xref: /kernel/linux/linux-6.6/fs/exfat/super.c (revision 62306a36)
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *  Copyright (C) 2012-2013 Samsung Electronics Co., Ltd.
4 */
5
6#include <linux/fs_context.h>
7#include <linux/fs_parser.h>
8#include <linux/module.h>
9#include <linux/init.h>
10#include <linux/time.h>
11#include <linux/mount.h>
12#include <linux/cred.h>
13#include <linux/statfs.h>
14#include <linux/seq_file.h>
15#include <linux/blkdev.h>
16#include <linux/fs_struct.h>
17#include <linux/iversion.h>
18#include <linux/nls.h>
19#include <linux/buffer_head.h>
20#include <linux/magic.h>
21
22#include "exfat_raw.h"
23#include "exfat_fs.h"
24
25static char exfat_default_iocharset[] = CONFIG_EXFAT_DEFAULT_IOCHARSET;
26static struct kmem_cache *exfat_inode_cachep;
27
28static void exfat_free_iocharset(struct exfat_sb_info *sbi)
29{
30	if (sbi->options.iocharset != exfat_default_iocharset)
31		kfree(sbi->options.iocharset);
32}
33
34static void exfat_put_super(struct super_block *sb)
35{
36	struct exfat_sb_info *sbi = EXFAT_SB(sb);
37
38	mutex_lock(&sbi->s_lock);
39	exfat_free_bitmap(sbi);
40	brelse(sbi->boot_bh);
41	mutex_unlock(&sbi->s_lock);
42
43	unload_nls(sbi->nls_io);
44	exfat_free_upcase_table(sbi);
45}
46
47static int exfat_sync_fs(struct super_block *sb, int wait)
48{
49	struct exfat_sb_info *sbi = EXFAT_SB(sb);
50	int err = 0;
51
52	if (!wait)
53		return 0;
54
55	/* If there are some dirty buffers in the bdev inode */
56	mutex_lock(&sbi->s_lock);
57	sync_blockdev(sb->s_bdev);
58	if (exfat_clear_volume_dirty(sb))
59		err = -EIO;
60	mutex_unlock(&sbi->s_lock);
61	return err;
62}
63
64static int exfat_statfs(struct dentry *dentry, struct kstatfs *buf)
65{
66	struct super_block *sb = dentry->d_sb;
67	struct exfat_sb_info *sbi = EXFAT_SB(sb);
68	unsigned long long id = huge_encode_dev(sb->s_bdev->bd_dev);
69
70	if (sbi->used_clusters == EXFAT_CLUSTERS_UNTRACKED) {
71		mutex_lock(&sbi->s_lock);
72		if (exfat_count_used_clusters(sb, &sbi->used_clusters)) {
73			mutex_unlock(&sbi->s_lock);
74			return -EIO;
75		}
76		mutex_unlock(&sbi->s_lock);
77	}
78
79	buf->f_type = sb->s_magic;
80	buf->f_bsize = sbi->cluster_size;
81	buf->f_blocks = sbi->num_clusters - 2; /* clu 0 & 1 */
82	buf->f_bfree = buf->f_blocks - sbi->used_clusters;
83	buf->f_bavail = buf->f_bfree;
84	buf->f_fsid = u64_to_fsid(id);
85	/* Unicode utf16 255 characters */
86	buf->f_namelen = EXFAT_MAX_FILE_LEN * NLS_MAX_CHARSET_SIZE;
87	return 0;
88}
89
90static int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flags)
91{
92	struct exfat_sb_info *sbi = EXFAT_SB(sb);
93	struct boot_sector *p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
94
95	/* retain persistent-flags */
96	new_flags |= sbi->vol_flags_persistent;
97
98	/* flags are not changed */
99	if (sbi->vol_flags == new_flags)
100		return 0;
101
102	sbi->vol_flags = new_flags;
103
104	/* skip updating volume dirty flag,
105	 * if this volume has been mounted with read-only
106	 */
107	if (sb_rdonly(sb))
108		return 0;
109
110	p_boot->vol_flags = cpu_to_le16(new_flags);
111
112	set_buffer_uptodate(sbi->boot_bh);
113	mark_buffer_dirty(sbi->boot_bh);
114
115	__sync_dirty_buffer(sbi->boot_bh, REQ_SYNC | REQ_FUA | REQ_PREFLUSH);
116
117	return 0;
118}
119
120int exfat_set_volume_dirty(struct super_block *sb)
121{
122	struct exfat_sb_info *sbi = EXFAT_SB(sb);
123
124	return exfat_set_vol_flags(sb, sbi->vol_flags | VOLUME_DIRTY);
125}
126
127int exfat_clear_volume_dirty(struct super_block *sb)
128{
129	struct exfat_sb_info *sbi = EXFAT_SB(sb);
130
131	return exfat_set_vol_flags(sb, sbi->vol_flags & ~VOLUME_DIRTY);
132}
133
134static int exfat_show_options(struct seq_file *m, struct dentry *root)
135{
136	struct super_block *sb = root->d_sb;
137	struct exfat_sb_info *sbi = EXFAT_SB(sb);
138	struct exfat_mount_options *opts = &sbi->options;
139
140	/* Show partition info */
141	if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
142		seq_printf(m, ",uid=%u",
143				from_kuid_munged(&init_user_ns, opts->fs_uid));
144	if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
145		seq_printf(m, ",gid=%u",
146				from_kgid_munged(&init_user_ns, opts->fs_gid));
147	seq_printf(m, ",fmask=%04o,dmask=%04o", opts->fs_fmask, opts->fs_dmask);
148	if (opts->allow_utime)
149		seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
150	if (opts->utf8)
151		seq_puts(m, ",iocharset=utf8");
152	else if (sbi->nls_io)
153		seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
154	if (opts->errors == EXFAT_ERRORS_CONT)
155		seq_puts(m, ",errors=continue");
156	else if (opts->errors == EXFAT_ERRORS_PANIC)
157		seq_puts(m, ",errors=panic");
158	else
159		seq_puts(m, ",errors=remount-ro");
160	if (opts->discard)
161		seq_puts(m, ",discard");
162	if (opts->keep_last_dots)
163		seq_puts(m, ",keep_last_dots");
164	if (opts->sys_tz)
165		seq_puts(m, ",sys_tz");
166	else if (opts->time_offset)
167		seq_printf(m, ",time_offset=%d", opts->time_offset);
168	return 0;
169}
170
171static struct inode *exfat_alloc_inode(struct super_block *sb)
172{
173	struct exfat_inode_info *ei;
174
175	ei = alloc_inode_sb(sb, exfat_inode_cachep, GFP_NOFS);
176	if (!ei)
177		return NULL;
178
179	init_rwsem(&ei->truncate_lock);
180	return &ei->vfs_inode;
181}
182
183static void exfat_free_inode(struct inode *inode)
184{
185	kmem_cache_free(exfat_inode_cachep, EXFAT_I(inode));
186}
187
188static const struct super_operations exfat_sops = {
189	.alloc_inode	= exfat_alloc_inode,
190	.free_inode	= exfat_free_inode,
191	.write_inode	= exfat_write_inode,
192	.evict_inode	= exfat_evict_inode,
193	.put_super	= exfat_put_super,
194	.sync_fs	= exfat_sync_fs,
195	.statfs		= exfat_statfs,
196	.show_options	= exfat_show_options,
197};
198
199enum {
200	Opt_uid,
201	Opt_gid,
202	Opt_umask,
203	Opt_dmask,
204	Opt_fmask,
205	Opt_allow_utime,
206	Opt_charset,
207	Opt_errors,
208	Opt_discard,
209	Opt_keep_last_dots,
210	Opt_sys_tz,
211	Opt_time_offset,
212
213	/* Deprecated options */
214	Opt_utf8,
215	Opt_debug,
216	Opt_namecase,
217	Opt_codepage,
218};
219
220static const struct constant_table exfat_param_enums[] = {
221	{ "continue",		EXFAT_ERRORS_CONT },
222	{ "panic",		EXFAT_ERRORS_PANIC },
223	{ "remount-ro",		EXFAT_ERRORS_RO },
224	{}
225};
226
227static const struct fs_parameter_spec exfat_parameters[] = {
228	fsparam_u32("uid",			Opt_uid),
229	fsparam_u32("gid",			Opt_gid),
230	fsparam_u32oct("umask",			Opt_umask),
231	fsparam_u32oct("dmask",			Opt_dmask),
232	fsparam_u32oct("fmask",			Opt_fmask),
233	fsparam_u32oct("allow_utime",		Opt_allow_utime),
234	fsparam_string("iocharset",		Opt_charset),
235	fsparam_enum("errors",			Opt_errors, exfat_param_enums),
236	fsparam_flag("discard",			Opt_discard),
237	fsparam_flag("keep_last_dots",		Opt_keep_last_dots),
238	fsparam_flag("sys_tz",			Opt_sys_tz),
239	fsparam_s32("time_offset",		Opt_time_offset),
240	__fsparam(NULL, "utf8",			Opt_utf8, fs_param_deprecated,
241		  NULL),
242	__fsparam(NULL, "debug",		Opt_debug, fs_param_deprecated,
243		  NULL),
244	__fsparam(fs_param_is_u32, "namecase",	Opt_namecase,
245		  fs_param_deprecated, NULL),
246	__fsparam(fs_param_is_u32, "codepage",	Opt_codepage,
247		  fs_param_deprecated, NULL),
248	{}
249};
250
251static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param)
252{
253	struct exfat_sb_info *sbi = fc->s_fs_info;
254	struct exfat_mount_options *opts = &sbi->options;
255	struct fs_parse_result result;
256	int opt;
257
258	opt = fs_parse(fc, exfat_parameters, param, &result);
259	if (opt < 0)
260		return opt;
261
262	switch (opt) {
263	case Opt_uid:
264		opts->fs_uid = make_kuid(current_user_ns(), result.uint_32);
265		break;
266	case Opt_gid:
267		opts->fs_gid = make_kgid(current_user_ns(), result.uint_32);
268		break;
269	case Opt_umask:
270		opts->fs_fmask = result.uint_32;
271		opts->fs_dmask = result.uint_32;
272		break;
273	case Opt_dmask:
274		opts->fs_dmask = result.uint_32;
275		break;
276	case Opt_fmask:
277		opts->fs_fmask = result.uint_32;
278		break;
279	case Opt_allow_utime:
280		opts->allow_utime = result.uint_32 & 0022;
281		break;
282	case Opt_charset:
283		exfat_free_iocharset(sbi);
284		opts->iocharset = param->string;
285		param->string = NULL;
286		break;
287	case Opt_errors:
288		opts->errors = result.uint_32;
289		break;
290	case Opt_discard:
291		opts->discard = 1;
292		break;
293	case Opt_keep_last_dots:
294		opts->keep_last_dots = 1;
295		break;
296	case Opt_sys_tz:
297		opts->sys_tz = 1;
298		break;
299	case Opt_time_offset:
300		/*
301		 * Make the limit 24 just in case someone invents something
302		 * unusual.
303		 */
304		if (result.int_32 < -24 * 60 || result.int_32 > 24 * 60)
305			return -EINVAL;
306		opts->time_offset = result.int_32;
307		break;
308	case Opt_utf8:
309	case Opt_debug:
310	case Opt_namecase:
311	case Opt_codepage:
312		break;
313	default:
314		return -EINVAL;
315	}
316
317	return 0;
318}
319
320static void exfat_hash_init(struct super_block *sb)
321{
322	struct exfat_sb_info *sbi = EXFAT_SB(sb);
323	int i;
324
325	spin_lock_init(&sbi->inode_hash_lock);
326	for (i = 0; i < EXFAT_HASH_SIZE; i++)
327		INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
328}
329
330static int exfat_read_root(struct inode *inode)
331{
332	struct super_block *sb = inode->i_sb;
333	struct exfat_sb_info *sbi = EXFAT_SB(sb);
334	struct exfat_inode_info *ei = EXFAT_I(inode);
335	struct exfat_chain cdir;
336	int num_subdirs, num_clu = 0;
337
338	exfat_chain_set(&ei->dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
339	ei->entry = -1;
340	ei->start_clu = sbi->root_dir;
341	ei->flags = ALLOC_FAT_CHAIN;
342	ei->type = TYPE_DIR;
343	ei->version = 0;
344	ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
345	ei->hint_stat.eidx = 0;
346	ei->hint_stat.clu = sbi->root_dir;
347	ei->hint_femp.eidx = EXFAT_HINT_NONE;
348
349	exfat_chain_set(&cdir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
350	if (exfat_count_num_clusters(sb, &cdir, &num_clu))
351		return -EIO;
352	i_size_write(inode, num_clu << sbi->cluster_size_bits);
353
354	num_subdirs = exfat_count_dir_entries(sb, &cdir);
355	if (num_subdirs < 0)
356		return -EIO;
357	set_nlink(inode, num_subdirs + EXFAT_MIN_SUBDIR);
358
359	inode->i_uid = sbi->options.fs_uid;
360	inode->i_gid = sbi->options.fs_gid;
361	inode_inc_iversion(inode);
362	inode->i_generation = 0;
363	inode->i_mode = exfat_make_mode(sbi, ATTR_SUBDIR, 0777);
364	inode->i_op = &exfat_dir_inode_operations;
365	inode->i_fop = &exfat_dir_operations;
366
367	inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9;
368	ei->i_pos = ((loff_t)sbi->root_dir << 32) | 0xffffffff;
369	ei->i_size_aligned = i_size_read(inode);
370	ei->i_size_ondisk = i_size_read(inode);
371
372	exfat_save_attr(inode, ATTR_SUBDIR);
373	inode->i_mtime = inode->i_atime = ei->i_crtime = inode_set_ctime_current(inode);
374	exfat_truncate_atime(&inode->i_atime);
375	return 0;
376}
377
378static int exfat_calibrate_blocksize(struct super_block *sb, int logical_sect)
379{
380	struct exfat_sb_info *sbi = EXFAT_SB(sb);
381
382	if (!is_power_of_2(logical_sect)) {
383		exfat_err(sb, "bogus logical sector size %u", logical_sect);
384		return -EIO;
385	}
386
387	if (logical_sect < sb->s_blocksize) {
388		exfat_err(sb, "logical sector size too small for device (logical sector size = %u)",
389			  logical_sect);
390		return -EIO;
391	}
392
393	if (logical_sect > sb->s_blocksize) {
394		brelse(sbi->boot_bh);
395		sbi->boot_bh = NULL;
396
397		if (!sb_set_blocksize(sb, logical_sect)) {
398			exfat_err(sb, "unable to set blocksize %u",
399				  logical_sect);
400			return -EIO;
401		}
402		sbi->boot_bh = sb_bread(sb, 0);
403		if (!sbi->boot_bh) {
404			exfat_err(sb, "unable to read boot sector (logical sector size = %lu)",
405				  sb->s_blocksize);
406			return -EIO;
407		}
408	}
409	return 0;
410}
411
412static int exfat_read_boot_sector(struct super_block *sb)
413{
414	struct boot_sector *p_boot;
415	struct exfat_sb_info *sbi = EXFAT_SB(sb);
416
417	/* set block size to read super block */
418	sb_min_blocksize(sb, 512);
419
420	/* read boot sector */
421	sbi->boot_bh = sb_bread(sb, 0);
422	if (!sbi->boot_bh) {
423		exfat_err(sb, "unable to read boot sector");
424		return -EIO;
425	}
426	p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
427
428	/* check the validity of BOOT */
429	if (le16_to_cpu((p_boot->signature)) != BOOT_SIGNATURE) {
430		exfat_err(sb, "invalid boot record signature");
431		return -EINVAL;
432	}
433
434	if (memcmp(p_boot->fs_name, STR_EXFAT, BOOTSEC_FS_NAME_LEN)) {
435		exfat_err(sb, "invalid fs_name"); /* fs_name may unprintable */
436		return -EINVAL;
437	}
438
439	/*
440	 * must_be_zero field must be filled with zero to prevent mounting
441	 * from FAT volume.
442	 */
443	if (memchr_inv(p_boot->must_be_zero, 0, sizeof(p_boot->must_be_zero)))
444		return -EINVAL;
445
446	if (p_boot->num_fats != 1 && p_boot->num_fats != 2) {
447		exfat_err(sb, "bogus number of FAT structure");
448		return -EINVAL;
449	}
450
451	/*
452	 * sect_size_bits could be at least 9 and at most 12.
453	 */
454	if (p_boot->sect_size_bits < EXFAT_MIN_SECT_SIZE_BITS ||
455	    p_boot->sect_size_bits > EXFAT_MAX_SECT_SIZE_BITS) {
456		exfat_err(sb, "bogus sector size bits : %u",
457				p_boot->sect_size_bits);
458		return -EINVAL;
459	}
460
461	/*
462	 * sect_per_clus_bits could be at least 0 and at most 25 - sect_size_bits.
463	 */
464	if (p_boot->sect_per_clus_bits > EXFAT_MAX_SECT_PER_CLUS_BITS(p_boot)) {
465		exfat_err(sb, "bogus sectors bits per cluster : %u",
466				p_boot->sect_per_clus_bits);
467		return -EINVAL;
468	}
469
470	sbi->sect_per_clus = 1 << p_boot->sect_per_clus_bits;
471	sbi->sect_per_clus_bits = p_boot->sect_per_clus_bits;
472	sbi->cluster_size_bits = p_boot->sect_per_clus_bits +
473		p_boot->sect_size_bits;
474	sbi->cluster_size = 1 << sbi->cluster_size_bits;
475	sbi->num_FAT_sectors = le32_to_cpu(p_boot->fat_length);
476	sbi->FAT1_start_sector = le32_to_cpu(p_boot->fat_offset);
477	sbi->FAT2_start_sector = le32_to_cpu(p_boot->fat_offset);
478	if (p_boot->num_fats == 2)
479		sbi->FAT2_start_sector += sbi->num_FAT_sectors;
480	sbi->data_start_sector = le32_to_cpu(p_boot->clu_offset);
481	sbi->num_sectors = le64_to_cpu(p_boot->vol_length);
482	/* because the cluster index starts with 2 */
483	sbi->num_clusters = le32_to_cpu(p_boot->clu_count) +
484		EXFAT_RESERVED_CLUSTERS;
485
486	sbi->root_dir = le32_to_cpu(p_boot->root_cluster);
487	sbi->dentries_per_clu = 1 <<
488		(sbi->cluster_size_bits - DENTRY_SIZE_BITS);
489
490	sbi->vol_flags = le16_to_cpu(p_boot->vol_flags);
491	sbi->vol_flags_persistent = sbi->vol_flags & (VOLUME_DIRTY | MEDIA_FAILURE);
492	sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;
493	sbi->used_clusters = EXFAT_CLUSTERS_UNTRACKED;
494
495	/* check consistencies */
496	if ((u64)sbi->num_FAT_sectors << p_boot->sect_size_bits <
497	    (u64)sbi->num_clusters * 4) {
498		exfat_err(sb, "bogus fat length");
499		return -EINVAL;
500	}
501
502	if (sbi->data_start_sector <
503	    (u64)sbi->FAT1_start_sector +
504	    (u64)sbi->num_FAT_sectors * p_boot->num_fats) {
505		exfat_err(sb, "bogus data start sector");
506		return -EINVAL;
507	}
508
509	if (sbi->vol_flags & VOLUME_DIRTY)
510		exfat_warn(sb, "Volume was not properly unmounted. Some data may be corrupt. Please run fsck.");
511	if (sbi->vol_flags & MEDIA_FAILURE)
512		exfat_warn(sb, "Medium has reported failures. Some data may be lost.");
513
514	/* exFAT file size is limited by a disk volume size */
515	sb->s_maxbytes = (u64)(sbi->num_clusters - EXFAT_RESERVED_CLUSTERS) <<
516		sbi->cluster_size_bits;
517
518	/* check logical sector size */
519	if (exfat_calibrate_blocksize(sb, 1 << p_boot->sect_size_bits))
520		return -EIO;
521
522	return 0;
523}
524
525static int exfat_verify_boot_region(struct super_block *sb)
526{
527	struct buffer_head *bh = NULL;
528	u32 chksum = 0;
529	__le32 *p_sig, *p_chksum;
530	int sn, i;
531
532	/* read boot sector sub-regions */
533	for (sn = 0; sn < 11; sn++) {
534		bh = sb_bread(sb, sn);
535		if (!bh)
536			return -EIO;
537
538		if (sn != 0 && sn <= 8) {
539			/* extended boot sector sub-regions */
540			p_sig = (__le32 *)&bh->b_data[sb->s_blocksize - 4];
541			if (le32_to_cpu(*p_sig) != EXBOOT_SIGNATURE)
542				exfat_warn(sb, "Invalid exboot-signature(sector = %d): 0x%08x",
543					   sn, le32_to_cpu(*p_sig));
544		}
545
546		chksum = exfat_calc_chksum32(bh->b_data, sb->s_blocksize,
547			chksum, sn ? CS_DEFAULT : CS_BOOT_SECTOR);
548		brelse(bh);
549	}
550
551	/* boot checksum sub-regions */
552	bh = sb_bread(sb, sn);
553	if (!bh)
554		return -EIO;
555
556	for (i = 0; i < sb->s_blocksize; i += sizeof(u32)) {
557		p_chksum = (__le32 *)&bh->b_data[i];
558		if (le32_to_cpu(*p_chksum) != chksum) {
559			exfat_err(sb, "Invalid boot checksum (boot checksum : 0x%08x, checksum : 0x%08x)",
560				  le32_to_cpu(*p_chksum), chksum);
561			brelse(bh);
562			return -EINVAL;
563		}
564	}
565	brelse(bh);
566	return 0;
567}
568
569/* mount the file system volume */
570static int __exfat_fill_super(struct super_block *sb)
571{
572	int ret;
573	struct exfat_sb_info *sbi = EXFAT_SB(sb);
574
575	ret = exfat_read_boot_sector(sb);
576	if (ret) {
577		exfat_err(sb, "failed to read boot sector");
578		goto free_bh;
579	}
580
581	ret = exfat_verify_boot_region(sb);
582	if (ret) {
583		exfat_err(sb, "invalid boot region");
584		goto free_bh;
585	}
586
587	ret = exfat_create_upcase_table(sb);
588	if (ret) {
589		exfat_err(sb, "failed to load upcase table");
590		goto free_bh;
591	}
592
593	ret = exfat_load_bitmap(sb);
594	if (ret) {
595		exfat_err(sb, "failed to load alloc-bitmap");
596		goto free_upcase_table;
597	}
598
599	ret = exfat_count_used_clusters(sb, &sbi->used_clusters);
600	if (ret) {
601		exfat_err(sb, "failed to scan clusters");
602		goto free_alloc_bitmap;
603	}
604
605	return 0;
606
607free_alloc_bitmap:
608	exfat_free_bitmap(sbi);
609free_upcase_table:
610	exfat_free_upcase_table(sbi);
611free_bh:
612	brelse(sbi->boot_bh);
613	return ret;
614}
615
616static int exfat_fill_super(struct super_block *sb, struct fs_context *fc)
617{
618	struct exfat_sb_info *sbi = sb->s_fs_info;
619	struct exfat_mount_options *opts = &sbi->options;
620	struct inode *root_inode;
621	int err;
622
623	if (opts->allow_utime == (unsigned short)-1)
624		opts->allow_utime = ~opts->fs_dmask & 0022;
625
626	if (opts->discard && !bdev_max_discard_sectors(sb->s_bdev)) {
627		exfat_warn(sb, "mounting with \"discard\" option, but the device does not support discard");
628		opts->discard = 0;
629	}
630
631	sb->s_flags |= SB_NODIRATIME;
632	sb->s_magic = EXFAT_SUPER_MAGIC;
633	sb->s_op = &exfat_sops;
634
635	sb->s_time_gran = 10 * NSEC_PER_MSEC;
636	sb->s_time_min = EXFAT_MIN_TIMESTAMP_SECS;
637	sb->s_time_max = EXFAT_MAX_TIMESTAMP_SECS;
638
639	err = __exfat_fill_super(sb);
640	if (err) {
641		exfat_err(sb, "failed to recognize exfat type");
642		goto check_nls_io;
643	}
644
645	/* set up enough so that it can read an inode */
646	exfat_hash_init(sb);
647
648	if (!strcmp(sbi->options.iocharset, "utf8"))
649		opts->utf8 = 1;
650	else {
651		sbi->nls_io = load_nls(sbi->options.iocharset);
652		if (!sbi->nls_io) {
653			exfat_err(sb, "IO charset %s not found",
654				  sbi->options.iocharset);
655			err = -EINVAL;
656			goto free_table;
657		}
658	}
659
660	if (sbi->options.utf8)
661		sb->s_d_op = &exfat_utf8_dentry_ops;
662	else
663		sb->s_d_op = &exfat_dentry_ops;
664
665	root_inode = new_inode(sb);
666	if (!root_inode) {
667		exfat_err(sb, "failed to allocate root inode");
668		err = -ENOMEM;
669		goto free_table;
670	}
671
672	root_inode->i_ino = EXFAT_ROOT_INO;
673	inode_set_iversion(root_inode, 1);
674	err = exfat_read_root(root_inode);
675	if (err) {
676		exfat_err(sb, "failed to initialize root inode");
677		goto put_inode;
678	}
679
680	exfat_hash_inode(root_inode, EXFAT_I(root_inode)->i_pos);
681	insert_inode_hash(root_inode);
682
683	sb->s_root = d_make_root(root_inode);
684	if (!sb->s_root) {
685		exfat_err(sb, "failed to get the root dentry");
686		err = -ENOMEM;
687		goto free_table;
688	}
689
690	return 0;
691
692put_inode:
693	iput(root_inode);
694	sb->s_root = NULL;
695
696free_table:
697	exfat_free_upcase_table(sbi);
698	exfat_free_bitmap(sbi);
699	brelse(sbi->boot_bh);
700
701check_nls_io:
702	unload_nls(sbi->nls_io);
703	return err;
704}
705
706static int exfat_get_tree(struct fs_context *fc)
707{
708	return get_tree_bdev(fc, exfat_fill_super);
709}
710
711static void exfat_free_sbi(struct exfat_sb_info *sbi)
712{
713	exfat_free_iocharset(sbi);
714	kfree(sbi);
715}
716
717static void exfat_free(struct fs_context *fc)
718{
719	struct exfat_sb_info *sbi = fc->s_fs_info;
720
721	if (sbi)
722		exfat_free_sbi(sbi);
723}
724
725static int exfat_reconfigure(struct fs_context *fc)
726{
727	fc->sb_flags |= SB_NODIRATIME;
728
729	/* volume flag will be updated in exfat_sync_fs */
730	sync_filesystem(fc->root->d_sb);
731	return 0;
732}
733
734static const struct fs_context_operations exfat_context_ops = {
735	.parse_param	= exfat_parse_param,
736	.get_tree	= exfat_get_tree,
737	.free		= exfat_free,
738	.reconfigure	= exfat_reconfigure,
739};
740
741static int exfat_init_fs_context(struct fs_context *fc)
742{
743	struct exfat_sb_info *sbi;
744
745	sbi = kzalloc(sizeof(struct exfat_sb_info), GFP_KERNEL);
746	if (!sbi)
747		return -ENOMEM;
748
749	mutex_init(&sbi->s_lock);
750	mutex_init(&sbi->bitmap_lock);
751	ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
752			DEFAULT_RATELIMIT_BURST);
753
754	sbi->options.fs_uid = current_uid();
755	sbi->options.fs_gid = current_gid();
756	sbi->options.fs_fmask = current->fs->umask;
757	sbi->options.fs_dmask = current->fs->umask;
758	sbi->options.allow_utime = -1;
759	sbi->options.iocharset = exfat_default_iocharset;
760	sbi->options.errors = EXFAT_ERRORS_RO;
761
762	fc->s_fs_info = sbi;
763	fc->ops = &exfat_context_ops;
764	return 0;
765}
766
767static void exfat_kill_sb(struct super_block *sb)
768{
769	struct exfat_sb_info *sbi = sb->s_fs_info;
770
771	kill_block_super(sb);
772	if (sbi)
773		exfat_free_sbi(sbi);
774}
775
776static struct file_system_type exfat_fs_type = {
777	.owner			= THIS_MODULE,
778	.name			= "exfat",
779	.init_fs_context	= exfat_init_fs_context,
780	.parameters		= exfat_parameters,
781	.kill_sb		= exfat_kill_sb,
782	.fs_flags		= FS_REQUIRES_DEV,
783};
784
785static void exfat_inode_init_once(void *foo)
786{
787	struct exfat_inode_info *ei = (struct exfat_inode_info *)foo;
788
789	spin_lock_init(&ei->cache_lru_lock);
790	ei->nr_caches = 0;
791	ei->cache_valid_id = EXFAT_CACHE_VALID + 1;
792	INIT_LIST_HEAD(&ei->cache_lru);
793	INIT_HLIST_NODE(&ei->i_hash_fat);
794	inode_init_once(&ei->vfs_inode);
795}
796
797static int __init init_exfat_fs(void)
798{
799	int err;
800
801	err = exfat_cache_init();
802	if (err)
803		return err;
804
805	exfat_inode_cachep = kmem_cache_create("exfat_inode_cache",
806			sizeof(struct exfat_inode_info),
807			0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
808			exfat_inode_init_once);
809	if (!exfat_inode_cachep) {
810		err = -ENOMEM;
811		goto shutdown_cache;
812	}
813
814	err = register_filesystem(&exfat_fs_type);
815	if (err)
816		goto destroy_cache;
817
818	return 0;
819
820destroy_cache:
821	kmem_cache_destroy(exfat_inode_cachep);
822shutdown_cache:
823	exfat_cache_shutdown();
824	return err;
825}
826
827static void __exit exit_exfat_fs(void)
828{
829	/*
830	 * Make sure all delayed rcu free inodes are flushed before we
831	 * destroy cache.
832	 */
833	rcu_barrier();
834	kmem_cache_destroy(exfat_inode_cachep);
835	unregister_filesystem(&exfat_fs_type);
836	exfat_cache_shutdown();
837}
838
839module_init(init_exfat_fs);
840module_exit(exit_exfat_fs);
841
842MODULE_ALIAS_FS("exfat");
843MODULE_LICENSE("GPL");
844MODULE_DESCRIPTION("exFAT filesystem support");
845MODULE_AUTHOR("Samsung Electronics Co., Ltd.");
846