fs/ext4/ioctl.c

   1 /*
   2  * linux/fs/ext4/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 <linux/fs.h>
  11 #include <linux/jbd2.h>
  12 #include <linux/capability.h>
  13 #include <linux/ext4_fs.h>
  14 #include <linux/ext4_jbd2.h>
  15 #include <linux/time.h>
  16 #include <linux/compat.h>
  17 #include <linux/smp_lock.h>
  18 #include <asm/uaccess.h>
  19
  20 int ext4_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
  21                 unsigned long arg)
  22 {
  23         struct ext4_inode_info *ei = EXT4_I(inode);
  24         unsigned int flags;
  25         unsigned short rsv_window_size;
  26
  27         ext4_debug ("cmd = %u, arg = %lu\n", cmd, arg);
  28
  29         switch (cmd) {
  30         case EXT4_IOC_GETFLAGS:
  31                 ext4_get_inode_flags(ei);
  32                 flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
  33                 return put_user(flags, (int __user *) arg);
  34         case EXT4_IOC_SETFLAGS: {
  35                 handle_t *handle = NULL;
  36                 int err;
  37                 struct ext4_iloc iloc;
  38                 unsigned int oldflags;
  39                 unsigned int jflag;
  40
  41                 if (IS_RDONLY(inode))
  42                         return -EROFS;
  43
  44                 if (!is_owner_or_cap(inode))
  45                         return -EACCES;
  46
  47                 if (get_user(flags, (int __user *) arg))
  48                         return -EFAULT;
  49
  50                 if (!S_ISDIR(inode->i_mode))
  51                         flags &= ~EXT4_DIRSYNC_FL;
  52
  53                 mutex_lock(&inode->i_mutex);
  54                 /* Is it quota file? Do not allow user to mess with it */
  55                 if (IS_NOQUOTA(inode)) {
  56                         mutex_unlock(&inode->i_mutex);
  57                         return -EPERM;
  58                 }
  59                 oldflags = ei->i_flags;
  60
  61                 /* The JOURNAL_DATA flag is modifiable only by root */
  62                 jflag = flags & EXT4_JOURNAL_DATA_FL;
  63
  64                 /*
  65                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  66                  * the relevant capability.
  67                  *
  68                  * This test looks nicer. Thanks to Pauline Middelink
  69                  */
  70                 if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
  71                         if (!capable(CAP_LINUX_IMMUTABLE)) {
  72                                 mutex_unlock(&inode->i_mutex);
  73                                 return -EPERM;
  74                         }
  75                 }
  76
  77                 /*
  78                  * The JOURNAL_DATA flag can only be changed by
  79                  * the relevant capability.
  80                  */
  81                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
  82                         if (!capable(CAP_SYS_RESOURCE)) {
  83                                 mutex_unlock(&inode->i_mutex);
  84                                 return -EPERM;
  85                         }
  86                 }
  87
  88
  89                 handle = ext4_journal_start(inode, 1);
  90                 if (IS_ERR(handle)) {
  91                         mutex_unlock(&inode->i_mutex);
  92                         return PTR_ERR(handle);
  93                 }
  94                 if (IS_SYNC(inode))
  95                         handle->h_sync = 1;
  96                 err = ext4_reserve_inode_write(handle, inode, &iloc);
  97                 if (err)
  98                         goto flags_err;
  99
 100                 flags = flags & EXT4_FL_USER_MODIFIABLE;
 101                 flags |= oldflags & ~EXT4_FL_USER_MODIFIABLE;
 102                 ei->i_flags = flags;
 103
 104                 ext4_set_inode_flags(inode);
 105                 inode->i_ctime = ext4_current_time(inode);
 106
 107                 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 108 flags_err:
 109                 ext4_journal_stop(handle);
 110                 if (err) {
 111                         mutex_unlock(&inode->i_mutex);
 112                         return err;
 113                 }
 114
 115                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
 116                         err = ext4_change_inode_journal_flag(inode, jflag);
 117                 mutex_unlock(&inode->i_mutex);
 118                 return err;
 119         }
 120         case EXT4_IOC_GETVERSION:
 121         case EXT4_IOC_GETVERSION_OLD:
 122                 return put_user(inode->i_generation, (int __user *) arg);
 123         case EXT4_IOC_SETVERSION:
 124         case EXT4_IOC_SETVERSION_OLD: {
 125                 handle_t *handle;
 126                 struct ext4_iloc iloc;
 127                 __u32 generation;
 128                 int err;
 129
 130                 if (!is_owner_or_cap(inode))
 131                         return -EPERM;
 132                 if (IS_RDONLY(inode))
 133                         return -EROFS;
 134                 if (get_user(generation, (int __user *) arg))
 135                         return -EFAULT;
 136
 137                 handle = ext4_journal_start(inode, 1);
 138                 if (IS_ERR(handle))
 139                         return PTR_ERR(handle);
 140                 err = ext4_reserve_inode_write(handle, inode, &iloc);
 141                 if (err == 0) {
 142                         inode->i_ctime = ext4_current_time(inode);
 143                         inode->i_generation = generation;
 144                         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 145                 }
 146                 ext4_journal_stop(handle);
 147                 return err;
 148         }
 149 #ifdef CONFIG_JBD2_DEBUG
 150         case EXT4_IOC_WAIT_FOR_READONLY:
 151                 /*
 152                  * This is racy - by the time we're woken up and running,
 153                  * the superblock could be released.  And the module could
 154                  * have been unloaded.  So sue me.
 155                  *
 156                  * Returns 1 if it slept, else zero.
 157                  */
 158                 {
 159                         struct super_block *sb = inode->i_sb;
 160                         DECLARE_WAITQUEUE(wait, current);
 161                         int ret = 0;
 162
 163                         set_current_state(TASK_INTERRUPTIBLE);
 164                         add_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
 165                         if (timer_pending(&EXT4_SB(sb)->turn_ro_timer)) {
 166                                 schedule();
 167                                 ret = 1;
 168                         }
 169                         remove_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
 170                         return ret;
 171                 }
 172 #endif
 173         case EXT4_IOC_GETRSVSZ:
 174                 if (test_opt(inode->i_sb, RESERVATION)
 175                         && S_ISREG(inode->i_mode)
 176                         && ei->i_block_alloc_info) {
 177                         rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
 178                         return put_user(rsv_window_size, (int __user *)arg);
 179                 }
 180                 return -ENOTTY;
 181         case EXT4_IOC_SETRSVSZ: {
 182
 183                 if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
 184                         return -ENOTTY;
 185
 186                 if (IS_RDONLY(inode))
 187                         return -EROFS;
 188
 189                 if (!is_owner_or_cap(inode))
 190                         return -EACCES;
 191
 192                 if (get_user(rsv_window_size, (int __user *)arg))
 193                         return -EFAULT;
 194
 195                 if (rsv_window_size > EXT4_MAX_RESERVE_BLOCKS)
 196                         rsv_window_size = EXT4_MAX_RESERVE_BLOCKS;
 197
 198                 /*
 199                  * need to allocate reservation structure for this inode
 200                  * before set the window size
 201                  */
 202                 mutex_lock(&ei->truncate_mutex);
 203                 if (!ei->i_block_alloc_info)
 204                         ext4_init_block_alloc_info(inode);
 205
 206                 if (ei->i_block_alloc_info){
 207                         struct ext4_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
 208                         rsv->rsv_goal_size = rsv_window_size;
 209                 }
 210                 mutex_unlock(&ei->truncate_mutex);
 211                 return 0;
 212         }
 213         case EXT4_IOC_GROUP_EXTEND: {
 214                 ext4_fsblk_t n_blocks_count;
 215                 struct super_block *sb = inode->i_sb;
 216                 int err;
 217
 218                 if (!capable(CAP_SYS_RESOURCE))
 219                         return -EPERM;
 220
 221                 if (IS_RDONLY(inode))
 222                         return -EROFS;
 223
 224                 if (get_user(n_blocks_count, (__u32 __user *)arg))
 225                         return -EFAULT;
 226
 227                 err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
 228                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 229                 jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 230                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 231
 232                 return err;
 233         }
 234         case EXT4_IOC_GROUP_ADD: {
 235                 struct ext4_new_group_data input;
 236                 struct super_block *sb = inode->i_sb;
 237                 int err;
 238
 239                 if (!capable(CAP_SYS_RESOURCE))
 240                         return -EPERM;
 241
 242                 if (IS_RDONLY(inode))
 243                         return -EROFS;
 244
 245                 if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
 246                                 sizeof(input)))
 247                         return -EFAULT;
 248
 249                 err = ext4_group_add(sb, &input);
 250                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 251                 jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 252                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 253
 254                 return err;
 255         }
 256
 257         default:
 258                 return -ENOTTY;
 259         }
 260 }
 261
 262 #ifdef CONFIG_COMPAT
 263 long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 264 {
 265         struct inode *inode = file->f_path.dentry->d_inode;
 266         int ret;
 267
 268         /* These are just misnamed, they actually get/put from/to user an int */
 269         switch (cmd) {
 270         case EXT4_IOC32_GETFLAGS:
 271                 cmd = EXT4_IOC_GETFLAGS;
 272                 break;
 273         case EXT4_IOC32_SETFLAGS:
 274                 cmd = EXT4_IOC_SETFLAGS;
 275                 break;
 276         case EXT4_IOC32_GETVERSION:
 277                 cmd = EXT4_IOC_GETVERSION;
 278                 break;
 279         case EXT4_IOC32_SETVERSION:
 280                 cmd = EXT4_IOC_SETVERSION;
 281                 break;
 282         case EXT4_IOC32_GROUP_EXTEND:
 283                 cmd = EXT4_IOC_GROUP_EXTEND;
 284                 break;
 285         case EXT4_IOC32_GETVERSION_OLD:
 286                 cmd = EXT4_IOC_GETVERSION_OLD;
 287                 break;
 288         case EXT4_IOC32_SETVERSION_OLD:
 289                 cmd = EXT4_IOC_SETVERSION_OLD;
 290                 break;
 291 #ifdef CONFIG_JBD2_DEBUG
 292         case EXT4_IOC32_WAIT_FOR_READONLY:
 293                 cmd = EXT4_IOC_WAIT_FOR_READONLY;
 294                 break;
 295 #endif
 296         case EXT4_IOC32_GETRSVSZ:
 297                 cmd = EXT4_IOC_GETRSVSZ;
 298                 break;
 299         case EXT4_IOC32_SETRSVSZ:
 300                 cmd = EXT4_IOC_SETRSVSZ;
 301                 break;
 302         case EXT4_IOC_GROUP_ADD:
 303                 break;
 304         default:
 305                 return -ENOIOCTLCMD;
 306         }
 307         lock_kernel();
 308         ret = ext4_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
 309         unlock_kernel();
 310         return ret;
 311 }
 312 #endif