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
25 static char exfat_default_iocharset[] = CONFIG_EXFAT_DEFAULT_IOCHARSET;
26 static struct kmem_cache *exfat_inode_cachep;
27
exfat_free_iocharset(struct exfat_sb_info * sbi)28 static 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
exfat_put_super(struct super_block * sb)34 static 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
exfat_sync_fs(struct super_block * sb,int wait)44 static int exfat_sync_fs(struct super_block *sb, int wait)
45 {
46 struct exfat_sb_info *sbi = EXFAT_SB(sb);
47 int err = 0;
48
49 if (unlikely(exfat_forced_shutdown(sb)))
50 return 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
exfat_statfs(struct dentry * dentry,struct kstatfs * buf)64 static 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 buf->f_type = sb->s_magic;
71 buf->f_bsize = sbi->cluster_size;
72 buf->f_blocks = sbi->num_clusters - 2; /* clu 0 & 1 */
73 buf->f_bfree = buf->f_blocks - sbi->used_clusters;
74 buf->f_bavail = buf->f_bfree;
75 buf->f_fsid = u64_to_fsid(id);
76 /* Unicode utf16 255 characters */
77 buf->f_namelen = EXFAT_MAX_FILE_LEN * NLS_MAX_CHARSET_SIZE;
78 return 0;
79 }
80
exfat_set_vol_flags(struct super_block * sb,unsigned short new_flags)81 static int exfat_set_vol_flags(struct super_block *sb, unsigned short new_flags)
82 {
83 struct exfat_sb_info *sbi = EXFAT_SB(sb);
84 struct boot_sector *p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
85
86 /* retain persistent-flags */
87 new_flags |= sbi->vol_flags_persistent;
88
89 /* flags are not changed */
90 if (sbi->vol_flags == new_flags)
91 return 0;
92
93 sbi->vol_flags = new_flags;
94
95 /* skip updating volume dirty flag,
96 * if this volume has been mounted with read-only
97 */
98 if (sb_rdonly(sb))
99 return 0;
100
101 p_boot->vol_flags = cpu_to_le16(new_flags);
102
103 set_buffer_uptodate(sbi->boot_bh);
104 mark_buffer_dirty(sbi->boot_bh);
105
106 __sync_dirty_buffer(sbi->boot_bh, REQ_SYNC | REQ_FUA | REQ_PREFLUSH);
107
108 return 0;
109 }
110
exfat_set_volume_dirty(struct super_block * sb)111 int exfat_set_volume_dirty(struct super_block *sb)
112 {
113 struct exfat_sb_info *sbi = EXFAT_SB(sb);
114
115 return exfat_set_vol_flags(sb, sbi->vol_flags | VOLUME_DIRTY);
116 }
117
exfat_clear_volume_dirty(struct super_block * sb)118 int exfat_clear_volume_dirty(struct super_block *sb)
119 {
120 struct exfat_sb_info *sbi = EXFAT_SB(sb);
121
122 return exfat_set_vol_flags(sb, sbi->vol_flags & ~VOLUME_DIRTY);
123 }
124
exfat_show_options(struct seq_file * m,struct dentry * root)125 static int exfat_show_options(struct seq_file *m, struct dentry *root)
126 {
127 struct super_block *sb = root->d_sb;
128 struct exfat_sb_info *sbi = EXFAT_SB(sb);
129 struct exfat_mount_options *opts = &sbi->options;
130
131 /* Show partition info */
132 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
133 seq_printf(m, ",uid=%u",
134 from_kuid_munged(&init_user_ns, opts->fs_uid));
135 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
136 seq_printf(m, ",gid=%u",
137 from_kgid_munged(&init_user_ns, opts->fs_gid));
138 seq_printf(m, ",fmask=%04o,dmask=%04o", opts->fs_fmask, opts->fs_dmask);
139 if (opts->allow_utime)
140 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
141 if (opts->utf8)
142 seq_puts(m, ",iocharset=utf8");
143 else if (sbi->nls_io)
144 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
145 if (opts->errors == EXFAT_ERRORS_CONT)
146 seq_puts(m, ",errors=continue");
147 else if (opts->errors == EXFAT_ERRORS_PANIC)
148 seq_puts(m, ",errors=panic");
149 else
150 seq_puts(m, ",errors=remount-ro");
151 if (opts->discard)
152 seq_puts(m, ",discard");
153 if (opts->keep_last_dots)
154 seq_puts(m, ",keep_last_dots");
155 if (opts->sys_tz)
156 seq_puts(m, ",sys_tz");
157 else if (opts->time_offset)
158 seq_printf(m, ",time_offset=%d", opts->time_offset);
159 if (opts->zero_size_dir)
160 seq_puts(m, ",zero_size_dir");
161 return 0;
162 }
163
exfat_force_shutdown(struct super_block * sb,u32 flags)164 int exfat_force_shutdown(struct super_block *sb, u32 flags)
165 {
166 int ret;
167 struct exfat_sb_info *sbi = sb->s_fs_info;
168 struct exfat_mount_options *opts = &sbi->options;
169
170 if (exfat_forced_shutdown(sb))
171 return 0;
172
173 switch (flags) {
174 case EXFAT_GOING_DOWN_DEFAULT:
175 case EXFAT_GOING_DOWN_FULLSYNC:
176 ret = bdev_freeze(sb->s_bdev);
177 if (ret)
178 return ret;
179 bdev_thaw(sb->s_bdev);
180 set_bit(EXFAT_FLAGS_SHUTDOWN, &sbi->s_exfat_flags);
181 break;
182 case EXFAT_GOING_DOWN_NOSYNC:
183 set_bit(EXFAT_FLAGS_SHUTDOWN, &sbi->s_exfat_flags);
184 break;
185 default:
186 return -EINVAL;
187 }
188
189 if (opts->discard)
190 opts->discard = 0;
191 return 0;
192 }
193
exfat_shutdown(struct super_block * sb)194 static void exfat_shutdown(struct super_block *sb)
195 {
196 exfat_force_shutdown(sb, EXFAT_GOING_DOWN_NOSYNC);
197 }
198
exfat_alloc_inode(struct super_block * sb)199 static struct inode *exfat_alloc_inode(struct super_block *sb)
200 {
201 struct exfat_inode_info *ei;
202
203 ei = alloc_inode_sb(sb, exfat_inode_cachep, GFP_NOFS);
204 if (!ei)
205 return NULL;
206
207 init_rwsem(&ei->truncate_lock);
208 return &ei->vfs_inode;
209 }
210
exfat_free_inode(struct inode * inode)211 static void exfat_free_inode(struct inode *inode)
212 {
213 kmem_cache_free(exfat_inode_cachep, EXFAT_I(inode));
214 }
215
216 static const struct super_operations exfat_sops = {
217 .alloc_inode = exfat_alloc_inode,
218 .free_inode = exfat_free_inode,
219 .write_inode = exfat_write_inode,
220 .evict_inode = exfat_evict_inode,
221 .put_super = exfat_put_super,
222 .sync_fs = exfat_sync_fs,
223 .statfs = exfat_statfs,
224 .show_options = exfat_show_options,
225 .shutdown = exfat_shutdown,
226 };
227
228 enum {
229 Opt_uid,
230 Opt_gid,
231 Opt_umask,
232 Opt_dmask,
233 Opt_fmask,
234 Opt_allow_utime,
235 Opt_charset,
236 Opt_errors,
237 Opt_discard,
238 Opt_keep_last_dots,
239 Opt_sys_tz,
240 Opt_time_offset,
241 Opt_zero_size_dir,
242
243 /* Deprecated options */
244 Opt_utf8,
245 Opt_debug,
246 Opt_namecase,
247 Opt_codepage,
248 };
249
250 static const struct constant_table exfat_param_enums[] = {
251 { "continue", EXFAT_ERRORS_CONT },
252 { "panic", EXFAT_ERRORS_PANIC },
253 { "remount-ro", EXFAT_ERRORS_RO },
254 {}
255 };
256
257 static const struct fs_parameter_spec exfat_parameters[] = {
258 fsparam_uid("uid", Opt_uid),
259 fsparam_gid("gid", Opt_gid),
260 fsparam_u32oct("umask", Opt_umask),
261 fsparam_u32oct("dmask", Opt_dmask),
262 fsparam_u32oct("fmask", Opt_fmask),
263 fsparam_u32oct("allow_utime", Opt_allow_utime),
264 fsparam_string("iocharset", Opt_charset),
265 fsparam_enum("errors", Opt_errors, exfat_param_enums),
266 fsparam_flag("discard", Opt_discard),
267 fsparam_flag("keep_last_dots", Opt_keep_last_dots),
268 fsparam_flag("sys_tz", Opt_sys_tz),
269 fsparam_s32("time_offset", Opt_time_offset),
270 fsparam_flag("zero_size_dir", Opt_zero_size_dir),
271 __fsparam(NULL, "utf8", Opt_utf8, fs_param_deprecated,
272 NULL),
273 __fsparam(NULL, "debug", Opt_debug, fs_param_deprecated,
274 NULL),
275 __fsparam(fs_param_is_u32, "namecase", Opt_namecase,
276 fs_param_deprecated, NULL),
277 __fsparam(fs_param_is_u32, "codepage", Opt_codepage,
278 fs_param_deprecated, NULL),
279 {}
280 };
281
exfat_parse_param(struct fs_context * fc,struct fs_parameter * param)282 static int exfat_parse_param(struct fs_context *fc, struct fs_parameter *param)
283 {
284 struct exfat_sb_info *sbi = fc->s_fs_info;
285 struct exfat_mount_options *opts = &sbi->options;
286 struct fs_parse_result result;
287 int opt;
288
289 opt = fs_parse(fc, exfat_parameters, param, &result);
290 if (opt < 0)
291 return opt;
292
293 switch (opt) {
294 case Opt_uid:
295 opts->fs_uid = result.uid;
296 break;
297 case Opt_gid:
298 opts->fs_gid = result.gid;
299 break;
300 case Opt_umask:
301 opts->fs_fmask = result.uint_32;
302 opts->fs_dmask = result.uint_32;
303 break;
304 case Opt_dmask:
305 opts->fs_dmask = result.uint_32;
306 break;
307 case Opt_fmask:
308 opts->fs_fmask = result.uint_32;
309 break;
310 case Opt_allow_utime:
311 opts->allow_utime = result.uint_32 & 0022;
312 break;
313 case Opt_charset:
314 exfat_free_iocharset(sbi);
315 opts->iocharset = param->string;
316 param->string = NULL;
317 break;
318 case Opt_errors:
319 opts->errors = result.uint_32;
320 break;
321 case Opt_discard:
322 opts->discard = 1;
323 break;
324 case Opt_keep_last_dots:
325 opts->keep_last_dots = 1;
326 break;
327 case Opt_sys_tz:
328 opts->sys_tz = 1;
329 break;
330 case Opt_time_offset:
331 /*
332 * Make the limit 24 just in case someone invents something
333 * unusual.
334 */
335 if (result.int_32 < -24 * 60 || result.int_32 > 24 * 60)
336 return -EINVAL;
337 opts->time_offset = result.int_32;
338 break;
339 case Opt_zero_size_dir:
340 opts->zero_size_dir = true;
341 break;
342 case Opt_utf8:
343 case Opt_debug:
344 case Opt_namecase:
345 case Opt_codepage:
346 break;
347 default:
348 return -EINVAL;
349 }
350
351 return 0;
352 }
353
exfat_hash_init(struct super_block * sb)354 static void exfat_hash_init(struct super_block *sb)
355 {
356 struct exfat_sb_info *sbi = EXFAT_SB(sb);
357 int i;
358
359 spin_lock_init(&sbi->inode_hash_lock);
360 for (i = 0; i < EXFAT_HASH_SIZE; i++)
361 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
362 }
363
exfat_read_root(struct inode * inode)364 static int exfat_read_root(struct inode *inode)
365 {
366 struct super_block *sb = inode->i_sb;
367 struct exfat_sb_info *sbi = EXFAT_SB(sb);
368 struct exfat_inode_info *ei = EXFAT_I(inode);
369 struct exfat_chain cdir;
370 int num_subdirs, num_clu = 0;
371
372 exfat_chain_set(&ei->dir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
373 ei->entry = -1;
374 ei->start_clu = sbi->root_dir;
375 ei->flags = ALLOC_FAT_CHAIN;
376 ei->type = TYPE_DIR;
377 ei->version = 0;
378 ei->hint_bmap.off = EXFAT_EOF_CLUSTER;
379 ei->hint_stat.eidx = 0;
380 ei->hint_stat.clu = sbi->root_dir;
381 ei->hint_femp.eidx = EXFAT_HINT_NONE;
382
383 exfat_chain_set(&cdir, sbi->root_dir, 0, ALLOC_FAT_CHAIN);
384 if (exfat_count_num_clusters(sb, &cdir, &num_clu))
385 return -EIO;
386 i_size_write(inode, num_clu << sbi->cluster_size_bits);
387
388 num_subdirs = exfat_count_dir_entries(sb, &cdir);
389 if (num_subdirs < 0)
390 return -EIO;
391 set_nlink(inode, num_subdirs + EXFAT_MIN_SUBDIR);
392
393 inode->i_uid = sbi->options.fs_uid;
394 inode->i_gid = sbi->options.fs_gid;
395 inode_inc_iversion(inode);
396 inode->i_generation = 0;
397 inode->i_mode = exfat_make_mode(sbi, EXFAT_ATTR_SUBDIR, 0777);
398 inode->i_op = &exfat_dir_inode_operations;
399 inode->i_fop = &exfat_dir_operations;
400
401 inode->i_blocks = round_up(i_size_read(inode), sbi->cluster_size) >> 9;
402 ei->i_pos = ((loff_t)sbi->root_dir << 32) | 0xffffffff;
403
404 exfat_save_attr(inode, EXFAT_ATTR_SUBDIR);
405 ei->i_crtime = simple_inode_init_ts(inode);
406 exfat_truncate_inode_atime(inode);
407 return 0;
408 }
409
exfat_calibrate_blocksize(struct super_block * sb,int logical_sect)410 static int exfat_calibrate_blocksize(struct super_block *sb, int logical_sect)
411 {
412 struct exfat_sb_info *sbi = EXFAT_SB(sb);
413
414 if (!is_power_of_2(logical_sect)) {
415 exfat_err(sb, "bogus logical sector size %u", logical_sect);
416 return -EIO;
417 }
418
419 if (logical_sect < sb->s_blocksize) {
420 exfat_err(sb, "logical sector size too small for device (logical sector size = %u)",
421 logical_sect);
422 return -EIO;
423 }
424
425 if (logical_sect > sb->s_blocksize) {
426 brelse(sbi->boot_bh);
427 sbi->boot_bh = NULL;
428
429 if (!sb_set_blocksize(sb, logical_sect)) {
430 exfat_err(sb, "unable to set blocksize %u",
431 logical_sect);
432 return -EIO;
433 }
434 sbi->boot_bh = sb_bread(sb, 0);
435 if (!sbi->boot_bh) {
436 exfat_err(sb, "unable to read boot sector (logical sector size = %lu)",
437 sb->s_blocksize);
438 return -EIO;
439 }
440 }
441 return 0;
442 }
443
exfat_read_boot_sector(struct super_block * sb)444 static int exfat_read_boot_sector(struct super_block *sb)
445 {
446 struct boot_sector *p_boot;
447 struct exfat_sb_info *sbi = EXFAT_SB(sb);
448
449 /* set block size to read super block */
450 sb_min_blocksize(sb, 512);
451
452 /* read boot sector */
453 sbi->boot_bh = sb_bread(sb, 0);
454 if (!sbi->boot_bh) {
455 exfat_err(sb, "unable to read boot sector");
456 return -EIO;
457 }
458 p_boot = (struct boot_sector *)sbi->boot_bh->b_data;
459
460 /* check the validity of BOOT */
461 if (le16_to_cpu((p_boot->signature)) != BOOT_SIGNATURE) {
462 exfat_err(sb, "invalid boot record signature");
463 return -EINVAL;
464 }
465
466 if (memcmp(p_boot->fs_name, STR_EXFAT, BOOTSEC_FS_NAME_LEN)) {
467 exfat_err(sb, "invalid fs_name"); /* fs_name may unprintable */
468 return -EINVAL;
469 }
470
471 /*
472 * must_be_zero field must be filled with zero to prevent mounting
473 * from FAT volume.
474 */
475 if (memchr_inv(p_boot->must_be_zero, 0, sizeof(p_boot->must_be_zero)))
476 return -EINVAL;
477
478 if (p_boot->num_fats != 1 && p_boot->num_fats != 2) {
479 exfat_err(sb, "bogus number of FAT structure");
480 return -EINVAL;
481 }
482
483 /*
484 * sect_size_bits could be at least 9 and at most 12.
485 */
486 if (p_boot->sect_size_bits < EXFAT_MIN_SECT_SIZE_BITS ||
487 p_boot->sect_size_bits > EXFAT_MAX_SECT_SIZE_BITS) {
488 exfat_err(sb, "bogus sector size bits : %u",
489 p_boot->sect_size_bits);
490 return -EINVAL;
491 }
492
493 /*
494 * sect_per_clus_bits could be at least 0 and at most 25 - sect_size_bits.
495 */
496 if (p_boot->sect_per_clus_bits > EXFAT_MAX_SECT_PER_CLUS_BITS(p_boot)) {
497 exfat_err(sb, "bogus sectors bits per cluster : %u",
498 p_boot->sect_per_clus_bits);
499 return -EINVAL;
500 }
501
502 sbi->sect_per_clus = 1 << p_boot->sect_per_clus_bits;
503 sbi->sect_per_clus_bits = p_boot->sect_per_clus_bits;
504 sbi->cluster_size_bits = p_boot->sect_per_clus_bits +
505 p_boot->sect_size_bits;
506 sbi->cluster_size = 1 << sbi->cluster_size_bits;
507 sbi->num_FAT_sectors = le32_to_cpu(p_boot->fat_length);
508 sbi->FAT1_start_sector = le32_to_cpu(p_boot->fat_offset);
509 sbi->FAT2_start_sector = le32_to_cpu(p_boot->fat_offset);
510 if (p_boot->num_fats == 2)
511 sbi->FAT2_start_sector += sbi->num_FAT_sectors;
512 sbi->data_start_sector = le32_to_cpu(p_boot->clu_offset);
513 sbi->num_sectors = le64_to_cpu(p_boot->vol_length);
514 /* because the cluster index starts with 2 */
515 sbi->num_clusters = le32_to_cpu(p_boot->clu_count) +
516 EXFAT_RESERVED_CLUSTERS;
517
518 sbi->root_dir = le32_to_cpu(p_boot->root_cluster);
519 sbi->dentries_per_clu = 1 <<
520 (sbi->cluster_size_bits - DENTRY_SIZE_BITS);
521
522 sbi->vol_flags = le16_to_cpu(p_boot->vol_flags);
523 sbi->vol_flags_persistent = sbi->vol_flags & (VOLUME_DIRTY | MEDIA_FAILURE);
524 sbi->clu_srch_ptr = EXFAT_FIRST_CLUSTER;
525
526 /* check consistencies */
527 if ((u64)sbi->num_FAT_sectors << p_boot->sect_size_bits <
528 (u64)sbi->num_clusters * 4) {
529 exfat_err(sb, "bogus fat length");
530 return -EINVAL;
531 }
532
533 if (sbi->data_start_sector <
534 (u64)sbi->FAT1_start_sector +
535 (u64)sbi->num_FAT_sectors * p_boot->num_fats) {
536 exfat_err(sb, "bogus data start sector");
537 return -EINVAL;
538 }
539
540 if (sbi->vol_flags & VOLUME_DIRTY)
541 exfat_warn(sb, "Volume was not properly unmounted. Some data may be corrupt. Please run fsck.");
542 if (sbi->vol_flags & MEDIA_FAILURE)
543 exfat_warn(sb, "Medium has reported failures. Some data may be lost.");
544
545 /* exFAT file size is limited by a disk volume size */
546 sb->s_maxbytes = (u64)(sbi->num_clusters - EXFAT_RESERVED_CLUSTERS) <<
547 sbi->cluster_size_bits;
548
549 /* check logical sector size */
550 if (exfat_calibrate_blocksize(sb, 1 << p_boot->sect_size_bits))
551 return -EIO;
552
553 return 0;
554 }
555
exfat_verify_boot_region(struct super_block * sb)556 static int exfat_verify_boot_region(struct super_block *sb)
557 {
558 struct buffer_head *bh = NULL;
559 u32 chksum = 0;
560 __le32 *p_sig, *p_chksum;
561 int sn, i;
562
563 /* read boot sector sub-regions */
564 for (sn = 0; sn < 11; sn++) {
565 bh = sb_bread(sb, sn);
566 if (!bh)
567 return -EIO;
568
569 if (sn != 0 && sn <= 8) {
570 /* extended boot sector sub-regions */
571 p_sig = (__le32 *)&bh->b_data[sb->s_blocksize - 4];
572 if (le32_to_cpu(*p_sig) != EXBOOT_SIGNATURE)
573 exfat_warn(sb, "Invalid exboot-signature(sector = %d): 0x%08x",
574 sn, le32_to_cpu(*p_sig));
575 }
576
577 chksum = exfat_calc_chksum32(bh->b_data, sb->s_blocksize,
578 chksum, sn ? CS_DEFAULT : CS_BOOT_SECTOR);
579 brelse(bh);
580 }
581
582 /* boot checksum sub-regions */
583 bh = sb_bread(sb, sn);
584 if (!bh)
585 return -EIO;
586
587 for (i = 0; i < sb->s_blocksize; i += sizeof(u32)) {
588 p_chksum = (__le32 *)&bh->b_data[i];
589 if (le32_to_cpu(*p_chksum) != chksum) {
590 exfat_err(sb, "Invalid boot checksum (boot checksum : 0x%08x, checksum : 0x%08x)",
591 le32_to_cpu(*p_chksum), chksum);
592 brelse(bh);
593 return -EINVAL;
594 }
595 }
596 brelse(bh);
597 return 0;
598 }
599
600 /* mount the file system volume */
__exfat_fill_super(struct super_block * sb)601 static int __exfat_fill_super(struct super_block *sb)
602 {
603 int ret;
604 struct exfat_sb_info *sbi = EXFAT_SB(sb);
605
606 ret = exfat_read_boot_sector(sb);
607 if (ret) {
608 exfat_err(sb, "failed to read boot sector");
609 goto free_bh;
610 }
611
612 ret = exfat_verify_boot_region(sb);
613 if (ret) {
614 exfat_err(sb, "invalid boot region");
615 goto free_bh;
616 }
617
618 ret = exfat_create_upcase_table(sb);
619 if (ret) {
620 exfat_err(sb, "failed to load upcase table");
621 goto free_bh;
622 }
623
624 ret = exfat_load_bitmap(sb);
625 if (ret) {
626 exfat_err(sb, "failed to load alloc-bitmap");
627 goto free_bh;
628 }
629
630 ret = exfat_count_used_clusters(sb, &sbi->used_clusters);
631 if (ret) {
632 exfat_err(sb, "failed to scan clusters");
633 goto free_alloc_bitmap;
634 }
635
636 return 0;
637
638 free_alloc_bitmap:
639 exfat_free_bitmap(sbi);
640 free_bh:
641 brelse(sbi->boot_bh);
642 return ret;
643 }
644
exfat_fill_super(struct super_block * sb,struct fs_context * fc)645 static int exfat_fill_super(struct super_block *sb, struct fs_context *fc)
646 {
647 struct exfat_sb_info *sbi = sb->s_fs_info;
648 struct exfat_mount_options *opts = &sbi->options;
649 struct inode *root_inode;
650 int err;
651
652 if (opts->allow_utime == (unsigned short)-1)
653 opts->allow_utime = ~opts->fs_dmask & 0022;
654
655 if (opts->discard && !bdev_max_discard_sectors(sb->s_bdev)) {
656 exfat_warn(sb, "mounting with \"discard\" option, but the device does not support discard");
657 opts->discard = 0;
658 }
659
660 sb->s_flags |= SB_NODIRATIME;
661 sb->s_magic = EXFAT_SUPER_MAGIC;
662 sb->s_op = &exfat_sops;
663
664 sb->s_time_gran = 10 * NSEC_PER_MSEC;
665 sb->s_time_min = EXFAT_MIN_TIMESTAMP_SECS;
666 sb->s_time_max = EXFAT_MAX_TIMESTAMP_SECS;
667
668 err = __exfat_fill_super(sb);
669 if (err) {
670 exfat_err(sb, "failed to recognize exfat type");
671 goto check_nls_io;
672 }
673
674 /* set up enough so that it can read an inode */
675 exfat_hash_init(sb);
676
677 if (!strcmp(sbi->options.iocharset, "utf8"))
678 opts->utf8 = 1;
679 else {
680 sbi->nls_io = load_nls(sbi->options.iocharset);
681 if (!sbi->nls_io) {
682 exfat_err(sb, "IO charset %s not found",
683 sbi->options.iocharset);
684 err = -EINVAL;
685 goto free_table;
686 }
687 }
688
689 if (sbi->options.utf8)
690 sb->s_d_op = &exfat_utf8_dentry_ops;
691 else
692 sb->s_d_op = &exfat_dentry_ops;
693
694 root_inode = new_inode(sb);
695 if (!root_inode) {
696 exfat_err(sb, "failed to allocate root inode");
697 err = -ENOMEM;
698 goto free_table;
699 }
700
701 root_inode->i_ino = EXFAT_ROOT_INO;
702 inode_set_iversion(root_inode, 1);
703 err = exfat_read_root(root_inode);
704 if (err) {
705 exfat_err(sb, "failed to initialize root inode");
706 goto put_inode;
707 }
708
709 exfat_hash_inode(root_inode, EXFAT_I(root_inode)->i_pos);
710 insert_inode_hash(root_inode);
711
712 sb->s_root = d_make_root(root_inode);
713 if (!sb->s_root) {
714 exfat_err(sb, "failed to get the root dentry");
715 err = -ENOMEM;
716 goto free_table;
717 }
718
719 return 0;
720
721 put_inode:
722 iput(root_inode);
723 sb->s_root = NULL;
724
725 free_table:
726 exfat_free_bitmap(sbi);
727 brelse(sbi->boot_bh);
728
729 check_nls_io:
730 return err;
731 }
732
exfat_get_tree(struct fs_context * fc)733 static int exfat_get_tree(struct fs_context *fc)
734 {
735 return get_tree_bdev(fc, exfat_fill_super);
736 }
737
exfat_free_sbi(struct exfat_sb_info * sbi)738 static void exfat_free_sbi(struct exfat_sb_info *sbi)
739 {
740 exfat_free_iocharset(sbi);
741 kfree(sbi);
742 }
743
exfat_free(struct fs_context * fc)744 static void exfat_free(struct fs_context *fc)
745 {
746 struct exfat_sb_info *sbi = fc->s_fs_info;
747
748 if (sbi)
749 exfat_free_sbi(sbi);
750 }
751
exfat_reconfigure(struct fs_context * fc)752 static int exfat_reconfigure(struct fs_context *fc)
753 {
754 fc->sb_flags |= SB_NODIRATIME;
755
756 /* volume flag will be updated in exfat_sync_fs */
757 sync_filesystem(fc->root->d_sb);
758 return 0;
759 }
760
761 static const struct fs_context_operations exfat_context_ops = {
762 .parse_param = exfat_parse_param,
763 .get_tree = exfat_get_tree,
764 .free = exfat_free,
765 .reconfigure = exfat_reconfigure,
766 };
767
exfat_init_fs_context(struct fs_context * fc)768 static int exfat_init_fs_context(struct fs_context *fc)
769 {
770 struct exfat_sb_info *sbi;
771
772 sbi = kzalloc(sizeof(struct exfat_sb_info), GFP_KERNEL);
773 if (!sbi)
774 return -ENOMEM;
775
776 mutex_init(&sbi->s_lock);
777 mutex_init(&sbi->bitmap_lock);
778 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
779 DEFAULT_RATELIMIT_BURST);
780
781 sbi->options.fs_uid = current_uid();
782 sbi->options.fs_gid = current_gid();
783 sbi->options.fs_fmask = current->fs->umask;
784 sbi->options.fs_dmask = current->fs->umask;
785 sbi->options.allow_utime = -1;
786 sbi->options.iocharset = exfat_default_iocharset;
787 sbi->options.errors = EXFAT_ERRORS_RO;
788
789 fc->s_fs_info = sbi;
790 fc->ops = &exfat_context_ops;
791 return 0;
792 }
793
delayed_free(struct rcu_head * p)794 static void delayed_free(struct rcu_head *p)
795 {
796 struct exfat_sb_info *sbi = container_of(p, struct exfat_sb_info, rcu);
797
798 unload_nls(sbi->nls_io);
799 exfat_free_upcase_table(sbi);
800 exfat_free_sbi(sbi);
801 }
802
exfat_kill_sb(struct super_block * sb)803 static void exfat_kill_sb(struct super_block *sb)
804 {
805 struct exfat_sb_info *sbi = sb->s_fs_info;
806
807 kill_block_super(sb);
808 if (sbi)
809 call_rcu(&sbi->rcu, delayed_free);
810 }
811
812 static struct file_system_type exfat_fs_type = {
813 .owner = THIS_MODULE,
814 .name = "exfat",
815 .init_fs_context = exfat_init_fs_context,
816 .parameters = exfat_parameters,
817 .kill_sb = exfat_kill_sb,
818 .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
819 };
820
exfat_inode_init_once(void * foo)821 static void exfat_inode_init_once(void *foo)
822 {
823 struct exfat_inode_info *ei = (struct exfat_inode_info *)foo;
824
825 spin_lock_init(&ei->cache_lru_lock);
826 ei->nr_caches = 0;
827 ei->cache_valid_id = EXFAT_CACHE_VALID + 1;
828 INIT_LIST_HEAD(&ei->cache_lru);
829 INIT_HLIST_NODE(&ei->i_hash_fat);
830 inode_init_once(&ei->vfs_inode);
831 }
832
init_exfat_fs(void)833 static int __init init_exfat_fs(void)
834 {
835 int err;
836
837 err = exfat_cache_init();
838 if (err)
839 return err;
840
841 exfat_inode_cachep = kmem_cache_create("exfat_inode_cache",
842 sizeof(struct exfat_inode_info),
843 0, SLAB_RECLAIM_ACCOUNT,
844 exfat_inode_init_once);
845 if (!exfat_inode_cachep) {
846 err = -ENOMEM;
847 goto shutdown_cache;
848 }
849
850 err = register_filesystem(&exfat_fs_type);
851 if (err)
852 goto destroy_cache;
853
854 return 0;
855
856 destroy_cache:
857 kmem_cache_destroy(exfat_inode_cachep);
858 shutdown_cache:
859 exfat_cache_shutdown();
860 return err;
861 }
862
exit_exfat_fs(void)863 static void __exit exit_exfat_fs(void)
864 {
865 /*
866 * Make sure all delayed rcu free inodes are flushed before we
867 * destroy cache.
868 */
869 rcu_barrier();
870 kmem_cache_destroy(exfat_inode_cachep);
871 unregister_filesystem(&exfat_fs_type);
872 exfat_cache_shutdown();
873 }
874
875 module_init(init_exfat_fs);
876 module_exit(exit_exfat_fs);
877
878 MODULE_ALIAS_FS("exfat");
879 MODULE_LICENSE("GPL");
880 MODULE_DESCRIPTION("exFAT filesystem support");
881 MODULE_AUTHOR("Samsung Electronics Co., Ltd.");
882