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/capability.h>
  12 #include <linux/time.h>
  13 #include <linux/compat.h>
  14 #include <linux/mount.h>
  15 #include <linux/file.h>
  16 #include <linux/random.h>
  17 #include <asm/uaccess.h>
  18 #include "ext4_jbd2.h"
  19 #include "ext4.h"
  20
  21 #define MAX_32_NUM ((((unsigned long long) 1) << 32) - 1)
  22
  23 /**
  24  * Swap memory between @a and @b for @len bytes.
  25  *
  26  * @a:          pointer to first memory area
  27  * @b:          pointer to second memory area
  28  * @len:        number of bytes to swap
  29  *
  30  */
  31 static void memswap(void *a, void *b, size_t len)
  32 {
  33         unsigned char *ap, *bp;
  34
  35         ap = (unsigned char *)a;
  36         bp = (unsigned char *)b;
  37         while (len-- > 0) {
  38                 swap(*ap, *bp);
  39                 ap++;
  40                 bp++;
  41         }
  42 }
  43
  44 /**
  45  * Swap i_data and associated attributes between @inode1 and @inode2.
  46  * This function is used for the primary swap between inode1 and inode2
  47  * and also to revert this primary swap in case of errors.
  48  *
  49  * Therefore you have to make sure, that calling this method twice
  50  * will revert all changes.
  51  *
  52  * @inode1:     pointer to first inode
  53  * @inode2:     pointer to second inode
  54  */
  55 static void swap_inode_data(struct inode *inode1, struct inode *inode2)
  56 {
  57         loff_t isize;
  58         struct ext4_inode_info *ei1;
  59         struct ext4_inode_info *ei2;
  60
  61         ei1 = EXT4_I(inode1);
  62         ei2 = EXT4_I(inode2);
  63
  64         memswap(&inode1->i_flags, &inode2->i_flags, sizeof(inode1->i_flags));
  65         memswap(&inode1->i_version, &inode2->i_version,
  66                   sizeof(inode1->i_version));
  67         memswap(&inode1->i_blocks, &inode2->i_blocks,
  68                   sizeof(inode1->i_blocks));
  69         memswap(&inode1->i_bytes, &inode2->i_bytes, sizeof(inode1->i_bytes));
  70         memswap(&inode1->i_atime, &inode2->i_atime, sizeof(inode1->i_atime));
  71         memswap(&inode1->i_mtime, &inode2->i_mtime, sizeof(inode1->i_mtime));
  72
  73         memswap(ei1->i_data, ei2->i_data, sizeof(ei1->i_data));
  74         memswap(&ei1->i_flags, &ei2->i_flags, sizeof(ei1->i_flags));
  75         memswap(&ei1->i_disksize, &ei2->i_disksize, sizeof(ei1->i_disksize));
  76         ext4_es_remove_extent(inode1, 0, EXT_MAX_BLOCKS);
  77         ext4_es_remove_extent(inode2, 0, EXT_MAX_BLOCKS);
  78
  79         isize = i_size_read(inode1);
  80         i_size_write(inode1, i_size_read(inode2));
  81         i_size_write(inode2, isize);
  82 }
  83
  84 /**
  85  * Swap the information from the given @inode and the inode
  86  * EXT4_BOOT_LOADER_INO. It will basically swap i_data and all other
  87  * important fields of the inodes.
  88  *
  89  * @sb:         the super block of the filesystem
  90  * @inode:      the inode to swap with EXT4_BOOT_LOADER_INO
  91  *
  92  */
  93 static long swap_inode_boot_loader(struct super_block *sb,
  94                                 struct inode *inode)
  95 {
  96         handle_t *handle;
  97         int err;
  98         struct inode *inode_bl;
  99         struct ext4_inode_info *ei_bl;
 100         struct ext4_sb_info *sbi = EXT4_SB(sb);
 101
 102         if (inode->i_nlink != 1 || !S_ISREG(inode->i_mode))
 103                 return -EINVAL;
 104
 105         if (!inode_owner_or_capable(inode) || !capable(CAP_SYS_ADMIN))
 106                 return -EPERM;
 107
 108         inode_bl = ext4_iget(sb, EXT4_BOOT_LOADER_INO);
 109         if (IS_ERR(inode_bl))
 110                 return PTR_ERR(inode_bl);
 111         ei_bl = EXT4_I(inode_bl);
 112
 113         filemap_flush(inode->i_mapping);
 114         filemap_flush(inode_bl->i_mapping);
 115
 116         /* Protect orig inodes against a truncate and make sure,
 117          * that only 1 swap_inode_boot_loader is running. */
 118         lock_two_nondirectories(inode, inode_bl);
 119
 120         truncate_inode_pages(&inode->i_data, 0);
 121         truncate_inode_pages(&inode_bl->i_data, 0);
 122
 123         /* Wait for all existing dio workers */
 124         ext4_inode_block_unlocked_dio(inode);
 125         ext4_inode_block_unlocked_dio(inode_bl);
 126         inode_dio_wait(inode);
 127         inode_dio_wait(inode_bl);
 128
 129         handle = ext4_journal_start(inode_bl, EXT4_HT_MOVE_EXTENTS, 2);
 130         if (IS_ERR(handle)) {
 131                 err = -EINVAL;
 132                 goto journal_err_out;
 133         }
 134
 135         /* Protect extent tree against block allocations via delalloc */
 136         ext4_double_down_write_data_sem(inode, inode_bl);
 137
 138         if (inode_bl->i_nlink == 0) {
 139                 /* this inode has never been used as a BOOT_LOADER */
 140                 set_nlink(inode_bl, 1);
 141                 i_uid_write(inode_bl, 0);
 142                 i_gid_write(inode_bl, 0);
 143                 inode_bl->i_flags = 0;
 144                 ei_bl->i_flags = 0;
 145                 inode_bl->i_version = 1;
 146                 i_size_write(inode_bl, 0);
 147                 inode_bl->i_mode = S_IFREG;
 148                 if (EXT4_HAS_INCOMPAT_FEATURE(sb,
 149                                               EXT4_FEATURE_INCOMPAT_EXTENTS)) {
 150                         ext4_set_inode_flag(inode_bl, EXT4_INODE_EXTENTS);
 151                         ext4_ext_tree_init(handle, inode_bl);
 152                 } else
 153                         memset(ei_bl->i_data, 0, sizeof(ei_bl->i_data));
 154         }
 155
 156         swap_inode_data(inode, inode_bl);
 157
 158         inode->i_ctime = inode_bl->i_ctime = ext4_current_time(inode);
 159
 160         spin_lock(&sbi->s_next_gen_lock);
 161         inode->i_generation = sbi->s_next_generation++;
 162         inode_bl->i_generation = sbi->s_next_generation++;
 163         spin_unlock(&sbi->s_next_gen_lock);
 164
 165         ext4_discard_preallocations(inode);
 166
 167         err = ext4_mark_inode_dirty(handle, inode);
 168         if (err < 0) {
 169                 ext4_warning(inode->i_sb,
 170                         "couldn't mark inode #%lu dirty (err %d)",
 171                         inode->i_ino, err);
 172                 /* Revert all changes: */
 173                 swap_inode_data(inode, inode_bl);
 174         } else {
 175                 err = ext4_mark_inode_dirty(handle, inode_bl);
 176                 if (err < 0) {
 177                         ext4_warning(inode_bl->i_sb,
 178                                 "couldn't mark inode #%lu dirty (err %d)",
 179                                 inode_bl->i_ino, err);
 180                         /* Revert all changes: */
 181                         swap_inode_data(inode, inode_bl);
 182                         ext4_mark_inode_dirty(handle, inode);
 183                 }
 184         }
 185         ext4_journal_stop(handle);
 186         ext4_double_up_write_data_sem(inode, inode_bl);
 187
 188 journal_err_out:
 189         ext4_inode_resume_unlocked_dio(inode);
 190         ext4_inode_resume_unlocked_dio(inode_bl);
 191         unlock_two_nondirectories(inode, inode_bl);
 192         iput(inode_bl);
 193         return err;
 194 }
 195
 196 static int uuid_is_zero(__u8 u[16])
 197 {
 198         int     i;
 199
 200         for (i = 0; i < 16; i++)
 201                 if (u[i])
 202                         return 0;
 203         return 1;
 204 }
 205
 206 long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 207 {
 208         struct inode *inode = file_inode(filp);
 209         struct super_block *sb = inode->i_sb;
 210         struct ext4_inode_info *ei = EXT4_I(inode);
 211         unsigned int flags;
 212
 213         ext4_debug("cmd = %u, arg = %lu\n", cmd, arg);
 214
 215         switch (cmd) {
 216         case EXT4_IOC_GETFLAGS:
 217                 ext4_get_inode_flags(ei);
 218                 flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
 219                 return put_user(flags, (int __user *) arg);
 220         case EXT4_IOC_SETFLAGS: {
 221                 handle_t *handle = NULL;
 222                 int err, migrate = 0;
 223                 struct ext4_iloc iloc;
 224                 unsigned int oldflags, mask, i;
 225                 unsigned int jflag;
 226
 227                 if (!inode_owner_or_capable(inode))
 228                         return -EACCES;
 229
 230                 if (get_user(flags, (int __user *) arg))
 231                         return -EFAULT;
 232
 233                 err = mnt_want_write_file(filp);
 234                 if (err)
 235                         return err;
 236
 237                 flags = ext4_mask_flags(inode->i_mode, flags);
 238
 239                 err = -EPERM;
 240                 mutex_lock(&inode->i_mutex);
 241                 /* Is it quota file? Do not allow user to mess with it */
 242                 if (IS_NOQUOTA(inode))
 243                         goto flags_out;
 244
 245                 oldflags = ei->i_flags;
 246
 247                 /* The JOURNAL_DATA flag is modifiable only by root */
 248                 jflag = flags & EXT4_JOURNAL_DATA_FL;
 249
 250                 /*
 251                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
 252                  * the relevant capability.
 253                  *
 254                  * This test looks nicer. Thanks to Pauline Middelink
 255                  */
 256                 if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
 257                         if (!capable(CAP_LINUX_IMMUTABLE))
 258                                 goto flags_out;
 259                 }
 260
 261                 /*
 262                  * The JOURNAL_DATA flag can only be changed by
 263                  * the relevant capability.
 264                  */
 265                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
 266                         if (!capable(CAP_SYS_RESOURCE))
 267                                 goto flags_out;
 268                 }
 269                 if ((flags ^ oldflags) & EXT4_EXTENTS_FL)
 270                         migrate = 1;
 271
 272                 if (flags & EXT4_EOFBLOCKS_FL) {
 273                         /* we don't support adding EOFBLOCKS flag */
 274                         if (!(oldflags & EXT4_EOFBLOCKS_FL)) {
 275                                 err = -EOPNOTSUPP;
 276                                 goto flags_out;
 277                         }
 278                 } else if (oldflags & EXT4_EOFBLOCKS_FL)
 279                         ext4_truncate(inode);
 280
 281                 handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
 282                 if (IS_ERR(handle)) {
 283                         err = PTR_ERR(handle);
 284                         goto flags_out;
 285                 }
 286                 if (IS_SYNC(inode))
 287                         ext4_handle_sync(handle);
 288                 err = ext4_reserve_inode_write(handle, inode, &iloc);
 289                 if (err)
 290                         goto flags_err;
 291
 292                 for (i = 0, mask = 1; i < 32; i++, mask <<= 1) {
 293                         if (!(mask & EXT4_FL_USER_MODIFIABLE))
 294                                 continue;
 295                         if (mask & flags)
 296                                 ext4_set_inode_flag(inode, i);
 297                         else
 298                                 ext4_clear_inode_flag(inode, i);
 299                 }
 300
 301                 ext4_set_inode_flags(inode);
 302                 inode->i_ctime = ext4_current_time(inode);
 303
 304                 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 305 flags_err:
 306                 ext4_journal_stop(handle);
 307                 if (err)
 308                         goto flags_out;
 309
 310                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
 311                         err = ext4_change_inode_journal_flag(inode, jflag);
 312                 if (err)
 313                         goto flags_out;
 314                 if (migrate) {
 315                         if (flags & EXT4_EXTENTS_FL)
 316                                 err = ext4_ext_migrate(inode);
 317                         else
 318                                 err = ext4_ind_migrate(inode);
 319                 }
 320
 321 flags_out:
 322                 mutex_unlock(&inode->i_mutex);
 323                 mnt_drop_write_file(filp);
 324                 return err;
 325         }
 326         case EXT4_IOC_GETVERSION:
 327         case EXT4_IOC_GETVERSION_OLD:
 328                 return put_user(inode->i_generation, (int __user *) arg);
 329         case EXT4_IOC_SETVERSION:
 330         case EXT4_IOC_SETVERSION_OLD: {
 331                 handle_t *handle;
 332                 struct ext4_iloc iloc;
 333                 __u32 generation;
 334                 int err;
 335
 336                 if (!inode_owner_or_capable(inode))
 337                         return -EPERM;
 338
 339                 if (ext4_has_metadata_csum(inode->i_sb)) {
 340                         ext4_warning(sb, "Setting inode version is not "
 341                                      "supported with metadata_csum enabled.");
 342                         return -ENOTTY;
 343                 }
 344
 345                 err = mnt_want_write_file(filp);
 346                 if (err)
 347                         return err;
 348                 if (get_user(generation, (int __user *) arg)) {
 349                         err = -EFAULT;
 350                         goto setversion_out;
 351                 }
 352
 353                 mutex_lock(&inode->i_mutex);
 354                 handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
 355                 if (IS_ERR(handle)) {
 356                         err = PTR_ERR(handle);
 357                         goto unlock_out;
 358                 }
 359                 err = ext4_reserve_inode_write(handle, inode, &iloc);
 360                 if (err == 0) {
 361                         inode->i_ctime = ext4_current_time(inode);
 362                         inode->i_generation = generation;
 363                         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 364                 }
 365                 ext4_journal_stop(handle);
 366
 367 unlock_out:
 368                 mutex_unlock(&inode->i_mutex);
 369 setversion_out:
 370                 mnt_drop_write_file(filp);
 371                 return err;
 372         }
 373         case EXT4_IOC_GROUP_EXTEND: {
 374                 ext4_fsblk_t n_blocks_count;
 375                 int err, err2=0;
 376
 377                 err = ext4_resize_begin(sb);
 378                 if (err)
 379                         return err;
 380
 381                 if (get_user(n_blocks_count, (__u32 __user *)arg)) {
 382                         err = -EFAULT;
 383                         goto group_extend_out;
 384                 }
 385
 386                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
 387                                EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
 388                         ext4_msg(sb, KERN_ERR,
 389                                  "Online resizing not supported with bigalloc");
 390                         err = -EOPNOTSUPP;
 391                         goto group_extend_out;
 392                 }
 393
 394                 err = mnt_want_write_file(filp);
 395                 if (err)
 396                         goto group_extend_out;
 397
 398                 err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
 399                 if (EXT4_SB(sb)->s_journal) {
 400                         jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 401                         err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 402                         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 403                 }
 404                 if (err == 0)
 405                         err = err2;
 406                 mnt_drop_write_file(filp);
 407 group_extend_out:
 408                 ext4_resize_end(sb);
 409                 return err;
 410         }
 411
 412         case EXT4_IOC_MOVE_EXT: {
 413                 struct move_extent me;
 414                 struct fd donor;
 415                 int err;
 416
 417                 if (!(filp->f_mode & FMODE_READ) ||
 418                     !(filp->f_mode & FMODE_WRITE))
 419                         return -EBADF;
 420
 421                 if (copy_from_user(&me,
 422                         (struct move_extent __user *)arg, sizeof(me)))
 423                         return -EFAULT;
 424                 me.moved_len = 0;
 425
 426                 donor = fdget(me.donor_fd);
 427                 if (!donor.file)
 428                         return -EBADF;
 429
 430                 if (!(donor.file->f_mode & FMODE_WRITE)) {
 431                         err = -EBADF;
 432                         goto mext_out;
 433                 }
 434
 435                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
 436                                EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
 437                         ext4_msg(sb, KERN_ERR,
 438                                  "Online defrag not supported with bigalloc");
 439                         err = -EOPNOTSUPP;
 440                         goto mext_out;
 441                 }
 442
 443                 err = mnt_want_write_file(filp);
 444                 if (err)
 445                         goto mext_out;
 446
 447                 err = ext4_move_extents(filp, donor.file, me.orig_start,
 448                                         me.donor_start, me.len, &me.moved_len);
 449                 mnt_drop_write_file(filp);
 450
 451                 if (copy_to_user((struct move_extent __user *)arg,
 452                                  &me, sizeof(me)))
 453                         err = -EFAULT;
 454 mext_out:
 455                 fdput(donor);
 456                 return err;
 457         }
 458
 459         case EXT4_IOC_GROUP_ADD: {
 460                 struct ext4_new_group_data input;
 461                 int err, err2=0;
 462
 463                 err = ext4_resize_begin(sb);
 464                 if (err)
 465                         return err;
 466
 467                 if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
 468                                 sizeof(input))) {
 469                         err = -EFAULT;
 470                         goto group_add_out;
 471                 }
 472
 473                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
 474                                EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
 475                         ext4_msg(sb, KERN_ERR,
 476                                  "Online resizing not supported with bigalloc");
 477                         err = -EOPNOTSUPP;
 478                         goto group_add_out;
 479                 }
 480
 481                 err = mnt_want_write_file(filp);
 482                 if (err)
 483                         goto group_add_out;
 484
 485                 err = ext4_group_add(sb, &input);
 486                 if (EXT4_SB(sb)->s_journal) {
 487                         jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 488                         err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 489                         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 490                 }
 491                 if (err == 0)
 492                         err = err2;
 493                 mnt_drop_write_file(filp);
 494                 if (!err && ext4_has_group_desc_csum(sb) &&
 495                     test_opt(sb, INIT_INODE_TABLE))
 496                         err = ext4_register_li_request(sb, input.group);
 497 group_add_out:
 498                 ext4_resize_end(sb);
 499                 return err;
 500         }
 501
 502         case EXT4_IOC_MIGRATE:
 503         {
 504                 int err;
 505                 if (!inode_owner_or_capable(inode))
 506                         return -EACCES;
 507
 508                 err = mnt_want_write_file(filp);
 509                 if (err)
 510                         return err;
 511                 /*
 512                  * inode_mutex prevent write and truncate on the file.
 513                  * Read still goes through. We take i_data_sem in
 514                  * ext4_ext_swap_inode_data before we switch the
 515                  * inode format to prevent read.
 516                  */
 517                 mutex_lock(&(inode->i_mutex));
 518                 err = ext4_ext_migrate(inode);
 519                 mutex_unlock(&(inode->i_mutex));
 520                 mnt_drop_write_file(filp);
 521                 return err;
 522         }
 523
 524         case EXT4_IOC_ALLOC_DA_BLKS:
 525         {
 526                 int err;
 527                 if (!inode_owner_or_capable(inode))
 528                         return -EACCES;
 529
 530                 err = mnt_want_write_file(filp);
 531                 if (err)
 532                         return err;
 533                 err = ext4_alloc_da_blocks(inode);
 534                 mnt_drop_write_file(filp);
 535                 return err;
 536         }
 537
 538         case EXT4_IOC_SWAP_BOOT:
 539         {
 540                 int err;
 541                 if (!(filp->f_mode & FMODE_WRITE))
 542                         return -EBADF;
 543                 err = mnt_want_write_file(filp);
 544                 if (err)
 545                         return err;
 546                 err = swap_inode_boot_loader(sb, inode);
 547                 mnt_drop_write_file(filp);
 548                 return err;
 549         }
 550
 551         case EXT4_IOC_RESIZE_FS: {
 552                 ext4_fsblk_t n_blocks_count;
 553                 int err = 0, err2 = 0;
 554                 ext4_group_t o_group = EXT4_SB(sb)->s_groups_count;
 555
 556                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
 557                                EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
 558                         ext4_msg(sb, KERN_ERR,
 559                                  "Online resizing not (yet) supported with bigalloc");
 560                         return -EOPNOTSUPP;
 561                 }
 562
 563                 if (copy_from_user(&n_blocks_count, (__u64 __user *)arg,
 564                                    sizeof(__u64))) {
 565                         return -EFAULT;
 566                 }
 567
 568                 err = ext4_resize_begin(sb);
 569                 if (err)
 570                         return err;
 571
 572                 err = mnt_want_write_file(filp);
 573                 if (err)
 574                         goto resizefs_out;
 575
 576                 err = ext4_resize_fs(sb, n_blocks_count);
 577                 if (EXT4_SB(sb)->s_journal) {
 578                         jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 579                         err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 580                         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 581                 }
 582                 if (err == 0)
 583                         err = err2;
 584                 mnt_drop_write_file(filp);
 585                 if (!err && (o_group > EXT4_SB(sb)->s_groups_count) &&
 586                     ext4_has_group_desc_csum(sb) &&
 587                     test_opt(sb, INIT_INODE_TABLE))
 588                         err = ext4_register_li_request(sb, o_group);
 589
 590 resizefs_out:
 591                 ext4_resize_end(sb);
 592                 return err;
 593         }
 594
 595         case FITRIM:
 596         {
 597                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
 598                 struct fstrim_range range;
 599                 int ret = 0;
 600
 601                 if (!capable(CAP_SYS_ADMIN))
 602                         return -EPERM;
 603
 604                 if (!blk_queue_discard(q))
 605                         return -EOPNOTSUPP;
 606
 607                 if (copy_from_user(&range, (struct fstrim_range __user *)arg,
 608                     sizeof(range)))
 609                         return -EFAULT;
 610
 611                 range.minlen = max((unsigned int)range.minlen,
 612                                    q->limits.discard_granularity);
 613                 ret = ext4_trim_fs(sb, &range);
 614                 if (ret < 0)
 615                         return ret;
 616
 617                 if (copy_to_user((struct fstrim_range __user *)arg, &range,
 618                     sizeof(range)))
 619                         return -EFAULT;
 620
 621                 return 0;
 622         }
 623         case EXT4_IOC_PRECACHE_EXTENTS:
 624                 return ext4_ext_precache(inode);
 625         case EXT4_IOC_SET_ENCRYPTION_POLICY: {
 626 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 627                 struct ext4_encryption_policy policy;
 628                 int err = 0;
 629
 630                 if (copy_from_user(&policy,
 631                                    (struct ext4_encryption_policy __user *)arg,
 632                                    sizeof(policy))) {
 633                         err = -EFAULT;
 634                         goto encryption_policy_out;
 635                 }
 636
 637                 err = ext4_process_policy(&policy, inode);
 638 encryption_policy_out:
 639                 return err;
 640 #else
 641                 return -EOPNOTSUPP;
 642 #endif
 643         }
 644         case EXT4_IOC_GET_ENCRYPTION_PWSALT: {
 645                 int err, err2;
 646                 struct ext4_sb_info *sbi = EXT4_SB(sb);
 647                 handle_t *handle;
 648
 649                 if (!ext4_sb_has_crypto(sb))
 650                         return -EOPNOTSUPP;
 651                 if (uuid_is_zero(sbi->s_es->s_encrypt_pw_salt)) {
 652                         err = mnt_want_write_file(filp);
 653                         if (err)
 654                                 return err;
 655                         handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
 656                         if (IS_ERR(handle)) {
 657                                 err = PTR_ERR(handle);
 658                                 goto pwsalt_err_exit;
 659                         }
 660                         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
 661                         if (err)
 662                                 goto pwsalt_err_journal;
 663                         generate_random_uuid(sbi->s_es->s_encrypt_pw_salt);
 664                         err = ext4_handle_dirty_metadata(handle, NULL,
 665                                                          sbi->s_sbh);
 666                 pwsalt_err_journal:
 667                         err2 = ext4_journal_stop(handle);
 668                         if (err2 && !err)
 669                                 err = err2;
 670                 pwsalt_err_exit:
 671                         mnt_drop_write_file(filp);
 672                         if (err)
 673                                 return err;
 674                 }
 675                 if (copy_to_user((void __user *) arg,
 676                                  sbi->s_es->s_encrypt_pw_salt, 16))
 677                         return -EFAULT;
 678                 return 0;
 679         }
 680         case EXT4_IOC_GET_ENCRYPTION_POLICY: {
 681 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 682                 struct ext4_encryption_policy policy;
 683                 int err = 0;
 684
 685                 if (!ext4_encrypted_inode(inode))
 686                         return -ENOENT;
 687                 err = ext4_get_policy(inode, &policy);
 688                 if (err)
 689                         return err;
 690                 if (copy_to_user((void __user *)arg, &policy, sizeof(policy)))
 691                         return -EFAULT;
 692                 return 0;
 693 #else
 694                 return -EOPNOTSUPP;
 695 #endif
 696         }
 697         default:
 698                 return -ENOTTY;
 699         }
 700 }
 701
 702 #ifdef CONFIG_COMPAT
 703 long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 704 {
 705         /* These are just misnamed, they actually get/put from/to user an int */
 706         switch (cmd) {
 707         case EXT4_IOC32_GETFLAGS:
 708                 cmd = EXT4_IOC_GETFLAGS;
 709                 break;
 710         case EXT4_IOC32_SETFLAGS:
 711                 cmd = EXT4_IOC_SETFLAGS;
 712                 break;
 713         case EXT4_IOC32_GETVERSION:
 714                 cmd = EXT4_IOC_GETVERSION;
 715                 break;
 716         case EXT4_IOC32_SETVERSION:
 717                 cmd = EXT4_IOC_SETVERSION;
 718                 break;
 719         case EXT4_IOC32_GROUP_EXTEND:
 720                 cmd = EXT4_IOC_GROUP_EXTEND;
 721                 break;
 722         case EXT4_IOC32_GETVERSION_OLD:
 723                 cmd = EXT4_IOC_GETVERSION_OLD;
 724                 break;
 725         case EXT4_IOC32_SETVERSION_OLD:
 726                 cmd = EXT4_IOC_SETVERSION_OLD;
 727                 break;
 728         case EXT4_IOC32_GETRSVSZ:
 729                 cmd = EXT4_IOC_GETRSVSZ;
 730                 break;
 731         case EXT4_IOC32_SETRSVSZ:
 732                 cmd = EXT4_IOC_SETRSVSZ;
 733                 break;
 734         case EXT4_IOC32_GROUP_ADD: {
 735                 struct compat_ext4_new_group_input __user *uinput;
 736                 struct ext4_new_group_input input;
 737                 mm_segment_t old_fs;
 738                 int err;
 739
 740                 uinput = compat_ptr(arg);
 741                 err = get_user(input.group, &uinput->group);
 742                 err |= get_user(input.block_bitmap, &uinput->block_bitmap);
 743                 err |= get_user(input.inode_bitmap, &uinput->inode_bitmap);
 744                 err |= get_user(input.inode_table, &uinput->inode_table);
 745                 err |= get_user(input.blocks_count, &uinput->blocks_count);
 746                 err |= get_user(input.reserved_blocks,
 747                                 &uinput->reserved_blocks);
 748                 if (err)
 749                         return -EFAULT;
 750                 old_fs = get_fs();
 751                 set_fs(KERNEL_DS);
 752                 err = ext4_ioctl(file, EXT4_IOC_GROUP_ADD,
 753                                  (unsigned long) &input);
 754                 set_fs(old_fs);
 755                 return err;
 756         }
 757         case EXT4_IOC_MOVE_EXT:
 758         case EXT4_IOC_RESIZE_FS:
 759         case EXT4_IOC_PRECACHE_EXTENTS:
 760         case EXT4_IOC_SET_ENCRYPTION_POLICY:
 761         case EXT4_IOC_GET_ENCRYPTION_PWSALT:
 762         case EXT4_IOC_GET_ENCRYPTION_POLICY:
 763                 break;
 764         default:
 765                 return -ENOIOCTLCMD;
 766         }
 767         return ext4_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 768 }
 769 #endif