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 unload_nls(sbi->nls_io);
44 exfat_free_upcase_table(sbi);
45 }
46
exfat_sync_fs(struct super_block * sb,int wait)47 static 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
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 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
exfat_set_vol_flags(struct super_block * sb,unsigned short new_flags)90 static 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
exfat_set_volume_dirty(struct super_block * sb)120 int 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
exfat_clear_volume_dirty(struct super_block * sb)127 int 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
exfat_show_options(struct seq_file * m,struct dentry * root)134 static 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
exfat_alloc_inode(struct super_block * sb)171 static 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
exfat_free_inode(struct inode * inode)183 static void exfat_free_inode(struct inode *inode)
184 {
185 kmem_cache_free(exfat_inode_cachep, EXFAT_I(inode));
186 }
187
188 static 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
199 enum {
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
220 static 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
227 static 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
exfat_parse_param(struct fs_context * fc,struct fs_parameter * param)251 static 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
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 = ei->i_crtime = inode_set_ctime_current(inode);
374 exfat_truncate_atime(&inode->i_atime);
375 return 0;
376 }
377
exfat_calibrate_blocksize(struct super_block * sb,int logical_sect)378 static 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
exfat_read_boot_sector(struct super_block * sb)412 static 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
exfat_verify_boot_region(struct super_block * sb)525 static 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 */
__exfat_fill_super(struct super_block * sb)570 static 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
607 free_alloc_bitmap:
608 exfat_free_bitmap(sbi);
609 free_upcase_table:
610 exfat_free_upcase_table(sbi);
611 free_bh:
612 brelse(sbi->boot_bh);
613 return ret;
614 }
615
exfat_fill_super(struct super_block * sb,struct fs_context * fc)616 static 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
692 put_inode:
693 iput(root_inode);
694 sb->s_root = NULL;
695
696 free_table:
697 exfat_free_upcase_table(sbi);
698 exfat_free_bitmap(sbi);
699 brelse(sbi->boot_bh);
700
701 check_nls_io:
702 unload_nls(sbi->nls_io);
703 return err;
704 }
705
exfat_get_tree(struct fs_context * fc)706 static int exfat_get_tree(struct fs_context *fc)
707 {
708 return get_tree_bdev(fc, exfat_fill_super);
709 }
710
exfat_free_sbi(struct exfat_sb_info * sbi)711 static void exfat_free_sbi(struct exfat_sb_info *sbi)
712 {
713 exfat_free_iocharset(sbi);
714 kfree(sbi);
715 }
716
exfat_free(struct fs_context * fc)717 static 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
exfat_reconfigure(struct fs_context * fc)725 static 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
734 static 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
exfat_init_fs_context(struct fs_context * fc)741 static 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
exfat_kill_sb(struct super_block * sb)767 static 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
776 static 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
exfat_inode_init_once(void * foo)785 static 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
init_exfat_fs(void)797 static 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
820 destroy_cache:
821 kmem_cache_destroy(exfat_inode_cachep);
822 shutdown_cache:
823 exfat_cache_shutdown();
824 return err;
825 }
826
exit_exfat_fs(void)827 static 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
839 module_init(init_exfat_fs);
840 module_exit(exit_exfat_fs);
841
842 MODULE_ALIAS_FS("exfat");
843 MODULE_LICENSE("GPL");
844 MODULE_DESCRIPTION("exFAT filesystem support");
845 MODULE_AUTHOR("Samsung Electronics Co., Ltd.");
846