sector_t dm_bufio_get_device_size(struct dm_bufio_client *c)
{
sector_t s = i_size_read(c->bdev->bd_inode) >> SECTOR_SHIFT;
+ if (s >= c->start)
+ s -= c->start;
+ else
+ s = 0;
if (likely(c->sectors_per_block_bits >= 0))
s >>= c->sectors_per_block_bits;
else