blob: baa85ec3b44d8ce6515ada780038ab0af1d350f1 [file] [log] [blame]
/*
* fat_write.c
*
* R/W (V)FAT 12/16/32 filesystem implementation by Donggeun Kim
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <command.h>
#include <config.h>
#include <fat.h>
#include <asm/byteorder.h>
#include <part.h>
#include <linux/ctype.h>
#include <div64.h>
#include <linux/math64.h>
#include "fat.c"
static void uppercase(char *str, int len)
{
int i;
for (i = 0; i < len; i++) {
*str = toupper(*str);
str++;
}
}
static int total_sector;
static int disk_write(__u32 block, __u32 nr_blocks, void *buf)
{
ulong ret;
if (!cur_dev)
return -1;
if (cur_part_info.start + block + nr_blocks >
cur_part_info.start + total_sector) {
printf("error: overflow occurs\n");
return -1;
}
ret = blk_dwrite(cur_dev, cur_part_info.start + block, nr_blocks, buf);
if (nr_blocks && ret == 0)
return -1;
return ret;
}
/*
* Set short name in directory entry
*/
static void set_name(dir_entry *dirent, const char *filename)
{
char s_name[VFAT_MAXLEN_BYTES];
char *period;
int period_location, len, i, ext_num;
if (filename == NULL)
return;
len = strlen(filename);
if (len == 0)
return;
strcpy(s_name, filename);
uppercase(s_name, len);
period = strchr(s_name, '.');
if (period == NULL) {
period_location = len;
ext_num = 0;
} else {
period_location = period - s_name;
ext_num = len - period_location - 1;
}
/* Pad spaces when the length of file name is shorter than eight */
if (period_location < 8) {
memcpy(dirent->name, s_name, period_location);
for (i = period_location; i < 8; i++)
dirent->name[i] = ' ';
} else if (period_location == 8) {
memcpy(dirent->name, s_name, period_location);
} else {
memcpy(dirent->name, s_name, 6);
dirent->name[6] = '~';
dirent->name[7] = '1';
}
if (ext_num < 3) {
memcpy(dirent->ext, s_name + period_location + 1, ext_num);
for (i = ext_num; i < 3; i++)
dirent->ext[i] = ' ';
} else
memcpy(dirent->ext, s_name + period_location + 1, 3);
debug("name : %s\n", dirent->name);
debug("ext : %s\n", dirent->ext);
}
static __u8 num_of_fats;
/*
* Write fat buffer into block device
*/
static int flush_fat_buffer(fsdata *mydata)
{
int getsize = FATBUFBLOCKS;
__u32 fatlength = mydata->fatlength;
__u8 *bufptr = mydata->fatbuf;
__u32 startblock = mydata->fatbufnum * FATBUFBLOCKS;
startblock += mydata->fat_sect;
if (getsize > fatlength)
getsize = fatlength;
/* Write FAT buf */
if (disk_write(startblock, getsize, bufptr) < 0) {
debug("error: writing FAT blocks\n");
return -1;
}
if (num_of_fats == 2) {
/* Update corresponding second FAT blocks */
startblock += mydata->fatlength;
if (disk_write(startblock, getsize, bufptr) < 0) {
debug("error: writing second FAT blocks\n");
return -1;
}
}
return 0;
}
/*
* Get the entry at index 'entry' in a FAT (12/16/32) table.
* On failure 0x00 is returned.
* When bufnum is changed, write back the previous fatbuf to the disk.
*/
static __u32 get_fatent_value(fsdata *mydata, __u32 entry)
{
__u32 bufnum;
__u32 off16, offset;
__u32 ret = 0x00;
__u16 val1, val2;
if (CHECK_CLUST(entry, mydata->fatsize)) {
printf("Error: Invalid FAT entry: 0x%08x\n", entry);
return ret;
}
switch (mydata->fatsize) {
case 32:
bufnum = entry / FAT32BUFSIZE;
offset = entry - bufnum * FAT32BUFSIZE;
break;
case 16:
bufnum = entry / FAT16BUFSIZE;
offset = entry - bufnum * FAT16BUFSIZE;
break;
case 12:
bufnum = entry / FAT12BUFSIZE;
offset = entry - bufnum * FAT12BUFSIZE;
break;
default:
/* Unsupported FAT size */
return ret;
}
debug("FAT%d: entry: 0x%04x = %d, offset: 0x%04x = %d\n",
mydata->fatsize, entry, entry, offset, offset);
/* Read a new block of FAT entries into the cache. */
if (bufnum != mydata->fatbufnum) {
int getsize = FATBUFBLOCKS;
__u8 *bufptr = mydata->fatbuf;
__u32 fatlength = mydata->fatlength;
__u32 startblock = bufnum * FATBUFBLOCKS;
if (getsize > fatlength)
getsize = fatlength;
fatlength *= mydata->sect_size; /* We want it in bytes now */
startblock += mydata->fat_sect; /* Offset from start of disk */
/* Write back the fatbuf to the disk */
if (mydata->fatbufnum != -1) {
if (flush_fat_buffer(mydata) < 0)
return -1;
}
if (disk_read(startblock, getsize, bufptr) < 0) {
debug("Error reading FAT blocks\n");
return ret;
}
mydata->fatbufnum = bufnum;
}
/* Get the actual entry from the table */
switch (mydata->fatsize) {
case 32:
ret = FAT2CPU32(((__u32 *) mydata->fatbuf)[offset]);
break;
case 16:
ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[offset]);
break;
case 12:
off16 = (offset * 3) / 4;
switch (offset & 0x3) {
case 0:
ret = FAT2CPU16(((__u16 *) mydata->fatbuf)[off16]);
ret &= 0xfff;
break;
case 1:
val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
val1 &= 0xf000;
val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
val2 &= 0x00ff;
ret = (val2 << 4) | (val1 >> 12);
break;
case 2:
val1 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
val1 &= 0xff00;
val2 = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16 + 1]);
val2 &= 0x000f;
ret = (val2 << 8) | (val1 >> 8);
break;
case 3:
ret = FAT2CPU16(((__u16 *)mydata->fatbuf)[off16]);
ret = (ret & 0xfff0) >> 4;
break;
default:
break;
}
break;
}
debug("FAT%d: ret: %08x, entry: %08x, offset: %04x\n",
mydata->fatsize, ret, entry, offset);
return ret;
}
/*
* Set the file name information from 'name' into 'slotptr',
*/
static int str2slot(dir_slot *slotptr, const char *name, int *idx)
{
int j, end_idx = 0;
for (j = 0; j <= 8; j += 2) {
if (name[*idx] == 0x00) {
slotptr->name0_4[j] = 0;
slotptr->name0_4[j + 1] = 0;
end_idx++;
goto name0_4;
}
slotptr->name0_4[j] = name[*idx];
(*idx)++;
end_idx++;
}
for (j = 0; j <= 10; j += 2) {
if (name[*idx] == 0x00) {
slotptr->name5_10[j] = 0;
slotptr->name5_10[j + 1] = 0;
end_idx++;
goto name5_10;
}
slotptr->name5_10[j] = name[*idx];
(*idx)++;
end_idx++;
}
for (j = 0; j <= 2; j += 2) {
if (name[*idx] == 0x00) {
slotptr->name11_12[j] = 0;
slotptr->name11_12[j + 1] = 0;
end_idx++;
goto name11_12;
}
slotptr->name11_12[j] = name[*idx];
(*idx)++;
end_idx++;
}
if (name[*idx] == 0x00)
return 1;
return 0;
/* Not used characters are filled with 0xff 0xff */
name0_4:
for (; end_idx < 5; end_idx++) {
slotptr->name0_4[end_idx * 2] = 0xff;
slotptr->name0_4[end_idx * 2 + 1] = 0xff;
}
end_idx = 5;
name5_10:
end_idx -= 5;
for (; end_idx < 6; end_idx++) {
slotptr->name5_10[end_idx * 2] = 0xff;
slotptr->name5_10[end_idx * 2 + 1] = 0xff;
}
end_idx = 11;
name11_12:
end_idx -= 11;
for (; end_idx < 2; end_idx++) {
slotptr->name11_12[end_idx * 2] = 0xff;
slotptr->name11_12[end_idx * 2 + 1] = 0xff;
}
return 1;
}
static int is_next_clust(fsdata *mydata, dir_entry *dentptr);
static void flush_dir_table(fsdata *mydata, dir_entry **dentptr);
/*
* Fill dir_slot entries with appropriate name, id, and attr
* The real directory entry is returned by 'dentptr'
*/
static void
fill_dir_slot(fsdata *mydata, dir_entry **dentptr, const char *l_name)
{
dir_slot *slotptr = (dir_slot *)get_contents_vfatname_block;
__u8 counter = 0, checksum;
int idx = 0, ret;
char s_name[16];
/* Get short file name and checksum value */
strncpy(s_name, (*dentptr)->name, 16);
checksum = mkcksum((*dentptr)->name, (*dentptr)->ext);
do {
memset(slotptr, 0x00, sizeof(dir_slot));
ret = str2slot(slotptr, l_name, &idx);
slotptr->id = ++counter;
slotptr->attr = ATTR_VFAT;
slotptr->alias_checksum = checksum;
slotptr++;
} while (ret == 0);
slotptr--;
slotptr->id |= LAST_LONG_ENTRY_MASK;
while (counter >= 1) {
if (is_next_clust(mydata, *dentptr)) {
/* A new cluster is allocated for directory table */
flush_dir_table(mydata, dentptr);
}
memcpy(*dentptr, slotptr, sizeof(dir_slot));
(*dentptr)++;
slotptr--;
counter--;
}
if (is_next_clust(mydata, *dentptr)) {
/* A new cluster is allocated for directory table */
flush_dir_table(mydata, dentptr);
}
}
static __u32 dir_curclust;
/*
* Extract the full long filename starting at 'retdent' (which is really
* a slot) into 'l_name'. If successful also copy the real directory entry
* into 'retdent'
* If additional adjacent cluster for directory entries is read into memory,
* then 'get_contents_vfatname_block' is copied into 'get_dentfromdir_block' and
* the location of the real directory entry is returned by 'retdent'
* Return 0 on success, -1 otherwise.
*/
static int
get_long_file_name(fsdata *mydata, int curclust, __u8 *cluster,
dir_entry **retdent, char *l_name)
{
dir_entry *realdent;
dir_slot *slotptr = (dir_slot *)(*retdent);
dir_slot *slotptr2 = NULL;
__u8 *buflimit = cluster + mydata->sect_size * ((curclust == 0) ?
PREFETCH_BLOCKS :
mydata->clust_size);
__u8 counter = (slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff;
int idx = 0, cur_position = 0;
if (counter > VFAT_MAXSEQ) {
debug("Error: VFAT name is too long\n");
return -1;
}
while ((__u8 *)slotptr < buflimit) {
if (counter == 0)
break;
if (((slotptr->id & ~LAST_LONG_ENTRY_MASK) & 0xff) != counter)
return -1;
slotptr++;
counter--;
}
if ((__u8 *)slotptr >= buflimit) {
if (curclust == 0)
return -1;
curclust = get_fatent_value(mydata, dir_curclust);
if (CHECK_CLUST(curclust, mydata->fatsize)) {
debug("curclust: 0x%x\n", curclust);
printf("Invalid FAT entry\n");
return -1;
}
dir_curclust = curclust;
if (get_cluster(mydata, curclust, get_contents_vfatname_block,
mydata->clust_size * mydata->sect_size) != 0) {
debug("Error: reading directory block\n");
return -1;
}
slotptr2 = (dir_slot *)get_contents_vfatname_block;
while (counter > 0) {
if (((slotptr2->id & ~LAST_LONG_ENTRY_MASK)
& 0xff) != counter)
return -1;
slotptr2++;
counter--;
}
/* Save the real directory entry */
realdent = (dir_entry *)slotptr2;
while ((__u8 *)slotptr2 > get_contents_vfatname_block) {
slotptr2--;
slot2str(slotptr2, l_name, &idx);
}
} else {
/* Save the real directory entry */
realdent = (dir_entry *)slotptr;
}
do {
slotptr--;
if (slot2str(slotptr, l_name, &idx))
break;
} while (!(slotptr->id & LAST_LONG_ENTRY_MASK));
l_name[idx] = '\0';
if (*l_name == DELETED_FLAG)
*l_name = '\0';
else if (*l_name == aRING)
*l_name = DELETED_FLAG;
downcase(l_name);
/* Return the real directory entry */
*retdent = realdent;
if (slotptr2) {
memcpy(get_dentfromdir_block, get_contents_vfatname_block,
mydata->clust_size * mydata->sect_size);
cur_position = (__u8 *)realdent - get_contents_vfatname_block;
*retdent = (dir_entry *) &get_dentfromdir_block[cur_position];
}
return 0;
}
/*
* Set the entry at index 'entry' in a FAT (16/32) table.
*/
static int set_fatent_value(fsdata *mydata, __u32 entry, __u32 entry_value)
{
__u32 bufnum, offset;
switch (mydata->fatsize) {
case 32:
bufnum = entry / FAT32BUFSIZE;
offset = entry - bufnum * FAT32BUFSIZE;
break;
case 16:
bufnum = entry / FAT16BUFSIZE;
offset = entry - bufnum * FAT16BUFSIZE;
break;
default:
/* Unsupported FAT size */
return -1;
}
/* Read a new block of FAT entries into the cache. */
if (bufnum != mydata->fatbufnum) {
int getsize = FATBUFBLOCKS;
__u8 *bufptr = mydata->fatbuf;
__u32 fatlength = mydata->fatlength;
__u32 startblock = bufnum * FATBUFBLOCKS;
fatlength *= mydata->sect_size;
startblock += mydata->fat_sect;
if (getsize > fatlength)
getsize = fatlength;
if (mydata->fatbufnum != -1) {
if (flush_fat_buffer(mydata) < 0)
return -1;
}
if (disk_read(startblock, getsize, bufptr) < 0) {
debug("Error reading FAT blocks\n");
return -1;
}
mydata->fatbufnum = bufnum;
}
/* Set the actual entry */
switch (mydata->fatsize) {
case 32:
((__u32 *) mydata->fatbuf)[offset] = cpu_to_le32(entry_value);
break;
case 16:
((__u16 *) mydata->fatbuf)[offset] = cpu_to_le16(entry_value);
break;
default:
return -1;
}
return 0;
}
/*
* Determine the entry value at index 'entry' in a FAT (16/32) table
*/
static __u32 determine_fatent(fsdata *mydata, __u32 entry)
{
__u32 next_fat, next_entry = entry + 1;
while (1) {
next_fat = get_fatent_value(mydata, next_entry);
if (next_fat == 0) {
set_fatent_value(mydata, entry, next_entry);
break;
}
next_entry++;
}
debug("FAT%d: entry: %08x, entry_value: %04x\n",
mydata->fatsize, entry, next_entry);
return next_entry;
}
/*
* Write at most 'size' bytes from 'buffer' into the specified cluster.
* Return 0 on success, -1 otherwise.
*/
static int
set_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer,
unsigned long size)
{
__u32 idx = 0;
__u32 startsect;
int ret;
if (clustnum > 0)
startsect = mydata->data_begin +
clustnum * mydata->clust_size;
else
startsect = mydata->rootdir_sect;
debug("clustnum: %d, startsect: %d\n", clustnum, startsect);
if ((unsigned long)buffer & (ARCH_DMA_MINALIGN - 1)) {
ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
printf("FAT: Misaligned buffer address (%p)\n", buffer);
while (size >= mydata->sect_size) {
memcpy(tmpbuf, buffer, mydata->sect_size);
ret = disk_write(startsect++, 1, tmpbuf);
if (ret != 1) {
debug("Error writing data (got %d)\n", ret);
return -1;
}
buffer += mydata->sect_size;
size -= mydata->sect_size;
}
} else if (size >= mydata->sect_size) {
idx = size / mydata->sect_size;
ret = disk_write(startsect, idx, buffer);
if (ret != idx) {
debug("Error writing data (got %d)\n", ret);
return -1;
}
startsect += idx;
idx *= mydata->sect_size;
buffer += idx;
size -= idx;
}
if (size) {
ALLOC_CACHE_ALIGN_BUFFER(__u8, tmpbuf, mydata->sect_size);
memcpy(tmpbuf, buffer, size);
ret = disk_write(startsect, 1, tmpbuf);
if (ret != 1) {
debug("Error writing data (got %d)\n", ret);
return -1;
}
}
return 0;
}
/*
* Find the first empty cluster
*/
static int find_empty_cluster(fsdata *mydata)
{
__u32 fat_val, entry = 3;
while (1) {
fat_val = get_fatent_value(mydata, entry);
if (fat_val == 0)
break;
entry++;
}
return entry;
}
/*
* Write directory entries in 'get_dentfromdir_block' to block device
*/
static void flush_dir_table(fsdata *mydata, dir_entry **dentptr)
{
int dir_newclust = 0;
if (set_cluster(mydata, dir_curclust,
get_dentfromdir_block,
mydata->clust_size * mydata->sect_size) != 0) {
printf("error: wrinting directory entry\n");
return;
}
dir_newclust = find_empty_cluster(mydata);
set_fatent_value(mydata, dir_curclust, dir_newclust);
if (mydata->fatsize == 32)
set_fatent_value(mydata, dir_newclust, 0xffffff8);
else if (mydata->fatsize == 16)
set_fatent_value(mydata, dir_newclust, 0xfff8);
dir_curclust = dir_newclust;
if (flush_fat_buffer(mydata) < 0)
return;
memset(get_dentfromdir_block, 0x00,
mydata->clust_size * mydata->sect_size);
*dentptr = (dir_entry *) get_dentfromdir_block;
}
/*
* Set empty cluster from 'entry' to the end of a file
*/
static int clear_fatent(fsdata *mydata, __u32 entry)
{
__u32 fat_val;
while (1) {
fat_val = get_fatent_value(mydata, entry);
if (fat_val != 0)
set_fatent_value(mydata, entry, 0);
else
break;
if (fat_val == 0xfffffff || fat_val == 0xffff)
break;
entry = fat_val;
}
/* Flush fat buffer */
if (flush_fat_buffer(mydata) < 0)
return -1;
return 0;
}
/*
* Write at most 'maxsize' bytes from 'buffer' into
* the file associated with 'dentptr'
* Update the number of bytes written in *gotsize and return 0
* or return -1 on fatal errors.
*/
static int
set_contents(fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
loff_t maxsize, loff_t *gotsize)
{
loff_t filesize = FAT2CPU32(dentptr->size);
unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
__u32 curclust = START(dentptr);
__u32 endclust = 0, newclust = 0;
loff_t actsize;
*gotsize = 0;
debug("Filesize: %llu bytes\n", filesize);
if (maxsize > 0 && filesize > maxsize)
filesize = maxsize;
debug("%llu bytes\n", filesize);
if (!curclust) {
if (filesize) {
debug("error: nonempty clusterless file!\n");
return -1;
}
return 0;
}
actsize = bytesperclust;
endclust = curclust;
do {
/* search for consecutive clusters */
while (actsize < filesize) {
newclust = determine_fatent(mydata, endclust);
if ((newclust - 1) != endclust)
goto getit;
if (CHECK_CLUST(newclust, mydata->fatsize)) {
debug("newclust: 0x%x\n", newclust);
debug("Invalid FAT entry\n");
return 0;
}
endclust = newclust;
actsize += bytesperclust;
}
/* set remaining bytes */
actsize = filesize;
if (set_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
debug("error: writing cluster\n");
return -1;
}
*gotsize += actsize;
/* Mark end of file in FAT */
if (mydata->fatsize == 16)
newclust = 0xffff;
else if (mydata->fatsize == 32)
newclust = 0xfffffff;
set_fatent_value(mydata, endclust, newclust);
return 0;
getit:
if (set_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
debug("error: writing cluster\n");
return -1;
}
*gotsize += actsize;
filesize -= actsize;
buffer += actsize;
if (CHECK_CLUST(newclust, mydata->fatsize)) {
debug("newclust: 0x%x\n", newclust);
debug("Invalid FAT entry\n");
return 0;
}
actsize = bytesperclust;
curclust = endclust = newclust;
} while (1);
}
/*
* Set start cluster in directory entry
*/
static void set_start_cluster(const fsdata *mydata, dir_entry *dentptr,
__u32 start_cluster)
{
if (mydata->fatsize == 32)
dentptr->starthi =
cpu_to_le16((start_cluster & 0xffff0000) >> 16);
dentptr->start = cpu_to_le16(start_cluster & 0xffff);
}
/*
* Fill dir_entry
*/
static void fill_dentry(fsdata *mydata, dir_entry *dentptr,
const char *filename, __u32 start_cluster, __u32 size, __u8 attr)
{
set_start_cluster(mydata, dentptr, start_cluster);
dentptr->size = cpu_to_le32(size);
dentptr->attr = attr;
set_name(dentptr, filename);
}
/*
* Check whether adding a file makes the file system to
* exceed the size of the block device
* Return -1 when overflow occurs, otherwise return 0
*/
static int check_overflow(fsdata *mydata, __u32 clustnum, loff_t size)
{
__u32 startsect, sect_num, offset;
if (clustnum > 0) {
startsect = mydata->data_begin +
clustnum * mydata->clust_size;
} else {
startsect = mydata->rootdir_sect;
}
sect_num = div_u64_rem(size, mydata->sect_size, &offset);
if (offset != 0)
sect_num++;
if (startsect + sect_num > cur_part_info.start + total_sector)
return -1;
return 0;
}
/*
* Check if adding several entries exceed one cluster boundary
*/
static int is_next_clust(fsdata *mydata, dir_entry *dentptr)
{
int cur_position;
cur_position = (__u8 *)dentptr - get_dentfromdir_block;
if (cur_position >= mydata->clust_size * mydata->sect_size)
return 1;
else
return 0;
}
static dir_entry *empty_dentptr;
/*
* Find a directory entry based on filename or start cluster number
* If the directory entry is not found,
* the new position for writing a directory entry will be returned
*/
static dir_entry *find_directory_entry(fsdata *mydata, int startsect,
char *filename, dir_entry *retdent, __u32 start)
{
__u32 curclust = (startsect - mydata->data_begin) / mydata->clust_size;
debug("get_dentfromdir: %s\n", filename);
while (1) {
dir_entry *dentptr;
int i;
if (get_cluster(mydata, curclust, get_dentfromdir_block,
mydata->clust_size * mydata->sect_size) != 0) {
printf("Error: reading directory block\n");
return NULL;
}
dentptr = (dir_entry *)get_dentfromdir_block;
dir_curclust = curclust;
for (i = 0; i < DIRENTSPERCLUST; i++) {
char s_name[14], l_name[VFAT_MAXLEN_BYTES];
l_name[0] = '\0';
if (dentptr->name[0] == DELETED_FLAG) {
dentptr++;
if (is_next_clust(mydata, dentptr))
break;
continue;
}
if ((dentptr->attr & ATTR_VOLUME)) {
if (vfat_enabled &&
(dentptr->attr & ATTR_VFAT) &&
(dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
get_long_file_name(mydata, curclust,
get_dentfromdir_block,
&dentptr, l_name);
debug("vfatname: |%s|\n", l_name);
} else {
/* Volume label or VFAT entry */
dentptr++;
if (is_next_clust(mydata, dentptr))
break;
continue;
}
}
if (dentptr->name[0] == 0) {
debug("Dentname == NULL - %d\n", i);
empty_dentptr = dentptr;
return NULL;
}
get_name(dentptr, s_name);
if (strcmp(filename, s_name)
&& strcmp(filename, l_name)) {
debug("Mismatch: |%s|%s|\n",
s_name, l_name);
dentptr++;
if (is_next_clust(mydata, dentptr))
break;
continue;
}
memcpy(retdent, dentptr, sizeof(dir_entry));
debug("DentName: %s", s_name);
debug(", start: 0x%x", START(dentptr));
debug(", size: 0x%x %s\n",
FAT2CPU32(dentptr->size),
(dentptr->attr & ATTR_DIR) ?
"(DIR)" : "");
return dentptr;
}
/*
* In FAT16/12, the root dir is locate before data area, shows
* in following:
* -------------------------------------------------------------
* | Boot | FAT1 & 2 | Root dir | Data (start from cluster #2) |
* -------------------------------------------------------------
*
* As a result if curclust is in Root dir, it is a negative
* number or 0, 1.
*
*/
if (mydata->fatsize != 32 && (int)curclust <= 1) {
/* Current clust is in root dir, set to next clust */
curclust++;
if ((int)curclust <= 1)
continue; /* continue to find */
/* Reach the end of root dir */
empty_dentptr = dentptr;
return NULL;
}
curclust = get_fatent_value(mydata, dir_curclust);
if (IS_LAST_CLUST(curclust, mydata->fatsize)) {
empty_dentptr = dentptr;
return NULL;
}
if (CHECK_CLUST(curclust, mydata->fatsize)) {
debug("curclust: 0x%x\n", curclust);
debug("Invalid FAT entry\n");
return NULL;
}
}
return NULL;
}
static int do_fat_write(const char *filename, void *buffer, loff_t size,
loff_t *actwrite)
{
dir_entry *dentptr, *retdent;
__u32 startsect;
__u32 start_cluster;
boot_sector bs;
volume_info volinfo;
fsdata datablock;
fsdata *mydata = &datablock;
int cursect;
int ret = -1, name_len;
char l_filename[VFAT_MAXLEN_BYTES];
*actwrite = size;
dir_curclust = 0;
if (read_bootsectandvi(&bs, &volinfo, &mydata->fatsize)) {
debug("error: reading boot sector\n");
return -1;
}
total_sector = bs.total_sect;
if (total_sector == 0)
total_sector = (int)cur_part_info.size; /* cast of lbaint_t */
if (mydata->fatsize == 32)
mydata->fatlength = bs.fat32_length;
else
mydata->fatlength = bs.fat_length;
mydata->fat_sect = bs.reserved;
cursect = mydata->rootdir_sect
= mydata->fat_sect + mydata->fatlength * bs.fats;
num_of_fats = bs.fats;
mydata->sect_size = (bs.sector_size[1] << 8) + bs.sector_size[0];
mydata->clust_size = bs.cluster_size;
if (mydata->fatsize == 32) {
mydata->data_begin = mydata->rootdir_sect -
(mydata->clust_size * 2);
} else {
int rootdir_size;
rootdir_size = ((bs.dir_entries[1] * (int)256 +
bs.dir_entries[0]) *
sizeof(dir_entry)) /
mydata->sect_size;
mydata->data_begin = mydata->rootdir_sect +
rootdir_size -
(mydata->clust_size * 2);
}
mydata->fatbufnum = -1;
mydata->fatbuf = memalign(ARCH_DMA_MINALIGN, FATBUFSIZE);
if (mydata->fatbuf == NULL) {
debug("Error: allocating memory\n");
return -1;
}
if (disk_read(cursect,
(mydata->fatsize == 32) ?
(mydata->clust_size) :
PREFETCH_BLOCKS, do_fat_read_at_block) < 0) {
debug("Error: reading rootdir block\n");
goto exit;
}
dentptr = (dir_entry *) do_fat_read_at_block;
name_len = strlen(filename);
if (name_len >= VFAT_MAXLEN_BYTES)
name_len = VFAT_MAXLEN_BYTES - 1;
memcpy(l_filename, filename, name_len);
l_filename[name_len] = 0; /* terminate the string */
downcase(l_filename);
startsect = mydata->rootdir_sect;
retdent = find_directory_entry(mydata, startsect,
l_filename, dentptr, 0);
if (retdent) {
/* Update file size and start_cluster in a directory entry */
retdent->size = cpu_to_le32(size);
start_cluster = START(retdent);
if (start_cluster) {
if (size) {
ret = check_overflow(mydata, start_cluster,
size);
if (ret) {
printf("Error: %llu overflow\n", size);
goto exit;
}
}
ret = clear_fatent(mydata, start_cluster);
if (ret) {
printf("Error: clearing FAT entries\n");
goto exit;
}
if (!size)
set_start_cluster(mydata, retdent, 0);
} else if (size) {
ret = start_cluster = find_empty_cluster(mydata);
if (ret < 0) {
printf("Error: finding empty cluster\n");
goto exit;
}
ret = check_overflow(mydata, start_cluster, size);
if (ret) {
printf("Error: %llu overflow\n", size);
goto exit;
}
set_start_cluster(mydata, retdent, start_cluster);
}
} else {
/* Set short name to set alias checksum field in dir_slot */
set_name(empty_dentptr, filename);
fill_dir_slot(mydata, &empty_dentptr, filename);
if (size) {
ret = start_cluster = find_empty_cluster(mydata);
if (ret < 0) {
printf("Error: finding empty cluster\n");
goto exit;
}
ret = check_overflow(mydata, start_cluster, size);
if (ret) {
printf("Error: %llu overflow\n", size);
goto exit;
}
} else {
start_cluster = 0;
}
/* Set attribute as archieve for regular file */
fill_dentry(mydata, empty_dentptr, filename,
start_cluster, size, 0x20);
retdent = empty_dentptr;
}
ret = set_contents(mydata, retdent, buffer, size, actwrite);
if (ret < 0) {
printf("Error: writing contents\n");
goto exit;
}
debug("attempt to write 0x%llx bytes\n", *actwrite);
/* Flush fat buffer */
ret = flush_fat_buffer(mydata);
if (ret) {
printf("Error: flush fat buffer\n");
goto exit;
}
/* Write directory table to device */
ret = set_cluster(mydata, dir_curclust, get_dentfromdir_block,
mydata->clust_size * mydata->sect_size);
if (ret)
printf("Error: writing directory entry\n");
exit:
free(mydata->fatbuf);
return ret;
}
int file_fat_write(const char *filename, void *buffer, loff_t offset,
loff_t maxsize, loff_t *actwrite)
{
if (offset != 0) {
printf("Error: non zero offset is currently not suported.\n");
return -1;
}
printf("writing %s\n", filename);
return do_fat_write(filename, buffer, maxsize, actwrite);
}