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ARM64: juno: add GPIO keys
[linux/fpc-iii.git] / fs / fat / inode.c
blobc06774658345effe930825df56caedb1c296e97e
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 <asm/unaligned.h>
22 #include "fat.h"
23
24 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET
25 /* if user don't select VFAT, this is undefined. */
26 #define CONFIG_FAT_DEFAULT_IOCHARSET ""
27 #endif
28
29 #define KB_IN_SECTORS 2
30
31 /*
32 * A deserialized copy of the on-disk structure laid out in struct
33 * fat_boot_sector.
34 */
35 struct fat_bios_param_block {
36 u16 fat_sector_size;
37 u8 fat_sec_per_clus;
38 u16 fat_reserved;
39 u8 fat_fats;
40 u16 fat_dir_entries;
41 u16 fat_sectors;
42 u16 fat_fat_length;
43 u32 fat_total_sect;
44
45 u8 fat16_state;
46 u32 fat16_vol_id;
47
48 u32 fat32_length;
49 u32 fat32_root_cluster;
50 u16 fat32_info_sector;
51 u8 fat32_state;
52 u32 fat32_vol_id;
53 };
54
55 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
56 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
57
58 static struct fat_floppy_defaults {
59 unsigned nr_sectors;
60 unsigned sec_per_clus;
61 unsigned dir_entries;
62 unsigned media;
63 unsigned fat_length;
64 } floppy_defaults[] = {
65 {
66 .nr_sectors = 160 * KB_IN_SECTORS,
67 .sec_per_clus = 1,
68 .dir_entries = 64,
69 .media = 0xFE,
70 .fat_length = 1,
71 },
72 {
73 .nr_sectors = 180 * KB_IN_SECTORS,
74 .sec_per_clus = 1,
75 .dir_entries = 64,
76 .media = 0xFC,
77 .fat_length = 2,
78 },
79 {
80 .nr_sectors = 320 * KB_IN_SECTORS,
81 .sec_per_clus = 2,
82 .dir_entries = 112,
83 .media = 0xFF,
84 .fat_length = 1,
85 },
86 {
87 .nr_sectors = 360 * KB_IN_SECTORS,
88 .sec_per_clus = 2,
89 .dir_entries = 112,
90 .media = 0xFD,
91 .fat_length = 2,
92 },
93 };
94
95 static int fat_add_cluster(struct inode *inode)
96 {
97 int err, cluster;
98
99 err = fat_alloc_clusters(inode, &cluster, 1);
100 if (err)
101 return err;
102 /* FIXME: this cluster should be added after data of this
103 * cluster is writed */
104 err = fat_chain_add(inode, cluster, 1);
105 if (err)
106 fat_free_clusters(inode, cluster);
107 return err;
108 }
109
110 static inline int __fat_get_block(struct inode *inode, sector_t iblock,
111 unsigned long *max_blocks,
112 struct buffer_head *bh_result, int create)
113 {
114 struct super_block *sb = inode->i_sb;
115 struct msdos_sb_info *sbi = MSDOS_SB(sb);
116 unsigned long mapped_blocks;
117 sector_t phys;
118 int err, offset;
119
120 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
121 if (err)
122 return err;
123 if (phys) {
124 map_bh(bh_result, sb, phys);
125 *max_blocks = min(mapped_blocks, *max_blocks);
126 return 0;
127 }
128 if (!create)
129 return 0;
130
131 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
132 fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)",
133 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
134 return -EIO;
135 }
136
137 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
138 if (!offset) {
139 /* TODO: multiple cluster allocation would be desirable. */
140 err = fat_add_cluster(inode);
141 if (err)
142 return err;
143 }
144 /* available blocks on this cluster */
145 mapped_blocks = sbi->sec_per_clus - offset;
146
147 *max_blocks = min(mapped_blocks, *max_blocks);
148 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
149
150 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
151 if (err)
152 return err;
153
154 BUG_ON(!phys);
155 BUG_ON(*max_blocks != mapped_blocks);
156 set_buffer_new(bh_result);
157 map_bh(bh_result, sb, phys);
158
159 return 0;
160 }
161
162 static int fat_get_block(struct inode *inode, sector_t iblock,
163 struct buffer_head *bh_result, int create)
164 {
165 struct super_block *sb = inode->i_sb;
166 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
167 int err;
168
169 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
170 if (err)
171 return err;
172 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
173 return 0;
174 }
175
176 static int fat_writepage(struct page *page, struct writeback_control *wbc)
177 {
178 return block_write_full_page(page, fat_get_block, wbc);
179 }
180
181 static int fat_writepages(struct address_space *mapping,
182 struct writeback_control *wbc)
183 {
184 return mpage_writepages(mapping, wbc, fat_get_block);
185 }
186
187 static int fat_readpage(struct file *file, struct page *page)
188 {
189 return mpage_readpage(page, fat_get_block);
190 }
191
192 static int fat_readpages(struct file *file, struct address_space *mapping,
193 struct list_head *pages, unsigned nr_pages)
194 {
195 return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
196 }
197
198 static void fat_write_failed(struct address_space *mapping, loff_t to)
199 {
200 struct inode *inode = mapping->host;
201
202 if (to > inode->i_size) {
203 truncate_pagecache(inode, inode->i_size);
204 fat_truncate_blocks(inode, inode->i_size);
205 }
206 }
207
208 static int fat_write_begin(struct file *file, struct address_space *mapping,
209 loff_t pos, unsigned len, unsigned flags,
210 struct page **pagep, void **fsdata)
211 {
212 int err;
213
214 *pagep = NULL;
215 err = cont_write_begin(file, mapping, pos, len, flags,
216 pagep, fsdata, fat_get_block,
217 &MSDOS_I(mapping->host)->mmu_private);
218 if (err < 0)
219 fat_write_failed(mapping, pos + len);
220 return err;
221 }
222
223 static int fat_write_end(struct file *file, struct address_space *mapping,
224 loff_t pos, unsigned len, unsigned copied,
225 struct page *pagep, void *fsdata)
226 {
227 struct inode *inode = mapping->host;
228 int err;
229 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
230 if (err < len)
231 fat_write_failed(mapping, pos + len);
232 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
233 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
234 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
235 mark_inode_dirty(inode);
236 }
237 return err;
238 }
239
240 static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
241 loff_t offset)
242 {
243 struct file *file = iocb->ki_filp;
244 struct address_space *mapping = file->f_mapping;
245 struct inode *inode = mapping->host;
246 size_t count = iov_iter_count(iter);
247 ssize_t ret;
248
249 if (iov_iter_rw(iter) == WRITE) {
250 /*
251 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
252 * so we need to update the ->mmu_private to block boundary.
253 *
254 * But we must fill the remaining area or hole by nul for
255 * updating ->mmu_private.
256 *
257 * Return 0, and fallback to normal buffered write.
258 */
259 loff_t size = offset + count;
260 if (MSDOS_I(inode)->mmu_private < size)
261 return 0;
262 }
263
264 /*
265 * FAT need to use the DIO_LOCKING for avoiding the race
266 * condition of fat_get_block() and ->truncate().
267 */
268 ret = blockdev_direct_IO(iocb, inode, iter, offset, fat_get_block);
269 if (ret < 0 && iov_iter_rw(iter) == WRITE)
270 fat_write_failed(mapping, offset + count);
271
272 return ret;
273 }
274
275 static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
276 {
277 sector_t blocknr;
278
279 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
280 down_read(&MSDOS_I(mapping->host)->truncate_lock);
281 blocknr = generic_block_bmap(mapping, block, fat_get_block);
282 up_read(&MSDOS_I(mapping->host)->truncate_lock);
283
284 return blocknr;
285 }
286
287 /*
288 * fat_block_truncate_page() zeroes out a mapping from file offset `from'
289 * up to the end of the block which corresponds to `from'.
290 * This is required during truncate to physically zeroout the tail end
291 * of that block so it doesn't yield old data if the file is later grown.
292 * Also, avoid causing failure from fsx for cases of "data past EOF"
293 */
294 int fat_block_truncate_page(struct inode *inode, loff_t from)
295 {
296 return block_truncate_page(inode->i_mapping, from, fat_get_block);
297 }
298
299 static const struct address_space_operations fat_aops = {
300 .readpage = fat_readpage,
301 .readpages = fat_readpages,
302 .writepage = fat_writepage,
303 .writepages = fat_writepages,
304 .write_begin = fat_write_begin,
305 .write_end = fat_write_end,
306 .direct_IO = fat_direct_IO,
307 .bmap = _fat_bmap
308 };
309
310 /*
311 * New FAT inode stuff. We do the following:
312 * a) i_ino is constant and has nothing with on-disk location.
313 * b) FAT manages its own cache of directory entries.
314 * c) *This* cache is indexed by on-disk location.
315 * d) inode has an associated directory entry, all right, but
316 * it may be unhashed.
317 * e) currently entries are stored within struct inode. That should
318 * change.
319 * f) we deal with races in the following way:
320 * 1. readdir() and lookup() do FAT-dir-cache lookup.
321 * 2. rename() unhashes the F-d-c entry and rehashes it in
322 * a new place.
323 * 3. unlink() and rmdir() unhash F-d-c entry.
324 * 4. fat_write_inode() checks whether the thing is unhashed.
325 * If it is we silently return. If it isn't we do bread(),
326 * check if the location is still valid and retry if it
327 * isn't. Otherwise we do changes.
328 * 5. Spinlock is used to protect hash/unhash/location check/lookup
329 * 6. fat_evict_inode() unhashes the F-d-c entry.
330 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
331 * and consider negative result as cache miss.
332 */
333
334 static void fat_hash_init(struct super_block *sb)
335 {
336 struct msdos_sb_info *sbi = MSDOS_SB(sb);
337 int i;
338
339 spin_lock_init(&sbi->inode_hash_lock);
340 for (i = 0; i < FAT_HASH_SIZE; i++)
341 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
342 }
343
344 static inline unsigned long fat_hash(loff_t i_pos)
345 {
346 return hash_32(i_pos, FAT_HASH_BITS);
347 }
348
349 static void dir_hash_init(struct super_block *sb)
350 {
351 struct msdos_sb_info *sbi = MSDOS_SB(sb);
352 int i;
353
354 spin_lock_init(&sbi->dir_hash_lock);
355 for (i = 0; i < FAT_HASH_SIZE; i++)
356 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]);
357 }
358
359 void fat_attach(struct inode *inode, loff_t i_pos)
360 {
361 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
362
363 if (inode->i_ino != MSDOS_ROOT_INO) {
364 struct hlist_head *head = sbi->inode_hashtable
365 + fat_hash(i_pos);
366
367 spin_lock(&sbi->inode_hash_lock);
368 MSDOS_I(inode)->i_pos = i_pos;
369 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
370 spin_unlock(&sbi->inode_hash_lock);
371 }
372
373 /* If NFS support is enabled, cache the mapping of start cluster
374 * to directory inode. This is used during reconnection of
375 * dentries to the filesystem root.
376 */
377 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
378 struct hlist_head *d_head = sbi->dir_hashtable;
379 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart);
380
381 spin_lock(&sbi->dir_hash_lock);
382 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head);
383 spin_unlock(&sbi->dir_hash_lock);
384 }
385 }
386 EXPORT_SYMBOL_GPL(fat_attach);
387
388 void fat_detach(struct inode *inode)
389 {
390 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
391 spin_lock(&sbi->inode_hash_lock);
392 MSDOS_I(inode)->i_pos = 0;
393 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
394 spin_unlock(&sbi->inode_hash_lock);
395
396 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
397 spin_lock(&sbi->dir_hash_lock);
398 hlist_del_init(&MSDOS_I(inode)->i_dir_hash);
399 spin_unlock(&sbi->dir_hash_lock);
400 }
401 }
402 EXPORT_SYMBOL_GPL(fat_detach);
403
404 struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
405 {
406 struct msdos_sb_info *sbi = MSDOS_SB(sb);
407 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
408 struct msdos_inode_info *i;
409 struct inode *inode = NULL;
410
411 spin_lock(&sbi->inode_hash_lock);
412 hlist_for_each_entry(i, head, i_fat_hash) {
413 BUG_ON(i->vfs_inode.i_sb != sb);
414 if (i->i_pos != i_pos)
415 continue;
416 inode = igrab(&i->vfs_inode);
417 if (inode)
418 break;
419 }
420 spin_unlock(&sbi->inode_hash_lock);
421 return inode;
422 }
423
424 static int is_exec(unsigned char *extension)
425 {
426 unsigned char exe_extensions[] = "EXECOMBAT", *walk;
427
428 for (walk = exe_extensions; *walk; walk += 3)
429 if (!strncmp(extension, walk, 3))
430 return 1;
431 return 0;
432 }
433
434 static int fat_calc_dir_size(struct inode *inode)
435 {
436 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
437 int ret, fclus, dclus;
438
439 inode->i_size = 0;
440 if (MSDOS_I(inode)->i_start == 0)
441 return 0;
442
443 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
444 if (ret < 0)
445 return ret;
446 inode->i_size = (fclus + 1) << sbi->cluster_bits;
447
448 return 0;
449 }
450
451 /* doesn't deal with root inode */
452 int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
453 {
454 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
455 int error;
456
457 MSDOS_I(inode)->i_pos = 0;
458 inode->i_uid = sbi->options.fs_uid;
459 inode->i_gid = sbi->options.fs_gid;
460 inode->i_version++;
461 inode->i_generation = get_seconds();
462
463 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
464 inode->i_generation &= ~1;
465 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
466 inode->i_op = sbi->dir_ops;
467 inode->i_fop = &fat_dir_operations;
468
469 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
470 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
471 error = fat_calc_dir_size(inode);
472 if (error < 0)
473 return error;
474 MSDOS_I(inode)->mmu_private = inode->i_size;
475
476 set_nlink(inode, fat_subdirs(inode));
477 } else { /* not a directory */
478 inode->i_generation |= 1;
479 inode->i_mode = fat_make_mode(sbi, de->attr,
480 ((sbi->options.showexec && !is_exec(de->name + 8))
481 ? S_IRUGO|S_IWUGO : S_IRWXUGO));
482 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
483
484 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
485 inode->i_size = le32_to_cpu(de->size);
486 inode->i_op = &fat_file_inode_operations;
487 inode->i_fop = &fat_file_operations;
488 inode->i_mapping->a_ops = &fat_aops;
489 MSDOS_I(inode)->mmu_private = inode->i_size;
490 }
491 if (de->attr & ATTR_SYS) {
492 if (sbi->options.sys_immutable)
493 inode->i_flags |= S_IMMUTABLE;
494 }
495 fat_save_attrs(inode, de->attr);
496
497 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
498 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
499
500 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
501 if (sbi->options.isvfat) {
502 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
503 de->cdate, de->ctime_cs);
504 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
505 } else
506 inode->i_ctime = inode->i_atime = inode->i_mtime;
507
508 return 0;
509 }
510
511 static inline void fat_lock_build_inode(struct msdos_sb_info *sbi)
512 {
513 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
514 mutex_lock(&sbi->nfs_build_inode_lock);
515 }
516
517 static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi)
518 {
519 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
520 mutex_unlock(&sbi->nfs_build_inode_lock);
521 }
522
523 struct inode *fat_build_inode(struct super_block *sb,
524 struct msdos_dir_entry *de, loff_t i_pos)
525 {
526 struct inode *inode;
527 int err;
528
529 fat_lock_build_inode(MSDOS_SB(sb));
530 inode = fat_iget(sb, i_pos);
531 if (inode)
532 goto out;
533 inode = new_inode(sb);
534 if (!inode) {
535 inode = ERR_PTR(-ENOMEM);
536 goto out;
537 }
538 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
539 inode->i_version = 1;
540 err = fat_fill_inode(inode, de);
541 if (err) {
542 iput(inode);
543 inode = ERR_PTR(err);
544 goto out;
545 }
546 fat_attach(inode, i_pos);
547 insert_inode_hash(inode);
548 out:
549 fat_unlock_build_inode(MSDOS_SB(sb));
550 return inode;
551 }
552
553 EXPORT_SYMBOL_GPL(fat_build_inode);
554
555 static void fat_evict_inode(struct inode *inode)
556 {
557 truncate_inode_pages_final(&inode->i_data);
558 if (!inode->i_nlink) {
559 inode->i_size = 0;
560 fat_truncate_blocks(inode, 0);
561 }
562 invalidate_inode_buffers(inode);
563 clear_inode(inode);
564 fat_cache_inval_inode(inode);
565 fat_detach(inode);
566 }
567
568 static void fat_set_state(struct super_block *sb,
569 unsigned int set, unsigned int force)
570 {
571 struct buffer_head *bh;
572 struct fat_boot_sector *b;
573 struct msdos_sb_info *sbi = MSDOS_SB(sb);
574
575 /* do not change any thing if mounted read only */
576 if ((sb->s_flags & MS_RDONLY) && !force)
577 return;
578
579 /* do not change state if fs was dirty */
580 if (sbi->dirty) {
581 /* warn only on set (mount). */
582 if (set)
583 fat_msg(sb, KERN_WARNING, "Volume was not properly "
584 "unmounted. Some data may be corrupt. "
585 "Please run fsck.");
586 return;
587 }
588
589 bh = sb_bread(sb, 0);
590 if (bh == NULL) {
591 fat_msg(sb, KERN_ERR, "unable to read boot sector "
592 "to mark fs as dirty");
593 return;
594 }
595
596 b = (struct fat_boot_sector *) bh->b_data;
597
598 if (sbi->fat_bits == 32) {
599 if (set)
600 b->fat32.state |= FAT_STATE_DIRTY;
601 else
602 b->fat32.state &= ~FAT_STATE_DIRTY;
603 } else /* fat 16 and 12 */ {
604 if (set)
605 b->fat16.state |= FAT_STATE_DIRTY;
606 else
607 b->fat16.state &= ~FAT_STATE_DIRTY;
608 }
609
610 mark_buffer_dirty(bh);
611 sync_dirty_buffer(bh);
612 brelse(bh);
613 }
614
615 static void delayed_free(struct rcu_head *p)
616 {
617 struct msdos_sb_info *sbi = container_of(p, struct msdos_sb_info, rcu);
618 unload_nls(sbi->nls_disk);
619 unload_nls(sbi->nls_io);
620 if (sbi->options.iocharset != fat_default_iocharset)
621 kfree(sbi->options.iocharset);
622 kfree(sbi);
623 }
624
625 static void fat_put_super(struct super_block *sb)
626 {
627 struct msdos_sb_info *sbi = MSDOS_SB(sb);
628
629 fat_set_state(sb, 0, 0);
630
631 iput(sbi->fsinfo_inode);
632 iput(sbi->fat_inode);
633
634 call_rcu(&sbi->rcu, delayed_free);
635 }
636
637 static struct kmem_cache *fat_inode_cachep;
638
639 static struct inode *fat_alloc_inode(struct super_block *sb)
640 {
641 struct msdos_inode_info *ei;
642 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
643 if (!ei)
644 return NULL;
645
646 init_rwsem(&ei->truncate_lock);
647 return &ei->vfs_inode;
648 }
649
650 static void fat_i_callback(struct rcu_head *head)
651 {
652 struct inode *inode = container_of(head, struct inode, i_rcu);
653 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
654 }
655
656 static void fat_destroy_inode(struct inode *inode)
657 {
658 call_rcu(&inode->i_rcu, fat_i_callback);
659 }
660
661 static void init_once(void *foo)
662 {
663 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
664
665 spin_lock_init(&ei->cache_lru_lock);
666 ei->nr_caches = 0;
667 ei->cache_valid_id = FAT_CACHE_VALID + 1;
668 INIT_LIST_HEAD(&ei->cache_lru);
669 INIT_HLIST_NODE(&ei->i_fat_hash);
670 INIT_HLIST_NODE(&ei->i_dir_hash);
671 inode_init_once(&ei->vfs_inode);
672 }
673
674 static int __init fat_init_inodecache(void)
675 {
676 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
677 sizeof(struct msdos_inode_info),
678 0, (SLAB_RECLAIM_ACCOUNT|
679 SLAB_MEM_SPREAD),
680 init_once);
681 if (fat_inode_cachep == NULL)
682 return -ENOMEM;
683 return 0;
684 }
685
686 static void __exit fat_destroy_inodecache(void)
687 {
688 /*
689 * Make sure all delayed rcu free inodes are flushed before we
690 * destroy cache.
691 */
692 rcu_barrier();
693 kmem_cache_destroy(fat_inode_cachep);
694 }
695
696 static int fat_remount(struct super_block *sb, int *flags, char *data)
697 {
698 int new_rdonly;
699 struct msdos_sb_info *sbi = MSDOS_SB(sb);
700 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
701
702 sync_filesystem(sb);
703
704 /* make sure we update state on remount. */
705 new_rdonly = *flags & MS_RDONLY;
706 if (new_rdonly != (sb->s_flags & MS_RDONLY)) {
707 if (new_rdonly)
708 fat_set_state(sb, 0, 0);
709 else
710 fat_set_state(sb, 1, 1);
711 }
712 return 0;
713 }
714
715 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
716 {
717 struct super_block *sb = dentry->d_sb;
718 struct msdos_sb_info *sbi = MSDOS_SB(sb);
719 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
720
721 /* If the count of free cluster is still unknown, counts it here. */
722 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
723 int err = fat_count_free_clusters(dentry->d_sb);
724 if (err)
725 return err;
726 }
727
728 buf->f_type = dentry->d_sb->s_magic;
729 buf->f_bsize = sbi->cluster_size;
730 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
731 buf->f_bfree = sbi->free_clusters;
732 buf->f_bavail = sbi->free_clusters;
733 buf->f_fsid.val[0] = (u32)id;
734 buf->f_fsid.val[1] = (u32)(id >> 32);
735 buf->f_namelen =
736 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE;
737
738 return 0;
739 }
740
741 static int __fat_write_inode(struct inode *inode, int wait)
742 {
743 struct super_block *sb = inode->i_sb;
744 struct msdos_sb_info *sbi = MSDOS_SB(sb);
745 struct buffer_head *bh;
746 struct msdos_dir_entry *raw_entry;
747 loff_t i_pos;
748 sector_t blocknr;
749 int err, offset;
750
751 if (inode->i_ino == MSDOS_ROOT_INO)
752 return 0;
753
754 retry:
755 i_pos = fat_i_pos_read(sbi, inode);
756 if (!i_pos)
757 return 0;
758
759 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset);
760 bh = sb_bread(sb, blocknr);
761 if (!bh) {
762 fat_msg(sb, KERN_ERR, "unable to read inode block "
763 "for updating (i_pos %lld)", i_pos);
764 return -EIO;
765 }
766 spin_lock(&sbi->inode_hash_lock);
767 if (i_pos != MSDOS_I(inode)->i_pos) {
768 spin_unlock(&sbi->inode_hash_lock);
769 brelse(bh);
770 goto retry;
771 }
772
773 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset];
774 if (S_ISDIR(inode->i_mode))
775 raw_entry->size = 0;
776 else
777 raw_entry->size = cpu_to_le32(inode->i_size);
778 raw_entry->attr = fat_make_attrs(inode);
779 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart);
780 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
781 &raw_entry->date, NULL);
782 if (sbi->options.isvfat) {
783 __le16 atime;
784 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
785 &raw_entry->cdate, &raw_entry->ctime_cs);
786 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
787 &raw_entry->adate, NULL);
788 }
789 spin_unlock(&sbi->inode_hash_lock);
790 mark_buffer_dirty(bh);
791 err = 0;
792 if (wait)
793 err = sync_dirty_buffer(bh);
794 brelse(bh);
795 return err;
796 }
797
798 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
799 {
800 int err;
801
802 if (inode->i_ino == MSDOS_FSINFO_INO) {
803 struct super_block *sb = inode->i_sb;
804
805 mutex_lock(&MSDOS_SB(sb)->s_lock);
806 err = fat_clusters_flush(sb);
807 mutex_unlock(&MSDOS_SB(sb)->s_lock);
808 } else
809 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
810
811 return err;
812 }
813
814 int fat_sync_inode(struct inode *inode)
815 {
816 return __fat_write_inode(inode, 1);
817 }
818
819 EXPORT_SYMBOL_GPL(fat_sync_inode);
820
821 static int fat_show_options(struct seq_file *m, struct dentry *root);
822 static const struct super_operations fat_sops = {
823 .alloc_inode = fat_alloc_inode,
824 .destroy_inode = fat_destroy_inode,
825 .write_inode = fat_write_inode,
826 .evict_inode = fat_evict_inode,
827 .put_super = fat_put_super,
828 .statfs = fat_statfs,
829 .remount_fs = fat_remount,
830
831 .show_options = fat_show_options,
832 };
833
834 static int fat_show_options(struct seq_file *m, struct dentry *root)
835 {
836 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb);
837 struct fat_mount_options *opts = &sbi->options;
838 int isvfat = opts->isvfat;
839
840 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
841 seq_printf(m, ",uid=%u",
842 from_kuid_munged(&init_user_ns, opts->fs_uid));
843 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
844 seq_printf(m, ",gid=%u",
845 from_kgid_munged(&init_user_ns, opts->fs_gid));
846 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
847 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
848 if (opts->allow_utime)
849 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
850 if (sbi->nls_disk)
851 /* strip "cp" prefix from displayed option */
852 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]);
853 if (isvfat) {
854 if (sbi->nls_io)
855 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
856
857 switch (opts->shortname) {
858 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
859 seq_puts(m, ",shortname=win95");
860 break;
861 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
862 seq_puts(m, ",shortname=winnt");
863 break;
864 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
865 seq_puts(m, ",shortname=mixed");
866 break;
867 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
868 seq_puts(m, ",shortname=lower");
869 break;
870 default:
871 seq_puts(m, ",shortname=unknown");
872 break;
873 }
874 }
875 if (opts->name_check != 'n')
876 seq_printf(m, ",check=%c", opts->name_check);
877 if (opts->usefree)
878 seq_puts(m, ",usefree");
879 if (opts->quiet)
880 seq_puts(m, ",quiet");
881 if (opts->showexec)
882 seq_puts(m, ",showexec");
883 if (opts->sys_immutable)
884 seq_puts(m, ",sys_immutable");
885 if (!isvfat) {
886 if (opts->dotsOK)
887 seq_puts(m, ",dotsOK=yes");
888 if (opts->nocase)
889 seq_puts(m, ",nocase");
890 } else {
891 if (opts->utf8)
892 seq_puts(m, ",utf8");
893 if (opts->unicode_xlate)
894 seq_puts(m, ",uni_xlate");
895 if (!opts->numtail)
896 seq_puts(m, ",nonumtail");
897 if (opts->rodir)
898 seq_puts(m, ",rodir");
899 }
900 if (opts->flush)
901 seq_puts(m, ",flush");
902 if (opts->tz_set) {
903 if (opts->time_offset)
904 seq_printf(m, ",time_offset=%d", opts->time_offset);
905 else
906 seq_puts(m, ",tz=UTC");
907 }
908 if (opts->errors == FAT_ERRORS_CONT)
909 seq_puts(m, ",errors=continue");
910 else if (opts->errors == FAT_ERRORS_PANIC)
911 seq_puts(m, ",errors=panic");
912 else
913 seq_puts(m, ",errors=remount-ro");
914 if (opts->nfs == FAT_NFS_NOSTALE_RO)
915 seq_puts(m, ",nfs=nostale_ro");
916 else if (opts->nfs)
917 seq_puts(m, ",nfs=stale_rw");
918 if (opts->discard)
919 seq_puts(m, ",discard");
920 if (opts->dos1xfloppy)
921 seq_puts(m, ",dos1xfloppy");
922
923 return 0;
924 }
925
926 enum {
927 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
928 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
929 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
930 Opt_immutable, Opt_dots, Opt_nodots,
931 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
932 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
933 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
934 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
935 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset,
936 Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err, Opt_dos1xfloppy,
937 };
938
939 static const match_table_t fat_tokens = {
940 {Opt_check_r, "check=relaxed"},
941 {Opt_check_s, "check=strict"},
942 {Opt_check_n, "check=normal"},
943 {Opt_check_r, "check=r"},
944 {Opt_check_s, "check=s"},
945 {Opt_check_n, "check=n"},
946 {Opt_uid, "uid=%u"},
947 {Opt_gid, "gid=%u"},
948 {Opt_umask, "umask=%o"},
949 {Opt_dmask, "dmask=%o"},
950 {Opt_fmask, "fmask=%o"},
951 {Opt_allow_utime, "allow_utime=%o"},
952 {Opt_codepage, "codepage=%u"},
953 {Opt_usefree, "usefree"},
954 {Opt_nocase, "nocase"},
955 {Opt_quiet, "quiet"},
956 {Opt_showexec, "showexec"},
957 {Opt_debug, "debug"},
958 {Opt_immutable, "sys_immutable"},
959 {Opt_flush, "flush"},
960 {Opt_tz_utc, "tz=UTC"},
961 {Opt_time_offset, "time_offset=%d"},
962 {Opt_err_cont, "errors=continue"},
963 {Opt_err_panic, "errors=panic"},
964 {Opt_err_ro, "errors=remount-ro"},
965 {Opt_discard, "discard"},
966 {Opt_nfs_stale_rw, "nfs"},
967 {Opt_nfs_stale_rw, "nfs=stale_rw"},
968 {Opt_nfs_nostale_ro, "nfs=nostale_ro"},
969 {Opt_dos1xfloppy, "dos1xfloppy"},
970 {Opt_obsolete, "conv=binary"},
971 {Opt_obsolete, "conv=text"},
972 {Opt_obsolete, "conv=auto"},
973 {Opt_obsolete, "conv=b"},
974 {Opt_obsolete, "conv=t"},
975 {Opt_obsolete, "conv=a"},
976 {Opt_obsolete, "fat=%u"},
977 {Opt_obsolete, "blocksize=%u"},
978 {Opt_obsolete, "cvf_format=%20s"},
979 {Opt_obsolete, "cvf_options=%100s"},
980 {Opt_obsolete, "posix"},
981 {Opt_err, NULL},
982 };
983 static const match_table_t msdos_tokens = {
984 {Opt_nodots, "nodots"},
985 {Opt_nodots, "dotsOK=no"},
986 {Opt_dots, "dots"},
987 {Opt_dots, "dotsOK=yes"},
988 {Opt_err, NULL}
989 };
990 static const match_table_t vfat_tokens = {
991 {Opt_charset, "iocharset=%s"},
992 {Opt_shortname_lower, "shortname=lower"},
993 {Opt_shortname_win95, "shortname=win95"},
994 {Opt_shortname_winnt, "shortname=winnt"},
995 {Opt_shortname_mixed, "shortname=mixed"},
996 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
997 {Opt_utf8_no, "utf8=no"},
998 {Opt_utf8_no, "utf8=false"},
999 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
1000 {Opt_utf8_yes, "utf8=yes"},
1001 {Opt_utf8_yes, "utf8=true"},
1002 {Opt_utf8_yes, "utf8"},
1003 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
1004 {Opt_uni_xl_no, "uni_xlate=no"},
1005 {Opt_uni_xl_no, "uni_xlate=false"},
1006 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
1007 {Opt_uni_xl_yes, "uni_xlate=yes"},
1008 {Opt_uni_xl_yes, "uni_xlate=true"},
1009 {Opt_uni_xl_yes, "uni_xlate"},
1010 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
1011 {Opt_nonumtail_no, "nonumtail=no"},
1012 {Opt_nonumtail_no, "nonumtail=false"},
1013 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
1014 {Opt_nonumtail_yes, "nonumtail=yes"},
1015 {Opt_nonumtail_yes, "nonumtail=true"},
1016 {Opt_nonumtail_yes, "nonumtail"},
1017 {Opt_rodir, "rodir"},
1018 {Opt_err, NULL}
1019 };
1020
1021 static int parse_options(struct super_block *sb, char *options, int is_vfat,
1022 int silent, int *debug, struct fat_mount_options *opts)
1023 {
1024 char *p;
1025 substring_t args[MAX_OPT_ARGS];
1026 int option;
1027 char *iocharset;
1028
1029 opts->isvfat = is_vfat;
1030
1031 opts->fs_uid = current_uid();
1032 opts->fs_gid = current_gid();
1033 opts->fs_fmask = opts->fs_dmask = current_umask();
1034 opts->allow_utime = -1;
1035 opts->codepage = fat_default_codepage;
1036 opts->iocharset = fat_default_iocharset;
1037 if (is_vfat) {
1038 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
1039 opts->rodir = 0;
1040 } else {
1041 opts->shortname = 0;
1042 opts->rodir = 1;
1043 }
1044 opts->name_check = 'n';
1045 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
1046 opts->utf8 = opts->unicode_xlate = 0;
1047 opts->numtail = 1;
1048 opts->usefree = opts->nocase = 0;
1049 opts->tz_set = 0;
1050 opts->nfs = 0;
1051 opts->errors = FAT_ERRORS_RO;
1052 *debug = 0;
1053
1054 if (!options)
1055 goto out;
1056
1057 while ((p = strsep(&options, ",")) != NULL) {
1058 int token;
1059 if (!*p)
1060 continue;
1061
1062 token = match_token(p, fat_tokens, args);
1063 if (token == Opt_err) {
1064 if (is_vfat)
1065 token = match_token(p, vfat_tokens, args);
1066 else
1067 token = match_token(p, msdos_tokens, args);
1068 }
1069 switch (token) {
1070 case Opt_check_s:
1071 opts->name_check = 's';
1072 break;
1073 case Opt_check_r:
1074 opts->name_check = 'r';
1075 break;
1076 case Opt_check_n:
1077 opts->name_check = 'n';
1078 break;
1079 case Opt_usefree:
1080 opts->usefree = 1;
1081 break;
1082 case Opt_nocase:
1083 if (!is_vfat)
1084 opts->nocase = 1;
1085 else {
1086 /* for backward compatibility */
1087 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1088 | VFAT_SFN_CREATE_WIN95;
1089 }
1090 break;
1091 case Opt_quiet:
1092 opts->quiet = 1;
1093 break;
1094 case Opt_showexec:
1095 opts->showexec = 1;
1096 break;
1097 case Opt_debug:
1098 *debug = 1;
1099 break;
1100 case Opt_immutable:
1101 opts->sys_immutable = 1;
1102 break;
1103 case Opt_uid:
1104 if (match_int(&args[0], &option))
1105 return -EINVAL;
1106 opts->fs_uid = make_kuid(current_user_ns(), option);
1107 if (!uid_valid(opts->fs_uid))
1108 return -EINVAL;
1109 break;
1110 case Opt_gid:
1111 if (match_int(&args[0], &option))
1112 return -EINVAL;
1113 opts->fs_gid = make_kgid(current_user_ns(), option);
1114 if (!gid_valid(opts->fs_gid))
1115 return -EINVAL;
1116 break;
1117 case Opt_umask:
1118 if (match_octal(&args[0], &option))
1119 return -EINVAL;
1120 opts->fs_fmask = opts->fs_dmask = option;
1121 break;
1122 case Opt_dmask:
1123 if (match_octal(&args[0], &option))
1124 return -EINVAL;
1125 opts->fs_dmask = option;
1126 break;
1127 case Opt_fmask:
1128 if (match_octal(&args[0], &option))
1129 return -EINVAL;
1130 opts->fs_fmask = option;
1131 break;
1132 case Opt_allow_utime:
1133 if (match_octal(&args[0], &option))
1134 return -EINVAL;
1135 opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1136 break;
1137 case Opt_codepage:
1138 if (match_int(&args[0], &option))
1139 return -EINVAL;
1140 opts->codepage = option;
1141 break;
1142 case Opt_flush:
1143 opts->flush = 1;
1144 break;
1145 case Opt_time_offset:
1146 if (match_int(&args[0], &option))
1147 return -EINVAL;
1148 if (option < -12 * 60 || option > 12 * 60)
1149 return -EINVAL;
1150 opts->tz_set = 1;
1151 opts->time_offset = option;
1152 break;
1153 case Opt_tz_utc:
1154 opts->tz_set = 1;
1155 opts->time_offset = 0;
1156 break;
1157 case Opt_err_cont:
1158 opts->errors = FAT_ERRORS_CONT;
1159 break;
1160 case Opt_err_panic:
1161 opts->errors = FAT_ERRORS_PANIC;
1162 break;
1163 case Opt_err_ro:
1164 opts->errors = FAT_ERRORS_RO;
1165 break;
1166 case Opt_nfs_stale_rw:
1167 opts->nfs = FAT_NFS_STALE_RW;
1168 break;
1169 case Opt_nfs_nostale_ro:
1170 opts->nfs = FAT_NFS_NOSTALE_RO;
1171 break;
1172 case Opt_dos1xfloppy:
1173 opts->dos1xfloppy = 1;
1174 break;
1175
1176 /* msdos specific */
1177 case Opt_dots:
1178 opts->dotsOK = 1;
1179 break;
1180 case Opt_nodots:
1181 opts->dotsOK = 0;
1182 break;
1183
1184 /* vfat specific */
1185 case Opt_charset:
1186 if (opts->iocharset != fat_default_iocharset)
1187 kfree(opts->iocharset);
1188 iocharset = match_strdup(&args[0]);
1189 if (!iocharset)
1190 return -ENOMEM;
1191 opts->iocharset = iocharset;
1192 break;
1193 case Opt_shortname_lower:
1194 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1195 | VFAT_SFN_CREATE_WIN95;
1196 break;
1197 case Opt_shortname_win95:
1198 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1199 | VFAT_SFN_CREATE_WIN95;
1200 break;
1201 case Opt_shortname_winnt:
1202 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1203 | VFAT_SFN_CREATE_WINNT;
1204 break;
1205 case Opt_shortname_mixed:
1206 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1207 | VFAT_SFN_CREATE_WIN95;
1208 break;
1209 case Opt_utf8_no: /* 0 or no or false */
1210 opts->utf8 = 0;
1211 break;
1212 case Opt_utf8_yes: /* empty or 1 or yes or true */
1213 opts->utf8 = 1;
1214 break;
1215 case Opt_uni_xl_no: /* 0 or no or false */
1216 opts->unicode_xlate = 0;
1217 break;
1218 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1219 opts->unicode_xlate = 1;
1220 break;
1221 case Opt_nonumtail_no: /* 0 or no or false */
1222 opts->numtail = 1; /* negated option */
1223 break;
1224 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1225 opts->numtail = 0; /* negated option */
1226 break;
1227 case Opt_rodir:
1228 opts->rodir = 1;
1229 break;
1230 case Opt_discard:
1231 opts->discard = 1;
1232 break;
1233
1234 /* obsolete mount options */
1235 case Opt_obsolete:
1236 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, "
1237 "not supported now", p);
1238 break;
1239 /* unknown option */
1240 default:
1241 if (!silent) {
1242 fat_msg(sb, KERN_ERR,
1243 "Unrecognized mount option \"%s\" "
1244 "or missing value", p);
1245 }
1246 return -EINVAL;
1247 }
1248 }
1249
1250 out:
1251 /* UTF-8 doesn't provide FAT semantics */
1252 if (!strcmp(opts->iocharset, "utf8")) {
1253 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset"
1254 " for FAT filesystems, filesystem will be "
1255 "case sensitive!");
1256 }
1257
1258 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1259 if (opts->allow_utime == (unsigned short)-1)
1260 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
1261 if (opts->unicode_xlate)
1262 opts->utf8 = 0;
1263 if (opts->nfs == FAT_NFS_NOSTALE_RO) {
1264 sb->s_flags |= MS_RDONLY;
1265 sb->s_export_op = &fat_export_ops_nostale;
1266 }
1267
1268 return 0;
1269 }
1270
1271 static int fat_read_root(struct inode *inode)
1272 {
1273 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
1274 int error;
1275
1276 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO;
1277 inode->i_uid = sbi->options.fs_uid;
1278 inode->i_gid = sbi->options.fs_gid;
1279 inode->i_version++;
1280 inode->i_generation = 0;
1281 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
1282 inode->i_op = sbi->dir_ops;
1283 inode->i_fop = &fat_dir_operations;
1284 if (sbi->fat_bits == 32) {
1285 MSDOS_I(inode)->i_start = sbi->root_cluster;
1286 error = fat_calc_dir_size(inode);
1287 if (error < 0)
1288 return error;
1289 } else {
1290 MSDOS_I(inode)->i_start = 0;
1291 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1292 }
1293 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1294 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1295 MSDOS_I(inode)->i_logstart = 0;
1296 MSDOS_I(inode)->mmu_private = inode->i_size;
1297
1298 fat_save_attrs(inode, ATTR_DIR);
1299 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1300 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1301 set_nlink(inode, fat_subdirs(inode)+2);
1302
1303 return 0;
1304 }
1305
1306 static unsigned long calc_fat_clusters(struct super_block *sb)
1307 {
1308 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1309
1310 /* Divide first to avoid overflow */
1311 if (sbi->fat_bits != 12) {
1312 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits;
1313 return ent_per_sec * sbi->fat_length;
1314 }
1315
1316 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1317 }
1318
1319 static bool fat_bpb_is_zero(struct fat_boot_sector *b)
1320 {
1321 if (get_unaligned_le16(&b->sector_size))
1322 return false;
1323 if (b->sec_per_clus)
1324 return false;
1325 if (b->reserved)
1326 return false;
1327 if (b->fats)
1328 return false;
1329 if (get_unaligned_le16(&b->dir_entries))
1330 return false;
1331 if (get_unaligned_le16(&b->sectors))
1332 return false;
1333 if (b->media)
1334 return false;
1335 if (b->fat_length)
1336 return false;
1337 if (b->secs_track)
1338 return false;
1339 if (b->heads)
1340 return false;
1341 return true;
1342 }
1343
1344 static int fat_read_bpb(struct super_block *sb, struct fat_boot_sector *b,
1345 int silent, struct fat_bios_param_block *bpb)
1346 {
1347 int error = -EINVAL;
1348
1349 /* Read in BPB ... */
1350 memset(bpb, 0, sizeof(*bpb));
1351 bpb->fat_sector_size = get_unaligned_le16(&b->sector_size);
1352 bpb->fat_sec_per_clus = b->sec_per_clus;
1353 bpb->fat_reserved = le16_to_cpu(b->reserved);
1354 bpb->fat_fats = b->fats;
1355 bpb->fat_dir_entries = get_unaligned_le16(&b->dir_entries);
1356 bpb->fat_sectors = get_unaligned_le16(&b->sectors);
1357 bpb->fat_fat_length = le16_to_cpu(b->fat_length);
1358 bpb->fat_total_sect = le32_to_cpu(b->total_sect);
1359
1360 bpb->fat16_state = b->fat16.state;
1361 bpb->fat16_vol_id = get_unaligned_le32(b->fat16.vol_id);
1362
1363 bpb->fat32_length = le32_to_cpu(b->fat32.length);
1364 bpb->fat32_root_cluster = le32_to_cpu(b->fat32.root_cluster);
1365 bpb->fat32_info_sector = le16_to_cpu(b->fat32.info_sector);
1366 bpb->fat32_state = b->fat32.state;
1367 bpb->fat32_vol_id = get_unaligned_le32(b->fat32.vol_id);
1368
1369 /* Validate this looks like a FAT filesystem BPB */
1370 if (!bpb->fat_reserved) {
1371 if (!silent)
1372 fat_msg(sb, KERN_ERR,
1373 "bogus number of reserved sectors");
1374 goto out;
1375 }
1376 if (!bpb->fat_fats) {
1377 if (!silent)
1378 fat_msg(sb, KERN_ERR, "bogus number of FAT structure");
1379 goto out;
1380 }
1381
1382 /*
1383 * Earlier we checked here that b->secs_track and b->head are nonzero,
1384 * but it turns out valid FAT filesystems can have zero there.
1385 */
1386
1387 if (!fat_valid_media(b->media)) {
1388 if (!silent)
1389 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)",
1390 (unsigned)b->media);
1391 goto out;
1392 }
1393
1394 if (!is_power_of_2(bpb->fat_sector_size)
1395 || (bpb->fat_sector_size < 512)
1396 || (bpb->fat_sector_size > 4096)) {
1397 if (!silent)
1398 fat_msg(sb, KERN_ERR, "bogus logical sector size %u",
1399 (unsigned)bpb->fat_sector_size);
1400 goto out;
1401 }
1402
1403 if (!is_power_of_2(bpb->fat_sec_per_clus)) {
1404 if (!silent)
1405 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u",
1406 (unsigned)bpb->fat_sec_per_clus);
1407 goto out;
1408 }
1409
1410 error = 0;
1411
1412 out:
1413 return error;
1414 }
1415
1416 static int fat_read_static_bpb(struct super_block *sb,
1417 struct fat_boot_sector *b, int silent,
1418 struct fat_bios_param_block *bpb)
1419 {
1420 static const char *notdos1x = "This doesn't look like a DOS 1.x volume";
1421
1422 struct fat_floppy_defaults *fdefaults = NULL;
1423 int error = -EINVAL;
1424 sector_t bd_sects;
1425 unsigned i;
1426
1427 bd_sects = i_size_read(sb->s_bdev->bd_inode) / SECTOR_SIZE;
1428
1429 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */
1430 if (b->ignored[0] != 0xeb || b->ignored[2] != 0x90) {
1431 if (!silent)
1432 fat_msg(sb, KERN_ERR,
1433 "%s; no bootstrapping code", notdos1x);
1434 goto out;
1435 }
1436
1437 /*
1438 * If any value in this region is non-zero, it isn't archaic
1439 * DOS.
1440 */
1441 if (!fat_bpb_is_zero(b)) {
1442 if (!silent)
1443 fat_msg(sb, KERN_ERR,
1444 "%s; DOS 2.x BPB is non-zero", notdos1x);
1445 goto out;
1446 }
1447
1448 for (i = 0; i < ARRAY_SIZE(floppy_defaults); i++) {
1449 if (floppy_defaults[i].nr_sectors == bd_sects) {
1450 fdefaults = &floppy_defaults[i];
1451 break;
1452 }
1453 }
1454
1455 if (fdefaults == NULL) {
1456 if (!silent)
1457 fat_msg(sb, KERN_WARNING,
1458 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)",
1459 (u64)bd_sects);
1460 goto out;
1461 }
1462
1463 if (!silent)
1464 fat_msg(sb, KERN_INFO,
1465 "This looks like a DOS 1.x volume; assuming default BPB values");
1466
1467 memset(bpb, 0, sizeof(*bpb));
1468 bpb->fat_sector_size = SECTOR_SIZE;
1469 bpb->fat_sec_per_clus = fdefaults->sec_per_clus;
1470 bpb->fat_reserved = 1;
1471 bpb->fat_fats = 2;
1472 bpb->fat_dir_entries = fdefaults->dir_entries;
1473 bpb->fat_sectors = fdefaults->nr_sectors;
1474 bpb->fat_fat_length = fdefaults->fat_length;
1475
1476 error = 0;
1477
1478 out:
1479 return error;
1480 }
1481
1482 /*
1483 * Read the super block of an MS-DOS FS.
1484 */
1485 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
1486 void (*setup)(struct super_block *))
1487 {
1488 struct inode *root_inode = NULL, *fat_inode = NULL;
1489 struct inode *fsinfo_inode = NULL;
1490 struct buffer_head *bh;
1491 struct fat_bios_param_block bpb;
1492 struct msdos_sb_info *sbi;
1493 u16 logical_sector_size;
1494 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1495 int debug;
1496 long error;
1497 char buf[50];
1498
1499 /*
1500 * GFP_KERNEL is ok here, because while we do hold the
1501 * supeblock lock, memory pressure can't call back into
1502 * the filesystem, since we're only just about to mount
1503 * it and have no inodes etc active!
1504 */
1505 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1506 if (!sbi)
1507 return -ENOMEM;
1508 sb->s_fs_info = sbi;
1509
1510 sb->s_flags |= MS_NODIRATIME;
1511 sb->s_magic = MSDOS_SUPER_MAGIC;
1512 sb->s_op = &fat_sops;
1513 sb->s_export_op = &fat_export_ops;
1514 mutex_init(&sbi->nfs_build_inode_lock);
1515 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
1516 DEFAULT_RATELIMIT_BURST);
1517
1518 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options);
1519 if (error)
1520 goto out_fail;
1521
1522 setup(sb); /* flavour-specific stuff that needs options */
1523
1524 error = -EIO;
1525 sb_min_blocksize(sb, 512);
1526 bh = sb_bread(sb, 0);
1527 if (bh == NULL) {
1528 fat_msg(sb, KERN_ERR, "unable to read boot sector");
1529 goto out_fail;
1530 }
1531
1532 error = fat_read_bpb(sb, (struct fat_boot_sector *)bh->b_data, silent,
1533 &bpb);
1534 if (error == -EINVAL && sbi->options.dos1xfloppy)
1535 error = fat_read_static_bpb(sb,
1536 (struct fat_boot_sector *)bh->b_data, silent, &bpb);
1537 brelse(bh);
1538
1539 if (error == -EINVAL)
1540 goto out_invalid;
1541 else if (error)
1542 goto out_fail;
1543
1544 logical_sector_size = bpb.fat_sector_size;
1545 sbi->sec_per_clus = bpb.fat_sec_per_clus;
1546
1547 error = -EIO;
1548 if (logical_sector_size < sb->s_blocksize) {
1549 fat_msg(sb, KERN_ERR, "logical sector size too small for device"
1550 " (logical sector size = %u)", logical_sector_size);
1551 goto out_fail;
1552 }
1553
1554 if (logical_sector_size > sb->s_blocksize) {
1555 struct buffer_head *bh_resize;
1556
1557 if (!sb_set_blocksize(sb, logical_sector_size)) {
1558 fat_msg(sb, KERN_ERR, "unable to set blocksize %u",
1559 logical_sector_size);
1560 goto out_fail;
1561 }
1562
1563 /* Verify that the larger boot sector is fully readable */
1564 bh_resize = sb_bread(sb, 0);
1565 if (bh_resize == NULL) {
1566 fat_msg(sb, KERN_ERR, "unable to read boot sector"
1567 " (logical sector size = %lu)",
1568 sb->s_blocksize);
1569 goto out_fail;
1570 }
1571 brelse(bh_resize);
1572 }
1573
1574 mutex_init(&sbi->s_lock);
1575 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1576 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1577 sbi->fats = bpb.fat_fats;
1578 sbi->fat_bits = 0; /* Don't know yet */
1579 sbi->fat_start = bpb.fat_reserved;
1580 sbi->fat_length = bpb.fat_fat_length;
1581 sbi->root_cluster = 0;
1582 sbi->free_clusters = -1; /* Don't know yet */
1583 sbi->free_clus_valid = 0;
1584 sbi->prev_free = FAT_START_ENT;
1585 sb->s_maxbytes = 0xffffffff;
1586
1587 if (!sbi->fat_length && bpb.fat32_length) {
1588 struct fat_boot_fsinfo *fsinfo;
1589 struct buffer_head *fsinfo_bh;
1590
1591 /* Must be FAT32 */
1592 sbi->fat_bits = 32;
1593 sbi->fat_length = bpb.fat32_length;
1594 sbi->root_cluster = bpb.fat32_root_cluster;
1595
1596 /* MC - if info_sector is 0, don't multiply by 0 */
1597 sbi->fsinfo_sector = bpb.fat32_info_sector;
1598 if (sbi->fsinfo_sector == 0)
1599 sbi->fsinfo_sector = 1;
1600
1601 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1602 if (fsinfo_bh == NULL) {
1603 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block"
1604 " (sector = %lu)", sbi->fsinfo_sector);
1605 goto out_fail;
1606 }
1607
1608 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1609 if (!IS_FSINFO(fsinfo)) {
1610 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
1611 "0x%08x, 0x%08x (sector = %lu)",
1612 le32_to_cpu(fsinfo->signature1),
1613 le32_to_cpu(fsinfo->signature2),
1614 sbi->fsinfo_sector);
1615 } else {
1616 if (sbi->options.usefree)
1617 sbi->free_clus_valid = 1;
1618 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1619 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1620 }
1621
1622 brelse(fsinfo_bh);
1623 }
1624
1625 /* interpret volume ID as a little endian 32 bit integer */
1626 if (sbi->fat_bits == 32)
1627 sbi->vol_id = bpb.fat32_vol_id;
1628 else /* fat 16 or 12 */
1629 sbi->vol_id = bpb.fat16_vol_id;
1630
1631 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1632 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1633
1634 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1635 sbi->dir_entries = bpb.fat_dir_entries;
1636 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1637 if (!silent)
1638 fat_msg(sb, KERN_ERR, "bogus directory-entries per block"
1639 " (%u)", sbi->dir_entries);
1640 goto out_invalid;
1641 }
1642
1643 rootdir_sectors = sbi->dir_entries
1644 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1645 sbi->data_start = sbi->dir_start + rootdir_sectors;
1646 total_sectors = bpb.fat_sectors;
1647 if (total_sectors == 0)
1648 total_sectors = bpb.fat_total_sect;
1649
1650 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1651
1652 if (sbi->fat_bits != 32)
1653 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1654
1655 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */
1656 if (sbi->fat_bits == 32)
1657 sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY;
1658 else /* fat 16 or 12 */
1659 sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY;
1660
1661 /* check that FAT table does not overflow */
1662 fat_clusters = calc_fat_clusters(sb);
1663 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1664 if (total_clusters > MAX_FAT(sb)) {
1665 if (!silent)
1666 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)",
1667 total_clusters);
1668 goto out_invalid;
1669 }
1670
1671 sbi->max_cluster = total_clusters + FAT_START_ENT;
1672 /* check the free_clusters, it's not necessarily correct */
1673 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1674 sbi->free_clusters = -1;
1675 /* check the prev_free, it's not necessarily correct */
1676 sbi->prev_free %= sbi->max_cluster;
1677 if (sbi->prev_free < FAT_START_ENT)
1678 sbi->prev_free = FAT_START_ENT;
1679
1680 /* set up enough so that it can read an inode */
1681 fat_hash_init(sb);
1682 dir_hash_init(sb);
1683 fat_ent_access_init(sb);
1684
1685 /*
1686 * The low byte of FAT's first entry must have same value with
1687 * media-field. But in real world, too many devices is
1688 * writing wrong value. So, removed that validity check.
1689 *
1690 * if (FAT_FIRST_ENT(sb, media) != first)
1691 */
1692
1693 error = -EINVAL;
1694 sprintf(buf, "cp%d", sbi->options.codepage);
1695 sbi->nls_disk = load_nls(buf);
1696 if (!sbi->nls_disk) {
1697 fat_msg(sb, KERN_ERR, "codepage %s not found", buf);
1698 goto out_fail;
1699 }
1700
1701 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1702 if (sbi->options.isvfat) {
1703 sbi->nls_io = load_nls(sbi->options.iocharset);
1704 if (!sbi->nls_io) {
1705 fat_msg(sb, KERN_ERR, "IO charset %s not found",
1706 sbi->options.iocharset);
1707 goto out_fail;
1708 }
1709 }
1710
1711 error = -ENOMEM;
1712 fat_inode = new_inode(sb);
1713 if (!fat_inode)
1714 goto out_fail;
1715 MSDOS_I(fat_inode)->i_pos = 0;
1716 sbi->fat_inode = fat_inode;
1717
1718 fsinfo_inode = new_inode(sb);
1719 if (!fsinfo_inode)
1720 goto out_fail;
1721 fsinfo_inode->i_ino = MSDOS_FSINFO_INO;
1722 sbi->fsinfo_inode = fsinfo_inode;
1723 insert_inode_hash(fsinfo_inode);
1724
1725 root_inode = new_inode(sb);
1726 if (!root_inode)
1727 goto out_fail;
1728 root_inode->i_ino = MSDOS_ROOT_INO;
1729 root_inode->i_version = 1;
1730 error = fat_read_root(root_inode);
1731 if (error < 0) {
1732 iput(root_inode);
1733 goto out_fail;
1734 }
1735 error = -ENOMEM;
1736 insert_inode_hash(root_inode);
1737 fat_attach(root_inode, 0);
1738 sb->s_root = d_make_root(root_inode);
1739 if (!sb->s_root) {
1740 fat_msg(sb, KERN_ERR, "get root inode failed");
1741 goto out_fail;
1742 }
1743
1744 if (sbi->options.discard) {
1745 struct request_queue *q = bdev_get_queue(sb->s_bdev);
1746 if (!blk_queue_discard(q))
1747 fat_msg(sb, KERN_WARNING,
1748 "mounting with \"discard\" option, but "
1749 "the device does not support discard");
1750 }
1751
1752 fat_set_state(sb, 1, 0);
1753 return 0;
1754
1755 out_invalid:
1756 error = -EINVAL;
1757 if (!silent)
1758 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem");
1759
1760 out_fail:
1761 if (fsinfo_inode)
1762 iput(fsinfo_inode);
1763 if (fat_inode)
1764 iput(fat_inode);
1765 unload_nls(sbi->nls_io);
1766 unload_nls(sbi->nls_disk);
1767 if (sbi->options.iocharset != fat_default_iocharset)
1768 kfree(sbi->options.iocharset);
1769 sb->s_fs_info = NULL;
1770 kfree(sbi);
1771 return error;
1772 }
1773
1774 EXPORT_SYMBOL_GPL(fat_fill_super);
1775
1776 /*
1777 * helper function for fat_flush_inodes. This writes both the inode
1778 * and the file data blocks, waiting for in flight data blocks before
1779 * the start of the call. It does not wait for any io started
1780 * during the call
1781 */
1782 static int writeback_inode(struct inode *inode)
1783 {
1784
1785 int ret;
1786
1787 /* if we used wait=1, sync_inode_metadata waits for the io for the
1788 * inode to finish. So wait=0 is sent down to sync_inode_metadata
1789 * and filemap_fdatawrite is used for the data blocks
1790 */
1791 ret = sync_inode_metadata(inode, 0);
1792 if (!ret)
1793 ret = filemap_fdatawrite(inode->i_mapping);
1794 return ret;
1795 }
1796
1797 /*
1798 * write data and metadata corresponding to i1 and i2. The io is
1799 * started but we do not wait for any of it to finish.
1800 *
1801 * filemap_flush is used for the block device, so if there is a dirty
1802 * page for a block already in flight, we will not wait and start the
1803 * io over again
1804 */
1805 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1806 {
1807 int ret = 0;
1808 if (!MSDOS_SB(sb)->options.flush)
1809 return 0;
1810 if (i1)
1811 ret = writeback_inode(i1);
1812 if (!ret && i2)
1813 ret = writeback_inode(i2);
1814 if (!ret) {
1815 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1816 ret = filemap_flush(mapping);
1817 }
1818 return ret;
1819 }
1820 EXPORT_SYMBOL_GPL(fat_flush_inodes);
1821
1822 static int __init init_fat_fs(void)
1823 {
1824 int err;
1825
1826 err = fat_cache_init();
1827 if (err)
1828 return err;
1829
1830 err = fat_init_inodecache();
1831 if (err)
1832 goto failed;
1833
1834 return 0;
1835
1836 failed:
1837 fat_cache_destroy();
1838 return err;
1839 }
1840
1841 static void __exit exit_fat_fs(void)
1842 {
1843 fat_cache_destroy();
1844 fat_destroy_inodecache();
1845 }
1846
1847 module_init(init_fat_fs)
1848 module_exit(exit_fat_fs)
1849
1850 MODULE_LICENSE("GPL");
Linux with added FPC-III support