Re: [PATCH 02/15] block: factor out a bio_integrity_setup_default helper

["Darrick J. Wong" <djwong@kernel.org>]

On Fri, Jan 23, 2026 at 07:08:33AM +0100, Christoph Hellwig wrote:
> On Thu, Jan 22, 2026 at 04:05:37PM -0800, Darrick J. Wong wrote:
> > On Wed, Jan 21, 2026 at 07:43:10AM +0100, Christoph Hellwig wrote:
> > > Add a helper to set the seed and check flag based on useful defaults
> > > from the profile.
> > > 
> > > Note that this includes a small behavior change, as we ow only sets the
> > 
> > "...as we only set the seed if..." ?
> 
> Yes.
> 
> > > +void bio_integrity_setup_default(struct bio *bio)
> > > +{
> > > +	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
> > > +	struct bio_integrity_payload *bip = bio_integrity(bio);
> > > +
> > > +	bip_set_seed(bip, bio->bi_iter.bi_sector);
> > > +
> > > +	if (bi->csum_type) {
> > > +		bip->bip_flags |= BIP_CHECK_GUARD;
> > > +		if (bi->csum_type == BLK_INTEGRITY_CSUM_IP)
> > 
> > /me wonders if this should be a switch, but it'd be a pretty lame one.
> > 
> > 	switch (bi->csum_type) {
> > 	case BLK_INTEGRITY_CSUM_NONE:
> > 		break;
> > 	case BLK_INTEGRITY_CSUM_IP:
> > 		bip->bip_flags |= BIP_IP_CHECKSUM;
> > 		fallthrough;
> > 	case BLK_INTEGRITY_CSUM_CRC:
> > 	case BLK_INTEGRITY_CSUM_CRC64:
> > 		bip->bip_flags |= BIP_CHECK_GUARD;
> > 		break;
> > 	}
> 
> I don't really think that's a good idea here.  BIP_IP_CHECKSUM is a
> really a special snowflake for SCSI HBA (and not even actual device)
> usage, so it should be treated like a special snowflake with the if.
> I sincerely hope no new special snowflakes will show up for the checksums
> in the future.

Fair enough.  The BIP_* flags encoding is ... odd. :)

--D