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/pagemap.h>
15 #include <linux/mpage.h>
16 #include <linux/vfs.h>
17 #include <linux/seq_file.h>
18 #include <linux/parser.h>
19 #include <linux/uio.h>
20 #include <linux/blkdev.h>
21 #include <linux/backing-dev.h>
22 #include <asm/unaligned.h>
25 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET
26 /* if user don't select VFAT, this is undefined. */
27 #define CONFIG_FAT_DEFAULT_IOCHARSET ""
30 #define KB_IN_SECTORS 2
33 * A deserialized copy of the on-disk structure laid out in struct
36 struct fat_bios_param_block
{
50 u32 fat32_root_cluster
;
51 u16 fat32_info_sector
;
56 static int fat_default_codepage
= CONFIG_FAT_DEFAULT_CODEPAGE
;
57 static char fat_default_iocharset
[] = CONFIG_FAT_DEFAULT_IOCHARSET
;
59 static struct fat_floppy_defaults
{
61 unsigned sec_per_clus
;
65 } floppy_defaults
[] = {
67 .nr_sectors
= 160 * KB_IN_SECTORS
,
74 .nr_sectors
= 180 * KB_IN_SECTORS
,
81 .nr_sectors
= 320 * KB_IN_SECTORS
,
88 .nr_sectors
= 360 * KB_IN_SECTORS
,
96 static int fat_add_cluster(struct inode
*inode
)
100 err
= fat_alloc_clusters(inode
, &cluster
, 1);
103 /* FIXME: this cluster should be added after data of this
104 * cluster is writed */
105 err
= fat_chain_add(inode
, cluster
, 1);
107 fat_free_clusters(inode
, cluster
);
111 static inline int __fat_get_block(struct inode
*inode
, sector_t iblock
,
112 unsigned long *max_blocks
,
113 struct buffer_head
*bh_result
, int create
)
115 struct super_block
*sb
= inode
->i_sb
;
116 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
117 unsigned long mapped_blocks
;
121 err
= fat_bmap(inode
, iblock
, &phys
, &mapped_blocks
, create
);
125 map_bh(bh_result
, sb
, phys
);
126 *max_blocks
= min(mapped_blocks
, *max_blocks
);
132 if (iblock
!= MSDOS_I(inode
)->mmu_private
>> sb
->s_blocksize_bits
) {
133 fat_fs_error(sb
, "corrupted file size (i_pos %lld, %lld)",
134 MSDOS_I(inode
)->i_pos
, MSDOS_I(inode
)->mmu_private
);
138 offset
= (unsigned long)iblock
& (sbi
->sec_per_clus
- 1);
140 /* TODO: multiple cluster allocation would be desirable. */
141 err
= fat_add_cluster(inode
);
145 /* available blocks on this cluster */
146 mapped_blocks
= sbi
->sec_per_clus
- offset
;
148 *max_blocks
= min(mapped_blocks
, *max_blocks
);
149 MSDOS_I(inode
)->mmu_private
+= *max_blocks
<< sb
->s_blocksize_bits
;
151 err
= fat_bmap(inode
, iblock
, &phys
, &mapped_blocks
, create
);
156 BUG_ON(*max_blocks
!= mapped_blocks
);
157 set_buffer_new(bh_result
);
158 map_bh(bh_result
, sb
, phys
);
163 static int fat_get_block(struct inode
*inode
, sector_t iblock
,
164 struct buffer_head
*bh_result
, int create
)
166 struct super_block
*sb
= inode
->i_sb
;
167 unsigned long max_blocks
= bh_result
->b_size
>> inode
->i_blkbits
;
170 err
= __fat_get_block(inode
, iblock
, &max_blocks
, bh_result
, create
);
173 bh_result
->b_size
= max_blocks
<< sb
->s_blocksize_bits
;
177 static int fat_writepage(struct page
*page
, struct writeback_control
*wbc
)
179 return block_write_full_page(page
, fat_get_block
, wbc
);
182 static int fat_writepages(struct address_space
*mapping
,
183 struct writeback_control
*wbc
)
185 return mpage_writepages(mapping
, wbc
, fat_get_block
);
188 static int fat_readpage(struct file
*file
, struct page
*page
)
190 return mpage_readpage(page
, fat_get_block
);
193 static int fat_readpages(struct file
*file
, struct address_space
*mapping
,
194 struct list_head
*pages
, unsigned nr_pages
)
196 return mpage_readpages(mapping
, pages
, nr_pages
, fat_get_block
);
199 static void fat_write_failed(struct address_space
*mapping
, loff_t to
)
201 struct inode
*inode
= mapping
->host
;
203 if (to
> inode
->i_size
) {
204 truncate_pagecache(inode
, inode
->i_size
);
205 fat_truncate_blocks(inode
, inode
->i_size
);
209 static int fat_write_begin(struct file
*file
, struct address_space
*mapping
,
210 loff_t pos
, unsigned len
, unsigned flags
,
211 struct page
**pagep
, void **fsdata
)
216 err
= cont_write_begin(file
, mapping
, pos
, len
, flags
,
217 pagep
, fsdata
, fat_get_block
,
218 &MSDOS_I(mapping
->host
)->mmu_private
);
220 fat_write_failed(mapping
, pos
+ len
);
224 static int fat_write_end(struct file
*file
, struct address_space
*mapping
,
225 loff_t pos
, unsigned len
, unsigned copied
,
226 struct page
*pagep
, void *fsdata
)
228 struct inode
*inode
= mapping
->host
;
230 err
= generic_write_end(file
, mapping
, pos
, len
, copied
, pagep
, fsdata
);
232 fat_write_failed(mapping
, pos
+ len
);
233 if (!(err
< 0) && !(MSDOS_I(inode
)->i_attrs
& ATTR_ARCH
)) {
234 inode
->i_mtime
= inode
->i_ctime
= CURRENT_TIME_SEC
;
235 MSDOS_I(inode
)->i_attrs
|= ATTR_ARCH
;
236 mark_inode_dirty(inode
);
241 static ssize_t
fat_direct_IO(struct kiocb
*iocb
, struct iov_iter
*iter
,
244 struct file
*file
= iocb
->ki_filp
;
245 struct address_space
*mapping
= file
->f_mapping
;
246 struct inode
*inode
= mapping
->host
;
247 size_t count
= iov_iter_count(iter
);
250 if (iov_iter_rw(iter
) == WRITE
) {
252 * FIXME: blockdev_direct_IO() doesn't use ->write_begin(),
253 * so we need to update the ->mmu_private to block boundary.
255 * But we must fill the remaining area or hole by nul for
256 * updating ->mmu_private.
258 * Return 0, and fallback to normal buffered write.
260 loff_t size
= offset
+ count
;
261 if (MSDOS_I(inode
)->mmu_private
< size
)
266 * FAT need to use the DIO_LOCKING for avoiding the race
267 * condition of fat_get_block() and ->truncate().
269 ret
= blockdev_direct_IO(iocb
, inode
, iter
, offset
, fat_get_block
);
270 if (ret
< 0 && iov_iter_rw(iter
) == WRITE
)
271 fat_write_failed(mapping
, offset
+ count
);
276 static sector_t
_fat_bmap(struct address_space
*mapping
, sector_t block
)
280 /* fat_get_cluster() assumes the requested blocknr isn't truncated. */
281 down_read(&MSDOS_I(mapping
->host
)->truncate_lock
);
282 blocknr
= generic_block_bmap(mapping
, block
, fat_get_block
);
283 up_read(&MSDOS_I(mapping
->host
)->truncate_lock
);
289 * fat_block_truncate_page() zeroes out a mapping from file offset `from'
290 * up to the end of the block which corresponds to `from'.
291 * This is required during truncate to physically zeroout the tail end
292 * of that block so it doesn't yield old data if the file is later grown.
293 * Also, avoid causing failure from fsx for cases of "data past EOF"
295 int fat_block_truncate_page(struct inode
*inode
, loff_t from
)
297 return block_truncate_page(inode
->i_mapping
, from
, fat_get_block
);
300 static const struct address_space_operations fat_aops
= {
301 .readpage
= fat_readpage
,
302 .readpages
= fat_readpages
,
303 .writepage
= fat_writepage
,
304 .writepages
= fat_writepages
,
305 .write_begin
= fat_write_begin
,
306 .write_end
= fat_write_end
,
307 .direct_IO
= fat_direct_IO
,
312 * New FAT inode stuff. We do the following:
313 * a) i_ino is constant and has nothing with on-disk location.
314 * b) FAT manages its own cache of directory entries.
315 * c) *This* cache is indexed by on-disk location.
316 * d) inode has an associated directory entry, all right, but
317 * it may be unhashed.
318 * e) currently entries are stored within struct inode. That should
320 * f) we deal with races in the following way:
321 * 1. readdir() and lookup() do FAT-dir-cache lookup.
322 * 2. rename() unhashes the F-d-c entry and rehashes it in
324 * 3. unlink() and rmdir() unhash F-d-c entry.
325 * 4. fat_write_inode() checks whether the thing is unhashed.
326 * If it is we silently return. If it isn't we do bread(),
327 * check if the location is still valid and retry if it
328 * isn't. Otherwise we do changes.
329 * 5. Spinlock is used to protect hash/unhash/location check/lookup
330 * 6. fat_evict_inode() unhashes the F-d-c entry.
331 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
332 * and consider negative result as cache miss.
335 static void fat_hash_init(struct super_block
*sb
)
337 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
340 spin_lock_init(&sbi
->inode_hash_lock
);
341 for (i
= 0; i
< FAT_HASH_SIZE
; i
++)
342 INIT_HLIST_HEAD(&sbi
->inode_hashtable
[i
]);
345 static inline unsigned long fat_hash(loff_t i_pos
)
347 return hash_32(i_pos
, FAT_HASH_BITS
);
350 static void dir_hash_init(struct super_block
*sb
)
352 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
355 spin_lock_init(&sbi
->dir_hash_lock
);
356 for (i
= 0; i
< FAT_HASH_SIZE
; i
++)
357 INIT_HLIST_HEAD(&sbi
->dir_hashtable
[i
]);
360 void fat_attach(struct inode
*inode
, loff_t i_pos
)
362 struct msdos_sb_info
*sbi
= MSDOS_SB(inode
->i_sb
);
364 if (inode
->i_ino
!= MSDOS_ROOT_INO
) {
365 struct hlist_head
*head
= sbi
->inode_hashtable
368 spin_lock(&sbi
->inode_hash_lock
);
369 MSDOS_I(inode
)->i_pos
= i_pos
;
370 hlist_add_head(&MSDOS_I(inode
)->i_fat_hash
, head
);
371 spin_unlock(&sbi
->inode_hash_lock
);
374 /* If NFS support is enabled, cache the mapping of start cluster
375 * to directory inode. This is used during reconnection of
376 * dentries to the filesystem root.
378 if (S_ISDIR(inode
->i_mode
) && sbi
->options
.nfs
) {
379 struct hlist_head
*d_head
= sbi
->dir_hashtable
;
380 d_head
+= fat_dir_hash(MSDOS_I(inode
)->i_logstart
);
382 spin_lock(&sbi
->dir_hash_lock
);
383 hlist_add_head(&MSDOS_I(inode
)->i_dir_hash
, d_head
);
384 spin_unlock(&sbi
->dir_hash_lock
);
387 EXPORT_SYMBOL_GPL(fat_attach
);
389 void fat_detach(struct inode
*inode
)
391 struct msdos_sb_info
*sbi
= MSDOS_SB(inode
->i_sb
);
392 spin_lock(&sbi
->inode_hash_lock
);
393 MSDOS_I(inode
)->i_pos
= 0;
394 hlist_del_init(&MSDOS_I(inode
)->i_fat_hash
);
395 spin_unlock(&sbi
->inode_hash_lock
);
397 if (S_ISDIR(inode
->i_mode
) && sbi
->options
.nfs
) {
398 spin_lock(&sbi
->dir_hash_lock
);
399 hlist_del_init(&MSDOS_I(inode
)->i_dir_hash
);
400 spin_unlock(&sbi
->dir_hash_lock
);
403 EXPORT_SYMBOL_GPL(fat_detach
);
405 struct inode
*fat_iget(struct super_block
*sb
, loff_t i_pos
)
407 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
408 struct hlist_head
*head
= sbi
->inode_hashtable
+ fat_hash(i_pos
);
409 struct msdos_inode_info
*i
;
410 struct inode
*inode
= NULL
;
412 spin_lock(&sbi
->inode_hash_lock
);
413 hlist_for_each_entry(i
, head
, i_fat_hash
) {
414 BUG_ON(i
->vfs_inode
.i_sb
!= sb
);
415 if (i
->i_pos
!= i_pos
)
417 inode
= igrab(&i
->vfs_inode
);
421 spin_unlock(&sbi
->inode_hash_lock
);
425 static int is_exec(unsigned char *extension
)
427 unsigned char exe_extensions
[] = "EXECOMBAT", *walk
;
429 for (walk
= exe_extensions
; *walk
; walk
+= 3)
430 if (!strncmp(extension
, walk
, 3))
435 static int fat_calc_dir_size(struct inode
*inode
)
437 struct msdos_sb_info
*sbi
= MSDOS_SB(inode
->i_sb
);
438 int ret
, fclus
, dclus
;
441 if (MSDOS_I(inode
)->i_start
== 0)
444 ret
= fat_get_cluster(inode
, FAT_ENT_EOF
, &fclus
, &dclus
);
447 inode
->i_size
= (fclus
+ 1) << sbi
->cluster_bits
;
452 /* doesn't deal with root inode */
453 int fat_fill_inode(struct inode
*inode
, struct msdos_dir_entry
*de
)
455 struct msdos_sb_info
*sbi
= MSDOS_SB(inode
->i_sb
);
458 MSDOS_I(inode
)->i_pos
= 0;
459 inode
->i_uid
= sbi
->options
.fs_uid
;
460 inode
->i_gid
= sbi
->options
.fs_gid
;
462 inode
->i_generation
= get_seconds();
464 if ((de
->attr
& ATTR_DIR
) && !IS_FREE(de
->name
)) {
465 inode
->i_generation
&= ~1;
466 inode
->i_mode
= fat_make_mode(sbi
, de
->attr
, S_IRWXUGO
);
467 inode
->i_op
= sbi
->dir_ops
;
468 inode
->i_fop
= &fat_dir_operations
;
470 MSDOS_I(inode
)->i_start
= fat_get_start(sbi
, de
);
471 MSDOS_I(inode
)->i_logstart
= MSDOS_I(inode
)->i_start
;
472 error
= fat_calc_dir_size(inode
);
475 MSDOS_I(inode
)->mmu_private
= inode
->i_size
;
477 set_nlink(inode
, fat_subdirs(inode
));
478 } else { /* not a directory */
479 inode
->i_generation
|= 1;
480 inode
->i_mode
= fat_make_mode(sbi
, de
->attr
,
481 ((sbi
->options
.showexec
&& !is_exec(de
->name
+ 8))
482 ? S_IRUGO
|S_IWUGO
: S_IRWXUGO
));
483 MSDOS_I(inode
)->i_start
= fat_get_start(sbi
, de
);
485 MSDOS_I(inode
)->i_logstart
= MSDOS_I(inode
)->i_start
;
486 inode
->i_size
= le32_to_cpu(de
->size
);
487 inode
->i_op
= &fat_file_inode_operations
;
488 inode
->i_fop
= &fat_file_operations
;
489 inode
->i_mapping
->a_ops
= &fat_aops
;
490 MSDOS_I(inode
)->mmu_private
= inode
->i_size
;
492 if (de
->attr
& ATTR_SYS
) {
493 if (sbi
->options
.sys_immutable
)
494 inode
->i_flags
|= S_IMMUTABLE
;
496 fat_save_attrs(inode
, de
->attr
);
498 inode
->i_blocks
= ((inode
->i_size
+ (sbi
->cluster_size
- 1))
499 & ~((loff_t
)sbi
->cluster_size
- 1)) >> 9;
501 fat_time_fat2unix(sbi
, &inode
->i_mtime
, de
->time
, de
->date
, 0);
502 if (sbi
->options
.isvfat
) {
503 fat_time_fat2unix(sbi
, &inode
->i_ctime
, de
->ctime
,
504 de
->cdate
, de
->ctime_cs
);
505 fat_time_fat2unix(sbi
, &inode
->i_atime
, 0, de
->adate
, 0);
507 inode
->i_ctime
= inode
->i_atime
= inode
->i_mtime
;
512 static inline void fat_lock_build_inode(struct msdos_sb_info
*sbi
)
514 if (sbi
->options
.nfs
== FAT_NFS_NOSTALE_RO
)
515 mutex_lock(&sbi
->nfs_build_inode_lock
);
518 static inline void fat_unlock_build_inode(struct msdos_sb_info
*sbi
)
520 if (sbi
->options
.nfs
== FAT_NFS_NOSTALE_RO
)
521 mutex_unlock(&sbi
->nfs_build_inode_lock
);
524 struct inode
*fat_build_inode(struct super_block
*sb
,
525 struct msdos_dir_entry
*de
, loff_t i_pos
)
530 fat_lock_build_inode(MSDOS_SB(sb
));
531 inode
= fat_iget(sb
, i_pos
);
534 inode
= new_inode(sb
);
536 inode
= ERR_PTR(-ENOMEM
);
539 inode
->i_ino
= iunique(sb
, MSDOS_ROOT_INO
);
540 inode
->i_version
= 1;
541 err
= fat_fill_inode(inode
, de
);
544 inode
= ERR_PTR(err
);
547 fat_attach(inode
, i_pos
);
548 insert_inode_hash(inode
);
550 fat_unlock_build_inode(MSDOS_SB(sb
));
554 EXPORT_SYMBOL_GPL(fat_build_inode
);
556 static void fat_evict_inode(struct inode
*inode
)
558 truncate_inode_pages_final(&inode
->i_data
);
559 if (!inode
->i_nlink
) {
561 fat_truncate_blocks(inode
, 0);
563 invalidate_inode_buffers(inode
);
565 fat_cache_inval_inode(inode
);
569 static void fat_set_state(struct super_block
*sb
,
570 unsigned int set
, unsigned int force
)
572 struct buffer_head
*bh
;
573 struct fat_boot_sector
*b
;
574 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
576 /* do not change any thing if mounted read only */
577 if ((sb
->s_flags
& MS_RDONLY
) && !force
)
580 /* do not change state if fs was dirty */
582 /* warn only on set (mount). */
584 fat_msg(sb
, KERN_WARNING
, "Volume was not properly "
585 "unmounted. Some data may be corrupt. "
590 bh
= sb_bread(sb
, 0);
592 fat_msg(sb
, KERN_ERR
, "unable to read boot sector "
593 "to mark fs as dirty");
597 b
= (struct fat_boot_sector
*) bh
->b_data
;
599 if (sbi
->fat_bits
== 32) {
601 b
->fat32
.state
|= FAT_STATE_DIRTY
;
603 b
->fat32
.state
&= ~FAT_STATE_DIRTY
;
604 } else /* fat 16 and 12 */ {
606 b
->fat16
.state
|= FAT_STATE_DIRTY
;
608 b
->fat16
.state
&= ~FAT_STATE_DIRTY
;
611 mark_buffer_dirty(bh
);
612 sync_dirty_buffer(bh
);
616 static void fat_reset_iocharset(struct fat_mount_options
*opts
)
618 if (opts
->iocharset
!= fat_default_iocharset
) {
619 /* Note: opts->iocharset can be NULL here */
620 kfree(opts
->iocharset
);
621 opts
->iocharset
= fat_default_iocharset
;
625 static void delayed_free(struct rcu_head
*p
)
627 struct msdos_sb_info
*sbi
= container_of(p
, struct msdos_sb_info
, rcu
);
628 unload_nls(sbi
->nls_disk
);
629 unload_nls(sbi
->nls_io
);
630 fat_reset_iocharset(&sbi
->options
);
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 /* Zeroing to allow iput() even if partial initialized inode. */
663 return &ei
->vfs_inode
;
666 static void fat_i_callback(struct rcu_head
*head
)
668 struct inode
*inode
= container_of(head
, struct inode
, i_rcu
);
669 kmem_cache_free(fat_inode_cachep
, MSDOS_I(inode
));
672 static void fat_destroy_inode(struct inode
*inode
)
674 call_rcu(&inode
->i_rcu
, fat_i_callback
);
677 static void init_once(void *foo
)
679 struct msdos_inode_info
*ei
= (struct msdos_inode_info
*)foo
;
681 spin_lock_init(&ei
->cache_lru_lock
);
683 ei
->cache_valid_id
= FAT_CACHE_VALID
+ 1;
684 INIT_LIST_HEAD(&ei
->cache_lru
);
685 INIT_HLIST_NODE(&ei
->i_fat_hash
);
686 INIT_HLIST_NODE(&ei
->i_dir_hash
);
687 inode_init_once(&ei
->vfs_inode
);
690 static int __init
fat_init_inodecache(void)
692 fat_inode_cachep
= kmem_cache_create("fat_inode_cache",
693 sizeof(struct msdos_inode_info
),
694 0, (SLAB_RECLAIM_ACCOUNT
|
697 if (fat_inode_cachep
== NULL
)
702 static void __exit
fat_destroy_inodecache(void)
705 * Make sure all delayed rcu free inodes are flushed before we
709 kmem_cache_destroy(fat_inode_cachep
);
712 static int fat_remount(struct super_block
*sb
, int *flags
, char *data
)
715 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
716 *flags
|= MS_NODIRATIME
| (sbi
->options
.isvfat
? 0 : MS_NOATIME
);
720 /* make sure we update state on remount. */
721 new_rdonly
= *flags
& MS_RDONLY
;
722 if (new_rdonly
!= (sb
->s_flags
& MS_RDONLY
)) {
724 fat_set_state(sb
, 0, 0);
726 fat_set_state(sb
, 1, 1);
731 static int fat_statfs(struct dentry
*dentry
, struct kstatfs
*buf
)
733 struct super_block
*sb
= dentry
->d_sb
;
734 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
735 u64 id
= huge_encode_dev(sb
->s_bdev
->bd_dev
);
737 /* If the count of free cluster is still unknown, counts it here. */
738 if (sbi
->free_clusters
== -1 || !sbi
->free_clus_valid
) {
739 int err
= fat_count_free_clusters(dentry
->d_sb
);
744 buf
->f_type
= dentry
->d_sb
->s_magic
;
745 buf
->f_bsize
= sbi
->cluster_size
;
746 buf
->f_blocks
= sbi
->max_cluster
- FAT_START_ENT
;
747 buf
->f_bfree
= sbi
->free_clusters
;
748 buf
->f_bavail
= sbi
->free_clusters
;
749 buf
->f_fsid
.val
[0] = (u32
)id
;
750 buf
->f_fsid
.val
[1] = (u32
)(id
>> 32);
752 (sbi
->options
.isvfat
? FAT_LFN_LEN
: 12) * NLS_MAX_CHARSET_SIZE
;
757 static int __fat_write_inode(struct inode
*inode
, int wait
)
759 struct super_block
*sb
= inode
->i_sb
;
760 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
761 struct buffer_head
*bh
;
762 struct msdos_dir_entry
*raw_entry
;
767 if (inode
->i_ino
== MSDOS_ROOT_INO
)
771 i_pos
= fat_i_pos_read(sbi
, inode
);
775 fat_get_blknr_offset(sbi
, i_pos
, &blocknr
, &offset
);
776 bh
= sb_bread(sb
, blocknr
);
778 fat_msg(sb
, KERN_ERR
, "unable to read inode block "
779 "for updating (i_pos %lld)", i_pos
);
782 spin_lock(&sbi
->inode_hash_lock
);
783 if (i_pos
!= MSDOS_I(inode
)->i_pos
) {
784 spin_unlock(&sbi
->inode_hash_lock
);
789 raw_entry
= &((struct msdos_dir_entry
*) (bh
->b_data
))[offset
];
790 if (S_ISDIR(inode
->i_mode
))
793 raw_entry
->size
= cpu_to_le32(inode
->i_size
);
794 raw_entry
->attr
= fat_make_attrs(inode
);
795 fat_set_start(raw_entry
, MSDOS_I(inode
)->i_logstart
);
796 fat_time_unix2fat(sbi
, &inode
->i_mtime
, &raw_entry
->time
,
797 &raw_entry
->date
, NULL
);
798 if (sbi
->options
.isvfat
) {
800 fat_time_unix2fat(sbi
, &inode
->i_ctime
, &raw_entry
->ctime
,
801 &raw_entry
->cdate
, &raw_entry
->ctime_cs
);
802 fat_time_unix2fat(sbi
, &inode
->i_atime
, &atime
,
803 &raw_entry
->adate
, NULL
);
805 spin_unlock(&sbi
->inode_hash_lock
);
806 mark_buffer_dirty(bh
);
809 err
= sync_dirty_buffer(bh
);
814 static int fat_write_inode(struct inode
*inode
, struct writeback_control
*wbc
)
818 if (inode
->i_ino
== MSDOS_FSINFO_INO
) {
819 struct super_block
*sb
= inode
->i_sb
;
821 mutex_lock(&MSDOS_SB(sb
)->s_lock
);
822 err
= fat_clusters_flush(sb
);
823 mutex_unlock(&MSDOS_SB(sb
)->s_lock
);
825 err
= __fat_write_inode(inode
, wbc
->sync_mode
== WB_SYNC_ALL
);
830 int fat_sync_inode(struct inode
*inode
)
832 return __fat_write_inode(inode
, 1);
835 EXPORT_SYMBOL_GPL(fat_sync_inode
);
837 static int fat_show_options(struct seq_file
*m
, struct dentry
*root
);
838 static const struct super_operations fat_sops
= {
839 .alloc_inode
= fat_alloc_inode
,
840 .destroy_inode
= fat_destroy_inode
,
841 .write_inode
= fat_write_inode
,
842 .evict_inode
= fat_evict_inode
,
843 .put_super
= fat_put_super
,
844 .statfs
= fat_statfs
,
845 .remount_fs
= fat_remount
,
847 .show_options
= fat_show_options
,
850 static int fat_show_options(struct seq_file
*m
, struct dentry
*root
)
852 struct msdos_sb_info
*sbi
= MSDOS_SB(root
->d_sb
);
853 struct fat_mount_options
*opts
= &sbi
->options
;
854 int isvfat
= opts
->isvfat
;
856 if (!uid_eq(opts
->fs_uid
, GLOBAL_ROOT_UID
))
857 seq_printf(m
, ",uid=%u",
858 from_kuid_munged(&init_user_ns
, opts
->fs_uid
));
859 if (!gid_eq(opts
->fs_gid
, GLOBAL_ROOT_GID
))
860 seq_printf(m
, ",gid=%u",
861 from_kgid_munged(&init_user_ns
, opts
->fs_gid
));
862 seq_printf(m
, ",fmask=%04o", opts
->fs_fmask
);
863 seq_printf(m
, ",dmask=%04o", opts
->fs_dmask
);
864 if (opts
->allow_utime
)
865 seq_printf(m
, ",allow_utime=%04o", opts
->allow_utime
);
867 /* strip "cp" prefix from displayed option */
868 seq_printf(m
, ",codepage=%s", &sbi
->nls_disk
->charset
[2]);
871 seq_printf(m
, ",iocharset=%s", sbi
->nls_io
->charset
);
873 switch (opts
->shortname
) {
874 case VFAT_SFN_DISPLAY_WIN95
| VFAT_SFN_CREATE_WIN95
:
875 seq_puts(m
, ",shortname=win95");
877 case VFAT_SFN_DISPLAY_WINNT
| VFAT_SFN_CREATE_WINNT
:
878 seq_puts(m
, ",shortname=winnt");
880 case VFAT_SFN_DISPLAY_WINNT
| VFAT_SFN_CREATE_WIN95
:
881 seq_puts(m
, ",shortname=mixed");
883 case VFAT_SFN_DISPLAY_LOWER
| VFAT_SFN_CREATE_WIN95
:
884 seq_puts(m
, ",shortname=lower");
887 seq_puts(m
, ",shortname=unknown");
891 if (opts
->name_check
!= 'n')
892 seq_printf(m
, ",check=%c", opts
->name_check
);
894 seq_puts(m
, ",usefree");
896 seq_puts(m
, ",quiet");
898 seq_puts(m
, ",showexec");
899 if (opts
->sys_immutable
)
900 seq_puts(m
, ",sys_immutable");
903 seq_puts(m
, ",dotsOK=yes");
905 seq_puts(m
, ",nocase");
908 seq_puts(m
, ",utf8");
909 if (opts
->unicode_xlate
)
910 seq_puts(m
, ",uni_xlate");
912 seq_puts(m
, ",nonumtail");
914 seq_puts(m
, ",rodir");
917 seq_puts(m
, ",flush");
919 if (opts
->time_offset
)
920 seq_printf(m
, ",time_offset=%d", opts
->time_offset
);
922 seq_puts(m
, ",tz=UTC");
924 if (opts
->errors
== FAT_ERRORS_CONT
)
925 seq_puts(m
, ",errors=continue");
926 else if (opts
->errors
== FAT_ERRORS_PANIC
)
927 seq_puts(m
, ",errors=panic");
929 seq_puts(m
, ",errors=remount-ro");
930 if (opts
->nfs
== FAT_NFS_NOSTALE_RO
)
931 seq_puts(m
, ",nfs=nostale_ro");
933 seq_puts(m
, ",nfs=stale_rw");
935 seq_puts(m
, ",discard");
936 if (opts
->dos1xfloppy
)
937 seq_puts(m
, ",dos1xfloppy");
943 Opt_check_n
, Opt_check_r
, Opt_check_s
, Opt_uid
, Opt_gid
,
944 Opt_umask
, Opt_dmask
, Opt_fmask
, Opt_allow_utime
, Opt_codepage
,
945 Opt_usefree
, Opt_nocase
, Opt_quiet
, Opt_showexec
, Opt_debug
,
946 Opt_immutable
, Opt_dots
, Opt_nodots
,
947 Opt_charset
, Opt_shortname_lower
, Opt_shortname_win95
,
948 Opt_shortname_winnt
, Opt_shortname_mixed
, Opt_utf8_no
, Opt_utf8_yes
,
949 Opt_uni_xl_no
, Opt_uni_xl_yes
, Opt_nonumtail_no
, Opt_nonumtail_yes
,
950 Opt_obsolete
, Opt_flush
, Opt_tz_utc
, Opt_rodir
, Opt_err_cont
,
951 Opt_err_panic
, Opt_err_ro
, Opt_discard
, Opt_nfs
, Opt_time_offset
,
952 Opt_nfs_stale_rw
, Opt_nfs_nostale_ro
, Opt_err
, Opt_dos1xfloppy
,
955 static const match_table_t fat_tokens
= {
956 {Opt_check_r
, "check=relaxed"},
957 {Opt_check_s
, "check=strict"},
958 {Opt_check_n
, "check=normal"},
959 {Opt_check_r
, "check=r"},
960 {Opt_check_s
, "check=s"},
961 {Opt_check_n
, "check=n"},
964 {Opt_umask
, "umask=%o"},
965 {Opt_dmask
, "dmask=%o"},
966 {Opt_fmask
, "fmask=%o"},
967 {Opt_allow_utime
, "allow_utime=%o"},
968 {Opt_codepage
, "codepage=%u"},
969 {Opt_usefree
, "usefree"},
970 {Opt_nocase
, "nocase"},
971 {Opt_quiet
, "quiet"},
972 {Opt_showexec
, "showexec"},
973 {Opt_debug
, "debug"},
974 {Opt_immutable
, "sys_immutable"},
975 {Opt_flush
, "flush"},
976 {Opt_tz_utc
, "tz=UTC"},
977 {Opt_time_offset
, "time_offset=%d"},
978 {Opt_err_cont
, "errors=continue"},
979 {Opt_err_panic
, "errors=panic"},
980 {Opt_err_ro
, "errors=remount-ro"},
981 {Opt_discard
, "discard"},
982 {Opt_nfs_stale_rw
, "nfs"},
983 {Opt_nfs_stale_rw
, "nfs=stale_rw"},
984 {Opt_nfs_nostale_ro
, "nfs=nostale_ro"},
985 {Opt_dos1xfloppy
, "dos1xfloppy"},
986 {Opt_obsolete
, "conv=binary"},
987 {Opt_obsolete
, "conv=text"},
988 {Opt_obsolete
, "conv=auto"},
989 {Opt_obsolete
, "conv=b"},
990 {Opt_obsolete
, "conv=t"},
991 {Opt_obsolete
, "conv=a"},
992 {Opt_obsolete
, "fat=%u"},
993 {Opt_obsolete
, "blocksize=%u"},
994 {Opt_obsolete
, "cvf_format=%20s"},
995 {Opt_obsolete
, "cvf_options=%100s"},
996 {Opt_obsolete
, "posix"},
999 static const match_table_t msdos_tokens
= {
1000 {Opt_nodots
, "nodots"},
1001 {Opt_nodots
, "dotsOK=no"},
1003 {Opt_dots
, "dotsOK=yes"},
1006 static const match_table_t vfat_tokens
= {
1007 {Opt_charset
, "iocharset=%s"},
1008 {Opt_shortname_lower
, "shortname=lower"},
1009 {Opt_shortname_win95
, "shortname=win95"},
1010 {Opt_shortname_winnt
, "shortname=winnt"},
1011 {Opt_shortname_mixed
, "shortname=mixed"},
1012 {Opt_utf8_no
, "utf8=0"}, /* 0 or no or false */
1013 {Opt_utf8_no
, "utf8=no"},
1014 {Opt_utf8_no
, "utf8=false"},
1015 {Opt_utf8_yes
, "utf8=1"}, /* empty or 1 or yes or true */
1016 {Opt_utf8_yes
, "utf8=yes"},
1017 {Opt_utf8_yes
, "utf8=true"},
1018 {Opt_utf8_yes
, "utf8"},
1019 {Opt_uni_xl_no
, "uni_xlate=0"}, /* 0 or no or false */
1020 {Opt_uni_xl_no
, "uni_xlate=no"},
1021 {Opt_uni_xl_no
, "uni_xlate=false"},
1022 {Opt_uni_xl_yes
, "uni_xlate=1"}, /* empty or 1 or yes or true */
1023 {Opt_uni_xl_yes
, "uni_xlate=yes"},
1024 {Opt_uni_xl_yes
, "uni_xlate=true"},
1025 {Opt_uni_xl_yes
, "uni_xlate"},
1026 {Opt_nonumtail_no
, "nonumtail=0"}, /* 0 or no or false */
1027 {Opt_nonumtail_no
, "nonumtail=no"},
1028 {Opt_nonumtail_no
, "nonumtail=false"},
1029 {Opt_nonumtail_yes
, "nonumtail=1"}, /* empty or 1 or yes or true */
1030 {Opt_nonumtail_yes
, "nonumtail=yes"},
1031 {Opt_nonumtail_yes
, "nonumtail=true"},
1032 {Opt_nonumtail_yes
, "nonumtail"},
1033 {Opt_rodir
, "rodir"},
1037 static int parse_options(struct super_block
*sb
, char *options
, int is_vfat
,
1038 int silent
, int *debug
, struct fat_mount_options
*opts
)
1041 substring_t args
[MAX_OPT_ARGS
];
1045 opts
->isvfat
= is_vfat
;
1047 opts
->fs_uid
= current_uid();
1048 opts
->fs_gid
= current_gid();
1049 opts
->fs_fmask
= opts
->fs_dmask
= current_umask();
1050 opts
->allow_utime
= -1;
1051 opts
->codepage
= fat_default_codepage
;
1052 fat_reset_iocharset(opts
);
1054 opts
->shortname
= VFAT_SFN_DISPLAY_WINNT
|VFAT_SFN_CREATE_WIN95
;
1057 opts
->shortname
= 0;
1060 opts
->name_check
= 'n';
1061 opts
->quiet
= opts
->showexec
= opts
->sys_immutable
= opts
->dotsOK
= 0;
1062 opts
->utf8
= opts
->unicode_xlate
= 0;
1064 opts
->usefree
= opts
->nocase
= 0;
1067 opts
->errors
= FAT_ERRORS_RO
;
1073 while ((p
= strsep(&options
, ",")) != NULL
) {
1078 token
= match_token(p
, fat_tokens
, args
);
1079 if (token
== Opt_err
) {
1081 token
= match_token(p
, vfat_tokens
, args
);
1083 token
= match_token(p
, msdos_tokens
, args
);
1087 opts
->name_check
= 's';
1090 opts
->name_check
= 'r';
1093 opts
->name_check
= 'n';
1102 /* for backward compatibility */
1103 opts
->shortname
= VFAT_SFN_DISPLAY_WIN95
1104 | VFAT_SFN_CREATE_WIN95
;
1117 opts
->sys_immutable
= 1;
1120 if (match_int(&args
[0], &option
))
1122 opts
->fs_uid
= make_kuid(current_user_ns(), option
);
1123 if (!uid_valid(opts
->fs_uid
))
1127 if (match_int(&args
[0], &option
))
1129 opts
->fs_gid
= make_kgid(current_user_ns(), option
);
1130 if (!gid_valid(opts
->fs_gid
))
1134 if (match_octal(&args
[0], &option
))
1136 opts
->fs_fmask
= opts
->fs_dmask
= option
;
1139 if (match_octal(&args
[0], &option
))
1141 opts
->fs_dmask
= option
;
1144 if (match_octal(&args
[0], &option
))
1146 opts
->fs_fmask
= option
;
1148 case Opt_allow_utime
:
1149 if (match_octal(&args
[0], &option
))
1151 opts
->allow_utime
= option
& (S_IWGRP
| S_IWOTH
);
1154 if (match_int(&args
[0], &option
))
1156 opts
->codepage
= option
;
1161 case Opt_time_offset
:
1162 if (match_int(&args
[0], &option
))
1164 if (option
< -12 * 60 || option
> 12 * 60)
1167 opts
->time_offset
= option
;
1171 opts
->time_offset
= 0;
1174 opts
->errors
= FAT_ERRORS_CONT
;
1177 opts
->errors
= FAT_ERRORS_PANIC
;
1180 opts
->errors
= FAT_ERRORS_RO
;
1182 case Opt_nfs_stale_rw
:
1183 opts
->nfs
= FAT_NFS_STALE_RW
;
1185 case Opt_nfs_nostale_ro
:
1186 opts
->nfs
= FAT_NFS_NOSTALE_RO
;
1188 case Opt_dos1xfloppy
:
1189 opts
->dos1xfloppy
= 1;
1192 /* msdos specific */
1202 fat_reset_iocharset(opts
);
1203 iocharset
= match_strdup(&args
[0]);
1206 opts
->iocharset
= iocharset
;
1208 case Opt_shortname_lower
:
1209 opts
->shortname
= VFAT_SFN_DISPLAY_LOWER
1210 | VFAT_SFN_CREATE_WIN95
;
1212 case Opt_shortname_win95
:
1213 opts
->shortname
= VFAT_SFN_DISPLAY_WIN95
1214 | VFAT_SFN_CREATE_WIN95
;
1216 case Opt_shortname_winnt
:
1217 opts
->shortname
= VFAT_SFN_DISPLAY_WINNT
1218 | VFAT_SFN_CREATE_WINNT
;
1220 case Opt_shortname_mixed
:
1221 opts
->shortname
= VFAT_SFN_DISPLAY_WINNT
1222 | VFAT_SFN_CREATE_WIN95
;
1224 case Opt_utf8_no
: /* 0 or no or false */
1227 case Opt_utf8_yes
: /* empty or 1 or yes or true */
1230 case Opt_uni_xl_no
: /* 0 or no or false */
1231 opts
->unicode_xlate
= 0;
1233 case Opt_uni_xl_yes
: /* empty or 1 or yes or true */
1234 opts
->unicode_xlate
= 1;
1236 case Opt_nonumtail_no
: /* 0 or no or false */
1237 opts
->numtail
= 1; /* negated option */
1239 case Opt_nonumtail_yes
: /* empty or 1 or yes or true */
1240 opts
->numtail
= 0; /* negated option */
1249 /* obsolete mount options */
1251 fat_msg(sb
, KERN_INFO
, "\"%s\" option is obsolete, "
1252 "not supported now", p
);
1254 /* unknown option */
1257 fat_msg(sb
, KERN_ERR
,
1258 "Unrecognized mount option \"%s\" "
1259 "or missing value", p
);
1266 /* UTF-8 doesn't provide FAT semantics */
1267 if (!strcmp(opts
->iocharset
, "utf8")) {
1268 fat_msg(sb
, KERN_WARNING
, "utf8 is not a recommended IO charset"
1269 " for FAT filesystems, filesystem will be "
1273 /* If user doesn't specify allow_utime, it's initialized from dmask. */
1274 if (opts
->allow_utime
== (unsigned short)-1)
1275 opts
->allow_utime
= ~opts
->fs_dmask
& (S_IWGRP
| S_IWOTH
);
1276 if (opts
->unicode_xlate
)
1278 if (opts
->nfs
== FAT_NFS_NOSTALE_RO
) {
1279 sb
->s_flags
|= MS_RDONLY
;
1280 sb
->s_export_op
= &fat_export_ops_nostale
;
1286 static int fat_read_root(struct inode
*inode
)
1288 struct msdos_sb_info
*sbi
= MSDOS_SB(inode
->i_sb
);
1291 MSDOS_I(inode
)->i_pos
= MSDOS_ROOT_INO
;
1292 inode
->i_uid
= sbi
->options
.fs_uid
;
1293 inode
->i_gid
= sbi
->options
.fs_gid
;
1295 inode
->i_generation
= 0;
1296 inode
->i_mode
= fat_make_mode(sbi
, ATTR_DIR
, S_IRWXUGO
);
1297 inode
->i_op
= sbi
->dir_ops
;
1298 inode
->i_fop
= &fat_dir_operations
;
1299 if (sbi
->fat_bits
== 32) {
1300 MSDOS_I(inode
)->i_start
= sbi
->root_cluster
;
1301 error
= fat_calc_dir_size(inode
);
1305 MSDOS_I(inode
)->i_start
= 0;
1306 inode
->i_size
= sbi
->dir_entries
* sizeof(struct msdos_dir_entry
);
1308 inode
->i_blocks
= ((inode
->i_size
+ (sbi
->cluster_size
- 1))
1309 & ~((loff_t
)sbi
->cluster_size
- 1)) >> 9;
1310 MSDOS_I(inode
)->i_logstart
= 0;
1311 MSDOS_I(inode
)->mmu_private
= inode
->i_size
;
1313 fat_save_attrs(inode
, ATTR_DIR
);
1314 inode
->i_mtime
.tv_sec
= inode
->i_atime
.tv_sec
= inode
->i_ctime
.tv_sec
= 0;
1315 inode
->i_mtime
.tv_nsec
= inode
->i_atime
.tv_nsec
= inode
->i_ctime
.tv_nsec
= 0;
1316 set_nlink(inode
, fat_subdirs(inode
)+2);
1321 static unsigned long calc_fat_clusters(struct super_block
*sb
)
1323 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
1325 /* Divide first to avoid overflow */
1326 if (sbi
->fat_bits
!= 12) {
1327 unsigned long ent_per_sec
= sb
->s_blocksize
* 8 / sbi
->fat_bits
;
1328 return ent_per_sec
* sbi
->fat_length
;
1331 return sbi
->fat_length
* sb
->s_blocksize
* 8 / sbi
->fat_bits
;
1334 static bool fat_bpb_is_zero(struct fat_boot_sector
*b
)
1336 if (get_unaligned_le16(&b
->sector_size
))
1338 if (b
->sec_per_clus
)
1344 if (get_unaligned_le16(&b
->dir_entries
))
1346 if (get_unaligned_le16(&b
->sectors
))
1359 static int fat_read_bpb(struct super_block
*sb
, struct fat_boot_sector
*b
,
1360 int silent
, struct fat_bios_param_block
*bpb
)
1362 int error
= -EINVAL
;
1364 /* Read in BPB ... */
1365 memset(bpb
, 0, sizeof(*bpb
));
1366 bpb
->fat_sector_size
= get_unaligned_le16(&b
->sector_size
);
1367 bpb
->fat_sec_per_clus
= b
->sec_per_clus
;
1368 bpb
->fat_reserved
= le16_to_cpu(b
->reserved
);
1369 bpb
->fat_fats
= b
->fats
;
1370 bpb
->fat_dir_entries
= get_unaligned_le16(&b
->dir_entries
);
1371 bpb
->fat_sectors
= get_unaligned_le16(&b
->sectors
);
1372 bpb
->fat_fat_length
= le16_to_cpu(b
->fat_length
);
1373 bpb
->fat_total_sect
= le32_to_cpu(b
->total_sect
);
1375 bpb
->fat16_state
= b
->fat16
.state
;
1376 bpb
->fat16_vol_id
= get_unaligned_le32(b
->fat16
.vol_id
);
1378 bpb
->fat32_length
= le32_to_cpu(b
->fat32
.length
);
1379 bpb
->fat32_root_cluster
= le32_to_cpu(b
->fat32
.root_cluster
);
1380 bpb
->fat32_info_sector
= le16_to_cpu(b
->fat32
.info_sector
);
1381 bpb
->fat32_state
= b
->fat32
.state
;
1382 bpb
->fat32_vol_id
= get_unaligned_le32(b
->fat32
.vol_id
);
1384 /* Validate this looks like a FAT filesystem BPB */
1385 if (!bpb
->fat_reserved
) {
1387 fat_msg(sb
, KERN_ERR
,
1388 "bogus number of reserved sectors");
1391 if (!bpb
->fat_fats
) {
1393 fat_msg(sb
, KERN_ERR
, "bogus number of FAT structure");
1398 * Earlier we checked here that b->secs_track and b->head are nonzero,
1399 * but it turns out valid FAT filesystems can have zero there.
1402 if (!fat_valid_media(b
->media
)) {
1404 fat_msg(sb
, KERN_ERR
, "invalid media value (0x%02x)",
1405 (unsigned)b
->media
);
1409 if (!is_power_of_2(bpb
->fat_sector_size
)
1410 || (bpb
->fat_sector_size
< 512)
1411 || (bpb
->fat_sector_size
> 4096)) {
1413 fat_msg(sb
, KERN_ERR
, "bogus logical sector size %u",
1414 (unsigned)bpb
->fat_sector_size
);
1418 if (!is_power_of_2(bpb
->fat_sec_per_clus
)) {
1420 fat_msg(sb
, KERN_ERR
, "bogus sectors per cluster %u",
1421 (unsigned)bpb
->fat_sec_per_clus
);
1425 if (bpb
->fat_fat_length
== 0 && bpb
->fat32_length
== 0) {
1427 fat_msg(sb
, KERN_ERR
, "bogus number of FAT sectors");
1437 static int fat_read_static_bpb(struct super_block
*sb
,
1438 struct fat_boot_sector
*b
, int silent
,
1439 struct fat_bios_param_block
*bpb
)
1441 static const char *notdos1x
= "This doesn't look like a DOS 1.x volume";
1443 struct fat_floppy_defaults
*fdefaults
= NULL
;
1444 int error
= -EINVAL
;
1448 bd_sects
= i_size_read(sb
->s_bdev
->bd_inode
) / SECTOR_SIZE
;
1450 /* 16-bit DOS 1.x reliably wrote bootstrap short-jmp code */
1451 if (b
->ignored
[0] != 0xeb || b
->ignored
[2] != 0x90) {
1453 fat_msg(sb
, KERN_ERR
,
1454 "%s; no bootstrapping code", notdos1x
);
1459 * If any value in this region is non-zero, it isn't archaic
1462 if (!fat_bpb_is_zero(b
)) {
1464 fat_msg(sb
, KERN_ERR
,
1465 "%s; DOS 2.x BPB is non-zero", notdos1x
);
1469 for (i
= 0; i
< ARRAY_SIZE(floppy_defaults
); i
++) {
1470 if (floppy_defaults
[i
].nr_sectors
== bd_sects
) {
1471 fdefaults
= &floppy_defaults
[i
];
1476 if (fdefaults
== NULL
) {
1478 fat_msg(sb
, KERN_WARNING
,
1479 "This looks like a DOS 1.x volume, but isn't a recognized floppy size (%llu sectors)",
1485 fat_msg(sb
, KERN_INFO
,
1486 "This looks like a DOS 1.x volume; assuming default BPB values");
1488 memset(bpb
, 0, sizeof(*bpb
));
1489 bpb
->fat_sector_size
= SECTOR_SIZE
;
1490 bpb
->fat_sec_per_clus
= fdefaults
->sec_per_clus
;
1491 bpb
->fat_reserved
= 1;
1493 bpb
->fat_dir_entries
= fdefaults
->dir_entries
;
1494 bpb
->fat_sectors
= fdefaults
->nr_sectors
;
1495 bpb
->fat_fat_length
= fdefaults
->fat_length
;
1504 * Read the super block of an MS-DOS FS.
1506 int fat_fill_super(struct super_block
*sb
, void *data
, int silent
, int isvfat
,
1507 void (*setup
)(struct super_block
*))
1509 struct inode
*root_inode
= NULL
, *fat_inode
= NULL
;
1510 struct inode
*fsinfo_inode
= NULL
;
1511 struct buffer_head
*bh
;
1512 struct fat_bios_param_block bpb
;
1513 struct msdos_sb_info
*sbi
;
1514 u16 logical_sector_size
;
1515 u32 total_sectors
, total_clusters
, fat_clusters
, rootdir_sectors
;
1521 * GFP_KERNEL is ok here, because while we do hold the
1522 * supeblock lock, memory pressure can't call back into
1523 * the filesystem, since we're only just about to mount
1524 * it and have no inodes etc active!
1526 sbi
= kzalloc(sizeof(struct msdos_sb_info
), GFP_KERNEL
);
1529 sb
->s_fs_info
= sbi
;
1531 sb
->s_flags
|= MS_NODIRATIME
;
1532 sb
->s_magic
= MSDOS_SUPER_MAGIC
;
1533 sb
->s_op
= &fat_sops
;
1534 sb
->s_export_op
= &fat_export_ops
;
1535 mutex_init(&sbi
->nfs_build_inode_lock
);
1536 ratelimit_state_init(&sbi
->ratelimit
, DEFAULT_RATELIMIT_INTERVAL
,
1537 DEFAULT_RATELIMIT_BURST
);
1539 error
= parse_options(sb
, data
, isvfat
, silent
, &debug
, &sbi
->options
);
1543 setup(sb
); /* flavour-specific stuff that needs options */
1546 sb_min_blocksize(sb
, 512);
1547 bh
= sb_bread(sb
, 0);
1549 fat_msg(sb
, KERN_ERR
, "unable to read boot sector");
1553 error
= fat_read_bpb(sb
, (struct fat_boot_sector
*)bh
->b_data
, silent
,
1555 if (error
== -EINVAL
&& sbi
->options
.dos1xfloppy
)
1556 error
= fat_read_static_bpb(sb
,
1557 (struct fat_boot_sector
*)bh
->b_data
, silent
, &bpb
);
1560 if (error
== -EINVAL
)
1565 logical_sector_size
= bpb
.fat_sector_size
;
1566 sbi
->sec_per_clus
= bpb
.fat_sec_per_clus
;
1569 if (logical_sector_size
< sb
->s_blocksize
) {
1570 fat_msg(sb
, KERN_ERR
, "logical sector size too small for device"
1571 " (logical sector size = %u)", logical_sector_size
);
1575 if (logical_sector_size
> sb
->s_blocksize
) {
1576 struct buffer_head
*bh_resize
;
1578 if (!sb_set_blocksize(sb
, logical_sector_size
)) {
1579 fat_msg(sb
, KERN_ERR
, "unable to set blocksize %u",
1580 logical_sector_size
);
1584 /* Verify that the larger boot sector is fully readable */
1585 bh_resize
= sb_bread(sb
, 0);
1586 if (bh_resize
== NULL
) {
1587 fat_msg(sb
, KERN_ERR
, "unable to read boot sector"
1588 " (logical sector size = %lu)",
1595 mutex_init(&sbi
->s_lock
);
1596 sbi
->cluster_size
= sb
->s_blocksize
* sbi
->sec_per_clus
;
1597 sbi
->cluster_bits
= ffs(sbi
->cluster_size
) - 1;
1598 sbi
->fats
= bpb
.fat_fats
;
1599 sbi
->fat_bits
= 0; /* Don't know yet */
1600 sbi
->fat_start
= bpb
.fat_reserved
;
1601 sbi
->fat_length
= bpb
.fat_fat_length
;
1602 sbi
->root_cluster
= 0;
1603 sbi
->free_clusters
= -1; /* Don't know yet */
1604 sbi
->free_clus_valid
= 0;
1605 sbi
->prev_free
= FAT_START_ENT
;
1606 sb
->s_maxbytes
= 0xffffffff;
1608 if (!sbi
->fat_length
&& bpb
.fat32_length
) {
1609 struct fat_boot_fsinfo
*fsinfo
;
1610 struct buffer_head
*fsinfo_bh
;
1614 sbi
->fat_length
= bpb
.fat32_length
;
1615 sbi
->root_cluster
= bpb
.fat32_root_cluster
;
1617 /* MC - if info_sector is 0, don't multiply by 0 */
1618 sbi
->fsinfo_sector
= bpb
.fat32_info_sector
;
1619 if (sbi
->fsinfo_sector
== 0)
1620 sbi
->fsinfo_sector
= 1;
1622 fsinfo_bh
= sb_bread(sb
, sbi
->fsinfo_sector
);
1623 if (fsinfo_bh
== NULL
) {
1624 fat_msg(sb
, KERN_ERR
, "bread failed, FSINFO block"
1625 " (sector = %lu)", sbi
->fsinfo_sector
);
1629 fsinfo
= (struct fat_boot_fsinfo
*)fsinfo_bh
->b_data
;
1630 if (!IS_FSINFO(fsinfo
)) {
1631 fat_msg(sb
, KERN_WARNING
, "Invalid FSINFO signature: "
1632 "0x%08x, 0x%08x (sector = %lu)",
1633 le32_to_cpu(fsinfo
->signature1
),
1634 le32_to_cpu(fsinfo
->signature2
),
1635 sbi
->fsinfo_sector
);
1637 if (sbi
->options
.usefree
)
1638 sbi
->free_clus_valid
= 1;
1639 sbi
->free_clusters
= le32_to_cpu(fsinfo
->free_clusters
);
1640 sbi
->prev_free
= le32_to_cpu(fsinfo
->next_cluster
);
1646 /* interpret volume ID as a little endian 32 bit integer */
1647 if (sbi
->fat_bits
== 32)
1648 sbi
->vol_id
= bpb
.fat32_vol_id
;
1649 else /* fat 16 or 12 */
1650 sbi
->vol_id
= bpb
.fat16_vol_id
;
1652 sbi
->dir_per_block
= sb
->s_blocksize
/ sizeof(struct msdos_dir_entry
);
1653 sbi
->dir_per_block_bits
= ffs(sbi
->dir_per_block
) - 1;
1655 sbi
->dir_start
= sbi
->fat_start
+ sbi
->fats
* sbi
->fat_length
;
1656 sbi
->dir_entries
= bpb
.fat_dir_entries
;
1657 if (sbi
->dir_entries
& (sbi
->dir_per_block
- 1)) {
1659 fat_msg(sb
, KERN_ERR
, "bogus directory-entries per block"
1660 " (%u)", sbi
->dir_entries
);
1664 rootdir_sectors
= sbi
->dir_entries
1665 * sizeof(struct msdos_dir_entry
) / sb
->s_blocksize
;
1666 sbi
->data_start
= sbi
->dir_start
+ rootdir_sectors
;
1667 total_sectors
= bpb
.fat_sectors
;
1668 if (total_sectors
== 0)
1669 total_sectors
= bpb
.fat_total_sect
;
1671 total_clusters
= (total_sectors
- sbi
->data_start
) / sbi
->sec_per_clus
;
1673 if (sbi
->fat_bits
!= 32)
1674 sbi
->fat_bits
= (total_clusters
> MAX_FAT12
) ? 16 : 12;
1676 /* some OSes set FAT_STATE_DIRTY and clean it on unmount. */
1677 if (sbi
->fat_bits
== 32)
1678 sbi
->dirty
= bpb
.fat32_state
& FAT_STATE_DIRTY
;
1679 else /* fat 16 or 12 */
1680 sbi
->dirty
= bpb
.fat16_state
& FAT_STATE_DIRTY
;
1682 /* check that FAT table does not overflow */
1683 fat_clusters
= calc_fat_clusters(sb
);
1684 total_clusters
= min(total_clusters
, fat_clusters
- FAT_START_ENT
);
1685 if (total_clusters
> MAX_FAT(sb
)) {
1687 fat_msg(sb
, KERN_ERR
, "count of clusters too big (%u)",
1692 sbi
->max_cluster
= total_clusters
+ FAT_START_ENT
;
1693 /* check the free_clusters, it's not necessarily correct */
1694 if (sbi
->free_clusters
!= -1 && sbi
->free_clusters
> total_clusters
)
1695 sbi
->free_clusters
= -1;
1696 /* check the prev_free, it's not necessarily correct */
1697 sbi
->prev_free
%= sbi
->max_cluster
;
1698 if (sbi
->prev_free
< FAT_START_ENT
)
1699 sbi
->prev_free
= FAT_START_ENT
;
1701 /* set up enough so that it can read an inode */
1704 fat_ent_access_init(sb
);
1707 * The low byte of FAT's first entry must have same value with
1708 * media-field. But in real world, too many devices is
1709 * writing wrong value. So, removed that validity check.
1711 * if (FAT_FIRST_ENT(sb, media) != first)
1715 sprintf(buf
, "cp%d", sbi
->options
.codepage
);
1716 sbi
->nls_disk
= load_nls(buf
);
1717 if (!sbi
->nls_disk
) {
1718 fat_msg(sb
, KERN_ERR
, "codepage %s not found", buf
);
1722 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1723 if (sbi
->options
.isvfat
) {
1724 sbi
->nls_io
= load_nls(sbi
->options
.iocharset
);
1726 fat_msg(sb
, KERN_ERR
, "IO charset %s not found",
1727 sbi
->options
.iocharset
);
1733 fat_inode
= new_inode(sb
);
1736 sbi
->fat_inode
= fat_inode
;
1738 fsinfo_inode
= new_inode(sb
);
1741 fsinfo_inode
->i_ino
= MSDOS_FSINFO_INO
;
1742 sbi
->fsinfo_inode
= fsinfo_inode
;
1743 insert_inode_hash(fsinfo_inode
);
1745 root_inode
= new_inode(sb
);
1748 root_inode
->i_ino
= MSDOS_ROOT_INO
;
1749 root_inode
->i_version
= 1;
1750 error
= fat_read_root(root_inode
);
1756 insert_inode_hash(root_inode
);
1757 fat_attach(root_inode
, 0);
1758 sb
->s_root
= d_make_root(root_inode
);
1760 fat_msg(sb
, KERN_ERR
, "get root inode failed");
1764 if (sbi
->options
.discard
) {
1765 struct request_queue
*q
= bdev_get_queue(sb
->s_bdev
);
1766 if (!blk_queue_discard(q
))
1767 fat_msg(sb
, KERN_WARNING
,
1768 "mounting with \"discard\" option, but "
1769 "the device does not support discard");
1772 fat_set_state(sb
, 1, 0);
1778 fat_msg(sb
, KERN_INFO
, "Can't find a valid FAT filesystem");
1785 unload_nls(sbi
->nls_io
);
1786 unload_nls(sbi
->nls_disk
);
1787 fat_reset_iocharset(&sbi
->options
);
1788 sb
->s_fs_info
= NULL
;
1793 EXPORT_SYMBOL_GPL(fat_fill_super
);
1796 * helper function for fat_flush_inodes. This writes both the inode
1797 * and the file data blocks, waiting for in flight data blocks before
1798 * the start of the call. It does not wait for any io started
1801 static int writeback_inode(struct inode
*inode
)
1806 /* if we used wait=1, sync_inode_metadata waits for the io for the
1807 * inode to finish. So wait=0 is sent down to sync_inode_metadata
1808 * and filemap_fdatawrite is used for the data blocks
1810 ret
= sync_inode_metadata(inode
, 0);
1812 ret
= filemap_fdatawrite(inode
->i_mapping
);
1817 * write data and metadata corresponding to i1 and i2. The io is
1818 * started but we do not wait for any of it to finish.
1820 * filemap_flush is used for the block device, so if there is a dirty
1821 * page for a block already in flight, we will not wait and start the
1824 int fat_flush_inodes(struct super_block
*sb
, struct inode
*i1
, struct inode
*i2
)
1827 if (!MSDOS_SB(sb
)->options
.flush
)
1830 ret
= writeback_inode(i1
);
1832 ret
= writeback_inode(i2
);
1834 struct address_space
*mapping
= sb
->s_bdev
->bd_inode
->i_mapping
;
1835 ret
= filemap_flush(mapping
);
1839 EXPORT_SYMBOL_GPL(fat_flush_inodes
);
1841 static int __init
init_fat_fs(void)
1845 err
= fat_cache_init();
1849 err
= fat_init_inodecache();
1856 fat_cache_destroy();
1860 static void __exit
exit_fat_fs(void)
1862 fat_cache_destroy();
1863 fat_destroy_inodecache();
1866 module_init(init_fat_fs
)
1867 module_exit(exit_fat_fs
)
1869 MODULE_LICENSE("GPL");