static void print_generic_info(const struct exfat_super_block* sb)
{
printf("Volume serial number 0x%08x\n",
le32_to_cpu(sb->volume_serial));
printf("FS version %hhu.%hhu\n",
sb->version.major, sb->version.minor);
printf("Sector size %10u\n",
SECTOR_SIZE(*sb));
printf("Cluster size %10u\n",
CLUSTER_SIZE(*sb));
}
int exfat_find_used_sectors(const struct exfat* ef, off_t* a, off_t* b)
{
cluster_t ca, cb;
if (*a == 0 && *b == 0)
ca = cb = EXFAT_FIRST_DATA_CLUSTER - 1;
else
{
ca = s2c(ef, *a);
cb = s2c(ef, *b);
}
if (find_used_clusters(ef, &ca, &cb) != 0)
return 1;
if (*a != 0 || *b != 0)
*a = c2s(ef, ca);
*b = c2s(ef, cb) + (CLUSTER_SIZE(*ef->sb) - 1) / SECTOR_SIZE(*ef->sb);
return 0;
}
void pm_open_file(com32sys_t *regs)
{
int rv;
struct file *file;
const char *name = MK_PTR(regs->es, regs->esi.w[0]);
char mangled_name[FILENAME_MAX];
dprintf("pm_open_file %s\n", name);
mangle_name(mangled_name, name);
rv = searchdir(mangled_name);
if (rv < 0) {
regs->eflags.l |= EFLAGS_CF;
} else {
file = handle_to_file(rv);
regs->eflags.l &= ~EFLAGS_CF;
regs->eax.l = file->inode->size;
regs->ecx.w[0] = SECTOR_SIZE(file->fs);
regs->esi.w[0] = rv;
}
}
void pm_load_high(com32sys_t *regs)
{
struct fs_info *fs;
uint32_t bytes;
uint32_t zero_mask;
bool have_more;
uint32_t bytes_read;
char *buf, *limit;
struct file *file;
uint32_t sector_mask;
size_t pad;
uint32_t retflags = 0;
bytes = regs->eax.l;
zero_mask = regs->edx.w[0];
buf = (char *)regs->edi.l;
limit = (char *)(regs->ebp.l & ~zero_mask);
file = handle_to_file(regs->esi.w[0]);
fs = file->fs;
sector_mask = SECTOR_SIZE(fs) - 1;
while (bytes) {
uint32_t sectors;
uint32_t chunk;
if (buf + SECTOR_SIZE(fs) > limit) {
/* Can't fit even one more sector in... */
retflags = EFLAGS_OF;
break;
}
chunk = bytes;
if (regs->ebx.w[0]) {
call16((void (*)(void))(size_t)regs->ebx.w[0], &zero_regs, NULL);
chunk = min(chunk, MAX_CHUNK);
}
if (chunk > (((char *)limit - buf) & ~sector_mask))
chunk = ((char *)limit - buf) & ~sector_mask;
sectors = (chunk + sector_mask) >> SECTOR_SHIFT(fs);
bytes_read = fs->fs_ops->getfssec(file, buf, sectors, &have_more);
if (bytes_read > chunk)
bytes_read = chunk;
buf += bytes_read;
bytes -= bytes_read;
if (!have_more) {
/*
* If we reach EOF, the filesystem driver will have already closed
* the underlying file... this really should be cleaner.
*/
_close_file(file);
regs->esi.w[0] = 0;
retflags = EFLAGS_CF;
break;
}
}
pad = (size_t)buf & zero_mask;
if (pad)
memset(buf, 0, pad);
regs->ebx.l = (size_t)buf;
regs->edi.l = (size_t)buf + pad;
set_flags(regs, retflags);
}
int exfat_mount(struct exfat* ef, const char* spec, const char* options)
{
int rc;
enum exfat_mode mode;
exfat_tzset();
memset(ef, 0, sizeof(struct exfat));
parse_options(ef, options);
if (match_option(options, "ro"))
mode = EXFAT_MODE_RO;
else if (match_option(options, "ro_fallback"))
mode = EXFAT_MODE_ANY;
else
mode = EXFAT_MODE_RW;
ef->dev = exfat_open(spec, mode);
if (ef->dev == NULL)
return -EIO;
if (exfat_get_mode(ef->dev) == EXFAT_MODE_RO)
{
if (mode == EXFAT_MODE_ANY)
ef->ro = -1;
else
ef->ro = 1;
}
ef->sb = malloc(sizeof(struct exfat_super_block));
if (ef->sb == NULL)
{
exfat_close(ef->dev);
exfat_error("failed to allocate memory for the super block");
return -ENOMEM;
}
memset(ef->sb, 0, sizeof(struct exfat_super_block));
if (exfat_pread(ef->dev, ef->sb, sizeof(struct exfat_super_block), 0) < 0)
{
exfat_close(ef->dev);
free(ef->sb);
exfat_error("failed to read boot sector");
return -EIO;
}
if (memcmp(ef->sb->oem_name, "EXFAT ", 8) != 0)
{
exfat_close(ef->dev);
free(ef->sb);
exfat_error("exFAT file system is not found");
return -EIO;
}
/* sector cannot be smaller than 512 bytes */
if (ef->sb->sector_bits < 9)
{
exfat_close(ef->dev);
exfat_error("too small sector size: 2^%hhd", ef->sb->sector_bits);
free(ef->sb);
return -EIO;
}
/* officially exFAT supports cluster size up to 32 MB */
if ((int) ef->sb->sector_bits + (int) ef->sb->spc_bits > 25)
{
exfat_close(ef->dev);
exfat_error("too big cluster size: 2^(%hhd+%hhd)",
ef->sb->sector_bits, ef->sb->spc_bits);
free(ef->sb);
return -EIO;
}
ef->zero_cluster = malloc(CLUSTER_SIZE(*ef->sb));
if (ef->zero_cluster == NULL)
{
exfat_close(ef->dev);
free(ef->sb);
exfat_error("failed to allocate zero sector");
return -ENOMEM;
}
/* use zero_cluster as a temporary buffer for VBR checksum verification */
if (!verify_vbr_checksum(ef->dev, ef->zero_cluster, SECTOR_SIZE(*ef->sb)))
{
free(ef->zero_cluster);
exfat_close(ef->dev);
free(ef->sb);
return -EIO;
}
memset(ef->zero_cluster, 0, CLUSTER_SIZE(*ef->sb));
if (ef->sb->version.major != 1 || ef->sb->version.minor != 0)
{
free(ef->zero_cluster);
exfat_close(ef->dev);
exfat_error("unsupported exFAT version: %hhu.%hhu",
ef->sb->version.major, ef->sb->version.minor);
free(ef->sb);
return -EIO;
}
if (ef->sb->fat_count != 1)
{
free(ef->zero_cluster);
exfat_close(ef->dev);
exfat_error("unsupported FAT count: %hhu", ef->sb->fat_count);
free(ef->sb);
return -EIO;
}
if (le64_to_cpu(ef->sb->sector_count) * SECTOR_SIZE(*ef->sb) >
exfat_get_size(ef->dev))
{
/* this can cause I/O errors later but we don't fail mounting to let
user rescue data */
exfat_warn("file system is larger than underlying device: "
"%"PRIu64" > %"PRIu64,
le64_to_cpu(ef->sb->sector_count) * SECTOR_SIZE(*ef->sb),
exfat_get_size(ef->dev));
}
ef->root = malloc(sizeof(struct exfat_node));
if (ef->root == NULL)
{
free(ef->zero_cluster);
exfat_close(ef->dev);
free(ef->sb);
exfat_error("failed to allocate root node");
return -ENOMEM;
}
memset(ef->root, 0, sizeof(struct exfat_node));
ef->root->flags = EXFAT_ATTRIB_DIR;
ef->root->start_cluster = le32_to_cpu(ef->sb->rootdir_cluster);
ef->root->fptr_cluster = ef->root->start_cluster;
ef->root->name[0] = cpu_to_le16('\0');
ef->root->size = rootdir_size(ef);
if (ef->root->size == 0)
{
free(ef->root);
free(ef->zero_cluster);
exfat_close(ef->dev);
free(ef->sb);
return -EIO;
}
/* exFAT does not have time attributes for the root directory */
ef->root->mtime = 0;
ef->root->atime = 0;
/* always keep at least 1 reference to the root node */
exfat_get_node(ef->root);
rc = exfat_cache_directory(ef, ef->root);
if (rc != 0)
goto error;
if (ef->upcase == NULL)
{
exfat_error("upcase table is not found");
goto error;
}
if (ef->cmap.chunk == NULL)
{
exfat_error("clusters bitmap is not found");
goto error;
}
if (prepare_super_block(ef) != 0)
goto error;
return 0;
error:
exfat_put_node(ef, ef->root);
exfat_reset_cache(ef);
free(ef->root);
free(ef->zero_cluster);
exfat_close(ef->dev);
free(ef->sb);
return -EIO;
}
uint32_t generic_getfssec(struct file *file, char *buf,
int sectors, bool *have_more)
{
struct inode *inode = file->inode;
struct fs_info *fs = file->fs;
struct disk *disk = fs->fs_dev->disk;
uint32_t bytes_read = 0;
uint32_t bytes_left = inode->size - file->offset;
uint32_t sectors_left =
(bytes_left + SECTOR_SIZE(fs) - 1) >> SECTOR_SHIFT(fs);
uint32_t lsector;
if (sectors > sectors_left)
sectors = sectors_left;
if (!sectors)
return 0;
lsector = file->offset >> SECTOR_SHIFT(fs);
dprintf("Offset: %u lsector: %u\n", file->offset, lsector);
if (lsector < inode->this_extent.lstart ||
lsector >= inode->this_extent.lstart + inode->this_extent.len) {
/* inode->this_extent unusable, maybe next_extent is... */
inode->this_extent = inode->next_extent;
}
if (lsector < inode->this_extent.lstart ||
lsector >= inode->this_extent.lstart + inode->this_extent.len) {
/* Still nothing useful... */
inode->this_extent.lstart = lsector;
inode->this_extent.len = 0;
} else {
/* We have some usable information */
uint32_t delta = lsector - inode->this_extent.lstart;
inode->this_extent.lstart = lsector;
inode->this_extent.len -= delta;
inode->this_extent.pstart
= next_psector(inode->this_extent.pstart, delta);
}
dprintf("this_extent: lstart %u pstart %llu len %u\n",
inode->this_extent.lstart,
inode->this_extent.pstart,
inode->this_extent.len);
while (sectors) {
uint32_t chunk;
size_t len;
while (sectors > inode->this_extent.len) {
if (!inode->next_extent.len ||
inode->next_extent.lstart !=
inode->this_extent.lstart + inode->this_extent.len)
get_next_extent(inode);
if (!inode->this_extent.len) {
/* Doesn't matter if it's contiguous... */
inode->this_extent = inode->next_extent;
if (!inode->next_extent.len) {
sectors = 0; /* Failed to get anything... we're dead */
break;
}
} else if (inode->next_extent.len &&
inode->next_extent.pstart == next_pstart(&inode->this_extent)) {
/* Coalesce extents and loop */
inode->this_extent.len += inode->next_extent.len;
} else {
/* Discontiguous extents */
break;
}
}
dprintf("this_extent: lstart %u pstart %llu len %u\n",
inode->this_extent.lstart,
inode->this_extent.pstart,
inode->this_extent.len);
chunk = min(sectors, inode->this_extent.len);
len = chunk << SECTOR_SHIFT(fs);
dprintf(" I/O: inode %p @ %u start %llu len %u\n",
inode, inode->this_extent.lstart,
inode->this_extent.pstart, chunk);
if (inode->this_extent.pstart == EXTENT_ZERO) {
memset(buf, 0, len);
} else {
disk->rdwr_sectors(disk, buf, inode->this_extent.pstart, chunk, 0);
inode->this_extent.pstart += chunk;
}
buf += len;
sectors -= chunk;
bytes_read += len;
inode->this_extent.lstart += chunk;
inode->this_extent.len -= chunk;
}
bytes_read = min(bytes_read, bytes_left);
file->offset += bytes_read;
if (have_more)
*have_more = bytes_read < bytes_left;
return bytes_read;
}
