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 new_dir_table(fat_itr
*itr
);
213 static int flush_dir(fat_itr
*itr
);
216 * Fill dir_slot entries with appropriate name, id, and attr
217 * 'itr' will point to a next entry
220 fill_dir_slot(fat_itr
*itr
, const char *l_name
)
222 __u8 temp_dir_slot_buffer
[MAX_LFN_SLOT
* sizeof(dir_slot
)];
223 dir_slot
*slotptr
= (dir_slot
*)temp_dir_slot_buffer
;
224 __u8 counter
= 0, checksum
;
227 /* Get short file name checksum value */
228 checksum
= mkcksum(itr
->dent
->name
, itr
->dent
->ext
);
231 memset(slotptr
, 0x00, sizeof(dir_slot
));
232 ret
= str2slot(slotptr
, l_name
, &idx
);
233 slotptr
->id
= ++counter
;
234 slotptr
->attr
= ATTR_VFAT
;
235 slotptr
->alias_checksum
= checksum
;
240 slotptr
->id
|= LAST_LONG_ENTRY_MASK
;
242 while (counter
>= 1) {
243 memcpy(itr
->dent
, slotptr
, sizeof(dir_slot
));
247 if (itr
->remaining
== 0)
250 /* allocate a cluster for more entries */
251 if (!fat_itr_next(itr
))
253 (!itr
->is_root
|| itr
->fsdata
->fatsize
== 32) &&
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 * set_sectors() - write data to sectors
393 * Write 'size' bytes from 'buffer' into the specified sector.
395 * @mydata: data to be written
396 * @startsect: sector to be written to
397 * @buffer: data to be written
398 * @size: bytes to be written (but not more than the size of a cluster)
399 * Return: 0 on success, -1 otherwise
402 set_sectors(fsdata
*mydata
, u32 startsect
, u8
*buffer
, u32 size
)
407 debug("startsect: %d\n", startsect
);
409 if ((unsigned long)buffer
& (ARCH_DMA_MINALIGN
- 1)) {
410 ALLOC_CACHE_ALIGN_BUFFER(__u8
, tmpbuf
, mydata
->sect_size
);
412 debug("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 nsects
= size
/ mydata
->sect_size
;
427 ret
= disk_write(startsect
, nsects
, buffer
);
429 debug("Error writing data (got %d)\n", ret
);
434 buffer
+= nsects
* mydata
->sect_size
;
435 size
-= nsects
* mydata
->sect_size
;
439 ALLOC_CACHE_ALIGN_BUFFER(__u8
, tmpbuf
, mydata
->sect_size
);
440 /* Do not leak content of stack */
441 memset(tmpbuf
, 0, mydata
->sect_size
);
442 memcpy(tmpbuf
, buffer
, size
);
443 ret
= disk_write(startsect
, 1, tmpbuf
);
445 debug("Error writing data (got %d)\n", ret
);
454 * set_cluster() - write data to cluster
456 * Write 'size' bytes from 'buffer' into the specified cluster.
458 * @mydata: data to be written
459 * @clustnum: cluster to be written to
460 * @buffer: data to be written
461 * @size: bytes to be written (but not more than the size of a cluster)
462 * Return: 0 on success, -1 otherwise
465 set_cluster(fsdata
*mydata
, u32 clustnum
, u8
*buffer
, u32 size
)
467 return set_sectors(mydata
, clust_to_sect(mydata
, clustnum
),
472 flush_dir(fat_itr
*itr
)
474 fsdata
*mydata
= itr
->fsdata
;
475 u32 startsect
, sect_offset
, nsects
;
477 if (!itr
->is_root
|| mydata
->fatsize
== 32)
478 return set_cluster(mydata
, itr
->clust
, itr
->block
,
479 mydata
->clust_size
* mydata
->sect_size
);
481 sect_offset
= itr
->clust
* mydata
->clust_size
;
482 startsect
= mydata
->rootdir_sect
+ sect_offset
;
483 /* do not write past the end of rootdir */
484 nsects
= min_t(u32
, mydata
->clust_size
,
485 mydata
->rootdir_size
- sect_offset
);
487 return set_sectors(mydata
, startsect
, itr
->block
,
488 nsects
* mydata
->sect_size
);
491 static __u8 tmpbuf_cluster
[MAX_CLUSTSIZE
] __aligned(ARCH_DMA_MINALIGN
);
494 * Read and modify data on existing and consecutive cluster blocks
497 get_set_cluster(fsdata
*mydata
, __u32 clustnum
, loff_t pos
, __u8
*buffer
,
498 loff_t size
, loff_t
*gotsize
)
500 unsigned int bytesperclust
= mydata
->clust_size
* mydata
->sect_size
;
503 int clustcount
, i
, ret
;
509 assert(pos
< bytesperclust
);
510 startsect
= clust_to_sect(mydata
, clustnum
);
512 debug("clustnum: %d, startsect: %d, pos: %lld\n",
513 clustnum
, startsect
, pos
);
515 /* partial write at beginning */
517 wsize
= min(bytesperclust
- pos
, size
);
518 ret
= disk_read(startsect
, mydata
->clust_size
, tmpbuf_cluster
);
519 if (ret
!= mydata
->clust_size
) {
520 debug("Error reading data (got %d)\n", ret
);
524 memcpy(tmpbuf_cluster
+ pos
, buffer
, wsize
);
525 ret
= disk_write(startsect
, mydata
->clust_size
, tmpbuf_cluster
);
526 if (ret
!= mydata
->clust_size
) {
527 debug("Error writing data (got %d)\n", ret
);
535 startsect
+= mydata
->clust_size
;
541 /* full-cluster write */
542 if (size
>= bytesperclust
) {
543 clustcount
= lldiv(size
, bytesperclust
);
545 if (!((unsigned long)buffer
& (ARCH_DMA_MINALIGN
- 1))) {
546 wsize
= clustcount
* bytesperclust
;
547 ret
= disk_write(startsect
,
548 clustcount
* mydata
->clust_size
,
550 if (ret
!= clustcount
* mydata
->clust_size
) {
551 debug("Error writing data (got %d)\n", ret
);
559 startsect
+= clustcount
* mydata
->clust_size
;
561 for (i
= 0; i
< clustcount
; i
++) {
562 memcpy(tmpbuf_cluster
, buffer
, bytesperclust
);
563 ret
= disk_write(startsect
,
566 if (ret
!= mydata
->clust_size
) {
567 debug("Error writing data (got %d)\n",
572 size
-= bytesperclust
;
573 buffer
+= bytesperclust
;
574 *gotsize
+= bytesperclust
;
576 startsect
+= mydata
->clust_size
;
581 /* partial write at end */
584 ret
= disk_read(startsect
, mydata
->clust_size
, tmpbuf_cluster
);
585 if (ret
!= mydata
->clust_size
) {
586 debug("Error reading data (got %d)\n", ret
);
589 memcpy(tmpbuf_cluster
, buffer
, wsize
);
590 ret
= disk_write(startsect
, mydata
->clust_size
, tmpbuf_cluster
);
591 if (ret
!= mydata
->clust_size
) {
592 debug("Error writing data (got %d)\n", ret
);
607 * Find the first empty cluster
609 static int find_empty_cluster(fsdata
*mydata
)
611 __u32 fat_val
, entry
= 3;
614 fat_val
= get_fatent(mydata
, entry
);
624 * Allocate a cluster for additional directory entries
626 static int new_dir_table(fat_itr
*itr
)
628 fsdata
*mydata
= itr
->fsdata
;
629 int dir_newclust
= 0;
630 unsigned int bytesperclust
= mydata
->clust_size
* mydata
->sect_size
;
632 dir_newclust
= find_empty_cluster(mydata
);
633 set_fatent_value(mydata
, itr
->clust
, dir_newclust
);
634 if (mydata
->fatsize
== 32)
635 set_fatent_value(mydata
, dir_newclust
, 0xffffff8);
636 else if (mydata
->fatsize
== 16)
637 set_fatent_value(mydata
, dir_newclust
, 0xfff8);
638 else if (mydata
->fatsize
== 12)
639 set_fatent_value(mydata
, dir_newclust
, 0xff8);
641 itr
->clust
= dir_newclust
;
642 itr
->next_clust
= dir_newclust
;
644 if (flush_dirty_fat_buffer(mydata
) < 0)
647 memset(itr
->block
, 0x00, bytesperclust
);
649 itr
->dent
= (dir_entry
*)itr
->block
;
650 itr
->last_cluster
= 1;
651 itr
->remaining
= bytesperclust
/ sizeof(dir_entry
) - 1;
657 * Set empty cluster from 'entry' to the end of a file
659 static int clear_fatent(fsdata
*mydata
, __u32 entry
)
663 while (!CHECK_CLUST(entry
, mydata
->fatsize
)) {
664 fat_val
= get_fatent(mydata
, entry
);
666 set_fatent_value(mydata
, entry
, 0);
673 /* Flush fat buffer */
674 if (flush_dirty_fat_buffer(mydata
) < 0)
681 * Set start cluster in directory entry
683 static void set_start_cluster(const fsdata
*mydata
, dir_entry
*dentptr
,
686 if (mydata
->fatsize
== 32)
688 cpu_to_le16((start_cluster
& 0xffff0000) >> 16);
689 dentptr
->start
= cpu_to_le16(start_cluster
& 0xffff);
693 * Check whether adding a file makes the file system to
694 * exceed the size of the block device
695 * Return -1 when overflow occurs, otherwise return 0
697 static int check_overflow(fsdata
*mydata
, __u32 clustnum
, loff_t size
)
699 __u32 startsect
, sect_num
, offset
;
702 startsect
= clust_to_sect(mydata
, clustnum
);
704 startsect
= mydata
->rootdir_sect
;
706 sect_num
= div_u64_rem(size
, mydata
->sect_size
, &offset
);
711 if (startsect
+ sect_num
> total_sector
)
717 * Write at most 'maxsize' bytes from 'buffer' into
718 * the file associated with 'dentptr'
719 * Update the number of bytes written in *gotsize and return 0
720 * or return -1 on fatal errors.
723 set_contents(fsdata
*mydata
, dir_entry
*dentptr
, loff_t pos
, __u8
*buffer
,
724 loff_t maxsize
, loff_t
*gotsize
)
726 unsigned int bytesperclust
= mydata
->clust_size
* mydata
->sect_size
;
727 __u32 curclust
= START(dentptr
);
728 __u32 endclust
= 0, newclust
= 0;
729 u64 cur_pos
, filesize
;
730 loff_t offset
, actsize
, wsize
;
733 filesize
= pos
+ maxsize
;
735 debug("%llu bytes\n", filesize
);
740 if (!CHECK_CLUST(curclust
, mydata
->fatsize
) ||
741 IS_LAST_CLUST(curclust
, mydata
->fatsize
)) {
742 clear_fatent(mydata
, curclust
);
743 set_start_cluster(mydata
, dentptr
, 0);
746 debug("curclust: 0x%x\n", curclust
);
747 debug("Invalid FAT entry\n");
756 /* go to cluster at pos */
757 cur_pos
= bytesperclust
;
761 if (IS_LAST_CLUST(curclust
, mydata
->fatsize
))
764 newclust
= get_fatent(mydata
, curclust
);
765 if (!IS_LAST_CLUST(newclust
, mydata
->fatsize
) &&
766 CHECK_CLUST(newclust
, mydata
->fatsize
)) {
767 debug("curclust: 0x%x\n", curclust
);
768 debug("Invalid FAT entry\n");
772 cur_pos
+= bytesperclust
;
775 if (IS_LAST_CLUST(curclust
, mydata
->fatsize
)) {
776 assert(pos
== cur_pos
);
780 assert(pos
< cur_pos
);
781 cur_pos
-= bytesperclust
;
784 assert(IS_LAST_CLUST(curclust
, mydata
->fatsize
) ||
785 !CHECK_CLUST(curclust
, mydata
->fatsize
));
788 /* search for allocated consecutive clusters */
789 actsize
= bytesperclust
;
792 if (filesize
<= (cur_pos
+ actsize
))
795 newclust
= get_fatent(mydata
, endclust
);
797 if (IS_LAST_CLUST(newclust
, mydata
->fatsize
))
799 if (CHECK_CLUST(newclust
, mydata
->fatsize
)) {
800 debug("curclust: 0x%x\n", curclust
);
801 debug("Invalid FAT entry\n");
805 actsize
+= bytesperclust
;
809 /* overwrite to <curclust..endclust> */
813 offset
= pos
- cur_pos
;
814 wsize
= min(cur_pos
+ actsize
, filesize
) - pos
;
815 if (get_set_cluster(mydata
, curclust
, offset
,
816 buffer
, wsize
, &actsize
)) {
817 printf("Error get-and-setting cluster\n");
822 cur_pos
+= offset
+ wsize
;
824 if (filesize
<= cur_pos
)
827 /* CHECK: newclust = get_fatent(mydata, endclust); */
829 if (IS_LAST_CLUST(newclust
, mydata
->fatsize
))
830 /* no more clusters */
836 if (filesize
<= cur_pos
) {
838 newclust
= get_fatent(mydata
, endclust
);
839 if (!IS_LAST_CLUST(newclust
, mydata
->fatsize
)) {
840 /* truncate the rest */
841 clear_fatent(mydata
, newclust
);
843 /* Mark end of file in FAT */
844 if (mydata
->fatsize
== 12)
846 else if (mydata
->fatsize
== 16)
848 else if (mydata
->fatsize
== 32)
849 newclust
= 0xfffffff;
850 set_fatent_value(mydata
, endclust
, newclust
);
858 assert(!do_div(cur_pos
, bytesperclust
));
861 /* allocate and write */
864 /* Assure that curclust is valid */
866 curclust
= find_empty_cluster(mydata
);
867 set_start_cluster(mydata
, dentptr
, curclust
);
869 newclust
= get_fatent(mydata
, curclust
);
871 if (IS_LAST_CLUST(newclust
, mydata
->fatsize
)) {
872 newclust
= determine_fatent(mydata
, curclust
);
873 set_fatent_value(mydata
, curclust
, newclust
);
876 debug("error: something wrong\n");
881 /* TODO: already partially written */
882 if (check_overflow(mydata
, curclust
, filesize
)) {
883 printf("Error: no space left: %llu\n", filesize
);
887 actsize
= bytesperclust
;
890 /* search for consecutive clusters */
891 while (actsize
< filesize
) {
892 newclust
= determine_fatent(mydata
, endclust
);
894 if ((newclust
- 1) != endclust
)
895 /* write to <curclust..endclust> */
898 if (CHECK_CLUST(newclust
, mydata
->fatsize
)) {
899 debug("newclust: 0x%x\n", newclust
);
900 debug("Invalid FAT entry\n");
904 actsize
+= bytesperclust
;
907 /* set remaining bytes */
909 if (set_cluster(mydata
, curclust
, buffer
, (u32
)actsize
) != 0) {
910 debug("error: writing cluster\n");
915 /* Mark end of file in FAT */
916 if (mydata
->fatsize
== 12)
918 else if (mydata
->fatsize
== 16)
920 else if (mydata
->fatsize
== 32)
921 newclust
= 0xfffffff;
922 set_fatent_value(mydata
, endclust
, newclust
);
926 if (set_cluster(mydata
, curclust
, buffer
, (u32
)actsize
) != 0) {
927 debug("error: writing cluster\n");
934 if (CHECK_CLUST(newclust
, mydata
->fatsize
)) {
935 debug("newclust: 0x%x\n", newclust
);
936 debug("Invalid FAT entry\n");
939 actsize
= bytesperclust
;
940 curclust
= endclust
= newclust
;
949 static void fill_dentry(fsdata
*mydata
, dir_entry
*dentptr
,
950 const char *filename
, __u32 start_cluster
, __u32 size
, __u8 attr
)
952 set_start_cluster(mydata
, dentptr
, start_cluster
);
953 dentptr
->size
= cpu_to_le32(size
);
955 dentptr
->attr
= attr
;
957 set_name(dentptr
, filename
);
961 * Find a directory entry based on filename or start cluster number
962 * If the directory entry is not found,
963 * the new position for writing a directory entry will be returned
965 static dir_entry
*find_directory_entry(fat_itr
*itr
, char *filename
)
969 while (fat_itr_next(itr
)) {
970 /* check both long and short name: */
971 if (!strcasecmp(filename
, itr
->name
))
973 else if (itr
->name
!= itr
->s_name
&&
974 !strcasecmp(filename
, itr
->s_name
))
980 if (itr
->dent
->name
[0] == '\0')
986 /* allocate a cluster for more entries */
988 (!itr
->is_root
|| itr
->fsdata
->fatsize
== 32) &&
990 /* indicate that allocating dent failed */
996 static int split_filename(char *filename
, char **dirname
, char **basename
)
998 char *p
, *last_slash
, *last_slash_cont
;
1003 last_slash_cont
= NULL
;
1005 if (ISDIRDELIM(*p
)) {
1007 last_slash_cont
= p
;
1008 /* continuous slashes */
1009 while (ISDIRDELIM(*p
))
1010 last_slash_cont
= p
++;
1018 if (last_slash_cont
== (filename
+ strlen(filename
) - 1)) {
1019 /* remove trailing slashes */
1024 if (last_slash
== filename
) {
1025 /* avoid ""(null) directory */
1029 *dirname
= filename
;
1032 *last_slash_cont
= '\0';
1033 *basename
= last_slash_cont
+ 1;
1035 *dirname
= "/"; /* root by default */
1036 *basename
= filename
;
1043 * normalize_longname() - check long file name and convert to lower case
1045 * We assume here that the FAT file system is using an 8bit code page.
1046 * Linux typically uses CP437, EDK2 assumes CP1250.
1048 * @l_filename: preallocated buffer receiving the normalized name
1049 * @filename: filename to normalize
1050 * Return: 0 on success, -1 on failure
1052 static int normalize_longname(char *l_filename
, const char *filename
)
1054 const char *p
, illegal
[] = "<>:\"/\\|?*";
1056 if (strlen(filename
) >= VFAT_MAXLEN_BYTES
)
1059 for (p
= filename
; *p
; ++p
) {
1060 if ((unsigned char)*p
< 0x20)
1062 if (strchr(illegal
, *p
))
1066 strcpy(l_filename
, filename
);
1067 downcase(l_filename
, VFAT_MAXLEN_BYTES
);
1072 int file_fat_write_at(const char *filename
, loff_t pos
, void *buffer
,
1073 loff_t size
, loff_t
*actwrite
)
1076 fsdata datablock
= { .fatbuf
= NULL
, };
1077 fsdata
*mydata
= &datablock
;
1078 fat_itr
*itr
= NULL
;
1080 char *filename_copy
, *parent
, *basename
;
1081 char l_filename
[VFAT_MAXLEN_BYTES
];
1083 debug("writing %s\n", filename
);
1085 filename_copy
= strdup(filename
);
1089 split_filename(filename_copy
, &parent
, &basename
);
1090 if (!strlen(basename
)) {
1095 filename
= basename
;
1096 if (normalize_longname(l_filename
, filename
)) {
1097 printf("FAT: illegal filename (%s)\n", filename
);
1102 itr
= malloc_cache_aligned(sizeof(fat_itr
));
1108 ret
= fat_itr_root(itr
, &datablock
);
1112 total_sector
= datablock
.total_sect
;
1114 ret
= fat_itr_resolve(itr
, parent
, TYPE_DIR
);
1116 printf("%s: doesn't exist (%d)\n", parent
, ret
);
1120 retdent
= find_directory_entry(itr
, l_filename
);
1123 if (fat_itr_isdir(itr
)) {
1130 /* Append to the end */
1131 pos
= FAT2CPU32(retdent
->size
);
1132 if (pos
> retdent
->size
) {
1133 /* No hole allowed */
1138 /* Update file size in a directory entry */
1139 retdent
->size
= cpu_to_le32(pos
+ size
);
1141 /* Create a new file */
1144 /* root dir cannot have "." or ".." */
1145 if (!strcmp(l_filename
, ".") ||
1146 !strcmp(l_filename
, "..")) {
1153 printf("Error: allocating new dir entry\n");
1159 /* No hole allowed */
1164 memset(itr
->dent
, 0, sizeof(*itr
->dent
));
1166 /* Calculate checksum for short name */
1167 set_name(itr
->dent
, filename
);
1169 /* Set long name entries */
1170 if (fill_dir_slot(itr
, filename
)) {
1175 /* Set short name entry */
1176 fill_dentry(itr
->fsdata
, itr
->dent
, filename
, 0, size
, 0x20);
1178 retdent
= itr
->dent
;
1181 ret
= set_contents(mydata
, retdent
, pos
, buffer
, size
, actwrite
);
1183 printf("Error: writing contents\n");
1187 debug("attempt to write 0x%llx bytes\n", *actwrite
);
1189 /* Flush fat buffer */
1190 ret
= flush_dirty_fat_buffer(mydata
);
1192 printf("Error: flush fat buffer\n");
1197 /* Write directory table to device */
1198 ret
= flush_dir(itr
);
1200 printf("Error: writing directory entry\n");
1205 free(filename_copy
);
1206 free(mydata
->fatbuf
);
1211 int file_fat_write(const char *filename
, void *buffer
, loff_t offset
,
1212 loff_t maxsize
, loff_t
*actwrite
)
1214 return file_fat_write_at(filename
, offset
, buffer
, maxsize
, actwrite
);
1217 static int fat_dir_entries(fat_itr
*itr
)
1220 fsdata fsdata
= { .fatbuf
= NULL
, }, *mydata
= &fsdata
;
1221 /* for FATBUFSIZE */
1224 dirs
= malloc_cache_aligned(sizeof(fat_itr
));
1226 debug("Error: allocating memory\n");
1231 /* duplicate fsdata */
1232 fat_itr_child(dirs
, itr
);
1233 fsdata
= *dirs
->fsdata
;
1235 /* allocate local fat buffer */
1236 fsdata
.fatbuf
= malloc_cache_aligned(FATBUFSIZE
);
1237 if (!fsdata
.fatbuf
) {
1238 debug("Error: allocating memory\n");
1242 fsdata
.fatbufnum
= -1;
1243 dirs
->fsdata
= &fsdata
;
1245 for (count
= 0; fat_itr_next(dirs
); count
++)
1249 free(fsdata
.fatbuf
);
1254 static int delete_dentry(fat_itr
*itr
)
1256 fsdata
*mydata
= itr
->fsdata
;
1257 dir_entry
*dentptr
= itr
->dent
;
1259 /* free cluster blocks */
1260 clear_fatent(mydata
, START(dentptr
));
1261 if (flush_dirty_fat_buffer(mydata
) < 0) {
1262 printf("Error: flush fat buffer\n");
1267 * update a directory entry
1269 * - long file name support
1270 * - find and mark the "new" first invalid entry as name[0]=0x00
1272 memset(dentptr
, 0, sizeof(*dentptr
));
1273 dentptr
->name
[0] = 0xe5;
1275 if (flush_dir(itr
)) {
1276 printf("error: writing directory entry\n");
1283 int fat_unlink(const char *filename
)
1285 fsdata fsdata
= { .fatbuf
= NULL
, };
1286 fat_itr
*itr
= NULL
;
1288 char *filename_copy
, *dirname
, *basename
;
1290 filename_copy
= strdup(filename
);
1291 if (!filename_copy
) {
1292 printf("Error: allocating memory\n");
1296 split_filename(filename_copy
, &dirname
, &basename
);
1298 if (!strcmp(dirname
, "/") && !strcmp(basename
, "")) {
1299 printf("Error: cannot remove root\n");
1304 itr
= malloc_cache_aligned(sizeof(fat_itr
));
1306 printf("Error: allocating memory\n");
1311 ret
= fat_itr_root(itr
, &fsdata
);
1315 total_sector
= fsdata
.total_sect
;
1317 ret
= fat_itr_resolve(itr
, dirname
, TYPE_DIR
);
1319 printf("%s: doesn't exist (%d)\n", dirname
, ret
);
1324 if (!find_directory_entry(itr
, basename
)) {
1325 printf("%s: doesn't exist\n", basename
);
1330 if (fat_itr_isdir(itr
)) {
1331 n_entries
= fat_dir_entries(itr
);
1332 if (n_entries
< 0) {
1336 if (n_entries
> 2) {
1337 printf("Error: directory is not empty: %d\n",
1344 ret
= delete_dentry(itr
);
1347 free(fsdata
.fatbuf
);
1349 free(filename_copy
);
1354 int fat_mkdir(const char *new_dirname
)
1357 fsdata datablock
= { .fatbuf
= NULL
, };
1358 fsdata
*mydata
= &datablock
;
1359 fat_itr
*itr
= NULL
;
1360 char *dirname_copy
, *parent
, *dirname
;
1361 char l_dirname
[VFAT_MAXLEN_BYTES
];
1364 unsigned int bytesperclust
;
1365 dir_entry
*dotdent
= NULL
;
1367 dirname_copy
= strdup(new_dirname
);
1371 split_filename(dirname_copy
, &parent
, &dirname
);
1372 if (!strlen(dirname
)) {
1377 if (normalize_longname(l_dirname
, dirname
)) {
1378 printf("FAT: illegal filename (%s)\n", dirname
);
1383 itr
= malloc_cache_aligned(sizeof(fat_itr
));
1389 ret
= fat_itr_root(itr
, &datablock
);
1393 total_sector
= datablock
.total_sect
;
1395 ret
= fat_itr_resolve(itr
, parent
, TYPE_DIR
);
1397 printf("%s: doesn't exist (%d)\n", parent
, ret
);
1401 retdent
= find_directory_entry(itr
, l_dirname
);
1404 printf("%s: already exists\n", l_dirname
);
1409 /* root dir cannot have "." or ".." */
1410 if (!strcmp(l_dirname
, ".") ||
1411 !strcmp(l_dirname
, "..")) {
1418 printf("Error: allocating new dir entry\n");
1423 memset(itr
->dent
, 0, sizeof(*itr
->dent
));
1425 /* Set short name to set alias checksum field in dir_slot */
1426 set_name(itr
->dent
, dirname
);
1427 fill_dir_slot(itr
, dirname
);
1429 /* Set attribute as archive for regular file */
1430 fill_dentry(itr
->fsdata
, itr
->dent
, dirname
, 0, 0,
1431 ATTR_DIR
| ATTR_ARCH
);
1433 retdent
= itr
->dent
;
1436 /* Default entries */
1437 bytesperclust
= mydata
->clust_size
* mydata
->sect_size
;
1438 dotdent
= malloc_cache_aligned(bytesperclust
);
1443 memset(dotdent
, 0, bytesperclust
);
1445 memcpy(dotdent
[0].name
, ". ", 8);
1446 memcpy(dotdent
[0].ext
, " ", 3);
1447 dotdent
[0].attr
= ATTR_DIR
| ATTR_ARCH
;
1449 memcpy(dotdent
[1].name
, ".. ", 8);
1450 memcpy(dotdent
[1].ext
, " ", 3);
1451 dotdent
[1].attr
= ATTR_DIR
| ATTR_ARCH
;
1452 set_start_cluster(mydata
, &dotdent
[1], itr
->start_clust
);
1454 ret
= set_contents(mydata
, retdent
, 0, (__u8
*)dotdent
,
1455 bytesperclust
, &actwrite
);
1457 printf("Error: writing contents\n");
1460 /* Write twice for "." */
1461 set_start_cluster(mydata
, &dotdent
[0], START(retdent
));
1462 ret
= set_contents(mydata
, retdent
, 0, (__u8
*)dotdent
,
1463 bytesperclust
, &actwrite
);
1465 printf("Error: writing contents\n");
1469 /* Flush fat buffer */
1470 ret
= flush_dirty_fat_buffer(mydata
);
1472 printf("Error: flush fat buffer\n");
1476 /* Write directory table to device */
1477 ret
= flush_dir(itr
);
1479 printf("Error: writing directory entry\n");
1483 free(mydata
->fatbuf
);