summaryrefslogtreecommitdiff
path: root/fs/ext4/ioctl.c
blob: 7ce85824211b924ff6f2eebd2786c5b569371bea (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
/*
 * linux/fs/ext4/ioctl.c
 *
 * Copyright (C) 1993, 1994, 1995
 * Remy Card (card@masi.ibp.fr)
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 */

#include <linux/fs.h>
#include <linux/capability.h>
#include <linux/time.h>
#include <linux/compat.h>
#include <linux/mount.h>
#include <linux/file.h>
#include <linux/random.h>
#include <asm/uaccess.h>
#include "ext4_jbd2.h"
#include "ext4.h"

#define MAX_32_NUM ((((unsigned long long) 1) << 32) - 1)

/**
 * Swap memory between @a and @b for @len bytes.
 *
 * @a:          pointer to first memory area
 * @b:          pointer to second memory area
 * @len:        number of bytes to swap
 *
 */
static void memswap(void *a, void *b, size_t len)
{
	unsigned char *ap, *bp;
	unsigned char tmp;

	ap = (unsigned char *)a;
	bp = (unsigned char *)b;
	while (len-- > 0) {
		tmp = *ap;
		*ap = *bp;
		*bp = tmp;
		ap++;
		bp++;
	}
}

/**
 * Swap i_data and associated attributes between @inode1 and @inode2.
 * This function is used for the primary swap between inode1 and inode2
 * and also to revert this primary swap in case of errors.
 *
 * Therefore you have to make sure, that calling this method twice
 * will revert all changes.
 *
 * @inode1:     pointer to first inode
 * @inode2:     pointer to second inode
 */
static void swap_inode_data(struct inode *inode1, struct inode *inode2)
{
	loff_t isize;
	struct ext4_inode_info *ei1;
	struct ext4_inode_info *ei2;

	ei1 = EXT4_I(inode1);
	ei2 = EXT4_I(inode2);

	memswap(&inode1->i_flags, &inode2->i_flags, sizeof(inode1->i_flags));
	memswap(&inode1->i_version, &inode2->i_version,
		  sizeof(inode1->i_version));
	memswap(&inode1->i_blocks, &inode2->i_blocks,
		  sizeof(inode1->i_blocks));
	memswap(&inode1->i_bytes, &inode2->i_bytes, sizeof(inode1->i_bytes));
	memswap(&inode1->i_atime, &inode2->i_atime, sizeof(inode1->i_atime));
	memswap(&inode1->i_mtime, &inode2->i_mtime, sizeof(inode1->i_mtime));

	memswap(ei1->i_data, ei2->i_data, sizeof(ei1->i_data));
	memswap(&ei1->i_flags, &ei2->i_flags, sizeof(ei1->i_flags));
	memswap(&ei1->i_disksize, &ei2->i_disksize, sizeof(ei1->i_disksize));
	ext4_es_remove_extent(inode1, 0, EXT_MAX_BLOCKS);
	ext4_es_remove_extent(inode2, 0, EXT_MAX_BLOCKS);

	isize = i_size_read(inode1);
	i_size_write(inode1, i_size_read(inode2));
	i_size_write(inode2, isize);
}

/**
 * Swap the information from the given @inode and the inode
 * EXT4_BOOT_LOADER_INO. It will basically swap i_data and all other
 * important fields of the inodes.
 *
 * @sb:         the super block of the filesystem
 * @inode:      the inode to swap with EXT4_BOOT_LOADER_INO
 *
 */
static long swap_inode_boot_loader(struct super_block *sb,
				struct inode *inode)
{
	handle_t *handle;
	int err;
	struct inode *inode_bl;
	struct ext4_inode_info *ei_bl;
	struct ext4_sb_info *sbi = EXT4_SB(sb);

	if (inode->i_nlink != 1 || !S_ISREG(inode->i_mode))
		return -EINVAL;

	if (!inode_owner_or_capable(inode) || !capable(CAP_SYS_ADMIN))
		return -EPERM;

	inode_bl = ext4_iget(sb, EXT4_BOOT_LOADER_INO);
	if (IS_ERR(inode_bl))
		return PTR_ERR(inode_bl);
	ei_bl = EXT4_I(inode_bl);

	filemap_flush(inode->i_mapping);
	filemap_flush(inode_bl->i_mapping);

	/* Protect orig inodes against a truncate and make sure,
	 * that only 1 swap_inode_boot_loader is running. */
	lock_two_nondirectories(inode, inode_bl);

	truncate_inode_pages(&inode->i_data, 0);
	truncate_inode_pages(&inode_bl->i_data, 0);

	/* Wait for all existing dio workers */
	ext4_inode_block_unlocked_dio(inode);
	ext4_inode_block_unlocked_dio(inode_bl);
	inode_dio_wait(inode);
	inode_dio_wait(inode_bl);

	handle = ext4_journal_start(inode_bl, EXT4_HT_MOVE_EXTENTS, 2);
	if (IS_ERR(handle)) {
		err = -EINVAL;
		goto journal_err_out;
	}

	/* Protect extent tree against block allocations via delalloc */
	ext4_double_down_write_data_sem(inode, inode_bl);

	if (inode_bl->i_nlink == 0) {
		/* this inode has never been used as a BOOT_LOADER */
		set_nlink(inode_bl, 1);
		i_uid_write(inode_bl, 0);
		i_gid_write(inode_bl, 0);
		inode_bl->i_flags = 0;
		ei_bl->i_flags = 0;
		inode_bl->i_version = 1;
		i_size_write(inode_bl, 0);
		inode_bl->i_mode = S_IFREG;
		if (EXT4_HAS_INCOMPAT_FEATURE(sb,
					      EXT4_FEATURE_INCOMPAT_EXTENTS)) {
			ext4_set_inode_flag(inode_bl, EXT4_INODE_EXTENTS);
			ext4_ext_tree_init(handle, inode_bl);
		} else
			memset(ei_bl->i_data, 0, sizeof(ei_bl->i_data));
	}

	swap_inode_data(inode, inode_bl);

	inode->i_ctime = inode_bl->i_ctime = ext4_current_time(inode);

	spin_lock(&sbi->s_next_gen_lock);
	inode->i_generation = sbi->s_next_generation++;
	inode_bl->i_generation = sbi->s_next_generation++;
	spin_unlock(&sbi->s_next_gen_lock);

	ext4_discard_preallocations(inode);

	err = ext4_mark_inode_dirty(handle, inode);
	if (err < 0) {
		ext4_warning(inode->i_sb,
			"couldn't mark inode #%lu dirty (err %d)",
			inode->i_ino, err);
		/* Revert all changes: */
		swap_inode_data(inode, inode_bl);
	} else {
		err = ext4_mark_inode_dirty(handle, inode_bl);
		if (err < 0) {
			ext4_warning(inode_bl->i_sb,
				"couldn't mark inode #%lu dirty (err %d)",
				inode_bl->i_ino, err);
			/* Revert all changes: */
			swap_inode_data(inode, inode_bl);
			ext4_mark_inode_dirty(handle, inode);
		}
	}
	ext4_journal_stop(handle);
	ext4_double_up_write_data_sem(inode, inode_bl);

journal_err_out:
	ext4_inode_resume_unlocked_dio(inode);
	ext4_inode_resume_unlocked_dio(inode_bl);
	unlock_two_nondirectories(inode, inode_bl);
	iput(inode_bl);
	return err;
}

static int uuid_is_zero(__u8 u[16])
{
	int	i;

	for (i = 0; i < 16; i++)
		if (u[i])
			return 0;
	return 1;
}

long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
	struct inode *inode = file_inode(filp);
	struct super_block *sb = inode->i_sb;
	struct ext4_inode_info *ei = EXT4_I(inode);
	unsigned int flags;

	ext4_debug("cmd = %u, arg = %lu\n", cmd, arg);

	switch (cmd) {
	case EXT4_IOC_GETFLAGS:
		ext4_get_inode_flags(ei);
		flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
		return put_user(flags, (int __user *) arg);
	case EXT4_IOC_SETFLAGS: {
		handle_t *handle = NULL;
		int err, migrate = 0;
		struct ext4_iloc iloc;
		unsigned int oldflags, mask, i;
		unsigned int jflag;

		if (!inode_owner_or_capable(inode))
			return -EACCES;

		if (get_user(flags, (int __user *) arg))
			return -EFAULT;

		err = mnt_want_write_file(filp);
		if (err)
			return err;

		flags = ext4_mask_flags(inode->i_mode, flags);

		err = -EPERM;
		mutex_lock(&inode->i_mutex);
		/* Is it quota file? Do not allow user to mess with it */
		if (IS_NOQUOTA(inode))
			goto flags_out;

		oldflags = ei->i_flags;

		/* The JOURNAL_DATA flag is modifiable only by root */
		jflag = flags & EXT4_JOURNAL_DATA_FL;

		/*
		 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
		 * the relevant capability.
		 *
		 * This test looks nicer. Thanks to Pauline Middelink
		 */
		if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
			if (!capable(CAP_LINUX_IMMUTABLE))
				goto flags_out;
		}

		/*
		 * The JOURNAL_DATA flag can only be changed by
		 * the relevant capability.
		 */
		if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
			if (!capable(CAP_SYS_RESOURCE))
				goto flags_out;
		}
		if ((flags ^ oldflags) & EXT4_EXTENTS_FL)
			migrate = 1;

		if (flags & EXT4_EOFBLOCKS_FL) {
			/* we don't support adding EOFBLOCKS flag */
			if (!(oldflags & EXT4_EOFBLOCKS_FL)) {
				err = -EOPNOTSUPP;
				goto flags_out;
			}
		} else if (oldflags & EXT4_EOFBLOCKS_FL)
			ext4_truncate(inode);

		handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
		if (IS_ERR(handle)) {
			err = PTR_ERR(handle);
			goto flags_out;
		}
		if (IS_SYNC(inode))
			ext4_handle_sync(handle);
		err = ext4_reserve_inode_write(handle, inode, &iloc);
		if (err)
			goto flags_err;

		for (i = 0, mask = 1; i < 32; i++, mask <<= 1) {
			if (!(mask & EXT4_FL_USER_MODIFIABLE))
				continue;
			if (mask & flags)
				ext4_set_inode_flag(inode, i);
			else
				ext4_clear_inode_flag(inode, i);
		}

		ext4_set_inode_flags(inode);
		inode->i_ctime = ext4_current_time(inode);

		err = ext4_mark_iloc_dirty(handle, inode, &iloc);
flags_err:
		ext4_journal_stop(handle);
		if (err)
			goto flags_out;

		if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
			err = ext4_change_inode_journal_flag(inode, jflag);
		if (err)
			goto flags_out;
		if (migrate) {
			if (flags & EXT4_EXTENTS_FL)
				err = ext4_ext_migrate(inode);
			else
				err = ext4_ind_migrate(inode);
		}

flags_out:
		mutex_unlock(&inode->i_mutex);
		mnt_drop_write_file(filp);
		return err;
	}
	case EXT4_IOC_GETVERSION:
	case EXT4_IOC_GETVERSION_OLD:
		return put_user(inode->i_generation, (int __user *) arg);
	case EXT4_IOC_SETVERSION:
	case EXT4_IOC_SETVERSION_OLD: {
		handle_t *handle;
		struct ext4_iloc iloc;
		__u32 generation;
		int err;

		if (!inode_owner_or_capable(inode))
			return -EPERM;

		if (ext4_has_metadata_csum(inode->i_sb)) {
			ext4_warning(sb, "Setting inode version is not "
				     "supported with metadata_csum enabled.");
			return -ENOTTY;
		}

		err = mnt_want_write_file(filp);
		if (err)
			return err;
		if (get_user(generation, (int __user *) arg)) {
			err = -EFAULT;
			goto setversion_out;
		}

		mutex_lock(&inode->i_mutex);
		handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
		if (IS_ERR(handle)) {
			err = PTR_ERR(handle);
			goto unlock_out;
		}
		err = ext4_reserve_inode_write(handle, inode, &iloc);
		if (err == 0) {
			inode->i_ctime = ext4_current_time(inode);
			inode->i_generation = generation;
			err = ext4_mark_iloc_dirty(handle, inode, &iloc);
		}
		ext4_journal_stop(handle);

unlock_out:
		mutex_unlock(&inode->i_mutex);
setversion_out:
		mnt_drop_write_file(filp);
		return err;
	}
	case EXT4_IOC_GROUP_EXTEND: {
		ext4_fsblk_t n_blocks_count;
		int err, err2=0;

		err = ext4_resize_begin(sb);
		if (err)
			return err;

		if (get_user(n_blocks_count, (__u32 __user *)arg)) {
			err = -EFAULT;
			goto group_extend_out;
		}

		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
			       EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
			ext4_msg(sb, KERN_ERR,
				 "Online resizing not supported with bigalloc");
			err = -EOPNOTSUPP;
			goto group_extend_out;
		}

		err = mnt_want_write_file(filp);
		if (err)
			goto group_extend_out;

		err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
		if (EXT4_SB(sb)->s_journal) {
			jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
			err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
			jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
		}
		if (err == 0)
			err = err2;
		mnt_drop_write_file(filp);
group_extend_out:
		ext4_resize_end(sb);
		return err;
	}

	case EXT4_IOC_MOVE_EXT: {
		struct move_extent me;
		struct fd donor;
		int err;

		if (!(filp->f_mode & FMODE_READ) ||
		    !(filp->f_mode & FMODE_WRITE))
			return -EBADF;

		if (copy_from_user(&me,
			(struct move_extent __user *)arg, sizeof(me)))
			return -EFAULT;
		me.moved_len = 0;

		donor = fdget(me.donor_fd);
		if (!donor.file)
			return -EBADF;

		if (!(donor.file->f_mode & FMODE_WRITE)) {
			err = -EBADF;
			goto mext_out;
		}

		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
			       EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
			ext4_msg(sb, KERN_ERR,
				 "Online defrag not supported with bigalloc");
			err = -EOPNOTSUPP;
			goto mext_out;
		}

		err = mnt_want_write_file(filp);
		if (err)
			goto mext_out;

		err = ext4_move_extents(filp, donor.file, me.orig_start,
					me.donor_start, me.len, &me.moved_len);
		mnt_drop_write_file(filp);

		if (copy_to_user((struct move_extent __user *)arg,
				 &me, sizeof(me)))
			err = -EFAULT;
mext_out:
		fdput(donor);
		return err;
	}

	case EXT4_IOC_GROUP_ADD: {
		struct ext4_new_group_data input;
		int err, err2=0;

		err = ext4_resize_begin(sb);
		if (err)
			return err;

		if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
				sizeof(input))) {
			err = -EFAULT;
			goto group_add_out;
		}

		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
			       EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
			ext4_msg(sb, KERN_ERR,
				 "Online resizing not supported with bigalloc");
			err = -EOPNOTSUPP;
			goto group_add_out;
		}

		err = mnt_want_write_file(filp);
		if (err)
			goto group_add_out;

		err = ext4_group_add(sb, &input);
		if (EXT4_SB(sb)->s_journal) {
			jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
			err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
			jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
		}
		if (err == 0)
			err = err2;
		mnt_drop_write_file(filp);
		if (!err && ext4_has_group_desc_csum(sb) &&
		    test_opt(sb, INIT_INODE_TABLE))
			err = ext4_register_li_request(sb, input.group);
group_add_out:
		ext4_resize_end(sb);
		return err;
	}

	case EXT4_IOC_MIGRATE:
	{
		int err;
		if (!inode_owner_or_capable(inode))
			return -EACCES;

		err = mnt_want_write_file(filp);
		if (err)
			return err;
		/*
		 * inode_mutex prevent write and truncate on the file.
		 * Read still goes through. We take i_data_sem in
		 * ext4_ext_swap_inode_data before we switch the
		 * inode format to prevent read.
		 */
		mutex_lock(&(inode->i_mutex));
		err = ext4_ext_migrate(inode);
		mutex_unlock(&(inode->i_mutex));
		mnt_drop_write_file(filp);
		return err;
	}

	case EXT4_IOC_ALLOC_DA_BLKS:
	{
		int err;
		if (!inode_owner_or_capable(inode))
			return -EACCES;

		err = mnt_want_write_file(filp);
		if (err)
			return err;
		err = ext4_alloc_da_blocks(inode);
		mnt_drop_write_file(filp);
		return err;
	}

	case EXT4_IOC_SWAP_BOOT:
	{
		int err;
		if (!(filp->f_mode & FMODE_WRITE))
			return -EBADF;
		err = mnt_want_write_file(filp);
		if (err)
			return err;
		err = swap_inode_boot_loader(sb, inode);
		mnt_drop_write_file(filp);
		return err;
	}

	case EXT4_IOC_RESIZE_FS: {
		ext4_fsblk_t n_blocks_count;
		int err = 0, err2 = 0;
		ext4_group_t o_group = EXT4_SB(sb)->s_groups_count;

		if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
			       EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
			ext4_msg(sb, KERN_ERR,
				 "Online resizing not (yet) supported with bigalloc");
			return -EOPNOTSUPP;
		}

		if (copy_from_user(&n_blocks_count, (__u64 __user *)arg,
				   sizeof(__u64))) {
			return -EFAULT;
		}

		err = ext4_resize_begin(sb);
		if (err)
			return err;

		err = mnt_want_write_file(filp);
		if (err)
			goto resizefs_out;

		err = ext4_resize_fs(sb, n_blocks_count);
		if (EXT4_SB(sb)->s_journal) {
			jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
			err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
			jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
		}
		if (err == 0)
			err = err2;
		mnt_drop_write_file(filp);
		if (!err && (o_group > EXT4_SB(sb)->s_groups_count) &&
		    ext4_has_group_desc_csum(sb) &&
		    test_opt(sb, INIT_INODE_TABLE))
			err = ext4_register_li_request(sb, o_group);

resizefs_out:
		ext4_resize_end(sb);
		return err;
	}

	case FITRIM:
	{
		struct request_queue *q = bdev_get_queue(sb->s_bdev);
		struct fstrim_range range;
		int ret = 0;

		if (!capable(CAP_SYS_ADMIN))
			return -EPERM;

		if (!blk_queue_discard(q))
			return -EOPNOTSUPP;

		if (copy_from_user(&range, (struct fstrim_range __user *)arg,
		    sizeof(range)))
			return -EFAULT;

		range.minlen = max((unsigned int)range.minlen,
				   q->limits.discard_granularity);
		ret = ext4_trim_fs(sb, &range);
		if (ret < 0)
			return ret;

		if (copy_to_user((struct fstrim_range __user *)arg, &range,
		    sizeof(range)))
			return -EFAULT;

		return 0;
	}
	case EXT4_IOC_PRECACHE_EXTENTS:
		return ext4_ext_precache(inode);
	case EXT4_IOC_SET_ENCRYPTION_POLICY: {
#ifdef CONFIG_EXT4_FS_ENCRYPTION
		struct ext4_encryption_policy policy;
		int err = 0;

		if (copy_from_user(&policy,
				   (struct ext4_encryption_policy __user *)arg,
				   sizeof(policy))) {
			err = -EFAULT;
			goto encryption_policy_out;
		}

		err = ext4_process_policy(&policy, inode);
encryption_policy_out:
		return err;
#else
		return -EOPNOTSUPP;
#endif
	}
	case EXT4_IOC_GET_ENCRYPTION_PWSALT: {
		int err, err2;
		struct ext4_sb_info *sbi = EXT4_SB(sb);
		handle_t *handle;

		if (!ext4_sb_has_crypto(sb))
			return -EOPNOTSUPP;
		if (uuid_is_zero(sbi->s_es->s_encrypt_pw_salt)) {
			err = mnt_want_write_file(filp);
			if (err)
				return err;
			handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
			if (IS_ERR(handle)) {
				err = PTR_ERR(handle);
				goto pwsalt_err_exit;
			}
			err = ext4_journal_get_write_access(handle, sbi->s_sbh);
			if (err)
				goto pwsalt_err_journal;
			generate_random_uuid(sbi->s_es->s_encrypt_pw_salt);
			err = ext4_handle_dirty_metadata(handle, NULL,
							 sbi->s_sbh);
		pwsalt_err_journal:
			err2 = ext4_journal_stop(handle);
			if (err2 && !err)
				err = err2;
		pwsalt_err_exit:
			mnt_drop_write_file(filp);
			if (err)
				return err;
		}
		if (copy_to_user((void __user *) arg,
				 sbi->s_es->s_encrypt_pw_salt, 16))
			return -EFAULT;
		return 0;
	}
	case EXT4_IOC_GET_ENCRYPTION_POLICY: {
#ifdef CONFIG_EXT4_FS_ENCRYPTION
		struct ext4_encryption_policy policy;
		int err = 0;

		if (!ext4_encrypted_inode(inode))
			return -ENOENT;
		err = ext4_get_policy(inode, &policy);
		if (err)
			return err;
		if (copy_to_user((void __user *)arg, &policy, sizeof(policy)))
			return -EFAULT;
		return 0;
#else
		return -EOPNOTSUPP;
#endif
	}
	default:
		return -ENOTTY;
	}
}

#ifdef CONFIG_COMPAT
long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	/* These are just misnamed, they actually get/put from/to user an int */
	switch (cmd) {
	case EXT4_IOC32_GETFLAGS:
		cmd = EXT4_IOC_GETFLAGS;
		break;
	case EXT4_IOC32_SETFLAGS:
		cmd = EXT4_IOC_SETFLAGS;
		break;
	case EXT4_IOC32_GETVERSION:
		cmd = EXT4_IOC_GETVERSION;
		break;
	case EXT4_IOC32_SETVERSION:
		cmd = EXT4_IOC_SETVERSION;
		break;
	case EXT4_IOC32_GROUP_EXTEND:
		cmd = EXT4_IOC_GROUP_EXTEND;
		break;
	case EXT4_IOC32_GETVERSION_OLD:
		cmd = EXT4_IOC_GETVERSION_OLD;
		break;
	case EXT4_IOC32_SETVERSION_OLD:
		cmd = EXT4_IOC_SETVERSION_OLD;
		break;
	case EXT4_IOC32_GETRSVSZ:
		cmd = EXT4_IOC_GETRSVSZ;
		break;
	case EXT4_IOC32_SETRSVSZ:
		cmd = EXT4_IOC_SETRSVSZ;
		break;
	case EXT4_IOC32_GROUP_ADD: {
		struct compat_ext4_new_group_input __user *uinput;
		struct ext4_new_group_input input;
		mm_segment_t old_fs;
		int err;

		uinput = compat_ptr(arg);
		err = get_user(input.group, &uinput->group);
		err |= get_user(input.block_bitmap, &uinput->block_bitmap);
		err |= get_user(input.inode_bitmap, &uinput->inode_bitmap);
		err |= get_user(input.inode_table, &uinput->inode_table);
		err |= get_user(input.blocks_count, &uinput->blocks_count);
		err |= get_user(input.reserved_blocks,
				&uinput->reserved_blocks);
		if (err)
			return -EFAULT;
		old_fs = get_fs();
		set_fs(KERNEL_DS);
		err = ext4_ioctl(file, EXT4_IOC_GROUP_ADD,
				 (unsigned long) &input);
		set_fs(old_fs);
		return err;
	}
	case EXT4_IOC_MOVE_EXT:
	case FITRIM:
	case EXT4_IOC_RESIZE_FS:
	case EXT4_IOC_PRECACHE_EXTENTS:
	case EXT4_IOC_SET_ENCRYPTION_POLICY:
	case EXT4_IOC_GET_ENCRYPTION_PWSALT:
	case EXT4_IOC_GET_ENCRYPTION_POLICY:
		break;
	default:
		return -ENOIOCTLCMD;
	}
	return ext4_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
}
#endif