fstests: Fix block device requirements and manual scratch mounts

Some tests require the scratch volume to be a block device,
although they don't do anything block device specific like
the device mapper tests. They actually only require a local
device and fail with network or overlay pseudo mount devices.

The same tests also try to mount the scratch device manually
after running _scratch_mkfs. For UBIFS, _scratch_mkfs simply
truncates the UBI volume and relies on the kernel to re-format
the volume on the next mount. This fails if the fs type is not
specified explicitly when mounting.

This patch replaces the block device requirement with a
generic check for a local device and adds a filesystem
specification to all manual mounts of the scratch device
to a mount point.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>
4 files changed