.
  66                 *
  67                 * This test looks nicer. Thanks to Pauline Middelink
  68                 */
  69                if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
  70                        if (!capable(CAP_LINUX_IMMUTABLE)) {
  71                                mutex_unlock(&inode->i_mutex);
  72                                ret = -EPERM;
  73                                goto setflags_out;
  74                        }
  75                }
  76
  77                flags = flags & EXT2_FL_USER_MODIFIABLE;
  78                flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
  79                ei->i_flags = flags;
  80
  81                ext2_set_inode_flags(inode);
  82                inode->i_ctime = CURRENT_TIME_SEC;
  83                mutex_unlock(&inode->i_mutex);
  84
  85                mark_inode_dirty(inode);
  86setflags_out:
  87                mnt_drop_write_file(filp);
  88                return ret;
  89        }
  90        case EXT2_IOC_GETVERSION:
  91                return put_user(inode->i_generation, (int __user *) arg);
  92        case EXT2_IOC_SETVERSION: {
  93                __u32 generation;
  94
  95                if (!inode_owner_or_capable(inode))
  96                        return -EPERM;
  97                ret = mnt_want_write_file(filp);
  98                if (ret)
  99                        return ret;
 100                if (get_user(generation, (int __user *) arg)) {
 101                        ret = -EFAULT;
 102                        goto setversion_out;
 103                }
 104
 105                mutex_lock(&inode->i_mutex);
 106                inode->i_ctime = CURRENT_TIME_SEC;
 107                inode->i_generation = generation;
 108                mutex_unlock(&inode->i_mutex);
 109
 110                mark_inode_dirty(inode);
 111setversion_out:
 112                mnt_drop_write_file(filp);
 113                return ret;
 114        }
 115        case EXT2_IOC_GETRSVSZ:
 116                if (test_opt(inode->i_sb, RESERVATION)
 117                        && S_ISREG(inode->i_mode)
 118                        && ei->i_block_alloc_info) {
 119                        rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
 120                        return put_user(rsv_window_size, (int __user *)arg);
 121                }
 122                return -ENOTTY;
 123        case EXT2_IOC_SETRSVSZ: {
 124
 125                if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
 126                        return -ENOTTY;
 127
 128                if (!inode_owner_or_capable(inode))
 129                        return -EACCES;
 130
 131                if (get_user(rsv_window_size, (int __user *)arg))
 132                        return -EFAULT;
 133
 134                ret = mnt_want_write_file(filp);
 135                if (ret)
 136                        return ret;
 137
 138                if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
 139                        rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;
 140
 141                /*
 142                 * need to allocate reservation structure for this inode
 143                 * before set the window size
 144                 */
 145                /*
 146                 * XXX What lock should protect the rsv_goal_size?
 147                 * Accessed in ext2_get_block only.  ext3 uses i_truncate.
 148                 */
 149                mutex_lock(&ei->truncate_mutex);
 150                if (!ei->i_block_alloc_info)
 151                        ext2_init_block_alloc_info(inode);
 152
 153                if (ei->i_block_alloc_info){
 154                        struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
 155                        rsv->rsv_goal_size = rsv_window_size;
 156                }
 157                mutex_unlock(&ei->truncate_mutex);
 158                mnt_drop_write_file(filp);
 159                return 0;
 160        }
 161        default:
 162                return -ENOTTY;
 163        }
 164}
 165
 166#ifdef CONFIG_COMPAT
 167long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 168{
 169        /* These are just misnamed, they actually get/put from/to user an int */
 170        switch (cmd) {
 171        case EXT2_IOC32_GETFLAGS:
 172                cmd = EXT2_IOC_GETFLAGS;
 173                break;
 174        case EXT2_IOC32_SETFLAGS:
 175                cmd = EXT2_IOC_SETFLAGS;
 176                break;
 177        case EXT2_IOC32_GETVERSION:
 178                cmd = EXT2_IOC_GETVERSION;
 179                break;
 180        case EXT2_IOC32_SETVERSION:
 181                cmd = EXT2_IOC_SETVERSION;
 182                break;
 183        default:
 184                return -ENOIOCTLCMD;
 185        }
 186        return ext2_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 187}
 188#endif
 189