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/mount.h>
22 #include <linux/vfs.h>
23 #include <linux/parser.h>
24 #include <linux/uio.h>
25 #include <linux/writeback.h>
26 #include <linux/log2.h>
27 #include <linux/hash.h>
28 #include <linux/blkdev.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 #define KB_IN_SECTORS 2
40 * A deserialized copy of the on-disk structure laid out in struct
43 struct fat_bios_param_block
{
57 u32 fat32_root_cluster
;
58 u16 fat32_info_sector
;
63 static int fat_default_codepage
= CONFIG_FAT_DEFAULT_CODEPAGE
;
64 static char fat_default_iocharset
[] = CONFIG_FAT_DEFAULT_IOCHARSET
;
66 static struct fat_floppy_defaults
{
68 unsigned sec_per_clus
;
72 } floppy_defaults
[] = {
74 .nr_sectors
= 160 * KB_IN_SECTORS
,
81 .nr_sectors
= 180 * KB_IN_SECTORS
,
88 .nr_sectors
= 320 * KB_IN_SECTORS
,
95 .nr_sectors
= 360 * KB_IN_SECTORS
,
103 static int fat_add_cluster(struct inode
*inode
)
107 err
= fat_alloc_clusters(inode
, &cluster
, 1);
110 /* FIXME: this cluster should be added after data of this
111 * cluster is writed */
112 err
= fat_chain_add(inode
, cluster
, 1);
114 fat_free_clusters(inode
, cluster
);
118 static inline int __fat_get_block(struct inode
*inode
, sector_t iblock
,
119 unsigned long *max_blocks
,
120 struct buffer_head
*bh_result
, int create
)
122 struct super_block
*sb
= inode
->i_sb
;
123 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
124 unsigned long mapped_blocks
;
128 err
= fat_bmap(inode
, iblock
, &phys
, &mapped_blocks
, create
);
132 map_bh(bh_result
, sb
, phys
);
133 *max_blocks
= min(mapped_blocks
, *max_blocks
);
139 if (iblock
!= MSDOS_I(inode
)->mmu_private
>> sb
->s_blocksize_bits
) {
140 fat_fs_error(sb
, "corrupted file size (i_pos %lld, %lld)",
141 MSDOS_I(inode
)->i_pos
, MSDOS_I(inode
)->mmu_private
);
145 offset
= (unsigned long)iblock
& (sbi
->sec_per_clus
- 1);
147 /* TODO: multiple cluster allocation would be desirable. */
148 err
= fat_add_cluster(inode
);
152 /* available blocks on this cluster */
153 mapped_blocks
= sbi
->sec_per_clus
- offset
;
155 *max_blocks
= min(mapped_blocks
, *max_blocks
);
156 MSDOS_I(inode
)->mmu_private
+= *max_blocks
<< sb
->s_blocksize_bits
;
158 err
= fat_bmap(inode
, iblock
, &phys
, &mapped_blocks
, create
);
163 BUG_ON(*max_blocks
!= mapped_blocks
);
164 set_buffer_new(bh_result
);
165 map_bh(bh_result
, sb
, phys
);
170 static int fat_get_block(struct inode
*inode
, sector_t iblock
,
171 struct buffer_head
*bh_result
, int create
)
173 struct super_block
*sb
= inode
->i_sb
;
174 unsigned long max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
177 err
= __fat_get_block(inode
, iblock
, &max_blocks
, bh_result
, create
);
180 bh_result
->b_size
= max_blocks
<< sb
->s_blocksize_bits
;
184 static int fat_writepage(struct page
*page
, struct writeback_control
*wbc
)
186 return block_write_full_page(page
, fat_get_block
, wbc
);
189 static int fat_writepages(struct address_space
*mapping
,
190 struct writeback_control
*wbc
)
192 return mpage_writepages(mapping
, wbc
, fat_get_block
);
195 static int fat_readpage(struct file
*file
, struct page
*page
)
197 return mpage_readpage(page
, fat_get_block
);
200 static int fat_readpages(struct file
*file
, struct address_space
*mapping
,
201 struct list_head
*pages
, unsigned nr_pages
)
203 return mpage_readpages(mapping
, pages
, nr_pages
, fat_get_block
);
206 static void fat_write_failed(struct address_space
*mapping
, loff_t to
)
208 struct inode
*inode
= mapping
->host
;
210 if (to
> inode
->i_size
) {
211 truncate_pagecache(inode
, inode
->i_size
);
212 fat_truncate_blocks(inode
, inode
->i_size
);
216 static int fat_write_begin(struct file
*file
, struct address_space
*mapping
,
217 loff_t pos
, unsigned len
, unsigned flags
,
218 struct page
**pagep
, void **fsdata
)
223 err
= cont_write_begin(file
, mapping
, pos
, len
, flags
,
224 pagep
, fsdata
, fat_get_block
,
225 &MSDOS_I(mapping
->host
)->mmu_private
);
227 fat_write_failed(mapping
, pos
+ len
);
231 static int fat_write_end(struct file
*file
, struct address_space
*mapping
,
232 loff_t pos
, unsigned len
, unsigned copied
,
233 struct page
*pagep
, void *fsdata
)
235 struct inode
*inode
= mapping
->host
;
237 err
= generic_write_end(file
, mapping
, pos
, len
, copied
, pagep
, fsdata
);
239 fat_write_failed(mapping
, pos
+ len
);
240 if (!(err
< 0) && !(MSDOS_I(inode
)->i_attrs
& ATTR_ARCH
)) {
241 inode
->i_mtime
= inode
->i_ctime
= CURRENT_TIME_SEC
;
242 MSDOS_I(inode
)->i_attrs
|= ATTR_ARCH
;
243 mark_inode_dirty(inode
);
248 static ssize_t
fat_direct_IO(int rw
, struct kiocb
*iocb
,
249 struct iov_iter
*iter
,
252 struct file
*file
= iocb
->ki_filp
;
253 struct address_space
*mapping
= file
->f_mapping
;
254 struct inode
*inode
= mapping
->host
;
255 size_t count
= iov_iter_count(iter
);
258 if (iov_iter_rw(iter
) == WRITE
) {
260 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
261 * so we need to update the ->mmu_private to block boundary.
263 * But we must fill the remaining area or hole by nul for
264 * updating ->mmu_private.
266 * Return 0, and fallback to normal buffered write.
268 loff_t size
= offset
+ count
;
269 if (MSDOS_I(inode
)->mmu_private
< size
)
274 * FAT need to use the DIO_LOCKING for avoiding the race
275 * condition of fat_get_block() and ->truncate().
277 ret
= blockdev_direct_IO(iocb
, inode
, iter
, offset
, fat_get_block
);
278 if (ret
< 0 && iov_iter_rw(iter
) == WRITE
)
279 fat_write_failed(mapping
, offset
+ count
);
284 static sector_t
_fat_bmap(struct address_space
*mapping
, sector_t block
)
288 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
289 down_read(&MSDOS_I(mapping
->host
)->truncate_lock
);
290 blocknr
= generic_block_bmap(mapping
, block
, fat_get_block
);
291 up_read(&MSDOS_I(mapping
->host
)->truncate_lock
);
297 * fat_block_truncate_page() zeroes out a mapping from file offset `from'
298 * up to the end of the block which corresponds to `from'.
299 * This is required during truncate to physically zeroout the tail end
300 * of that block so it doesn't yield old data if the file is later grown.
301 * Also, avoid causing failure from fsx for cases of "data past EOF"
303 int fat_block_truncate_page(struct inode
*inode
, loff_t from
)
305 return block_truncate_page(inode
->i_mapping
, from
, fat_get_block
);
308 static const struct address_space_operations fat_aops
= {
309 .readpage
= fat_readpage
,
310 .readpages
= fat_readpages
,
311 .writepage
= fat_writepage
,
312 .writepages
= fat_writepages
,
313 .write_begin
= fat_write_begin
,
314 .write_end
= fat_write_end
,
315 .direct_IO
= fat_direct_IO
,
320 * New FAT inode stuff. We do the following:
321 * a) i_ino is constant and has nothing with on-disk location.
322 * b) FAT manages its own cache of directory entries.
323 * c) *This* cache is indexed by on-disk location.
324 * d) inode has an associated directory entry, all right, but
325 * it may be unhashed.
326 * e) currently entries are stored within struct inode. That should
328 * f) we deal with races in the following way:
329 * 1. readdir() and lookup() do FAT-dir-cache lookup.
330 * 2. rename() unhashes the F-d-c entry and rehashes it in
332 * 3. unlink() and rmdir() unhash F-d-c entry.
333 * 4. fat_write_inode() checks whether the thing is unhashed.
334 * If it is we silently return. If it isn't we do bread(),
335 * check if the location is still valid and retry if it
336 * isn't. Otherwise we do changes.
337 * 5. Spinlock is used to protect hash/unhash/location check/lookup
338 * 6. fat_evict_inode() unhashes the F-d-c entry.
339 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
340 * and consider negative result as cache miss.
343 static void fat_hash_init(struct super_block
*sb
)
345 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
348 spin_lock_init(&sbi
->inode_hash_lock
);
349 for (i
= 0; i
< FAT_HASH_SIZE
; i
++)
350 INIT_HLIST_HEAD(&sbi
->inode_hashtable
[i
]);
353 static inline unsigned long fat_hash(loff_t i_pos
)
355 return hash_32(i_pos
, FAT_HASH_BITS
);
358 static void dir_hash_init(struct super_block
*sb
)
360 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
363 spin_lock_init(&sbi
->dir_hash_lock
);
364 for (i
= 0; i
< FAT_HASH_SIZE
; i
++)
365 INIT_HLIST_HEAD(&sbi
->dir_hashtable
[i
]);
368 void fat_attach(struct inode
*inode
, loff_t i_pos
)
370 struct msdos_sb_info
*sbi
= MSDOS_SB(inode
->i_sb
);
372 if (inode
->i_ino
!= MSDOS_ROOT_INO
) {
373 struct hlist_head
*head
= sbi
->inode_hashtable
376 spin_lock(&sbi
->inode_hash_lock
);
377 MSDOS_I(inode
)->i_pos
= i_pos
;
378 hlist_add_head(&MSDOS_I(inode
)->i_fat_hash
, head
);
379 spin_unlock(&sbi
->inode_hash_lock
);
382 /* If NFS support is enabled, cache the mapping of start cluster
383 * to directory inode. This is used during reconnection of
384 * dentries to the filesystem root.
386 if (S_ISDIR(inode
->i_mode
) && sbi
->options
.nfs
) {
387 struct hlist_head
*d_head
= sbi
->dir_hashtable
;
388 d_head
+= fat_dir_hash(MSDOS_I(inode
)->i_logstart
);
390 spin_lock(&sbi
->dir_hash_lock
);
391 hlist_add_head(&MSDOS_I(inode
)->i_dir_hash
, d_head
);
392 spin_unlock(&sbi
->dir_hash_lock
);
395 EXPORT_SYMBOL_GPL(fat_attach
);
397 void fat_detach(struct inode
*inode
)
399 struct msdos_sb_info
*sbi
= MSDOS_SB(inode
->i_sb
);
400 spin_lock(&sbi
->inode_hash_lock
);
401 MSDOS_I(inode
)->i_pos
= 0;
402 hlist_del_init(&MSDOS_I(inode
)->i_fat_hash
);
403 spin_unlock(&sbi
->inode_hash_lock
);
405 if (S_ISDIR(inode
->i_mode
) && sbi
->options
.nfs
) {
406 spin_lock(&sbi
->dir_hash_lock
);
407 hlist_del_init(&MSDOS_I(inode
)->i_dir_hash
);
408 spin_unlock(&sbi
->dir_hash_lock
);
411 EXPORT_SYMBOL_GPL(fat_detach
);
413 struct inode
*fat_iget(struct super_block
*sb
, loff_t i_pos
)
415 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
416 struct hlist_head
*head
= sbi
->inode_hashtable
+ fat_hash(i_pos
);
417 struct msdos_inode_info
*i
;
418 struct inode
*inode
= NULL
;
420 spin_lock(&sbi
->inode_hash_lock
);
421 hlist_for_each_entry(i
, head
, i_fat_hash
) {
422 BUG_ON(i
->vfs_inode
.i_sb
!= sb
);
423 if (i
->i_pos
!= i_pos
)
425 inode
= igrab(&i
->vfs_inode
);
429 spin_unlock(&sbi
->inode_hash_lock
);
433 static int is_exec(unsigned char *extension
)
435 unsigned char exe_extensions
[] = "EXECOMBAT", *walk
;
437 for (walk
= exe_extensions
; *walk
; walk
+= 3)
438 if (!strncmp(extension
, walk
, 3))
443 static int fat_calc_dir_size(struct inode
*inode
)
445 struct msdos_sb_info
*sbi
= MSDOS_SB(inode
->i_sb
);
446 int ret
, fclus
, dclus
;
449 if (MSDOS_I(inode
)->i_start
== 0)
452 ret
= fat_get_cluster(inode
, FAT_ENT_EOF
, &fclus
, &dclus
);
455 inode
->i_size
= (fclus
+ 1) << sbi
->cluster_bits
;
460 /* doesn't deal with root inode */
461 int fat_fill_inode(struct inode
*inode
, struct msdos_dir_entry
*de
)
463 struct msdos_sb_info
*sbi
= MSDOS_SB(inode
->i_sb
);
466 MSDOS_I(inode
)->i_pos
= 0;
467 inode
->i_uid
= sbi
->options
.fs_uid
;
468 inode
->i_gid
= sbi
->options
.fs_gid
;
470 inode
->i_generation
= get_seconds();
472 if ((de
->attr
& ATTR_DIR
) && !IS_FREE(de
->name
)) {
473 inode
->i_generation
&= ~1;
474 inode
->i_mode
= fat_make_mode(sbi
, de
->attr
, S_IRWXUGO
);
475 inode
->i_op
= sbi
->dir_ops
;
476 inode
->i_fop
= &fat_dir_operations
;
478 MSDOS_I(inode
)->i_start
= fat_get_start(sbi
, de
);
479 MSDOS_I(inode
)->i_logstart
= MSDOS_I(inode
)->i_start
;
480 error
= fat_calc_dir_size(inode
);
483 MSDOS_I(inode
)->mmu_private
= inode
->i_size
;
485 set_nlink(inode
, fat_subdirs(inode
));
486 } else { /* not a directory */
487 inode
->i_generation
|= 1;
488 inode
->i_mode
= fat_make_mode(sbi
, de
->attr
,
489 ((sbi
->options
.showexec
&& !is_exec(de
->name
+ 8))
490 ? S_IRUGO
|S_IWUGO
: S_IRWXUGO
));
491 MSDOS_I(inode
)->i_start
= fat_get_start(sbi
, de
);
493 MSDOS_I(inode
)->i_logstart
= MSDOS_I(inode
)->i_start
;
494 inode
->i_size
= le32_to_cpu(de
->size
);
495 inode
->i_op
= &fat_file_inode_operations
;
496 inode
->i_fop
= &fat_file_operations
;
497 inode
->i_mapping
->a_ops
= &fat_aops
;
498 MSDOS_I(inode
)->mmu_private
= inode
->i_size
;
500 if (de
->attr
& ATTR_SYS
) {
501 if (sbi
->options
.sys_immutable
)
502 inode
->i_flags
|= S_IMMUTABLE
;
504 fat_save_attrs(inode
, de
->attr
);
506 inode
->i_blocks
= ((inode
->i_size
+ (sbi
->cluster_size
- 1))
507 & ~((loff_t
)sbi
->cluster_size
- 1)) >> 9;
509 fat_time_fat2unix(sbi
, &inode
->i_mtime
, de
->time
, de
->date
, 0);
510 if (sbi
->options
.isvfat
) {
511 fat_time_fat2unix(sbi
, &inode
->i_ctime
, de
->ctime
,
512 de
->cdate
, de
->ctime_cs
);
513 fat_time_fat2unix(sbi
, &inode
->i_atime
, 0, de
->adate
, 0);
515 inode
->i_ctime
= inode
->i_atime
= inode
->i_mtime
;
520 static inline void fat_lock_build_inode(struct msdos_sb_info
*sbi
)
522 if (sbi
->options
.nfs
== FAT_NFS_NOSTALE_RO
)
523 mutex_lock(&sbi
->nfs_build_inode_lock
);
526 static inline void fat_unlock_build_inode(struct msdos_sb_info
*sbi
)
528 if (sbi
->options
.nfs
== FAT_NFS_NOSTALE_RO
)
529 mutex_unlock(&sbi
->nfs_build_inode_lock
);
532 struct inode
*fat_build_inode(struct super_block
*sb
,
533 struct msdos_dir_entry
*de
, loff_t i_pos
)
538 fat_lock_build_inode(MSDOS_SB(sb
));
539 inode
= fat_iget(sb
, i_pos
);
542 inode
= new_inode(sb
);
544 inode
= ERR_PTR(-ENOMEM
);
547 inode
->i_ino
= iunique(sb
, MSDOS_ROOT_INO
);
548 inode
->i_version
= 1;
549 err
= fat_fill_inode(inode
, de
);
552 inode
= ERR_PTR(err
);
555 fat_attach(inode
, i_pos
);
556 insert_inode_hash(inode
);
558 fat_unlock_build_inode(MSDOS_SB(sb
));
562 EXPORT_SYMBOL_GPL(fat_build_inode
);
564 static void fat_evict_inode(struct inode
*inode
)
566 truncate_inode_pages_final(&inode
->i_data
);
567 if (!inode
->i_nlink
) {
569 fat_truncate_blocks(inode
, 0);
571 invalidate_inode_buffers(inode
);
573 fat_cache_inval_inode(inode
);
577 static void fat_set_state(struct super_block
*sb
,
578 unsigned int set
, unsigned int force
)
580 struct buffer_head
*bh
;
581 struct fat_boot_sector
*b
;
582 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
584 /* do not change any thing if mounted read only */
585 if ((sb
->s_flags
& MS_RDONLY
) && !force
)
588 /* do not change state if fs was dirty */
590 /* warn only on set (mount). */
592 fat_msg(sb
, KERN_WARNING
, "Volume was not properly "
593 "unmounted. Some data may be corrupt. "
598 bh
= sb_bread(sb
, 0);
600 fat_msg(sb
, KERN_ERR
, "unable to read boot sector "
601 "to mark fs as dirty");
605 b
= (struct fat_boot_sector
*) bh
->b_data
;
607 if (sbi
->fat_bits
== 32) {
609 b
->fat32
.state
|= FAT_STATE_DIRTY
;
611 b
->fat32
.state
&= ~FAT_STATE_DIRTY
;
612 } else /* fat 16 and 12 */ {
614 b
->fat16
.state
|= FAT_STATE_DIRTY
;
616 b
->fat16
.state
&= ~FAT_STATE_DIRTY
;
619 mark_buffer_dirty(bh
);
620 sync_dirty_buffer(bh
);
624 static void delayed_free(struct rcu_head
*p
)
626 struct msdos_sb_info
*sbi
= container_of(p
, struct msdos_sb_info
, rcu
);
627 unload_nls(sbi
->nls_disk
);
628 unload_nls(sbi
->nls_io
);
629 if (sbi
->options
.iocharset
!= fat_default_iocharset
)
630 kfree(sbi
->options
.iocharset
);
634 static void fat_put_super(struct super_block
*sb
)
636 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
638 fat_set_state(sb
, 0, 0);
640 iput(sbi
->fsinfo_inode
);
641 iput(sbi
->fat_inode
);
643 call_rcu(&sbi
->rcu
, delayed_free
);
646 static struct kmem_cache
*fat_inode_cachep
;
648 static struct inode
*fat_alloc_inode(struct super_block
*sb
)
650 struct msdos_inode_info
*ei
;
651 ei
= kmem_cache_alloc(fat_inode_cachep
, GFP_NOFS
);
655 init_rwsem(&ei
->truncate_lock
);
656 return &ei
->vfs_inode
;
659 static void fat_i_callback(struct rcu_head
*head
)
661 struct inode
*inode
= container_of(head
, struct inode
, i_rcu
);
662 kmem_cache_free(fat_inode_cachep
, MSDOS_I(inode
));
665 static void fat_destroy_inode(struct inode
*inode
)
667 call_rcu(&inode
->i_rcu
, fat_i_callback
);
670 static void init_once(void *foo
)
672 struct msdos_inode_info
*ei
= (struct msdos_inode_info
*)foo
;
674 spin_lock_init(&ei
->cache_lru_lock
);
676 ei
->cache_valid_id
= FAT_CACHE_VALID
+ 1;
677 INIT_LIST_HEAD(&ei
->cache_lru
);
678 INIT_HLIST_NODE(&ei
->i_fat_hash
);
679 INIT_HLIST_NODE(&ei
->i_dir_hash
);
680 inode_init_once(&ei
->vfs_inode
);
683 static int __init
fat_init_inodecache(void)
685 fat_inode_cachep
= kmem_cache_create("fat_inode_cache",
686 sizeof(struct msdos_inode_info
),
687 0, (SLAB_RECLAIM_ACCOUNT
|
690 if (fat_inode_cachep
== NULL
)
695 static void __exit
fat_destroy_inodecache(void)
698 * Make sure all delayed rcu free inodes are flushed before we
702 kmem_cache_destroy(fat_inode_cachep
);
705 static int fat_remount(struct super_block
*sb
, int *flags
, char *data
)
708 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
709 *flags
|= MS_NODIRATIME
| (sbi
->options
.isvfat
? 0 : MS_NOATIME
);
713 /* make sure we update state on remount. */
714 new_rdonly
= *flags
& MS_RDONLY
;
715 if (new_rdonly
!= (sb
->s_flags
& MS_RDONLY
)) {
717 fat_set_state(sb
, 0, 0);
719 fat_set_state(sb
, 1, 1);
724 static int fat_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
726 struct super_block
*sb
= dentry
->d_sb
;
727 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
728 u64 id
= huge_encode_dev(sb
->s_bdev
->bd_dev
);
730 /* If the count of free cluster is still unknown, counts it here. */
731 if (sbi
->free_clusters
== -1 || !sbi
->free_clus_valid
) {
732 int err
= fat_count_free_clusters(dentry
->d_sb
);
737 buf
->f_type
= dentry
->d_sb
->s_magic
;
738 buf
->f_bsize
= sbi
->cluster_size
;
739 buf
->f_blocks
= sbi
->max_cluster
- FAT_START_ENT
;
740 buf
->f_bfree
= sbi
->free_clusters
;
741 buf
->f_bavail
= sbi
->free_clusters
;
742 buf
->f_fsid
.val
[0] = (u32
)id
;
743 buf
->f_fsid
.val
[1] = (u32
)(id
>> 32);
745 (sbi
->options
.isvfat
? FAT_LFN_LEN
: 12) * NLS_MAX_CHARSET_SIZE
;
750 static int __fat_write_inode(struct inode
*inode
, int wait
)
752 struct super_block
*sb
= inode
->i_sb
;
753 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
754 struct buffer_head
*bh
;
755 struct msdos_dir_entry
*raw_entry
;
760 if (inode
->i_ino
== MSDOS_ROOT_INO
)
764 i_pos
= fat_i_pos_read(sbi
, inode
);
768 fat_get_blknr_offset(sbi
, i_pos
, &blocknr
, &offset
);
769 bh
= sb_bread(sb
, blocknr
);
771 fat_msg(sb
, KERN_ERR
, "unable to read inode block "
772 "for updating (i_pos %lld)", i_pos
);
775 spin_lock(&sbi
->inode_hash_lock
);
776 if (i_pos
!= MSDOS_I(inode
)->i_pos
) {
777 spin_unlock(&sbi
->inode_hash_lock
);
782 raw_entry
= &((struct msdos_dir_entry
*) (bh
->b_data
))[offset
];
783 if (S_ISDIR(inode
->i_mode
))
786 raw_entry
->size
= cpu_to_le32(inode
->i_size
);
787 raw_entry
->attr
= fat_make_attrs(inode
);
788 fat_set_start(raw_entry
, MSDOS_I(inode
)->i_logstart
);
789 fat_time_unix2fat(sbi
, &inode
->i_mtime
, &raw_entry
->time
,
790 &raw_entry
->date
, NULL
);
791 if (sbi
->options
.isvfat
) {
793 fat_time_unix2fat(sbi
, &inode
->i_ctime
, &raw_entry
->ctime
,
794 &raw_entry
->cdate
, &raw_entry
->ctime_cs
);
795 fat_time_unix2fat(sbi
, &inode
->i_atime
, &atime
,
796 &raw_entry
->adate
, NULL
);
798 spin_unlock(&sbi
->inode_hash_lock
);
799 mark_buffer_dirty(bh
);
802 err
= sync_dirty_buffer(bh
);
807 static int fat_write_inode(struct inode
*inode
, struct writeback_control
*wbc
)
811 if (inode
->i_ino
== MSDOS_FSINFO_INO
) {
812 struct super_block
*sb
= inode
->i_sb
;
814 mutex_lock(&MSDOS_SB(sb
)->s_lock
);
815 err
= fat_clusters_flush(sb
);
816 mutex_unlock(&MSDOS_SB(sb
)->s_lock
);
818 err
= __fat_write_inode(inode
, wbc
->sync_mode
== WB_SYNC_ALL
);
823 int fat_sync_inode(struct inode
*inode
)
825 return __fat_write_inode(inode
, 1);
828 EXPORT_SYMBOL_GPL(fat_sync_inode
);
830 static int fat_show_options(struct seq_file
*m
, struct dentry
*root
);
831 static const struct super_operations fat_sops
= {
832 .alloc_inode
= fat_alloc_inode
,
833 .destroy_inode
= fat_destroy_inode
,
834 .write_inode
= fat_write_inode
,
835 .evict_inode
= fat_evict_inode
,
836 .put_super
= fat_put_super
,
837 .statfs
= fat_statfs
,
838 .remount_fs
= fat_remount
,
840 .show_options
= fat_show_options
,
843 static int fat_show_options(struct seq_file
*m
, struct dentry
*root
)
845 struct msdos_sb_info
*sbi
= MSDOS_SB(root
->d_sb
);
846 struct fat_mount_options
*opts
= &sbi
->options
;
847 int isvfat
= opts
->isvfat
;
849 if (!uid_eq(opts
->fs_uid
, GLOBAL_ROOT_UID
))
850 seq_printf(m
, ",uid=%u",
851 from_kuid_munged(&init_user_ns
, opts
->fs_uid
));
852 if (!gid_eq(opts
->fs_gid
, GLOBAL_ROOT_GID
))
853 seq_printf(m
, ",gid=%u",
854 from_kgid_munged(&init_user_ns
, opts
->fs_gid
));
855 seq_printf(m
, ",fmask=%04o", opts
->fs_fmask
);
856 seq_printf(m
, ",dmask=%04o", opts
->fs_dmask
);
857 if (opts
->allow_utime
)
858 seq_printf(m
, ",allow_utime=%04o", opts
->allow_utime
);
860 /* strip "cp" prefix from displayed option */
861 seq_printf(m
, ",codepage=%s", &sbi
->nls_disk
->charset
[2]);
864 seq_printf(m
, ",iocharset=%s", sbi
->nls_io
->charset
);
866 switch (opts
->shortname
) {
867 case VFAT_SFN_DISPLAY_WIN95
| VFAT_SFN_CREATE_WIN95
:
868 seq_puts(m
, ",shortname=win95");
870 case VFAT_SFN_DISPLAY_WINNT
| VFAT_SFN_CREATE_WINNT
:
871 seq_puts(m
, ",shortname=winnt");
873 case VFAT_SFN_DISPLAY_WINNT
| VFAT_SFN_CREATE_WIN95
:
874 seq_puts(m
, ",shortname=mixed");
876 case VFAT_SFN_DISPLAY_LOWER
| VFAT_SFN_CREATE_WIN95
:
877 seq_puts(m
, ",shortname=lower");
880 seq_puts(m
, ",shortname=unknown");
884 if (opts
->name_check
!= 'n')
885 seq_printf(m
, ",check=%c", opts
->name_check
);
887 seq_puts(m
, ",usefree");
889 seq_puts(m
, ",quiet");
891 seq_puts(m
, ",showexec");
892 if (opts
->sys_immutable
)
893 seq_puts(m
, ",sys_immutable");
896 seq_puts(m
, ",dotsOK=yes");
898 seq_puts(m
, ",nocase");
901 seq_puts(m
, ",utf8");
902 if (opts
->unicode_xlate
)
903 seq_puts(m
, ",uni_xlate");
905 seq_puts(m
, ",nonumtail");
907 seq_puts(m
, ",rodir");
910 seq_puts(m
, ",flush");
912 if (opts
->time_offset
)
913 seq_printf(m
, ",time_offset=%d", opts
->time_offset
);
915 seq_puts(m
, ",tz=UTC");
917 if (opts
->errors
== FAT_ERRORS_CONT
)
918 seq_puts(m
, ",errors=continue");
919 else if (opts
->errors
== FAT_ERRORS_PANIC
)
920 seq_puts(m
, ",errors=panic");
922 seq_puts(m
, ",errors=remount-ro");
923 if (opts
->nfs
== FAT_NFS_NOSTALE_RO
)
924 seq_puts(m
, ",nfs=nostale_ro");
926 seq_puts(m
, ",nfs=stale_rw");
928 seq_puts(m
, ",discard");
929 if (opts
->dos1xfloppy
)
930 seq_puts(m
, ",dos1xfloppy");
936 Opt_check_n
, Opt_check_r
, Opt_check_s
, Opt_uid
, Opt_gid
,
937 Opt_umask
, Opt_dmask
, Opt_fmask
, Opt_allow_utime
, Opt_codepage
,
938 Opt_usefree
, Opt_nocase
, Opt_quiet
, Opt_showexec
, Opt_debug
,
939 Opt_immutable
, Opt_dots
, Opt_nodots
,
940 Opt_charset
, Opt_shortname_lower
, Opt_shortname_win95
,
941 Opt_shortname_winnt
, Opt_shortname_mixed
, Opt_utf8_no
, Opt_utf8_yes
,
942 Opt_uni_xl_no
, Opt_uni_xl_yes
, Opt_nonumtail_no
, Opt_nonumtail_yes
,
943 Opt_obsolete
, Opt_flush
, Opt_tz_utc
, Opt_rodir
, Opt_err_cont
,
944 Opt_err_panic
, Opt_err_ro
, Opt_discard
, Opt_nfs
, Opt_time_offset
,
945 Opt_nfs_stale_rw
, Opt_nfs_nostale_ro
, Opt_err
, Opt_dos1xfloppy
,
948 static const match_table_t fat_tokens
= {
949 {Opt_check_r
, "check=relaxed"},
950 {Opt_check_s
, "check=strict"},
951 {Opt_check_n
, "check=normal"},
952 {Opt_check_r
, "check=r"},
953 {Opt_check_s
, "check=s"},
954 {Opt_check_n
, "check=n"},
957 {Opt_umask
, "umask=%o"},
958 {Opt_dmask
, "dmask=%o"},
959 {Opt_fmask
, "fmask=%o"},
960 {Opt_allow_utime
, "allow_utime=%o"},
961 {Opt_codepage
, "codepage=%u"},
962 {Opt_usefree
, "usefree"},
963 {Opt_nocase
, "nocase"},
964 {Opt_quiet
, "quiet"},
965 {Opt_showexec
, "showexec"},
966 {Opt_debug
, "debug"},
967 {Opt_immutable
, "sys_immutable"},
968 {Opt_flush
, "flush"},
969 {Opt_tz_utc
, "tz=UTC"},
970 {Opt_time_offset
, "time_offset=%d"},
971 {Opt_err_cont
, "errors=continue"},
972 {Opt_err_panic
, "errors=panic"},
973 {Opt_err_ro
, "errors=remount-ro"},
974 {Opt_discard
, "discard"},
975 {Opt_nfs_stale_rw
, "nfs"},
976 {Opt_nfs_stale_rw
, "nfs=stale_rw"},
977 {Opt_nfs_nostale_ro
, "nfs=nostale_ro"},
978 {Opt_dos1xfloppy
, "dos1xfloppy"},
979 {Opt_obsolete
, "conv=binary"},
980 {Opt_obsolete
, "conv=text"},
981 {Opt_obsolete
, "conv=auto"},
982 {Opt_obsolete
, "conv=b"},
983 {Opt_obsolete
, "conv=t"},
984 {Opt_obsolete
, "conv=a"},
985 {Opt_obsolete
, "fat=%u"},
986 {Opt_obsolete
, "blocksize=%u"},
987 {Opt_obsolete
, "cvf_format=%20s"},
988 {Opt_obsolete
, "cvf_options=%100s"},
989 {Opt_obsolete
, "posix"},
992 static const match_table_t msdos_tokens
= {
993 {Opt_nodots
, "nodots"},
994 {Opt_nodots
, "dotsOK=no"},
996 {Opt_dots
, "dotsOK=yes"},
999 static const match_table_t vfat_tokens
= {
1000 {Opt_charset
, "iocharset=%s"},
1001 {Opt_shortname_lower
, "shortname=lower"},
1002 {Opt_shortname_win95
, "shortname=win95"},
1003 {Opt_shortname_winnt
, "shortname=winnt"},
1004 {Opt_shortname_mixed
, "shortname=mixed"},
1005 {Opt_utf8_no
, "utf8=0"}, /* 0 or no or false */
1006 {Opt_utf8_no
, "utf8=no"},
1007 {Opt_utf8_no
, "utf8=false"},
1008 {Opt_utf8_yes
, "utf8=1"}, /* empty or 1 or yes or true */
1009 {Opt_utf8_yes
, "utf8=yes"},
1010 {Opt_utf8_yes
, "utf8=true"},
1011 {Opt_utf8_yes
, "utf8"},
1012 {Opt_uni_xl_no
, "uni_xlate=0"}, /* 0 or no or false */
1013 {Opt_uni_xl_no
, "uni_xlate=no"},
1014 {Opt_uni_xl_no
, "uni_xlate=false"},
1015 {Opt_uni_xl_yes
, "uni_xlate=1"}, /* empty or 1 or yes or true */
1016 {Opt_uni_xl_yes
, "uni_xlate=yes"},
1017 {Opt_uni_xl_yes
, "uni_xlate=true"},
1018 {Opt_uni_xl_yes
, "uni_xlate"},
1019 {Opt_nonumtail_no
, "nonumtail=0"}, /* 0 or no or false */
1020 {Opt_nonumtail_no
, "nonumtail=no"},
1021 {Opt_nonumtail_no
, "nonumtail=false"},
1022 {Opt_nonumtail_yes
, "nonumtail=1"}, /* empty or 1 or yes or true */
1023 {Opt_nonumtail_yes
, "nonumtail=yes"},
1024 {Opt_nonumtail_yes
, "nonumtail=true"},
1025 {Opt_nonumtail_yes
, "nonumtail"},
1026 {Opt_rodir
, "rodir"},
1030 static int parse_options(struct super_block
*sb
, char *options
, int is_vfat
,
1031 int silent
, int *debug
, struct fat_mount_options
*opts
)
1034 substring_t args
[MAX_OPT_ARGS
];
1038 opts
->isvfat
= is_vfat
;
1040 opts
->fs_uid
= current_uid();
1041 opts
->fs_gid
= current_gid();
1042 opts
->fs_fmask
= opts
->fs_dmask
= current_umask();
1043 opts
->allow_utime
= -1;
1044 opts
->codepage
= fat_default_codepage
;
1045 opts
->iocharset
= fat_default_iocharset
;
1047 opts
->shortname
= VFAT_SFN_DISPLAY_WINNT
|VFAT_SFN_CREATE_WIN95
;
1050 opts
->shortname
= 0;
1053 opts
->name_check
= 'n';
1054 opts
->quiet
= opts
->showexec
= opts
->sys_immutable
= opts
->dotsOK
= 0;
1055 opts
->utf8
= opts
->unicode_xlate
= 0;
1057 opts
->usefree
= opts
->nocase
= 0;
1060 opts
->errors
= FAT_ERRORS_RO
;
1066 while ((p
= strsep(&options
, ",")) != NULL
) {
1071 token
= match_token(p
, fat_tokens
, args
);
1072 if (token
== Opt_err
) {
1074 token
= match_token(p
, vfat_tokens
, args
);
1076 token
= match_token(p
, msdos_tokens
, args
);
1080 opts
->name_check
= 's';
1083 opts
->name_check
= 'r';
1086 opts
->name_check
= 'n';
1095 /* for backward compatibility */
1096 opts
->shortname
= VFAT_SFN_DISPLAY_WIN95
1097 | VFAT_SFN_CREATE_WIN95
;
1110 opts
->sys_immutable
= 1;
1113 if (match_int(&args
[0], &option
))
1115 opts
->fs_uid
= make_kuid(current_user_ns(), option
);
1116 if (!uid_valid(opts
->fs_uid
))
1120 if (match_int(&args
[0], &option
))
1122 opts
->fs_gid
= make_kgid(current_user_ns(), option
);
1123 if (!gid_valid(opts
->fs_gid
))
1127 if (match_octal(&args
[0], &option
))
1129 opts
->fs_fmask
= opts
->fs_dmask
= option
;
1132 if (match_octal(&args
[0], &option
))
1134 opts
->fs_dmask
= option
;
1137 if (match_octal(&args
[0], &option
))
1139 opts
->fs_fmask
= option
;
1141 case Opt_allow_utime
:
1142 if (match_octal(&args
[0], &option
))
1144 opts
->allow_utime
= option
& (S_IWGRP
| S_IWOTH
);
1147 if (match_int(&args
[0], &option
))
1149 opts
->codepage
= option
;
1154 case Opt_time_offset
:
1155 if (match_int(&args
[0], &option
))
1157 if (option
< -12 * 60 || option
> 12 * 60)
1160 opts
->time_offset
= option
;
1164 opts
->time_offset
= 0;
1167 opts
->errors
= FAT_ERRORS_CONT
;
1170 opts
->errors
= FAT_ERRORS_PANIC
;
1173 opts
->errors
= FAT_ERRORS_RO
;
1175 case Opt_nfs_stale_rw
:
1176 opts
->nfs
= FAT_NFS_STALE_RW
;
1178 case Opt_nfs_nostale_ro
:
1179 opts
->nfs
= FAT_NFS_NOSTALE_RO
;
1181 case Opt_dos1xfloppy
:
1182 opts
->dos1xfloppy
= 1;
1185 /* msdos specific */
1195 if (opts
->iocharset
!= fat_default_iocharset
)
1196 kfree(opts
->iocharset
);
1197 iocharset
= match_strdup(&args
[0]);
1200 opts
->iocharset
= iocharset
;
1202 case Opt_shortname_lower
:
1203 opts
->shortname
= VFAT_SFN_DISPLAY_LOWER
1204 | VFAT_SFN_CREATE_WIN95
;
1206 case Opt_shortname_win95
:
1207 opts
->shortname
= VFAT_SFN_DISPLAY_WIN95
1208 | VFAT_SFN_CREATE_WIN95
;
1210 case Opt_shortname_winnt
:
1211 opts
->shortname
= VFAT_SFN_DISPLAY_WINNT
1212 | VFAT_SFN_CREATE_WINNT
;
1214 case Opt_shortname_mixed
:
1215 opts
->shortname
= VFAT_SFN_DISPLAY_WINNT
1216 | VFAT_SFN_CREATE_WIN95
;
1218 case Opt_utf8_no
: /* 0 or no or false */
1221 case Opt_utf8_yes
: /* empty or 1 or yes or true */
1224 case Opt_uni_xl_no
: /* 0 or no or false */
1225 opts
->unicode_xlate
= 0;
1227 case Opt_uni_xl_yes
: /* empty or 1 or yes or true */
1228 opts
->unicode_xlate
= 1;
1230 case Opt_nonumtail_no
: /* 0 or no or false */
1231 opts
->numtail
= 1; /* negated option */
1233 case Opt_nonumtail_yes
: /* empty or 1 or yes or true */
1234 opts
->numtail
= 0; /* negated option */
1243 /* obsolete mount options */
1245 fat_msg(sb
, KERN_INFO
, "\"%s\" option is obsolete, "
1246 "not supported now", p
);
1248 /* unknown option */
1251 fat_msg(sb
, KERN_ERR
,
1252 "Unrecognized mount option \"%s\" "
1253 "or missing value", p
);
1260 /* UTF-8 doesn't provide FAT semantics */
1261 if (!strcmp(opts
->iocharset
, "utf8")) {
1262 fat_msg(sb
, KERN_WARNING
, "utf8 is not a recommended IO charset"
1263 " for FAT filesystems, filesystem will be "
1267 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1268 if (opts
->allow_utime
== (unsigned short)-1)
1269 opts
->allow_utime
= ~opts
->fs_dmask
& (S_IWGRP
| S_IWOTH
);
1270 if (opts
->unicode_xlate
)
1272 if (opts
->nfs
== FAT_NFS_NOSTALE_RO
) {
1273 sb
->s_flags
|= MS_RDONLY
;
1274 sb
->s_export_op
= &fat_export_ops_nostale
;
1280 static int fat_read_root(struct inode
*inode
)
1282 struct super_block
*sb
= inode
->i_sb
;
1283 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
1286 MSDOS_I(inode
)->i_pos
= MSDOS_ROOT_INO
;
1287 inode
->i_uid
= sbi
->options
.fs_uid
;
1288 inode
->i_gid
= sbi
->options
.fs_gid
;
1290 inode
->i_generation
= 0;
1291 inode
->i_mode
= fat_make_mode(sbi
, ATTR_DIR
, S_IRWXUGO
);
1292 inode
->i_op
= sbi
->dir_ops
;
1293 inode
->i_fop
= &fat_dir_operations
;
1294 if (sbi
->fat_bits
== 32) {
1295 MSDOS_I(inode
)->i_start
= sbi
->root_cluster
;
1296 error
= fat_calc_dir_size(inode
);
1300 MSDOS_I(inode
)->i_start
= 0;
1301 inode
->i_size
= sbi
->dir_entries
* sizeof(struct msdos_dir_entry
);
1303 inode
->i_blocks
= ((inode
->i_size
+ (sbi
->cluster_size
- 1))
1304 & ~((loff_t
)sbi
->cluster_size
- 1)) >> 9;
1305 MSDOS_I(inode
)->i_logstart
= 0;
1306 MSDOS_I(inode
)->mmu_private
= inode
->i_size
;
1308 fat_save_attrs(inode
, ATTR_DIR
);
1309 inode
->i_mtime
.tv_sec
= inode
->i_atime
.tv_sec
= inode
->i_ctime
.tv_sec
= 0;
1310 inode
->i_mtime
.tv_nsec
= inode
->i_atime
.tv_nsec
= inode
->i_ctime
.tv_nsec
= 0;
1311 set_nlink(inode
, fat_subdirs(inode
)+2);
1316 static unsigned long calc_fat_clusters(struct super_block
*sb
)
1318 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
1320 /* Divide first to avoid overflow */
1321 if (sbi
->fat_bits
!= 12) {
1322 unsigned long ent_per_sec
= sb
->s_blocksize
* 8 / sbi
->fat_bits
;
1323 return ent_per_sec
* sbi
->fat_length
;
1326 return sbi
->fat_length
* sb
->s_blocksize
* 8 / sbi
->fat_bits
;
1329 static bool fat_bpb_is_zero(struct fat_boot_sector
*b
)
1331 if (get_unaligned_le16(&b
->sector_size
))
1333 if (b
->sec_per_clus
)
1339 if (get_unaligned_le16(&b
->dir_entries
))
1341 if (get_unaligned_le16(&b
->sectors
))
1354 static int fat_read_bpb(struct super_block
*sb
, struct fat_boot_sector
*b
,
1355 int silent
, struct fat_bios_param_block
*bpb
)
1357 int error
= -EINVAL
;
1359 /* Read in BPB ... */
1360 memset(bpb
, 0, sizeof(*bpb
));
1361 bpb
->fat_sector_size
= get_unaligned_le16(&b
->sector_size
);
1362 bpb
->fat_sec_per_clus
= b
->sec_per_clus
;
1363 bpb
->fat_reserved
= le16_to_cpu(b
->reserved
);
1364 bpb
->fat_fats
= b
->fats
;
1365 bpb
->fat_dir_entries
= get_unaligned_le16(&b
->dir_entries
);
1366 bpb
->fat_sectors
= get_unaligned_le16(&b
->sectors
);
1367 bpb
->fat_fat_length
= le16_to_cpu(b
->fat_length
);
1368 bpb
->fat_total_sect
= le32_to_cpu(b
->total_sect
);
1370 bpb
->fat16_state
= b
->fat16
.state
;
1371 bpb
->fat16_vol_id
= get_unaligned_le32(b
->fat16
.vol_id
);
1373 bpb
->fat32_length
= le32_to_cpu(b
->fat32
.length
);
1374 bpb
->fat32_root_cluster
= le32_to_cpu(b
->fat32
.root_cluster
);
1375 bpb
->fat32_info_sector
= le16_to_cpu(b
->fat32
.info_sector
);
1376 bpb
->fat32_state
= b
->fat32
.state
;
1377 bpb
->fat32_vol_id
= get_unaligned_le32(b
->fat32
.vol_id
);
1379 /* Validate this looks like a FAT filesystem BPB */
1380 if (!bpb
->fat_reserved
) {
1382 fat_msg(sb
, KERN_ERR
,
1383 "bogus number of reserved sectors");
1386 if (!bpb
->fat_fats
) {
1388 fat_msg(sb
, KERN_ERR
, "bogus number of FAT structure");
1393 * Earlier we checked here that b->secs_track and b->head are nonzero,
1394 * but it turns out valid FAT filesystems can have zero there.
1397 if (!fat_valid_media(b
->media
)) {
1399 fat_msg(sb
, KERN_ERR
, "invalid media value (0x%02x)",
1400 (unsigned)b
->media
);
1404 if (!is_power_of_2(bpb
->fat_sector_size
)
1405 || (bpb
->fat_sector_size
< 512)
1406 || (bpb
->fat_sector_size
> 4096)) {
1408 fat_msg(sb
, KERN_ERR
, "bogus logical sector size %u",
1409 (unsigned)bpb
->fat_sector_size
);
1413 if (!is_power_of_2(bpb
->fat_sec_per_clus
)) {
1415 fat_msg(sb
, KERN_ERR
, "bogus sectors per cluster %u",
1416 (unsigned)bpb
->fat_sec_per_clus
);
1426 static int fat_read_static_bpb(struct super_block
*sb
,
1427 struct fat_boot_sector
*b
, int silent
,
1428 struct fat_bios_param_block
*bpb
)
1430 static const char *notdos1x
= "This doesn't look like a DOS 1.x volume";
1432 struct fat_floppy_defaults
*fdefaults
= NULL
;
1433 int error
= -EINVAL
;
1437 bd_sects
= i_size_read(sb
->s_bdev
->bd_inode
) / SECTOR_SIZE
;
1439 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */
1440 if (b
->ignored
[0] != 0xeb || b
->ignored
[2] != 0x90) {
1442 fat_msg(sb
, KERN_ERR
,
1443 "%s; no bootstrapping code", notdos1x
);
1448 * If any value in this region is non-zero, it isn't archaic
1451 if (!fat_bpb_is_zero(b
)) {
1453 fat_msg(sb
, KERN_ERR
,
1454 "%s; DOS 2.x BPB is non-zero", notdos1x
);
1458 for (i
= 0; i
< ARRAY_SIZE(floppy_defaults
); i
++) {
1459 if (floppy_defaults
[i
].nr_sectors
== bd_sects
) {
1460 fdefaults
= &floppy_defaults
[i
];
1465 if (fdefaults
== NULL
) {
1467 fat_msg(sb
, KERN_WARNING
,
1468 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)",
1474 fat_msg(sb
, KERN_INFO
,
1475 "This looks like a DOS 1.x volume; assuming default BPB values");
1477 memset(bpb
, 0, sizeof(*bpb
));
1478 bpb
->fat_sector_size
= SECTOR_SIZE
;
1479 bpb
->fat_sec_per_clus
= fdefaults
->sec_per_clus
;
1480 bpb
->fat_reserved
= 1;
1482 bpb
->fat_dir_entries
= fdefaults
->dir_entries
;
1483 bpb
->fat_sectors
= fdefaults
->nr_sectors
;
1484 bpb
->fat_fat_length
= fdefaults
->fat_length
;
1493 * Read the super block of an MS-DOS FS.
1495 int fat_fill_super(struct super_block
*sb
, void *data
, int silent
, int isvfat
,
1496 void (*setup
)(struct super_block
*))
1498 struct inode
*root_inode
= NULL
, *fat_inode
= NULL
;
1499 struct inode
*fsinfo_inode
= NULL
;
1500 struct buffer_head
*bh
;
1501 struct fat_bios_param_block bpb
;
1502 struct msdos_sb_info
*sbi
;
1503 u16 logical_sector_size
;
1504 u32 total_sectors
, total_clusters
, fat_clusters
, rootdir_sectors
;
1510 * GFP_KERNEL is ok here, because while we do hold the
1511 * supeblock lock, memory pressure can't call back into
1512 * the filesystem, since we're only just about to mount
1513 * it and have no inodes etc active!
1515 sbi
= kzalloc(sizeof(struct msdos_sb_info
), GFP_KERNEL
);
1518 sb
->s_fs_info
= sbi
;
1520 sb
->s_flags
|= MS_NODIRATIME
;
1521 sb
->s_magic
= MSDOS_SUPER_MAGIC
;
1522 sb
->s_op
= &fat_sops
;
1523 sb
->s_export_op
= &fat_export_ops
;
1524 mutex_init(&sbi
->nfs_build_inode_lock
);
1525 ratelimit_state_init(&sbi
->ratelimit
, DEFAULT_RATELIMIT_INTERVAL
,
1526 DEFAULT_RATELIMIT_BURST
);
1528 error
= parse_options(sb
, data
, isvfat
, silent
, &debug
, &sbi
->options
);
1532 setup(sb
); /* flavour-specific stuff that needs options */
1535 sb_min_blocksize(sb
, 512);
1536 bh
= sb_bread(sb
, 0);
1538 fat_msg(sb
, KERN_ERR
, "unable to read boot sector");
1542 error
= fat_read_bpb(sb
, (struct fat_boot_sector
*)bh
->b_data
, silent
,
1544 if (error
== -EINVAL
&& sbi
->options
.dos1xfloppy
)
1545 error
= fat_read_static_bpb(sb
,
1546 (struct fat_boot_sector
*)bh
->b_data
, silent
, &bpb
);
1549 if (error
== -EINVAL
)
1554 logical_sector_size
= bpb
.fat_sector_size
;
1555 sbi
->sec_per_clus
= bpb
.fat_sec_per_clus
;
1558 if (logical_sector_size
< sb
->s_blocksize
) {
1559 fat_msg(sb
, KERN_ERR
, "logical sector size too small for device"
1560 " (logical sector size = %u)", logical_sector_size
);
1564 if (logical_sector_size
> sb
->s_blocksize
) {
1565 struct buffer_head
*bh_resize
;
1567 if (!sb_set_blocksize(sb
, logical_sector_size
)) {
1568 fat_msg(sb
, KERN_ERR
, "unable to set blocksize %u",
1569 logical_sector_size
);
1573 /* Verify that the larger boot sector is fully readable */
1574 bh_resize
= sb_bread(sb
, 0);
1575 if (bh_resize
== NULL
) {
1576 fat_msg(sb
, KERN_ERR
, "unable to read boot sector"
1577 " (logical sector size = %lu)",
1584 mutex_init(&sbi
->s_lock
);
1585 sbi
->cluster_size
= sb
->s_blocksize
* sbi
->sec_per_clus
;
1586 sbi
->cluster_bits
= ffs(sbi
->cluster_size
) - 1;
1587 sbi
->fats
= bpb
.fat_fats
;
1588 sbi
->fat_bits
= 0; /* Don't know yet */
1589 sbi
->fat_start
= bpb
.fat_reserved
;
1590 sbi
->fat_length
= bpb
.fat_fat_length
;
1591 sbi
->root_cluster
= 0;
1592 sbi
->free_clusters
= -1; /* Don't know yet */
1593 sbi
->free_clus_valid
= 0;
1594 sbi
->prev_free
= FAT_START_ENT
;
1595 sb
->s_maxbytes
= 0xffffffff;
1597 if (!sbi
->fat_length
&& bpb
.fat32_length
) {
1598 struct fat_boot_fsinfo
*fsinfo
;
1599 struct buffer_head
*fsinfo_bh
;
1603 sbi
->fat_length
= bpb
.fat32_length
;
1604 sbi
->root_cluster
= bpb
.fat32_root_cluster
;
1606 /* MC - if info_sector is 0, don't multiply by 0 */
1607 sbi
->fsinfo_sector
= bpb
.fat32_info_sector
;
1608 if (sbi
->fsinfo_sector
== 0)
1609 sbi
->fsinfo_sector
= 1;
1611 fsinfo_bh
= sb_bread(sb
, sbi
->fsinfo_sector
);
1612 if (fsinfo_bh
== NULL
) {
1613 fat_msg(sb
, KERN_ERR
, "bread failed, FSINFO block"
1614 " (sector = %lu)", sbi
->fsinfo_sector
);
1618 fsinfo
= (struct fat_boot_fsinfo
*)fsinfo_bh
->b_data
;
1619 if (!IS_FSINFO(fsinfo
)) {
1620 fat_msg(sb
, KERN_WARNING
, "Invalid FSINFO signature: "
1621 "0x%08x, 0x%08x (sector = %lu)",
1622 le32_to_cpu(fsinfo
->signature1
),
1623 le32_to_cpu(fsinfo
->signature2
),
1624 sbi
->fsinfo_sector
);
1626 if (sbi
->options
.usefree
)
1627 sbi
->free_clus_valid
= 1;
1628 sbi
->free_clusters
= le32_to_cpu(fsinfo
->free_clusters
);
1629 sbi
->prev_free
= le32_to_cpu(fsinfo
->next_cluster
);
1635 /* interpret volume ID as a little endian 32 bit integer */
1636 if (sbi
->fat_bits
== 32)
1637 sbi
->vol_id
= bpb
.fat32_vol_id
;
1638 else /* fat 16 or 12 */
1639 sbi
->vol_id
= bpb
.fat16_vol_id
;
1641 sbi
->dir_per_block
= sb
->s_blocksize
/ sizeof(struct msdos_dir_entry
);
1642 sbi
->dir_per_block_bits
= ffs(sbi
->dir_per_block
) - 1;
1644 sbi
->dir_start
= sbi
->fat_start
+ sbi
->fats
* sbi
->fat_length
;
1645 sbi
->dir_entries
= bpb
.fat_dir_entries
;
1646 if (sbi
->dir_entries
& (sbi
->dir_per_block
- 1)) {
1648 fat_msg(sb
, KERN_ERR
, "bogus directory-entries per block"
1649 " (%u)", sbi
->dir_entries
);
1653 rootdir_sectors
= sbi
->dir_entries
1654 * sizeof(struct msdos_dir_entry
) / sb
->s_blocksize
;
1655 sbi
->data_start
= sbi
->dir_start
+ rootdir_sectors
;
1656 total_sectors
= bpb
.fat_sectors
;
1657 if (total_sectors
== 0)
1658 total_sectors
= bpb
.fat_total_sect
;
1660 total_clusters
= (total_sectors
- sbi
->data_start
) / sbi
->sec_per_clus
;
1662 if (sbi
->fat_bits
!= 32)
1663 sbi
->fat_bits
= (total_clusters
> MAX_FAT12
) ? 16 : 12;
1665 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */
1666 if (sbi
->fat_bits
== 32)
1667 sbi
->dirty
= bpb
.fat32_state
& FAT_STATE_DIRTY
;
1668 else /* fat 16 or 12 */
1669 sbi
->dirty
= bpb
.fat16_state
& FAT_STATE_DIRTY
;
1671 /* check that FAT table does not overflow */
1672 fat_clusters
= calc_fat_clusters(sb
);
1673 total_clusters
= min(total_clusters
, fat_clusters
- FAT_START_ENT
);
1674 if (total_clusters
> MAX_FAT(sb
)) {
1676 fat_msg(sb
, KERN_ERR
, "count of clusters too big (%u)",
1681 sbi
->max_cluster
= total_clusters
+ FAT_START_ENT
;
1682 /* check the free_clusters, it's not necessarily correct */
1683 if (sbi
->free_clusters
!= -1 && sbi
->free_clusters
> total_clusters
)
1684 sbi
->free_clusters
= -1;
1685 /* check the prev_free, it's not necessarily correct */
1686 sbi
->prev_free
%= sbi
->max_cluster
;
1687 if (sbi
->prev_free
< FAT_START_ENT
)
1688 sbi
->prev_free
= FAT_START_ENT
;
1690 /* set up enough so that it can read an inode */
1693 fat_ent_access_init(sb
);
1696 * The low byte of FAT's first entry must have same value with
1697 * media-field. But in real world, too many devices is
1698 * writing wrong value. So, removed that validity check.
1700 * if (FAT_FIRST_ENT(sb, media) != first)
1704 sprintf(buf
, "cp%d", sbi
->options
.codepage
);
1705 sbi
->nls_disk
= load_nls(buf
);
1706 if (!sbi
->nls_disk
) {
1707 fat_msg(sb
, KERN_ERR
, "codepage %s not found", buf
);
1711 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1712 if (sbi
->options
.isvfat
) {
1713 sbi
->nls_io
= load_nls(sbi
->options
.iocharset
);
1715 fat_msg(sb
, KERN_ERR
, "IO charset %s not found",
1716 sbi
->options
.iocharset
);
1722 fat_inode
= new_inode(sb
);
1725 MSDOS_I(fat_inode
)->i_pos
= 0;
1726 sbi
->fat_inode
= fat_inode
;
1728 fsinfo_inode
= new_inode(sb
);
1731 fsinfo_inode
->i_ino
= MSDOS_FSINFO_INO
;
1732 sbi
->fsinfo_inode
= fsinfo_inode
;
1733 insert_inode_hash(fsinfo_inode
);
1735 root_inode
= new_inode(sb
);
1738 root_inode
->i_ino
= MSDOS_ROOT_INO
;
1739 root_inode
->i_version
= 1;
1740 error
= fat_read_root(root_inode
);
1746 insert_inode_hash(root_inode
);
1747 fat_attach(root_inode
, 0);
1748 sb
->s_root
= d_make_root(root_inode
);
1750 fat_msg(sb
, KERN_ERR
, "get root inode failed");
1754 if (sbi
->options
.discard
) {
1755 struct request_queue
*q
= bdev_get_queue(sb
->s_bdev
);
1756 if (!blk_queue_discard(q
))
1757 fat_msg(sb
, KERN_WARNING
,
1758 "mounting with \"discard\" option, but "
1759 "the device does not support discard");
1762 fat_set_state(sb
, 1, 0);
1768 fat_msg(sb
, KERN_INFO
, "Can't find a valid FAT filesystem");
1775 unload_nls(sbi
->nls_io
);
1776 unload_nls(sbi
->nls_disk
);
1777 if (sbi
->options
.iocharset
!= fat_default_iocharset
)
1778 kfree(sbi
->options
.iocharset
);
1779 sb
->s_fs_info
= NULL
;
1784 EXPORT_SYMBOL_GPL(fat_fill_super
);
1787 * helper function for fat_flush_inodes. This writes both the inode
1788 * and the file data blocks, waiting for in flight data blocks before
1789 * the start of the call. It does not wait for any io started
1792 static int writeback_inode(struct inode
*inode
)
1797 /* if we used wait=1, sync_inode_metadata waits for the io for the
1798 * inode to finish. So wait=0 is sent down to sync_inode_metadata
1799 * and filemap_fdatawrite is used for the data blocks
1801 ret
= sync_inode_metadata(inode
, 0);
1803 ret
= filemap_fdatawrite(inode
->i_mapping
);
1808 * write data and metadata corresponding to i1 and i2. The io is
1809 * started but we do not wait for any of it to finish.
1811 * filemap_flush is used for the block device, so if there is a dirty
1812 * page for a block already in flight, we will not wait and start the
1815 int fat_flush_inodes(struct super_block
*sb
, struct inode
*i1
, struct inode
*i2
)
1818 if (!MSDOS_SB(sb
)->options
.flush
)
1821 ret
= writeback_inode(i1
);
1823 ret
= writeback_inode(i2
);
1825 struct address_space
*mapping
= sb
->s_bdev
->bd_inode
->i_mapping
;
1826 ret
= filemap_flush(mapping
);
1830 EXPORT_SYMBOL_GPL(fat_flush_inodes
);
1832 static int __init
init_fat_fs(void)
1836 err
= fat_cache_init();
1840 err
= fat_init_inodecache();
1847 fat_cache_destroy();
1851 static void __exit
exit_fat_fs(void)
1853 fat_cache_destroy();
1854 fat_destroy_inodecache();
1857 module_init(init_fat_fs
)
1858 module_exit(exit_fat_fs
)
1860 MODULE_LICENSE("GPL");