summaryrefslogtreecommitdiff
path: root/fs/fat/fat.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/fat/fat.c')
-rw-r--r--fs/fat/fat.c258
1 files changed, 164 insertions, 94 deletions
diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index bc46cc5..41ae15e 100644
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -37,7 +37,7 @@
/*
* Convert a string to lowercase.
*/
-static void downcase (char *str)
+static void downcase(char *str)
{
while (*str != '\0') {
TOLOWER(*str);
@@ -62,7 +62,7 @@ static int disk_read(__u32 block, __u32 nr_blocks, void *buf)
cur_part_info.start + block, nr_blocks, buf);
}
-int fat_register_device (block_dev_desc_t * dev_desc, int part_no)
+int fat_register_device(block_dev_desc_t * dev_desc, int part_no)
{
ALLOC_CACHE_ALIGN_BUFFER(unsigned char, buffer, dev_desc->blksz);
@@ -127,7 +127,7 @@ int fat_register_device (block_dev_desc_t * dev_desc, int part_no)
* Get the first occurence of a directory delimiter ('/' or '\') in a string.
* Return index into string if found, -1 otherwise.
*/
-static int dirdelim (char *str)
+static int dirdelim(char *str)
{
char *start = str;
@@ -142,7 +142,7 @@ static int dirdelim (char *str)
/*
* Extract zero terminated short name from a directory entry.
*/
-static void get_name (dir_entry *dirent, char *s_name)
+static void get_name(dir_entry *dirent, char *s_name)
{
char *ptr;
@@ -171,7 +171,7 @@ static void get_name (dir_entry *dirent, char *s_name)
* Get the entry at index 'entry' in a FAT (12/16/32) table.
* On failure 0x00 is returned.
*/
-static __u32 get_fatent (fsdata *mydata, __u32 entry)
+static __u32 get_fatent(fsdata *mydata, __u32 entry)
{
__u32 bufnum;
__u32 off16, offset;
@@ -207,10 +207,9 @@ static __u32 get_fatent (fsdata *mydata, __u32 entry)
__u32 fatlength = mydata->fatlength;
__u32 startblock = bufnum * FATBUFBLOCKS;
- if (getsize > fatlength)
- getsize = fatlength;
+ if (startblock + getsize > fatlength)
+ getsize = fatlength - startblock;
- fatlength *= mydata->sect_size; /* We want it in bytes now */
startblock += mydata->fat_sect; /* Offset from start of disk */
if (disk_read(startblock, getsize, bufptr) < 0) {
@@ -270,12 +269,10 @@ static __u32 get_fatent (fsdata *mydata, __u32 entry)
* Return 0 on success, -1 otherwise.
*/
static int
-get_cluster (fsdata *mydata, __u32 clustnum, __u8 *buffer,
- unsigned long size)
+get_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer, unsigned long size)
{
__u32 idx = 0;
__u32 startsect;
- __u32 nr_sect;
int ret;
if (clustnum > 0) {
@@ -287,38 +284,60 @@ get_cluster (fsdata *mydata, __u32 clustnum, __u8 *buffer,
debug("gc - clustnum: %d, startsect: %d\n", clustnum, startsect);
- nr_sect = size / mydata->sect_size;
- ret = disk_read(startsect, nr_sect, buffer);
- if (ret != nr_sect) {
- debug("Error reading data (got %d)\n", ret);
- return -1;
- }
- if (size % mydata->sect_size) {
+ 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) {
+ ret = disk_read(startsect++, 1, tmpbuf);
+ if (ret != 1) {
+ debug("Error reading data (got %d)\n", ret);
+ return -1;
+ }
+
+ memcpy(buffer, tmpbuf, mydata->sect_size);
+ buffer += mydata->sect_size;
+ size -= mydata->sect_size;
+ }
+ } else {
idx = size / mydata->sect_size;
- ret = disk_read(startsect + idx, 1, tmpbuf);
+ ret = disk_read(startsect, idx, buffer);
+ if (ret != idx) {
+ debug("Error reading 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);
+
+ ret = disk_read(startsect, 1, tmpbuf);
if (ret != 1) {
debug("Error reading data (got %d)\n", ret);
return -1;
}
- buffer += idx * mydata->sect_size;
- memcpy(buffer, tmpbuf, size % mydata->sect_size);
- return 0;
+ memcpy(buffer, tmpbuf, size);
}
return 0;
}
/*
- * Read at most 'maxsize' bytes from the file associated with 'dentptr'
+ * Read at most 'maxsize' bytes from 'pos' in the file associated with 'dentptr'
* into 'buffer'.
* Return the number of bytes read or -1 on fatal errors.
*/
+__u8 get_contents_vfatname_block[MAX_CLUSTSIZE]
+ __aligned(ARCH_DMA_MINALIGN);
+
static long
-get_contents (fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
- unsigned long maxsize)
+get_contents(fsdata *mydata, dir_entry *dentptr, unsigned long pos,
+ __u8 *buffer, unsigned long maxsize)
{
unsigned long filesize = FAT2CPU32(dentptr->size), gotsize = 0;
unsigned int bytesperclust = mydata->clust_size * mydata->sect_size;
@@ -328,12 +347,59 @@ get_contents (fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
debug("Filesize: %ld bytes\n", filesize);
- if (maxsize > 0 && filesize > maxsize)
- filesize = maxsize;
+ if (pos >= filesize) {
+ debug("Read position past EOF: %lu\n", pos);
+ return gotsize;
+ }
+
+ if (maxsize > 0 && filesize > pos + maxsize)
+ filesize = pos + maxsize;
debug("%ld bytes\n", filesize);
actsize = bytesperclust;
+
+ /* go to cluster at pos */
+ while (actsize <= pos) {
+ curclust = get_fatent(mydata, curclust);
+ if (CHECK_CLUST(curclust, mydata->fatsize)) {
+ debug("curclust: 0x%x\n", curclust);
+ debug("Invalid FAT entry\n");
+ return gotsize;
+ }
+ actsize += bytesperclust;
+ }
+
+ /* actsize > pos */
+ actsize -= bytesperclust;
+ filesize -= actsize;
+ pos -= actsize;
+
+ /* align to beginning of next cluster if any */
+ if (pos) {
+ actsize = min(filesize, bytesperclust);
+ if (get_cluster(mydata, curclust, get_contents_vfatname_block,
+ (int)actsize) != 0) {
+ printf("Error reading cluster\n");
+ return -1;
+ }
+ filesize -= actsize;
+ actsize -= pos;
+ memcpy(buffer, get_contents_vfatname_block + pos, actsize);
+ gotsize += actsize;
+ if (!filesize)
+ return gotsize;
+ buffer += actsize;
+
+ curclust = get_fatent(mydata, curclust);
+ if (CHECK_CLUST(curclust, mydata->fatsize)) {
+ debug("curclust: 0x%x\n", curclust);
+ debug("Invalid FAT entry\n");
+ return gotsize;
+ }
+ }
+
+ actsize = bytesperclust;
endclust = curclust;
do {
@@ -351,21 +417,9 @@ get_contents (fsdata *mydata, dir_entry *dentptr, __u8 *buffer,
actsize += bytesperclust;
}
- /* actsize >= file size */
- actsize -= bytesperclust;
-
- /* get remaining clusters */
- if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
- printf("Error reading cluster\n");
- return -1;
- }
-
/* get remaining bytes */
- gotsize += (int)actsize;
- filesize -= actsize;
- buffer += actsize;
actsize = filesize;
- if (get_cluster(mydata, endclust, buffer, (int)actsize) != 0) {
+ if (get_cluster(mydata, curclust, buffer, (int)actsize) != 0) {
printf("Error reading cluster\n");
return -1;
}
@@ -397,7 +451,7 @@ getit:
* starting at l_name[*idx].
* Return 1 if terminator (zero byte) is found, 0 otherwise.
*/
-static int slot2str (dir_slot *slotptr, char *l_name, int *idx)
+static int slot2str(dir_slot *slotptr, char *l_name, int *idx)
{
int j;
@@ -429,12 +483,9 @@ static int slot2str (dir_slot *slotptr, char *l_name, int *idx)
* into 'retdent'
* Return 0 on success, -1 otherwise.
*/
-__u8 get_vfatname_block[MAX_CLUSTSIZE]
- __aligned(ARCH_DMA_MINALIGN);
-
static int
-get_vfatname (fsdata *mydata, int curclust, __u8 *cluster,
- dir_entry *retdent, char *l_name)
+get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
+ dir_entry *retdent, char *l_name)
{
dir_entry *realdent;
dir_slot *slotptr = (dir_slot *)retdent;
@@ -470,13 +521,13 @@ get_vfatname (fsdata *mydata, int curclust, __u8 *cluster,
return -1;
}
- if (get_cluster(mydata, curclust, get_vfatname_block,
+ 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_vfatname_block;
+ slotptr2 = (dir_slot *)get_contents_vfatname_block;
while (counter > 0) {
if (((slotptr2->id & ~LAST_LONG_ENTRY_MASK)
& 0xff) != counter)
@@ -487,7 +538,7 @@ get_vfatname (fsdata *mydata, int curclust, __u8 *cluster,
/* Save the real directory entry */
realdent = (dir_entry *)slotptr2;
- while ((__u8 *)slotptr2 > get_vfatname_block) {
+ while ((__u8 *)slotptr2 > get_contents_vfatname_block) {
slotptr2--;
slot2str(slotptr2, l_name, &idx);
}
@@ -516,7 +567,7 @@ get_vfatname (fsdata *mydata, int curclust, __u8 *cluster,
}
/* Calculate short name checksum */
-static __u8 mkcksum (const char *str)
+static __u8 mkcksum(const char *str)
{
int i;
@@ -537,9 +588,9 @@ static __u8 mkcksum (const char *str)
__u8 get_dentfromdir_block[MAX_CLUSTSIZE]
__aligned(ARCH_DMA_MINALIGN);
-static dir_entry *get_dentfromdir (fsdata *mydata, int startsect,
- char *filename, dir_entry *retdent,
- int dols)
+static dir_entry *get_dentfromdir(fsdata *mydata, int startsect,
+ char *filename, dir_entry *retdent,
+ int dols)
{
__u16 prevcksum = 0xffff;
__u32 curclust = START(retdent);
@@ -699,7 +750,7 @@ static dir_entry *get_dentfromdir (fsdata *mydata, int startsect,
* Read boot sector and volume info from a FAT filesystem
*/
static int
-read_bootsectandvi (boot_sector *bs, volume_info *volinfo, int *fatsize)
+read_bootsectandvi(boot_sector *bs, volume_info *volinfo, int *fatsize)
{
__u8 *block;
volume_info *vistart;
@@ -716,7 +767,7 @@ read_bootsectandvi (boot_sector *bs, volume_info *volinfo, int *fatsize)
return -1;
}
- if (disk_read (0, 1, block) < 0) {
+ if (disk_read(0, 1, block) < 0) {
debug("Error: reading block\n");
goto fail;
}
@@ -766,19 +817,19 @@ exit:
return ret;
}
-__u8 do_fat_read_block[MAX_CLUSTSIZE]
+__u8 do_fat_read_at_block[MAX_CLUSTSIZE]
__aligned(ARCH_DMA_MINALIGN);
long
-do_fat_read (const char *filename, void *buffer, unsigned long maxsize,
- int dols)
+do_fat_read_at(const char *filename, unsigned long pos, void *buffer,
+ unsigned long maxsize, int dols)
{
char fnamecopy[2048];
boot_sector bs;
volume_info volinfo;
fsdata datablock;
fsdata *mydata = &datablock;
- dir_entry *dentptr;
+ dir_entry *dentptr = NULL;
__u16 prevcksum = 0xffff;
char *subname = "";
__u32 cursect;
@@ -877,19 +928,21 @@ do_fat_read (const char *filename, void *buffer, unsigned long maxsize,
while (1) {
int i;
- debug("FAT read sect=%d, clust_size=%d, DIRENTSPERBLOCK=%zd\n",
- cursect, mydata->clust_size, DIRENTSPERBLOCK);
+ if (j == 0) {
+ debug("FAT read sect=%d, clust_size=%d, DIRENTSPERBLOCK=%zd\n",
+ cursect, mydata->clust_size, DIRENTSPERBLOCK);
- if (disk_read(cursect,
- (mydata->fatsize == 32) ?
- (mydata->clust_size) :
- PREFETCH_BLOCKS,
- do_fat_read_block) < 0) {
- debug("Error: reading rootdir block\n");
- goto exit;
- }
+ 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_block;
+ dentptr = (dir_entry *) do_fat_read_at_block;
+ }
for (i = 0; i < DIRENTSPERBLOCK; i++) {
char s_name[14], l_name[VFAT_MAXLEN_BYTES];
@@ -908,7 +961,7 @@ do_fat_read (const char *filename, void *buffer, unsigned long maxsize,
get_vfatname(mydata,
root_cluster,
- do_fat_read_block,
+ do_fat_read_at_block,
dentptr, l_name);
if (dols == LS_ROOT) {
@@ -1031,28 +1084,33 @@ do_fat_read (const char *filename, void *buffer, unsigned long maxsize,
* completely processed.
*/
++j;
- int fat32_end = 0;
- if ((mydata->fatsize == 32) && (j == mydata->clust_size)) {
- int nxtsect = 0;
- int nxt_clust = 0;
+ int rootdir_end = 0;
+ if (mydata->fatsize == 32) {
+ if (j == mydata->clust_size) {
+ int nxtsect = 0;
+ int nxt_clust = 0;
- nxt_clust = get_fatent(mydata, root_cluster);
- fat32_end = CHECK_CLUST(nxt_clust, 32);
+ nxt_clust = get_fatent(mydata, root_cluster);
+ rootdir_end = CHECK_CLUST(nxt_clust, 32);
- nxtsect = mydata->data_begin +
- (nxt_clust * mydata->clust_size);
+ nxtsect = mydata->data_begin +
+ (nxt_clust * mydata->clust_size);
- root_cluster = nxt_clust;
+ root_cluster = nxt_clust;
- cursect = nxtsect;
- j = 0;
+ cursect = nxtsect;
+ j = 0;
+ }
} else {
- cursect++;
+ if (j == PREFETCH_BLOCKS)
+ j = 0;
+
+ rootdir_end = (++cursect - mydata->rootdir_sect >=
+ rootdir_size);
}
/* If end of rootdir reached */
- if ((mydata->fatsize == 32 && fat32_end) ||
- (mydata->fatsize != 32 && j == rootdir_size)) {
+ if (rootdir_end) {
if (dols == LS_ROOT) {
printf("\n%d file(s), %d dir(s)\n\n",
files, dirs);
@@ -1099,14 +1157,14 @@ rootdir_done:
goto exit;
}
- if (idx >= 0) {
- if (!(dentptr->attr & ATTR_DIR))
- goto exit;
+ if (isdir && !(dentptr->attr & ATTR_DIR))
+ goto exit;
+
+ if (idx >= 0)
subname = nextname;
- }
}
- ret = get_contents(mydata, dentptr, buffer, maxsize);
+ ret = get_contents(mydata, dentptr, pos, buffer, maxsize);
debug("Size: %d, got: %ld\n", FAT2CPU32(dentptr->size), ret);
exit:
@@ -1114,7 +1172,13 @@ exit:
return ret;
}
-int file_fat_detectfs (void)
+long
+do_fat_read(const char *filename, void *buffer, unsigned long maxsize, int dols)
+{
+ return do_fat_read_at(filename, 0, buffer, maxsize, dols);
+}
+
+int file_fat_detectfs(void)
{
boot_sector bs;
volume_info volinfo;
@@ -1177,13 +1241,19 @@ int file_fat_detectfs (void)
return 0;
}
-int file_fat_ls (const char *dir)
+int file_fat_ls(const char *dir)
{
return do_fat_read(dir, NULL, 0, LS_YES);
}
-long file_fat_read (const char *filename, void *buffer, unsigned long maxsize)
+long file_fat_read_at(const char *filename, unsigned long pos, void *buffer,
+ unsigned long maxsize)
{
printf("reading %s\n", filename);
- return do_fat_read(filename, buffer, maxsize, LS_NO);
+ return do_fat_read_at(filename, pos, buffer, maxsize, LS_NO);
+}
+
+long file_fat_read(const char *filename, void *buffer, unsigned long maxsize)
+{
+ return file_fat_read_at(filename, 0, buffer, maxsize);
}