Re: [PATCH] blk-integrity: support bvec straddling block data

[Keith Busch <kbusch@kernel.org>]

On Thu, Oct 23, 2025 at 10:22:01AM +0200, Christoph Hellwig wrote:
> On Wed, Oct 22, 2025 at 04:52:31PM -0700, Keith Busch wrote:
> > +	union {
> > +		u64		crc64;
> > +		__be16		t10pi;
> > +	};
> 
> Any good reason to keep the t10pi in be format except that is how
> the existing t10_pi_csum wrapper works?

I'm honestly confused how BLK_INTEGRITY_CSUM_IP works. It forces
coercion to __be16 type, but the csum calculation indicates it is not a
BE format. And it doesn't handle partials like how we have CSUM_CRC
working, so it seems broken on multiple fronts. But I don't have any IP
checksum capable drives to test with.
 
> > +		if (iter->remaining)
> > +			continue;
> 
> I find the structure with the remaining continue here a bit confusing.
> I guess the code would benefit from being split into an out loop over
> the integrity intervals and an inner loop over the potentially smaller
> buffers to make this clear.  Even more so with the skip case in the
> verify path.

We already do have an outer and inner loop, though iterating the data
buffers is currently the outer loop. I'll think about this a bit more to
find a more intuitive solution.