summaryrefslogtreecommitdiff
path: root/fs/exfat/super.c
blob: ea17e8ed50674dc3d659fd4475649001d105c279 (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
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
 */

#include <linux/fs_context.h>
#include <linux/fs_parser.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/mount.h>
#include <linux/cred.h>
#include <linux/statfs.h>
#include <linux/seq_file.h>
#include <linux/blkdev.h>
#include <linux/fs_struct.h>
#include <linux/iversion.h>
#include <linux/nls.h>
#include <linux/buffer_head.h>

#include "exfat_raw.h"
#include "exfat_fs.h"

static char exfat_default_iocharset[] = CONFIG_EXFAT_DEFAULT_IOCHARSET;
static struct kmem_cache *exfat_inode_cachep;

static void exfat_free_iocharset(struct exfat_sb_info *sbi)
{
	if (sbi->options.iocharset != exfat_default_iocharset)
		kfree(sbi->options.iocharset);
}

static void exfat_delayed_free(struct rcu_head *p)
{
	struct exfat_sb_info *sbi = container_of(p, struct exfat_sb_info, rcu);

	unload_nls(sbi->nls_io);
	exfat_free_iocharset(sbi);
	exfat_free_upcase_table(sbi);
	kfree(sbi);
}

static void exfat_put_super(struct super_block *sb)
{
	struct exfat_sb_info *sbi = EXFAT_SB(sb);

	mutex_lock(&sbi->s_lock);
	exfat_free_bitmap(sbi);
	brelse(sbi->boot_bh);
	mutex_unlock(&sbi->s_lock);

	call_rcu(&sbi->rcu, exfat_delayed_free);
}

static int exfat_sync_fs(struct super_block *sb, int wait)
{
	struct exfat_sb_info *sbi = EXFAT_SB(sb);
	int err = 0;

	if (!wait)
		return 0;

	/* If there are some dirty buffers in the bdev inode */
	mutex_lock(&sbi->s_lock);
	sync_blockdev(sb->s_bdev);
	if (exfat_clear_volume_dirty(sb))
		err = -EIO;
	mutex_unlock(&sbi->s_lock);
	return err;
}

static int exfat_statfs(struct dentry *dentry, struct kstatfs *buf)
{
	struct super_block *sb = dentry->d_sb;
	struct exfat_sb_info *sbi = EXFAT_SB(sb);
	unsigned long long id = huge_encode_dev(sb->s_bdev->bd_dev);

	if (sbi->used_clusters == EXFAT_CLUSTERS_UNTRACKED) {
		mutex_lock(&sbi->s_lock);
		if (exfat_count_used_clusters(sb, &sbi->used_clusters)) {
			mutex_unlock(&sbi->s_lock);
			return -EIO;
		}
		mutex_unlock(&sbi->s_lock);
	}

	buf->f_type = sb->s_magic;
	buf->f_bsize = sbi->cluster_size;
	buf->f_blocks = sbi->num_clusters - 2; /* clu 0 & 1 */
	buf->f_bfree = buf->f_blocks - sbi->used_clusters;
	buf->f_bavail = buf->f_bfree;
	buf->f_fsid = u64_to_fsid(id);
	/* Unicode utf16 255 characters */
	buf->f_namelen = EXFAT_MAX_FILE_LEN * NLS_MAX_CHARSET_SIZE;
	return 0;
}

static int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flags)
{
	struct exfat_sb_info *sbi = EXFAT_SB(sb);
	struct boot_sector *p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
	bool sync;

	/* retain persistent-flags */
	new_flags |= sbi->vol_flags_persistent;

	/* flags are not changed */
	if (sbi->vol_flags == new_flags)
		return 0;

	sbi->vol_flags = new_flags;

	/* skip updating volume dirty flag,
	 * if this volume has been mounted with read-only
	 */
	if (sb_rdonly(sb))
		return 0;

	p_boot->vol_flags = cpu_to_le16(new_flags);

	if ((new_flags & VOLUME_DIRTY) && !buffer_dirty(sbi->boot_bh))
		sync = true;
	else
		sync = false;

	set_buffer_uptodate(sbi->boot_bh);
	mark_buffer_dirty(sbi->boot_bh);

	if (sync)
		sync_dirty_buffer(sbi->boot_bh);
	return 0;
}

int exfat_set_volume_dirty(struct super_block *sb)
{
	struct exfat_sb_info *sbi = EXFAT_SB(sb);

	return exfat_set_vol_flags(sb, sbi->vol_flags | VOLUME_DIRTY);
}

int exfat_clear_volume_dirty(struct super_block *sb)
{
	struct exfat_sb_info *sbi = EXFAT_SB(sb);

	return exfat_set_vol_flags(sb, sbi->vol_flags & ~VOLUME_DIRTY);
}

static int exfat_show_options(struct seq_file *m, struct dentry *root)
{
	struct super_block *sb = root->d_sb;
	struct exfat_sb_info *sbi = EXFAT_SB(sb);
	struct exfat_mount_options *opts = &sbi->options;

	/* Show partition info */
	if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
		seq_printf(m, ",uid=%u",
				from_kuid_munged(&init_user_ns, opts->fs_uid));
	if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
		seq_printf(m, ",gid=%u",
				from_kgid_munged(&init_user_ns, opts->fs_gid));
	seq_printf(m, ",fmask=%04o,dmask=%04o", opts->fs_fmask, opts->fs_dmask);
	if (opts->allow_utime)
		seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
	if (opts->utf8)
		seq_puts(m, ",iocharset=utf8");
	else if (sbi->nls_io)
		seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
	if (opts->errors == EXFAT_ERRORS_CONT)
		seq_puts(m, ",errors=continue");
	else if (opts->errors == EXFAT_ERRORS_PANIC)
		seq_puts(m, ",errors=panic");
	else
		seq_puts(m, ",errors=remount-ro");
	if (opts->discard)
		seq_puts(m, ",discard");
	if (opts->time_offset)
		seq_printf(m, ",time_offset=%d", opts->time_offset);
	return 0;
}

static struct inode *exfat_alloc_inode(struct super_block *sb)
{
	struct exfat_inode_info *ei;

	ei = kmem_cache_alloc(exfat_inode_cachep, GFP_NOFS);
	if (!ei)
		return NULL;

	init_rwsem(&ei->truncate_lock);
	return &ei->vfs_inode;
}

static void exfat_free_inode(struct inode *inode)
{
	kmem_cache_free(exfat_inode_cachep, EXFAT_I(inode));
}

static const struct super_operations exfat_sops = {
	.alloc_inode	= exfat_alloc_inode,
	.free_inode	= exfat_free_inode,
	.write_inode	= exfat_write_inode,
	.evict_inode	= exfat_evict_inode,
	.put_super	= exfat_put_super,
	.sync_fs	= exfat_sync_fs,
	.statfs		= exfat_statfs,
	.show_options	= exfat_show_options,
};

enum {
	Opt_uid,
	Opt_gid,
	Opt_umask,
	Opt_dmask,
	Opt_fmask,
	Opt_allow_utime,
	Opt_charset,
	Opt_errors,
	Opt_discard,
	Opt_time_offset,

	/* Deprecated options */
	Opt_utf8,
	Opt_debug,
	Opt_namecase,
	Opt_codepage,
};

static const struct constant_table exfat_param_enums[] = {
	{ "continue",		EXFAT_ERRORS_CONT },
	{ "panic",		EXFAT_ERRORS_PANIC },
	{ "remount-ro",		EXFAT_ERRORS_RO },
	{}
};

static const struct fs_parameter_spec exfat_parameters[] = {
	fsparam_u32("uid",			Opt_uid),
	fsparam_u32("gid",			Opt_gid),
	fsparam_u32oct("umask",			Opt_umask),
	fsparam_u32oct("dmask",			Opt_dmask),
	fsparam_u32oct("fmask",			Opt_fmask),
	fsparam_u32oct("allow_utime",		Opt_allow_utime),
	fsparam_string("iocharset",		Opt_charset),
	fsparam_enum("errors",			Opt_errors, exfat_param_enums),
	fsparam_flag("discard",			Opt_discard),
	fsparam_s32("time_offset",		Opt_time_offset),
	__fsparam(NULL, "utf8",			Opt_utf8, fs_param_deprecated,
		  NULL),
	__fsparam(NULL, "debug",		Opt_debug, fs_param_deprecated,
		  NULL),
	__fsparam(fs_param_is_u32, "namecase",	Opt_namecase,
		  fs_param_deprecated, NULL),
	__fsparam(fs_param_is_u32, "codepage",	Opt_codepage,
		  fs_param_deprecated, NULL),
	{}
};

static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
	struct exfat_sb_info *sbi = fc->s_fs_info;
	struct exfat_mount_options *opts = &sbi->options;
	struct fs_parse_result result;
	int opt;

	opt = fs_parse(fc, exfat_parameters, param, &result);
	if (opt < 0)
		return opt;

	switch (opt) {
	case Opt_uid:
		opts->fs_uid = make_kuid(current_user_ns(), result.uint_32);
		break;
	case Opt_gid:
		opts->fs_gid = make_kgid(current_user_ns(), result.uint_32);
		break;
	case Opt_umask:
		opts->fs_fmask = result.uint_32;
		opts->fs_dmask = result.uint_32;
		break;
	case Opt_dmask:
		opts->fs_dmask = result.uint_32;
		break;
	case Opt_fmask:
		opts->fs_fmask = result.uint_32;
		break;
	case Opt_allow_utime:
		opts->allow_utime = result.uint_32 & 0022;
		break;
	case Opt_charset:
		exfat_free_iocharset(sbi);
		opts->iocharset = param->string;
		param->string = NULL;
		break;
	case Opt_errors:
		opts->errors = result.uint_32;
		break;
	case Opt_discard:
		opts->discard = 1;
		break;
	case Opt_time_offset:
		/*
		 * Make the limit 24 just in case someone invents something
		 * unusual.
		 */
		if (result.int_32 < -24 * 60 || result.int_32 > 24 * 60)
			return -EINVAL;
		opts->time_offset = result.int_32;
		break;
	case Opt_utf8:
	case Opt_debug:
	case Opt_namecase:
	case Opt_codepage:
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

static void exfat_hash_init(struct super_block *sb)
{
	struct exfat_sb_info *sbi = EXFAT_SB(sb);
	int i;

	spin_lock_init(&sbi->inode_hash_lock);
	for (i = 0; i < EXFAT_HASH_SIZE; i++)
		INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
}

static int exfat_read_root(struct inode *inode)
{
	struct super_block *sb = inode->i_sb;
	struct exfat_sb_info *sbi = EXFAT_SB(sb);
	struct exfat_inode_info *ei = EXFAT_I(inode);
	struct exfat_chain cdir;
	int num_subdirs, num_clu = 0;

	exfat_chain_set(&ei->dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
	ei->entry = -1;
	ei->start_clu = sbi->root_dir;
	ei->flags = ALLOC_FAT_CHAIN;
	ei->type = TYPE_DIR;
	ei->version = 0;
	ei->rwoffset = 0;
	ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
	ei->hint_stat.eidx = 0;
	ei->hint_stat.clu = sbi->root_dir;
	ei->hint_femp.eidx = EXFAT_HINT_NONE;

	exfat_chain_set(&cdir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
	if (exfat_count_num_clusters(sb, &cdir, &num_clu))
		return -EIO;
	i_size_write(inode, num_clu << sbi->cluster_size_bits);

	num_subdirs = exfat_count_dir_entries(sb, &cdir);
	if (num_subdirs < 0)
		return -EIO;
	set_nlink(inode, num_subdirs + EXFAT_MIN_SUBDIR);

	inode->i_uid = sbi->options.fs_uid;
	inode->i_gid = sbi->options.fs_gid;
	inode_inc_iversion(inode);
	inode->i_generation = 0;
	inode->i_mode = exfat_make_mode(sbi, ATTR_SUBDIR, 0777);
	inode->i_op = &exfat_dir_inode_operations;
	inode->i_fop = &exfat_dir_operations;

	inode->i_blocks = ((i_size_read(inode) + (sbi->cluster_size - 1))
			& ~(sbi->cluster_size - 1)) >> inode->i_blkbits;
	EXFAT_I(inode)->i_pos = ((loff_t)sbi->root_dir << 32) | 0xffffffff;
	EXFAT_I(inode)->i_size_aligned = i_size_read(inode);
	EXFAT_I(inode)->i_size_ondisk = i_size_read(inode);

	exfat_save_attr(inode, ATTR_SUBDIR);
	inode->i_mtime = inode->i_atime = inode->i_ctime = ei->i_crtime =
		current_time(inode);
	exfat_truncate_atime(&inode->i_atime);
	exfat_cache_init_inode(inode);
	return 0;
}

static int exfat_calibrate_blocksize(struct super_block *sb, int logical_sect)
{
	struct exfat_sb_info *sbi = EXFAT_SB(sb);

	if (!is_power_of_2(logical_sect) ||
	    logical_sect < 512 || logical_sect > 4096) {
		exfat_err(sb, "bogus logical sector size %u", logical_sect);
		return -EIO;
	}

	if (logical_sect < sb->s_blocksize) {
		exfat_err(sb, "logical sector size too small for device (logical sector size = %u)",
			  logical_sect);
		return -EIO;
	}

	if (logical_sect > sb->s_blocksize) {
		brelse(sbi->boot_bh);
		sbi->boot_bh = NULL;

		if (!sb_set_blocksize(sb, logical_sect)) {
			exfat_err(sb, "unable to set blocksize %u",
				  logical_sect);
			return -EIO;
		}
		sbi->boot_bh = sb_bread(sb, 0);
		if (!sbi->boot_bh) {
			exfat_err(sb, "unable to read boot sector (logical sector size = %lu)",
				  sb->s_blocksize);
			return -EIO;
		}
	}
	return 0;
}

static int exfat_read_boot_sector(struct super_block *sb)
{
	struct boot_sector *p_boot;
	struct exfat_sb_info *sbi = EXFAT_SB(sb);

	/* set block size to read super block */
	sb_min_blocksize(sb, 512);

	/* read boot sector */
	sbi->boot_bh = sb_bread(sb, 0);
	if (!sbi->boot_bh) {
		exfat_err(sb, "unable to read boot sector");
		return -EIO;
	}
	p_boot = (struct boot_sector *)sbi->boot_bh->b_data;

	/* check the validity of BOOT */
	if (le16_to_cpu((p_boot->signature)) != BOOT_SIGNATURE) {
		exfat_err(sb, "invalid boot record signature");
		return -EINVAL;
	}

	if (memcmp(p_boot->fs_name, STR_EXFAT, BOOTSEC_FS_NAME_LEN)) {
		exfat_err(sb, "invalid fs_name"); /* fs_name may unprintable */
		return -EINVAL;
	}

	/*
	 * must_be_zero field must be filled with zero to prevent mounting
	 * from FAT volume.
	 */
	if (memchr_inv(p_boot->must_be_zero, 0, sizeof(p_boot->must_be_zero)))
		return -EINVAL;

	if (p_boot->num_fats != 1 && p_boot->num_fats != 2) {
		exfat_err(sb, "bogus number of FAT structure");
		return -EINVAL;
	}

	sbi->sect_per_clus = 1 << p_boot->sect_per_clus_bits;
	sbi->sect_per_clus_bits = p_boot->sect_per_clus_bits;
	sbi->cluster_size_bits = p_boot->sect_per_clus_bits +
		p_boot->sect_size_bits;
	sbi->cluster_size = 1 << sbi->cluster_size_bits;
	sbi->num_FAT_sectors = le32_to_cpu(p_boot->fat_length);
	sbi->FAT1_start_sector = le32_to_cpu(p_boot->fat_offset);
	sbi->FAT2_start_sector = le32_to_cpu(p_boot->fat_offset);
	if (p_boot->num_fats == 2)
		sbi->FAT2_start_sector += sbi->num_FAT_sectors;
	sbi->data_start_sector = le32_to_cpu(p_boot->clu_offset);
	sbi->num_sectors = le64_to_cpu(p_boot->vol_length);
	/* because the cluster index starts with 2 */
	sbi->num_clusters = le32_to_cpu(p_boot->clu_count) +
		EXFAT_RESERVED_CLUSTERS;

	sbi->root_dir = le32_to_cpu(p_boot->root_cluster);
	sbi->dentries_per_clu = 1 <<
		(sbi->cluster_size_bits - DENTRY_SIZE_BITS);

	sbi->vol_flags = le16_to_cpu(p_boot->vol_flags);
	sbi->vol_flags_persistent = sbi->vol_flags & (VOLUME_DIRTY | MEDIA_FAILURE);
	sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;
	sbi->used_clusters = EXFAT_CLUSTERS_UNTRACKED;

	/* check consistencies */
	if (sbi->num_FAT_sectors << p_boot->sect_size_bits <
	    sbi->num_clusters * 4) {
		exfat_err(sb, "bogus fat length");
		return -EINVAL;
	}
	if (sbi->data_start_sector <
	    sbi->FAT1_start_sector + sbi->num_FAT_sectors * p_boot->num_fats) {
		exfat_err(sb, "bogus data start sector");
		return -EINVAL;
	}
	if (sbi->vol_flags & VOLUME_DIRTY)
		exfat_warn(sb, "Volume was not properly unmounted. Some data may be corrupt. Please run fsck.");
	if (sbi->vol_flags & MEDIA_FAILURE)
		exfat_warn(sb, "Medium has reported failures. Some data may be lost.");

	/* exFAT file size is limited by a disk volume size */
	sb->s_maxbytes = (u64)(sbi->num_clusters - EXFAT_RESERVED_CLUSTERS) <<
		sbi->cluster_size_bits;

	/* check logical sector size */
	if (exfat_calibrate_blocksize(sb, 1 << p_boot->sect_size_bits))
		return -EIO;

	return 0;
}

static int exfat_verify_boot_region(struct super_block *sb)
{
	struct buffer_head *bh = NULL;
	u32 chksum = 0;
	__le32 *p_sig, *p_chksum;
	int sn, i;

	/* read boot sector sub-regions */
	for (sn = 0; sn < 11; sn++) {
		bh = sb_bread(sb, sn);
		if (!bh)
			return -EIO;

		if (sn != 0 && sn <= 8) {
			/* extended boot sector sub-regions */
			p_sig = (__le32 *)&bh->b_data[sb->s_blocksize - 4];
			if (le32_to_cpu(*p_sig) != EXBOOT_SIGNATURE)
				exfat_warn(sb, "Invalid exboot-signature(sector = %d): 0x%08x",
					   sn, le32_to_cpu(*p_sig));
		}

		chksum = exfat_calc_chksum32(bh->b_data, sb->s_blocksize,
			chksum, sn ? CS_DEFAULT : CS_BOOT_SECTOR);
		brelse(bh);
	}

	/* boot checksum sub-regions */
	bh = sb_bread(sb, sn);
	if (!bh)
		return -EIO;

	for (i = 0; i < sb->s_blocksize; i += sizeof(u32)) {
		p_chksum = (__le32 *)&bh->b_data[i];
		if (le32_to_cpu(*p_chksum) != chksum) {
			exfat_err(sb, "Invalid boot checksum (boot checksum : 0x%08x, checksum : 0x%08x)",
				  le32_to_cpu(*p_chksum), chksum);
			brelse(bh);
			return -EINVAL;
		}
	}
	brelse(bh);
	return 0;
}

/* mount the file system volume */
static int __exfat_fill_super(struct super_block *sb)
{
	int ret;
	struct exfat_sb_info *sbi = EXFAT_SB(sb);

	ret = exfat_read_boot_sector(sb);
	if (ret) {
		exfat_err(sb, "failed to read boot sector");
		goto free_bh;
	}

	ret = exfat_verify_boot_region(sb);
	if (ret) {
		exfat_err(sb, "invalid boot region");
		goto free_bh;
	}

	ret = exfat_create_upcase_table(sb);
	if (ret) {
		exfat_err(sb, "failed to load upcase table");
		goto free_bh;
	}

	ret = exfat_load_bitmap(sb);
	if (ret) {
		exfat_err(sb, "failed to load alloc-bitmap");
		goto free_upcase_table;
	}

	ret = exfat_count_used_clusters(sb, &sbi->used_clusters);
	if (ret) {
		exfat_err(sb, "failed to scan clusters");
		goto free_alloc_bitmap;
	}

	return 0;

free_alloc_bitmap:
	exfat_free_bitmap(sbi);
free_upcase_table:
	exfat_free_upcase_table(sbi);
free_bh:
	brelse(sbi->boot_bh);
	return ret;
}

static int exfat_fill_super(struct super_block *sb, struct fs_context *fc)
{
	struct exfat_sb_info *sbi = sb->s_fs_info;
	struct exfat_mount_options *opts = &sbi->options;
	struct inode *root_inode;
	int err;

	if (opts->allow_utime == (unsigned short)-1)
		opts->allow_utime = ~opts->fs_dmask & 0022;

	if (opts->discard) {
		struct request_queue *q = bdev_get_queue(sb->s_bdev);

		if (!blk_queue_discard(q)) {
			exfat_warn(sb, "mounting with \"discard\" option, but the device does not support discard");
			opts->discard = 0;
		}
	}

	sb->s_flags |= SB_NODIRATIME;
	sb->s_magic = EXFAT_SUPER_MAGIC;
	sb->s_op = &exfat_sops;

	sb->s_time_gran = 10 * NSEC_PER_MSEC;
	sb->s_time_min = EXFAT_MIN_TIMESTAMP_SECS;
	sb->s_time_max = EXFAT_MAX_TIMESTAMP_SECS;

	err = __exfat_fill_super(sb);
	if (err) {
		exfat_err(sb, "failed to recognize exfat type");
		goto check_nls_io;
	}

	/* set up enough so that it can read an inode */
	exfat_hash_init(sb);

	if (!strcmp(sbi->options.iocharset, "utf8"))
		opts->utf8 = 1;
	else {
		sbi->nls_io = load_nls(sbi->options.iocharset);
		if (!sbi->nls_io) {
			exfat_err(sb, "IO charset %s not found",
				  sbi->options.iocharset);
			err = -EINVAL;
			goto free_table;
		}
	}

	if (sbi->options.utf8)
		sb->s_d_op = &exfat_utf8_dentry_ops;
	else
		sb->s_d_op = &exfat_dentry_ops;

	root_inode = new_inode(sb);
	if (!root_inode) {
		exfat_err(sb, "failed to allocate root inode");
		err = -ENOMEM;
		goto free_table;
	}

	root_inode->i_ino = EXFAT_ROOT_INO;
	inode_set_iversion(root_inode, 1);
	err = exfat_read_root(root_inode);
	if (err) {
		exfat_err(sb, "failed to initialize root inode");
		goto put_inode;
	}

	exfat_hash_inode(root_inode, EXFAT_I(root_inode)->i_pos);
	insert_inode_hash(root_inode);

	sb->s_root = d_make_root(root_inode);
	if (!sb->s_root) {
		exfat_err(sb, "failed to get the root dentry");
		err = -ENOMEM;
		goto put_inode;
	}

	return 0;

put_inode:
	iput(root_inode);
	sb->s_root = NULL;

free_table:
	exfat_free_upcase_table(sbi);
	exfat_free_bitmap(sbi);
	brelse(sbi->boot_bh);

check_nls_io:
	unload_nls(sbi->nls_io);
	exfat_free_iocharset(sbi);
	sb->s_fs_info = NULL;
	kfree(sbi);
	return err;
}

static int exfat_get_tree(struct fs_context *fc)
{
	return get_tree_bdev(fc, exfat_fill_super);
}

static void exfat_free(struct fs_context *fc)
{
	struct exfat_sb_info *sbi = fc->s_fs_info;

	if (sbi) {
		exfat_free_iocharset(sbi);
		kfree(sbi);
	}
}

static int exfat_reconfigure(struct fs_context *fc)
{
	fc->sb_flags |= SB_NODIRATIME;

	/* volume flag will be updated in exfat_sync_fs */
	sync_filesystem(fc->root->d_sb);
	return 0;
}

static const struct fs_context_operations exfat_context_ops = {
	.parse_param	= exfat_parse_param,
	.get_tree	= exfat_get_tree,
	.free		= exfat_free,
	.reconfigure	= exfat_reconfigure,
};

static int exfat_init_fs_context(struct fs_context *fc)
{
	struct exfat_sb_info *sbi;

	sbi = kzalloc(sizeof(struct exfat_sb_info), GFP_KERNEL);
	if (!sbi)
		return -ENOMEM;

	mutex_init(&sbi->s_lock);
	ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
			DEFAULT_RATELIMIT_BURST);

	sbi->options.fs_uid = current_uid();
	sbi->options.fs_gid = current_gid();
	sbi->options.fs_fmask = current->fs->umask;
	sbi->options.fs_dmask = current->fs->umask;
	sbi->options.allow_utime = -1;
	sbi->options.iocharset = exfat_default_iocharset;
	sbi->options.errors = EXFAT_ERRORS_RO;

	fc->s_fs_info = sbi;
	fc->ops = &exfat_context_ops;
	return 0;
}

static struct file_system_type exfat_fs_type = {
	.owner			= THIS_MODULE,
	.name			= "exfat",
	.init_fs_context	= exfat_init_fs_context,
	.parameters		= exfat_parameters,
	.kill_sb		= kill_block_super,
	.fs_flags		= FS_REQUIRES_DEV,
};

static void exfat_inode_init_once(void *foo)
{
	struct exfat_inode_info *ei = (struct exfat_inode_info *)foo;

	INIT_HLIST_NODE(&ei->i_hash_fat);
	inode_init_once(&ei->vfs_inode);
}

static int __init init_exfat_fs(void)
{
	int err;

	err = exfat_cache_init();
	if (err)
		return err;

	exfat_inode_cachep = kmem_cache_create("exfat_inode_cache",
			sizeof(struct exfat_inode_info),
			0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
			exfat_inode_init_once);
	if (!exfat_inode_cachep) {
		err = -ENOMEM;
		goto shutdown_cache;
	}

	err = register_filesystem(&exfat_fs_type);
	if (err)
		goto destroy_cache;

	return 0;

destroy_cache:
	kmem_cache_destroy(exfat_inode_cachep);
shutdown_cache:
	exfat_cache_shutdown();
	return err;
}

static void __exit exit_exfat_fs(void)
{
	/*
	 * Make sure all delayed rcu free inodes are flushed before we
	 * destroy cache.
	 */
	rcu_barrier();
	kmem_cache_destroy(exfat_inode_cachep);
	unregister_filesystem(&exfat_fs_type);
	exfat_cache_shutdown();
}

module_init(init_exfat_fs);
module_exit(exit_exfat_fs);

MODULE_ALIAS_FS("exfat");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("exFAT filesystem support");
MODULE_AUTHOR("Samsung Electronics Co., Ltd.");