Re: [PATCH 1/3] block: bio-integrity: add PI iovec to bio

["Martin K. Petersen" <martin.petersen@oracle.com>]

Alexander,

Thanks for working on this!

> +		if (bip->bip_flags & BIP_RELEASE_PAGES) {
> +			bio_integrity_payload_release_pages(bip);
> +		}

In my parallel attempt the flag was called BIP_USER_MAPPED to mirror
BIO_USER_MAPPED. But with the latter now gone it doesn't really
matter. BIP_RELEASE_PAGES is fine.

I find bio_integrity_payload_release_pages() a bit long. All the other
functions just use a bio_integrity_ prefix and take a bio. But no
biggie.

> +int bio_integrity_add_pi_iovec(struct bio *bio, struct iovec *pi_iov)

bio_integrity_add_iovec(), please. _pi is redundant.


> +	bip_set_seed(bip, bio->bi_iter.bi_sector);
> +
> +	if (bi->flags & BLK_INTEGRITY_IP_CHECKSUM)
> +		bip->bip_flags |= BIP_IP_CHECKSUM;

The last couple of months I have been working on a version of our DIX/PI
qualification tooling that does not depend on the DB I/O stack.

For the test tooling to work I need to be able to pass the seed and the
BIP_* flags as part of the command. The tooling needs to be able to
select the type of checksum and to be able to disable checking for
initiator and target on a per-I/O basis. So these would need to be
passed in.

Note that extended PI formats have been defined in NVMe. These allow for
larger CRCs and reference tags to be specified in addition to a storage
tag. So we'll need to be careful when defining the SQE fields here.

-- 
Martin K. Petersen	Oracle Linux Engineering