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
24 static char exfat_default_iocharset[] = CONFIG_EXFAT_DEFAULT_IOCHARSET;
25 static struct kmem_cache *exfat_inode_cachep;
26
exfat_free_iocharset(struct exfat_sb_info * sbi)27 static 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
exfat_delayed_free(struct rcu_head * p)33 static 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
exfat_put_super(struct super_block * sb)43 static 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
exfat_sync_fs(struct super_block * sb,int wait)55 static 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
exfat_statfs(struct dentry * dentry,struct kstatfs * buf)72 static 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
exfat_set_vol_flags(struct super_block * sb,unsigned short new_flags)98 static 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
exfat_set_volume_dirty(struct super_block * sb)134 int 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
exfat_clear_volume_dirty(struct super_block * sb)141 int 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
exfat_show_options(struct seq_file * m,struct dentry * root)148 static 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
exfat_alloc_inode(struct super_block * sb)181 static 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
exfat_free_inode(struct inode * inode)193 static void exfat_free_inode(struct inode *inode)
194 {
195 kmem_cache_free(exfat_inode_cachep, EXFAT_I(inode));
196 }
197
198 static 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
209 enum {
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
228 static 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
235 static 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
exfat_parse_param(struct fs_context * fc,struct fs_parameter * param)257 static 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
exfat_hash_init(struct super_block * sb)320 static 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
exfat_read_root(struct inode * inode)330 static 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
exfat_calibrate_blocksize(struct super_block * sb,int logical_sect)379 static 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
exfat_read_boot_sector(struct super_block * sb)413 static 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
exfat_verify_boot_region(struct super_block * sb)526 static 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 */
__exfat_fill_super(struct super_block * sb)571 static 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
608 free_alloc_bitmap:
609 exfat_free_bitmap(sbi);
610 free_upcase_table:
611 exfat_free_upcase_table(sbi);
612 free_bh:
613 brelse(sbi->boot_bh);
614 return ret;
615 }
616
exfat_fill_super(struct super_block * sb,struct fs_context * fc)617 static 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
697 put_inode:
698 iput(root_inode);
699 sb->s_root = NULL;
700
701 free_table:
702 exfat_free_upcase_table(sbi);
703 exfat_free_bitmap(sbi);
704 brelse(sbi->boot_bh);
705
706 check_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
exfat_get_tree(struct fs_context * fc)714 static int exfat_get_tree(struct fs_context *fc)
715 {
716 return get_tree_bdev(fc, exfat_fill_super);
717 }
718
exfat_free(struct fs_context * fc)719 static 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
exfat_reconfigure(struct fs_context * fc)729 static 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
738 static 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
exfat_init_fs_context(struct fs_context * fc)745 static 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
770 static 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
exfat_inode_init_once(void * foo)779 static 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
init_exfat_fs(void)791 static 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
814 destroy_cache:
815 kmem_cache_destroy(exfat_inode_cachep);
816 shutdown_cache:
817 exfat_cache_shutdown();
818 return err;
819 }
820
exit_exfat_fs(void)821 static 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
833 module_init(init_exfat_fs);
834 module_exit(exit_exfat_fs);
835
836 MODULE_ALIAS_FS("exfat");
837 MODULE_LICENSE("GPL");
838 MODULE_IMPORT_NS(ANDROID_GKI_VFS_EXPORT_ONLY);
839 MODULE_DESCRIPTION("exFAT filesystem support");
840 MODULE_AUTHOR("Samsung Electronics Co., Ltd.");
841