4 * directory handling functions for fat-based filesystems
6 * Written 1992,1993 by Werner Almesberger
8 * Hidden files 1995 by Albert Cahalan <albert@ccs.neu.edu> <adc@coe.neu.edu>
10 * VFAT extensions by Gordon Chaffee <chaffee@plateau.cs.berkeley.edu>
11 * Merged with msdos fs by Henrik Storner <storner@osiris.ping.dk>
12 * Rewritten for constant inumbers. Plugged buffer overrun in readdir(). AV
13 * Short name translation 1999, 2001 by Wolfram Pienkoss <wp@bszh.de>
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/time.h>
19 #include <linux/buffer_head.h>
20 #include <linux/compat.h>
21 #include <asm/uaccess.h>
22 #include <linux/kernel.h>
26 * Maximum buffer size of short name.
27 * [(MSDOS_NAME + '.') * max one char + nul]
28 * For msdos style, ['.' (hidden) + MSDOS_NAME + '.' + nul]
30 #define FAT_MAX_SHORT_SIZE ((MSDOS_NAME + 1) * NLS_MAX_CHARSET_SIZE + 1)
32 * Maximum buffer size of unicode chars from slots.
33 * [(max longname slots * 13 (size in a slot) + nul) * sizeof(wchar_t)]
35 #define FAT_MAX_UNI_CHARS ((MSDOS_SLOTS - 1) * 13 + 1)
36 #define FAT_MAX_UNI_SIZE (FAT_MAX_UNI_CHARS * sizeof(wchar_t))
38 static inline loff_t
fat_make_i_pos(struct super_block
*sb
,
39 struct buffer_head
*bh
,
40 struct msdos_dir_entry
*de
)
42 return ((loff_t
)bh
->b_blocknr
<< MSDOS_SB(sb
)->dir_per_block_bits
)
43 | (de
- (struct msdos_dir_entry
*)bh
->b_data
);
46 static inline void fat_dir_readahead(struct inode
*dir
, sector_t iblock
,
49 struct super_block
*sb
= dir
->i_sb
;
50 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
51 struct buffer_head
*bh
;
54 /* This is not a first sector of cluster, or sec_per_clus == 1 */
55 if ((iblock
& (sbi
->sec_per_clus
- 1)) || sbi
->sec_per_clus
== 1)
57 /* root dir of FAT12/FAT16 */
58 if ((sbi
->fat_bits
!= 32) && (dir
->i_ino
== MSDOS_ROOT_INO
))
61 bh
= sb_find_get_block(sb
, phys
);
62 if (bh
== NULL
|| !buffer_uptodate(bh
)) {
63 for (sec
= 0; sec
< sbi
->sec_per_clus
; sec
++)
64 sb_breadahead(sb
, phys
+ sec
);
69 /* Returns the inode number of the directory entry at offset pos. If bh is
70 non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
72 AV. Most often we do it item-by-item. Makes sense to optimize.
73 AV. OK, there we go: if both bh and de are non-NULL we assume that we just
74 AV. want the next entry (took one explicit de=NULL in vfat/namei.c).
75 AV. It's done in fat_get_entry() (inlined), here the slow case lives.
76 AV. Additionally, when we return -1 (i.e. reached the end of directory)
79 static int fat__get_entry(struct inode
*dir
, loff_t
*pos
,
80 struct buffer_head
**bh
, struct msdos_dir_entry
**de
)
82 struct super_block
*sb
= dir
->i_sb
;
83 sector_t phys
, iblock
;
84 unsigned long mapped_blocks
;
92 iblock
= *pos
>> sb
->s_blocksize_bits
;
93 err
= fat_bmap(dir
, iblock
, &phys
, &mapped_blocks
, 0);
95 return -1; /* beyond EOF or error */
97 fat_dir_readahead(dir
, iblock
, phys
);
99 *bh
= sb_bread(sb
, phys
);
101 printk(KERN_ERR
"FAT: Directory bread(block %llu) failed\n",
103 /* skip this block */
104 *pos
= (iblock
+ 1) << sb
->s_blocksize_bits
;
108 offset
= *pos
& (sb
->s_blocksize
- 1);
109 *pos
+= sizeof(struct msdos_dir_entry
);
110 *de
= (struct msdos_dir_entry
*)((*bh
)->b_data
+ offset
);
115 static inline int fat_get_entry(struct inode
*dir
, loff_t
*pos
,
116 struct buffer_head
**bh
,
117 struct msdos_dir_entry
**de
)
119 /* Fast stuff first */
121 (*de
- (struct msdos_dir_entry
*)(*bh
)->b_data
) < MSDOS_SB(dir
->i_sb
)->dir_per_block
- 1) {
122 *pos
+= sizeof(struct msdos_dir_entry
);
126 return fat__get_entry(dir
, pos
, bh
, de
);
130 * Convert Unicode 16 to UTF-8, translated Unicode, or ASCII.
131 * If uni_xlate is enabled and we can't get a 1:1 conversion, use a
132 * colon as an escape character since it is normally invalid on the vfat
133 * filesystem. The following four characters are the hexadecimal digits
134 * of Unicode value. This lets us do a full dump and restore of Unicode
135 * filenames. We could get into some trouble with long Unicode names,
136 * but ignore that right now.
137 * Ahem... Stack smashing in ring 0 isn't fun. Fixed.
139 static int uni16_to_x8(unsigned char *ascii
, const wchar_t *uni
, int len
,
140 int uni_xlate
, struct nls_table
*nls
)
150 while (*ip
&& ((len
- NLS_MAX_CHARSET_SIZE
) > 0)) {
152 if ((charlen
= nls
->uni2char(ec
, op
, NLS_MAX_CHARSET_SIZE
)) > 0) {
156 if (uni_xlate
== 1) {
158 op
= pack_hex_byte(op
, ec
>> 8);
159 op
= pack_hex_byte(op
, ec
);
169 printk(KERN_WARNING
"FAT: filename was truncated while "
177 static inline int fat_uni_to_x8(struct msdos_sb_info
*sbi
, const wchar_t *uni
,
178 unsigned char *buf
, int size
)
180 if (sbi
->options
.utf8
)
181 return utf16s_to_utf8s(uni
, FAT_MAX_UNI_CHARS
,
182 UTF16_HOST_ENDIAN
, buf
, size
);
184 return uni16_to_x8(buf
, uni
, size
, sbi
->options
.unicode_xlate
,
189 fat_short2uni(struct nls_table
*t
, unsigned char *c
, int clen
, wchar_t *uni
)
193 charlen
= t
->char2uni(c
, clen
, uni
);
195 *uni
= 0x003f; /* a question mark */
202 fat_short2lower_uni(struct nls_table
*t
, unsigned char *c
, int clen
, wchar_t *uni
)
207 charlen
= t
->char2uni(c
, clen
, &wc
);
209 *uni
= 0x003f; /* a question mark */
211 } else if (charlen
<= 1) {
212 unsigned char nc
= t
->charset2lower
[*c
];
217 if ( (charlen
= t
->char2uni(&nc
, 1, uni
)) < 0) {
218 *uni
= 0x003f; /* a question mark */
228 fat_shortname2uni(struct nls_table
*nls
, unsigned char *buf
, int buf_size
,
229 wchar_t *uni_buf
, unsigned short opt
, int lower
)
233 if (opt
& VFAT_SFN_DISPLAY_LOWER
)
234 len
= fat_short2lower_uni(nls
, buf
, buf_size
, uni_buf
);
235 else if (opt
& VFAT_SFN_DISPLAY_WIN95
)
236 len
= fat_short2uni(nls
, buf
, buf_size
, uni_buf
);
237 else if (opt
& VFAT_SFN_DISPLAY_WINNT
) {
239 len
= fat_short2lower_uni(nls
, buf
, buf_size
, uni_buf
);
241 len
= fat_short2uni(nls
, buf
, buf_size
, uni_buf
);
243 len
= fat_short2uni(nls
, buf
, buf_size
, uni_buf
);
248 static inline int fat_name_match(struct msdos_sb_info
*sbi
,
249 const unsigned char *a
, int a_len
,
250 const unsigned char *b
, int b_len
)
255 if (sbi
->options
.name_check
!= 's')
256 return !nls_strnicmp(sbi
->nls_io
, a
, b
, a_len
);
258 return !memcmp(a
, b
, a_len
);
261 enum { PARSE_INVALID
= 1, PARSE_NOT_LONGNAME
, PARSE_EOF
, };
264 * fat_parse_long - Parse extended directory entry.
266 * This function returns zero on success, negative value on error, or one of
269 * %PARSE_INVALID - Directory entry is invalid.
270 * %PARSE_NOT_LONGNAME - Directory entry does not contain longname.
271 * %PARSE_EOF - Directory has no more entries.
273 static int fat_parse_long(struct inode
*dir
, loff_t
*pos
,
274 struct buffer_head
**bh
, struct msdos_dir_entry
**de
,
275 wchar_t **unicode
, unsigned char *nr_slots
)
277 struct msdos_dir_slot
*ds
;
278 unsigned char id
, slot
, slots
, alias_checksum
;
281 *unicode
= __getname();
289 ds
= (struct msdos_dir_slot
*)*de
;
292 return PARSE_INVALID
;
294 if (slots
> 20 || !slots
) /* ceil(256 * 2 / 26) */
295 return PARSE_INVALID
;
297 alias_checksum
= ds
->alias_checksum
;
305 fat16_towchar(*unicode
+ offset
, ds
->name0_4
, 5);
306 fat16_towchar(*unicode
+ offset
+ 5, ds
->name5_10
, 6);
307 fat16_towchar(*unicode
+ offset
+ 11, ds
->name11_12
, 2);
310 (*unicode
)[offset
+ 13] = 0;
311 if (fat_get_entry(dir
, pos
, bh
, de
) < 0)
315 ds
= (struct msdos_dir_slot
*)*de
;
316 if (ds
->attr
!= ATTR_EXT
)
317 return PARSE_NOT_LONGNAME
;
318 if ((ds
->id
& ~0x40) != slot
)
320 if (ds
->alias_checksum
!= alias_checksum
)
323 if ((*de
)->name
[0] == DELETED_FLAG
)
324 return PARSE_INVALID
;
325 if ((*de
)->attr
== ATTR_EXT
)
327 if (IS_FREE((*de
)->name
) || ((*de
)->attr
& ATTR_VOLUME
))
328 return PARSE_INVALID
;
329 if (fat_checksum((*de
)->name
) != alias_checksum
)
336 * Return values: negative -> error, 0 -> not found, positive -> found,
337 * value is the total amount of slots, including the shortname entry.
339 int fat_search_long(struct inode
*inode
, const unsigned char *name
,
340 int name_len
, struct fat_slot_info
*sinfo
)
342 struct super_block
*sb
= inode
->i_sb
;
343 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
344 struct buffer_head
*bh
= NULL
;
345 struct msdos_dir_entry
*de
;
346 struct nls_table
*nls_disk
= sbi
->nls_disk
;
347 unsigned char nr_slots
;
348 wchar_t bufuname
[14];
349 wchar_t *unicode
= NULL
;
350 unsigned char work
[MSDOS_NAME
];
351 unsigned char bufname
[FAT_MAX_SHORT_SIZE
];
352 unsigned short opt_shortname
= sbi
->options
.shortname
;
354 int chl
, i
, j
, last_u
, err
, len
;
358 if (fat_get_entry(inode
, &cpos
, &bh
, &de
) == -1)
362 if (de
->name
[0] == DELETED_FLAG
)
364 if (de
->attr
!= ATTR_EXT
&& (de
->attr
& ATTR_VOLUME
))
366 if (de
->attr
!= ATTR_EXT
&& IS_FREE(de
->name
))
368 if (de
->attr
== ATTR_EXT
) {
369 int status
= fat_parse_long(inode
, &cpos
, &bh
, &de
,
370 &unicode
, &nr_slots
);
374 } else if (status
== PARSE_INVALID
)
376 else if (status
== PARSE_NOT_LONGNAME
)
378 else if (status
== PARSE_EOF
)
382 memcpy(work
, de
->name
, sizeof(de
->name
));
383 /* see namei.c, msdos_format_name */
386 for (i
= 0, j
= 0, last_u
= 0; i
< 8;) {
389 chl
= fat_shortname2uni(nls_disk
, &work
[i
], 8 - i
,
390 &bufuname
[j
++], opt_shortname
,
391 de
->lcase
& CASE_LOWER_BASE
);
401 fat_short2uni(nls_disk
, ".", 1, &bufuname
[j
++]);
402 for (i
= 8; i
< MSDOS_NAME
;) {
405 chl
= fat_shortname2uni(nls_disk
, &work
[i
],
407 &bufuname
[j
++], opt_shortname
,
408 de
->lcase
& CASE_LOWER_EXT
);
420 /* Compare shortname */
421 bufuname
[last_u
] = 0x0000;
422 len
= fat_uni_to_x8(sbi
, bufuname
, bufname
, sizeof(bufname
));
423 if (fat_name_match(sbi
, name
, name_len
, bufname
, len
))
427 void *longname
= unicode
+ FAT_MAX_UNI_CHARS
;
428 int size
= PATH_MAX
- FAT_MAX_UNI_SIZE
;
430 /* Compare longname */
431 len
= fat_uni_to_x8(sbi
, unicode
, longname
, size
);
432 if (fat_name_match(sbi
, name
, name_len
, longname
, len
))
438 nr_slots
++; /* include the de */
439 sinfo
->slot_off
= cpos
- nr_slots
* sizeof(*de
);
440 sinfo
->nr_slots
= nr_slots
;
443 sinfo
->i_pos
= fat_make_i_pos(sb
, sinfo
->bh
, sinfo
->de
);
452 EXPORT_SYMBOL_GPL(fat_search_long
);
454 struct fat_ioctl_filldir_callback
{
458 const char *longname
;
460 const char *shortname
;
464 static int __fat_readdir(struct inode
*inode
, struct file
*filp
, void *dirent
,
465 filldir_t filldir
, int short_only
, int both
)
467 struct super_block
*sb
= inode
->i_sb
;
468 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
469 struct buffer_head
*bh
;
470 struct msdos_dir_entry
*de
;
471 struct nls_table
*nls_disk
= sbi
->nls_disk
;
472 unsigned char nr_slots
;
473 wchar_t bufuname
[14];
474 wchar_t *unicode
= NULL
;
475 unsigned char c
, work
[MSDOS_NAME
];
476 unsigned char bufname
[FAT_MAX_SHORT_SIZE
], *ptname
= bufname
;
477 unsigned short opt_shortname
= sbi
->options
.shortname
;
478 int isvfat
= sbi
->options
.isvfat
;
479 int nocase
= sbi
->options
.nocase
;
480 const char *fill_name
= NULL
;
482 unsigned long lpos
, dummy
, *furrfu
= &lpos
;
484 int chi
, chl
, i
, i2
, j
, last
, last_u
, dotoffset
= 0, fill_len
= 0;
490 /* Fake . and .. for the root directory. */
491 if (inode
->i_ino
== MSDOS_ROOT_INO
) {
493 if (filldir(dirent
, "..", cpos
+1, cpos
, MSDOS_ROOT_INO
, DT_DIR
) < 0)
504 if (cpos
& (sizeof(struct msdos_dir_entry
) - 1)) {
511 if (fat_get_entry(inode
, &cpos
, &bh
, &de
) == -1)
516 * Check for long filename entry, but if short_only, we don't
517 * need to parse long filename.
519 if (isvfat
&& !short_only
) {
520 if (de
->name
[0] == DELETED_FLAG
)
522 if (de
->attr
!= ATTR_EXT
&& (de
->attr
& ATTR_VOLUME
))
524 if (de
->attr
!= ATTR_EXT
&& IS_FREE(de
->name
))
527 if ((de
->attr
& ATTR_VOLUME
) || IS_FREE(de
->name
))
531 if (isvfat
&& de
->attr
== ATTR_EXT
) {
532 int status
= fat_parse_long(inode
, &cpos
, &bh
, &de
,
533 &unicode
, &nr_slots
);
538 } else if (status
== PARSE_INVALID
)
540 else if (status
== PARSE_NOT_LONGNAME
)
542 else if (status
== PARSE_EOF
)
546 void *longname
= unicode
+ FAT_MAX_UNI_CHARS
;
547 int size
= PATH_MAX
- FAT_MAX_UNI_SIZE
;
548 int len
= fat_uni_to_x8(sbi
, unicode
, longname
, size
);
550 fill_name
= longname
;
552 /* !both && !short_only, so we don't need shortname. */
558 if (sbi
->options
.dotsOK
) {
561 if (de
->attr
& ATTR_HIDDEN
) {
567 memcpy(work
, de
->name
, sizeof(de
->name
));
568 /* see namei.c, msdos_format_name */
571 for (i
= 0, j
= 0, last
= 0, last_u
= 0; i
< 8;) {
574 chl
= fat_shortname2uni(nls_disk
, &work
[i
], 8 - i
,
575 &bufuname
[j
++], opt_shortname
,
576 de
->lcase
& CASE_LOWER_BASE
);
578 ptname
[i
++] = (!nocase
&& c
>='A' && c
<='Z') ? c
+32 : c
;
585 for (chi
= 0; chi
< chl
&& i
< 8; chi
++) {
593 fat_short2uni(nls_disk
, ".", 1, &bufuname
[j
++]);
595 for (i2
= 8; i2
< MSDOS_NAME
;) {
598 chl
= fat_shortname2uni(nls_disk
, &work
[i2
], MSDOS_NAME
- i2
,
599 &bufuname
[j
++], opt_shortname
,
600 de
->lcase
& CASE_LOWER_EXT
);
603 ptname
[i
++] = (!nocase
&& c
>='A' && c
<='Z') ? c
+32 : c
;
610 for (chi
= 0; chi
< chl
&& i2
< MSDOS_NAME
; chi
++) {
611 ptname
[i
++] = work
[i2
++];
619 i
= last
+ dotoffset
;
623 bufuname
[j
] = 0x0000;
624 i
= fat_uni_to_x8(sbi
, bufuname
, bufname
, sizeof(bufname
));
627 /* hack for fat_ioctl_filldir() */
628 struct fat_ioctl_filldir_callback
*p
= dirent
;
630 p
->longname
= fill_name
;
631 p
->long_len
= fill_len
;
632 p
->shortname
= bufname
;
642 lpos
= cpos
- (nr_slots
+ 1) * sizeof(struct msdos_dir_entry
);
643 if (!memcmp(de
->name
, MSDOS_DOT
, MSDOS_NAME
))
645 else if (!memcmp(de
->name
, MSDOS_DOTDOT
, MSDOS_NAME
)) {
646 inum
= parent_ino(filp
->f_path
.dentry
);
648 loff_t i_pos
= fat_make_i_pos(sb
, bh
, de
);
649 struct inode
*tmp
= fat_iget(sb
, i_pos
);
654 inum
= iunique(sb
, MSDOS_ROOT_INO
);
657 if (filldir(dirent
, fill_name
, fill_len
, *furrfu
, inum
,
658 (de
->attr
& ATTR_DIR
) ? DT_DIR
: DT_REG
) < 0)
676 static int fat_readdir(struct file
*filp
, void *dirent
, filldir_t filldir
)
678 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
679 return __fat_readdir(inode
, filp
, dirent
, filldir
, 0, 0);
682 #define FAT_IOCTL_FILLDIR_FUNC(func, dirent_type) \
683 static int func(void *__buf, const char *name, int name_len, \
684 loff_t offset, u64 ino, unsigned int d_type) \
686 struct fat_ioctl_filldir_callback *buf = __buf; \
687 struct dirent_type __user *d1 = buf->dirent; \
688 struct dirent_type __user *d2 = d1 + 1; \
694 if (name != NULL) { \
695 /* dirent has only short name */ \
696 if (name_len >= sizeof(d1->d_name)) \
697 name_len = sizeof(d1->d_name) - 1; \
699 if (put_user(0, d2->d_name) || \
700 put_user(0, &d2->d_reclen) || \
701 copy_to_user(d1->d_name, name, name_len) || \
702 put_user(0, d1->d_name + name_len) || \
703 put_user(name_len, &d1->d_reclen)) \
706 /* dirent has short and long name */ \
707 const char *longname = buf->longname; \
708 int long_len = buf->long_len; \
709 const char *shortname = buf->shortname; \
710 int short_len = buf->short_len; \
712 if (long_len >= sizeof(d1->d_name)) \
713 long_len = sizeof(d1->d_name) - 1; \
714 if (short_len >= sizeof(d1->d_name)) \
715 short_len = sizeof(d1->d_name) - 1; \
717 if (copy_to_user(d2->d_name, longname, long_len) || \
718 put_user(0, d2->d_name + long_len) || \
719 put_user(long_len, &d2->d_reclen) || \
720 put_user(ino, &d2->d_ino) || \
721 put_user(offset, &d2->d_off) || \
722 copy_to_user(d1->d_name, shortname, short_len) || \
723 put_user(0, d1->d_name + short_len) || \
724 put_user(short_len, &d1->d_reclen)) \
729 buf->result = -EFAULT; \
733 FAT_IOCTL_FILLDIR_FUNC(fat_ioctl_filldir
, __fat_dirent
)
735 static int fat_ioctl_readdir(struct inode
*inode
, struct file
*filp
,
736 void __user
*dirent
, filldir_t filldir
,
737 int short_only
, int both
)
739 struct fat_ioctl_filldir_callback buf
;
744 mutex_lock(&inode
->i_mutex
);
746 if (!IS_DEADDIR(inode
)) {
747 ret
= __fat_readdir(inode
, filp
, &buf
, filldir
,
750 mutex_unlock(&inode
->i_mutex
);
756 static long fat_dir_ioctl(struct file
*filp
, unsigned int cmd
,
759 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
760 struct __fat_dirent __user
*d1
= (struct __fat_dirent __user
*)arg
;
761 int short_only
, both
;
764 case VFAT_IOCTL_READDIR_SHORT
:
768 case VFAT_IOCTL_READDIR_BOTH
:
773 return fat_generic_ioctl(filp
, cmd
, arg
);
776 if (!access_ok(VERIFY_WRITE
, d1
, sizeof(struct __fat_dirent
[2])))
779 * Yes, we don't need this put_user() absolutely. However old
780 * code didn't return the right value. So, app use this value,
781 * in order to check whether it is EOF.
783 if (put_user(0, &d1
->d_reclen
))
786 return fat_ioctl_readdir(inode
, filp
, d1
, fat_ioctl_filldir
,
791 #define VFAT_IOCTL_READDIR_BOTH32 _IOR('r', 1, struct compat_dirent[2])
792 #define VFAT_IOCTL_READDIR_SHORT32 _IOR('r', 2, struct compat_dirent[2])
794 FAT_IOCTL_FILLDIR_FUNC(fat_compat_ioctl_filldir
, compat_dirent
)
796 static long fat_compat_dir_ioctl(struct file
*filp
, unsigned cmd
,
799 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
800 struct compat_dirent __user
*d1
= compat_ptr(arg
);
801 int short_only
, both
;
804 case VFAT_IOCTL_READDIR_SHORT32
:
808 case VFAT_IOCTL_READDIR_BOTH32
:
813 return fat_generic_ioctl(filp
, cmd
, (unsigned long)arg
);
816 if (!access_ok(VERIFY_WRITE
, d1
, sizeof(struct compat_dirent
[2])))
819 * Yes, we don't need this put_user() absolutely. However old
820 * code didn't return the right value. So, app use this value,
821 * in order to check whether it is EOF.
823 if (put_user(0, &d1
->d_reclen
))
826 return fat_ioctl_readdir(inode
, filp
, d1
, fat_compat_ioctl_filldir
,
829 #endif /* CONFIG_COMPAT */
831 const struct file_operations fat_dir_operations
= {
832 .llseek
= generic_file_llseek
,
833 .read
= generic_read_dir
,
834 .readdir
= fat_readdir
,
835 .unlocked_ioctl
= fat_dir_ioctl
,
837 .compat_ioctl
= fat_compat_dir_ioctl
,
839 .fsync
= fat_file_fsync
,
842 static int fat_get_short_entry(struct inode
*dir
, loff_t
*pos
,
843 struct buffer_head
**bh
,
844 struct msdos_dir_entry
**de
)
846 while (fat_get_entry(dir
, pos
, bh
, de
) >= 0) {
847 /* free entry or long name entry or volume label */
848 if (!IS_FREE((*de
)->name
) && !((*de
)->attr
& ATTR_VOLUME
))
855 * The ".." entry can not provide the "struct fat_slot_info" informations
856 * for inode. So, this function provide the some informations only.
858 int fat_get_dotdot_entry(struct inode
*dir
, struct buffer_head
**bh
,
859 struct msdos_dir_entry
**de
, loff_t
*i_pos
)
865 while (fat_get_short_entry(dir
, &offset
, bh
, de
) >= 0) {
866 if (!strncmp((*de
)->name
, MSDOS_DOTDOT
, MSDOS_NAME
)) {
867 *i_pos
= fat_make_i_pos(dir
->i_sb
, *bh
, *de
);
874 EXPORT_SYMBOL_GPL(fat_get_dotdot_entry
);
876 /* See if directory is empty */
877 int fat_dir_empty(struct inode
*dir
)
879 struct buffer_head
*bh
;
880 struct msdos_dir_entry
*de
;
886 while (fat_get_short_entry(dir
, &cpos
, &bh
, &de
) >= 0) {
887 if (strncmp(de
->name
, MSDOS_DOT
, MSDOS_NAME
) &&
888 strncmp(de
->name
, MSDOS_DOTDOT
, MSDOS_NAME
)) {
897 EXPORT_SYMBOL_GPL(fat_dir_empty
);
900 * fat_subdirs counts the number of sub-directories of dir. It can be run
901 * on directories being created.
903 int fat_subdirs(struct inode
*dir
)
905 struct buffer_head
*bh
;
906 struct msdos_dir_entry
*de
;
912 while (fat_get_short_entry(dir
, &cpos
, &bh
, &de
) >= 0) {
913 if (de
->attr
& ATTR_DIR
)
921 * Scans a directory for a given file (name points to its formatted name).
922 * Returns an error code or zero.
924 int fat_scan(struct inode
*dir
, const unsigned char *name
,
925 struct fat_slot_info
*sinfo
)
927 struct super_block
*sb
= dir
->i_sb
;
931 while (fat_get_short_entry(dir
, &sinfo
->slot_off
, &sinfo
->bh
,
933 if (!strncmp(sinfo
->de
->name
, name
, MSDOS_NAME
)) {
934 sinfo
->slot_off
-= sizeof(*sinfo
->de
);
936 sinfo
->i_pos
= fat_make_i_pos(sb
, sinfo
->bh
, sinfo
->de
);
943 EXPORT_SYMBOL_GPL(fat_scan
);
945 static int __fat_remove_entries(struct inode
*dir
, loff_t pos
, int nr_slots
)
947 struct super_block
*sb
= dir
->i_sb
;
948 struct buffer_head
*bh
;
949 struct msdos_dir_entry
*de
, *endp
;
950 int err
= 0, orig_slots
;
954 if (fat_get_entry(dir
, &pos
, &bh
, &de
) < 0) {
959 orig_slots
= nr_slots
;
960 endp
= (struct msdos_dir_entry
*)(bh
->b_data
+ sb
->s_blocksize
);
961 while (nr_slots
&& de
< endp
) {
962 de
->name
[0] = DELETED_FLAG
;
966 mark_buffer_dirty_inode(bh
, dir
);
968 err
= sync_dirty_buffer(bh
);
973 /* pos is *next* de's position, so this does `- sizeof(de)' */
974 pos
+= ((orig_slots
- nr_slots
) * sizeof(*de
)) - sizeof(*de
);
980 int fat_remove_entries(struct inode
*dir
, struct fat_slot_info
*sinfo
)
982 struct msdos_dir_entry
*de
;
983 struct buffer_head
*bh
;
984 int err
= 0, nr_slots
;
987 * First stage: Remove the shortname. By this, the directory
990 nr_slots
= sinfo
->nr_slots
;
995 while (nr_slots
&& de
>= (struct msdos_dir_entry
*)bh
->b_data
) {
996 de
->name
[0] = DELETED_FLAG
;
1000 mark_buffer_dirty_inode(bh
, dir
);
1001 if (IS_DIRSYNC(dir
))
1002 err
= sync_dirty_buffer(bh
);
1010 * Second stage: remove the remaining longname slots.
1011 * (This directory entry is already removed, and so return
1014 err
= __fat_remove_entries(dir
, sinfo
->slot_off
, nr_slots
);
1017 "FAT: Couldn't remove the long name slots\n");
1021 dir
->i_mtime
= dir
->i_atime
= CURRENT_TIME_SEC
;
1022 if (IS_DIRSYNC(dir
))
1023 (void)fat_sync_inode(dir
);
1025 mark_inode_dirty(dir
);
1030 EXPORT_SYMBOL_GPL(fat_remove_entries
);
1032 static int fat_zeroed_cluster(struct inode
*dir
, sector_t blknr
, int nr_used
,
1033 struct buffer_head
**bhs
, int nr_bhs
)
1035 struct super_block
*sb
= dir
->i_sb
;
1036 sector_t last_blknr
= blknr
+ MSDOS_SB(sb
)->sec_per_clus
;
1039 /* Zeroing the unused blocks on this cluster */
1042 while (blknr
< last_blknr
) {
1043 bhs
[n
] = sb_getblk(sb
, blknr
);
1048 memset(bhs
[n
]->b_data
, 0, sb
->s_blocksize
);
1049 set_buffer_uptodate(bhs
[n
]);
1050 mark_buffer_dirty_inode(bhs
[n
], dir
);
1055 if (IS_DIRSYNC(dir
)) {
1056 err
= fat_sync_bhs(bhs
, n
);
1060 for (i
= 0; i
< n
; i
++)
1065 if (IS_DIRSYNC(dir
)) {
1066 err
= fat_sync_bhs(bhs
, n
);
1070 for (i
= 0; i
< n
; i
++)
1076 for (i
= 0; i
< n
; i
++)
1081 int fat_alloc_new_dir(struct inode
*dir
, struct timespec
*ts
)
1083 struct super_block
*sb
= dir
->i_sb
;
1084 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
1085 struct buffer_head
*bhs
[MAX_BUF_PER_PAGE
];
1086 struct msdos_dir_entry
*de
;
1092 err
= fat_alloc_clusters(dir
, &cluster
, 1);
1096 blknr
= fat_clus_to_blknr(sbi
, cluster
);
1097 bhs
[0] = sb_getblk(sb
, blknr
);
1103 fat_time_unix2fat(sbi
, ts
, &time
, &date
, &time_cs
);
1105 de
= (struct msdos_dir_entry
*)bhs
[0]->b_data
;
1106 /* filling the new directory slots ("." and ".." entries) */
1107 memcpy(de
[0].name
, MSDOS_DOT
, MSDOS_NAME
);
1108 memcpy(de
[1].name
, MSDOS_DOTDOT
, MSDOS_NAME
);
1109 de
->attr
= de
[1].attr
= ATTR_DIR
;
1110 de
[0].lcase
= de
[1].lcase
= 0;
1111 de
[0].time
= de
[1].time
= time
;
1112 de
[0].date
= de
[1].date
= date
;
1113 if (sbi
->options
.isvfat
) {
1114 /* extra timestamps */
1115 de
[0].ctime
= de
[1].ctime
= time
;
1116 de
[0].ctime_cs
= de
[1].ctime_cs
= time_cs
;
1117 de
[0].adate
= de
[0].cdate
= de
[1].adate
= de
[1].cdate
= date
;
1119 de
[0].ctime
= de
[1].ctime
= 0;
1120 de
[0].ctime_cs
= de
[1].ctime_cs
= 0;
1121 de
[0].adate
= de
[0].cdate
= de
[1].adate
= de
[1].cdate
= 0;
1123 de
[0].start
= cpu_to_le16(cluster
);
1124 de
[0].starthi
= cpu_to_le16(cluster
>> 16);
1125 de
[1].start
= cpu_to_le16(MSDOS_I(dir
)->i_logstart
);
1126 de
[1].starthi
= cpu_to_le16(MSDOS_I(dir
)->i_logstart
>> 16);
1127 de
[0].size
= de
[1].size
= 0;
1128 memset(de
+ 2, 0, sb
->s_blocksize
- 2 * sizeof(*de
));
1129 set_buffer_uptodate(bhs
[0]);
1130 mark_buffer_dirty_inode(bhs
[0], dir
);
1132 err
= fat_zeroed_cluster(dir
, blknr
, 1, bhs
, MAX_BUF_PER_PAGE
);
1139 fat_free_clusters(dir
, cluster
);
1144 EXPORT_SYMBOL_GPL(fat_alloc_new_dir
);
1146 static int fat_add_new_entries(struct inode
*dir
, void *slots
, int nr_slots
,
1147 int *nr_cluster
, struct msdos_dir_entry
**de
,
1148 struct buffer_head
**bh
, loff_t
*i_pos
)
1150 struct super_block
*sb
= dir
->i_sb
;
1151 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
1152 struct buffer_head
*bhs
[MAX_BUF_PER_PAGE
];
1153 sector_t blknr
, start_blknr
, last_blknr
;
1154 unsigned long size
, copy
;
1155 int err
, i
, n
, offset
, cluster
[2];
1158 * The minimum cluster size is 512bytes, and maximum entry
1159 * size is 32*slots (672bytes). So, iff the cluster size is
1160 * 512bytes, we may need two clusters.
1162 size
= nr_slots
* sizeof(struct msdos_dir_entry
);
1163 *nr_cluster
= (size
+ (sbi
->cluster_size
- 1)) >> sbi
->cluster_bits
;
1164 BUG_ON(*nr_cluster
> 2);
1166 err
= fat_alloc_clusters(dir
, cluster
, *nr_cluster
);
1171 * First stage: Fill the directory entry. NOTE: This cluster
1172 * is not referenced from any inode yet, so updates order is
1177 start_blknr
= blknr
= fat_clus_to_blknr(sbi
, cluster
[i
]);
1178 last_blknr
= start_blknr
+ sbi
->sec_per_clus
;
1179 while (blknr
< last_blknr
) {
1180 bhs
[n
] = sb_getblk(sb
, blknr
);
1186 /* fill the directory entry */
1187 copy
= min(size
, sb
->s_blocksize
);
1188 memcpy(bhs
[n
]->b_data
, slots
, copy
);
1191 set_buffer_uptodate(bhs
[n
]);
1192 mark_buffer_dirty_inode(bhs
[n
], dir
);
1198 } while (++i
< *nr_cluster
);
1200 memset(bhs
[n
]->b_data
+ copy
, 0, sb
->s_blocksize
- copy
);
1201 offset
= copy
- sizeof(struct msdos_dir_entry
);
1204 *de
= (struct msdos_dir_entry
*)((*bh
)->b_data
+ offset
);
1205 *i_pos
= fat_make_i_pos(sb
, *bh
, *de
);
1207 /* Second stage: clear the rest of cluster, and write outs */
1208 err
= fat_zeroed_cluster(dir
, start_blknr
, ++n
, bhs
, MAX_BUF_PER_PAGE
);
1219 for (i
= 0; i
< n
; i
++)
1221 fat_free_clusters(dir
, cluster
[0]);
1226 int fat_add_entries(struct inode
*dir
, void *slots
, int nr_slots
,
1227 struct fat_slot_info
*sinfo
)
1229 struct super_block
*sb
= dir
->i_sb
;
1230 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
1231 struct buffer_head
*bh
, *prev
, *bhs
[3]; /* 32*slots (672bytes) */
1232 struct msdos_dir_entry
*de
;
1233 int err
, free_slots
, i
, nr_bhs
;
1236 sinfo
->nr_slots
= nr_slots
;
1238 /* First stage: search free direcotry entries */
1239 free_slots
= nr_bhs
= 0;
1243 while (fat_get_entry(dir
, &pos
, &bh
, &de
) > -1) {
1244 /* check the maximum size of directory */
1245 if (pos
>= FAT_MAX_DIR_SIZE
)
1248 if (IS_FREE(de
->name
)) {
1251 bhs
[nr_bhs
] = prev
= bh
;
1255 if (free_slots
== nr_slots
)
1258 for (i
= 0; i
< nr_bhs
; i
++)
1261 free_slots
= nr_bhs
= 0;
1264 if (dir
->i_ino
== MSDOS_ROOT_INO
) {
1265 if (sbi
->fat_bits
!= 32)
1267 } else if (MSDOS_I(dir
)->i_start
== 0) {
1268 printk(KERN_ERR
"FAT: Corrupted directory (i_pos %lld)\n",
1269 MSDOS_I(dir
)->i_pos
);
1276 pos
-= free_slots
* sizeof(*de
);
1277 nr_slots
-= free_slots
;
1280 * Second stage: filling the free entries with new entries.
1281 * NOTE: If this slots has shortname, first, we write
1282 * the long name slots, then write the short name.
1284 int size
= free_slots
* sizeof(*de
);
1285 int offset
= pos
& (sb
->s_blocksize
- 1);
1286 int long_bhs
= nr_bhs
- (nr_slots
== 0);
1288 /* Fill the long name slots. */
1289 for (i
= 0; i
< long_bhs
; i
++) {
1290 int copy
= min_t(int, sb
->s_blocksize
- offset
, size
);
1291 memcpy(bhs
[i
]->b_data
+ offset
, slots
, copy
);
1292 mark_buffer_dirty_inode(bhs
[i
], dir
);
1297 if (long_bhs
&& IS_DIRSYNC(dir
))
1298 err
= fat_sync_bhs(bhs
, long_bhs
);
1299 if (!err
&& i
< nr_bhs
) {
1300 /* Fill the short name slot. */
1301 int copy
= min_t(int, sb
->s_blocksize
- offset
, size
);
1302 memcpy(bhs
[i
]->b_data
+ offset
, slots
, copy
);
1303 mark_buffer_dirty_inode(bhs
[i
], dir
);
1304 if (IS_DIRSYNC(dir
))
1305 err
= sync_dirty_buffer(bhs
[i
]);
1307 for (i
= 0; i
< nr_bhs
; i
++)
1314 int cluster
, nr_cluster
;
1317 * Third stage: allocate the cluster for new entries.
1318 * And initialize the cluster with new entries, then
1319 * add the cluster to dir.
1321 cluster
= fat_add_new_entries(dir
, slots
, nr_slots
, &nr_cluster
,
1327 err
= fat_chain_add(dir
, cluster
, nr_cluster
);
1329 fat_free_clusters(dir
, cluster
);
1332 if (dir
->i_size
& (sbi
->cluster_size
- 1)) {
1333 fat_fs_error(sb
, "Odd directory size");
1334 dir
->i_size
= (dir
->i_size
+ sbi
->cluster_size
- 1)
1335 & ~((loff_t
)sbi
->cluster_size
- 1);
1337 dir
->i_size
+= nr_cluster
<< sbi
->cluster_bits
;
1338 MSDOS_I(dir
)->mmu_private
+= nr_cluster
<< sbi
->cluster_bits
;
1340 sinfo
->slot_off
= pos
;
1343 sinfo
->i_pos
= fat_make_i_pos(sb
, sinfo
->bh
, sinfo
->de
);
1349 for (i
= 0; i
< nr_bhs
; i
++)
1356 __fat_remove_entries(dir
, pos
, free_slots
);
1360 EXPORT_SYMBOL_GPL(fat_add_entries
);