kernel/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_feature_extents(sb)) {
 149                         ext4_set_inode_flag(inode_bl, EXT4_INODE_EXTENTS);
 150                         ext4_ext_tree_init(handle, inode_bl);
 151                 } else
 152                         memset(ei_bl->i_data, 0, sizeof(ei_bl->i_data));
 153         }
 154
 155         swap_inode_data(inode, inode_bl);
 156
 157         inode->i_ctime = inode_bl->i_ctime = ext4_current_time(inode);
 158
 159         spin_lock(&sbi->s_next_gen_lock);
 160         inode->i_generation = sbi->s_next_generation++;
 161         inode_bl->i_generation = sbi->s_next_generation++;
 162         spin_unlock(&sbi->s_next_gen_lock);
 163
 164         ext4_discard_preallocations(inode);
 165
 166         err = ext4_mark_inode_dirty(handle, inode);
 167         if (err < 0) {
 168                 ext4_warning(inode->i_sb,
 169                         "couldn't mark inode #%lu dirty (err %d)",
 170                         inode->i_ino, err);
 171                 /* Revert all changes: */
 172                 swap_inode_data(inode, inode_bl);
 173         } else {
 174                 err = ext4_mark_inode_dirty(handle, inode_bl);
 175                 if (err < 0) {
 176                         ext4_warning(inode_bl->i_sb,
 177                                 "couldn't mark inode #%lu dirty (err %d)",
 178                                 inode_bl->i_ino, err);
 179                         /* Revert all changes: */
 180                         swap_inode_data(inode, inode_bl);
 181                         ext4_mark_inode_dirty(handle, inode);
 182                 }
 183         }
 184         ext4_journal_stop(handle);
 185         ext4_double_up_write_data_sem(inode, inode_bl);
 186
 187 journal_err_out:
 188         ext4_inode_resume_unlocked_dio(inode);
 189         ext4_inode_resume_unlocked_dio(inode_bl);
 190         unlock_two_nondirectories(inode, inode_bl);
 191         iput(inode_bl);
 192         return err;
 193 }
 194
 195 static int uuid_is_zero(__u8 u[16])
 196 {
 197         int     i;
 198
 199         for (i = 0; i < 16; i++)
 200                 if (u[i])
 201                         return 0;
 202         return 1;
 203 }
 204
 205 long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 206 {
 207         struct inode *inode = file_inode(filp);
 208         struct super_block *sb = inode->i_sb;
 209         struct ext4_inode_info *ei = EXT4_I(inode);
 210         unsigned int flags;
 211
 212         ext4_debug("cmd = %u, arg = %lu\n", cmd, arg);
 213
 214         switch (cmd) {
 215         case EXT4_IOC_GETFLAGS:
 216                 ext4_get_inode_flags(ei);
 217                 flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
 218                 return put_user(flags, (int __user *) arg);
 219         case EXT4_IOC_SETFLAGS: {
 220                 handle_t *handle = NULL;
 221                 int err, migrate = 0;
 222                 struct ext4_iloc iloc;
 223                 unsigned int oldflags, mask, i;
 224                 unsigned int jflag;
 225
 226                 if (!inode_owner_or_capable(inode))
 227                         return -EACCES;
 228
 229                 if (get_user(flags, (int __user *) arg))
 230                         return -EFAULT;
 231
 232                 err = mnt_want_write_file(filp);
 233                 if (err)
 234                         return err;
 235
 236                 flags = ext4_mask_flags(inode->i_mode, flags);
 237
 238                 err = -EPERM;
 239                 mutex_lock(&inode->i_mutex);
 240                 /* Is it quota file? Do not allow user to mess with it */
 241                 if (IS_NOQUOTA(inode))
 242                         goto flags_out;
 243
 244                 oldflags = ei->i_flags;
 245
 246                 /* The JOURNAL_DATA flag is modifiable only by root */
 247                 jflag = flags & EXT4_JOURNAL_DATA_FL;
 248
 249                 /*
 250                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
 251                  * the relevant capability.
 252                  *
 253                  * This test looks nicer. Thanks to Pauline Middelink
 254                  */
 255                 if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
 256                         if (!capable(CAP_LINUX_IMMUTABLE))
 257                                 goto flags_out;
 258                 }
 259
 260                 /*
 261                  * The JOURNAL_DATA flag can only be changed by
 262                  * the relevant capability.
 263                  */
 264                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
 265                         if (!capable(CAP_SYS_RESOURCE))
 266                                 goto flags_out;
 267                 }
 268                 if ((flags ^ oldflags) & EXT4_EXTENTS_FL)
 269                         migrate = 1;
 270
 271                 if (flags & EXT4_EOFBLOCKS_FL) {
 272                         /* we don't support adding EOFBLOCKS flag */
 273                         if (!(oldflags & EXT4_EOFBLOCKS_FL)) {
 274                                 err = -EOPNOTSUPP;
 275                                 goto flags_out;
 276                         }
 277                 } else if (oldflags & EXT4_EOFBLOCKS_FL)
 278                         ext4_truncate(inode);
 279
 280                 handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
 281                 if (IS_ERR(handle)) {
 282                         err = PTR_ERR(handle);
 283                         goto flags_out;
 284                 }
 285                 if (IS_SYNC(inode))
 286                         ext4_handle_sync(handle);
 287                 err = ext4_reserve_inode_write(handle, inode, &iloc);
 288                 if (err)
 289                         goto flags_err;
 290
 291                 for (i = 0, mask = 1; i < 32; i++, mask <<= 1) {
 292                         if (!(mask & EXT4_FL_USER_MODIFIABLE))
 293                                 continue;
 294                         if (mask & flags)
 295                                 ext4_set_inode_flag(inode, i);
 296                         else
 297                                 ext4_clear_inode_flag(inode, i);
 298                 }
 299
 300                 ext4_set_inode_flags(inode);
 301                 inode->i_ctime = ext4_current_time(inode);
 302
 303                 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 304 flags_err:
 305                 ext4_journal_stop(handle);
 306                 if (err)
 307                         goto flags_out;
 308
 309                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
 310                         err = ext4_change_inode_journal_flag(inode, jflag);
 311                 if (err)
 312                         goto flags_out;
 313                 if (migrate) {
 314                         if (flags & EXT4_EXTENTS_FL)
 315                                 err = ext4_ext_migrate(inode);
 316                         else
 317                                 err = ext4_ind_migrate(inode);
 318                 }
 319
 320 flags_out:
 321                 mutex_unlock(&inode->i_mutex);
 322                 mnt_drop_write_file(filp);
 323                 return err;
 324         }
 325         case EXT4_IOC_GETVERSION:
 326         case EXT4_IOC_GETVERSION_OLD:
 327                 return put_user(inode->i_generation, (int __user *) arg);
 328         case EXT4_IOC_SETVERSION:
 329         case EXT4_IOC_SETVERSION_OLD: {
 330                 handle_t *handle;
 331                 struct ext4_iloc iloc;
 332                 __u32 generation;
 333                 int err;
 334
 335                 if (!inode_owner_or_capable(inode))
 336                         return -EPERM;
 337
 338                 if (ext4_has_metadata_csum(inode->i_sb)) {
 339                         ext4_warning(sb, "Setting inode version is not "
 340                                      "supported with metadata_csum enabled.");
 341                         return -ENOTTY;
 342                 }
 343
 344                 err = mnt_want_write_file(filp);
 345                 if (err)
 346                         return err;
 347                 if (get_user(generation, (int __user *) arg)) {
 348                         err = -EFAULT;
 349                         goto setversion_out;
 350                 }
 351
 352                 mutex_lock(&inode->i_mutex);
 353                 handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
 354                 if (IS_ERR(handle)) {
 355                         err = PTR_ERR(handle);
 356                         goto unlock_out;
 357                 }
 358                 err = ext4_reserve_inode_write(handle, inode, &iloc);
 359                 if (err == 0) {
 360                         inode->i_ctime = ext4_current_time(inode);
 361                         inode->i_generation = generation;
 362                         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 363                 }
 364                 ext4_journal_stop(handle);
 365
 366 unlock_out:
 367                 mutex_unlock(&inode->i_mutex);
 368 setversion_out:
 369                 mnt_drop_write_file(filp);
 370                 return err;
 371         }
 372         case EXT4_IOC_GROUP_EXTEND: {
 373                 ext4_fsblk_t n_blocks_count;
 374                 int err, err2=0;
 375
 376                 err = ext4_resize_begin(sb);
 377                 if (err)
 378                         return err;
 379
 380                 if (get_user(n_blocks_count, (__u32 __user *)arg)) {
 381                         err = -EFAULT;
 382                         goto group_extend_out;
 383                 }
 384
 385                 if (ext4_has_feature_bigalloc(sb)) {
 386                         ext4_msg(sb, KERN_ERR,
 387                                  "Online resizing not supported with bigalloc");
 388                         err = -EOPNOTSUPP;
 389                         goto group_extend_out;
 390                 }
 391
 392                 err = mnt_want_write_file(filp);
 393                 if (err)
 394                         goto group_extend_out;
 395
 396                 err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
 397                 if (EXT4_SB(sb)->s_journal) {
 398                         jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 399                         err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 400                         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 401                 }
 402                 if (err == 0)
 403                         err = err2;
 404                 mnt_drop_write_file(filp);
 405 group_extend_out:
 406                 ext4_resize_end(sb);
 407                 return err;
 408         }
 409
 410         case EXT4_IOC_MOVE_EXT: {
 411                 struct move_extent me;
 412                 struct fd donor;
 413                 int err;
 414
 415                 if (!(filp->f_mode & FMODE_READ) ||
 416                     !(filp->f_mode & FMODE_WRITE))
 417                         return -EBADF;
 418
 419                 if (copy_from_user(&me,
 420                         (struct move_extent __user *)arg, sizeof(me)))
 421                         return -EFAULT;
 422                 me.moved_len = 0;
 423
 424                 donor = fdget(me.donor_fd);
 425                 if (!donor.file)
 426                         return -EBADF;
 427
 428                 if (!(donor.file->f_mode & FMODE_WRITE)) {
 429                         err = -EBADF;
 430                         goto mext_out;
 431                 }
 432
 433                 if (ext4_has_feature_bigalloc(sb)) {
 434                         ext4_msg(sb, KERN_ERR,
 435                                  "Online defrag not supported with bigalloc");
 436                         err = -EOPNOTSUPP;
 437                         goto mext_out;
 438                 }
 439
 440                 err = mnt_want_write_file(filp);
 441                 if (err)
 442                         goto mext_out;
 443
 444                 err = ext4_move_extents(filp, donor.file, me.orig_start,
 445                                         me.donor_start, me.len, &me.moved_len);
 446                 mnt_drop_write_file(filp);
 447
 448                 if (copy_to_user((struct move_extent __user *)arg,
 449                                  &me, sizeof(me)))
 450                         err = -EFAULT;
 451 mext_out:
 452                 fdput(donor);
 453                 return err;
 454         }
 455
 456         case EXT4_IOC_GROUP_ADD: {
 457                 struct ext4_new_group_data input;
 458                 int err, err2=0;
 459
 460                 err = ext4_resize_begin(sb);
 461                 if (err)
 462                         return err;
 463
 464                 if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
 465                                 sizeof(input))) {
 466                         err = -EFAULT;
 467                         goto group_add_out;
 468                 }
 469
 470                 if (ext4_has_feature_bigalloc(sb)) {
 471                         ext4_msg(sb, KERN_ERR,
 472                                  "Online resizing not supported with bigalloc");
 473                         err = -EOPNOTSUPP;
 474                         goto group_add_out;
 475                 }
 476
 477                 err = mnt_want_write_file(filp);
 478                 if (err)
 479                         goto group_add_out;
 480
 481                 err = ext4_group_add(sb, &input);
 482                 if (EXT4_SB(sb)->s_journal) {
 483                         jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 484                         err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 485                         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 486                 }
 487                 if (err == 0)
 488                         err = err2;
 489                 mnt_drop_write_file(filp);
 490                 if (!err && ext4_has_group_desc_csum(sb) &&
 491                     test_opt(sb, INIT_INODE_TABLE))
 492                         err = ext4_register_li_request(sb, input.group);
 493 group_add_out:
 494                 ext4_resize_end(sb);
 495                 return err;
 496         }
 497
 498         case EXT4_IOC_MIGRATE:
 499         {
 500                 int err;
 501                 if (!inode_owner_or_capable(inode))
 502                         return -EACCES;
 503
 504                 err = mnt_want_write_file(filp);
 505                 if (err)
 506                         return err;
 507                 /*
 508                  * inode_mutex prevent write and truncate on the file.
 509                  * Read still goes through. We take i_data_sem in
 510                  * ext4_ext_swap_inode_data before we switch the
 511                  * inode format to prevent read.
 512                  */
 513                 mutex_lock(&(inode->i_mutex));
 514                 err = ext4_ext_migrate(inode);
 515                 mutex_unlock(&(inode->i_mutex));
 516                 mnt_drop_write_file(filp);
 517                 return err;
 518         }
 519
 520         case EXT4_IOC_ALLOC_DA_BLKS:
 521         {
 522                 int err;
 523                 if (!inode_owner_or_capable(inode))
 524                         return -EACCES;
 525
 526                 err = mnt_want_write_file(filp);
 527                 if (err)
 528                         return err;
 529                 err = ext4_alloc_da_blocks(inode);
 530                 mnt_drop_write_file(filp);
 531                 return err;
 532         }
 533
 534         case EXT4_IOC_SWAP_BOOT:
 535         {
 536                 int err;
 537                 if (!(filp->f_mode & FMODE_WRITE))
 538                         return -EBADF;
 539                 err = mnt_want_write_file(filp);
 540                 if (err)
 541                         return err;
 542                 err = swap_inode_boot_loader(sb, inode);
 543                 mnt_drop_write_file(filp);
 544                 return err;
 545         }
 546
 547         case EXT4_IOC_RESIZE_FS: {
 548                 ext4_fsblk_t n_blocks_count;
 549                 int err = 0, err2 = 0;
 550                 ext4_group_t o_group = EXT4_SB(sb)->s_groups_count;
 551
 552                 if (ext4_has_feature_bigalloc(sb)) {
 553                         ext4_msg(sb, KERN_ERR,
 554                                  "Online resizing not (yet) supported with bigalloc");
 555                         return -EOPNOTSUPP;
 556                 }
 557
 558                 if (copy_from_user(&n_blocks_count, (__u64 __user *)arg,
 559                                    sizeof(__u64))) {
 560                         return -EFAULT;
 561                 }
 562
 563                 err = ext4_resize_begin(sb);
 564                 if (err)
 565                         return err;
 566
 567                 err = mnt_want_write_file(filp);
 568                 if (err)
 569                         goto resizefs_out;
 570
 571                 err = ext4_resize_fs(sb, n_blocks_count);
 572                 if (EXT4_SB(sb)->s_journal) {
 573                         jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 574                         err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 575                         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 576                 }
 577                 if (err == 0)
 578                         err = err2;
 579                 mnt_drop_write_file(filp);
 580                 if (!err && (o_group > EXT4_SB(sb)->s_groups_count) &&
 581                     ext4_has_group_desc_csum(sb) &&
 582                     test_opt(sb, INIT_INODE_TABLE))
 583                         err = ext4_register_li_request(sb, o_group);
 584
 585 resizefs_out:
 586                 ext4_resize_end(sb);
 587                 return err;
 588         }
 589
 590         case FITRIM:
 591         {
 592                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
 593                 struct fstrim_range range;
 594                 int ret = 0;
 595
 596                 if (!capable(CAP_SYS_ADMIN))
 597                         return -EPERM;
 598
 599                 if (!blk_queue_discard(q))
 600                         return -EOPNOTSUPP;
 601
 602                 if (copy_from_user(&range, (struct fstrim_range __user *)arg,
 603                     sizeof(range)))
 604                         return -EFAULT;
 605
 606                 range.minlen = max((unsigned int)range.minlen,
 607                                    q->limits.discard_granularity);
 608                 ret = ext4_trim_fs(sb, &range);
 609                 if (ret < 0)
 610                         return ret;
 611
 612                 if (copy_to_user((struct fstrim_range __user *)arg, &range,
 613                     sizeof(range)))
 614                         return -EFAULT;
 615
 616                 return 0;
 617         }
 618         case EXT4_IOC_PRECACHE_EXTENTS:
 619                 return ext4_ext_precache(inode);
 620         case EXT4_IOC_SET_ENCRYPTION_POLICY: {
 621 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 622                 struct ext4_encryption_policy policy;
 623                 int err = 0;
 624
 625                 if (copy_from_user(&policy,
 626                                    (struct ext4_encryption_policy __user *)arg,
 627                                    sizeof(policy))) {
 628                         err = -EFAULT;
 629                         goto encryption_policy_out;
 630                 }
 631
 632                 err = ext4_process_policy(&policy, inode);
 633 encryption_policy_out:
 634                 return err;
 635 #else
 636                 return -EOPNOTSUPP;
 637 #endif
 638         }
 639         case EXT4_IOC_GET_ENCRYPTION_PWSALT: {
 640                 int err, err2;
 641                 struct ext4_sb_info *sbi = EXT4_SB(sb);
 642                 handle_t *handle;
 643
 644                 if (!ext4_sb_has_crypto(sb))
 645                         return -EOPNOTSUPP;
 646                 if (uuid_is_zero(sbi->s_es->s_encrypt_pw_salt)) {
 647                         err = mnt_want_write_file(filp);
 648                         if (err)
 649                                 return err;
 650                         handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
 651                         if (IS_ERR(handle)) {
 652                                 err = PTR_ERR(handle);
 653                                 goto pwsalt_err_exit;
 654                         }
 655                         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
 656                         if (err)
 657                                 goto pwsalt_err_journal;
 658                         generate_random_uuid(sbi->s_es->s_encrypt_pw_salt);
 659                         err = ext4_handle_dirty_metadata(handle, NULL,
 660                                                          sbi->s_sbh);
 661                 pwsalt_err_journal:
 662                         err2 = ext4_journal_stop(handle);
 663                         if (err2 && !err)
 664                                 err = err2;
 665                 pwsalt_err_exit:
 666                         mnt_drop_write_file(filp);
 667                         if (err)
 668                                 return err;
 669                 }
 670                 if (copy_to_user((void __user *) arg,
 671                                  sbi->s_es->s_encrypt_pw_salt, 16))
 672                         return -EFAULT;
 673                 return 0;
 674         }
 675         case EXT4_IOC_GET_ENCRYPTION_POLICY: {
 676 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 677                 struct ext4_encryption_policy policy;
 678                 int err = 0;
 679
 680                 if (!ext4_encrypted_inode(inode))
 681                         return -ENOENT;
 682                 err = ext4_get_policy(inode, &policy);
 683                 if (err)
 684                         return err;
 685                 if (copy_to_user((void __user *)arg, &policy, sizeof(policy)))
 686                         return -EFAULT;
 687                 return 0;
 688 #else
 689                 return -EOPNOTSUPP;
 690 #endif
 691         }
 692         default:
 693                 return -ENOTTY;
 694         }
 695 }
 696
 697 #ifdef CONFIG_COMPAT
 698 long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 699 {
 700         /* These are just misnamed, they actually get/put from/to user an int */
 701         switch (cmd) {
 702         case EXT4_IOC32_GETFLAGS:
 703                 cmd = EXT4_IOC_GETFLAGS;
 704                 break;
 705         case EXT4_IOC32_SETFLAGS:
 706                 cmd = EXT4_IOC_SETFLAGS;
 707                 break;
 708         case EXT4_IOC32_GETVERSION:
 709                 cmd = EXT4_IOC_GETVERSION;
 710                 break;
 711         case EXT4_IOC32_SETVERSION:
 712                 cmd = EXT4_IOC_SETVERSION;
 713                 break;
 714         case EXT4_IOC32_GROUP_EXTEND:
 715                 cmd = EXT4_IOC_GROUP_EXTEND;
 716                 break;
 717         case EXT4_IOC32_GETVERSION_OLD:
 718                 cmd = EXT4_IOC_GETVERSION_OLD;
 719                 break;
 720         case EXT4_IOC32_SETVERSION_OLD:
 721                 cmd = EXT4_IOC_SETVERSION_OLD;
 722                 break;
 723         case EXT4_IOC32_GETRSVSZ:
 724                 cmd = EXT4_IOC_GETRSVSZ;
 725                 break;
 726         case EXT4_IOC32_SETRSVSZ:
 727                 cmd = EXT4_IOC_SETRSVSZ;
 728                 break;
 729         case EXT4_IOC32_GROUP_ADD: {
 730                 struct compat_ext4_new_group_input __user *uinput;
 731                 struct ext4_new_group_input input;
 732                 mm_segment_t old_fs;
 733                 int err;
 734
 735                 uinput = compat_ptr(arg);
 736                 err = get_user(input.group, &uinput->group);
 737                 err |= get_user(input.block_bitmap, &uinput->block_bitmap);
 738                 err |= get_user(input.inode_bitmap, &uinput->inode_bitmap);
 739                 err |= get_user(input.inode_table, &uinput->inode_table);
 740                 err |= get_user(input.blocks_count, &uinput->blocks_count);
 741                 err |= get_user(input.reserved_blocks,
 742                                 &uinput->reserved_blocks);
 743                 if (err)
 744                         return -EFAULT;
 745                 old_fs = get_fs();
 746                 set_fs(KERNEL_DS);
 747                 err = ext4_ioctl(file, EXT4_IOC_GROUP_ADD,
 748                                  (unsigned long) &input);
 749                 set_fs(old_fs);
 750                 return err;
 751         }
 752         case EXT4_IOC_MOVE_EXT:
 753         case EXT4_IOC_RESIZE_FS:
 754         case EXT4_IOC_PRECACHE_EXTENTS:
 755         case EXT4_IOC_SET_ENCRYPTION_POLICY:
 756         case EXT4_IOC_GET_ENCRYPTION_PWSALT:
 757         case EXT4_IOC_GET_ENCRYPTION_POLICY:
 758                 break;
 759         default:
 760                 return -ENOIOCTLCMD;
 761         }
 762         return ext4_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 763 }
 764 #endif