?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
gpio: rcar: Fix runtime PM imbalance on error
[linux/fpc-iii.git] / fs / fat / inode.c
blob71946da8438849859b5240d199b216cf0b424f55
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 /* Zeroing to allow iput() even if partial initialized inode. */
754 ei->mmu_private = 0;
755 ei->i_start = 0;
756 ei->i_logstart = 0;
757 ei->i_attrs = 0;
758 ei->i_pos = 0;
759
760 return &ei->vfs_inode;
761 }
762
763 static void fat_free_inode(struct inode *inode)
764 {
765 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
766 }
767
768 static void init_once(void *foo)
769 {
770 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
771
772 spin_lock_init(&ei->cache_lru_lock);
773 ei->nr_caches = 0;
774 ei->cache_valid_id = FAT_CACHE_VALID + 1;
775 INIT_LIST_HEAD(&ei->cache_lru);
776 INIT_HLIST_NODE(&ei->i_fat_hash);
777 INIT_HLIST_NODE(&ei->i_dir_hash);
778 inode_init_once(&ei->vfs_inode);
779 }
780
781 static int __init fat_init_inodecache(void)
782 {
783 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
784 sizeof(struct msdos_inode_info),
785 0, (SLAB_RECLAIM_ACCOUNT|
786 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
787 init_once);
788 if (fat_inode_cachep == NULL)
789 return -ENOMEM;
790 return 0;
791 }
792
793 static void __exit fat_destroy_inodecache(void)
794 {
795 /*
796 * Make sure all delayed rcu free inodes are flushed before we
797 * destroy cache.
798 */
799 rcu_barrier();
800 kmem_cache_destroy(fat_inode_cachep);
801 }
802
803 static int fat_remount(struct super_block *sb, int *flags, char *data)
804 {
805 bool new_rdonly;
806 struct msdos_sb_info *sbi = MSDOS_SB(sb);
807 *flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME);
808
809 sync_filesystem(sb);
810
811 /* make sure we update state on remount. */
812 new_rdonly = *flags & SB_RDONLY;
813 if (new_rdonly != sb_rdonly(sb)) {
814 if (new_rdonly)
815 fat_set_state(sb, 0, 0);
816 else
817 fat_set_state(sb, 1, 1);
818 }
819 return 0;
820 }
821
822 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
823 {
824 struct super_block *sb = dentry->d_sb;
825 struct msdos_sb_info *sbi = MSDOS_SB(sb);
826 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
827
828 /* If the count of free cluster is still unknown, counts it here. */
829 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
830 int err = fat_count_free_clusters(dentry->d_sb);
831 if (err)
832 return err;
833 }
834
835 buf->f_type = dentry->d_sb->s_magic;
836 buf->f_bsize = sbi->cluster_size;
837 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
838 buf->f_bfree = sbi->free_clusters;
839 buf->f_bavail = sbi->free_clusters;
840 buf->f_fsid.val[0] = (u32)id;
841 buf->f_fsid.val[1] = (u32)(id >> 32);
842 buf->f_namelen =
843 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE;
844
845 return 0;
846 }
847
848 static int __fat_write_inode(struct inode *inode, int wait)
849 {
850 struct super_block *sb = inode->i_sb;
851 struct msdos_sb_info *sbi = MSDOS_SB(sb);
852 struct buffer_head *bh;
853 struct msdos_dir_entry *raw_entry;
854 loff_t i_pos;
855 sector_t blocknr;
856 int err, offset;
857
858 if (inode->i_ino == MSDOS_ROOT_INO)
859 return 0;
860
861 retry:
862 i_pos = fat_i_pos_read(sbi, inode);
863 if (!i_pos)
864 return 0;
865
866 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset);
867 bh = sb_bread(sb, blocknr);
868 if (!bh) {
869 fat_msg(sb, KERN_ERR, "unable to read inode block "
870 "for updating (i_pos %lld)", i_pos);
871 return -EIO;
872 }
873 spin_lock(&sbi->inode_hash_lock);
874 if (i_pos != MSDOS_I(inode)->i_pos) {
875 spin_unlock(&sbi->inode_hash_lock);
876 brelse(bh);
877 goto retry;
878 }
879
880 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset];
881 if (S_ISDIR(inode->i_mode))
882 raw_entry->size = 0;
883 else
884 raw_entry->size = cpu_to_le32(inode->i_size);
885 raw_entry->attr = fat_make_attrs(inode);
886 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart);
887 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
888 &raw_entry->date, NULL);
889 if (sbi->options.isvfat) {
890 __le16 atime;
891 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
892 &raw_entry->cdate, &raw_entry->ctime_cs);
893 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
894 &raw_entry->adate, NULL);
895 }
896 spin_unlock(&sbi->inode_hash_lock);
897 mark_buffer_dirty(bh);
898 err = 0;
899 if (wait)
900 err = sync_dirty_buffer(bh);
901 brelse(bh);
902 return err;
903 }
904
905 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
906 {
907 int err;
908
909 if (inode->i_ino == MSDOS_FSINFO_INO) {
910 struct super_block *sb = inode->i_sb;
911
912 mutex_lock(&MSDOS_SB(sb)->s_lock);
913 err = fat_clusters_flush(sb);
914 mutex_unlock(&MSDOS_SB(sb)->s_lock);
915 } else
916 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
917
918 return err;
919 }
920
921 int fat_sync_inode(struct inode *inode)
922 {
923 return __fat_write_inode(inode, 1);
924 }
925
926 EXPORT_SYMBOL_GPL(fat_sync_inode);
927
928 static int fat_show_options(struct seq_file *m, struct dentry *root);
929 static const struct super_operations fat_sops = {
930 .alloc_inode = fat_alloc_inode,
931 .free_inode = fat_free_inode,
932 .write_inode = fat_write_inode,
933 .evict_inode = fat_evict_inode,
934 .put_super = fat_put_super,
935 .statfs = fat_statfs,
936 .remount_fs = fat_remount,
937
938 .show_options = fat_show_options,
939 };
940
941 static int fat_show_options(struct seq_file *m, struct dentry *root)
942 {
943 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb);
944 struct fat_mount_options *opts = &sbi->options;
945 int isvfat = opts->isvfat;
946
947 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
948 seq_printf(m, ",uid=%u",
949 from_kuid_munged(&init_user_ns, opts->fs_uid));
950 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
951 seq_printf(m, ",gid=%u",
952 from_kgid_munged(&init_user_ns, opts->fs_gid));
953 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
954 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
955 if (opts->allow_utime)
956 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
957 if (sbi->nls_disk)
958 /* strip "cp" prefix from displayed option */
959 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]);
960 if (isvfat) {
961 if (sbi->nls_io)
962 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
963
964 switch (opts->shortname) {
965 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
966 seq_puts(m, ",shortname=win95");
967 break;
968 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
969 seq_puts(m, ",shortname=winnt");
970 break;
971 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
972 seq_puts(m, ",shortname=mixed");
973 break;
974 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
975 seq_puts(m, ",shortname=lower");
976 break;
977 default:
978 seq_puts(m, ",shortname=unknown");
979 break;
980 }
981 }
982 if (opts->name_check != 'n')
983 seq_printf(m, ",check=%c", opts->name_check);
984 if (opts->usefree)
985 seq_puts(m, ",usefree");
986 if (opts->quiet)
987 seq_puts(m, ",quiet");
988 if (opts->showexec)
989 seq_puts(m, ",showexec");
990 if (opts->sys_immutable)
991 seq_puts(m, ",sys_immutable");
992 if (!isvfat) {
993 if (opts->dotsOK)
994 seq_puts(m, ",dotsOK=yes");
995 if (opts->nocase)
996 seq_puts(m, ",nocase");
997 } else {
998 if (opts->utf8)
999 seq_puts(m, ",utf8");
1000 if (opts->unicode_xlate)
1001 seq_puts(m, ",uni_xlate");
1002 if (!opts->numtail)
1003 seq_puts(m, ",nonumtail");
1004 if (opts->rodir)
1005 seq_puts(m, ",rodir");
1006 }
1007 if (opts->flush)
1008 seq_puts(m, ",flush");
1009 if (opts->tz_set) {
1010 if (opts->time_offset)
1011 seq_printf(m, ",time_offset=%d", opts->time_offset);
1012 else
1013 seq_puts(m, ",tz=UTC");
1014 }
1015 if (opts->errors == FAT_ERRORS_CONT)
1016 seq_puts(m, ",errors=continue");
1017 else if (opts->errors == FAT_ERRORS_PANIC)
1018 seq_puts(m, ",errors=panic");
1019 else
1020 seq_puts(m, ",errors=remount-ro");
1021 if (opts->nfs == FAT_NFS_NOSTALE_RO)
1022 seq_puts(m, ",nfs=nostale_ro");
1023 else if (opts->nfs)
1024 seq_puts(m, ",nfs=stale_rw");
1025 if (opts->discard)
1026 seq_puts(m, ",discard");
1027 if (opts->dos1xfloppy)
1028 seq_puts(m, ",dos1xfloppy");
1029
1030 return 0;
1031 }
1032
1033 enum {
1034 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
1035 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
1036 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
1037 Opt_immutable, Opt_dots, Opt_nodots,
1038 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
1039 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
1040 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
1041 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
1042 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset,
1043 Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy,
1044 };
1045
1046 static const match_table_t fat_tokens = {
1047 {Opt_check_r, "check=relaxed"},
1048 {Opt_check_s, "check=strict"},
1049 {Opt_check_n, "check=normal"},
1050 {Opt_check_r, "check=r"},
1051 {Opt_check_s, "check=s"},
1052 {Opt_check_n, "check=n"},
1053 {Opt_uid, "uid=%u"},
1054 {Opt_gid, "gid=%u"},
1055 {Opt_umask, "umask=%o"},
1056 {Opt_dmask, "dmask=%o"},
1057 {Opt_fmask, "fmask=%o"},
1058 {Opt_allow_utime, "allow_utime=%o"},
1059 {Opt_codepage, "codepage=%u"},
1060 {Opt_usefree, "usefree"},
1061 {Opt_nocase, "nocase"},
1062 {Opt_quiet, "quiet"},
1063 {Opt_showexec, "showexec"},
1064 {Opt_debug, "debug"},
1065 {Opt_immutable, "sys_immutable"},
1066 {Opt_flush, "flush"},
1067 {Opt_tz_utc, "tz=UTC"},
1068 {Opt_time_offset, "time_offset=%d"},
1069 {Opt_err_cont, "errors=continue"},
1070 {Opt_err_panic, "errors=panic"},
1071 {Opt_err_ro, "errors=remount-ro"},
1072 {Opt_discard, "discard"},
1073 {Opt_nfs_stale_rw, "nfs"},
1074 {Opt_nfs_stale_rw, "nfs=stale_rw"},
1075 {Opt_nfs_nostale_ro, "nfs=nostale_ro"},
1076 {Opt_dos1xfloppy, "dos1xfloppy"},
1077 {Opt_obsolete, "conv=binary"},
1078 {Opt_obsolete, "conv=text"},
1079 {Opt_obsolete, "conv=auto"},
1080 {Opt_obsolete, "conv=b"},
1081 {Opt_obsolete, "conv=t"},
1082 {Opt_obsolete, "conv=a"},
1083 {Opt_obsolete, "fat=%u"},
1084 {Opt_obsolete, "blocksize=%u"},
1085 {Opt_obsolete, "cvf_format=%20s"},
1086 {Opt_obsolete, "cvf_options=%100s"},
1087 {Opt_obsolete, "posix"},
1088 {Opt_err, NULL},
1089 };
1090 static const match_table_t msdos_tokens = {
1091 {Opt_nodots, "nodots"},
1092 {Opt_nodots, "dotsOK=no"},
1093 {Opt_dots, "dots"},
1094 {Opt_dots, "dotsOK=yes"},
1095 {Opt_err, NULL}
1096 };
1097 static const match_table_t vfat_tokens = {
1098 {Opt_charset, "iocharset=%s"},
1099 {Opt_shortname_lower, "shortname=lower"},
1100 {Opt_shortname_win95, "shortname=win95"},
1101 {Opt_shortname_winnt, "shortname=winnt"},
1102 {Opt_shortname_mixed, "shortname=mixed"},
1103 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
1104 {Opt_utf8_no, "utf8=no"},
1105 {Opt_utf8_no, "utf8=false"},
1106 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
1107 {Opt_utf8_yes, "utf8=yes"},
1108 {Opt_utf8_yes, "utf8=true"},
1109 {Opt_utf8_yes, "utf8"},
1110 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
1111 {Opt_uni_xl_no, "uni_xlate=no"},
1112 {Opt_uni_xl_no, "uni_xlate=false"},
1113 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
1114 {Opt_uni_xl_yes, "uni_xlate=yes"},
1115 {Opt_uni_xl_yes, "uni_xlate=true"},
1116 {Opt_uni_xl_yes, "uni_xlate"},
1117 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
1118 {Opt_nonumtail_no, "nonumtail=no"},
1119 {Opt_nonumtail_no, "nonumtail=false"},
1120 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
1121 {Opt_nonumtail_yes, "nonumtail=yes"},
1122 {Opt_nonumtail_yes, "nonumtail=true"},
1123 {Opt_nonumtail_yes, "nonumtail"},
1124 {Opt_rodir, "rodir"},
1125 {Opt_err, NULL}
1126 };
1127
1128 static int parse_options(struct super_block *sb, char *options, int is_vfat,
1129 int silent, int *debug, struct fat_mount_options *opts)
1130 {
1131 char *p;
1132 substring_t args[MAX_OPT_ARGS];
1133 int option;
1134 char *iocharset;
1135
1136 opts->isvfat = is_vfat;
1137
1138 opts->fs_uid = current_uid();
1139 opts->fs_gid = current_gid();
1140 opts->fs_fmask = opts->fs_dmask = current_umask();
1141 opts->allow_utime = -1;
1142 opts->codepage = fat_default_codepage;
1143 fat_reset_iocharset(opts);
1144 if (is_vfat) {
1145 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
1146 opts->rodir = 0;
1147 } else {
1148 opts->shortname = 0;
1149 opts->rodir = 1;
1150 }
1151 opts->name_check = 'n';
1152 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
1153 opts->unicode_xlate = 0;
1154 opts->numtail = 1;
1155 opts->usefree = opts->nocase = 0;
1156 opts->tz_set = 0;
1157 opts->nfs = 0;
1158 opts->errors = FAT_ERRORS_RO;
1159 *debug = 0;
1160
1161 opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat;
1162
1163 if (!options)
1164 goto out;
1165
1166 while ((p = strsep(&options, ",")) != NULL) {
1167 int token;
1168 if (!*p)
1169 continue;
1170
1171 token = match_token(p, fat_tokens, args);
1172 if (token == Opt_err) {
1173 if (is_vfat)
1174 token = match_token(p, vfat_tokens, args);
1175 else
1176 token = match_token(p, msdos_tokens, args);
1177 }
1178 switch (token) {
1179 case Opt_check_s:
1180 opts->name_check = 's';
1181 break;
1182 case Opt_check_r:
1183 opts->name_check = 'r';
1184 break;
1185 case Opt_check_n:
1186 opts->name_check = 'n';
1187 break;
1188 case Opt_usefree:
1189 opts->usefree = 1;
1190 break;
1191 case Opt_nocase:
1192 if (!is_vfat)
1193 opts->nocase = 1;
1194 else {
1195 /* for backward compatibility */
1196 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1197 | VFAT_SFN_CREATE_WIN95;
1198 }
1199 break;
1200 case Opt_quiet:
1201 opts->quiet = 1;
1202 break;
1203 case Opt_showexec:
1204 opts->showexec = 1;
1205 break;
1206 case Opt_debug:
1207 *debug = 1;
1208 break;
1209 case Opt_immutable:
1210 opts->sys_immutable = 1;
1211 break;
1212 case Opt_uid:
1213 if (match_int(&args[0], &option))
1214 return -EINVAL;
1215 opts->fs_uid = make_kuid(current_user_ns(), option);
1216 if (!uid_valid(opts->fs_uid))
1217 return -EINVAL;
1218 break;
1219 case Opt_gid:
1220 if (match_int(&args[0], &option))
1221 return -EINVAL;
1222 opts->fs_gid = make_kgid(current_user_ns(), option);
1223 if (!gid_valid(opts->fs_gid))
1224 return -EINVAL;
1225 break;
1226 case Opt_umask:
1227 if (match_octal(&args[0], &option))
1228 return -EINVAL;
1229 opts->fs_fmask = opts->fs_dmask = option;
1230 break;
1231 case Opt_dmask:
1232 if (match_octal(&args[0], &option))
1233 return -EINVAL;
1234 opts->fs_dmask = option;
1235 break;
1236 case Opt_fmask:
1237 if (match_octal(&args[0], &option))
1238 return -EINVAL;
1239 opts->fs_fmask = option;
1240 break;
1241 case Opt_allow_utime:
1242 if (match_octal(&args[0], &option))
1243 return -EINVAL;
1244 opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1245 break;
1246 case Opt_codepage:
1247 if (match_int(&args[0], &option))
1248 return -EINVAL;
1249 opts->codepage = option;
1250 break;
1251 case Opt_flush:
1252 opts->flush = 1;
1253 break;
1254 case Opt_time_offset:
1255 if (match_int(&args[0], &option))
1256 return -EINVAL;
1257 /*
1258 * GMT+-12 zones may have DST corrections so at least
1259 * 13 hours difference is needed. Make the limit 24
1260 * just in case someone invents something unusual.
1261 */
1262 if (option < -24 * 60 || option > 24 * 60)
1263 return -EINVAL;
1264 opts->tz_set = 1;
1265 opts->time_offset = option;
1266 break;
1267 case Opt_tz_utc:
1268 opts->tz_set = 1;
1269 opts->time_offset = 0;
1270 break;
1271 case Opt_err_cont:
1272 opts->errors = FAT_ERRORS_CONT;
1273 break;
1274 case Opt_err_panic:
1275 opts->errors = FAT_ERRORS_PANIC;
1276 break;
1277 case Opt_err_ro:
1278 opts->errors = FAT_ERRORS_RO;
1279 break;
1280 case Opt_nfs_stale_rw:
1281 opts->nfs = FAT_NFS_STALE_RW;
1282 break;
1283 case Opt_nfs_nostale_ro:
1284 opts->nfs = FAT_NFS_NOSTALE_RO;
1285 break;
1286 case Opt_dos1xfloppy:
1287 opts->dos1xfloppy = 1;
1288 break;
1289
1290 /* msdos specific */
1291 case Opt_dots:
1292 opts->dotsOK = 1;
1293 break;
1294 case Opt_nodots:
1295 opts->dotsOK = 0;
1296 break;
1297
1298 /* vfat specific */
1299 case Opt_charset:
1300 fat_reset_iocharset(opts);
1301 iocharset = match_strdup(&args[0]);
1302 if (!iocharset)
1303 return -ENOMEM;
1304 opts->iocharset = iocharset;
1305 break;
1306 case Opt_shortname_lower:
1307 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1308 | VFAT_SFN_CREATE_WIN95;
1309 break;
1310 case Opt_shortname_win95:
1311 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1312 | VFAT_SFN_CREATE_WIN95;
1313 break;
1314 case Opt_shortname_winnt:
1315 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1316 | VFAT_SFN_CREATE_WINNT;
1317 break;
1318 case Opt_shortname_mixed:
1319 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1320 | VFAT_SFN_CREATE_WIN95;
1321 break;
1322 case Opt_utf8_no: /* 0 or no or false */
1323 opts->utf8 = 0;
1324 break;
1325 case Opt_utf8_yes: /* empty or 1 or yes or true */
1326 opts->utf8 = 1;
1327 break;
1328 case Opt_uni_xl_no: /* 0 or no or false */
1329 opts->unicode_xlate = 0;
1330 break;
1331 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1332 opts->unicode_xlate = 1;
1333 break;
1334 case Opt_nonumtail_no: /* 0 or no or false */
1335 opts->numtail = 1; /* negated option */
1336 break;
1337 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1338 opts->numtail = 0; /* negated option */
1339 break;
1340 case Opt_rodir:
1341 opts->rodir = 1;
1342 break;
1343 case Opt_discard:
1344 opts->discard = 1;
1345 break;
1346
1347 /* obsolete mount options */
1348 case Opt_obsolete:
1349 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, "
1350 "not supported now", p);
1351 break;
1352 /* unknown option */
1353 default:
1354 if (!silent) {
1355 fat_msg(sb, KERN_ERR,
1356 "Unrecognized mount option \"%s\" "
1357 "or missing value", p);
1358 }
1359 return -EINVAL;
1360 }
1361 }
1362
1363 out:
1364 /* UTF-8 doesn't provide FAT semantics */
1365 if (!strcmp(opts->iocharset, "utf8")) {
1366 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset"
1367 " for FAT filesystems, filesystem will be "
1368 "case sensitive!");
1369 }
1370
1371 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1372 if (opts->allow_utime == (unsigned short)-1)
1373 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
1374 if (opts->unicode_xlate)
1375 opts->utf8 = 0;
1376 if (opts->nfs == FAT_NFS_NOSTALE_RO) {
1377 sb->s_flags |= SB_RDONLY;
1378 sb->s_export_op = &fat_export_ops_nostale;
1379 }
1380
1381 return 0;
1382 }
1383
1384 static int fat_read_root(struct inode *inode)
1385 {
1386 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
1387 int error;
1388
1389 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO;
1390 inode->i_uid = sbi->options.fs_uid;
1391 inode->i_gid = sbi->options.fs_gid;
1392 inode_inc_iversion(inode);
1393 inode->i_generation = 0;
1394 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
1395 inode->i_op = sbi->dir_ops;
1396 inode->i_fop = &fat_dir_operations;
1397 if (is_fat32(sbi)) {
1398 MSDOS_I(inode)->i_start = sbi->root_cluster;
1399 error = fat_calc_dir_size(inode);
1400 if (error < 0)
1401 return error;
1402 } else {
1403 MSDOS_I(inode)->i_start = 0;
1404 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1405 }
1406 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1407 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1408 MSDOS_I(inode)->i_logstart = 0;
1409 MSDOS_I(inode)->mmu_private = inode->i_size;
1410
1411 fat_save_attrs(inode, ATTR_DIR);
1412 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1413 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1414 set_nlink(inode, fat_subdirs(inode)+2);
1415
1416 return 0;
1417 }
1418
1419 static unsigned long calc_fat_clusters(struct super_block *sb)
1420 {
1421 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1422
1423 /* Divide first to avoid overflow */
1424 if (!is_fat12(sbi)) {
1425 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits;
1426 return ent_per_sec * sbi->fat_length;
1427 }
1428
1429 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1430 }
1431
1432 static bool fat_bpb_is_zero(struct fat_boot_sector *b)
1433 {
1434 if (get_unaligned_le16(&b->sector_size))
1435 return false;
1436 if (b->sec_per_clus)
1437 return false;
1438 if (b->reserved)
1439 return false;
1440 if (b->fats)
1441 return false;
1442 if (get_unaligned_le16(&b->dir_entries))
1443 return false;
1444 if (get_unaligned_le16(&b->sectors))
1445 return false;
1446 if (b->media)
1447 return false;
1448 if (b->fat_length)
1449 return false;
1450 if (b->secs_track)
1451 return false;
1452 if (b->heads)
1453 return false;
1454 return true;
1455 }
1456
1457 static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b,
1458 int silent, struct fat_bios_param_block *bpb)
1459 {
1460 int error = -EINVAL;
1461
1462 /* Read in BPB ... */
1463 memset(bpb, 0, sizeof(*bpb));
1464 bpb->fat_sector_size = get_unaligned_le16(&b->sector_size);
1465 bpb->fat_sec_per_clus = b->sec_per_clus;
1466 bpb->fat_reserved = le16_to_cpu(b->reserved);
1467 bpb->fat_fats = b->fats;
1468 bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries);
1469 bpb->fat_sectors = get_unaligned_le16(&b->sectors);
1470 bpb->fat_fat_length = le16_to_cpu(b->fat_length);
1471 bpb->fat_total_sect = le32_to_cpu(b->total_sect);
1472
1473 bpb->fat16_state = b->fat16.state;
1474 bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id);
1475
1476 bpb->fat32_length = le32_to_cpu(b->fat32.length);
1477 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster);
1478 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector);
1479 bpb->fat32_state = b->fat32.state;
1480 bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id);
1481
1482 /* Validate this looks like a FAT filesystem BPB */
1483 if (!bpb->fat_reserved) {
1484 if (!silent)
1485 fat_msg(sb, KERN_ERR,
1486 "bogus number of reserved sectors");
1487 goto out;
1488 }
1489 if (!bpb->fat_fats) {
1490 if (!silent)
1491 fat_msg(sb, KERN_ERR, "bogus number of FAT structure");
1492 goto out;
1493 }
1494
1495 /*
1496 * Earlier we checked here that b->secs_track and b->head are nonzero,
1497 * but it turns out valid FAT filesystems can have zero there.
1498 */
1499
1500 if (!fat_valid_media(b->media)) {
1501 if (!silent)
1502 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)",
1503 (unsigned)b->media);
1504 goto out;
1505 }
1506
1507 if (!is_power_of_2(bpb->fat_sector_size)
1508 || (bpb->fat_sector_size < 512)
1509 || (bpb->fat_sector_size > 4096)) {
1510 if (!silent)
1511 fat_msg(sb, KERN_ERR, "bogus logical sector size %u",
1512 (unsigned)bpb->fat_sector_size);
1513 goto out;
1514 }
1515
1516 if (!is_power_of_2(bpb->fat_sec_per_clus)) {
1517 if (!silent)
1518 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u",
1519 (unsigned)bpb->fat_sec_per_clus);
1520 goto out;
1521 }
1522
1523 error = 0;
1524
1525 out:
1526 return error;
1527 }
1528
1529 static int fat_read_static_bpb(struct super_block *sb,
1530 struct fat_boot_sector *b, int silent,
1531 struct fat_bios_param_block *bpb)
1532 {
1533 static const char *notdos1x = "This doesn't look like a DOS 1.x volume";
1534
1535 struct fat_floppy_defaults *fdefaults = NULL;
1536 int error = -EINVAL;
1537 sector_t bd_sects;
1538 unsigned i;
1539
1540 bd_sects = i_size_read(sb->s_bdev->bd_inode) / SECTOR_SIZE;
1541
1542 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */
1543 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) {
1544 if (!silent)
1545 fat_msg(sb, KERN_ERR,
1546 "%s; no bootstrapping code", notdos1x);
1547 goto out;
1548 }
1549
1550 /*
1551 * If any value in this region is non-zero, it isn't archaic
1552 * DOS.
1553 */
1554 if (!fat_bpb_is_zero(b)) {
1555 if (!silent)
1556 fat_msg(sb, KERN_ERR,
1557 "%s; DOS 2.x BPB is non-zero", notdos1x);
1558 goto out;
1559 }
1560
1561 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) {
1562 if (floppy_defaults[i].nr_sectors == bd_sects) {
1563 fdefaults = &floppy_defaults[i];
1564 break;
1565 }
1566 }
1567
1568 if (fdefaults == NULL) {
1569 if (!silent)
1570 fat_msg(sb, KERN_WARNING,
1571 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)",
1572 (u64)bd_sects);
1573 goto out;
1574 }
1575
1576 if (!silent)
1577 fat_msg(sb, KERN_INFO,
1578 "This looks like a DOS 1.x volume; assuming default BPB values");
1579
1580 memset(bpb, 0, sizeof(*bpb));
1581 bpb->fat_sector_size = SECTOR_SIZE;
1582 bpb->fat_sec_per_clus = fdefaults->sec_per_clus;
1583 bpb->fat_reserved = 1;
1584 bpb->fat_fats = 2;
1585 bpb->fat_dir_entries = fdefaults->dir_entries;
1586 bpb->fat_sectors = fdefaults->nr_sectors;
1587 bpb->fat_fat_length = fdefaults->fat_length;
1588
1589 error = 0;
1590
1591 out:
1592 return error;
1593 }
1594
1595 /*
1596 * Read the super block of an MS-DOS FS.
1597 */
1598 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
1599 void (*setup)(struct super_block *))
1600 {
1601 struct inode *root_inode = NULL, *fat_inode = NULL;
1602 struct inode *fsinfo_inode = NULL;
1603 struct buffer_head *bh;
1604 struct fat_bios_param_block bpb;
1605 struct msdos_sb_info *sbi;
1606 u16 logical_sector_size;
1607 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1608 int debug;
1609 long error;
1610 char buf[50];
1611 struct timespec64 ts;
1612
1613 /*
1614 * GFP_KERNEL is ok here, because while we do hold the
1615 * superblock lock, memory pressure can't call back into
1616 * the filesystem, since we're only just about to mount
1617 * it and have no inodes etc active!
1618 */
1619 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1620 if (!sbi)
1621 return -ENOMEM;
1622 sb->s_fs_info = sbi;
1623
1624 sb->s_flags |= SB_NODIRATIME;
1625 sb->s_magic = MSDOS_SUPER_MAGIC;
1626 sb->s_op = &fat_sops;
1627 sb->s_export_op = &fat_export_ops;
1628 /*
1629 * fat timestamps are complex and truncated by fat itself, so
1630 * we set 1 here to be fast
1631 */
1632 sb->s_time_gran = 1;
1633 mutex_init(&sbi->nfs_build_inode_lock);
1634 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
1635 DEFAULT_RATELIMIT_BURST);
1636
1637 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options);
1638 if (error)
1639 goto out_fail;
1640
1641 setup(sb); /* flavour-specific stuff that needs options */
1642
1643 error = -EIO;
1644 sb_min_blocksize(sb, 512);
1645 bh = sb_bread(sb, 0);
1646 if (bh == NULL) {
1647 fat_msg(sb, KERN_ERR, "unable to read boot sector");
1648 goto out_fail;
1649 }
1650
1651 error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent,
1652 &bpb);
1653 if (error == -EINVAL && sbi->options.dos1xfloppy)
1654 error = fat_read_static_bpb(sb,
1655 (struct fat_boot_sector *)bh->b_data, silent, &bpb);
1656 brelse(bh);
1657
1658 if (error == -EINVAL)
1659 goto out_invalid;
1660 else if (error)
1661 goto out_fail;
1662
1663 logical_sector_size = bpb.fat_sector_size;
1664 sbi->sec_per_clus = bpb.fat_sec_per_clus;
1665
1666 error = -EIO;
1667 if (logical_sector_size < sb->s_blocksize) {
1668 fat_msg(sb, KERN_ERR, "logical sector size too small for device"
1669 " (logical sector size = %u)", logical_sector_size);
1670 goto out_fail;
1671 }
1672
1673 if (logical_sector_size > sb->s_blocksize) {
1674 struct buffer_head *bh_resize;
1675
1676 if (!sb_set_blocksize(sb, logical_sector_size)) {
1677 fat_msg(sb, KERN_ERR, "unable to set blocksize %u",
1678 logical_sector_size);
1679 goto out_fail;
1680 }
1681
1682 /* Verify that the larger boot sector is fully readable */
1683 bh_resize = sb_bread(sb, 0);
1684 if (bh_resize == NULL) {
1685 fat_msg(sb, KERN_ERR, "unable to read boot sector"
1686 " (logical sector size = %lu)",
1687 sb->s_blocksize);
1688 goto out_fail;
1689 }
1690 brelse(bh_resize);
1691 }
1692
1693 mutex_init(&sbi->s_lock);
1694 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1695 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1696 sbi->fats = bpb.fat_fats;
1697 sbi->fat_bits = 0; /* Don't know yet */
1698 sbi->fat_start = bpb.fat_reserved;
1699 sbi->fat_length = bpb.fat_fat_length;
1700 sbi->root_cluster = 0;
1701 sbi->free_clusters = -1; /* Don't know yet */
1702 sbi->free_clus_valid = 0;
1703 sbi->prev_free = FAT_START_ENT;
1704 sb->s_maxbytes = 0xffffffff;
1705 fat_time_fat2unix(sbi, &ts, 0, cpu_to_le16(FAT_DATE_MIN), 0);
1706 sb->s_time_min = ts.tv_sec;
1707
1708 fat_time_fat2unix(sbi, &ts, cpu_to_le16(FAT_TIME_MAX),
1709 cpu_to_le16(FAT_DATE_MAX), 0);
1710 sb->s_time_max = ts.tv_sec;
1711
1712 if (!sbi->fat_length && bpb.fat32_length) {
1713 struct fat_boot_fsinfo *fsinfo;
1714 struct buffer_head *fsinfo_bh;
1715
1716 /* Must be FAT32 */
1717 sbi->fat_bits = 32;
1718 sbi->fat_length = bpb.fat32_length;
1719 sbi->root_cluster = bpb.fat32_root_cluster;
1720
1721 /* MC - if info_sector is 0, don't multiply by 0 */
1722 sbi->fsinfo_sector = bpb.fat32_info_sector;
1723 if (sbi->fsinfo_sector == 0)
1724 sbi->fsinfo_sector = 1;
1725
1726 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1727 if (fsinfo_bh == NULL) {
1728 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block"
1729 " (sector = %lu)", sbi->fsinfo_sector);
1730 goto out_fail;
1731 }
1732
1733 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1734 if (!IS_FSINFO(fsinfo)) {
1735 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
1736 "0x%08x, 0x%08x (sector = %lu)",
1737 le32_to_cpu(fsinfo->signature1),
1738 le32_to_cpu(fsinfo->signature2),
1739 sbi->fsinfo_sector);
1740 } else {
1741 if (sbi->options.usefree)
1742 sbi->free_clus_valid = 1;
1743 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1744 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1745 }
1746
1747 brelse(fsinfo_bh);
1748 }
1749
1750 /* interpret volume ID as a little endian 32 bit integer */
1751 if (is_fat32(sbi))
1752 sbi->vol_id = bpb.fat32_vol_id;
1753 else /* fat 16 or 12 */
1754 sbi->vol_id = bpb.fat16_vol_id;
1755
1756 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1757 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1758
1759 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1760 sbi->dir_entries = bpb.fat_dir_entries;
1761 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1762 if (!silent)
1763 fat_msg(sb, KERN_ERR, "bogus number of directory entries"
1764 " (%u)", sbi->dir_entries);
1765 goto out_invalid;
1766 }
1767
1768 rootdir_sectors = sbi->dir_entries
1769 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1770 sbi->data_start = sbi->dir_start + rootdir_sectors;
1771 total_sectors = bpb.fat_sectors;
1772 if (total_sectors == 0)
1773 total_sectors = bpb.fat_total_sect;
1774
1775 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1776
1777 if (!is_fat32(sbi))
1778 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1779
1780 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */
1781 if (is_fat32(sbi))
1782 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY;
1783 else /* fat 16 or 12 */
1784 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY;
1785
1786 /* check that FAT table does not overflow */
1787 fat_clusters = calc_fat_clusters(sb);
1788 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1789 if (total_clusters > max_fat(sb)) {
1790 if (!silent)
1791 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)",
1792 total_clusters);
1793 goto out_invalid;
1794 }
1795
1796 sbi->max_cluster = total_clusters + FAT_START_ENT;
1797 /* check the free_clusters, it's not necessarily correct */
1798 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1799 sbi->free_clusters = -1;
1800 /* check the prev_free, it's not necessarily correct */
1801 sbi->prev_free %= sbi->max_cluster;
1802 if (sbi->prev_free < FAT_START_ENT)
1803 sbi->prev_free = FAT_START_ENT;
1804
1805 /* set up enough so that it can read an inode */
1806 fat_hash_init(sb);
1807 dir_hash_init(sb);
1808 fat_ent_access_init(sb);
1809
1810 /*
1811 * The low byte of the first FAT entry must have the same value as
1812 * the media field of the boot sector. But in real world, too many
1813 * devices are writing wrong values. So, removed that validity check.
1814 *
1815 * The removed check compared the first FAT entry to a value dependent
1816 * on the media field like this:
1817 * == (0x0F00 | media), for FAT12
1818 * == (0XFF00 | media), for FAT16
1819 * == (0x0FFFFF | media), for FAT32
1820 */
1821
1822 error = -EINVAL;
1823 sprintf(buf, "cp%d", sbi->options.codepage);
1824 sbi->nls_disk = load_nls(buf);
1825 if (!sbi->nls_disk) {
1826 fat_msg(sb, KERN_ERR, "codepage %s not found", buf);
1827 goto out_fail;
1828 }
1829
1830 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1831 if (sbi->options.isvfat) {
1832 sbi->nls_io = load_nls(sbi->options.iocharset);
1833 if (!sbi->nls_io) {
1834 fat_msg(sb, KERN_ERR, "IO charset %s not found",
1835 sbi->options.iocharset);
1836 goto out_fail;
1837 }
1838 }
1839
1840 error = -ENOMEM;
1841 fat_inode = new_inode(sb);
1842 if (!fat_inode)
1843 goto out_fail;
1844 sbi->fat_inode = fat_inode;
1845
1846 fsinfo_inode = new_inode(sb);
1847 if (!fsinfo_inode)
1848 goto out_fail;
1849 fsinfo_inode->i_ino = MSDOS_FSINFO_INO;
1850 sbi->fsinfo_inode = fsinfo_inode;
1851 insert_inode_hash(fsinfo_inode);
1852
1853 root_inode = new_inode(sb);
1854 if (!root_inode)
1855 goto out_fail;
1856 root_inode->i_ino = MSDOS_ROOT_INO;
1857 inode_set_iversion(root_inode, 1);
1858 error = fat_read_root(root_inode);
1859 if (error < 0) {
1860 iput(root_inode);
1861 goto out_fail;
1862 }
1863 error = -ENOMEM;
1864 insert_inode_hash(root_inode);
1865 fat_attach(root_inode, 0);
1866 sb->s_root = d_make_root(root_inode);
1867 if (!sb->s_root) {
1868 fat_msg(sb, KERN_ERR, "get root inode failed");
1869 goto out_fail;
1870 }
1871
1872 if (sbi->options.discard) {
1873 struct request_queue *q = bdev_get_queue(sb->s_bdev);
1874 if (!blk_queue_discard(q))
1875 fat_msg(sb, KERN_WARNING,
1876 "mounting with \"discard\" option, but "
1877 "the device does not support discard");
1878 }
1879
1880 fat_set_state(sb, 1, 0);
1881 return 0;
1882
1883 out_invalid:
1884 error = -EINVAL;
1885 if (!silent)
1886 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem");
1887
1888 out_fail:
1889 if (fsinfo_inode)
1890 iput(fsinfo_inode);
1891 if (fat_inode)
1892 iput(fat_inode);
1893 unload_nls(sbi->nls_io);
1894 unload_nls(sbi->nls_disk);
1895 fat_reset_iocharset(&sbi->options);
1896 sb->s_fs_info = NULL;
1897 kfree(sbi);
1898 return error;
1899 }
1900
1901 EXPORT_SYMBOL_GPL(fat_fill_super);
1902
1903 /*
1904 * helper function for fat_flush_inodes. This writes both the inode
1905 * and the file data blocks, waiting for in flight data blocks before
1906 * the start of the call. It does not wait for any io started
1907 * during the call
1908 */
1909 static int writeback_inode(struct inode *inode)
1910 {
1911
1912 int ret;
1913
1914 /* if we used wait=1, sync_inode_metadata waits for the io for the
1915 * inode to finish. So wait=0 is sent down to sync_inode_metadata
1916 * and filemap_fdatawrite is used for the data blocks
1917 */
1918 ret = sync_inode_metadata(inode, 0);
1919 if (!ret)
1920 ret = filemap_fdatawrite(inode->i_mapping);
1921 return ret;
1922 }
1923
1924 /*
1925 * write data and metadata corresponding to i1 and i2. The io is
1926 * started but we do not wait for any of it to finish.
1927 *
1928 * filemap_flush is used for the block device, so if there is a dirty
1929 * page for a block already in flight, we will not wait and start the
1930 * io over again
1931 */
1932 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1933 {
1934 int ret = 0;
1935 if (!MSDOS_SB(sb)->options.flush)
1936 return 0;
1937 if (i1)
1938 ret = writeback_inode(i1);
1939 if (!ret && i2)
1940 ret = writeback_inode(i2);
1941 if (!ret) {
1942 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1943 ret = filemap_flush(mapping);
1944 }
1945 return ret;
1946 }
1947 EXPORT_SYMBOL_GPL(fat_flush_inodes);
1948
1949 static int __init init_fat_fs(void)
1950 {
1951 int err;
1952
1953 err = fat_cache_init();
1954 if (err)
1955 return err;
1956
1957 err = fat_init_inodecache();
1958 if (err)
1959 goto failed;
1960
1961 return 0;
1962
1963 failed:
1964 fat_cache_destroy();
1965 return err;
1966 }
1967
1968 static void __exit exit_fat_fs(void)
1969 {
1970 fat_cache_destroy();
1971 fat_destroy_inodecache();
1972 }
1973
1974 module_init(init_fat_fs)
1975 module_exit(exit_fat_fs)
1976
1977 MODULE_LICENSE("GPL");
Linux with added FPC-III support