/* Read LEN bytes from the file described by DATA starting with byte
POS. Return the amount of read bytes in READ. */
static grub_ssize_t
grub_hfs_read_file (struct grub_hfs_data *data,
void NESTED_FUNC_ATTR (*read_hook) (grub_disk_addr_t sector,
unsigned offset, unsigned length),
grub_off_t pos, grub_size_t len, char *buf)
{
grub_off_t i;
grub_off_t blockcnt;
blockcnt = grub_divmod64 (((len + pos)
+ data->blksz - 1), data->blksz, 0);
for (i = grub_divmod64 (pos, data->blksz, 0); i < blockcnt; i++)
{
grub_disk_addr_t blknr;
grub_off_t blockoff;
grub_off_t blockend = data->blksz;
int skipfirst = 0;
grub_divmod64 (pos, data->blksz, &blockoff);
blknr = grub_hfs_block (data, data->extents, data->fileid, i, 1);
if (grub_errno)
return -1;
/* Last block. */
if (i == blockcnt - 1)
{
grub_divmod64 ((len + pos), data->blksz, &blockend);
/* The last portion is exactly EXT2_BLOCK_SIZE (data). */
if (! blockend)
blockend = data->blksz;
}
/* First block. */
if (i == grub_divmod64 (pos, data->blksz, 0))
{
skipfirst = blockoff;
blockend -= skipfirst;
}
/* If the block number is 0 this block is not stored on disk but
is zero filled instead. */
if (blknr)
{
data->disk->read_hook = read_hook;
grub_disk_read (data->disk, blknr, skipfirst,
blockend, buf);
data->disk->read_hook = 0;
if (grub_errno)
return -1;
}
buf += data->blksz - skipfirst;
}
return len;
}
/* Read LEN bytes from the file described by DATA starting with byte
POS. Return the amount of read bytes in READ. */
static grub_ssize_t
grub_hfs_read_file (struct grub_hfs_data *data,
void (*read_hook) (grub_disk_addr_t sector,
unsigned offset, unsigned length,
void *closure),
void *closure,
int pos, grub_size_t len, char *buf)
{
int i;
int blockcnt;
blockcnt = ((len + pos)
+ data->blksz - 1) / data->blksz;
for (i = pos / data->blksz; i < blockcnt; i++)
{
int blknr;
int blockoff = pos % data->blksz;
int blockend = data->blksz;
int skipfirst = 0;
blknr = grub_hfs_block (data, data->extents, data->fileid, i, 1);
if (grub_errno)
return -1;
/* Last block. */
if (i == blockcnt - 1)
{
blockend = (len + pos) % data->blksz;
/* The last portion is exactly EXT2_BLOCK_SIZE (data). */
if (! blockend)
blockend = data->blksz;
}
/* First block. */
if (i == pos / data->blksz)
{
skipfirst = blockoff;
blockend -= skipfirst;
}
/* If the block number is 0 this block is not stored on disk but
is zero filled instead. */
if (blknr)
{
data->disk->read_hook = read_hook;
data->disk->closure = closure;
grub_disk_read (data->disk, blknr, skipfirst,
blockend, buf);
data->disk->read_hook = 0;
if (grub_errno)
return -1;
}
buf += data->blksz - skipfirst;
}
return len;
}
/* Read LEN bytes from the file described by DATA starting with byte
POS. Return the amount of read bytes in READ. */
static grub_ssize_t
grub_hfs_read_file (struct grub_hfs_data *data,
grub_disk_read_hook_t read_hook, void *read_hook_data,
grub_uint32_t pos, grub_size_t len, char *buf)
{
grub_off_t i;
grub_off_t blockcnt;
/* Files are at most 2G/4G - 1 bytes on hfs. Avoid 64-bit division.
Moreover len > 0 as checked in upper layer. */
blockcnt = (len + pos - 1) / data->blksz + 1;
for (i = pos / data->blksz; i < blockcnt; i++)
{
grub_disk_addr_t blknr;
grub_off_t blockoff;
grub_off_t blockend = data->blksz;
int skipfirst = 0;
blockoff = pos % data->blksz;
blknr = grub_hfs_block (data, data->extents, data->fileid, i, 1);
if (grub_errno)
return -1;
/* Last block. */
if (i == blockcnt - 1)
{
blockend = (len + pos) % data->blksz;
/* The last portion is exactly EXT2_BLOCK_SIZE (data). */
if (! blockend)
blockend = data->blksz;
}
/* First block. */
if (i == pos / data->blksz)
{
skipfirst = blockoff;
blockend -= skipfirst;
}
/* If the block number is 0 this block is not stored on disk but
is zero filled instead. */
if (blknr)
{
data->disk->read_hook = read_hook;
data->disk->read_hook_data = read_hook_data;
grub_disk_read (data->disk, blknr, skipfirst,
blockend, buf);
data->disk->read_hook = 0;
if (grub_errno)
return -1;
}
buf += data->blksz - skipfirst;
}
return len;
}
