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/msdos_fs.h>
20 #include <linux/smp_lock.h>
21 #include <linux/buffer_head.h>
22 #include <linux/compat.h>
23 #include <asm/uaccess.h>
25 static inline loff_t
fat_make_i_pos(struct super_block
*sb
,
26 struct buffer_head
*bh
,
27 struct msdos_dir_entry
*de
)
29 return ((loff_t
)bh
->b_blocknr
<< MSDOS_SB(sb
)->dir_per_block_bits
)
30 | (de
- (struct msdos_dir_entry
*)bh
->b_data
);
33 static inline void fat_dir_readahead(struct inode
*dir
, sector_t iblock
,
36 struct super_block
*sb
= dir
->i_sb
;
37 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
38 struct buffer_head
*bh
;
41 /* This is not a first sector of cluster, or sec_per_clus == 1 */
42 if ((iblock
& (sbi
->sec_per_clus
- 1)) || sbi
->sec_per_clus
== 1)
44 /* root dir of FAT12/FAT16 */
45 if ((sbi
->fat_bits
!= 32) && (dir
->i_ino
== MSDOS_ROOT_INO
))
48 bh
= sb_find_get_block(sb
, phys
);
49 if (bh
== NULL
|| !buffer_uptodate(bh
)) {
50 for (sec
= 0; sec
< sbi
->sec_per_clus
; sec
++)
51 sb_breadahead(sb
, phys
+ sec
);
56 /* Returns the inode number of the directory entry at offset pos. If bh is
57 non-NULL, it is brelse'd before. Pos is incremented. The buffer header is
59 AV. Most often we do it item-by-item. Makes sense to optimize.
60 AV. OK, there we go: if both bh and de are non-NULL we assume that we just
61 AV. want the next entry (took one explicit de=NULL in vfat/namei.c).
62 AV. It's done in fat_get_entry() (inlined), here the slow case lives.
63 AV. Additionally, when we return -1 (i.e. reached the end of directory)
66 static int fat__get_entry(struct inode
*dir
, loff_t
*pos
,
67 struct buffer_head
**bh
, struct msdos_dir_entry
**de
)
69 struct super_block
*sb
= dir
->i_sb
;
70 sector_t phys
, iblock
;
71 unsigned long mapped_blocks
;
79 iblock
= *pos
>> sb
->s_blocksize_bits
;
80 err
= fat_bmap(dir
, iblock
, &phys
, &mapped_blocks
);
82 return -1; /* beyond EOF or error */
84 fat_dir_readahead(dir
, iblock
, phys
);
86 *bh
= sb_bread(sb
, phys
);
88 printk(KERN_ERR
"FAT: Directory bread(block %llu) failed\n",
89 (unsigned long long)phys
);
91 *pos
= (iblock
+ 1) << sb
->s_blocksize_bits
;
95 offset
= *pos
& (sb
->s_blocksize
- 1);
96 *pos
+= sizeof(struct msdos_dir_entry
);
97 *de
= (struct msdos_dir_entry
*)((*bh
)->b_data
+ offset
);
102 static inline int fat_get_entry(struct inode
*dir
, loff_t
*pos
,
103 struct buffer_head
**bh
,
104 struct msdos_dir_entry
**de
)
106 /* Fast stuff first */
108 (*de
- (struct msdos_dir_entry
*)(*bh
)->b_data
) < MSDOS_SB(dir
->i_sb
)->dir_per_block
- 1) {
109 *pos
+= sizeof(struct msdos_dir_entry
);
113 return fat__get_entry(dir
, pos
, bh
, de
);
117 * Convert Unicode 16 to UTF-8, translated Unicode, or ASCII.
118 * If uni_xlate is enabled and we can't get a 1:1 conversion, use a
119 * colon as an escape character since it is normally invalid on the vfat
120 * filesystem. The following four characters are the hexadecimal digits
121 * of Unicode value. This lets us do a full dump and restore of Unicode
122 * filenames. We could get into some trouble with long Unicode names,
123 * but ignore that right now.
124 * Ahem... Stack smashing in ring 0 isn't fun. Fixed.
126 static int uni16_to_x8(unsigned char *ascii
, const wchar_t *uni
, int len
,
127 int uni_xlate
, struct nls_table
*nls
)
131 unsigned char *op
, nc
;
138 while (*ip
&& ((len
- NLS_MAX_CHARSET_SIZE
) > 0)) {
140 if ( (charlen
= nls
->uni2char(ec
, op
, NLS_MAX_CHARSET_SIZE
)) > 0) {
144 if (uni_xlate
== 1) {
146 for (k
= 4; k
> 0; k
--) {
148 op
[k
] = nc
> 9 ? nc
+ ('a' - 10)
162 printk(KERN_WARNING
"FAT: filename was truncated while "
170 static inline int fat_uni_to_x8(struct msdos_sb_info
*sbi
, const wchar_t *uni
,
171 unsigned char *buf
, int size
)
173 if (sbi
->options
.utf8
)
174 return utf8_wcstombs(buf
, uni
, size
);
176 return uni16_to_x8(buf
, uni
, size
, sbi
->options
.unicode_xlate
,
181 fat_short2uni(struct nls_table
*t
, unsigned char *c
, int clen
, wchar_t *uni
)
185 charlen
= t
->char2uni(c
, clen
, uni
);
187 *uni
= 0x003f; /* a question mark */
194 fat_short2lower_uni(struct nls_table
*t
, unsigned char *c
, int clen
, wchar_t *uni
)
199 charlen
= t
->char2uni(c
, clen
, &wc
);
201 *uni
= 0x003f; /* a question mark */
203 } else if (charlen
<= 1) {
204 unsigned char nc
= t
->charset2lower
[*c
];
209 if ( (charlen
= t
->char2uni(&nc
, 1, uni
)) < 0) {
210 *uni
= 0x003f; /* a question mark */
220 fat_shortname2uni(struct nls_table
*nls
, unsigned char *buf
, int buf_size
,
221 wchar_t *uni_buf
, unsigned short opt
, int lower
)
225 if (opt
& VFAT_SFN_DISPLAY_LOWER
)
226 len
= fat_short2lower_uni(nls
, buf
, buf_size
, uni_buf
);
227 else if (opt
& VFAT_SFN_DISPLAY_WIN95
)
228 len
= fat_short2uni(nls
, buf
, buf_size
, uni_buf
);
229 else if (opt
& VFAT_SFN_DISPLAY_WINNT
) {
231 len
= fat_short2lower_uni(nls
, buf
, buf_size
, uni_buf
);
233 len
= fat_short2uni(nls
, buf
, buf_size
, uni_buf
);
235 len
= fat_short2uni(nls
, buf
, buf_size
, uni_buf
);
240 static inline int fat_name_match(struct msdos_sb_info
*sbi
,
241 const unsigned char *a
, int a_len
,
242 const unsigned char *b
, int b_len
)
247 if (sbi
->options
.name_check
!= 's')
248 return !nls_strnicmp(sbi
->nls_io
, a
, b
, a_len
);
250 return !memcmp(a
, b
, a_len
);
253 enum { PARSE_INVALID
= 1, PARSE_NOT_LONGNAME
, PARSE_EOF
, };
256 * fat_parse_long - Parse extended directory entry.
258 * This function returns zero on success, negative value on error, or one of
261 * %PARSE_INVALID - Directory entry is invalid.
262 * %PARSE_NOT_LONGNAME - Directory entry does not contain longname.
263 * %PARSE_EOF - Directory has no more entries.
265 static int fat_parse_long(struct inode
*dir
, loff_t
*pos
,
266 struct buffer_head
**bh
, struct msdos_dir_entry
**de
,
267 wchar_t **unicode
, unsigned char *nr_slots
)
269 struct msdos_dir_slot
*ds
;
270 unsigned char id
, slot
, slots
, alias_checksum
;
273 *unicode
= __getname();
281 ds
= (struct msdos_dir_slot
*)*de
;
284 return PARSE_INVALID
;
286 if (slots
> 20 || !slots
) /* ceil(256 * 2 / 26) */
287 return PARSE_INVALID
;
289 alias_checksum
= ds
->alias_checksum
;
297 fat16_towchar(*unicode
+ offset
, ds
->name0_4
, 5);
298 fat16_towchar(*unicode
+ offset
+ 5, ds
->name5_10
, 6);
299 fat16_towchar(*unicode
+ offset
+ 11, ds
->name11_12
, 2);
302 (*unicode
)[offset
+ 13] = 0;
303 if (fat_get_entry(dir
, pos
, bh
, de
) < 0)
307 ds
= (struct msdos_dir_slot
*)*de
;
308 if (ds
->attr
!= ATTR_EXT
)
309 return PARSE_NOT_LONGNAME
;
310 if ((ds
->id
& ~0x40) != slot
)
312 if (ds
->alias_checksum
!= alias_checksum
)
315 if ((*de
)->name
[0] == DELETED_FLAG
)
316 return PARSE_INVALID
;
317 if ((*de
)->attr
== ATTR_EXT
)
319 if (IS_FREE((*de
)->name
) || ((*de
)->attr
& ATTR_VOLUME
))
320 return PARSE_INVALID
;
321 if (fat_checksum((*de
)->name
) != alias_checksum
)
328 * Maximum buffer size of short name.
329 * [(MSDOS_NAME + '.') * max one char + nul]
330 * For msdos style, ['.' (hidden) + MSDOS_NAME + '.' + nul]
332 #define FAT_MAX_SHORT_SIZE ((MSDOS_NAME + 1) * NLS_MAX_CHARSET_SIZE + 1)
334 * Maximum buffer size of unicode chars from slots.
335 * [(max longname slots * 13 (size in a slot) + nul) * sizeof(wchar_t)]
337 #define FAT_MAX_UNI_CHARS ((MSDOS_SLOTS - 1) * 13 + 1)
338 #define FAT_MAX_UNI_SIZE (FAT_MAX_UNI_CHARS * sizeof(wchar_t))
341 * Return values: negative -> error, 0 -> not found, positive -> found,
342 * value is the total amount of slots, including the shortname entry.
344 int fat_search_long(struct inode
*inode
, const unsigned char *name
,
345 int name_len
, struct fat_slot_info
*sinfo
)
347 struct super_block
*sb
= inode
->i_sb
;
348 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
349 struct buffer_head
*bh
= NULL
;
350 struct msdos_dir_entry
*de
;
351 struct nls_table
*nls_disk
= sbi
->nls_disk
;
352 unsigned char nr_slots
;
353 wchar_t bufuname
[14];
354 wchar_t *unicode
= NULL
;
355 unsigned char work
[MSDOS_NAME
];
356 unsigned char bufname
[FAT_MAX_SHORT_SIZE
];
357 unsigned short opt_shortname
= sbi
->options
.shortname
;
359 int chl
, i
, j
, last_u
, err
, len
;
363 if (fat_get_entry(inode
, &cpos
, &bh
, &de
) == -1)
367 if (de
->name
[0] == DELETED_FLAG
)
369 if (de
->attr
!= ATTR_EXT
&& (de
->attr
& ATTR_VOLUME
))
371 if (de
->attr
!= ATTR_EXT
&& IS_FREE(de
->name
))
373 if (de
->attr
== ATTR_EXT
) {
374 int status
= fat_parse_long(inode
, &cpos
, &bh
, &de
,
375 &unicode
, &nr_slots
);
378 else if (status
== PARSE_INVALID
)
380 else if (status
== PARSE_NOT_LONGNAME
)
382 else if (status
== PARSE_EOF
)
386 memcpy(work
, de
->name
, sizeof(de
->name
));
387 /* see namei.c, msdos_format_name */
390 for (i
= 0, j
= 0, last_u
= 0; i
< 8;) {
393 chl
= fat_shortname2uni(nls_disk
, &work
[i
], 8 - i
,
394 &bufuname
[j
++], opt_shortname
,
395 de
->lcase
& CASE_LOWER_BASE
);
405 fat_short2uni(nls_disk
, ".", 1, &bufuname
[j
++]);
406 for (i
= 8; i
< MSDOS_NAME
;) {
409 chl
= fat_shortname2uni(nls_disk
, &work
[i
],
411 &bufuname
[j
++], opt_shortname
,
412 de
->lcase
& CASE_LOWER_EXT
);
424 /* Compare shortname */
425 bufuname
[last_u
] = 0x0000;
426 len
= fat_uni_to_x8(sbi
, bufuname
, bufname
, sizeof(bufname
));
427 if (fat_name_match(sbi
, name
, name_len
, bufname
, len
))
431 void *longname
= unicode
+ FAT_MAX_UNI_CHARS
;
432 int size
= PATH_MAX
- FAT_MAX_UNI_SIZE
;
434 /* Compare longname */
435 len
= fat_uni_to_x8(sbi
, unicode
, longname
, size
);
436 if (fat_name_match(sbi
, name
, name_len
, longname
, len
))
442 nr_slots
++; /* include the de */
443 sinfo
->slot_off
= cpos
- nr_slots
* sizeof(*de
);
444 sinfo
->nr_slots
= nr_slots
;
447 sinfo
->i_pos
= fat_make_i_pos(sb
, sinfo
->bh
, sinfo
->de
);
456 EXPORT_SYMBOL_GPL(fat_search_long
);
458 struct fat_ioctl_filldir_callback
{
462 const char *longname
;
464 const char *shortname
;
468 static int __fat_readdir(struct inode
*inode
, struct file
*filp
, void *dirent
,
469 filldir_t filldir
, int short_only
, int both
)
471 struct super_block
*sb
= inode
->i_sb
;
472 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
473 struct buffer_head
*bh
;
474 struct msdos_dir_entry
*de
;
475 struct nls_table
*nls_disk
= sbi
->nls_disk
;
476 unsigned char nr_slots
;
477 wchar_t bufuname
[14];
478 wchar_t *unicode
= NULL
;
479 unsigned char c
, work
[MSDOS_NAME
];
480 unsigned char bufname
[FAT_MAX_SHORT_SIZE
], *ptname
= bufname
;
481 unsigned short opt_shortname
= sbi
->options
.shortname
;
482 int isvfat
= sbi
->options
.isvfat
;
483 int nocase
= sbi
->options
.nocase
;
484 const char *fill_name
= NULL
;
486 unsigned long lpos
, dummy
, *furrfu
= &lpos
;
488 int chi
, chl
, i
, i2
, j
, last
, last_u
, dotoffset
= 0, fill_len
= 0;
494 /* Fake . and .. for the root directory. */
495 if (inode
->i_ino
== MSDOS_ROOT_INO
) {
497 if (filldir(dirent
, "..", cpos
+1, cpos
, MSDOS_ROOT_INO
, DT_DIR
) < 0)
508 if (cpos
& (sizeof(struct msdos_dir_entry
) - 1)) {
515 if (fat_get_entry(inode
, &cpos
, &bh
, &de
) == -1)
520 * Check for long filename entry, but if short_only, we don't
521 * need to parse long filename.
523 if (isvfat
&& !short_only
) {
524 if (de
->name
[0] == DELETED_FLAG
)
526 if (de
->attr
!= ATTR_EXT
&& (de
->attr
& ATTR_VOLUME
))
528 if (de
->attr
!= ATTR_EXT
&& IS_FREE(de
->name
))
531 if ((de
->attr
& ATTR_VOLUME
) || IS_FREE(de
->name
))
535 if (isvfat
&& de
->attr
== ATTR_EXT
) {
536 int status
= fat_parse_long(inode
, &cpos
, &bh
, &de
,
537 &unicode
, &nr_slots
);
542 } else if (status
== PARSE_INVALID
)
544 else if (status
== PARSE_NOT_LONGNAME
)
546 else if (status
== PARSE_EOF
)
550 void *longname
= unicode
+ FAT_MAX_UNI_CHARS
;
551 int size
= PATH_MAX
- FAT_MAX_UNI_SIZE
;
552 int len
= fat_uni_to_x8(sbi
, unicode
, longname
, size
);
554 fill_name
= longname
;
556 /* !both && !short_only, so we don't need shortname. */
562 if (sbi
->options
.dotsOK
) {
565 if (de
->attr
& ATTR_HIDDEN
) {
571 memcpy(work
, de
->name
, sizeof(de
->name
));
572 /* see namei.c, msdos_format_name */
575 for (i
= 0, j
= 0, last
= 0, last_u
= 0; i
< 8;) {
578 chl
= fat_shortname2uni(nls_disk
, &work
[i
], 8 - i
,
579 &bufuname
[j
++], opt_shortname
,
580 de
->lcase
& CASE_LOWER_BASE
);
582 ptname
[i
++] = (!nocase
&& c
>='A' && c
<='Z') ? c
+32 : c
;
589 for (chi
= 0; chi
< chl
&& i
< 8; chi
++) {
597 fat_short2uni(nls_disk
, ".", 1, &bufuname
[j
++]);
599 for (i2
= 8; i2
< MSDOS_NAME
;) {
602 chl
= fat_shortname2uni(nls_disk
, &work
[i2
], MSDOS_NAME
- i2
,
603 &bufuname
[j
++], opt_shortname
,
604 de
->lcase
& CASE_LOWER_EXT
);
607 ptname
[i
++] = (!nocase
&& c
>='A' && c
<='Z') ? c
+32 : c
;
614 for (chi
= 0; chi
< chl
&& i2
< MSDOS_NAME
; chi
++) {
615 ptname
[i
++] = work
[i2
++];
623 i
= last
+ dotoffset
;
627 bufuname
[j
] = 0x0000;
628 i
= fat_uni_to_x8(sbi
, bufuname
, bufname
, sizeof(bufname
));
631 /* hack for fat_ioctl_filldir() */
632 struct fat_ioctl_filldir_callback
*p
= dirent
;
634 p
->longname
= fill_name
;
635 p
->long_len
= fill_len
;
636 p
->shortname
= bufname
;
646 lpos
= cpos
- (nr_slots
+ 1) * sizeof(struct msdos_dir_entry
);
647 if (!memcmp(de
->name
, MSDOS_DOT
, MSDOS_NAME
))
649 else if (!memcmp(de
->name
, MSDOS_DOTDOT
, MSDOS_NAME
)) {
650 inum
= parent_ino(filp
->f_path
.dentry
);
652 loff_t i_pos
= fat_make_i_pos(sb
, bh
, de
);
653 struct inode
*tmp
= fat_iget(sb
, i_pos
);
658 inum
= iunique(sb
, MSDOS_ROOT_INO
);
661 if (filldir(dirent
, fill_name
, fill_len
, *furrfu
, inum
,
662 (de
->attr
& ATTR_DIR
) ? DT_DIR
: DT_REG
) < 0)
680 static int fat_readdir(struct file
*filp
, void *dirent
, filldir_t filldir
)
682 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
683 return __fat_readdir(inode
, filp
, dirent
, filldir
, 0, 0);
686 #define FAT_IOCTL_FILLDIR_FUNC(func, dirent_type) \
687 static int func(void *__buf, const char *name, int name_len, \
688 loff_t offset, u64 ino, unsigned int d_type) \
690 struct fat_ioctl_filldir_callback *buf = __buf; \
691 struct dirent_type __user *d1 = buf->dirent; \
692 struct dirent_type __user *d2 = d1 + 1; \
698 if (name != NULL) { \
699 /* dirent has only short name */ \
700 if (name_len >= sizeof(d1->d_name)) \
701 name_len = sizeof(d1->d_name) - 1; \
703 if (put_user(0, d2->d_name) || \
704 put_user(0, &d2->d_reclen) || \
705 copy_to_user(d1->d_name, name, name_len) || \
706 put_user(0, d1->d_name + name_len) || \
707 put_user(name_len, &d1->d_reclen)) \
710 /* dirent has short and long name */ \
711 const char *longname = buf->longname; \
712 int long_len = buf->long_len; \
713 const char *shortname = buf->shortname; \
714 int short_len = buf->short_len; \
716 if (long_len >= sizeof(d1->d_name)) \
717 long_len = sizeof(d1->d_name) - 1; \
718 if (short_len >= sizeof(d1->d_name)) \
719 short_len = sizeof(d1->d_name) - 1; \
721 if (copy_to_user(d2->d_name, longname, long_len) || \
722 put_user(0, d2->d_name + long_len) || \
723 put_user(long_len, &d2->d_reclen) || \
724 put_user(ino, &d2->d_ino) || \
725 put_user(offset, &d2->d_off) || \
726 copy_to_user(d1->d_name, shortname, short_len) || \
727 put_user(0, d1->d_name + short_len) || \
728 put_user(short_len, &d1->d_reclen)) \
733 buf->result = -EFAULT; \
737 FAT_IOCTL_FILLDIR_FUNC(fat_ioctl_filldir
, __fat_dirent
)
739 static int fat_ioctl_readdir(struct inode
*inode
, struct file
*filp
,
740 void __user
*dirent
, filldir_t filldir
,
741 int short_only
, int both
)
743 struct fat_ioctl_filldir_callback buf
;
748 mutex_lock(&inode
->i_mutex
);
750 if (!IS_DEADDIR(inode
)) {
751 ret
= __fat_readdir(inode
, filp
, &buf
, filldir
,
754 mutex_unlock(&inode
->i_mutex
);
760 static int fat_dir_ioctl(struct inode
*inode
, struct file
*filp
,
761 unsigned int cmd
, unsigned long arg
)
763 struct __fat_dirent __user
*d1
= (struct __fat_dirent __user
*)arg
;
764 int short_only
, both
;
767 case VFAT_IOCTL_READDIR_SHORT
:
771 case VFAT_IOCTL_READDIR_BOTH
:
776 return fat_generic_ioctl(inode
, filp
, cmd
, arg
);
779 if (!access_ok(VERIFY_WRITE
, d1
, sizeof(struct __fat_dirent
[2])))
782 * Yes, we don't need this put_user() absolutely. However old
783 * code didn't return the right value. So, app use this value,
784 * in order to check whether it is EOF.
786 if (put_user(0, &d1
->d_reclen
))
789 return fat_ioctl_readdir(inode
, filp
, d1
, fat_ioctl_filldir
,
794 #define VFAT_IOCTL_READDIR_BOTH32 _IOR('r', 1, struct compat_dirent[2])
795 #define VFAT_IOCTL_READDIR_SHORT32 _IOR('r', 2, struct compat_dirent[2])
797 FAT_IOCTL_FILLDIR_FUNC(fat_compat_ioctl_filldir
, compat_dirent
)
799 static long fat_compat_dir_ioctl(struct file
*filp
, unsigned cmd
,
802 struct inode
*inode
= filp
->f_path
.dentry
->d_inode
;
803 struct compat_dirent __user
*d1
= compat_ptr(arg
);
804 int short_only
, both
;
807 case VFAT_IOCTL_READDIR_SHORT32
:
811 case VFAT_IOCTL_READDIR_BOTH32
:
819 if (!access_ok(VERIFY_WRITE
, d1
, sizeof(struct compat_dirent
[2])))
822 * Yes, we don't need this put_user() absolutely. However old
823 * code didn't return the right value. So, app use this value,
824 * in order to check whether it is EOF.
826 if (put_user(0, &d1
->d_reclen
))
829 return fat_ioctl_readdir(inode
, filp
, d1
, fat_compat_ioctl_filldir
,
832 #endif /* CONFIG_COMPAT */
834 const struct file_operations fat_dir_operations
= {
835 .read
= generic_read_dir
,
836 .readdir
= fat_readdir
,
837 .ioctl
= fat_dir_ioctl
,
839 .compat_ioctl
= fat_compat_dir_ioctl
,
844 static int fat_get_short_entry(struct inode
*dir
, loff_t
*pos
,
845 struct buffer_head
**bh
,
846 struct msdos_dir_entry
**de
)
848 while (fat_get_entry(dir
, pos
, bh
, de
) >= 0) {
849 /* free entry or long name entry or volume label */
850 if (!IS_FREE((*de
)->name
) && !((*de
)->attr
& ATTR_VOLUME
))
857 * The ".." entry can not provide the "struct fat_slot_info" informations
858 * for inode. So, this function provide the some informations only.
860 int fat_get_dotdot_entry(struct inode
*dir
, struct buffer_head
**bh
,
861 struct msdos_dir_entry
**de
, loff_t
*i_pos
)
867 while (fat_get_short_entry(dir
, &offset
, bh
, de
) >= 0) {
868 if (!strncmp((*de
)->name
, MSDOS_DOTDOT
, MSDOS_NAME
)) {
869 *i_pos
= fat_make_i_pos(dir
->i_sb
, *bh
, *de
);
876 EXPORT_SYMBOL_GPL(fat_get_dotdot_entry
);
878 /* See if directory is empty */
879 int fat_dir_empty(struct inode
*dir
)
881 struct buffer_head
*bh
;
882 struct msdos_dir_entry
*de
;
888 while (fat_get_short_entry(dir
, &cpos
, &bh
, &de
) >= 0) {
889 if (strncmp(de
->name
, MSDOS_DOT
, MSDOS_NAME
) &&
890 strncmp(de
->name
, MSDOS_DOTDOT
, MSDOS_NAME
)) {
899 EXPORT_SYMBOL_GPL(fat_dir_empty
);
902 * fat_subdirs counts the number of sub-directories of dir. It can be run
903 * on directories being created.
905 int fat_subdirs(struct inode
*dir
)
907 struct buffer_head
*bh
;
908 struct msdos_dir_entry
*de
;
914 while (fat_get_short_entry(dir
, &cpos
, &bh
, &de
) >= 0) {
915 if (de
->attr
& ATTR_DIR
)
923 * Scans a directory for a given file (name points to its formatted name).
924 * Returns an error code or zero.
926 int fat_scan(struct inode
*dir
, const unsigned char *name
,
927 struct fat_slot_info
*sinfo
)
929 struct super_block
*sb
= dir
->i_sb
;
933 while (fat_get_short_entry(dir
, &sinfo
->slot_off
, &sinfo
->bh
,
935 if (!strncmp(sinfo
->de
->name
, name
, MSDOS_NAME
)) {
936 sinfo
->slot_off
-= sizeof(*sinfo
->de
);
938 sinfo
->i_pos
= fat_make_i_pos(sb
, sinfo
->bh
, sinfo
->de
);
945 EXPORT_SYMBOL_GPL(fat_scan
);
947 static int __fat_remove_entries(struct inode
*dir
, loff_t pos
, int nr_slots
)
949 struct super_block
*sb
= dir
->i_sb
;
950 struct buffer_head
*bh
;
951 struct msdos_dir_entry
*de
, *endp
;
952 int err
= 0, orig_slots
;
956 if (fat_get_entry(dir
, &pos
, &bh
, &de
) < 0) {
961 orig_slots
= nr_slots
;
962 endp
= (struct msdos_dir_entry
*)(bh
->b_data
+ sb
->s_blocksize
);
963 while (nr_slots
&& de
< endp
) {
964 de
->name
[0] = DELETED_FLAG
;
968 mark_buffer_dirty(bh
);
970 err
= sync_dirty_buffer(bh
);
975 /* pos is *next* de's position, so this does `- sizeof(de)' */
976 pos
+= ((orig_slots
- nr_slots
) * sizeof(*de
)) - sizeof(*de
);
982 int fat_remove_entries(struct inode
*dir
, struct fat_slot_info
*sinfo
)
984 struct msdos_dir_entry
*de
;
985 struct buffer_head
*bh
;
986 int err
= 0, nr_slots
;
989 * First stage: Remove the shortname. By this, the directory
992 nr_slots
= sinfo
->nr_slots
;
997 while (nr_slots
&& de
>= (struct msdos_dir_entry
*)bh
->b_data
) {
998 de
->name
[0] = DELETED_FLAG
;
1002 mark_buffer_dirty(bh
);
1003 if (IS_DIRSYNC(dir
))
1004 err
= sync_dirty_buffer(bh
);
1012 * Second stage: remove the remaining longname slots.
1013 * (This directory entry is already removed, and so return
1016 err
= __fat_remove_entries(dir
, sinfo
->slot_off
, nr_slots
);
1019 "FAT: Couldn't remove the long name slots\n");
1023 dir
->i_mtime
= dir
->i_atime
= CURRENT_TIME_SEC
;
1024 if (IS_DIRSYNC(dir
))
1025 (void)fat_sync_inode(dir
);
1027 mark_inode_dirty(dir
);
1032 EXPORT_SYMBOL_GPL(fat_remove_entries
);
1034 static int fat_zeroed_cluster(struct inode
*dir
, sector_t blknr
, int nr_used
,
1035 struct buffer_head
**bhs
, int nr_bhs
)
1037 struct super_block
*sb
= dir
->i_sb
;
1038 sector_t last_blknr
= blknr
+ MSDOS_SB(sb
)->sec_per_clus
;
1041 /* Zeroing the unused blocks on this cluster */
1044 while (blknr
< last_blknr
) {
1045 bhs
[n
] = sb_getblk(sb
, blknr
);
1050 memset(bhs
[n
]->b_data
, 0, sb
->s_blocksize
);
1051 set_buffer_uptodate(bhs
[n
]);
1052 mark_buffer_dirty(bhs
[n
]);
1057 if (IS_DIRSYNC(dir
)) {
1058 err
= fat_sync_bhs(bhs
, n
);
1062 for (i
= 0; i
< n
; i
++)
1067 if (IS_DIRSYNC(dir
)) {
1068 err
= fat_sync_bhs(bhs
, n
);
1072 for (i
= 0; i
< n
; i
++)
1078 for (i
= 0; i
< n
; i
++)
1083 int fat_alloc_new_dir(struct inode
*dir
, struct timespec
*ts
)
1085 struct super_block
*sb
= dir
->i_sb
;
1086 struct msdos_sb_info
*sbi
= MSDOS_SB(sb
);
1087 struct buffer_head
*bhs
[MAX_BUF_PER_PAGE
];
1088 struct msdos_dir_entry
*de
;
1093 err
= fat_alloc_clusters(dir
, &cluster
, 1);
1097 blknr
= fat_clus_to_blknr(sbi
, cluster
);
1098 bhs
[0] = sb_getblk(sb
, blknr
);
1104 fat_date_unix2dos(ts
->tv_sec
, &time
, &date
, sbi
->options
.tz_utc
);
1106 de
= (struct msdos_dir_entry
*)bhs
[0]->b_data
;
1107 /* filling the new directory slots ("." and ".." entries) */
1108 memcpy(de
[0].name
, MSDOS_DOT
, MSDOS_NAME
);
1109 memcpy(de
[1].name
, MSDOS_DOTDOT
, MSDOS_NAME
);
1110 de
->attr
= de
[1].attr
= ATTR_DIR
;
1111 de
[0].lcase
= de
[1].lcase
= 0;
1112 de
[0].time
= de
[1].time
= time
;
1113 de
[0].date
= de
[1].date
= date
;
1114 de
[0].ctime_cs
= de
[1].ctime_cs
= 0;
1115 if (sbi
->options
.isvfat
) {
1116 /* extra timestamps */
1117 de
[0].ctime
= de
[1].ctime
= time
;
1118 de
[0].adate
= de
[0].cdate
= de
[1].adate
= de
[1].cdate
= date
;
1120 de
[0].ctime
= de
[1].ctime
= 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(bhs
[0]);
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(bhs
[n
]);
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(bhs
[i
]);
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(bhs
[i
]);
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_panic(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
);