Recently a problem was reported on test 225 when using a 512 byte
block size. I couldn't reproduce this problem using MKFS_OPTION="-b
size=512". The problem is that some tests use the TEST_DEV and
MKFS_OPTION only applies to the SCRATCH_DEV. To change the block
size of these tests, you need to specifically mkfs the TEST_DEV to
use those block sizes. This is not a typical test config - the
TEST_DEV is not supposed to be remade frequently, as it is designed
to be used for aging and testing aged filesystems.
Change a couple of tests that are testing hole/allocation patterns
to use the scratch device so that we get test coverage on multiple
block sizes, not just the default 4k block size filesystems.