fs/ubifs/ioctl.c

   1 /*
   2  * This file is part of UBIFS.
   3  *
   4  * Copyright (C) 2006-2008 Nokia Corporation.
   5  * Copyright (C) 2006, 2007 University of Szeged, Hungary
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 as published by
   9  * the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14  * more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along with
  17  * this program; if not, write to the Free Software Foundation, Inc., 51
  18  * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  19  *
  20  * Authors: Zoltan Sogor
  21  *          Artem Bityutskiy (Битюцкий Артём)
  22  *          Adrian Hunter
  23  */
  24
  25 /* This file implements EXT2-compatible extended attribute ioctl() calls */
  26
  27 #include <linux/compat.h>
  28 #include <linux/mount.h>
  29 #include "ubifs.h"
  30
  31 /**
  32  * ubifs_set_inode_flags - set VFS inode flags.
  33  * @inode: VFS inode to set flags for
  34  *
  35  * This function propagates flags from UBIFS inode object to VFS inode object.
  36  */
  37 void ubifs_set_inode_flags(struct inode *inode)
  38 {
  39         unsigned int flags = ubifs_inode(inode)->flags;
  40
  41         inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_DIRSYNC |
  42                             S_ENCRYPTED);
  43         if (flags & UBIFS_SYNC_FL)
  44                 inode->i_flags |= S_SYNC;
  45         if (flags & UBIFS_APPEND_FL)
  46                 inode->i_flags |= S_APPEND;
  47         if (flags & UBIFS_IMMUTABLE_FL)
  48                 inode->i_flags |= S_IMMUTABLE;
  49         if (flags & UBIFS_DIRSYNC_FL)
  50                 inode->i_flags |= S_DIRSYNC;
  51         if (flags & UBIFS_CRYPT_FL)
  52                 inode->i_flags |= S_ENCRYPTED;
  53 }
  54
  55 /*
  56  * ioctl2ubifs - convert ioctl inode flags to UBIFS inode flags.
  57  * @ioctl_flags: flags to convert
  58  *
  59  * This function converts ioctl flags (@FS_COMPR_FL, etc) to UBIFS inode flags
  60  * (@UBIFS_COMPR_FL, etc).
  61  */
  62 static int ioctl2ubifs(int ioctl_flags)
  63 {
  64         int ubifs_flags = 0;
  65
  66         if (ioctl_flags & FS_COMPR_FL)
  67                 ubifs_flags |= UBIFS_COMPR_FL;
  68         if (ioctl_flags & FS_SYNC_FL)
  69                 ubifs_flags |= UBIFS_SYNC_FL;
  70         if (ioctl_flags & FS_APPEND_FL)
  71                 ubifs_flags |= UBIFS_APPEND_FL;
  72         if (ioctl_flags & FS_IMMUTABLE_FL)
  73                 ubifs_flags |= UBIFS_IMMUTABLE_FL;
  74         if (ioctl_flags & FS_DIRSYNC_FL)
  75                 ubifs_flags |= UBIFS_DIRSYNC_FL;
  76
  77         return ubifs_flags;
  78 }
  79
  80 /*
  81  * ubifs2ioctl - convert UBIFS inode flags to ioctl inode flags.
  82  * @ubifs_flags: flags to convert
  83  *
  84  * This function converts UBIFS inode flags (@UBIFS_COMPR_FL, etc) to ioctl
  85  * flags (@FS_COMPR_FL, etc).
  86  */
  87 static int ubifs2ioctl(int ubifs_flags)
  88 {
  89         int ioctl_flags = 0;
  90
  91         if (ubifs_flags & UBIFS_COMPR_FL)
  92                 ioctl_flags |= FS_COMPR_FL;
  93         if (ubifs_flags & UBIFS_SYNC_FL)
  94                 ioctl_flags |= FS_SYNC_FL;
  95         if (ubifs_flags & UBIFS_APPEND_FL)
  96                 ioctl_flags |= FS_APPEND_FL;
  97         if (ubifs_flags & UBIFS_IMMUTABLE_FL)
  98                 ioctl_flags |= FS_IMMUTABLE_FL;
  99         if (ubifs_flags & UBIFS_DIRSYNC_FL)
 100                 ioctl_flags |= FS_DIRSYNC_FL;
 101
 102         return ioctl_flags;
 103 }
 104
 105 static int setflags(struct inode *inode, int flags)
 106 {
 107         int oldflags, err, release;
 108         struct ubifs_inode *ui = ubifs_inode(inode);
 109         struct ubifs_info *c = inode->i_sb->s_fs_info;
 110         struct ubifs_budget_req req = { .dirtied_ino = 1,
 111                                         .dirtied_ino_d = ui->data_len };
 112
 113         err = ubifs_budget_space(c, &req);
 114         if (err)
 115                 return err;
 116
 117         /*
 118          * The IMMUTABLE and APPEND_ONLY flags can only be changed by
 119          * the relevant capability.
 120          */
 121         mutex_lock(&ui->ui_mutex);
 122         oldflags = ubifs2ioctl(ui->flags);
 123         if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
 124                 if (!capable(CAP_LINUX_IMMUTABLE)) {
 125                         err = -EPERM;
 126                         goto out_unlock;
 127                 }
 128         }
 129
 130         ui->flags = ioctl2ubifs(flags);
 131         ubifs_set_inode_flags(inode);
 132         inode->i_ctime = current_time(inode);
 133         release = ui->dirty;
 134         mark_inode_dirty_sync(inode);
 135         mutex_unlock(&ui->ui_mutex);
 136
 137         if (release)
 138                 ubifs_release_budget(c, &req);
 139         if (IS_SYNC(inode))
 140                 err = write_inode_now(inode, 1);
 141         return err;
 142
 143 out_unlock:
 144         ubifs_err(c, "can't modify inode %lu attributes", inode->i_ino);
 145         mutex_unlock(&ui->ui_mutex);
 146         ubifs_release_budget(c, &req);
 147         return err;
 148 }
 149
 150 long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 151 {
 152         int flags, err;
 153         struct inode *inode = file_inode(file);
 154
 155         switch (cmd) {
 156         case FS_IOC_GETFLAGS:
 157                 flags = ubifs2ioctl(ubifs_inode(inode)->flags);
 158
 159                 dbg_gen("get flags: %#x, i_flags %#x", flags, inode->i_flags);
 160                 return put_user(flags, (int __user *) arg);
 161
 162         case FS_IOC_SETFLAGS: {
 163                 if (IS_RDONLY(inode))
 164                         return -EROFS;
 165
 166                 if (!inode_owner_or_capable(inode))
 167                         return -EACCES;
 168
 169                 if (get_user(flags, (int __user *) arg))
 170                         return -EFAULT;
 171
 172                 if (!S_ISDIR(inode->i_mode))
 173                         flags &= ~FS_DIRSYNC_FL;
 174
 175                 /*
 176                  * Make sure the file-system is read-write and make sure it
 177                  * will not become read-only while we are changing the flags.
 178                  */
 179                 err = mnt_want_write_file(file);
 180                 if (err)
 181                         return err;
 182                 dbg_gen("set flags: %#x, i_flags %#x", flags, inode->i_flags);
 183                 err = setflags(inode, flags);
 184                 mnt_drop_write_file(file);
 185                 return err;
 186         }
 187         case FS_IOC_SET_ENCRYPTION_POLICY: {
 188 #ifdef CONFIG_UBIFS_FS_ENCRYPTION
 189                 struct ubifs_info *c = inode->i_sb->s_fs_info;
 190
 191                 err = ubifs_enable_encryption(c);
 192                 if (err)
 193                         return err;
 194
 195                 return fscrypt_ioctl_set_policy(file, (const void __user *)arg);
 196 #else
 197                 return -EOPNOTSUPP;
 198 #endif
 199         }
 200         case FS_IOC_GET_ENCRYPTION_POLICY: {
 201 #ifdef CONFIG_UBIFS_FS_ENCRYPTION
 202                 return fscrypt_ioctl_get_policy(file, (void __user *)arg);
 203 #else
 204                 return -EOPNOTSUPP;
 205 #endif
 206         }
 207
 208         default:
 209                 return -ENOTTY;
 210         }
 211 }
 212
 213 #ifdef CONFIG_COMPAT
 214 long ubifs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 215 {
 216         switch (cmd) {
 217         case FS_IOC32_GETFLAGS:
 218                 cmd = FS_IOC_GETFLAGS;
 219                 break;
 220         case FS_IOC32_SETFLAGS:
 221                 cmd = FS_IOC_SETFLAGS;
 222                 break;
 223         case FS_IOC_SET_ENCRYPTION_POLICY:
 224         case FS_IOC_GET_ENCRYPTION_POLICY:
 225                 break;
 226         default:
 227                 return -ENOIOCTLCMD;
 228         }
 229         return ubifs_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
 230 }
 231 #endif