static int _dev_read_ahead_dev(struct device *dev, uint32_t *read_ahead)
{
long read_ahead_long;
if (dev->read_ahead != -1) {
*read_ahead = (uint32_t) dev->read_ahead;
return 1;
}
if (!dev_open_readonly(dev))
return_0;
if (ioctl(dev->fd, BLKRAGET, &read_ahead_long) < 0) {
log_sys_error("ioctl BLKRAGET", dev_name(dev));
if (!dev_close(dev))
stack;
return 0;
}
*read_ahead = (uint32_t) read_ahead_long;
dev->read_ahead = read_ahead_long;
log_very_verbose("%s: read_ahead is %u sectors",
dev_name(dev), *read_ahead);
if (!dev_close(dev))
stack;
return 1;
}
struct disk_list *read_disk(const struct format_type *fmt, struct device *dev,
struct dm_pool *mem, const char *vg_name)
{
struct disk_list *dl;
if (!dev_open_readonly(dev))
return_NULL;
dl = __read_disk(fmt, dev, mem, vg_name);
if (!dev_close(dev))
stack;
return dl;
}
/*
* Returns -1 on error
*/
int dev_is_md(struct device *dev, uint64_t *sb)
{
int ret = 1;
md_minor_version_t minor;
uint64_t size, sb_offset;
if (!dev_get_size(dev, &size)) {
stack;
return -1;
}
if (size < MD_RESERVED_SECTORS * 2)
return 0;
if (!dev_open_readonly(dev)) {
stack;
return -1;
}
/* Check if it is an md component device. */
/* Version 0.90.0 */
sb_offset = MD_NEW_SIZE_SECTORS(size) << SECTOR_SHIFT;
if (_dev_has_md_magic(dev, sb_offset))
goto out;
minor = MD_MINOR_VERSION_MIN;
/* Version 1, try v1.0 -> v1.2 */
do {
sb_offset = _v1_sb_offset(size, minor);
if (_dev_has_md_magic(dev, sb_offset))
goto out;
} while (++minor <= MD_MINOR_VERSION_MAX);
ret = 0;
out:
if (!dev_close(dev))
stack;
if (ret && sb)
*sb = sb_offset;
return ret;
}
int dev_is_luks(struct device *dev, uint64_t *signature)
{
char buf[LUKS_SIGNATURE_SIZE];
int ret = -1;
if (!dev_open_readonly(dev)) {
stack;
return -1;
}
*signature = 0;
if (!dev_read(dev, 0, LUKS_SIGNATURE_SIZE, buf))
goto_out;
ret = memcmp(buf, LUKS_SIGNATURE, LUKS_SIGNATURE_SIZE) ? 0 : 1;
out:
if (!dev_close(dev))
stack;
return ret;
}