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Merge tag 'mtd/fixes-for-5.2-final' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6/linux-2.6-arm.git] / fs / fat / inode.c
blob05689198f5aff712b771916b52893ac9a0196959
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/fs/fat/inode.c
4 *
5 * Written 1992,1993 by Werner Almesberger
6 * VFAT extensions by Gordon Chaffee, merged with msdos fs by Henrik Storner
7 * Rewritten for the constant inumbers support by Al Viro
8 *
9 * Fixes:
10 *
11 * Max Cohan: Fixed invalid FSINFO offset when info_sector is 0
12 */
13
14 #include <linux/module.h>
15 #include <linux/pagemap.h>
16 #include <linux/mpage.h>
17 #include <linux/vfs.h>
18 #include <linux/seq_file.h>
19 #include <linux/parser.h>
20 #include <linux/uio.h>
21 #include <linux/blkdev.h>
22 #include <linux/backing-dev.h>
23 #include <asm/unaligned.h>
24 #include <linux/iversion.h>
25 #include "fat.h"
26
27 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET
28 /* if user don't select VFAT, this is undefined. */
29 #define CONFIG_FAT_DEFAULT_IOCHARSET ""
30 #endif
31
32 #define KB_IN_SECTORS 2
33
34 /*
35 * A deserialized copy of the on-disk structure laid out in struct
36 * fat_boot_sector.
37 */
38 struct fat_bios_param_block {
39 u16 fat_sector_size;
40 u8 fat_sec_per_clus;
41 u16 fat_reserved;
42 u8 fat_fats;
43 u16 fat_dir_entries;
44 u16 fat_sectors;
45 u16 fat_fat_length;
46 u32 fat_total_sect;
47
48 u8 fat16_state;
49 u32 fat16_vol_id;
50
51 u32 fat32_length;
52 u32 fat32_root_cluster;
53 u16 fat32_info_sector;
54 u8 fat32_state;
55 u32 fat32_vol_id;
56 };
57
58 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
59 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
60
61 static struct fat_floppy_defaults {
62 unsigned nr_sectors;
63 unsigned sec_per_clus;
64 unsigned dir_entries;
65 unsigned media;
66 unsigned fat_length;
67 } floppy_defaults[] = {
68 {
69 .nr_sectors = 160 * KB_IN_SECTORS,
70 .sec_per_clus = 1,
71 .dir_entries = 64,
72 .media = 0xFE,
73 .fat_length = 1,
74 },
75 {
76 .nr_sectors = 180 * KB_IN_SECTORS,
77 .sec_per_clus = 1,
78 .dir_entries = 64,
79 .media = 0xFC,
80 .fat_length = 2,
81 },
82 {
83 .nr_sectors = 320 * KB_IN_SECTORS,
84 .sec_per_clus = 2,
85 .dir_entries = 112,
86 .media = 0xFF,
87 .fat_length = 1,
88 },
89 {
90 .nr_sectors = 360 * KB_IN_SECTORS,
91 .sec_per_clus = 2,
92 .dir_entries = 112,
93 .media = 0xFD,
94 .fat_length = 2,
95 },
96 };
97
98 int fat_add_cluster(struct inode *inode)
99 {
100 int err, cluster;
101
102 err = fat_alloc_clusters(inode, &cluster, 1);
103 if (err)
104 return err;
105 /* FIXME: this cluster should be added after data of this
106 * cluster is writed */
107 err = fat_chain_add(inode, cluster, 1);
108 if (err)
109 fat_free_clusters(inode, cluster);
110 return err;
111 }
112
113 static inline int __fat_get_block(struct inode *inode, sector_t iblock,
114 unsigned long *max_blocks,
115 struct buffer_head *bh_result, int create)
116 {
117 struct super_block *sb = inode->i_sb;
118 struct msdos_sb_info *sbi = MSDOS_SB(sb);
119 unsigned long mapped_blocks;
120 sector_t phys, last_block;
121 int err, offset;
122
123 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false);
124 if (err)
125 return err;
126 if (phys) {
127 map_bh(bh_result, sb, phys);
128 *max_blocks = min(mapped_blocks, *max_blocks);
129 return 0;
130 }
131 if (!create)
132 return 0;
133
134 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
135 fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)",
136 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
137 return -EIO;
138 }
139
140 last_block = inode->i_blocks >> (sb->s_blocksize_bits - 9);
141 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
142 /*
143 * allocate a cluster according to the following.
144 * 1) no more available blocks
145 * 2) not part of fallocate region
146 */
147 if (!offset && !(iblock < last_block)) {
148 /* TODO: multiple cluster allocation would be desirable. */
149 err = fat_add_cluster(inode);
150 if (err)
151 return err;
152 }
153 /* available blocks on this cluster */
154 mapped_blocks = sbi->sec_per_clus - offset;
155
156 *max_blocks = min(mapped_blocks, *max_blocks);
157 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
158
159 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false);
160 if (err)
161 return err;
162 if (!phys) {
163 fat_fs_error(sb,
164 "invalid FAT chain (i_pos %lld, last_block %llu)",
165 MSDOS_I(inode)->i_pos,
166 (unsigned long long)last_block);
167 return -EIO;
168 }
169
170 BUG_ON(*max_blocks != mapped_blocks);
171 set_buffer_new(bh_result);
172 map_bh(bh_result, sb, phys);
173
174 return 0;
175 }
176
177 static int fat_get_block(struct inode *inode, sector_t iblock,
178 struct buffer_head *bh_result, int create)
179 {
180 struct super_block *sb = inode->i_sb;
181 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
182 int err;
183
184 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
185 if (err)
186 return err;
187 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
188 return 0;
189 }
190
191 static int fat_writepage(struct page *page, struct writeback_control *wbc)
192 {
193 return block_write_full_page(page, fat_get_block, wbc);
194 }
195
196 static int fat_writepages(struct address_space *mapping,
197 struct writeback_control *wbc)
198 {
199 return mpage_writepages(mapping, wbc, fat_get_block);
200 }
201
202 static int fat_readpage(struct file *file, struct page *page)
203 {
204 return mpage_readpage(page, fat_get_block);
205 }
206
207 static int fat_readpages(struct file *file, struct address_space *mapping,
208 struct list_head *pages, unsigned nr_pages)
209 {
210 return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
211 }
212
213 static void fat_write_failed(struct address_space *mapping, loff_t to)
214 {
215 struct inode *inode = mapping->host;
216
217 if (to > inode->i_size) {
218 truncate_pagecache(inode, inode->i_size);
219 fat_truncate_blocks(inode, inode->i_size);
220 }
221 }
222
223 static int fat_write_begin(struct file *file, struct address_space *mapping,
224 loff_t pos, unsigned len, unsigned flags,
225 struct page **pagep, void **fsdata)
226 {
227 int err;
228
229 *pagep = NULL;
230 err = cont_write_begin(file, mapping, pos, len, flags,
231 pagep, fsdata, fat_get_block,
232 &MSDOS_I(mapping->host)->mmu_private);
233 if (err < 0)
234 fat_write_failed(mapping, pos + len);
235 return err;
236 }
237
238 static int fat_write_end(struct file *file, struct address_space *mapping,
239 loff_t pos, unsigned len, unsigned copied,
240 struct page *pagep, void *fsdata)
241 {
242 struct inode *inode = mapping->host;
243 int err;
244 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
245 if (err < len)
246 fat_write_failed(mapping, pos + len);
247 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
248 fat_truncate_time(inode, NULL, S_CTIME|S_MTIME);
249 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
250 mark_inode_dirty(inode);
251 }
252 return err;
253 }
254
255 static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
256 {
257 struct file *file = iocb->ki_filp;
258 struct address_space *mapping = file->f_mapping;
259 struct inode *inode = mapping->host;
260 size_t count = iov_iter_count(iter);
261 loff_t offset = iocb->ki_pos;
262 ssize_t ret;
263
264 if (iov_iter_rw(iter) == WRITE) {
265 /*
266 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
267 * so we need to update the ->mmu_private to block boundary.
268 *
269 * But we must fill the remaining area or hole by nul for
270 * updating ->mmu_private.
271 *
272 * Return 0, and fallback to normal buffered write.
273 */
274 loff_t size = offset + count;
275 if (MSDOS_I(inode)->mmu_private < size)
276 return 0;
277 }
278
279 /*
280 * FAT need to use the DIO_LOCKING for avoiding the race
281 * condition of fat_get_block() and ->truncate().
282 */
283 ret = blockdev_direct_IO(iocb, inode, iter, fat_get_block);
284 if (ret < 0 && iov_iter_rw(iter) == WRITE)
285 fat_write_failed(mapping, offset + count);
286
287 return ret;
288 }
289
290 static int fat_get_block_bmap(struct inode *inode, sector_t iblock,
291 struct buffer_head *bh_result, int create)
292 {
293 struct super_block *sb = inode->i_sb;
294 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
295 int err;
296 sector_t bmap;
297 unsigned long mapped_blocks;
298
299 BUG_ON(create != 0);
300
301 err = fat_bmap(inode, iblock, &bmap, &mapped_blocks, create, true);
302 if (err)
303 return err;
304
305 if (bmap) {
306 map_bh(bh_result, sb, bmap);
307 max_blocks = min(mapped_blocks, max_blocks);
308 }
309
310 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
311
312 return 0;
313 }
314
315 static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
316 {
317 sector_t blocknr;
318
319 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
320 down_read(&MSDOS_I(mapping->host)->truncate_lock);
321 blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap);
322 up_read(&MSDOS_I(mapping->host)->truncate_lock);
323
324 return blocknr;
325 }
326
327 /*
328 * fat_block_truncate_page() zeroes out a mapping from file offset `from'
329 * up to the end of the block which corresponds to `from'.
330 * This is required during truncate to physically zeroout the tail end
331 * of that block so it doesn't yield old data if the file is later grown.
332 * Also, avoid causing failure from fsx for cases of "data past EOF"
333 */
334 int fat_block_truncate_page(struct inode *inode, loff_t from)
335 {
336 return block_truncate_page(inode->i_mapping, from, fat_get_block);
337 }
338
339 static const struct address_space_operations fat_aops = {
340 .readpage = fat_readpage,
341 .readpages = fat_readpages,
342 .writepage = fat_writepage,
343 .writepages = fat_writepages,
344 .write_begin = fat_write_begin,
345 .write_end = fat_write_end,
346 .direct_IO = fat_direct_IO,
347 .bmap = _fat_bmap
348 };
349
350 /*
351 * New FAT inode stuff. We do the following:
352 * a) i_ino is constant and has nothing with on-disk location.
353 * b) FAT manages its own cache of directory entries.
354 * c) *This* cache is indexed by on-disk location.
355 * d) inode has an associated directory entry, all right, but
356 * it may be unhashed.
357 * e) currently entries are stored within struct inode. That should
358 * change.
359 * f) we deal with races in the following way:
360 * 1. readdir() and lookup() do FAT-dir-cache lookup.
361 * 2. rename() unhashes the F-d-c entry and rehashes it in
362 * a new place.
363 * 3. unlink() and rmdir() unhash F-d-c entry.
364 * 4. fat_write_inode() checks whether the thing is unhashed.
365 * If it is we silently return. If it isn't we do bread(),
366 * check if the location is still valid and retry if it
367 * isn't. Otherwise we do changes.
368 * 5. Spinlock is used to protect hash/unhash/location check/lookup
369 * 6. fat_evict_inode() unhashes the F-d-c entry.
370 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
371 * and consider negative result as cache miss.
372 */
373
374 static void fat_hash_init(struct super_block *sb)
375 {
376 struct msdos_sb_info *sbi = MSDOS_SB(sb);
377 int i;
378
379 spin_lock_init(&sbi->inode_hash_lock);
380 for (i = 0; i < FAT_HASH_SIZE; i++)
381 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
382 }
383
384 static inline unsigned long fat_hash(loff_t i_pos)
385 {
386 return hash_32(i_pos, FAT_HASH_BITS);
387 }
388
389 static void dir_hash_init(struct super_block *sb)
390 {
391 struct msdos_sb_info *sbi = MSDOS_SB(sb);
392 int i;
393
394 spin_lock_init(&sbi->dir_hash_lock);
395 for (i = 0; i < FAT_HASH_SIZE; i++)
396 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]);
397 }
398
399 void fat_attach(struct inode *inode, loff_t i_pos)
400 {
401 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
402
403 if (inode->i_ino != MSDOS_ROOT_INO) {
404 struct hlist_head *head = sbi->inode_hashtable
405 + fat_hash(i_pos);
406
407 spin_lock(&sbi->inode_hash_lock);
408 MSDOS_I(inode)->i_pos = i_pos;
409 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
410 spin_unlock(&sbi->inode_hash_lock);
411 }
412
413 /* If NFS support is enabled, cache the mapping of start cluster
414 * to directory inode. This is used during reconnection of
415 * dentries to the filesystem root.
416 */
417 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
418 struct hlist_head *d_head = sbi->dir_hashtable;
419 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart);
420
421 spin_lock(&sbi->dir_hash_lock);
422 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head);
423 spin_unlock(&sbi->dir_hash_lock);
424 }
425 }
426 EXPORT_SYMBOL_GPL(fat_attach);
427
428 void fat_detach(struct inode *inode)
429 {
430 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
431 spin_lock(&sbi->inode_hash_lock);
432 MSDOS_I(inode)->i_pos = 0;
433 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
434 spin_unlock(&sbi->inode_hash_lock);
435
436 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
437 spin_lock(&sbi->dir_hash_lock);
438 hlist_del_init(&MSDOS_I(inode)->i_dir_hash);
439 spin_unlock(&sbi->dir_hash_lock);
440 }
441 }
442 EXPORT_SYMBOL_GPL(fat_detach);
443
444 struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
445 {
446 struct msdos_sb_info *sbi = MSDOS_SB(sb);
447 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
448 struct msdos_inode_info *i;
449 struct inode *inode = NULL;
450
451 spin_lock(&sbi->inode_hash_lock);
452 hlist_for_each_entry(i, head, i_fat_hash) {
453 BUG_ON(i->vfs_inode.i_sb != sb);
454 if (i->i_pos != i_pos)
455 continue;
456 inode = igrab(&i->vfs_inode);
457 if (inode)
458 break;
459 }
460 spin_unlock(&sbi->inode_hash_lock);
461 return inode;
462 }
463
464 static int is_exec(unsigned char *extension)
465 {
466 unsigned char exe_extensions[] = "EXECOMBAT", *walk;
467
468 for (walk = exe_extensions; *walk; walk += 3)
469 if (!strncmp(extension, walk, 3))
470 return 1;
471 return 0;
472 }
473
474 static int fat_calc_dir_size(struct inode *inode)
475 {
476 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
477 int ret, fclus, dclus;
478
479 inode->i_size = 0;
480 if (MSDOS_I(inode)->i_start == 0)
481 return 0;
482
483 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
484 if (ret < 0)
485 return ret;
486 inode->i_size = (fclus + 1) << sbi->cluster_bits;
487
488 return 0;
489 }
490
491 static int fat_validate_dir(struct inode *dir)
492 {
493 struct super_block *sb = dir->i_sb;
494
495 if (dir->i_nlink < 2) {
496 /* Directory should have "."/".." entries at least. */
497 fat_fs_error(sb, "corrupted directory (invalid entries)");
498 return -EIO;
499 }
500 if (MSDOS_I(dir)->i_start == 0 ||
501 MSDOS_I(dir)->i_start == MSDOS_SB(sb)->root_cluster) {
502 /* Directory should point valid cluster. */
503 fat_fs_error(sb, "corrupted directory (invalid i_start)");
504 return -EIO;
505 }
506 return 0;
507 }
508
509 /* doesn't deal with root inode */
510 int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
511 {
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, &inode->i_mtime, de->time, de->date, 0);
563 if (sbi->options.isvfat) {
564 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
565 de->cdate, de->ctime_cs);
566 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
567 } else
568 fat_truncate_time(inode, &inode->i_mtime, S_ATIME|S_CTIME);
569
570 return 0;
571 }
572
573 static inline void fat_lock_build_inode(struct msdos_sb_info *sbi)
574 {
575 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
576 mutex_lock(&sbi->nfs_build_inode_lock);
577 }
578
579 static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi)
580 {
581 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
582 mutex_unlock(&sbi->nfs_build_inode_lock);
583 }
584
585 struct inode *fat_build_inode(struct super_block *sb,
586 struct msdos_dir_entry *de, loff_t i_pos)
587 {
588 struct inode *inode;
589 int err;
590
591 fat_lock_build_inode(MSDOS_SB(sb));
592 inode = fat_iget(sb, i_pos);
593 if (inode)
594 goto out;
595 inode = new_inode(sb);
596 if (!inode) {
597 inode = ERR_PTR(-ENOMEM);
598 goto out;
599 }
600 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
601 inode_set_iversion(inode, 1);
602 err = fat_fill_inode(inode, de);
603 if (err) {
604 iput(inode);
605 inode = ERR_PTR(err);
606 goto out;
607 }
608 fat_attach(inode, i_pos);
609 insert_inode_hash(inode);
610 out:
611 fat_unlock_build_inode(MSDOS_SB(sb));
612 return inode;
613 }
614
615 EXPORT_SYMBOL_GPL(fat_build_inode);
616
617 static int __fat_write_inode(struct inode *inode, int wait);
618
619 static void fat_free_eofblocks(struct inode *inode)
620 {
621 /* Release unwritten fallocated blocks on inode eviction. */
622 if ((inode->i_blocks << 9) >
623 round_up(MSDOS_I(inode)->mmu_private,
624 MSDOS_SB(inode->i_sb)->cluster_size)) {
625 int err;
626
627 fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private);
628 /* Fallocate results in updating the i_start/iogstart
629 * for the zero byte file. So, make it return to
630 * original state during evict and commit it to avoid
631 * any corruption on the next access to the cluster
632 * chain for the file.
633 */
634 err = __fat_write_inode(inode, inode_needs_sync(inode));
635 if (err) {
636 fat_msg(inode->i_sb, KERN_WARNING, "Failed to "
637 "update on disk inode for unused "
638 "fallocated blocks, inode could be "
639 "corrupted. Please run fsck");
640 }
641
642 }
643 }
644
645 static void fat_evict_inode(struct inode *inode)
646 {
647 truncate_inode_pages_final(&inode->i_data);
648 if (!inode->i_nlink) {
649 inode->i_size = 0;
650 fat_truncate_blocks(inode, 0);
651 } else
652 fat_free_eofblocks(inode);
653
654 invalidate_inode_buffers(inode);
655 clear_inode(inode);
656 fat_cache_inval_inode(inode);
657 fat_detach(inode);
658 }
659
660 static void fat_set_state(struct super_block *sb,
661 unsigned int set, unsigned int force)
662 {
663 struct buffer_head *bh;
664 struct fat_boot_sector *b;
665 struct msdos_sb_info *sbi = MSDOS_SB(sb);
666
667 /* do not change any thing if mounted read only */
668 if (sb_rdonly(sb) && !force)
669 return;
670
671 /* do not change state if fs was dirty */
672 if (sbi->dirty) {
673 /* warn only on set (mount). */
674 if (set)
675 fat_msg(sb, KERN_WARNING, "Volume was not properly "
676 "unmounted. Some data may be corrupt. "
677 "Please run fsck.");
678 return;
679 }
680
681 bh = sb_bread(sb, 0);
682 if (bh == NULL) {
683 fat_msg(sb, KERN_ERR, "unable to read boot sector "
684 "to mark fs as dirty");
685 return;
686 }
687
688 b = (struct fat_boot_sector *) bh->b_data;
689
690 if (is_fat32(sbi)) {
691 if (set)
692 b->fat32.state |= FAT_STATE_DIRTY;
693 else
694 b->fat32.state &= ~FAT_STATE_DIRTY;
695 } else /* fat 16 and 12 */ {
696 if (set)
697 b->fat16.state |= FAT_STATE_DIRTY;
698 else
699 b->fat16.state &= ~FAT_STATE_DIRTY;
700 }
701
702 mark_buffer_dirty(bh);
703 sync_dirty_buffer(bh);
704 brelse(bh);
705 }
706
707 static void fat_reset_iocharset(struct fat_mount_options *opts)
708 {
709 if (opts->iocharset != fat_default_iocharset) {
710 /* Note: opts->iocharset can be NULL here */
711 kfree(opts->iocharset);
712 opts->iocharset = fat_default_iocharset;
713 }
714 }
715
716 static void delayed_free(struct rcu_head *p)
717 {
718 struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu);
719 unload_nls(sbi->nls_disk);
720 unload_nls(sbi->nls_io);
721 fat_reset_iocharset(&sbi->options);
722 kfree(sbi);
723 }
724
725 static void fat_put_super(struct super_block *sb)
726 {
727 struct msdos_sb_info *sbi = MSDOS_SB(sb);
728
729 fat_set_state(sb, 0, 0);
730
731 iput(sbi->fsinfo_inode);
732 iput(sbi->fat_inode);
733
734 call_rcu(&sbi->rcu, delayed_free);
735 }
736
737 static struct kmem_cache *fat_inode_cachep;
738
739 static struct inode *fat_alloc_inode(struct super_block *sb)
740 {
741 struct msdos_inode_info *ei;
742 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
743 if (!ei)
744 return NULL;
745
746 init_rwsem(&ei->truncate_lock);
747 return &ei->vfs_inode;
748 }
749
750 static void fat_free_inode(struct inode *inode)
751 {
752 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
753 }
754
755 static void init_once(void *foo)
756 {
757 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
758
759 spin_lock_init(&ei->cache_lru_lock);
760 ei->nr_caches = 0;
761 ei->cache_valid_id = FAT_CACHE_VALID + 1;
762 INIT_LIST_HEAD(&ei->cache_lru);
763 INIT_HLIST_NODE(&ei->i_fat_hash);
764 INIT_HLIST_NODE(&ei->i_dir_hash);
765 inode_init_once(&ei->vfs_inode);
766 }
767
768 static int __init fat_init_inodecache(void)
769 {
770 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
771 sizeof(struct msdos_inode_info),
772 0, (SLAB_RECLAIM_ACCOUNT|
773 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
774 init_once);
775 if (fat_inode_cachep == NULL)
776 return -ENOMEM;
777 return 0;
778 }
779
780 static void __exit fat_destroy_inodecache(void)
781 {
782 /*
783 * Make sure all delayed rcu free inodes are flushed before we
784 * destroy cache.
785 */
786 rcu_barrier();
787 kmem_cache_destroy(fat_inode_cachep);
788 }
789
790 static int fat_remount(struct super_block *sb, int *flags, char *data)
791 {
792 bool new_rdonly;
793 struct msdos_sb_info *sbi = MSDOS_SB(sb);
794 *flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME);
795
796 sync_filesystem(sb);
797
798 /* make sure we update state on remount. */
799 new_rdonly = *flags & SB_RDONLY;
800 if (new_rdonly != sb_rdonly(sb)) {
801 if (new_rdonly)
802 fat_set_state(sb, 0, 0);
803 else
804 fat_set_state(sb, 1, 1);
805 }
806 return 0;
807 }
808
809 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
810 {
811 struct super_block *sb = dentry->d_sb;
812 struct msdos_sb_info *sbi = MSDOS_SB(sb);
813 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
814
815 /* If the count of free cluster is still unknown, counts it here. */
816 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
817 int err = fat_count_free_clusters(dentry->d_sb);
818 if (err)
819 return err;
820 }
821
822 buf->f_type = dentry->d_sb->s_magic;
823 buf->f_bsize = sbi->cluster_size;
824 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
825 buf->f_bfree = sbi->free_clusters;
826 buf->f_bavail = sbi->free_clusters;
827 buf->f_fsid.val[0] = (u32)id;
828 buf->f_fsid.val[1] = (u32)(id >> 32);
829 buf->f_namelen =
830 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE;
831
832 return 0;
833 }
834
835 static int __fat_write_inode(struct inode *inode, int wait)
836 {
837 struct super_block *sb = inode->i_sb;
838 struct msdos_sb_info *sbi = MSDOS_SB(sb);
839 struct buffer_head *bh;
840 struct msdos_dir_entry *raw_entry;
841 loff_t i_pos;
842 sector_t blocknr;
843 int err, offset;
844
845 if (inode->i_ino == MSDOS_ROOT_INO)
846 return 0;
847
848 retry:
849 i_pos = fat_i_pos_read(sbi, inode);
850 if (!i_pos)
851 return 0;
852
853 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset);
854 bh = sb_bread(sb, blocknr);
855 if (!bh) {
856 fat_msg(sb, KERN_ERR, "unable to read inode block "
857 "for updating (i_pos %lld)", i_pos);
858 return -EIO;
859 }
860 spin_lock(&sbi->inode_hash_lock);
861 if (i_pos != MSDOS_I(inode)->i_pos) {
862 spin_unlock(&sbi->inode_hash_lock);
863 brelse(bh);
864 goto retry;
865 }
866
867 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset];
868 if (S_ISDIR(inode->i_mode))
869 raw_entry->size = 0;
870 else
871 raw_entry->size = cpu_to_le32(inode->i_size);
872 raw_entry->attr = fat_make_attrs(inode);
873 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart);
874 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
875 &raw_entry->date, NULL);
876 if (sbi->options.isvfat) {
877 __le16 atime;
878 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
879 &raw_entry->cdate, &raw_entry->ctime_cs);
880 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
881 &raw_entry->adate, NULL);
882 }
883 spin_unlock(&sbi->inode_hash_lock);
884 mark_buffer_dirty(bh);
885 err = 0;
886 if (wait)
887 err = sync_dirty_buffer(bh);
888 brelse(bh);
889 return err;
890 }
891
892 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
893 {
894 int err;
895
896 if (inode->i_ino == MSDOS_FSINFO_INO) {
897 struct super_block *sb = inode->i_sb;
898
899 mutex_lock(&MSDOS_SB(sb)->s_lock);
900 err = fat_clusters_flush(sb);
901 mutex_unlock(&MSDOS_SB(sb)->s_lock);
902 } else
903 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
904
905 return err;
906 }
907
908 int fat_sync_inode(struct inode *inode)
909 {
910 return __fat_write_inode(inode, 1);
911 }
912
913 EXPORT_SYMBOL_GPL(fat_sync_inode);
914
915 static int fat_show_options(struct seq_file *m, struct dentry *root);
916 static const struct super_operations fat_sops = {
917 .alloc_inode = fat_alloc_inode,
918 .free_inode = fat_free_inode,
919 .write_inode = fat_write_inode,
920 .evict_inode = fat_evict_inode,
921 .put_super = fat_put_super,
922 .statfs = fat_statfs,
923 .remount_fs = fat_remount,
924
925 .show_options = fat_show_options,
926 };
927
928 static int fat_show_options(struct seq_file *m, struct dentry *root)
929 {
930 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb);
931 struct fat_mount_options *opts = &sbi->options;
932 int isvfat = opts->isvfat;
933
934 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
935 seq_printf(m, ",uid=%u",
936 from_kuid_munged(&init_user_ns, opts->fs_uid));
937 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
938 seq_printf(m, ",gid=%u",
939 from_kgid_munged(&init_user_ns, opts->fs_gid));
940 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
941 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
942 if (opts->allow_utime)
943 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
944 if (sbi->nls_disk)
945 /* strip "cp" prefix from displayed option */
946 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]);
947 if (isvfat) {
948 if (sbi->nls_io)
949 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
950
951 switch (opts->shortname) {
952 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
953 seq_puts(m, ",shortname=win95");
954 break;
955 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
956 seq_puts(m, ",shortname=winnt");
957 break;
958 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
959 seq_puts(m, ",shortname=mixed");
960 break;
961 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
962 seq_puts(m, ",shortname=lower");
963 break;
964 default:
965 seq_puts(m, ",shortname=unknown");
966 break;
967 }
968 }
969 if (opts->name_check != 'n')
970 seq_printf(m, ",check=%c", opts->name_check);
971 if (opts->usefree)
972 seq_puts(m, ",usefree");
973 if (opts->quiet)
974 seq_puts(m, ",quiet");
975 if (opts->showexec)
976 seq_puts(m, ",showexec");
977 if (opts->sys_immutable)
978 seq_puts(m, ",sys_immutable");
979 if (!isvfat) {
980 if (opts->dotsOK)
981 seq_puts(m, ",dotsOK=yes");
982 if (opts->nocase)
983 seq_puts(m, ",nocase");
984 } else {
985 if (opts->utf8)
986 seq_puts(m, ",utf8");
987 if (opts->unicode_xlate)
988 seq_puts(m, ",uni_xlate");
989 if (!opts->numtail)
990 seq_puts(m, ",nonumtail");
991 if (opts->rodir)
992 seq_puts(m, ",rodir");
993 }
994 if (opts->flush)
995 seq_puts(m, ",flush");
996 if (opts->tz_set) {
997 if (opts->time_offset)
998 seq_printf(m, ",time_offset=%d", opts->time_offset);
999 else
1000 seq_puts(m, ",tz=UTC");
1001 }
1002 if (opts->errors == FAT_ERRORS_CONT)
1003 seq_puts(m, ",errors=continue");
1004 else if (opts->errors == FAT_ERRORS_PANIC)
1005 seq_puts(m, ",errors=panic");
1006 else
1007 seq_puts(m, ",errors=remount-ro");
1008 if (opts->nfs == FAT_NFS_NOSTALE_RO)
1009 seq_puts(m, ",nfs=nostale_ro");
1010 else if (opts->nfs)
1011 seq_puts(m, ",nfs=stale_rw");
1012 if (opts->discard)
1013 seq_puts(m, ",discard");
1014 if (opts->dos1xfloppy)
1015 seq_puts(m, ",dos1xfloppy");
1016
1017 return 0;
1018 }
1019
1020 enum {
1021 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
1022 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
1023 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
1024 Opt_immutable, Opt_dots, Opt_nodots,
1025 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
1026 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
1027 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
1028 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
1029 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset,
1030 Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy,
1031 };
1032
1033 static const match_table_t fat_tokens = {
1034 {Opt_check_r, "check=relaxed"},
1035 {Opt_check_s, "check=strict"},
1036 {Opt_check_n, "check=normal"},
1037 {Opt_check_r, "check=r"},
1038 {Opt_check_s, "check=s"},
1039 {Opt_check_n, "check=n"},
1040 {Opt_uid, "uid=%u"},
1041 {Opt_gid, "gid=%u"},
1042 {Opt_umask, "umask=%o"},
1043 {Opt_dmask, "dmask=%o"},
1044 {Opt_fmask, "fmask=%o"},
1045 {Opt_allow_utime, "allow_utime=%o"},
1046 {Opt_codepage, "codepage=%u"},
1047 {Opt_usefree, "usefree"},
1048 {Opt_nocase, "nocase"},
1049 {Opt_quiet, "quiet"},
1050 {Opt_showexec, "showexec"},
1051 {Opt_debug, "debug"},
1052 {Opt_immutable, "sys_immutable"},
1053 {Opt_flush, "flush"},
1054 {Opt_tz_utc, "tz=UTC"},
1055 {Opt_time_offset, "time_offset=%d"},
1056 {Opt_err_cont, "errors=continue"},
1057 {Opt_err_panic, "errors=panic"},
1058 {Opt_err_ro, "errors=remount-ro"},
1059 {Opt_discard, "discard"},
1060 {Opt_nfs_stale_rw, "nfs"},
1061 {Opt_nfs_stale_rw, "nfs=stale_rw"},
1062 {Opt_nfs_nostale_ro, "nfs=nostale_ro"},
1063 {Opt_dos1xfloppy, "dos1xfloppy"},
1064 {Opt_obsolete, "conv=binary"},
1065 {Opt_obsolete, "conv=text"},
1066 {Opt_obsolete, "conv=auto"},
1067 {Opt_obsolete, "conv=b"},
1068 {Opt_obsolete, "conv=t"},
1069 {Opt_obsolete, "conv=a"},
1070 {Opt_obsolete, "fat=%u"},
1071 {Opt_obsolete, "blocksize=%u"},
1072 {Opt_obsolete, "cvf_format=%20s"},
1073 {Opt_obsolete, "cvf_options=%100s"},
1074 {Opt_obsolete, "posix"},
1075 {Opt_err, NULL},
1076 };
1077 static const match_table_t msdos_tokens = {
1078 {Opt_nodots, "nodots"},
1079 {Opt_nodots, "dotsOK=no"},
1080 {Opt_dots, "dots"},
1081 {Opt_dots, "dotsOK=yes"},
1082 {Opt_err, NULL}
1083 };
1084 static const match_table_t vfat_tokens = {
1085 {Opt_charset, "iocharset=%s"},
1086 {Opt_shortname_lower, "shortname=lower"},
1087 {Opt_shortname_win95, "shortname=win95"},
1088 {Opt_shortname_winnt, "shortname=winnt"},
1089 {Opt_shortname_mixed, "shortname=mixed"},
1090 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
1091 {Opt_utf8_no, "utf8=no"},
1092 {Opt_utf8_no, "utf8=false"},
1093 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
1094 {Opt_utf8_yes, "utf8=yes"},
1095 {Opt_utf8_yes, "utf8=true"},
1096 {Opt_utf8_yes, "utf8"},
1097 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
1098 {Opt_uni_xl_no, "uni_xlate=no"},
1099 {Opt_uni_xl_no, "uni_xlate=false"},
1100 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
1101 {Opt_uni_xl_yes, "uni_xlate=yes"},
1102 {Opt_uni_xl_yes, "uni_xlate=true"},
1103 {Opt_uni_xl_yes, "uni_xlate"},
1104 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
1105 {Opt_nonumtail_no, "nonumtail=no"},
1106 {Opt_nonumtail_no, "nonumtail=false"},
1107 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
1108 {Opt_nonumtail_yes, "nonumtail=yes"},
1109 {Opt_nonumtail_yes, "nonumtail=true"},
1110 {Opt_nonumtail_yes, "nonumtail"},
1111 {Opt_rodir, "rodir"},
1112 {Opt_err, NULL}
1113 };
1114
1115 static int parse_options(struct super_block *sb, char *options, int is_vfat,
1116 int silent, int *debug, struct fat_mount_options *opts)
1117 {
1118 char *p;
1119 substring_t args[MAX_OPT_ARGS];
1120 int option;
1121 char *iocharset;
1122
1123 opts->isvfat = is_vfat;
1124
1125 opts->fs_uid = current_uid();
1126 opts->fs_gid = current_gid();
1127 opts->fs_fmask = opts->fs_dmask = current_umask();
1128 opts->allow_utime = -1;
1129 opts->codepage = fat_default_codepage;
1130 fat_reset_iocharset(opts);
1131 if (is_vfat) {
1132 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
1133 opts->rodir = 0;
1134 } else {
1135 opts->shortname = 0;
1136 opts->rodir = 1;
1137 }
1138 opts->name_check = 'n';
1139 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
1140 opts->unicode_xlate = 0;
1141 opts->numtail = 1;
1142 opts->usefree = opts->nocase = 0;
1143 opts->tz_set = 0;
1144 opts->nfs = 0;
1145 opts->errors = FAT_ERRORS_RO;
1146 *debug = 0;
1147
1148 opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat;
1149
1150 if (!options)
1151 goto out;
1152
1153 while ((p = strsep(&options, ",")) != NULL) {
1154 int token;
1155 if (!*p)
1156 continue;
1157
1158 token = match_token(p, fat_tokens, args);
1159 if (token == Opt_err) {
1160 if (is_vfat)
1161 token = match_token(p, vfat_tokens, args);
1162 else
1163 token = match_token(p, msdos_tokens, args);
1164 }
1165 switch (token) {
1166 case Opt_check_s:
1167 opts->name_check = 's';
1168 break;
1169 case Opt_check_r:
1170 opts->name_check = 'r';
1171 break;
1172 case Opt_check_n:
1173 opts->name_check = 'n';
1174 break;
1175 case Opt_usefree:
1176 opts->usefree = 1;
1177 break;
1178 case Opt_nocase:
1179 if (!is_vfat)
1180 opts->nocase = 1;
1181 else {
1182 /* for backward compatibility */
1183 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1184 | VFAT_SFN_CREATE_WIN95;
1185 }
1186 break;
1187 case Opt_quiet:
1188 opts->quiet = 1;
1189 break;
1190 case Opt_showexec:
1191 opts->showexec = 1;
1192 break;
1193 case Opt_debug:
1194 *debug = 1;
1195 break;
1196 case Opt_immutable:
1197 opts->sys_immutable = 1;
1198 break;
1199 case Opt_uid:
1200 if (match_int(&args[0], &option))
1201 return -EINVAL;
1202 opts->fs_uid = make_kuid(current_user_ns(), option);
1203 if (!uid_valid(opts->fs_uid))
1204 return -EINVAL;
1205 break;
1206 case Opt_gid:
1207 if (match_int(&args[0], &option))
1208 return -EINVAL;
1209 opts->fs_gid = make_kgid(current_user_ns(), option);
1210 if (!gid_valid(opts->fs_gid))
1211 return -EINVAL;
1212 break;
1213 case Opt_umask:
1214 if (match_octal(&args[0], &option))
1215 return -EINVAL;
1216 opts->fs_fmask = opts->fs_dmask = option;
1217 break;
1218 case Opt_dmask:
1219 if (match_octal(&args[0], &option))
1220 return -EINVAL;
1221 opts->fs_dmask = option;
1222 break;
1223 case Opt_fmask:
1224 if (match_octal(&args[0], &option))
1225 return -EINVAL;
1226 opts->fs_fmask = option;
1227 break;
1228 case Opt_allow_utime:
1229 if (match_octal(&args[0], &option))
1230 return -EINVAL;
1231 opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1232 break;
1233 case Opt_codepage:
1234 if (match_int(&args[0], &option))
1235 return -EINVAL;
1236 opts->codepage = option;
1237 break;
1238 case Opt_flush:
1239 opts->flush = 1;
1240 break;
1241 case Opt_time_offset:
1242 if (match_int(&args[0], &option))
1243 return -EINVAL;
1244 /*
1245 * GMT+-12 zones may have DST corrections so at least
1246 * 13 hours difference is needed. Make the limit 24
1247 * just in case someone invents something unusual.
1248 */
1249 if (option < -24 * 60 || option > 24 * 60)
1250 return -EINVAL;
1251 opts->tz_set = 1;
1252 opts->time_offset = option;
1253 break;
1254 case Opt_tz_utc:
1255 opts->tz_set = 1;
1256 opts->time_offset = 0;
1257 break;
1258 case Opt_err_cont:
1259 opts->errors = FAT_ERRORS_CONT;
1260 break;
1261 case Opt_err_panic:
1262 opts->errors = FAT_ERRORS_PANIC;
1263 break;
1264 case Opt_err_ro:
1265 opts->errors = FAT_ERRORS_RO;
1266 break;
1267 case Opt_nfs_stale_rw:
1268 opts->nfs = FAT_NFS_STALE_RW;
1269 break;
1270 case Opt_nfs_nostale_ro:
1271 opts->nfs = FAT_NFS_NOSTALE_RO;
1272 break;
1273 case Opt_dos1xfloppy:
1274 opts->dos1xfloppy = 1;
1275 break;
1276
1277 /* msdos specific */
1278 case Opt_dots:
1279 opts->dotsOK = 1;
1280 break;
1281 case Opt_nodots:
1282 opts->dotsOK = 0;
1283 break;
1284
1285 /* vfat specific */
1286 case Opt_charset:
1287 fat_reset_iocharset(opts);
1288 iocharset = match_strdup(&args[0]);
1289 if (!iocharset)
1290 return -ENOMEM;
1291 opts->iocharset = iocharset;
1292 break;
1293 case Opt_shortname_lower:
1294 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1295 | VFAT_SFN_CREATE_WIN95;
1296 break;
1297 case Opt_shortname_win95:
1298 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1299 | VFAT_SFN_CREATE_WIN95;
1300 break;
1301 case Opt_shortname_winnt:
1302 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1303 | VFAT_SFN_CREATE_WINNT;
1304 break;
1305 case Opt_shortname_mixed:
1306 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1307 | VFAT_SFN_CREATE_WIN95;
1308 break;
1309 case Opt_utf8_no: /* 0 or no or false */
1310 opts->utf8 = 0;
1311 break;
1312 case Opt_utf8_yes: /* empty or 1 or yes or true */
1313 opts->utf8 = 1;
1314 break;
1315 case Opt_uni_xl_no: /* 0 or no or false */
1316 opts->unicode_xlate = 0;
1317 break;
1318 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1319 opts->unicode_xlate = 1;
1320 break;
1321 case Opt_nonumtail_no: /* 0 or no or false */
1322 opts->numtail = 1; /* negated option */
1323 break;
1324 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1325 opts->numtail = 0; /* negated option */
1326 break;
1327 case Opt_rodir:
1328 opts->rodir = 1;
1329 break;
1330 case Opt_discard:
1331 opts->discard = 1;
1332 break;
1333
1334 /* obsolete mount options */
1335 case Opt_obsolete:
1336 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, "
1337 "not supported now", p);
1338 break;
1339 /* unknown option */
1340 default:
1341 if (!silent) {
1342 fat_msg(sb, KERN_ERR,
1343 "Unrecognized mount option \"%s\" "
1344 "or missing value", p);
1345 }
1346 return -EINVAL;
1347 }
1348 }
1349
1350 out:
1351 /* UTF-8 doesn't provide FAT semantics */
1352 if (!strcmp(opts->iocharset, "utf8")) {
1353 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset"
1354 " for FAT filesystems, filesystem will be "
1355 "case sensitive!");
1356 }
1357
1358 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1359 if (opts->allow_utime == (unsigned short)-1)
1360 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
1361 if (opts->unicode_xlate)
1362 opts->utf8 = 0;
1363 if (opts->nfs == FAT_NFS_NOSTALE_RO) {
1364 sb->s_flags |= SB_RDONLY;
1365 sb->s_export_op = &fat_export_ops_nostale;
1366 }
1367
1368 return 0;
1369 }
1370
1371 static void fat_dummy_inode_init(struct inode *inode)
1372 {
1373 /* Initialize this dummy inode to work as no-op. */
1374 MSDOS_I(inode)->mmu_private = 0;
1375 MSDOS_I(inode)->i_start = 0;
1376 MSDOS_I(inode)->i_logstart = 0;
1377 MSDOS_I(inode)->i_attrs = 0;
1378 MSDOS_I(inode)->i_pos = 0;
1379 }
1380
1381 static int fat_read_root(struct inode *inode)
1382 {
1383 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
1384 int error;
1385
1386 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO;
1387 inode->i_uid = sbi->options.fs_uid;
1388 inode->i_gid = sbi->options.fs_gid;
1389 inode_inc_iversion(inode);
1390 inode->i_generation = 0;
1391 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
1392 inode->i_op = sbi->dir_ops;
1393 inode->i_fop = &fat_dir_operations;
1394 if (is_fat32(sbi)) {
1395 MSDOS_I(inode)->i_start = sbi->root_cluster;
1396 error = fat_calc_dir_size(inode);
1397 if (error < 0)
1398 return error;
1399 } else {
1400 MSDOS_I(inode)->i_start = 0;
1401 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1402 }
1403 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1404 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1405 MSDOS_I(inode)->i_logstart = 0;
1406 MSDOS_I(inode)->mmu_private = inode->i_size;
1407
1408 fat_save_attrs(inode, ATTR_DIR);
1409 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1410 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1411 set_nlink(inode, fat_subdirs(inode)+2);
1412
1413 return 0;
1414 }
1415
1416 static unsigned long calc_fat_clusters(struct super_block *sb)
1417 {
1418 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1419
1420 /* Divide first to avoid overflow */
1421 if (!is_fat12(sbi)) {
1422 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits;
1423 return ent_per_sec * sbi->fat_length;
1424 }
1425
1426 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1427 }
1428
1429 static bool fat_bpb_is_zero(struct fat_boot_sector *b)
1430 {
1431 if (get_unaligned_le16(&b->sector_size))
1432 return false;
1433 if (b->sec_per_clus)
1434 return false;
1435 if (b->reserved)
1436 return false;
1437 if (b->fats)
1438 return false;
1439 if (get_unaligned_le16(&b->dir_entries))
1440 return false;
1441 if (get_unaligned_le16(&b->sectors))
1442 return false;
1443 if (b->media)
1444 return false;
1445 if (b->fat_length)
1446 return false;
1447 if (b->secs_track)
1448 return false;
1449 if (b->heads)
1450 return false;
1451 return true;
1452 }
1453
1454 static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b,
1455 int silent, struct fat_bios_param_block *bpb)
1456 {
1457 int error = -EINVAL;
1458
1459 /* Read in BPB ... */
1460 memset(bpb, 0, sizeof(*bpb));
1461 bpb->fat_sector_size = get_unaligned_le16(&b->sector_size);
1462 bpb->fat_sec_per_clus = b->sec_per_clus;
1463 bpb->fat_reserved = le16_to_cpu(b->reserved);
1464 bpb->fat_fats = b->fats;
1465 bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries);
1466 bpb->fat_sectors = get_unaligned_le16(&b->sectors);
1467 bpb->fat_fat_length = le16_to_cpu(b->fat_length);
1468 bpb->fat_total_sect = le32_to_cpu(b->total_sect);
1469
1470 bpb->fat16_state = b->fat16.state;
1471 bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id);
1472
1473 bpb->fat32_length = le32_to_cpu(b->fat32.length);
1474 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster);
1475 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector);
1476 bpb->fat32_state = b->fat32.state;
1477 bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id);
1478
1479 /* Validate this looks like a FAT filesystem BPB */
1480 if (!bpb->fat_reserved) {
1481 if (!silent)
1482 fat_msg(sb, KERN_ERR,
1483 "bogus number of reserved sectors");
1484 goto out;
1485 }
1486 if (!bpb->fat_fats) {
1487 if (!silent)
1488 fat_msg(sb, KERN_ERR, "bogus number of FAT structure");
1489 goto out;
1490 }
1491
1492 /*
1493 * Earlier we checked here that b->secs_track and b->head are nonzero,
1494 * but it turns out valid FAT filesystems can have zero there.
1495 */
1496
1497 if (!fat_valid_media(b->media)) {
1498 if (!silent)
1499 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)",
1500 (unsigned)b->media);
1501 goto out;
1502 }
1503
1504 if (!is_power_of_2(bpb->fat_sector_size)
1505 || (bpb->fat_sector_size < 512)
1506 || (bpb->fat_sector_size > 4096)) {
1507 if (!silent)
1508 fat_msg(sb, KERN_ERR, "bogus logical sector size %u",
1509 (unsigned)bpb->fat_sector_size);
1510 goto out;
1511 }
1512
1513 if (!is_power_of_2(bpb->fat_sec_per_clus)) {
1514 if (!silent)
1515 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u",
1516 (unsigned)bpb->fat_sec_per_clus);
1517 goto out;
1518 }
1519
1520 error = 0;
1521
1522 out:
1523 return error;
1524 }
1525
1526 static int fat_read_static_bpb(struct super_block *sb,
1527 struct fat_boot_sector *b, int silent,
1528 struct fat_bios_param_block *bpb)
1529 {
1530 static const char *notdos1x = "This doesn't look like a DOS 1.x volume";
1531
1532 struct fat_floppy_defaults *fdefaults = NULL;
1533 int error = -EINVAL;
1534 sector_t bd_sects;
1535 unsigned i;
1536
1537 bd_sects = i_size_read(sb->s_bdev->bd_inode) / SECTOR_SIZE;
1538
1539 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */
1540 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) {
1541 if (!silent)
1542 fat_msg(sb, KERN_ERR,
1543 "%s; no bootstrapping code", notdos1x);
1544 goto out;
1545 }
1546
1547 /*
1548 * If any value in this region is non-zero, it isn't archaic
1549 * DOS.
1550 */
1551 if (!fat_bpb_is_zero(b)) {
1552 if (!silent)
1553 fat_msg(sb, KERN_ERR,
1554 "%s; DOS 2.x BPB is non-zero", notdos1x);
1555 goto out;
1556 }
1557
1558 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) {
1559 if (floppy_defaults[i].nr_sectors == bd_sects) {
1560 fdefaults = &floppy_defaults[i];
1561 break;
1562 }
1563 }
1564
1565 if (fdefaults == NULL) {
1566 if (!silent)
1567 fat_msg(sb, KERN_WARNING,
1568 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)",
1569 (u64)bd_sects);
1570 goto out;
1571 }
1572
1573 if (!silent)
1574 fat_msg(sb, KERN_INFO,
1575 "This looks like a DOS 1.x volume; assuming default BPB values");
1576
1577 memset(bpb, 0, sizeof(*bpb));
1578 bpb->fat_sector_size = SECTOR_SIZE;
1579 bpb->fat_sec_per_clus = fdefaults->sec_per_clus;
1580 bpb->fat_reserved = 1;
1581 bpb->fat_fats = 2;
1582 bpb->fat_dir_entries = fdefaults->dir_entries;
1583 bpb->fat_sectors = fdefaults->nr_sectors;
1584 bpb->fat_fat_length = fdefaults->fat_length;
1585
1586 error = 0;
1587
1588 out:
1589 return error;
1590 }
1591
1592 /*
1593 * Read the super block of an MS-DOS FS.
1594 */
1595 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
1596 void (*setup)(struct super_block *))
1597 {
1598 struct inode *root_inode = NULL, *fat_inode = NULL;
1599 struct inode *fsinfo_inode = NULL;
1600 struct buffer_head *bh;
1601 struct fat_bios_param_block bpb;
1602 struct msdos_sb_info *sbi;
1603 u16 logical_sector_size;
1604 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1605 int debug;
1606 long error;
1607 char buf[50];
1608
1609 /*
1610 * GFP_KERNEL is ok here, because while we do hold the
1611 * superblock lock, memory pressure can't call back into
1612 * the filesystem, since we're only just about to mount
1613 * it and have no inodes etc active!
1614 */
1615 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1616 if (!sbi)
1617 return -ENOMEM;
1618 sb->s_fs_info = sbi;
1619
1620 sb->s_flags |= SB_NODIRATIME;
1621 sb->s_magic = MSDOS_SUPER_MAGIC;
1622 sb->s_op = &fat_sops;
1623 sb->s_export_op = &fat_export_ops;
1624 /*
1625 * fat timestamps are complex and truncated by fat itself, so
1626 * we set 1 here to be fast
1627 */
1628 sb->s_time_gran = 1;
1629 mutex_init(&sbi->nfs_build_inode_lock);
1630 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
1631 DEFAULT_RATELIMIT_BURST);
1632
1633 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options);
1634 if (error)
1635 goto out_fail;
1636
1637 setup(sb); /* flavour-specific stuff that needs options */
1638
1639 error = -EIO;
1640 sb_min_blocksize(sb, 512);
1641 bh = sb_bread(sb, 0);
1642 if (bh == NULL) {
1643 fat_msg(sb, KERN_ERR, "unable to read boot sector");
1644 goto out_fail;
1645 }
1646
1647 error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent,
1648 &bpb);
1649 if (error == -EINVAL && sbi->options.dos1xfloppy)
1650 error = fat_read_static_bpb(sb,
1651 (struct fat_boot_sector *)bh->b_data, silent, &bpb);
1652 brelse(bh);
1653
1654 if (error == -EINVAL)
1655 goto out_invalid;
1656 else if (error)
1657 goto out_fail;
1658
1659 logical_sector_size = bpb.fat_sector_size;
1660 sbi->sec_per_clus = bpb.fat_sec_per_clus;
1661
1662 error = -EIO;
1663 if (logical_sector_size < sb->s_blocksize) {
1664 fat_msg(sb, KERN_ERR, "logical sector size too small for device"
1665 " (logical sector size = %u)", logical_sector_size);
1666 goto out_fail;
1667 }
1668
1669 if (logical_sector_size > sb->s_blocksize) {
1670 struct buffer_head *bh_resize;
1671
1672 if (!sb_set_blocksize(sb, logical_sector_size)) {
1673 fat_msg(sb, KERN_ERR, "unable to set blocksize %u",
1674 logical_sector_size);
1675 goto out_fail;
1676 }
1677
1678 /* Verify that the larger boot sector is fully readable */
1679 bh_resize = sb_bread(sb, 0);
1680 if (bh_resize == NULL) {
1681 fat_msg(sb, KERN_ERR, "unable to read boot sector"
1682 " (logical sector size = %lu)",
1683 sb->s_blocksize);
1684 goto out_fail;
1685 }
1686 brelse(bh_resize);
1687 }
1688
1689 mutex_init(&sbi->s_lock);
1690 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1691 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1692 sbi->fats = bpb.fat_fats;
1693 sbi->fat_bits = 0; /* Don't know yet */
1694 sbi->fat_start = bpb.fat_reserved;
1695 sbi->fat_length = bpb.fat_fat_length;
1696 sbi->root_cluster = 0;
1697 sbi->free_clusters = -1; /* Don't know yet */
1698 sbi->free_clus_valid = 0;
1699 sbi->prev_free = FAT_START_ENT;
1700 sb->s_maxbytes = 0xffffffff;
1701
1702 if (!sbi->fat_length && bpb.fat32_length) {
1703 struct fat_boot_fsinfo *fsinfo;
1704 struct buffer_head *fsinfo_bh;
1705
1706 /* Must be FAT32 */
1707 sbi->fat_bits = 32;
1708 sbi->fat_length = bpb.fat32_length;
1709 sbi->root_cluster = bpb.fat32_root_cluster;
1710
1711 /* MC - if info_sector is 0, don't multiply by 0 */
1712 sbi->fsinfo_sector = bpb.fat32_info_sector;
1713 if (sbi->fsinfo_sector == 0)
1714 sbi->fsinfo_sector = 1;
1715
1716 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1717 if (fsinfo_bh == NULL) {
1718 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block"
1719 " (sector = %lu)", sbi->fsinfo_sector);
1720 goto out_fail;
1721 }
1722
1723 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1724 if (!IS_FSINFO(fsinfo)) {
1725 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
1726 "0x%08x, 0x%08x (sector = %lu)",
1727 le32_to_cpu(fsinfo->signature1),
1728 le32_to_cpu(fsinfo->signature2),
1729 sbi->fsinfo_sector);
1730 } else {
1731 if (sbi->options.usefree)
1732 sbi->free_clus_valid = 1;
1733 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1734 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1735 }
1736
1737 brelse(fsinfo_bh);
1738 }
1739
1740 /* interpret volume ID as a little endian 32 bit integer */
1741 if (is_fat32(sbi))
1742 sbi->vol_id = bpb.fat32_vol_id;
1743 else /* fat 16 or 12 */
1744 sbi->vol_id = bpb.fat16_vol_id;
1745
1746 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1747 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1748
1749 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1750 sbi->dir_entries = bpb.fat_dir_entries;
1751 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1752 if (!silent)
1753 fat_msg(sb, KERN_ERR, "bogus number of directory entries"
1754 " (%u)", sbi->dir_entries);
1755 goto out_invalid;
1756 }
1757
1758 rootdir_sectors = sbi->dir_entries
1759 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1760 sbi->data_start = sbi->dir_start + rootdir_sectors;
1761 total_sectors = bpb.fat_sectors;
1762 if (total_sectors == 0)
1763 total_sectors = bpb.fat_total_sect;
1764
1765 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1766
1767 if (!is_fat32(sbi))
1768 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1769
1770 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */
1771 if (is_fat32(sbi))
1772 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY;
1773 else /* fat 16 or 12 */
1774 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY;
1775
1776 /* check that FAT table does not overflow */
1777 fat_clusters = calc_fat_clusters(sb);
1778 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1779 if (total_clusters > max_fat(sb)) {
1780 if (!silent)
1781 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)",
1782 total_clusters);
1783 goto out_invalid;
1784 }
1785
1786 sbi->max_cluster = total_clusters + FAT_START_ENT;
1787 /* check the free_clusters, it's not necessarily correct */
1788 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1789 sbi->free_clusters = -1;
1790 /* check the prev_free, it's not necessarily correct */
1791 sbi->prev_free %= sbi->max_cluster;
1792 if (sbi->prev_free < FAT_START_ENT)
1793 sbi->prev_free = FAT_START_ENT;
1794
1795 /* set up enough so that it can read an inode */
1796 fat_hash_init(sb);
1797 dir_hash_init(sb);
1798 fat_ent_access_init(sb);
1799
1800 /*
1801 * The low byte of the first FAT entry must have the same value as
1802 * the media field of the boot sector. But in real world, too many
1803 * devices are writing wrong values. So, removed that validity check.
1804 *
1805 * The removed check compared the first FAT entry to a value dependent
1806 * on the media field like this:
1807 * == (0x0F00 | media), for FAT12
1808 * == (0XFF00 | media), for FAT16
1809 * == (0x0FFFFF | media), for FAT32
1810 */
1811
1812 error = -EINVAL;
1813 sprintf(buf, "cp%d", sbi->options.codepage);
1814 sbi->nls_disk = load_nls(buf);
1815 if (!sbi->nls_disk) {
1816 fat_msg(sb, KERN_ERR, "codepage %s not found", buf);
1817 goto out_fail;
1818 }
1819
1820 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1821 if (sbi->options.isvfat) {
1822 sbi->nls_io = load_nls(sbi->options.iocharset);
1823 if (!sbi->nls_io) {
1824 fat_msg(sb, KERN_ERR, "IO charset %s not found",
1825 sbi->options.iocharset);
1826 goto out_fail;
1827 }
1828 }
1829
1830 error = -ENOMEM;
1831 fat_inode = new_inode(sb);
1832 if (!fat_inode)
1833 goto out_fail;
1834 fat_dummy_inode_init(fat_inode);
1835 sbi->fat_inode = fat_inode;
1836
1837 fsinfo_inode = new_inode(sb);
1838 if (!fsinfo_inode)
1839 goto out_fail;
1840 fat_dummy_inode_init(fsinfo_inode);
1841 fsinfo_inode->i_ino = MSDOS_FSINFO_INO;
1842 sbi->fsinfo_inode = fsinfo_inode;
1843 insert_inode_hash(fsinfo_inode);
1844
1845 root_inode = new_inode(sb);
1846 if (!root_inode)
1847 goto out_fail;
1848 root_inode->i_ino = MSDOS_ROOT_INO;
1849 inode_set_iversion(root_inode, 1);
1850 error = fat_read_root(root_inode);
1851 if (error < 0) {
1852 iput(root_inode);
1853 goto out_fail;
1854 }
1855 error = -ENOMEM;
1856 insert_inode_hash(root_inode);
1857 fat_attach(root_inode, 0);
1858 sb->s_root = d_make_root(root_inode);
1859 if (!sb->s_root) {
1860 fat_msg(sb, KERN_ERR, "get root inode failed");
1861 goto out_fail;
1862 }
1863
1864 if (sbi->options.discard) {
1865 struct request_queue *q = bdev_get_queue(sb->s_bdev);
1866 if (!blk_queue_discard(q))
1867 fat_msg(sb, KERN_WARNING,
1868 "mounting with \"discard\" option, but "
1869 "the device does not support discard");
1870 }
1871
1872 fat_set_state(sb, 1, 0);
1873 return 0;
1874
1875 out_invalid:
1876 error = -EINVAL;
1877 if (!silent)
1878 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem");
1879
1880 out_fail:
1881 if (fsinfo_inode)
1882 iput(fsinfo_inode);
1883 if (fat_inode)
1884 iput(fat_inode);
1885 unload_nls(sbi->nls_io);
1886 unload_nls(sbi->nls_disk);
1887 fat_reset_iocharset(&sbi->options);
1888 sb->s_fs_info = NULL;
1889 kfree(sbi);
1890 return error;
1891 }
1892
1893 EXPORT_SYMBOL_GPL(fat_fill_super);
1894
1895 /*
1896 * helper function for fat_flush_inodes. This writes both the inode
1897 * and the file data blocks, waiting for in flight data blocks before
1898 * the start of the call. It does not wait for any io started
1899 * during the call
1900 */
1901 static int writeback_inode(struct inode *inode)
1902 {
1903
1904 int ret;
1905
1906 /* if we used wait=1, sync_inode_metadata waits for the io for the
1907 * inode to finish. So wait=0 is sent down to sync_inode_metadata
1908 * and filemap_fdatawrite is used for the data blocks
1909 */
1910 ret = sync_inode_metadata(inode, 0);
1911 if (!ret)
1912 ret = filemap_fdatawrite(inode->i_mapping);
1913 return ret;
1914 }
1915
1916 /*
1917 * write data and metadata corresponding to i1 and i2. The io is
1918 * started but we do not wait for any of it to finish.
1919 *
1920 * filemap_flush is used for the block device, so if there is a dirty
1921 * page for a block already in flight, we will not wait and start the
1922 * io over again
1923 */
1924 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1925 {
1926 int ret = 0;
1927 if (!MSDOS_SB(sb)->options.flush)
1928 return 0;
1929 if (i1)
1930 ret = writeback_inode(i1);
1931 if (!ret && i2)
1932 ret = writeback_inode(i2);
1933 if (!ret) {
1934 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1935 ret = filemap_flush(mapping);
1936 }
1937 return ret;
1938 }
1939 EXPORT_SYMBOL_GPL(fat_flush_inodes);
1940
1941 static int __init init_fat_fs(void)
1942 {
1943 int err;
1944
1945 err = fat_cache_init();
1946 if (err)
1947 return err;
1948
1949 err = fat_init_inodecache();
1950 if (err)
1951 goto failed;
1952
1953 return 0;
1954
1955 failed:
1956 fat_cache_destroy();
1957 return err;
1958 }
1959
1960 static void __exit exit_fat_fs(void)
1961 {
1962 fat_cache_destroy();
1963 fat_destroy_inodecache();
1964 }
1965
1966 module_init(init_fat_fs)
1967 module_exit(exit_fat_fs)
1968
1969 MODULE_LICENSE("GPL");
Mirror of linux-2.6-arm at arm.linux.org.uk