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
10 * Max Cohan: Fixed invalid FSINFO offset when info_sector is 0
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>
32 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET
33 /* if user don't select VFAT, this is undefined. */
34 #define CONFIG_FAT_DEFAULT_IOCHARSET ""
37 static int fat_default_codepage
= CONFIG_FAT_DEFAULT_CODEPAGE
;
38 static char fat_default_iocharset
[] = CONFIG_FAT_DEFAULT_IOCHARSET
;
41 static int fat_add_cluster(struct inode
*inode
)
45 err
= fat_alloc_clusters(inode
, &cluster
, 1);
48 /* FIXME: this cluster should be added after data of this
49 * cluster is writed */
50 err
= fat_chain_add(inode
, cluster
, 1);
52 fat_free_clusters(inode
, cluster
);
56 static inline int __fat_get_block(struct inode
*inode
, sector_t iblock
,
57 unsigned long *max_blocks
,
58 struct buffer_head
*bh_result
, int create
)
60 struct super_block
*sb
= inode
->i_sb
;
61 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
62 unsigned long mapped_blocks
;
66 err
= fat_bmap(inode
, iblock
, &phys
, &mapped_blocks
, create
);
70 map_bh(bh_result
, sb
, phys
);
71 *max_blocks
= min(mapped_blocks
, *max_blocks
);
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
);
83 offset
= (unsigned long)iblock
& (sbi
->sec_per_clus
- 1);
85 /* TODO: multiple cluster allocation would be desirable. */
86 err
= fat_add_cluster(inode
);
90 /* available blocks on this cluster */
91 mapped_blocks
= sbi
->sec_per_clus
- offset
;
93 *max_blocks
= min(mapped_blocks
, *max_blocks
);
94 MSDOS_I(inode
)->mmu_private
+= *max_blocks
<< sb
->s_blocksize_bits
;
96 err
= fat_bmap(inode
, iblock
, &phys
, &mapped_blocks
, create
);
101 BUG_ON(*max_blocks
!= mapped_blocks
);
102 set_buffer_new(bh_result
);
103 map_bh(bh_result
, sb
, phys
);
108 static int fat_get_block(struct inode
*inode
, sector_t iblock
,
109 struct buffer_head
*bh_result
, int create
)
111 struct super_block
*sb
= inode
->i_sb
;
112 unsigned long max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
115 err
= __fat_get_block(inode
, iblock
, &max_blocks
, bh_result
, create
);
118 bh_result
->b_size
= max_blocks
<< sb
->s_blocksize_bits
;
122 static int fat_writepage(struct page
*page
, struct writeback_control
*wbc
)
124 return block_write_full_page(page
, fat_get_block
, wbc
);
127 static int fat_writepages(struct address_space
*mapping
,
128 struct writeback_control
*wbc
)
130 return mpage_writepages(mapping
, wbc
, fat_get_block
);
133 static int fat_readpage(struct file
*file
, struct page
*page
)
135 return mpage_readpage(page
, fat_get_block
);
138 static int fat_readpages(struct file
*file
, struct address_space
*mapping
,
139 struct list_head
*pages
, unsigned nr_pages
)
141 return mpage_readpages(mapping
, pages
, nr_pages
, fat_get_block
);
144 static void fat_write_failed(struct address_space
*mapping
, loff_t to
)
146 struct inode
*inode
= mapping
->host
;
148 if (to
> inode
->i_size
) {
149 truncate_pagecache(inode
, to
, inode
->i_size
);
150 fat_truncate_blocks(inode
, inode
->i_size
);
154 static 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
)
161 err
= cont_write_begin(file
, mapping
, pos
, len
, flags
,
162 pagep
, fsdata
, fat_get_block
,
163 &MSDOS_I(mapping
->host
)->mmu_private
);
165 fat_write_failed(mapping
, pos
+ len
);
169 static 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
)
173 struct inode
*inode
= mapping
->host
;
175 err
= generic_write_end(file
, mapping
, pos
, len
, copied
, pagep
, fsdata
);
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
);
186 static ssize_t
fat_direct_IO(int rw
, struct kiocb
*iocb
,
187 const struct iovec
*iov
,
188 loff_t offset
, unsigned long nr_segs
)
190 struct file
*file
= iocb
->ki_filp
;
191 struct address_space
*mapping
= file
->f_mapping
;
192 struct inode
*inode
= mapping
->host
;
197 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
198 * so we need to update the ->mmu_private to block boundary.
200 * But we must fill the remaining area or hole by nul for
201 * updating ->mmu_private.
203 * Return 0, and fallback to normal buffered write.
205 loff_t size
= offset
+ iov_length(iov
, nr_segs
);
206 if (MSDOS_I(inode
)->mmu_private
< size
)
211 * FAT need to use the DIO_LOCKING for avoiding the race
212 * condition of fat_get_block() and ->truncate().
214 ret
= blockdev_direct_IO(rw
, iocb
, inode
, iov
, offset
, nr_segs
,
216 if (ret
< 0 && (rw
& WRITE
))
217 fat_write_failed(mapping
, offset
+ iov_length(iov
, nr_segs
));
222 static sector_t
_fat_bmap(struct address_space
*mapping
, sector_t block
)
226 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
227 down_read(&MSDOS_I(mapping
->host
)->truncate_lock
);
228 blocknr
= generic_block_bmap(mapping
, block
, fat_get_block
);
229 up_read(&MSDOS_I(mapping
->host
)->truncate_lock
);
234 static const struct address_space_operations fat_aops
= {
235 .readpage
= fat_readpage
,
236 .readpages
= fat_readpages
,
237 .writepage
= fat_writepage
,
238 .writepages
= fat_writepages
,
239 .write_begin
= fat_write_begin
,
240 .write_end
= fat_write_end
,
241 .direct_IO
= fat_direct_IO
,
246 * New FAT inode stuff. We do the following:
247 * a) i_ino is constant and has nothing with on-disk location.
248 * b) FAT manages its own cache of directory entries.
249 * c) *This* cache is indexed by on-disk location.
250 * d) inode has an associated directory entry, all right, but
251 * it may be unhashed.
252 * e) currently entries are stored within struct inode. That should
254 * f) we deal with races in the following way:
255 * 1. readdir() and lookup() do FAT-dir-cache lookup.
256 * 2. rename() unhashes the F-d-c entry and rehashes it in
258 * 3. unlink() and rmdir() unhash F-d-c entry.
259 * 4. fat_write_inode() checks whether the thing is unhashed.
260 * If it is we silently return. If it isn't we do bread(),
261 * check if the location is still valid and retry if it
262 * isn't. Otherwise we do changes.
263 * 5. Spinlock is used to protect hash/unhash/location check/lookup
264 * 6. fat_evict_inode() unhashes the F-d-c entry.
265 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
266 * and consider negative result as cache miss.
269 static void fat_hash_init(struct super_block
*sb
)
271 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
274 spin_lock_init(&sbi
->inode_hash_lock
);
275 for (i
= 0; i
< FAT_HASH_SIZE
; i
++)
276 INIT_HLIST_HEAD(&sbi
->inode_hashtable
[i
]);
279 static inline unsigned long fat_hash(loff_t i_pos
)
281 return hash_32(i_pos
, FAT_HASH_BITS
);
284 void fat_attach(struct inode
*inode
, loff_t i_pos
)
286 struct msdos_sb_info
*sbi
= MSDOS_SB(inode
->i_sb
);
287 struct hlist_head
*head
= sbi
->inode_hashtable
+ fat_hash(i_pos
);
289 spin_lock(&sbi
->inode_hash_lock
);
290 MSDOS_I(inode
)->i_pos
= i_pos
;
291 hlist_add_head(&MSDOS_I(inode
)->i_fat_hash
, head
);
292 spin_unlock(&sbi
->inode_hash_lock
);
294 EXPORT_SYMBOL_GPL(fat_attach
);
296 void fat_detach(struct inode
*inode
)
298 struct msdos_sb_info
*sbi
= MSDOS_SB(inode
->i_sb
);
299 spin_lock(&sbi
->inode_hash_lock
);
300 MSDOS_I(inode
)->i_pos
= 0;
301 hlist_del_init(&MSDOS_I(inode
)->i_fat_hash
);
302 spin_unlock(&sbi
->inode_hash_lock
);
304 EXPORT_SYMBOL_GPL(fat_detach
);
306 struct inode
*fat_iget(struct super_block
*sb
, loff_t i_pos
)
308 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
309 struct hlist_head
*head
= sbi
->inode_hashtable
+ fat_hash(i_pos
);
310 struct hlist_node
*_p
;
311 struct msdos_inode_info
*i
;
312 struct inode
*inode
= NULL
;
314 spin_lock(&sbi
->inode_hash_lock
);
315 hlist_for_each_entry(i
, _p
, head
, i_fat_hash
) {
316 BUG_ON(i
->vfs_inode
.i_sb
!= sb
);
317 if (i
->i_pos
!= i_pos
)
319 inode
= igrab(&i
->vfs_inode
);
323 spin_unlock(&sbi
->inode_hash_lock
);
327 static int is_exec(unsigned char *extension
)
329 unsigned char *exe_extensions
= "EXECOMBAT", *walk
;
331 for (walk
= exe_extensions
; *walk
; walk
+= 3)
332 if (!strncmp(extension
, walk
, 3))
337 static int fat_calc_dir_size(struct inode
*inode
)
339 struct msdos_sb_info
*sbi
= MSDOS_SB(inode
->i_sb
);
340 int ret
, fclus
, dclus
;
343 if (MSDOS_I(inode
)->i_start
== 0)
346 ret
= fat_get_cluster(inode
, FAT_ENT_EOF
, &fclus
, &dclus
);
349 inode
->i_size
= (fclus
+ 1) << sbi
->cluster_bits
;
354 /* doesn't deal with root inode */
355 static int fat_fill_inode(struct inode
*inode
, struct msdos_dir_entry
*de
)
357 struct msdos_sb_info
*sbi
= MSDOS_SB(inode
->i_sb
);
360 MSDOS_I(inode
)->i_pos
= 0;
361 inode
->i_uid
= sbi
->options
.fs_uid
;
362 inode
->i_gid
= sbi
->options
.fs_gid
;
364 inode
->i_generation
= get_seconds();
366 if ((de
->attr
& ATTR_DIR
) && !IS_FREE(de
->name
)) {
367 inode
->i_generation
&= ~1;
368 inode
->i_mode
= fat_make_mode(sbi
, de
->attr
, S_IRWXUGO
);
369 inode
->i_op
= sbi
->dir_ops
;
370 inode
->i_fop
= &fat_dir_operations
;
372 MSDOS_I(inode
)->i_start
= le16_to_cpu(de
->start
);
373 if (sbi
->fat_bits
== 32)
374 MSDOS_I(inode
)->i_start
|= (le16_to_cpu(de
->starthi
) << 16);
376 MSDOS_I(inode
)->i_logstart
= MSDOS_I(inode
)->i_start
;
377 error
= fat_calc_dir_size(inode
);
380 MSDOS_I(inode
)->mmu_private
= inode
->i_size
;
382 set_nlink(inode
, fat_subdirs(inode
));
383 } else { /* not a directory */
384 inode
->i_generation
|= 1;
385 inode
->i_mode
= fat_make_mode(sbi
, de
->attr
,
386 ((sbi
->options
.showexec
&& !is_exec(de
->name
+ 8))
387 ? S_IRUGO
|S_IWUGO
: S_IRWXUGO
));
388 MSDOS_I(inode
)->i_start
= le16_to_cpu(de
->start
);
389 if (sbi
->fat_bits
== 32)
390 MSDOS_I(inode
)->i_start
|= (le16_to_cpu(de
->starthi
) << 16);
392 MSDOS_I(inode
)->i_logstart
= MSDOS_I(inode
)->i_start
;
393 inode
->i_size
= le32_to_cpu(de
->size
);
394 inode
->i_op
= &fat_file_inode_operations
;
395 inode
->i_fop
= &fat_file_operations
;
396 inode
->i_mapping
->a_ops
= &fat_aops
;
397 MSDOS_I(inode
)->mmu_private
= inode
->i_size
;
399 if (de
->attr
& ATTR_SYS
) {
400 if (sbi
->options
.sys_immutable
)
401 inode
->i_flags
|= S_IMMUTABLE
;
403 fat_save_attrs(inode
, de
->attr
);
405 inode
->i_blocks
= ((inode
->i_size
+ (sbi
->cluster_size
- 1))
406 & ~((loff_t
)sbi
->cluster_size
- 1)) >> 9;
408 fat_time_fat2unix(sbi
, &inode
->i_mtime
, de
->time
, de
->date
, 0);
409 if (sbi
->options
.isvfat
) {
410 fat_time_fat2unix(sbi
, &inode
->i_ctime
, de
->ctime
,
411 de
->cdate
, de
->ctime_cs
);
412 fat_time_fat2unix(sbi
, &inode
->i_atime
, 0, de
->adate
, 0);
414 inode
->i_ctime
= inode
->i_atime
= inode
->i_mtime
;
419 struct inode
*fat_build_inode(struct super_block
*sb
,
420 struct msdos_dir_entry
*de
, loff_t i_pos
)
425 inode
= fat_iget(sb
, i_pos
);
428 inode
= new_inode(sb
);
430 inode
= ERR_PTR(-ENOMEM
);
433 inode
->i_ino
= iunique(sb
, MSDOS_ROOT_INO
);
434 inode
->i_version
= 1;
435 err
= fat_fill_inode(inode
, de
);
438 inode
= ERR_PTR(err
);
441 fat_attach(inode
, i_pos
);
442 insert_inode_hash(inode
);
447 EXPORT_SYMBOL_GPL(fat_build_inode
);
449 static void fat_evict_inode(struct inode
*inode
)
451 truncate_inode_pages(&inode
->i_data
, 0);
452 if (!inode
->i_nlink
) {
454 fat_truncate_blocks(inode
, 0);
456 invalidate_inode_buffers(inode
);
458 fat_cache_inval_inode(inode
);
462 static void fat_put_super(struct super_block
*sb
)
464 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
466 iput(sbi
->fsinfo_inode
);
467 iput(sbi
->fat_inode
);
469 unload_nls(sbi
->nls_disk
);
470 unload_nls(sbi
->nls_io
);
472 if (sbi
->options
.iocharset
!= fat_default_iocharset
)
473 kfree(sbi
->options
.iocharset
);
475 sb
->s_fs_info
= NULL
;
479 static struct kmem_cache
*fat_inode_cachep
;
481 static struct inode
*fat_alloc_inode(struct super_block
*sb
)
483 struct msdos_inode_info
*ei
;
484 ei
= kmem_cache_alloc(fat_inode_cachep
, GFP_NOFS
);
488 init_rwsem(&ei
->truncate_lock
);
489 return &ei
->vfs_inode
;
492 static void fat_i_callback(struct rcu_head
*head
)
494 struct inode
*inode
= container_of(head
, struct inode
, i_rcu
);
495 kmem_cache_free(fat_inode_cachep
, MSDOS_I(inode
));
498 static void fat_destroy_inode(struct inode
*inode
)
500 call_rcu(&inode
->i_rcu
, fat_i_callback
);
503 static void init_once(void *foo
)
505 struct msdos_inode_info
*ei
= (struct msdos_inode_info
*)foo
;
507 spin_lock_init(&ei
->cache_lru_lock
);
509 ei
->cache_valid_id
= FAT_CACHE_VALID
+ 1;
510 INIT_LIST_HEAD(&ei
->cache_lru
);
511 INIT_HLIST_NODE(&ei
->i_fat_hash
);
512 inode_init_once(&ei
->vfs_inode
);
515 static int __init
fat_init_inodecache(void)
517 fat_inode_cachep
= kmem_cache_create("fat_inode_cache",
518 sizeof(struct msdos_inode_info
),
519 0, (SLAB_RECLAIM_ACCOUNT
|
522 if (fat_inode_cachep
== NULL
)
527 static void __exit
fat_destroy_inodecache(void)
529 kmem_cache_destroy(fat_inode_cachep
);
532 static int fat_remount(struct super_block
*sb
, int *flags
, char *data
)
534 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
535 *flags
|= MS_NODIRATIME
| (sbi
->options
.isvfat
? 0 : MS_NOATIME
);
539 static int fat_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
541 struct super_block
*sb
= dentry
->d_sb
;
542 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
543 u64 id
= huge_encode_dev(sb
->s_bdev
->bd_dev
);
545 /* If the count of free cluster is still unknown, counts it here. */
546 if (sbi
->free_clusters
== -1 || !sbi
->free_clus_valid
) {
547 int err
= fat_count_free_clusters(dentry
->d_sb
);
552 buf
->f_type
= dentry
->d_sb
->s_magic
;
553 buf
->f_bsize
= sbi
->cluster_size
;
554 buf
->f_blocks
= sbi
->max_cluster
- FAT_START_ENT
;
555 buf
->f_bfree
= sbi
->free_clusters
;
556 buf
->f_bavail
= sbi
->free_clusters
;
557 buf
->f_fsid
.val
[0] = (u32
)id
;
558 buf
->f_fsid
.val
[1] = (u32
)(id
>> 32);
560 (sbi
->options
.isvfat
? FAT_LFN_LEN
: 12) * NLS_MAX_CHARSET_SIZE
;
565 static inline loff_t
fat_i_pos_read(struct msdos_sb_info
*sbi
,
569 #if BITS_PER_LONG == 32
570 spin_lock(&sbi
->inode_hash_lock
);
572 i_pos
= MSDOS_I(inode
)->i_pos
;
573 #if BITS_PER_LONG == 32
574 spin_unlock(&sbi
->inode_hash_lock
);
579 static int __fat_write_inode(struct inode
*inode
, int wait
)
581 struct super_block
*sb
= inode
->i_sb
;
582 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
583 struct buffer_head
*bh
;
584 struct msdos_dir_entry
*raw_entry
;
588 if (inode
->i_ino
== MSDOS_ROOT_INO
)
592 i_pos
= fat_i_pos_read(sbi
, inode
);
596 bh
= sb_bread(sb
, i_pos
>> sbi
->dir_per_block_bits
);
598 fat_msg(sb
, KERN_ERR
, "unable to read inode block "
599 "for updating (i_pos %lld)", i_pos
);
602 spin_lock(&sbi
->inode_hash_lock
);
603 if (i_pos
!= MSDOS_I(inode
)->i_pos
) {
604 spin_unlock(&sbi
->inode_hash_lock
);
609 raw_entry
= &((struct msdos_dir_entry
*) (bh
->b_data
))
610 [i_pos
& (sbi
->dir_per_block
- 1)];
611 if (S_ISDIR(inode
->i_mode
))
614 raw_entry
->size
= cpu_to_le32(inode
->i_size
);
615 raw_entry
->attr
= fat_make_attrs(inode
);
616 raw_entry
->start
= cpu_to_le16(MSDOS_I(inode
)->i_logstart
);
617 raw_entry
->starthi
= cpu_to_le16(MSDOS_I(inode
)->i_logstart
>> 16);
618 fat_time_unix2fat(sbi
, &inode
->i_mtime
, &raw_entry
->time
,
619 &raw_entry
->date
, NULL
);
620 if (sbi
->options
.isvfat
) {
622 fat_time_unix2fat(sbi
, &inode
->i_ctime
, &raw_entry
->ctime
,
623 &raw_entry
->cdate
, &raw_entry
->ctime_cs
);
624 fat_time_unix2fat(sbi
, &inode
->i_atime
, &atime
,
625 &raw_entry
->adate
, NULL
);
627 spin_unlock(&sbi
->inode_hash_lock
);
628 mark_buffer_dirty(bh
);
631 err
= sync_dirty_buffer(bh
);
636 static int fat_write_inode(struct inode
*inode
, struct writeback_control
*wbc
)
640 if (inode
->i_ino
== MSDOS_FSINFO_INO
) {
641 struct super_block
*sb
= inode
->i_sb
;
644 err
= fat_clusters_flush(sb
);
647 err
= __fat_write_inode(inode
, wbc
->sync_mode
== WB_SYNC_ALL
);
652 int fat_sync_inode(struct inode
*inode
)
654 return __fat_write_inode(inode
, 1);
657 EXPORT_SYMBOL_GPL(fat_sync_inode
);
659 static int fat_show_options(struct seq_file
*m
, struct dentry
*root
);
660 static const struct super_operations fat_sops
= {
661 .alloc_inode
= fat_alloc_inode
,
662 .destroy_inode
= fat_destroy_inode
,
663 .write_inode
= fat_write_inode
,
664 .evict_inode
= fat_evict_inode
,
665 .put_super
= fat_put_super
,
666 .statfs
= fat_statfs
,
667 .remount_fs
= fat_remount
,
669 .show_options
= fat_show_options
,
673 * a FAT file handle with fhtype 3 is
674 * 0/ i_ino - for fast, reliable lookup if still in the cache
675 * 1/ i_generation - to see if i_ino is still valid
676 * bit 0 == 0 iff directory
677 * 2/ i_pos(8-39) - if ino has changed, but still in cache
678 * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
679 * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
681 * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
682 * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
683 * of i_logstart is used to store the directory entry offset.
686 static struct dentry
*fat_fh_to_dentry(struct super_block
*sb
,
687 struct fid
*fid
, int fh_len
, int fh_type
)
689 struct inode
*inode
= NULL
;
692 if (fh_len
< 5 || fh_type
!= 3)
695 inode
= ilookup(sb
, fh
[0]);
696 if (!inode
|| inode
->i_generation
!= fh
[1]) {
703 int i_logstart
= fh
[3] & 0x0fffffff;
705 i_pos
= (loff_t
)fh
[2] << 8;
706 i_pos
|= ((fh
[3] >> 24) & 0xf0) | (fh
[4] >> 28);
708 /* try 2 - see if i_pos is in F-d-c
709 * require i_logstart to be the same
710 * Will fail if you truncate and then re-write
713 inode
= fat_iget(sb
, i_pos
);
714 if (inode
&& MSDOS_I(inode
)->i_logstart
!= i_logstart
) {
721 * For now, do nothing if the inode is not found.
723 * What we could do is:
725 * - follow the file starting at fh[4], and record the ".." entry,
726 * and the name of the fh[2] entry.
727 * - then follow the ".." file finding the next step up.
729 * This way we build a path to the root of the tree. If this works, we
730 * lookup the path and so get this inode into the cache. Finally try
731 * the fat_iget lookup again. If that fails, then we are totally out
732 * of luck. But all that is for another day
734 return d_obtain_alias(inode
);
738 fat_encode_fh(struct inode
*inode
, __u32
*fh
, int *lenp
, struct inode
*parent
)
741 u32 ipos_h
, ipos_m
, ipos_l
;
745 return 255; /* no room */
748 ipos_h
= MSDOS_I(inode
)->i_pos
>> 8;
749 ipos_m
= (MSDOS_I(inode
)->i_pos
& 0xf0) << 24;
750 ipos_l
= (MSDOS_I(inode
)->i_pos
& 0x0f) << 28;
752 fh
[0] = inode
->i_ino
;
753 fh
[1] = inode
->i_generation
;
755 fh
[3] = ipos_m
| MSDOS_I(inode
)->i_logstart
;
758 fh
[4] |= MSDOS_I(parent
)->i_logstart
;
762 static struct dentry
*fat_get_parent(struct dentry
*child
)
764 struct super_block
*sb
= child
->d_sb
;
765 struct buffer_head
*bh
;
766 struct msdos_dir_entry
*de
;
768 struct dentry
*parent
;
774 err
= fat_get_dotdot_entry(child
->d_inode
, &bh
, &de
, &i_pos
);
776 parent
= ERR_PTR(err
);
779 inode
= fat_build_inode(sb
, de
, i_pos
);
782 parent
= d_obtain_alias(inode
);
789 static const struct export_operations fat_export_ops
= {
790 .encode_fh
= fat_encode_fh
,
791 .fh_to_dentry
= fat_fh_to_dentry
,
792 .get_parent
= fat_get_parent
,
795 static int fat_show_options(struct seq_file
*m
, struct dentry
*root
)
797 struct msdos_sb_info
*sbi
= MSDOS_SB(root
->d_sb
);
798 struct fat_mount_options
*opts
= &sbi
->options
;
799 int isvfat
= opts
->isvfat
;
801 if (opts
->fs_uid
!= 0)
802 seq_printf(m
, ",uid=%u", opts
->fs_uid
);
803 if (opts
->fs_gid
!= 0)
804 seq_printf(m
, ",gid=%u", opts
->fs_gid
);
805 seq_printf(m
, ",fmask=%04o", opts
->fs_fmask
);
806 seq_printf(m
, ",dmask=%04o", opts
->fs_dmask
);
807 if (opts
->allow_utime
)
808 seq_printf(m
, ",allow_utime=%04o", opts
->allow_utime
);
810 seq_printf(m
, ",codepage=%s", sbi
->nls_disk
->charset
);
813 seq_printf(m
, ",iocharset=%s", sbi
->nls_io
->charset
);
815 switch (opts
->shortname
) {
816 case VFAT_SFN_DISPLAY_WIN95
| VFAT_SFN_CREATE_WIN95
:
817 seq_puts(m
, ",shortname=win95");
819 case VFAT_SFN_DISPLAY_WINNT
| VFAT_SFN_CREATE_WINNT
:
820 seq_puts(m
, ",shortname=winnt");
822 case VFAT_SFN_DISPLAY_WINNT
| VFAT_SFN_CREATE_WIN95
:
823 seq_puts(m
, ",shortname=mixed");
825 case VFAT_SFN_DISPLAY_LOWER
| VFAT_SFN_CREATE_WIN95
:
826 seq_puts(m
, ",shortname=lower");
829 seq_puts(m
, ",shortname=unknown");
833 if (opts
->name_check
!= 'n')
834 seq_printf(m
, ",check=%c", opts
->name_check
);
836 seq_puts(m
, ",usefree");
838 seq_puts(m
, ",quiet");
840 seq_puts(m
, ",showexec");
841 if (opts
->sys_immutable
)
842 seq_puts(m
, ",sys_immutable");
845 seq_puts(m
, ",dotsOK=yes");
847 seq_puts(m
, ",nocase");
850 seq_puts(m
, ",utf8");
851 if (opts
->unicode_xlate
)
852 seq_puts(m
, ",uni_xlate");
854 seq_puts(m
, ",nonumtail");
856 seq_puts(m
, ",rodir");
859 seq_puts(m
, ",flush");
861 seq_puts(m
, ",tz=UTC");
862 if (opts
->errors
== FAT_ERRORS_CONT
)
863 seq_puts(m
, ",errors=continue");
864 else if (opts
->errors
== FAT_ERRORS_PANIC
)
865 seq_puts(m
, ",errors=panic");
867 seq_puts(m
, ",errors=remount-ro");
869 seq_puts(m
, ",discard");
875 Opt_check_n
, Opt_check_r
, Opt_check_s
, Opt_uid
, Opt_gid
,
876 Opt_umask
, Opt_dmask
, Opt_fmask
, Opt_allow_utime
, Opt_codepage
,
877 Opt_usefree
, Opt_nocase
, Opt_quiet
, Opt_showexec
, Opt_debug
,
878 Opt_immutable
, Opt_dots
, Opt_nodots
,
879 Opt_charset
, Opt_shortname_lower
, Opt_shortname_win95
,
880 Opt_shortname_winnt
, Opt_shortname_mixed
, Opt_utf8_no
, Opt_utf8_yes
,
881 Opt_uni_xl_no
, Opt_uni_xl_yes
, Opt_nonumtail_no
, Opt_nonumtail_yes
,
882 Opt_obsolete
, Opt_flush
, Opt_tz_utc
, Opt_rodir
, Opt_err_cont
,
883 Opt_err_panic
, Opt_err_ro
, Opt_discard
, Opt_err
,
886 static const match_table_t fat_tokens
= {
887 {Opt_check_r
, "check=relaxed"},
888 {Opt_check_s
, "check=strict"},
889 {Opt_check_n
, "check=normal"},
890 {Opt_check_r
, "check=r"},
891 {Opt_check_s
, "check=s"},
892 {Opt_check_n
, "check=n"},
895 {Opt_umask
, "umask=%o"},
896 {Opt_dmask
, "dmask=%o"},
897 {Opt_fmask
, "fmask=%o"},
898 {Opt_allow_utime
, "allow_utime=%o"},
899 {Opt_codepage
, "codepage=%u"},
900 {Opt_usefree
, "usefree"},
901 {Opt_nocase
, "nocase"},
902 {Opt_quiet
, "quiet"},
903 {Opt_showexec
, "showexec"},
904 {Opt_debug
, "debug"},
905 {Opt_immutable
, "sys_immutable"},
906 {Opt_flush
, "flush"},
907 {Opt_tz_utc
, "tz=UTC"},
908 {Opt_err_cont
, "errors=continue"},
909 {Opt_err_panic
, "errors=panic"},
910 {Opt_err_ro
, "errors=remount-ro"},
911 {Opt_discard
, "discard"},
912 {Opt_obsolete
, "conv=binary"},
913 {Opt_obsolete
, "conv=text"},
914 {Opt_obsolete
, "conv=auto"},
915 {Opt_obsolete
, "conv=b"},
916 {Opt_obsolete
, "conv=t"},
917 {Opt_obsolete
, "conv=a"},
918 {Opt_obsolete
, "fat=%u"},
919 {Opt_obsolete
, "blocksize=%u"},
920 {Opt_obsolete
, "cvf_format=%20s"},
921 {Opt_obsolete
, "cvf_options=%100s"},
922 {Opt_obsolete
, "posix"},
925 static const match_table_t msdos_tokens
= {
926 {Opt_nodots
, "nodots"},
927 {Opt_nodots
, "dotsOK=no"},
929 {Opt_dots
, "dotsOK=yes"},
932 static const match_table_t vfat_tokens
= {
933 {Opt_charset
, "iocharset=%s"},
934 {Opt_shortname_lower
, "shortname=lower"},
935 {Opt_shortname_win95
, "shortname=win95"},
936 {Opt_shortname_winnt
, "shortname=winnt"},
937 {Opt_shortname_mixed
, "shortname=mixed"},
938 {Opt_utf8_no
, "utf8=0"}, /* 0 or no or false */
939 {Opt_utf8_no
, "utf8=no"},
940 {Opt_utf8_no
, "utf8=false"},
941 {Opt_utf8_yes
, "utf8=1"}, /* empty or 1 or yes or true */
942 {Opt_utf8_yes
, "utf8=yes"},
943 {Opt_utf8_yes
, "utf8=true"},
944 {Opt_utf8_yes
, "utf8"},
945 {Opt_uni_xl_no
, "uni_xlate=0"}, /* 0 or no or false */
946 {Opt_uni_xl_no
, "uni_xlate=no"},
947 {Opt_uni_xl_no
, "uni_xlate=false"},
948 {Opt_uni_xl_yes
, "uni_xlate=1"}, /* empty or 1 or yes or true */
949 {Opt_uni_xl_yes
, "uni_xlate=yes"},
950 {Opt_uni_xl_yes
, "uni_xlate=true"},
951 {Opt_uni_xl_yes
, "uni_xlate"},
952 {Opt_nonumtail_no
, "nonumtail=0"}, /* 0 or no or false */
953 {Opt_nonumtail_no
, "nonumtail=no"},
954 {Opt_nonumtail_no
, "nonumtail=false"},
955 {Opt_nonumtail_yes
, "nonumtail=1"}, /* empty or 1 or yes or true */
956 {Opt_nonumtail_yes
, "nonumtail=yes"},
957 {Opt_nonumtail_yes
, "nonumtail=true"},
958 {Opt_nonumtail_yes
, "nonumtail"},
959 {Opt_rodir
, "rodir"},
963 static int parse_options(struct super_block
*sb
, char *options
, int is_vfat
,
964 int silent
, int *debug
, struct fat_mount_options
*opts
)
967 substring_t args
[MAX_OPT_ARGS
];
971 opts
->isvfat
= is_vfat
;
973 opts
->fs_uid
= current_uid();
974 opts
->fs_gid
= current_gid();
975 opts
->fs_fmask
= opts
->fs_dmask
= current_umask();
976 opts
->allow_utime
= -1;
977 opts
->codepage
= fat_default_codepage
;
978 opts
->iocharset
= fat_default_iocharset
;
980 opts
->shortname
= VFAT_SFN_DISPLAY_WINNT
|VFAT_SFN_CREATE_WIN95
;
986 opts
->name_check
= 'n';
987 opts
->quiet
= opts
->showexec
= opts
->sys_immutable
= opts
->dotsOK
= 0;
988 opts
->utf8
= opts
->unicode_xlate
= 0;
990 opts
->usefree
= opts
->nocase
= 0;
992 opts
->errors
= FAT_ERRORS_RO
;
998 while ((p
= strsep(&options
, ",")) != NULL
) {
1003 token
= match_token(p
, fat_tokens
, args
);
1004 if (token
== Opt_err
) {
1006 token
= match_token(p
, vfat_tokens
, args
);
1008 token
= match_token(p
, msdos_tokens
, args
);
1012 opts
->name_check
= 's';
1015 opts
->name_check
= 'r';
1018 opts
->name_check
= 'n';
1027 /* for backward compatibility */
1028 opts
->shortname
= VFAT_SFN_DISPLAY_WIN95
1029 | VFAT_SFN_CREATE_WIN95
;
1042 opts
->sys_immutable
= 1;
1045 if (match_int(&args
[0], &option
))
1047 opts
->fs_uid
= option
;
1050 if (match_int(&args
[0], &option
))
1052 opts
->fs_gid
= option
;
1055 if (match_octal(&args
[0], &option
))
1057 opts
->fs_fmask
= opts
->fs_dmask
= option
;
1060 if (match_octal(&args
[0], &option
))
1062 opts
->fs_dmask
= option
;
1065 if (match_octal(&args
[0], &option
))
1067 opts
->fs_fmask
= option
;
1069 case Opt_allow_utime
:
1070 if (match_octal(&args
[0], &option
))
1072 opts
->allow_utime
= option
& (S_IWGRP
| S_IWOTH
);
1075 if (match_int(&args
[0], &option
))
1077 opts
->codepage
= option
;
1086 opts
->errors
= FAT_ERRORS_CONT
;
1089 opts
->errors
= FAT_ERRORS_PANIC
;
1092 opts
->errors
= FAT_ERRORS_RO
;
1095 /* msdos specific */
1105 if (opts
->iocharset
!= fat_default_iocharset
)
1106 kfree(opts
->iocharset
);
1107 iocharset
= match_strdup(&args
[0]);
1110 opts
->iocharset
= iocharset
;
1112 case Opt_shortname_lower
:
1113 opts
->shortname
= VFAT_SFN_DISPLAY_LOWER
1114 | VFAT_SFN_CREATE_WIN95
;
1116 case Opt_shortname_win95
:
1117 opts
->shortname
= VFAT_SFN_DISPLAY_WIN95
1118 | VFAT_SFN_CREATE_WIN95
;
1120 case Opt_shortname_winnt
:
1121 opts
->shortname
= VFAT_SFN_DISPLAY_WINNT
1122 | VFAT_SFN_CREATE_WINNT
;
1124 case Opt_shortname_mixed
:
1125 opts
->shortname
= VFAT_SFN_DISPLAY_WINNT
1126 | VFAT_SFN_CREATE_WIN95
;
1128 case Opt_utf8_no
: /* 0 or no or false */
1131 case Opt_utf8_yes
: /* empty or 1 or yes or true */
1134 case Opt_uni_xl_no
: /* 0 or no or false */
1135 opts
->unicode_xlate
= 0;
1137 case Opt_uni_xl_yes
: /* empty or 1 or yes or true */
1138 opts
->unicode_xlate
= 1;
1140 case Opt_nonumtail_no
: /* 0 or no or false */
1141 opts
->numtail
= 1; /* negated option */
1143 case Opt_nonumtail_yes
: /* empty or 1 or yes or true */
1144 opts
->numtail
= 0; /* negated option */
1153 /* obsolete mount options */
1155 fat_msg(sb
, KERN_INFO
, "\"%s\" option is obsolete, "
1156 "not supported now", p
);
1158 /* unknown option */
1161 fat_msg(sb
, KERN_ERR
,
1162 "Unrecognized mount option \"%s\" "
1163 "or missing value", p
);
1170 /* UTF-8 doesn't provide FAT semantics */
1171 if (!strcmp(opts
->iocharset
, "utf8")) {
1172 fat_msg(sb
, KERN_WARNING
, "utf8 is not a recommended IO charset"
1173 " for FAT filesystems, filesystem will be "
1177 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1178 if (opts
->allow_utime
== (unsigned short)-1)
1179 opts
->allow_utime
= ~opts
->fs_dmask
& (S_IWGRP
| S_IWOTH
);
1180 if (opts
->unicode_xlate
)
1186 static int fat_read_root(struct inode
*inode
)
1188 struct super_block
*sb
= inode
->i_sb
;
1189 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
1192 MSDOS_I(inode
)->i_pos
= 0;
1193 inode
->i_uid
= sbi
->options
.fs_uid
;
1194 inode
->i_gid
= sbi
->options
.fs_gid
;
1196 inode
->i_generation
= 0;
1197 inode
->i_mode
= fat_make_mode(sbi
, ATTR_DIR
, S_IRWXUGO
);
1198 inode
->i_op
= sbi
->dir_ops
;
1199 inode
->i_fop
= &fat_dir_operations
;
1200 if (sbi
->fat_bits
== 32) {
1201 MSDOS_I(inode
)->i_start
= sbi
->root_cluster
;
1202 error
= fat_calc_dir_size(inode
);
1206 MSDOS_I(inode
)->i_start
= 0;
1207 inode
->i_size
= sbi
->dir_entries
* sizeof(struct msdos_dir_entry
);
1209 inode
->i_blocks
= ((inode
->i_size
+ (sbi
->cluster_size
- 1))
1210 & ~((loff_t
)sbi
->cluster_size
- 1)) >> 9;
1211 MSDOS_I(inode
)->i_logstart
= 0;
1212 MSDOS_I(inode
)->mmu_private
= inode
->i_size
;
1214 fat_save_attrs(inode
, ATTR_DIR
);
1215 inode
->i_mtime
.tv_sec
= inode
->i_atime
.tv_sec
= inode
->i_ctime
.tv_sec
= 0;
1216 inode
->i_mtime
.tv_nsec
= inode
->i_atime
.tv_nsec
= inode
->i_ctime
.tv_nsec
= 0;
1217 set_nlink(inode
, fat_subdirs(inode
)+2);
1223 * Read the super block of an MS-DOS FS.
1225 int fat_fill_super(struct super_block
*sb
, void *data
, int silent
, int isvfat
,
1226 void (*setup
)(struct super_block
*))
1228 struct inode
*root_inode
= NULL
, *fat_inode
= NULL
;
1229 struct inode
*fsinfo_inode
= NULL
;
1230 struct buffer_head
*bh
;
1231 struct fat_boot_sector
*b
;
1232 struct msdos_sb_info
*sbi
;
1233 u16 logical_sector_size
;
1234 u32 total_sectors
, total_clusters
, fat_clusters
, rootdir_sectors
;
1241 * GFP_KERNEL is ok here, because while we do hold the
1242 * supeblock lock, memory pressure can't call back into
1243 * the filesystem, since we're only just about to mount
1244 * it and have no inodes etc active!
1246 sbi
= kzalloc(sizeof(struct msdos_sb_info
), GFP_KERNEL
);
1249 sb
->s_fs_info
= sbi
;
1251 sb
->s_flags
|= MS_NODIRATIME
;
1252 sb
->s_magic
= MSDOS_SUPER_MAGIC
;
1253 sb
->s_op
= &fat_sops
;
1254 sb
->s_export_op
= &fat_export_ops
;
1255 ratelimit_state_init(&sbi
->ratelimit
, DEFAULT_RATELIMIT_INTERVAL
,
1256 DEFAULT_RATELIMIT_BURST
);
1258 error
= parse_options(sb
, data
, isvfat
, silent
, &debug
, &sbi
->options
);
1262 setup(sb
); /* flavour-specific stuff that needs options */
1265 sb_min_blocksize(sb
, 512);
1266 bh
= sb_bread(sb
, 0);
1268 fat_msg(sb
, KERN_ERR
, "unable to read boot sector");
1272 b
= (struct fat_boot_sector
*) bh
->b_data
;
1275 fat_msg(sb
, KERN_ERR
, "bogus number of reserved sectors");
1281 fat_msg(sb
, KERN_ERR
, "bogus number of FAT structure");
1287 * Earlier we checked here that b->secs_track and b->head are nonzero,
1288 * but it turns out valid FAT filesystems can have zero there.
1292 if (!fat_valid_media(media
)) {
1294 fat_msg(sb
, KERN_ERR
, "invalid media value (0x%02x)",
1299 logical_sector_size
= get_unaligned_le16(&b
->sector_size
);
1300 if (!is_power_of_2(logical_sector_size
)
1301 || (logical_sector_size
< 512)
1302 || (logical_sector_size
> 4096)) {
1304 fat_msg(sb
, KERN_ERR
, "bogus logical sector size %u",
1305 logical_sector_size
);
1309 sbi
->sec_per_clus
= b
->sec_per_clus
;
1310 if (!is_power_of_2(sbi
->sec_per_clus
)) {
1312 fat_msg(sb
, KERN_ERR
, "bogus sectors per cluster %u",
1318 if (logical_sector_size
< sb
->s_blocksize
) {
1319 fat_msg(sb
, KERN_ERR
, "logical sector size too small for device"
1320 " (logical sector size = %u)", logical_sector_size
);
1324 if (logical_sector_size
> sb
->s_blocksize
) {
1327 if (!sb_set_blocksize(sb
, logical_sector_size
)) {
1328 fat_msg(sb
, KERN_ERR
, "unable to set blocksize %u",
1329 logical_sector_size
);
1332 bh
= sb_bread(sb
, 0);
1334 fat_msg(sb
, KERN_ERR
, "unable to read boot sector"
1335 " (logical sector size = %lu)",
1339 b
= (struct fat_boot_sector
*) bh
->b_data
;
1342 sbi
->cluster_size
= sb
->s_blocksize
* sbi
->sec_per_clus
;
1343 sbi
->cluster_bits
= ffs(sbi
->cluster_size
) - 1;
1344 sbi
->fats
= b
->fats
;
1345 sbi
->fat_bits
= 0; /* Don't know yet */
1346 sbi
->fat_start
= le16_to_cpu(b
->reserved
);
1347 sbi
->fat_length
= le16_to_cpu(b
->fat_length
);
1348 sbi
->root_cluster
= 0;
1349 sbi
->free_clusters
= -1; /* Don't know yet */
1350 sbi
->free_clus_valid
= 0;
1351 sbi
->prev_free
= FAT_START_ENT
;
1352 sb
->s_maxbytes
= 0xffffffff;
1354 if (!sbi
->fat_length
&& b
->fat32_length
) {
1355 struct fat_boot_fsinfo
*fsinfo
;
1356 struct buffer_head
*fsinfo_bh
;
1360 sbi
->fat_length
= le32_to_cpu(b
->fat32_length
);
1361 sbi
->root_cluster
= le32_to_cpu(b
->root_cluster
);
1363 /* MC - if info_sector is 0, don't multiply by 0 */
1364 sbi
->fsinfo_sector
= le16_to_cpu(b
->info_sector
);
1365 if (sbi
->fsinfo_sector
== 0)
1366 sbi
->fsinfo_sector
= 1;
1368 fsinfo_bh
= sb_bread(sb
, sbi
->fsinfo_sector
);
1369 if (fsinfo_bh
== NULL
) {
1370 fat_msg(sb
, KERN_ERR
, "bread failed, FSINFO block"
1371 " (sector = %lu)", sbi
->fsinfo_sector
);
1376 fsinfo
= (struct fat_boot_fsinfo
*)fsinfo_bh
->b_data
;
1377 if (!IS_FSINFO(fsinfo
)) {
1378 fat_msg(sb
, KERN_WARNING
, "Invalid FSINFO signature: "
1379 "0x%08x, 0x%08x (sector = %lu)",
1380 le32_to_cpu(fsinfo
->signature1
),
1381 le32_to_cpu(fsinfo
->signature2
),
1382 sbi
->fsinfo_sector
);
1384 if (sbi
->options
.usefree
)
1385 sbi
->free_clus_valid
= 1;
1386 sbi
->free_clusters
= le32_to_cpu(fsinfo
->free_clusters
);
1387 sbi
->prev_free
= le32_to_cpu(fsinfo
->next_cluster
);
1393 sbi
->dir_per_block
= sb
->s_blocksize
/ sizeof(struct msdos_dir_entry
);
1394 sbi
->dir_per_block_bits
= ffs(sbi
->dir_per_block
) - 1;
1396 sbi
->dir_start
= sbi
->fat_start
+ sbi
->fats
* sbi
->fat_length
;
1397 sbi
->dir_entries
= get_unaligned_le16(&b
->dir_entries
);
1398 if (sbi
->dir_entries
& (sbi
->dir_per_block
- 1)) {
1400 fat_msg(sb
, KERN_ERR
, "bogus directroy-entries per block"
1401 " (%u)", sbi
->dir_entries
);
1406 rootdir_sectors
= sbi
->dir_entries
1407 * sizeof(struct msdos_dir_entry
) / sb
->s_blocksize
;
1408 sbi
->data_start
= sbi
->dir_start
+ rootdir_sectors
;
1409 total_sectors
= get_unaligned_le16(&b
->sectors
);
1410 if (total_sectors
== 0)
1411 total_sectors
= le32_to_cpu(b
->total_sect
);
1413 total_clusters
= (total_sectors
- sbi
->data_start
) / sbi
->sec_per_clus
;
1415 if (sbi
->fat_bits
!= 32)
1416 sbi
->fat_bits
= (total_clusters
> MAX_FAT12
) ? 16 : 12;
1418 /* check that FAT table does not overflow */
1419 fat_clusters
= sbi
->fat_length
* sb
->s_blocksize
* 8 / sbi
->fat_bits
;
1420 total_clusters
= min(total_clusters
, fat_clusters
- FAT_START_ENT
);
1421 if (total_clusters
> MAX_FAT(sb
)) {
1423 fat_msg(sb
, KERN_ERR
, "count of clusters too big (%u)",
1429 sbi
->max_cluster
= total_clusters
+ FAT_START_ENT
;
1430 /* check the free_clusters, it's not necessarily correct */
1431 if (sbi
->free_clusters
!= -1 && sbi
->free_clusters
> total_clusters
)
1432 sbi
->free_clusters
= -1;
1433 /* check the prev_free, it's not necessarily correct */
1434 sbi
->prev_free
%= sbi
->max_cluster
;
1435 if (sbi
->prev_free
< FAT_START_ENT
)
1436 sbi
->prev_free
= FAT_START_ENT
;
1440 /* set up enough so that it can read an inode */
1442 fat_ent_access_init(sb
);
1445 * The low byte of FAT's first entry must have same value with
1446 * media-field. But in real world, too many devices is
1447 * writing wrong value. So, removed that validity check.
1449 * if (FAT_FIRST_ENT(sb, media) != first)
1453 sprintf(buf
, "cp%d", sbi
->options
.codepage
);
1454 sbi
->nls_disk
= load_nls(buf
);
1455 if (!sbi
->nls_disk
) {
1456 fat_msg(sb
, KERN_ERR
, "codepage %s not found", buf
);
1460 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1461 if (sbi
->options
.isvfat
) {
1462 sbi
->nls_io
= load_nls(sbi
->options
.iocharset
);
1464 fat_msg(sb
, KERN_ERR
, "IO charset %s not found",
1465 sbi
->options
.iocharset
);
1471 fat_inode
= new_inode(sb
);
1474 MSDOS_I(fat_inode
)->i_pos
= 0;
1475 sbi
->fat_inode
= fat_inode
;
1477 fsinfo_inode
= new_inode(sb
);
1480 fsinfo_inode
->i_ino
= MSDOS_FSINFO_INO
;
1481 sbi
->fsinfo_inode
= fsinfo_inode
;
1482 insert_inode_hash(fsinfo_inode
);
1484 root_inode
= new_inode(sb
);
1487 root_inode
->i_ino
= MSDOS_ROOT_INO
;
1488 root_inode
->i_version
= 1;
1489 error
= fat_read_root(root_inode
);
1495 insert_inode_hash(root_inode
);
1496 sb
->s_root
= d_make_root(root_inode
);
1498 fat_msg(sb
, KERN_ERR
, "get root inode failed");
1507 fat_msg(sb
, KERN_INFO
, "Can't find a valid FAT filesystem");
1514 unload_nls(sbi
->nls_io
);
1515 unload_nls(sbi
->nls_disk
);
1516 if (sbi
->options
.iocharset
!= fat_default_iocharset
)
1517 kfree(sbi
->options
.iocharset
);
1518 sb
->s_fs_info
= NULL
;
1523 EXPORT_SYMBOL_GPL(fat_fill_super
);
1526 * helper function for fat_flush_inodes. This writes both the inode
1527 * and the file data blocks, waiting for in flight data blocks before
1528 * the start of the call. It does not wait for any io started
1531 static int writeback_inode(struct inode
*inode
)
1535 struct address_space
*mapping
= inode
->i_mapping
;
1536 struct writeback_control wbc
= {
1537 .sync_mode
= WB_SYNC_NONE
,
1540 /* if we used WB_SYNC_ALL, sync_inode waits for the io for the
1541 * inode to finish. So WB_SYNC_NONE is sent down to sync_inode
1542 * and filemap_fdatawrite is used for the data blocks
1544 ret
= sync_inode(inode
, &wbc
);
1546 ret
= filemap_fdatawrite(mapping
);
1551 * write data and metadata corresponding to i1 and i2. The io is
1552 * started but we do not wait for any of it to finish.
1554 * filemap_flush is used for the block device, so if there is a dirty
1555 * page for a block already in flight, we will not wait and start the
1558 int fat_flush_inodes(struct super_block
*sb
, struct inode
*i1
, struct inode
*i2
)
1561 if (!MSDOS_SB(sb
)->options
.flush
)
1564 ret
= writeback_inode(i1
);
1566 ret
= writeback_inode(i2
);
1568 struct address_space
*mapping
= sb
->s_bdev
->bd_inode
->i_mapping
;
1569 ret
= filemap_flush(mapping
);
1573 EXPORT_SYMBOL_GPL(fat_flush_inodes
);
1575 static int __init
init_fat_fs(void)
1579 err
= fat_cache_init();
1583 err
= fat_init_inodecache();
1590 fat_cache_destroy();
1594 static void __exit
exit_fat_fs(void)
1596 fat_cache_destroy();
1597 fat_destroy_inodecache();
1600 module_init(init_fat_fs
)
1601 module_exit(exit_fat_fs
)
1603 MODULE_LICENSE("GPL");