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Merge tag 'iversion-v4.16-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton...
[mirror_ubuntu-focal-kernel.git] / fs / fat / inode.c
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 <linux/iversion.h>
24 #include "fat.h"
25
26 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET
27 /* if user don't select VFAT, this is undefined. */
28 #define CONFIG_FAT_DEFAULT_IOCHARSET ""
29 #endif
30
31 #define KB_IN_SECTORS 2
32
33 /*
34 * A deserialized copy of the on-disk structure laid out in struct
35 * fat_boot_sector.
36 */
37 struct fat_bios_param_block {
38 u16 fat_sector_size;
39 u8 fat_sec_per_clus;
40 u16 fat_reserved;
41 u8 fat_fats;
42 u16 fat_dir_entries;
43 u16 fat_sectors;
44 u16 fat_fat_length;
45 u32 fat_total_sect;
46
47 u8 fat16_state;
48 u32 fat16_vol_id;
49
50 u32 fat32_length;
51 u32 fat32_root_cluster;
52 u16 fat32_info_sector;
53 u8 fat32_state;
54 u32 fat32_vol_id;
55 };
56
57 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
58 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
59
60 static struct fat_floppy_defaults {
61 unsigned nr_sectors;
62 unsigned sec_per_clus;
63 unsigned dir_entries;
64 unsigned media;
65 unsigned fat_length;
66 } floppy_defaults[] = {
67 {
68 .nr_sectors = 160 * KB_IN_SECTORS,
69 .sec_per_clus = 1,
70 .dir_entries = 64,
71 .media = 0xFE,
72 .fat_length = 1,
73 },
74 {
75 .nr_sectors = 180 * KB_IN_SECTORS,
76 .sec_per_clus = 1,
77 .dir_entries = 64,
78 .media = 0xFC,
79 .fat_length = 2,
80 },
81 {
82 .nr_sectors = 320 * KB_IN_SECTORS,
83 .sec_per_clus = 2,
84 .dir_entries = 112,
85 .media = 0xFF,
86 .fat_length = 1,
87 },
88 {
89 .nr_sectors = 360 * KB_IN_SECTORS,
90 .sec_per_clus = 2,
91 .dir_entries = 112,
92 .media = 0xFD,
93 .fat_length = 2,
94 },
95 };
96
97 int fat_add_cluster(struct inode *inode)
98 {
99 int err, cluster;
100
101 err = fat_alloc_clusters(inode, &cluster, 1);
102 if (err)
103 return err;
104 /* FIXME: this cluster should be added after data of this
105 * cluster is writed */
106 err = fat_chain_add(inode, cluster, 1);
107 if (err)
108 fat_free_clusters(inode, cluster);
109 return err;
110 }
111
112 static inline int __fat_get_block(struct inode *inode, sector_t iblock,
113 unsigned long *max_blocks,
114 struct buffer_head *bh_result, int create)
115 {
116 struct super_block *sb = inode->i_sb;
117 struct msdos_sb_info *sbi = MSDOS_SB(sb);
118 unsigned long mapped_blocks;
119 sector_t phys, last_block;
120 int err, offset;
121
122 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false);
123 if (err)
124 return err;
125 if (phys) {
126 map_bh(bh_result, sb, phys);
127 *max_blocks = min(mapped_blocks, *max_blocks);
128 return 0;
129 }
130 if (!create)
131 return 0;
132
133 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
134 fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)",
135 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
136 return -EIO;
137 }
138
139 last_block = inode->i_blocks >> (sb->s_blocksize_bits - 9);
140 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
141 /*
142 * allocate a cluster according to the following.
143 * 1) no more available blocks
144 * 2) not part of fallocate region
145 */
146 if (!offset && !(iblock < last_block)) {
147 /* TODO: multiple cluster allocation would be desirable. */
148 err = fat_add_cluster(inode);
149 if (err)
150 return err;
151 }
152 /* available blocks on this cluster */
153 mapped_blocks = sbi->sec_per_clus - offset;
154
155 *max_blocks = min(mapped_blocks, *max_blocks);
156 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
157
158 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false);
159 if (err)
160 return err;
161
162 BUG_ON(!phys);
163 BUG_ON(*max_blocks != mapped_blocks);
164 set_buffer_new(bh_result);
165 map_bh(bh_result, sb, phys);
166
167 return 0;
168 }
169
170 static int fat_get_block(struct inode *inode, sector_t iblock,
171 struct buffer_head *bh_result, int create)
172 {
173 struct super_block *sb = inode->i_sb;
174 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
175 int err;
176
177 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
178 if (err)
179 return err;
180 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
181 return 0;
182 }
183
184 static int fat_writepage(struct page *page, struct writeback_control *wbc)
185 {
186 return block_write_full_page(page, fat_get_block, wbc);
187 }
188
189 static int fat_writepages(struct address_space *mapping,
190 struct writeback_control *wbc)
191 {
192 return mpage_writepages(mapping, wbc, fat_get_block);
193 }
194
195 static int fat_readpage(struct file *file, struct page *page)
196 {
197 return mpage_readpage(page, fat_get_block);
198 }
199
200 static int fat_readpages(struct file *file, struct address_space *mapping,
201 struct list_head *pages, unsigned nr_pages)
202 {
203 return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
204 }
205
206 static void fat_write_failed(struct address_space *mapping, loff_t to)
207 {
208 struct inode *inode = mapping->host;
209
210 if (to > inode->i_size) {
211 truncate_pagecache(inode, inode->i_size);
212 fat_truncate_blocks(inode, inode->i_size);
213 }
214 }
215
216 static int fat_write_begin(struct file *file, struct address_space *mapping,
217 loff_t pos, unsigned len, unsigned flags,
218 struct page **pagep, void **fsdata)
219 {
220 int err;
221
222 *pagep = NULL;
223 err = cont_write_begin(file, mapping, pos, len, flags,
224 pagep, fsdata, fat_get_block,
225 &MSDOS_I(mapping->host)->mmu_private);
226 if (err < 0)
227 fat_write_failed(mapping, pos + len);
228 return err;
229 }
230
231 static int fat_write_end(struct file *file, struct address_space *mapping,
232 loff_t pos, unsigned len, unsigned copied,
233 struct page *pagep, void *fsdata)
234 {
235 struct inode *inode = mapping->host;
236 int err;
237 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
238 if (err < len)
239 fat_write_failed(mapping, pos + len);
240 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
241 inode->i_mtime = inode->i_ctime = current_time(inode);
242 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
243 mark_inode_dirty(inode);
244 }
245 return err;
246 }
247
248 static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
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 loff_t offset = iocb->ki_pos;
255 ssize_t ret;
256
257 if (iov_iter_rw(iter) == WRITE) {
258 /*
259 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
260 * so we need to update the ->mmu_private to block boundary.
261 *
262 * But we must fill the remaining area or hole by nul for
263 * updating ->mmu_private.
264 *
265 * Return 0, and fallback to normal buffered write.
266 */
267 loff_t size = offset + count;
268 if (MSDOS_I(inode)->mmu_private < size)
269 return 0;
270 }
271
272 /*
273 * FAT need to use the DIO_LOCKING for avoiding the race
274 * condition of fat_get_block() and ->truncate().
275 */
276 ret = blockdev_direct_IO(iocb, inode, iter, fat_get_block);
277 if (ret < 0 && iov_iter_rw(iter) == WRITE)
278 fat_write_failed(mapping, offset + count);
279
280 return ret;
281 }
282
283 static int fat_get_block_bmap(struct inode *inode, sector_t iblock,
284 struct buffer_head *bh_result, int create)
285 {
286 struct super_block *sb = inode->i_sb;
287 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
288 int err;
289 sector_t bmap;
290 unsigned long mapped_blocks;
291
292 BUG_ON(create != 0);
293
294 err = fat_bmap(inode, iblock, &bmap, &mapped_blocks, create, true);
295 if (err)
296 return err;
297
298 if (bmap) {
299 map_bh(bh_result, sb, bmap);
300 max_blocks = min(mapped_blocks, max_blocks);
301 }
302
303 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
304
305 return 0;
306 }
307
308 static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
309 {
310 sector_t blocknr;
311
312 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
313 down_read(&MSDOS_I(mapping->host)->truncate_lock);
314 blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap);
315 up_read(&MSDOS_I(mapping->host)->truncate_lock);
316
317 return blocknr;
318 }
319
320 /*
321 * fat_block_truncate_page() zeroes out a mapping from file offset `from'
322 * up to the end of the block which corresponds to `from'.
323 * This is required during truncate to physically zeroout the tail end
324 * of that block so it doesn't yield old data if the file is later grown.
325 * Also, avoid causing failure from fsx for cases of "data past EOF"
326 */
327 int fat_block_truncate_page(struct inode *inode, loff_t from)
328 {
329 return block_truncate_page(inode->i_mapping, from, fat_get_block);
330 }
331
332 static const struct address_space_operations fat_aops = {
333 .readpage = fat_readpage,
334 .readpages = fat_readpages,
335 .writepage = fat_writepage,
336 .writepages = fat_writepages,
337 .write_begin = fat_write_begin,
338 .write_end = fat_write_end,
339 .direct_IO = fat_direct_IO,
340 .bmap = _fat_bmap
341 };
342
343 /*
344 * New FAT inode stuff. We do the following:
345 * a) i_ino is constant and has nothing with on-disk location.
346 * b) FAT manages its own cache of directory entries.
347 * c) *This* cache is indexed by on-disk location.
348 * d) inode has an associated directory entry, all right, but
349 * it may be unhashed.
350 * e) currently entries are stored within struct inode. That should
351 * change.
352 * f) we deal with races in the following way:
353 * 1. readdir() and lookup() do FAT-dir-cache lookup.
354 * 2. rename() unhashes the F-d-c entry and rehashes it in
355 * a new place.
356 * 3. unlink() and rmdir() unhash F-d-c entry.
357 * 4. fat_write_inode() checks whether the thing is unhashed.
358 * If it is we silently return. If it isn't we do bread(),
359 * check if the location is still valid and retry if it
360 * isn't. Otherwise we do changes.
361 * 5. Spinlock is used to protect hash/unhash/location check/lookup
362 * 6. fat_evict_inode() unhashes the F-d-c entry.
363 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
364 * and consider negative result as cache miss.
365 */
366
367 static void fat_hash_init(struct super_block *sb)
368 {
369 struct msdos_sb_info *sbi = MSDOS_SB(sb);
370 int i;
371
372 spin_lock_init(&sbi->inode_hash_lock);
373 for (i = 0; i < FAT_HASH_SIZE; i++)
374 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
375 }
376
377 static inline unsigned long fat_hash(loff_t i_pos)
378 {
379 return hash_32(i_pos, FAT_HASH_BITS);
380 }
381
382 static void dir_hash_init(struct super_block *sb)
383 {
384 struct msdos_sb_info *sbi = MSDOS_SB(sb);
385 int i;
386
387 spin_lock_init(&sbi->dir_hash_lock);
388 for (i = 0; i < FAT_HASH_SIZE; i++)
389 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]);
390 }
391
392 void fat_attach(struct inode *inode, loff_t i_pos)
393 {
394 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
395
396 if (inode->i_ino != MSDOS_ROOT_INO) {
397 struct hlist_head *head = sbi->inode_hashtable
398 + fat_hash(i_pos);
399
400 spin_lock(&sbi->inode_hash_lock);
401 MSDOS_I(inode)->i_pos = i_pos;
402 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
403 spin_unlock(&sbi->inode_hash_lock);
404 }
405
406 /* If NFS support is enabled, cache the mapping of start cluster
407 * to directory inode. This is used during reconnection of
408 * dentries to the filesystem root.
409 */
410 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
411 struct hlist_head *d_head = sbi->dir_hashtable;
412 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart);
413
414 spin_lock(&sbi->dir_hash_lock);
415 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head);
416 spin_unlock(&sbi->dir_hash_lock);
417 }
418 }
419 EXPORT_SYMBOL_GPL(fat_attach);
420
421 void fat_detach(struct inode *inode)
422 {
423 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
424 spin_lock(&sbi->inode_hash_lock);
425 MSDOS_I(inode)->i_pos = 0;
426 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
427 spin_unlock(&sbi->inode_hash_lock);
428
429 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
430 spin_lock(&sbi->dir_hash_lock);
431 hlist_del_init(&MSDOS_I(inode)->i_dir_hash);
432 spin_unlock(&sbi->dir_hash_lock);
433 }
434 }
435 EXPORT_SYMBOL_GPL(fat_detach);
436
437 struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
438 {
439 struct msdos_sb_info *sbi = MSDOS_SB(sb);
440 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
441 struct msdos_inode_info *i;
442 struct inode *inode = NULL;
443
444 spin_lock(&sbi->inode_hash_lock);
445 hlist_for_each_entry(i, head, i_fat_hash) {
446 BUG_ON(i->vfs_inode.i_sb != sb);
447 if (i->i_pos != i_pos)
448 continue;
449 inode = igrab(&i->vfs_inode);
450 if (inode)
451 break;
452 }
453 spin_unlock(&sbi->inode_hash_lock);
454 return inode;
455 }
456
457 static int is_exec(unsigned char *extension)
458 {
459 unsigned char exe_extensions[] = "EXECOMBAT", *walk;
460
461 for (walk = exe_extensions; *walk; walk += 3)
462 if (!strncmp(extension, walk, 3))
463 return 1;
464 return 0;
465 }
466
467 static int fat_calc_dir_size(struct inode *inode)
468 {
469 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
470 int ret, fclus, dclus;
471
472 inode->i_size = 0;
473 if (MSDOS_I(inode)->i_start == 0)
474 return 0;
475
476 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
477 if (ret < 0)
478 return ret;
479 inode->i_size = (fclus + 1) << sbi->cluster_bits;
480
481 return 0;
482 }
483
484 static int fat_validate_dir(struct inode *dir)
485 {
486 struct super_block *sb = dir->i_sb;
487
488 if (dir->i_nlink < 2) {
489 /* Directory should have "."/".." entries at least. */
490 fat_fs_error(sb, "corrupted directory (invalid entries)");
491 return -EIO;
492 }
493 if (MSDOS_I(dir)->i_start == 0 ||
494 MSDOS_I(dir)->i_start == MSDOS_SB(sb)->root_cluster) {
495 /* Directory should point valid cluster. */
496 fat_fs_error(sb, "corrupted directory (invalid i_start)");
497 return -EIO;
498 }
499 return 0;
500 }
501
502 /* doesn't deal with root inode */
503 int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
504 {
505 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
506 int error;
507
508 MSDOS_I(inode)->i_pos = 0;
509 inode->i_uid = sbi->options.fs_uid;
510 inode->i_gid = sbi->options.fs_gid;
511 inode_inc_iversion(inode);
512 inode->i_generation = get_seconds();
513
514 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
515 inode->i_generation &= ~1;
516 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
517 inode->i_op = sbi->dir_ops;
518 inode->i_fop = &fat_dir_operations;
519
520 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
521 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
522 error = fat_calc_dir_size(inode);
523 if (error < 0)
524 return error;
525 MSDOS_I(inode)->mmu_private = inode->i_size;
526
527 set_nlink(inode, fat_subdirs(inode));
528
529 error = fat_validate_dir(inode);
530 if (error < 0)
531 return error;
532 } else { /* not a directory */
533 inode->i_generation |= 1;
534 inode->i_mode = fat_make_mode(sbi, de->attr,
535 ((sbi->options.showexec && !is_exec(de->name + 8))
536 ? S_IRUGO|S_IWUGO : S_IRWXUGO));
537 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
538
539 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
540 inode->i_size = le32_to_cpu(de->size);
541 inode->i_op = &fat_file_inode_operations;
542 inode->i_fop = &fat_file_operations;
543 inode->i_mapping->a_ops = &fat_aops;
544 MSDOS_I(inode)->mmu_private = inode->i_size;
545 }
546 if (de->attr & ATTR_SYS) {
547 if (sbi->options.sys_immutable)
548 inode->i_flags |= S_IMMUTABLE;
549 }
550 fat_save_attrs(inode, de->attr);
551
552 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
553 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
554
555 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
556 if (sbi->options.isvfat) {
557 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
558 de->cdate, de->ctime_cs);
559 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
560 } else
561 inode->i_ctime = inode->i_atime = inode->i_mtime;
562
563 return 0;
564 }
565
566 static inline void fat_lock_build_inode(struct msdos_sb_info *sbi)
567 {
568 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
569 mutex_lock(&sbi->nfs_build_inode_lock);
570 }
571
572 static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi)
573 {
574 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
575 mutex_unlock(&sbi->nfs_build_inode_lock);
576 }
577
578 struct inode *fat_build_inode(struct super_block *sb,
579 struct msdos_dir_entry *de, loff_t i_pos)
580 {
581 struct inode *inode;
582 int err;
583
584 fat_lock_build_inode(MSDOS_SB(sb));
585 inode = fat_iget(sb, i_pos);
586 if (inode)
587 goto out;
588 inode = new_inode(sb);
589 if (!inode) {
590 inode = ERR_PTR(-ENOMEM);
591 goto out;
592 }
593 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
594 inode_set_iversion(inode, 1);
595 err = fat_fill_inode(inode, de);
596 if (err) {
597 iput(inode);
598 inode = ERR_PTR(err);
599 goto out;
600 }
601 fat_attach(inode, i_pos);
602 insert_inode_hash(inode);
603 out:
604 fat_unlock_build_inode(MSDOS_SB(sb));
605 return inode;
606 }
607
608 EXPORT_SYMBOL_GPL(fat_build_inode);
609
610 static int __fat_write_inode(struct inode *inode, int wait);
611
612 static void fat_free_eofblocks(struct inode *inode)
613 {
614 /* Release unwritten fallocated blocks on inode eviction. */
615 if ((inode->i_blocks << 9) >
616 round_up(MSDOS_I(inode)->mmu_private,
617 MSDOS_SB(inode->i_sb)->cluster_size)) {
618 int err;
619
620 fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private);
621 /* Fallocate results in updating the i_start/iogstart
622 * for the zero byte file. So, make it return to
623 * original state during evict and commit it to avoid
624 * any corruption on the next access to the cluster
625 * chain for the file.
626 */
627 err = __fat_write_inode(inode, inode_needs_sync(inode));
628 if (err) {
629 fat_msg(inode->i_sb, KERN_WARNING, "Failed to "
630 "update on disk inode for unused "
631 "fallocated blocks, inode could be "
632 "corrupted. Please run fsck");
633 }
634
635 }
636 }
637
638 static void fat_evict_inode(struct inode *inode)
639 {
640 truncate_inode_pages_final(&inode->i_data);
641 if (!inode->i_nlink) {
642 inode->i_size = 0;
643 fat_truncate_blocks(inode, 0);
644 } else
645 fat_free_eofblocks(inode);
646
647 invalidate_inode_buffers(inode);
648 clear_inode(inode);
649 fat_cache_inval_inode(inode);
650 fat_detach(inode);
651 }
652
653 static void fat_set_state(struct super_block *sb,
654 unsigned int set, unsigned int force)
655 {
656 struct buffer_head *bh;
657 struct fat_boot_sector *b;
658 struct msdos_sb_info *sbi = MSDOS_SB(sb);
659
660 /* do not change any thing if mounted read only */
661 if (sb_rdonly(sb) && !force)
662 return;
663
664 /* do not change state if fs was dirty */
665 if (sbi->dirty) {
666 /* warn only on set (mount). */
667 if (set)
668 fat_msg(sb, KERN_WARNING, "Volume was not properly "
669 "unmounted. Some data may be corrupt. "
670 "Please run fsck.");
671 return;
672 }
673
674 bh = sb_bread(sb, 0);
675 if (bh == NULL) {
676 fat_msg(sb, KERN_ERR, "unable to read boot sector "
677 "to mark fs as dirty");
678 return;
679 }
680
681 b = (struct fat_boot_sector *) bh->b_data;
682
683 if (sbi->fat_bits == 32) {
684 if (set)
685 b->fat32.state |= FAT_STATE_DIRTY;
686 else
687 b->fat32.state &= ~FAT_STATE_DIRTY;
688 } else /* fat 16 and 12 */ {
689 if (set)
690 b->fat16.state |= FAT_STATE_DIRTY;
691 else
692 b->fat16.state &= ~FAT_STATE_DIRTY;
693 }
694
695 mark_buffer_dirty(bh);
696 sync_dirty_buffer(bh);
697 brelse(bh);
698 }
699
700 static void delayed_free(struct rcu_head *p)
701 {
702 struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu);
703 unload_nls(sbi->nls_disk);
704 unload_nls(sbi->nls_io);
705 if (sbi->options.iocharset != fat_default_iocharset)
706 kfree(sbi->options.iocharset);
707 kfree(sbi);
708 }
709
710 static void fat_put_super(struct super_block *sb)
711 {
712 struct msdos_sb_info *sbi = MSDOS_SB(sb);
713
714 fat_set_state(sb, 0, 0);
715
716 iput(sbi->fsinfo_inode);
717 iput(sbi->fat_inode);
718
719 call_rcu(&sbi->rcu, delayed_free);
720 }
721
722 static struct kmem_cache *fat_inode_cachep;
723
724 static struct inode *fat_alloc_inode(struct super_block *sb)
725 {
726 struct msdos_inode_info *ei;
727 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
728 if (!ei)
729 return NULL;
730
731 init_rwsem(&ei->truncate_lock);
732 return &ei->vfs_inode;
733 }
734
735 static void fat_i_callback(struct rcu_head *head)
736 {
737 struct inode *inode = container_of(head, struct inode, i_rcu);
738 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
739 }
740
741 static void fat_destroy_inode(struct inode *inode)
742 {
743 call_rcu(&inode->i_rcu, fat_i_callback);
744 }
745
746 static void init_once(void *foo)
747 {
748 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
749
750 spin_lock_init(&ei->cache_lru_lock);
751 ei->nr_caches = 0;
752 ei->cache_valid_id = FAT_CACHE_VALID + 1;
753 INIT_LIST_HEAD(&ei->cache_lru);
754 INIT_HLIST_NODE(&ei->i_fat_hash);
755 INIT_HLIST_NODE(&ei->i_dir_hash);
756 inode_init_once(&ei->vfs_inode);
757 }
758
759 static int __init fat_init_inodecache(void)
760 {
761 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
762 sizeof(struct msdos_inode_info),
763 0, (SLAB_RECLAIM_ACCOUNT|
764 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
765 init_once);
766 if (fat_inode_cachep == NULL)
767 return -ENOMEM;
768 return 0;
769 }
770
771 static void __exit fat_destroy_inodecache(void)
772 {
773 /*
774 * Make sure all delayed rcu free inodes are flushed before we
775 * destroy cache.
776 */
777 rcu_barrier();
778 kmem_cache_destroy(fat_inode_cachep);
779 }
780
781 static int fat_remount(struct super_block *sb, int *flags, char *data)
782 {
783 bool new_rdonly;
784 struct msdos_sb_info *sbi = MSDOS_SB(sb);
785 *flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME);
786
787 sync_filesystem(sb);
788
789 /* make sure we update state on remount. */
790 new_rdonly = *flags & SB_RDONLY;
791 if (new_rdonly != sb_rdonly(sb)) {
792 if (new_rdonly)
793 fat_set_state(sb, 0, 0);
794 else
795 fat_set_state(sb, 1, 1);
796 }
797 return 0;
798 }
799
800 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
801 {
802 struct super_block *sb = dentry->d_sb;
803 struct msdos_sb_info *sbi = MSDOS_SB(sb);
804 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
805
806 /* If the count of free cluster is still unknown, counts it here. */
807 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
808 int err = fat_count_free_clusters(dentry->d_sb);
809 if (err)
810 return err;
811 }
812
813 buf->f_type = dentry->d_sb->s_magic;
814 buf->f_bsize = sbi->cluster_size;
815 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
816 buf->f_bfree = sbi->free_clusters;
817 buf->f_bavail = sbi->free_clusters;
818 buf->f_fsid.val[0] = (u32)id;
819 buf->f_fsid.val[1] = (u32)(id >> 32);
820 buf->f_namelen =
821 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE;
822
823 return 0;
824 }
825
826 static int __fat_write_inode(struct inode *inode, int wait)
827 {
828 struct super_block *sb = inode->i_sb;
829 struct msdos_sb_info *sbi = MSDOS_SB(sb);
830 struct buffer_head *bh;
831 struct msdos_dir_entry *raw_entry;
832 loff_t i_pos;
833 sector_t blocknr;
834 int err, offset;
835
836 if (inode->i_ino == MSDOS_ROOT_INO)
837 return 0;
838
839 retry:
840 i_pos = fat_i_pos_read(sbi, inode);
841 if (!i_pos)
842 return 0;
843
844 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset);
845 bh = sb_bread(sb, blocknr);
846 if (!bh) {
847 fat_msg(sb, KERN_ERR, "unable to read inode block "
848 "for updating (i_pos %lld)", i_pos);
849 return -EIO;
850 }
851 spin_lock(&sbi->inode_hash_lock);
852 if (i_pos != MSDOS_I(inode)->i_pos) {
853 spin_unlock(&sbi->inode_hash_lock);
854 brelse(bh);
855 goto retry;
856 }
857
858 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset];
859 if (S_ISDIR(inode->i_mode))
860 raw_entry->size = 0;
861 else
862 raw_entry->size = cpu_to_le32(inode->i_size);
863 raw_entry->attr = fat_make_attrs(inode);
864 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart);
865 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
866 &raw_entry->date, NULL);
867 if (sbi->options.isvfat) {
868 __le16 atime;
869 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
870 &raw_entry->cdate, &raw_entry->ctime_cs);
871 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
872 &raw_entry->adate, NULL);
873 }
874 spin_unlock(&sbi->inode_hash_lock);
875 mark_buffer_dirty(bh);
876 err = 0;
877 if (wait)
878 err = sync_dirty_buffer(bh);
879 brelse(bh);
880 return err;
881 }
882
883 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
884 {
885 int err;
886
887 if (inode->i_ino == MSDOS_FSINFO_INO) {
888 struct super_block *sb = inode->i_sb;
889
890 mutex_lock(&MSDOS_SB(sb)->s_lock);
891 err = fat_clusters_flush(sb);
892 mutex_unlock(&MSDOS_SB(sb)->s_lock);
893 } else
894 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
895
896 return err;
897 }
898
899 int fat_sync_inode(struct inode *inode)
900 {
901 return __fat_write_inode(inode, 1);
902 }
903
904 EXPORT_SYMBOL_GPL(fat_sync_inode);
905
906 static int fat_show_options(struct seq_file *m, struct dentry *root);
907 static const struct super_operations fat_sops = {
908 .alloc_inode = fat_alloc_inode,
909 .destroy_inode = fat_destroy_inode,
910 .write_inode = fat_write_inode,
911 .evict_inode = fat_evict_inode,
912 .put_super = fat_put_super,
913 .statfs = fat_statfs,
914 .remount_fs = fat_remount,
915
916 .show_options = fat_show_options,
917 };
918
919 static int fat_show_options(struct seq_file *m, struct dentry *root)
920 {
921 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb);
922 struct fat_mount_options *opts = &sbi->options;
923 int isvfat = opts->isvfat;
924
925 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
926 seq_printf(m, ",uid=%u",
927 from_kuid_munged(&init_user_ns, opts->fs_uid));
928 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
929 seq_printf(m, ",gid=%u",
930 from_kgid_munged(&init_user_ns, opts->fs_gid));
931 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
932 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
933 if (opts->allow_utime)
934 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
935 if (sbi->nls_disk)
936 /* strip "cp" prefix from displayed option */
937 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]);
938 if (isvfat) {
939 if (sbi->nls_io)
940 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
941
942 switch (opts->shortname) {
943 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
944 seq_puts(m, ",shortname=win95");
945 break;
946 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
947 seq_puts(m, ",shortname=winnt");
948 break;
949 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
950 seq_puts(m, ",shortname=mixed");
951 break;
952 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
953 seq_puts(m, ",shortname=lower");
954 break;
955 default:
956 seq_puts(m, ",shortname=unknown");
957 break;
958 }
959 }
960 if (opts->name_check != 'n')
961 seq_printf(m, ",check=%c", opts->name_check);
962 if (opts->usefree)
963 seq_puts(m, ",usefree");
964 if (opts->quiet)
965 seq_puts(m, ",quiet");
966 if (opts->showexec)
967 seq_puts(m, ",showexec");
968 if (opts->sys_immutable)
969 seq_puts(m, ",sys_immutable");
970 if (!isvfat) {
971 if (opts->dotsOK)
972 seq_puts(m, ",dotsOK=yes");
973 if (opts->nocase)
974 seq_puts(m, ",nocase");
975 } else {
976 if (opts->utf8)
977 seq_puts(m, ",utf8");
978 if (opts->unicode_xlate)
979 seq_puts(m, ",uni_xlate");
980 if (!opts->numtail)
981 seq_puts(m, ",nonumtail");
982 if (opts->rodir)
983 seq_puts(m, ",rodir");
984 }
985 if (opts->flush)
986 seq_puts(m, ",flush");
987 if (opts->tz_set) {
988 if (opts->time_offset)
989 seq_printf(m, ",time_offset=%d", opts->time_offset);
990 else
991 seq_puts(m, ",tz=UTC");
992 }
993 if (opts->errors == FAT_ERRORS_CONT)
994 seq_puts(m, ",errors=continue");
995 else if (opts->errors == FAT_ERRORS_PANIC)
996 seq_puts(m, ",errors=panic");
997 else
998 seq_puts(m, ",errors=remount-ro");
999 if (opts->nfs == FAT_NFS_NOSTALE_RO)
1000 seq_puts(m, ",nfs=nostale_ro");
1001 else if (opts->nfs)
1002 seq_puts(m, ",nfs=stale_rw");
1003 if (opts->discard)
1004 seq_puts(m, ",discard");
1005 if (opts->dos1xfloppy)
1006 seq_puts(m, ",dos1xfloppy");
1007
1008 return 0;
1009 }
1010
1011 enum {
1012 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
1013 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
1014 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
1015 Opt_immutable, Opt_dots, Opt_nodots,
1016 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
1017 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
1018 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
1019 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
1020 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset,
1021 Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy,
1022 };
1023
1024 static const match_table_t fat_tokens = {
1025 {Opt_check_r, "check=relaxed"},
1026 {Opt_check_s, "check=strict"},
1027 {Opt_check_n, "check=normal"},
1028 {Opt_check_r, "check=r"},
1029 {Opt_check_s, "check=s"},
1030 {Opt_check_n, "check=n"},
1031 {Opt_uid, "uid=%u"},
1032 {Opt_gid, "gid=%u"},
1033 {Opt_umask, "umask=%o"},
1034 {Opt_dmask, "dmask=%o"},
1035 {Opt_fmask, "fmask=%o"},
1036 {Opt_allow_utime, "allow_utime=%o"},
1037 {Opt_codepage, "codepage=%u"},
1038 {Opt_usefree, "usefree"},
1039 {Opt_nocase, "nocase"},
1040 {Opt_quiet, "quiet"},
1041 {Opt_showexec, "showexec"},
1042 {Opt_debug, "debug"},
1043 {Opt_immutable, "sys_immutable"},
1044 {Opt_flush, "flush"},
1045 {Opt_tz_utc, "tz=UTC"},
1046 {Opt_time_offset, "time_offset=%d"},
1047 {Opt_err_cont, "errors=continue"},
1048 {Opt_err_panic, "errors=panic"},
1049 {Opt_err_ro, "errors=remount-ro"},
1050 {Opt_discard, "discard"},
1051 {Opt_nfs_stale_rw, "nfs"},
1052 {Opt_nfs_stale_rw, "nfs=stale_rw"},
1053 {Opt_nfs_nostale_ro, "nfs=nostale_ro"},
1054 {Opt_dos1xfloppy, "dos1xfloppy"},
1055 {Opt_obsolete, "conv=binary"},
1056 {Opt_obsolete, "conv=text"},
1057 {Opt_obsolete, "conv=auto"},
1058 {Opt_obsolete, "conv=b"},
1059 {Opt_obsolete, "conv=t"},
1060 {Opt_obsolete, "conv=a"},
1061 {Opt_obsolete, "fat=%u"},
1062 {Opt_obsolete, "blocksize=%u"},
1063 {Opt_obsolete, "cvf_format=%20s"},
1064 {Opt_obsolete, "cvf_options=%100s"},
1065 {Opt_obsolete, "posix"},
1066 {Opt_err, NULL},
1067 };
1068 static const match_table_t msdos_tokens = {
1069 {Opt_nodots, "nodots"},
1070 {Opt_nodots, "dotsOK=no"},
1071 {Opt_dots, "dots"},
1072 {Opt_dots, "dotsOK=yes"},
1073 {Opt_err, NULL}
1074 };
1075 static const match_table_t vfat_tokens = {
1076 {Opt_charset, "iocharset=%s"},
1077 {Opt_shortname_lower, "shortname=lower"},
1078 {Opt_shortname_win95, "shortname=win95"},
1079 {Opt_shortname_winnt, "shortname=winnt"},
1080 {Opt_shortname_mixed, "shortname=mixed"},
1081 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
1082 {Opt_utf8_no, "utf8=no"},
1083 {Opt_utf8_no, "utf8=false"},
1084 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
1085 {Opt_utf8_yes, "utf8=yes"},
1086 {Opt_utf8_yes, "utf8=true"},
1087 {Opt_utf8_yes, "utf8"},
1088 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
1089 {Opt_uni_xl_no, "uni_xlate=no"},
1090 {Opt_uni_xl_no, "uni_xlate=false"},
1091 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
1092 {Opt_uni_xl_yes, "uni_xlate=yes"},
1093 {Opt_uni_xl_yes, "uni_xlate=true"},
1094 {Opt_uni_xl_yes, "uni_xlate"},
1095 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
1096 {Opt_nonumtail_no, "nonumtail=no"},
1097 {Opt_nonumtail_no, "nonumtail=false"},
1098 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
1099 {Opt_nonumtail_yes, "nonumtail=yes"},
1100 {Opt_nonumtail_yes, "nonumtail=true"},
1101 {Opt_nonumtail_yes, "nonumtail"},
1102 {Opt_rodir, "rodir"},
1103 {Opt_err, NULL}
1104 };
1105
1106 static int parse_options(struct super_block *sb, char *options, int is_vfat,
1107 int silent, int *debug, struct fat_mount_options *opts)
1108 {
1109 char *p;
1110 substring_t args[MAX_OPT_ARGS];
1111 int option;
1112 char *iocharset;
1113
1114 opts->isvfat = is_vfat;
1115
1116 opts->fs_uid = current_uid();
1117 opts->fs_gid = current_gid();
1118 opts->fs_fmask = opts->fs_dmask = current_umask();
1119 opts->allow_utime = -1;
1120 opts->codepage = fat_default_codepage;
1121 opts->iocharset = fat_default_iocharset;
1122 if (is_vfat) {
1123 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
1124 opts->rodir = 0;
1125 } else {
1126 opts->shortname = 0;
1127 opts->rodir = 1;
1128 }
1129 opts->name_check = 'n';
1130 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
1131 opts->unicode_xlate = 0;
1132 opts->numtail = 1;
1133 opts->usefree = opts->nocase = 0;
1134 opts->tz_set = 0;
1135 opts->nfs = 0;
1136 opts->errors = FAT_ERRORS_RO;
1137 *debug = 0;
1138
1139 opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat;
1140
1141 if (!options)
1142 goto out;
1143
1144 while ((p = strsep(&options, ",")) != NULL) {
1145 int token;
1146 if (!*p)
1147 continue;
1148
1149 token = match_token(p, fat_tokens, args);
1150 if (token == Opt_err) {
1151 if (is_vfat)
1152 token = match_token(p, vfat_tokens, args);
1153 else
1154 token = match_token(p, msdos_tokens, args);
1155 }
1156 switch (token) {
1157 case Opt_check_s:
1158 opts->name_check = 's';
1159 break;
1160 case Opt_check_r:
1161 opts->name_check = 'r';
1162 break;
1163 case Opt_check_n:
1164 opts->name_check = 'n';
1165 break;
1166 case Opt_usefree:
1167 opts->usefree = 1;
1168 break;
1169 case Opt_nocase:
1170 if (!is_vfat)
1171 opts->nocase = 1;
1172 else {
1173 /* for backward compatibility */
1174 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1175 | VFAT_SFN_CREATE_WIN95;
1176 }
1177 break;
1178 case Opt_quiet:
1179 opts->quiet = 1;
1180 break;
1181 case Opt_showexec:
1182 opts->showexec = 1;
1183 break;
1184 case Opt_debug:
1185 *debug = 1;
1186 break;
1187 case Opt_immutable:
1188 opts->sys_immutable = 1;
1189 break;
1190 case Opt_uid:
1191 if (match_int(&args[0], &option))
1192 return -EINVAL;
1193 opts->fs_uid = make_kuid(current_user_ns(), option);
1194 if (!uid_valid(opts->fs_uid))
1195 return -EINVAL;
1196 break;
1197 case Opt_gid:
1198 if (match_int(&args[0], &option))
1199 return -EINVAL;
1200 opts->fs_gid = make_kgid(current_user_ns(), option);
1201 if (!gid_valid(opts->fs_gid))
1202 return -EINVAL;
1203 break;
1204 case Opt_umask:
1205 if (match_octal(&args[0], &option))
1206 return -EINVAL;
1207 opts->fs_fmask = opts->fs_dmask = option;
1208 break;
1209 case Opt_dmask:
1210 if (match_octal(&args[0], &option))
1211 return -EINVAL;
1212 opts->fs_dmask = option;
1213 break;
1214 case Opt_fmask:
1215 if (match_octal(&args[0], &option))
1216 return -EINVAL;
1217 opts->fs_fmask = option;
1218 break;
1219 case Opt_allow_utime:
1220 if (match_octal(&args[0], &option))
1221 return -EINVAL;
1222 opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1223 break;
1224 case Opt_codepage:
1225 if (match_int(&args[0], &option))
1226 return -EINVAL;
1227 opts->codepage = option;
1228 break;
1229 case Opt_flush:
1230 opts->flush = 1;
1231 break;
1232 case Opt_time_offset:
1233 if (match_int(&args[0], &option))
1234 return -EINVAL;
1235 /*
1236 * GMT+-12 zones may have DST corrections so at least
1237 * 13 hours difference is needed. Make the limit 24
1238 * just in case someone invents something unusual.
1239 */
1240 if (option < -24 * 60 || option > 24 * 60)
1241 return -EINVAL;
1242 opts->tz_set = 1;
1243 opts->time_offset = option;
1244 break;
1245 case Opt_tz_utc:
1246 opts->tz_set = 1;
1247 opts->time_offset = 0;
1248 break;
1249 case Opt_err_cont:
1250 opts->errors = FAT_ERRORS_CONT;
1251 break;
1252 case Opt_err_panic:
1253 opts->errors = FAT_ERRORS_PANIC;
1254 break;
1255 case Opt_err_ro:
1256 opts->errors = FAT_ERRORS_RO;
1257 break;
1258 case Opt_nfs_stale_rw:
1259 opts->nfs = FAT_NFS_STALE_RW;
1260 break;
1261 case Opt_nfs_nostale_ro:
1262 opts->nfs = FAT_NFS_NOSTALE_RO;
1263 break;
1264 case Opt_dos1xfloppy:
1265 opts->dos1xfloppy = 1;
1266 break;
1267
1268 /* msdos specific */
1269 case Opt_dots:
1270 opts->dotsOK = 1;
1271 break;
1272 case Opt_nodots:
1273 opts->dotsOK = 0;
1274 break;
1275
1276 /* vfat specific */
1277 case Opt_charset:
1278 if (opts->iocharset != fat_default_iocharset)
1279 kfree(opts->iocharset);
1280 iocharset = match_strdup(&args[0]);
1281 if (!iocharset)
1282 return -ENOMEM;
1283 opts->iocharset = iocharset;
1284 break;
1285 case Opt_shortname_lower:
1286 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1287 | VFAT_SFN_CREATE_WIN95;
1288 break;
1289 case Opt_shortname_win95:
1290 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1291 | VFAT_SFN_CREATE_WIN95;
1292 break;
1293 case Opt_shortname_winnt:
1294 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1295 | VFAT_SFN_CREATE_WINNT;
1296 break;
1297 case Opt_shortname_mixed:
1298 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1299 | VFAT_SFN_CREATE_WIN95;
1300 break;
1301 case Opt_utf8_no: /* 0 or no or false */
1302 opts->utf8 = 0;
1303 break;
1304 case Opt_utf8_yes: /* empty or 1 or yes or true */
1305 opts->utf8 = 1;
1306 break;
1307 case Opt_uni_xl_no: /* 0 or no or false */
1308 opts->unicode_xlate = 0;
1309 break;
1310 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1311 opts->unicode_xlate = 1;
1312 break;
1313 case Opt_nonumtail_no: /* 0 or no or false */
1314 opts->numtail = 1; /* negated option */
1315 break;
1316 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1317 opts->numtail = 0; /* negated option */
1318 break;
1319 case Opt_rodir:
1320 opts->rodir = 1;
1321 break;
1322 case Opt_discard:
1323 opts->discard = 1;
1324 break;
1325
1326 /* obsolete mount options */
1327 case Opt_obsolete:
1328 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, "
1329 "not supported now", p);
1330 break;
1331 /* unknown option */
1332 default:
1333 if (!silent) {
1334 fat_msg(sb, KERN_ERR,
1335 "Unrecognized mount option \"%s\" "
1336 "or missing value", p);
1337 }
1338 return -EINVAL;
1339 }
1340 }
1341
1342 out:
1343 /* UTF-8 doesn't provide FAT semantics */
1344 if (!strcmp(opts->iocharset, "utf8")) {
1345 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset"
1346 " for FAT filesystems, filesystem will be "
1347 "case sensitive!");
1348 }
1349
1350 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1351 if (opts->allow_utime == (unsigned short)-1)
1352 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
1353 if (opts->unicode_xlate)
1354 opts->utf8 = 0;
1355 if (opts->nfs == FAT_NFS_NOSTALE_RO) {
1356 sb->s_flags |= SB_RDONLY;
1357 sb->s_export_op = &fat_export_ops_nostale;
1358 }
1359
1360 return 0;
1361 }
1362
1363 static void fat_dummy_inode_init(struct inode *inode)
1364 {
1365 /* Initialize this dummy inode to work as no-op. */
1366 MSDOS_I(inode)->mmu_private = 0;
1367 MSDOS_I(inode)->i_start = 0;
1368 MSDOS_I(inode)->i_logstart = 0;
1369 MSDOS_I(inode)->i_attrs = 0;
1370 MSDOS_I(inode)->i_pos = 0;
1371 }
1372
1373 static int fat_read_root(struct inode *inode)
1374 {
1375 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
1376 int error;
1377
1378 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO;
1379 inode->i_uid = sbi->options.fs_uid;
1380 inode->i_gid = sbi->options.fs_gid;
1381 inode_inc_iversion(inode);
1382 inode->i_generation = 0;
1383 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
1384 inode->i_op = sbi->dir_ops;
1385 inode->i_fop = &fat_dir_operations;
1386 if (sbi->fat_bits == 32) {
1387 MSDOS_I(inode)->i_start = sbi->root_cluster;
1388 error = fat_calc_dir_size(inode);
1389 if (error < 0)
1390 return error;
1391 } else {
1392 MSDOS_I(inode)->i_start = 0;
1393 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1394 }
1395 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1396 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1397 MSDOS_I(inode)->i_logstart = 0;
1398 MSDOS_I(inode)->mmu_private = inode->i_size;
1399
1400 fat_save_attrs(inode, ATTR_DIR);
1401 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1402 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1403 set_nlink(inode, fat_subdirs(inode)+2);
1404
1405 return 0;
1406 }
1407
1408 static unsigned long calc_fat_clusters(struct super_block *sb)
1409 {
1410 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1411
1412 /* Divide first to avoid overflow */
1413 if (sbi->fat_bits != 12) {
1414 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits;
1415 return ent_per_sec * sbi->fat_length;
1416 }
1417
1418 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1419 }
1420
1421 static bool fat_bpb_is_zero(struct fat_boot_sector *b)
1422 {
1423 if (get_unaligned_le16(&b->sector_size))
1424 return false;
1425 if (b->sec_per_clus)
1426 return false;
1427 if (b->reserved)
1428 return false;
1429 if (b->fats)
1430 return false;
1431 if (get_unaligned_le16(&b->dir_entries))
1432 return false;
1433 if (get_unaligned_le16(&b->sectors))
1434 return false;
1435 if (b->media)
1436 return false;
1437 if (b->fat_length)
1438 return false;
1439 if (b->secs_track)
1440 return false;
1441 if (b->heads)
1442 return false;
1443 return true;
1444 }
1445
1446 static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b,
1447 int silent, struct fat_bios_param_block *bpb)
1448 {
1449 int error = -EINVAL;
1450
1451 /* Read in BPB ... */
1452 memset(bpb, 0, sizeof(*bpb));
1453 bpb->fat_sector_size = get_unaligned_le16(&b->sector_size);
1454 bpb->fat_sec_per_clus = b->sec_per_clus;
1455 bpb->fat_reserved = le16_to_cpu(b->reserved);
1456 bpb->fat_fats = b->fats;
1457 bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries);
1458 bpb->fat_sectors = get_unaligned_le16(&b->sectors);
1459 bpb->fat_fat_length = le16_to_cpu(b->fat_length);
1460 bpb->fat_total_sect = le32_to_cpu(b->total_sect);
1461
1462 bpb->fat16_state = b->fat16.state;
1463 bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id);
1464
1465 bpb->fat32_length = le32_to_cpu(b->fat32.length);
1466 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster);
1467 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector);
1468 bpb->fat32_state = b->fat32.state;
1469 bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id);
1470
1471 /* Validate this looks like a FAT filesystem BPB */
1472 if (!bpb->fat_reserved) {
1473 if (!silent)
1474 fat_msg(sb, KERN_ERR,
1475 "bogus number of reserved sectors");
1476 goto out;
1477 }
1478 if (!bpb->fat_fats) {
1479 if (!silent)
1480 fat_msg(sb, KERN_ERR, "bogus number of FAT structure");
1481 goto out;
1482 }
1483
1484 /*
1485 * Earlier we checked here that b->secs_track and b->head are nonzero,
1486 * but it turns out valid FAT filesystems can have zero there.
1487 */
1488
1489 if (!fat_valid_media(b->media)) {
1490 if (!silent)
1491 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)",
1492 (unsigned)b->media);
1493 goto out;
1494 }
1495
1496 if (!is_power_of_2(bpb->fat_sector_size)
1497 || (bpb->fat_sector_size < 512)
1498 || (bpb->fat_sector_size > 4096)) {
1499 if (!silent)
1500 fat_msg(sb, KERN_ERR, "bogus logical sector size %u",
1501 (unsigned)bpb->fat_sector_size);
1502 goto out;
1503 }
1504
1505 if (!is_power_of_2(bpb->fat_sec_per_clus)) {
1506 if (!silent)
1507 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u",
1508 (unsigned)bpb->fat_sec_per_clus);
1509 goto out;
1510 }
1511
1512 error = 0;
1513
1514 out:
1515 return error;
1516 }
1517
1518 static int fat_read_static_bpb(struct super_block *sb,
1519 struct fat_boot_sector *b, int silent,
1520 struct fat_bios_param_block *bpb)
1521 {
1522 static const char *notdos1x = "This doesn't look like a DOS 1.x volume";
1523
1524 struct fat_floppy_defaults *fdefaults = NULL;
1525 int error = -EINVAL;
1526 sector_t bd_sects;
1527 unsigned i;
1528
1529 bd_sects = i_size_read(sb->s_bdev->bd_inode) / SECTOR_SIZE;
1530
1531 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */
1532 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) {
1533 if (!silent)
1534 fat_msg(sb, KERN_ERR,
1535 "%s; no bootstrapping code", notdos1x);
1536 goto out;
1537 }
1538
1539 /*
1540 * If any value in this region is non-zero, it isn't archaic
1541 * DOS.
1542 */
1543 if (!fat_bpb_is_zero(b)) {
1544 if (!silent)
1545 fat_msg(sb, KERN_ERR,
1546 "%s; DOS 2.x BPB is non-zero", notdos1x);
1547 goto out;
1548 }
1549
1550 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) {
1551 if (floppy_defaults[i].nr_sectors == bd_sects) {
1552 fdefaults = &floppy_defaults[i];
1553 break;
1554 }
1555 }
1556
1557 if (fdefaults == NULL) {
1558 if (!silent)
1559 fat_msg(sb, KERN_WARNING,
1560 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)",
1561 (u64)bd_sects);
1562 goto out;
1563 }
1564
1565 if (!silent)
1566 fat_msg(sb, KERN_INFO,
1567 "This looks like a DOS 1.x volume; assuming default BPB values");
1568
1569 memset(bpb, 0, sizeof(*bpb));
1570 bpb->fat_sector_size = SECTOR_SIZE;
1571 bpb->fat_sec_per_clus = fdefaults->sec_per_clus;
1572 bpb->fat_reserved = 1;
1573 bpb->fat_fats = 2;
1574 bpb->fat_dir_entries = fdefaults->dir_entries;
1575 bpb->fat_sectors = fdefaults->nr_sectors;
1576 bpb->fat_fat_length = fdefaults->fat_length;
1577
1578 error = 0;
1579
1580 out:
1581 return error;
1582 }
1583
1584 /*
1585 * Read the super block of an MS-DOS FS.
1586 */
1587 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
1588 void (*setup)(struct super_block *))
1589 {
1590 struct inode *root_inode = NULL, *fat_inode = NULL;
1591 struct inode *fsinfo_inode = NULL;
1592 struct buffer_head *bh;
1593 struct fat_bios_param_block bpb;
1594 struct msdos_sb_info *sbi;
1595 u16 logical_sector_size;
1596 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1597 int debug;
1598 long error;
1599 char buf[50];
1600
1601 /*
1602 * GFP_KERNEL is ok here, because while we do hold the
1603 * superblock lock, memory pressure can't call back into
1604 * the filesystem, since we're only just about to mount
1605 * it and have no inodes etc active!
1606 */
1607 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1608 if (!sbi)
1609 return -ENOMEM;
1610 sb->s_fs_info = sbi;
1611
1612 sb->s_flags |= SB_NODIRATIME;
1613 sb->s_magic = MSDOS_SUPER_MAGIC;
1614 sb->s_op = &fat_sops;
1615 sb->s_export_op = &fat_export_ops;
1616 mutex_init(&sbi->nfs_build_inode_lock);
1617 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
1618 DEFAULT_RATELIMIT_BURST);
1619
1620 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options);
1621 if (error)
1622 goto out_fail;
1623
1624 setup(sb); /* flavour-specific stuff that needs options */
1625
1626 error = -EIO;
1627 sb_min_blocksize(sb, 512);
1628 bh = sb_bread(sb, 0);
1629 if (bh == NULL) {
1630 fat_msg(sb, KERN_ERR, "unable to read boot sector");
1631 goto out_fail;
1632 }
1633
1634 error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent,
1635 &bpb);
1636 if (error == -EINVAL && sbi->options.dos1xfloppy)
1637 error = fat_read_static_bpb(sb,
1638 (struct fat_boot_sector *)bh->b_data, silent, &bpb);
1639 brelse(bh);
1640
1641 if (error == -EINVAL)
1642 goto out_invalid;
1643 else if (error)
1644 goto out_fail;
1645
1646 logical_sector_size = bpb.fat_sector_size;
1647 sbi->sec_per_clus = bpb.fat_sec_per_clus;
1648
1649 error = -EIO;
1650 if (logical_sector_size < sb->s_blocksize) {
1651 fat_msg(sb, KERN_ERR, "logical sector size too small for device"
1652 " (logical sector size = %u)", logical_sector_size);
1653 goto out_fail;
1654 }
1655
1656 if (logical_sector_size > sb->s_blocksize) {
1657 struct buffer_head *bh_resize;
1658
1659 if (!sb_set_blocksize(sb, logical_sector_size)) {
1660 fat_msg(sb, KERN_ERR, "unable to set blocksize %u",
1661 logical_sector_size);
1662 goto out_fail;
1663 }
1664
1665 /* Verify that the larger boot sector is fully readable */
1666 bh_resize = sb_bread(sb, 0);
1667 if (bh_resize == NULL) {
1668 fat_msg(sb, KERN_ERR, "unable to read boot sector"
1669 " (logical sector size = %lu)",
1670 sb->s_blocksize);
1671 goto out_fail;
1672 }
1673 brelse(bh_resize);
1674 }
1675
1676 mutex_init(&sbi->s_lock);
1677 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1678 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1679 sbi->fats = bpb.fat_fats;
1680 sbi->fat_bits = 0; /* Don't know yet */
1681 sbi->fat_start = bpb.fat_reserved;
1682 sbi->fat_length = bpb.fat_fat_length;
1683 sbi->root_cluster = 0;
1684 sbi->free_clusters = -1; /* Don't know yet */
1685 sbi->free_clus_valid = 0;
1686 sbi->prev_free = FAT_START_ENT;
1687 sb->s_maxbytes = 0xffffffff;
1688
1689 if (!sbi->fat_length && bpb.fat32_length) {
1690 struct fat_boot_fsinfo *fsinfo;
1691 struct buffer_head *fsinfo_bh;
1692
1693 /* Must be FAT32 */
1694 sbi->fat_bits = 32;
1695 sbi->fat_length = bpb.fat32_length;
1696 sbi->root_cluster = bpb.fat32_root_cluster;
1697
1698 /* MC - if info_sector is 0, don't multiply by 0 */
1699 sbi->fsinfo_sector = bpb.fat32_info_sector;
1700 if (sbi->fsinfo_sector == 0)
1701 sbi->fsinfo_sector = 1;
1702
1703 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1704 if (fsinfo_bh == NULL) {
1705 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block"
1706 " (sector = %lu)", sbi->fsinfo_sector);
1707 goto out_fail;
1708 }
1709
1710 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1711 if (!IS_FSINFO(fsinfo)) {
1712 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
1713 "0x%08x, 0x%08x (sector = %lu)",
1714 le32_to_cpu(fsinfo->signature1),
1715 le32_to_cpu(fsinfo->signature2),
1716 sbi->fsinfo_sector);
1717 } else {
1718 if (sbi->options.usefree)
1719 sbi->free_clus_valid = 1;
1720 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1721 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1722 }
1723
1724 brelse(fsinfo_bh);
1725 }
1726
1727 /* interpret volume ID as a little endian 32 bit integer */
1728 if (sbi->fat_bits == 32)
1729 sbi->vol_id = bpb.fat32_vol_id;
1730 else /* fat 16 or 12 */
1731 sbi->vol_id = bpb.fat16_vol_id;
1732
1733 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1734 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1735
1736 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1737 sbi->dir_entries = bpb.fat_dir_entries;
1738 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1739 if (!silent)
1740 fat_msg(sb, KERN_ERR, "bogus number of directory entries"
1741 " (%u)", sbi->dir_entries);
1742 goto out_invalid;
1743 }
1744
1745 rootdir_sectors = sbi->dir_entries
1746 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1747 sbi->data_start = sbi->dir_start + rootdir_sectors;
1748 total_sectors = bpb.fat_sectors;
1749 if (total_sectors == 0)
1750 total_sectors = bpb.fat_total_sect;
1751
1752 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1753
1754 if (sbi->fat_bits != 32)
1755 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1756
1757 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */
1758 if (sbi->fat_bits == 32)
1759 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY;
1760 else /* fat 16 or 12 */
1761 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY;
1762
1763 /* check that FAT table does not overflow */
1764 fat_clusters = calc_fat_clusters(sb);
1765 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1766 if (total_clusters > MAX_FAT(sb)) {
1767 if (!silent)
1768 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)",
1769 total_clusters);
1770 goto out_invalid;
1771 }
1772
1773 sbi->max_cluster = total_clusters + FAT_START_ENT;
1774 /* check the free_clusters, it's not necessarily correct */
1775 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1776 sbi->free_clusters = -1;
1777 /* check the prev_free, it's not necessarily correct */
1778 sbi->prev_free %= sbi->max_cluster;
1779 if (sbi->prev_free < FAT_START_ENT)
1780 sbi->prev_free = FAT_START_ENT;
1781
1782 /* set up enough so that it can read an inode */
1783 fat_hash_init(sb);
1784 dir_hash_init(sb);
1785 fat_ent_access_init(sb);
1786
1787 /*
1788 * The low byte of FAT's first entry must have same value with
1789 * media-field. But in real world, too many devices is
1790 * writing wrong value. So, removed that validity check.
1791 *
1792 * if (FAT_FIRST_ENT(sb, media) != first)
1793 */
1794
1795 error = -EINVAL;
1796 sprintf(buf, "cp%d", sbi->options.codepage);
1797 sbi->nls_disk = load_nls(buf);
1798 if (!sbi->nls_disk) {
1799 fat_msg(sb, KERN_ERR, "codepage %s not found", buf);
1800 goto out_fail;
1801 }
1802
1803 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1804 if (sbi->options.isvfat) {
1805 sbi->nls_io = load_nls(sbi->options.iocharset);
1806 if (!sbi->nls_io) {
1807 fat_msg(sb, KERN_ERR, "IO charset %s not found",
1808 sbi->options.iocharset);
1809 goto out_fail;
1810 }
1811 }
1812
1813 error = -ENOMEM;
1814 fat_inode = new_inode(sb);
1815 if (!fat_inode)
1816 goto out_fail;
1817 fat_dummy_inode_init(fat_inode);
1818 sbi->fat_inode = fat_inode;
1819
1820 fsinfo_inode = new_inode(sb);
1821 if (!fsinfo_inode)
1822 goto out_fail;
1823 fat_dummy_inode_init(fsinfo_inode);
1824 fsinfo_inode->i_ino = MSDOS_FSINFO_INO;
1825 sbi->fsinfo_inode = fsinfo_inode;
1826 insert_inode_hash(fsinfo_inode);
1827
1828 root_inode = new_inode(sb);
1829 if (!root_inode)
1830 goto out_fail;
1831 root_inode->i_ino = MSDOS_ROOT_INO;
1832 inode_set_iversion(root_inode, 1);
1833 error = fat_read_root(root_inode);
1834 if (error < 0) {
1835 iput(root_inode);
1836 goto out_fail;
1837 }
1838 error = -ENOMEM;
1839 insert_inode_hash(root_inode);
1840 fat_attach(root_inode, 0);
1841 sb->s_root = d_make_root(root_inode);
1842 if (!sb->s_root) {
1843 fat_msg(sb, KERN_ERR, "get root inode failed");
1844 goto out_fail;
1845 }
1846
1847 if (sbi->options.discard) {
1848 struct request_queue *q = bdev_get_queue(sb->s_bdev);
1849 if (!blk_queue_discard(q))
1850 fat_msg(sb, KERN_WARNING,
1851 "mounting with \"discard\" option, but "
1852 "the device does not support discard");
1853 }
1854
1855 fat_set_state(sb, 1, 0);
1856 return 0;
1857
1858 out_invalid:
1859 error = -EINVAL;
1860 if (!silent)
1861 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem");
1862
1863 out_fail:
1864 if (fsinfo_inode)
1865 iput(fsinfo_inode);
1866 if (fat_inode)
1867 iput(fat_inode);
1868 unload_nls(sbi->nls_io);
1869 unload_nls(sbi->nls_disk);
1870 if (sbi->options.iocharset != fat_default_iocharset)
1871 kfree(sbi->options.iocharset);
1872 sb->s_fs_info = NULL;
1873 kfree(sbi);
1874 return error;
1875 }
1876
1877 EXPORT_SYMBOL_GPL(fat_fill_super);
1878
1879 /*
1880 * helper function for fat_flush_inodes. This writes both the inode
1881 * and the file data blocks, waiting for in flight data blocks before
1882 * the start of the call. It does not wait for any io started
1883 * during the call
1884 */
1885 static int writeback_inode(struct inode *inode)
1886 {
1887
1888 int ret;
1889
1890 /* if we used wait=1, sync_inode_metadata waits for the io for the
1891 * inode to finish. So wait=0 is sent down to sync_inode_metadata
1892 * and filemap_fdatawrite is used for the data blocks
1893 */
1894 ret = sync_inode_metadata(inode, 0);
1895 if (!ret)
1896 ret = filemap_fdatawrite(inode->i_mapping);
1897 return ret;
1898 }
1899
1900 /*
1901 * write data and metadata corresponding to i1 and i2. The io is
1902 * started but we do not wait for any of it to finish.
1903 *
1904 * filemap_flush is used for the block device, so if there is a dirty
1905 * page for a block already in flight, we will not wait and start the
1906 * io over again
1907 */
1908 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1909 {
1910 int ret = 0;
1911 if (!MSDOS_SB(sb)->options.flush)
1912 return 0;
1913 if (i1)
1914 ret = writeback_inode(i1);
1915 if (!ret && i2)
1916 ret = writeback_inode(i2);
1917 if (!ret) {
1918 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1919 ret = filemap_flush(mapping);
1920 }
1921 return ret;
1922 }
1923 EXPORT_SYMBOL_GPL(fat_flush_inodes);
1924
1925 static int __init init_fat_fs(void)
1926 {
1927 int err;
1928
1929 err = fat_cache_init();
1930 if (err)
1931 return err;
1932
1933 err = fat_init_inodecache();
1934 if (err)
1935 goto failed;
1936
1937 return 0;
1938
1939 failed:
1940 fat_cache_destroy();
1941 return err;
1942 }
1943
1944 static void __exit exit_fat_fs(void)
1945 {
1946 fat_cache_destroy();
1947 fat_destroy_inodecache();
1948 }
1949
1950 module_init(init_fat_fs)
1951 module_exit(exit_fat_fs)
1952
1953 MODULE_LICENSE("GPL");
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