1
2
3
4
5
6
7
8
9
10
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/exportfs.h>
22#include <linux/mount.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 <asm/unaligned.h>
30#include "fat.h"
31
32#ifndef CONFIG_FAT_DEFAULT_IOCHARSET
33
34#define CONFIG_FAT_DEFAULT_IOCHARSET ""
35#endif
36
37static int fat_default_codepage = CONFIG_FAT_DEFAULT_CODEPAGE;
38static char fat_default_iocharset[] = CONFIG_FAT_DEFAULT_IOCHARSET;
39
40
41static int fat_add_cluster(struct inode *inode)
42{
43 int err, cluster;
44
45 err = fat_alloc_clusters(inode, &cluster, 1);
46 if (err)
47 return err;
48
49
50 err = fat_chain_add(inode, cluster, 1);
51 if (err)
52 fat_free_clusters(inode, cluster);
53 return err;
54}
55
56static inline int __fat_get_block(struct inode *inode, sector_t iblock,
57 unsigned long *max_blocks,
58 struct buffer_head *bh_result, int create)
59{
60 struct super_block *sb = inode->i_sb;
61 struct msdos_sb_info *sbi = MSDOS_SB(sb);
62 unsigned long mapped_blocks;
63 sector_t phys;
64 int err, offset;
65
66 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
67 if (err)
68 return err;
69 if (phys) {
70 map_bh(bh_result, sb, phys);
71 *max_blocks = min(mapped_blocks, *max_blocks);
72 return 0;
73 }
74 if (!create)
75 return 0;
76
77 if (iblock != MSDOS_I(inode)->mmu_private >> sb->s_blocksize_bits) {
78 fat_fs_error(sb, "corrupted file size (i_pos %lld, %lld)",
79 MSDOS_I(inode)->i_pos, MSDOS_I(inode)->mmu_private);
80 return -EIO;
81 }
82
83 offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
84 if (!offset) {
85
86 err = fat_add_cluster(inode);
87 if (err)
88 return err;
89 }
90
91 mapped_blocks = sbi->sec_per_clus - offset;
92
93 *max_blocks = min(mapped_blocks, *max_blocks);
94 MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
95
96 err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
97 if (err)
98 return err;
99
100 BUG_ON(!phys);
101 BUG_ON(*max_blocks != mapped_blocks);
102 set_buffer_new(bh_result);
103 map_bh(bh_result, sb, phys);
104
105 return 0;
106}
107
108static int fat_get_block(struct inode *inode, sector_t iblock,
109 struct buffer_head *bh_result, int create)
110{
111 struct super_block *sb = inode->i_sb;
112 unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
113 int err;
114
115 err = __fat_get_block(inode, iblock, &max_blocks, bh_result, create);
116 if (err)
117 return err;
118 bh_result->b_size = max_blocks << sb->s_blocksize_bits;
119 return 0;
120}
121
122static int fat_writepage(struct page *page, struct writeback_control *wbc)
123{
124 return block_write_full_page(page, fat_get_block, wbc);
125}
126
127static int fat_writepages(struct address_space *mapping,
128 struct writeback_control *wbc)
129{
130 return mpage_writepages(mapping, wbc, fat_get_block);
131}
132
133static int fat_readpage(struct file *file, struct page *page)
134{
135 return mpage_readpage(page, fat_get_block);
136}
137
138static int fat_readpages(struct file *file, struct address_space *mapping,
139 struct list_head *pages, unsigned nr_pages)
140{
141 return mpage_readpages(mapping, pages, nr_pages, fat_get_block);
142}
143
144static void fat_write_failed(struct address_space *mapping, loff_t to)
145{
146 struct inode *inode = mapping->host;
147
148 if (to > inode->i_size) {
149 truncate_pagecache(inode, to, inode->i_size);
150 fat_truncate_blocks(inode, inode->i_size);
151 }
152}
153
154static int fat_write_begin(struct file *file, struct address_space *mapping,
155 loff_t pos, unsigned len, unsigned flags,
156 struct page **pagep, void **fsdata)
157{
158 int err;
159
160 *pagep = NULL;
161 err = cont_write_begin(file, mapping, pos, len, flags,
162 pagep, fsdata, fat_get_block,
163 &MSDOS_I(mapping->host)->mmu_private);
164 if (err < 0)
165 fat_write_failed(mapping, pos + len);
166 return err;
167}
168
169static int fat_write_end(struct file *file, struct address_space *mapping,
170 loff_t pos, unsigned len, unsigned copied,
171 struct page *pagep, void *fsdata)
172{
173 struct inode *inode = mapping->host;
174 int err;
175 err = generic_write_end(file, mapping, pos, len, copied, pagep, fsdata);
176 if (err < len)
177 fat_write_failed(mapping, pos + len);
178 if (!(err < 0) && !(MSDOS_I(inode)->i_attrs & ATTR_ARCH)) {
179 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
180 MSDOS_I(inode)->i_attrs |= ATTR_ARCH;
181 mark_inode_dirty(inode);
182 }
183 return err;
184}
185
186static ssize_t fat_direct_IO(int rw, struct kiocb *iocb,
187 const struct iovec *iov,
188 loff_t offset, unsigned long nr_segs)
189{
190 struct file *file = iocb->ki_filp;
191 struct address_space *mapping = file->f_mapping;
192 struct inode *inode = mapping->host;
193 ssize_t ret;
194
195 if (rw == WRITE) {
196
197
198
199
200
201
202
203
204
205 loff_t size = offset + iov_length(iov, nr_segs);
206 if (MSDOS_I(inode)->mmu_private < size)
207 return 0;
208 }
209
210
211
212
213
214 ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev,
215 iov, offset, nr_segs, fat_get_block, NULL);
216 if (ret < 0 && (rw & WRITE))
217 fat_write_failed(mapping, offset + iov_length(iov, nr_segs));
218
219 return ret;
220}
221
222static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
223{
224 sector_t blocknr;
225
226
227 down_read(&mapping->host->i_alloc_sem);
228 blocknr = generic_block_bmap(mapping, block, fat_get_block);
229 up_read(&mapping->host->i_alloc_sem);
230
231 return blocknr;
232}
233
234static const struct address_space_operations fat_aops = {
235 .readpage = fat_readpage,
236 .readpages = fat_readpages,
237 .writepage = fat_writepage,
238 .writepages = fat_writepages,
239 .sync_page = block_sync_page,
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
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270static 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
280static inline unsigned long fat_hash(loff_t i_pos)
281{
282 return hash_32(i_pos, FAT_HASH_BITS);
283}
284
285void fat_attach(struct inode *inode, loff_t i_pos)
286{
287 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
288 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
289
290 spin_lock(&sbi->inode_hash_lock);
291 MSDOS_I(inode)->i_pos = i_pos;
292 hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head);
293 spin_unlock(&sbi->inode_hash_lock);
294}
295EXPORT_SYMBOL_GPL(fat_attach);
296
297void fat_detach(struct inode *inode)
298{
299 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
300 spin_lock(&sbi->inode_hash_lock);
301 MSDOS_I(inode)->i_pos = 0;
302 hlist_del_init(&MSDOS_I(inode)->i_fat_hash);
303 spin_unlock(&sbi->inode_hash_lock);
304}
305EXPORT_SYMBOL_GPL(fat_detach);
306
307struct inode *fat_iget(struct super_block *sb, loff_t i_pos)
308{
309 struct msdos_sb_info *sbi = MSDOS_SB(sb);
310 struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos);
311 struct hlist_node *_p;
312 struct msdos_inode_info *i;
313 struct inode *inode = NULL;
314
315 spin_lock(&sbi->inode_hash_lock);
316 hlist_for_each_entry(i, _p, head, i_fat_hash) {
317 BUG_ON(i->vfs_inode.i_sb != sb);
318 if (i->i_pos != i_pos)
319 continue;
320 inode = igrab(&i->vfs_inode);
321 if (inode)
322 break;
323 }
324 spin_unlock(&sbi->inode_hash_lock);
325 return inode;
326}
327
328static int is_exec(unsigned char *extension)
329{
330 unsigned char *exe_extensions = "EXECOMBAT", *walk;
331
332 for (walk = exe_extensions; *walk; walk += 3)
333 if (!strncmp(extension, walk, 3))
334 return 1;
335 return 0;
336}
337
338static int fat_calc_dir_size(struct inode *inode)
339{
340 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
341 int ret, fclus, dclus;
342
343 inode->i_size = 0;
344 if (MSDOS_I(inode)->i_start == 0)
345 return 0;
346
347 ret = fat_get_cluster(inode, FAT_ENT_EOF, &fclus, &dclus);
348 if (ret < 0)
349 return ret;
350 inode->i_size = (fclus + 1) << sbi->cluster_bits;
351
352 return 0;
353}
354
355
356static int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
357{
358 struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
359 int error;
360
361 MSDOS_I(inode)->i_pos = 0;
362 inode->i_uid = sbi->options.fs_uid;
363 inode->i_gid = sbi->options.fs_gid;
364 inode->i_version++;
365 inode->i_generation = get_seconds();
366
367 if ((de->attr & ATTR_DIR) && !IS_FREE(de->name)) {
368 inode->i_generation &= ~1;
369 inode->i_mode = fat_make_mode(sbi, de->attr, S_IRWXUGO);
370 inode->i_op = sbi->dir_ops;
371 inode->i_fop = &fat_dir_operations;
372
373 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
374 if (sbi->fat_bits == 32)
375 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
376
377 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
378 error = fat_calc_dir_size(inode);
379 if (error < 0)
380 return error;
381 MSDOS_I(inode)->mmu_private = inode->i_size;
382
383 inode->i_nlink = fat_subdirs(inode);
384 } else {
385 inode->i_generation |= 1;
386 inode->i_mode = fat_make_mode(sbi, de->attr,
387 ((sbi->options.showexec && !is_exec(de->name + 8))
388 ? S_IRUGO|S_IWUGO : S_IRWXUGO));
389 MSDOS_I(inode)->i_start = le16_to_cpu(de->start);
390 if (sbi->fat_bits == 32)
391 MSDOS_I(inode)->i_start |= (le16_to_cpu(de->starthi) << 16);
392
393 MSDOS_I(inode)->i_logstart = MSDOS_I(inode)->i_start;
394 inode->i_size = le32_to_cpu(de->size);
395 inode->i_op = &fat_file_inode_operations;
396 inode->i_fop = &fat_file_operations;
397 inode->i_mapping->a_ops = &fat_aops;
398 MSDOS_I(inode)->mmu_private = inode->i_size;
399 }
400 if (de->attr & ATTR_SYS) {
401 if (sbi->options.sys_immutable)
402 inode->i_flags |= S_IMMUTABLE;
403 }
404 fat_save_attrs(inode, de->attr);
405
406 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
407 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
408
409 fat_time_fat2unix(sbi, &inode->i_mtime, de->time, de->date, 0);
410 if (sbi->options.isvfat) {
411 fat_time_fat2unix(sbi, &inode->i_ctime, de->ctime,
412 de->cdate, de->ctime_cs);
413 fat_time_fat2unix(sbi, &inode->i_atime, 0, de->adate, 0);
414 } else
415 inode->i_ctime = inode->i_atime = inode->i_mtime;
416
417 return 0;
418}
419
420struct inode *fat_build_inode(struct super_block *sb,
421 struct msdos_dir_entry *de, loff_t i_pos)
422{
423 struct inode *inode;
424 int err;
425
426 inode = fat_iget(sb, i_pos);
427 if (inode)
428 goto out;
429 inode = new_inode(sb);
430 if (!inode) {
431 inode = ERR_PTR(-ENOMEM);
432 goto out;
433 }
434 inode->i_ino = iunique(sb, MSDOS_ROOT_INO);
435 inode->i_version = 1;
436 err = fat_fill_inode(inode, de);
437 if (err) {
438 iput(inode);
439 inode = ERR_PTR(err);
440 goto out;
441 }
442 fat_attach(inode, i_pos);
443 insert_inode_hash(inode);
444out:
445 return inode;
446}
447
448EXPORT_SYMBOL_GPL(fat_build_inode);
449
450static void fat_evict_inode(struct inode *inode)
451{
452 truncate_inode_pages(&inode->i_data, 0);
453 if (!inode->i_nlink) {
454 inode->i_size = 0;
455 fat_truncate_blocks(inode, 0);
456 }
457 invalidate_inode_buffers(inode);
458 end_writeback(inode);
459 fat_cache_inval_inode(inode);
460 fat_detach(inode);
461}
462
463static void fat_write_super(struct super_block *sb)
464{
465 lock_super(sb);
466 sb->s_dirt = 0;
467
468 if (!(sb->s_flags & MS_RDONLY))
469 fat_clusters_flush(sb);
470 unlock_super(sb);
471}
472
473static int fat_sync_fs(struct super_block *sb, int wait)
474{
475 int err = 0;
476
477 if (sb->s_dirt) {
478 lock_super(sb);
479 sb->s_dirt = 0;
480 err = fat_clusters_flush(sb);
481 unlock_super(sb);
482 }
483
484 return err;
485}
486
487static void fat_put_super(struct super_block *sb)
488{
489 struct msdos_sb_info *sbi = MSDOS_SB(sb);
490
491 if (sb->s_dirt)
492 fat_write_super(sb);
493
494 iput(sbi->fat_inode);
495
496 unload_nls(sbi->nls_disk);
497 unload_nls(sbi->nls_io);
498
499 if (sbi->options.iocharset != fat_default_iocharset)
500 kfree(sbi->options.iocharset);
501
502 sb->s_fs_info = NULL;
503 kfree(sbi);
504}
505
506static struct kmem_cache *fat_inode_cachep;
507
508static struct inode *fat_alloc_inode(struct super_block *sb)
509{
510 struct msdos_inode_info *ei;
511 ei = kmem_cache_alloc(fat_inode_cachep, GFP_NOFS);
512 if (!ei)
513 return NULL;
514 return &ei->vfs_inode;
515}
516
517static void fat_i_callback(struct rcu_head *head)
518{
519 struct inode *inode = container_of(head, struct inode, i_rcu);
520 INIT_LIST_HEAD(&inode->i_dentry);
521 kmem_cache_free(fat_inode_cachep, MSDOS_I(inode));
522}
523
524static void fat_destroy_inode(struct inode *inode)
525{
526 call_rcu(&inode->i_rcu, fat_i_callback);
527}
528
529static void init_once(void *foo)
530{
531 struct msdos_inode_info *ei = (struct msdos_inode_info *)foo;
532
533 spin_lock_init(&ei->cache_lru_lock);
534 ei->nr_caches = 0;
535 ei->cache_valid_id = FAT_CACHE_VALID + 1;
536 INIT_LIST_HEAD(&ei->cache_lru);
537 INIT_HLIST_NODE(&ei->i_fat_hash);
538 inode_init_once(&ei->vfs_inode);
539}
540
541static int __init fat_init_inodecache(void)
542{
543 fat_inode_cachep = kmem_cache_create("fat_inode_cache",
544 sizeof(struct msdos_inode_info),
545 0, (SLAB_RECLAIM_ACCOUNT|
546 SLAB_MEM_SPREAD),
547 init_once);
548 if (fat_inode_cachep == NULL)
549 return -ENOMEM;
550 return 0;
551}
552
553static void __exit fat_destroy_inodecache(void)
554{
555 kmem_cache_destroy(fat_inode_cachep);
556}
557
558static int fat_remount(struct super_block *sb, int *flags, char *data)
559{
560 struct msdos_sb_info *sbi = MSDOS_SB(sb);
561 *flags |= MS_NODIRATIME | (sbi->options.isvfat ? 0 : MS_NOATIME);
562 return 0;
563}
564
565static int fat_statfs(struct dentry *dentry, struct kstatfs *buf)
566{
567 struct super_block *sb = dentry->d_sb;
568 struct msdos_sb_info *sbi = MSDOS_SB(sb);
569 u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
570
571
572 if (sbi->free_clusters == -1 || !sbi->free_clus_valid) {
573 int err = fat_count_free_clusters(dentry->d_sb);
574 if (err)
575 return err;
576 }
577
578 buf->f_type = dentry->d_sb->s_magic;
579 buf->f_bsize = sbi->cluster_size;
580 buf->f_blocks = sbi->max_cluster - FAT_START_ENT;
581 buf->f_bfree = sbi->free_clusters;
582 buf->f_bavail = sbi->free_clusters;
583 buf->f_fsid.val[0] = (u32)id;
584 buf->f_fsid.val[1] = (u32)(id >> 32);
585 buf->f_namelen = sbi->options.isvfat ? FAT_LFN_LEN : 12;
586
587 return 0;
588}
589
590static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi,
591 struct inode *inode)
592{
593 loff_t i_pos;
594#if BITS_PER_LONG == 32
595 spin_lock(&sbi->inode_hash_lock);
596#endif
597 i_pos = MSDOS_I(inode)->i_pos;
598#if BITS_PER_LONG == 32
599 spin_unlock(&sbi->inode_hash_lock);
600#endif
601 return i_pos;
602}
603
604static int __fat_write_inode(struct inode *inode, int wait)
605{
606 struct super_block *sb = inode->i_sb;
607 struct msdos_sb_info *sbi = MSDOS_SB(sb);
608 struct buffer_head *bh;
609 struct msdos_dir_entry *raw_entry;
610 loff_t i_pos;
611 int err;
612
613 if (inode->i_ino == MSDOS_ROOT_INO)
614 return 0;
615
616retry:
617 i_pos = fat_i_pos_read(sbi, inode);
618 if (!i_pos)
619 return 0;
620
621 bh = sb_bread(sb, i_pos >> sbi->dir_per_block_bits);
622 if (!bh) {
623 printk(KERN_ERR "FAT: unable to read inode block "
624 "for updating (i_pos %lld)\n", i_pos);
625 return -EIO;
626 }
627 spin_lock(&sbi->inode_hash_lock);
628 if (i_pos != MSDOS_I(inode)->i_pos) {
629 spin_unlock(&sbi->inode_hash_lock);
630 brelse(bh);
631 goto retry;
632 }
633
634 raw_entry = &((struct msdos_dir_entry *) (bh->b_data))
635 [i_pos & (sbi->dir_per_block - 1)];
636 if (S_ISDIR(inode->i_mode))
637 raw_entry->size = 0;
638 else
639 raw_entry->size = cpu_to_le32(inode->i_size);
640 raw_entry->attr = fat_make_attrs(inode);
641 raw_entry->start = cpu_to_le16(MSDOS_I(inode)->i_logstart);
642 raw_entry->starthi = cpu_to_le16(MSDOS_I(inode)->i_logstart >> 16);
643 fat_time_unix2fat(sbi, &inode->i_mtime, &raw_entry->time,
644 &raw_entry->date, NULL);
645 if (sbi->options.isvfat) {
646 __le16 atime;
647 fat_time_unix2fat(sbi, &inode->i_ctime, &raw_entry->ctime,
648 &raw_entry->cdate, &raw_entry->ctime_cs);
649 fat_time_unix2fat(sbi, &inode->i_atime, &atime,
650 &raw_entry->adate, NULL);
651 }
652 spin_unlock(&sbi->inode_hash_lock);
653 mark_buffer_dirty(bh);
654 err = 0;
655 if (wait)
656 err = sync_dirty_buffer(bh);
657 brelse(bh);
658 return err;
659}
660
661static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
662{
663 return __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
664}
665
666int fat_sync_inode(struct inode *inode)
667{
668 return __fat_write_inode(inode, 1);
669}
670
671EXPORT_SYMBOL_GPL(fat_sync_inode);
672
673static int fat_show_options(struct seq_file *m, struct vfsmount *mnt);
674static const struct super_operations fat_sops = {
675 .alloc_inode = fat_alloc_inode,
676 .destroy_inode = fat_destroy_inode,
677 .write_inode = fat_write_inode,
678 .evict_inode = fat_evict_inode,
679 .put_super = fat_put_super,
680 .write_super = fat_write_super,
681 .sync_fs = fat_sync_fs,
682 .statfs = fat_statfs,
683 .remount_fs = fat_remount,
684
685 .show_options = fat_show_options,
686};
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702static struct dentry *fat_fh_to_dentry(struct super_block *sb,
703 struct fid *fid, int fh_len, int fh_type)
704{
705 struct inode *inode = NULL;
706 u32 *fh = fid->raw;
707
708 if (fh_len < 5 || fh_type != 3)
709 return NULL;
710
711 inode = ilookup(sb, fh[0]);
712 if (!inode || inode->i_generation != fh[1]) {
713 if (inode)
714 iput(inode);
715 inode = NULL;
716 }
717 if (!inode) {
718 loff_t i_pos;
719 int i_logstart = fh[3] & 0x0fffffff;
720
721 i_pos = (loff_t)fh[2] << 8;
722 i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28);
723
724
725
726
727
728
729 inode = fat_iget(sb, i_pos);
730 if (inode && MSDOS_I(inode)->i_logstart != i_logstart) {
731 iput(inode);
732 inode = NULL;
733 }
734 }
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750 return d_obtain_alias(inode);
751}
752
753static int
754fat_encode_fh(struct dentry *de, __u32 *fh, int *lenp, int connectable)
755{
756 int len = *lenp;
757 struct inode *inode = de->d_inode;
758 u32 ipos_h, ipos_m, ipos_l;
759
760 if (len < 5)
761 return 255;
762
763 ipos_h = MSDOS_I(inode)->i_pos >> 8;
764 ipos_m = (MSDOS_I(inode)->i_pos & 0xf0) << 24;
765 ipos_l = (MSDOS_I(inode)->i_pos & 0x0f) << 28;
766 *lenp = 5;
767 fh[0] = inode->i_ino;
768 fh[1] = inode->i_generation;
769 fh[2] = ipos_h;
770 fh[3] = ipos_m | MSDOS_I(inode)->i_logstart;
771 spin_lock(&de->d_lock);
772 fh[4] = ipos_l | MSDOS_I(de->d_parent->d_inode)->i_logstart;
773 spin_unlock(&de->d_lock);
774 return 3;
775}
776
777static struct dentry *fat_get_parent(struct dentry *child)
778{
779 struct super_block *sb = child->d_sb;
780 struct buffer_head *bh;
781 struct msdos_dir_entry *de;
782 loff_t i_pos;
783 struct dentry *parent;
784 struct inode *inode;
785 int err;
786
787 lock_super(sb);
788
789 err = fat_get_dotdot_entry(child->d_inode, &bh, &de, &i_pos);
790 if (err) {
791 parent = ERR_PTR(err);
792 goto out;
793 }
794 inode = fat_build_inode(sb, de, i_pos);
795 brelse(bh);
796
797 parent = d_obtain_alias(inode);
798out:
799 unlock_super(sb);
800
801 return parent;
802}
803
804static const struct export_operations fat_export_ops = {
805 .encode_fh = fat_encode_fh,
806 .fh_to_dentry = fat_fh_to_dentry,
807 .get_parent = fat_get_parent,
808};
809
810static int fat_show_options(struct seq_file *m, struct vfsmount *mnt)
811{
812 struct msdos_sb_info *sbi = MSDOS_SB(mnt->mnt_sb);
813 struct fat_mount_options *opts = &sbi->options;
814 int isvfat = opts->isvfat;
815
816 if (opts->fs_uid != 0)
817 seq_printf(m, ",uid=%u", opts->fs_uid);
818 if (opts->fs_gid != 0)
819 seq_printf(m, ",gid=%u", opts->fs_gid);
820 seq_printf(m, ",fmask=%04o", opts->fs_fmask);
821 seq_printf(m, ",dmask=%04o", opts->fs_dmask);
822 if (opts->allow_utime)
823 seq_printf(m, ",allow_utime=%04o", opts->allow_utime);
824 if (sbi->nls_disk)
825 seq_printf(m, ",codepage=%s", sbi->nls_disk->charset);
826 if (isvfat) {
827 if (sbi->nls_io)
828 seq_printf(m, ",iocharset=%s", sbi->nls_io->charset);
829
830 switch (opts->shortname) {
831 case VFAT_SFN_DISPLAY_WIN95 | VFAT_SFN_CREATE_WIN95:
832 seq_puts(m, ",shortname=win95");
833 break;
834 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WINNT:
835 seq_puts(m, ",shortname=winnt");
836 break;
837 case VFAT_SFN_DISPLAY_WINNT | VFAT_SFN_CREATE_WIN95:
838 seq_puts(m, ",shortname=mixed");
839 break;
840 case VFAT_SFN_DISPLAY_LOWER | VFAT_SFN_CREATE_WIN95:
841 seq_puts(m, ",shortname=lower");
842 break;
843 default:
844 seq_puts(m, ",shortname=unknown");
845 break;
846 }
847 }
848 if (opts->name_check != 'n')
849 seq_printf(m, ",check=%c", opts->name_check);
850 if (opts->usefree)
851 seq_puts(m, ",usefree");
852 if (opts->quiet)
853 seq_puts(m, ",quiet");
854 if (opts->showexec)
855 seq_puts(m, ",showexec");
856 if (opts->sys_immutable)
857 seq_puts(m, ",sys_immutable");
858 if (!isvfat) {
859 if (opts->dotsOK)
860 seq_puts(m, ",dotsOK=yes");
861 if (opts->nocase)
862 seq_puts(m, ",nocase");
863 } else {
864 if (opts->utf8)
865 seq_puts(m, ",utf8");
866 if (opts->unicode_xlate)
867 seq_puts(m, ",uni_xlate");
868 if (!opts->numtail)
869 seq_puts(m, ",nonumtail");
870 if (opts->rodir)
871 seq_puts(m, ",rodir");
872 }
873 if (opts->flush)
874 seq_puts(m, ",flush");
875 if (opts->tz_utc)
876 seq_puts(m, ",tz=UTC");
877 if (opts->errors == FAT_ERRORS_CONT)
878 seq_puts(m, ",errors=continue");
879 else if (opts->errors == FAT_ERRORS_PANIC)
880 seq_puts(m, ",errors=panic");
881 else
882 seq_puts(m, ",errors=remount-ro");
883 if (opts->discard)
884 seq_puts(m, ",discard");
885
886 return 0;
887}
888
889enum {
890 Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,
891 Opt_umask, Opt_dmask, Opt_fmask, Opt_allow_utime, Opt_codepage,
892 Opt_usefree, Opt_nocase, Opt_quiet, Opt_showexec, Opt_debug,
893 Opt_immutable, Opt_dots, Opt_nodots,
894 Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
895 Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes,
896 Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes,
897 Opt_obsolate, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont,
898 Opt_err_panic, Opt_err_ro, Opt_discard, Opt_err,
899};
900
901static const match_table_t fat_tokens = {
902 {Opt_check_r, "check=relaxed"},
903 {Opt_check_s, "check=strict"},
904 {Opt_check_n, "check=normal"},
905 {Opt_check_r, "check=r"},
906 {Opt_check_s, "check=s"},
907 {Opt_check_n, "check=n"},
908 {Opt_uid, "uid=%u"},
909 {Opt_gid, "gid=%u"},
910 {Opt_umask, "umask=%o"},
911 {Opt_dmask, "dmask=%o"},
912 {Opt_fmask, "fmask=%o"},
913 {Opt_allow_utime, "allow_utime=%o"},
914 {Opt_codepage, "codepage=%u"},
915 {Opt_usefree, "usefree"},
916 {Opt_nocase, "nocase"},
917 {Opt_quiet, "quiet"},
918 {Opt_showexec, "showexec"},
919 {Opt_debug, "debug"},
920 {Opt_immutable, "sys_immutable"},
921 {Opt_flush, "flush"},
922 {Opt_tz_utc, "tz=UTC"},
923 {Opt_err_cont, "errors=continue"},
924 {Opt_err_panic, "errors=panic"},
925 {Opt_err_ro, "errors=remount-ro"},
926 {Opt_discard, "discard"},
927 {Opt_obsolate, "conv=binary"},
928 {Opt_obsolate, "conv=text"},
929 {Opt_obsolate, "conv=auto"},
930 {Opt_obsolate, "conv=b"},
931 {Opt_obsolate, "conv=t"},
932 {Opt_obsolate, "conv=a"},
933 {Opt_obsolate, "fat=%u"},
934 {Opt_obsolate, "blocksize=%u"},
935 {Opt_obsolate, "cvf_format=%20s"},
936 {Opt_obsolate, "cvf_options=%100s"},
937 {Opt_obsolate, "posix"},
938 {Opt_err, NULL},
939};
940static const match_table_t msdos_tokens = {
941 {Opt_nodots, "nodots"},
942 {Opt_nodots, "dotsOK=no"},
943 {Opt_dots, "dots"},
944 {Opt_dots, "dotsOK=yes"},
945 {Opt_err, NULL}
946};
947static const match_table_t vfat_tokens = {
948 {Opt_charset, "iocharset=%s"},
949 {Opt_shortname_lower, "shortname=lower"},
950 {Opt_shortname_win95, "shortname=win95"},
951 {Opt_shortname_winnt, "shortname=winnt"},
952 {Opt_shortname_mixed, "shortname=mixed"},
953 {Opt_utf8_no, "utf8=0"},
954 {Opt_utf8_no, "utf8=no"},
955 {Opt_utf8_no, "utf8=false"},
956 {Opt_utf8_yes, "utf8=1"},
957 {Opt_utf8_yes, "utf8=yes"},
958 {Opt_utf8_yes, "utf8=true"},
959 {Opt_utf8_yes, "utf8"},
960 {Opt_uni_xl_no, "uni_xlate=0"},
961 {Opt_uni_xl_no, "uni_xlate=no"},
962 {Opt_uni_xl_no, "uni_xlate=false"},
963 {Opt_uni_xl_yes, "uni_xlate=1"},
964 {Opt_uni_xl_yes, "uni_xlate=yes"},
965 {Opt_uni_xl_yes, "uni_xlate=true"},
966 {Opt_uni_xl_yes, "uni_xlate"},
967 {Opt_nonumtail_no, "nonumtail=0"},
968 {Opt_nonumtail_no, "nonumtail=no"},
969 {Opt_nonumtail_no, "nonumtail=false"},
970 {Opt_nonumtail_yes, "nonumtail=1"},
971 {Opt_nonumtail_yes, "nonumtail=yes"},
972 {Opt_nonumtail_yes, "nonumtail=true"},
973 {Opt_nonumtail_yes, "nonumtail"},
974 {Opt_rodir, "rodir"},
975 {Opt_err, NULL}
976};
977
978static int parse_options(char *options, int is_vfat, int silent, int *debug,
979 struct fat_mount_options *opts)
980{
981 char *p;
982 substring_t args[MAX_OPT_ARGS];
983 int option;
984 char *iocharset;
985
986 opts->isvfat = is_vfat;
987
988 opts->fs_uid = current_uid();
989 opts->fs_gid = current_gid();
990 opts->fs_fmask = opts->fs_dmask = current_umask();
991 opts->allow_utime = -1;
992 opts->codepage = fat_default_codepage;
993 opts->iocharset = fat_default_iocharset;
994 if (is_vfat) {
995 opts->shortname = VFAT_SFN_DISPLAY_WINNT|VFAT_SFN_CREATE_WIN95;
996 opts->rodir = 0;
997 } else {
998 opts->shortname = 0;
999 opts->rodir = 1;
1000 }
1001 opts->name_check = 'n';
1002 opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK = 0;
1003 opts->utf8 = opts->unicode_xlate = 0;
1004 opts->numtail = 1;
1005 opts->usefree = opts->nocase = 0;
1006 opts->tz_utc = 0;
1007 opts->errors = FAT_ERRORS_RO;
1008 *debug = 0;
1009
1010 if (!options)
1011 goto out;
1012
1013 while ((p = strsep(&options, ",")) != NULL) {
1014 int token;
1015 if (!*p)
1016 continue;
1017
1018 token = match_token(p, fat_tokens, args);
1019 if (token == Opt_err) {
1020 if (is_vfat)
1021 token = match_token(p, vfat_tokens, args);
1022 else
1023 token = match_token(p, msdos_tokens, args);
1024 }
1025 switch (token) {
1026 case Opt_check_s:
1027 opts->name_check = 's';
1028 break;
1029 case Opt_check_r:
1030 opts->name_check = 'r';
1031 break;
1032 case Opt_check_n:
1033 opts->name_check = 'n';
1034 break;
1035 case Opt_usefree:
1036 opts->usefree = 1;
1037 break;
1038 case Opt_nocase:
1039 if (!is_vfat)
1040 opts->nocase = 1;
1041 else {
1042
1043 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1044 | VFAT_SFN_CREATE_WIN95;
1045 }
1046 break;
1047 case Opt_quiet:
1048 opts->quiet = 1;
1049 break;
1050 case Opt_showexec:
1051 opts->showexec = 1;
1052 break;
1053 case Opt_debug:
1054 *debug = 1;
1055 break;
1056 case Opt_immutable:
1057 opts->sys_immutable = 1;
1058 break;
1059 case Opt_uid:
1060 if (match_int(&args[0], &option))
1061 return 0;
1062 opts->fs_uid = option;
1063 break;
1064 case Opt_gid:
1065 if (match_int(&args[0], &option))
1066 return 0;
1067 opts->fs_gid = option;
1068 break;
1069 case Opt_umask:
1070 if (match_octal(&args[0], &option))
1071 return 0;
1072 opts->fs_fmask = opts->fs_dmask = option;
1073 break;
1074 case Opt_dmask:
1075 if (match_octal(&args[0], &option))
1076 return 0;
1077 opts->fs_dmask = option;
1078 break;
1079 case Opt_fmask:
1080 if (match_octal(&args[0], &option))
1081 return 0;
1082 opts->fs_fmask = option;
1083 break;
1084 case Opt_allow_utime:
1085 if (match_octal(&args[0], &option))
1086 return 0;
1087 opts->allow_utime = option & (S_IWGRP | S_IWOTH);
1088 break;
1089 case Opt_codepage:
1090 if (match_int(&args[0], &option))
1091 return 0;
1092 opts->codepage = option;
1093 break;
1094 case Opt_flush:
1095 opts->flush = 1;
1096 break;
1097 case Opt_tz_utc:
1098 opts->tz_utc = 1;
1099 break;
1100 case Opt_err_cont:
1101 opts->errors = FAT_ERRORS_CONT;
1102 break;
1103 case Opt_err_panic:
1104 opts->errors = FAT_ERRORS_PANIC;
1105 break;
1106 case Opt_err_ro:
1107 opts->errors = FAT_ERRORS_RO;
1108 break;
1109
1110
1111 case Opt_dots:
1112 opts->dotsOK = 1;
1113 break;
1114 case Opt_nodots:
1115 opts->dotsOK = 0;
1116 break;
1117
1118
1119 case Opt_charset:
1120 if (opts->iocharset != fat_default_iocharset)
1121 kfree(opts->iocharset);
1122 iocharset = match_strdup(&args[0]);
1123 if (!iocharset)
1124 return -ENOMEM;
1125 opts->iocharset = iocharset;
1126 break;
1127 case Opt_shortname_lower:
1128 opts->shortname = VFAT_SFN_DISPLAY_LOWER
1129 | VFAT_SFN_CREATE_WIN95;
1130 break;
1131 case Opt_shortname_win95:
1132 opts->shortname = VFAT_SFN_DISPLAY_WIN95
1133 | VFAT_SFN_CREATE_WIN95;
1134 break;
1135 case Opt_shortname_winnt:
1136 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1137 | VFAT_SFN_CREATE_WINNT;
1138 break;
1139 case Opt_shortname_mixed:
1140 opts->shortname = VFAT_SFN_DISPLAY_WINNT
1141 | VFAT_SFN_CREATE_WIN95;
1142 break;
1143 case Opt_utf8_no:
1144 opts->utf8 = 0;
1145 break;
1146 case Opt_utf8_yes:
1147 opts->utf8 = 1;
1148 break;
1149 case Opt_uni_xl_no:
1150 opts->unicode_xlate = 0;
1151 break;
1152 case Opt_uni_xl_yes:
1153 opts->unicode_xlate = 1;
1154 break;
1155 case Opt_nonumtail_no:
1156 opts->numtail = 1;
1157 break;
1158 case Opt_nonumtail_yes:
1159 opts->numtail = 0;
1160 break;
1161 case Opt_rodir:
1162 opts->rodir = 1;
1163 break;
1164 case Opt_discard:
1165 opts->discard = 1;
1166 break;
1167
1168
1169 case Opt_obsolate:
1170 printk(KERN_INFO "FAT: \"%s\" option is obsolete, "
1171 "not supported now\n", p);
1172 break;
1173
1174 default:
1175 if (!silent) {
1176 printk(KERN_ERR
1177 "FAT: Unrecognized mount option \"%s\" "
1178 "or missing value\n", p);
1179 }
1180 return -EINVAL;
1181 }
1182 }
1183
1184out:
1185
1186 if (!strcmp(opts->iocharset, "utf8")) {
1187 printk(KERN_ERR "FAT: utf8 is not a recommended IO charset"
1188 " for FAT filesystems, filesystem will be "
1189 "case sensitive!\n");
1190 }
1191
1192
1193 if (opts->allow_utime == (unsigned short)-1)
1194 opts->allow_utime = ~opts->fs_dmask & (S_IWGRP | S_IWOTH);
1195 if (opts->unicode_xlate)
1196 opts->utf8 = 0;
1197
1198 return 0;
1199}
1200
1201static int fat_read_root(struct inode *inode)
1202{
1203 struct super_block *sb = inode->i_sb;
1204 struct msdos_sb_info *sbi = MSDOS_SB(sb);
1205 int error;
1206
1207 MSDOS_I(inode)->i_pos = 0;
1208 inode->i_uid = sbi->options.fs_uid;
1209 inode->i_gid = sbi->options.fs_gid;
1210 inode->i_version++;
1211 inode->i_generation = 0;
1212 inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);
1213 inode->i_op = sbi->dir_ops;
1214 inode->i_fop = &fat_dir_operations;
1215 if (sbi->fat_bits == 32) {
1216 MSDOS_I(inode)->i_start = sbi->root_cluster;
1217 error = fat_calc_dir_size(inode);
1218 if (error < 0)
1219 return error;
1220 } else {
1221 MSDOS_I(inode)->i_start = 0;
1222 inode->i_size = sbi->dir_entries * sizeof(struct msdos_dir_entry);
1223 }
1224 inode->i_blocks = ((inode->i_size + (sbi->cluster_size - 1))
1225 & ~((loff_t)sbi->cluster_size - 1)) >> 9;
1226 MSDOS_I(inode)->i_logstart = 0;
1227 MSDOS_I(inode)->mmu_private = inode->i_size;
1228
1229 fat_save_attrs(inode, ATTR_DIR);
1230 inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
1231 inode->i_mtime.tv_nsec = inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1232 inode->i_nlink = fat_subdirs(inode)+2;
1233
1234 return 0;
1235}
1236
1237
1238
1239
1240int fat_fill_super(struct super_block *sb, void *data, int silent,
1241 const struct inode_operations *fs_dir_inode_ops, int isvfat,
1242 void (*setup)(struct super_block *))
1243{
1244 struct inode *root_inode = NULL, *fat_inode = NULL;
1245 struct buffer_head *bh;
1246 struct fat_boot_sector *b;
1247 struct msdos_sb_info *sbi;
1248 u16 logical_sector_size;
1249 u32 total_sectors, total_clusters, fat_clusters, rootdir_sectors;
1250 int debug;
1251 unsigned int media;
1252 long error;
1253 char buf[50];
1254
1255
1256
1257
1258
1259
1260
1261 sbi = kzalloc(sizeof(struct msdos_sb_info), GFP_KERNEL);
1262 if (!sbi)
1263 return -ENOMEM;
1264 sb->s_fs_info = sbi;
1265
1266 sb->s_flags |= MS_NODIRATIME;
1267 sb->s_magic = MSDOS_SUPER_MAGIC;
1268 sb->s_op = &fat_sops;
1269 sb->s_export_op = &fat_export_ops;
1270 sbi->dir_ops = fs_dir_inode_ops;
1271 ratelimit_state_init(&sbi->ratelimit, DEFAULT_RATELIMIT_INTERVAL,
1272 DEFAULT_RATELIMIT_BURST);
1273
1274 error = parse_options(data, isvfat, silent, &debug, &sbi->options);
1275 if (error)
1276 goto out_fail;
1277
1278 setup(sb);
1279
1280 error = -EIO;
1281 sb_min_blocksize(sb, 512);
1282 bh = sb_bread(sb, 0);
1283 if (bh == NULL) {
1284 printk(KERN_ERR "FAT: unable to read boot sector\n");
1285 goto out_fail;
1286 }
1287
1288 b = (struct fat_boot_sector *) bh->b_data;
1289 if (!b->reserved) {
1290 if (!silent)
1291 printk(KERN_ERR "FAT: bogus number of reserved sectors\n");
1292 brelse(bh);
1293 goto out_invalid;
1294 }
1295 if (!b->fats) {
1296 if (!silent)
1297 printk(KERN_ERR "FAT: bogus number of FAT structure\n");
1298 brelse(bh);
1299 goto out_invalid;
1300 }
1301
1302
1303
1304
1305
1306
1307 media = b->media;
1308 if (!fat_valid_media(media)) {
1309 if (!silent)
1310 printk(KERN_ERR "FAT: invalid media value (0x%02x)\n",
1311 media);
1312 brelse(bh);
1313 goto out_invalid;
1314 }
1315 logical_sector_size = get_unaligned_le16(&b->sector_size);
1316 if (!is_power_of_2(logical_sector_size)
1317 || (logical_sector_size < 512)
1318 || (logical_sector_size > 4096)) {
1319 if (!silent)
1320 printk(KERN_ERR "FAT: bogus logical sector size %u\n",
1321 logical_sector_size);
1322 brelse(bh);
1323 goto out_invalid;
1324 }
1325 sbi->sec_per_clus = b->sec_per_clus;
1326 if (!is_power_of_2(sbi->sec_per_clus)) {
1327 if (!silent)
1328 printk(KERN_ERR "FAT: bogus sectors per cluster %u\n",
1329 sbi->sec_per_clus);
1330 brelse(bh);
1331 goto out_invalid;
1332 }
1333
1334 if (logical_sector_size < sb->s_blocksize) {
1335 printk(KERN_ERR "FAT: logical sector size too small for device"
1336 " (logical sector size = %u)\n", logical_sector_size);
1337 brelse(bh);
1338 goto out_fail;
1339 }
1340 if (logical_sector_size > sb->s_blocksize) {
1341 brelse(bh);
1342
1343 if (!sb_set_blocksize(sb, logical_sector_size)) {
1344 printk(KERN_ERR "FAT: unable to set blocksize %u\n",
1345 logical_sector_size);
1346 goto out_fail;
1347 }
1348 bh = sb_bread(sb, 0);
1349 if (bh == NULL) {
1350 printk(KERN_ERR "FAT: unable to read boot sector"
1351 " (logical sector size = %lu)\n",
1352 sb->s_blocksize);
1353 goto out_fail;
1354 }
1355 b = (struct fat_boot_sector *) bh->b_data;
1356 }
1357
1358 sbi->cluster_size = sb->s_blocksize * sbi->sec_per_clus;
1359 sbi->cluster_bits = ffs(sbi->cluster_size) - 1;
1360 sbi->fats = b->fats;
1361 sbi->fat_bits = 0;
1362 sbi->fat_start = le16_to_cpu(b->reserved);
1363 sbi->fat_length = le16_to_cpu(b->fat_length);
1364 sbi->root_cluster = 0;
1365 sbi->free_clusters = -1;
1366 sbi->free_clus_valid = 0;
1367 sbi->prev_free = FAT_START_ENT;
1368
1369 if (!sbi->fat_length && b->fat32_length) {
1370 struct fat_boot_fsinfo *fsinfo;
1371 struct buffer_head *fsinfo_bh;
1372
1373
1374 sbi->fat_bits = 32;
1375 sbi->fat_length = le32_to_cpu(b->fat32_length);
1376 sbi->root_cluster = le32_to_cpu(b->root_cluster);
1377
1378 sb->s_maxbytes = 0xffffffff;
1379
1380
1381 sbi->fsinfo_sector = le16_to_cpu(b->info_sector);
1382 if (sbi->fsinfo_sector == 0)
1383 sbi->fsinfo_sector = 1;
1384
1385 fsinfo_bh = sb_bread(sb, sbi->fsinfo_sector);
1386 if (fsinfo_bh == NULL) {
1387 printk(KERN_ERR "FAT: bread failed, FSINFO block"
1388 " (sector = %lu)\n", sbi->fsinfo_sector);
1389 brelse(bh);
1390 goto out_fail;
1391 }
1392
1393 fsinfo = (struct fat_boot_fsinfo *)fsinfo_bh->b_data;
1394 if (!IS_FSINFO(fsinfo)) {
1395 printk(KERN_WARNING "FAT: Invalid FSINFO signature: "
1396 "0x%08x, 0x%08x (sector = %lu)\n",
1397 le32_to_cpu(fsinfo->signature1),
1398 le32_to_cpu(fsinfo->signature2),
1399 sbi->fsinfo_sector);
1400 } else {
1401 if (sbi->options.usefree)
1402 sbi->free_clus_valid = 1;
1403 sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);
1404 sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);
1405 }
1406
1407 brelse(fsinfo_bh);
1408 }
1409
1410 sbi->dir_per_block = sb->s_blocksize / sizeof(struct msdos_dir_entry);
1411 sbi->dir_per_block_bits = ffs(sbi->dir_per_block) - 1;
1412
1413 sbi->dir_start = sbi->fat_start + sbi->fats * sbi->fat_length;
1414 sbi->dir_entries = get_unaligned_le16(&b->dir_entries);
1415 if (sbi->dir_entries & (sbi->dir_per_block - 1)) {
1416 if (!silent)
1417 printk(KERN_ERR "FAT: bogus directroy-entries per block"
1418 " (%u)\n", sbi->dir_entries);
1419 brelse(bh);
1420 goto out_invalid;
1421 }
1422
1423 rootdir_sectors = sbi->dir_entries
1424 * sizeof(struct msdos_dir_entry) / sb->s_blocksize;
1425 sbi->data_start = sbi->dir_start + rootdir_sectors;
1426 total_sectors = get_unaligned_le16(&b->sectors);
1427 if (total_sectors == 0)
1428 total_sectors = le32_to_cpu(b->total_sect);
1429
1430 total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;
1431
1432 if (sbi->fat_bits != 32)
1433 sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;
1434
1435
1436 fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits;
1437 total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT);
1438 if (total_clusters > MAX_FAT(sb)) {
1439 if (!silent)
1440 printk(KERN_ERR "FAT: count of clusters too big (%u)\n",
1441 total_clusters);
1442 brelse(bh);
1443 goto out_invalid;
1444 }
1445
1446 sbi->max_cluster = total_clusters + FAT_START_ENT;
1447
1448 if (sbi->free_clusters != -1 && sbi->free_clusters > total_clusters)
1449 sbi->free_clusters = -1;
1450
1451 sbi->prev_free %= sbi->max_cluster;
1452 if (sbi->prev_free < FAT_START_ENT)
1453 sbi->prev_free = FAT_START_ENT;
1454
1455 brelse(bh);
1456
1457
1458 fat_hash_init(sb);
1459 fat_ent_access_init(sb);
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469 error = -EINVAL;
1470 sprintf(buf, "cp%d", sbi->options.codepage);
1471 sbi->nls_disk = load_nls(buf);
1472 if (!sbi->nls_disk) {
1473 printk(KERN_ERR "FAT: codepage %s not found\n", buf);
1474 goto out_fail;
1475 }
1476
1477
1478 if (sbi->options.isvfat) {
1479 sbi->nls_io = load_nls(sbi->options.iocharset);
1480 if (!sbi->nls_io) {
1481 printk(KERN_ERR "FAT: IO charset %s not found\n",
1482 sbi->options.iocharset);
1483 goto out_fail;
1484 }
1485 }
1486
1487 error = -ENOMEM;
1488 fat_inode = new_inode(sb);
1489 if (!fat_inode)
1490 goto out_fail;
1491 MSDOS_I(fat_inode)->i_pos = 0;
1492 sbi->fat_inode = fat_inode;
1493 root_inode = new_inode(sb);
1494 if (!root_inode)
1495 goto out_fail;
1496 root_inode->i_ino = MSDOS_ROOT_INO;
1497 root_inode->i_version = 1;
1498 error = fat_read_root(root_inode);
1499 if (error < 0)
1500 goto out_fail;
1501 error = -ENOMEM;
1502 insert_inode_hash(root_inode);
1503 sb->s_root = d_alloc_root(root_inode);
1504 if (!sb->s_root) {
1505 printk(KERN_ERR "FAT: get root inode failed\n");
1506 goto out_fail;
1507 }
1508
1509 return 0;
1510
1511out_invalid:
1512 error = -EINVAL;
1513 if (!silent)
1514 printk(KERN_INFO "VFS: Can't find a valid FAT filesystem"
1515 " on dev %s.\n", sb->s_id);
1516
1517out_fail:
1518 if (fat_inode)
1519 iput(fat_inode);
1520 if (root_inode)
1521 iput(root_inode);
1522 unload_nls(sbi->nls_io);
1523 unload_nls(sbi->nls_disk);
1524 if (sbi->options.iocharset != fat_default_iocharset)
1525 kfree(sbi->options.iocharset);
1526 sb->s_fs_info = NULL;
1527 kfree(sbi);
1528 return error;
1529}
1530
1531EXPORT_SYMBOL_GPL(fat_fill_super);
1532
1533
1534
1535
1536
1537
1538
1539static int writeback_inode(struct inode *inode)
1540{
1541
1542 int ret;
1543 struct address_space *mapping = inode->i_mapping;
1544 struct writeback_control wbc = {
1545 .sync_mode = WB_SYNC_NONE,
1546 .nr_to_write = 0,
1547 };
1548
1549
1550
1551
1552 ret = sync_inode(inode, &wbc);
1553 if (!ret)
1554 ret = filemap_fdatawrite(mapping);
1555 return ret;
1556}
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2)
1567{
1568 int ret = 0;
1569 if (!MSDOS_SB(sb)->options.flush)
1570 return 0;
1571 if (i1)
1572 ret = writeback_inode(i1);
1573 if (!ret && i2)
1574 ret = writeback_inode(i2);
1575 if (!ret) {
1576 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
1577 ret = filemap_flush(mapping);
1578 }
1579 return ret;
1580}
1581EXPORT_SYMBOL_GPL(fat_flush_inodes);
1582
1583static int __init init_fat_fs(void)
1584{
1585 int err;
1586
1587 err = fat_cache_init();
1588 if (err)
1589 return err;
1590
1591 err = fat_init_inodecache();
1592 if (err)
1593 goto failed;
1594
1595 return 0;
1596
1597failed:
1598 fat_cache_destroy();
1599 return err;
1600}
1601
1602static void __exit exit_fat_fs(void)
1603{
1604 fat_cache_destroy();
1605 fat_destroy_inodecache();
1606}
1607
1608module_init(init_fat_fs)
1609module_exit(exit_fat_fs)
1610
1611MODULE_LICENSE("GPL");
1612