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/smp_lock.h>
18 #include <linux/seq_file.h>
19 #include <linux/msdos_fs.h>
20 #include <linux/pagemap.h>
21 #include <linux/mpage.h>
22 #include <linux/buffer_head.h>
23 #include <linux/mount.h>
24 #include <linux/vfs.h>
25 #include <linux/parser.h>
26 #include <asm/unaligned.h>
28 #ifndef CONFIG_FAT_DEFAULT_IOCHARSET
29 /* if user don't select VFAT, this is undefined. */
30 #define CONFIG_FAT_DEFAULT_IOCHARSET ""
33 static int fat_default_codepage
= CONFIG_FAT_DEFAULT_CODEPAGE
;
34 static char fat_default_iocharset
[] = CONFIG_FAT_DEFAULT_IOCHARSET
;
37 static int fat_add_cluster(struct inode
*inode
)
41 err
= fat_alloc_clusters(inode
, &cluster
, 1);
44 /* FIXME: this cluster should be added after data of this
45 * cluster is writed */
46 err
= fat_chain_add(inode
, cluster
, 1);
48 fat_free_clusters(inode
, cluster
);
52 static int fat_get_block(struct inode
*inode
, sector_t iblock
,
53 struct buffer_head
*bh_result
, int create
)
55 struct super_block
*sb
= inode
->i_sb
;
59 err
= fat_bmap(inode
, iblock
, &phys
);
63 map_bh(bh_result
, sb
, phys
);
68 if (iblock
!= MSDOS_I(inode
)->mmu_private
>> sb
->s_blocksize_bits
) {
69 fat_fs_panic(sb
, "corrupted file size (i_pos %lld, %lld)",
70 MSDOS_I(inode
)->i_pos
, MSDOS_I(inode
)->mmu_private
);
73 if (!((unsigned long)iblock
& (MSDOS_SB(sb
)->sec_per_clus
- 1))) {
74 err
= fat_add_cluster(inode
);
78 MSDOS_I(inode
)->mmu_private
+= sb
->s_blocksize
;
79 err
= fat_bmap(inode
, iblock
, &phys
);
84 set_buffer_new(bh_result
);
85 map_bh(bh_result
, sb
, phys
);
89 static int fat_writepage(struct page
*page
, struct writeback_control
*wbc
)
91 return block_write_full_page(page
, fat_get_block
, wbc
);
94 static int fat_writepages(struct address_space
*mapping
,
95 struct writeback_control
*wbc
)
97 return mpage_writepages(mapping
, wbc
, fat_get_block
);
100 static int fat_readpage(struct file
*file
, struct page
*page
)
102 return mpage_readpage(page
, fat_get_block
);
105 static int fat_readpages(struct file
*file
, struct address_space
*mapping
,
106 struct list_head
*pages
, unsigned nr_pages
)
108 return mpage_readpages(mapping
, pages
, nr_pages
, fat_get_block
);
111 static int fat_prepare_write(struct file
*file
, struct page
*page
,
112 unsigned from
, unsigned to
)
114 return cont_prepare_write(page
, from
, to
, fat_get_block
,
115 &MSDOS_I(page
->mapping
->host
)->mmu_private
);
118 static int fat_commit_write(struct file
*file
, struct page
*page
,
119 unsigned from
, unsigned to
)
121 struct inode
*inode
= page
->mapping
->host
;
122 int err
= generic_commit_write(file
, page
, from
, to
);
123 if (!err
&& !(MSDOS_I(inode
)->i_attrs
& ATTR_ARCH
)) {
124 inode
->i_mtime
= inode
->i_ctime
= CURRENT_TIME_SEC
;
125 MSDOS_I(inode
)->i_attrs
|= ATTR_ARCH
;
126 mark_inode_dirty(inode
);
131 static sector_t
_fat_bmap(struct address_space
*mapping
, sector_t block
)
133 return generic_block_bmap(mapping
, block
, fat_get_block
);
136 static struct address_space_operations fat_aops
= {
137 .readpage
= fat_readpage
,
138 .readpages
= fat_readpages
,
139 .writepage
= fat_writepage
,
140 .writepages
= fat_writepages
,
141 .sync_page
= block_sync_page
,
142 .prepare_write
= fat_prepare_write
,
143 .commit_write
= fat_commit_write
,
148 * New FAT inode stuff. We do the following:
149 * a) i_ino is constant and has nothing with on-disk location.
150 * b) FAT manages its own cache of directory entries.
151 * c) *This* cache is indexed by on-disk location.
152 * d) inode has an associated directory entry, all right, but
153 * it may be unhashed.
154 * e) currently entries are stored within struct inode. That should
156 * f) we deal with races in the following way:
157 * 1. readdir() and lookup() do FAT-dir-cache lookup.
158 * 2. rename() unhashes the F-d-c entry and rehashes it in
160 * 3. unlink() and rmdir() unhash F-d-c entry.
161 * 4. fat_write_inode() checks whether the thing is unhashed.
162 * If it is we silently return. If it isn't we do bread(),
163 * check if the location is still valid and retry if it
164 * isn't. Otherwise we do changes.
165 * 5. Spinlock is used to protect hash/unhash/location check/lookup
166 * 6. fat_clear_inode() unhashes the F-d-c entry.
167 * 7. lookup() and readdir() do igrab() if they find a F-d-c entry
168 * and consider negative result as cache miss.
171 static void fat_hash_init(struct super_block
*sb
)
173 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
176 spin_lock_init(&sbi
->inode_hash_lock
);
177 for (i
= 0; i
< FAT_HASH_SIZE
; i
++)
178 INIT_HLIST_HEAD(&sbi
->inode_hashtable
[i
]);
181 static inline unsigned long fat_hash(struct super_block
*sb
, loff_t i_pos
)
183 unsigned long tmp
= (unsigned long)i_pos
| (unsigned long) sb
;
184 tmp
= tmp
+ (tmp
>> FAT_HASH_BITS
) + (tmp
>> FAT_HASH_BITS
* 2);
185 return tmp
& FAT_HASH_MASK
;
188 void fat_attach(struct inode
*inode
, loff_t i_pos
)
190 struct super_block
*sb
= inode
->i_sb
;
191 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
193 spin_lock(&sbi
->inode_hash_lock
);
194 MSDOS_I(inode
)->i_pos
= i_pos
;
195 hlist_add_head(&MSDOS_I(inode
)->i_fat_hash
,
196 sbi
->inode_hashtable
+ fat_hash(sb
, i_pos
));
197 spin_unlock(&sbi
->inode_hash_lock
);
200 EXPORT_SYMBOL_GPL(fat_attach
);
202 void fat_detach(struct inode
*inode
)
204 struct msdos_sb_info
*sbi
= MSDOS_SB(inode
->i_sb
);
205 spin_lock(&sbi
->inode_hash_lock
);
206 MSDOS_I(inode
)->i_pos
= 0;
207 hlist_del_init(&MSDOS_I(inode
)->i_fat_hash
);
208 spin_unlock(&sbi
->inode_hash_lock
);
211 EXPORT_SYMBOL_GPL(fat_detach
);
213 struct inode
*fat_iget(struct super_block
*sb
, loff_t i_pos
)
215 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
216 struct hlist_head
*head
= sbi
->inode_hashtable
+ fat_hash(sb
, i_pos
);
217 struct hlist_node
*_p
;
218 struct msdos_inode_info
*i
;
219 struct inode
*inode
= NULL
;
221 spin_lock(&sbi
->inode_hash_lock
);
222 hlist_for_each_entry(i
, _p
, head
, i_fat_hash
) {
223 BUG_ON(i
->vfs_inode
.i_sb
!= sb
);
224 if (i
->i_pos
!= i_pos
)
226 inode
= igrab(&i
->vfs_inode
);
230 spin_unlock(&sbi
->inode_hash_lock
);
234 static int is_exec(unsigned char *extension
)
236 unsigned char *exe_extensions
= "EXECOMBAT", *walk
;
238 for (walk
= exe_extensions
; *walk
; walk
+= 3)
239 if (!strncmp(extension
, walk
, 3))
244 static int fat_calc_dir_size(struct inode
*inode
)
246 struct msdos_sb_info
*sbi
= MSDOS_SB(inode
->i_sb
);
247 int ret
, fclus
, dclus
;
250 if (MSDOS_I(inode
)->i_start
== 0)
253 ret
= fat_get_cluster(inode
, FAT_ENT_EOF
, &fclus
, &dclus
);
256 inode
->i_size
= (fclus
+ 1) << sbi
->cluster_bits
;
261 /* doesn't deal with root inode */
262 static int fat_fill_inode(struct inode
*inode
, struct msdos_dir_entry
*de
)
264 struct msdos_sb_info
*sbi
= MSDOS_SB(inode
->i_sb
);
267 MSDOS_I(inode
)->i_pos
= 0;
268 inode
->i_uid
= sbi
->options
.fs_uid
;
269 inode
->i_gid
= sbi
->options
.fs_gid
;
271 inode
->i_generation
= get_seconds();
273 if ((de
->attr
& ATTR_DIR
) && !IS_FREE(de
->name
)) {
274 inode
->i_generation
&= ~1;
275 inode
->i_mode
= MSDOS_MKMODE(de
->attr
,
276 S_IRWXUGO
& ~sbi
->options
.fs_dmask
) | S_IFDIR
;
277 inode
->i_op
= sbi
->dir_ops
;
278 inode
->i_fop
= &fat_dir_operations
;
280 MSDOS_I(inode
)->i_start
= le16_to_cpu(de
->start
);
281 if (sbi
->fat_bits
== 32)
282 MSDOS_I(inode
)->i_start
|= (le16_to_cpu(de
->starthi
) << 16);
284 MSDOS_I(inode
)->i_logstart
= MSDOS_I(inode
)->i_start
;
285 error
= fat_calc_dir_size(inode
);
288 MSDOS_I(inode
)->mmu_private
= inode
->i_size
;
290 inode
->i_nlink
= fat_subdirs(inode
);
291 } else { /* not a directory */
292 inode
->i_generation
|= 1;
293 inode
->i_mode
= MSDOS_MKMODE(de
->attr
,
294 ((sbi
->options
.showexec
&&
296 ? S_IRUGO
|S_IWUGO
: S_IRWXUGO
)
297 & ~sbi
->options
.fs_fmask
) | S_IFREG
;
298 MSDOS_I(inode
)->i_start
= le16_to_cpu(de
->start
);
299 if (sbi
->fat_bits
== 32)
300 MSDOS_I(inode
)->i_start
|= (le16_to_cpu(de
->starthi
) << 16);
302 MSDOS_I(inode
)->i_logstart
= MSDOS_I(inode
)->i_start
;
303 inode
->i_size
= le32_to_cpu(de
->size
);
304 inode
->i_op
= &fat_file_inode_operations
;
305 inode
->i_fop
= &fat_file_operations
;
306 inode
->i_mapping
->a_ops
= &fat_aops
;
307 MSDOS_I(inode
)->mmu_private
= inode
->i_size
;
309 if (de
->attr
& ATTR_SYS
) {
310 if (sbi
->options
.sys_immutable
)
311 inode
->i_flags
|= S_IMMUTABLE
;
313 MSDOS_I(inode
)->i_attrs
= de
->attr
& ATTR_UNUSED
;
314 /* this is as close to the truth as we can get ... */
315 inode
->i_blksize
= sbi
->cluster_size
;
316 inode
->i_blocks
= ((inode
->i_size
+ (sbi
->cluster_size
- 1))
317 & ~((loff_t
)sbi
->cluster_size
- 1)) >> 9;
318 inode
->i_mtime
.tv_sec
=
319 date_dos2unix(le16_to_cpu(de
->time
), le16_to_cpu(de
->date
));
320 inode
->i_mtime
.tv_nsec
= 0;
321 if (sbi
->options
.isvfat
) {
322 int secs
= de
->ctime_cs
/ 100;
323 int csecs
= de
->ctime_cs
% 100;
324 inode
->i_ctime
.tv_sec
=
325 date_dos2unix(le16_to_cpu(de
->ctime
),
326 le16_to_cpu(de
->cdate
)) + secs
;
327 inode
->i_ctime
.tv_nsec
= csecs
* 10000000;
328 inode
->i_atime
.tv_sec
=
329 date_dos2unix(le16_to_cpu(0), le16_to_cpu(de
->adate
));
330 inode
->i_atime
.tv_nsec
= 0;
332 inode
->i_ctime
= inode
->i_atime
= inode
->i_mtime
;
337 struct inode
*fat_build_inode(struct super_block
*sb
,
338 struct msdos_dir_entry
*de
, loff_t i_pos
)
343 inode
= fat_iget(sb
, i_pos
);
346 inode
= new_inode(sb
);
348 inode
= ERR_PTR(-ENOMEM
);
351 inode
->i_ino
= iunique(sb
, MSDOS_ROOT_INO
);
352 inode
->i_version
= 1;
353 err
= fat_fill_inode(inode
, de
);
356 inode
= ERR_PTR(err
);
359 fat_attach(inode
, i_pos
);
360 insert_inode_hash(inode
);
365 EXPORT_SYMBOL_GPL(fat_build_inode
);
367 static void fat_delete_inode(struct inode
*inode
)
369 truncate_inode_pages(&inode
->i_data
, 0);
371 if (!is_bad_inode(inode
)) {
378 static void fat_clear_inode(struct inode
*inode
)
380 struct msdos_sb_info
*sbi
= MSDOS_SB(inode
->i_sb
);
382 if (is_bad_inode(inode
))
385 spin_lock(&sbi
->inode_hash_lock
);
386 fat_cache_inval_inode(inode
);
387 hlist_del_init(&MSDOS_I(inode
)->i_fat_hash
);
388 spin_unlock(&sbi
->inode_hash_lock
);
392 static void fat_write_super(struct super_block
*sb
)
396 if (!(sb
->s_flags
& MS_RDONLY
))
397 fat_clusters_flush(sb
);
400 static void fat_put_super(struct super_block
*sb
)
402 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
405 unload_nls(sbi
->nls_disk
);
406 sbi
->nls_disk
= NULL
;
407 sbi
->options
.codepage
= fat_default_codepage
;
410 unload_nls(sbi
->nls_io
);
413 if (sbi
->options
.iocharset
!= fat_default_iocharset
) {
414 kfree(sbi
->options
.iocharset
);
415 sbi
->options
.iocharset
= fat_default_iocharset
;
418 sb
->s_fs_info
= NULL
;
422 static kmem_cache_t
*fat_inode_cachep
;
424 static struct inode
*fat_alloc_inode(struct super_block
*sb
)
426 struct msdos_inode_info
*ei
;
427 ei
= kmem_cache_alloc(fat_inode_cachep
, SLAB_KERNEL
);
430 return &ei
->vfs_inode
;
433 static void fat_destroy_inode(struct inode
*inode
)
435 kmem_cache_free(fat_inode_cachep
, MSDOS_I(inode
));
438 static void init_once(void * foo
, kmem_cache_t
* cachep
, unsigned long flags
)
440 struct msdos_inode_info
*ei
= (struct msdos_inode_info
*)foo
;
442 if ((flags
& (SLAB_CTOR_VERIFY
|SLAB_CTOR_CONSTRUCTOR
)) ==
443 SLAB_CTOR_CONSTRUCTOR
) {
444 spin_lock_init(&ei
->cache_lru_lock
);
446 ei
->cache_valid_id
= FAT_CACHE_VALID
+ 1;
447 INIT_LIST_HEAD(&ei
->cache_lru
);
448 INIT_HLIST_NODE(&ei
->i_fat_hash
);
449 inode_init_once(&ei
->vfs_inode
);
453 static int __init
fat_init_inodecache(void)
455 fat_inode_cachep
= kmem_cache_create("fat_inode_cache",
456 sizeof(struct msdos_inode_info
),
457 0, SLAB_RECLAIM_ACCOUNT
,
459 if (fat_inode_cachep
== NULL
)
464 static void __exit
fat_destroy_inodecache(void)
466 if (kmem_cache_destroy(fat_inode_cachep
))
467 printk(KERN_INFO
"fat_inode_cache: not all structures were freed\n");
470 static int fat_remount(struct super_block
*sb
, int *flags
, char *data
)
472 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
473 *flags
|= MS_NODIRATIME
| (sbi
->options
.isvfat
? 0 : MS_NOATIME
);
477 static int fat_statfs(struct super_block
*sb
, struct kstatfs
*buf
)
479 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
481 /* If the count of free cluster is still unknown, counts it here. */
482 if (sbi
->free_clusters
== -1) {
483 int err
= fat_count_free_clusters(sb
);
488 buf
->f_type
= sb
->s_magic
;
489 buf
->f_bsize
= sbi
->cluster_size
;
490 buf
->f_blocks
= sbi
->max_cluster
- FAT_START_ENT
;
491 buf
->f_bfree
= sbi
->free_clusters
;
492 buf
->f_bavail
= sbi
->free_clusters
;
493 buf
->f_namelen
= sbi
->options
.isvfat
? 260 : 12;
498 static int fat_write_inode(struct inode
*inode
, int wait
)
500 struct super_block
*sb
= inode
->i_sb
;
501 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
502 struct buffer_head
*bh
;
503 struct msdos_dir_entry
*raw_entry
;
508 i_pos
= MSDOS_I(inode
)->i_pos
;
509 if (inode
->i_ino
== MSDOS_ROOT_INO
|| !i_pos
)
513 bh
= sb_bread(sb
, i_pos
>> sbi
->dir_per_block_bits
);
515 printk(KERN_ERR
"FAT: unable to read inode block "
516 "for updating (i_pos %lld)\n", i_pos
);
520 spin_lock(&sbi
->inode_hash_lock
);
521 if (i_pos
!= MSDOS_I(inode
)->i_pos
) {
522 spin_unlock(&sbi
->inode_hash_lock
);
528 raw_entry
= &((struct msdos_dir_entry
*) (bh
->b_data
))
529 [i_pos
& (sbi
->dir_per_block
- 1)];
530 if (S_ISDIR(inode
->i_mode
))
533 raw_entry
->size
= cpu_to_le32(inode
->i_size
);
534 raw_entry
->attr
= fat_attr(inode
);
535 raw_entry
->start
= cpu_to_le16(MSDOS_I(inode
)->i_logstart
);
536 raw_entry
->starthi
= cpu_to_le16(MSDOS_I(inode
)->i_logstart
>> 16);
537 fat_date_unix2dos(inode
->i_mtime
.tv_sec
, &raw_entry
->time
, &raw_entry
->date
);
538 if (sbi
->options
.isvfat
) {
540 fat_date_unix2dos(inode
->i_ctime
.tv_sec
,&raw_entry
->ctime
,&raw_entry
->cdate
);
541 fat_date_unix2dos(inode
->i_atime
.tv_sec
,&atime
,&raw_entry
->adate
);
542 raw_entry
->ctime_cs
= (inode
->i_ctime
.tv_sec
& 1) * 100 +
543 inode
->i_ctime
.tv_nsec
/ 10000000;
545 spin_unlock(&sbi
->inode_hash_lock
);
546 mark_buffer_dirty(bh
);
548 err
= sync_dirty_buffer(bh
);
555 int fat_sync_inode(struct inode
*inode
)
557 return fat_write_inode(inode
, 1);
560 EXPORT_SYMBOL_GPL(fat_sync_inode
);
562 static int fat_show_options(struct seq_file
*m
, struct vfsmount
*mnt
);
563 static struct super_operations fat_sops
= {
564 .alloc_inode
= fat_alloc_inode
,
565 .destroy_inode
= fat_destroy_inode
,
566 .write_inode
= fat_write_inode
,
567 .delete_inode
= fat_delete_inode
,
568 .put_super
= fat_put_super
,
569 .write_super
= fat_write_super
,
570 .statfs
= fat_statfs
,
571 .clear_inode
= fat_clear_inode
,
572 .remount_fs
= fat_remount
,
574 .read_inode
= make_bad_inode
,
576 .show_options
= fat_show_options
,
580 * a FAT file handle with fhtype 3 is
581 * 0/ i_ino - for fast, reliable lookup if still in the cache
582 * 1/ i_generation - to see if i_ino is still valid
583 * bit 0 == 0 iff directory
584 * 2/ i_pos(8-39) - if ino has changed, but still in cache
585 * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos
586 * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc
588 * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum
589 * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits
590 * of i_logstart is used to store the directory entry offset.
593 static struct dentry
*
594 fat_decode_fh(struct super_block
*sb
, __u32
*fh
, int len
, int fhtype
,
595 int (*acceptable
)(void *context
, struct dentry
*de
),
599 return ERR_PTR(-ESTALE
);
601 return ERR_PTR(-ESTALE
);
603 return sb
->s_export_op
->find_exported_dentry(sb
, fh
, NULL
, acceptable
, context
);
606 static struct dentry
*fat_get_dentry(struct super_block
*sb
, void *inump
)
608 struct inode
*inode
= NULL
;
609 struct dentry
*result
;
612 inode
= iget(sb
, fh
[0]);
613 if (!inode
|| is_bad_inode(inode
) || inode
->i_generation
!= fh
[1]) {
620 int i_logstart
= fh
[3] & 0x0fffffff;
622 i_pos
= (loff_t
)fh
[2] << 8;
623 i_pos
|= ((fh
[3] >> 24) & 0xf0) | (fh
[4] >> 28);
625 /* try 2 - see if i_pos is in F-d-c
626 * require i_logstart to be the same
627 * Will fail if you truncate and then re-write
630 inode
= fat_iget(sb
, i_pos
);
631 if (inode
&& MSDOS_I(inode
)->i_logstart
!= i_logstart
) {
637 /* For now, do nothing
638 * What we could do is:
639 * follow the file starting at fh[4], and record
640 * the ".." entry, and the name of the fh[2] entry.
641 * The follow the ".." file finding the next step up.
642 * This way we build a path to the root of
643 * the tree. If this works, we lookup the path and so
644 * get this inode into the cache.
645 * Finally try the fat_iget lookup again
646 * If that fails, then weare totally out of luck
647 * But all that is for another day
651 return ERR_PTR(-ESTALE
);
654 /* now to find a dentry.
655 * If possible, get a well-connected one
657 result
= d_alloc_anon(inode
);
658 if (result
== NULL
) {
660 return ERR_PTR(-ENOMEM
);
662 result
->d_op
= sb
->s_root
->d_op
;
667 fat_encode_fh(struct dentry
*de
, __u32
*fh
, int *lenp
, int connectable
)
670 struct inode
*inode
= de
->d_inode
;
671 u32 ipos_h
, ipos_m
, ipos_l
;
674 return 255; /* no room */
676 ipos_h
= MSDOS_I(inode
)->i_pos
>> 8;
677 ipos_m
= (MSDOS_I(inode
)->i_pos
& 0xf0) << 24;
678 ipos_l
= (MSDOS_I(inode
)->i_pos
& 0x0f) << 28;
680 fh
[0] = inode
->i_ino
;
681 fh
[1] = inode
->i_generation
;
683 fh
[3] = ipos_m
| MSDOS_I(inode
)->i_logstart
;
684 spin_lock(&de
->d_lock
);
685 fh
[4] = ipos_l
| MSDOS_I(de
->d_parent
->d_inode
)->i_logstart
;
686 spin_unlock(&de
->d_lock
);
690 static struct dentry
*fat_get_parent(struct dentry
*child
)
692 struct buffer_head
*bh
;
693 struct msdos_dir_entry
*de
;
695 struct dentry
*parent
;
701 err
= fat_get_dotdot_entry(child
->d_inode
, &bh
, &de
, &i_pos
);
703 parent
= ERR_PTR(err
);
706 inode
= fat_build_inode(child
->d_sb
, de
, i_pos
);
709 parent
= ERR_PTR(PTR_ERR(inode
));
712 parent
= d_alloc_anon(inode
);
715 parent
= ERR_PTR(-ENOMEM
);
723 static struct export_operations fat_export_ops
= {
724 .decode_fh
= fat_decode_fh
,
725 .encode_fh
= fat_encode_fh
,
726 .get_dentry
= fat_get_dentry
,
727 .get_parent
= fat_get_parent
,
730 static int fat_show_options(struct seq_file
*m
, struct vfsmount
*mnt
)
732 struct msdos_sb_info
*sbi
= MSDOS_SB(mnt
->mnt_sb
);
733 struct fat_mount_options
*opts
= &sbi
->options
;
734 int isvfat
= opts
->isvfat
;
736 if (opts
->fs_uid
!= 0)
737 seq_printf(m
, ",uid=%u", opts
->fs_uid
);
738 if (opts
->fs_gid
!= 0)
739 seq_printf(m
, ",gid=%u", opts
->fs_gid
);
740 seq_printf(m
, ",fmask=%04o", opts
->fs_fmask
);
741 seq_printf(m
, ",dmask=%04o", opts
->fs_dmask
);
743 seq_printf(m
, ",codepage=%s", sbi
->nls_disk
->charset
);
746 seq_printf(m
, ",iocharset=%s", sbi
->nls_io
->charset
);
748 switch (opts
->shortname
) {
749 case VFAT_SFN_DISPLAY_WIN95
| VFAT_SFN_CREATE_WIN95
:
750 seq_puts(m
, ",shortname=win95");
752 case VFAT_SFN_DISPLAY_WINNT
| VFAT_SFN_CREATE_WINNT
:
753 seq_puts(m
, ",shortname=winnt");
755 case VFAT_SFN_DISPLAY_WINNT
| VFAT_SFN_CREATE_WIN95
:
756 seq_puts(m
, ",shortname=mixed");
758 case VFAT_SFN_DISPLAY_LOWER
| VFAT_SFN_CREATE_WIN95
:
759 /* seq_puts(m, ",shortname=lower"); */
762 seq_puts(m
, ",shortname=unknown");
766 if (opts
->name_check
!= 'n')
767 seq_printf(m
, ",check=%c", opts
->name_check
);
769 seq_puts(m
, ",quiet");
771 seq_puts(m
, ",showexec");
772 if (opts
->sys_immutable
)
773 seq_puts(m
, ",sys_immutable");
776 seq_puts(m
, ",dotsOK=yes");
778 seq_puts(m
, ",nocase");
781 seq_puts(m
, ",utf8");
782 if (opts
->unicode_xlate
)
783 seq_puts(m
, ",uni_xlate");
785 seq_puts(m
, ",nonumtail");
792 Opt_check_n
, Opt_check_r
, Opt_check_s
, Opt_uid
, Opt_gid
,
793 Opt_umask
, Opt_dmask
, Opt_fmask
, Opt_codepage
, Opt_nocase
,
794 Opt_quiet
, Opt_showexec
, Opt_debug
, Opt_immutable
,
795 Opt_dots
, Opt_nodots
,
796 Opt_charset
, Opt_shortname_lower
, Opt_shortname_win95
,
797 Opt_shortname_winnt
, Opt_shortname_mixed
, Opt_utf8_no
, Opt_utf8_yes
,
798 Opt_uni_xl_no
, Opt_uni_xl_yes
, Opt_nonumtail_no
, Opt_nonumtail_yes
,
799 Opt_obsolate
, Opt_err
,
802 static match_table_t fat_tokens
= {
803 {Opt_check_r
, "check=relaxed"},
804 {Opt_check_s
, "check=strict"},
805 {Opt_check_n
, "check=normal"},
806 {Opt_check_r
, "check=r"},
807 {Opt_check_s
, "check=s"},
808 {Opt_check_n
, "check=n"},
811 {Opt_umask
, "umask=%o"},
812 {Opt_dmask
, "dmask=%o"},
813 {Opt_fmask
, "fmask=%o"},
814 {Opt_codepage
, "codepage=%u"},
815 {Opt_nocase
, "nocase"},
816 {Opt_quiet
, "quiet"},
817 {Opt_showexec
, "showexec"},
818 {Opt_debug
, "debug"},
819 {Opt_immutable
, "sys_immutable"},
820 {Opt_obsolate
, "conv=binary"},
821 {Opt_obsolate
, "conv=text"},
822 {Opt_obsolate
, "conv=auto"},
823 {Opt_obsolate
, "conv=b"},
824 {Opt_obsolate
, "conv=t"},
825 {Opt_obsolate
, "conv=a"},
826 {Opt_obsolate
, "fat=%u"},
827 {Opt_obsolate
, "blocksize=%u"},
828 {Opt_obsolate
, "cvf_format=%20s"},
829 {Opt_obsolate
, "cvf_options=%100s"},
830 {Opt_obsolate
, "posix"},
833 static match_table_t msdos_tokens
= {
834 {Opt_nodots
, "nodots"},
835 {Opt_nodots
, "dotsOK=no"},
837 {Opt_dots
, "dotsOK=yes"},
840 static match_table_t vfat_tokens
= {
841 {Opt_charset
, "iocharset=%s"},
842 {Opt_shortname_lower
, "shortname=lower"},
843 {Opt_shortname_win95
, "shortname=win95"},
844 {Opt_shortname_winnt
, "shortname=winnt"},
845 {Opt_shortname_mixed
, "shortname=mixed"},
846 {Opt_utf8_no
, "utf8=0"}, /* 0 or no or false */
847 {Opt_utf8_no
, "utf8=no"},
848 {Opt_utf8_no
, "utf8=false"},
849 {Opt_utf8_yes
, "utf8=1"}, /* empty or 1 or yes or true */
850 {Opt_utf8_yes
, "utf8=yes"},
851 {Opt_utf8_yes
, "utf8=true"},
852 {Opt_utf8_yes
, "utf8"},
853 {Opt_uni_xl_no
, "uni_xlate=0"}, /* 0 or no or false */
854 {Opt_uni_xl_no
, "uni_xlate=no"},
855 {Opt_uni_xl_no
, "uni_xlate=false"},
856 {Opt_uni_xl_yes
, "uni_xlate=1"}, /* empty or 1 or yes or true */
857 {Opt_uni_xl_yes
, "uni_xlate=yes"},
858 {Opt_uni_xl_yes
, "uni_xlate=true"},
859 {Opt_uni_xl_yes
, "uni_xlate"},
860 {Opt_nonumtail_no
, "nonumtail=0"}, /* 0 or no or false */
861 {Opt_nonumtail_no
, "nonumtail=no"},
862 {Opt_nonumtail_no
, "nonumtail=false"},
863 {Opt_nonumtail_yes
, "nonumtail=1"}, /* empty or 1 or yes or true */
864 {Opt_nonumtail_yes
, "nonumtail=yes"},
865 {Opt_nonumtail_yes
, "nonumtail=true"},
866 {Opt_nonumtail_yes
, "nonumtail"},
870 static int parse_options(char *options
, int is_vfat
, int silent
, int *debug
,
871 struct fat_mount_options
*opts
)
874 substring_t args
[MAX_OPT_ARGS
];
878 opts
->isvfat
= is_vfat
;
880 opts
->fs_uid
= current
->uid
;
881 opts
->fs_gid
= current
->gid
;
882 opts
->fs_fmask
= opts
->fs_dmask
= current
->fs
->umask
;
883 opts
->codepage
= fat_default_codepage
;
884 opts
->iocharset
= fat_default_iocharset
;
886 opts
->shortname
= VFAT_SFN_DISPLAY_LOWER
|VFAT_SFN_CREATE_WIN95
;
889 opts
->name_check
= 'n';
890 opts
->quiet
= opts
->showexec
= opts
->sys_immutable
= opts
->dotsOK
= 0;
891 opts
->utf8
= opts
->unicode_xlate
= 0;
899 while ((p
= strsep(&options
, ",")) != NULL
) {
904 token
= match_token(p
, fat_tokens
, args
);
905 if (token
== Opt_err
) {
907 token
= match_token(p
, vfat_tokens
, args
);
909 token
= match_token(p
, msdos_tokens
, args
);
913 opts
->name_check
= 's';
916 opts
->name_check
= 'r';
919 opts
->name_check
= 'n';
925 /* for backward compatibility */
926 opts
->shortname
= VFAT_SFN_DISPLAY_WIN95
927 | VFAT_SFN_CREATE_WIN95
;
940 opts
->sys_immutable
= 1;
943 if (match_int(&args
[0], &option
))
945 opts
->fs_uid
= option
;
948 if (match_int(&args
[0], &option
))
950 opts
->fs_gid
= option
;
953 if (match_octal(&args
[0], &option
))
955 opts
->fs_fmask
= opts
->fs_dmask
= option
;
958 if (match_octal(&args
[0], &option
))
960 opts
->fs_dmask
= option
;
963 if (match_octal(&args
[0], &option
))
965 opts
->fs_fmask
= option
;
968 if (match_int(&args
[0], &option
))
970 opts
->codepage
= option
;
983 if (opts
->iocharset
!= fat_default_iocharset
)
984 kfree(opts
->iocharset
);
985 iocharset
= match_strdup(&args
[0]);
988 opts
->iocharset
= iocharset
;
990 case Opt_shortname_lower
:
991 opts
->shortname
= VFAT_SFN_DISPLAY_LOWER
992 | VFAT_SFN_CREATE_WIN95
;
994 case Opt_shortname_win95
:
995 opts
->shortname
= VFAT_SFN_DISPLAY_WIN95
996 | VFAT_SFN_CREATE_WIN95
;
998 case Opt_shortname_winnt
:
999 opts
->shortname
= VFAT_SFN_DISPLAY_WINNT
1000 | VFAT_SFN_CREATE_WINNT
;
1002 case Opt_shortname_mixed
:
1003 opts
->shortname
= VFAT_SFN_DISPLAY_WINNT
1004 | VFAT_SFN_CREATE_WIN95
;
1006 case Opt_utf8_no
: /* 0 or no or false */
1009 case Opt_utf8_yes
: /* empty or 1 or yes or true */
1012 case Opt_uni_xl_no
: /* 0 or no or false */
1013 opts
->unicode_xlate
= 0;
1015 case Opt_uni_xl_yes
: /* empty or 1 or yes or true */
1016 opts
->unicode_xlate
= 1;
1018 case Opt_nonumtail_no
: /* 0 or no or false */
1019 opts
->numtail
= 1; /* negated option */
1021 case Opt_nonumtail_yes
: /* empty or 1 or yes or true */
1022 opts
->numtail
= 0; /* negated option */
1025 /* obsolete mount options */
1027 printk(KERN_INFO
"FAT: \"%s\" option is obsolete, "
1028 "not supported now\n", p
);
1030 /* unknown option */
1034 "FAT: Unrecognized mount option \"%s\" "
1035 "or missing value\n", p
);
1040 /* UTF8 doesn't provide FAT semantics */
1041 if (!strcmp(opts
->iocharset
, "utf8")) {
1042 printk(KERN_ERR
"FAT: utf8 is not a recommended IO charset"
1043 " for FAT filesystems, filesystem will be case sensitive!\n");
1046 if (opts
->unicode_xlate
)
1052 static int fat_read_root(struct inode
*inode
)
1054 struct super_block
*sb
= inode
->i_sb
;
1055 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
1058 MSDOS_I(inode
)->i_pos
= 0;
1059 inode
->i_uid
= sbi
->options
.fs_uid
;
1060 inode
->i_gid
= sbi
->options
.fs_gid
;
1062 inode
->i_generation
= 0;
1063 inode
->i_mode
= (S_IRWXUGO
& ~sbi
->options
.fs_dmask
) | S_IFDIR
;
1064 inode
->i_op
= sbi
->dir_ops
;
1065 inode
->i_fop
= &fat_dir_operations
;
1066 if (sbi
->fat_bits
== 32) {
1067 MSDOS_I(inode
)->i_start
= sbi
->root_cluster
;
1068 error
= fat_calc_dir_size(inode
);
1072 MSDOS_I(inode
)->i_start
= 0;
1073 inode
->i_size
= sbi
->dir_entries
* sizeof(struct msdos_dir_entry
);
1075 inode
->i_blksize
= sbi
->cluster_size
;
1076 inode
->i_blocks
= ((inode
->i_size
+ (sbi
->cluster_size
- 1))
1077 & ~((loff_t
)sbi
->cluster_size
- 1)) >> 9;
1078 MSDOS_I(inode
)->i_logstart
= 0;
1079 MSDOS_I(inode
)->mmu_private
= inode
->i_size
;
1081 MSDOS_I(inode
)->i_attrs
= ATTR_NONE
;
1082 inode
->i_mtime
.tv_sec
= inode
->i_atime
.tv_sec
= inode
->i_ctime
.tv_sec
= 0;
1083 inode
->i_mtime
.tv_nsec
= inode
->i_atime
.tv_nsec
= inode
->i_ctime
.tv_nsec
= 0;
1084 inode
->i_nlink
= fat_subdirs(inode
)+2;
1090 * Read the super block of an MS-DOS FS.
1092 int fat_fill_super(struct super_block
*sb
, void *data
, int silent
,
1093 struct inode_operations
*fs_dir_inode_ops
, int isvfat
)
1095 struct inode
*root_inode
= NULL
;
1096 struct buffer_head
*bh
;
1097 struct fat_boot_sector
*b
;
1098 struct msdos_sb_info
*sbi
;
1099 u16 logical_sector_size
;
1100 u32 total_sectors
, total_clusters
, fat_clusters
, rootdir_sectors
;
1106 sbi
= kmalloc(sizeof(struct msdos_sb_info
), GFP_KERNEL
);
1109 sb
->s_fs_info
= sbi
;
1110 memset(sbi
, 0, sizeof(struct msdos_sb_info
));
1112 sb
->s_flags
|= MS_NODIRATIME
;
1113 sb
->s_magic
= MSDOS_SUPER_MAGIC
;
1114 sb
->s_op
= &fat_sops
;
1115 sb
->s_export_op
= &fat_export_ops
;
1116 sbi
->dir_ops
= fs_dir_inode_ops
;
1118 error
= parse_options(data
, isvfat
, silent
, &debug
, &sbi
->options
);
1123 sb_min_blocksize(sb
, 512);
1124 bh
= sb_bread(sb
, 0);
1126 printk(KERN_ERR
"FAT: unable to read boot sector\n");
1130 b
= (struct fat_boot_sector
*) bh
->b_data
;
1133 printk(KERN_ERR
"FAT: bogus number of reserved sectors\n");
1139 printk(KERN_ERR
"FAT: bogus number of FAT structure\n");
1145 * Earlier we checked here that b->secs_track and b->head are nonzero,
1146 * but it turns out valid FAT filesystems can have zero there.
1150 if (!FAT_VALID_MEDIA(media
)) {
1152 printk(KERN_ERR
"FAT: invalid media value (0x%02x)\n",
1157 logical_sector_size
=
1158 le16_to_cpu(get_unaligned((__le16
*)&b
->sector_size
));
1159 if (!logical_sector_size
1160 || (logical_sector_size
& (logical_sector_size
- 1))
1161 || (logical_sector_size
< 512)
1162 || (PAGE_CACHE_SIZE
< logical_sector_size
)) {
1164 printk(KERN_ERR
"FAT: bogus logical sector size %u\n",
1165 logical_sector_size
);
1169 sbi
->sec_per_clus
= b
->sec_per_clus
;
1170 if (!sbi
->sec_per_clus
1171 || (sbi
->sec_per_clus
& (sbi
->sec_per_clus
- 1))) {
1173 printk(KERN_ERR
"FAT: bogus sectors per cluster %u\n",
1179 if (logical_sector_size
< sb
->s_blocksize
) {
1180 printk(KERN_ERR
"FAT: logical sector size too small for device"
1181 " (logical sector size = %u)\n", logical_sector_size
);
1185 if (logical_sector_size
> sb
->s_blocksize
) {
1188 if (!sb_set_blocksize(sb
, logical_sector_size
)) {
1189 printk(KERN_ERR
"FAT: unable to set blocksize %u\n",
1190 logical_sector_size
);
1193 bh
= sb_bread(sb
, 0);
1195 printk(KERN_ERR
"FAT: unable to read boot sector"
1196 " (logical sector size = %lu)\n",
1200 b
= (struct fat_boot_sector
*) bh
->b_data
;
1203 sbi
->cluster_size
= sb
->s_blocksize
* sbi
->sec_per_clus
;
1204 sbi
->cluster_bits
= ffs(sbi
->cluster_size
) - 1;
1205 sbi
->fats
= b
->fats
;
1206 sbi
->fat_bits
= 0; /* Don't know yet */
1207 sbi
->fat_start
= le16_to_cpu(b
->reserved
);
1208 sbi
->fat_length
= le16_to_cpu(b
->fat_length
);
1209 sbi
->root_cluster
= 0;
1210 sbi
->free_clusters
= -1; /* Don't know yet */
1211 sbi
->prev_free
= FAT_START_ENT
;
1213 if (!sbi
->fat_length
&& b
->fat32_length
) {
1214 struct fat_boot_fsinfo
*fsinfo
;
1215 struct buffer_head
*fsinfo_bh
;
1219 sbi
->fat_length
= le32_to_cpu(b
->fat32_length
);
1220 sbi
->root_cluster
= le32_to_cpu(b
->root_cluster
);
1222 sb
->s_maxbytes
= 0xffffffff;
1224 /* MC - if info_sector is 0, don't multiply by 0 */
1225 sbi
->fsinfo_sector
= le16_to_cpu(b
->info_sector
);
1226 if (sbi
->fsinfo_sector
== 0)
1227 sbi
->fsinfo_sector
= 1;
1229 fsinfo_bh
= sb_bread(sb
, sbi
->fsinfo_sector
);
1230 if (fsinfo_bh
== NULL
) {
1231 printk(KERN_ERR
"FAT: bread failed, FSINFO block"
1232 " (sector = %lu)\n", sbi
->fsinfo_sector
);
1237 fsinfo
= (struct fat_boot_fsinfo
*)fsinfo_bh
->b_data
;
1238 if (!IS_FSINFO(fsinfo
)) {
1240 "FAT: Did not find valid FSINFO signature.\n"
1241 " Found signature1 0x%08x signature2 0x%08x"
1242 " (sector = %lu)\n",
1243 le32_to_cpu(fsinfo
->signature1
),
1244 le32_to_cpu(fsinfo
->signature2
),
1245 sbi
->fsinfo_sector
);
1247 sbi
->free_clusters
= le32_to_cpu(fsinfo
->free_clusters
);
1248 sbi
->prev_free
= le32_to_cpu(fsinfo
->next_cluster
);
1254 sbi
->dir_per_block
= sb
->s_blocksize
/ sizeof(struct msdos_dir_entry
);
1255 sbi
->dir_per_block_bits
= ffs(sbi
->dir_per_block
) - 1;
1257 sbi
->dir_start
= sbi
->fat_start
+ sbi
->fats
* sbi
->fat_length
;
1259 le16_to_cpu(get_unaligned((__le16
*)&b
->dir_entries
));
1260 if (sbi
->dir_entries
& (sbi
->dir_per_block
- 1)) {
1262 printk(KERN_ERR
"FAT: bogus directroy-entries per block"
1263 " (%u)\n", sbi
->dir_entries
);
1268 rootdir_sectors
= sbi
->dir_entries
1269 * sizeof(struct msdos_dir_entry
) / sb
->s_blocksize
;
1270 sbi
->data_start
= sbi
->dir_start
+ rootdir_sectors
;
1271 total_sectors
= le16_to_cpu(get_unaligned((__le16
*)&b
->sectors
));
1272 if (total_sectors
== 0)
1273 total_sectors
= le32_to_cpu(b
->total_sect
);
1275 total_clusters
= (total_sectors
- sbi
->data_start
) / sbi
->sec_per_clus
;
1277 if (sbi
->fat_bits
!= 32)
1278 sbi
->fat_bits
= (total_clusters
> MAX_FAT12
) ? 16 : 12;
1280 /* check that FAT table does not overflow */
1281 fat_clusters
= sbi
->fat_length
* sb
->s_blocksize
* 8 / sbi
->fat_bits
;
1282 total_clusters
= min(total_clusters
, fat_clusters
- FAT_START_ENT
);
1283 if (total_clusters
> MAX_FAT(sb
)) {
1285 printk(KERN_ERR
"FAT: count of clusters too big (%u)\n",
1291 sbi
->max_cluster
= total_clusters
+ FAT_START_ENT
;
1292 /* check the free_clusters, it's not necessarily correct */
1293 if (sbi
->free_clusters
!= -1 && sbi
->free_clusters
> total_clusters
)
1294 sbi
->free_clusters
= -1;
1295 /* check the prev_free, it's not necessarily correct */
1296 sbi
->prev_free
%= sbi
->max_cluster
;
1297 if (sbi
->prev_free
< FAT_START_ENT
)
1298 sbi
->prev_free
= FAT_START_ENT
;
1302 /* set up enough so that it can read an inode */
1304 fat_ent_access_init(sb
);
1307 * The low byte of FAT's first entry must have same value with
1308 * media-field. But in real world, too many devices is
1309 * writing wrong value. So, removed that validity check.
1311 * if (FAT_FIRST_ENT(sb, media) != first)
1315 sprintf(buf
, "cp%d", sbi
->options
.codepage
);
1316 sbi
->nls_disk
= load_nls(buf
);
1317 if (!sbi
->nls_disk
) {
1318 printk(KERN_ERR
"FAT: codepage %s not found\n", buf
);
1322 /* FIXME: utf8 is using iocharset for upper/lower conversion */
1323 if (sbi
->options
.isvfat
) {
1324 sbi
->nls_io
= load_nls(sbi
->options
.iocharset
);
1326 printk(KERN_ERR
"FAT: IO charset %s not found\n",
1327 sbi
->options
.iocharset
);
1333 root_inode
= new_inode(sb
);
1336 root_inode
->i_ino
= MSDOS_ROOT_INO
;
1337 root_inode
->i_version
= 1;
1338 error
= fat_read_root(root_inode
);
1342 insert_inode_hash(root_inode
);
1343 sb
->s_root
= d_alloc_root(root_inode
);
1345 printk(KERN_ERR
"FAT: get root inode failed\n");
1354 printk(KERN_INFO
"VFS: Can't find a valid FAT filesystem"
1355 " on dev %s.\n", sb
->s_id
);
1361 unload_nls(sbi
->nls_io
);
1363 unload_nls(sbi
->nls_disk
);
1364 if (sbi
->options
.iocharset
!= fat_default_iocharset
)
1365 kfree(sbi
->options
.iocharset
);
1366 sb
->s_fs_info
= NULL
;
1371 EXPORT_SYMBOL_GPL(fat_fill_super
);
1373 int __init
fat_cache_init(void);
1374 void fat_cache_destroy(void);
1376 static int __init
init_fat_fs(void)
1380 err
= fat_cache_init();
1384 err
= fat_init_inodecache();
1391 fat_cache_destroy();
1395 static void __exit
exit_fat_fs(void)
1397 fat_cache_destroy();
1398 fat_destroy_inodecache();
1401 module_init(init_fat_fs
)
1402 module_exit(exit_fat_fs
)
1404 MODULE_LICENSE("GPL");