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arm64: simplify kernel segment mapping granularity
[linux/fpc-iii.git] / fs / fat / inode.c
blob226281068a46171208787af6c49f70e3c38ca37a
1 /*
2 * linux/fs/fat/inode.c
3 *
4 * Written 1992,1993 by Werner Almesberger
5 * VFAT extensions by Gordon Chaffee, merged with msdos fs by Henrik Storner
6 * Rewritten for the constant inumbers support by Al Viro
7 *
8 * Fixes:
9 *
10 * Max Cohan: Fixed invalid FSINFO offset when info_sector is 0
11 */
12
13 #include <linux/module.h>
14 #include <linux/pagemap.h>
15 #include <linux/mpage.h>
16 #include <linux/vfs.h>
17 #include <linux/seq_file.h>
18 #include <linux/parser.h>
19 #include <linux/uio.h>
20 #include <linux/blkdev.h>
21 #include <linux/backing-dev.h>
22 #include <asm/unaligned.h>
23 #include "fat.h"
24
25 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET
26 /* if user don't select VFAT, this is undefined. */
27 #define CONFIG_FAT_DEFAULT_IOCHARSET ""
28 #endif
29
30 #define KB_IN_SECTORS 2
31
32 /*
33 * A deserialized copy of the on-disk structure laid out in struct
34 * fat_boot_sector.
35 */
36 struct fat_bios_param_block {
37 u16 fat_sector_size;
38 u8 fat_sec_per_clus;
39 u16 fat_reserved;
40 u8 fat_fats;
41 u16 fat_dir_entries;
42 u16 fat_sectors;
43 u16 fat_fat_length;
44 u32 fat_total_sect;
45
46 u8 fat16_state;
47 u32 fat16_vol_id;
48
49 u32 fat32_length;
50 u32 fat32_root_cluster;
51 u16 fat32_info_sector;
52 u8 fat32_state;
53 u32 fat32_vol_id;
54 };
55
56 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
57 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
58
59 static struct fat_floppy_defaults {
60 unsigned nr_sectors;
61 unsigned sec_per_clus;
62 unsigned dir_entries;
63 unsigned media;
64 unsigned fat_length;
65 } floppy_defaults[] = {
66 {
67 .nr_sectors = 160 * KB_IN_SECTORS,
68 .sec_per_clus = 1,
69 .dir_entries = 64,
70 .media = 0xFE,
71 .fat_length = 1,
72 },
73 {
74 .nr_sectors = 180 * KB_IN_SECTORS,
75 .sec_per_clus = 1,
76 .dir_entries = 64,
77 .media = 0xFC,
78 .fat_length = 2,
79 },
80 {
81 .nr_sectors = 320 * KB_IN_SECTORS,
82 .sec_per_clus = 2,
83 .dir_entries = 112,
84 .media = 0xFF,
85 .fat_length = 1,
86 },
87 {
88 .nr_sectors = 360 * KB_IN_SECTORS,
89 .sec_per_clus = 2,
90 .dir_entries = 112,
91 .media = 0xFD,
92 .fat_length = 2,
93 },
94 };
95
96 int fat_add_cluster(struct inode *inode)
97 {
98 int err, cluster;
99
100 err = fat_alloc_clusters(inode, &cluster, 1);
101 if (err)
102 return err;
103 /* FIXME: this cluster should be added after data of this
104 * cluster is writed */
105 err = fat_chain_add(inode, cluster, 1);
106 if (err)
107 fat_free_clusters(inode, cluster);
108 return err;
109 }
110
111 static inline int __fat_get_block(struct inode *inode, sector_t iblock,
112 unsigned long *max_blocks,
113 struct buffer_head *bh_result, int create)
114 {
115 struct super_block *sb = inode->i_sb;
116 struct msdos_sb_info *sbi = MSDOS_SB(sb);
117 unsigned long mapped_blocks;
118 sector_t phys, last_block;
119 int err, offset;
120
121 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false);
122 if (err)
123 return err;
124 if (phys) {
125 map_bh(bh_result, sb, phys);
126 *max_blocks = min(mapped_blocks, *max_blocks);
127 return 0;
128 }
129 if (!create)
130 return 0;
131
132 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
133 fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)",
134 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
135 return -EIO;
136 }
137
138 last_block = inode->i_blocks >> (sb->s_blocksize_bits - 9);
139 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
140 /*
141 * allocate a cluster according to the following.
142 * 1) no more available blocks
143 * 2) not part of fallocate region
144 */
145 if (!offset && !(iblock < last_block)) {
146 /* TODO: multiple cluster allocation would be desirable. */
147 err = fat_add_cluster(inode);
148 if (err)
149 return err;
150 }
151 /* available blocks on this cluster */
152 mapped_blocks = sbi->sec_per_clus - offset;
153
154 *max_blocks = min(mapped_blocks, *max_blocks);
155 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
156
157 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false);
158 if (err)
159 return err;
160
161 BUG_ON(!phys);
162 BUG_ON(*max_blocks != mapped_blocks);
163 set_buffer_new(bh_result);
164 map_bh(bh_result, sb, phys);
165
166 return 0;
167 }
168
169 static int fat_get_block(struct inode *inode, sector_t iblock,
170 struct buffer_head *bh_result, int create)
171 {
172 struct super_block *sb = inode->i_sb;
173 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
174 int err;
175
176 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
177 if (err)
178 return err;
179 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
180 return 0;
181 }
182
183 static int fat_writepage(struct page *page, struct writeback_control *wbc)
184 {
185 return block_write_full_page(page, fat_get_block, wbc);
186 }
187
188 static int fat_writepages(struct address_space *mapping,
189 struct writeback_control *wbc)
190 {
191 return mpage_writepages(mapping, wbc, fat_get_block);
192 }
193
194 static int fat_readpage(struct file *file, struct page *page)
195 {
196 return mpage_readpage(page, fat_get_block);
197 }
198
199 static int fat_readpages(struct file *file, struct address_space *mapping,
200 struct list_head *pages, unsigned nr_pages)
201 {
202 return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
203 }
204
205 static void fat_write_failed(struct address_space *mapping, loff_t to)
206 {
207 struct inode *inode = mapping->host;
208
209 if (to > inode->i_size) {
210 truncate_pagecache(inode, inode->i_size);
211 fat_truncate_blocks(inode, inode->i_size);
212 }
213 }
214
215 static int fat_write_begin(struct file *file, struct address_space *mapping,
216 loff_t pos, unsigned len, unsigned flags,
217 struct page **pagep, void **fsdata)
218 {
219 int err;
220
221 *pagep = NULL;
222 err = cont_write_begin(file, mapping, pos, len, flags,
223 pagep, fsdata, fat_get_block,
224 &MSDOS_I(mapping->host)->mmu_private);
225 if (err < 0)
226 fat_write_failed(mapping, pos + len);
227 return err;
228 }
229
230 static int fat_write_end(struct file *file, struct address_space *mapping,
231 loff_t pos, unsigned len, unsigned copied,
232 struct page *pagep, void *fsdata)
233 {
234 struct inode *inode = mapping->host;
235 int err;
236 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
237 if (err < len)
238 fat_write_failed(mapping, pos + len);
239 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
240 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
241 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
242 mark_inode_dirty(inode);
243 }
244 return err;
245 }
246
247 static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
248 loff_t offset)
249 {
250 struct file *file = iocb->ki_filp;
251 struct address_space *mapping = file->f_mapping;
252 struct inode *inode = mapping->host;
253 size_t count = iov_iter_count(iter);
254 ssize_t ret;
255
256 if (iov_iter_rw(iter) == WRITE) {
257 /*
258 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
259 * so we need to update the ->mmu_private to block boundary.
260 *
261 * But we must fill the remaining area or hole by nul for
262 * updating ->mmu_private.
263 *
264 * Return 0, and fallback to normal buffered write.
265 */
266 loff_t size = offset + count;
267 if (MSDOS_I(inode)->mmu_private < size)
268 return 0;
269 }
270
271 /*
272 * FAT need to use the DIO_LOCKING for avoiding the race
273 * condition of fat_get_block() and ->truncate().
274 */
275 ret = blockdev_direct_IO(iocb, inode, iter, offset, fat_get_block);
276 if (ret < 0 && iov_iter_rw(iter) == WRITE)
277 fat_write_failed(mapping, offset + count);
278
279 return ret;
280 }
281
282 static int fat_get_block_bmap(struct inode *inode, sector_t iblock,
283 struct buffer_head *bh_result, int create)
284 {
285 struct super_block *sb = inode->i_sb;
286 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
287 int err;
288 sector_t bmap;
289 unsigned long mapped_blocks;
290
291 BUG_ON(create != 0);
292
293 err = fat_bmap(inode, iblock, &bmap, &mapped_blocks, create, true);
294 if (err)
295 return err;
296
297 if (bmap) {
298 map_bh(bh_result, sb, bmap);
299 max_blocks = min(mapped_blocks, max_blocks);
300 }
301
302 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
303
304 return 0;
305 }
306
307 static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
308 {
309 sector_t blocknr;
310
311 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
312 down_read(&MSDOS_I(mapping->host)->truncate_lock);
313 blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap);
314 up_read(&MSDOS_I(mapping->host)->truncate_lock);
315
316 return blocknr;
317 }
318
319 /*
320 * fat_block_truncate_page() zeroes out a mapping from file offset `from'
321 * up to the end of the block which corresponds to `from'.
322 * This is required during truncate to physically zeroout the tail end
323 * of that block so it doesn't yield old data if the file is later grown.
324 * Also, avoid causing failure from fsx for cases of "data past EOF"
325 */
326 int fat_block_truncate_page(struct inode *inode, loff_t from)
327 {
328 return block_truncate_page(inode->i_mapping, from, fat_get_block);
329 }
330
331 static const struct address_space_operations fat_aops = {
332 .readpage = fat_readpage,
333 .readpages = fat_readpages,
334 .writepage = fat_writepage,
335 .writepages = fat_writepages,
336 .write_begin = fat_write_begin,
337 .write_end = fat_write_end,
338 .direct_IO = fat_direct_IO,
339 .bmap = _fat_bmap
340 };
341
342 /*
343 * New FAT inode stuff. We do the following:
344 * a) i_ino is constant and has nothing with on-disk location.
345 * b) FAT manages its own cache of directory entries.
346 * c) *This* cache is indexed by on-disk location.
347 * d) inode has an associated directory entry, all right, but
348 * it may be unhashed.
349 * e) currently entries are stored within struct inode. That should
350 * change.
351 * f) we deal with races in the following way:
352 * 1. readdir() and lookup() do FAT-dir-cache lookup.
353 * 2. rename() unhashes the F-d-c entry and rehashes it in
354 * a new place.
355 * 3. unlink() and rmdir() unhash F-d-c entry.
356 * 4. fat_write_inode() checks whether the thing is unhashed.
357 * If it is we silently return. If it isn't we do bread(),
358 * check if the location is still valid and retry if it
359 * isn't. Otherwise we do changes.
360 * 5. Spinlock is used to protect hash/unhash/location check/lookup
361 * 6. fat_evict_inode() unhashes the F-d-c entry.
362 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
363 * and consider negative result as cache miss.
364 */
365
366 static void fat_hash_init(struct super_block *sb)
367 {
368 struct msdos_sb_info *sbi = MSDOS_SB(sb);
369 int i;
370
371 spin_lock_init(&sbi->inode_hash_lock);
372 for (i = 0; i < FAT_HASH_SIZE; i++)
373 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
374 }
375
376 static inline unsigned long fat_hash(loff_t i_pos)
377 {
378 return hash_32(i_pos, FAT_HASH_BITS);
379 }
380
381 static void dir_hash_init(struct super_block *sb)
382 {
383 struct msdos_sb_info *sbi = MSDOS_SB(sb);
384 int i;
385
386 spin_lock_init(&sbi->dir_hash_lock);
387 for (i = 0; i < FAT_HASH_SIZE; i++)
388 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]);
389 }
390
391 void fat_attach(struct inode *inode, loff_t i_pos)
392 {
393 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
394
395 if (inode->i_ino != MSDOS_ROOT_INO) {
396 struct hlist_head *head = sbi->inode_hashtable
397 + fat_hash(i_pos);
398
399 spin_lock(&sbi->inode_hash_lock);
400 MSDOS_I(inode)->i_pos = i_pos;
401 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
402 spin_unlock(&sbi->inode_hash_lock);
403 }
404
405 /* If NFS support is enabled, cache the mapping of start cluster
406 * to directory inode. This is used during reconnection of
407 * dentries to the filesystem root.
408 */
409 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
410 struct hlist_head *d_head = sbi->dir_hashtable;
411 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart);
412
413 spin_lock(&sbi->dir_hash_lock);
414 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head);
415 spin_unlock(&sbi->dir_hash_lock);
416 }
417 }
418 EXPORT_SYMBOL_GPL(fat_attach);
419
420 void fat_detach(struct inode *inode)
421 {
422 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
423 spin_lock(&sbi->inode_hash_lock);
424 MSDOS_I(inode)->i_pos = 0;
425 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
426 spin_unlock(&sbi->inode_hash_lock);
427
428 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
429 spin_lock(&sbi->dir_hash_lock);
430 hlist_del_init(&MSDOS_I(inode)->i_dir_hash);
431 spin_unlock(&sbi->dir_hash_lock);
432 }
433 }
434 EXPORT_SYMBOL_GPL(fat_detach);
435
436 struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
437 {
438 struct msdos_sb_info *sbi = MSDOS_SB(sb);
439 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
440 struct msdos_inode_info *i;
441 struct inode *inode = NULL;
442
443 spin_lock(&sbi->inode_hash_lock);
444 hlist_for_each_entry(i, head, i_fat_hash) {
445 BUG_ON(i->vfs_inode.i_sb != sb);
446 if (i->i_pos != i_pos)
447 continue;
448 inode = igrab(&i->vfs_inode);
449 if (inode)
450 break;
451 }
452 spin_unlock(&sbi->inode_hash_lock);
453 return inode;
454 }
455
456 static int is_exec(unsigned char *extension)
457 {
458 unsigned char exe_extensions[] = "EXECOMBAT", *walk;
459
460 for (walk = exe_extensions; *walk; walk += 3)
461 if (!strncmp(extension, walk, 3))
462 return 1;
463 return 0;
464 }
465
466 static int fat_calc_dir_size(struct inode *inode)
467 {
468 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
469 int ret, fclus, dclus;
470
471 inode->i_size = 0;
472 if (MSDOS_I(inode)->i_start == 0)
473 return 0;
474
475 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
476 if (ret < 0)
477 return ret;
478 inode->i_size = (fclus + 1) << sbi->cluster_bits;
479
480 return 0;
481 }
482
483 static int fat_validate_dir(struct inode *dir)
484 {
485 struct super_block *sb = dir->i_sb;
486
487 if (dir->i_nlink < 2) {
488 /* Directory should have "."/".." entries at least. */
489 fat_fs_error(sb, "corrupted directory (invalid entries)");
490 return -EIO;
491 }
492 if (MSDOS_I(dir)->i_start == 0 ||
493 MSDOS_I(dir)->i_start == MSDOS_SB(sb)->root_cluster) {
494 /* Directory should point valid cluster. */
495 fat_fs_error(sb, "corrupted directory (invalid i_start)");
496 return -EIO;
497 }
498 return 0;
499 }
500
501 /* doesn't deal with root inode */
502 int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
503 {
504 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
505 int error;
506
507 MSDOS_I(inode)->i_pos = 0;
508 inode->i_uid = sbi->options.fs_uid;
509 inode->i_gid = sbi->options.fs_gid;
510 inode->i_version++;
511 inode->i_generation = get_seconds();
512
513 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
514 inode->i_generation &= ~1;
515 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
516 inode->i_op = sbi->dir_ops;
517 inode->i_fop = &fat_dir_operations;
518
519 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
520 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
521 error = fat_calc_dir_size(inode);
522 if (error < 0)
523 return error;
524 MSDOS_I(inode)->mmu_private = inode->i_size;
525
526 set_nlink(inode, fat_subdirs(inode));
527
528 error = fat_validate_dir(inode);
529 if (error < 0)
530 return error;
531 } else { /* not a directory */
532 inode->i_generation |= 1;
533 inode->i_mode = fat_make_mode(sbi, de->attr,
534 ((sbi->options.showexec && !is_exec(de->name + 8))
535 ? S_IRUGO|S_IWUGO : S_IRWXUGO));
536 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
537
538 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
539 inode->i_size = le32_to_cpu(de->size);
540 inode->i_op = &fat_file_inode_operations;
541 inode->i_fop = &fat_file_operations;
542 inode->i_mapping->a_ops = &fat_aops;
543 MSDOS_I(inode)->mmu_private = inode->i_size;
544 }
545 if (de->attr & ATTR_SYS) {
546 if (sbi->options.sys_immutable)
547 inode->i_flags |= S_IMMUTABLE;
548 }
549 fat_save_attrs(inode, de->attr);
550
551 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
552 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
553
554 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
555 if (sbi->options.isvfat) {
556 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
557 de->cdate, de->ctime_cs);
558 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
559 } else
560 inode->i_ctime = inode->i_atime = inode->i_mtime;
561
562 return 0;
563 }
564
565 static inline void fat_lock_build_inode(struct msdos_sb_info *sbi)
566 {
567 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
568 mutex_lock(&sbi->nfs_build_inode_lock);
569 }
570
571 static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi)
572 {
573 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
574 mutex_unlock(&sbi->nfs_build_inode_lock);
575 }
576
577 struct inode *fat_build_inode(struct super_block *sb,
578 struct msdos_dir_entry *de, loff_t i_pos)
579 {
580 struct inode *inode;
581 int err;
582
583 fat_lock_build_inode(MSDOS_SB(sb));
584 inode = fat_iget(sb, i_pos);
585 if (inode)
586 goto out;
587 inode = new_inode(sb);
588 if (!inode) {
589 inode = ERR_PTR(-ENOMEM);
590 goto out;
591 }
592 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
593 inode->i_version = 1;
594 err = fat_fill_inode(inode, de);
595 if (err) {
596 iput(inode);
597 inode = ERR_PTR(err);
598 goto out;
599 }
600 fat_attach(inode, i_pos);
601 insert_inode_hash(inode);
602 out:
603 fat_unlock_build_inode(MSDOS_SB(sb));
604 return inode;
605 }
606
607 EXPORT_SYMBOL_GPL(fat_build_inode);
608
609 static int __fat_write_inode(struct inode *inode, int wait);
610
611 static void fat_free_eofblocks(struct inode *inode)
612 {
613 /* Release unwritten fallocated blocks on inode eviction. */
614 if ((inode->i_blocks << 9) >
615 round_up(MSDOS_I(inode)->mmu_private,
616 MSDOS_SB(inode->i_sb)->cluster_size)) {
617 int err;
618
619 fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private);
620 /* Fallocate results in updating the i_start/iogstart
621 * for the zero byte file. So, make it return to
622 * original state during evict and commit it to avoid
623 * any corruption on the next access to the cluster
624 * chain for the file.
625 */
626 err = __fat_write_inode(inode, inode_needs_sync(inode));
627 if (err) {
628 fat_msg(inode->i_sb, KERN_WARNING, "Failed to "
629 "update on disk inode for unused "
630 "fallocated blocks, inode could be "
631 "corrupted. Please run fsck");
632 }
633
634 }
635 }
636
637 static void fat_evict_inode(struct inode *inode)
638 {
639 truncate_inode_pages_final(&inode->i_data);
640 if (!inode->i_nlink) {
641 inode->i_size = 0;
642 fat_truncate_blocks(inode, 0);
643 } else
644 fat_free_eofblocks(inode);
645
646 invalidate_inode_buffers(inode);
647 clear_inode(inode);
648 fat_cache_inval_inode(inode);
649 fat_detach(inode);
650 }
651
652 static void fat_set_state(struct super_block *sb,
653 unsigned int set, unsigned int force)
654 {
655 struct buffer_head *bh;
656 struct fat_boot_sector *b;
657 struct msdos_sb_info *sbi = MSDOS_SB(sb);
658
659 /* do not change any thing if mounted read only */
660 if ((sb->s_flags & MS_RDONLY) && !force)
661 return;
662
663 /* do not change state if fs was dirty */
664 if (sbi->dirty) {
665 /* warn only on set (mount). */
666 if (set)
667 fat_msg(sb, KERN_WARNING, "Volume was not properly "
668 "unmounted. Some data may be corrupt. "
669 "Please run fsck.");
670 return;
671 }
672
673 bh = sb_bread(sb, 0);
674 if (bh == NULL) {
675 fat_msg(sb, KERN_ERR, "unable to read boot sector "
676 "to mark fs as dirty");
677 return;
678 }
679
680 b = (struct fat_boot_sector *) bh->b_data;
681
682 if (sbi->fat_bits == 32) {
683 if (set)
684 b->fat32.state |= FAT_STATE_DIRTY;
685 else
686 b->fat32.state &= ~FAT_STATE_DIRTY;
687 } else /* fat 16 and 12 */ {
688 if (set)
689 b->fat16.state |= FAT_STATE_DIRTY;
690 else
691 b->fat16.state &= ~FAT_STATE_DIRTY;
692 }
693
694 mark_buffer_dirty(bh);
695 sync_dirty_buffer(bh);
696 brelse(bh);
697 }
698
699 static void delayed_free(struct rcu_head *p)
700 {
701 struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu);
702 unload_nls(sbi->nls_disk);
703 unload_nls(sbi->nls_io);
704 if (sbi->options.iocharset != fat_default_iocharset)
705 kfree(sbi->options.iocharset);
706 kfree(sbi);
707 }
708
709 static void fat_put_super(struct super_block *sb)
710 {
711 struct msdos_sb_info *sbi = MSDOS_SB(sb);
712
713 fat_set_state(sb, 0, 0);
714
715 iput(sbi->fsinfo_inode);
716 iput(sbi->fat_inode);
717
718 call_rcu(&sbi->rcu, delayed_free);
719 }
720
721 static struct kmem_cache *fat_inode_cachep;
722
723 static struct inode *fat_alloc_inode(struct super_block *sb)
724 {
725 struct msdos_inode_info *ei;
726 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
727 if (!ei)
728 return NULL;
729
730 init_rwsem(&ei->truncate_lock);
731 return &ei->vfs_inode;
732 }
733
734 static void fat_i_callback(struct rcu_head *head)
735 {
736 struct inode *inode = container_of(head, struct inode, i_rcu);
737 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
738 }
739
740 static void fat_destroy_inode(struct inode *inode)
741 {
742 call_rcu(&inode->i_rcu, fat_i_callback);
743 }
744
745 static void init_once(void *foo)
746 {
747 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
748
749 spin_lock_init(&ei->cache_lru_lock);
750 ei->nr_caches = 0;
751 ei->cache_valid_id = FAT_CACHE_VALID + 1;
752 INIT_LIST_HEAD(&ei->cache_lru);
753 INIT_HLIST_NODE(&ei->i_fat_hash);
754 INIT_HLIST_NODE(&ei->i_dir_hash);
755 inode_init_once(&ei->vfs_inode);
756 }
757
758 static int __init fat_init_inodecache(void)
759 {
760 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
761 sizeof(struct msdos_inode_info),
762 0, (SLAB_RECLAIM_ACCOUNT|
763 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
764 init_once);
765 if (fat_inode_cachep == NULL)
766 return -ENOMEM;
767 return 0;
768 }
769
770 static void __exit fat_destroy_inodecache(void)
771 {
772 /*
773 * Make sure all delayed rcu free inodes are flushed before we
774 * destroy cache.
775 */
776 rcu_barrier();
777 kmem_cache_destroy(fat_inode_cachep);
778 }
779
780 static int fat_remount(struct super_block *sb, int *flags, char *data)
781 {
782 int new_rdonly;
783 struct msdos_sb_info *sbi = MSDOS_SB(sb);
784 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
785
786 sync_filesystem(sb);
787
788 /* make sure we update state on remount. */
789 new_rdonly = *flags & MS_RDONLY;
790 if (new_rdonly != (sb->s_flags & MS_RDONLY)) {
791 if (new_rdonly)
792 fat_set_state(sb, 0, 0);
793 else
794 fat_set_state(sb, 1, 1);
795 }
796 return 0;
797 }
798
799 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
800 {
801 struct super_block *sb = dentry->d_sb;
802 struct msdos_sb_info *sbi = MSDOS_SB(sb);
803 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
804
805 /* If the count of free cluster is still unknown, counts it here. */
806 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
807 int err = fat_count_free_clusters(dentry->d_sb);
808 if (err)
809 return err;
810 }
811
812 buf->f_type = dentry->d_sb->s_magic;
813 buf->f_bsize = sbi->cluster_size;
814 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
815 buf->f_bfree = sbi->free_clusters;
816 buf->f_bavail = sbi->free_clusters;
817 buf->f_fsid.val[0] = (u32)id;
818 buf->f_fsid.val[1] = (u32)(id >> 32);
819 buf->f_namelen =
820 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE;
821
822 return 0;
823 }
824
825 static int __fat_write_inode(struct inode *inode, int wait)
826 {
827 struct super_block *sb = inode->i_sb;
828 struct msdos_sb_info *sbi = MSDOS_SB(sb);
829 struct buffer_head *bh;
830 struct msdos_dir_entry *raw_entry;
831 loff_t i_pos;
832 sector_t blocknr;
833 int err, offset;
834
835 if (inode->i_ino == MSDOS_ROOT_INO)
836 return 0;
837
838 retry:
839 i_pos = fat_i_pos_read(sbi, inode);
840 if (!i_pos)
841 return 0;
842
843 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset);
844 bh = sb_bread(sb, blocknr);
845 if (!bh) {
846 fat_msg(sb, KERN_ERR, "unable to read inode block "
847 "for updating (i_pos %lld)", i_pos);
848 return -EIO;
849 }
850 spin_lock(&sbi->inode_hash_lock);
851 if (i_pos != MSDOS_I(inode)->i_pos) {
852 spin_unlock(&sbi->inode_hash_lock);
853 brelse(bh);
854 goto retry;
855 }
856
857 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset];
858 if (S_ISDIR(inode->i_mode))
859 raw_entry->size = 0;
860 else
861 raw_entry->size = cpu_to_le32(inode->i_size);
862 raw_entry->attr = fat_make_attrs(inode);
863 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart);
864 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
865 &raw_entry->date, NULL);
866 if (sbi->options.isvfat) {
867 __le16 atime;
868 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
869 &raw_entry->cdate, &raw_entry->ctime_cs);
870 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
871 &raw_entry->adate, NULL);
872 }
873 spin_unlock(&sbi->inode_hash_lock);
874 mark_buffer_dirty(bh);
875 err = 0;
876 if (wait)
877 err = sync_dirty_buffer(bh);
878 brelse(bh);
879 return err;
880 }
881
882 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
883 {
884 int err;
885
886 if (inode->i_ino == MSDOS_FSINFO_INO) {
887 struct super_block *sb = inode->i_sb;
888
889 mutex_lock(&MSDOS_SB(sb)->s_lock);
890 err = fat_clusters_flush(sb);
891 mutex_unlock(&MSDOS_SB(sb)->s_lock);
892 } else
893 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
894
895 return err;
896 }
897
898 int fat_sync_inode(struct inode *inode)
899 {
900 return __fat_write_inode(inode, 1);
901 }
902
903 EXPORT_SYMBOL_GPL(fat_sync_inode);
904
905 static int fat_show_options(struct seq_file *m, struct dentry *root);
906 static const struct super_operations fat_sops = {
907 .alloc_inode = fat_alloc_inode,
908 .destroy_inode = fat_destroy_inode,
909 .write_inode = fat_write_inode,
910 .evict_inode = fat_evict_inode,
911 .put_super = fat_put_super,
912 .statfs = fat_statfs,
913 .remount_fs = fat_remount,
914
915 .show_options = fat_show_options,
916 };
917
918 static int fat_show_options(struct seq_file *m, struct dentry *root)
919 {
920 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb);
921 struct fat_mount_options *opts = &sbi->options;
922 int isvfat = opts->isvfat;
923
924 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
925 seq_printf(m, ",uid=%u",
926 from_kuid_munged(&init_user_ns, opts->fs_uid));
927 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
928 seq_printf(m, ",gid=%u",
929 from_kgid_munged(&init_user_ns, opts->fs_gid));
930 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
931 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
932 if (opts->allow_utime)
933 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
934 if (sbi->nls_disk)
935 /* strip "cp" prefix from displayed option */
936 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]);
937 if (isvfat) {
938 if (sbi->nls_io)
939 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
940
941 switch (opts->shortname) {
942 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
943 seq_puts(m, ",shortname=win95");
944 break;
945 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
946 seq_puts(m, ",shortname=winnt");
947 break;
948 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
949 seq_puts(m, ",shortname=mixed");
950 break;
951 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
952 seq_puts(m, ",shortname=lower");
953 break;
954 default:
955 seq_puts(m, ",shortname=unknown");
956 break;
957 }
958 }
959 if (opts->name_check != 'n')
960 seq_printf(m, ",check=%c", opts->name_check);
961 if (opts->usefree)
962 seq_puts(m, ",usefree");
963 if (opts->quiet)
964 seq_puts(m, ",quiet");
965 if (opts->showexec)
966 seq_puts(m, ",showexec");
967 if (opts->sys_immutable)
968 seq_puts(m, ",sys_immutable");
969 if (!isvfat) {
970 if (opts->dotsOK)
971 seq_puts(m, ",dotsOK=yes");
972 if (opts->nocase)
973 seq_puts(m, ",nocase");
974 } else {
975 if (opts->utf8)
976 seq_puts(m, ",utf8");
977 if (opts->unicode_xlate)
978 seq_puts(m, ",uni_xlate");
979 if (!opts->numtail)
980 seq_puts(m, ",nonumtail");
981 if (opts->rodir)
982 seq_puts(m, ",rodir");
983 }
984 if (opts->flush)
985 seq_puts(m, ",flush");
986 if (opts->tz_set) {
987 if (opts->time_offset)
988 seq_printf(m, ",time_offset=%d", opts->time_offset);
989 else
990 seq_puts(m, ",tz=UTC");
991 }
992 if (opts->errors == FAT_ERRORS_CONT)
993 seq_puts(m, ",errors=continue");
994 else if (opts->errors == FAT_ERRORS_PANIC)
995 seq_puts(m, ",errors=panic");
996 else
997 seq_puts(m, ",errors=remount-ro");
998 if (opts->nfs == FAT_NFS_NOSTALE_RO)
999 seq_puts(m, ",nfs=nostale_ro");
1000 else if (opts->nfs)
1001 seq_puts(m, ",nfs=stale_rw");
1002 if (opts->discard)
1003 seq_puts(m, ",discard");
1004 if (opts->dos1xfloppy)
1005 seq_puts(m, ",dos1xfloppy");
1006
1007 return 0;
1008 }
1009
1010 enum {
1011 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
1012 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
1013 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
1014 Opt_immutable, Opt_dots, Opt_nodots,
1015 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
1016 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
1017 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
1018 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
1019 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset,
1020 Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy,
1021 };
1022
1023 static const match_table_t fat_tokens = {
1024 {Opt_check_r, "check=relaxed"},
1025 {Opt_check_s, "check=strict"},
1026 {Opt_check_n, "check=normal"},
1027 {Opt_check_r, "check=r"},
1028 {Opt_check_s, "check=s"},
1029 {Opt_check_n, "check=n"},
1030 {Opt_uid, "uid=%u"},
1031 {Opt_gid, "gid=%u"},
1032 {Opt_umask, "umask=%o"},
1033 {Opt_dmask, "dmask=%o"},
1034 {Opt_fmask, "fmask=%o"},
1035 {Opt_allow_utime, "allow_utime=%o"},
1036 {Opt_codepage, "codepage=%u"},
1037 {Opt_usefree, "usefree"},
1038 {Opt_nocase, "nocase"},
1039 {Opt_quiet, "quiet"},
1040 {Opt_showexec, "showexec"},
1041 {Opt_debug, "debug"},
1042 {Opt_immutable, "sys_immutable"},
1043 {Opt_flush, "flush"},
1044 {Opt_tz_utc, "tz=UTC"},
1045 {Opt_time_offset, "time_offset=%d"},
1046 {Opt_err_cont, "errors=continue"},
1047 {Opt_err_panic, "errors=panic"},
1048 {Opt_err_ro, "errors=remount-ro"},
1049 {Opt_discard, "discard"},
1050 {Opt_nfs_stale_rw, "nfs"},
1051 {Opt_nfs_stale_rw, "nfs=stale_rw"},
1052 {Opt_nfs_nostale_ro, "nfs=nostale_ro"},
1053 {Opt_dos1xfloppy, "dos1xfloppy"},
1054 {Opt_obsolete, "conv=binary"},
1055 {Opt_obsolete, "conv=text"},
1056 {Opt_obsolete, "conv=auto"},
1057 {Opt_obsolete, "conv=b"},
1058 {Opt_obsolete, "conv=t"},
1059 {Opt_obsolete, "conv=a"},
1060 {Opt_obsolete, "fat=%u"},
1061 {Opt_obsolete, "blocksize=%u"},
1062 {Opt_obsolete, "cvf_format=%20s"},
1063 {Opt_obsolete, "cvf_options=%100s"},
1064 {Opt_obsolete, "posix"},
1065 {Opt_err, NULL},
1066 };
1067 static const match_table_t msdos_tokens = {
1068 {Opt_nodots, "nodots"},
1069 {Opt_nodots, "dotsOK=no"},
1070 {Opt_dots, "dots"},
1071 {Opt_dots, "dotsOK=yes"},
1072 {Opt_err, NULL}
1073 };
1074 static const match_table_t vfat_tokens = {
1075 {Opt_charset, "iocharset=%s"},
1076 {Opt_shortname_lower, "shortname=lower"},
1077 {Opt_shortname_win95, "shortname=win95"},
1078 {Opt_shortname_winnt, "shortname=winnt"},
1079 {Opt_shortname_mixed, "shortname=mixed"},
1080 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
1081 {Opt_utf8_no, "utf8=no"},
1082 {Opt_utf8_no, "utf8=false"},
1083 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
1084 {Opt_utf8_yes, "utf8=yes"},
1085 {Opt_utf8_yes, "utf8=true"},
1086 {Opt_utf8_yes, "utf8"},
1087 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
1088 {Opt_uni_xl_no, "uni_xlate=no"},
1089 {Opt_uni_xl_no, "uni_xlate=false"},
1090 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
1091 {Opt_uni_xl_yes, "uni_xlate=yes"},
1092 {Opt_uni_xl_yes, "uni_xlate=true"},
1093 {Opt_uni_xl_yes, "uni_xlate"},
1094 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
1095 {Opt_nonumtail_no, "nonumtail=no"},
1096 {Opt_nonumtail_no, "nonumtail=false"},
1097 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
1098 {Opt_nonumtail_yes, "nonumtail=yes"},
1099 {Opt_nonumtail_yes, "nonumtail=true"},
1100 {Opt_nonumtail_yes, "nonumtail"},
1101 {Opt_rodir, "rodir"},
1102 {Opt_err, NULL}
1103 };
1104
1105 static int parse_options(struct super_block *sb, char *options, int is_vfat,
1106 int silent, int *debug, struct fat_mount_options *opts)
1107 {
1108 char *p;
1109 substring_t args[MAX_OPT_ARGS];
1110 int option;
1111 char *iocharset;
1112
1113 opts->isvfat = is_vfat;
1114
1115 opts->fs_uid = current_uid();
1116 opts->fs_gid = current_gid();
1117 opts->fs_fmask = opts->fs_dmask = current_umask();
1118 opts->allow_utime = -1;
1119 opts->codepage = fat_default_codepage;
1120 opts->iocharset = fat_default_iocharset;
1121 if (is_vfat) {
1122 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
1123 opts->rodir = 0;
1124 } else {
1125 opts->shortname = 0;
1126 opts->rodir = 1;
1127 }
1128 opts->name_check = 'n';
1129 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
1130 opts->unicode_xlate = 0;
1131 opts->numtail = 1;
1132 opts->usefree = opts->nocase = 0;
1133 opts->tz_set = 0;
1134 opts->nfs = 0;
1135 opts->errors = FAT_ERRORS_RO;
1136 *debug = 0;
1137
1138 opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat;
1139
1140 if (!options)
1141 goto out;
1142
1143 while ((p = strsep(&options, ",")) != NULL) {
1144 int token;
1145 if (!*p)
1146 continue;
1147
1148 token = match_token(p, fat_tokens, args);
1149 if (token == Opt_err) {
1150 if (is_vfat)
1151 token = match_token(p, vfat_tokens, args);
1152 else
1153 token = match_token(p, msdos_tokens, args);
1154 }
1155 switch (token) {
1156 case Opt_check_s:
1157 opts->name_check = 's';
1158 break;
1159 case Opt_check_r:
1160 opts->name_check = 'r';
1161 break;
1162 case Opt_check_n:
1163 opts->name_check = 'n';
1164 break;
1165 case Opt_usefree:
1166 opts->usefree = 1;
1167 break;
1168 case Opt_nocase:
1169 if (!is_vfat)
1170 opts->nocase = 1;
1171 else {
1172 /* for backward compatibility */
1173 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1174 | VFAT_SFN_CREATE_WIN95;
1175 }
1176 break;
1177 case Opt_quiet:
1178 opts->quiet = 1;
1179 break;
1180 case Opt_showexec:
1181 opts->showexec = 1;
1182 break;
1183 case Opt_debug:
1184 *debug = 1;
1185 break;
1186 case Opt_immutable:
1187 opts->sys_immutable = 1;
1188 break;
1189 case Opt_uid:
1190 if (match_int(&args[0], &option))
1191 return -EINVAL;
1192 opts->fs_uid = make_kuid(current_user_ns(), option);
1193 if (!uid_valid(opts->fs_uid))
1194 return -EINVAL;
1195 break;
1196 case Opt_gid:
1197 if (match_int(&args[0], &option))
1198 return -EINVAL;
1199 opts->fs_gid = make_kgid(current_user_ns(), option);
1200 if (!gid_valid(opts->fs_gid))
1201 return -EINVAL;
1202 break;
1203 case Opt_umask:
1204 if (match_octal(&args[0], &option))
1205 return -EINVAL;
1206 opts->fs_fmask = opts->fs_dmask = option;
1207 break;
1208 case Opt_dmask:
1209 if (match_octal(&args[0], &option))
1210 return -EINVAL;
1211 opts->fs_dmask = option;
1212 break;
1213 case Opt_fmask:
1214 if (match_octal(&args[0], &option))
1215 return -EINVAL;
1216 opts->fs_fmask = option;
1217 break;
1218 case Opt_allow_utime:
1219 if (match_octal(&args[0], &option))
1220 return -EINVAL;
1221 opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1222 break;
1223 case Opt_codepage:
1224 if (match_int(&args[0], &option))
1225 return -EINVAL;
1226 opts->codepage = option;
1227 break;
1228 case Opt_flush:
1229 opts->flush = 1;
1230 break;
1231 case Opt_time_offset:
1232 if (match_int(&args[0], &option))
1233 return -EINVAL;
1234 /*
1235 * GMT+-12 zones may have DST corrections so at least
1236 * 13 hours difference is needed. Make the limit 24
1237 * just in case someone invents something unusual.
1238 */
1239 if (option < -24 * 60 || option > 24 * 60)
1240 return -EINVAL;
1241 opts->tz_set = 1;
1242 opts->time_offset = option;
1243 break;
1244 case Opt_tz_utc:
1245 opts->tz_set = 1;
1246 opts->time_offset = 0;
1247 break;
1248 case Opt_err_cont:
1249 opts->errors = FAT_ERRORS_CONT;
1250 break;
1251 case Opt_err_panic:
1252 opts->errors = FAT_ERRORS_PANIC;
1253 break;
1254 case Opt_err_ro:
1255 opts->errors = FAT_ERRORS_RO;
1256 break;
1257 case Opt_nfs_stale_rw:
1258 opts->nfs = FAT_NFS_STALE_RW;
1259 break;
1260 case Opt_nfs_nostale_ro:
1261 opts->nfs = FAT_NFS_NOSTALE_RO;
1262 break;
1263 case Opt_dos1xfloppy:
1264 opts->dos1xfloppy = 1;
1265 break;
1266
1267 /* msdos specific */
1268 case Opt_dots:
1269 opts->dotsOK = 1;
1270 break;
1271 case Opt_nodots:
1272 opts->dotsOK = 0;
1273 break;
1274
1275 /* vfat specific */
1276 case Opt_charset:
1277 if (opts->iocharset != fat_default_iocharset)
1278 kfree(opts->iocharset);
1279 iocharset = match_strdup(&args[0]);
1280 if (!iocharset)
1281 return -ENOMEM;
1282 opts->iocharset = iocharset;
1283 break;
1284 case Opt_shortname_lower:
1285 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1286 | VFAT_SFN_CREATE_WIN95;
1287 break;
1288 case Opt_shortname_win95:
1289 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1290 | VFAT_SFN_CREATE_WIN95;
1291 break;
1292 case Opt_shortname_winnt:
1293 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1294 | VFAT_SFN_CREATE_WINNT;
1295 break;
1296 case Opt_shortname_mixed:
1297 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1298 | VFAT_SFN_CREATE_WIN95;
1299 break;
1300 case Opt_utf8_no: /* 0 or no or false */
1301 opts->utf8 = 0;
1302 break;
1303 case Opt_utf8_yes: /* empty or 1 or yes or true */
1304 opts->utf8 = 1;
1305 break;
1306 case Opt_uni_xl_no: /* 0 or no or false */
1307 opts->unicode_xlate = 0;
1308 break;
1309 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1310 opts->unicode_xlate = 1;
1311 break;
1312 case Opt_nonumtail_no: /* 0 or no or false */
1313 opts->numtail = 1; /* negated option */
1314 break;
1315 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1316 opts->numtail = 0; /* negated option */
1317 break;
1318 case Opt_rodir:
1319 opts->rodir = 1;
1320 break;
1321 case Opt_discard:
1322 opts->discard = 1;
1323 break;
1324
1325 /* obsolete mount options */
1326 case Opt_obsolete:
1327 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, "
1328 "not supported now", p);
1329 break;
1330 /* unknown option */
1331 default:
1332 if (!silent) {
1333 fat_msg(sb, KERN_ERR,
1334 "Unrecognized mount option \"%s\" "
1335 "or missing value", p);
1336 }
1337 return -EINVAL;
1338 }
1339 }
1340
1341 out:
1342 /* UTF-8 doesn't provide FAT semantics */
1343 if (!strcmp(opts->iocharset, "utf8")) {
1344 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset"
1345 " for FAT filesystems, filesystem will be "
1346 "case sensitive!");
1347 }
1348
1349 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1350 if (opts->allow_utime == (unsigned short)-1)
1351 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
1352 if (opts->unicode_xlate)
1353 opts->utf8 = 0;
1354 if (opts->nfs == FAT_NFS_NOSTALE_RO) {
1355 sb->s_flags |= MS_RDONLY;
1356 sb->s_export_op = &fat_export_ops_nostale;
1357 }
1358
1359 return 0;
1360 }
1361
1362 static int fat_read_root(struct inode *inode)
1363 {
1364 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
1365 int error;
1366
1367 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO;
1368 inode->i_uid = sbi->options.fs_uid;
1369 inode->i_gid = sbi->options.fs_gid;
1370 inode->i_version++;
1371 inode->i_generation = 0;
1372 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
1373 inode->i_op = sbi->dir_ops;
1374 inode->i_fop = &fat_dir_operations;
1375 if (sbi->fat_bits == 32) {
1376 MSDOS_I(inode)->i_start = sbi->root_cluster;
1377 error = fat_calc_dir_size(inode);
1378 if (error < 0)
1379 return error;
1380 } else {
1381 MSDOS_I(inode)->i_start = 0;
1382 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1383 }
1384 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1385 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1386 MSDOS_I(inode)->i_logstart = 0;
1387 MSDOS_I(inode)->mmu_private = inode->i_size;
1388
1389 fat_save_attrs(inode, ATTR_DIR);
1390 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1391 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1392 set_nlink(inode, fat_subdirs(inode)+2);
1393
1394 return 0;
1395 }
1396
1397 static unsigned long calc_fat_clusters(struct super_block *sb)
1398 {
1399 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1400
1401 /* Divide first to avoid overflow */
1402 if (sbi->fat_bits != 12) {
1403 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits;
1404 return ent_per_sec * sbi->fat_length;
1405 }
1406
1407 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1408 }
1409
1410 static bool fat_bpb_is_zero(struct fat_boot_sector *b)
1411 {
1412 if (get_unaligned_le16(&b->sector_size))
1413 return false;
1414 if (b->sec_per_clus)
1415 return false;
1416 if (b->reserved)
1417 return false;
1418 if (b->fats)
1419 return false;
1420 if (get_unaligned_le16(&b->dir_entries))
1421 return false;
1422 if (get_unaligned_le16(&b->sectors))
1423 return false;
1424 if (b->media)
1425 return false;
1426 if (b->fat_length)
1427 return false;
1428 if (b->secs_track)
1429 return false;
1430 if (b->heads)
1431 return false;
1432 return true;
1433 }
1434
1435 static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b,
1436 int silent, struct fat_bios_param_block *bpb)
1437 {
1438 int error = -EINVAL;
1439
1440 /* Read in BPB ... */
1441 memset(bpb, 0, sizeof(*bpb));
1442 bpb->fat_sector_size = get_unaligned_le16(&b->sector_size);
1443 bpb->fat_sec_per_clus = b->sec_per_clus;
1444 bpb->fat_reserved = le16_to_cpu(b->reserved);
1445 bpb->fat_fats = b->fats;
1446 bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries);
1447 bpb->fat_sectors = get_unaligned_le16(&b->sectors);
1448 bpb->fat_fat_length = le16_to_cpu(b->fat_length);
1449 bpb->fat_total_sect = le32_to_cpu(b->total_sect);
1450
1451 bpb->fat16_state = b->fat16.state;
1452 bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id);
1453
1454 bpb->fat32_length = le32_to_cpu(b->fat32.length);
1455 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster);
1456 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector);
1457 bpb->fat32_state = b->fat32.state;
1458 bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id);
1459
1460 /* Validate this looks like a FAT filesystem BPB */
1461 if (!bpb->fat_reserved) {
1462 if (!silent)
1463 fat_msg(sb, KERN_ERR,
1464 "bogus number of reserved sectors");
1465 goto out;
1466 }
1467 if (!bpb->fat_fats) {
1468 if (!silent)
1469 fat_msg(sb, KERN_ERR, "bogus number of FAT structure");
1470 goto out;
1471 }
1472
1473 /*
1474 * Earlier we checked here that b->secs_track and b->head are nonzero,
1475 * but it turns out valid FAT filesystems can have zero there.
1476 */
1477
1478 if (!fat_valid_media(b->media)) {
1479 if (!silent)
1480 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)",
1481 (unsigned)b->media);
1482 goto out;
1483 }
1484
1485 if (!is_power_of_2(bpb->fat_sector_size)
1486 || (bpb->fat_sector_size < 512)
1487 || (bpb->fat_sector_size > 4096)) {
1488 if (!silent)
1489 fat_msg(sb, KERN_ERR, "bogus logical sector size %u",
1490 (unsigned)bpb->fat_sector_size);
1491 goto out;
1492 }
1493
1494 if (!is_power_of_2(bpb->fat_sec_per_clus)) {
1495 if (!silent)
1496 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u",
1497 (unsigned)bpb->fat_sec_per_clus);
1498 goto out;
1499 }
1500
1501 error = 0;
1502
1503 out:
1504 return error;
1505 }
1506
1507 static int fat_read_static_bpb(struct super_block *sb,
1508 struct fat_boot_sector *b, int silent,
1509 struct fat_bios_param_block *bpb)
1510 {
1511 static const char *notdos1x = "This doesn't look like a DOS 1.x volume";
1512
1513 struct fat_floppy_defaults *fdefaults = NULL;
1514 int error = -EINVAL;
1515 sector_t bd_sects;
1516 unsigned i;
1517
1518 bd_sects = i_size_read(sb->s_bdev->bd_inode) / SECTOR_SIZE;
1519
1520 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */
1521 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) {
1522 if (!silent)
1523 fat_msg(sb, KERN_ERR,
1524 "%s; no bootstrapping code", notdos1x);
1525 goto out;
1526 }
1527
1528 /*
1529 * If any value in this region is non-zero, it isn't archaic
1530 * DOS.
1531 */
1532 if (!fat_bpb_is_zero(b)) {
1533 if (!silent)
1534 fat_msg(sb, KERN_ERR,
1535 "%s; DOS 2.x BPB is non-zero", notdos1x);
1536 goto out;
1537 }
1538
1539 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) {
1540 if (floppy_defaults[i].nr_sectors == bd_sects) {
1541 fdefaults = &floppy_defaults[i];
1542 break;
1543 }
1544 }
1545
1546 if (fdefaults == NULL) {
1547 if (!silent)
1548 fat_msg(sb, KERN_WARNING,
1549 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)",
1550 (u64)bd_sects);
1551 goto out;
1552 }
1553
1554 if (!silent)
1555 fat_msg(sb, KERN_INFO,
1556 "This looks like a DOS 1.x volume; assuming default BPB values");
1557
1558 memset(bpb, 0, sizeof(*bpb));
1559 bpb->fat_sector_size = SECTOR_SIZE;
1560 bpb->fat_sec_per_clus = fdefaults->sec_per_clus;
1561 bpb->fat_reserved = 1;
1562 bpb->fat_fats = 2;
1563 bpb->fat_dir_entries = fdefaults->dir_entries;
1564 bpb->fat_sectors = fdefaults->nr_sectors;
1565 bpb->fat_fat_length = fdefaults->fat_length;
1566
1567 error = 0;
1568
1569 out:
1570 return error;
1571 }
1572
1573 /*
1574 * Read the super block of an MS-DOS FS.
1575 */
1576 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
1577 void (*setup)(struct super_block *))
1578 {
1579 struct inode *root_inode = NULL, *fat_inode = NULL;
1580 struct inode *fsinfo_inode = NULL;
1581 struct buffer_head *bh;
1582 struct fat_bios_param_block bpb;
1583 struct msdos_sb_info *sbi;
1584 u16 logical_sector_size;
1585 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1586 int debug;
1587 long error;
1588 char buf[50];
1589
1590 /*
1591 * GFP_KERNEL is ok here, because while we do hold the
1592 * supeblock lock, memory pressure can't call back into
1593 * the filesystem, since we're only just about to mount
1594 * it and have no inodes etc active!
1595 */
1596 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1597 if (!sbi)
1598 return -ENOMEM;
1599 sb->s_fs_info = sbi;
1600
1601 sb->s_flags |= MS_NODIRATIME;
1602 sb->s_magic = MSDOS_SUPER_MAGIC;
1603 sb->s_op = &fat_sops;
1604 sb->s_export_op = &fat_export_ops;
1605 mutex_init(&sbi->nfs_build_inode_lock);
1606 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
1607 DEFAULT_RATELIMIT_BURST);
1608
1609 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options);
1610 if (error)
1611 goto out_fail;
1612
1613 setup(sb); /* flavour-specific stuff that needs options */
1614
1615 error = -EIO;
1616 sb_min_blocksize(sb, 512);
1617 bh = sb_bread(sb, 0);
1618 if (bh == NULL) {
1619 fat_msg(sb, KERN_ERR, "unable to read boot sector");
1620 goto out_fail;
1621 }
1622
1623 error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent,
1624 &bpb);
1625 if (error == -EINVAL && sbi->options.dos1xfloppy)
1626 error = fat_read_static_bpb(sb,
1627 (struct fat_boot_sector *)bh->b_data, silent, &bpb);
1628 brelse(bh);
1629
1630 if (error == -EINVAL)
1631 goto out_invalid;
1632 else if (error)
1633 goto out_fail;
1634
1635 logical_sector_size = bpb.fat_sector_size;
1636 sbi->sec_per_clus = bpb.fat_sec_per_clus;
1637
1638 error = -EIO;
1639 if (logical_sector_size < sb->s_blocksize) {
1640 fat_msg(sb, KERN_ERR, "logical sector size too small for device"
1641 " (logical sector size = %u)", logical_sector_size);
1642 goto out_fail;
1643 }
1644
1645 if (logical_sector_size > sb->s_blocksize) {
1646 struct buffer_head *bh_resize;
1647
1648 if (!sb_set_blocksize(sb, logical_sector_size)) {
1649 fat_msg(sb, KERN_ERR, "unable to set blocksize %u",
1650 logical_sector_size);
1651 goto out_fail;
1652 }
1653
1654 /* Verify that the larger boot sector is fully readable */
1655 bh_resize = sb_bread(sb, 0);
1656 if (bh_resize == NULL) {
1657 fat_msg(sb, KERN_ERR, "unable to read boot sector"
1658 " (logical sector size = %lu)",
1659 sb->s_blocksize);
1660 goto out_fail;
1661 }
1662 brelse(bh_resize);
1663 }
1664
1665 mutex_init(&sbi->s_lock);
1666 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1667 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1668 sbi->fats = bpb.fat_fats;
1669 sbi->fat_bits = 0; /* Don't know yet */
1670 sbi->fat_start = bpb.fat_reserved;
1671 sbi->fat_length = bpb.fat_fat_length;
1672 sbi->root_cluster = 0;
1673 sbi->free_clusters = -1; /* Don't know yet */
1674 sbi->free_clus_valid = 0;
1675 sbi->prev_free = FAT_START_ENT;
1676 sb->s_maxbytes = 0xffffffff;
1677
1678 if (!sbi->fat_length && bpb.fat32_length) {
1679 struct fat_boot_fsinfo *fsinfo;
1680 struct buffer_head *fsinfo_bh;
1681
1682 /* Must be FAT32 */
1683 sbi->fat_bits = 32;
1684 sbi->fat_length = bpb.fat32_length;
1685 sbi->root_cluster = bpb.fat32_root_cluster;
1686
1687 /* MC - if info_sector is 0, don't multiply by 0 */
1688 sbi->fsinfo_sector = bpb.fat32_info_sector;
1689 if (sbi->fsinfo_sector == 0)
1690 sbi->fsinfo_sector = 1;
1691
1692 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1693 if (fsinfo_bh == NULL) {
1694 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block"
1695 " (sector = %lu)", sbi->fsinfo_sector);
1696 goto out_fail;
1697 }
1698
1699 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1700 if (!IS_FSINFO(fsinfo)) {
1701 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
1702 "0x%08x, 0x%08x (sector = %lu)",
1703 le32_to_cpu(fsinfo->signature1),
1704 le32_to_cpu(fsinfo->signature2),
1705 sbi->fsinfo_sector);
1706 } else {
1707 if (sbi->options.usefree)
1708 sbi->free_clus_valid = 1;
1709 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1710 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1711 }
1712
1713 brelse(fsinfo_bh);
1714 }
1715
1716 /* interpret volume ID as a little endian 32 bit integer */
1717 if (sbi->fat_bits == 32)
1718 sbi->vol_id = bpb.fat32_vol_id;
1719 else /* fat 16 or 12 */
1720 sbi->vol_id = bpb.fat16_vol_id;
1721
1722 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1723 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1724
1725 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1726 sbi->dir_entries = bpb.fat_dir_entries;
1727 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1728 if (!silent)
1729 fat_msg(sb, KERN_ERR, "bogus directory-entries per block"
1730 " (%u)", sbi->dir_entries);
1731 goto out_invalid;
1732 }
1733
1734 rootdir_sectors = sbi->dir_entries
1735 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1736 sbi->data_start = sbi->dir_start + rootdir_sectors;
1737 total_sectors = bpb.fat_sectors;
1738 if (total_sectors == 0)
1739 total_sectors = bpb.fat_total_sect;
1740
1741 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1742
1743 if (sbi->fat_bits != 32)
1744 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1745
1746 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */
1747 if (sbi->fat_bits == 32)
1748 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY;
1749 else /* fat 16 or 12 */
1750 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY;
1751
1752 /* check that FAT table does not overflow */
1753 fat_clusters = calc_fat_clusters(sb);
1754 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1755 if (total_clusters > MAX_FAT(sb)) {
1756 if (!silent)
1757 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)",
1758 total_clusters);
1759 goto out_invalid;
1760 }
1761
1762 sbi->max_cluster = total_clusters + FAT_START_ENT;
1763 /* check the free_clusters, it's not necessarily correct */
1764 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1765 sbi->free_clusters = -1;
1766 /* check the prev_free, it's not necessarily correct */
1767 sbi->prev_free %= sbi->max_cluster;
1768 if (sbi->prev_free < FAT_START_ENT)
1769 sbi->prev_free = FAT_START_ENT;
1770
1771 /* set up enough so that it can read an inode */
1772 fat_hash_init(sb);
1773 dir_hash_init(sb);
1774 fat_ent_access_init(sb);
1775
1776 /*
1777 * The low byte of FAT's first entry must have same value with
1778 * media-field. But in real world, too many devices is
1779 * writing wrong value. So, removed that validity check.
1780 *
1781 * if (FAT_FIRST_ENT(sb, media) != first)
1782 */
1783
1784 error = -EINVAL;
1785 sprintf(buf, "cp%d", sbi->options.codepage);
1786 sbi->nls_disk = load_nls(buf);
1787 if (!sbi->nls_disk) {
1788 fat_msg(sb, KERN_ERR, "codepage %s not found", buf);
1789 goto out_fail;
1790 }
1791
1792 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1793 if (sbi->options.isvfat) {
1794 sbi->nls_io = load_nls(sbi->options.iocharset);
1795 if (!sbi->nls_io) {
1796 fat_msg(sb, KERN_ERR, "IO charset %s not found",
1797 sbi->options.iocharset);
1798 goto out_fail;
1799 }
1800 }
1801
1802 error = -ENOMEM;
1803 fat_inode = new_inode(sb);
1804 if (!fat_inode)
1805 goto out_fail;
1806 MSDOS_I(fat_inode)->i_pos = 0;
1807 sbi->fat_inode = fat_inode;
1808
1809 fsinfo_inode = new_inode(sb);
1810 if (!fsinfo_inode)
1811 goto out_fail;
1812 fsinfo_inode->i_ino = MSDOS_FSINFO_INO;
1813 sbi->fsinfo_inode = fsinfo_inode;
1814 insert_inode_hash(fsinfo_inode);
1815
1816 root_inode = new_inode(sb);
1817 if (!root_inode)
1818 goto out_fail;
1819 root_inode->i_ino = MSDOS_ROOT_INO;
1820 root_inode->i_version = 1;
1821 error = fat_read_root(root_inode);
1822 if (error < 0) {
1823 iput(root_inode);
1824 goto out_fail;
1825 }
1826 error = -ENOMEM;
1827 insert_inode_hash(root_inode);
1828 fat_attach(root_inode, 0);
1829 sb->s_root = d_make_root(root_inode);
1830 if (!sb->s_root) {
1831 fat_msg(sb, KERN_ERR, "get root inode failed");
1832 goto out_fail;
1833 }
1834
1835 if (sbi->options.discard) {
1836 struct request_queue *q = bdev_get_queue(sb->s_bdev);
1837 if (!blk_queue_discard(q))
1838 fat_msg(sb, KERN_WARNING,
1839 "mounting with \"discard\" option, but "
1840 "the device does not support discard");
1841 }
1842
1843 fat_set_state(sb, 1, 0);
1844 return 0;
1845
1846 out_invalid:
1847 error = -EINVAL;
1848 if (!silent)
1849 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem");
1850
1851 out_fail:
1852 if (fsinfo_inode)
1853 iput(fsinfo_inode);
1854 if (fat_inode)
1855 iput(fat_inode);
1856 unload_nls(sbi->nls_io);
1857 unload_nls(sbi->nls_disk);
1858 if (sbi->options.iocharset != fat_default_iocharset)
1859 kfree(sbi->options.iocharset);
1860 sb->s_fs_info = NULL;
1861 kfree(sbi);
1862 return error;
1863 }
1864
1865 EXPORT_SYMBOL_GPL(fat_fill_super);
1866
1867 /*
1868 * helper function for fat_flush_inodes. This writes both the inode
1869 * and the file data blocks, waiting for in flight data blocks before
1870 * the start of the call. It does not wait for any io started
1871 * during the call
1872 */
1873 static int writeback_inode(struct inode *inode)
1874 {
1875
1876 int ret;
1877
1878 /* if we used wait=1, sync_inode_metadata waits for the io for the
1879 * inode to finish. So wait=0 is sent down to sync_inode_metadata
1880 * and filemap_fdatawrite is used for the data blocks
1881 */
1882 ret = sync_inode_metadata(inode, 0);
1883 if (!ret)
1884 ret = filemap_fdatawrite(inode->i_mapping);
1885 return ret;
1886 }
1887
1888 /*
1889 * write data and metadata corresponding to i1 and i2. The io is
1890 * started but we do not wait for any of it to finish.
1891 *
1892 * filemap_flush is used for the block device, so if there is a dirty
1893 * page for a block already in flight, we will not wait and start the
1894 * io over again
1895 */
1896 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1897 {
1898 int ret = 0;
1899 if (!MSDOS_SB(sb)->options.flush)
1900 return 0;
1901 if (i1)
1902 ret = writeback_inode(i1);
1903 if (!ret && i2)
1904 ret = writeback_inode(i2);
1905 if (!ret) {
1906 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1907 ret = filemap_flush(mapping);
1908 }
1909 return ret;
1910 }
1911 EXPORT_SYMBOL_GPL(fat_flush_inodes);
1912
1913 static int __init init_fat_fs(void)
1914 {
1915 int err;
1916
1917 err = fat_cache_init();
1918 if (err)
1919 return err;
1920
1921 err = fat_init_inodecache();
1922 if (err)
1923 goto failed;
1924
1925 return 0;
1926
1927 failed:
1928 fat_cache_destroy();
1929 return err;
1930 }
1931
1932 static void __exit exit_fat_fs(void)
1933 {
1934 fat_cache_destroy();
1935 fat_destroy_inodecache();
1936 }
1937
1938 module_init(init_fat_fs)
1939 module_exit(exit_fat_fs)
1940
1941 MODULE_LICENSE("GPL");
Linux with added FPC-III support