block: use integrity interval instead of sector as seed

bio_integrity_setup_default() and blk_integrity_iterate() set the
integrity seed (initial reference tag) to the absolute address in the
block device in units of 512-byte sectors. The seed is correctly
incremented/decremented in units of integrity intervals in
bio_integrity_map_iter(), bio_integrity_advance(), and
blk_integrity_interval(). As a result, the ref tag written or read to a
particular integrity interval on a block device with integrity interval
size > 512 bytes varies with the starting offset of the read/write.

Convert the initial seed to units of integrity intervals so a consistent
ref tag is used for each integrity interval.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Fixes: 3be91c4 ("block: Deprecate the use of the term sector in the context of block integrity")
Fixes: 63573e3 ("bio-integrity: Restore original iterator on verify stage")

Author: calebsander

block/bio-integrity.c

@@ -106,7 +106,7 @@ 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);
+	bip_set_seed(bip, bio_integrity_intervals(bi, bio->bi_iter.bi_sector));
 
 	if (bi->csum_type) {
 		bip->bip_flags |= BIP_CHECK_GUARD;

block/t10-pi.c

@@ -317,7 +317,7 @@ static blk_status_t blk_integrity_iterate(struct bio *bio,
 		.data_iter = *data_iter,
 		.prot_iter = bip->bip_iter,
 		.interval_remaining = 1 << bi->interval_exp,
-		.seed = data_iter->bi_sector,
+		.seed = bio_integrity_intervals(bi, data_iter->bi_sector),
 		.csum = 0,
 	};
 	blk_status_t ret = BLK_STS_OK;