Re: [PATCHSET 02/12] fstests: fix logwrites zeroing

Christoph Hellwig
2025-02-19T05:55:36Z

I don't want to block this part as it's an improvement over the current
state, but all these games of trying to detect if discard zeroes all
data despite making no such guarantee whatsoever and being explicitly
allowed to zero some but not all data just feels wrong.

The right thing would be to use the BLKZEROOUT, but AFAIK the problem is
that dm-thin doesn't support that. Given that the dm-thin discard
implementation seems do always zero, it should be able to just be
reusable for BLKZEROOUT. Can the dm maintainers look into that as it
is a pretty glaring omission?