xref: /kernel/linux/linux-5.10/fs/exfat/super.c (revision 8c2ecf20)
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
21#include "exfat_raw.h"
22#include "exfat_fs.h"
23
24static char exfat_default_iocharset[] = CONFIG_EXFAT_DEFAULT_IOCHARSET;
25static struct kmem_cache *exfat_inode_cachep;
26
27static void exfat_free_iocharset(struct exfat_sb_info *sbi)
28{
29	if (sbi->options.iocharset != exfat_default_iocharset)
30		kfree(sbi->options.iocharset);
31}
32
33static void exfat_delayed_free(struct rcu_head *p)
34{
35	struct exfat_sb_info *sbi = container_of(p, struct exfat_sb_info, rcu);
36
37	unload_nls(sbi->nls_io);
38	exfat_free_iocharset(sbi);
39	exfat_free_upcase_table(sbi);
40	kfree(sbi);
41}
42
43static void exfat_put_super(struct super_block *sb)
44{
45	struct exfat_sb_info *sbi = EXFAT_SB(sb);
46
47	mutex_lock(&sbi->s_lock);
48	exfat_free_bitmap(sbi);
49	brelse(sbi->boot_bh);
50	mutex_unlock(&sbi->s_lock);
51
52	call_rcu(&sbi->rcu, exfat_delayed_free);
53}
54
55static int exfat_sync_fs(struct super_block *sb, int wait)
56{
57	struct exfat_sb_info *sbi = EXFAT_SB(sb);
58	int err = 0;
59
60	if (!wait)
61		return 0;
62
63	/* If there are some dirty buffers in the bdev inode */
64	mutex_lock(&sbi->s_lock);
65	sync_blockdev(sb->s_bdev);
66	if (exfat_clear_volume_dirty(sb))
67		err = -EIO;
68	mutex_unlock(&sbi->s_lock);
69	return err;
70}
71
72static int exfat_statfs(struct dentry *dentry, struct kstatfs *buf)
73{
74	struct super_block *sb = dentry->d_sb;
75	struct exfat_sb_info *sbi = EXFAT_SB(sb);
76	unsigned long long id = huge_encode_dev(sb->s_bdev->bd_dev);
77
78	if (sbi->used_clusters == EXFAT_CLUSTERS_UNTRACKED) {
79		mutex_lock(&sbi->s_lock);
80		if (exfat_count_used_clusters(sb, &sbi->used_clusters)) {
81			mutex_unlock(&sbi->s_lock);
82			return -EIO;
83		}
84		mutex_unlock(&sbi->s_lock);
85	}
86
87	buf->f_type = sb->s_magic;
88	buf->f_bsize = sbi->cluster_size;
89	buf->f_blocks = sbi->num_clusters - 2; /* clu 0 & 1 */
90	buf->f_bfree = buf->f_blocks - sbi->used_clusters;
91	buf->f_bavail = buf->f_bfree;
92	buf->f_fsid = u64_to_fsid(id);
93	/* Unicode utf16 255 characters */
94	buf->f_namelen = EXFAT_MAX_FILE_LEN * NLS_MAX_CHARSET_SIZE;
95	return 0;
96}
97
98static int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flags)
99{
100	struct exfat_sb_info *sbi = EXFAT_SB(sb);
101	struct boot_sector *p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
102	bool sync;
103
104	/* retain persistent-flags */
105	new_flags |= sbi->vol_flags_persistent;
106
107	/* flags are not changed */
108	if (sbi->vol_flags == new_flags)
109		return 0;
110
111	sbi->vol_flags = new_flags;
112
113	/* skip updating volume dirty flag,
114	 * if this volume has been mounted with read-only
115	 */
116	if (sb_rdonly(sb))
117		return 0;
118
119	p_boot->vol_flags = cpu_to_le16(new_flags);
120
121	if ((new_flags & VOLUME_DIRTY) && !buffer_dirty(sbi->boot_bh))
122		sync = true;
123	else
124		sync = false;
125
126	set_buffer_uptodate(sbi->boot_bh);
127	mark_buffer_dirty(sbi->boot_bh);
128
129	if (sync)
130		sync_dirty_buffer(sbi->boot_bh);
131	return 0;
132}
133
134int exfat_set_volume_dirty(struct super_block *sb)
135{
136	struct exfat_sb_info *sbi = EXFAT_SB(sb);
137
138	return exfat_set_vol_flags(sb, sbi->vol_flags | VOLUME_DIRTY);
139}
140
141int exfat_clear_volume_dirty(struct super_block *sb)
142{
143	struct exfat_sb_info *sbi = EXFAT_SB(sb);
144
145	return exfat_set_vol_flags(sb, sbi->vol_flags & ~VOLUME_DIRTY);
146}
147
148static int exfat_show_options(struct seq_file *m, struct dentry *root)
149{
150	struct super_block *sb = root->d_sb;
151	struct exfat_sb_info *sbi = EXFAT_SB(sb);
152	struct exfat_mount_options *opts = &sbi->options;
153
154	/* Show partition info */
155	if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
156		seq_printf(m, ",uid=%u",
157				from_kuid_munged(&init_user_ns, opts->fs_uid));
158	if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
159		seq_printf(m, ",gid=%u",
160				from_kgid_munged(&init_user_ns, opts->fs_gid));
161	seq_printf(m, ",fmask=%04o,dmask=%04o", opts->fs_fmask, opts->fs_dmask);
162	if (opts->allow_utime)
163		seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
164	if (opts->utf8)
165		seq_puts(m, ",iocharset=utf8");
166	else if (sbi->nls_io)
167		seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
168	if (opts->errors == EXFAT_ERRORS_CONT)
169		seq_puts(m, ",errors=continue");
170	else if (opts->errors == EXFAT_ERRORS_PANIC)
171		seq_puts(m, ",errors=panic");
172	else
173		seq_puts(m, ",errors=remount-ro");
174	if (opts->discard)
175		seq_puts(m, ",discard");
176	if (opts->time_offset)
177		seq_printf(m, ",time_offset=%d", opts->time_offset);
178	return 0;
179}
180
181static struct inode *exfat_alloc_inode(struct super_block *sb)
182{
183	struct exfat_inode_info *ei;
184
185	ei = kmem_cache_alloc(exfat_inode_cachep, GFP_NOFS);
186	if (!ei)
187		return NULL;
188
189	init_rwsem(&ei->truncate_lock);
190	return &ei->vfs_inode;
191}
192
193static void exfat_free_inode(struct inode *inode)
194{
195	kmem_cache_free(exfat_inode_cachep, EXFAT_I(inode));
196}
197
198static const struct super_operations exfat_sops = {
199	.alloc_inode	= exfat_alloc_inode,
200	.free_inode	= exfat_free_inode,
201	.write_inode	= exfat_write_inode,
202	.evict_inode	= exfat_evict_inode,
203	.put_super	= exfat_put_super,
204	.sync_fs	= exfat_sync_fs,
205	.statfs		= exfat_statfs,
206	.show_options	= exfat_show_options,
207};
208
209enum {
210	Opt_uid,
211	Opt_gid,
212	Opt_umask,
213	Opt_dmask,
214	Opt_fmask,
215	Opt_allow_utime,
216	Opt_charset,
217	Opt_errors,
218	Opt_discard,
219	Opt_time_offset,
220
221	/* Deprecated options */
222	Opt_utf8,
223	Opt_debug,
224	Opt_namecase,
225	Opt_codepage,
226};
227
228static const struct constant_table exfat_param_enums[] = {
229	{ "continue",		EXFAT_ERRORS_CONT },
230	{ "panic",		EXFAT_ERRORS_PANIC },
231	{ "remount-ro",		EXFAT_ERRORS_RO },
232	{}
233};
234
235static const struct fs_parameter_spec exfat_parameters[] = {
236	fsparam_u32("uid",			Opt_uid),
237	fsparam_u32("gid",			Opt_gid),
238	fsparam_u32oct("umask",			Opt_umask),
239	fsparam_u32oct("dmask",			Opt_dmask),
240	fsparam_u32oct("fmask",			Opt_fmask),
241	fsparam_u32oct("allow_utime",		Opt_allow_utime),
242	fsparam_string("iocharset",		Opt_charset),
243	fsparam_enum("errors",			Opt_errors, exfat_param_enums),
244	fsparam_flag("discard",			Opt_discard),
245	fsparam_s32("time_offset",		Opt_time_offset),
246	__fsparam(NULL, "utf8",			Opt_utf8, fs_param_deprecated,
247		  NULL),
248	__fsparam(NULL, "debug",		Opt_debug, fs_param_deprecated,
249		  NULL),
250	__fsparam(fs_param_is_u32, "namecase",	Opt_namecase,
251		  fs_param_deprecated, NULL),
252	__fsparam(fs_param_is_u32, "codepage",	Opt_codepage,
253		  fs_param_deprecated, NULL),
254	{}
255};
256
257static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param)
258{
259	struct exfat_sb_info *sbi = fc->s_fs_info;
260	struct exfat_mount_options *opts = &sbi->options;
261	struct fs_parse_result result;
262	int opt;
263
264	opt = fs_parse(fc, exfat_parameters, param, &result);
265	if (opt < 0)
266		return opt;
267
268	switch (opt) {
269	case Opt_uid:
270		opts->fs_uid = make_kuid(current_user_ns(), result.uint_32);
271		break;
272	case Opt_gid:
273		opts->fs_gid = make_kgid(current_user_ns(), result.uint_32);
274		break;
275	case Opt_umask:
276		opts->fs_fmask = result.uint_32;
277		opts->fs_dmask = result.uint_32;
278		break;
279	case Opt_dmask:
280		opts->fs_dmask = result.uint_32;
281		break;
282	case Opt_fmask:
283		opts->fs_fmask = result.uint_32;
284		break;
285	case Opt_allow_utime:
286		opts->allow_utime = result.uint_32 & 0022;
287		break;
288	case Opt_charset:
289		exfat_free_iocharset(sbi);
290		opts->iocharset = param->string;
291		param->string = NULL;
292		break;
293	case Opt_errors:
294		opts->errors = result.uint_32;
295		break;
296	case Opt_discard:
297		opts->discard = 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 = inode->i_ctime = ei->i_crtime =
374		current_time(inode);
375	exfat_truncate_atime(&inode->i_atime);
376	return 0;
377}
378
379static int exfat_calibrate_blocksize(struct super_block *sb, int logical_sect)
380{
381	struct exfat_sb_info *sbi = EXFAT_SB(sb);
382
383	if (!is_power_of_2(logical_sect)) {
384		exfat_err(sb, "bogus logical sector size %u", logical_sect);
385		return -EIO;
386	}
387
388	if (logical_sect < sb->s_blocksize) {
389		exfat_err(sb, "logical sector size too small for device (logical sector size = %u)",
390			  logical_sect);
391		return -EIO;
392	}
393
394	if (logical_sect > sb->s_blocksize) {
395		brelse(sbi->boot_bh);
396		sbi->boot_bh = NULL;
397
398		if (!sb_set_blocksize(sb, logical_sect)) {
399			exfat_err(sb, "unable to set blocksize %u",
400				  logical_sect);
401			return -EIO;
402		}
403		sbi->boot_bh = sb_bread(sb, 0);
404		if (!sbi->boot_bh) {
405			exfat_err(sb, "unable to read boot sector (logical sector size = %lu)",
406				  sb->s_blocksize);
407			return -EIO;
408		}
409	}
410	return 0;
411}
412
413static int exfat_read_boot_sector(struct super_block *sb)
414{
415	struct boot_sector *p_boot;
416	struct exfat_sb_info *sbi = EXFAT_SB(sb);
417
418	/* set block size to read super block */
419	sb_min_blocksize(sb, 512);
420
421	/* read boot sector */
422	sbi->boot_bh = sb_bread(sb, 0);
423	if (!sbi->boot_bh) {
424		exfat_err(sb, "unable to read boot sector");
425		return -EIO;
426	}
427	p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
428
429	/* check the validity of BOOT */
430	if (le16_to_cpu((p_boot->signature)) != BOOT_SIGNATURE) {
431		exfat_err(sb, "invalid boot record signature");
432		return -EINVAL;
433	}
434
435	if (memcmp(p_boot->fs_name, STR_EXFAT, BOOTSEC_FS_NAME_LEN)) {
436		exfat_err(sb, "invalid fs_name"); /* fs_name may unprintable */
437		return -EINVAL;
438	}
439
440	/*
441	 * must_be_zero field must be filled with zero to prevent mounting
442	 * from FAT volume.
443	 */
444	if (memchr_inv(p_boot->must_be_zero, 0, sizeof(p_boot->must_be_zero)))
445		return -EINVAL;
446
447	if (p_boot->num_fats != 1 && p_boot->num_fats != 2) {
448		exfat_err(sb, "bogus number of FAT structure");
449		return -EINVAL;
450	}
451
452	/*
453	 * sect_size_bits could be at least 9 and at most 12.
454	 */
455	if (p_boot->sect_size_bits < EXFAT_MIN_SECT_SIZE_BITS ||
456	    p_boot->sect_size_bits > EXFAT_MAX_SECT_SIZE_BITS) {
457		exfat_err(sb, "bogus sector size bits : %u\n",
458				p_boot->sect_size_bits);
459		return -EINVAL;
460	}
461
462	/*
463	 * sect_per_clus_bits could be at least 0 and at most 25 - sect_size_bits.
464	 */
465	if (p_boot->sect_per_clus_bits > EXFAT_MAX_SECT_PER_CLUS_BITS(p_boot)) {
466		exfat_err(sb, "bogus sectors bits per cluster : %u\n",
467				p_boot->sect_per_clus_bits);
468		return -EINVAL;
469	}
470
471	sbi->sect_per_clus = 1 << p_boot->sect_per_clus_bits;
472	sbi->sect_per_clus_bits = p_boot->sect_per_clus_bits;
473	sbi->cluster_size_bits = p_boot->sect_per_clus_bits +
474		p_boot->sect_size_bits;
475	sbi->cluster_size = 1 << sbi->cluster_size_bits;
476	sbi->num_FAT_sectors = le32_to_cpu(p_boot->fat_length);
477	sbi->FAT1_start_sector = le32_to_cpu(p_boot->fat_offset);
478	sbi->FAT2_start_sector = le32_to_cpu(p_boot->fat_offset);
479	if (p_boot->num_fats == 2)
480		sbi->FAT2_start_sector += sbi->num_FAT_sectors;
481	sbi->data_start_sector = le32_to_cpu(p_boot->clu_offset);
482	sbi->num_sectors = le64_to_cpu(p_boot->vol_length);
483	/* because the cluster index starts with 2 */
484	sbi->num_clusters = le32_to_cpu(p_boot->clu_count) +
485		EXFAT_RESERVED_CLUSTERS;
486
487	sbi->root_dir = le32_to_cpu(p_boot->root_cluster);
488	sbi->dentries_per_clu = 1 <<
489		(sbi->cluster_size_bits - DENTRY_SIZE_BITS);
490
491	sbi->vol_flags = le16_to_cpu(p_boot->vol_flags);
492	sbi->vol_flags_persistent = sbi->vol_flags & (VOLUME_DIRTY | MEDIA_FAILURE);
493	sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;
494	sbi->used_clusters = EXFAT_CLUSTERS_UNTRACKED;
495
496	/* check consistencies */
497	if ((u64)sbi->num_FAT_sectors << p_boot->sect_size_bits <
498	    (u64)sbi->num_clusters * 4) {
499		exfat_err(sb, "bogus fat length");
500		return -EINVAL;
501	}
502
503	if (sbi->data_start_sector <
504	    (u64)sbi->FAT1_start_sector +
505	    (u64)sbi->num_FAT_sectors * p_boot->num_fats) {
506		exfat_err(sb, "bogus data start sector");
507		return -EINVAL;
508	}
509
510	if (sbi->vol_flags & VOLUME_DIRTY)
511		exfat_warn(sb, "Volume was not properly unmounted. Some data may be corrupt. Please run fsck.");
512	if (sbi->vol_flags & MEDIA_FAILURE)
513		exfat_warn(sb, "Medium has reported failures. Some data may be lost.");
514
515	/* exFAT file size is limited by a disk volume size */
516	sb->s_maxbytes = (u64)(sbi->num_clusters - EXFAT_RESERVED_CLUSTERS) <<
517		sbi->cluster_size_bits;
518
519	/* check logical sector size */
520	if (exfat_calibrate_blocksize(sb, 1 << p_boot->sect_size_bits))
521		return -EIO;
522
523	return 0;
524}
525
526static int exfat_verify_boot_region(struct super_block *sb)
527{
528	struct buffer_head *bh = NULL;
529	u32 chksum = 0;
530	__le32 *p_sig, *p_chksum;
531	int sn, i;
532
533	/* read boot sector sub-regions */
534	for (sn = 0; sn < 11; sn++) {
535		bh = sb_bread(sb, sn);
536		if (!bh)
537			return -EIO;
538
539		if (sn != 0 && sn <= 8) {
540			/* extended boot sector sub-regions */
541			p_sig = (__le32 *)&bh->b_data[sb->s_blocksize - 4];
542			if (le32_to_cpu(*p_sig) != EXBOOT_SIGNATURE)
543				exfat_warn(sb, "Invalid exboot-signature(sector = %d): 0x%08x",
544					   sn, le32_to_cpu(*p_sig));
545		}
546
547		chksum = exfat_calc_chksum32(bh->b_data, sb->s_blocksize,
548			chksum, sn ? CS_DEFAULT : CS_BOOT_SECTOR);
549		brelse(bh);
550	}
551
552	/* boot checksum sub-regions */
553	bh = sb_bread(sb, sn);
554	if (!bh)
555		return -EIO;
556
557	for (i = 0; i < sb->s_blocksize; i += sizeof(u32)) {
558		p_chksum = (__le32 *)&bh->b_data[i];
559		if (le32_to_cpu(*p_chksum) != chksum) {
560			exfat_err(sb, "Invalid boot checksum (boot checksum : 0x%08x, checksum : 0x%08x)",
561				  le32_to_cpu(*p_chksum), chksum);
562			brelse(bh);
563			return -EINVAL;
564		}
565	}
566	brelse(bh);
567	return 0;
568}
569
570/* mount the file system volume */
571static int __exfat_fill_super(struct super_block *sb)
572{
573	int ret;
574	struct exfat_sb_info *sbi = EXFAT_SB(sb);
575
576	ret = exfat_read_boot_sector(sb);
577	if (ret) {
578		exfat_err(sb, "failed to read boot sector");
579		goto free_bh;
580	}
581
582	ret = exfat_verify_boot_region(sb);
583	if (ret) {
584		exfat_err(sb, "invalid boot region");
585		goto free_bh;
586	}
587
588	ret = exfat_create_upcase_table(sb);
589	if (ret) {
590		exfat_err(sb, "failed to load upcase table");
591		goto free_bh;
592	}
593
594	ret = exfat_load_bitmap(sb);
595	if (ret) {
596		exfat_err(sb, "failed to load alloc-bitmap");
597		goto free_upcase_table;
598	}
599
600	ret = exfat_count_used_clusters(sb, &sbi->used_clusters);
601	if (ret) {
602		exfat_err(sb, "failed to scan clusters");
603		goto free_alloc_bitmap;
604	}
605
606	return 0;
607
608free_alloc_bitmap:
609	exfat_free_bitmap(sbi);
610free_upcase_table:
611	exfat_free_upcase_table(sbi);
612free_bh:
613	brelse(sbi->boot_bh);
614	return ret;
615}
616
617static int exfat_fill_super(struct super_block *sb, struct fs_context *fc)
618{
619	struct exfat_sb_info *sbi = sb->s_fs_info;
620	struct exfat_mount_options *opts = &sbi->options;
621	struct inode *root_inode;
622	int err;
623
624	if (opts->allow_utime == (unsigned short)-1)
625		opts->allow_utime = ~opts->fs_dmask & 0022;
626
627	if (opts->discard) {
628		struct request_queue *q = bdev_get_queue(sb->s_bdev);
629
630		if (!blk_queue_discard(q)) {
631			exfat_warn(sb, "mounting with \"discard\" option, but the device does not support discard");
632			opts->discard = 0;
633		}
634	}
635
636	sb->s_flags |= SB_NODIRATIME;
637	sb->s_magic = EXFAT_SUPER_MAGIC;
638	sb->s_op = &exfat_sops;
639
640	sb->s_time_gran = 10 * NSEC_PER_MSEC;
641	sb->s_time_min = EXFAT_MIN_TIMESTAMP_SECS;
642	sb->s_time_max = EXFAT_MAX_TIMESTAMP_SECS;
643
644	err = __exfat_fill_super(sb);
645	if (err) {
646		exfat_err(sb, "failed to recognize exfat type");
647		goto check_nls_io;
648	}
649
650	/* set up enough so that it can read an inode */
651	exfat_hash_init(sb);
652
653	if (!strcmp(sbi->options.iocharset, "utf8"))
654		opts->utf8 = 1;
655	else {
656		sbi->nls_io = load_nls(sbi->options.iocharset);
657		if (!sbi->nls_io) {
658			exfat_err(sb, "IO charset %s not found",
659				  sbi->options.iocharset);
660			err = -EINVAL;
661			goto free_table;
662		}
663	}
664
665	if (sbi->options.utf8)
666		sb->s_d_op = &exfat_utf8_dentry_ops;
667	else
668		sb->s_d_op = &exfat_dentry_ops;
669
670	root_inode = new_inode(sb);
671	if (!root_inode) {
672		exfat_err(sb, "failed to allocate root inode");
673		err = -ENOMEM;
674		goto free_table;
675	}
676
677	root_inode->i_ino = EXFAT_ROOT_INO;
678	inode_set_iversion(root_inode, 1);
679	err = exfat_read_root(root_inode);
680	if (err) {
681		exfat_err(sb, "failed to initialize root inode");
682		goto put_inode;
683	}
684
685	exfat_hash_inode(root_inode, EXFAT_I(root_inode)->i_pos);
686	insert_inode_hash(root_inode);
687
688	sb->s_root = d_make_root(root_inode);
689	if (!sb->s_root) {
690		exfat_err(sb, "failed to get the root dentry");
691		err = -ENOMEM;
692		goto free_table;
693	}
694
695	return 0;
696
697put_inode:
698	iput(root_inode);
699	sb->s_root = NULL;
700
701free_table:
702	exfat_free_upcase_table(sbi);
703	exfat_free_bitmap(sbi);
704	brelse(sbi->boot_bh);
705
706check_nls_io:
707	unload_nls(sbi->nls_io);
708	exfat_free_iocharset(sbi);
709	sb->s_fs_info = NULL;
710	kfree(sbi);
711	return err;
712}
713
714static int exfat_get_tree(struct fs_context *fc)
715{
716	return get_tree_bdev(fc, exfat_fill_super);
717}
718
719static void exfat_free(struct fs_context *fc)
720{
721	struct exfat_sb_info *sbi = fc->s_fs_info;
722
723	if (sbi) {
724		exfat_free_iocharset(sbi);
725		kfree(sbi);
726	}
727}
728
729static int exfat_reconfigure(struct fs_context *fc)
730{
731	fc->sb_flags |= SB_NODIRATIME;
732
733	/* volume flag will be updated in exfat_sync_fs */
734	sync_filesystem(fc->root->d_sb);
735	return 0;
736}
737
738static const struct fs_context_operations exfat_context_ops = {
739	.parse_param	= exfat_parse_param,
740	.get_tree	= exfat_get_tree,
741	.free		= exfat_free,
742	.reconfigure	= exfat_reconfigure,
743};
744
745static int exfat_init_fs_context(struct fs_context *fc)
746{
747	struct exfat_sb_info *sbi;
748
749	sbi = kzalloc(sizeof(struct exfat_sb_info), GFP_KERNEL);
750	if (!sbi)
751		return -ENOMEM;
752
753	mutex_init(&sbi->s_lock);
754	ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
755			DEFAULT_RATELIMIT_BURST);
756
757	sbi->options.fs_uid = current_uid();
758	sbi->options.fs_gid = current_gid();
759	sbi->options.fs_fmask = current->fs->umask;
760	sbi->options.fs_dmask = current->fs->umask;
761	sbi->options.allow_utime = -1;
762	sbi->options.iocharset = exfat_default_iocharset;
763	sbi->options.errors = EXFAT_ERRORS_RO;
764
765	fc->s_fs_info = sbi;
766	fc->ops = &exfat_context_ops;
767	return 0;
768}
769
770static struct file_system_type exfat_fs_type = {
771	.owner			= THIS_MODULE,
772	.name			= "exfat",
773	.init_fs_context	= exfat_init_fs_context,
774	.parameters		= exfat_parameters,
775	.kill_sb		= kill_block_super,
776	.fs_flags		= FS_REQUIRES_DEV,
777};
778
779static void exfat_inode_init_once(void *foo)
780{
781	struct exfat_inode_info *ei = (struct exfat_inode_info *)foo;
782
783	spin_lock_init(&ei->cache_lru_lock);
784	ei->nr_caches = 0;
785	ei->cache_valid_id = EXFAT_CACHE_VALID + 1;
786	INIT_LIST_HEAD(&ei->cache_lru);
787	INIT_HLIST_NODE(&ei->i_hash_fat);
788	inode_init_once(&ei->vfs_inode);
789}
790
791static int __init init_exfat_fs(void)
792{
793	int err;
794
795	err = exfat_cache_init();
796	if (err)
797		return err;
798
799	exfat_inode_cachep = kmem_cache_create("exfat_inode_cache",
800			sizeof(struct exfat_inode_info),
801			0, SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
802			exfat_inode_init_once);
803	if (!exfat_inode_cachep) {
804		err = -ENOMEM;
805		goto shutdown_cache;
806	}
807
808	err = register_filesystem(&exfat_fs_type);
809	if (err)
810		goto destroy_cache;
811
812	return 0;
813
814destroy_cache:
815	kmem_cache_destroy(exfat_inode_cachep);
816shutdown_cache:
817	exfat_cache_shutdown();
818	return err;
819}
820
821static void __exit exit_exfat_fs(void)
822{
823	/*
824	 * Make sure all delayed rcu free inodes are flushed before we
825	 * destroy cache.
826	 */
827	rcu_barrier();
828	kmem_cache_destroy(exfat_inode_cachep);
829	unregister_filesystem(&exfat_fs_type);
830	exfat_cache_shutdown();
831}
832
833module_init(init_exfat_fs);
834module_exit(exit_exfat_fs);
835
836MODULE_ALIAS_FS("exfat");
837MODULE_LICENSE("GPL");
838MODULE_DESCRIPTION("exFAT filesystem support");
839MODULE_AUTHOR("Samsung Electronics Co., Ltd.");
840