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         unsigned char tmp;
  35
  36         ap = (unsigned char *)a;
  37         bp = (unsigned char *)b;
  38         while (len-- > 0) {
  39                 tmp = *ap;
  40                 *ap = *bp;
  41                 *bp = tmp;
  42                 ap++;
  43                 bp++;
  44         }
  45 }
  46
  47 /**
  48  * Swap i_data and associated attributes between @inode1 and @inode2.
  49  * This function is used for the primary swap between inode1 and inode2
  50  * and also to revert this primary swap in case of errors.
  51  *
  52  * Therefore you have to make sure, that calling this method twice
  53  * will revert all changes.
  54  *
  55  * @inode1:     pointer to first inode
  56  * @inode2:     pointer to second inode
  57  */
  58 static void swap_inode_data(struct inode *inode1, struct inode *inode2)
  59 {
  60         loff_t isize;
  61         struct ext4_inode_info *ei1;
  62         struct ext4_inode_info *ei2;
  63
  64         ei1 = EXT4_I(inode1);
  65         ei2 = EXT4_I(inode2);
  66
  67         memswap(&inode1->i_flags, &inode2->i_flags, sizeof(inode1->i_flags));
  68         memswap(&inode1->i_version, &inode2->i_version,
  69                   sizeof(inode1->i_version));
  70         memswap(&inode1->i_blocks, &inode2->i_blocks,
  71                   sizeof(inode1->i_blocks));
  72         memswap(&inode1->i_bytes, &inode2->i_bytes, sizeof(inode1->i_bytes));
  73         memswap(&inode1->i_atime, &inode2->i_atime, sizeof(inode1->i_atime));
  74         memswap(&inode1->i_mtime, &inode2->i_mtime, sizeof(inode1->i_mtime));
  75
  76         memswap(ei1->i_data, ei2->i_data, sizeof(ei1->i_data));
  77         memswap(&ei1->i_flags, &ei2->i_flags, sizeof(ei1->i_flags));
  78         memswap(&ei1->i_disksize, &ei2->i_disksize, sizeof(ei1->i_disksize));
  79         ext4_es_remove_extent(inode1, 0, EXT_MAX_BLOCKS);
  80         ext4_es_remove_extent(inode2, 0, EXT_MAX_BLOCKS);
  81
  82         isize = i_size_read(inode1);
  83         i_size_write(inode1, i_size_read(inode2));
  84         i_size_write(inode2, isize);
  85 }
  86
  87 /**
  88  * Swap the information from the given @inode and the inode
  89  * EXT4_BOOT_LOADER_INO. It will basically swap i_data and all other
  90  * important fields of the inodes.
  91  *
  92  * @sb:         the super block of the filesystem
  93  * @inode:      the inode to swap with EXT4_BOOT_LOADER_INO
  94  *
  95  */
  96 static long swap_inode_boot_loader(struct super_block *sb,
  97                                 struct inode *inode)
  98 {
  99         handle_t *handle;
 100         int err;
 101         struct inode *inode_bl;
 102         struct ext4_inode_info *ei_bl;
 103         struct ext4_sb_info *sbi = EXT4_SB(sb);
 104
 105         if (inode->i_nlink != 1 || !S_ISREG(inode->i_mode))
 106                 return -EINVAL;
 107
 108         if (!inode_owner_or_capable(inode) || !capable(CAP_SYS_ADMIN))
 109                 return -EPERM;
 110
 111         inode_bl = ext4_iget(sb, EXT4_BOOT_LOADER_INO);
 112         if (IS_ERR(inode_bl))
 113                 return PTR_ERR(inode_bl);
 114         ei_bl = EXT4_I(inode_bl);
 115
 116         filemap_flush(inode->i_mapping);
 117         filemap_flush(inode_bl->i_mapping);
 118
 119         /* Protect orig inodes against a truncate and make sure,
 120          * that only 1 swap_inode_boot_loader is running. */
 121         lock_two_nondirectories(inode, inode_bl);
 122
 123         truncate_inode_pages(&inode->i_data, 0);
 124         truncate_inode_pages(&inode_bl->i_data, 0);
 125
 126         /* Wait for all existing dio workers */
 127         ext4_inode_block_unlocked_dio(inode);
 128         ext4_inode_block_unlocked_dio(inode_bl);
 129         inode_dio_wait(inode);
 130         inode_dio_wait(inode_bl);
 131
 132         handle = ext4_journal_start(inode_bl, EXT4_HT_MOVE_EXTENTS, 2);
 133         if (IS_ERR(handle)) {
 134                 err = -EINVAL;
 135                 goto journal_err_out;
 136         }
 137
 138         /* Protect extent tree against block allocations via delalloc */
 139         ext4_double_down_write_data_sem(inode, inode_bl);
 140
 141         if (inode_bl->i_nlink == 0) {
 142                 /* this inode has never been used as a BOOT_LOADER */
 143                 set_nlink(inode_bl, 1);
 144                 i_uid_write(inode_bl, 0);
 145                 i_gid_write(inode_bl, 0);
 146                 inode_bl->i_flags = 0;
 147                 ei_bl->i_flags = 0;
 148                 inode_bl->i_version = 1;
 149                 i_size_write(inode_bl, 0);
 150                 inode_bl->i_mode = S_IFREG;
 151                 if (EXT4_HAS_INCOMPAT_FEATURE(sb,
 152                                               EXT4_FEATURE_INCOMPAT_EXTENTS)) {
 153                         ext4_set_inode_flag(inode_bl, EXT4_INODE_EXTENTS);
 154                         ext4_ext_tree_init(handle, inode_bl);
 155                 } else
 156                         memset(ei_bl->i_data, 0, sizeof(ei_bl->i_data));
 157         }
 158
 159         swap_inode_data(inode, inode_bl);
 160
 161         inode->i_ctime = inode_bl->i_ctime = ext4_current_time(inode);
 162
 163         spin_lock(&sbi->s_next_gen_lock);
 164         inode->i_generation = sbi->s_next_generation++;
 165         inode_bl->i_generation = sbi->s_next_generation++;
 166         spin_unlock(&sbi->s_next_gen_lock);
 167
 168         ext4_discard_preallocations(inode);
 169
 170         err = ext4_mark_inode_dirty(handle, inode);
 171         if (err < 0) {
 172                 ext4_warning(inode->i_sb,
 173                         "couldn't mark inode #%lu dirty (err %d)",
 174                         inode->i_ino, err);
 175                 /* Revert all changes: */
 176                 swap_inode_data(inode, inode_bl);
 177         } else {
 178                 err = ext4_mark_inode_dirty(handle, inode_bl);
 179                 if (err < 0) {
 180                         ext4_warning(inode_bl->i_sb,
 181                                 "couldn't mark inode #%lu dirty (err %d)",
 182                                 inode_bl->i_ino, err);
 183                         /* Revert all changes: */
 184                         swap_inode_data(inode, inode_bl);
 185                         ext4_mark_inode_dirty(handle, inode);
 186                 }
 187         }
 188         ext4_journal_stop(handle);
 189         ext4_double_up_write_data_sem(inode, inode_bl);
 190
 191 journal_err_out:
 192         ext4_inode_resume_unlocked_dio(inode);
 193         ext4_inode_resume_unlocked_dio(inode_bl);
 194         unlock_two_nondirectories(inode, inode_bl);
 195         iput(inode_bl);
 196         return err;
 197 }
 198
 199 static int uuid_is_zero(__u8 u[16])
 200 {
 201         int     i;
 202
 203         for (i = 0; i < 16; i++)
 204                 if (u[i])
 205                         return 0;
 206         return 1;
 207 }
 208
 209 long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 210 {
 211         struct inode *inode = file_inode(filp);
 212         struct super_block *sb = inode->i_sb;
 213         struct ext4_inode_info *ei = EXT4_I(inode);
 214         unsigned int flags;
 215
 216         ext4_debug("cmd = %u, arg = %lu\n", cmd, arg);
 217
 218         switch (cmd) {
 219         case EXT4_IOC_GETFLAGS:
 220                 ext4_get_inode_flags(ei);
 221                 flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
 222                 return put_user(flags, (int __user *) arg);
 223         case EXT4_IOC_SETFLAGS: {
 224                 handle_t *handle = NULL;
 225                 int err, migrate = 0;
 226                 struct ext4_iloc iloc;
 227                 unsigned int oldflags, mask, i;
 228                 unsigned int jflag;
 229
 230                 if (!inode_owner_or_capable(inode))
 231                         return -EACCES;
 232
 233                 if (get_user(flags, (int __user *) arg))
 234                         return -EFAULT;
 235
 236                 err = mnt_want_write_file(filp);
 237                 if (err)
 238                         return err;
 239
 240                 flags = ext4_mask_flags(inode->i_mode, flags);
 241
 242                 err = -EPERM;
 243                 mutex_lock(&inode->i_mutex);
 244                 /* Is it quota file? Do not allow user to mess with it */
 245                 if (IS_NOQUOTA(inode))
 246                         goto flags_out;
 247
 248                 oldflags = ei->i_flags;
 249
 250                 /* The JOURNAL_DATA flag is modifiable only by root */
 251                 jflag = flags & EXT4_JOURNAL_DATA_FL;
 252
 253                 /*
 254                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
 255                  * the relevant capability.
 256                  *
 257                  * This test looks nicer. Thanks to Pauline Middelink
 258                  */
 259                 if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
 260                         if (!capable(CAP_LINUX_IMMUTABLE))
 261                                 goto flags_out;
 262                 }
 263
 264                 /*
 265                  * The JOURNAL_DATA flag can only be changed by
 266                  * the relevant capability.
 267                  */
 268                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
 269                         if (!capable(CAP_SYS_RESOURCE))
 270                                 goto flags_out;
 271                 }
 272                 if ((flags ^ oldflags) & EXT4_EXTENTS_FL)
 273                         migrate = 1;
 274
 275                 if (flags & EXT4_EOFBLOCKS_FL) {
 276                         /* we don't support adding EOFBLOCKS flag */
 277                         if (!(oldflags & EXT4_EOFBLOCKS_FL)) {
 278                                 err = -EOPNOTSUPP;
 279                                 goto flags_out;
 280                         }
 281                 } else if (oldflags & EXT4_EOFBLOCKS_FL)
 282                         ext4_truncate(inode);
 283
 284                 handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
 285                 if (IS_ERR(handle)) {
 286                         err = PTR_ERR(handle);
 287                         goto flags_out;
 288                 }
 289                 if (IS_SYNC(inode))
 290                         ext4_handle_sync(handle);
 291                 err = ext4_reserve_inode_write(handle, inode, &iloc);
 292                 if (err)
 293                         goto flags_err;
 294
 295                 for (i = 0, mask = 1; i < 32; i++, mask <<= 1) {
 296                         if (!(mask & EXT4_FL_USER_MODIFIABLE))
 297                                 continue;
 298                         if (mask & flags)
 299                                 ext4_set_inode_flag(inode, i);
 300                         else
 301                                 ext4_clear_inode_flag(inode, i);
 302                 }
 303
 304                 ext4_set_inode_flags(inode);
 305                 inode->i_ctime = ext4_current_time(inode);
 306
 307                 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 308 flags_err:
 309                 ext4_journal_stop(handle);
 310                 if (err)
 311                         goto flags_out;
 312
 313                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
 314                         err = ext4_change_inode_journal_flag(inode, jflag);
 315                 if (err)
 316                         goto flags_out;
 317                 if (migrate) {
 318                         if (flags & EXT4_EXTENTS_FL)
 319                                 err = ext4_ext_migrate(inode);
 320                         else
 321                                 err = ext4_ind_migrate(inode);
 322                 }
 323
 324 flags_out:
 325                 mutex_unlock(&inode->i_mutex);
 326                 mnt_drop_write_file(filp);
 327                 return err;
 328         }
 329         case EXT4_IOC_GETVERSION:
 330         case EXT4_IOC_GETVERSION_OLD:
 331                 return put_user(inode->i_generation, (int __user *) arg);
 332         case EXT4_IOC_SETVERSION:
 333         case EXT4_IOC_SETVERSION_OLD: {
 334                 handle_t *handle;
 335                 struct ext4_iloc iloc;
 336                 __u32 generation;
 337                 int err;
 338
 339                 if (!inode_owner_or_capable(inode))
 340                         return -EPERM;
 341
 342                 if (ext4_has_metadata_csum(inode->i_sb)) {
 343                         ext4_warning(sb, "Setting inode version is not "
 344                                      "supported with metadata_csum enabled.");
 345                         return -ENOTTY;
 346                 }
 347
 348                 err = mnt_want_write_file(filp);
 349                 if (err)
 350                         return err;
 351                 if (get_user(generation, (int __user *) arg)) {
 352                         err = -EFAULT;
 353                         goto setversion_out;
 354                 }
 355
 356                 mutex_lock(&inode->i_mutex);
 357                 handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
 358                 if (IS_ERR(handle)) {
 359                         err = PTR_ERR(handle);
 360                         goto unlock_out;
 361                 }
 362                 err = ext4_reserve_inode_write(handle, inode, &iloc);
 363                 if (err == 0) {
 364                         inode->i_ctime = ext4_current_time(inode);
 365                         inode->i_generation = generation;
 366                         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 367                 }
 368                 ext4_journal_stop(handle);
 369
 370 unlock_out:
 371                 mutex_unlock(&inode->i_mutex);
 372 setversion_out:
 373                 mnt_drop_write_file(filp);
 374                 return err;
 375         }
 376         case EXT4_IOC_GROUP_EXTEND: {
 377                 ext4_fsblk_t n_blocks_count;
 378                 int err, err2=0;
 379
 380                 err = ext4_resize_begin(sb);
 381                 if (err)
 382                         return err;
 383
 384                 if (get_user(n_blocks_count, (__u32 __user *)arg)) {
 385                         err = -EFAULT;
 386                         goto group_extend_out;
 387                 }
 388
 389                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
 390                                EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
 391                         ext4_msg(sb, KERN_ERR,
 392                                  "Online resizing not supported with bigalloc");
 393                         err = -EOPNOTSUPP;
 394                         goto group_extend_out;
 395                 }
 396
 397                 err = mnt_want_write_file(filp);
 398                 if (err)
 399                         goto group_extend_out;
 400
 401                 err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
 402                 if (EXT4_SB(sb)->s_journal) {
 403                         jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 404                         err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 405                         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 406                 }
 407                 if (err == 0)
 408                         err = err2;
 409                 mnt_drop_write_file(filp);
 410 group_extend_out:
 411                 ext4_resize_end(sb);
 412                 return err;
 413         }
 414
 415         case EXT4_IOC_MOVE_EXT: {
 416                 struct move_extent me;
 417                 struct fd donor;
 418                 int err;
 419
 420                 if (!(filp->f_mode & FMODE_READ) ||
 421                     !(filp->f_mode & FMODE_WRITE))
 422                         return -EBADF;
 423
 424                 if (copy_from_user(&me,
 425                         (struct move_extent __user *)arg, sizeof(me)))
 426                         return -EFAULT;
 427                 me.moved_len = 0;
 428
 429                 donor = fdget(me.donor_fd);
 430                 if (!donor.file)
 431                         return -EBADF;
 432
 433                 if (!(donor.file->f_mode & FMODE_WRITE)) {
 434                         err = -EBADF;
 435                         goto mext_out;
 436                 }
 437
 438                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
 439                                EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
 440                         ext4_msg(sb, KERN_ERR,
 441                                  "Online defrag not supported with bigalloc");
 442                         err = -EOPNOTSUPP;
 443                         goto mext_out;
 444                 }
 445
 446                 err = mnt_want_write_file(filp);
 447                 if (err)
 448                         goto mext_out;
 449
 450                 err = ext4_move_extents(filp, donor.file, me.orig_start,
 451                                         me.donor_start, me.len, &me.moved_len);
 452                 mnt_drop_write_file(filp);
 453
 454                 if (copy_to_user((struct move_extent __user *)arg,
 455                                  &me, sizeof(me)))
 456                         err = -EFAULT;
 457 mext_out:
 458                 fdput(donor);
 459                 return err;
 460         }
 461
 462         case EXT4_IOC_GROUP_ADD: {
 463                 struct ext4_new_group_data input;
 464                 int err, err2=0;
 465
 466                 err = ext4_resize_begin(sb);
 467                 if (err)
 468                         return err;
 469
 470                 if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
 471                                 sizeof(input))) {
 472                         err = -EFAULT;
 473                         goto group_add_out;
 474                 }
 475
 476                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
 477                                EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
 478                         ext4_msg(sb, KERN_ERR,
 479                                  "Online resizing not supported with bigalloc");
 480                         err = -EOPNOTSUPP;
 481                         goto group_add_out;
 482                 }
 483
 484                 err = mnt_want_write_file(filp);
 485                 if (err)
 486                         goto group_add_out;
 487
 488                 err = ext4_group_add(sb, &input);
 489                 if (EXT4_SB(sb)->s_journal) {
 490                         jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 491                         err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 492                         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 493                 }
 494                 if (err == 0)
 495                         err = err2;
 496                 mnt_drop_write_file(filp);
 497                 if (!err && ext4_has_group_desc_csum(sb) &&
 498                     test_opt(sb, INIT_INODE_TABLE))
 499                         err = ext4_register_li_request(sb, input.group);
 500 group_add_out:
 501                 ext4_resize_end(sb);
 502                 return err;
 503         }
 504
 505         case EXT4_IOC_MIGRATE:
 506         {
 507                 int err;
 508                 if (!inode_owner_or_capable(inode))
 509                         return -EACCES;
 510
 511                 err = mnt_want_write_file(filp);
 512                 if (err)
 513                         return err;
 514                 /*
 515                  * inode_mutex prevent write and truncate on the file.
 516                  * Read still goes through. We take i_data_sem in
 517                  * ext4_ext_swap_inode_data before we switch the
 518                  * inode format to prevent read.
 519                  */
 520                 mutex_lock(&(inode->i_mutex));
 521                 err = ext4_ext_migrate(inode);
 522                 mutex_unlock(&(inode->i_mutex));
 523                 mnt_drop_write_file(filp);
 524                 return err;
 525         }
 526
 527         case EXT4_IOC_ALLOC_DA_BLKS:
 528         {
 529                 int err;
 530                 if (!inode_owner_or_capable(inode))
 531                         return -EACCES;
 532
 533                 err = mnt_want_write_file(filp);
 534                 if (err)
 535                         return err;
 536                 err = ext4_alloc_da_blocks(inode);
 537                 mnt_drop_write_file(filp);
 538                 return err;
 539         }
 540
 541         case EXT4_IOC_SWAP_BOOT:
 542         {
 543                 int err;
 544                 if (!(filp->f_mode & FMODE_WRITE))
 545                         return -EBADF;
 546                 err = mnt_want_write_file(filp);
 547                 if (err)
 548                         return err;
 549                 err = swap_inode_boot_loader(sb, inode);
 550                 mnt_drop_write_file(filp);
 551                 return err;
 552         }
 553
 554         case EXT4_IOC_RESIZE_FS: {
 555                 ext4_fsblk_t n_blocks_count;
 556                 int err = 0, err2 = 0;
 557                 ext4_group_t o_group = EXT4_SB(sb)->s_groups_count;
 558
 559                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
 560                                EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
 561                         ext4_msg(sb, KERN_ERR,
 562                                  "Online resizing not (yet) supported with bigalloc");
 563                         return -EOPNOTSUPP;
 564                 }
 565
 566                 if (copy_from_user(&n_blocks_count, (__u64 __user *)arg,
 567                                    sizeof(__u64))) {
 568                         return -EFAULT;
 569                 }
 570
 571                 err = ext4_resize_begin(sb);
 572                 if (err)
 573                         return err;
 574
 575                 err = mnt_want_write_file(filp);
 576                 if (err)
 577                         goto resizefs_out;
 578
 579                 err = ext4_resize_fs(sb, n_blocks_count);
 580                 if (EXT4_SB(sb)->s_journal) {
 581                         jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 582                         err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 583                         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 584                 }
 585                 if (err == 0)
 586                         err = err2;
 587                 mnt_drop_write_file(filp);
 588                 if (!err && (o_group > EXT4_SB(sb)->s_groups_count) &&
 589                     ext4_has_group_desc_csum(sb) &&
 590                     test_opt(sb, INIT_INODE_TABLE))
 591                         err = ext4_register_li_request(sb, o_group);
 592
 593 resizefs_out:
 594                 ext4_resize_end(sb);
 595                 return err;
 596         }
 597
 598         case FITRIM:
 599         {
 600                 struct request_queue *q = bdev_get_queue(sb->s_bdev);
 601                 struct fstrim_range range;
 602                 int ret = 0;
 603
 604                 if (!capable(CAP_SYS_ADMIN))
 605                         return -EPERM;
 606
 607                 if (!blk_queue_discard(q))
 608                         return -EOPNOTSUPP;
 609
 610                 if (copy_from_user(&range, (struct fstrim_range __user *)arg,
 611                     sizeof(range)))
 612                         return -EFAULT;
 613
 614                 range.minlen = max((unsigned int)range.minlen,
 615                                    q->limits.discard_granularity);
 616                 ret = ext4_trim_fs(sb, &range);
 617                 if (ret < 0)
 618                         return ret;
 619
 620                 if (copy_to_user((struct fstrim_range __user *)arg, &range,
 621                     sizeof(range)))
 622                         return -EFAULT;
 623
 624                 return 0;
 625         }
 626         case EXT4_IOC_PRECACHE_EXTENTS:
 627                 return ext4_ext_precache(inode);
 628         case EXT4_IOC_SET_ENCRYPTION_POLICY: {
 629 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 630                 struct ext4_encryption_policy policy;
 631                 int err = 0;
 632
 633                 if (copy_from_user(&policy,
 634                                    (struct ext4_encryption_policy __user *)arg,
 635                                    sizeof(policy))) {
 636                         err = -EFAULT;
 637                         goto encryption_policy_out;
 638                 }
 639
 640                 err = mnt_want_write_file(filp);
 641                 if (err)
 642                         goto encryption_policy_out;
 643
 644                 err = ext4_process_policy(&policy, inode);
 645
 646                 mnt_drop_write_file(filp);
 647 encryption_policy_out:
 648                 return err;
 649 #else
 650                 return -EOPNOTSUPP;
 651 #endif
 652         }
 653         case EXT4_IOC_GET_ENCRYPTION_PWSALT: {
 654                 int err, err2;
 655                 struct ext4_sb_info *sbi = EXT4_SB(sb);
 656                 handle_t *handle;
 657
 658                 if (!ext4_sb_has_crypto(sb))
 659                         return -EOPNOTSUPP;
 660                 if (uuid_is_zero(sbi->s_es->s_encrypt_pw_salt)) {
 661                         err = mnt_want_write_file(filp);
 662                         if (err)
 663                                 return err;
 664                         handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
 665                         if (IS_ERR(handle)) {
 666                                 err = PTR_ERR(handle);
 667                                 goto pwsalt_err_exit;
 668                         }
 669                         err = ext4_journal_get_write_access(handle, sbi->s_sbh);
 670                         if (err)
 671                                 goto pwsalt_err_journal;
 672                         generate_random_uuid(sbi->s_es->s_encrypt_pw_salt);
 673                         err = ext4_handle_dirty_metadata(handle, NULL,
 674                                                          sbi->s_sbh);
 675                 pwsalt_err_journal:
 676                         err2 = ext4_journal_stop(handle);
 677                         if (err2 && !err)
 678                                 err = err2;
 679                 pwsalt_err_exit:
 680                         mnt_drop_write_file(filp);
 681                         if (err)
 682                                 return err;
 683                 }
 684                 if (copy_to_user((void *) arg, sbi->s_es->s_encrypt_pw_salt,
 685                                  16))
 686                         return -EFAULT;
 687                 return 0;
 688         }
 689         case EXT4_IOC_GET_ENCRYPTION_POLICY: {
 690 #ifdef CONFIG_EXT4_FS_ENCRYPTION
 691                 struct ext4_encryption_policy policy;
 692                 int err = 0;
 693
 694                 if (!ext4_encrypted_inode(inode))
 695                         return -ENOENT;
 696                 err = ext4_get_policy(inode, &policy);
 697                 if (err)
 698                         return err;
 699                 if (copy_to_user((void *)arg, &policy, sizeof(policy)))
 700                         return -EFAULT;
 701                 return 0;
 702 #else
 703                 return -EOPNOTSUPP;
 704 #endif
 705         }
 706         default:
 707                 return -ENOTTY;
 708         }
 709 }
 710
 711 #ifdef CONFIG_COMPAT
 712 long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 713 {
 714         /* These are just misnamed, they actually get/put from/to user an int */
 715         switch (cmd) {
 716         case EXT4_IOC32_GETFLAGS:
 717                 cmd = EXT4_IOC_GETFLAGS;
 718                 break;
 719         case EXT4_IOC32_SETFLAGS:
 720                 cmd = EXT4_IOC_SETFLAGS;
 721                 break;
 722         case EXT4_IOC32_GETVERSION:
 723                 cmd = EXT4_IOC_GETVERSION;
 724                 break;
 725         case EXT4_IOC32_SETVERSION:
 726                 cmd = EXT4_IOC_SETVERSION;
 727                 break;
 728         case EXT4_IOC32_GROUP_EXTEND:
 729                 cmd = EXT4_IOC_GROUP_EXTEND;
 730                 break;
 731         case EXT4_IOC32_GETVERSION_OLD:
 732                 cmd = EXT4_IOC_GETVERSION_OLD;
 733                 break;
 734         case EXT4_IOC32_SETVERSION_OLD:
 735                 cmd = EXT4_IOC_SETVERSION_OLD;
 736                 break;
 737         case EXT4_IOC32_GETRSVSZ:
 738                 cmd = EXT4_IOC_GETRSVSZ;
 739                 break;
 740         case EXT4_IOC32_SETRSVSZ:
 741                 cmd = EXT4_IOC_SETRSVSZ;
 742                 break;
 743         case EXT4_IOC32_GROUP_ADD: {
 744                 struct compat_ext4_new_group_input __user *uinput;
 745                 struct ext4_new_group_input input;
 746                 mm_segment_t old_fs;
 747                 int err;
 748
 749                 uinput = compat_ptr(arg);
 750                 err = get_user(input.group, &uinput->group);
 751                 err |= get_user(input.block_bitmap, &uinput->block_bitmap);
 752                 err |= get_user(input.inode_bitmap, &uinput->inode_bitmap);
 753                 err |= get_user(input.inode_table, &uinput->inode_table);
 754                 err |= get_user(input.blocks_count, &uinput->blocks_count);
 755                 err |= get_user(input.reserved_blocks,
 756                                 &uinput->reserved_blocks);
 757                 if (err)
 758                         return -EFAULT;
 759                 old_fs = get_fs();
 760                 set_fs(KERNEL_DS);
 761                 err = ext4_ioctl(file, EXT4_IOC_GROUP_ADD,
 762                                  (unsigned long) &input);
 763                 set_fs(old_fs);
 764                 return err;
 765         }
 766         case EXT4_IOC_MOVE_EXT:
 767         case FITRIM:
 768         case EXT4_IOC_RESIZE_FS:
 769         case EXT4_IOC_PRECACHE_EXTENTS:
 770         case EXT4_IOC_SET_ENCRYPTION_POLICY:
 771         case EXT4_IOC_GET_ENCRYPTION_PWSALT:
 772         case EXT4_IOC_GET_ENCRYPTION_POLICY:
 773                 break;
 774         default:
 775                 return -ENOIOCTLCMD;
 776         }
 777         return ext4_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 778 }
 779 #endif