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perf list: Add missing documentation for --desc and --debug options
[linux/fpc-iii.git] / fs / fat / inode.c
blobbfd589ea74c01ebf74e4866d920759143b01be16
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 if (!phys) {
162 fat_fs_error(sb,
163 "invalid FAT chain (i_pos %lld, last_block %llu)",
164 MSDOS_I(inode)->i_pos,
165 (unsigned long long)last_block);
166 return -EIO;
167 }
168
169 BUG_ON(*max_blocks != mapped_blocks);
170 set_buffer_new(bh_result);
171 map_bh(bh_result, sb, phys);
172
173 return 0;
174 }
175
176 static int fat_get_block(struct inode *inode, sector_t iblock,
177 struct buffer_head *bh_result, int create)
178 {
179 struct super_block *sb = inode->i_sb;
180 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
181 int err;
182
183 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
184 if (err)
185 return err;
186 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
187 return 0;
188 }
189
190 static int fat_writepage(struct page *page, struct writeback_control *wbc)
191 {
192 return block_write_full_page(page, fat_get_block, wbc);
193 }
194
195 static int fat_writepages(struct address_space *mapping,
196 struct writeback_control *wbc)
197 {
198 return mpage_writepages(mapping, wbc, fat_get_block);
199 }
200
201 static int fat_readpage(struct file *file, struct page *page)
202 {
203 return mpage_readpage(page, fat_get_block);
204 }
205
206 static int fat_readpages(struct file *file, struct address_space *mapping,
207 struct list_head *pages, unsigned nr_pages)
208 {
209 return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
210 }
211
212 static void fat_write_failed(struct address_space *mapping, loff_t to)
213 {
214 struct inode *inode = mapping->host;
215
216 if (to > inode->i_size) {
217 truncate_pagecache(inode, inode->i_size);
218 fat_truncate_blocks(inode, inode->i_size);
219 }
220 }
221
222 static int fat_write_begin(struct file *file, struct address_space *mapping,
223 loff_t pos, unsigned len, unsigned flags,
224 struct page **pagep, void **fsdata)
225 {
226 int err;
227
228 *pagep = NULL;
229 err = cont_write_begin(file, mapping, pos, len, flags,
230 pagep, fsdata, fat_get_block,
231 &MSDOS_I(mapping->host)->mmu_private);
232 if (err < 0)
233 fat_write_failed(mapping, pos + len);
234 return err;
235 }
236
237 static int fat_write_end(struct file *file, struct address_space *mapping,
238 loff_t pos, unsigned len, unsigned copied,
239 struct page *pagep, void *fsdata)
240 {
241 struct inode *inode = mapping->host;
242 int err;
243 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
244 if (err < len)
245 fat_write_failed(mapping, pos + len);
246 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
247 inode->i_mtime = inode->i_ctime = current_time(inode);
248 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
249 mark_inode_dirty(inode);
250 }
251 return err;
252 }
253
254 static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
255 {
256 struct file *file = iocb->ki_filp;
257 struct address_space *mapping = file->f_mapping;
258 struct inode *inode = mapping->host;
259 size_t count = iov_iter_count(iter);
260 loff_t offset = iocb->ki_pos;
261 ssize_t ret;
262
263 if (iov_iter_rw(iter) == WRITE) {
264 /*
265 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
266 * so we need to update the ->mmu_private to block boundary.
267 *
268 * But we must fill the remaining area or hole by nul for
269 * updating ->mmu_private.
270 *
271 * Return 0, and fallback to normal buffered write.
272 */
273 loff_t size = offset + count;
274 if (MSDOS_I(inode)->mmu_private < size)
275 return 0;
276 }
277
278 /*
279 * FAT need to use the DIO_LOCKING for avoiding the race
280 * condition of fat_get_block() and ->truncate().
281 */
282 ret = blockdev_direct_IO(iocb, inode, iter, fat_get_block);
283 if (ret < 0 && iov_iter_rw(iter) == WRITE)
284 fat_write_failed(mapping, offset + count);
285
286 return ret;
287 }
288
289 static int fat_get_block_bmap(struct inode *inode, sector_t iblock,
290 struct buffer_head *bh_result, int create)
291 {
292 struct super_block *sb = inode->i_sb;
293 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
294 int err;
295 sector_t bmap;
296 unsigned long mapped_blocks;
297
298 BUG_ON(create != 0);
299
300 err = fat_bmap(inode, iblock, &bmap, &mapped_blocks, create, true);
301 if (err)
302 return err;
303
304 if (bmap) {
305 map_bh(bh_result, sb, bmap);
306 max_blocks = min(mapped_blocks, max_blocks);
307 }
308
309 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
310
311 return 0;
312 }
313
314 static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
315 {
316 sector_t blocknr;
317
318 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
319 down_read(&MSDOS_I(mapping->host)->truncate_lock);
320 blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap);
321 up_read(&MSDOS_I(mapping->host)->truncate_lock);
322
323 return blocknr;
324 }
325
326 /*
327 * fat_block_truncate_page() zeroes out a mapping from file offset `from'
328 * up to the end of the block which corresponds to `from'.
329 * This is required during truncate to physically zeroout the tail end
330 * of that block so it doesn't yield old data if the file is later grown.
331 * Also, avoid causing failure from fsx for cases of "data past EOF"
332 */
333 int fat_block_truncate_page(struct inode *inode, loff_t from)
334 {
335 return block_truncate_page(inode->i_mapping, from, fat_get_block);
336 }
337
338 static const struct address_space_operations fat_aops = {
339 .readpage = fat_readpage,
340 .readpages = fat_readpages,
341 .writepage = fat_writepage,
342 .writepages = fat_writepages,
343 .write_begin = fat_write_begin,
344 .write_end = fat_write_end,
345 .direct_IO = fat_direct_IO,
346 .bmap = _fat_bmap
347 };
348
349 /*
350 * New FAT inode stuff. We do the following:
351 * a) i_ino is constant and has nothing with on-disk location.
352 * b) FAT manages its own cache of directory entries.
353 * c) *This* cache is indexed by on-disk location.
354 * d) inode has an associated directory entry, all right, but
355 * it may be unhashed.
356 * e) currently entries are stored within struct inode. That should
357 * change.
358 * f) we deal with races in the following way:
359 * 1. readdir() and lookup() do FAT-dir-cache lookup.
360 * 2. rename() unhashes the F-d-c entry and rehashes it in
361 * a new place.
362 * 3. unlink() and rmdir() unhash F-d-c entry.
363 * 4. fat_write_inode() checks whether the thing is unhashed.
364 * If it is we silently return. If it isn't we do bread(),
365 * check if the location is still valid and retry if it
366 * isn't. Otherwise we do changes.
367 * 5. Spinlock is used to protect hash/unhash/location check/lookup
368 * 6. fat_evict_inode() unhashes the F-d-c entry.
369 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
370 * and consider negative result as cache miss.
371 */
372
373 static void fat_hash_init(struct super_block *sb)
374 {
375 struct msdos_sb_info *sbi = MSDOS_SB(sb);
376 int i;
377
378 spin_lock_init(&sbi->inode_hash_lock);
379 for (i = 0; i < FAT_HASH_SIZE; i++)
380 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
381 }
382
383 static inline unsigned long fat_hash(loff_t i_pos)
384 {
385 return hash_32(i_pos, FAT_HASH_BITS);
386 }
387
388 static void dir_hash_init(struct super_block *sb)
389 {
390 struct msdos_sb_info *sbi = MSDOS_SB(sb);
391 int i;
392
393 spin_lock_init(&sbi->dir_hash_lock);
394 for (i = 0; i < FAT_HASH_SIZE; i++)
395 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]);
396 }
397
398 void fat_attach(struct inode *inode, loff_t i_pos)
399 {
400 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
401
402 if (inode->i_ino != MSDOS_ROOT_INO) {
403 struct hlist_head *head = sbi->inode_hashtable
404 + fat_hash(i_pos);
405
406 spin_lock(&sbi->inode_hash_lock);
407 MSDOS_I(inode)->i_pos = i_pos;
408 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
409 spin_unlock(&sbi->inode_hash_lock);
410 }
411
412 /* If NFS support is enabled, cache the mapping of start cluster
413 * to directory inode. This is used during reconnection of
414 * dentries to the filesystem root.
415 */
416 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
417 struct hlist_head *d_head = sbi->dir_hashtable;
418 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart);
419
420 spin_lock(&sbi->dir_hash_lock);
421 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head);
422 spin_unlock(&sbi->dir_hash_lock);
423 }
424 }
425 EXPORT_SYMBOL_GPL(fat_attach);
426
427 void fat_detach(struct inode *inode)
428 {
429 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
430 spin_lock(&sbi->inode_hash_lock);
431 MSDOS_I(inode)->i_pos = 0;
432 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
433 spin_unlock(&sbi->inode_hash_lock);
434
435 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
436 spin_lock(&sbi->dir_hash_lock);
437 hlist_del_init(&MSDOS_I(inode)->i_dir_hash);
438 spin_unlock(&sbi->dir_hash_lock);
439 }
440 }
441 EXPORT_SYMBOL_GPL(fat_detach);
442
443 struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
444 {
445 struct msdos_sb_info *sbi = MSDOS_SB(sb);
446 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
447 struct msdos_inode_info *i;
448 struct inode *inode = NULL;
449
450 spin_lock(&sbi->inode_hash_lock);
451 hlist_for_each_entry(i, head, i_fat_hash) {
452 BUG_ON(i->vfs_inode.i_sb != sb);
453 if (i->i_pos != i_pos)
454 continue;
455 inode = igrab(&i->vfs_inode);
456 if (inode)
457 break;
458 }
459 spin_unlock(&sbi->inode_hash_lock);
460 return inode;
461 }
462
463 static int is_exec(unsigned char *extension)
464 {
465 unsigned char exe_extensions[] = "EXECOMBAT", *walk;
466
467 for (walk = exe_extensions; *walk; walk += 3)
468 if (!strncmp(extension, walk, 3))
469 return 1;
470 return 0;
471 }
472
473 static int fat_calc_dir_size(struct inode *inode)
474 {
475 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
476 int ret, fclus, dclus;
477
478 inode->i_size = 0;
479 if (MSDOS_I(inode)->i_start == 0)
480 return 0;
481
482 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
483 if (ret < 0)
484 return ret;
485 inode->i_size = (fclus + 1) << sbi->cluster_bits;
486
487 return 0;
488 }
489
490 static int fat_validate_dir(struct inode *dir)
491 {
492 struct super_block *sb = dir->i_sb;
493
494 if (dir->i_nlink < 2) {
495 /* Directory should have "."/".." entries at least. */
496 fat_fs_error(sb, "corrupted directory (invalid entries)");
497 return -EIO;
498 }
499 if (MSDOS_I(dir)->i_start == 0 ||
500 MSDOS_I(dir)->i_start == MSDOS_SB(sb)->root_cluster) {
501 /* Directory should point valid cluster. */
502 fat_fs_error(sb, "corrupted directory (invalid i_start)");
503 return -EIO;
504 }
505 return 0;
506 }
507
508 /* doesn't deal with root inode */
509 int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
510 {
511 struct timespec ts;
512 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
513 int error;
514
515 MSDOS_I(inode)->i_pos = 0;
516 inode->i_uid = sbi->options.fs_uid;
517 inode->i_gid = sbi->options.fs_gid;
518 inode_inc_iversion(inode);
519 inode->i_generation = get_seconds();
520
521 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
522 inode->i_generation &= ~1;
523 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
524 inode->i_op = sbi->dir_ops;
525 inode->i_fop = &fat_dir_operations;
526
527 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
528 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
529 error = fat_calc_dir_size(inode);
530 if (error < 0)
531 return error;
532 MSDOS_I(inode)->mmu_private = inode->i_size;
533
534 set_nlink(inode, fat_subdirs(inode));
535
536 error = fat_validate_dir(inode);
537 if (error < 0)
538 return error;
539 } else { /* not a directory */
540 inode->i_generation |= 1;
541 inode->i_mode = fat_make_mode(sbi, de->attr,
542 ((sbi->options.showexec && !is_exec(de->name + 8))
543 ? S_IRUGO|S_IWUGO : S_IRWXUGO));
544 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
545
546 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
547 inode->i_size = le32_to_cpu(de->size);
548 inode->i_op = &fat_file_inode_operations;
549 inode->i_fop = &fat_file_operations;
550 inode->i_mapping->a_ops = &fat_aops;
551 MSDOS_I(inode)->mmu_private = inode->i_size;
552 }
553 if (de->attr & ATTR_SYS) {
554 if (sbi->options.sys_immutable)
555 inode->i_flags |= S_IMMUTABLE;
556 }
557 fat_save_attrs(inode, de->attr);
558
559 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
560 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
561
562 fat_time_fat2unix(sbi, &ts, de->time, de->date, 0);
563 inode->i_mtime = timespec_to_timespec64(ts);
564 if (sbi->options.isvfat) {
565 fat_time_fat2unix(sbi, &ts, de->ctime,
566 de->cdate, de->ctime_cs);
567 inode->i_ctime = timespec_to_timespec64(ts);
568 fat_time_fat2unix(sbi, &ts, 0, de->adate, 0);
569 inode->i_atime = timespec_to_timespec64(ts);
570 } else
571 inode->i_ctime = inode->i_atime = inode->i_mtime;
572
573 return 0;
574 }
575
576 static inline void fat_lock_build_inode(struct msdos_sb_info *sbi)
577 {
578 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
579 mutex_lock(&sbi->nfs_build_inode_lock);
580 }
581
582 static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi)
583 {
584 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
585 mutex_unlock(&sbi->nfs_build_inode_lock);
586 }
587
588 struct inode *fat_build_inode(struct super_block *sb,
589 struct msdos_dir_entry *de, loff_t i_pos)
590 {
591 struct inode *inode;
592 int err;
593
594 fat_lock_build_inode(MSDOS_SB(sb));
595 inode = fat_iget(sb, i_pos);
596 if (inode)
597 goto out;
598 inode = new_inode(sb);
599 if (!inode) {
600 inode = ERR_PTR(-ENOMEM);
601 goto out;
602 }
603 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
604 inode_set_iversion(inode, 1);
605 err = fat_fill_inode(inode, de);
606 if (err) {
607 iput(inode);
608 inode = ERR_PTR(err);
609 goto out;
610 }
611 fat_attach(inode, i_pos);
612 insert_inode_hash(inode);
613 out:
614 fat_unlock_build_inode(MSDOS_SB(sb));
615 return inode;
616 }
617
618 EXPORT_SYMBOL_GPL(fat_build_inode);
619
620 static int __fat_write_inode(struct inode *inode, int wait);
621
622 static void fat_free_eofblocks(struct inode *inode)
623 {
624 /* Release unwritten fallocated blocks on inode eviction. */
625 if ((inode->i_blocks << 9) >
626 round_up(MSDOS_I(inode)->mmu_private,
627 MSDOS_SB(inode->i_sb)->cluster_size)) {
628 int err;
629
630 fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private);
631 /* Fallocate results in updating the i_start/iogstart
632 * for the zero byte file. So, make it return to
633 * original state during evict and commit it to avoid
634 * any corruption on the next access to the cluster
635 * chain for the file.
636 */
637 err = __fat_write_inode(inode, inode_needs_sync(inode));
638 if (err) {
639 fat_msg(inode->i_sb, KERN_WARNING, "Failed to "
640 "update on disk inode for unused "
641 "fallocated blocks, inode could be "
642 "corrupted. Please run fsck");
643 }
644
645 }
646 }
647
648 static void fat_evict_inode(struct inode *inode)
649 {
650 truncate_inode_pages_final(&inode->i_data);
651 if (!inode->i_nlink) {
652 inode->i_size = 0;
653 fat_truncate_blocks(inode, 0);
654 } else
655 fat_free_eofblocks(inode);
656
657 invalidate_inode_buffers(inode);
658 clear_inode(inode);
659 fat_cache_inval_inode(inode);
660 fat_detach(inode);
661 }
662
663 static void fat_set_state(struct super_block *sb,
664 unsigned int set, unsigned int force)
665 {
666 struct buffer_head *bh;
667 struct fat_boot_sector *b;
668 struct msdos_sb_info *sbi = MSDOS_SB(sb);
669
670 /* do not change any thing if mounted read only */
671 if (sb_rdonly(sb) && !force)
672 return;
673
674 /* do not change state if fs was dirty */
675 if (sbi->dirty) {
676 /* warn only on set (mount). */
677 if (set)
678 fat_msg(sb, KERN_WARNING, "Volume was not properly "
679 "unmounted. Some data may be corrupt. "
680 "Please run fsck.");
681 return;
682 }
683
684 bh = sb_bread(sb, 0);
685 if (bh == NULL) {
686 fat_msg(sb, KERN_ERR, "unable to read boot sector "
687 "to mark fs as dirty");
688 return;
689 }
690
691 b = (struct fat_boot_sector *) bh->b_data;
692
693 if (sbi->fat_bits == 32) {
694 if (set)
695 b->fat32.state |= FAT_STATE_DIRTY;
696 else
697 b->fat32.state &= ~FAT_STATE_DIRTY;
698 } else /* fat 16 and 12 */ {
699 if (set)
700 b->fat16.state |= FAT_STATE_DIRTY;
701 else
702 b->fat16.state &= ~FAT_STATE_DIRTY;
703 }
704
705 mark_buffer_dirty(bh);
706 sync_dirty_buffer(bh);
707 brelse(bh);
708 }
709
710 static void fat_reset_iocharset(struct fat_mount_options *opts)
711 {
712 if (opts->iocharset != fat_default_iocharset) {
713 /* Note: opts->iocharset can be NULL here */
714 kfree(opts->iocharset);
715 opts->iocharset = fat_default_iocharset;
716 }
717 }
718
719 static void delayed_free(struct rcu_head *p)
720 {
721 struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu);
722 unload_nls(sbi->nls_disk);
723 unload_nls(sbi->nls_io);
724 fat_reset_iocharset(&sbi->options);
725 kfree(sbi);
726 }
727
728 static void fat_put_super(struct super_block *sb)
729 {
730 struct msdos_sb_info *sbi = MSDOS_SB(sb);
731
732 fat_set_state(sb, 0, 0);
733
734 iput(sbi->fsinfo_inode);
735 iput(sbi->fat_inode);
736
737 call_rcu(&sbi->rcu, delayed_free);
738 }
739
740 static struct kmem_cache *fat_inode_cachep;
741
742 static struct inode *fat_alloc_inode(struct super_block *sb)
743 {
744 struct msdos_inode_info *ei;
745 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
746 if (!ei)
747 return NULL;
748
749 init_rwsem(&ei->truncate_lock);
750 return &ei->vfs_inode;
751 }
752
753 static void fat_i_callback(struct rcu_head *head)
754 {
755 struct inode *inode = container_of(head, struct inode, i_rcu);
756 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
757 }
758
759 static void fat_destroy_inode(struct inode *inode)
760 {
761 call_rcu(&inode->i_rcu, fat_i_callback);
762 }
763
764 static void init_once(void *foo)
765 {
766 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
767
768 spin_lock_init(&ei->cache_lru_lock);
769 ei->nr_caches = 0;
770 ei->cache_valid_id = FAT_CACHE_VALID + 1;
771 INIT_LIST_HEAD(&ei->cache_lru);
772 INIT_HLIST_NODE(&ei->i_fat_hash);
773 INIT_HLIST_NODE(&ei->i_dir_hash);
774 inode_init_once(&ei->vfs_inode);
775 }
776
777 static int __init fat_init_inodecache(void)
778 {
779 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
780 sizeof(struct msdos_inode_info),
781 0, (SLAB_RECLAIM_ACCOUNT|
782 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
783 init_once);
784 if (fat_inode_cachep == NULL)
785 return -ENOMEM;
786 return 0;
787 }
788
789 static void __exit fat_destroy_inodecache(void)
790 {
791 /*
792 * Make sure all delayed rcu free inodes are flushed before we
793 * destroy cache.
794 */
795 rcu_barrier();
796 kmem_cache_destroy(fat_inode_cachep);
797 }
798
799 static int fat_remount(struct super_block *sb, int *flags, char *data)
800 {
801 bool new_rdonly;
802 struct msdos_sb_info *sbi = MSDOS_SB(sb);
803 *flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME);
804
805 sync_filesystem(sb);
806
807 /* make sure we update state on remount. */
808 new_rdonly = *flags & SB_RDONLY;
809 if (new_rdonly != sb_rdonly(sb)) {
810 if (new_rdonly)
811 fat_set_state(sb, 0, 0);
812 else
813 fat_set_state(sb, 1, 1);
814 }
815 return 0;
816 }
817
818 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
819 {
820 struct super_block *sb = dentry->d_sb;
821 struct msdos_sb_info *sbi = MSDOS_SB(sb);
822 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
823
824 /* If the count of free cluster is still unknown, counts it here. */
825 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
826 int err = fat_count_free_clusters(dentry->d_sb);
827 if (err)
828 return err;
829 }
830
831 buf->f_type = dentry->d_sb->s_magic;
832 buf->f_bsize = sbi->cluster_size;
833 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
834 buf->f_bfree = sbi->free_clusters;
835 buf->f_bavail = sbi->free_clusters;
836 buf->f_fsid.val[0] = (u32)id;
837 buf->f_fsid.val[1] = (u32)(id >> 32);
838 buf->f_namelen =
839 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE;
840
841 return 0;
842 }
843
844 static int __fat_write_inode(struct inode *inode, int wait)
845 {
846 struct timespec ts;
847 struct super_block *sb = inode->i_sb;
848 struct msdos_sb_info *sbi = MSDOS_SB(sb);
849 struct buffer_head *bh;
850 struct msdos_dir_entry *raw_entry;
851 loff_t i_pos;
852 sector_t blocknr;
853 int err, offset;
854
855 if (inode->i_ino == MSDOS_ROOT_INO)
856 return 0;
857
858 retry:
859 i_pos = fat_i_pos_read(sbi, inode);
860 if (!i_pos)
861 return 0;
862
863 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset);
864 bh = sb_bread(sb, blocknr);
865 if (!bh) {
866 fat_msg(sb, KERN_ERR, "unable to read inode block "
867 "for updating (i_pos %lld)", i_pos);
868 return -EIO;
869 }
870 spin_lock(&sbi->inode_hash_lock);
871 if (i_pos != MSDOS_I(inode)->i_pos) {
872 spin_unlock(&sbi->inode_hash_lock);
873 brelse(bh);
874 goto retry;
875 }
876
877 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset];
878 if (S_ISDIR(inode->i_mode))
879 raw_entry->size = 0;
880 else
881 raw_entry->size = cpu_to_le32(inode->i_size);
882 raw_entry->attr = fat_make_attrs(inode);
883 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart);
884 ts = timespec64_to_timespec(inode->i_mtime);
885 fat_time_unix2fat(sbi, &ts, &raw_entry->time,
886 &raw_entry->date, NULL);
887 if (sbi->options.isvfat) {
888 __le16 atime;
889 ts = timespec64_to_timespec(inode->i_ctime);
890 fat_time_unix2fat(sbi, &ts, &raw_entry->ctime,
891 &raw_entry->cdate, &raw_entry->ctime_cs);
892 ts = timespec64_to_timespec(inode->i_atime);
893 fat_time_unix2fat(sbi, &ts, &atime,
894 &raw_entry->adate, NULL);
895 }
896 spin_unlock(&sbi->inode_hash_lock);
897 mark_buffer_dirty(bh);
898 err = 0;
899 if (wait)
900 err = sync_dirty_buffer(bh);
901 brelse(bh);
902 return err;
903 }
904
905 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
906 {
907 int err;
908
909 if (inode->i_ino == MSDOS_FSINFO_INO) {
910 struct super_block *sb = inode->i_sb;
911
912 mutex_lock(&MSDOS_SB(sb)->s_lock);
913 err = fat_clusters_flush(sb);
914 mutex_unlock(&MSDOS_SB(sb)->s_lock);
915 } else
916 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
917
918 return err;
919 }
920
921 int fat_sync_inode(struct inode *inode)
922 {
923 return __fat_write_inode(inode, 1);
924 }
925
926 EXPORT_SYMBOL_GPL(fat_sync_inode);
927
928 static int fat_show_options(struct seq_file *m, struct dentry *root);
929 static const struct super_operations fat_sops = {
930 .alloc_inode = fat_alloc_inode,
931 .destroy_inode = fat_destroy_inode,
932 .write_inode = fat_write_inode,
933 .evict_inode = fat_evict_inode,
934 .put_super = fat_put_super,
935 .statfs = fat_statfs,
936 .remount_fs = fat_remount,
937
938 .show_options = fat_show_options,
939 };
940
941 static int fat_show_options(struct seq_file *m, struct dentry *root)
942 {
943 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb);
944 struct fat_mount_options *opts = &sbi->options;
945 int isvfat = opts->isvfat;
946
947 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
948 seq_printf(m, ",uid=%u",
949 from_kuid_munged(&init_user_ns, opts->fs_uid));
950 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
951 seq_printf(m, ",gid=%u",
952 from_kgid_munged(&init_user_ns, opts->fs_gid));
953 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
954 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
955 if (opts->allow_utime)
956 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
957 if (sbi->nls_disk)
958 /* strip "cp" prefix from displayed option */
959 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]);
960 if (isvfat) {
961 if (sbi->nls_io)
962 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
963
964 switch (opts->shortname) {
965 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
966 seq_puts(m, ",shortname=win95");
967 break;
968 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
969 seq_puts(m, ",shortname=winnt");
970 break;
971 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
972 seq_puts(m, ",shortname=mixed");
973 break;
974 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
975 seq_puts(m, ",shortname=lower");
976 break;
977 default:
978 seq_puts(m, ",shortname=unknown");
979 break;
980 }
981 }
982 if (opts->name_check != 'n')
983 seq_printf(m, ",check=%c", opts->name_check);
984 if (opts->usefree)
985 seq_puts(m, ",usefree");
986 if (opts->quiet)
987 seq_puts(m, ",quiet");
988 if (opts->showexec)
989 seq_puts(m, ",showexec");
990 if (opts->sys_immutable)
991 seq_puts(m, ",sys_immutable");
992 if (!isvfat) {
993 if (opts->dotsOK)
994 seq_puts(m, ",dotsOK=yes");
995 if (opts->nocase)
996 seq_puts(m, ",nocase");
997 } else {
998 if (opts->utf8)
999 seq_puts(m, ",utf8");
1000 if (opts->unicode_xlate)
1001 seq_puts(m, ",uni_xlate");
1002 if (!opts->numtail)
1003 seq_puts(m, ",nonumtail");
1004 if (opts->rodir)
1005 seq_puts(m, ",rodir");
1006 }
1007 if (opts->flush)
1008 seq_puts(m, ",flush");
1009 if (opts->tz_set) {
1010 if (opts->time_offset)
1011 seq_printf(m, ",time_offset=%d", opts->time_offset);
1012 else
1013 seq_puts(m, ",tz=UTC");
1014 }
1015 if (opts->errors == FAT_ERRORS_CONT)
1016 seq_puts(m, ",errors=continue");
1017 else if (opts->errors == FAT_ERRORS_PANIC)
1018 seq_puts(m, ",errors=panic");
1019 else
1020 seq_puts(m, ",errors=remount-ro");
1021 if (opts->nfs == FAT_NFS_NOSTALE_RO)
1022 seq_puts(m, ",nfs=nostale_ro");
1023 else if (opts->nfs)
1024 seq_puts(m, ",nfs=stale_rw");
1025 if (opts->discard)
1026 seq_puts(m, ",discard");
1027 if (opts->dos1xfloppy)
1028 seq_puts(m, ",dos1xfloppy");
1029
1030 return 0;
1031 }
1032
1033 enum {
1034 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
1035 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
1036 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
1037 Opt_immutable, Opt_dots, Opt_nodots,
1038 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
1039 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
1040 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
1041 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
1042 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset,
1043 Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy,
1044 };
1045
1046 static const match_table_t fat_tokens = {
1047 {Opt_check_r, "check=relaxed"},
1048 {Opt_check_s, "check=strict"},
1049 {Opt_check_n, "check=normal"},
1050 {Opt_check_r, "check=r"},
1051 {Opt_check_s, "check=s"},
1052 {Opt_check_n, "check=n"},
1053 {Opt_uid, "uid=%u"},
1054 {Opt_gid, "gid=%u"},
1055 {Opt_umask, "umask=%o"},
1056 {Opt_dmask, "dmask=%o"},
1057 {Opt_fmask, "fmask=%o"},
1058 {Opt_allow_utime, "allow_utime=%o"},
1059 {Opt_codepage, "codepage=%u"},
1060 {Opt_usefree, "usefree"},
1061 {Opt_nocase, "nocase"},
1062 {Opt_quiet, "quiet"},
1063 {Opt_showexec, "showexec"},
1064 {Opt_debug, "debug"},
1065 {Opt_immutable, "sys_immutable"},
1066 {Opt_flush, "flush"},
1067 {Opt_tz_utc, "tz=UTC"},
1068 {Opt_time_offset, "time_offset=%d"},
1069 {Opt_err_cont, "errors=continue"},
1070 {Opt_err_panic, "errors=panic"},
1071 {Opt_err_ro, "errors=remount-ro"},
1072 {Opt_discard, "discard"},
1073 {Opt_nfs_stale_rw, "nfs"},
1074 {Opt_nfs_stale_rw, "nfs=stale_rw"},
1075 {Opt_nfs_nostale_ro, "nfs=nostale_ro"},
1076 {Opt_dos1xfloppy, "dos1xfloppy"},
1077 {Opt_obsolete, "conv=binary"},
1078 {Opt_obsolete, "conv=text"},
1079 {Opt_obsolete, "conv=auto"},
1080 {Opt_obsolete, "conv=b"},
1081 {Opt_obsolete, "conv=t"},
1082 {Opt_obsolete, "conv=a"},
1083 {Opt_obsolete, "fat=%u"},
1084 {Opt_obsolete, "blocksize=%u"},
1085 {Opt_obsolete, "cvf_format=%20s"},
1086 {Opt_obsolete, "cvf_options=%100s"},
1087 {Opt_obsolete, "posix"},
1088 {Opt_err, NULL},
1089 };
1090 static const match_table_t msdos_tokens = {
1091 {Opt_nodots, "nodots"},
1092 {Opt_nodots, "dotsOK=no"},
1093 {Opt_dots, "dots"},
1094 {Opt_dots, "dotsOK=yes"},
1095 {Opt_err, NULL}
1096 };
1097 static const match_table_t vfat_tokens = {
1098 {Opt_charset, "iocharset=%s"},
1099 {Opt_shortname_lower, "shortname=lower"},
1100 {Opt_shortname_win95, "shortname=win95"},
1101 {Opt_shortname_winnt, "shortname=winnt"},
1102 {Opt_shortname_mixed, "shortname=mixed"},
1103 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
1104 {Opt_utf8_no, "utf8=no"},
1105 {Opt_utf8_no, "utf8=false"},
1106 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
1107 {Opt_utf8_yes, "utf8=yes"},
1108 {Opt_utf8_yes, "utf8=true"},
1109 {Opt_utf8_yes, "utf8"},
1110 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
1111 {Opt_uni_xl_no, "uni_xlate=no"},
1112 {Opt_uni_xl_no, "uni_xlate=false"},
1113 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
1114 {Opt_uni_xl_yes, "uni_xlate=yes"},
1115 {Opt_uni_xl_yes, "uni_xlate=true"},
1116 {Opt_uni_xl_yes, "uni_xlate"},
1117 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
1118 {Opt_nonumtail_no, "nonumtail=no"},
1119 {Opt_nonumtail_no, "nonumtail=false"},
1120 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
1121 {Opt_nonumtail_yes, "nonumtail=yes"},
1122 {Opt_nonumtail_yes, "nonumtail=true"},
1123 {Opt_nonumtail_yes, "nonumtail"},
1124 {Opt_rodir, "rodir"},
1125 {Opt_err, NULL}
1126 };
1127
1128 static int parse_options(struct super_block *sb, char *options, int is_vfat,
1129 int silent, int *debug, struct fat_mount_options *opts)
1130 {
1131 char *p;
1132 substring_t args[MAX_OPT_ARGS];
1133 int option;
1134 char *iocharset;
1135
1136 opts->isvfat = is_vfat;
1137
1138 opts->fs_uid = current_uid();
1139 opts->fs_gid = current_gid();
1140 opts->fs_fmask = opts->fs_dmask = current_umask();
1141 opts->allow_utime = -1;
1142 opts->codepage = fat_default_codepage;
1143 fat_reset_iocharset(opts);
1144 if (is_vfat) {
1145 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
1146 opts->rodir = 0;
1147 } else {
1148 opts->shortname = 0;
1149 opts->rodir = 1;
1150 }
1151 opts->name_check = 'n';
1152 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
1153 opts->unicode_xlate = 0;
1154 opts->numtail = 1;
1155 opts->usefree = opts->nocase = 0;
1156 opts->tz_set = 0;
1157 opts->nfs = 0;
1158 opts->errors = FAT_ERRORS_RO;
1159 *debug = 0;
1160
1161 opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat;
1162
1163 if (!options)
1164 goto out;
1165
1166 while ((p = strsep(&options, ",")) != NULL) {
1167 int token;
1168 if (!*p)
1169 continue;
1170
1171 token = match_token(p, fat_tokens, args);
1172 if (token == Opt_err) {
1173 if (is_vfat)
1174 token = match_token(p, vfat_tokens, args);
1175 else
1176 token = match_token(p, msdos_tokens, args);
1177 }
1178 switch (token) {
1179 case Opt_check_s:
1180 opts->name_check = 's';
1181 break;
1182 case Opt_check_r:
1183 opts->name_check = 'r';
1184 break;
1185 case Opt_check_n:
1186 opts->name_check = 'n';
1187 break;
1188 case Opt_usefree:
1189 opts->usefree = 1;
1190 break;
1191 case Opt_nocase:
1192 if (!is_vfat)
1193 opts->nocase = 1;
1194 else {
1195 /* for backward compatibility */
1196 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1197 | VFAT_SFN_CREATE_WIN95;
1198 }
1199 break;
1200 case Opt_quiet:
1201 opts->quiet = 1;
1202 break;
1203 case Opt_showexec:
1204 opts->showexec = 1;
1205 break;
1206 case Opt_debug:
1207 *debug = 1;
1208 break;
1209 case Opt_immutable:
1210 opts->sys_immutable = 1;
1211 break;
1212 case Opt_uid:
1213 if (match_int(&args[0], &option))
1214 return -EINVAL;
1215 opts->fs_uid = make_kuid(current_user_ns(), option);
1216 if (!uid_valid(opts->fs_uid))
1217 return -EINVAL;
1218 break;
1219 case Opt_gid:
1220 if (match_int(&args[0], &option))
1221 return -EINVAL;
1222 opts->fs_gid = make_kgid(current_user_ns(), option);
1223 if (!gid_valid(opts->fs_gid))
1224 return -EINVAL;
1225 break;
1226 case Opt_umask:
1227 if (match_octal(&args[0], &option))
1228 return -EINVAL;
1229 opts->fs_fmask = opts->fs_dmask = option;
1230 break;
1231 case Opt_dmask:
1232 if (match_octal(&args[0], &option))
1233 return -EINVAL;
1234 opts->fs_dmask = option;
1235 break;
1236 case Opt_fmask:
1237 if (match_octal(&args[0], &option))
1238 return -EINVAL;
1239 opts->fs_fmask = option;
1240 break;
1241 case Opt_allow_utime:
1242 if (match_octal(&args[0], &option))
1243 return -EINVAL;
1244 opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1245 break;
1246 case Opt_codepage:
1247 if (match_int(&args[0], &option))
1248 return -EINVAL;
1249 opts->codepage = option;
1250 break;
1251 case Opt_flush:
1252 opts->flush = 1;
1253 break;
1254 case Opt_time_offset:
1255 if (match_int(&args[0], &option))
1256 return -EINVAL;
1257 /*
1258 * GMT+-12 zones may have DST corrections so at least
1259 * 13 hours difference is needed. Make the limit 24
1260 * just in case someone invents something unusual.
1261 */
1262 if (option < -24 * 60 || option > 24 * 60)
1263 return -EINVAL;
1264 opts->tz_set = 1;
1265 opts->time_offset = option;
1266 break;
1267 case Opt_tz_utc:
1268 opts->tz_set = 1;
1269 opts->time_offset = 0;
1270 break;
1271 case Opt_err_cont:
1272 opts->errors = FAT_ERRORS_CONT;
1273 break;
1274 case Opt_err_panic:
1275 opts->errors = FAT_ERRORS_PANIC;
1276 break;
1277 case Opt_err_ro:
1278 opts->errors = FAT_ERRORS_RO;
1279 break;
1280 case Opt_nfs_stale_rw:
1281 opts->nfs = FAT_NFS_STALE_RW;
1282 break;
1283 case Opt_nfs_nostale_ro:
1284 opts->nfs = FAT_NFS_NOSTALE_RO;
1285 break;
1286 case Opt_dos1xfloppy:
1287 opts->dos1xfloppy = 1;
1288 break;
1289
1290 /* msdos specific */
1291 case Opt_dots:
1292 opts->dotsOK = 1;
1293 break;
1294 case Opt_nodots:
1295 opts->dotsOK = 0;
1296 break;
1297
1298 /* vfat specific */
1299 case Opt_charset:
1300 fat_reset_iocharset(opts);
1301 iocharset = match_strdup(&args[0]);
1302 if (!iocharset)
1303 return -ENOMEM;
1304 opts->iocharset = iocharset;
1305 break;
1306 case Opt_shortname_lower:
1307 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1308 | VFAT_SFN_CREATE_WIN95;
1309 break;
1310 case Opt_shortname_win95:
1311 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1312 | VFAT_SFN_CREATE_WIN95;
1313 break;
1314 case Opt_shortname_winnt:
1315 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1316 | VFAT_SFN_CREATE_WINNT;
1317 break;
1318 case Opt_shortname_mixed:
1319 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1320 | VFAT_SFN_CREATE_WIN95;
1321 break;
1322 case Opt_utf8_no: /* 0 or no or false */
1323 opts->utf8 = 0;
1324 break;
1325 case Opt_utf8_yes: /* empty or 1 or yes or true */
1326 opts->utf8 = 1;
1327 break;
1328 case Opt_uni_xl_no: /* 0 or no or false */
1329 opts->unicode_xlate = 0;
1330 break;
1331 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1332 opts->unicode_xlate = 1;
1333 break;
1334 case Opt_nonumtail_no: /* 0 or no or false */
1335 opts->numtail = 1; /* negated option */
1336 break;
1337 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1338 opts->numtail = 0; /* negated option */
1339 break;
1340 case Opt_rodir:
1341 opts->rodir = 1;
1342 break;
1343 case Opt_discard:
1344 opts->discard = 1;
1345 break;
1346
1347 /* obsolete mount options */
1348 case Opt_obsolete:
1349 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, "
1350 "not supported now", p);
1351 break;
1352 /* unknown option */
1353 default:
1354 if (!silent) {
1355 fat_msg(sb, KERN_ERR,
1356 "Unrecognized mount option \"%s\" "
1357 "or missing value", p);
1358 }
1359 return -EINVAL;
1360 }
1361 }
1362
1363 out:
1364 /* UTF-8 doesn't provide FAT semantics */
1365 if (!strcmp(opts->iocharset, "utf8")) {
1366 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset"
1367 " for FAT filesystems, filesystem will be "
1368 "case sensitive!");
1369 }
1370
1371 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1372 if (opts->allow_utime == (unsigned short)-1)
1373 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
1374 if (opts->unicode_xlate)
1375 opts->utf8 = 0;
1376 if (opts->nfs == FAT_NFS_NOSTALE_RO) {
1377 sb->s_flags |= SB_RDONLY;
1378 sb->s_export_op = &fat_export_ops_nostale;
1379 }
1380
1381 return 0;
1382 }
1383
1384 static void fat_dummy_inode_init(struct inode *inode)
1385 {
1386 /* Initialize this dummy inode to work as no-op. */
1387 MSDOS_I(inode)->mmu_private = 0;
1388 MSDOS_I(inode)->i_start = 0;
1389 MSDOS_I(inode)->i_logstart = 0;
1390 MSDOS_I(inode)->i_attrs = 0;
1391 MSDOS_I(inode)->i_pos = 0;
1392 }
1393
1394 static int fat_read_root(struct inode *inode)
1395 {
1396 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
1397 int error;
1398
1399 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO;
1400 inode->i_uid = sbi->options.fs_uid;
1401 inode->i_gid = sbi->options.fs_gid;
1402 inode_inc_iversion(inode);
1403 inode->i_generation = 0;
1404 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
1405 inode->i_op = sbi->dir_ops;
1406 inode->i_fop = &fat_dir_operations;
1407 if (sbi->fat_bits == 32) {
1408 MSDOS_I(inode)->i_start = sbi->root_cluster;
1409 error = fat_calc_dir_size(inode);
1410 if (error < 0)
1411 return error;
1412 } else {
1413 MSDOS_I(inode)->i_start = 0;
1414 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1415 }
1416 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1417 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1418 MSDOS_I(inode)->i_logstart = 0;
1419 MSDOS_I(inode)->mmu_private = inode->i_size;
1420
1421 fat_save_attrs(inode, ATTR_DIR);
1422 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1423 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1424 set_nlink(inode, fat_subdirs(inode)+2);
1425
1426 return 0;
1427 }
1428
1429 static unsigned long calc_fat_clusters(struct super_block *sb)
1430 {
1431 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1432
1433 /* Divide first to avoid overflow */
1434 if (sbi->fat_bits != 12) {
1435 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits;
1436 return ent_per_sec * sbi->fat_length;
1437 }
1438
1439 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1440 }
1441
1442 static bool fat_bpb_is_zero(struct fat_boot_sector *b)
1443 {
1444 if (get_unaligned_le16(&b->sector_size))
1445 return false;
1446 if (b->sec_per_clus)
1447 return false;
1448 if (b->reserved)
1449 return false;
1450 if (b->fats)
1451 return false;
1452 if (get_unaligned_le16(&b->dir_entries))
1453 return false;
1454 if (get_unaligned_le16(&b->sectors))
1455 return false;
1456 if (b->media)
1457 return false;
1458 if (b->fat_length)
1459 return false;
1460 if (b->secs_track)
1461 return false;
1462 if (b->heads)
1463 return false;
1464 return true;
1465 }
1466
1467 static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b,
1468 int silent, struct fat_bios_param_block *bpb)
1469 {
1470 int error = -EINVAL;
1471
1472 /* Read in BPB ... */
1473 memset(bpb, 0, sizeof(*bpb));
1474 bpb->fat_sector_size = get_unaligned_le16(&b->sector_size);
1475 bpb->fat_sec_per_clus = b->sec_per_clus;
1476 bpb->fat_reserved = le16_to_cpu(b->reserved);
1477 bpb->fat_fats = b->fats;
1478 bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries);
1479 bpb->fat_sectors = get_unaligned_le16(&b->sectors);
1480 bpb->fat_fat_length = le16_to_cpu(b->fat_length);
1481 bpb->fat_total_sect = le32_to_cpu(b->total_sect);
1482
1483 bpb->fat16_state = b->fat16.state;
1484 bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id);
1485
1486 bpb->fat32_length = le32_to_cpu(b->fat32.length);
1487 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster);
1488 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector);
1489 bpb->fat32_state = b->fat32.state;
1490 bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id);
1491
1492 /* Validate this looks like a FAT filesystem BPB */
1493 if (!bpb->fat_reserved) {
1494 if (!silent)
1495 fat_msg(sb, KERN_ERR,
1496 "bogus number of reserved sectors");
1497 goto out;
1498 }
1499 if (!bpb->fat_fats) {
1500 if (!silent)
1501 fat_msg(sb, KERN_ERR, "bogus number of FAT structure");
1502 goto out;
1503 }
1504
1505 /*
1506 * Earlier we checked here that b->secs_track and b->head are nonzero,
1507 * but it turns out valid FAT filesystems can have zero there.
1508 */
1509
1510 if (!fat_valid_media(b->media)) {
1511 if (!silent)
1512 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)",
1513 (unsigned)b->media);
1514 goto out;
1515 }
1516
1517 if (!is_power_of_2(bpb->fat_sector_size)
1518 || (bpb->fat_sector_size < 512)
1519 || (bpb->fat_sector_size > 4096)) {
1520 if (!silent)
1521 fat_msg(sb, KERN_ERR, "bogus logical sector size %u",
1522 (unsigned)bpb->fat_sector_size);
1523 goto out;
1524 }
1525
1526 if (!is_power_of_2(bpb->fat_sec_per_clus)) {
1527 if (!silent)
1528 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u",
1529 (unsigned)bpb->fat_sec_per_clus);
1530 goto out;
1531 }
1532
1533 error = 0;
1534
1535 out:
1536 return error;
1537 }
1538
1539 static int fat_read_static_bpb(struct super_block *sb,
1540 struct fat_boot_sector *b, int silent,
1541 struct fat_bios_param_block *bpb)
1542 {
1543 static const char *notdos1x = "This doesn't look like a DOS 1.x volume";
1544
1545 struct fat_floppy_defaults *fdefaults = NULL;
1546 int error = -EINVAL;
1547 sector_t bd_sects;
1548 unsigned i;
1549
1550 bd_sects = i_size_read(sb->s_bdev->bd_inode) / SECTOR_SIZE;
1551
1552 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */
1553 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) {
1554 if (!silent)
1555 fat_msg(sb, KERN_ERR,
1556 "%s; no bootstrapping code", notdos1x);
1557 goto out;
1558 }
1559
1560 /*
1561 * If any value in this region is non-zero, it isn't archaic
1562 * DOS.
1563 */
1564 if (!fat_bpb_is_zero(b)) {
1565 if (!silent)
1566 fat_msg(sb, KERN_ERR,
1567 "%s; DOS 2.x BPB is non-zero", notdos1x);
1568 goto out;
1569 }
1570
1571 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) {
1572 if (floppy_defaults[i].nr_sectors == bd_sects) {
1573 fdefaults = &floppy_defaults[i];
1574 break;
1575 }
1576 }
1577
1578 if (fdefaults == NULL) {
1579 if (!silent)
1580 fat_msg(sb, KERN_WARNING,
1581 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)",
1582 (u64)bd_sects);
1583 goto out;
1584 }
1585
1586 if (!silent)
1587 fat_msg(sb, KERN_INFO,
1588 "This looks like a DOS 1.x volume; assuming default BPB values");
1589
1590 memset(bpb, 0, sizeof(*bpb));
1591 bpb->fat_sector_size = SECTOR_SIZE;
1592 bpb->fat_sec_per_clus = fdefaults->sec_per_clus;
1593 bpb->fat_reserved = 1;
1594 bpb->fat_fats = 2;
1595 bpb->fat_dir_entries = fdefaults->dir_entries;
1596 bpb->fat_sectors = fdefaults->nr_sectors;
1597 bpb->fat_fat_length = fdefaults->fat_length;
1598
1599 error = 0;
1600
1601 out:
1602 return error;
1603 }
1604
1605 /*
1606 * Read the super block of an MS-DOS FS.
1607 */
1608 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
1609 void (*setup)(struct super_block *))
1610 {
1611 struct inode *root_inode = NULL, *fat_inode = NULL;
1612 struct inode *fsinfo_inode = NULL;
1613 struct buffer_head *bh;
1614 struct fat_bios_param_block bpb;
1615 struct msdos_sb_info *sbi;
1616 u16 logical_sector_size;
1617 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1618 int debug;
1619 long error;
1620 char buf[50];
1621
1622 /*
1623 * GFP_KERNEL is ok here, because while we do hold the
1624 * superblock lock, memory pressure can't call back into
1625 * the filesystem, since we're only just about to mount
1626 * it and have no inodes etc active!
1627 */
1628 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1629 if (!sbi)
1630 return -ENOMEM;
1631 sb->s_fs_info = sbi;
1632
1633 sb->s_flags |= SB_NODIRATIME;
1634 sb->s_magic = MSDOS_SUPER_MAGIC;
1635 sb->s_op = &fat_sops;
1636 sb->s_export_op = &fat_export_ops;
1637 mutex_init(&sbi->nfs_build_inode_lock);
1638 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
1639 DEFAULT_RATELIMIT_BURST);
1640
1641 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options);
1642 if (error)
1643 goto out_fail;
1644
1645 setup(sb); /* flavour-specific stuff that needs options */
1646
1647 error = -EIO;
1648 sb_min_blocksize(sb, 512);
1649 bh = sb_bread(sb, 0);
1650 if (bh == NULL) {
1651 fat_msg(sb, KERN_ERR, "unable to read boot sector");
1652 goto out_fail;
1653 }
1654
1655 error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent,
1656 &bpb);
1657 if (error == -EINVAL && sbi->options.dos1xfloppy)
1658 error = fat_read_static_bpb(sb,
1659 (struct fat_boot_sector *)bh->b_data, silent, &bpb);
1660 brelse(bh);
1661
1662 if (error == -EINVAL)
1663 goto out_invalid;
1664 else if (error)
1665 goto out_fail;
1666
1667 logical_sector_size = bpb.fat_sector_size;
1668 sbi->sec_per_clus = bpb.fat_sec_per_clus;
1669
1670 error = -EIO;
1671 if (logical_sector_size < sb->s_blocksize) {
1672 fat_msg(sb, KERN_ERR, "logical sector size too small for device"
1673 " (logical sector size = %u)", logical_sector_size);
1674 goto out_fail;
1675 }
1676
1677 if (logical_sector_size > sb->s_blocksize) {
1678 struct buffer_head *bh_resize;
1679
1680 if (!sb_set_blocksize(sb, logical_sector_size)) {
1681 fat_msg(sb, KERN_ERR, "unable to set blocksize %u",
1682 logical_sector_size);
1683 goto out_fail;
1684 }
1685
1686 /* Verify that the larger boot sector is fully readable */
1687 bh_resize = sb_bread(sb, 0);
1688 if (bh_resize == NULL) {
1689 fat_msg(sb, KERN_ERR, "unable to read boot sector"
1690 " (logical sector size = %lu)",
1691 sb->s_blocksize);
1692 goto out_fail;
1693 }
1694 brelse(bh_resize);
1695 }
1696
1697 mutex_init(&sbi->s_lock);
1698 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1699 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1700 sbi->fats = bpb.fat_fats;
1701 sbi->fat_bits = 0; /* Don't know yet */
1702 sbi->fat_start = bpb.fat_reserved;
1703 sbi->fat_length = bpb.fat_fat_length;
1704 sbi->root_cluster = 0;
1705 sbi->free_clusters = -1; /* Don't know yet */
1706 sbi->free_clus_valid = 0;
1707 sbi->prev_free = FAT_START_ENT;
1708 sb->s_maxbytes = 0xffffffff;
1709
1710 if (!sbi->fat_length && bpb.fat32_length) {
1711 struct fat_boot_fsinfo *fsinfo;
1712 struct buffer_head *fsinfo_bh;
1713
1714 /* Must be FAT32 */
1715 sbi->fat_bits = 32;
1716 sbi->fat_length = bpb.fat32_length;
1717 sbi->root_cluster = bpb.fat32_root_cluster;
1718
1719 /* MC - if info_sector is 0, don't multiply by 0 */
1720 sbi->fsinfo_sector = bpb.fat32_info_sector;
1721 if (sbi->fsinfo_sector == 0)
1722 sbi->fsinfo_sector = 1;
1723
1724 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1725 if (fsinfo_bh == NULL) {
1726 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block"
1727 " (sector = %lu)", sbi->fsinfo_sector);
1728 goto out_fail;
1729 }
1730
1731 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1732 if (!IS_FSINFO(fsinfo)) {
1733 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
1734 "0x%08x, 0x%08x (sector = %lu)",
1735 le32_to_cpu(fsinfo->signature1),
1736 le32_to_cpu(fsinfo->signature2),
1737 sbi->fsinfo_sector);
1738 } else {
1739 if (sbi->options.usefree)
1740 sbi->free_clus_valid = 1;
1741 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1742 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1743 }
1744
1745 brelse(fsinfo_bh);
1746 }
1747
1748 /* interpret volume ID as a little endian 32 bit integer */
1749 if (sbi->fat_bits == 32)
1750 sbi->vol_id = bpb.fat32_vol_id;
1751 else /* fat 16 or 12 */
1752 sbi->vol_id = bpb.fat16_vol_id;
1753
1754 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1755 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1756
1757 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1758 sbi->dir_entries = bpb.fat_dir_entries;
1759 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1760 if (!silent)
1761 fat_msg(sb, KERN_ERR, "bogus number of directory entries"
1762 " (%u)", sbi->dir_entries);
1763 goto out_invalid;
1764 }
1765
1766 rootdir_sectors = sbi->dir_entries
1767 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1768 sbi->data_start = sbi->dir_start + rootdir_sectors;
1769 total_sectors = bpb.fat_sectors;
1770 if (total_sectors == 0)
1771 total_sectors = bpb.fat_total_sect;
1772
1773 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1774
1775 if (sbi->fat_bits != 32)
1776 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1777
1778 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */
1779 if (sbi->fat_bits == 32)
1780 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY;
1781 else /* fat 16 or 12 */
1782 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY;
1783
1784 /* check that FAT table does not overflow */
1785 fat_clusters = calc_fat_clusters(sb);
1786 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1787 if (total_clusters > MAX_FAT(sb)) {
1788 if (!silent)
1789 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)",
1790 total_clusters);
1791 goto out_invalid;
1792 }
1793
1794 sbi->max_cluster = total_clusters + FAT_START_ENT;
1795 /* check the free_clusters, it's not necessarily correct */
1796 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1797 sbi->free_clusters = -1;
1798 /* check the prev_free, it's not necessarily correct */
1799 sbi->prev_free %= sbi->max_cluster;
1800 if (sbi->prev_free < FAT_START_ENT)
1801 sbi->prev_free = FAT_START_ENT;
1802
1803 /* set up enough so that it can read an inode */
1804 fat_hash_init(sb);
1805 dir_hash_init(sb);
1806 fat_ent_access_init(sb);
1807
1808 /*
1809 * The low byte of FAT's first entry must have same value with
1810 * media-field. But in real world, too many devices is
1811 * writing wrong value. So, removed that validity check.
1812 *
1813 * if (FAT_FIRST_ENT(sb, media) != first)
1814 */
1815
1816 error = -EINVAL;
1817 sprintf(buf, "cp%d", sbi->options.codepage);
1818 sbi->nls_disk = load_nls(buf);
1819 if (!sbi->nls_disk) {
1820 fat_msg(sb, KERN_ERR, "codepage %s not found", buf);
1821 goto out_fail;
1822 }
1823
1824 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1825 if (sbi->options.isvfat) {
1826 sbi->nls_io = load_nls(sbi->options.iocharset);
1827 if (!sbi->nls_io) {
1828 fat_msg(sb, KERN_ERR, "IO charset %s not found",
1829 sbi->options.iocharset);
1830 goto out_fail;
1831 }
1832 }
1833
1834 error = -ENOMEM;
1835 fat_inode = new_inode(sb);
1836 if (!fat_inode)
1837 goto out_fail;
1838 fat_dummy_inode_init(fat_inode);
1839 sbi->fat_inode = fat_inode;
1840
1841 fsinfo_inode = new_inode(sb);
1842 if (!fsinfo_inode)
1843 goto out_fail;
1844 fat_dummy_inode_init(fsinfo_inode);
1845 fsinfo_inode->i_ino = MSDOS_FSINFO_INO;
1846 sbi->fsinfo_inode = fsinfo_inode;
1847 insert_inode_hash(fsinfo_inode);
1848
1849 root_inode = new_inode(sb);
1850 if (!root_inode)
1851 goto out_fail;
1852 root_inode->i_ino = MSDOS_ROOT_INO;
1853 inode_set_iversion(root_inode, 1);
1854 error = fat_read_root(root_inode);
1855 if (error < 0) {
1856 iput(root_inode);
1857 goto out_fail;
1858 }
1859 error = -ENOMEM;
1860 insert_inode_hash(root_inode);
1861 fat_attach(root_inode, 0);
1862 sb->s_root = d_make_root(root_inode);
1863 if (!sb->s_root) {
1864 fat_msg(sb, KERN_ERR, "get root inode failed");
1865 goto out_fail;
1866 }
1867
1868 if (sbi->options.discard) {
1869 struct request_queue *q = bdev_get_queue(sb->s_bdev);
1870 if (!blk_queue_discard(q))
1871 fat_msg(sb, KERN_WARNING,
1872 "mounting with \"discard\" option, but "
1873 "the device does not support discard");
1874 }
1875
1876 fat_set_state(sb, 1, 0);
1877 return 0;
1878
1879 out_invalid:
1880 error = -EINVAL;
1881 if (!silent)
1882 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem");
1883
1884 out_fail:
1885 if (fsinfo_inode)
1886 iput(fsinfo_inode);
1887 if (fat_inode)
1888 iput(fat_inode);
1889 unload_nls(sbi->nls_io);
1890 unload_nls(sbi->nls_disk);
1891 fat_reset_iocharset(&sbi->options);
1892 sb->s_fs_info = NULL;
1893 kfree(sbi);
1894 return error;
1895 }
1896
1897 EXPORT_SYMBOL_GPL(fat_fill_super);
1898
1899 /*
1900 * helper function for fat_flush_inodes. This writes both the inode
1901 * and the file data blocks, waiting for in flight data blocks before
1902 * the start of the call. It does not wait for any io started
1903 * during the call
1904 */
1905 static int writeback_inode(struct inode *inode)
1906 {
1907
1908 int ret;
1909
1910 /* if we used wait=1, sync_inode_metadata waits for the io for the
1911 * inode to finish. So wait=0 is sent down to sync_inode_metadata
1912 * and filemap_fdatawrite is used for the data blocks
1913 */
1914 ret = sync_inode_metadata(inode, 0);
1915 if (!ret)
1916 ret = filemap_fdatawrite(inode->i_mapping);
1917 return ret;
1918 }
1919
1920 /*
1921 * write data and metadata corresponding to i1 and i2. The io is
1922 * started but we do not wait for any of it to finish.
1923 *
1924 * filemap_flush is used for the block device, so if there is a dirty
1925 * page for a block already in flight, we will not wait and start the
1926 * io over again
1927 */
1928 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1929 {
1930 int ret = 0;
1931 if (!MSDOS_SB(sb)->options.flush)
1932 return 0;
1933 if (i1)
1934 ret = writeback_inode(i1);
1935 if (!ret && i2)
1936 ret = writeback_inode(i2);
1937 if (!ret) {
1938 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1939 ret = filemap_flush(mapping);
1940 }
1941 return ret;
1942 }
1943 EXPORT_SYMBOL_GPL(fat_flush_inodes);
1944
1945 static int __init init_fat_fs(void)
1946 {
1947 int err;
1948
1949 err = fat_cache_init();
1950 if (err)
1951 return err;
1952
1953 err = fat_init_inodecache();
1954 if (err)
1955 goto failed;
1956
1957 return 0;
1958
1959 failed:
1960 fat_cache_destroy();
1961 return err;
1962 }
1963
1964 static void __exit exit_fat_fs(void)
1965 {
1966 fat_cache_destroy();
1967 fat_destroy_inodecache();
1968 }
1969
1970 module_init(init_fat_fs)
1971 module_exit(exit_fat_fs)
1972
1973 MODULE_LICENSE("GPL");
Linux with added FPC-III support