1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/fs/fat/inode.c
4 *
5 * Written 1992,1993 by Werner Almesberger
6 * VFAT extensions by Gordon Chaffee, merged with msdos fs by Henrik Storner
7 * Rewritten for the constant inumbers support by Al Viro
8 *
9 * Fixes:
10 *
11 * Max Cohan: Fixed invalid FSINFO offset when info_sector is 0
12 */
13
14#include <linux/module.h>
15#include <linux/pagemap.h>
16#include <linux/mpage.h>
17#include <linux/vfs.h>
18#include <linux/seq_file.h>
19#include <linux/uio.h>
20#include <linux/blkdev.h>
21#include <linux/backing-dev.h>
22#include <linux/unaligned.h>
23#include <linux/random.h>
24#include <linux/iversion.h>
25#include "fat.h"
26
27#ifndef CONFIG_FAT_DEFAULT_IOCHARSET
28/* if user don't select VFAT, this is undefined. */
29#define CONFIG_FAT_DEFAULT_IOCHARSET ""
30#endif
31
32#define KB_IN_SECTORS 2
33
34/* DOS dates from 1980/1/1 through 2107/12/31 */
35#define FAT_DATE_MIN (0<<9 | 1<<5 | 1)
36#define FAT_DATE_MAX (127<<9 | 12<<5 | 31)
37#define FAT_TIME_MAX (23<<11 | 59<<5 | 29)
38
39/*
40 * A deserialized copy of the on-disk structure laid out in struct
41 * fat_boot_sector.
42 */
43struct fat_bios_param_block {
44 u16 fat_sector_size;
45 u8 fat_sec_per_clus;
46 u16 fat_reserved;
47 u8 fat_fats;
48 u16 fat_dir_entries;
49 u16 fat_sectors;
50 u16 fat_fat_length;
51 u32 fat_total_sect;
52
53 u8 fat16_state;
54 u32 fat16_vol_id;
55
56 u32 fat32_length;
57 u32 fat32_root_cluster;
58 u16 fat32_info_sector;
59 u8 fat32_state;
60 u32 fat32_vol_id;
61};
62
63static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
64static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
65
66static struct fat_floppy_defaults {
67 unsigned nr_sectors;
68 unsigned sec_per_clus;
69 unsigned dir_entries;
70 unsigned media;
71 unsigned fat_length;
72} floppy_defaults[] = {
73{
74 .nr_sectors = 160 * KB_IN_SECTORS,
75 .sec_per_clus = 1,
76 .dir_entries = 64,
77 .media = 0xFE,
78 .fat_length = 1,
79},
80{
81 .nr_sectors = 180 * KB_IN_SECTORS,
82 .sec_per_clus = 1,
83 .dir_entries = 64,
84 .media = 0xFC,
85 .fat_length = 2,
86},
87{
88 .nr_sectors = 320 * KB_IN_SECTORS,
89 .sec_per_clus = 2,
90 .dir_entries = 112,
91 .media = 0xFF,
92 .fat_length = 1,
93},
94{
95 .nr_sectors = 360 * KB_IN_SECTORS,
96 .sec_per_clus = 2,
97 .dir_entries = 112,
98 .media = 0xFD,
99 .fat_length = 2,
100},
101};
102
103int fat_add_cluster(struct inode *inode)
104{
105 int err, cluster;
106
107 err = fat_alloc_clusters(inode, cluster: &cluster, nr_cluster: 1);
108 if (err)
109 return err;
110 /* FIXME: this cluster should be added after data of this
111 * cluster is writed */
112 err = fat_chain_add(inode, new_dclus: cluster, nr_cluster: 1);
113 if (err)
114 fat_free_clusters(inode, cluster);
115 return err;
116}
117
118static inline int __fat_get_block(struct inode *inode, sector_t iblock,
119 unsigned long *max_blocks,
120 struct buffer_head *bh_result, int create)
121{
122 struct super_block *sb = inode->i_sb;
123 struct msdos_sb_info *sbi = MSDOS_SB(sb);
124 unsigned long mapped_blocks;
125 sector_t phys, last_block;
126 int err, offset;
127
128 err = fat_bmap(inode, sector: iblock, phys: &phys, mapped_blocks: &mapped_blocks, create, from_bmap: false);
129 if (err)
130 return err;
131 if (phys) {
132 map_bh(bh: bh_result, sb, block: phys);
133 *max_blocks = min(mapped_blocks, *max_blocks);
134 return 0;
135 }
136 if (!create)
137 return 0;
138
139 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
140 fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)",
141 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
142 return -EIO;
143 }
144
145 last_block = inode->i_blocks >> (sb->s_blocksize_bits - 9);
146 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
147 /*
148 * allocate a cluster according to the following.
149 * 1) no more available blocks
150 * 2) not part of fallocate region
151 */
152 if (!offset && !(iblock < last_block)) {
153 /* TODO: multiple cluster allocation would be desirable. */
154 err = fat_add_cluster(inode);
155 if (err)
156 return err;
157 }
158 /* available blocks on this cluster */
159 mapped_blocks = sbi->sec_per_clus - offset;
160
161 *max_blocks = min(mapped_blocks, *max_blocks);
162 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
163
164 err = fat_bmap(inode, sector: iblock, phys: &phys, mapped_blocks: &mapped_blocks, create, from_bmap: false);
165 if (err)
166 return err;
167 if (!phys) {
168 fat_fs_error(sb,
169 "invalid FAT chain (i_pos %lld, last_block %llu)",
170 MSDOS_I(inode)->i_pos,
171 (unsigned long long)last_block);
172 return -EIO;
173 }
174
175 BUG_ON(*max_blocks != mapped_blocks);
176 set_buffer_new(bh_result);
177 map_bh(bh: bh_result, sb, block: phys);
178
179 return 0;
180}
181
182static int fat_get_block(struct inode *inode, sector_t iblock,
183 struct buffer_head *bh_result, int create)
184{
185 struct super_block *sb = inode->i_sb;
186 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
187 int err;
188
189 err = __fat_get_block(inode, iblock, max_blocks: &max_blocks, bh_result, create);
190 if (err)
191 return err;
192 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
193 return 0;
194}
195
196static int fat_writepages(struct address_space *mapping,
197 struct writeback_control *wbc)
198{
199 return mpage_writepages(mapping, wbc, get_block: fat_get_block);
200}
201
202static int fat_read_folio(struct file *file, struct folio *folio)
203{
204 return mpage_read_folio(folio, get_block: fat_get_block);
205}
206
207static void fat_readahead(struct readahead_control *rac)
208{
209 mpage_readahead(rac, get_block: fat_get_block);
210}
211
212static void fat_write_failed(struct address_space *mapping, loff_t to)
213{
214 struct inode *inode = mapping->host;
215
216 if (to > inode->i_size) {
217 truncate_pagecache(inode, new: inode->i_size);
218 fat_truncate_blocks(inode, offset: inode->i_size);
219 }
220}
221
222static int fat_write_begin(const struct kiocb *iocb,
223 struct address_space *mapping,
224 loff_t pos, unsigned len,
225 struct folio **foliop, void **fsdata)
226{
227 int err;
228
229 err = cont_write_begin(iocb, mapping, pos, len,
230 foliop, fsdata, fat_get_block,
231 &MSDOS_I(inode: mapping->host)->mmu_private);
232 if (err < 0)
233 fat_write_failed(mapping, to: pos + len);
234 return err;
235}
236
237static int fat_write_end(const struct kiocb *iocb,
238 struct address_space *mapping,
239 loff_t pos, unsigned len, unsigned copied,
240 struct folio *folio, void *fsdata)
241{
242 struct inode *inode = mapping->host;
243 int err;
244 err = generic_write_end(iocb, mapping, pos, len, copied, folio, fsdata);
245 if (err < len)
246 fat_write_failed(mapping, to: pos + len);
247 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
248 fat_truncate_time(inode, NULL, flags: S_CTIME|S_MTIME);
249 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
250 mark_inode_dirty(inode);
251 }
252 return err;
253}
254
255static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
256{
257 struct file *file = iocb->ki_filp;
258 struct address_space *mapping = file->f_mapping;
259 struct inode *inode = mapping->host;
260 size_t count = iov_iter_count(i: iter);
261 loff_t offset = iocb->ki_pos;
262 ssize_t ret;
263
264 if (iov_iter_rw(i: iter) == WRITE) {
265 /*
266 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
267 * so we need to update the ->mmu_private to block boundary.
268 *
269 * But we must fill the remaining area or hole by nul for
270 * updating ->mmu_private.
271 *
272 * Return 0, and fallback to normal buffered write.
273 */
274 loff_t size = offset + count;
275 if (MSDOS_I(inode)->mmu_private < size)
276 return 0;
277 }
278
279 /*
280 * FAT need to use the DIO_LOCKING for avoiding the race
281 * condition of fat_get_block() and ->truncate().
282 */
283 ret = blockdev_direct_IO(iocb, inode, iter, get_block: fat_get_block);
284 if (ret < 0 && iov_iter_rw(i: iter) == WRITE)
285 fat_write_failed(mapping, to: offset + count);
286
287 return ret;
288}
289
290static int fat_get_block_bmap(struct inode *inode, sector_t iblock,
291 struct buffer_head *bh_result, int create)
292{
293 struct super_block *sb = inode->i_sb;
294 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
295 int err;
296 sector_t bmap;
297 unsigned long mapped_blocks;
298
299 BUG_ON(create != 0);
300
301 err = fat_bmap(inode, sector: iblock, phys: &bmap, mapped_blocks: &mapped_blocks, create, from_bmap: true);
302 if (err)
303 return err;
304
305 if (bmap) {
306 map_bh(bh: bh_result, sb, block: bmap);
307 max_blocks = min(mapped_blocks, max_blocks);
308 }
309
310 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
311
312 return 0;
313}
314
315static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
316{
317 sector_t blocknr;
318
319 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
320 down_read(sem: &MSDOS_I(inode: mapping->host)->truncate_lock);
321 blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap);
322 up_read(sem: &MSDOS_I(inode: mapping->host)->truncate_lock);
323
324 return blocknr;
325}
326
327/*
328 * fat_block_truncate_page() zeroes out a mapping from file offset `from'
329 * up to the end of the block which corresponds to `from'.
330 * This is required during truncate to physically zeroout the tail end
331 * of that block so it doesn't yield old data if the file is later grown.
332 * Also, avoid causing failure from fsx for cases of "data past EOF"
333 */
334int fat_block_truncate_page(struct inode *inode, loff_t from)
335{
336 return block_truncate_page(inode->i_mapping, from, fat_get_block);
337}
338
339static const struct address_space_operations fat_aops = {
340 .dirty_folio = block_dirty_folio,
341 .invalidate_folio = block_invalidate_folio,
342 .read_folio = fat_read_folio,
343 .readahead = fat_readahead,
344 .writepages = fat_writepages,
345 .write_begin = fat_write_begin,
346 .write_end = fat_write_end,
347 .direct_IO = fat_direct_IO,
348 .bmap = _fat_bmap,
349 .migrate_folio = buffer_migrate_folio,
350};
351
352/*
353 * New FAT inode stuff. We do the following:
354 * a) i_ino is constant and has nothing with on-disk location.
355 * b) FAT manages its own cache of directory entries.
356 * c) *This* cache is indexed by on-disk location.
357 * d) inode has an associated directory entry, all right, but
358 * it may be unhashed.
359 * e) currently entries are stored within struct inode. That should
360 * change.
361 * f) we deal with races in the following way:
362 * 1. readdir() and lookup() do FAT-dir-cache lookup.
363 * 2. rename() unhashes the F-d-c entry and rehashes it in
364 * a new place.
365 * 3. unlink() and rmdir() unhash F-d-c entry.
366 * 4. fat_write_inode() checks whether the thing is unhashed.
367 * If it is we silently return. If it isn't we do bread(),
368 * check if the location is still valid and retry if it
369 * isn't. Otherwise we do changes.
370 * 5. Spinlock is used to protect hash/unhash/location check/lookup
371 * 6. fat_evict_inode() unhashes the F-d-c entry.
372 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
373 * and consider negative result as cache miss.
374 */
375
376static void fat_hash_init(struct super_block *sb)
377{
378 struct msdos_sb_info *sbi = MSDOS_SB(sb);
379 int i;
380
381 spin_lock_init(&sbi->inode_hash_lock);
382 for (i = 0; i < FAT_HASH_SIZE; i++)
383 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
384}
385
386static inline unsigned long fat_hash(loff_t i_pos)
387{
388 return hash_32(val: i_pos, FAT_HASH_BITS);
389}
390
391static void dir_hash_init(struct super_block *sb)
392{
393 struct msdos_sb_info *sbi = MSDOS_SB(sb);
394 int i;
395
396 spin_lock_init(&sbi->dir_hash_lock);
397 for (i = 0; i < FAT_HASH_SIZE; i++)
398 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]);
399}
400
401void fat_attach(struct inode *inode, loff_t i_pos)
402{
403 struct msdos_sb_info *sbi = MSDOS_SB(sb: inode->i_sb);
404
405 if (inode->i_ino != MSDOS_ROOT_INO) {
406 struct hlist_head *head = sbi->inode_hashtable
407 + fat_hash(i_pos);
408
409 spin_lock(lock: &sbi->inode_hash_lock);
410 MSDOS_I(inode)->i_pos = i_pos;
411 hlist_add_head(n: &MSDOS_I(inode)->i_fat_hash, h: head);
412 spin_unlock(lock: &sbi->inode_hash_lock);
413 }
414
415 /* If NFS support is enabled, cache the mapping of start cluster
416 * to directory inode. This is used during reconnection of
417 * dentries to the filesystem root.
418 */
419 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
420 struct hlist_head *d_head = sbi->dir_hashtable;
421 d_head += fat_dir_hash(logstart: MSDOS_I(inode)->i_logstart);
422
423 spin_lock(lock: &sbi->dir_hash_lock);
424 hlist_add_head(n: &MSDOS_I(inode)->i_dir_hash, h: d_head);
425 spin_unlock(lock: &sbi->dir_hash_lock);
426 }
427}
428EXPORT_SYMBOL_GPL(fat_attach);
429
430void fat_detach(struct inode *inode)
431{
432 struct msdos_sb_info *sbi = MSDOS_SB(sb: inode->i_sb);
433 spin_lock(lock: &sbi->inode_hash_lock);
434 MSDOS_I(inode)->i_pos = 0;
435 hlist_del_init(n: &MSDOS_I(inode)->i_fat_hash);
436 spin_unlock(lock: &sbi->inode_hash_lock);
437
438 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
439 spin_lock(lock: &sbi->dir_hash_lock);
440 hlist_del_init(n: &MSDOS_I(inode)->i_dir_hash);
441 spin_unlock(lock: &sbi->dir_hash_lock);
442 }
443}
444EXPORT_SYMBOL_GPL(fat_detach);
445
446struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
447{
448 struct msdos_sb_info *sbi = MSDOS_SB(sb);
449 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
450 struct msdos_inode_info *i;
451 struct inode *inode = NULL;
452
453 spin_lock(lock: &sbi->inode_hash_lock);
454 hlist_for_each_entry(i, head, i_fat_hash) {
455 BUG_ON(i->vfs_inode.i_sb != sb);
456 if (i->i_pos != i_pos)
457 continue;
458 inode = igrab(&i->vfs_inode);
459 if (inode)
460 break;
461 }
462 spin_unlock(lock: &sbi->inode_hash_lock);
463 return inode;
464}
465
466static int is_exec(unsigned char *extension)
467{
468 unsigned char exe_extensions[] = "EXECOMBAT", *walk;
469
470 for (walk = exe_extensions; *walk; walk += 3)
471 if (!strncmp(extension, walk, 3))
472 return 1;
473 return 0;
474}
475
476static int fat_calc_dir_size(struct inode *inode)
477{
478 struct msdos_sb_info *sbi = MSDOS_SB(sb: inode->i_sb);
479 int ret, fclus, dclus;
480
481 inode->i_size = 0;
482 if (MSDOS_I(inode)->i_start == 0)
483 return 0;
484
485 ret = fat_get_cluster(inode, FAT_ENT_EOF, fclus: &fclus, dclus: &dclus);
486 if (ret < 0)
487 return ret;
488 inode->i_size = (fclus + 1) << sbi->cluster_bits;
489
490 return 0;
491}
492
493static int fat_validate_dir(struct inode *dir)
494{
495 struct super_block *sb = dir->i_sb;
496
497 if (dir->i_nlink < 2) {
498 /* Directory should have "."/".." entries at least. */
499 fat_fs_error(sb, "corrupted directory (invalid entries)");
500 return -EIO;
501 }
502 if (MSDOS_I(inode: dir)->i_start == 0 ||
503 MSDOS_I(inode: dir)->i_start == MSDOS_SB(sb)->root_cluster) {
504 /* Directory should point valid cluster. */
505 fat_fs_error(sb, "corrupted directory (invalid i_start)");
506 return -EIO;
507 }
508 return 0;
509}
510
511/* doesn't deal with root inode */
512int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
513{
514 struct msdos_sb_info *sbi = MSDOS_SB(sb: inode->i_sb);
515 struct timespec64 mtime;
516 int error;
517
518 MSDOS_I(inode)->i_pos = 0;
519 inode->i_uid = sbi->options.fs_uid;
520 inode->i_gid = sbi->options.fs_gid;
521 inode_inc_iversion(inode);
522 inode->i_generation = get_random_u32();
523
524 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
525 inode->i_generation &= ~1;
526 inode->i_mode = fat_make_mode(sbi, attrs: de->attr, S_IRWXUGO);
527 inode->i_op = sbi->dir_ops;
528 inode->i_fop = &fat_dir_operations;
529
530 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
531 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
532 error = fat_calc_dir_size(inode);
533 if (error < 0)
534 return error;
535 MSDOS_I(inode)->mmu_private = inode->i_size;
536
537 set_nlink(inode, nlink: fat_subdirs(dir: inode));
538
539 error = fat_validate_dir(dir: inode);
540 if (error < 0)
541 return error;
542 } else { /* not a directory */
543 inode->i_generation |= 1;
544 inode->i_mode = fat_make_mode(sbi, attrs: de->attr,
545 mode: ((sbi->options.showexec && !is_exec(extension: de->name + 8))
546 ? S_IRUGO|S_IWUGO : S_IRWXUGO));
547 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
548
549 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
550 inode->i_size = le32_to_cpu(de->size);
551 inode->i_op = &fat_file_inode_operations;
552 inode->i_fop = &fat_file_operations;
553 inode->i_mapping->a_ops = &fat_aops;
554 MSDOS_I(inode)->mmu_private = inode->i_size;
555 }
556 if (de->attr & ATTR_SYS) {
557 if (sbi->options.sys_immutable)
558 inode->i_flags |= S_IMMUTABLE;
559 }
560 fat_save_attrs(inode, attrs: de->attr);
561
562 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
563 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
564
565 fat_time_fat2unix(sbi, ts: &mtime, time: de->time, date: de->date, time_cs: 0);
566 inode_set_mtime_to_ts(inode, ts: mtime);
567 inode_set_ctime_to_ts(inode, ts: mtime);
568 if (sbi->options.isvfat) {
569 struct timespec64 atime;
570
571 fat_time_fat2unix(sbi, ts: &atime, time: 0, date: de->adate, time_cs: 0);
572 inode_set_atime_to_ts(inode, ts: atime);
573 fat_time_fat2unix(sbi, ts: &MSDOS_I(inode)->i_crtime, time: de->ctime,
574 date: de->cdate, time_cs: de->ctime_cs);
575 } else
576 inode_set_atime_to_ts(inode, ts: fat_truncate_atime(sbi, ts: &mtime));
577
578 return 0;
579}
580
581static inline void fat_lock_build_inode(struct msdos_sb_info *sbi)
582{
583 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
584 mutex_lock(lock: &sbi->nfs_build_inode_lock);
585}
586
587static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi)
588{
589 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
590 mutex_unlock(lock: &sbi->nfs_build_inode_lock);
591}
592
593struct inode *fat_build_inode(struct super_block *sb,
594 struct msdos_dir_entry *de, loff_t i_pos)
595{
596 struct inode *inode;
597 int err;
598
599 fat_lock_build_inode(sbi: MSDOS_SB(sb));
600 inode = fat_iget(sb, i_pos);
601 if (inode)
602 goto out;
603 inode = new_inode(sb);
604 if (!inode) {
605 inode = ERR_PTR(error: -ENOMEM);
606 goto out;
607 }
608 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
609 inode_set_iversion(inode, val: 1);
610 err = fat_fill_inode(inode, de);
611 if (err) {
612 iput(inode);
613 inode = ERR_PTR(error: err);
614 goto out;
615 }
616 fat_attach(inode, i_pos);
617 insert_inode_hash(inode);
618out:
619 fat_unlock_build_inode(sbi: MSDOS_SB(sb));
620 return inode;
621}
622
623EXPORT_SYMBOL_GPL(fat_build_inode);
624
625static int __fat_write_inode(struct inode *inode, int wait);
626
627static void fat_free_eofblocks(struct inode *inode)
628{
629 /* Release unwritten fallocated blocks on inode eviction. */
630 if ((inode->i_blocks << 9) >
631 round_up(MSDOS_I(inode)->mmu_private,
632 MSDOS_SB(inode->i_sb)->cluster_size)) {
633 int err;
634
635 fat_truncate_blocks(inode, offset: MSDOS_I(inode)->mmu_private);
636 /* Fallocate results in updating the i_start/iogstart
637 * for the zero byte file. So, make it return to
638 * original state during evict and commit it to avoid
639 * any corruption on the next access to the cluster
640 * chain for the file.
641 */
642 err = __fat_write_inode(inode, wait: inode_needs_sync(inode));
643 if (err) {
644 fat_msg(inode->i_sb, KERN_WARNING, "Failed to "
645 "update on disk inode for unused "
646 "fallocated blocks, inode could be "
647 "corrupted. Please run fsck");
648 }
649
650 }
651}
652
653static void fat_evict_inode(struct inode *inode)
654{
655 truncate_inode_pages_final(&inode->i_data);
656 if (!inode->i_nlink) {
657 inode->i_size = 0;
658 fat_truncate_blocks(inode, offset: 0);
659 } else
660 fat_free_eofblocks(inode);
661
662 invalidate_inode_buffers(inode);
663 clear_inode(inode);
664 fat_cache_inval_inode(inode);
665 fat_detach(inode);
666}
667
668static void fat_set_state(struct super_block *sb,
669 unsigned int set, unsigned int force)
670{
671 struct buffer_head *bh;
672 struct fat_boot_sector *b;
673 struct msdos_sb_info *sbi = MSDOS_SB(sb);
674
675 /* do not change any thing if mounted read only */
676 if (sb_rdonly(sb) && !force)
677 return;
678
679 /* do not change state if fs was dirty */
680 if (sbi->dirty) {
681 /* warn only on set (mount). */
682 if (set)
683 fat_msg(sb, KERN_WARNING, "Volume was not properly "
684 "unmounted. Some data may be corrupt. "
685 "Please run fsck.");
686 return;
687 }
688
689 bh = sb_bread(sb, block: 0);
690 if (bh == NULL) {
691 fat_msg(sb, KERN_ERR, "unable to read boot sector "
692 "to mark fs as dirty");
693 return;
694 }
695
696 b = (struct fat_boot_sector *) bh->b_data;
697
698 if (is_fat32(sbi)) {
699 if (set)
700 b->fat32.state |= FAT_STATE_DIRTY;
701 else
702 b->fat32.state &= ~FAT_STATE_DIRTY;
703 } else /* fat 16 and 12 */ {
704 if (set)
705 b->fat16.state |= FAT_STATE_DIRTY;
706 else
707 b->fat16.state &= ~FAT_STATE_DIRTY;
708 }
709
710 mark_buffer_dirty(bh);
711 sync_dirty_buffer(bh);
712 brelse(bh);
713}
714
715static void fat_reset_iocharset(struct fat_mount_options *opts)
716{
717 if (opts->iocharset != fat_default_iocharset) {
718 /* Note: opts->iocharset can be NULL here */
719 kfree(objp: opts->iocharset);
720 opts->iocharset = fat_default_iocharset;
721 }
722}
723
724static void delayed_free(struct rcu_head *p)
725{
726 struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu);
727 unload_nls(sbi->nls_disk);
728 unload_nls(sbi->nls_io);
729 fat_reset_iocharset(opts: &sbi->options);
730 kfree(objp: sbi);
731}
732
733static void fat_put_super(struct super_block *sb)
734{
735 struct msdos_sb_info *sbi = MSDOS_SB(sb);
736
737 fat_set_state(sb, set: 0, force: 0);
738
739 iput(sbi->fsinfo_inode);
740 iput(sbi->fat_inode);
741
742 call_rcu(head: &sbi->rcu, func: delayed_free);
743}
744
745static struct kmem_cache *fat_inode_cachep;
746
747static struct inode *fat_alloc_inode(struct super_block *sb)
748{
749 struct msdos_inode_info *ei;
750 ei = alloc_inode_sb(sb, fat_inode_cachep, GFP_NOFS);
751 if (!ei)
752 return NULL;
753
754 init_rwsem(&ei->truncate_lock);
755 /* Zeroing to allow iput() even if partial initialized inode. */
756 ei->mmu_private = 0;
757 ei->i_start = 0;
758 ei->i_logstart = 0;
759 ei->i_attrs = 0;
760 ei->i_pos = 0;
761 ei->i_crtime.tv_sec = 0;
762 ei->i_crtime.tv_nsec = 0;
763
764 return &ei->vfs_inode;
765}
766
767static void fat_free_inode(struct inode *inode)
768{
769 kmem_cache_free(s: fat_inode_cachep, objp: MSDOS_I(inode));
770}
771
772static void init_once(void *foo)
773{
774 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
775
776 spin_lock_init(&ei->cache_lru_lock);
777 ei->nr_caches = 0;
778 ei->cache_valid_id = FAT_CACHE_VALID + 1;
779 INIT_LIST_HEAD(list: &ei->cache_lru);
780 INIT_HLIST_NODE(h: &ei->i_fat_hash);
781 INIT_HLIST_NODE(h: &ei->i_dir_hash);
782 inode_init_once(&ei->vfs_inode);
783}
784
785static int __init fat_init_inodecache(void)
786{
787 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
788 sizeof(struct msdos_inode_info),
789 0, (SLAB_RECLAIM_ACCOUNT|
790 SLAB_ACCOUNT),
791 init_once);
792 if (fat_inode_cachep == NULL)
793 return -ENOMEM;
794 return 0;
795}
796
797static void __exit fat_destroy_inodecache(void)
798{
799 /*
800 * Make sure all delayed rcu free inodes are flushed before we
801 * destroy cache.
802 */
803 rcu_barrier();
804 kmem_cache_destroy(s: fat_inode_cachep);
805}
806
807int fat_reconfigure(struct fs_context *fc)
808{
809 bool new_rdonly;
810 struct super_block *sb = fc->root->d_sb;
811 struct msdos_sb_info *sbi = MSDOS_SB(sb);
812 fc->sb_flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME);
813
814 sync_filesystem(sb);
815
816 /* make sure we update state on remount. */
817 new_rdonly = fc->sb_flags & SB_RDONLY;
818 if (new_rdonly != sb_rdonly(sb)) {
819 if (new_rdonly)
820 fat_set_state(sb, set: 0, force: 0);
821 else
822 fat_set_state(sb, set: 1, force: 1);
823 }
824 return 0;
825}
826EXPORT_SYMBOL_GPL(fat_reconfigure);
827
828static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
829{
830 struct super_block *sb = dentry->d_sb;
831 struct msdos_sb_info *sbi = MSDOS_SB(sb);
832 u64 id = huge_encode_dev(dev: sb->s_bdev->bd_dev);
833
834 /* If the count of free cluster is still unknown, counts it here. */
835 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
836 int err = fat_count_free_clusters(sb: dentry->d_sb);
837 if (err)
838 return err;
839 }
840
841 buf->f_type = dentry->d_sb->s_magic;
842 buf->f_bsize = sbi->cluster_size;
843 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
844 buf->f_bfree = sbi->free_clusters;
845 buf->f_bavail = sbi->free_clusters;
846 buf->f_fsid = u64_to_fsid(v: id);
847 buf->f_namelen =
848 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE;
849
850 return 0;
851}
852
853static int __fat_write_inode(struct inode *inode, int wait)
854{
855 struct super_block *sb = inode->i_sb;
856 struct msdos_sb_info *sbi = MSDOS_SB(sb);
857 struct buffer_head *bh;
858 struct msdos_dir_entry *raw_entry;
859 struct timespec64 mtime;
860 loff_t i_pos;
861 sector_t blocknr;
862 int err, offset;
863
864 if (inode->i_ino == MSDOS_ROOT_INO)
865 return 0;
866
867retry:
868 i_pos = fat_i_pos_read(sbi, inode);
869 if (!i_pos)
870 return 0;
871
872 fat_get_blknr_offset(sbi, i_pos, blknr: &blocknr, offset: &offset);
873 bh = sb_bread(sb, block: blocknr);
874 if (!bh) {
875 fat_msg(sb, KERN_ERR, "unable to read inode block "
876 "for updating (i_pos %lld)", i_pos);
877 return -EIO;
878 }
879 spin_lock(lock: &sbi->inode_hash_lock);
880 if (i_pos != MSDOS_I(inode)->i_pos) {
881 spin_unlock(lock: &sbi->inode_hash_lock);
882 brelse(bh);
883 goto retry;
884 }
885
886 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset];
887 if (S_ISDIR(inode->i_mode))
888 raw_entry->size = 0;
889 else
890 raw_entry->size = cpu_to_le32(inode->i_size);
891 raw_entry->attr = fat_make_attrs(inode);
892 fat_set_start(de: raw_entry, cluster: MSDOS_I(inode)->i_logstart);
893 mtime = inode_get_mtime(inode);
894 fat_time_unix2fat(sbi, ts: &mtime, time: &raw_entry->time,
895 date: &raw_entry->date, NULL);
896 if (sbi->options.isvfat) {
897 struct timespec64 ts = inode_get_atime(inode);
898 __le16 atime;
899
900 fat_time_unix2fat(sbi, ts: &ts, time: &atime, date: &raw_entry->adate, NULL);
901 fat_time_unix2fat(sbi, ts: &MSDOS_I(inode)->i_crtime, time: &raw_entry->ctime,
902 date: &raw_entry->cdate, time_cs: &raw_entry->ctime_cs);
903 }
904 spin_unlock(lock: &sbi->inode_hash_lock);
905 mark_buffer_dirty(bh);
906 err = 0;
907 if (wait)
908 err = sync_dirty_buffer(bh);
909 brelse(bh);
910 return err;
911}
912
913static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
914{
915 int err;
916
917 if (inode->i_ino == MSDOS_FSINFO_INO) {
918 struct super_block *sb = inode->i_sb;
919
920 mutex_lock(lock: &MSDOS_SB(sb)->s_lock);
921 err = fat_clusters_flush(sb);
922 mutex_unlock(lock: &MSDOS_SB(sb)->s_lock);
923 } else
924 err = __fat_write_inode(inode, wait: wbc->sync_mode == WB_SYNC_ALL);
925
926 return err;
927}
928
929int fat_sync_inode(struct inode *inode)
930{
931 return __fat_write_inode(inode, wait: 1);
932}
933
934EXPORT_SYMBOL_GPL(fat_sync_inode);
935
936static int fat_show_options(struct seq_file *m, struct dentry *root);
937static const struct super_operations fat_sops = {
938 .alloc_inode = fat_alloc_inode,
939 .free_inode = fat_free_inode,
940 .write_inode = fat_write_inode,
941 .evict_inode = fat_evict_inode,
942 .put_super = fat_put_super,
943 .statfs = fat_statfs,
944 .show_options = fat_show_options,
945};
946
947static int fat_show_options(struct seq_file *m, struct dentry *root)
948{
949 struct msdos_sb_info *sbi = MSDOS_SB(sb: root->d_sb);
950 struct fat_mount_options *opts = &sbi->options;
951 int isvfat = opts->isvfat;
952
953 if (!uid_eq(left: opts->fs_uid, GLOBAL_ROOT_UID))
954 seq_printf(m, ",uid=%u",
955 from_kuid_munged(&init_user_ns, opts->fs_uid));
956 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
957 seq_printf(m, ",gid=%u",
958 from_kgid_munged(&init_user_ns, opts->fs_gid));
959 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
960 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
961 if (opts->allow_utime)
962 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
963 if (sbi->nls_disk)
964 /* strip "cp" prefix from displayed option */
965 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]);
966 if (isvfat) {
967 if (sbi->nls_io)
968 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
969
970 switch (opts->shortname) {
971 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
972 seq_puts(m, ",shortname=win95");
973 break;
974 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
975 seq_puts(m, ",shortname=winnt");
976 break;
977 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
978 seq_puts(m, ",shortname=mixed");
979 break;
980 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
981 seq_puts(m, ",shortname=lower");
982 break;
983 default:
984 seq_puts(m, ",shortname=unknown");
985 break;
986 }
987 }
988 if (opts->name_check != 'n')
989 seq_printf(m, ",check=%c", opts->name_check);
990 if (opts->usefree)
991 seq_puts(m, ",usefree");
992 if (opts->quiet)
993 seq_puts(m, ",quiet");
994 if (opts->showexec)
995 seq_puts(m, ",showexec");
996 if (opts->sys_immutable)
997 seq_puts(m, ",sys_immutable");
998 if (!isvfat) {
999 if (opts->dotsOK)
1000 seq_puts(m, ",dotsOK=yes");
1001 if (opts->nocase)
1002 seq_puts(m, ",nocase");
1003 } else {
1004 if (opts->utf8)
1005 seq_puts(m, ",utf8");
1006 if (opts->unicode_xlate)
1007 seq_puts(m, ",uni_xlate");
1008 if (!opts->numtail)
1009 seq_puts(m, ",nonumtail");
1010 if (opts->rodir)
1011 seq_puts(m, ",rodir");
1012 }
1013 if (opts->flush)
1014 seq_puts(m, ",flush");
1015 if (opts->tz_set) {
1016 if (opts->time_offset)
1017 seq_printf(m, ",time_offset=%d", opts->time_offset);
1018 else
1019 seq_puts(m, ",tz=UTC");
1020 }
1021 if (opts->errors == FAT_ERRORS_CONT)
1022 seq_puts(m, ",errors=continue");
1023 else if (opts->errors == FAT_ERRORS_PANIC)
1024 seq_puts(m, ",errors=panic");
1025 else
1026 seq_puts(m, ",errors=remount-ro");
1027 if (opts->nfs == FAT_NFS_NOSTALE_RO)
1028 seq_puts(m, ",nfs=nostale_ro");
1029 else if (opts->nfs)
1030 seq_puts(m, ",nfs=stale_rw");
1031 if (opts->discard)
1032 seq_puts(m, ",discard");
1033 if (opts->dos1xfloppy)
1034 seq_puts(m, ",dos1xfloppy");
1035
1036 return 0;
1037}
1038
1039enum {
1040 Opt_check, Opt_uid, Opt_gid, Opt_umask, Opt_dmask, Opt_fmask,
1041 Opt_allow_utime, Opt_codepage, Opt_usefree, Opt_nocase, Opt_quiet,
1042 Opt_showexec, Opt_debug, Opt_immutable, Opt_dots, Opt_dotsOK,
1043 Opt_charset, Opt_shortname, Opt_utf8, Opt_utf8_bool,
1044 Opt_uni_xl, Opt_uni_xl_bool, Opt_nonumtail, Opt_nonumtail_bool,
1045 Opt_obsolete, Opt_flush, Opt_tz, Opt_rodir, Opt_errors, Opt_discard,
1046 Opt_nfs, Opt_nfs_enum, Opt_time_offset, Opt_dos1xfloppy,
1047};
1048
1049static const struct constant_table fat_param_check[] = {
1050 {"relaxed", 'r'},
1051 {.name: "r", .value: 'r'},
1052 {.name: "strict", .value: 's'},
1053 {.name: "s", .value: 's'},
1054 {.name: "normal", .value: 'n'},
1055 {.name: "n", .value: 'n'},
1056 {}
1057};
1058
1059static const struct constant_table fat_param_tz[] = {
1060 {"UTC", 0},
1061 {}
1062};
1063
1064static const struct constant_table fat_param_errors[] = {
1065 {"continue", FAT_ERRORS_CONT},
1066 {.name: "panic", FAT_ERRORS_PANIC},
1067 {.name: "remount-ro", FAT_ERRORS_RO},
1068 {}
1069};
1070
1071
1072static const struct constant_table fat_param_nfs[] = {
1073 {"stale_rw", FAT_NFS_STALE_RW},
1074 {.name: "nostale_ro", FAT_NFS_NOSTALE_RO},
1075 {}
1076};
1077
1078/*
1079 * These are all obsolete but we still reject invalid options.
1080 * The corresponding values are therefore meaningless.
1081 */
1082static const struct constant_table fat_param_conv[] = {
1083 {"binary", 0},
1084 {.name: "text", .value: 0},
1085 {.name: "auto", .value: 0},
1086 {.name: "b", .value: 0},
1087 {.name: "t", .value: 0},
1088 {.name: "a", .value: 0},
1089 {}
1090};
1091
1092/* Core options. See below for vfat and msdos extras */
1093const struct fs_parameter_spec fat_param_spec[] = {
1094 fsparam_enum ("check", Opt_check, fat_param_check),
1095 fsparam_uid ("uid", Opt_uid),
1096 fsparam_gid ("gid", Opt_gid),
1097 fsparam_u32oct ("umask", Opt_umask),
1098 fsparam_u32oct ("dmask", Opt_dmask),
1099 fsparam_u32oct ("fmask", Opt_fmask),
1100 fsparam_u32oct ("allow_utime", Opt_allow_utime),
1101 fsparam_u32 ("codepage", Opt_codepage),
1102 fsparam_flag ("usefree", Opt_usefree),
1103 fsparam_flag ("nocase", Opt_nocase),
1104 fsparam_flag ("quiet", Opt_quiet),
1105 fsparam_flag ("showexec", Opt_showexec),
1106 fsparam_flag ("debug", Opt_debug),
1107 fsparam_flag ("sys_immutable", Opt_immutable),
1108 fsparam_flag ("flush", Opt_flush),
1109 fsparam_enum ("tz", Opt_tz, fat_param_tz),
1110 fsparam_s32 ("time_offset", Opt_time_offset),
1111 fsparam_enum ("errors", Opt_errors, fat_param_errors),
1112 fsparam_flag ("discard", Opt_discard),
1113 fsparam_flag ("nfs", Opt_nfs),
1114 fsparam_enum ("nfs", Opt_nfs_enum, fat_param_nfs),
1115 fsparam_flag ("dos1xfloppy", Opt_dos1xfloppy),
1116 __fsparam(fs_param_is_enum, "conv",
1117 Opt_obsolete, fs_param_deprecated, fat_param_conv),
1118 __fsparam(fs_param_is_u32, "fat",
1119 Opt_obsolete, fs_param_deprecated, NULL),
1120 __fsparam(fs_param_is_u32, "blocksize",
1121 Opt_obsolete, fs_param_deprecated, NULL),
1122 __fsparam(fs_param_is_string, "cvf_format",
1123 Opt_obsolete, fs_param_deprecated, NULL),
1124 __fsparam(fs_param_is_string, "cvf_options",
1125 Opt_obsolete, fs_param_deprecated, NULL),
1126 __fsparam(NULL, "posix",
1127 Opt_obsolete, fs_param_deprecated, NULL),
1128 {}
1129};
1130EXPORT_SYMBOL_GPL(fat_param_spec);
1131
1132static const struct fs_parameter_spec msdos_param_spec[] = {
1133 fsparam_flag_no ("dots", Opt_dots),
1134 fsparam_bool ("dotsOK", Opt_dotsOK),
1135 {}
1136};
1137
1138static const struct constant_table fat_param_shortname[] = {
1139 {"lower", VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95},
1140 {"win95", VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95},
1141 {"winnt", VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT},
1142 {"mixed", VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95},
1143 {}
1144};
1145
1146static const struct fs_parameter_spec vfat_param_spec[] = {
1147 fsparam_string ("iocharset", Opt_charset),
1148 fsparam_enum ("shortname", Opt_shortname, fat_param_shortname),
1149 fsparam_flag ("utf8", Opt_utf8),
1150 fsparam_bool ("utf8", Opt_utf8_bool),
1151 fsparam_flag ("uni_xlate", Opt_uni_xl),
1152 fsparam_bool ("uni_xlate", Opt_uni_xl_bool),
1153 fsparam_flag ("nonumtail", Opt_nonumtail),
1154 fsparam_bool ("nonumtail", Opt_nonumtail_bool),
1155 fsparam_flag ("rodir", Opt_rodir),
1156 {}
1157};
1158
1159int fat_parse_param(struct fs_context *fc, struct fs_parameter *param,
1160 bool is_vfat)
1161{
1162 struct fat_mount_options *opts = fc->fs_private;
1163 struct fs_parse_result result;
1164 int opt;
1165
1166 /* remount options have traditionally been ignored */
1167 if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE)
1168 return 0;
1169
1170 opt = fs_parse(fc, desc: fat_param_spec, param, result: &result);
1171 /* If option not found in fat_param_spec, try vfat/msdos options */
1172 if (opt == -ENOPARAM) {
1173 if (is_vfat)
1174 opt = fs_parse(fc, desc: vfat_param_spec, param, result: &result);
1175 else
1176 opt = fs_parse(fc, desc: msdos_param_spec, param, result: &result);
1177 }
1178
1179 if (opt < 0)
1180 return opt;
1181
1182 switch (opt) {
1183 case Opt_check:
1184 opts->name_check = result.uint_32;
1185 break;
1186 case Opt_usefree:
1187 opts->usefree = 1;
1188 break;
1189 case Opt_nocase:
1190 if (!is_vfat)
1191 opts->nocase = 1;
1192 else {
1193 /* for backward compatibility */
1194 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1195 | VFAT_SFN_CREATE_WIN95;
1196 }
1197 break;
1198 case Opt_quiet:
1199 opts->quiet = 1;
1200 break;
1201 case Opt_showexec:
1202 opts->showexec = 1;
1203 break;
1204 case Opt_debug:
1205 opts->debug = 1;
1206 break;
1207 case Opt_immutable:
1208 opts->sys_immutable = 1;
1209 break;
1210 case Opt_uid:
1211 opts->fs_uid = result.uid;
1212 break;
1213 case Opt_gid:
1214 opts->fs_gid = result.gid;
1215 break;
1216 case Opt_umask:
1217 opts->fs_fmask = opts->fs_dmask = result.uint_32;
1218 break;
1219 case Opt_dmask:
1220 opts->fs_dmask = result.uint_32;
1221 break;
1222 case Opt_fmask:
1223 opts->fs_fmask = result.uint_32;
1224 break;
1225 case Opt_allow_utime:
1226 opts->allow_utime = result.uint_32 & (S_IWGRP | S_IWOTH);
1227 break;
1228 case Opt_codepage:
1229 opts->codepage = result.uint_32;
1230 break;
1231 case Opt_flush:
1232 opts->flush = 1;
1233 break;
1234 case Opt_time_offset:
1235 /*
1236 * GMT+-12 zones may have DST corrections so at least
1237 * 13 hours difference is needed. Make the limit 24
1238 * just in case someone invents something unusual.
1239 */
1240 if (result.int_32 < -24 * 60 || result.int_32 > 24 * 60)
1241 return -EINVAL;
1242 opts->tz_set = 1;
1243 opts->time_offset = result.int_32;
1244 break;
1245 case Opt_tz:
1246 opts->tz_set = 1;
1247 opts->time_offset = result.uint_32;
1248 break;
1249 case Opt_errors:
1250 opts->errors = result.uint_32;
1251 break;
1252 case Opt_nfs:
1253 opts->nfs = FAT_NFS_STALE_RW;
1254 break;
1255 case Opt_nfs_enum:
1256 opts->nfs = result.uint_32;
1257 break;
1258 case Opt_dos1xfloppy:
1259 opts->dos1xfloppy = 1;
1260 break;
1261
1262 /* msdos specific */
1263 case Opt_dots: /* dots / nodots */
1264 opts->dotsOK = !result.negated;
1265 break;
1266 case Opt_dotsOK: /* dotsOK = yes/no */
1267 opts->dotsOK = result.boolean;
1268 break;
1269
1270 /* vfat specific */
1271 case Opt_charset:
1272 fat_reset_iocharset(opts);
1273 opts->iocharset = param->string;
1274 param->string = NULL; /* Steal string */
1275 break;
1276 case Opt_shortname:
1277 opts->shortname = result.uint_32;
1278 break;
1279 case Opt_utf8:
1280 opts->utf8 = 1;
1281 break;
1282 case Opt_utf8_bool:
1283 opts->utf8 = result.boolean;
1284 break;
1285 case Opt_uni_xl:
1286 opts->unicode_xlate = 1;
1287 break;
1288 case Opt_uni_xl_bool:
1289 opts->unicode_xlate = result.boolean;
1290 break;
1291 case Opt_nonumtail:
1292 opts->numtail = 0; /* negated option */
1293 break;
1294 case Opt_nonumtail_bool:
1295 opts->numtail = !result.boolean; /* negated option */
1296 break;
1297 case Opt_rodir:
1298 opts->rodir = 1;
1299 break;
1300 case Opt_discard:
1301 opts->discard = 1;
1302 break;
1303
1304 /* obsolete mount options */
1305 case Opt_obsolete:
1306 printk(KERN_INFO "FAT-fs: \"%s\" option is obsolete, "
1307 "not supported now", param->key);
1308 break;
1309 default:
1310 return -EINVAL;
1311 }
1312
1313 return 0;
1314}
1315EXPORT_SYMBOL_GPL(fat_parse_param);
1316
1317static int fat_read_root(struct inode *inode)
1318{
1319 struct msdos_sb_info *sbi = MSDOS_SB(sb: inode->i_sb);
1320 int error;
1321
1322 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO;
1323 inode->i_uid = sbi->options.fs_uid;
1324 inode->i_gid = sbi->options.fs_gid;
1325 inode_inc_iversion(inode);
1326 inode->i_generation = 0;
1327 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
1328 inode->i_op = sbi->dir_ops;
1329 inode->i_fop = &fat_dir_operations;
1330 if (is_fat32(sbi)) {
1331 MSDOS_I(inode)->i_start = sbi->root_cluster;
1332 error = fat_calc_dir_size(inode);
1333 if (error < 0)
1334 return error;
1335 } else {
1336 MSDOS_I(inode)->i_start = 0;
1337 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1338 }
1339 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1340 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1341 MSDOS_I(inode)->i_logstart = 0;
1342 MSDOS_I(inode)->mmu_private = inode->i_size;
1343
1344 fat_save_attrs(inode, ATTR_DIR);
1345 inode_set_mtime_to_ts(inode,
1346 ts: inode_set_atime_to_ts(inode, ts: inode_set_ctime(inode, sec: 0, nsec: 0)));
1347 set_nlink(inode, nlink: fat_subdirs(dir: inode)+2);
1348
1349 return 0;
1350}
1351
1352static unsigned long calc_fat_clusters(struct super_block *sb)
1353{
1354 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1355
1356 /* Divide first to avoid overflow */
1357 if (!is_fat12(sbi)) {
1358 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits;
1359 return ent_per_sec * sbi->fat_length;
1360 }
1361
1362 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1363}
1364
1365static bool fat_bpb_is_zero(struct fat_boot_sector *b)
1366{
1367 if (get_unaligned_le16(p: &b->sector_size))
1368 return false;
1369 if (b->sec_per_clus)
1370 return false;
1371 if (b->reserved)
1372 return false;
1373 if (b->fats)
1374 return false;
1375 if (get_unaligned_le16(p: &b->dir_entries))
1376 return false;
1377 if (get_unaligned_le16(p: &b->sectors))
1378 return false;
1379 if (b->media)
1380 return false;
1381 if (b->fat_length)
1382 return false;
1383 if (b->secs_track)
1384 return false;
1385 if (b->heads)
1386 return false;
1387 return true;
1388}
1389
1390static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b,
1391 int silent, struct fat_bios_param_block *bpb)
1392{
1393 int error = -EINVAL;
1394
1395 /* Read in BPB ... */
1396 memset(s: bpb, c: 0, n: sizeof(*bpb));
1397 bpb->fat_sector_size = get_unaligned_le16(p: &b->sector_size);
1398 bpb->fat_sec_per_clus = b->sec_per_clus;
1399 bpb->fat_reserved = le16_to_cpu(b->reserved);
1400 bpb->fat_fats = b->fats;
1401 bpb->fat_dir_entries = get_unaligned_le16(p: &b->dir_entries);
1402 bpb->fat_sectors = get_unaligned_le16(p: &b->sectors);
1403 bpb->fat_fat_length = le16_to_cpu(b->fat_length);
1404 bpb->fat_total_sect = le32_to_cpu(b->total_sect);
1405
1406 bpb->fat16_state = b->fat16.state;
1407 bpb->fat16_vol_id = get_unaligned_le32(p: b->fat16.vol_id);
1408
1409 bpb->fat32_length = le32_to_cpu(b->fat32.length);
1410 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster);
1411 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector);
1412 bpb->fat32_state = b->fat32.state;
1413 bpb->fat32_vol_id = get_unaligned_le32(p: b->fat32.vol_id);
1414
1415 /* Validate this looks like a FAT filesystem BPB */
1416 if (!bpb->fat_reserved) {
1417 if (!silent)
1418 fat_msg(sb, KERN_ERR,
1419 "bogus number of reserved sectors");
1420 goto out;
1421 }
1422 if (!bpb->fat_fats) {
1423 if (!silent)
1424 fat_msg(sb, KERN_ERR, "bogus number of FAT structure");
1425 goto out;
1426 }
1427
1428 /*
1429 * Earlier we checked here that b->secs_track and b->head are nonzero,
1430 * but it turns out valid FAT filesystems can have zero there.
1431 */
1432
1433 if (!fat_valid_media(media: b->media)) {
1434 if (!silent)
1435 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)",
1436 (unsigned)b->media);
1437 goto out;
1438 }
1439
1440 if (!is_power_of_2(n: bpb->fat_sector_size)
1441 || (bpb->fat_sector_size < 512)
1442 || (bpb->fat_sector_size > 4096)) {
1443 if (!silent)
1444 fat_msg(sb, KERN_ERR, "bogus logical sector size %u",
1445 (unsigned)bpb->fat_sector_size);
1446 goto out;
1447 }
1448
1449 if (!is_power_of_2(n: bpb->fat_sec_per_clus)) {
1450 if (!silent)
1451 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u",
1452 (unsigned)bpb->fat_sec_per_clus);
1453 goto out;
1454 }
1455
1456 if (bpb->fat_fat_length == 0 && bpb->fat32_length == 0) {
1457 if (!silent)
1458 fat_msg(sb, KERN_ERR, "bogus number of FAT sectors");
1459 goto out;
1460 }
1461
1462 error = 0;
1463
1464out:
1465 return error;
1466}
1467
1468static int fat_read_static_bpb(struct super_block *sb,
1469 struct fat_boot_sector *b, int silent,
1470 struct fat_bios_param_block *bpb)
1471{
1472 static const char *notdos1x = "This doesn't look like a DOS 1.x volume";
1473 sector_t bd_sects = bdev_nr_sectors(bdev: sb->s_bdev);
1474 struct fat_floppy_defaults *fdefaults = NULL;
1475 int error = -EINVAL;
1476 unsigned i;
1477
1478 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */
1479 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) {
1480 if (!silent)
1481 fat_msg(sb, KERN_ERR,
1482 "%s; no bootstrapping code", notdos1x);
1483 goto out;
1484 }
1485
1486 /*
1487 * If any value in this region is non-zero, it isn't archaic
1488 * DOS.
1489 */
1490 if (!fat_bpb_is_zero(b)) {
1491 if (!silent)
1492 fat_msg(sb, KERN_ERR,
1493 "%s; DOS 2.x BPB is non-zero", notdos1x);
1494 goto out;
1495 }
1496
1497 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) {
1498 if (floppy_defaults[i].nr_sectors == bd_sects) {
1499 fdefaults = &floppy_defaults[i];
1500 break;
1501 }
1502 }
1503
1504 if (fdefaults == NULL) {
1505 if (!silent)
1506 fat_msg(sb, KERN_WARNING,
1507 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)",
1508 (u64)bd_sects);
1509 goto out;
1510 }
1511
1512 if (!silent)
1513 fat_msg(sb, KERN_INFO,
1514 "This looks like a DOS 1.x volume; assuming default BPB values");
1515
1516 memset(s: bpb, c: 0, n: sizeof(*bpb));
1517 bpb->fat_sector_size = SECTOR_SIZE;
1518 bpb->fat_sec_per_clus = fdefaults->sec_per_clus;
1519 bpb->fat_reserved = 1;
1520 bpb->fat_fats = 2;
1521 bpb->fat_dir_entries = fdefaults->dir_entries;
1522 bpb->fat_sectors = fdefaults->nr_sectors;
1523 bpb->fat_fat_length = fdefaults->fat_length;
1524
1525 error = 0;
1526
1527out:
1528 return error;
1529}
1530
1531/*
1532 * Read the super block of an MS-DOS FS.
1533 */
1534int fat_fill_super(struct super_block *sb, struct fs_context *fc,
1535 void (*setup)(struct super_block *))
1536{
1537 struct fat_mount_options *opts = fc->fs_private;
1538 int silent = fc->sb_flags & SB_SILENT;
1539 struct inode *root_inode = NULL, *fat_inode = NULL;
1540 struct inode *fsinfo_inode = NULL;
1541 struct buffer_head *bh;
1542 struct fat_bios_param_block bpb;
1543 struct msdos_sb_info *sbi;
1544 u16 logical_sector_size;
1545 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1546 long error;
1547 char buf[50];
1548 struct timespec64 ts;
1549
1550 /*
1551 * GFP_KERNEL is ok here, because while we do hold the
1552 * superblock lock, memory pressure can't call back into
1553 * the filesystem, since we're only just about to mount
1554 * it and have no inodes etc active!
1555 */
1556 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1557 if (!sbi)
1558 return -ENOMEM;
1559 sb->s_fs_info = sbi;
1560
1561 sb->s_flags |= SB_NODIRATIME;
1562 sb->s_magic = MSDOS_SUPER_MAGIC;
1563 sb->s_op = &fat_sops;
1564 sb->s_export_op = &fat_export_ops;
1565 /*
1566 * fat timestamps are complex and truncated by fat itself, so
1567 * we set 1 here to be fast
1568 */
1569 sb->s_time_gran = 1;
1570 mutex_init(&sbi->nfs_build_inode_lock);
1571 ratelimit_state_init(rs: &sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
1572 DEFAULT_RATELIMIT_BURST);
1573
1574 /* UTF-8 doesn't provide FAT semantics */
1575 if (!strcmp(opts->iocharset, "utf8")) {
1576 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset"
1577 " for FAT filesystems, filesystem will be"
1578 " case sensitive!");
1579 }
1580
1581 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1582 if (opts->allow_utime == (unsigned short)-1)
1583 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
1584 if (opts->unicode_xlate)
1585 opts->utf8 = 0;
1586 if (opts->nfs == FAT_NFS_NOSTALE_RO) {
1587 sb->s_flags |= SB_RDONLY;
1588 sb->s_export_op = &fat_export_ops_nostale;
1589 }
1590
1591 /* Apply parsed options to sbi (structure copy) */
1592 sbi->options = *opts;
1593 /* Transfer ownership of iocharset to sbi->options */
1594 opts->iocharset = NULL;
1595
1596 setup(sb); /* flavour-specific stuff that needs options */
1597
1598 error = -EIO;
1599 sb_min_blocksize(sb, 512);
1600 bh = sb_bread(sb, block: 0);
1601 if (bh == NULL) {
1602 fat_msg(sb, KERN_ERR, "unable to read boot sector");
1603 goto out_fail;
1604 }
1605
1606 error = fat_read_bpb(sb, b: (struct fat_boot_sector *)bh->b_data, silent,
1607 bpb: &bpb);
1608 if (error == -EINVAL && sbi->options.dos1xfloppy)
1609 error = fat_read_static_bpb(sb,
1610 b: (struct fat_boot_sector *)bh->b_data, silent, bpb: &bpb);
1611 brelse(bh);
1612
1613 if (error == -EINVAL)
1614 goto out_invalid;
1615 else if (error)
1616 goto out_fail;
1617
1618 logical_sector_size = bpb.fat_sector_size;
1619 sbi->sec_per_clus = bpb.fat_sec_per_clus;
1620
1621 error = -EIO;
1622 if (logical_sector_size < sb->s_blocksize) {
1623 fat_msg(sb, KERN_ERR, "logical sector size too small for device"
1624 " (logical sector size = %u)", logical_sector_size);
1625 goto out_fail;
1626 }
1627
1628 if (logical_sector_size > sb->s_blocksize) {
1629 struct buffer_head *bh_resize;
1630
1631 if (!sb_set_blocksize(sb, logical_sector_size)) {
1632 fat_msg(sb, KERN_ERR, "unable to set blocksize %u",
1633 logical_sector_size);
1634 goto out_fail;
1635 }
1636
1637 /* Verify that the larger boot sector is fully readable */
1638 bh_resize = sb_bread(sb, block: 0);
1639 if (bh_resize == NULL) {
1640 fat_msg(sb, KERN_ERR, "unable to read boot sector"
1641 " (logical sector size = %lu)",
1642 sb->s_blocksize);
1643 goto out_fail;
1644 }
1645 brelse(bh: bh_resize);
1646 }
1647
1648 mutex_init(&sbi->s_lock);
1649 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1650 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1651 sbi->fats = bpb.fat_fats;
1652 sbi->fat_bits = 0; /* Don't know yet */
1653 sbi->fat_start = bpb.fat_reserved;
1654 sbi->fat_length = bpb.fat_fat_length;
1655 sbi->root_cluster = 0;
1656 sbi->free_clusters = -1; /* Don't know yet */
1657 sbi->free_clus_valid = 0;
1658 sbi->prev_free = FAT_START_ENT;
1659 sb->s_maxbytes = 0xffffffff;
1660 fat_time_fat2unix(sbi, ts: &ts, time: 0, cpu_to_le16(FAT_DATE_MIN), time_cs: 0);
1661 sb->s_time_min = ts.tv_sec;
1662
1663 fat_time_fat2unix(sbi, ts: &ts, cpu_to_le16(FAT_TIME_MAX),
1664 cpu_to_le16(FAT_DATE_MAX), time_cs: 0);
1665 sb->s_time_max = ts.tv_sec;
1666
1667 if (!sbi->fat_length && bpb.fat32_length) {
1668 struct fat_boot_fsinfo *fsinfo;
1669 struct buffer_head *fsinfo_bh;
1670
1671 /* Must be FAT32 */
1672 sbi->fat_bits = 32;
1673 sbi->fat_length = bpb.fat32_length;
1674 sbi->root_cluster = bpb.fat32_root_cluster;
1675
1676 /* MC - if info_sector is 0, don't multiply by 0 */
1677 sbi->fsinfo_sector = bpb.fat32_info_sector;
1678 if (sbi->fsinfo_sector == 0)
1679 sbi->fsinfo_sector = 1;
1680
1681 fsinfo_bh = sb_bread(sb, block: sbi->fsinfo_sector);
1682 if (fsinfo_bh == NULL) {
1683 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block"
1684 " (sector = %lu)", sbi->fsinfo_sector);
1685 goto out_fail;
1686 }
1687
1688 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1689 if (!IS_FSINFO(fsinfo)) {
1690 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
1691 "0x%08x, 0x%08x (sector = %lu)",
1692 le32_to_cpu(fsinfo->signature1),
1693 le32_to_cpu(fsinfo->signature2),
1694 sbi->fsinfo_sector);
1695 } else {
1696 if (sbi->options.usefree)
1697 sbi->free_clus_valid = 1;
1698 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1699 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1700 }
1701
1702 brelse(bh: fsinfo_bh);
1703 }
1704
1705 /* interpret volume ID as a little endian 32 bit integer */
1706 if (is_fat32(sbi))
1707 sbi->vol_id = bpb.fat32_vol_id;
1708 else /* fat 16 or 12 */
1709 sbi->vol_id = bpb.fat16_vol_id;
1710
1711 __le32 vol_id_le = cpu_to_le32(sbi->vol_id);
1712 super_set_uuid(sb, uuid: (void *) &vol_id_le, len: sizeof(vol_id_le));
1713
1714 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1715 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1716
1717 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1718 sbi->dir_entries = bpb.fat_dir_entries;
1719 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1720 if (!silent)
1721 fat_msg(sb, KERN_ERR, "bogus number of directory entries"
1722 " (%u)", sbi->dir_entries);
1723 goto out_invalid;
1724 }
1725
1726 rootdir_sectors = sbi->dir_entries
1727 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1728 sbi->data_start = sbi->dir_start + rootdir_sectors;
1729 total_sectors = bpb.fat_sectors;
1730 if (total_sectors == 0)
1731 total_sectors = bpb.fat_total_sect;
1732
1733 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1734
1735 if (!is_fat32(sbi))
1736 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1737
1738 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */
1739 if (is_fat32(sbi))
1740 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY;
1741 else /* fat 16 or 12 */
1742 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY;
1743
1744 /* check that FAT table does not overflow */
1745 fat_clusters = calc_fat_clusters(sb);
1746 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1747 if (total_clusters > max_fat(sb)) {
1748 if (!silent)
1749 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)",
1750 total_clusters);
1751 goto out_invalid;
1752 }
1753
1754 sbi->max_cluster = total_clusters + FAT_START_ENT;
1755 /* check the free_clusters, it's not necessarily correct */
1756 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1757 sbi->free_clusters = -1;
1758 /* check the prev_free, it's not necessarily correct */
1759 sbi->prev_free %= sbi->max_cluster;
1760 if (sbi->prev_free < FAT_START_ENT)
1761 sbi->prev_free = FAT_START_ENT;
1762
1763 /* set up enough so that it can read an inode */
1764 fat_hash_init(sb);
1765 dir_hash_init(sb);
1766 fat_ent_access_init(sb);
1767
1768 /*
1769 * The low byte of the first FAT entry must have the same value as
1770 * the media field of the boot sector. But in real world, too many
1771 * devices are writing wrong values. So, removed that validity check.
1772 *
1773 * The removed check compared the first FAT entry to a value dependent
1774 * on the media field like this:
1775 * == (0x0F00 | media), for FAT12
1776 * == (0XFF00 | media), for FAT16
1777 * == (0x0FFFFF | media), for FAT32
1778 */
1779
1780 error = -EINVAL;
1781 sprintf(buf, fmt: "cp%d", sbi->options.codepage);
1782 sbi->nls_disk = load_nls(charset: buf);
1783 if (!sbi->nls_disk) {
1784 fat_msg(sb, KERN_ERR, "codepage %s not found", buf);
1785 goto out_fail;
1786 }
1787
1788 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1789 if (sbi->options.isvfat) {
1790 sbi->nls_io = load_nls(charset: sbi->options.iocharset);
1791 if (!sbi->nls_io) {
1792 fat_msg(sb, KERN_ERR, "IO charset %s not found",
1793 sbi->options.iocharset);
1794 goto out_fail;
1795 }
1796 }
1797
1798 error = -ENOMEM;
1799 fat_inode = new_inode(sb);
1800 if (!fat_inode)
1801 goto out_fail;
1802 sbi->fat_inode = fat_inode;
1803
1804 fsinfo_inode = new_inode(sb);
1805 if (!fsinfo_inode)
1806 goto out_fail;
1807 fsinfo_inode->i_ino = MSDOS_FSINFO_INO;
1808 sbi->fsinfo_inode = fsinfo_inode;
1809 insert_inode_hash(inode: fsinfo_inode);
1810
1811 root_inode = new_inode(sb);
1812 if (!root_inode)
1813 goto out_fail;
1814 root_inode->i_ino = MSDOS_ROOT_INO;
1815 inode_set_iversion(inode: root_inode, val: 1);
1816 error = fat_read_root(inode: root_inode);
1817 if (error < 0) {
1818 iput(root_inode);
1819 goto out_fail;
1820 }
1821 error = -ENOMEM;
1822 insert_inode_hash(inode: root_inode);
1823 fat_attach(root_inode, 0);
1824 sb->s_root = d_make_root(root_inode);
1825 if (!sb->s_root) {
1826 fat_msg(sb, KERN_ERR, "get root inode failed");
1827 goto out_fail;
1828 }
1829
1830 if (sbi->options.discard && !bdev_max_discard_sectors(bdev: sb->s_bdev))
1831 fat_msg(sb, KERN_WARNING,
1832 "mounting with \"discard\" option, but the device does not support discard");
1833
1834 fat_set_state(sb, set: 1, force: 0);
1835 return 0;
1836
1837out_invalid:
1838 error = -EINVAL;
1839 if (!silent)
1840 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem");
1841
1842out_fail:
1843 iput(fsinfo_inode);
1844 iput(fat_inode);
1845 unload_nls(sbi->nls_io);
1846 unload_nls(sbi->nls_disk);
1847 fat_reset_iocharset(opts: &sbi->options);
1848 sb->s_fs_info = NULL;
1849 kfree(objp: sbi);
1850 return error;
1851}
1852
1853EXPORT_SYMBOL_GPL(fat_fill_super);
1854
1855/*
1856 * helper function for fat_flush_inodes. This writes both the inode
1857 * and the file data blocks, waiting for in flight data blocks before
1858 * the start of the call. It does not wait for any io started
1859 * during the call
1860 */
1861static int writeback_inode(struct inode *inode)
1862{
1863
1864 int ret;
1865
1866 /* if we used wait=1, sync_inode_metadata waits for the io for the
1867 * inode to finish. So wait=0 is sent down to sync_inode_metadata
1868 * and filemap_fdatawrite is used for the data blocks
1869 */
1870 ret = sync_inode_metadata(inode, wait: 0);
1871 if (!ret)
1872 ret = filemap_fdatawrite(inode->i_mapping);
1873 return ret;
1874}
1875
1876/*
1877 * write data and metadata corresponding to i1 and i2. The io is
1878 * started but we do not wait for any of it to finish.
1879 *
1880 * filemap_flush is used for the block device, so if there is a dirty
1881 * page for a block already in flight, we will not wait and start the
1882 * io over again
1883 */
1884int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1885{
1886 int ret = 0;
1887 if (!MSDOS_SB(sb)->options.flush)
1888 return 0;
1889 if (i1)
1890 ret = writeback_inode(inode: i1);
1891 if (!ret && i2)
1892 ret = writeback_inode(inode: i2);
1893 if (!ret)
1894 ret = sync_blockdev_nowait(bdev: sb->s_bdev);
1895 return ret;
1896}
1897EXPORT_SYMBOL_GPL(fat_flush_inodes);
1898
1899int fat_init_fs_context(struct fs_context *fc, bool is_vfat)
1900{
1901 struct fat_mount_options *opts;
1902
1903 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
1904 if (!opts)
1905 return -ENOMEM;
1906
1907 opts->isvfat = is_vfat;
1908 opts->fs_uid = current_uid();
1909 opts->fs_gid = current_gid();
1910 opts->fs_fmask = opts->fs_dmask = current_umask();
1911 opts->allow_utime = -1;
1912 opts->codepage = fat_default_codepage;
1913 fat_reset_iocharset(opts);
1914 if (is_vfat) {
1915 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
1916 opts->rodir = 0;
1917 } else {
1918 opts->shortname = 0;
1919 opts->rodir = 1;
1920 }
1921 opts->name_check = 'n';
1922 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
1923 opts->unicode_xlate = 0;
1924 opts->numtail = 1;
1925 opts->usefree = opts->nocase = 0;
1926 opts->tz_set = 0;
1927 opts->nfs = 0;
1928 opts->errors = FAT_ERRORS_RO;
1929 opts->debug = 0;
1930
1931 opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat;
1932
1933 fc->fs_private = opts;
1934 /* fc->ops assigned by caller */
1935
1936 return 0;
1937}
1938EXPORT_SYMBOL_GPL(fat_init_fs_context);
1939
1940void fat_free_fc(struct fs_context *fc)
1941{
1942 struct fat_mount_options *opts = fc->fs_private;
1943
1944 if (opts->iocharset != fat_default_iocharset)
1945 kfree(objp: opts->iocharset);
1946 kfree(objp: fc->fs_private);
1947}
1948EXPORT_SYMBOL_GPL(fat_free_fc);
1949
1950static int __init init_fat_fs(void)
1951{
1952 int err;
1953
1954 err = fat_cache_init();
1955 if (err)
1956 return err;
1957
1958 err = fat_init_inodecache();
1959 if (err)
1960 goto failed;
1961
1962 return 0;
1963
1964failed:
1965 fat_cache_destroy();
1966 return err;
1967}
1968
1969static void __exit exit_fat_fs(void)
1970{
1971 fat_cache_destroy();
1972 fat_destroy_inodecache();
1973}
1974
1975module_init(init_fat_fs)
1976module_exit(exit_fat_fs)
1977
1978MODULE_DESCRIPTION("Core FAT filesystem support");
1979MODULE_LICENSE("GPL");
1980