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/time.h>
  14 #include <linux/compat.h>
  15 #include <linux/mount.h>
  16 #include <linux/file.h>
  17 #include <asm/uaccess.h>
  18 #include "ext4_jbd2.h"
  19 #include "ext4.h"
  20
  21 long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  22 {
  23         struct inode *inode = filp->f_dentry->d_inode;
  24         struct ext4_inode_info *ei = EXT4_I(inode);
  25         unsigned int flags;
  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, migrate = 0;
  37                 struct ext4_iloc iloc;
  38                 unsigned int oldflags;
  39                 unsigned int jflag;
  40
  41                 if (!is_owner_or_cap(inode))
  42                         return -EACCES;
  43
  44                 if (get_user(flags, (int __user *) arg))
  45                         return -EFAULT;
  46
  47                 err = mnt_want_write(filp->f_path.mnt);
  48                 if (err)
  49                         return err;
  50
  51                 flags = ext4_mask_flags(inode->i_mode, flags);
  52
  53                 err = -EPERM;
  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                         goto flags_out;
  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                                 goto flags_out;
  73                 }
  74
  75                 /*
  76                  * The JOURNAL_DATA flag can only be changed by
  77                  * the relevant capability.
  78                  */
  79                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
  80                         if (!capable(CAP_SYS_RESOURCE))
  81                                 goto flags_out;
  82                 }
  83                 if (oldflags & EXT4_EXTENTS_FL) {
  84                         /* We don't support clearning extent flags */
  85                         if (!(flags & EXT4_EXTENTS_FL)) {
  86                                 err = -EOPNOTSUPP;
  87                                 goto flags_out;
  88                         }
  89                 } else if (flags & EXT4_EXTENTS_FL) {
  90                         /* migrate the file */
  91                         migrate = 1;
  92                         flags &= ~EXT4_EXTENTS_FL;
  93                 }
  94
  95                 if (flags & EXT4_EOFBLOCKS_FL) {
  96                         /* we don't support adding EOFBLOCKS flag */
  97                         if (!(oldflags & EXT4_EOFBLOCKS_FL)) {
  98                                 err = -EOPNOTSUPP;
  99                                 goto flags_out;
 100                         }
 101                 } else if (oldflags & EXT4_EOFBLOCKS_FL)
 102                         ext4_truncate(inode);
 103
 104                 handle = ext4_journal_start(inode, 1);
 105                 if (IS_ERR(handle)) {
 106                         err = PTR_ERR(handle);
 107                         goto flags_out;
 108                 }
 109                 if (IS_SYNC(inode))
 110                         ext4_handle_sync(handle);
 111                 err = ext4_reserve_inode_write(handle, inode, &iloc);
 112                 if (err)
 113                         goto flags_err;
 114
 115                 flags = flags & EXT4_FL_USER_MODIFIABLE;
 116                 flags |= oldflags & ~EXT4_FL_USER_MODIFIABLE;
 117                 ei->i_flags = flags;
 118
 119                 ext4_set_inode_flags(inode);
 120                 inode->i_ctime = ext4_current_time(inode);
 121
 122                 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 123 flags_err:
 124                 ext4_journal_stop(handle);
 125                 if (err)
 126                         goto flags_out;
 127
 128                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
 129                         err = ext4_change_inode_journal_flag(inode, jflag);
 130                 if (err)
 131                         goto flags_out;
 132                 if (migrate)
 133                         err = ext4_ext_migrate(inode);
 134 flags_out:
 135                 mutex_unlock(&inode->i_mutex);
 136                 mnt_drop_write(filp->f_path.mnt);
 137                 return err;
 138         }
 139         case EXT4_IOC_GETVERSION:
 140         case EXT4_IOC_GETVERSION_OLD:
 141                 return put_user(inode->i_generation, (int __user *) arg);
 142         case EXT4_IOC_SETVERSION:
 143         case EXT4_IOC_SETVERSION_OLD: {
 144                 handle_t *handle;
 145                 struct ext4_iloc iloc;
 146                 __u32 generation;
 147                 int err;
 148
 149                 if (!is_owner_or_cap(inode))
 150                         return -EPERM;
 151
 152                 err = mnt_want_write(filp->f_path.mnt);
 153                 if (err)
 154                         return err;
 155                 if (get_user(generation, (int __user *) arg)) {
 156                         err = -EFAULT;
 157                         goto setversion_out;
 158                 }
 159
 160                 handle = ext4_journal_start(inode, 1);
 161                 if (IS_ERR(handle)) {
 162                         err = PTR_ERR(handle);
 163                         goto setversion_out;
 164                 }
 165                 err = ext4_reserve_inode_write(handle, inode, &iloc);
 166                 if (err == 0) {
 167                         inode->i_ctime = ext4_current_time(inode);
 168                         inode->i_generation = generation;
 169                         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 170                 }
 171                 ext4_journal_stop(handle);
 172 setversion_out:
 173                 mnt_drop_write(filp->f_path.mnt);
 174                 return err;
 175         }
 176 #ifdef CONFIG_JBD2_DEBUG
 177         case EXT4_IOC_WAIT_FOR_READONLY:
 178                 /*
 179                  * This is racy - by the time we're woken up and running,
 180                  * the superblock could be released.  And the module could
 181                  * have been unloaded.  So sue me.
 182                  *
 183                  * Returns 1 if it slept, else zero.
 184                  */
 185                 {
 186                         struct super_block *sb = inode->i_sb;
 187                         DECLARE_WAITQUEUE(wait, current);
 188                         int ret = 0;
 189
 190                         set_current_state(TASK_INTERRUPTIBLE);
 191                         add_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
 192                         if (timer_pending(&EXT4_SB(sb)->turn_ro_timer)) {
 193                                 schedule();
 194                                 ret = 1;
 195                         }
 196                         remove_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
 197                         return ret;
 198                 }
 199 #endif
 200         case EXT4_IOC_GROUP_EXTEND: {
 201                 ext4_fsblk_t n_blocks_count;
 202                 struct super_block *sb = inode->i_sb;
 203                 int err, err2=0;
 204
 205                 if (!capable(CAP_SYS_RESOURCE))
 206                         return -EPERM;
 207
 208                 if (get_user(n_blocks_count, (__u32 __user *)arg))
 209                         return -EFAULT;
 210
 211                 err = mnt_want_write(filp->f_path.mnt);
 212                 if (err)
 213                         return err;
 214
 215                 err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
 216                 if (EXT4_SB(sb)->s_journal) {
 217                         jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 218                         err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 219                         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 220                 }
 221                 if (err == 0)
 222                         err = err2;
 223                 mnt_drop_write(filp->f_path.mnt);
 224
 225                 return err;
 226         }
 227
 228         case EXT4_IOC_MOVE_EXT: {
 229                 struct move_extent me;
 230                 struct file *donor_filp;
 231                 int err;
 232
 233                 if (!(filp->f_mode & FMODE_READ) ||
 234                     !(filp->f_mode & FMODE_WRITE))
 235                         return -EBADF;
 236
 237                 if (copy_from_user(&me,
 238                         (struct move_extent __user *)arg, sizeof(me)))
 239                         return -EFAULT;
 240                 me.moved_len = 0;
 241
 242                 donor_filp = fget(me.donor_fd);
 243                 if (!donor_filp)
 244                         return -EBADF;
 245
 246                 if (!(donor_filp->f_mode & FMODE_WRITE)) {
 247                         err = -EBADF;
 248                         goto mext_out;
 249                 }
 250
 251                 err = mnt_want_write(filp->f_path.mnt);
 252                 if (err)
 253                         goto mext_out;
 254
 255                 err = ext4_move_extents(filp, donor_filp, me.orig_start,
 256                                         me.donor_start, me.len, &me.moved_len);
 257                 mnt_drop_write(filp->f_path.mnt);
 258                 if (me.moved_len > 0)
 259                         file_remove_suid(donor_filp);
 260
 261                 if (copy_to_user((struct move_extent __user *)arg,
 262                                  &me, sizeof(me)))
 263                         err = -EFAULT;
 264 mext_out:
 265                 fput(donor_filp);
 266                 return err;
 267         }
 268
 269         case EXT4_IOC_GROUP_ADD: {
 270                 struct ext4_new_group_data input;
 271                 struct super_block *sb = inode->i_sb;
 272                 int err, err2=0;
 273
 274                 if (!capable(CAP_SYS_RESOURCE))
 275                         return -EPERM;
 276
 277                 if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
 278                                 sizeof(input)))
 279                         return -EFAULT;
 280
 281                 err = mnt_want_write(filp->f_path.mnt);
 282                 if (err)
 283                         return err;
 284
 285                 err = ext4_group_add(sb, &input);
 286                 if (EXT4_SB(sb)->s_journal) {
 287                         jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 288                         err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 289                         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 290                 }
 291                 if (err == 0)
 292                         err = err2;
 293                 mnt_drop_write(filp->f_path.mnt);
 294
 295                 return err;
 296         }
 297
 298         case EXT4_IOC_MIGRATE:
 299         {
 300                 int err;
 301                 if (!is_owner_or_cap(inode))
 302                         return -EACCES;
 303
 304                 err = mnt_want_write(filp->f_path.mnt);
 305                 if (err)
 306                         return err;
 307                 /*
 308                  * inode_mutex prevent write and truncate on the file.
 309                  * Read still goes through. We take i_data_sem in
 310                  * ext4_ext_swap_inode_data before we switch the
 311                  * inode format to prevent read.
 312                  */
 313                 mutex_lock(&(inode->i_mutex));
 314                 err = ext4_ext_migrate(inode);
 315                 mutex_unlock(&(inode->i_mutex));
 316                 mnt_drop_write(filp->f_path.mnt);
 317                 return err;
 318         }
 319
 320         case EXT4_IOC_ALLOC_DA_BLKS:
 321         {
 322                 int err;
 323                 if (!is_owner_or_cap(inode))
 324                         return -EACCES;
 325
 326                 err = mnt_want_write(filp->f_path.mnt);
 327                 if (err)
 328                         return err;
 329                 err = ext4_alloc_da_blocks(inode);
 330                 mnt_drop_write(filp->f_path.mnt);
 331                 return err;
 332         }
 333
 334         default:
 335                 return -ENOTTY;
 336         }
 337 }
 338
 339 #ifdef CONFIG_COMPAT
 340 long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 341 {
 342         /* These are just misnamed, they actually get/put from/to user an int */
 343         switch (cmd) {
 344         case EXT4_IOC32_GETFLAGS:
 345                 cmd = EXT4_IOC_GETFLAGS;
 346                 break;
 347         case EXT4_IOC32_SETFLAGS:
 348                 cmd = EXT4_IOC_SETFLAGS;
 349                 break;
 350         case EXT4_IOC32_GETVERSION:
 351                 cmd = EXT4_IOC_GETVERSION;
 352                 break;
 353         case EXT4_IOC32_SETVERSION:
 354                 cmd = EXT4_IOC_SETVERSION;
 355                 break;
 356         case EXT4_IOC32_GROUP_EXTEND:
 357                 cmd = EXT4_IOC_GROUP_EXTEND;
 358                 break;
 359         case EXT4_IOC32_GETVERSION_OLD:
 360                 cmd = EXT4_IOC_GETVERSION_OLD;
 361                 break;
 362         case EXT4_IOC32_SETVERSION_OLD:
 363                 cmd = EXT4_IOC_SETVERSION_OLD;
 364                 break;
 365 #ifdef CONFIG_JBD2_DEBUG
 366         case EXT4_IOC32_WAIT_FOR_READONLY:
 367                 cmd = EXT4_IOC_WAIT_FOR_READONLY;
 368                 break;
 369 #endif
 370         case EXT4_IOC32_GETRSVSZ:
 371                 cmd = EXT4_IOC_GETRSVSZ;
 372                 break;
 373         case EXT4_IOC32_SETRSVSZ:
 374                 cmd = EXT4_IOC_SETRSVSZ;
 375                 break;
 376         case EXT4_IOC32_GROUP_ADD: {
 377                 struct compat_ext4_new_group_input __user *uinput;
 378                 struct ext4_new_group_input input;
 379                 mm_segment_t old_fs;
 380                 int err;
 381
 382                 uinput = compat_ptr(arg);
 383                 err = get_user(input.group, &uinput->group);
 384                 err |= get_user(input.block_bitmap, &uinput->block_bitmap);
 385                 err |= get_user(input.inode_bitmap, &uinput->inode_bitmap);
 386                 err |= get_user(input.inode_table, &uinput->inode_table);
 387                 err |= get_user(input.blocks_count, &uinput->blocks_count);
 388                 err |= get_user(input.reserved_blocks,
 389                                 &uinput->reserved_blocks);
 390                 if (err)
 391                         return -EFAULT;
 392                 old_fs = get_fs();
 393                 set_fs(KERNEL_DS);
 394                 err = ext4_ioctl(file, EXT4_IOC_GROUP_ADD,
 395                                  (unsigned long) &input);
 396                 set_fs(old_fs);
 397                 return err;
 398         }
 399         case EXT4_IOC_MOVE_EXT:
 400                 break;
 401         default:
 402                 return -ENOIOCTLCMD;
 403         }
 404         return ext4_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 405 }
 406 #endif