grub_util_fd_t
grub_util_fd_open_device (const grub_disk_t disk, grub_disk_addr_t sector, int flags,
grub_disk_addr_t *max)
{
grub_util_fd_t fd;
struct grub_util_hostdisk_data *data = disk->data;
*max = ~0ULL;
flags |= GRUB_UTIL_FD_O_SYNC;
if (data->dev && strcmp (data->dev, map[disk->id].device) == 0 &&
data->access_mode == (flags & O_ACCMODE))
{
grub_dprintf ("hostdisk", "reusing open device `%s'\n", data->dev);
fd = data->fd;
}
else
{
free (data->dev);
data->dev = 0;
if (GRUB_UTIL_FD_IS_VALID(data->fd))
{
if (data->access_mode == O_RDWR || data->access_mode == O_WRONLY)
grub_util_fd_sync (data->fd);
grub_util_fd_close (data->fd);
data->fd = GRUB_UTIL_FD_INVALID;
}
fd = grub_util_fd_open (map[disk->id].device, flags);
if (GRUB_UTIL_FD_IS_VALID(fd))
{
data->dev = xstrdup (map[disk->id].device);
data->access_mode = (flags & O_ACCMODE);
data->fd = fd;
}
}
if (!GRUB_UTIL_FD_IS_VALID(data->fd))
{
grub_error (GRUB_ERR_BAD_DEVICE, N_("cannot open `%s': %s"),
map[disk->id].device, grub_util_fd_strerror ());
return GRUB_UTIL_FD_INVALID;
}
if (grub_util_fd_seek (fd, sector << disk->log_sector_size))
{
grub_util_fd_close (fd);
grub_error (GRUB_ERR_BAD_DEVICE, N_("cannot seek `%s': %s"),
map[disk->id].device, grub_util_fd_strerror ());
return GRUB_UTIL_FD_INVALID;
}
return fd;
}
static grub_ssize_t
grub_hostfs_read (grub_file_t file, char *buf, grub_size_t len)
{
struct grub_hostfs_data *data;
data = file->data;
if (grub_util_fd_seek (data->f, file->offset) != 0)
{
grub_error (GRUB_ERR_OUT_OF_RANGE, N_("cannot seek `%s': %s"),
data->filename, grub_util_fd_strerror ());
return -1;
}
unsigned int s = grub_util_fd_read (data->f, buf, len);
if (s != len)
grub_error (GRUB_ERR_FILE_READ_ERROR, N_("cannot read `%s': %s"),
data->filename, grub_util_fd_strerror ());
return (signed) s;
}
int
grub_util_fd_open_device (const grub_disk_t disk, grub_disk_addr_t sector, int flags,
grub_disk_addr_t *max)
{
grub_util_fd_t fd;
struct grub_util_hostdisk_data *data = disk->data;
*max = ~0ULL;
#ifdef O_LARGEFILE
flags |= O_LARGEFILE;
#endif
#ifdef O_SYNC
flags |= O_SYNC;
#endif
#ifdef O_FSYNC
flags |= O_FSYNC;
#endif
#ifdef O_BINARY
flags |= O_BINARY;
#endif
/* Linux has a bug that the disk cache for a whole disk is not consistent
with the one for a partition of the disk. */
{
int is_partition = 0;
char dev[PATH_MAX];
grub_disk_addr_t part_start = 0;
part_start = grub_partition_get_start (disk->partition);
strcpy (dev, grub_util_biosdisk_get_osdev (disk));
if (disk->partition
&& strncmp (dev, "/dev/", 5) == 0)
{
if (sector >= part_start)
is_partition = grub_hostdisk_linux_find_partition (dev, part_start);
else
*max = part_start - sector;
}
reopen:
if (data->dev && strcmp (data->dev, dev) == 0 &&
data->access_mode == (flags & O_ACCMODE))
{
grub_dprintf ("hostdisk", "reusing open device `%s'\n", dev);
fd = data->fd;
}
else
{
free (data->dev);
data->dev = 0;
if (data->fd != -1)
{
if (data->access_mode == O_RDWR || data->access_mode == O_WRONLY)
{
fsync (data->fd);
if (data->is_disk)
ioctl (data->fd, BLKFLSBUF, 0);
}
close (data->fd);
data->fd = -1;
}
/* Open the partition. */
grub_dprintf ("hostdisk", "opening the device `%s' in open_device()\n", dev);
fd = open (dev, flags);
if (fd < 0)
{
grub_error (GRUB_ERR_BAD_DEVICE, N_("cannot open `%s': %s"),
dev, strerror (errno));
return -1;
}
data->dev = xstrdup (dev);
data->access_mode = (flags & O_ACCMODE);
data->fd = fd;
if (data->is_disk)
ioctl (data->fd, BLKFLSBUF, 0);
}
if (is_partition)
{
*max = grub_util_get_fd_size (fd, dev, 0);
*max >>= disk->log_sector_size;
if (sector - part_start >= *max)
{
*max = disk->partition->len - (sector - part_start);
if (*max == 0)
*max = ~0ULL;
is_partition = 0;
strcpy (dev, grub_util_biosdisk_get_osdev (disk));
goto reopen;
}
sector -= part_start;
*max -= sector;
}
}
if (grub_util_fd_seek (fd, sector << disk->log_sector_size))
{
close (fd);
grub_error (GRUB_ERR_BAD_DEVICE, N_("cannot seek `%s': %s"),
grub_util_biosdisk_get_osdev (disk), strerror (errno));
return -1;
}
return fd;
}