1 // SPDX-License-Identifier: GPL-2.0+
5 * R/W (V)FAT 12/16/32 filesystem implementation by Donggeun Kim
12 #include <asm/byteorder.h>
14 #include <linux/ctype.h>
16 #include <linux/math64.h>
19 static void uppercase(char *str
, int len
)
23 for (i
= 0; i
< len
; i
++) {
29 static int total_sector
;
30 static int disk_write(__u32 block
, __u32 nr_blocks
, void *buf
)
37 if (cur_part_info
.start
+ block
+ nr_blocks
>
38 cur_part_info
.start
+ total_sector
) {
39 printf("error: overflow occurs\n");
43 ret
= blk_dwrite(cur_dev
, cur_part_info
.start
+ block
, nr_blocks
, buf
);
44 if (nr_blocks
&& ret
== 0)
51 * Set short name in directory entry
53 static void set_name(dir_entry
*dirent
, const char *filename
)
55 char s_name
[VFAT_MAXLEN_BYTES
];
57 int period_location
, len
, i
, ext_num
;
62 len
= strlen(filename
);
66 strcpy(s_name
, filename
);
67 uppercase(s_name
, len
);
69 period
= strchr(s_name
, '.');
71 period_location
= len
;
74 period_location
= period
- s_name
;
75 ext_num
= len
- period_location
- 1;
78 /* Pad spaces when the length of file name is shorter than eight */
79 if (period_location
< 8) {
80 memcpy(dirent
->name
, s_name
, period_location
);
81 for (i
= period_location
; i
< 8; i
++)
82 dirent
->name
[i
] = ' ';
83 } else if (period_location
== 8) {
84 memcpy(dirent
->name
, s_name
, period_location
);
86 memcpy(dirent
->name
, s_name
, 6);
87 dirent
->name
[6] = '~';
88 dirent
->name
[7] = '1';
92 memcpy(dirent
->ext
, s_name
+ period_location
+ 1, ext_num
);
93 for (i
= ext_num
; i
< 3; i
++)
96 memcpy(dirent
->ext
, s_name
+ period_location
+ 1, 3);
98 debug("name : %s\n", dirent
->name
);
99 debug("ext : %s\n", dirent
->ext
);
103 * Write fat buffer into block device
105 static int flush_dirty_fat_buffer(fsdata
*mydata
)
107 int getsize
= FATBUFBLOCKS
;
108 __u32 fatlength
= mydata
->fatlength
;
109 __u8
*bufptr
= mydata
->fatbuf
;
110 __u32 startblock
= mydata
->fatbufnum
* FATBUFBLOCKS
;
112 debug("debug: evicting %d, dirty: %d\n", mydata
->fatbufnum
,
113 (int)mydata
->fat_dirty
);
115 if ((!mydata
->fat_dirty
) || (mydata
->fatbufnum
== -1))
118 /* Cap length if fatlength is not a multiple of FATBUFBLOCKS */
119 if (startblock
+ getsize
> fatlength
)
120 getsize
= fatlength
- startblock
;
122 startblock
+= mydata
->fat_sect
;
125 if (disk_write(startblock
, getsize
, bufptr
) < 0) {
126 debug("error: writing FAT blocks\n");
130 if (mydata
->fats
== 2) {
131 /* Update corresponding second FAT blocks */
132 startblock
+= mydata
->fatlength
;
133 if (disk_write(startblock
, getsize
, bufptr
) < 0) {
134 debug("error: writing second FAT blocks\n");
138 mydata
->fat_dirty
= 0;
144 * Set the file name information from 'name' into 'slotptr',
146 static int str2slot(dir_slot
*slotptr
, const char *name
, int *idx
)
150 for (j
= 0; j
<= 8; j
+= 2) {
151 if (name
[*idx
] == 0x00) {
152 slotptr
->name0_4
[j
] = 0;
153 slotptr
->name0_4
[j
+ 1] = 0;
157 slotptr
->name0_4
[j
] = name
[*idx
];
161 for (j
= 0; j
<= 10; j
+= 2) {
162 if (name
[*idx
] == 0x00) {
163 slotptr
->name5_10
[j
] = 0;
164 slotptr
->name5_10
[j
+ 1] = 0;
168 slotptr
->name5_10
[j
] = name
[*idx
];
172 for (j
= 0; j
<= 2; j
+= 2) {
173 if (name
[*idx
] == 0x00) {
174 slotptr
->name11_12
[j
] = 0;
175 slotptr
->name11_12
[j
+ 1] = 0;
179 slotptr
->name11_12
[j
] = name
[*idx
];
184 if (name
[*idx
] == 0x00)
188 /* Not used characters are filled with 0xff 0xff */
190 for (; end_idx
< 5; end_idx
++) {
191 slotptr
->name0_4
[end_idx
* 2] = 0xff;
192 slotptr
->name0_4
[end_idx
* 2 + 1] = 0xff;
197 for (; end_idx
< 6; end_idx
++) {
198 slotptr
->name5_10
[end_idx
* 2] = 0xff;
199 slotptr
->name5_10
[end_idx
* 2 + 1] = 0xff;
204 for (; end_idx
< 2; end_idx
++) {
205 slotptr
->name11_12
[end_idx
* 2] = 0xff;
206 slotptr
->name11_12
[end_idx
* 2 + 1] = 0xff;
212 static int flush_dir_table(fat_itr
*itr
);
215 * Fill dir_slot entries with appropriate name, id, and attr
216 * 'itr' will point to a next entry
219 fill_dir_slot(fat_itr
*itr
, const char *l_name
)
221 __u8 temp_dir_slot_buffer
[MAX_LFN_SLOT
* sizeof(dir_slot
)];
222 dir_slot
*slotptr
= (dir_slot
*)temp_dir_slot_buffer
;
223 __u8 counter
= 0, checksum
;
226 /* Get short file name checksum value */
227 checksum
= mkcksum(itr
->dent
->name
, itr
->dent
->ext
);
230 memset(slotptr
, 0x00, sizeof(dir_slot
));
231 ret
= str2slot(slotptr
, l_name
, &idx
);
232 slotptr
->id
= ++counter
;
233 slotptr
->attr
= ATTR_VFAT
;
234 slotptr
->alias_checksum
= checksum
;
239 slotptr
->id
|= LAST_LONG_ENTRY_MASK
;
241 while (counter
>= 1) {
242 memcpy(itr
->dent
, slotptr
, sizeof(dir_slot
));
245 if (!fat_itr_next(itr
))
246 if (!itr
->dent
&& !itr
->is_root
&& flush_dir_table(itr
))
250 if (!itr
->dent
&& !itr
->is_root
)
252 * don't care return value here because we have already
253 * finished completing an entry with name, only ending up
256 flush_dir_table(itr
);
262 * Set the entry at index 'entry' in a FAT (12/16/32) table.
264 static int set_fatent_value(fsdata
*mydata
, __u32 entry
, __u32 entry_value
)
266 __u32 bufnum
, offset
, off16
;
269 switch (mydata
->fatsize
) {
271 bufnum
= entry
/ FAT32BUFSIZE
;
272 offset
= entry
- bufnum
* FAT32BUFSIZE
;
275 bufnum
= entry
/ FAT16BUFSIZE
;
276 offset
= entry
- bufnum
* FAT16BUFSIZE
;
279 bufnum
= entry
/ FAT12BUFSIZE
;
280 offset
= entry
- bufnum
* FAT12BUFSIZE
;
283 /* Unsupported FAT size */
287 /* Read a new block of FAT entries into the cache. */
288 if (bufnum
!= mydata
->fatbufnum
) {
289 int getsize
= FATBUFBLOCKS
;
290 __u8
*bufptr
= mydata
->fatbuf
;
291 __u32 fatlength
= mydata
->fatlength
;
292 __u32 startblock
= bufnum
* FATBUFBLOCKS
;
294 /* Cap length if fatlength is not a multiple of FATBUFBLOCKS */
295 if (startblock
+ getsize
> fatlength
)
296 getsize
= fatlength
- startblock
;
298 if (flush_dirty_fat_buffer(mydata
) < 0)
301 startblock
+= mydata
->fat_sect
;
303 if (disk_read(startblock
, getsize
, bufptr
) < 0) {
304 debug("Error reading FAT blocks\n");
307 mydata
->fatbufnum
= bufnum
;
311 mydata
->fat_dirty
= 1;
313 /* Set the actual entry */
314 switch (mydata
->fatsize
) {
316 ((__u32
*) mydata
->fatbuf
)[offset
] = cpu_to_le32(entry_value
);
319 ((__u16
*) mydata
->fatbuf
)[offset
] = cpu_to_le16(entry_value
);
322 off16
= (offset
* 3) / 4;
324 switch (offset
& 0x3) {
326 val1
= cpu_to_le16(entry_value
) & 0xfff;
327 ((__u16
*)mydata
->fatbuf
)[off16
] &= ~0xfff;
328 ((__u16
*)mydata
->fatbuf
)[off16
] |= val1
;
331 val1
= cpu_to_le16(entry_value
) & 0xf;
332 val2
= (cpu_to_le16(entry_value
) >> 4) & 0xff;
334 ((__u16
*)mydata
->fatbuf
)[off16
] &= ~0xf000;
335 ((__u16
*)mydata
->fatbuf
)[off16
] |= (val1
<< 12);
337 ((__u16
*)mydata
->fatbuf
)[off16
+ 1] &= ~0xff;
338 ((__u16
*)mydata
->fatbuf
)[off16
+ 1] |= val2
;
341 val1
= cpu_to_le16(entry_value
) & 0xff;
342 val2
= (cpu_to_le16(entry_value
) >> 8) & 0xf;
344 ((__u16
*)mydata
->fatbuf
)[off16
] &= ~0xff00;
345 ((__u16
*)mydata
->fatbuf
)[off16
] |= (val1
<< 8);
347 ((__u16
*)mydata
->fatbuf
)[off16
+ 1] &= ~0xf;
348 ((__u16
*)mydata
->fatbuf
)[off16
+ 1] |= val2
;
351 val1
= cpu_to_le16(entry_value
) & 0xfff;
352 ((__u16
*)mydata
->fatbuf
)[off16
] &= ~0xfff0;
353 ((__u16
*)mydata
->fatbuf
)[off16
] |= (val1
<< 4);
368 * Determine the next free cluster after 'entry' in a FAT (12/16/32) table
369 * and link it to 'entry'. EOC marker is not set on returned entry.
371 static __u32
determine_fatent(fsdata
*mydata
, __u32 entry
)
373 __u32 next_fat
, next_entry
= entry
+ 1;
376 next_fat
= get_fatent(mydata
, next_entry
);
378 /* found free entry, link to entry */
379 set_fatent_value(mydata
, entry
, next_entry
);
384 debug("FAT%d: entry: %08x, entry_value: %04x\n",
385 mydata
->fatsize
, entry
, next_entry
);
391 * Write at most 'size' bytes from 'buffer' into the specified cluster.
392 * Return 0 on success, -1 otherwise.
395 set_cluster(fsdata
*mydata
, __u32 clustnum
, __u8
*buffer
,
403 startsect
= clust_to_sect(mydata
, clustnum
);
405 startsect
= mydata
->rootdir_sect
;
407 debug("clustnum: %d, startsect: %d\n", clustnum
, startsect
);
409 if ((unsigned long)buffer
& (ARCH_DMA_MINALIGN
- 1)) {
410 ALLOC_CACHE_ALIGN_BUFFER(__u8
, tmpbuf
, mydata
->sect_size
);
412 printf("FAT: Misaligned buffer address (%p)\n", buffer
);
414 while (size
>= mydata
->sect_size
) {
415 memcpy(tmpbuf
, buffer
, mydata
->sect_size
);
416 ret
= disk_write(startsect
++, 1, tmpbuf
);
418 debug("Error writing data (got %d)\n", ret
);
422 buffer
+= mydata
->sect_size
;
423 size
-= mydata
->sect_size
;
425 } else if (size
>= mydata
->sect_size
) {
426 idx
= size
/ mydata
->sect_size
;
427 ret
= disk_write(startsect
, idx
, buffer
);
429 debug("Error writing data (got %d)\n", ret
);
434 idx
*= mydata
->sect_size
;
440 ALLOC_CACHE_ALIGN_BUFFER(__u8
, tmpbuf
, mydata
->sect_size
);
442 memcpy(tmpbuf
, buffer
, size
);
443 ret
= disk_write(startsect
, 1, tmpbuf
);
445 debug("Error writing data (got %d)\n", ret
);
453 static __u8 tmpbuf_cluster
[MAX_CLUSTSIZE
] __aligned(ARCH_DMA_MINALIGN
);
456 * Read and modify data on existing and consecutive cluster blocks
459 get_set_cluster(fsdata
*mydata
, __u32 clustnum
, loff_t pos
, __u8
*buffer
,
460 loff_t size
, loff_t
*gotsize
)
462 unsigned int bytesperclust
= mydata
->clust_size
* mydata
->sect_size
;
465 int clustcount
, i
, ret
;
471 assert(pos
< bytesperclust
);
472 startsect
= clust_to_sect(mydata
, clustnum
);
474 debug("clustnum: %d, startsect: %d, pos: %lld\n",
475 clustnum
, startsect
, pos
);
477 /* partial write at beginning */
479 wsize
= min(bytesperclust
- pos
, size
);
480 ret
= disk_read(startsect
, mydata
->clust_size
, tmpbuf_cluster
);
481 if (ret
!= mydata
->clust_size
) {
482 debug("Error reading data (got %d)\n", ret
);
486 memcpy(tmpbuf_cluster
+ pos
, buffer
, wsize
);
487 ret
= disk_write(startsect
, mydata
->clust_size
, tmpbuf_cluster
);
488 if (ret
!= mydata
->clust_size
) {
489 debug("Error writing data (got %d)\n", ret
);
497 startsect
+= mydata
->clust_size
;
503 /* full-cluster write */
504 if (size
>= bytesperclust
) {
505 clustcount
= lldiv(size
, bytesperclust
);
507 if (!((unsigned long)buffer
& (ARCH_DMA_MINALIGN
- 1))) {
508 wsize
= clustcount
* bytesperclust
;
509 ret
= disk_write(startsect
,
510 clustcount
* mydata
->clust_size
,
512 if (ret
!= clustcount
* mydata
->clust_size
) {
513 debug("Error writing data (got %d)\n", ret
);
521 startsect
+= clustcount
* mydata
->clust_size
;
523 for (i
= 0; i
< clustcount
; i
++) {
524 memcpy(tmpbuf_cluster
, buffer
, bytesperclust
);
525 ret
= disk_write(startsect
,
528 if (ret
!= mydata
->clust_size
) {
529 debug("Error writing data (got %d)\n",
534 size
-= bytesperclust
;
535 buffer
+= bytesperclust
;
536 *gotsize
+= bytesperclust
;
538 startsect
+= mydata
->clust_size
;
543 /* partial write at end */
546 ret
= disk_read(startsect
, mydata
->clust_size
, tmpbuf_cluster
);
547 if (ret
!= mydata
->clust_size
) {
548 debug("Error reading data (got %d)\n", ret
);
551 memcpy(tmpbuf_cluster
, buffer
, wsize
);
552 ret
= disk_write(startsect
, mydata
->clust_size
, tmpbuf_cluster
);
553 if (ret
!= mydata
->clust_size
) {
554 debug("Error writing data (got %d)\n", ret
);
569 * Find the first empty cluster
571 static int find_empty_cluster(fsdata
*mydata
)
573 __u32 fat_val
, entry
= 3;
576 fat_val
= get_fatent(mydata
, entry
);
586 * Write directory entries in itr's buffer to block device
588 static int flush_dir_table(fat_itr
*itr
)
590 fsdata
*mydata
= itr
->fsdata
;
591 int dir_newclust
= 0;
592 unsigned int bytesperclust
= mydata
->clust_size
* mydata
->sect_size
;
594 if (set_cluster(mydata
, itr
->clust
, itr
->block
, bytesperclust
) != 0) {
595 printf("error: writing directory entry\n");
598 dir_newclust
= find_empty_cluster(mydata
);
599 set_fatent_value(mydata
, itr
->clust
, dir_newclust
);
600 if (mydata
->fatsize
== 32)
601 set_fatent_value(mydata
, dir_newclust
, 0xffffff8);
602 else if (mydata
->fatsize
== 16)
603 set_fatent_value(mydata
, dir_newclust
, 0xfff8);
604 else if (mydata
->fatsize
== 12)
605 set_fatent_value(mydata
, dir_newclust
, 0xff8);
607 itr
->clust
= dir_newclust
;
608 itr
->next_clust
= dir_newclust
;
610 if (flush_dirty_fat_buffer(mydata
) < 0)
613 memset(itr
->block
, 0x00, bytesperclust
);
615 itr
->dent
= (dir_entry
*)itr
->block
;
616 itr
->last_cluster
= 1;
617 itr
->remaining
= bytesperclust
/ sizeof(dir_entry
) - 1;
623 * Set empty cluster from 'entry' to the end of a file
625 static int clear_fatent(fsdata
*mydata
, __u32 entry
)
629 while (!CHECK_CLUST(entry
, mydata
->fatsize
)) {
630 fat_val
= get_fatent(mydata
, entry
);
632 set_fatent_value(mydata
, entry
, 0);
639 /* Flush fat buffer */
640 if (flush_dirty_fat_buffer(mydata
) < 0)
647 * Set start cluster in directory entry
649 static void set_start_cluster(const fsdata
*mydata
, dir_entry
*dentptr
,
652 if (mydata
->fatsize
== 32)
654 cpu_to_le16((start_cluster
& 0xffff0000) >> 16);
655 dentptr
->start
= cpu_to_le16(start_cluster
& 0xffff);
659 * Check whether adding a file makes the file system to
660 * exceed the size of the block device
661 * Return -1 when overflow occurs, otherwise return 0
663 static int check_overflow(fsdata
*mydata
, __u32 clustnum
, loff_t size
)
665 __u32 startsect
, sect_num
, offset
;
668 startsect
= clust_to_sect(mydata
, clustnum
);
670 startsect
= mydata
->rootdir_sect
;
672 sect_num
= div_u64_rem(size
, mydata
->sect_size
, &offset
);
677 if (startsect
+ sect_num
> total_sector
)
683 * Write at most 'maxsize' bytes from 'buffer' into
684 * the file associated with 'dentptr'
685 * Update the number of bytes written in *gotsize and return 0
686 * or return -1 on fatal errors.
689 set_contents(fsdata
*mydata
, dir_entry
*dentptr
, loff_t pos
, __u8
*buffer
,
690 loff_t maxsize
, loff_t
*gotsize
)
693 unsigned int bytesperclust
= mydata
->clust_size
* mydata
->sect_size
;
694 __u32 curclust
= START(dentptr
);
695 __u32 endclust
= 0, newclust
= 0;
696 loff_t cur_pos
, offset
, actsize
, wsize
;
699 filesize
= pos
+ maxsize
;
701 debug("%llu bytes\n", filesize
);
706 if (!CHECK_CLUST(curclust
, mydata
->fatsize
) ||
707 IS_LAST_CLUST(curclust
, mydata
->fatsize
)) {
708 clear_fatent(mydata
, curclust
);
709 set_start_cluster(mydata
, dentptr
, 0);
712 debug("curclust: 0x%x\n", curclust
);
713 debug("Invalid FAT entry\n");
722 /* go to cluster at pos */
723 cur_pos
= bytesperclust
;
727 if (IS_LAST_CLUST(curclust
, mydata
->fatsize
))
730 newclust
= get_fatent(mydata
, curclust
);
731 if (!IS_LAST_CLUST(newclust
, mydata
->fatsize
) &&
732 CHECK_CLUST(newclust
, mydata
->fatsize
)) {
733 debug("curclust: 0x%x\n", curclust
);
734 debug("Invalid FAT entry\n");
738 cur_pos
+= bytesperclust
;
741 if (IS_LAST_CLUST(curclust
, mydata
->fatsize
)) {
742 assert(pos
== cur_pos
);
746 assert(pos
< cur_pos
);
747 cur_pos
-= bytesperclust
;
750 assert(IS_LAST_CLUST(curclust
, mydata
->fatsize
) ||
751 !CHECK_CLUST(curclust
, mydata
->fatsize
));
754 /* search for allocated consecutive clusters */
755 actsize
= bytesperclust
;
758 if (filesize
<= (cur_pos
+ actsize
))
761 newclust
= get_fatent(mydata
, endclust
);
763 if (IS_LAST_CLUST(newclust
, mydata
->fatsize
))
765 if (CHECK_CLUST(newclust
, mydata
->fatsize
)) {
766 debug("curclust: 0x%x\n", curclust
);
767 debug("Invalid FAT entry\n");
771 actsize
+= bytesperclust
;
775 /* overwrite to <curclust..endclust> */
779 offset
= pos
- cur_pos
;
780 wsize
= min(cur_pos
+ actsize
, filesize
) - pos
;
781 if (get_set_cluster(mydata
, curclust
, offset
,
782 buffer
, wsize
, &actsize
)) {
783 printf("Error get-and-setting cluster\n");
788 cur_pos
+= offset
+ wsize
;
790 if (filesize
<= cur_pos
)
793 /* CHECK: newclust = get_fatent(mydata, endclust); */
795 if (IS_LAST_CLUST(newclust
, mydata
->fatsize
))
796 /* no more clusters */
802 if (filesize
<= cur_pos
) {
804 newclust
= get_fatent(mydata
, endclust
);
805 if (!IS_LAST_CLUST(newclust
, mydata
->fatsize
)) {
806 /* truncate the rest */
807 clear_fatent(mydata
, newclust
);
809 /* Mark end of file in FAT */
810 if (mydata
->fatsize
== 12)
812 else if (mydata
->fatsize
== 16)
814 else if (mydata
->fatsize
== 32)
815 newclust
= 0xfffffff;
816 set_fatent_value(mydata
, endclust
, newclust
);
824 assert(!(cur_pos
% bytesperclust
));
827 /* allocate and write */
830 /* Assure that curclust is valid */
832 curclust
= find_empty_cluster(mydata
);
833 set_start_cluster(mydata
, dentptr
, curclust
);
835 newclust
= get_fatent(mydata
, curclust
);
837 if (IS_LAST_CLUST(newclust
, mydata
->fatsize
)) {
838 newclust
= determine_fatent(mydata
, curclust
);
839 set_fatent_value(mydata
, curclust
, newclust
);
842 debug("error: something wrong\n");
847 /* TODO: already partially written */
848 if (check_overflow(mydata
, curclust
, filesize
)) {
849 printf("Error: no space left: %llu\n", filesize
);
853 actsize
= bytesperclust
;
856 /* search for consecutive clusters */
857 while (actsize
< filesize
) {
858 newclust
= determine_fatent(mydata
, endclust
);
860 if ((newclust
- 1) != endclust
)
861 /* write to <curclust..endclust> */
864 if (CHECK_CLUST(newclust
, mydata
->fatsize
)) {
865 debug("newclust: 0x%x\n", newclust
);
866 debug("Invalid FAT entry\n");
870 actsize
+= bytesperclust
;
873 /* set remaining bytes */
875 if (set_cluster(mydata
, curclust
, buffer
, (int)actsize
) != 0) {
876 debug("error: writing cluster\n");
881 /* Mark end of file in FAT */
882 if (mydata
->fatsize
== 12)
884 else if (mydata
->fatsize
== 16)
886 else if (mydata
->fatsize
== 32)
887 newclust
= 0xfffffff;
888 set_fatent_value(mydata
, endclust
, newclust
);
892 if (set_cluster(mydata
, curclust
, buffer
, (int)actsize
) != 0) {
893 debug("error: writing cluster\n");
900 if (CHECK_CLUST(newclust
, mydata
->fatsize
)) {
901 debug("newclust: 0x%x\n", newclust
);
902 debug("Invalid FAT entry\n");
905 actsize
= bytesperclust
;
906 curclust
= endclust
= newclust
;
915 static void fill_dentry(fsdata
*mydata
, dir_entry
*dentptr
,
916 const char *filename
, __u32 start_cluster
, __u32 size
, __u8 attr
)
918 set_start_cluster(mydata
, dentptr
, start_cluster
);
919 dentptr
->size
= cpu_to_le32(size
);
921 dentptr
->attr
= attr
;
923 set_name(dentptr
, filename
);
927 * Find a directory entry based on filename or start cluster number
928 * If the directory entry is not found,
929 * the new position for writing a directory entry will be returned
931 static dir_entry
*find_directory_entry(fat_itr
*itr
, char *filename
)
935 while (fat_itr_next(itr
)) {
936 /* check both long and short name: */
937 if (!strcasecmp(filename
, itr
->name
))
939 else if (itr
->name
!= itr
->s_name
&&
940 !strcasecmp(filename
, itr
->s_name
))
946 if (itr
->dent
->name
[0] == '\0')
952 if (!itr
->dent
&& !itr
->is_root
&& flush_dir_table(itr
))
953 /* indicate that allocating dent failed */
959 static int split_filename(char *filename
, char **dirname
, char **basename
)
961 char *p
, *last_slash
, *last_slash_cont
;
966 last_slash_cont
= NULL
;
968 if (ISDIRDELIM(*p
)) {
971 /* continuous slashes */
972 while (ISDIRDELIM(*p
))
973 last_slash_cont
= p
++;
981 if (last_slash_cont
== (filename
+ strlen(filename
) - 1)) {
982 /* remove trailing slashes */
987 if (last_slash
== filename
) {
988 /* avoid ""(null) directory */
995 *last_slash_cont
= '\0';
996 *basename
= last_slash_cont
+ 1;
998 *dirname
= "/"; /* root by default */
999 *basename
= filename
;
1005 static int normalize_longname(char *l_filename
, const char *filename
)
1007 const char *p
, legal
[] = "!#$%&\'()-.@^`_{}~";
1011 /* Check that the filename is valid */
1012 for (p
= filename
; p
< filename
+ strlen(filename
); p
++) {
1015 if (('0' <= c
) && (c
<= '9'))
1017 if (('A' <= c
) && (c
<= 'Z'))
1019 if (('a' <= c
) && (c
<= 'z'))
1021 if (strchr(legal
, c
))
1024 if ((0x80 <= c
) && (c
<= 0xff))
1031 name_len
= strlen(filename
);
1032 if (name_len
>= VFAT_MAXLEN_BYTES
)
1033 /* should return an error? */
1034 name_len
= VFAT_MAXLEN_BYTES
- 1;
1036 memcpy(l_filename
, filename
, name_len
);
1037 l_filename
[name_len
] = 0; /* terminate the string */
1038 downcase(l_filename
, INT_MAX
);
1043 int file_fat_write_at(const char *filename
, loff_t pos
, void *buffer
,
1044 loff_t size
, loff_t
*actwrite
)
1047 fsdata datablock
= { .fatbuf
= NULL
, };
1048 fsdata
*mydata
= &datablock
;
1049 fat_itr
*itr
= NULL
;
1051 char *filename_copy
, *parent
, *basename
;
1052 char l_filename
[VFAT_MAXLEN_BYTES
];
1054 debug("writing %s\n", filename
);
1056 filename_copy
= strdup(filename
);
1060 split_filename(filename_copy
, &parent
, &basename
);
1061 if (!strlen(basename
)) {
1066 filename
= basename
;
1067 if (normalize_longname(l_filename
, filename
)) {
1068 printf("FAT: illegal filename (%s)\n", filename
);
1073 itr
= malloc_cache_aligned(sizeof(fat_itr
));
1079 ret
= fat_itr_root(itr
, &datablock
);
1083 total_sector
= datablock
.total_sect
;
1085 ret
= fat_itr_resolve(itr
, parent
, TYPE_DIR
);
1087 printf("%s: doesn't exist (%d)\n", parent
, ret
);
1091 retdent
= find_directory_entry(itr
, l_filename
);
1094 if (fat_itr_isdir(itr
)) {
1101 /* Append to the end */
1102 pos
= FAT2CPU32(retdent
->size
);
1103 if (pos
> retdent
->size
) {
1104 /* No hole allowed */
1109 /* Update file size in a directory entry */
1110 retdent
->size
= cpu_to_le32(pos
+ size
);
1112 /* Create a new file */
1115 /* root dir cannot have "." or ".." */
1116 if (!strcmp(l_filename
, ".") ||
1117 !strcmp(l_filename
, "..")) {
1124 printf("Error: allocating new dir entry\n");
1130 /* No hole allowed */
1135 memset(itr
->dent
, 0, sizeof(*itr
->dent
));
1137 /* Set short name to set alias checksum field in dir_slot */
1138 set_name(itr
->dent
, filename
);
1139 if (fill_dir_slot(itr
, filename
)) {
1144 /* Set attribute as archive for regular file */
1145 fill_dentry(itr
->fsdata
, itr
->dent
, filename
, 0, size
, 0x20);
1147 retdent
= itr
->dent
;
1150 ret
= set_contents(mydata
, retdent
, pos
, buffer
, size
, actwrite
);
1152 printf("Error: writing contents\n");
1156 debug("attempt to write 0x%llx bytes\n", *actwrite
);
1158 /* Flush fat buffer */
1159 ret
= flush_dirty_fat_buffer(mydata
);
1161 printf("Error: flush fat buffer\n");
1166 /* Write directory table to device */
1167 ret
= set_cluster(mydata
, itr
->clust
, itr
->block
,
1168 mydata
->clust_size
* mydata
->sect_size
);
1170 printf("Error: writing directory entry\n");
1175 free(filename_copy
);
1176 free(mydata
->fatbuf
);
1181 int file_fat_write(const char *filename
, void *buffer
, loff_t offset
,
1182 loff_t maxsize
, loff_t
*actwrite
)
1184 return file_fat_write_at(filename
, offset
, buffer
, maxsize
, actwrite
);
1187 static int fat_dir_entries(fat_itr
*itr
)
1190 fsdata fsdata
= { .fatbuf
= NULL
, }, *mydata
= &fsdata
;
1191 /* for FATBUFSIZE */
1194 dirs
= malloc_cache_aligned(sizeof(fat_itr
));
1196 debug("Error: allocating memory\n");
1201 /* duplicate fsdata */
1202 fat_itr_child(dirs
, itr
);
1203 fsdata
= *dirs
->fsdata
;
1205 /* allocate local fat buffer */
1206 fsdata
.fatbuf
= malloc_cache_aligned(FATBUFSIZE
);
1207 if (!fsdata
.fatbuf
) {
1208 debug("Error: allocating memory\n");
1212 fsdata
.fatbufnum
= -1;
1213 dirs
->fsdata
= &fsdata
;
1215 for (count
= 0; fat_itr_next(dirs
); count
++)
1219 free(fsdata
.fatbuf
);
1224 static int delete_dentry(fat_itr
*itr
)
1226 fsdata
*mydata
= itr
->fsdata
;
1227 dir_entry
*dentptr
= itr
->dent
;
1229 /* free cluster blocks */
1230 clear_fatent(mydata
, START(dentptr
));
1231 if (flush_dirty_fat_buffer(mydata
) < 0) {
1232 printf("Error: flush fat buffer\n");
1237 * update a directory entry
1239 * - long file name support
1240 * - find and mark the "new" first invalid entry as name[0]=0x00
1242 memset(dentptr
, 0, sizeof(*dentptr
));
1243 dentptr
->name
[0] = 0xe5;
1245 if (set_cluster(mydata
, itr
->clust
, itr
->block
,
1246 mydata
->clust_size
* mydata
->sect_size
) != 0) {
1247 printf("error: writing directory entry\n");
1254 int fat_unlink(const char *filename
)
1256 fsdata fsdata
= { .fatbuf
= NULL
, };
1257 fat_itr
*itr
= NULL
;
1259 char *filename_copy
, *dirname
, *basename
;
1261 filename_copy
= strdup(filename
);
1262 split_filename(filename_copy
, &dirname
, &basename
);
1264 if (!strcmp(dirname
, "/") && !strcmp(basename
, "")) {
1265 printf("Error: cannot remove root\n");
1270 itr
= malloc_cache_aligned(sizeof(fat_itr
));
1272 printf("Error: allocating memory\n");
1276 ret
= fat_itr_root(itr
, &fsdata
);
1280 total_sector
= fsdata
.total_sect
;
1282 ret
= fat_itr_resolve(itr
, dirname
, TYPE_DIR
);
1284 printf("%s: doesn't exist (%d)\n", dirname
, ret
);
1289 if (!find_directory_entry(itr
, basename
)) {
1290 printf("%s: doesn't exist\n", basename
);
1295 if (fat_itr_isdir(itr
)) {
1296 n_entries
= fat_dir_entries(itr
);
1297 if (n_entries
< 0) {
1301 if (n_entries
> 2) {
1302 printf("Error: directory is not empty: %d\n",
1309 ret
= delete_dentry(itr
);
1312 free(fsdata
.fatbuf
);
1314 free(filename_copy
);
1319 int fat_mkdir(const char *new_dirname
)
1322 fsdata datablock
= { .fatbuf
= NULL
, };
1323 fsdata
*mydata
= &datablock
;
1324 fat_itr
*itr
= NULL
;
1325 char *dirname_copy
, *parent
, *dirname
;
1326 char l_dirname
[VFAT_MAXLEN_BYTES
];
1329 unsigned int bytesperclust
;
1330 dir_entry
*dotdent
= NULL
;
1332 dirname_copy
= strdup(new_dirname
);
1336 split_filename(dirname_copy
, &parent
, &dirname
);
1337 if (!strlen(dirname
)) {
1342 if (normalize_longname(l_dirname
, dirname
)) {
1343 printf("FAT: illegal filename (%s)\n", dirname
);
1348 itr
= malloc_cache_aligned(sizeof(fat_itr
));
1354 ret
= fat_itr_root(itr
, &datablock
);
1358 total_sector
= datablock
.total_sect
;
1360 ret
= fat_itr_resolve(itr
, parent
, TYPE_DIR
);
1362 printf("%s: doesn't exist (%d)\n", parent
, ret
);
1366 retdent
= find_directory_entry(itr
, l_dirname
);
1369 printf("%s: already exists\n", l_dirname
);
1374 /* root dir cannot have "." or ".." */
1375 if (!strcmp(l_dirname
, ".") ||
1376 !strcmp(l_dirname
, "..")) {
1383 printf("Error: allocating new dir entry\n");
1388 memset(itr
->dent
, 0, sizeof(*itr
->dent
));
1390 /* Set short name to set alias checksum field in dir_slot */
1391 set_name(itr
->dent
, dirname
);
1392 fill_dir_slot(itr
, dirname
);
1394 /* Set attribute as archive for regular file */
1395 fill_dentry(itr
->fsdata
, itr
->dent
, dirname
, 0, 0,
1396 ATTR_DIR
| ATTR_ARCH
);
1398 retdent
= itr
->dent
;
1401 /* Default entries */
1402 bytesperclust
= mydata
->clust_size
* mydata
->sect_size
;
1403 dotdent
= malloc_cache_aligned(bytesperclust
);
1408 memset(dotdent
, 0, bytesperclust
);
1410 memcpy(dotdent
[0].name
, ". ", 8);
1411 memcpy(dotdent
[0].ext
, " ", 3);
1412 dotdent
[0].attr
= ATTR_DIR
| ATTR_ARCH
;
1414 memcpy(dotdent
[1].name
, ".. ", 8);
1415 memcpy(dotdent
[1].ext
, " ", 3);
1416 dotdent
[1].attr
= ATTR_DIR
| ATTR_ARCH
;
1417 set_start_cluster(mydata
, &dotdent
[1], itr
->start_clust
);
1419 ret
= set_contents(mydata
, retdent
, 0, (__u8
*)dotdent
,
1420 bytesperclust
, &actwrite
);
1422 printf("Error: writing contents\n");
1425 /* Write twice for "." */
1426 set_start_cluster(mydata
, &dotdent
[0], START(retdent
));
1427 ret
= set_contents(mydata
, retdent
, 0, (__u8
*)dotdent
,
1428 bytesperclust
, &actwrite
);
1430 printf("Error: writing contents\n");
1434 /* Flush fat buffer */
1435 ret
= flush_dirty_fat_buffer(mydata
);
1437 printf("Error: flush fat buffer\n");
1441 /* Write directory table to device */
1442 ret
= set_cluster(mydata
, itr
->clust
, itr
->block
,
1443 mydata
->clust_size
* mydata
->sect_size
);
1445 printf("Error: writing directory entry\n");
1449 free(mydata
->fatbuf
);