Re: [PATCH v2 2/3] generic/574: corrupt btrfs merkle tree data

Boris Burkov
2021-04-08T18:49:41Z

On Thu, Apr 08, 2021 at 11:41:42AM -0700, Eric Biggers wrote:
> On Thu, Apr 08, 2021 at 11:30:12AM -0700, Boris Burkov wrote:
> >
> > Note that there is a bit of a kludge here: since btrfs_corrupt_block
> > doesn't handle streaming corruption bytes from stdin (I could change
> > that, but it feels like overkill for this purpose), I just read the
> > first corruption byte and duplicate it for the desired length. That is
> > how the test is using the interface in practice, anyway.
>
> If that's the problem, couldn't you just write the data to a temporary file?

Sorry, I was a bit too vague. It doesn't have a file or stdin interface,
as far as I know.

btrfs-corrupt-block has your typical "kitchen sink of flags" interface and
doesn't currently read input from streams/files. I extended that
interface in the simplest way to support arbitrary corruption, which
didn't fit with the stream based corruption this test does.

my options seem to be:
shoehorn the "byte, length" interface into this test or
shoehorn the "stream corruption input in" interface into
btrfs-corrupt-block.

I have no problem with either, the former was just less work because I
already wrote it that way. If the junk I did here is a deal-breaker, I
don't mind modifying btrfs-corrupt-block.

>
> - Eric

Thanks for the quick review,
Boris