Current isa-l has possibility to return corrupted decoded data or
corrupted reconstructed data on decode/reconstruct without error code.
That is from the specification of isa-l rs vandermond matrix discussed
at [1]. With many # of parities cases, we may hit the case above due to
failing to get the inverse matrix from the encode matrix.
The isa-l maintener gbtucker suggests a good way to detect the failing
inverse matrix, that we should handle the return value gf_invert_matrix.
If gf_invert_matrix returns not 0, we should stop to decode/reconstruct
and return failure return code to the caller immediately. Otherwise, the
caller regards the garbage data/fragment as correct one.
And this patch adds the specific test case we can hit the issue (it
happens not so general).
1: https://github.com/01org/isa-l/issues/10
Related-Change: I6eb150d9d0c3febf233570fa7729f9f72df2e9be
Change-Id: Icee788a0931fe692fe0de31fabc4ba450e338a87
74eaa374c1