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perf tools: Don't clone maps from parent when synthesizing forks
[linux/fpc-iii.git] / fs / fat / inode.c
blobd6b81e31f9f5d827be92ffad4cf240fa32e5f767
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 msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
512 int error;
513
514 MSDOS_I(inode)->i_pos = 0;
515 inode->i_uid = sbi->options.fs_uid;
516 inode->i_gid = sbi->options.fs_gid;
517 inode_inc_iversion(inode);
518 inode->i_generation = get_seconds();
519
520 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
521 inode->i_generation &= ~1;
522 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
523 inode->i_op = sbi->dir_ops;
524 inode->i_fop = &fat_dir_operations;
525
526 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
527 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
528 error = fat_calc_dir_size(inode);
529 if (error < 0)
530 return error;
531 MSDOS_I(inode)->mmu_private = inode->i_size;
532
533 set_nlink(inode, fat_subdirs(inode));
534
535 error = fat_validate_dir(inode);
536 if (error < 0)
537 return error;
538 } else { /* not a directory */
539 inode->i_generation |= 1;
540 inode->i_mode = fat_make_mode(sbi, de->attr,
541 ((sbi->options.showexec && !is_exec(de->name + 8))
542 ? S_IRUGO|S_IWUGO : S_IRWXUGO));
543 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
544
545 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
546 inode->i_size = le32_to_cpu(de->size);
547 inode->i_op = &fat_file_inode_operations;
548 inode->i_fop = &fat_file_operations;
549 inode->i_mapping->a_ops = &fat_aops;
550 MSDOS_I(inode)->mmu_private = inode->i_size;
551 }
552 if (de->attr & ATTR_SYS) {
553 if (sbi->options.sys_immutable)
554 inode->i_flags |= S_IMMUTABLE;
555 }
556 fat_save_attrs(inode, de->attr);
557
558 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
559 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
560
561 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
562 if (sbi->options.isvfat) {
563 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
564 de->cdate, de->ctime_cs);
565 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
566 } else
567 inode->i_ctime = inode->i_atime = inode->i_mtime;
568
569 return 0;
570 }
571
572 static inline void fat_lock_build_inode(struct msdos_sb_info *sbi)
573 {
574 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
575 mutex_lock(&sbi->nfs_build_inode_lock);
576 }
577
578 static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi)
579 {
580 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
581 mutex_unlock(&sbi->nfs_build_inode_lock);
582 }
583
584 struct inode *fat_build_inode(struct super_block *sb,
585 struct msdos_dir_entry *de, loff_t i_pos)
586 {
587 struct inode *inode;
588 int err;
589
590 fat_lock_build_inode(MSDOS_SB(sb));
591 inode = fat_iget(sb, i_pos);
592 if (inode)
593 goto out;
594 inode = new_inode(sb);
595 if (!inode) {
596 inode = ERR_PTR(-ENOMEM);
597 goto out;
598 }
599 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
600 inode_set_iversion(inode, 1);
601 err = fat_fill_inode(inode, de);
602 if (err) {
603 iput(inode);
604 inode = ERR_PTR(err);
605 goto out;
606 }
607 fat_attach(inode, i_pos);
608 insert_inode_hash(inode);
609 out:
610 fat_unlock_build_inode(MSDOS_SB(sb));
611 return inode;
612 }
613
614 EXPORT_SYMBOL_GPL(fat_build_inode);
615
616 static int __fat_write_inode(struct inode *inode, int wait);
617
618 static void fat_free_eofblocks(struct inode *inode)
619 {
620 /* Release unwritten fallocated blocks on inode eviction. */
621 if ((inode->i_blocks << 9) >
622 round_up(MSDOS_I(inode)->mmu_private,
623 MSDOS_SB(inode->i_sb)->cluster_size)) {
624 int err;
625
626 fat_truncate_blocks(inode, MSDOS_I(inode)->mmu_private);
627 /* Fallocate results in updating the i_start/iogstart
628 * for the zero byte file. So, make it return to
629 * original state during evict and commit it to avoid
630 * any corruption on the next access to the cluster
631 * chain for the file.
632 */
633 err = __fat_write_inode(inode, inode_needs_sync(inode));
634 if (err) {
635 fat_msg(inode->i_sb, KERN_WARNING, "Failed to "
636 "update on disk inode for unused "
637 "fallocated blocks, inode could be "
638 "corrupted. Please run fsck");
639 }
640
641 }
642 }
643
644 static void fat_evict_inode(struct inode *inode)
645 {
646 truncate_inode_pages_final(&inode->i_data);
647 if (!inode->i_nlink) {
648 inode->i_size = 0;
649 fat_truncate_blocks(inode, 0);
650 } else
651 fat_free_eofblocks(inode);
652
653 invalidate_inode_buffers(inode);
654 clear_inode(inode);
655 fat_cache_inval_inode(inode);
656 fat_detach(inode);
657 }
658
659 static void fat_set_state(struct super_block *sb,
660 unsigned int set, unsigned int force)
661 {
662 struct buffer_head *bh;
663 struct fat_boot_sector *b;
664 struct msdos_sb_info *sbi = MSDOS_SB(sb);
665
666 /* do not change any thing if mounted read only */
667 if (sb_rdonly(sb) && !force)
668 return;
669
670 /* do not change state if fs was dirty */
671 if (sbi->dirty) {
672 /* warn only on set (mount). */
673 if (set)
674 fat_msg(sb, KERN_WARNING, "Volume was not properly "
675 "unmounted. Some data may be corrupt. "
676 "Please run fsck.");
677 return;
678 }
679
680 bh = sb_bread(sb, 0);
681 if (bh == NULL) {
682 fat_msg(sb, KERN_ERR, "unable to read boot sector "
683 "to mark fs as dirty");
684 return;
685 }
686
687 b = (struct fat_boot_sector *) bh->b_data;
688
689 if (sbi->fat_bits == 32) {
690 if (set)
691 b->fat32.state |= FAT_STATE_DIRTY;
692 else
693 b->fat32.state &= ~FAT_STATE_DIRTY;
694 } else /* fat 16 and 12 */ {
695 if (set)
696 b->fat16.state |= FAT_STATE_DIRTY;
697 else
698 b->fat16.state &= ~FAT_STATE_DIRTY;
699 }
700
701 mark_buffer_dirty(bh);
702 sync_dirty_buffer(bh);
703 brelse(bh);
704 }
705
706 static void fat_reset_iocharset(struct fat_mount_options *opts)
707 {
708 if (opts->iocharset != fat_default_iocharset) {
709 /* Note: opts->iocharset can be NULL here */
710 kfree(opts->iocharset);
711 opts->iocharset = fat_default_iocharset;
712 }
713 }
714
715 static void delayed_free(struct rcu_head *p)
716 {
717 struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu);
718 unload_nls(sbi->nls_disk);
719 unload_nls(sbi->nls_io);
720 fat_reset_iocharset(&sbi->options);
721 kfree(sbi);
722 }
723
724 static void fat_put_super(struct super_block *sb)
725 {
726 struct msdos_sb_info *sbi = MSDOS_SB(sb);
727
728 fat_set_state(sb, 0, 0);
729
730 iput(sbi->fsinfo_inode);
731 iput(sbi->fat_inode);
732
733 call_rcu(&sbi->rcu, delayed_free);
734 }
735
736 static struct kmem_cache *fat_inode_cachep;
737
738 static struct inode *fat_alloc_inode(struct super_block *sb)
739 {
740 struct msdos_inode_info *ei;
741 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
742 if (!ei)
743 return NULL;
744
745 init_rwsem(&ei->truncate_lock);
746 return &ei->vfs_inode;
747 }
748
749 static void fat_i_callback(struct rcu_head *head)
750 {
751 struct inode *inode = container_of(head, struct inode, i_rcu);
752 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
753 }
754
755 static void fat_destroy_inode(struct inode *inode)
756 {
757 call_rcu(&inode->i_rcu, fat_i_callback);
758 }
759
760 static void init_once(void *foo)
761 {
762 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
763
764 spin_lock_init(&ei->cache_lru_lock);
765 ei->nr_caches = 0;
766 ei->cache_valid_id = FAT_CACHE_VALID + 1;
767 INIT_LIST_HEAD(&ei->cache_lru);
768 INIT_HLIST_NODE(&ei->i_fat_hash);
769 INIT_HLIST_NODE(&ei->i_dir_hash);
770 inode_init_once(&ei->vfs_inode);
771 }
772
773 static int __init fat_init_inodecache(void)
774 {
775 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
776 sizeof(struct msdos_inode_info),
777 0, (SLAB_RECLAIM_ACCOUNT|
778 SLAB_MEM_SPREAD|SLAB_ACCOUNT),
779 init_once);
780 if (fat_inode_cachep == NULL)
781 return -ENOMEM;
782 return 0;
783 }
784
785 static void __exit fat_destroy_inodecache(void)
786 {
787 /*
788 * Make sure all delayed rcu free inodes are flushed before we
789 * destroy cache.
790 */
791 rcu_barrier();
792 kmem_cache_destroy(fat_inode_cachep);
793 }
794
795 static int fat_remount(struct super_block *sb, int *flags, char *data)
796 {
797 bool new_rdonly;
798 struct msdos_sb_info *sbi = MSDOS_SB(sb);
799 *flags |= SB_NODIRATIME | (sbi->options.isvfat ? 0 : SB_NOATIME);
800
801 sync_filesystem(sb);
802
803 /* make sure we update state on remount. */
804 new_rdonly = *flags & SB_RDONLY;
805 if (new_rdonly != sb_rdonly(sb)) {
806 if (new_rdonly)
807 fat_set_state(sb, 0, 0);
808 else
809 fat_set_state(sb, 1, 1);
810 }
811 return 0;
812 }
813
814 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
815 {
816 struct super_block *sb = dentry->d_sb;
817 struct msdos_sb_info *sbi = MSDOS_SB(sb);
818 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
819
820 /* If the count of free cluster is still unknown, counts it here. */
821 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
822 int err = fat_count_free_clusters(dentry->d_sb);
823 if (err)
824 return err;
825 }
826
827 buf->f_type = dentry->d_sb->s_magic;
828 buf->f_bsize = sbi->cluster_size;
829 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
830 buf->f_bfree = sbi->free_clusters;
831 buf->f_bavail = sbi->free_clusters;
832 buf->f_fsid.val[0] = (u32)id;
833 buf->f_fsid.val[1] = (u32)(id >> 32);
834 buf->f_namelen =
835 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE;
836
837 return 0;
838 }
839
840 static int __fat_write_inode(struct inode *inode, int wait)
841 {
842 struct super_block *sb = inode->i_sb;
843 struct msdos_sb_info *sbi = MSDOS_SB(sb);
844 struct buffer_head *bh;
845 struct msdos_dir_entry *raw_entry;
846 loff_t i_pos;
847 sector_t blocknr;
848 int err, offset;
849
850 if (inode->i_ino == MSDOS_ROOT_INO)
851 return 0;
852
853 retry:
854 i_pos = fat_i_pos_read(sbi, inode);
855 if (!i_pos)
856 return 0;
857
858 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset);
859 bh = sb_bread(sb, blocknr);
860 if (!bh) {
861 fat_msg(sb, KERN_ERR, "unable to read inode block "
862 "for updating (i_pos %lld)", i_pos);
863 return -EIO;
864 }
865 spin_lock(&sbi->inode_hash_lock);
866 if (i_pos != MSDOS_I(inode)->i_pos) {
867 spin_unlock(&sbi->inode_hash_lock);
868 brelse(bh);
869 goto retry;
870 }
871
872 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset];
873 if (S_ISDIR(inode->i_mode))
874 raw_entry->size = 0;
875 else
876 raw_entry->size = cpu_to_le32(inode->i_size);
877 raw_entry->attr = fat_make_attrs(inode);
878 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart);
879 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
880 &raw_entry->date, NULL);
881 if (sbi->options.isvfat) {
882 __le16 atime;
883 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
884 &raw_entry->cdate, &raw_entry->ctime_cs);
885 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
886 &raw_entry->adate, NULL);
887 }
888 spin_unlock(&sbi->inode_hash_lock);
889 mark_buffer_dirty(bh);
890 err = 0;
891 if (wait)
892 err = sync_dirty_buffer(bh);
893 brelse(bh);
894 return err;
895 }
896
897 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
898 {
899 int err;
900
901 if (inode->i_ino == MSDOS_FSINFO_INO) {
902 struct super_block *sb = inode->i_sb;
903
904 mutex_lock(&MSDOS_SB(sb)->s_lock);
905 err = fat_clusters_flush(sb);
906 mutex_unlock(&MSDOS_SB(sb)->s_lock);
907 } else
908 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
909
910 return err;
911 }
912
913 int fat_sync_inode(struct inode *inode)
914 {
915 return __fat_write_inode(inode, 1);
916 }
917
918 EXPORT_SYMBOL_GPL(fat_sync_inode);
919
920 static int fat_show_options(struct seq_file *m, struct dentry *root);
921 static const struct super_operations fat_sops = {
922 .alloc_inode = fat_alloc_inode,
923 .destroy_inode = fat_destroy_inode,
924 .write_inode = fat_write_inode,
925 .evict_inode = fat_evict_inode,
926 .put_super = fat_put_super,
927 .statfs = fat_statfs,
928 .remount_fs = fat_remount,
929
930 .show_options = fat_show_options,
931 };
932
933 static int fat_show_options(struct seq_file *m, struct dentry *root)
934 {
935 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb);
936 struct fat_mount_options *opts = &sbi->options;
937 int isvfat = opts->isvfat;
938
939 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
940 seq_printf(m, ",uid=%u",
941 from_kuid_munged(&init_user_ns, opts->fs_uid));
942 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
943 seq_printf(m, ",gid=%u",
944 from_kgid_munged(&init_user_ns, opts->fs_gid));
945 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
946 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
947 if (opts->allow_utime)
948 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
949 if (sbi->nls_disk)
950 /* strip "cp" prefix from displayed option */
951 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]);
952 if (isvfat) {
953 if (sbi->nls_io)
954 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
955
956 switch (opts->shortname) {
957 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
958 seq_puts(m, ",shortname=win95");
959 break;
960 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
961 seq_puts(m, ",shortname=winnt");
962 break;
963 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
964 seq_puts(m, ",shortname=mixed");
965 break;
966 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
967 seq_puts(m, ",shortname=lower");
968 break;
969 default:
970 seq_puts(m, ",shortname=unknown");
971 break;
972 }
973 }
974 if (opts->name_check != 'n')
975 seq_printf(m, ",check=%c", opts->name_check);
976 if (opts->usefree)
977 seq_puts(m, ",usefree");
978 if (opts->quiet)
979 seq_puts(m, ",quiet");
980 if (opts->showexec)
981 seq_puts(m, ",showexec");
982 if (opts->sys_immutable)
983 seq_puts(m, ",sys_immutable");
984 if (!isvfat) {
985 if (opts->dotsOK)
986 seq_puts(m, ",dotsOK=yes");
987 if (opts->nocase)
988 seq_puts(m, ",nocase");
989 } else {
990 if (opts->utf8)
991 seq_puts(m, ",utf8");
992 if (opts->unicode_xlate)
993 seq_puts(m, ",uni_xlate");
994 if (!opts->numtail)
995 seq_puts(m, ",nonumtail");
996 if (opts->rodir)
997 seq_puts(m, ",rodir");
998 }
999 if (opts->flush)
1000 seq_puts(m, ",flush");
1001 if (opts->tz_set) {
1002 if (opts->time_offset)
1003 seq_printf(m, ",time_offset=%d", opts->time_offset);
1004 else
1005 seq_puts(m, ",tz=UTC");
1006 }
1007 if (opts->errors == FAT_ERRORS_CONT)
1008 seq_puts(m, ",errors=continue");
1009 else if (opts->errors == FAT_ERRORS_PANIC)
1010 seq_puts(m, ",errors=panic");
1011 else
1012 seq_puts(m, ",errors=remount-ro");
1013 if (opts->nfs == FAT_NFS_NOSTALE_RO)
1014 seq_puts(m, ",nfs=nostale_ro");
1015 else if (opts->nfs)
1016 seq_puts(m, ",nfs=stale_rw");
1017 if (opts->discard)
1018 seq_puts(m, ",discard");
1019 if (opts->dos1xfloppy)
1020 seq_puts(m, ",dos1xfloppy");
1021
1022 return 0;
1023 }
1024
1025 enum {
1026 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
1027 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
1028 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
1029 Opt_immutable, Opt_dots, Opt_nodots,
1030 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
1031 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
1032 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
1033 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
1034 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset,
1035 Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy,
1036 };
1037
1038 static const match_table_t fat_tokens = {
1039 {Opt_check_r, "check=relaxed"},
1040 {Opt_check_s, "check=strict"},
1041 {Opt_check_n, "check=normal"},
1042 {Opt_check_r, "check=r"},
1043 {Opt_check_s, "check=s"},
1044 {Opt_check_n, "check=n"},
1045 {Opt_uid, "uid=%u"},
1046 {Opt_gid, "gid=%u"},
1047 {Opt_umask, "umask=%o"},
1048 {Opt_dmask, "dmask=%o"},
1049 {Opt_fmask, "fmask=%o"},
1050 {Opt_allow_utime, "allow_utime=%o"},
1051 {Opt_codepage, "codepage=%u"},
1052 {Opt_usefree, "usefree"},
1053 {Opt_nocase, "nocase"},
1054 {Opt_quiet, "quiet"},
1055 {Opt_showexec, "showexec"},
1056 {Opt_debug, "debug"},
1057 {Opt_immutable, "sys_immutable"},
1058 {Opt_flush, "flush"},
1059 {Opt_tz_utc, "tz=UTC"},
1060 {Opt_time_offset, "time_offset=%d"},
1061 {Opt_err_cont, "errors=continue"},
1062 {Opt_err_panic, "errors=panic"},
1063 {Opt_err_ro, "errors=remount-ro"},
1064 {Opt_discard, "discard"},
1065 {Opt_nfs_stale_rw, "nfs"},
1066 {Opt_nfs_stale_rw, "nfs=stale_rw"},
1067 {Opt_nfs_nostale_ro, "nfs=nostale_ro"},
1068 {Opt_dos1xfloppy, "dos1xfloppy"},
1069 {Opt_obsolete, "conv=binary"},
1070 {Opt_obsolete, "conv=text"},
1071 {Opt_obsolete, "conv=auto"},
1072 {Opt_obsolete, "conv=b"},
1073 {Opt_obsolete, "conv=t"},
1074 {Opt_obsolete, "conv=a"},
1075 {Opt_obsolete, "fat=%u"},
1076 {Opt_obsolete, "blocksize=%u"},
1077 {Opt_obsolete, "cvf_format=%20s"},
1078 {Opt_obsolete, "cvf_options=%100s"},
1079 {Opt_obsolete, "posix"},
1080 {Opt_err, NULL},
1081 };
1082 static const match_table_t msdos_tokens = {
1083 {Opt_nodots, "nodots"},
1084 {Opt_nodots, "dotsOK=no"},
1085 {Opt_dots, "dots"},
1086 {Opt_dots, "dotsOK=yes"},
1087 {Opt_err, NULL}
1088 };
1089 static const match_table_t vfat_tokens = {
1090 {Opt_charset, "iocharset=%s"},
1091 {Opt_shortname_lower, "shortname=lower"},
1092 {Opt_shortname_win95, "shortname=win95"},
1093 {Opt_shortname_winnt, "shortname=winnt"},
1094 {Opt_shortname_mixed, "shortname=mixed"},
1095 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
1096 {Opt_utf8_no, "utf8=no"},
1097 {Opt_utf8_no, "utf8=false"},
1098 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
1099 {Opt_utf8_yes, "utf8=yes"},
1100 {Opt_utf8_yes, "utf8=true"},
1101 {Opt_utf8_yes, "utf8"},
1102 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
1103 {Opt_uni_xl_no, "uni_xlate=no"},
1104 {Opt_uni_xl_no, "uni_xlate=false"},
1105 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
1106 {Opt_uni_xl_yes, "uni_xlate=yes"},
1107 {Opt_uni_xl_yes, "uni_xlate=true"},
1108 {Opt_uni_xl_yes, "uni_xlate"},
1109 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
1110 {Opt_nonumtail_no, "nonumtail=no"},
1111 {Opt_nonumtail_no, "nonumtail=false"},
1112 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
1113 {Opt_nonumtail_yes, "nonumtail=yes"},
1114 {Opt_nonumtail_yes, "nonumtail=true"},
1115 {Opt_nonumtail_yes, "nonumtail"},
1116 {Opt_rodir, "rodir"},
1117 {Opt_err, NULL}
1118 };
1119
1120 static int parse_options(struct super_block *sb, char *options, int is_vfat,
1121 int silent, int *debug, struct fat_mount_options *opts)
1122 {
1123 char *p;
1124 substring_t args[MAX_OPT_ARGS];
1125 int option;
1126 char *iocharset;
1127
1128 opts->isvfat = is_vfat;
1129
1130 opts->fs_uid = current_uid();
1131 opts->fs_gid = current_gid();
1132 opts->fs_fmask = opts->fs_dmask = current_umask();
1133 opts->allow_utime = -1;
1134 opts->codepage = fat_default_codepage;
1135 fat_reset_iocharset(opts);
1136 if (is_vfat) {
1137 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
1138 opts->rodir = 0;
1139 } else {
1140 opts->shortname = 0;
1141 opts->rodir = 1;
1142 }
1143 opts->name_check = 'n';
1144 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
1145 opts->unicode_xlate = 0;
1146 opts->numtail = 1;
1147 opts->usefree = opts->nocase = 0;
1148 opts->tz_set = 0;
1149 opts->nfs = 0;
1150 opts->errors = FAT_ERRORS_RO;
1151 *debug = 0;
1152
1153 opts->utf8 = IS_ENABLED(CONFIG_FAT_DEFAULT_UTF8) && is_vfat;
1154
1155 if (!options)
1156 goto out;
1157
1158 while ((p = strsep(&options, ",")) != NULL) {
1159 int token;
1160 if (!*p)
1161 continue;
1162
1163 token = match_token(p, fat_tokens, args);
1164 if (token == Opt_err) {
1165 if (is_vfat)
1166 token = match_token(p, vfat_tokens, args);
1167 else
1168 token = match_token(p, msdos_tokens, args);
1169 }
1170 switch (token) {
1171 case Opt_check_s:
1172 opts->name_check = 's';
1173 break;
1174 case Opt_check_r:
1175 opts->name_check = 'r';
1176 break;
1177 case Opt_check_n:
1178 opts->name_check = 'n';
1179 break;
1180 case Opt_usefree:
1181 opts->usefree = 1;
1182 break;
1183 case Opt_nocase:
1184 if (!is_vfat)
1185 opts->nocase = 1;
1186 else {
1187 /* for backward compatibility */
1188 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1189 | VFAT_SFN_CREATE_WIN95;
1190 }
1191 break;
1192 case Opt_quiet:
1193 opts->quiet = 1;
1194 break;
1195 case Opt_showexec:
1196 opts->showexec = 1;
1197 break;
1198 case Opt_debug:
1199 *debug = 1;
1200 break;
1201 case Opt_immutable:
1202 opts->sys_immutable = 1;
1203 break;
1204 case Opt_uid:
1205 if (match_int(&args[0], &option))
1206 return -EINVAL;
1207 opts->fs_uid = make_kuid(current_user_ns(), option);
1208 if (!uid_valid(opts->fs_uid))
1209 return -EINVAL;
1210 break;
1211 case Opt_gid:
1212 if (match_int(&args[0], &option))
1213 return -EINVAL;
1214 opts->fs_gid = make_kgid(current_user_ns(), option);
1215 if (!gid_valid(opts->fs_gid))
1216 return -EINVAL;
1217 break;
1218 case Opt_umask:
1219 if (match_octal(&args[0], &option))
1220 return -EINVAL;
1221 opts->fs_fmask = opts->fs_dmask = option;
1222 break;
1223 case Opt_dmask:
1224 if (match_octal(&args[0], &option))
1225 return -EINVAL;
1226 opts->fs_dmask = option;
1227 break;
1228 case Opt_fmask:
1229 if (match_octal(&args[0], &option))
1230 return -EINVAL;
1231 opts->fs_fmask = option;
1232 break;
1233 case Opt_allow_utime:
1234 if (match_octal(&args[0], &option))
1235 return -EINVAL;
1236 opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1237 break;
1238 case Opt_codepage:
1239 if (match_int(&args[0], &option))
1240 return -EINVAL;
1241 opts->codepage = option;
1242 break;
1243 case Opt_flush:
1244 opts->flush = 1;
1245 break;
1246 case Opt_time_offset:
1247 if (match_int(&args[0], &option))
1248 return -EINVAL;
1249 /*
1250 * GMT+-12 zones may have DST corrections so at least
1251 * 13 hours difference is needed. Make the limit 24
1252 * just in case someone invents something unusual.
1253 */
1254 if (option < -24 * 60 || option > 24 * 60)
1255 return -EINVAL;
1256 opts->tz_set = 1;
1257 opts->time_offset = option;
1258 break;
1259 case Opt_tz_utc:
1260 opts->tz_set = 1;
1261 opts->time_offset = 0;
1262 break;
1263 case Opt_err_cont:
1264 opts->errors = FAT_ERRORS_CONT;
1265 break;
1266 case Opt_err_panic:
1267 opts->errors = FAT_ERRORS_PANIC;
1268 break;
1269 case Opt_err_ro:
1270 opts->errors = FAT_ERRORS_RO;
1271 break;
1272 case Opt_nfs_stale_rw:
1273 opts->nfs = FAT_NFS_STALE_RW;
1274 break;
1275 case Opt_nfs_nostale_ro:
1276 opts->nfs = FAT_NFS_NOSTALE_RO;
1277 break;
1278 case Opt_dos1xfloppy:
1279 opts->dos1xfloppy = 1;
1280 break;
1281
1282 /* msdos specific */
1283 case Opt_dots:
1284 opts->dotsOK = 1;
1285 break;
1286 case Opt_nodots:
1287 opts->dotsOK = 0;
1288 break;
1289
1290 /* vfat specific */
1291 case Opt_charset:
1292 fat_reset_iocharset(opts);
1293 iocharset = match_strdup(&args[0]);
1294 if (!iocharset)
1295 return -ENOMEM;
1296 opts->iocharset = iocharset;
1297 break;
1298 case Opt_shortname_lower:
1299 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1300 | VFAT_SFN_CREATE_WIN95;
1301 break;
1302 case Opt_shortname_win95:
1303 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1304 | VFAT_SFN_CREATE_WIN95;
1305 break;
1306 case Opt_shortname_winnt:
1307 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1308 | VFAT_SFN_CREATE_WINNT;
1309 break;
1310 case Opt_shortname_mixed:
1311 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1312 | VFAT_SFN_CREATE_WIN95;
1313 break;
1314 case Opt_utf8_no: /* 0 or no or false */
1315 opts->utf8 = 0;
1316 break;
1317 case Opt_utf8_yes: /* empty or 1 or yes or true */
1318 opts->utf8 = 1;
1319 break;
1320 case Opt_uni_xl_no: /* 0 or no or false */
1321 opts->unicode_xlate = 0;
1322 break;
1323 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1324 opts->unicode_xlate = 1;
1325 break;
1326 case Opt_nonumtail_no: /* 0 or no or false */
1327 opts->numtail = 1; /* negated option */
1328 break;
1329 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1330 opts->numtail = 0; /* negated option */
1331 break;
1332 case Opt_rodir:
1333 opts->rodir = 1;
1334 break;
1335 case Opt_discard:
1336 opts->discard = 1;
1337 break;
1338
1339 /* obsolete mount options */
1340 case Opt_obsolete:
1341 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, "
1342 "not supported now", p);
1343 break;
1344 /* unknown option */
1345 default:
1346 if (!silent) {
1347 fat_msg(sb, KERN_ERR,
1348 "Unrecognized mount option \"%s\" "
1349 "or missing value", p);
1350 }
1351 return -EINVAL;
1352 }
1353 }
1354
1355 out:
1356 /* UTF-8 doesn't provide FAT semantics */
1357 if (!strcmp(opts->iocharset, "utf8")) {
1358 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset"
1359 " for FAT filesystems, filesystem will be "
1360 "case sensitive!");
1361 }
1362
1363 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1364 if (opts->allow_utime == (unsigned short)-1)
1365 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
1366 if (opts->unicode_xlate)
1367 opts->utf8 = 0;
1368 if (opts->nfs == FAT_NFS_NOSTALE_RO) {
1369 sb->s_flags |= SB_RDONLY;
1370 sb->s_export_op = &fat_export_ops_nostale;
1371 }
1372
1373 return 0;
1374 }
1375
1376 static void fat_dummy_inode_init(struct inode *inode)
1377 {
1378 /* Initialize this dummy inode to work as no-op. */
1379 MSDOS_I(inode)->mmu_private = 0;
1380 MSDOS_I(inode)->i_start = 0;
1381 MSDOS_I(inode)->i_logstart = 0;
1382 MSDOS_I(inode)->i_attrs = 0;
1383 MSDOS_I(inode)->i_pos = 0;
1384 }
1385
1386 static int fat_read_root(struct inode *inode)
1387 {
1388 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
1389 int error;
1390
1391 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO;
1392 inode->i_uid = sbi->options.fs_uid;
1393 inode->i_gid = sbi->options.fs_gid;
1394 inode_inc_iversion(inode);
1395 inode->i_generation = 0;
1396 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
1397 inode->i_op = sbi->dir_ops;
1398 inode->i_fop = &fat_dir_operations;
1399 if (sbi->fat_bits == 32) {
1400 MSDOS_I(inode)->i_start = sbi->root_cluster;
1401 error = fat_calc_dir_size(inode);
1402 if (error < 0)
1403 return error;
1404 } else {
1405 MSDOS_I(inode)->i_start = 0;
1406 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1407 }
1408 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1409 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1410 MSDOS_I(inode)->i_logstart = 0;
1411 MSDOS_I(inode)->mmu_private = inode->i_size;
1412
1413 fat_save_attrs(inode, ATTR_DIR);
1414 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1415 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1416 set_nlink(inode, fat_subdirs(inode)+2);
1417
1418 return 0;
1419 }
1420
1421 static unsigned long calc_fat_clusters(struct super_block *sb)
1422 {
1423 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1424
1425 /* Divide first to avoid overflow */
1426 if (sbi->fat_bits != 12) {
1427 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits;
1428 return ent_per_sec * sbi->fat_length;
1429 }
1430
1431 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1432 }
1433
1434 static bool fat_bpb_is_zero(struct fat_boot_sector *b)
1435 {
1436 if (get_unaligned_le16(&b->sector_size))
1437 return false;
1438 if (b->sec_per_clus)
1439 return false;
1440 if (b->reserved)
1441 return false;
1442 if (b->fats)
1443 return false;
1444 if (get_unaligned_le16(&b->dir_entries))
1445 return false;
1446 if (get_unaligned_le16(&b->sectors))
1447 return false;
1448 if (b->media)
1449 return false;
1450 if (b->fat_length)
1451 return false;
1452 if (b->secs_track)
1453 return false;
1454 if (b->heads)
1455 return false;
1456 return true;
1457 }
1458
1459 static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b,
1460 int silent, struct fat_bios_param_block *bpb)
1461 {
1462 int error = -EINVAL;
1463
1464 /* Read in BPB ... */
1465 memset(bpb, 0, sizeof(*bpb));
1466 bpb->fat_sector_size = get_unaligned_le16(&b->sector_size);
1467 bpb->fat_sec_per_clus = b->sec_per_clus;
1468 bpb->fat_reserved = le16_to_cpu(b->reserved);
1469 bpb->fat_fats = b->fats;
1470 bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries);
1471 bpb->fat_sectors = get_unaligned_le16(&b->sectors);
1472 bpb->fat_fat_length = le16_to_cpu(b->fat_length);
1473 bpb->fat_total_sect = le32_to_cpu(b->total_sect);
1474
1475 bpb->fat16_state = b->fat16.state;
1476 bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id);
1477
1478 bpb->fat32_length = le32_to_cpu(b->fat32.length);
1479 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster);
1480 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector);
1481 bpb->fat32_state = b->fat32.state;
1482 bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id);
1483
1484 /* Validate this looks like a FAT filesystem BPB */
1485 if (!bpb->fat_reserved) {
1486 if (!silent)
1487 fat_msg(sb, KERN_ERR,
1488 "bogus number of reserved sectors");
1489 goto out;
1490 }
1491 if (!bpb->fat_fats) {
1492 if (!silent)
1493 fat_msg(sb, KERN_ERR, "bogus number of FAT structure");
1494 goto out;
1495 }
1496
1497 /*
1498 * Earlier we checked here that b->secs_track and b->head are nonzero,
1499 * but it turns out valid FAT filesystems can have zero there.
1500 */
1501
1502 if (!fat_valid_media(b->media)) {
1503 if (!silent)
1504 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)",
1505 (unsigned)b->media);
1506 goto out;
1507 }
1508
1509 if (!is_power_of_2(bpb->fat_sector_size)
1510 || (bpb->fat_sector_size < 512)
1511 || (bpb->fat_sector_size > 4096)) {
1512 if (!silent)
1513 fat_msg(sb, KERN_ERR, "bogus logical sector size %u",
1514 (unsigned)bpb->fat_sector_size);
1515 goto out;
1516 }
1517
1518 if (!is_power_of_2(bpb->fat_sec_per_clus)) {
1519 if (!silent)
1520 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u",
1521 (unsigned)bpb->fat_sec_per_clus);
1522 goto out;
1523 }
1524
1525 error = 0;
1526
1527 out:
1528 return error;
1529 }
1530
1531 static int fat_read_static_bpb(struct super_block *sb,
1532 struct fat_boot_sector *b, int silent,
1533 struct fat_bios_param_block *bpb)
1534 {
1535 static const char *notdos1x = "This doesn't look like a DOS 1.x volume";
1536
1537 struct fat_floppy_defaults *fdefaults = NULL;
1538 int error = -EINVAL;
1539 sector_t bd_sects;
1540 unsigned i;
1541
1542 bd_sects = i_size_read(sb->s_bdev->bd_inode) / SECTOR_SIZE;
1543
1544 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */
1545 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) {
1546 if (!silent)
1547 fat_msg(sb, KERN_ERR,
1548 "%s; no bootstrapping code", notdos1x);
1549 goto out;
1550 }
1551
1552 /*
1553 * If any value in this region is non-zero, it isn't archaic
1554 * DOS.
1555 */
1556 if (!fat_bpb_is_zero(b)) {
1557 if (!silent)
1558 fat_msg(sb, KERN_ERR,
1559 "%s; DOS 2.x BPB is non-zero", notdos1x);
1560 goto out;
1561 }
1562
1563 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) {
1564 if (floppy_defaults[i].nr_sectors == bd_sects) {
1565 fdefaults = &floppy_defaults[i];
1566 break;
1567 }
1568 }
1569
1570 if (fdefaults == NULL) {
1571 if (!silent)
1572 fat_msg(sb, KERN_WARNING,
1573 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)",
1574 (u64)bd_sects);
1575 goto out;
1576 }
1577
1578 if (!silent)
1579 fat_msg(sb, KERN_INFO,
1580 "This looks like a DOS 1.x volume; assuming default BPB values");
1581
1582 memset(bpb, 0, sizeof(*bpb));
1583 bpb->fat_sector_size = SECTOR_SIZE;
1584 bpb->fat_sec_per_clus = fdefaults->sec_per_clus;
1585 bpb->fat_reserved = 1;
1586 bpb->fat_fats = 2;
1587 bpb->fat_dir_entries = fdefaults->dir_entries;
1588 bpb->fat_sectors = fdefaults->nr_sectors;
1589 bpb->fat_fat_length = fdefaults->fat_length;
1590
1591 error = 0;
1592
1593 out:
1594 return error;
1595 }
1596
1597 /*
1598 * Read the super block of an MS-DOS FS.
1599 */
1600 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
1601 void (*setup)(struct super_block *))
1602 {
1603 struct inode *root_inode = NULL, *fat_inode = NULL;
1604 struct inode *fsinfo_inode = NULL;
1605 struct buffer_head *bh;
1606 struct fat_bios_param_block bpb;
1607 struct msdos_sb_info *sbi;
1608 u16 logical_sector_size;
1609 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1610 int debug;
1611 long error;
1612 char buf[50];
1613
1614 /*
1615 * GFP_KERNEL is ok here, because while we do hold the
1616 * superblock lock, memory pressure can't call back into
1617 * the filesystem, since we're only just about to mount
1618 * it and have no inodes etc active!
1619 */
1620 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1621 if (!sbi)
1622 return -ENOMEM;
1623 sb->s_fs_info = sbi;
1624
1625 sb->s_flags |= SB_NODIRATIME;
1626 sb->s_magic = MSDOS_SUPER_MAGIC;
1627 sb->s_op = &fat_sops;
1628 sb->s_export_op = &fat_export_ops;
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 (sbi->fat_bits == 32)
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 (sbi->fat_bits != 32)
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 (sbi->fat_bits == 32)
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 FAT's first entry must have same value with
1802 * media-field. But in real world, too many devices is
1803 * writing wrong value. So, removed that validity check.
1804 *
1805 * if (FAT_FIRST_ENT(sb, media) != first)
1806 */
1807
1808 error = -EINVAL;
1809 sprintf(buf, "cp%d", sbi->options.codepage);
1810 sbi->nls_disk = load_nls(buf);
1811 if (!sbi->nls_disk) {
1812 fat_msg(sb, KERN_ERR, "codepage %s not found", buf);
1813 goto out_fail;
1814 }
1815
1816 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1817 if (sbi->options.isvfat) {
1818 sbi->nls_io = load_nls(sbi->options.iocharset);
1819 if (!sbi->nls_io) {
1820 fat_msg(sb, KERN_ERR, "IO charset %s not found",
1821 sbi->options.iocharset);
1822 goto out_fail;
1823 }
1824 }
1825
1826 error = -ENOMEM;
1827 fat_inode = new_inode(sb);
1828 if (!fat_inode)
1829 goto out_fail;
1830 fat_dummy_inode_init(fat_inode);
1831 sbi->fat_inode = fat_inode;
1832
1833 fsinfo_inode = new_inode(sb);
1834 if (!fsinfo_inode)
1835 goto out_fail;
1836 fat_dummy_inode_init(fsinfo_inode);
1837 fsinfo_inode->i_ino = MSDOS_FSINFO_INO;
1838 sbi->fsinfo_inode = fsinfo_inode;
1839 insert_inode_hash(fsinfo_inode);
1840
1841 root_inode = new_inode(sb);
1842 if (!root_inode)
1843 goto out_fail;
1844 root_inode->i_ino = MSDOS_ROOT_INO;
1845 inode_set_iversion(root_inode, 1);
1846 error = fat_read_root(root_inode);
1847 if (error < 0) {
1848 iput(root_inode);
1849 goto out_fail;
1850 }
1851 error = -ENOMEM;
1852 insert_inode_hash(root_inode);
1853 fat_attach(root_inode, 0);
1854 sb->s_root = d_make_root(root_inode);
1855 if (!sb->s_root) {
1856 fat_msg(sb, KERN_ERR, "get root inode failed");
1857 goto out_fail;
1858 }
1859
1860 if (sbi->options.discard) {
1861 struct request_queue *q = bdev_get_queue(sb->s_bdev);
1862 if (!blk_queue_discard(q))
1863 fat_msg(sb, KERN_WARNING,
1864 "mounting with \"discard\" option, but "
1865 "the device does not support discard");
1866 }
1867
1868 fat_set_state(sb, 1, 0);
1869 return 0;
1870
1871 out_invalid:
1872 error = -EINVAL;
1873 if (!silent)
1874 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem");
1875
1876 out_fail:
1877 if (fsinfo_inode)
1878 iput(fsinfo_inode);
1879 if (fat_inode)
1880 iput(fat_inode);
1881 unload_nls(sbi->nls_io);
1882 unload_nls(sbi->nls_disk);
1883 fat_reset_iocharset(&sbi->options);
1884 sb->s_fs_info = NULL;
1885 kfree(sbi);
1886 return error;
1887 }
1888
1889 EXPORT_SYMBOL_GPL(fat_fill_super);
1890
1891 /*
1892 * helper function for fat_flush_inodes. This writes both the inode
1893 * and the file data blocks, waiting for in flight data blocks before
1894 * the start of the call. It does not wait for any io started
1895 * during the call
1896 */
1897 static int writeback_inode(struct inode *inode)
1898 {
1899
1900 int ret;
1901
1902 /* if we used wait=1, sync_inode_metadata waits for the io for the
1903 * inode to finish. So wait=0 is sent down to sync_inode_metadata
1904 * and filemap_fdatawrite is used for the data blocks
1905 */
1906 ret = sync_inode_metadata(inode, 0);
1907 if (!ret)
1908 ret = filemap_fdatawrite(inode->i_mapping);
1909 return ret;
1910 }
1911
1912 /*
1913 * write data and metadata corresponding to i1 and i2. The io is
1914 * started but we do not wait for any of it to finish.
1915 *
1916 * filemap_flush is used for the block device, so if there is a dirty
1917 * page for a block already in flight, we will not wait and start the
1918 * io over again
1919 */
1920 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1921 {
1922 int ret = 0;
1923 if (!MSDOS_SB(sb)->options.flush)
1924 return 0;
1925 if (i1)
1926 ret = writeback_inode(i1);
1927 if (!ret && i2)
1928 ret = writeback_inode(i2);
1929 if (!ret) {
1930 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1931 ret = filemap_flush(mapping);
1932 }
1933 return ret;
1934 }
1935 EXPORT_SYMBOL_GPL(fat_flush_inodes);
1936
1937 static int __init init_fat_fs(void)
1938 {
1939 int err;
1940
1941 err = fat_cache_init();
1942 if (err)
1943 return err;
1944
1945 err = fat_init_inodecache();
1946 if (err)
1947 goto failed;
1948
1949 return 0;
1950
1951 failed:
1952 fat_cache_destroy();
1953 return err;
1954 }
1955
1956 static void __exit exit_fat_fs(void)
1957 {
1958 fat_cache_destroy();
1959 fat_destroy_inodecache();
1960 }
1961
1962 module_init(init_fat_fs)
1963 module_exit(exit_fat_fs)
1964
1965 MODULE_LICENSE("GPL");
Linux with added FPC-III support