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Automatic merge of rsync://rsync.kernel.org/pub/scm/linux/kernel/git/gregkh/driver...
[linux-2.6/verdex.git] / fs / fat / inode.c
blob8ccee8415488af2eab846aaa017d68d25a7bba8d
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/smp_lock.h>
18 #include <linux/seq_file.h>
19 #include <linux/msdos_fs.h>
20 #include <linux/pagemap.h>
21 #include <linux/buffer_head.h>
22 #include <linux/mount.h>
23 #include <linux/vfs.h>
24 #include <linux/parser.h>
25 #include <asm/unaligned.h>
26
27 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET
28 /* if user don't select VFAT, this is undefined. */
29 #define CONFIG_FAT_DEFAULT_IOCHARSET ""
30 #endif
31
32 static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
33 static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
34
35
36 static int fat_add_cluster(struct inode *inode)
37 {
38 int err, cluster;
39
40 err = fat_alloc_clusters(inode, &cluster, 1);
41 if (err)
42 return err;
43 /* FIXME: this cluster should be added after data of this
44 * cluster is writed */
45 err = fat_chain_add(inode, cluster, 1);
46 if (err)
47 fat_free_clusters(inode, cluster);
48 return err;
49 }
50
51 static int fat_get_block(struct inode *inode, sector_t iblock,
52 struct buffer_head *bh_result, int create)
53 {
54 struct super_block *sb = inode->i_sb;
55 sector_t phys;
56 int err;
57
58 err = fat_bmap(inode, iblock, &phys);
59 if (err)
60 return err;
61 if (phys) {
62 map_bh(bh_result, sb, phys);
63 return 0;
64 }
65 if (!create)
66 return 0;
67 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
68 fat_fs_panic(sb, "corrupted file size (i_pos %lld, %lld)",
69 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
70 return -EIO;
71 }
72 if (!((unsigned long)iblock & (MSDOS_SB(sb)->sec_per_clus - 1))) {
73 err = fat_add_cluster(inode);
74 if (err)
75 return err;
76 }
77 MSDOS_I(inode)->mmu_private += sb->s_blocksize;
78 err = fat_bmap(inode, iblock, &phys);
79 if (err)
80 return err;
81 if (!phys)
82 BUG();
83 set_buffer_new(bh_result);
84 map_bh(bh_result, sb, phys);
85 return 0;
86 }
87
88 static int fat_writepage(struct page *page, struct writeback_control *wbc)
89 {
90 return block_write_full_page(page, fat_get_block, wbc);
91 }
92
93 static int fat_readpage(struct file *file, struct page *page)
94 {
95 return block_read_full_page(page, fat_get_block);
96 }
97
98 static int fat_prepare_write(struct file *file, struct page *page,
99 unsigned from, unsigned to)
100 {
101 return cont_prepare_write(page, from, to, fat_get_block,
102 &MSDOS_I(page->mapping->host)->mmu_private);
103 }
104
105 static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
106 {
107 return generic_block_bmap(mapping, block, fat_get_block);
108 }
109
110 static struct address_space_operations fat_aops = {
111 .readpage = fat_readpage,
112 .writepage = fat_writepage,
113 .sync_page = block_sync_page,
114 .prepare_write = fat_prepare_write,
115 .commit_write = generic_commit_write,
116 .bmap = _fat_bmap
117 };
118
119 /*
120 * New FAT inode stuff. We do the following:
121 * a) i_ino is constant and has nothing with on-disk location.
122 * b) FAT manages its own cache of directory entries.
123 * c) *This* cache is indexed by on-disk location.
124 * d) inode has an associated directory entry, all right, but
125 * it may be unhashed.
126 * e) currently entries are stored within struct inode. That should
127 * change.
128 * f) we deal with races in the following way:
129 * 1. readdir() and lookup() do FAT-dir-cache lookup.
130 * 2. rename() unhashes the F-d-c entry and rehashes it in
131 * a new place.
132 * 3. unlink() and rmdir() unhash F-d-c entry.
133 * 4. fat_write_inode() checks whether the thing is unhashed.
134 * If it is we silently return. If it isn't we do bread(),
135 * check if the location is still valid and retry if it
136 * isn't. Otherwise we do changes.
137 * 5. Spinlock is used to protect hash/unhash/location check/lookup
138 * 6. fat_clear_inode() unhashes the F-d-c entry.
139 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
140 * and consider negative result as cache miss.
141 */
142
143 static void fat_hash_init(struct super_block *sb)
144 {
145 struct msdos_sb_info *sbi = MSDOS_SB(sb);
146 int i;
147
148 spin_lock_init(&sbi->inode_hash_lock);
149 for (i = 0; i < FAT_HASH_SIZE; i++)
150 INIT_HLIST_HEAD(&sbi->inode_hashtable[i]);
151 }
152
153 static inline unsigned long fat_hash(struct super_block *sb, loff_t i_pos)
154 {
155 unsigned long tmp = (unsigned long)i_pos | (unsigned long) sb;
156 tmp = tmp + (tmp >> FAT_HASH_BITS) + (tmp >> FAT_HASH_BITS * 2);
157 return tmp & FAT_HASH_MASK;
158 }
159
160 void fat_attach(struct inode *inode, loff_t i_pos)
161 {
162 struct super_block *sb = inode->i_sb;
163 struct msdos_sb_info *sbi = MSDOS_SB(sb);
164
165 spin_lock(&sbi->inode_hash_lock);
166 MSDOS_I(inode)->i_pos = i_pos;
167 hlist_add_head(&MSDOS_I(inode)->i_fat_hash,
168 sbi->inode_hashtable + fat_hash(sb, i_pos));
169 spin_unlock(&sbi->inode_hash_lock);
170 }
171
172 EXPORT_SYMBOL(fat_attach);
173
174 void fat_detach(struct inode *inode)
175 {
176 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
177 spin_lock(&sbi->inode_hash_lock);
178 MSDOS_I(inode)->i_pos = 0;
179 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
180 spin_unlock(&sbi->inode_hash_lock);
181 }
182
183 EXPORT_SYMBOL(fat_detach);
184
185 struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
186 {
187 struct msdos_sb_info *sbi = MSDOS_SB(sb);
188 struct hlist_head *head = sbi->inode_hashtable + fat_hash(sb, i_pos);
189 struct hlist_node *_p;
190 struct msdos_inode_info *i;
191 struct inode *inode = NULL;
192
193 spin_lock(&sbi->inode_hash_lock);
194 hlist_for_each_entry(i, _p, head, i_fat_hash) {
195 BUG_ON(i->vfs_inode.i_sb != sb);
196 if (i->i_pos != i_pos)
197 continue;
198 inode = igrab(&i->vfs_inode);
199 if (inode)
200 break;
201 }
202 spin_unlock(&sbi->inode_hash_lock);
203 return inode;
204 }
205
206 static int is_exec(unsigned char *extension)
207 {
208 unsigned char *exe_extensions = "EXECOMBAT", *walk;
209
210 for (walk = exe_extensions; *walk; walk += 3)
211 if (!strncmp(extension, walk, 3))
212 return 1;
213 return 0;
214 }
215
216 static int fat_calc_dir_size(struct inode *inode)
217 {
218 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
219 int ret, fclus, dclus;
220
221 inode->i_size = 0;
222 if (MSDOS_I(inode)->i_start == 0)
223 return 0;
224
225 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
226 if (ret < 0)
227 return ret;
228 inode->i_size = (fclus + 1) << sbi->cluster_bits;
229
230 return 0;
231 }
232
233 /* doesn't deal with root inode */
234 static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
235 {
236 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
237 int error;
238
239 MSDOS_I(inode)->i_pos = 0;
240 inode->i_uid = sbi->options.fs_uid;
241 inode->i_gid = sbi->options.fs_gid;
242 inode->i_version++;
243 inode->i_generation = get_seconds();
244
245 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
246 inode->i_generation &= ~1;
247 inode->i_mode = MSDOS_MKMODE(de->attr,
248 S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
249 inode->i_op = sbi->dir_ops;
250 inode->i_fop = &fat_dir_operations;
251
252 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
253 if (sbi->fat_bits == 32)
254 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
255
256 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
257 error = fat_calc_dir_size(inode);
258 if (error < 0)
259 return error;
260 MSDOS_I(inode)->mmu_private = inode->i_size;
261
262 inode->i_nlink = fat_subdirs(inode);
263 } else { /* not a directory */
264 inode->i_generation |= 1;
265 inode->i_mode = MSDOS_MKMODE(de->attr,
266 ((sbi->options.showexec &&
267 !is_exec(de->ext))
268 ? S_IRUGO|S_IWUGO : S_IRWXUGO)
269 & ~sbi->options.fs_fmask) | S_IFREG;
270 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
271 if (sbi->fat_bits == 32)
272 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
273
274 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
275 inode->i_size = le32_to_cpu(de->size);
276 inode->i_op = &fat_file_inode_operations;
277 inode->i_fop = &fat_file_operations;
278 inode->i_mapping->a_ops = &fat_aops;
279 MSDOS_I(inode)->mmu_private = inode->i_size;
280 }
281 if (de->attr & ATTR_SYS) {
282 if (sbi->options.sys_immutable)
283 inode->i_flags |= S_IMMUTABLE;
284 }
285 MSDOS_I(inode)->i_attrs = de->attr & ATTR_UNUSED;
286 /* this is as close to the truth as we can get ... */
287 inode->i_blksize = sbi->cluster_size;
288 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
289 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
290 inode->i_mtime.tv_sec = inode->i_atime.tv_sec =
291 date_dos2unix(le16_to_cpu(de->time), le16_to_cpu(de->date));
292 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = 0;
293 if (sbi->options.isvfat) {
294 int secs = de->ctime_cs / 100;
295 int csecs = de->ctime_cs % 100;
296 inode->i_ctime.tv_sec =
297 date_dos2unix(le16_to_cpu(de->ctime),
298 le16_to_cpu(de->cdate)) + secs;
299 inode->i_ctime.tv_nsec = csecs * 10000000;
300 } else
301 inode->i_ctime = inode->i_mtime;
302
303 return 0;
304 }
305
306 struct inode *fat_build_inode(struct super_block *sb,
307 struct msdos_dir_entry *de, loff_t i_pos)
308 {
309 struct inode *inode;
310 int err;
311
312 inode = fat_iget(sb, i_pos);
313 if (inode)
314 goto out;
315 inode = new_inode(sb);
316 if (!inode) {
317 inode = ERR_PTR(-ENOMEM);
318 goto out;
319 }
320 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
321 inode->i_version = 1;
322 err = fat_fill_inode(inode, de);
323 if (err) {
324 iput(inode);
325 inode = ERR_PTR(err);
326 goto out;
327 }
328 fat_attach(inode, i_pos);
329 insert_inode_hash(inode);
330 out:
331 return inode;
332 }
333
334 EXPORT_SYMBOL(fat_build_inode);
335
336 static void fat_delete_inode(struct inode *inode)
337 {
338 if (!is_bad_inode(inode)) {
339 inode->i_size = 0;
340 fat_truncate(inode);
341 }
342 clear_inode(inode);
343 }
344
345 static void fat_clear_inode(struct inode *inode)
346 {
347 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
348
349 if (is_bad_inode(inode))
350 return;
351 lock_kernel();
352 spin_lock(&sbi->inode_hash_lock);
353 fat_cache_inval_inode(inode);
354 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
355 spin_unlock(&sbi->inode_hash_lock);
356 unlock_kernel();
357 }
358
359 static void fat_put_super(struct super_block *sb)
360 {
361 struct msdos_sb_info *sbi = MSDOS_SB(sb);
362
363 if (!(sb->s_flags & MS_RDONLY))
364 fat_clusters_flush(sb);
365
366 if (sbi->nls_disk) {
367 unload_nls(sbi->nls_disk);
368 sbi->nls_disk = NULL;
369 sbi->options.codepage = fat_default_codepage;
370 }
371 if (sbi->nls_io) {
372 unload_nls(sbi->nls_io);
373 sbi->nls_io = NULL;
374 }
375 if (sbi->options.iocharset != fat_default_iocharset) {
376 kfree(sbi->options.iocharset);
377 sbi->options.iocharset = fat_default_iocharset;
378 }
379
380 sb->s_fs_info = NULL;
381 kfree(sbi);
382 }
383
384 static kmem_cache_t *fat_inode_cachep;
385
386 static struct inode *fat_alloc_inode(struct super_block *sb)
387 {
388 struct msdos_inode_info *ei;
389 ei = kmem_cache_alloc(fat_inode_cachep, SLAB_KERNEL);
390 if (!ei)
391 return NULL;
392 return &ei->vfs_inode;
393 }
394
395 static void fat_destroy_inode(struct inode *inode)
396 {
397 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
398 }
399
400 static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
401 {
402 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
403
404 if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
405 SLAB_CTOR_CONSTRUCTOR) {
406 spin_lock_init(&ei->cache_lru_lock);
407 ei->nr_caches = 0;
408 ei->cache_valid_id = FAT_CACHE_VALID + 1;
409 INIT_LIST_HEAD(&ei->cache_lru);
410 INIT_HLIST_NODE(&ei->i_fat_hash);
411 inode_init_once(&ei->vfs_inode);
412 }
413 }
414
415 static int __init fat_init_inodecache(void)
416 {
417 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
418 sizeof(struct msdos_inode_info),
419 0, SLAB_RECLAIM_ACCOUNT,
420 init_once, NULL);
421 if (fat_inode_cachep == NULL)
422 return -ENOMEM;
423 return 0;
424 }
425
426 static void __exit fat_destroy_inodecache(void)
427 {
428 if (kmem_cache_destroy(fat_inode_cachep))
429 printk(KERN_INFO "fat_inode_cache: not all structures were freed\n");
430 }
431
432 static int fat_remount(struct super_block *sb, int *flags, char *data)
433 {
434 struct msdos_sb_info *sbi = MSDOS_SB(sb);
435 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
436 return 0;
437 }
438
439 static int fat_statfs(struct super_block *sb, struct kstatfs *buf)
440 {
441 struct msdos_sb_info *sbi = MSDOS_SB(sb);
442
443 /* If the count of free cluster is still unknown, counts it here. */
444 if (sbi->free_clusters == -1) {
445 int err = fat_count_free_clusters(sb);
446 if (err)
447 return err;
448 }
449
450 buf->f_type = sb->s_magic;
451 buf->f_bsize = sbi->cluster_size;
452 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
453 buf->f_bfree = sbi->free_clusters;
454 buf->f_bavail = sbi->free_clusters;
455 buf->f_namelen = sbi->options.isvfat ? 260 : 12;
456
457 return 0;
458 }
459
460 static int fat_write_inode(struct inode *inode, int wait)
461 {
462 struct super_block *sb = inode->i_sb;
463 struct msdos_sb_info *sbi = MSDOS_SB(sb);
464 struct buffer_head *bh;
465 struct msdos_dir_entry *raw_entry;
466 loff_t i_pos;
467 int err = 0;
468
469 retry:
470 i_pos = MSDOS_I(inode)->i_pos;
471 if (inode->i_ino == MSDOS_ROOT_INO || !i_pos)
472 return 0;
473
474 lock_kernel();
475 bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
476 if (!bh) {
477 printk(KERN_ERR "FAT: unable to read inode block "
478 "for updating (i_pos %lld)\n", i_pos);
479 err = -EIO;
480 goto out;
481 }
482 spin_lock(&sbi->inode_hash_lock);
483 if (i_pos != MSDOS_I(inode)->i_pos) {
484 spin_unlock(&sbi->inode_hash_lock);
485 brelse(bh);
486 unlock_kernel();
487 goto retry;
488 }
489
490 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
491 [i_pos & (sbi->dir_per_block - 1)];
492 if (S_ISDIR(inode->i_mode))
493 raw_entry->size = 0;
494 else
495 raw_entry->size = cpu_to_le32(inode->i_size);
496 raw_entry->attr = fat_attr(inode);
497 raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
498 raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
499 fat_date_unix2dos(inode->i_mtime.tv_sec, &raw_entry->time, &raw_entry->date);
500 if (sbi->options.isvfat) {
501 fat_date_unix2dos(inode->i_ctime.tv_sec,&raw_entry->ctime,&raw_entry->cdate);
502 raw_entry->ctime_cs = (inode->i_ctime.tv_sec & 1) * 100 +
503 inode->i_ctime.tv_nsec / 10000000;
504 }
505 spin_unlock(&sbi->inode_hash_lock);
506 mark_buffer_dirty(bh);
507 if (wait)
508 err = sync_dirty_buffer(bh);
509 brelse(bh);
510 out:
511 unlock_kernel();
512 return err;
513 }
514
515 int fat_sync_inode(struct inode *inode)
516 {
517 return fat_write_inode(inode, 1);
518 }
519
520 EXPORT_SYMBOL(fat_sync_inode);
521
522 static int fat_show_options(struct seq_file *m, struct vfsmount *mnt);
523 static struct super_operations fat_sops = {
524 .alloc_inode = fat_alloc_inode,
525 .destroy_inode = fat_destroy_inode,
526 .write_inode = fat_write_inode,
527 .delete_inode = fat_delete_inode,
528 .put_super = fat_put_super,
529 .statfs = fat_statfs,
530 .clear_inode = fat_clear_inode,
531 .remount_fs = fat_remount,
532
533 .read_inode = make_bad_inode,
534
535 .show_options = fat_show_options,
536 };
537
538 /*
539 * a FAT file handle with fhtype 3 is
540 * 0/ i_ino - for fast, reliable lookup if still in the cache
541 * 1/ i_generation - to see if i_ino is still valid
542 * bit 0 == 0 iff directory
543 * 2/ i_pos(8-39) - if ino has changed, but still in cache
544 * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
545 * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
546 *
547 * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
548 * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
549 * of i_logstart is used to store the directory entry offset.
550 */
551
552 static struct dentry *
553 fat_decode_fh(struct super_block *sb, __u32 *fh, int len, int fhtype,
554 int (*acceptable)(void *context, struct dentry *de),
555 void *context)
556 {
557 if (fhtype != 3)
558 return ERR_PTR(-ESTALE);
559 if (len < 5)
560 return ERR_PTR(-ESTALE);
561
562 return sb->s_export_op->find_exported_dentry(sb, fh, NULL, acceptable, context);
563 }
564
565 static struct dentry *fat_get_dentry(struct super_block *sb, void *inump)
566 {
567 struct inode *inode = NULL;
568 struct dentry *result;
569 __u32 *fh = inump;
570
571 inode = iget(sb, fh[0]);
572 if (!inode || is_bad_inode(inode) || inode->i_generation != fh[1]) {
573 if (inode)
574 iput(inode);
575 inode = NULL;
576 }
577 if (!inode) {
578 loff_t i_pos;
579 int i_logstart = fh[3] & 0x0fffffff;
580
581 i_pos = (loff_t)fh[2] << 8;
582 i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
583
584 /* try 2 - see if i_pos is in F-d-c
585 * require i_logstart to be the same
586 * Will fail if you truncate and then re-write
587 */
588
589 inode = fat_iget(sb, i_pos);
590 if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
591 iput(inode);
592 inode = NULL;
593 }
594 }
595 if (!inode) {
596 /* For now, do nothing
597 * What we could do is:
598 * follow the file starting at fh[4], and record
599 * the ".." entry, and the name of the fh[2] entry.
600 * The follow the ".." file finding the next step up.
601 * This way we build a path to the root of
602 * the tree. If this works, we lookup the path and so
603 * get this inode into the cache.
604 * Finally try the fat_iget lookup again
605 * If that fails, then weare totally out of luck
606 * But all that is for another day
607 */
608 }
609 if (!inode)
610 return ERR_PTR(-ESTALE);
611
612
613 /* now to find a dentry.
614 * If possible, get a well-connected one
615 */
616 result = d_alloc_anon(inode);
617 if (result == NULL) {
618 iput(inode);
619 return ERR_PTR(-ENOMEM);
620 }
621 result->d_op = sb->s_root->d_op;
622 return result;
623 }
624
625 static int
626 fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
627 {
628 int len = *lenp;
629 struct inode *inode = de->d_inode;
630 u32 ipos_h, ipos_m, ipos_l;
631
632 if (len < 5)
633 return 255; /* no room */
634
635 ipos_h = MSDOS_I(inode)->i_pos >> 8;
636 ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
637 ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
638 *lenp = 5;
639 fh[0] = inode->i_ino;
640 fh[1] = inode->i_generation;
641 fh[2] = ipos_h;
642 fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
643 spin_lock(&de->d_lock);
644 fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
645 spin_unlock(&de->d_lock);
646 return 3;
647 }
648
649 static struct dentry *fat_get_parent(struct dentry *child)
650 {
651 struct buffer_head *bh;
652 struct msdos_dir_entry *de;
653 loff_t i_pos;
654 struct dentry *parent;
655 struct inode *inode;
656 int err;
657
658 lock_kernel();
659
660 err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos);
661 if (err) {
662 parent = ERR_PTR(err);
663 goto out;
664 }
665 inode = fat_build_inode(child->d_sb, de, i_pos);
666 brelse(bh);
667 if (IS_ERR(inode)) {
668 parent = ERR_PTR(PTR_ERR(inode));
669 goto out;
670 }
671 parent = d_alloc_anon(inode);
672 if (!parent) {
673 iput(inode);
674 parent = ERR_PTR(-ENOMEM);
675 }
676 out:
677 unlock_kernel();
678
679 return parent;
680 }
681
682 static struct export_operations fat_export_ops = {
683 .decode_fh = fat_decode_fh,
684 .encode_fh = fat_encode_fh,
685 .get_dentry = fat_get_dentry,
686 .get_parent = fat_get_parent,
687 };
688
689 static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
690 {
691 struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb);
692 struct fat_mount_options *opts = &sbi->options;
693 int isvfat = opts->isvfat;
694
695 if (opts->fs_uid != 0)
696 seq_printf(m, ",uid=%u", opts->fs_uid);
697 if (opts->fs_gid != 0)
698 seq_printf(m, ",gid=%u", opts->fs_gid);
699 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
700 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
701 if (sbi->nls_disk)
702 seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
703 if (isvfat) {
704 if (sbi->nls_io)
705 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
706
707 switch (opts->shortname) {
708 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
709 seq_puts(m, ",shortname=win95");
710 break;
711 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
712 seq_puts(m, ",shortname=winnt");
713 break;
714 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
715 seq_puts(m, ",shortname=mixed");
716 break;
717 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
718 /* seq_puts(m, ",shortname=lower"); */
719 break;
720 default:
721 seq_puts(m, ",shortname=unknown");
722 break;
723 }
724 }
725 if (opts->name_check != 'n')
726 seq_printf(m, ",check=%c", opts->name_check);
727 if (opts->quiet)
728 seq_puts(m, ",quiet");
729 if (opts->showexec)
730 seq_puts(m, ",showexec");
731 if (opts->sys_immutable)
732 seq_puts(m, ",sys_immutable");
733 if (!isvfat) {
734 if (opts->dotsOK)
735 seq_puts(m, ",dotsOK=yes");
736 if (opts->nocase)
737 seq_puts(m, ",nocase");
738 } else {
739 if (opts->utf8)
740 seq_puts(m, ",utf8");
741 if (opts->unicode_xlate)
742 seq_puts(m, ",uni_xlate");
743 if (!opts->numtail)
744 seq_puts(m, ",nonumtail");
745 }
746
747 return 0;
748 }
749
750 enum {
751 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
752 Opt_umask, Opt_dmask, Opt_fmask, Opt_codepage, Opt_nocase,
753 Opt_quiet, Opt_showexec, Opt_debug, Opt_immutable,
754 Opt_dots, Opt_nodots,
755 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
756 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
757 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
758 Opt_obsolate, Opt_err,
759 };
760
761 static match_table_t fat_tokens = {
762 {Opt_check_r, "check=relaxed"},
763 {Opt_check_s, "check=strict"},
764 {Opt_check_n, "check=normal"},
765 {Opt_check_r, "check=r"},
766 {Opt_check_s, "check=s"},
767 {Opt_check_n, "check=n"},
768 {Opt_uid, "uid=%u"},
769 {Opt_gid, "gid=%u"},
770 {Opt_umask, "umask=%o"},
771 {Opt_dmask, "dmask=%o"},
772 {Opt_fmask, "fmask=%o"},
773 {Opt_codepage, "codepage=%u"},
774 {Opt_nocase, "nocase"},
775 {Opt_quiet, "quiet"},
776 {Opt_showexec, "showexec"},
777 {Opt_debug, "debug"},
778 {Opt_immutable, "sys_immutable"},
779 {Opt_obsolate, "conv=binary"},
780 {Opt_obsolate, "conv=text"},
781 {Opt_obsolate, "conv=auto"},
782 {Opt_obsolate, "conv=b"},
783 {Opt_obsolate, "conv=t"},
784 {Opt_obsolate, "conv=a"},
785 {Opt_obsolate, "fat=%u"},
786 {Opt_obsolate, "blocksize=%u"},
787 {Opt_obsolate, "cvf_format=%20s"},
788 {Opt_obsolate, "cvf_options=%100s"},
789 {Opt_obsolate, "posix"},
790 {Opt_err, NULL}
791 };
792 static match_table_t msdos_tokens = {
793 {Opt_nodots, "nodots"},
794 {Opt_nodots, "dotsOK=no"},
795 {Opt_dots, "dots"},
796 {Opt_dots, "dotsOK=yes"},
797 {Opt_err, NULL}
798 };
799 static match_table_t vfat_tokens = {
800 {Opt_charset, "iocharset=%s"},
801 {Opt_shortname_lower, "shortname=lower"},
802 {Opt_shortname_win95, "shortname=win95"},
803 {Opt_shortname_winnt, "shortname=winnt"},
804 {Opt_shortname_mixed, "shortname=mixed"},
805 {Opt_utf8_no, "utf8=0"}, /* 0 or no or false */
806 {Opt_utf8_no, "utf8=no"},
807 {Opt_utf8_no, "utf8=false"},
808 {Opt_utf8_yes, "utf8=1"}, /* empty or 1 or yes or true */
809 {Opt_utf8_yes, "utf8=yes"},
810 {Opt_utf8_yes, "utf8=true"},
811 {Opt_utf8_yes, "utf8"},
812 {Opt_uni_xl_no, "uni_xlate=0"}, /* 0 or no or false */
813 {Opt_uni_xl_no, "uni_xlate=no"},
814 {Opt_uni_xl_no, "uni_xlate=false"},
815 {Opt_uni_xl_yes, "uni_xlate=1"}, /* empty or 1 or yes or true */
816 {Opt_uni_xl_yes, "uni_xlate=yes"},
817 {Opt_uni_xl_yes, "uni_xlate=true"},
818 {Opt_uni_xl_yes, "uni_xlate"},
819 {Opt_nonumtail_no, "nonumtail=0"}, /* 0 or no or false */
820 {Opt_nonumtail_no, "nonumtail=no"},
821 {Opt_nonumtail_no, "nonumtail=false"},
822 {Opt_nonumtail_yes, "nonumtail=1"}, /* empty or 1 or yes or true */
823 {Opt_nonumtail_yes, "nonumtail=yes"},
824 {Opt_nonumtail_yes, "nonumtail=true"},
825 {Opt_nonumtail_yes, "nonumtail"},
826 {Opt_err, NULL}
827 };
828
829 static int parse_options(char *options, int is_vfat, int *debug,
830 struct fat_mount_options *opts)
831 {
832 char *p;
833 substring_t args[MAX_OPT_ARGS];
834 int option;
835 char *iocharset;
836
837 opts->isvfat = is_vfat;
838
839 opts->fs_uid = current->uid;
840 opts->fs_gid = current->gid;
841 opts->fs_fmask = opts->fs_dmask = current->fs->umask;
842 opts->codepage = fat_default_codepage;
843 opts->iocharset = fat_default_iocharset;
844 if (is_vfat)
845 opts->shortname = VFAT_SFN_DISPLAY_LOWER|VFAT_SFN_CREATE_WIN95;
846 else
847 opts->shortname = 0;
848 opts->name_check = 'n';
849 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
850 opts->utf8 = opts->unicode_xlate = 0;
851 opts->numtail = 1;
852 opts->nocase = 0;
853 *debug = 0;
854
855 if (!options)
856 return 0;
857
858 while ((p = strsep(&options, ",")) != NULL) {
859 int token;
860 if (!*p)
861 continue;
862
863 token = match_token(p, fat_tokens, args);
864 if (token == Opt_err) {
865 if (is_vfat)
866 token = match_token(p, vfat_tokens, args);
867 else
868 token = match_token(p, msdos_tokens, args);
869 }
870 switch (token) {
871 case Opt_check_s:
872 opts->name_check = 's';
873 break;
874 case Opt_check_r:
875 opts->name_check = 'r';
876 break;
877 case Opt_check_n:
878 opts->name_check = 'n';
879 break;
880 case Opt_nocase:
881 if (!is_vfat)
882 opts->nocase = 1;
883 else {
884 /* for backward compatibility */
885 opts->shortname = VFAT_SFN_DISPLAY_WIN95
886 | VFAT_SFN_CREATE_WIN95;
887 }
888 break;
889 case Opt_quiet:
890 opts->quiet = 1;
891 break;
892 case Opt_showexec:
893 opts->showexec = 1;
894 break;
895 case Opt_debug:
896 *debug = 1;
897 break;
898 case Opt_immutable:
899 opts->sys_immutable = 1;
900 break;
901 case Opt_uid:
902 if (match_int(&args[0], &option))
903 return 0;
904 opts->fs_uid = option;
905 break;
906 case Opt_gid:
907 if (match_int(&args[0], &option))
908 return 0;
909 opts->fs_gid = option;
910 break;
911 case Opt_umask:
912 if (match_octal(&args[0], &option))
913 return 0;
914 opts->fs_fmask = opts->fs_dmask = option;
915 break;
916 case Opt_dmask:
917 if (match_octal(&args[0], &option))
918 return 0;
919 opts->fs_dmask = option;
920 break;
921 case Opt_fmask:
922 if (match_octal(&args[0], &option))
923 return 0;
924 opts->fs_fmask = option;
925 break;
926 case Opt_codepage:
927 if (match_int(&args[0], &option))
928 return 0;
929 opts->codepage = option;
930 break;
931
932 /* msdos specific */
933 case Opt_dots:
934 opts->dotsOK = 1;
935 break;
936 case Opt_nodots:
937 opts->dotsOK = 0;
938 break;
939
940 /* vfat specific */
941 case Opt_charset:
942 if (opts->iocharset != fat_default_iocharset)
943 kfree(opts->iocharset);
944 iocharset = match_strdup(&args[0]);
945 if (!iocharset)
946 return -ENOMEM;
947 opts->iocharset = iocharset;
948 break;
949 case Opt_shortname_lower:
950 opts->shortname = VFAT_SFN_DISPLAY_LOWER
951 | VFAT_SFN_CREATE_WIN95;
952 break;
953 case Opt_shortname_win95:
954 opts->shortname = VFAT_SFN_DISPLAY_WIN95
955 | VFAT_SFN_CREATE_WIN95;
956 break;
957 case Opt_shortname_winnt:
958 opts->shortname = VFAT_SFN_DISPLAY_WINNT
959 | VFAT_SFN_CREATE_WINNT;
960 break;
961 case Opt_shortname_mixed:
962 opts->shortname = VFAT_SFN_DISPLAY_WINNT
963 | VFAT_SFN_CREATE_WIN95;
964 break;
965 case Opt_utf8_no: /* 0 or no or false */
966 opts->utf8 = 0;
967 break;
968 case Opt_utf8_yes: /* empty or 1 or yes or true */
969 opts->utf8 = 1;
970 break;
971 case Opt_uni_xl_no: /* 0 or no or false */
972 opts->unicode_xlate = 0;
973 break;
974 case Opt_uni_xl_yes: /* empty or 1 or yes or true */
975 opts->unicode_xlate = 1;
976 break;
977 case Opt_nonumtail_no: /* 0 or no or false */
978 opts->numtail = 1; /* negated option */
979 break;
980 case Opt_nonumtail_yes: /* empty or 1 or yes or true */
981 opts->numtail = 0; /* negated option */
982 break;
983
984 /* obsolete mount options */
985 case Opt_obsolate:
986 printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
987 "not supported now\n", p);
988 break;
989 /* unknown option */
990 default:
991 printk(KERN_ERR "FAT: Unrecognized mount option \"%s\" "
992 "or missing value\n", p);
993 return -EINVAL;
994 }
995 }
996 /* UTF8 doesn't provide FAT semantics */
997 if (!strcmp(opts->iocharset, "utf8")) {
998 printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
999 " for FAT filesystems, filesystem will be case sensitive!\n");
1000 }
1001
1002 if (opts->unicode_xlate)
1003 opts->utf8 = 0;
1004
1005 return 0;
1006 }
1007
1008 static int fat_read_root(struct inode *inode)
1009 {
1010 struct super_block *sb = inode->i_sb;
1011 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1012 int error;
1013
1014 MSDOS_I(inode)->i_pos = 0;
1015 inode->i_uid = sbi->options.fs_uid;
1016 inode->i_gid = sbi->options.fs_gid;
1017 inode->i_version++;
1018 inode->i_generation = 0;
1019 inode->i_mode = (S_IRWXUGO & ~sbi->options.fs_dmask) | S_IFDIR;
1020 inode->i_op = sbi->dir_ops;
1021 inode->i_fop = &fat_dir_operations;
1022 if (sbi->fat_bits == 32) {
1023 MSDOS_I(inode)->i_start = sbi->root_cluster;
1024 error = fat_calc_dir_size(inode);
1025 if (error < 0)
1026 return error;
1027 } else {
1028 MSDOS_I(inode)->i_start = 0;
1029 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1030 }
1031 inode->i_blksize = sbi->cluster_size;
1032 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1033 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1034 MSDOS_I(inode)->i_logstart = 0;
1035 MSDOS_I(inode)->mmu_private = inode->i_size;
1036
1037 MSDOS_I(inode)->i_attrs = ATTR_NONE;
1038 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1039 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1040 inode->i_nlink = fat_subdirs(inode)+2;
1041
1042 return 0;
1043 }
1044
1045 /*
1046 * Read the super block of an MS-DOS FS.
1047 */
1048 int fat_fill_super(struct super_block *sb, void *data, int silent,
1049 struct inode_operations *fs_dir_inode_ops, int isvfat)
1050 {
1051 struct inode *root_inode = NULL;
1052 struct buffer_head *bh;
1053 struct fat_boot_sector *b;
1054 struct msdos_sb_info *sbi;
1055 u16 logical_sector_size;
1056 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1057 int debug;
1058 unsigned int media;
1059 long error;
1060 char buf[50];
1061
1062 sbi = kmalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1063 if (!sbi)
1064 return -ENOMEM;
1065 sb->s_fs_info = sbi;
1066 memset(sbi, 0, sizeof(struct msdos_sb_info));
1067
1068 sb->s_flags |= MS_NODIRATIME;
1069 sb->s_magic = MSDOS_SUPER_MAGIC;
1070 sb->s_op = &fat_sops;
1071 sb->s_export_op = &fat_export_ops;
1072 sbi->dir_ops = fs_dir_inode_ops;
1073
1074 error = parse_options(data, isvfat, &debug, &sbi->options);
1075 if (error)
1076 goto out_fail;
1077
1078 error = -EIO;
1079 sb_min_blocksize(sb, 512);
1080 bh = sb_bread(sb, 0);
1081 if (bh == NULL) {
1082 printk(KERN_ERR "FAT: unable to read boot sector\n");
1083 goto out_fail;
1084 }
1085
1086 b = (struct fat_boot_sector *) bh->b_data;
1087 if (!b->reserved) {
1088 if (!silent)
1089 printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
1090 brelse(bh);
1091 goto out_invalid;
1092 }
1093 if (!b->fats) {
1094 if (!silent)
1095 printk(KERN_ERR "FAT: bogus number of FAT structure\n");
1096 brelse(bh);
1097 goto out_invalid;
1098 }
1099
1100 /*
1101 * Earlier we checked here that b->secs_track and b->head are nonzero,
1102 * but it turns out valid FAT filesystems can have zero there.
1103 */
1104
1105 media = b->media;
1106 if (!FAT_VALID_MEDIA(media)) {
1107 if (!silent)
1108 printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
1109 media);
1110 brelse(bh);
1111 goto out_invalid;
1112 }
1113 logical_sector_size =
1114 le16_to_cpu(get_unaligned((__le16 *)&b->sector_size));
1115 if (!logical_sector_size
1116 || (logical_sector_size & (logical_sector_size - 1))
1117 || (logical_sector_size < 512)
1118 || (PAGE_CACHE_SIZE < logical_sector_size)) {
1119 if (!silent)
1120 printk(KERN_ERR "FAT: bogus logical sector size %u\n",
1121 logical_sector_size);
1122 brelse(bh);
1123 goto out_invalid;
1124 }
1125 sbi->sec_per_clus = b->sec_per_clus;
1126 if (!sbi->sec_per_clus
1127 || (sbi->sec_per_clus & (sbi->sec_per_clus - 1))) {
1128 if (!silent)
1129 printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
1130 sbi->sec_per_clus);
1131 brelse(bh);
1132 goto out_invalid;
1133 }
1134
1135 if (logical_sector_size < sb->s_blocksize) {
1136 printk(KERN_ERR "FAT: logical sector size too small for device"
1137 " (logical sector size = %u)\n", logical_sector_size);
1138 brelse(bh);
1139 goto out_fail;
1140 }
1141 if (logical_sector_size > sb->s_blocksize) {
1142 brelse(bh);
1143
1144 if (!sb_set_blocksize(sb, logical_sector_size)) {
1145 printk(KERN_ERR "FAT: unable to set blocksize %u\n",
1146 logical_sector_size);
1147 goto out_fail;
1148 }
1149 bh = sb_bread(sb, 0);
1150 if (bh == NULL) {
1151 printk(KERN_ERR "FAT: unable to read boot sector"
1152 " (logical sector size = %lu)\n",
1153 sb->s_blocksize);
1154 goto out_fail;
1155 }
1156 b = (struct fat_boot_sector *) bh->b_data;
1157 }
1158
1159 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1160 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1161 sbi->fats = b->fats;
1162 sbi->fat_bits = 0; /* Don't know yet */
1163 sbi->fat_start = le16_to_cpu(b->reserved);
1164 sbi->fat_length = le16_to_cpu(b->fat_length);
1165 sbi->root_cluster = 0;
1166 sbi->free_clusters = -1; /* Don't know yet */
1167 sbi->prev_free = FAT_START_ENT;
1168
1169 if (!sbi->fat_length && b->fat32_length) {
1170 struct fat_boot_fsinfo *fsinfo;
1171 struct buffer_head *fsinfo_bh;
1172
1173 /* Must be FAT32 */
1174 sbi->fat_bits = 32;
1175 sbi->fat_length = le32_to_cpu(b->fat32_length);
1176 sbi->root_cluster = le32_to_cpu(b->root_cluster);
1177
1178 sb->s_maxbytes = 0xffffffff;
1179
1180 /* MC - if info_sector is 0, don't multiply by 0 */
1181 sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
1182 if (sbi->fsinfo_sector == 0)
1183 sbi->fsinfo_sector = 1;
1184
1185 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1186 if (fsinfo_bh == NULL) {
1187 printk(KERN_ERR "FAT: bread failed, FSINFO block"
1188 " (sector = %lu)\n", sbi->fsinfo_sector);
1189 brelse(bh);
1190 goto out_fail;
1191 }
1192
1193 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1194 if (!IS_FSINFO(fsinfo)) {
1195 printk(KERN_WARNING
1196 "FAT: Did not find valid FSINFO signature.\n"
1197 " Found signature1 0x%08x signature2 0x%08x"
1198 " (sector = %lu)\n",
1199 le32_to_cpu(fsinfo->signature1),
1200 le32_to_cpu(fsinfo->signature2),
1201 sbi->fsinfo_sector);
1202 } else {
1203 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1204 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1205 }
1206
1207 brelse(fsinfo_bh);
1208 }
1209
1210 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1211 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1212
1213 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1214 sbi->dir_entries =
1215 le16_to_cpu(get_unaligned((__le16 *)&b->dir_entries));
1216 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1217 if (!silent)
1218 printk(KERN_ERR "FAT: bogus directroy-entries per block"
1219 " (%u)\n", sbi->dir_entries);
1220 brelse(bh);
1221 goto out_invalid;
1222 }
1223
1224 rootdir_sectors = sbi->dir_entries
1225 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1226 sbi->data_start = sbi->dir_start + rootdir_sectors;
1227 total_sectors = le16_to_cpu(get_unaligned((__le16 *)&b->sectors));
1228 if (total_sectors == 0)
1229 total_sectors = le32_to_cpu(b->total_sect);
1230
1231 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1232
1233 if (sbi->fat_bits != 32)
1234 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1235
1236 /* check that FAT table does not overflow */
1237 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1238 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1239 if (total_clusters > MAX_FAT(sb)) {
1240 if (!silent)
1241 printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
1242 total_clusters);
1243 brelse(bh);
1244 goto out_invalid;
1245 }
1246
1247 sbi->max_cluster = total_clusters + FAT_START_ENT;
1248 /* check the free_clusters, it's not necessarily correct */
1249 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1250 sbi->free_clusters = -1;
1251 /* check the prev_free, it's not necessarily correct */
1252 sbi->prev_free %= sbi->max_cluster;
1253 if (sbi->prev_free < FAT_START_ENT)
1254 sbi->prev_free = FAT_START_ENT;
1255
1256 brelse(bh);
1257
1258 /* set up enough so that it can read an inode */
1259 fat_hash_init(sb);
1260 fat_ent_access_init(sb);
1261
1262 /*
1263 * The low byte of FAT's first entry must have same value with
1264 * media-field. But in real world, too many devices is
1265 * writing wrong value. So, removed that validity check.
1266 *
1267 * if (FAT_FIRST_ENT(sb, media) != first)
1268 */
1269
1270 error = -EINVAL;
1271 sprintf(buf, "cp%d", sbi->options.codepage);
1272 sbi->nls_disk = load_nls(buf);
1273 if (!sbi->nls_disk) {
1274 printk(KERN_ERR "FAT: codepage %s not found\n", buf);
1275 goto out_fail;
1276 }
1277
1278 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1279 if (sbi->options.isvfat) {
1280 sbi->nls_io = load_nls(sbi->options.iocharset);
1281 if (!sbi->nls_io) {
1282 printk(KERN_ERR "FAT: IO charset %s not found\n",
1283 sbi->options.iocharset);
1284 goto out_fail;
1285 }
1286 }
1287
1288 error = -ENOMEM;
1289 root_inode = new_inode(sb);
1290 if (!root_inode)
1291 goto out_fail;
1292 root_inode->i_ino = MSDOS_ROOT_INO;
1293 root_inode->i_version = 1;
1294 error = fat_read_root(root_inode);
1295 if (error < 0)
1296 goto out_fail;
1297 error = -ENOMEM;
1298 insert_inode_hash(root_inode);
1299 sb->s_root = d_alloc_root(root_inode);
1300 if (!sb->s_root) {
1301 printk(KERN_ERR "FAT: get root inode failed\n");
1302 goto out_fail;
1303 }
1304
1305 return 0;
1306
1307 out_invalid:
1308 error = -EINVAL;
1309 if (!silent)
1310 printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
1311 " on dev %s.\n", sb->s_id);
1312
1313 out_fail:
1314 if (root_inode)
1315 iput(root_inode);
1316 if (sbi->nls_io)
1317 unload_nls(sbi->nls_io);
1318 if (sbi->nls_disk)
1319 unload_nls(sbi->nls_disk);
1320 if (sbi->options.iocharset != fat_default_iocharset)
1321 kfree(sbi->options.iocharset);
1322 sb->s_fs_info = NULL;
1323 kfree(sbi);
1324 return error;
1325 }
1326
1327 EXPORT_SYMBOL(fat_fill_super);
1328
1329 int __init fat_cache_init(void);
1330 void __exit fat_cache_destroy(void);
1331
1332 static int __init init_fat_fs(void)
1333 {
1334 int ret;
1335
1336 ret = fat_cache_init();
1337 if (ret < 0)
1338 return ret;
1339 return fat_init_inodecache();
1340 }
1341
1342 static void __exit exit_fat_fs(void)
1343 {
1344 fat_cache_destroy();
1345 fat_destroy_inodecache();
1346 }
1347
1348 module_init(init_fat_fs)
1349 module_exit(exit_fat_fs)
1350
1351 MODULE_LICENSE("GPL");
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