4 * R/W (V)FAT 12/16/32 filesystem implementation by Donggeun Kim
6 * SPDX-License-Identifier: GPL-2.0+
13 #include <asm/byteorder.h>
15 #include <linux/ctype.h>
17 #include <linux/math64.h>
20 static void uppercase(char *str
, int len
)
24 for (i
= 0; i
< len
; i
++) {
30 static int total_sector
;
31 static int disk_write(__u32 block
, __u32 nr_blocks
, void *buf
)
38 if (cur_part_info
.start
+ block
+ nr_blocks
>
39 cur_part_info
.start
+ total_sector
) {
40 printf("error: overflow occurs\n");
44 ret
= blk_dwrite(cur_dev
, cur_part_info
.start
+ block
, nr_blocks
, buf
);
45 if (nr_blocks
&& ret
== 0)
52 * Set short name in directory entry
54 static void set_name(dir_entry
*dirent
, const char *filename
)
56 char s_name
[VFAT_MAXLEN_BYTES
];
58 int period_location
, len
, i
, ext_num
;
63 len
= strlen(filename
);
67 strcpy(s_name
, filename
);
68 uppercase(s_name
, len
);
70 period
= strchr(s_name
, '.');
72 period_location
= len
;
75 period_location
= period
- s_name
;
76 ext_num
= len
- period_location
- 1;
79 /* Pad spaces when the length of file name is shorter than eight */
80 if (period_location
< 8) {
81 memcpy(dirent
->name
, s_name
, period_location
);
82 for (i
= period_location
; i
< 8; i
++)
83 dirent
->name
[i
] = ' ';
84 } else if (period_location
== 8) {
85 memcpy(dirent
->name
, s_name
, period_location
);
87 memcpy(dirent
->name
, s_name
, 6);
88 dirent
->name
[6] = '~';
89 dirent
->name
[7] = '1';
93 memcpy(dirent
->ext
, s_name
+ period_location
+ 1, ext_num
);
94 for (i
= ext_num
; i
< 3; i
++)
97 memcpy(dirent
->ext
, s_name
+ period_location
+ 1, 3);
99 debug("name : %s\n", dirent
->name
);
100 debug("ext : %s\n", dirent
->ext
);
103 static __u8 num_of_fats
;
105 * Write fat buffer into block device
107 static int flush_fat_buffer(fsdata
*mydata
)
109 int getsize
= FATBUFBLOCKS
;
110 __u32 fatlength
= mydata
->fatlength
;
111 __u8
*bufptr
= mydata
->fatbuf
;
112 __u32 startblock
= mydata
->fatbufnum
* FATBUFBLOCKS
;
114 startblock
+= mydata
->fat_sect
;
116 if (getsize
> fatlength
)
120 if (disk_write(startblock
, getsize
, bufptr
) < 0) {
121 debug("error: writing FAT blocks\n");
125 if (num_of_fats
== 2) {
126 /* Update corresponding second FAT blocks */
127 startblock
+= mydata
->fatlength
;
128 if (disk_write(startblock
, getsize
, bufptr
) < 0) {
129 debug("error: writing second FAT blocks\n");
138 * Get the entry at index 'entry' in a FAT (12/16/32) table.
139 * On failure 0x00 is returned.
140 * When bufnum is changed, write back the previous fatbuf to the disk.
142 static __u32
get_fatent_value(fsdata
*mydata
, __u32 entry
)
149 if (CHECK_CLUST(entry
, mydata
->fatsize
)) {
150 printf("Error: Invalid FAT entry: 0x%08x\n", entry
);
154 switch (mydata
->fatsize
) {
156 bufnum
= entry
/ FAT32BUFSIZE
;
157 offset
= entry
- bufnum
* FAT32BUFSIZE
;
160 bufnum
= entry
/ FAT16BUFSIZE
;
161 offset
= entry
- bufnum
* FAT16BUFSIZE
;
164 bufnum
= entry
/ FAT12BUFSIZE
;
165 offset
= entry
- bufnum
* FAT12BUFSIZE
;
169 /* Unsupported FAT size */
173 debug("FAT%d: entry: 0x%04x = %d, offset: 0x%04x = %d\n",
174 mydata
->fatsize
, entry
, entry
, offset
, offset
);
176 /* Read a new block of FAT entries into the cache. */
177 if (bufnum
!= mydata
->fatbufnum
) {
178 int getsize
= FATBUFBLOCKS
;
179 __u8
*bufptr
= mydata
->fatbuf
;
180 __u32 fatlength
= mydata
->fatlength
;
181 __u32 startblock
= bufnum
* FATBUFBLOCKS
;
183 if (getsize
> fatlength
)
186 fatlength
*= mydata
->sect_size
; /* We want it in bytes now */
187 startblock
+= mydata
->fat_sect
; /* Offset from start of disk */
189 /* Write back the fatbuf to the disk */
190 if (mydata
->fatbufnum
!= -1) {
191 if (flush_fat_buffer(mydata
) < 0)
195 if (disk_read(startblock
, getsize
, bufptr
) < 0) {
196 debug("Error reading FAT blocks\n");
199 mydata
->fatbufnum
= bufnum
;
202 /* Get the actual entry from the table */
203 switch (mydata
->fatsize
) {
205 ret
= FAT2CPU32(((__u32
*) mydata
->fatbuf
)[offset
]);
208 ret
= FAT2CPU16(((__u16
*) mydata
->fatbuf
)[offset
]);
211 off16
= (offset
* 3) / 4;
213 switch (offset
& 0x3) {
215 ret
= FAT2CPU16(((__u16
*) mydata
->fatbuf
)[off16
]);
219 val1
= FAT2CPU16(((__u16
*)mydata
->fatbuf
)[off16
]);
221 val2
= FAT2CPU16(((__u16
*)mydata
->fatbuf
)[off16
+ 1]);
223 ret
= (val2
<< 4) | (val1
>> 12);
226 val1
= FAT2CPU16(((__u16
*)mydata
->fatbuf
)[off16
]);
228 val2
= FAT2CPU16(((__u16
*)mydata
->fatbuf
)[off16
+ 1]);
230 ret
= (val2
<< 8) | (val1
>> 8);
233 ret
= FAT2CPU16(((__u16
*)mydata
->fatbuf
)[off16
]);
234 ret
= (ret
& 0xfff0) >> 4;
241 debug("FAT%d: ret: %08x, entry: %08x, offset: %04x\n",
242 mydata
->fatsize
, ret
, entry
, offset
);
248 * Set the file name information from 'name' into 'slotptr',
250 static int str2slot(dir_slot
*slotptr
, const char *name
, int *idx
)
254 for (j
= 0; j
<= 8; j
+= 2) {
255 if (name
[*idx
] == 0x00) {
256 slotptr
->name0_4
[j
] = 0;
257 slotptr
->name0_4
[j
+ 1] = 0;
261 slotptr
->name0_4
[j
] = name
[*idx
];
265 for (j
= 0; j
<= 10; j
+= 2) {
266 if (name
[*idx
] == 0x00) {
267 slotptr
->name5_10
[j
] = 0;
268 slotptr
->name5_10
[j
+ 1] = 0;
272 slotptr
->name5_10
[j
] = name
[*idx
];
276 for (j
= 0; j
<= 2; j
+= 2) {
277 if (name
[*idx
] == 0x00) {
278 slotptr
->name11_12
[j
] = 0;
279 slotptr
->name11_12
[j
+ 1] = 0;
283 slotptr
->name11_12
[j
] = name
[*idx
];
288 if (name
[*idx
] == 0x00)
292 /* Not used characters are filled with 0xff 0xff */
294 for (; end_idx
< 5; end_idx
++) {
295 slotptr
->name0_4
[end_idx
* 2] = 0xff;
296 slotptr
->name0_4
[end_idx
* 2 + 1] = 0xff;
301 for (; end_idx
< 6; end_idx
++) {
302 slotptr
->name5_10
[end_idx
* 2] = 0xff;
303 slotptr
->name5_10
[end_idx
* 2 + 1] = 0xff;
308 for (; end_idx
< 2; end_idx
++) {
309 slotptr
->name11_12
[end_idx
* 2] = 0xff;
310 slotptr
->name11_12
[end_idx
* 2 + 1] = 0xff;
316 static int is_next_clust(fsdata
*mydata
, dir_entry
*dentptr
);
317 static void flush_dir_table(fsdata
*mydata
, dir_entry
**dentptr
);
320 * Fill dir_slot entries with appropriate name, id, and attr
321 * The real directory entry is returned by 'dentptr'
324 fill_dir_slot(fsdata
*mydata
, dir_entry
**dentptr
, const char *l_name
)
326 dir_slot
*slotptr
= (dir_slot
*)get_contents_vfatname_block
;
327 __u8 counter
= 0, checksum
;
331 /* Get short file name and checksum value */
332 strncpy(s_name
, (*dentptr
)->name
, 16);
333 checksum
= mkcksum((*dentptr
)->name
, (*dentptr
)->ext
);
336 memset(slotptr
, 0x00, sizeof(dir_slot
));
337 ret
= str2slot(slotptr
, l_name
, &idx
);
338 slotptr
->id
= ++counter
;
339 slotptr
->attr
= ATTR_VFAT
;
340 slotptr
->alias_checksum
= checksum
;
345 slotptr
->id
|= LAST_LONG_ENTRY_MASK
;
347 while (counter
>= 1) {
348 if (is_next_clust(mydata
, *dentptr
)) {
349 /* A new cluster is allocated for directory table */
350 flush_dir_table(mydata
, dentptr
);
352 memcpy(*dentptr
, slotptr
, sizeof(dir_slot
));
358 if (is_next_clust(mydata
, *dentptr
)) {
359 /* A new cluster is allocated for directory table */
360 flush_dir_table(mydata
, dentptr
);
364 static __u32 dir_curclust
;
367 * Extract the full long filename starting at 'retdent' (which is really
368 * a slot) into 'l_name'. If successful also copy the real directory entry
370 * If additional adjacent cluster for directory entries is read into memory,
371 * then 'get_contents_vfatname_block' is copied into 'get_dentfromdir_block' and
372 * the location of the real directory entry is returned by 'retdent'
373 * Return 0 on success, -1 otherwise.
376 get_long_file_name(fsdata
*mydata
, int curclust
, __u8
*cluster
,
377 dir_entry
**retdent
, char *l_name
)
380 dir_slot
*slotptr
= (dir_slot
*)(*retdent
);
381 dir_slot
*slotptr2
= NULL
;
382 __u8
*buflimit
= cluster
+ mydata
->sect_size
* ((curclust
== 0) ?
385 __u8 counter
= (slotptr
->id
& ~LAST_LONG_ENTRY_MASK
) & 0xff;
386 int idx
= 0, cur_position
= 0;
388 if (counter
> VFAT_MAXSEQ
) {
389 debug("Error: VFAT name is too long\n");
393 while ((__u8
*)slotptr
< buflimit
) {
396 if (((slotptr
->id
& ~LAST_LONG_ENTRY_MASK
) & 0xff) != counter
)
402 if ((__u8
*)slotptr
>= buflimit
) {
405 curclust
= get_fatent_value(mydata
, dir_curclust
);
406 if (CHECK_CLUST(curclust
, mydata
->fatsize
)) {
407 debug("curclust: 0x%x\n", curclust
);
408 printf("Invalid FAT entry\n");
412 dir_curclust
= curclust
;
414 if (get_cluster(mydata
, curclust
, get_contents_vfatname_block
,
415 mydata
->clust_size
* mydata
->sect_size
) != 0) {
416 debug("Error: reading directory block\n");
420 slotptr2
= (dir_slot
*)get_contents_vfatname_block
;
421 while (counter
> 0) {
422 if (((slotptr2
->id
& ~LAST_LONG_ENTRY_MASK
)
429 /* Save the real directory entry */
430 realdent
= (dir_entry
*)slotptr2
;
431 while ((__u8
*)slotptr2
> get_contents_vfatname_block
) {
433 slot2str(slotptr2
, l_name
, &idx
);
436 /* Save the real directory entry */
437 realdent
= (dir_entry
*)slotptr
;
442 if (slot2str(slotptr
, l_name
, &idx
))
444 } while (!(slotptr
->id
& LAST_LONG_ENTRY_MASK
));
447 if (*l_name
== DELETED_FLAG
)
449 else if (*l_name
== aRING
)
450 *l_name
= DELETED_FLAG
;
453 /* Return the real directory entry */
457 memcpy(get_dentfromdir_block
, get_contents_vfatname_block
,
458 mydata
->clust_size
* mydata
->sect_size
);
459 cur_position
= (__u8
*)realdent
- get_contents_vfatname_block
;
460 *retdent
= (dir_entry
*) &get_dentfromdir_block
[cur_position
];
467 * Set the entry at index 'entry' in a FAT (16/32) table.
469 static int set_fatent_value(fsdata
*mydata
, __u32 entry
, __u32 entry_value
)
471 __u32 bufnum
, offset
;
473 switch (mydata
->fatsize
) {
475 bufnum
= entry
/ FAT32BUFSIZE
;
476 offset
= entry
- bufnum
* FAT32BUFSIZE
;
479 bufnum
= entry
/ FAT16BUFSIZE
;
480 offset
= entry
- bufnum
* FAT16BUFSIZE
;
483 /* Unsupported FAT size */
487 /* Read a new block of FAT entries into the cache. */
488 if (bufnum
!= mydata
->fatbufnum
) {
489 int getsize
= FATBUFBLOCKS
;
490 __u8
*bufptr
= mydata
->fatbuf
;
491 __u32 fatlength
= mydata
->fatlength
;
492 __u32 startblock
= bufnum
* FATBUFBLOCKS
;
494 fatlength
*= mydata
->sect_size
;
495 startblock
+= mydata
->fat_sect
;
497 if (getsize
> fatlength
)
500 if (mydata
->fatbufnum
!= -1) {
501 if (flush_fat_buffer(mydata
) < 0)
505 if (disk_read(startblock
, getsize
, bufptr
) < 0) {
506 debug("Error reading FAT blocks\n");
509 mydata
->fatbufnum
= bufnum
;
512 /* Set the actual entry */
513 switch (mydata
->fatsize
) {
515 ((__u32
*) mydata
->fatbuf
)[offset
] = cpu_to_le32(entry_value
);
518 ((__u16
*) mydata
->fatbuf
)[offset
] = cpu_to_le16(entry_value
);
528 * Determine the entry value at index 'entry' in a FAT (16/32) table
530 static __u32
determine_fatent(fsdata
*mydata
, __u32 entry
)
532 __u32 next_fat
, next_entry
= entry
+ 1;
535 next_fat
= get_fatent_value(mydata
, next_entry
);
537 set_fatent_value(mydata
, entry
, next_entry
);
542 debug("FAT%d: entry: %08x, entry_value: %04x\n",
543 mydata
->fatsize
, entry
, next_entry
);
549 * Write at most 'size' bytes from 'buffer' into the specified cluster.
550 * Return 0 on success, -1 otherwise.
553 set_cluster(fsdata
*mydata
, __u32 clustnum
, __u8
*buffer
,
561 startsect
= mydata
->data_begin
+
562 clustnum
* mydata
->clust_size
;
564 startsect
= mydata
->rootdir_sect
;
566 debug("clustnum: %d, startsect: %d\n", clustnum
, startsect
);
568 if ((unsigned long)buffer
& (ARCH_DMA_MINALIGN
- 1)) {
569 ALLOC_CACHE_ALIGN_BUFFER(__u8
, tmpbuf
, mydata
->sect_size
);
571 printf("FAT: Misaligned buffer address (%p)\n", buffer
);
573 while (size
>= mydata
->sect_size
) {
574 memcpy(tmpbuf
, buffer
, mydata
->sect_size
);
575 ret
= disk_write(startsect
++, 1, tmpbuf
);
577 debug("Error writing data (got %d)\n", ret
);
581 buffer
+= mydata
->sect_size
;
582 size
-= mydata
->sect_size
;
584 } else if (size
>= mydata
->sect_size
) {
585 idx
= size
/ mydata
->sect_size
;
586 ret
= disk_write(startsect
, idx
, buffer
);
588 debug("Error writing data (got %d)\n", ret
);
593 idx
*= mydata
->sect_size
;
599 ALLOC_CACHE_ALIGN_BUFFER(__u8
, tmpbuf
, mydata
->sect_size
);
601 memcpy(tmpbuf
, buffer
, size
);
602 ret
= disk_write(startsect
, 1, tmpbuf
);
604 debug("Error writing data (got %d)\n", ret
);
613 * Find the first empty cluster
615 static int find_empty_cluster(fsdata
*mydata
)
617 __u32 fat_val
, entry
= 3;
620 fat_val
= get_fatent_value(mydata
, entry
);
630 * Write directory entries in 'get_dentfromdir_block' to block device
632 static void flush_dir_table(fsdata
*mydata
, dir_entry
**dentptr
)
634 int dir_newclust
= 0;
636 if (set_cluster(mydata
, dir_curclust
,
637 get_dentfromdir_block
,
638 mydata
->clust_size
* mydata
->sect_size
) != 0) {
639 printf("error: wrinting directory entry\n");
642 dir_newclust
= find_empty_cluster(mydata
);
643 set_fatent_value(mydata
, dir_curclust
, dir_newclust
);
644 if (mydata
->fatsize
== 32)
645 set_fatent_value(mydata
, dir_newclust
, 0xffffff8);
646 else if (mydata
->fatsize
== 16)
647 set_fatent_value(mydata
, dir_newclust
, 0xfff8);
649 dir_curclust
= dir_newclust
;
651 if (flush_fat_buffer(mydata
) < 0)
654 memset(get_dentfromdir_block
, 0x00,
655 mydata
->clust_size
* mydata
->sect_size
);
657 *dentptr
= (dir_entry
*) get_dentfromdir_block
;
661 * Set empty cluster from 'entry' to the end of a file
663 static int clear_fatent(fsdata
*mydata
, __u32 entry
)
668 fat_val
= get_fatent_value(mydata
, entry
);
670 set_fatent_value(mydata
, entry
, 0);
674 if (fat_val
== 0xfffffff || fat_val
== 0xffff)
680 /* Flush fat buffer */
681 if (flush_fat_buffer(mydata
) < 0)
688 * Write at most 'maxsize' bytes from 'buffer' into
689 * the file associated with 'dentptr'
690 * Update the number of bytes written in *gotsize and return 0
691 * or return -1 on fatal errors.
694 set_contents(fsdata
*mydata
, dir_entry
*dentptr
, __u8
*buffer
,
695 loff_t maxsize
, loff_t
*gotsize
)
697 loff_t filesize
= FAT2CPU32(dentptr
->size
);
698 unsigned int bytesperclust
= mydata
->clust_size
* mydata
->sect_size
;
699 __u32 curclust
= START(dentptr
);
700 __u32 endclust
= 0, newclust
= 0;
704 debug("Filesize: %llu bytes\n", filesize
);
706 if (maxsize
> 0 && filesize
> maxsize
)
709 debug("%llu bytes\n", filesize
);
713 debug("error: nonempty clusterless file!\n");
719 actsize
= bytesperclust
;
722 /* search for consecutive clusters */
723 while (actsize
< filesize
) {
724 newclust
= determine_fatent(mydata
, endclust
);
726 if ((newclust
- 1) != endclust
)
729 if (CHECK_CLUST(newclust
, mydata
->fatsize
)) {
730 debug("newclust: 0x%x\n", newclust
);
731 debug("Invalid FAT entry\n");
735 actsize
+= bytesperclust
;
738 /* set remaining bytes */
740 if (set_cluster(mydata
, curclust
, buffer
, (int)actsize
) != 0) {
741 debug("error: writing cluster\n");
746 /* Mark end of file in FAT */
747 if (mydata
->fatsize
== 16)
749 else if (mydata
->fatsize
== 32)
750 newclust
= 0xfffffff;
751 set_fatent_value(mydata
, endclust
, newclust
);
755 if (set_cluster(mydata
, curclust
, buffer
, (int)actsize
) != 0) {
756 debug("error: writing cluster\n");
763 if (CHECK_CLUST(newclust
, mydata
->fatsize
)) {
764 debug("newclust: 0x%x\n", newclust
);
765 debug("Invalid FAT entry\n");
768 actsize
= bytesperclust
;
769 curclust
= endclust
= newclust
;
774 * Set start cluster in directory entry
776 static void set_start_cluster(const fsdata
*mydata
, dir_entry
*dentptr
,
779 if (mydata
->fatsize
== 32)
781 cpu_to_le16((start_cluster
& 0xffff0000) >> 16);
782 dentptr
->start
= cpu_to_le16(start_cluster
& 0xffff);
788 static void fill_dentry(fsdata
*mydata
, dir_entry
*dentptr
,
789 const char *filename
, __u32 start_cluster
, __u32 size
, __u8 attr
)
791 set_start_cluster(mydata
, dentptr
, start_cluster
);
792 dentptr
->size
= cpu_to_le32(size
);
794 dentptr
->attr
= attr
;
796 set_name(dentptr
, filename
);
800 * Check whether adding a file makes the file system to
801 * exceed the size of the block device
802 * Return -1 when overflow occurs, otherwise return 0
804 static int check_overflow(fsdata
*mydata
, __u32 clustnum
, loff_t size
)
806 __u32 startsect
, sect_num
, offset
;
809 startsect
= mydata
->data_begin
+
810 clustnum
* mydata
->clust_size
;
812 startsect
= mydata
->rootdir_sect
;
815 sect_num
= div_u64_rem(size
, mydata
->sect_size
, &offset
);
820 if (startsect
+ sect_num
> cur_part_info
.start
+ total_sector
)
826 * Check if adding several entries exceed one cluster boundary
828 static int is_next_clust(fsdata
*mydata
, dir_entry
*dentptr
)
832 cur_position
= (__u8
*)dentptr
- get_dentfromdir_block
;
834 if (cur_position
>= mydata
->clust_size
* mydata
->sect_size
)
840 static dir_entry
*empty_dentptr
;
842 * Find a directory entry based on filename or start cluster number
843 * If the directory entry is not found,
844 * the new position for writing a directory entry will be returned
846 static dir_entry
*find_directory_entry(fsdata
*mydata
, int startsect
,
847 char *filename
, dir_entry
*retdent
, __u32 start
)
849 __u32 curclust
= (startsect
- mydata
->data_begin
) / mydata
->clust_size
;
851 debug("get_dentfromdir: %s\n", filename
);
858 if (get_cluster(mydata
, curclust
, get_dentfromdir_block
,
859 mydata
->clust_size
* mydata
->sect_size
) != 0) {
860 printf("Error: reading directory block\n");
864 dentptr
= (dir_entry
*)get_dentfromdir_block
;
866 dir_curclust
= curclust
;
868 for (i
= 0; i
< DIRENTSPERCLUST
; i
++) {
869 char s_name
[14], l_name
[VFAT_MAXLEN_BYTES
];
872 if (dentptr
->name
[0] == DELETED_FLAG
) {
874 if (is_next_clust(mydata
, dentptr
))
878 if ((dentptr
->attr
& ATTR_VOLUME
)) {
880 (dentptr
->attr
& ATTR_VFAT
) &&
881 (dentptr
->name
[0] & LAST_LONG_ENTRY_MASK
)) {
882 get_long_file_name(mydata
, curclust
,
883 get_dentfromdir_block
,
885 debug("vfatname: |%s|\n", l_name
);
887 /* Volume label or VFAT entry */
889 if (is_next_clust(mydata
, dentptr
))
894 if (dentptr
->name
[0] == 0) {
895 debug("Dentname == NULL - %d\n", i
);
896 empty_dentptr
= dentptr
;
900 get_name(dentptr
, s_name
);
902 if (strcmp(filename
, s_name
)
903 && strcmp(filename
, l_name
)) {
904 debug("Mismatch: |%s|%s|\n",
907 if (is_next_clust(mydata
, dentptr
))
912 memcpy(retdent
, dentptr
, sizeof(dir_entry
));
914 debug("DentName: %s", s_name
);
915 debug(", start: 0x%x", START(dentptr
));
916 debug(", size: 0x%x %s\n",
917 FAT2CPU32(dentptr
->size
),
918 (dentptr
->attr
& ATTR_DIR
) ?
925 * In FAT16/12, the root dir is locate before data area, shows
927 * -------------------------------------------------------------
928 * | Boot | FAT1 & 2 | Root dir | Data (start from cluster #2) |
929 * -------------------------------------------------------------
931 * As a result if curclust is in Root dir, it is a negative
935 if (mydata
->fatsize
!= 32 && (int)curclust
<= 1) {
936 /* Current clust is in root dir, set to next clust */
938 if ((int)curclust
<= 1)
939 continue; /* continue to find */
941 /* Reach the end of root dir */
942 empty_dentptr
= dentptr
;
946 curclust
= get_fatent_value(mydata
, dir_curclust
);
947 if (IS_LAST_CLUST(curclust
, mydata
->fatsize
)) {
948 empty_dentptr
= dentptr
;
951 if (CHECK_CLUST(curclust
, mydata
->fatsize
)) {
952 debug("curclust: 0x%x\n", curclust
);
953 debug("Invalid FAT entry\n");
961 static int do_fat_write(const char *filename
, void *buffer
, loff_t size
,
964 dir_entry
*dentptr
, *retdent
;
970 fsdata
*mydata
= &datablock
;
972 int ret
= -1, name_len
;
973 char l_filename
[VFAT_MAXLEN_BYTES
];
978 if (read_bootsectandvi(&bs
, &volinfo
, &mydata
->fatsize
)) {
979 debug("error: reading boot sector\n");
983 total_sector
= bs
.total_sect
;
984 if (total_sector
== 0)
985 total_sector
= (int)cur_part_info
.size
; /* cast of lbaint_t */
987 if (mydata
->fatsize
== 32)
988 mydata
->fatlength
= bs
.fat32_length
;
990 mydata
->fatlength
= bs
.fat_length
;
992 mydata
->fat_sect
= bs
.reserved
;
994 cursect
= mydata
->rootdir_sect
995 = mydata
->fat_sect
+ mydata
->fatlength
* bs
.fats
;
996 num_of_fats
= bs
.fats
;
998 mydata
->sect_size
= (bs
.sector_size
[1] << 8) + bs
.sector_size
[0];
999 mydata
->clust_size
= bs
.cluster_size
;
1001 if (mydata
->fatsize
== 32) {
1002 mydata
->data_begin
= mydata
->rootdir_sect
-
1003 (mydata
->clust_size
* 2);
1007 rootdir_size
= ((bs
.dir_entries
[1] * (int)256 +
1008 bs
.dir_entries
[0]) *
1009 sizeof(dir_entry
)) /
1011 mydata
->data_begin
= mydata
->rootdir_sect
+
1013 (mydata
->clust_size
* 2);
1016 mydata
->fatbufnum
= -1;
1017 mydata
->fatbuf
= memalign(ARCH_DMA_MINALIGN
, FATBUFSIZE
);
1018 if (mydata
->fatbuf
== NULL
) {
1019 debug("Error: allocating memory\n");
1023 if (disk_read(cursect
,
1024 (mydata
->fatsize
== 32) ?
1025 (mydata
->clust_size
) :
1026 PREFETCH_BLOCKS
, do_fat_read_at_block
) < 0) {
1027 debug("Error: reading rootdir block\n");
1030 dentptr
= (dir_entry
*) do_fat_read_at_block
;
1032 name_len
= strlen(filename
);
1033 if (name_len
>= VFAT_MAXLEN_BYTES
)
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
);
1040 startsect
= mydata
->rootdir_sect
;
1041 retdent
= find_directory_entry(mydata
, startsect
,
1042 l_filename
, dentptr
, 0);
1044 /* Update file size and start_cluster in a directory entry */
1045 retdent
->size
= cpu_to_le32(size
);
1046 start_cluster
= START(retdent
);
1048 if (start_cluster
) {
1050 ret
= check_overflow(mydata
, start_cluster
,
1053 printf("Error: %llu overflow\n", size
);
1058 ret
= clear_fatent(mydata
, start_cluster
);
1060 printf("Error: clearing FAT entries\n");
1065 set_start_cluster(mydata
, retdent
, 0);
1067 ret
= start_cluster
= find_empty_cluster(mydata
);
1069 printf("Error: finding empty cluster\n");
1073 ret
= check_overflow(mydata
, start_cluster
, size
);
1075 printf("Error: %llu overflow\n", size
);
1079 set_start_cluster(mydata
, retdent
, start_cluster
);
1082 /* Set short name to set alias checksum field in dir_slot */
1083 set_name(empty_dentptr
, filename
);
1084 fill_dir_slot(mydata
, &empty_dentptr
, filename
);
1087 ret
= start_cluster
= find_empty_cluster(mydata
);
1089 printf("Error: finding empty cluster\n");
1093 ret
= check_overflow(mydata
, start_cluster
, size
);
1095 printf("Error: %llu overflow\n", size
);
1102 /* Set attribute as archieve for regular file */
1103 fill_dentry(mydata
, empty_dentptr
, filename
,
1104 start_cluster
, size
, 0x20);
1106 retdent
= empty_dentptr
;
1109 ret
= set_contents(mydata
, retdent
, buffer
, size
, actwrite
);
1111 printf("Error: writing contents\n");
1114 debug("attempt to write 0x%llx bytes\n", *actwrite
);
1116 /* Flush fat buffer */
1117 ret
= flush_fat_buffer(mydata
);
1119 printf("Error: flush fat buffer\n");
1123 /* Write directory table to device */
1124 ret
= set_cluster(mydata
, dir_curclust
, get_dentfromdir_block
,
1125 mydata
->clust_size
* mydata
->sect_size
);
1127 printf("Error: writing directory entry\n");
1130 free(mydata
->fatbuf
);
1134 int file_fat_write(const char *filename
, void *buffer
, loff_t offset
,
1135 loff_t maxsize
, loff_t
*actwrite
)
1138 printf("Error: non zero offset is currently not supported.\n");
1142 printf("writing %s\n", filename
);
1143 return do_fat_write(filename
, buffer
, maxsize
, actwrite
);