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spi: efm32: Convert to use GPIO descriptors
[linux/fpc-iii.git] / fs / fat / inode.c
blob594b05ae16c9bf04584ae9c6c4dba50dbdecffcb
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/parser.h>
20 #include <linux/uio.h>
21 #include <linux/blkdev.h>
22 #include <linux/backing-dev.h>
23 #include <asm/unaligned.h>
24 #include <linux/random.h>
25 #include <linux/iversion.h>
26 #include "fat.h"
27
28 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET
29 /* if user don't select VFAT, this is undefined. */
30 #define CONFIG_FAT_DEFAULT_IOCHARSET ""
31 #endif
32
33 #define KB_IN_SECTORS 2
34
35 /* DOS dates from 1980/1/1 through 2107/12/31 */
36 #define FAT_DATE_MIN (0<<9 | 1<<5 | 1)
37 #define FAT_DATE_MAX (127<<9 | 12<<5 | 31)
38 #define FAT_TIME_MAX (23<<11 | 59<<5 | 29)
39
40 /*
41 * A deserialized copy of the on-disk structure laid out in struct
42 * fat_boot_sector.
43 */
44 struct fat_bios_param_block {
45 u16 fat_sector_size;
46 u8 fat_sec_per_clus;
47 u16 fat_reserved;
48 u8 fat_fats;
49 u16 fat_dir_entries;
50 u16 fat_sectors;
51 u16 fat_fat_length;
52 u32 fat_total_sect;
53
54 u8 fat16_state;
55 u32 fat16_vol_id;
56
57 u32 fat32_length;
58 u32 fat32_root_cluster;
59 u16 fat32_info_sector;
60 u8 fat32_state;
61 u32 fat32_vol_id;
62 };
63
64 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
65 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
66
67 static struct fat_floppy_defaults {
68 unsigned nr_sectors;
69 unsigned sec_per_clus;
70 unsigned dir_entries;
71 unsigned media;
72 unsigned fat_length;
73 } floppy_defaults[] = {
74 {
75 .nr_sectors = 160 * KB_IN_SECTORS,
76 .sec_per_clus = 1,
77 .dir_entries = 64,
78 .media = 0xFE,
79 .fat_length = 1,
80 },
81 {
82 .nr_sectors = 180 * KB_IN_SECTORS,
83 .sec_per_clus = 1,
84 .dir_entries = 64,
85 .media = 0xFC,
86 .fat_length = 2,
87 },
88 {
89 .nr_sectors = 320 * KB_IN_SECTORS,
90 .sec_per_clus = 2,
91 .dir_entries = 112,
92 .media = 0xFF,
93 .fat_length = 1,
94 },
95 {
96 .nr_sectors = 360 * KB_IN_SECTORS,
97 .sec_per_clus = 2,
98 .dir_entries = 112,
99 .media = 0xFD,
100 .fat_length = 2,
101 },
102 };
103
104 int fat_add_cluster(struct inode *inode)
105 {
106 int err, cluster;
107
108 err = fat_alloc_clusters(inode, &cluster, 1);
109 if (err)
110 return err;
111 /* FIXME: this cluster should be added after data of this
112 * cluster is writed */
113 err = fat_chain_add(inode, cluster, 1);
114 if (err)
115 fat_free_clusters(inode, cluster);
116 return err;
117 }
118
119 static inline int __fat_get_block(struct inode *inode, sector_t iblock,
120 unsigned long *max_blocks,
121 struct buffer_head *bh_result, int create)
122 {
123 struct super_block *sb = inode->i_sb;
124 struct msdos_sb_info *sbi = MSDOS_SB(sb);
125 unsigned long mapped_blocks;
126 sector_t phys, last_block;
127 int err, offset;
128
129 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false);
130 if (err)
131 return err;
132 if (phys) {
133 map_bh(bh_result, sb, phys);
134 *max_blocks = min(mapped_blocks, *max_blocks);
135 return 0;
136 }
137 if (!create)
138 return 0;
139
140 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
141 fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)",
142 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
143 return -EIO;
144 }
145
146 last_block = inode->i_blocks >> (sb->s_blocksize_bits - 9);
147 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
148 /*
149 * allocate a cluster according to the following.
150 * 1) no more available blocks
151 * 2) not part of fallocate region
152 */
153 if (!offset && !(iblock < last_block)) {
154 /* TODO: multiple cluster allocation would be desirable. */
155 err = fat_add_cluster(inode);
156 if (err)
157 return err;
158 }
159 /* available blocks on this cluster */
160 mapped_blocks = sbi->sec_per_clus - offset;
161
162 *max_blocks = min(mapped_blocks, *max_blocks);
163 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
164
165 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false);
166 if (err)
167 return err;
168 if (!phys) {
169 fat_fs_error(sb,
170 "invalid FAT chain (i_pos %lld, last_block %llu)",
171 MSDOS_I(inode)->i_pos,
172 (unsigned long long)last_block);
173 return -EIO;
174 }
175
176 BUG_ON(*max_blocks != mapped_blocks);
177 set_buffer_new(bh_result);
178 map_bh(bh_result, sb, phys);
179
180 return 0;
181 }
182
183 static int fat_get_block(struct inode *inode, sector_t iblock,
184 struct buffer_head *bh_result, int create)
185 {
186 struct super_block *sb = inode->i_sb;
187 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
188 int err;
189
190 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
191 if (err)
192 return err;
193 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
194 return 0;
195 }
196
197 static int fat_writepage(struct page *page, struct writeback_control *wbc)
198 {
199 return block_write_full_page(page, fat_get_block, wbc);
200 }
201
202 static int fat_writepages(struct address_space *mapping,
203 struct writeback_control *wbc)
204 {
205 return mpage_writepages(mapping, wbc, fat_get_block);
206 }
207
208 static int fat_readpage(struct file *file, struct page *page)
209 {
210 return mpage_readpage(page, fat_get_block);
211 }
212
213 static int fat_readpages(struct file *file, struct address_space *mapping,
214 struct list_head *pages, unsigned nr_pages)
215 {
216 return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
217 }
218
219 static void fat_write_failed(struct address_space *mapping, loff_t to)
220 {
221 struct inode *inode = mapping->host;
222
223 if (to > inode->i_size) {
224 truncate_pagecache(inode, inode->i_size);
225 fat_truncate_blocks(inode, inode->i_size);
226 }
227 }
228
229 static int fat_write_begin(struct file *file, struct address_space *mapping,
230 loff_t pos, unsigned len, unsigned flags,
231 struct page **pagep, void **fsdata)
232 {
233 int err;
234
235 *pagep = NULL;
236 err = cont_write_begin(file, mapping, pos, len, flags,
237 pagep, fsdata, fat_get_block,
238 &MSDOS_I(mapping->host)->mmu_private);
239 if (err < 0)
240 fat_write_failed(mapping, pos + len);
241 return err;
242 }
243
244 static int fat_write_end(struct file *file, struct address_space *mapping,
245 loff_t pos, unsigned len, unsigned copied,
246 struct page *pagep, void *fsdata)
247 {
248 struct inode *inode = mapping->host;
249 int err;
250 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
251 if (err < len)
252 fat_write_failed(mapping, pos + len);
253 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
254 fat_truncate_time(inode, NULL, S_CTIME|S_MTIME);
255 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
256 mark_inode_dirty(inode);
257 }
258 return err;
259 }
260
261 static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
262 {
263 struct file *file = iocb->ki_filp;
264 struct address_space *mapping = file->f_mapping;
265 struct inode *inode = mapping->host;
266 size_t count = iov_iter_count(iter);
267 loff_t offset = iocb->ki_pos;
268 ssize_t ret;
269
270 if (iov_iter_rw(iter) == WRITE) {
271 /*
272 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
273 * so we need to update the ->mmu_private to block boundary.
274 *
275 * But we must fill the remaining area or hole by nul for
276 * updating ->mmu_private.
277 *
278 * Return 0, and fallback to normal buffered write.
279 */
280 loff_t size = offset + count;
281 if (MSDOS_I(inode)->mmu_private < size)
282 return 0;
283 }
284
285 /*
286 * FAT need to use the DIO_LOCKING for avoiding the race
287 * condition of fat_get_block() and ->truncate().
288 */
289 ret = blockdev_direct_IO(iocb, inode, iter, fat_get_block);
290 if (ret < 0 && iov_iter_rw(iter) == WRITE)
291 fat_write_failed(mapping, offset + count);
292
293 return ret;
294 }
295
296 static int fat_get_block_bmap(struct inode *inode, sector_t iblock,
297 struct buffer_head *bh_result, int create)
298 {
299 struct super_block *sb = inode->i_sb;
300 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
301 int err;
302 sector_t bmap;
303 unsigned long mapped_blocks;
304
305 BUG_ON(create != 0);
306
307 err = fat_bmap(inode, iblock, &bmap, &mapped_blocks, create, true);
308 if (err)
309 return err;
310
311 if (bmap) {
312 map_bh(bh_result, sb, bmap);
313 max_blocks = min(mapped_blocks, max_blocks);
314 }
315
316 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
317
318 return 0;
319 }
320
321 static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
322 {
323 sector_t blocknr;
324
325 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
326 down_read(&MSDOS_I(mapping->host)->truncate_lock);
327 blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap);
328 up_read(&MSDOS_I(mapping->host)->truncate_lock);
329
330 return blocknr;
331 }
332
333 /*
334 * fat_block_truncate_page() zeroes out a mapping from file offset `from'
335 * up to the end of the block which corresponds to `from'.
336 * This is required during truncate to physically zeroout the tail end
337 * of that block so it doesn't yield old data if the file is later grown.
338 * Also, avoid causing failure from fsx for cases of "data past EOF"
339 */
340 int fat_block_truncate_page(struct inode *inode, loff_t from)
341 {
342 return block_truncate_page(inode->i_mapping, from, fat_get_block);
343 }
344
345 static const struct address_space_operations fat_aops = {
346 .readpage = fat_readpage,
347 .readpages = fat_readpages,
348 .writepage = fat_writepage,
349 .writepages = fat_writepages,
350 .write_begin = fat_write_begin,
351 .write_end = fat_write_end,
352 .direct_IO = fat_direct_IO,
353 .bmap = _fat_bmap
354 };
355
356 /*
357 * New FAT inode stuff. We do the following:
358 * a) i_ino is constant and has nothing with on-disk location.
359 * b) FAT manages its own cache of directory entries.
360 * c) *This* cache is indexed by on-disk location.
361 * d) inode has an associated directory entry, all right, but
362 * it may be unhashed.
363 * e) currently entries are stored within struct inode. That should
364 * change.
365 * f) we deal with races in the following way:
366 * 1. readdir() and lookup() do FAT-dir-cache lookup.
367 * 2. rename() unhashes the F-d-c entry and rehashes it in
368 * a new place.
369 * 3. unlink() and rmdir() unhash F-d-c entry.
370 * 4. fat_write_inode() checks whether the thing is unhashed.
371 * If it is we silently return. If it isn't we do bread(),
372 * check if the location is still valid and retry if it
373 * isn't. Otherwise we do changes.
374 * 5. Spinlock is used to protect hash/unhash/location check/lookup
375 * 6. fat_evict_inode() unhashes the F-d-c entry.
376 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
377 * and consider negative result as cache miss.
378 */
379
380 static void fat_hash_init(struct super_block *sb)
381 {
382 struct msdos_sb_info *sbi = MSDOS_SB(sb);
383 int i;
384
385 spin_lock_init(&sbi->inode_hash_lock);
386 for (i = 0; i < FAT_HASH_SIZE; i++)
387 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
388 }
389
390 static inline unsigned long fat_hash(loff_t i_pos)
391 {
392 return hash_32(i_pos, FAT_HASH_BITS);
393 }
394
395 static void dir_hash_init(struct super_block *sb)
396 {
397 struct msdos_sb_info *sbi = MSDOS_SB(sb);
398 int i;
399
400 spin_lock_init(&sbi->dir_hash_lock);
401 for (i = 0; i < FAT_HASH_SIZE; i++)
402 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]);
403 }
404
405 void fat_attach(struct inode *inode, loff_t i_pos)
406 {
407 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
408
409 if (inode->i_ino != MSDOS_ROOT_INO) {
410 struct hlist_head *head = sbi->inode_hashtable
411 + fat_hash(i_pos);
412
413 spin_lock(&sbi->inode_hash_lock);
414 MSDOS_I(inode)->i_pos = i_pos;
415 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
416 spin_unlock(&sbi->inode_hash_lock);
417 }
418
419 /* If NFS support is enabled, cache the mapping of start cluster
420 * to directory inode. This is used during reconnection of
421 * dentries to the filesystem root.
422 */
423 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
424 struct hlist_head *d_head = sbi->dir_hashtable;
425 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart);
426
427 spin_lock(&sbi->dir_hash_lock);
428 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head);
429 spin_unlock(&sbi->dir_hash_lock);
430 }
431 }
432 EXPORT_SYMBOL_GPL(fat_attach);
433
434 void fat_detach(struct inode *inode)
435 {
436 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
437 spin_lock(&sbi->inode_hash_lock);
438 MSDOS_I(inode)->i_pos = 0;
439 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
440 spin_unlock(&sbi->inode_hash_lock);
441
442 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
443 spin_lock(&sbi->dir_hash_lock);
444 hlist_del_init(&MSDOS_I(inode)->i_dir_hash);
445 spin_unlock(&sbi->dir_hash_lock);
446 }
447 }
448 EXPORT_SYMBOL_GPL(fat_detach);
449
450 struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
451 {
452 struct msdos_sb_info *sbi = MSDOS_SB(sb);
453 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
454 struct msdos_inode_info *i;
455 struct inode *inode = NULL;
456
457 spin_lock(&sbi->inode_hash_lock);
458 hlist_for_each_entry(i, head, i_fat_hash) {
459 BUG_ON(i->vfs_inode.i_sb != sb);
460 if (i->i_pos != i_pos)
461 continue;
462 inode = igrab(&i->vfs_inode);
463 if (inode)
464 break;
465 }
466 spin_unlock(&sbi->inode_hash_lock);
467 return inode;
468 }
469
470 static int is_exec(unsigned char *extension)
471 {
472 unsigned char exe_extensions[] = "EXECOMBAT", *walk;
473
474 for (walk = exe_extensions; *walk; walk += 3)
475 if (!strncmp(extension, walk, 3))
476 return 1;
477 return 0;
478 }
479
480 static int fat_calc_dir_size(struct inode *inode)
481 {
482 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
483 int ret, fclus, dclus;
484
485 inode->i_size = 0;
486 if (MSDOS_I(inode)->i_start == 0)
487 return 0;
488
489 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
490 if (ret < 0)
491 return ret;
492 inode->i_size = (fclus + 1) << sbi->cluster_bits;
493
494 return 0;
495 }
496
497 static int fat_validate_dir(struct inode *dir)
498 {
499 struct super_block *sb = dir->i_sb;
500
501 if (dir->i_nlink < 2) {
502 /* Directory should have "."/".." entries at least. */
503 fat_fs_error(sb, "corrupted directory (invalid entries)");
504 return -EIO;
505 }
506 if (MSDOS_I(dir)->i_start == 0 ||
507 MSDOS_I(dir)->i_start == MSDOS_SB(sb)->root_cluster) {
508 /* Directory should point valid cluster. */
509 fat_fs_error(sb, "corrupted directory (invalid i_start)");
510 return -EIO;
511 }
512 return 0;
513 }
514
515 /* doesn't deal with root inode */
516 int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
517 {
518 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
519 int error;
520
521 MSDOS_I(inode)->i_pos = 0;
522 inode->i_uid = sbi->options.fs_uid;
523 inode->i_gid = sbi->options.fs_gid;
524 inode_inc_iversion(inode);
525 inode->i_generation = prandom_u32();
526
527 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
528 inode->i_generation &= ~1;
529 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
530 inode->i_op = sbi->dir_ops;
531 inode->i_fop = &fat_dir_operations;
532
533 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
534 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
535 error = fat_calc_dir_size(inode);
536 if (error < 0)
537 return error;
538 MSDOS_I(inode)->mmu_private = inode->i_size;
539
540 set_nlink(inode, fat_subdirs(inode));
541
542 error = fat_validate_dir(inode);
543 if (error < 0)
544 return error;
545 } else { /* not a directory */
546 inode->i_generation |= 1;
547 inode->i_mode = fat_make_mode(sbi, de->attr,
548 ((sbi->options.showexec && !is_exec(de->name + 8))
549 ? S_IRUGO|S_IWUGO : S_IRWXUGO));
550 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
551
552 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
553 inode->i_size = le32_to_cpu(de->size);
554 inode->i_op = &fat_file_inode_operations;
555 inode->i_fop = &fat_file_operations;
556 inode->i_mapping->a_ops = &fat_aops;
557 MSDOS_I(inode)->mmu_private = inode->i_size;
558 }
559 if (de->attr & ATTR_SYS) {
560 if (sbi->options.sys_immutable)
561 inode->i_flags |= S_IMMUTABLE;
562 }
563 fat_save_attrs(inode, de->attr);
564
565 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
566 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
567
568 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
569 if (sbi->options.isvfat) {
570 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
571 de->cdate, de->ctime_cs);
572 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
573 } else
574 fat_truncate_time(inode, &inode->i_mtime, S_ATIME|S_CTIME);
575
576 return 0;
577 }
578
579 static inline void fat_lock_build_inode(struct msdos_sb_info *sbi)
580 {
581 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
582 mutex_lock(&sbi->nfs_build_inode_lock);
583 }
584
585 static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi)
586 {
587 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
588 mutex_unlock(&sbi->nfs_build_inode_lock);
589 }
590
591 struct inode *fat_build_inode(struct super_block *sb,
592 struct msdos_dir_entry *de, loff_t i_pos)
593 {
594 struct inode *inode;
595 int err;
596
597 fat_lock_build_inode(MSDOS_SB(sb));
598 inode = fat_iget(sb, i_pos);
599 if (inode)
600 goto out;
601 inode = new_inode(sb);
602 if (!inode) {
603 inode = ERR_PTR(-ENOMEM);
604 goto out;
605 }
606 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
607 inode_set_iversion(inode, 1);
608 err = fat_fill_inode(inode, de);
609 if (err) {
610 iput(inode);
611 inode = ERR_PTR(err);
612 goto out;
613 }
614 fat_attach(inode, i_pos);
615 insert_inode_hash(inode);
616 out:
617 fat_unlock_build_inode(MSDOS_SB(sb));
618 return inode;
619 }
620
621 EXPORT_SYMBOL_GPL(fat_build_inode);
622
623 static int __fat_write_inode(struct inode *inode, int wait);
624
625 static void fat_free_eofblocks(struct inode *inode)
626 {
627 /* Release unwritten fallocated blocks on inode eviction. */
628 if ((inode->i_blocks << 9) >
629 round_up(MSDOS_I(inode)->mmu_private,
630 MSDOS_SB(inode->i_sb)->cluster_size)) {
631 int err;
632
633 fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private);
634 /* Fallocate results in updating the i_start/iogstart
635 * for the zero byte file. So, make it return to
636 * original state during evict and commit it to avoid
637 * any corruption on the next access to the cluster
638 * chain for the file.
639 */
640 err = __fat_write_inode(inode, inode_needs_sync(inode));
641 if (err) {
642 fat_msg(inode->i_sb, KERN_WARNING, "Failed to "
643 "update on disk inode for unused "
644 "fallocated blocks, inode could be "
645 "corrupted. Please run fsck");
646 }
647
648 }
649 }
650
651 static void fat_evict_inode(struct inode *inode)
652 {
653 truncate_inode_pages_final(&inode->i_data);
654 if (!inode->i_nlink) {
655 inode->i_size = 0;
656 fat_truncate_blocks(inode, 0);
657 } else
658 fat_free_eofblocks(inode);
659
660 invalidate_inode_buffers(inode);
661 clear_inode(inode);
662 fat_cache_inval_inode(inode);
663 fat_detach(inode);
664 }
665
666 static void fat_set_state(struct super_block *sb,
667 unsigned int set, unsigned int force)
668 {
669 struct buffer_head *bh;
670 struct fat_boot_sector *b;
671 struct msdos_sb_info *sbi = MSDOS_SB(sb);
672
673 /* do not change any thing if mounted read only */
674 if (sb_rdonly(sb) && !force)
675 return;
676
677 /* do not change state if fs was dirty */
678 if (sbi->dirty) {
679 /* warn only on set (mount). */
680 if (set)
681 fat_msg(sb, KERN_WARNING, "Volume was not properly "
682 "unmounted. Some data may be corrupt. "
683 "Please run fsck.");
684 return;
685 }
686
687 bh = sb_bread(sb, 0);
688 if (bh == NULL) {
689 fat_msg(sb, KERN_ERR, "unable to read boot sector "
690 "to mark fs as dirty");
691 return;
692 }
693
694 b = (struct fat_boot_sector *) bh->b_data;
695
696 if (is_fat32(sbi)) {
697 if (set)
698 b->fat32.state |= FAT_STATE_DIRTY;
699 else
700 b->fat32.state &= ~FAT_STATE_DIRTY;
701 } else /* fat 16 and 12 */ {
702 if (set)
703 b->fat16.state |= FAT_STATE_DIRTY;
704 else
705 b->fat16.state &= ~FAT_STATE_DIRTY;
706 }
707
708 mark_buffer_dirty(bh);
709 sync_dirty_buffer(bh);
710 brelse(bh);
711 }
712
713 static void fat_reset_iocharset(struct fat_mount_options *opts)
714 {
715 if (opts->iocharset != fat_default_iocharset) {
716 /* Note: opts->iocharset can be NULL here */
717 kfree(opts->iocharset);
718 opts->iocharset = fat_default_iocharset;
719 }
720 }
721
722 static void delayed_free(struct rcu_head *p)
723 {
724 struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu);
725 unload_nls(sbi->nls_disk);
726 unload_nls(sbi->nls_io);
727 fat_reset_iocharset(&sbi->options);
728 kfree(sbi);
729 }
730
731 static void fat_put_super(struct super_block *sb)
732 {
733 struct msdos_sb_info *sbi = MSDOS_SB(sb);
734
735 fat_set_state(sb, 0, 0);
736
737 iput(sbi->fsinfo_inode);
738 iput(sbi->fat_inode);
739
740 call_rcu(&sbi->rcu, delayed_free);
741 }
742
743 static struct kmem_cache *fat_inode_cachep;
744
745 static struct inode *fat_alloc_inode(struct super_block *sb)
746 {
747 struct msdos_inode_info *ei;
748 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
749 if (!ei)
750 return NULL;
751
752 init_rwsem(&ei->truncate_lock);
753 return &ei->vfs_inode;
754 }
755
756 static void fat_free_inode(struct inode *inode)
757 {
758 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
759 }
760
761 static void init_once(void *foo)
762 {
763 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
764
765 spin_lock_init(&ei->cache_lru_lock);
766 ei->nr_caches = 0;
767 ei->cache_valid_id = FAT_CACHE_VALID + 1;
768 INIT_LIST_HEAD(&ei->cache_lru);
769 INIT_HLIST_NODE(&ei->i_fat_hash);
770 INIT_HLIST_NODE(&ei->i_dir_hash);
771 inode_init_once(&ei->vfs_inode);
772 }
773
774 static int __init fat_init_inodecache(void)
775 {
776 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
777 sizeof(struct msdos_inode_info),
778 0, (SLAB_RECLAIM_ACCOUNT|
779 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
780 init_once);
781 if (fat_inode_cachep == NULL)
782 return -ENOMEM;
783 return 0;
784 }
785
786 static void __exit fat_destroy_inodecache(void)
787 {
788 /*
789 * Make sure all delayed rcu free inodes are flushed before we
790 * destroy cache.
791 */
792 rcu_barrier();
793 kmem_cache_destroy(fat_inode_cachep);
794 }
795
796 static int fat_remount(struct super_block *sb, int *flags, char *data)
797 {
798 bool new_rdonly;
799 struct msdos_sb_info *sbi = MSDOS_SB(sb);
800 *flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME);
801
802 sync_filesystem(sb);
803
804 /* make sure we update state on remount. */
805 new_rdonly = *flags & SB_RDONLY;
806 if (new_rdonly != sb_rdonly(sb)) {
807 if (new_rdonly)
808 fat_set_state(sb, 0, 0);
809 else
810 fat_set_state(sb, 1, 1);
811 }
812 return 0;
813 }
814
815 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
816 {
817 struct super_block *sb = dentry->d_sb;
818 struct msdos_sb_info *sbi = MSDOS_SB(sb);
819 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
820
821 /* If the count of free cluster is still unknown, counts it here. */
822 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
823 int err = fat_count_free_clusters(dentry->d_sb);
824 if (err)
825 return err;
826 }
827
828 buf->f_type = dentry->d_sb->s_magic;
829 buf->f_bsize = sbi->cluster_size;
830 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
831 buf->f_bfree = sbi->free_clusters;
832 buf->f_bavail = sbi->free_clusters;
833 buf->f_fsid.val[0] = (u32)id;
834 buf->f_fsid.val[1] = (u32)(id >> 32);
835 buf->f_namelen =
836 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE;
837
838 return 0;
839 }
840
841 static int __fat_write_inode(struct inode *inode, int wait)
842 {
843 struct super_block *sb = inode->i_sb;
844 struct msdos_sb_info *sbi = MSDOS_SB(sb);
845 struct buffer_head *bh;
846 struct msdos_dir_entry *raw_entry;
847 loff_t i_pos;
848 sector_t blocknr;
849 int err, offset;
850
851 if (inode->i_ino == MSDOS_ROOT_INO)
852 return 0;
853
854 retry:
855 i_pos = fat_i_pos_read(sbi, inode);
856 if (!i_pos)
857 return 0;
858
859 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset);
860 bh = sb_bread(sb, blocknr);
861 if (!bh) {
862 fat_msg(sb, KERN_ERR, "unable to read inode block "
863 "for updating (i_pos %lld)", i_pos);
864 return -EIO;
865 }
866 spin_lock(&sbi->inode_hash_lock);
867 if (i_pos != MSDOS_I(inode)->i_pos) {
868 spin_unlock(&sbi->inode_hash_lock);
869 brelse(bh);
870 goto retry;
871 }
872
873 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset];
874 if (S_ISDIR(inode->i_mode))
875 raw_entry->size = 0;
876 else
877 raw_entry->size = cpu_to_le32(inode->i_size);
878 raw_entry->attr = fat_make_attrs(inode);
879 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart);
880 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
881 &raw_entry->date, NULL);
882 if (sbi->options.isvfat) {
883 __le16 atime;
884 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
885 &raw_entry->cdate, &raw_entry->ctime_cs);
886 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
887 &raw_entry->adate, NULL);
888 }
889 spin_unlock(&sbi->inode_hash_lock);
890 mark_buffer_dirty(bh);
891 err = 0;
892 if (wait)
893 err = sync_dirty_buffer(bh);
894 brelse(bh);
895 return err;
896 }
897
898 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
899 {
900 int err;
901
902 if (inode->i_ino == MSDOS_FSINFO_INO) {
903 struct super_block *sb = inode->i_sb;
904
905 mutex_lock(&MSDOS_SB(sb)->s_lock);
906 err = fat_clusters_flush(sb);
907 mutex_unlock(&MSDOS_SB(sb)->s_lock);
908 } else
909 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
910
911 return err;
912 }
913
914 int fat_sync_inode(struct inode *inode)
915 {
916 return __fat_write_inode(inode, 1);
917 }
918
919 EXPORT_SYMBOL_GPL(fat_sync_inode);
920
921 static int fat_show_options(struct seq_file *m, struct dentry *root);
922 static const struct super_operations fat_sops = {
923 .alloc_inode = fat_alloc_inode,
924 .free_inode = fat_free_inode,
925 .write_inode = fat_write_inode,
926 .evict_inode = fat_evict_inode,
927 .put_super = fat_put_super,
928 .statfs = fat_statfs,
929 .remount_fs = fat_remount,
930
931 .show_options = fat_show_options,
932 };
933
934 static int fat_show_options(struct seq_file *m, struct dentry *root)
935 {
936 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb);
937 struct fat_mount_options *opts = &sbi->options;
938 int isvfat = opts->isvfat;
939
940 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
941 seq_printf(m, ",uid=%u",
942 from_kuid_munged(&init_user_ns, opts->fs_uid));
943 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
944 seq_printf(m, ",gid=%u",
945 from_kgid_munged(&init_user_ns, opts->fs_gid));
946 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
947 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
948 if (opts->allow_utime)
949 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
950 if (sbi->nls_disk)
951 /* strip "cp" prefix from displayed option */
952 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]);
953 if (isvfat) {
954 if (sbi->nls_io)
955 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
956
957 switch (opts->shortname) {
958 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
959 seq_puts(m, ",shortname=win95");
960 break;
961 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
962 seq_puts(m, ",shortname=winnt");
963 break;
964 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
965 seq_puts(m, ",shortname=mixed");
966 break;
967 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
968 seq_puts(m, ",shortname=lower");
969 break;
970 default:
971 seq_puts(m, ",shortname=unknown");
972 break;
973 }
974 }
975 if (opts->name_check != 'n')
976 seq_printf(m, ",check=%c", opts->name_check);
977 if (opts->usefree)
978 seq_puts(m, ",usefree");
979 if (opts->quiet)
980 seq_puts(m, ",quiet");
981 if (opts->showexec)
982 seq_puts(m, ",showexec");
983 if (opts->sys_immutable)
984 seq_puts(m, ",sys_immutable");
985 if (!isvfat) {
986 if (opts->dotsOK)
987 seq_puts(m, ",dotsOK=yes");
988 if (opts->nocase)
989 seq_puts(m, ",nocase");
990 } else {
991 if (opts->utf8)
992 seq_puts(m, ",utf8");
993 if (opts->unicode_xlate)
994 seq_puts(m, ",uni_xlate");
995 if (!opts->numtail)
996 seq_puts(m, ",nonumtail");
997 if (opts->rodir)
998 seq_puts(m, ",rodir");
999 }
1000 if (opts->flush)
1001 seq_puts(m, ",flush");
1002 if (opts->tz_set) {
1003 if (opts->time_offset)
1004 seq_printf(m, ",time_offset=%d", opts->time_offset);
1005 else
1006 seq_puts(m, ",tz=UTC");
1007 }
1008 if (opts->errors == FAT_ERRORS_CONT)
1009 seq_puts(m, ",errors=continue");
1010 else if (opts->errors == FAT_ERRORS_PANIC)
1011 seq_puts(m, ",errors=panic");
1012 else
1013 seq_puts(m, ",errors=remount-ro");
1014 if (opts->nfs == FAT_NFS_NOSTALE_RO)
1015 seq_puts(m, ",nfs=nostale_ro");
1016 else if (opts->nfs)
1017 seq_puts(m, ",nfs=stale_rw");
1018 if (opts->discard)
1019 seq_puts(m, ",discard");
1020 if (opts->dos1xfloppy)
1021 seq_puts(m, ",dos1xfloppy");
1022
1023 return 0;
1024 }
1025
1026 enum {
1027 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
1028 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
1029 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
1030 Opt_immutable, Opt_dots, Opt_nodots,
1031 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
1032 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
1033 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
1034 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
1035 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset,
1036 Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy,
1037 };
1038
1039 static const match_table_t fat_tokens = {
1040 {Opt_check_r, "check=relaxed"},
1041 {Opt_check_s, "check=strict"},
1042 {Opt_check_n, "check=normal"},
1043 {Opt_check_r, "check=r"},
1044 {Opt_check_s, "check=s"},
1045 {Opt_check_n, "check=n"},
1046 {Opt_uid, "uid=%u"},
1047 {Opt_gid, "gid=%u"},
1048 {Opt_umask, "umask=%o"},
1049 {Opt_dmask, "dmask=%o"},
1050 {Opt_fmask, "fmask=%o"},
1051 {Opt_allow_utime, "allow_utime=%o"},
1052 {Opt_codepage, "codepage=%u"},
1053 {Opt_usefree, "usefree"},
1054 {Opt_nocase, "nocase"},
1055 {Opt_quiet, "quiet"},
1056 {Opt_showexec, "showexec"},
1057 {Opt_debug, "debug"},
1058 {Opt_immutable, "sys_immutable"},
1059 {Opt_flush, "flush"},
1060 {Opt_tz_utc, "tz=UTC"},
1061 {Opt_time_offset, "time_offset=%d"},
1062 {Opt_err_cont, "errors=continue"},
1063 {Opt_err_panic, "errors=panic"},
1064 {Opt_err_ro, "errors=remount-ro"},
1065 {Opt_discard, "discard"},
1066 {Opt_nfs_stale_rw, "nfs"},
1067 {Opt_nfs_stale_rw, "nfs=stale_rw"},
1068 {Opt_nfs_nostale_ro, "nfs=nostale_ro"},
1069 {Opt_dos1xfloppy, "dos1xfloppy"},
1070 {Opt_obsolete, "conv=binary"},
1071 {Opt_obsolete, "conv=text"},
1072 {Opt_obsolete, "conv=auto"},
1073 {Opt_obsolete, "conv=b"},
1074 {Opt_obsolete, "conv=t"},
1075 {Opt_obsolete, "conv=a"},
1076 {Opt_obsolete, "fat=%u"},
1077 {Opt_obsolete, "blocksize=%u"},
1078 {Opt_obsolete, "cvf_format=%20s"},
1079 {Opt_obsolete, "cvf_options=%100s"},
1080 {Opt_obsolete, "posix"},
1081 {Opt_err, NULL},
1082 };
1083 static const match_table_t msdos_tokens = {
1084 {Opt_nodots, "nodots"},
1085 {Opt_nodots, "dotsOK=no"},
1086 {Opt_dots, "dots"},
1087 {Opt_dots, "dotsOK=yes"},
1088 {Opt_err, NULL}
1089 };
1090 static const match_table_t vfat_tokens = {
1091 {Opt_charset, "iocharset=%s"},
1092 {Opt_shortname_lower, "shortname=lower"},
1093 {Opt_shortname_win95, "shortname=win95"},
1094 {Opt_shortname_winnt, "shortname=winnt"},
1095 {Opt_shortname_mixed, "shortname=mixed"},
1096 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
1097 {Opt_utf8_no, "utf8=no"},
1098 {Opt_utf8_no, "utf8=false"},
1099 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
1100 {Opt_utf8_yes, "utf8=yes"},
1101 {Opt_utf8_yes, "utf8=true"},
1102 {Opt_utf8_yes, "utf8"},
1103 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
1104 {Opt_uni_xl_no, "uni_xlate=no"},
1105 {Opt_uni_xl_no, "uni_xlate=false"},
1106 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
1107 {Opt_uni_xl_yes, "uni_xlate=yes"},
1108 {Opt_uni_xl_yes, "uni_xlate=true"},
1109 {Opt_uni_xl_yes, "uni_xlate"},
1110 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
1111 {Opt_nonumtail_no, "nonumtail=no"},
1112 {Opt_nonumtail_no, "nonumtail=false"},
1113 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
1114 {Opt_nonumtail_yes, "nonumtail=yes"},
1115 {Opt_nonumtail_yes, "nonumtail=true"},
1116 {Opt_nonumtail_yes, "nonumtail"},
1117 {Opt_rodir, "rodir"},
1118 {Opt_err, NULL}
1119 };
1120
1121 static int parse_options(struct super_block *sb, char *options, int is_vfat,
1122 int silent, int *debug, struct fat_mount_options *opts)
1123 {
1124 char *p;
1125 substring_t args[MAX_OPT_ARGS];
1126 int option;
1127 char *iocharset;
1128
1129 opts->isvfat = is_vfat;
1130
1131 opts->fs_uid = current_uid();
1132 opts->fs_gid = current_gid();
1133 opts->fs_fmask = opts->fs_dmask = current_umask();
1134 opts->allow_utime = -1;
1135 opts->codepage = fat_default_codepage;
1136 fat_reset_iocharset(opts);
1137 if (is_vfat) {
1138 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
1139 opts->rodir = 0;
1140 } else {
1141 opts->shortname = 0;
1142 opts->rodir = 1;
1143 }
1144 opts->name_check = 'n';
1145 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
1146 opts->unicode_xlate = 0;
1147 opts->numtail = 1;
1148 opts->usefree = opts->nocase = 0;
1149 opts->tz_set = 0;
1150 opts->nfs = 0;
1151 opts->errors = FAT_ERRORS_RO;
1152 *debug = 0;
1153
1154 opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat;
1155
1156 if (!options)
1157 goto out;
1158
1159 while ((p = strsep(&options, ",")) != NULL) {
1160 int token;
1161 if (!*p)
1162 continue;
1163
1164 token = match_token(p, fat_tokens, args);
1165 if (token == Opt_err) {
1166 if (is_vfat)
1167 token = match_token(p, vfat_tokens, args);
1168 else
1169 token = match_token(p, msdos_tokens, args);
1170 }
1171 switch (token) {
1172 case Opt_check_s:
1173 opts->name_check = 's';
1174 break;
1175 case Opt_check_r:
1176 opts->name_check = 'r';
1177 break;
1178 case Opt_check_n:
1179 opts->name_check = 'n';
1180 break;
1181 case Opt_usefree:
1182 opts->usefree = 1;
1183 break;
1184 case Opt_nocase:
1185 if (!is_vfat)
1186 opts->nocase = 1;
1187 else {
1188 /* for backward compatibility */
1189 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1190 | VFAT_SFN_CREATE_WIN95;
1191 }
1192 break;
1193 case Opt_quiet:
1194 opts->quiet = 1;
1195 break;
1196 case Opt_showexec:
1197 opts->showexec = 1;
1198 break;
1199 case Opt_debug:
1200 *debug = 1;
1201 break;
1202 case Opt_immutable:
1203 opts->sys_immutable = 1;
1204 break;
1205 case Opt_uid:
1206 if (match_int(&args[0], &option))
1207 return -EINVAL;
1208 opts->fs_uid = make_kuid(current_user_ns(), option);
1209 if (!uid_valid(opts->fs_uid))
1210 return -EINVAL;
1211 break;
1212 case Opt_gid:
1213 if (match_int(&args[0], &option))
1214 return -EINVAL;
1215 opts->fs_gid = make_kgid(current_user_ns(), option);
1216 if (!gid_valid(opts->fs_gid))
1217 return -EINVAL;
1218 break;
1219 case Opt_umask:
1220 if (match_octal(&args[0], &option))
1221 return -EINVAL;
1222 opts->fs_fmask = opts->fs_dmask = option;
1223 break;
1224 case Opt_dmask:
1225 if (match_octal(&args[0], &option))
1226 return -EINVAL;
1227 opts->fs_dmask = option;
1228 break;
1229 case Opt_fmask:
1230 if (match_octal(&args[0], &option))
1231 return -EINVAL;
1232 opts->fs_fmask = option;
1233 break;
1234 case Opt_allow_utime:
1235 if (match_octal(&args[0], &option))
1236 return -EINVAL;
1237 opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1238 break;
1239 case Opt_codepage:
1240 if (match_int(&args[0], &option))
1241 return -EINVAL;
1242 opts->codepage = option;
1243 break;
1244 case Opt_flush:
1245 opts->flush = 1;
1246 break;
1247 case Opt_time_offset:
1248 if (match_int(&args[0], &option))
1249 return -EINVAL;
1250 /*
1251 * GMT+-12 zones may have DST corrections so at least
1252 * 13 hours difference is needed. Make the limit 24
1253 * just in case someone invents something unusual.
1254 */
1255 if (option < -24 * 60 || option > 24 * 60)
1256 return -EINVAL;
1257 opts->tz_set = 1;
1258 opts->time_offset = option;
1259 break;
1260 case Opt_tz_utc:
1261 opts->tz_set = 1;
1262 opts->time_offset = 0;
1263 break;
1264 case Opt_err_cont:
1265 opts->errors = FAT_ERRORS_CONT;
1266 break;
1267 case Opt_err_panic:
1268 opts->errors = FAT_ERRORS_PANIC;
1269 break;
1270 case Opt_err_ro:
1271 opts->errors = FAT_ERRORS_RO;
1272 break;
1273 case Opt_nfs_stale_rw:
1274 opts->nfs = FAT_NFS_STALE_RW;
1275 break;
1276 case Opt_nfs_nostale_ro:
1277 opts->nfs = FAT_NFS_NOSTALE_RO;
1278 break;
1279 case Opt_dos1xfloppy:
1280 opts->dos1xfloppy = 1;
1281 break;
1282
1283 /* msdos specific */
1284 case Opt_dots:
1285 opts->dotsOK = 1;
1286 break;
1287 case Opt_nodots:
1288 opts->dotsOK = 0;
1289 break;
1290
1291 /* vfat specific */
1292 case Opt_charset:
1293 fat_reset_iocharset(opts);
1294 iocharset = match_strdup(&args[0]);
1295 if (!iocharset)
1296 return -ENOMEM;
1297 opts->iocharset = iocharset;
1298 break;
1299 case Opt_shortname_lower:
1300 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1301 | VFAT_SFN_CREATE_WIN95;
1302 break;
1303 case Opt_shortname_win95:
1304 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1305 | VFAT_SFN_CREATE_WIN95;
1306 break;
1307 case Opt_shortname_winnt:
1308 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1309 | VFAT_SFN_CREATE_WINNT;
1310 break;
1311 case Opt_shortname_mixed:
1312 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1313 | VFAT_SFN_CREATE_WIN95;
1314 break;
1315 case Opt_utf8_no: /* 0 or no or false */
1316 opts->utf8 = 0;
1317 break;
1318 case Opt_utf8_yes: /* empty or 1 or yes or true */
1319 opts->utf8 = 1;
1320 break;
1321 case Opt_uni_xl_no: /* 0 or no or false */
1322 opts->unicode_xlate = 0;
1323 break;
1324 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1325 opts->unicode_xlate = 1;
1326 break;
1327 case Opt_nonumtail_no: /* 0 or no or false */
1328 opts->numtail = 1; /* negated option */
1329 break;
1330 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1331 opts->numtail = 0; /* negated option */
1332 break;
1333 case Opt_rodir:
1334 opts->rodir = 1;
1335 break;
1336 case Opt_discard:
1337 opts->discard = 1;
1338 break;
1339
1340 /* obsolete mount options */
1341 case Opt_obsolete:
1342 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, "
1343 "not supported now", p);
1344 break;
1345 /* unknown option */
1346 default:
1347 if (!silent) {
1348 fat_msg(sb, KERN_ERR,
1349 "Unrecognized mount option \"%s\" "
1350 "or missing value", p);
1351 }
1352 return -EINVAL;
1353 }
1354 }
1355
1356 out:
1357 /* UTF-8 doesn't provide FAT semantics */
1358 if (!strcmp(opts->iocharset, "utf8")) {
1359 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset"
1360 " for FAT filesystems, filesystem will be "
1361 "case sensitive!");
1362 }
1363
1364 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1365 if (opts->allow_utime == (unsigned short)-1)
1366 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
1367 if (opts->unicode_xlate)
1368 opts->utf8 = 0;
1369 if (opts->nfs == FAT_NFS_NOSTALE_RO) {
1370 sb->s_flags |= SB_RDONLY;
1371 sb->s_export_op = &fat_export_ops_nostale;
1372 }
1373
1374 return 0;
1375 }
1376
1377 static void fat_dummy_inode_init(struct inode *inode)
1378 {
1379 /* Initialize this dummy inode to work as no-op. */
1380 MSDOS_I(inode)->mmu_private = 0;
1381 MSDOS_I(inode)->i_start = 0;
1382 MSDOS_I(inode)->i_logstart = 0;
1383 MSDOS_I(inode)->i_attrs = 0;
1384 MSDOS_I(inode)->i_pos = 0;
1385 }
1386
1387 static int fat_read_root(struct inode *inode)
1388 {
1389 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
1390 int error;
1391
1392 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO;
1393 inode->i_uid = sbi->options.fs_uid;
1394 inode->i_gid = sbi->options.fs_gid;
1395 inode_inc_iversion(inode);
1396 inode->i_generation = 0;
1397 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
1398 inode->i_op = sbi->dir_ops;
1399 inode->i_fop = &fat_dir_operations;
1400 if (is_fat32(sbi)) {
1401 MSDOS_I(inode)->i_start = sbi->root_cluster;
1402 error = fat_calc_dir_size(inode);
1403 if (error < 0)
1404 return error;
1405 } else {
1406 MSDOS_I(inode)->i_start = 0;
1407 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1408 }
1409 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1410 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1411 MSDOS_I(inode)->i_logstart = 0;
1412 MSDOS_I(inode)->mmu_private = inode->i_size;
1413
1414 fat_save_attrs(inode, ATTR_DIR);
1415 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1416 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1417 set_nlink(inode, fat_subdirs(inode)+2);
1418
1419 return 0;
1420 }
1421
1422 static unsigned long calc_fat_clusters(struct super_block *sb)
1423 {
1424 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1425
1426 /* Divide first to avoid overflow */
1427 if (!is_fat12(sbi)) {
1428 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits;
1429 return ent_per_sec * sbi->fat_length;
1430 }
1431
1432 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1433 }
1434
1435 static bool fat_bpb_is_zero(struct fat_boot_sector *b)
1436 {
1437 if (get_unaligned_le16(&b->sector_size))
1438 return false;
1439 if (b->sec_per_clus)
1440 return false;
1441 if (b->reserved)
1442 return false;
1443 if (b->fats)
1444 return false;
1445 if (get_unaligned_le16(&b->dir_entries))
1446 return false;
1447 if (get_unaligned_le16(&b->sectors))
1448 return false;
1449 if (b->media)
1450 return false;
1451 if (b->fat_length)
1452 return false;
1453 if (b->secs_track)
1454 return false;
1455 if (b->heads)
1456 return false;
1457 return true;
1458 }
1459
1460 static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b,
1461 int silent, struct fat_bios_param_block *bpb)
1462 {
1463 int error = -EINVAL;
1464
1465 /* Read in BPB ... */
1466 memset(bpb, 0, sizeof(*bpb));
1467 bpb->fat_sector_size = get_unaligned_le16(&b->sector_size);
1468 bpb->fat_sec_per_clus = b->sec_per_clus;
1469 bpb->fat_reserved = le16_to_cpu(b->reserved);
1470 bpb->fat_fats = b->fats;
1471 bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries);
1472 bpb->fat_sectors = get_unaligned_le16(&b->sectors);
1473 bpb->fat_fat_length = le16_to_cpu(b->fat_length);
1474 bpb->fat_total_sect = le32_to_cpu(b->total_sect);
1475
1476 bpb->fat16_state = b->fat16.state;
1477 bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id);
1478
1479 bpb->fat32_length = le32_to_cpu(b->fat32.length);
1480 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster);
1481 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector);
1482 bpb->fat32_state = b->fat32.state;
1483 bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id);
1484
1485 /* Validate this looks like a FAT filesystem BPB */
1486 if (!bpb->fat_reserved) {
1487 if (!silent)
1488 fat_msg(sb, KERN_ERR,
1489 "bogus number of reserved sectors");
1490 goto out;
1491 }
1492 if (!bpb->fat_fats) {
1493 if (!silent)
1494 fat_msg(sb, KERN_ERR, "bogus number of FAT structure");
1495 goto out;
1496 }
1497
1498 /*
1499 * Earlier we checked here that b->secs_track and b->head are nonzero,
1500 * but it turns out valid FAT filesystems can have zero there.
1501 */
1502
1503 if (!fat_valid_media(b->media)) {
1504 if (!silent)
1505 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)",
1506 (unsigned)b->media);
1507 goto out;
1508 }
1509
1510 if (!is_power_of_2(bpb->fat_sector_size)
1511 || (bpb->fat_sector_size < 512)
1512 || (bpb->fat_sector_size > 4096)) {
1513 if (!silent)
1514 fat_msg(sb, KERN_ERR, "bogus logical sector size %u",
1515 (unsigned)bpb->fat_sector_size);
1516 goto out;
1517 }
1518
1519 if (!is_power_of_2(bpb->fat_sec_per_clus)) {
1520 if (!silent)
1521 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u",
1522 (unsigned)bpb->fat_sec_per_clus);
1523 goto out;
1524 }
1525
1526 error = 0;
1527
1528 out:
1529 return error;
1530 }
1531
1532 static int fat_read_static_bpb(struct super_block *sb,
1533 struct fat_boot_sector *b, int silent,
1534 struct fat_bios_param_block *bpb)
1535 {
1536 static const char *notdos1x = "This doesn't look like a DOS 1.x volume";
1537
1538 struct fat_floppy_defaults *fdefaults = NULL;
1539 int error = -EINVAL;
1540 sector_t bd_sects;
1541 unsigned i;
1542
1543 bd_sects = i_size_read(sb->s_bdev->bd_inode) / SECTOR_SIZE;
1544
1545 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */
1546 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) {
1547 if (!silent)
1548 fat_msg(sb, KERN_ERR,
1549 "%s; no bootstrapping code", notdos1x);
1550 goto out;
1551 }
1552
1553 /*
1554 * If any value in this region is non-zero, it isn't archaic
1555 * DOS.
1556 */
1557 if (!fat_bpb_is_zero(b)) {
1558 if (!silent)
1559 fat_msg(sb, KERN_ERR,
1560 "%s; DOS 2.x BPB is non-zero", notdos1x);
1561 goto out;
1562 }
1563
1564 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) {
1565 if (floppy_defaults[i].nr_sectors == bd_sects) {
1566 fdefaults = &floppy_defaults[i];
1567 break;
1568 }
1569 }
1570
1571 if (fdefaults == NULL) {
1572 if (!silent)
1573 fat_msg(sb, KERN_WARNING,
1574 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)",
1575 (u64)bd_sects);
1576 goto out;
1577 }
1578
1579 if (!silent)
1580 fat_msg(sb, KERN_INFO,
1581 "This looks like a DOS 1.x volume; assuming default BPB values");
1582
1583 memset(bpb, 0, sizeof(*bpb));
1584 bpb->fat_sector_size = SECTOR_SIZE;
1585 bpb->fat_sec_per_clus = fdefaults->sec_per_clus;
1586 bpb->fat_reserved = 1;
1587 bpb->fat_fats = 2;
1588 bpb->fat_dir_entries = fdefaults->dir_entries;
1589 bpb->fat_sectors = fdefaults->nr_sectors;
1590 bpb->fat_fat_length = fdefaults->fat_length;
1591
1592 error = 0;
1593
1594 out:
1595 return error;
1596 }
1597
1598 /*
1599 * Read the super block of an MS-DOS FS.
1600 */
1601 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
1602 void (*setup)(struct super_block *))
1603 {
1604 struct inode *root_inode = NULL, *fat_inode = NULL;
1605 struct inode *fsinfo_inode = NULL;
1606 struct buffer_head *bh;
1607 struct fat_bios_param_block bpb;
1608 struct msdos_sb_info *sbi;
1609 u16 logical_sector_size;
1610 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1611 int debug;
1612 long error;
1613 char buf[50];
1614 struct timespec64 ts;
1615
1616 /*
1617 * GFP_KERNEL is ok here, because while we do hold the
1618 * superblock lock, memory pressure can't call back into
1619 * the filesystem, since we're only just about to mount
1620 * it and have no inodes etc active!
1621 */
1622 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1623 if (!sbi)
1624 return -ENOMEM;
1625 sb->s_fs_info = sbi;
1626
1627 sb->s_flags |= SB_NODIRATIME;
1628 sb->s_magic = MSDOS_SUPER_MAGIC;
1629 sb->s_op = &fat_sops;
1630 sb->s_export_op = &fat_export_ops;
1631 /*
1632 * fat timestamps are complex and truncated by fat itself, so
1633 * we set 1 here to be fast
1634 */
1635 sb->s_time_gran = 1;
1636 mutex_init(&sbi->nfs_build_inode_lock);
1637 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
1638 DEFAULT_RATELIMIT_BURST);
1639
1640 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options);
1641 if (error)
1642 goto out_fail;
1643
1644 setup(sb); /* flavour-specific stuff that needs options */
1645
1646 error = -EIO;
1647 sb_min_blocksize(sb, 512);
1648 bh = sb_bread(sb, 0);
1649 if (bh == NULL) {
1650 fat_msg(sb, KERN_ERR, "unable to read boot sector");
1651 goto out_fail;
1652 }
1653
1654 error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent,
1655 &bpb);
1656 if (error == -EINVAL && sbi->options.dos1xfloppy)
1657 error = fat_read_static_bpb(sb,
1658 (struct fat_boot_sector *)bh->b_data, silent, &bpb);
1659 brelse(bh);
1660
1661 if (error == -EINVAL)
1662 goto out_invalid;
1663 else if (error)
1664 goto out_fail;
1665
1666 logical_sector_size = bpb.fat_sector_size;
1667 sbi->sec_per_clus = bpb.fat_sec_per_clus;
1668
1669 error = -EIO;
1670 if (logical_sector_size < sb->s_blocksize) {
1671 fat_msg(sb, KERN_ERR, "logical sector size too small for device"
1672 " (logical sector size = %u)", logical_sector_size);
1673 goto out_fail;
1674 }
1675
1676 if (logical_sector_size > sb->s_blocksize) {
1677 struct buffer_head *bh_resize;
1678
1679 if (!sb_set_blocksize(sb, logical_sector_size)) {
1680 fat_msg(sb, KERN_ERR, "unable to set blocksize %u",
1681 logical_sector_size);
1682 goto out_fail;
1683 }
1684
1685 /* Verify that the larger boot sector is fully readable */
1686 bh_resize = sb_bread(sb, 0);
1687 if (bh_resize == NULL) {
1688 fat_msg(sb, KERN_ERR, "unable to read boot sector"
1689 " (logical sector size = %lu)",
1690 sb->s_blocksize);
1691 goto out_fail;
1692 }
1693 brelse(bh_resize);
1694 }
1695
1696 mutex_init(&sbi->s_lock);
1697 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1698 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1699 sbi->fats = bpb.fat_fats;
1700 sbi->fat_bits = 0; /* Don't know yet */
1701 sbi->fat_start = bpb.fat_reserved;
1702 sbi->fat_length = bpb.fat_fat_length;
1703 sbi->root_cluster = 0;
1704 sbi->free_clusters = -1; /* Don't know yet */
1705 sbi->free_clus_valid = 0;
1706 sbi->prev_free = FAT_START_ENT;
1707 sb->s_maxbytes = 0xffffffff;
1708 fat_time_fat2unix(sbi, &ts, 0, cpu_to_le16(FAT_DATE_MIN), 0);
1709 sb->s_time_min = ts.tv_sec;
1710
1711 fat_time_fat2unix(sbi, &ts, cpu_to_le16(FAT_TIME_MAX),
1712 cpu_to_le16(FAT_DATE_MAX), 0);
1713 sb->s_time_max = ts.tv_sec;
1714
1715 if (!sbi->fat_length && bpb.fat32_length) {
1716 struct fat_boot_fsinfo *fsinfo;
1717 struct buffer_head *fsinfo_bh;
1718
1719 /* Must be FAT32 */
1720 sbi->fat_bits = 32;
1721 sbi->fat_length = bpb.fat32_length;
1722 sbi->root_cluster = bpb.fat32_root_cluster;
1723
1724 /* MC - if info_sector is 0, don't multiply by 0 */
1725 sbi->fsinfo_sector = bpb.fat32_info_sector;
1726 if (sbi->fsinfo_sector == 0)
1727 sbi->fsinfo_sector = 1;
1728
1729 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1730 if (fsinfo_bh == NULL) {
1731 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block"
1732 " (sector = %lu)", sbi->fsinfo_sector);
1733 goto out_fail;
1734 }
1735
1736 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1737 if (!IS_FSINFO(fsinfo)) {
1738 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
1739 "0x%08x, 0x%08x (sector = %lu)",
1740 le32_to_cpu(fsinfo->signature1),
1741 le32_to_cpu(fsinfo->signature2),
1742 sbi->fsinfo_sector);
1743 } else {
1744 if (sbi->options.usefree)
1745 sbi->free_clus_valid = 1;
1746 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1747 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1748 }
1749
1750 brelse(fsinfo_bh);
1751 }
1752
1753 /* interpret volume ID as a little endian 32 bit integer */
1754 if (is_fat32(sbi))
1755 sbi->vol_id = bpb.fat32_vol_id;
1756 else /* fat 16 or 12 */
1757 sbi->vol_id = bpb.fat16_vol_id;
1758
1759 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1760 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1761
1762 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1763 sbi->dir_entries = bpb.fat_dir_entries;
1764 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1765 if (!silent)
1766 fat_msg(sb, KERN_ERR, "bogus number of directory entries"
1767 " (%u)", sbi->dir_entries);
1768 goto out_invalid;
1769 }
1770
1771 rootdir_sectors = sbi->dir_entries
1772 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1773 sbi->data_start = sbi->dir_start + rootdir_sectors;
1774 total_sectors = bpb.fat_sectors;
1775 if (total_sectors == 0)
1776 total_sectors = bpb.fat_total_sect;
1777
1778 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1779
1780 if (!is_fat32(sbi))
1781 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1782
1783 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */
1784 if (is_fat32(sbi))
1785 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY;
1786 else /* fat 16 or 12 */
1787 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY;
1788
1789 /* check that FAT table does not overflow */
1790 fat_clusters = calc_fat_clusters(sb);
1791 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1792 if (total_clusters > max_fat(sb)) {
1793 if (!silent)
1794 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)",
1795 total_clusters);
1796 goto out_invalid;
1797 }
1798
1799 sbi->max_cluster = total_clusters + FAT_START_ENT;
1800 /* check the free_clusters, it's not necessarily correct */
1801 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1802 sbi->free_clusters = -1;
1803 /* check the prev_free, it's not necessarily correct */
1804 sbi->prev_free %= sbi->max_cluster;
1805 if (sbi->prev_free < FAT_START_ENT)
1806 sbi->prev_free = FAT_START_ENT;
1807
1808 /* set up enough so that it can read an inode */
1809 fat_hash_init(sb);
1810 dir_hash_init(sb);
1811 fat_ent_access_init(sb);
1812
1813 /*
1814 * The low byte of the first FAT entry must have the same value as
1815 * the media field of the boot sector. But in real world, too many
1816 * devices are writing wrong values. So, removed that validity check.
1817 *
1818 * The removed check compared the first FAT entry to a value dependent
1819 * on the media field like this:
1820 * == (0x0F00 | media), for FAT12
1821 * == (0XFF00 | media), for FAT16
1822 * == (0x0FFFFF | media), for FAT32
1823 */
1824
1825 error = -EINVAL;
1826 sprintf(buf, "cp%d", sbi->options.codepage);
1827 sbi->nls_disk = load_nls(buf);
1828 if (!sbi->nls_disk) {
1829 fat_msg(sb, KERN_ERR, "codepage %s not found", buf);
1830 goto out_fail;
1831 }
1832
1833 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1834 if (sbi->options.isvfat) {
1835 sbi->nls_io = load_nls(sbi->options.iocharset);
1836 if (!sbi->nls_io) {
1837 fat_msg(sb, KERN_ERR, "IO charset %s not found",
1838 sbi->options.iocharset);
1839 goto out_fail;
1840 }
1841 }
1842
1843 error = -ENOMEM;
1844 fat_inode = new_inode(sb);
1845 if (!fat_inode)
1846 goto out_fail;
1847 fat_dummy_inode_init(fat_inode);
1848 sbi->fat_inode = fat_inode;
1849
1850 fsinfo_inode = new_inode(sb);
1851 if (!fsinfo_inode)
1852 goto out_fail;
1853 fat_dummy_inode_init(fsinfo_inode);
1854 fsinfo_inode->i_ino = MSDOS_FSINFO_INO;
1855 sbi->fsinfo_inode = fsinfo_inode;
1856 insert_inode_hash(fsinfo_inode);
1857
1858 root_inode = new_inode(sb);
1859 if (!root_inode)
1860 goto out_fail;
1861 root_inode->i_ino = MSDOS_ROOT_INO;
1862 inode_set_iversion(root_inode, 1);
1863 error = fat_read_root(root_inode);
1864 if (error < 0) {
1865 iput(root_inode);
1866 goto out_fail;
1867 }
1868 error = -ENOMEM;
1869 insert_inode_hash(root_inode);
1870 fat_attach(root_inode, 0);
1871 sb->s_root = d_make_root(root_inode);
1872 if (!sb->s_root) {
1873 fat_msg(sb, KERN_ERR, "get root inode failed");
1874 goto out_fail;
1875 }
1876
1877 if (sbi->options.discard) {
1878 struct request_queue *q = bdev_get_queue(sb->s_bdev);
1879 if (!blk_queue_discard(q))
1880 fat_msg(sb, KERN_WARNING,
1881 "mounting with \"discard\" option, but "
1882 "the device does not support discard");
1883 }
1884
1885 fat_set_state(sb, 1, 0);
1886 return 0;
1887
1888 out_invalid:
1889 error = -EINVAL;
1890 if (!silent)
1891 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem");
1892
1893 out_fail:
1894 if (fsinfo_inode)
1895 iput(fsinfo_inode);
1896 if (fat_inode)
1897 iput(fat_inode);
1898 unload_nls(sbi->nls_io);
1899 unload_nls(sbi->nls_disk);
1900 fat_reset_iocharset(&sbi->options);
1901 sb->s_fs_info = NULL;
1902 kfree(sbi);
1903 return error;
1904 }
1905
1906 EXPORT_SYMBOL_GPL(fat_fill_super);
1907
1908 /*
1909 * helper function for fat_flush_inodes. This writes both the inode
1910 * and the file data blocks, waiting for in flight data blocks before
1911 * the start of the call. It does not wait for any io started
1912 * during the call
1913 */
1914 static int writeback_inode(struct inode *inode)
1915 {
1916
1917 int ret;
1918
1919 /* if we used wait=1, sync_inode_metadata waits for the io for the
1920 * inode to finish. So wait=0 is sent down to sync_inode_metadata
1921 * and filemap_fdatawrite is used for the data blocks
1922 */
1923 ret = sync_inode_metadata(inode, 0);
1924 if (!ret)
1925 ret = filemap_fdatawrite(inode->i_mapping);
1926 return ret;
1927 }
1928
1929 /*
1930 * write data and metadata corresponding to i1 and i2. The io is
1931 * started but we do not wait for any of it to finish.
1932 *
1933 * filemap_flush is used for the block device, so if there is a dirty
1934 * page for a block already in flight, we will not wait and start the
1935 * io over again
1936 */
1937 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1938 {
1939 int ret = 0;
1940 if (!MSDOS_SB(sb)->options.flush)
1941 return 0;
1942 if (i1)
1943 ret = writeback_inode(i1);
1944 if (!ret && i2)
1945 ret = writeback_inode(i2);
1946 if (!ret) {
1947 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1948 ret = filemap_flush(mapping);
1949 }
1950 return ret;
1951 }
1952 EXPORT_SYMBOL_GPL(fat_flush_inodes);
1953
1954 static int __init init_fat_fs(void)
1955 {
1956 int err;
1957
1958 err = fat_cache_init();
1959 if (err)
1960 return err;
1961
1962 err = fat_init_inodecache();
1963 if (err)
1964 goto failed;
1965
1966 return 0;
1967
1968 failed:
1969 fat_cache_destroy();
1970 return err;
1971 }
1972
1973 static void __exit exit_fat_fs(void)
1974 {
1975 fat_cache_destroy();
1976 fat_destroy_inodecache();
1977 }
1978
1979 module_init(init_fat_fs)
1980 module_exit(exit_fat_fs)
1981
1982 MODULE_LICENSE("GPL");
Linux with added FPC-III support