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Linux 3.12.28
[linux/fpc-iii.git] / fs / fat / inode.c
blob0062da21dd8b7995aa1764bfd943cde9d2e22364
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/init.h>
15 #include <linux/time.h>
16 #include <linux/slab.h>
17 #include <linux/seq_file.h>
18 #include <linux/pagemap.h>
19 #include <linux/mpage.h>
20 #include <linux/buffer_head.h>
21 #include <linux/mount.h>
22 #include <linux/aio.h>
23 #include <linux/vfs.h>
24 #include <linux/parser.h>
25 #include <linux/uio.h>
26 #include <linux/writeback.h>
27 #include <linux/log2.h>
28 #include <linux/hash.h>
29 #include <linux/blkdev.h>
30 #include <asm/unaligned.h>
31 #include "fat.h"
32
33 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET
34 /* if user don't select VFAT, this is undefined. */
35 #define CONFIG_FAT_DEFAULT_IOCHARSET ""
36 #endif
37
38 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
39 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
40
41
42 static int fat_add_cluster(struct inode *inode)
43 {
44 int err, cluster;
45
46 err = fat_alloc_clusters(inode, &cluster, 1);
47 if (err)
48 return err;
49 /* FIXME: this cluster should be added after data of this
50 * cluster is writed */
51 err = fat_chain_add(inode, cluster, 1);
52 if (err)
53 fat_free_clusters(inode, cluster);
54 return err;
55 }
56
57 static inline int __fat_get_block(struct inode *inode, sector_t iblock,
58 unsigned long *max_blocks,
59 struct buffer_head *bh_result, int create)
60 {
61 struct super_block *sb = inode->i_sb;
62 struct msdos_sb_info *sbi = MSDOS_SB(sb);
63 unsigned long mapped_blocks;
64 sector_t phys;
65 int err, offset;
66
67 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
68 if (err)
69 return err;
70 if (phys) {
71 map_bh(bh_result, sb, phys);
72 *max_blocks = min(mapped_blocks, *max_blocks);
73 return 0;
74 }
75 if (!create)
76 return 0;
77
78 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
79 fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)",
80 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
81 return -EIO;
82 }
83
84 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
85 if (!offset) {
86 /* TODO: multiple cluster allocation would be desirable. */
87 err = fat_add_cluster(inode);
88 if (err)
89 return err;
90 }
91 /* available blocks on this cluster */
92 mapped_blocks = sbi->sec_per_clus - offset;
93
94 *max_blocks = min(mapped_blocks, *max_blocks);
95 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
96
97 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
98 if (err)
99 return err;
100
101 BUG_ON(!phys);
102 BUG_ON(*max_blocks != mapped_blocks);
103 set_buffer_new(bh_result);
104 map_bh(bh_result, sb, phys);
105
106 return 0;
107 }
108
109 static int fat_get_block(struct inode *inode, sector_t iblock,
110 struct buffer_head *bh_result, int create)
111 {
112 struct super_block *sb = inode->i_sb;
113 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
114 int err;
115
116 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
117 if (err)
118 return err;
119 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
120 return 0;
121 }
122
123 static int fat_writepage(struct page *page, struct writeback_control *wbc)
124 {
125 return block_write_full_page(page, fat_get_block, wbc);
126 }
127
128 static int fat_writepages(struct address_space *mapping,
129 struct writeback_control *wbc)
130 {
131 return mpage_writepages(mapping, wbc, fat_get_block);
132 }
133
134 static int fat_readpage(struct file *file, struct page *page)
135 {
136 return mpage_readpage(page, fat_get_block);
137 }
138
139 static int fat_readpages(struct file *file, struct address_space *mapping,
140 struct list_head *pages, unsigned nr_pages)
141 {
142 return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
143 }
144
145 static void fat_write_failed(struct address_space *mapping, loff_t to)
146 {
147 struct inode *inode = mapping->host;
148
149 if (to > inode->i_size) {
150 truncate_pagecache(inode, inode->i_size);
151 fat_truncate_blocks(inode, inode->i_size);
152 }
153 }
154
155 static int fat_write_begin(struct file *file, struct address_space *mapping,
156 loff_t pos, unsigned len, unsigned flags,
157 struct page **pagep, void **fsdata)
158 {
159 int err;
160
161 *pagep = NULL;
162 err = cont_write_begin(file, mapping, pos, len, flags,
163 pagep, fsdata, fat_get_block,
164 &MSDOS_I(mapping->host)->mmu_private);
165 if (err < 0)
166 fat_write_failed(mapping, pos + len);
167 return err;
168 }
169
170 static int fat_write_end(struct file *file, struct address_space *mapping,
171 loff_t pos, unsigned len, unsigned copied,
172 struct page *pagep, void *fsdata)
173 {
174 struct inode *inode = mapping->host;
175 int err;
176 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
177 if (err < len)
178 fat_write_failed(mapping, pos + len);
179 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
180 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
181 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
182 mark_inode_dirty(inode);
183 }
184 return err;
185 }
186
187 static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
188 const struct iovec *iov,
189 loff_t offset, unsigned long nr_segs)
190 {
191 struct file *file = iocb->ki_filp;
192 struct address_space *mapping = file->f_mapping;
193 struct inode *inode = mapping->host;
194 ssize_t ret;
195
196 if (rw == WRITE) {
197 /*
198 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
199 * so we need to update the ->mmu_private to block boundary.
200 *
201 * But we must fill the remaining area or hole by nul for
202 * updating ->mmu_private.
203 *
204 * Return 0, and fallback to normal buffered write.
205 */
206 loff_t size = offset + iov_length(iov, nr_segs);
207 if (MSDOS_I(inode)->mmu_private < size)
208 return 0;
209 }
210
211 /*
212 * FAT need to use the DIO_LOCKING for avoiding the race
213 * condition of fat_get_block() and ->truncate().
214 */
215 ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
216 fat_get_block);
217 if (ret < 0 && (rw & WRITE))
218 fat_write_failed(mapping, offset + iov_length(iov, nr_segs));
219
220 return ret;
221 }
222
223 static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
224 {
225 sector_t blocknr;
226
227 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
228 down_read(&MSDOS_I(mapping->host)->truncate_lock);
229 blocknr = generic_block_bmap(mapping, block, fat_get_block);
230 up_read(&MSDOS_I(mapping->host)->truncate_lock);
231
232 return blocknr;
233 }
234
235 static const struct address_space_operations fat_aops = {
236 .readpage = fat_readpage,
237 .readpages = fat_readpages,
238 .writepage = fat_writepage,
239 .writepages = fat_writepages,
240 .write_begin = fat_write_begin,
241 .write_end = fat_write_end,
242 .direct_IO = fat_direct_IO,
243 .bmap = _fat_bmap
244 };
245
246 /*
247 * New FAT inode stuff. We do the following:
248 * a) i_ino is constant and has nothing with on-disk location.
249 * b) FAT manages its own cache of directory entries.
250 * c) *This* cache is indexed by on-disk location.
251 * d) inode has an associated directory entry, all right, but
252 * it may be unhashed.
253 * e) currently entries are stored within struct inode. That should
254 * change.
255 * f) we deal with races in the following way:
256 * 1. readdir() and lookup() do FAT-dir-cache lookup.
257 * 2. rename() unhashes the F-d-c entry and rehashes it in
258 * a new place.
259 * 3. unlink() and rmdir() unhash F-d-c entry.
260 * 4. fat_write_inode() checks whether the thing is unhashed.
261 * If it is we silently return. If it isn't we do bread(),
262 * check if the location is still valid and retry if it
263 * isn't. Otherwise we do changes.
264 * 5. Spinlock is used to protect hash/unhash/location check/lookup
265 * 6. fat_evict_inode() unhashes the F-d-c entry.
266 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
267 * and consider negative result as cache miss.
268 */
269
270 static void fat_hash_init(struct super_block *sb)
271 {
272 struct msdos_sb_info *sbi = MSDOS_SB(sb);
273 int i;
274
275 spin_lock_init(&sbi->inode_hash_lock);
276 for (i = 0; i < FAT_HASH_SIZE; i++)
277 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
278 }
279
280 static inline unsigned long fat_hash(loff_t i_pos)
281 {
282 return hash_32(i_pos, FAT_HASH_BITS);
283 }
284
285 static void dir_hash_init(struct super_block *sb)
286 {
287 struct msdos_sb_info *sbi = MSDOS_SB(sb);
288 int i;
289
290 spin_lock_init(&sbi->dir_hash_lock);
291 for (i = 0; i < FAT_HASH_SIZE; i++)
292 INIT_HLIST_HEAD(&sbi->dir_hashtable[i]);
293 }
294
295 void fat_attach(struct inode *inode, loff_t i_pos)
296 {
297 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
298
299 if (inode->i_ino != MSDOS_ROOT_INO) {
300 struct hlist_head *head = sbi->inode_hashtable
301 + fat_hash(i_pos);
302
303 spin_lock(&sbi->inode_hash_lock);
304 MSDOS_I(inode)->i_pos = i_pos;
305 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
306 spin_unlock(&sbi->inode_hash_lock);
307 }
308
309 /* If NFS support is enabled, cache the mapping of start cluster
310 * to directory inode. This is used during reconnection of
311 * dentries to the filesystem root.
312 */
313 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
314 struct hlist_head *d_head = sbi->dir_hashtable;
315 d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart);
316
317 spin_lock(&sbi->dir_hash_lock);
318 hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head);
319 spin_unlock(&sbi->dir_hash_lock);
320 }
321 }
322 EXPORT_SYMBOL_GPL(fat_attach);
323
324 void fat_detach(struct inode *inode)
325 {
326 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
327 spin_lock(&sbi->inode_hash_lock);
328 MSDOS_I(inode)->i_pos = 0;
329 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
330 spin_unlock(&sbi->inode_hash_lock);
331
332 if (S_ISDIR(inode->i_mode) && sbi->options.nfs) {
333 spin_lock(&sbi->dir_hash_lock);
334 hlist_del_init(&MSDOS_I(inode)->i_dir_hash);
335 spin_unlock(&sbi->dir_hash_lock);
336 }
337 }
338 EXPORT_SYMBOL_GPL(fat_detach);
339
340 struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
341 {
342 struct msdos_sb_info *sbi = MSDOS_SB(sb);
343 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
344 struct msdos_inode_info *i;
345 struct inode *inode = NULL;
346
347 spin_lock(&sbi->inode_hash_lock);
348 hlist_for_each_entry(i, head, i_fat_hash) {
349 BUG_ON(i->vfs_inode.i_sb != sb);
350 if (i->i_pos != i_pos)
351 continue;
352 inode = igrab(&i->vfs_inode);
353 if (inode)
354 break;
355 }
356 spin_unlock(&sbi->inode_hash_lock);
357 return inode;
358 }
359
360 static int is_exec(unsigned char *extension)
361 {
362 unsigned char *exe_extensions = "EXECOMBAT", *walk;
363
364 for (walk = exe_extensions; *walk; walk += 3)
365 if (!strncmp(extension, walk, 3))
366 return 1;
367 return 0;
368 }
369
370 static int fat_calc_dir_size(struct inode *inode)
371 {
372 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
373 int ret, fclus, dclus;
374
375 inode->i_size = 0;
376 if (MSDOS_I(inode)->i_start == 0)
377 return 0;
378
379 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
380 if (ret < 0)
381 return ret;
382 inode->i_size = (fclus + 1) << sbi->cluster_bits;
383
384 return 0;
385 }
386
387 /* doesn't deal with root inode */
388 int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
389 {
390 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
391 int error;
392
393 MSDOS_I(inode)->i_pos = 0;
394 inode->i_uid = sbi->options.fs_uid;
395 inode->i_gid = sbi->options.fs_gid;
396 inode->i_version++;
397 inode->i_generation = get_seconds();
398
399 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
400 inode->i_generation &= ~1;
401 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
402 inode->i_op = sbi->dir_ops;
403 inode->i_fop = &fat_dir_operations;
404
405 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
406 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
407 error = fat_calc_dir_size(inode);
408 if (error < 0)
409 return error;
410 MSDOS_I(inode)->mmu_private = inode->i_size;
411
412 set_nlink(inode, fat_subdirs(inode));
413 } else { /* not a directory */
414 inode->i_generation |= 1;
415 inode->i_mode = fat_make_mode(sbi, de->attr,
416 ((sbi->options.showexec && !is_exec(de->name + 8))
417 ? S_IRUGO|S_IWUGO : S_IRWXUGO));
418 MSDOS_I(inode)->i_start = fat_get_start(sbi, de);
419
420 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
421 inode->i_size = le32_to_cpu(de->size);
422 inode->i_op = &fat_file_inode_operations;
423 inode->i_fop = &fat_file_operations;
424 inode->i_mapping->a_ops = &fat_aops;
425 MSDOS_I(inode)->mmu_private = inode->i_size;
426 }
427 if (de->attr & ATTR_SYS) {
428 if (sbi->options.sys_immutable)
429 inode->i_flags |= S_IMMUTABLE;
430 }
431 fat_save_attrs(inode, de->attr);
432
433 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
434 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
435
436 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
437 if (sbi->options.isvfat) {
438 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
439 de->cdate, de->ctime_cs);
440 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
441 } else
442 inode->i_ctime = inode->i_atime = inode->i_mtime;
443
444 return 0;
445 }
446
447 static inline void fat_lock_build_inode(struct msdos_sb_info *sbi)
448 {
449 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
450 mutex_lock(&sbi->nfs_build_inode_lock);
451 }
452
453 static inline void fat_unlock_build_inode(struct msdos_sb_info *sbi)
454 {
455 if (sbi->options.nfs == FAT_NFS_NOSTALE_RO)
456 mutex_unlock(&sbi->nfs_build_inode_lock);
457 }
458
459 struct inode *fat_build_inode(struct super_block *sb,
460 struct msdos_dir_entry *de, loff_t i_pos)
461 {
462 struct inode *inode;
463 int err;
464
465 fat_lock_build_inode(MSDOS_SB(sb));
466 inode = fat_iget(sb, i_pos);
467 if (inode)
468 goto out;
469 inode = new_inode(sb);
470 if (!inode) {
471 inode = ERR_PTR(-ENOMEM);
472 goto out;
473 }
474 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
475 inode->i_version = 1;
476 err = fat_fill_inode(inode, de);
477 if (err) {
478 iput(inode);
479 inode = ERR_PTR(err);
480 goto out;
481 }
482 fat_attach(inode, i_pos);
483 insert_inode_hash(inode);
484 out:
485 fat_unlock_build_inode(MSDOS_SB(sb));
486 return inode;
487 }
488
489 EXPORT_SYMBOL_GPL(fat_build_inode);
490
491 static void fat_evict_inode(struct inode *inode)
492 {
493 truncate_inode_pages(&inode->i_data, 0);
494 if (!inode->i_nlink) {
495 inode->i_size = 0;
496 fat_truncate_blocks(inode, 0);
497 }
498 invalidate_inode_buffers(inode);
499 clear_inode(inode);
500 fat_cache_inval_inode(inode);
501 fat_detach(inode);
502 }
503
504 static void fat_set_state(struct super_block *sb,
505 unsigned int set, unsigned int force)
506 {
507 struct buffer_head *bh;
508 struct fat_boot_sector *b;
509 struct msdos_sb_info *sbi = sb->s_fs_info;
510
511 /* do not change any thing if mounted read only */
512 if ((sb->s_flags & MS_RDONLY) && !force)
513 return;
514
515 /* do not change state if fs was dirty */
516 if (sbi->dirty) {
517 /* warn only on set (mount). */
518 if (set)
519 fat_msg(sb, KERN_WARNING, "Volume was not properly "
520 "unmounted. Some data may be corrupt. "
521 "Please run fsck.");
522 return;
523 }
524
525 bh = sb_bread(sb, 0);
526 if (bh == NULL) {
527 fat_msg(sb, KERN_ERR, "unable to read boot sector "
528 "to mark fs as dirty");
529 return;
530 }
531
532 b = (struct fat_boot_sector *) bh->b_data;
533
534 if (sbi->fat_bits == 32) {
535 if (set)
536 b->fat32.state |= FAT_STATE_DIRTY;
537 else
538 b->fat32.state &= ~FAT_STATE_DIRTY;
539 } else /* fat 16 and 12 */ {
540 if (set)
541 b->fat16.state |= FAT_STATE_DIRTY;
542 else
543 b->fat16.state &= ~FAT_STATE_DIRTY;
544 }
545
546 mark_buffer_dirty(bh);
547 sync_dirty_buffer(bh);
548 brelse(bh);
549 }
550
551 static void fat_put_super(struct super_block *sb)
552 {
553 struct msdos_sb_info *sbi = MSDOS_SB(sb);
554
555 fat_set_state(sb, 0, 0);
556
557 iput(sbi->fsinfo_inode);
558 iput(sbi->fat_inode);
559
560 unload_nls(sbi->nls_disk);
561 unload_nls(sbi->nls_io);
562
563 if (sbi->options.iocharset != fat_default_iocharset)
564 kfree(sbi->options.iocharset);
565
566 sb->s_fs_info = NULL;
567 kfree(sbi);
568 }
569
570 static struct kmem_cache *fat_inode_cachep;
571
572 static struct inode *fat_alloc_inode(struct super_block *sb)
573 {
574 struct msdos_inode_info *ei;
575 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
576 if (!ei)
577 return NULL;
578
579 init_rwsem(&ei->truncate_lock);
580 return &ei->vfs_inode;
581 }
582
583 static void fat_i_callback(struct rcu_head *head)
584 {
585 struct inode *inode = container_of(head, struct inode, i_rcu);
586 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
587 }
588
589 static void fat_destroy_inode(struct inode *inode)
590 {
591 call_rcu(&inode->i_rcu, fat_i_callback);
592 }
593
594 static void init_once(void *foo)
595 {
596 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
597
598 spin_lock_init(&ei->cache_lru_lock);
599 ei->nr_caches = 0;
600 ei->cache_valid_id = FAT_CACHE_VALID + 1;
601 INIT_LIST_HEAD(&ei->cache_lru);
602 INIT_HLIST_NODE(&ei->i_fat_hash);
603 INIT_HLIST_NODE(&ei->i_dir_hash);
604 inode_init_once(&ei->vfs_inode);
605 }
606
607 static int __init fat_init_inodecache(void)
608 {
609 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
610 sizeof(struct msdos_inode_info),
611 0, (SLAB_RECLAIM_ACCOUNT|
612 SLAB_MEM_SPREAD),
613 init_once);
614 if (fat_inode_cachep == NULL)
615 return -ENOMEM;
616 return 0;
617 }
618
619 static void __exit fat_destroy_inodecache(void)
620 {
621 /*
622 * Make sure all delayed rcu free inodes are flushed before we
623 * destroy cache.
624 */
625 rcu_barrier();
626 kmem_cache_destroy(fat_inode_cachep);
627 }
628
629 static int fat_remount(struct super_block *sb, int *flags, char *data)
630 {
631 int new_rdonly;
632 struct msdos_sb_info *sbi = MSDOS_SB(sb);
633 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
634
635 /* make sure we update state on remount. */
636 new_rdonly = *flags & MS_RDONLY;
637 if (new_rdonly != (sb->s_flags & MS_RDONLY)) {
638 if (new_rdonly)
639 fat_set_state(sb, 0, 0);
640 else
641 fat_set_state(sb, 1, 1);
642 }
643 return 0;
644 }
645
646 static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
647 {
648 struct super_block *sb = dentry->d_sb;
649 struct msdos_sb_info *sbi = MSDOS_SB(sb);
650 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
651
652 /* If the count of free cluster is still unknown, counts it here. */
653 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
654 int err = fat_count_free_clusters(dentry->d_sb);
655 if (err)
656 return err;
657 }
658
659 buf->f_type = dentry->d_sb->s_magic;
660 buf->f_bsize = sbi->cluster_size;
661 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
662 buf->f_bfree = sbi->free_clusters;
663 buf->f_bavail = sbi->free_clusters;
664 buf->f_fsid.val[0] = (u32)id;
665 buf->f_fsid.val[1] = (u32)(id >> 32);
666 buf->f_namelen =
667 (sbi->options.isvfat ? FAT_LFN_LEN : 12) * NLS_MAX_CHARSET_SIZE;
668
669 return 0;
670 }
671
672 static int __fat_write_inode(struct inode *inode, int wait)
673 {
674 struct super_block *sb = inode->i_sb;
675 struct msdos_sb_info *sbi = MSDOS_SB(sb);
676 struct buffer_head *bh;
677 struct msdos_dir_entry *raw_entry;
678 loff_t i_pos;
679 sector_t blocknr;
680 int err, offset;
681
682 if (inode->i_ino == MSDOS_ROOT_INO)
683 return 0;
684
685 retry:
686 i_pos = fat_i_pos_read(sbi, inode);
687 if (!i_pos)
688 return 0;
689
690 fat_get_blknr_offset(sbi, i_pos, &blocknr, &offset);
691 bh = sb_bread(sb, blocknr);
692 if (!bh) {
693 fat_msg(sb, KERN_ERR, "unable to read inode block "
694 "for updating (i_pos %lld)", i_pos);
695 return -EIO;
696 }
697 spin_lock(&sbi->inode_hash_lock);
698 if (i_pos != MSDOS_I(inode)->i_pos) {
699 spin_unlock(&sbi->inode_hash_lock);
700 brelse(bh);
701 goto retry;
702 }
703
704 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))[offset];
705 if (S_ISDIR(inode->i_mode))
706 raw_entry->size = 0;
707 else
708 raw_entry->size = cpu_to_le32(inode->i_size);
709 raw_entry->attr = fat_make_attrs(inode);
710 fat_set_start(raw_entry, MSDOS_I(inode)->i_logstart);
711 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
712 &raw_entry->date, NULL);
713 if (sbi->options.isvfat) {
714 __le16 atime;
715 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
716 &raw_entry->cdate, &raw_entry->ctime_cs);
717 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
718 &raw_entry->adate, NULL);
719 }
720 spin_unlock(&sbi->inode_hash_lock);
721 mark_buffer_dirty(bh);
722 err = 0;
723 if (wait)
724 err = sync_dirty_buffer(bh);
725 brelse(bh);
726 return err;
727 }
728
729 static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
730 {
731 int err;
732
733 if (inode->i_ino == MSDOS_FSINFO_INO) {
734 struct super_block *sb = inode->i_sb;
735
736 mutex_lock(&MSDOS_SB(sb)->s_lock);
737 err = fat_clusters_flush(sb);
738 mutex_unlock(&MSDOS_SB(sb)->s_lock);
739 } else
740 err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
741
742 return err;
743 }
744
745 int fat_sync_inode(struct inode *inode)
746 {
747 return __fat_write_inode(inode, 1);
748 }
749
750 EXPORT_SYMBOL_GPL(fat_sync_inode);
751
752 static int fat_show_options(struct seq_file *m, struct dentry *root);
753 static const struct super_operations fat_sops = {
754 .alloc_inode = fat_alloc_inode,
755 .destroy_inode = fat_destroy_inode,
756 .write_inode = fat_write_inode,
757 .evict_inode = fat_evict_inode,
758 .put_super = fat_put_super,
759 .statfs = fat_statfs,
760 .remount_fs = fat_remount,
761
762 .show_options = fat_show_options,
763 };
764
765 static int fat_show_options(struct seq_file *m, struct dentry *root)
766 {
767 struct msdos_sb_info *sbi = MSDOS_SB(root->d_sb);
768 struct fat_mount_options *opts = &sbi->options;
769 int isvfat = opts->isvfat;
770
771 if (!uid_eq(opts->fs_uid, GLOBAL_ROOT_UID))
772 seq_printf(m, ",uid=%u",
773 from_kuid_munged(&init_user_ns, opts->fs_uid));
774 if (!gid_eq(opts->fs_gid, GLOBAL_ROOT_GID))
775 seq_printf(m, ",gid=%u",
776 from_kgid_munged(&init_user_ns, opts->fs_gid));
777 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
778 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
779 if (opts->allow_utime)
780 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
781 if (sbi->nls_disk)
782 /* strip "cp" prefix from displayed option */
783 seq_printf(m, ",codepage=%s", &sbi->nls_disk->charset[2]);
784 if (isvfat) {
785 if (sbi->nls_io)
786 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
787
788 switch (opts->shortname) {
789 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
790 seq_puts(m, ",shortname=win95");
791 break;
792 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
793 seq_puts(m, ",shortname=winnt");
794 break;
795 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
796 seq_puts(m, ",shortname=mixed");
797 break;
798 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
799 seq_puts(m, ",shortname=lower");
800 break;
801 default:
802 seq_puts(m, ",shortname=unknown");
803 break;
804 }
805 }
806 if (opts->name_check != 'n')
807 seq_printf(m, ",check=%c", opts->name_check);
808 if (opts->usefree)
809 seq_puts(m, ",usefree");
810 if (opts->quiet)
811 seq_puts(m, ",quiet");
812 if (opts->showexec)
813 seq_puts(m, ",showexec");
814 if (opts->sys_immutable)
815 seq_puts(m, ",sys_immutable");
816 if (!isvfat) {
817 if (opts->dotsOK)
818 seq_puts(m, ",dotsOK=yes");
819 if (opts->nocase)
820 seq_puts(m, ",nocase");
821 } else {
822 if (opts->utf8)
823 seq_puts(m, ",utf8");
824 if (opts->unicode_xlate)
825 seq_puts(m, ",uni_xlate");
826 if (!opts->numtail)
827 seq_puts(m, ",nonumtail");
828 if (opts->rodir)
829 seq_puts(m, ",rodir");
830 }
831 if (opts->flush)
832 seq_puts(m, ",flush");
833 if (opts->tz_set) {
834 if (opts->time_offset)
835 seq_printf(m, ",time_offset=%d", opts->time_offset);
836 else
837 seq_puts(m, ",tz=UTC");
838 }
839 if (opts->errors == FAT_ERRORS_CONT)
840 seq_puts(m, ",errors=continue");
841 else if (opts->errors == FAT_ERRORS_PANIC)
842 seq_puts(m, ",errors=panic");
843 else
844 seq_puts(m, ",errors=remount-ro");
845 if (opts->nfs == FAT_NFS_NOSTALE_RO)
846 seq_puts(m, ",nfs=nostale_ro");
847 else if (opts->nfs)
848 seq_puts(m, ",nfs=stale_rw");
849 if (opts->discard)
850 seq_puts(m, ",discard");
851
852 return 0;
853 }
854
855 enum {
856 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
857 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
858 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
859 Opt_immutable, Opt_dots, Opt_nodots,
860 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
861 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
862 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
863 Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
864 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_time_offset,
865 Opt_nfs_stale_rw, Opt_nfs_nostale_ro, Opt_err,
866 };
867
868 static const match_table_t fat_tokens = {
869 {Opt_check_r, "check=relaxed"},
870 {Opt_check_s, "check=strict"},
871 {Opt_check_n, "check=normal"},
872 {Opt_check_r, "check=r"},
873 {Opt_check_s, "check=s"},
874 {Opt_check_n, "check=n"},
875 {Opt_uid, "uid=%u"},
876 {Opt_gid, "gid=%u"},
877 {Opt_umask, "umask=%o"},
878 {Opt_dmask, "dmask=%o"},
879 {Opt_fmask, "fmask=%o"},
880 {Opt_allow_utime, "allow_utime=%o"},
881 {Opt_codepage, "codepage=%u"},
882 {Opt_usefree, "usefree"},
883 {Opt_nocase, "nocase"},
884 {Opt_quiet, "quiet"},
885 {Opt_showexec, "showexec"},
886 {Opt_debug, "debug"},
887 {Opt_immutable, "sys_immutable"},
888 {Opt_flush, "flush"},
889 {Opt_tz_utc, "tz=UTC"},
890 {Opt_time_offset, "time_offset=%d"},
891 {Opt_err_cont, "errors=continue"},
892 {Opt_err_panic, "errors=panic"},
893 {Opt_err_ro, "errors=remount-ro"},
894 {Opt_discard, "discard"},
895 {Opt_nfs_stale_rw, "nfs"},
896 {Opt_nfs_stale_rw, "nfs=stale_rw"},
897 {Opt_nfs_nostale_ro, "nfs=nostale_ro"},
898 {Opt_obsolete, "conv=binary"},
899 {Opt_obsolete, "conv=text"},
900 {Opt_obsolete, "conv=auto"},
901 {Opt_obsolete, "conv=b"},
902 {Opt_obsolete, "conv=t"},
903 {Opt_obsolete, "conv=a"},
904 {Opt_obsolete, "fat=%u"},
905 {Opt_obsolete, "blocksize=%u"},
906 {Opt_obsolete, "cvf_format=%20s"},
907 {Opt_obsolete, "cvf_options=%100s"},
908 {Opt_obsolete, "posix"},
909 {Opt_err, NULL},
910 };
911 static const match_table_t msdos_tokens = {
912 {Opt_nodots, "nodots"},
913 {Opt_nodots, "dotsOK=no"},
914 {Opt_dots, "dots"},
915 {Opt_dots, "dotsOK=yes"},
916 {Opt_err, NULL}
917 };
918 static const match_table_t vfat_tokens = {
919 {Opt_charset, "iocharset=%s"},
920 {Opt_shortname_lower, "shortname=lower"},
921 {Opt_shortname_win95, "shortname=win95"},
922 {Opt_shortname_winnt, "shortname=winnt"},
923 {Opt_shortname_mixed, "shortname=mixed"},
924 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
925 {Opt_utf8_no, "utf8=no"},
926 {Opt_utf8_no, "utf8=false"},
927 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
928 {Opt_utf8_yes, "utf8=yes"},
929 {Opt_utf8_yes, "utf8=true"},
930 {Opt_utf8_yes, "utf8"},
931 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
932 {Opt_uni_xl_no, "uni_xlate=no"},
933 {Opt_uni_xl_no, "uni_xlate=false"},
934 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
935 {Opt_uni_xl_yes, "uni_xlate=yes"},
936 {Opt_uni_xl_yes, "uni_xlate=true"},
937 {Opt_uni_xl_yes, "uni_xlate"},
938 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
939 {Opt_nonumtail_no, "nonumtail=no"},
940 {Opt_nonumtail_no, "nonumtail=false"},
941 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
942 {Opt_nonumtail_yes, "nonumtail=yes"},
943 {Opt_nonumtail_yes, "nonumtail=true"},
944 {Opt_nonumtail_yes, "nonumtail"},
945 {Opt_rodir, "rodir"},
946 {Opt_err, NULL}
947 };
948
949 static int parse_options(struct super_block *sb, char *options, int is_vfat,
950 int silent, int *debug, struct fat_mount_options *opts)
951 {
952 char *p;
953 substring_t args[MAX_OPT_ARGS];
954 int option;
955 char *iocharset;
956
957 opts->isvfat = is_vfat;
958
959 opts->fs_uid = current_uid();
960 opts->fs_gid = current_gid();
961 opts->fs_fmask = opts->fs_dmask = current_umask();
962 opts->allow_utime = -1;
963 opts->codepage = fat_default_codepage;
964 opts->iocharset = fat_default_iocharset;
965 if (is_vfat) {
966 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
967 opts->rodir = 0;
968 } else {
969 opts->shortname = 0;
970 opts->rodir = 1;
971 }
972 opts->name_check = 'n';
973 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
974 opts->utf8 = opts->unicode_xlate = 0;
975 opts->numtail = 1;
976 opts->usefree = opts->nocase = 0;
977 opts->tz_set = 0;
978 opts->nfs = 0;
979 opts->errors = FAT_ERRORS_RO;
980 *debug = 0;
981
982 if (!options)
983 goto out;
984
985 while ((p = strsep(&options, ",")) != NULL) {
986 int token;
987 if (!*p)
988 continue;
989
990 token = match_token(p, fat_tokens, args);
991 if (token == Opt_err) {
992 if (is_vfat)
993 token = match_token(p, vfat_tokens, args);
994 else
995 token = match_token(p, msdos_tokens, args);
996 }
997 switch (token) {
998 case Opt_check_s:
999 opts->name_check = 's';
1000 break;
1001 case Opt_check_r:
1002 opts->name_check = 'r';
1003 break;
1004 case Opt_check_n:
1005 opts->name_check = 'n';
1006 break;
1007 case Opt_usefree:
1008 opts->usefree = 1;
1009 break;
1010 case Opt_nocase:
1011 if (!is_vfat)
1012 opts->nocase = 1;
1013 else {
1014 /* for backward compatibility */
1015 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1016 | VFAT_SFN_CREATE_WIN95;
1017 }
1018 break;
1019 case Opt_quiet:
1020 opts->quiet = 1;
1021 break;
1022 case Opt_showexec:
1023 opts->showexec = 1;
1024 break;
1025 case Opt_debug:
1026 *debug = 1;
1027 break;
1028 case Opt_immutable:
1029 opts->sys_immutable = 1;
1030 break;
1031 case Opt_uid:
1032 if (match_int(&args[0], &option))
1033 return -EINVAL;
1034 opts->fs_uid = make_kuid(current_user_ns(), option);
1035 if (!uid_valid(opts->fs_uid))
1036 return -EINVAL;
1037 break;
1038 case Opt_gid:
1039 if (match_int(&args[0], &option))
1040 return -EINVAL;
1041 opts->fs_gid = make_kgid(current_user_ns(), option);
1042 if (!gid_valid(opts->fs_gid))
1043 return -EINVAL;
1044 break;
1045 case Opt_umask:
1046 if (match_octal(&args[0], &option))
1047 return -EINVAL;
1048 opts->fs_fmask = opts->fs_dmask = option;
1049 break;
1050 case Opt_dmask:
1051 if (match_octal(&args[0], &option))
1052 return -EINVAL;
1053 opts->fs_dmask = option;
1054 break;
1055 case Opt_fmask:
1056 if (match_octal(&args[0], &option))
1057 return -EINVAL;
1058 opts->fs_fmask = option;
1059 break;
1060 case Opt_allow_utime:
1061 if (match_octal(&args[0], &option))
1062 return -EINVAL;
1063 opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1064 break;
1065 case Opt_codepage:
1066 if (match_int(&args[0], &option))
1067 return -EINVAL;
1068 opts->codepage = option;
1069 break;
1070 case Opt_flush:
1071 opts->flush = 1;
1072 break;
1073 case Opt_time_offset:
1074 if (match_int(&args[0], &option))
1075 return -EINVAL;
1076 if (option < -12 * 60 || option > 12 * 60)
1077 return -EINVAL;
1078 opts->tz_set = 1;
1079 opts->time_offset = option;
1080 break;
1081 case Opt_tz_utc:
1082 opts->tz_set = 1;
1083 opts->time_offset = 0;
1084 break;
1085 case Opt_err_cont:
1086 opts->errors = FAT_ERRORS_CONT;
1087 break;
1088 case Opt_err_panic:
1089 opts->errors = FAT_ERRORS_PANIC;
1090 break;
1091 case Opt_err_ro:
1092 opts->errors = FAT_ERRORS_RO;
1093 break;
1094 case Opt_nfs_stale_rw:
1095 opts->nfs = FAT_NFS_STALE_RW;
1096 break;
1097 case Opt_nfs_nostale_ro:
1098 opts->nfs = FAT_NFS_NOSTALE_RO;
1099 break;
1100
1101 /* msdos specific */
1102 case Opt_dots:
1103 opts->dotsOK = 1;
1104 break;
1105 case Opt_nodots:
1106 opts->dotsOK = 0;
1107 break;
1108
1109 /* vfat specific */
1110 case Opt_charset:
1111 if (opts->iocharset != fat_default_iocharset)
1112 kfree(opts->iocharset);
1113 iocharset = match_strdup(&args[0]);
1114 if (!iocharset)
1115 return -ENOMEM;
1116 opts->iocharset = iocharset;
1117 break;
1118 case Opt_shortname_lower:
1119 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1120 | VFAT_SFN_CREATE_WIN95;
1121 break;
1122 case Opt_shortname_win95:
1123 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1124 | VFAT_SFN_CREATE_WIN95;
1125 break;
1126 case Opt_shortname_winnt:
1127 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1128 | VFAT_SFN_CREATE_WINNT;
1129 break;
1130 case Opt_shortname_mixed:
1131 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1132 | VFAT_SFN_CREATE_WIN95;
1133 break;
1134 case Opt_utf8_no: /* 0 or no or false */
1135 opts->utf8 = 0;
1136 break;
1137 case Opt_utf8_yes: /* empty or 1 or yes or true */
1138 opts->utf8 = 1;
1139 break;
1140 case Opt_uni_xl_no: /* 0 or no or false */
1141 opts->unicode_xlate = 0;
1142 break;
1143 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
1144 opts->unicode_xlate = 1;
1145 break;
1146 case Opt_nonumtail_no: /* 0 or no or false */
1147 opts->numtail = 1; /* negated option */
1148 break;
1149 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
1150 opts->numtail = 0; /* negated option */
1151 break;
1152 case Opt_rodir:
1153 opts->rodir = 1;
1154 break;
1155 case Opt_discard:
1156 opts->discard = 1;
1157 break;
1158
1159 /* obsolete mount options */
1160 case Opt_obsolete:
1161 fat_msg(sb, KERN_INFO, "\"%s\" option is obsolete, "
1162 "not supported now", p);
1163 break;
1164 /* unknown option */
1165 default:
1166 if (!silent) {
1167 fat_msg(sb, KERN_ERR,
1168 "Unrecognized mount option \"%s\" "
1169 "or missing value", p);
1170 }
1171 return -EINVAL;
1172 }
1173 }
1174
1175 out:
1176 /* UTF-8 doesn't provide FAT semantics */
1177 if (!strcmp(opts->iocharset, "utf8")) {
1178 fat_msg(sb, KERN_WARNING, "utf8 is not a recommended IO charset"
1179 " for FAT filesystems, filesystem will be "
1180 "case sensitive!");
1181 }
1182
1183 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1184 if (opts->allow_utime == (unsigned short)-1)
1185 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
1186 if (opts->unicode_xlate)
1187 opts->utf8 = 0;
1188 if (opts->nfs == FAT_NFS_NOSTALE_RO) {
1189 sb->s_flags |= MS_RDONLY;
1190 sb->s_export_op = &fat_export_ops_nostale;
1191 }
1192
1193 return 0;
1194 }
1195
1196 static int fat_read_root(struct inode *inode)
1197 {
1198 struct super_block *sb = inode->i_sb;
1199 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1200 int error;
1201
1202 MSDOS_I(inode)->i_pos = MSDOS_ROOT_INO;
1203 inode->i_uid = sbi->options.fs_uid;
1204 inode->i_gid = sbi->options.fs_gid;
1205 inode->i_version++;
1206 inode->i_generation = 0;
1207 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
1208 inode->i_op = sbi->dir_ops;
1209 inode->i_fop = &fat_dir_operations;
1210 if (sbi->fat_bits == 32) {
1211 MSDOS_I(inode)->i_start = sbi->root_cluster;
1212 error = fat_calc_dir_size(inode);
1213 if (error < 0)
1214 return error;
1215 } else {
1216 MSDOS_I(inode)->i_start = 0;
1217 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1218 }
1219 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1220 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1221 MSDOS_I(inode)->i_logstart = 0;
1222 MSDOS_I(inode)->mmu_private = inode->i_size;
1223
1224 fat_save_attrs(inode, ATTR_DIR);
1225 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1226 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1227 set_nlink(inode, fat_subdirs(inode)+2);
1228
1229 return 0;
1230 }
1231
1232 static unsigned long calc_fat_clusters(struct super_block *sb)
1233 {
1234 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1235
1236 /* Divide first to avoid overflow */
1237 if (sbi->fat_bits != 12) {
1238 unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits;
1239 return ent_per_sec * sbi->fat_length;
1240 }
1241
1242 return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1243 }
1244
1245 /*
1246 * Read the super block of an MS-DOS FS.
1247 */
1248 int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat,
1249 void (*setup)(struct super_block *))
1250 {
1251 struct inode *root_inode = NULL, *fat_inode = NULL;
1252 struct inode *fsinfo_inode = NULL;
1253 struct buffer_head *bh;
1254 struct fat_boot_sector *b;
1255 struct msdos_sb_info *sbi;
1256 u16 logical_sector_size;
1257 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1258 int debug;
1259 unsigned int media;
1260 long error;
1261 char buf[50];
1262
1263 /*
1264 * GFP_KERNEL is ok here, because while we do hold the
1265 * supeblock lock, memory pressure can't call back into
1266 * the filesystem, since we're only just about to mount
1267 * it and have no inodes etc active!
1268 */
1269 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1270 if (!sbi)
1271 return -ENOMEM;
1272 sb->s_fs_info = sbi;
1273
1274 sb->s_flags |= MS_NODIRATIME;
1275 sb->s_magic = MSDOS_SUPER_MAGIC;
1276 sb->s_op = &fat_sops;
1277 sb->s_export_op = &fat_export_ops;
1278 mutex_init(&sbi->nfs_build_inode_lock);
1279 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
1280 DEFAULT_RATELIMIT_BURST);
1281
1282 error = parse_options(sb, data, isvfat, silent, &debug, &sbi->options);
1283 if (error)
1284 goto out_fail;
1285
1286 setup(sb); /* flavour-specific stuff that needs options */
1287
1288 error = -EIO;
1289 sb_min_blocksize(sb, 512);
1290 bh = sb_bread(sb, 0);
1291 if (bh == NULL) {
1292 fat_msg(sb, KERN_ERR, "unable to read boot sector");
1293 goto out_fail;
1294 }
1295
1296 b = (struct fat_boot_sector *) bh->b_data;
1297 if (!b->reserved) {
1298 if (!silent)
1299 fat_msg(sb, KERN_ERR, "bogus number of reserved sectors");
1300 brelse(bh);
1301 goto out_invalid;
1302 }
1303 if (!b->fats) {
1304 if (!silent)
1305 fat_msg(sb, KERN_ERR, "bogus number of FAT structure");
1306 brelse(bh);
1307 goto out_invalid;
1308 }
1309
1310 /*
1311 * Earlier we checked here that b->secs_track and b->head are nonzero,
1312 * but it turns out valid FAT filesystems can have zero there.
1313 */
1314
1315 media = b->media;
1316 if (!fat_valid_media(media)) {
1317 if (!silent)
1318 fat_msg(sb, KERN_ERR, "invalid media value (0x%02x)",
1319 media);
1320 brelse(bh);
1321 goto out_invalid;
1322 }
1323 logical_sector_size = get_unaligned_le16(&b->sector_size);
1324 if (!is_power_of_2(logical_sector_size)
1325 || (logical_sector_size < 512)
1326 || (logical_sector_size > 4096)) {
1327 if (!silent)
1328 fat_msg(sb, KERN_ERR, "bogus logical sector size %u",
1329 logical_sector_size);
1330 brelse(bh);
1331 goto out_invalid;
1332 }
1333 sbi->sec_per_clus = b->sec_per_clus;
1334 if (!is_power_of_2(sbi->sec_per_clus)) {
1335 if (!silent)
1336 fat_msg(sb, KERN_ERR, "bogus sectors per cluster %u",
1337 sbi->sec_per_clus);
1338 brelse(bh);
1339 goto out_invalid;
1340 }
1341
1342 if (logical_sector_size < sb->s_blocksize) {
1343 fat_msg(sb, KERN_ERR, "logical sector size too small for device"
1344 " (logical sector size = %u)", logical_sector_size);
1345 brelse(bh);
1346 goto out_fail;
1347 }
1348 if (logical_sector_size > sb->s_blocksize) {
1349 brelse(bh);
1350
1351 if (!sb_set_blocksize(sb, logical_sector_size)) {
1352 fat_msg(sb, KERN_ERR, "unable to set blocksize %u",
1353 logical_sector_size);
1354 goto out_fail;
1355 }
1356 bh = sb_bread(sb, 0);
1357 if (bh == NULL) {
1358 fat_msg(sb, KERN_ERR, "unable to read boot sector"
1359 " (logical sector size = %lu)",
1360 sb->s_blocksize);
1361 goto out_fail;
1362 }
1363 b = (struct fat_boot_sector *) bh->b_data;
1364 }
1365
1366 mutex_init(&sbi->s_lock);
1367 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1368 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1369 sbi->fats = b->fats;
1370 sbi->fat_bits = 0; /* Don't know yet */
1371 sbi->fat_start = le16_to_cpu(b->reserved);
1372 sbi->fat_length = le16_to_cpu(b->fat_length);
1373 sbi->root_cluster = 0;
1374 sbi->free_clusters = -1; /* Don't know yet */
1375 sbi->free_clus_valid = 0;
1376 sbi->prev_free = FAT_START_ENT;
1377 sb->s_maxbytes = 0xffffffff;
1378
1379 if (!sbi->fat_length && b->fat32.length) {
1380 struct fat_boot_fsinfo *fsinfo;
1381 struct buffer_head *fsinfo_bh;
1382
1383 /* Must be FAT32 */
1384 sbi->fat_bits = 32;
1385 sbi->fat_length = le32_to_cpu(b->fat32.length);
1386 sbi->root_cluster = le32_to_cpu(b->fat32.root_cluster);
1387
1388 /* MC - if info_sector is 0, don't multiply by 0 */
1389 sbi->fsinfo_sector = le16_to_cpu(b->fat32.info_sector);
1390 if (sbi->fsinfo_sector == 0)
1391 sbi->fsinfo_sector = 1;
1392
1393 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1394 if (fsinfo_bh == NULL) {
1395 fat_msg(sb, KERN_ERR, "bread failed, FSINFO block"
1396 " (sector = %lu)", sbi->fsinfo_sector);
1397 brelse(bh);
1398 goto out_fail;
1399 }
1400
1401 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1402 if (!IS_FSINFO(fsinfo)) {
1403 fat_msg(sb, KERN_WARNING, "Invalid FSINFO signature: "
1404 "0x%08x, 0x%08x (sector = %lu)",
1405 le32_to_cpu(fsinfo->signature1),
1406 le32_to_cpu(fsinfo->signature2),
1407 sbi->fsinfo_sector);
1408 } else {
1409 if (sbi->options.usefree)
1410 sbi->free_clus_valid = 1;
1411 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1412 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1413 }
1414
1415 brelse(fsinfo_bh);
1416 }
1417
1418 /* interpret volume ID as a little endian 32 bit integer */
1419 if (sbi->fat_bits == 32)
1420 sbi->vol_id = (((u32)b->fat32.vol_id[0]) |
1421 ((u32)b->fat32.vol_id[1] << 8) |
1422 ((u32)b->fat32.vol_id[2] << 16) |
1423 ((u32)b->fat32.vol_id[3] << 24));
1424 else /* fat 16 or 12 */
1425 sbi->vol_id = (((u32)b->fat16.vol_id[0]) |
1426 ((u32)b->fat16.vol_id[1] << 8) |
1427 ((u32)b->fat16.vol_id[2] << 16) |
1428 ((u32)b->fat16.vol_id[3] << 24));
1429
1430 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1431 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1432
1433 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1434 sbi->dir_entries = get_unaligned_le16(&b->dir_entries);
1435 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1436 if (!silent)
1437 fat_msg(sb, KERN_ERR, "bogus directory-entries per block"
1438 " (%u)", sbi->dir_entries);
1439 brelse(bh);
1440 goto out_invalid;
1441 }
1442
1443 rootdir_sectors = sbi->dir_entries
1444 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1445 sbi->data_start = sbi->dir_start + rootdir_sectors;
1446 total_sectors = get_unaligned_le16(&b->sectors);
1447 if (total_sectors == 0)
1448 total_sectors = le32_to_cpu(b->total_sect);
1449
1450 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1451
1452 if (sbi->fat_bits != 32)
1453 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1454
1455 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */
1456 if (sbi->fat_bits == 32)
1457 sbi->dirty = b->fat32.state & FAT_STATE_DIRTY;
1458 else /* fat 16 or 12 */
1459 sbi->dirty = b->fat16.state & FAT_STATE_DIRTY;
1460
1461 /* check that FAT table does not overflow */
1462 fat_clusters = calc_fat_clusters(sb);
1463 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1464 if (total_clusters > MAX_FAT(sb)) {
1465 if (!silent)
1466 fat_msg(sb, KERN_ERR, "count of clusters too big (%u)",
1467 total_clusters);
1468 brelse(bh);
1469 goto out_invalid;
1470 }
1471
1472 sbi->max_cluster = total_clusters + FAT_START_ENT;
1473 /* check the free_clusters, it's not necessarily correct */
1474 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1475 sbi->free_clusters = -1;
1476 /* check the prev_free, it's not necessarily correct */
1477 sbi->prev_free %= sbi->max_cluster;
1478 if (sbi->prev_free < FAT_START_ENT)
1479 sbi->prev_free = FAT_START_ENT;
1480
1481 brelse(bh);
1482
1483 /* set up enough so that it can read an inode */
1484 fat_hash_init(sb);
1485 dir_hash_init(sb);
1486 fat_ent_access_init(sb);
1487
1488 /*
1489 * The low byte of FAT's first entry must have same value with
1490 * media-field. But in real world, too many devices is
1491 * writing wrong value. So, removed that validity check.
1492 *
1493 * if (FAT_FIRST_ENT(sb, media) != first)
1494 */
1495
1496 error = -EINVAL;
1497 sprintf(buf, "cp%d", sbi->options.codepage);
1498 sbi->nls_disk = load_nls(buf);
1499 if (!sbi->nls_disk) {
1500 fat_msg(sb, KERN_ERR, "codepage %s not found", buf);
1501 goto out_fail;
1502 }
1503
1504 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1505 if (sbi->options.isvfat) {
1506 sbi->nls_io = load_nls(sbi->options.iocharset);
1507 if (!sbi->nls_io) {
1508 fat_msg(sb, KERN_ERR, "IO charset %s not found",
1509 sbi->options.iocharset);
1510 goto out_fail;
1511 }
1512 }
1513
1514 error = -ENOMEM;
1515 fat_inode = new_inode(sb);
1516 if (!fat_inode)
1517 goto out_fail;
1518 MSDOS_I(fat_inode)->i_pos = 0;
1519 sbi->fat_inode = fat_inode;
1520
1521 fsinfo_inode = new_inode(sb);
1522 if (!fsinfo_inode)
1523 goto out_fail;
1524 fsinfo_inode->i_ino = MSDOS_FSINFO_INO;
1525 sbi->fsinfo_inode = fsinfo_inode;
1526 insert_inode_hash(fsinfo_inode);
1527
1528 root_inode = new_inode(sb);
1529 if (!root_inode)
1530 goto out_fail;
1531 root_inode->i_ino = MSDOS_ROOT_INO;
1532 root_inode->i_version = 1;
1533 error = fat_read_root(root_inode);
1534 if (error < 0) {
1535 iput(root_inode);
1536 goto out_fail;
1537 }
1538 error = -ENOMEM;
1539 insert_inode_hash(root_inode);
1540 fat_attach(root_inode, 0);
1541 sb->s_root = d_make_root(root_inode);
1542 if (!sb->s_root) {
1543 fat_msg(sb, KERN_ERR, "get root inode failed");
1544 goto out_fail;
1545 }
1546
1547 if (sbi->options.discard) {
1548 struct request_queue *q = bdev_get_queue(sb->s_bdev);
1549 if (!blk_queue_discard(q))
1550 fat_msg(sb, KERN_WARNING,
1551 "mounting with \"discard\" option, but "
1552 "the device does not support discard");
1553 }
1554
1555 fat_set_state(sb, 1, 0);
1556 return 0;
1557
1558 out_invalid:
1559 error = -EINVAL;
1560 if (!silent)
1561 fat_msg(sb, KERN_INFO, "Can't find a valid FAT filesystem");
1562
1563 out_fail:
1564 if (fsinfo_inode)
1565 iput(fsinfo_inode);
1566 if (fat_inode)
1567 iput(fat_inode);
1568 unload_nls(sbi->nls_io);
1569 unload_nls(sbi->nls_disk);
1570 if (sbi->options.iocharset != fat_default_iocharset)
1571 kfree(sbi->options.iocharset);
1572 sb->s_fs_info = NULL;
1573 kfree(sbi);
1574 return error;
1575 }
1576
1577 EXPORT_SYMBOL_GPL(fat_fill_super);
1578
1579 /*
1580 * helper function for fat_flush_inodes. This writes both the inode
1581 * and the file data blocks, waiting for in flight data blocks before
1582 * the start of the call. It does not wait for any io started
1583 * during the call
1584 */
1585 static int writeback_inode(struct inode *inode)
1586 {
1587
1588 int ret;
1589
1590 /* if we used wait=1, sync_inode_metadata waits for the io for the
1591 * inode to finish. So wait=0 is sent down to sync_inode_metadata
1592 * and filemap_fdatawrite is used for the data blocks
1593 */
1594 ret = sync_inode_metadata(inode, 0);
1595 if (!ret)
1596 ret = filemap_fdatawrite(inode->i_mapping);
1597 return ret;
1598 }
1599
1600 /*
1601 * write data and metadata corresponding to i1 and i2. The io is
1602 * started but we do not wait for any of it to finish.
1603 *
1604 * filemap_flush is used for the block device, so if there is a dirty
1605 * page for a block already in flight, we will not wait and start the
1606 * io over again
1607 */
1608 int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1609 {
1610 int ret = 0;
1611 if (!MSDOS_SB(sb)->options.flush)
1612 return 0;
1613 if (i1)
1614 ret = writeback_inode(i1);
1615 if (!ret && i2)
1616 ret = writeback_inode(i2);
1617 if (!ret) {
1618 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1619 ret = filemap_flush(mapping);
1620 }
1621 return ret;
1622 }
1623 EXPORT_SYMBOL_GPL(fat_flush_inodes);
1624
1625 static int __init init_fat_fs(void)
1626 {
1627 int err;
1628
1629 err = fat_cache_init();
1630 if (err)
1631 return err;
1632
1633 err = fat_init_inodecache();
1634 if (err)
1635 goto failed;
1636
1637 return 0;
1638
1639 failed:
1640 fat_cache_destroy();
1641 return err;
1642 }
1643
1644 static void __exit exit_fat_fs(void)
1645 {
1646 fat_cache_destroy();
1647 fat_destroy_inodecache();
1648 }
1649
1650 module_init(init_fat_fs)
1651 module_exit(exit_fat_fs)
1652
1653 MODULE_LICENSE("GPL");
Linux with added FPC-III support